Nitrous oxide emissions in Midwest US maize production vary widely with band-injected N fertilizer rates, timing and nitrapyrin presence

Science.gov (United States)

Burzaco, Juan P.; Smith, Doug R.; Vyn, Tony J.

2013-09-01

Nitrification inhibitors have the potential to reduce N2O emissions from maize fields, but optimal results may depend on deployment of integrated N fertilizer management systems that increase yields achieved per unit of N2O lost. A new micro-encapsulated formulation of nitrapyrin for liquid N fertilizers became available to US farmers in 2010. Our research objectives were to (i) assess the impacts of urea-ammonium nitrate (UAN) management practices (timing, rate and nitrification inhibitor) and environmental variables on growing-season N2O fluxes and (ii) identify UAN treatment combinations that both reduce N2O emissions and optimize maize productivity. Field experiments near West Lafayette, Indiana in 2010 and 2011 examined three N rates (0, 90 and 180 kg N ha-1), two timings (pre-emergence and side-dress) and presence or absence of nitrapyrin. Mean cumulative N2O-N emissions (Q10 corrected) were 0.81, 1.83 and 3.52 kg N2O-N ha-1 for the rates of 0, 90 and 180 kg N ha-1, respectively; 1.80 and 2.31 kg N2O-N ha-1 for pre-emergence and side-dress timings, respectively; and 1.77 versus 2.34 kg N2O-N ha-1 for with and without nitrapyrin, respectively. Yield-scaled N2O-N emissions increased with N rates as anticipated (averaging 167, 204 and 328 g N2O-N Mg grain-1 for the 0, 90 and 180 kg N ha-1 rates), but were 22% greater with the side-dress timing than the pre-emergence timing (when averaged across N rates and inhibitor treatments) because of environmental conditions following later applications. Overall yield-scaled N2O-N emissions were 22% lower with nitrapyrin than without the inhibitor, but these did not interact with N rate or timing.

A Study of the Determinants of Emissions Unit Allowance Price in the European Union Emissions Trading Scheme

Directory of Open Access Journals (Sweden)

Alina Maydybura

2011-12-01

Full Text Available In 2005 the European Union (EU began the first phase of the largest and most ambitious emissions trading system (EU ETS ever attempted, which then applied to all members of the EU. In its second phase whichbegan in 2008 the EU ETS now applies to all 27 members of the EU together with Norway, Iceland and Lichtenstein, the members of the European Economic Area (EEA which are not members of the Union. Inthe first phase of the EU ETS permits to emit carbon into the atmosphere known as European Union Allowances (EUA were traded in a market where the price rose to €30 and eventually fell to well below 10 Euro cents as the imperfections of the market became obvious. In the second phase which began in 2008 the price has fluctuated between €30 and €8. EUA are traded in a manner which is similar to the trading of financial instruments and a range of derivatives has developed with the total value of the market now above €120b, a growing market dominated by a few large players.This paper reports some results of an empirical investigation into the factors which appear to drive the carbon price and the key determinants of the price of an EUA. Over the last decade a number of environmental products have been developed alongside the EUA, including Certified Emissions Reductions (CERs, Renewable Energy Certificates and White Certificates (energy efficiency credits and markets have developed for a range of these environmental products. A better understanding of the determinants of these markets willhelp regulators manage these new markets and this paper aims to enhance our knowledge of the market.

Nitrous oxide emissions in Midwest US maize production vary widely with band-injected N fertilizer rates, timing and nitrapyrin presence

International Nuclear Information System (INIS)

Burzaco, Juan P; Vyn, Tony J; Smith, Doug R

2013-01-01

Nitrification inhibitors have the potential to reduce N 2 O emissions from maize fields, but optimal results may depend on deployment of integrated N fertilizer management systems that increase yields achieved per unit of N 2 O lost. A new micro-encapsulated formulation of nitrapyrin for liquid N fertilizers became available to US farmers in 2010. Our research objectives were to (i) assess the impacts of urea–ammonium nitrate (UAN) management practices (timing, rate and nitrification inhibitor) and environmental variables on growing-season N 2 O fluxes and (ii) identify UAN treatment combinations that both reduce N 2 O emissions and optimize maize productivity. Field experiments near West Lafayette, Indiana in 2010 and 2011 examined three N rates (0, 90 and 180 kg N ha −1 ), two timings (pre-emergence and side-dress) and presence or absence of nitrapyrin. Mean cumulative N 2 O–N emissions (Q 10 corrected) were 0.81, 1.83 and 3.52 kg N 2 O–N ha −1 for the rates of 0, 90 and 180 kg N ha −1 , respectively; 1.80 and 2.31 kg N 2 O–N ha −1 for pre-emergence and side-dress timings, respectively; and 1.77 versus 2.34 kg N 2 O–N ha −1 for with and without nitrapyrin, respectively. Yield-scaled N 2 O–N emissions increased with N rates as anticipated (averaging 167, 204 and 328 g N 2 O–N Mg grain −1 for the 0, 90 and 180 kg N ha −1 rates), but were 22% greater with the side-dress timing than the pre-emergence timing (when averaged across N rates and inhibitor treatments) because of environmental conditions following later applications. Overall yield-scaled N 2 O–N emissions were 22% lower with nitrapyrin than without the inhibitor, but these did not interact with N rate or timing. (letter)

Tradeable emission permits regulations in the presence of imperfectly competitive product markets. Welfare implications

International Nuclear Information System (INIS)

Sartzetakis, E.S.

1997-01-01

In the present paper, we analyse the interaction of a competitive market for emission permits with an oligopolistic product market. It is well known that a competitive permits market achieves the cost minimizing distribution of abatement effort among the polluting firms for a given reduction in emissions. However, when the product market is oligopolistic, it may redistribute production inefficiently among firms. It has been suggested that this inefficiency can outweigh the gains obtained from using emission permits instead of command and control. Although this argument is clearly correct under full information, it is shown in the present paper that it reverses under incomplete information. In particular, it is shown that when tradeable emission permits are specified according to the standard textbook example, they yield higher social welfare than the command and control regulation. 1 fig., 2 appendices, 11 refs

Extreme ultraviolet emission and confinement of tin plasmas in the presence of a magnetic field

Energy Technology Data Exchange (ETDEWEB)

Roy, Amitava, E-mail: roy@fzu.cz, E-mail: aroy@barc.gov.in [School of Nuclear Engineering and Center for Materials Under Extreme Environment(CMUXE), Purdue University, West Lafayette, Indiana 47907 (United States); HiLASE Project, Department of Diode-pumped Lasers, Institute of Physics of the ASCR, Na Slovance 2, 18221 Prague (Czech Republic); Murtaza Hassan, Syed; Harilal, Sivanandan S.; Hassanein, Ahmed [School of Nuclear Engineering and Center for Materials Under Extreme Environment(CMUXE), Purdue University, West Lafayette, Indiana 47907 (United States); Endo, Akira; Mocek, Tomas [HiLASE Project, Department of Diode-pumped Lasers, Institute of Physics of the ASCR, Na Slovance 2, 18221 Prague (Czech Republic)

2014-05-15

We investigated the role of a guiding magnetic field on extreme ultraviolet (EUV) and ion emission from a laser produced Sn plasma for various laser pulse duration and intensity. For producing plasmas, planar slabs of pure Sn were irradiated with 1064 nm, Nd:YAG laser pulses with varying pulse duration (5–15 ns) and intensity. A magnetic trap was fabricated with the use of two neodymium permanent magnets which provided a magnetic field strength ∼0.5 T along the plume expansion direction. Our results indicate that the EUV conversion efficiency do not depend significantly on applied axial magnetic field. Faraday Cup ion analysis of Sn plasma show that the ion flux reduces by a factor of ∼5 with the application of an axial magnetic field. It was found that the plasma plume expand in the lateral direction with peak velocity measured to be ∼1.2 cm/μs and reduced to ∼0.75 cm/μs with the application of an axial magnetic field. The plume expansion features recorded using fast photography in the presence and absence of 0.5 T axial magnetic field are simulated using particle-in-cell code. Our simulation results qualitatively predict the plasma behavior.

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.

Metal-enhanced fluorescence exciplex emission.

Science.gov (United States)

Zhang, Yongxia; Mali, Buddha L; Geddes, Chris D

2012-01-01

In this letter, we report the first observation of metal-enhanced exciplex fluorescence, observed from anthracene in the presence of diethylaniline. Anthracene in the presence of diethylaniline in close proximity to Silver Island Films (SIFs) shows enhanced monomer and exciplex emission as compared to a non-silvered control sample containing no silver nanoparticles. Our findings suggest two complementary methods for the enhancement: (i) surface plasmons can radiate coupled monomer and exciplex fluorescence efficiently, and (ii) enhanced absorption (enhanced electric near-field) further facilitates enhanced emission. Our exciplex studies help us to further understand the complex photophysics of the metal-enhanced fluorescence technology. Copyright © 2011 Elsevier B.V. All rights reserved.

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.

Infrared emission from isolated dust clouds in the presence of very small dust grains

Science.gov (United States)

Lis, Dariusz C.; Leung, Chun M.

1991-01-01

Models of the effects of small grain-generated temperature fluctuations on the IR spectrum and surface brightness of externally heated interstellar dust clouds are presently constructed on the basis of a continuum radiation transport computer code which encompasses the transient heating of small dust grains. The models assume a constant fractional abundance of large and small grains throughout the given cloud. A comparison of model results with IRAS observations indicates that the observed 12-25 micron band emissions are associated with about 10-A radius grains, while the 60-100 micron emission is primarily due to large grains which are heated under the equilibrium conditions.

Effect of dimethylamine on the gas phase sulfuric acid concentration measured by Chemical Ionization Mass Spectrometry

CERN Document Server

Rondo, L.; Kürten, A.; Adamov, A.; Bianchi, F.; Breitenlechner, M.; Duplissy, J.; Franchin, A.; Dommen, J.; Donahue, N. M.; Dunne, E. M.; Flagan, R. C.; Hakala, J.; Hansel, A.; Keskinen, H.; Kim, J.; Jokinen, T.; Lehtipalo, K.; Leiminger, M.; Praplan, A.; Riccobono, F.; Rissanen, M. P.; Sarnela, N.; Schobesberger, S.; Simon, M.; Sipilä, M.; Smith, J. N.; Tomé, A.; Tröstl, J.; Tsagkogeorgas, G.; Vaattovaara, P.; Winkler, P. M.; Williamson, C.; Wimmer, D.; Baltensperger, U.; Kirkby, J.; Kulmala, M.; Petäjä, T.; Worsnop, D. R.; Curtius, J.

2016-01-01

Sulfuric acid is widely recognized as a very important substance driving atmospheric aerosolnucleation. Based on quantum chemical calculations it has been suggested that the quantitative detectionof gas phase sulfuric acid (H2SO4) by use of Chemical Ionization Mass Spectrometry (CIMS) could be biased inthe presence of gas phase amines such as dimethylamine (DMA). An experiment (CLOUD7 campaign) was setup at the CLOUD (Cosmics Leaving OUtdoor Droplets) chamber to investigate the quantitative detection ofH2SO4in the presence of dimethylamine by CIMS at atmospherically relevant concentrations. For the first time inthe CLOUD experiment, the monomer sulfuric acid concentration was measured by a CIMS and by two CI-APi-TOF(Chemical Ionization-Atmospheric Pressure interface-Time Of Flight) mass spectrometers. In addition, neutralsulfuric acid clusters were measured with the CI-APi-TOFs. The CLOUD7 measurements show that in the presenceof dimethylamine (<5 to 70 pptv) the sulfuric acid monomer measured by the CIMS...

Fiber optics spectrochemical emission sensors

Science.gov (United States)

Griffin, Jeffrey W.; Olsen, Khris B.

1992-01-01

A method of in situ monitoring of a body of a fluid stored in a tank or groundwater or vadose zone gases in a well for the presence of selected chemical species uses a probe insertable into the well or tank via a cable and having electrical apparatus for exciting selected chemical species in the body of fluid. The probe can have a pair of electrodes for initiating a spark or a plasma cell for maintaining a plasma to excite the selected chemical species. The probe also has optical apparatus for receiving optical emissions emitted by the excited species and optically transmitting the emissions via the cable to an analysis location outside the well. The analysis includes detecting a selected wavelength in the emissions indicative of the presence of the selected chemical species. A plurality of probes can be suspended at an end of a respective cable, with the transmitting and analyzing steps for each probe being synchronized sequentially for one set of support equipment and instrumentation to monitor at multiple test points. The optical apparatus is arranged about the light guide axis so that the selected chemical species are excited the fluid in alignment with the light guide axis and optical emissions are received from the excited chemical species along such axis.

Spontaneous light emission in complex nanostructures

Science.gov (United States)

Blanco, L. A.; García de Abajo, F. J.

2004-05-01

The spontaneous emission of an excited atom surrounded by different materials is studied in the framework of a semiclassical approach, where the transition dipole moment acts as the source of the emission field. The emission in the presence of semiinfinite media, metallic nanorings, spheres, gratings, and other complex geometries is investigated. Strong emission enhancement effects are obtained in some of these geometries associated to the excitation of plasmons (e.g., in nanorings or spheres). Furthermore, the emission is shown to take place only along narrow angular distributions when the atom is located inside a low-index dielectric and near its planar surface, or when metallic nanogratings are employed at certain resonant wave lengths. In particular, axially symmetric gratings made of real silver metal are considered, and both emission rate enhancement and focused far-field emission are achieved simultaneously when the grating is decorated with further nanostructures.

Study of luminous emissions associated to electron emissions in radiofrequency cavities

International Nuclear Information System (INIS)

Maissa, S.

1996-01-01

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)

The ABAG biogenic emissions inventory project

Science.gov (United States)

Carson-Henry, C. (Editor)

1982-01-01

The ability to identify the role of biogenic hydrocarbon emissions in contributing to overall ozone production in the Bay Area, and to identify the significance of that role, were investigated in a joint project of the Association of Bay Area Governments (ABAG) and NASA/Ames Research Center. Ozone, which is produced when nitrogen oxides and hydrocarbons combine in the presence of sunlight, is a primary factor in air quality planning. In investigating the role of biogenic emissions, this project employed a pre-existing land cover classification to define areal extent of land cover types. Emission factors were then derived for those cover types. The land cover data and emission factors were integrated into an existing geographic information system, where they were combined to form a Biogenic Hydrocarbon Emissions Inventory. The emissions inventory information was then integrated into an existing photochemical dispersion model.

A cost-emission model for fuel cell/PV/battery hybrid energy system in the presence of demand response program: ε-constraint method and fuzzy satisfying approach

International Nuclear Information System (INIS)

Nojavan, Sayyad; Majidi, Majid; Najafi-Ghalelou, Afshin; Ghahramani, Mehrdad; Zare, Kazem

2017-01-01

Highlights: • Cost-emission performance of PV/battery/fuel cell hybrid energy system is studied. • Multi-objective optimization model for cost-emission performance is proposed. • ε-constraint method is proposed to produce Pareto solutions of multi-objective model. • Fuzzy satisfying approach selected the best optimal solution from Pareto solutions. • Demand response program is proposed to reduce both cost and emission. - Abstract: Optimal operation of hybrid energy systems is a big challenge in power systems. Nowadays, in addition to the optimum performance of energy systems, their pollution issue has been a hot topic between researchers. In this paper, a multi-objective model is proposed for economic and environmental operation of a battery/fuel cell/photovoltaic (PV) hybrid energy system in the presence of demand response program (DRP). In the proposed paper, the first objective function is minimization of total cost of hybrid energy system. The second objective function is minimization of total CO_2 emission which is in conflict with the first objective function. So, a multi-objective optimization model is presented to model the hybrid system’s optimal and environmental performance problem with considering DRP. The proposed multi-objective model is solved by ε-constraint method and then fuzzy satisfying technique is employed to select the best possible solution. Also, positive effects of DRP on the economic and environmental performance of hybrid system are analyzed. A mixed-integer linear program is used to simulate the proposed model and the obtained results are compared with weighted sum approach to show the effectiveness of proposed method.

Cooperative emission in ion implanted Yb:YAG waveguides

Energy Technology Data Exchange (ETDEWEB)

Vazquez, G V; Desirena, H; De la Rosa, E [Centro de Investigaciones en Optica, Loma del Bosque 115, Lomas del Campestre, 37150 Leon, Guanajuato (Mexico); Flores-Romero, E; Rickards, J; Trejo-Luna, R [Instituto de Fisica, UNAM, Apartado Postal 20364, 01000 Mexico, D. F. (Mexico); Marquez, H, E-mail: gvvazquez@cio.mx [Departamento de Optica, CICESE, Km 107 Carr. Tijuana-Ensenada, 22860 Ensenada, B. C. (Mexico)

2011-01-01

In this work, we report the analysis of spectroscopic properties of waveguides fabricated by ion implantation in YAG doped with Yb{sup 3+} ions. Three emission bands were detected in the blue, green and red regions under 970-nm excitation. The strong blue-green emission can be explained by a cooperative process between ytterbium ion pairs, leading to emission centered at 514 nm. The additional blue bands as well as green and red emission bands are attributed to the presence of Tm{sup 3+} and Er{sup 3+} traces. The results include absorption and emission curves as well as decay time rates.

Cooperative emission in ion implanted Yb:YAG waveguides

International Nuclear Information System (INIS)

Vazquez, G V; Desirena, H; De la Rosa, E; Flores-Romero, E; Rickards, J; Trejo-Luna, R; Marquez, H

2011-01-01

In this work, we report the analysis of spectroscopic properties of waveguides fabricated by ion implantation in YAG doped with Yb 3+ ions. Three emission bands were detected in the blue, green and red regions under 970-nm excitation. The strong blue-green emission can be explained by a cooperative process between ytterbium ion pairs, leading to emission centered at 514 nm. The additional blue bands as well as green and red emission bands are attributed to the presence of Tm 3+ and Er 3+ traces. The results include absorption and emission curves as well as decay time rates.

Predator-induced reduction of freshwater carbon dioxide emissions

Science.gov (United States)

Atwood, Trisha B.; Hammill, Edd; Greig, Hamish S.; Kratina, Pavel; Shurin, Jonathan B.; Srivastava, Diane S.; Richardson, John S.

2013-03-01

Predators can influence the exchange of carbon dioxide between ecosystems and the atmosphere by altering ecosystem processes such as decomposition and primary production, according to food web theory. Empirical knowledge of such an effect in freshwater systems is limited, but it has been suggested that predators in odd-numbered food chains suppress freshwater carbon dioxide emissions, and predators in even-numbered food chains enhance emissions. Here, we report experiments in three-tier food chains in experimental ponds, streams and bromeliads in Canada and Costa Rica in the presence or absence of fish (Gasterosteus aculeatus) and invertebrate (Hesperoperla pacifica and Mecistogaster modesta) predators. We monitored carbon dioxide fluxes along with prey and primary producer biomass. We found substantially reduced carbon dioxide emissions in the presence of predators in all systems, despite differences in predator type, hydrology, climatic region, ecological zone and level of in situ primary production. We also observed lower amounts of prey biomass and higher amounts of algal and detrital biomass in the presence of predators. We conclude that predators have the potential to markedly influence carbon dioxide dynamics in freshwater systems.

Fluxon induced resistance and field emission

CERN Document Server

Calatroni, Sergio; Darriulat, Pierre; Peck, M A; Valente, A M; Van't Hof, C A

2000-01-01

The surface resistance of superconducting niobium films induced by the presence of trapped magnetic flux, presumably in the form of a pinned fluxon lattice, is shown to be modified by the presence of a field emitting impurity or defect. The modification takes the form of an additional surface resistance proportional to the density of the fluxon lattice and increasing linearly with the amplitude of the microwave above a threshold significantly lower than the field emission threshold. Such an effect, precursor of electron emission, is observed here for the first time in a study using radiofrequency cavities operated at their fundamental 1.5 GHz frequency. The measured properties of the additional surface resistance severely constrain possible explanations of the observed effect.

Spontaneous emission of electromagnetic radiation in turbulent plasmas

Energy Technology Data Exchange (ETDEWEB)

Ziebell, L. F., E-mail: luiz.ziebell@ufrgs.br [Instituto de Física, UFRGS, Porto Alegre, Rio Grande do Sul (Brazil); Yoon, P. H., E-mail: yoonp@umd.edu [School of Space Research, Kyung Hee University, Yongin, Gyeonggi 446-701, South Korea and University of Maryland, College Park, Maryland 20742 (United States); Simões, F. J. R.; Pavan, J. [Instituto de Física e Matemática, UFPel, Pelotas, Rio Grande do Sul (Brazil); Gaelzer, R. [Instituto de Física, UFRGS, Porto Alegre, Rio Grande do Sul (Brazil); Instituto de Física e Matemática, UFPel, Pelotas, Rio Grande do Sul (Brazil)

2014-01-15

Known radiation emission mechanisms in plasmas include bremmstrahlung (or free-free emission), gyro- and synchrotron radiation, cyclotron maser, and plasma emission. For unmagnetized plasmas, only bremmstrahlung and plasma emissions are viable. Of these, bremmstrahlung becomes inoperative in the absence of collisions, and the plasma emission requires the presence of electron beam, followed by various scattering and conversion processes. The present Letter proposes a new type of radiation emission process for plasmas in a state of thermodynamic quasi-equilibrium between particles and enhanced Langmuir turbulence. The radiation emission mechanism proposed in the present Letter is not predicted by the linear theory of thermal plasmas, but it relies on nonlinear wave-particle resonance processes. The electromagnetic particle-in-cell numerical simulation supports the new mechanism.

Outstanding field emission properties of wet-processed titanium dioxide coated carbon nanotube based field emission devices

Energy Technology Data Exchange (ETDEWEB)

Xu, Jinzhuo; Ou-Yang, Wei, E-mail: ouyangwei@phy.ecnu.edu.cn; Chen, Xiaohong; Guo, Pingsheng; Piao, Xianqing; Sun, Zhuo [Engineering Research Center for Nanophotonics and Advanced Instrument, Ministry of Education, Department of Physics, East China Normal University, 3663 North Zhongshan Road, Shanghai 200062 (China); Xu, Peng; Wang, Miao [Department of Physics, Zhejiang University, 38 ZheDa Road, Hangzhou 310027 (China); Li, Jun [Department of Electronic Science and Technology, Tongji University, 4800 Caoan Road, Shanghai 201804 (China)

2015-02-16

Field emission devices using a wet-processed composite cathode of carbon nanotube films coated with titanium dioxide exhibit outstanding field emission characteristics, including ultralow turn on field of 0.383 V μm{sup −1} and threshold field of 0.657 V μm{sup −1} corresponding with a very high field enhancement factor of 20 000, exceptional current stability, and excellent emission uniformity. The improved field emission properties are attributed to the enhanced edge effect simultaneously with the reduced screening effect, and the lowered work function of the composite cathode. In addition, the highly stable electron emission is found due to the presence of titanium dioxide nanoparticles on the carbon nanotubes, which prohibits the cathode from the influence of ions and free radical created in the emission process as well as residual oxygen gas in the device. The high-performance solution-processed composite cathode demonstrates great potential application in vacuum electronic devices.

Solar Plasma Radio Emission in the Presence of Imbalanced Turbulence of Kinetic-Scale Alfvén Waves

Science.gov (United States)

Lyubchyk, O.; Kontar, E. P.; Voitenko, Y. M.; Bian, N. H.; Melrose, D. B.

2017-09-01

We study the influence of kinetic-scale Alfvénic turbulence on the generation of plasma radio emission in the solar coronal regions where the ratio β of plasma to magnetic pressure is lower than the electron-to-ion mass ratio me/mi. The present study is motivated by the phenomenon of solar type I radio storms that are associated with the strong magnetic field of active regions. The measured brightness temperature of the type I storms can be up to 10^{10} K for continuum emission, and can exceed 10^{11} K for type I bursts. At present, there is no generally accepted theory explaining such high brightness temperatures and some other properties of the type I storms. We propose a model with an imbalanced turbulence of kinetic-scale Alfvén waves that produce an asymmetric quasi-linear plateau on the upper half of the electron velocity distribution. The Landau damping of resonant Langmuir waves is suppressed and their amplitudes grow spontaneously above the thermal level. The estimated saturation level of Langmuir waves is high enough to generate observed type I radio emission at the fundamental plasma frequency. Harmonic emission does not appear in our model because the backward-propagating Langmuir waves undergo strong Landau damping. Our model predicts 100% polarization in the sense of the ordinary (o-) mode of type I emission.

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

Science.gov (United States)

2015-09-19

response to shear stress (τ, N m-2) induced by the PI-SWERL®, the viscosity of the fluid exerts a torque (N m-1) that eventually balances with τ. The...Engelbrecht et al. (2012) from CCSEM measurements, report that these silicate mineral particles are largely coated by a veneer of clay minerals and fine...content does not, by itself, contribute to the high emissions observed at YTC. The presence of high clay content can constrain the emissions by

Journal of Biosciences | Indian Academy of Sciences

Indian Academy of Sciences (India)

... already reported mutations. A single haplotype having quadruple mutation was found inthe dhfr gene. The study reports higher degree of antifolate drug resistance as evidenced by the presence of multiple pointmutations in dhps and dhfr genes. The findings of this study strongly discourage the use SP as a partner drug in ...

Diagnostics of pre-breakdown light emission in a helium coplanar barrier discharge: the presence of neutral bremsstrahlung

Science.gov (United States)

Navrátil, Zdeněk; Morávek, Tomáš; Ráheľ, Jozef; Čech, Jan; Lalinský, Ondřej; Trunec, David

2017-05-01

Weak light emission (˜10-3 of active discharge signal; average count rate ˜ 1 photon s-1 nm-1) associated with surface charge relaxation during the dark phase of a helium diffuse coplanar barrier discharge was studied by optical emission spectroscopy, using a technique of phase-resolved single photon counting. The optical emission spectra of the dark phase contained luminescent bands of the dielectrics used (Al2O3, AlN) and spectral lines from the gas constituents (OH*, {{{N}}}2* , {{{N}}}2+* , He*, He{}2* , O*). During the charge relaxation event, a broad continuum appeared in the optical emission spectra, consisting of bremsstrahlung radiation and amplified luminescence of the dielectric barrier. The analysis presented suggests that the bremsstrahlung radiation originated from slow electrons colliding with neutral helium atoms. The fitting procedure we developed reproduced well the observed shape of the continuum. Moreover, it provided a method for the determination of electric field strength in the discharge during this particular phase. The electric field reached 1 kV cm-1 during the charge relaxation event.

Flagging and correcting non-spectral matrix interferences with spatial emission profiles and gradient dilution in inductively coupled plasma-atomic emission spectrometry

International Nuclear Information System (INIS)

Cheung, Yan; Schwartz, Andrew J.; Chan, George C.-Y.; Hieftje, Gary M.

2015-01-01

Matrix interference remains one of the most daunting challenges commonly encountered in inductively coupled plasma-atomic emission spectrometry (ICP-AES). In the present study, a method is described that enables identification and correction of matrix interferences in axial-viewed ICP-AES through a combination of spatial mapping and on-line gradient dilution. Cross-sectional emission maps of the plasma are used to indicate the presence of non-spectral (plasma-related and sample-introduction-related) matrix interferences. In particular, apparent concentrations of an analyte species determined at various radial locations in the plasma differ in the presence of a matrix interference, which allows the interference to be flagged. To correct for the interference, progressive, on-line dilution of the sample, performed by a gradient high-performance liquid-chromatograph pump, is utilized. The spatially dependent intensities of analyte emission are monitored at different levels of sample dilution. As the dilution proceeds, the matrix-induced signal variation is reduced. At a dilution where the determined concentrations become independent of location in the plasma, the matrix interference is minimized. - Highlights: • Non-spectral matrix interference in ICP-AES is flagged and minimized. • Emission from different locations of the plasma are collected simultaneously. • Spatially dependent determined concentrations indicate the presence of interference. • Gradient dilution is performed on both calibration standards and sample. • Optimal dilution factor to minimize interference is found as dilution increases

Flagging and correcting non-spectral matrix interferences with spatial emission profiles and gradient dilution in inductively coupled plasma-atomic emission spectrometry

Energy Technology Data Exchange (ETDEWEB)

Cheung, Yan; Schwartz, Andrew J.; Chan, George C.-Y.; Hieftje, Gary M., E-mail: hieftje@indiana.edu

2015-08-01

Matrix interference remains one of the most daunting challenges commonly encountered in inductively coupled plasma-atomic emission spectrometry (ICP-AES). In the present study, a method is described that enables identification and correction of matrix interferences in axial-viewed ICP-AES through a combination of spatial mapping and on-line gradient dilution. Cross-sectional emission maps of the plasma are used to indicate the presence of non-spectral (plasma-related and sample-introduction-related) matrix interferences. In particular, apparent concentrations of an analyte species determined at various radial locations in the plasma differ in the presence of a matrix interference, which allows the interference to be flagged. To correct for the interference, progressive, on-line dilution of the sample, performed by a gradient high-performance liquid-chromatograph pump, is utilized. The spatially dependent intensities of analyte emission are monitored at different levels of sample dilution. As the dilution proceeds, the matrix-induced signal variation is reduced. At a dilution where the determined concentrations become independent of location in the plasma, the matrix interference is minimized. - Highlights: • Non-spectral matrix interference in ICP-AES is flagged and minimized. • Emission from different locations of the plasma are collected simultaneously. • Spatially dependent determined concentrations indicate the presence of interference. • Gradient dilution is performed on both calibration standards and sample. • Optimal dilution factor to minimize interference is found as dilution increases.

Pulsar kicks from majoron emission

International Nuclear Information System (INIS)

Farzan, Yasaman; Gelmini, Graciela; Kusenko, Alexander

2005-01-01

We show that majoron emission from a hot nascent neutron star can be anisotropic in the presence of a strong magnetic field. If majorons carry a non-negligible fraction of the supernova energy, the resulting recoil velocity of a neutron star can explain the observed velocities of pulsars

Coherence energies in pre-equilibrium emission

International Nuclear Information System (INIS)

De Rosa, A.; Inglima, C.; Perillo, E.; Rosato, E.; Sandoli, M.; Spadaccini, G.

1979-01-01

A method, based on the spectral density analysis, has been developped in order to evaluate coherence of statistical fluctuations. It is specially suitable for reactions showing the contemporary presence of different emission mechanism (e.g. preequilibrium and evaporation - like mechanism)

Acoustic emission during low temperature phase transformations in plutonium

International Nuclear Information System (INIS)

Khejpl, K.; Karpenter, S.

1988-01-01

To study the nature of phase transformations in plutonium and plutonium-gallium alloys (0.3 and 0.57% Ga) the measurement of acoustic emission is conducted. The presence of acoustic emission testifies to martensitic character of transformation, related to sharp local changes in the volume, which cause elastic waves. It is detected that during α reversible β transformations in non-alloyed plutonium acoustic emission is absent, and that testifies to nonmartensitic nature of the transformations. σ reversible α transformation in plutonium-gallium alloys is accompanied by the appearance of acoustic emission, i.e. it is of martensitic origin

Gamma-ray emission profile measurements during JET ICRH discharges

Energy Technology Data Exchange (ETDEWEB)

Jarvis, O N; Marcus, F B; Sadler, G; Van Belle, P [Commission of the European Communities, Abingdon (United Kingdom). JET Joint Undertaking; Howarth, P J.A. [Birmingham Univ. (United Kingdom); Adams, J M; Bond, D S [UKAEA Harwell Lab. (United Kingdom). Energy Technology Div.

1994-07-01

Gamma-ray emission from plasma-impurity reactions caused by minority ICRH accelerating fuel ions to MeV energies has been measured using the JET neutron profile monitor. A successful data analysis technique has been used to isolate the RF-induced gamma-ray emission that was detected, enabling profiles of gamma-ray emission to be obtained. The 2-d gamma-ray emission profiles show that virtually all the radiation originates from the low field side of the RF resonance layer, as expected from RF-induced pitch angle diffusion. The emission profiles indicate the presence of a small population of resonant {sup 3}He ions that possess orbits lying near the passing-trapped boundary. 6 refs., 4 figs.

Infrared dust emission from globular clusters

International Nuclear Information System (INIS)

Angeletti, L.; Capuzzo-Dolcetta, R.; Giannone, P.; Blanco, A.; Bussoletti, E.

1982-01-01

The implications of the presence of a central cloud in the cores of globular clusters were investigated recently. A possible mechanism of confinement of dust in the central region of our cluster models was also explored. The grain temperature and infrared emission have now been computed for rather realistic grain compositions. The grain components were assumed to be graphite and/or silicates. The central clouds turned out to be roughly isothermal. The wavelengths of maximum emission came out to be larger than 20 μm in all studied cases. An application of the theoretical results to five globular clusters showed that the predictable infrared emission for 47 Tuc, M4 and M22 should be detectable by means of present instrumentation aboard flying platforms. (author)

Infrared dust emission from globular clusters

Energy Technology Data Exchange (ETDEWEB)

Angeletti, L; Capuzzo-Dolcetta, R; Giannone, P. (Rome Univ. (Italy). Osservatorio Astronomico); Blanco, A; Bussoletti, E [Lecce Univ. (Italy). Ist. di Fisica

1982-05-01

The implications of the presence of a central cloud in the cores of globular clusters were investigated recently. A possible mechanism of confinement of dust in the central region of our cluster models was also explored. The grain temperature and infrared emission have now been computed for rather realistic grain compositions. The grain components were assumed to be graphite and/or silicates. The central clouds turned out to be roughly isothermal. The wavelengths of maximum emission came out to be larger than 20 ..mu..m in all studied cases. An application of the theoretical results to five globular clusters showed that the predictable infrared emission for 47 Tuc, M4 and M22 should be detectable by means of present instrumentation aboard flying platforms.

2.0 to 2.4 micron spectroscopy of T Tauri stars

Science.gov (United States)

Hamann, F.; Simon, M.; Ridgway, S. T.

1988-03-01

Velocity-resolved 2.0-2.5-micron observations of the T Tau stars T, DF, DG, DK, HL, and RY Tau, SU Aur, and GW Ori are presented. For each of these stars except SU Aur, the Brackett gamma line was detected in emission with line widths inthe range of about 130-230 km/s. The Brackett gamma line profile of SU Aur is complex, having components of both emission and absorption. The first measurement of CO band-head emission in DG Tau is reported, and it is shown that published radio continuum fluxes of young stars far exceed what could be produced in an envelope ionized by only the stellar photospheric Lyman continuum. The excess of radio emission is found to be much greater in low-luminosity sources (e.g., the T Tau stars).

On the Estimation of the CO2 Emission, Economic Growth and Energy Consumption Nexus Using Dynamic OLS in the Presence of Multicollinearity

Directory of Open Access Journals (Sweden)

Kristofer Månsson

2018-04-01

Full Text Available This paper introduces shrinkage estimators (Ridge DOLS for the dynamic ordinary least squares (DOLS cointegration estimator, which extends the model for use in the presence of multicollinearity between the explanatory variables in the cointegration vector. Both analytically and by using simulation techniques, we conclude that our new Ridge DOLS approach exhibits lower mean square errors (MSE than the traditional DOLS method. Therefore, based on the MSE performance criteria, our Monte Carlo simulations demonstrate that our new method outperforms the DOLS under empirically relevant magnitudes of multicollinearity. Moreover, we show the advantages of this new method by more accurately estimating the environmental Kuznets curve (EKC, where the income and squared income are related to carbon dioxide emissions. Furthermore, we also illustrate the practical use of the method when augmenting the EKC curve with energy consumption. In summary, regardless of whether we use analytical, simulation-based, or empirical approaches, we can consistently conclude that it is possible to estimate these types of relationships in a considerably more accurate manner using our newly suggested method.

Bremsstrahlung in the presence of a laser field

Energy Technology Data Exchange (ETDEWEB)

Dondera, M. [Department of Physics, University of Bucharest, Bucharest-Magurele MG11, 76900 (Romania); Florescu, Viorica [Department of Physics, University of Bucharest, Bucharest-Magurele MG11, 76900 (Romania)]. E-mail: flor@barutu.fizica.unibuc.ro

2006-10-15

For the process of spontaneous one photon emission by an electron scattered on a potential in the presence of a monochromatic laser field, we review the formalism and the approximations on which the existing nonrelativistic calculations are based, in classical and quantum descriptions. In the case of the Coulomb potential, we give new numerical results for the radiation spectrum, using either the Born approximation [Karapetyan, P.V., Fedorov, M.V., 1978. Spontaneous electron bremmstrahlung in the field of an intense electromagnetic wave. Zh. Teor. Fiz. 75, 816-826 [Sov. Phys. JETP 48, 412 (1979)

Bremsstrahlung in the presence of a laser field

International Nuclear Information System (INIS)

Dondera, M.; Florescu, Viorica

2006-01-01

For the process of spontaneous one photon emission by an electron scattered on a potential in the presence of a monochromatic laser field, we review the formalism and the approximations on which the existing nonrelativistic calculations are based, in classical and quantum descriptions. In the case of the Coulomb potential, we give new numerical results for the radiation spectrum, using either the Born approximation [Karapetyan, P.V., Fedorov, M.V., 1978. Spontaneous electron bremmstrahlung in the field of an intense electromagnetic wave. Zh. Teor. Fiz. 75, 816-826 [Sov. Phys. JETP 48, 412 (1979)

Proton-Induced X-Ray Emission Analysis of Crematorium Emissions

Science.gov (United States)

Ali, Salina; Nadareski, Benjamin; Yoskowitz, Joshua; Labrake, Scott; Vineyard, Michael

2014-09-01

There has been considerable debate in recent years about possible mercury emissions from crematoria due to amalgam tooth restorations. We have performed a proton-induced X-ray emission (PIXE) analysis of aerosol and soil samples taken near the Vale Cemetery Crematorium in Schenectady, NY, to address this concern. The aerosol samples were collected on the roof of the crematorium using a nine-stage, cascade impactor that separates the particulate matter by aerodynamic diameter and deposits it onto thin Kapton foils. The soil samples were collected at several different distances from the crematorium and compressed into pellets with a hydraulic press. The Kapton foils containing the aerosol samples and the soil pellets were bombarded with 2.2-MeV protons from the 1.1-MV tandem Pelletron accelerator in the Union College Ion-Beam Analysis Laboratory. We measured significant concentrations of sulfur, phosphorus, potassium, calcium, and iron, but essentially no mercury in the aerosol samples. The lower limit of detection for airborne mercury in this experiment was approximately 0.2 ng / m3. The PIXE analysis of the soil samples showed the presence of elements commonly found in soil (Si, K, Ca, Ti, Mn, Fe), but no trace of mercury. There has been considerable debate in recent years about possible mercury emissions from crematoria due to amalgam tooth restorations. We have performed a proton-induced X-ray emission (PIXE) analysis of aerosol and soil samples taken near the Vale Cemetery Crematorium in Schenectady, NY, to address this concern. The aerosol samples were collected on the roof of the crematorium using a nine-stage, cascade impactor that separates the particulate matter by aerodynamic diameter and deposits it onto thin Kapton foils. The soil samples were collected at several different distances from the crematorium and compressed into pellets with a hydraulic press. The Kapton foils containing the aerosol samples and the soil pellets were bombarded with 2.2-Me

PLASMA EMISSION BY COUNTER-STREAMING ELECTRON BEAMS

Energy Technology Data Exchange (ETDEWEB)

Ziebell, L. F.; Petruzzellis, L. T.; Gaelzer, R. [Instituto de Física, UFRGS, Porto Alegre, RS (Brazil); Yoon, P. H. [Institute for Physical Science and Technology, University of Maryland, College Park, MD (United States); Pavan, J., E-mail: luiz.ziebell@ufrgs.br, E-mail: yoonp@umd.edu, E-mail: joel.pavan@ufpel.edu.br [Instituto de Física e Matemática, UFPel, Pelotas, RS (Brazil)

2016-02-10

The radiation emission mechanism responsible for both type-II and type-III solar radio bursts is commonly accepted as plasma emission. Recently Ganse et al. suggested that type-II radio bursts may be enhanced when the electron foreshock geometry of a coronal mass ejection contains a double hump structure. They reasoned that the counter-streaming electron beams that exist between the double shocks may enhance the nonlinear coalescence interaction, thereby giving rise to more efficient generation of radiation. Ganse et al. employed a particle-in-cell simulation to study such a scenario. The present paper revisits the same problem with EM weak turbulence theory, and show that the fundamental (F) emission is not greatly affected by the presence of counter-streaming beams, but the harmonic (H) emission becomes somewhat more effective when the two beams are present. The present finding is thus complementary to the work by Ganse et al.

Ion induced high energy electron emission from copper

International Nuclear Information System (INIS)

Ruano, G.; Ferron, J.

2008-01-01

We present measurements of secondary electron emission from Cu induced by low energy bombardment (1-5 keV) of noble gas (He + , Ne + and Ar + ) and Li + ions. We identify different potential and kinetic mechanisms and find the presence of high energetic secondary electrons for a couple of ion-target combinations. In order to understand the presence of these fast electrons we need to consider the Fermi shuttle mechanism and the different ion neutralization efficiencies.

Rebalancing: The Cost of Shifting to the Pacific

Science.gov (United States)

2013-03-01

Iraq and Afghanistan.”3 2 While in Australia, President Obama highlighted some benefits of the increased presence in the Pacific. This change...to promote free trade with nine other countries: Australia, Brunei, Chili , Japan, Malaysia, New Zealand, Peru, Singapore, and Vietnam. 6 In...The using unit is responsible for compiling with all customs and agricultural inspections requirements. To better convey the benefits of the

Electron transport in the presence of a Coulomb field

International Nuclear Information System (INIS)

Burgdoerfer, J.; Gibbons, J.

1990-01-01

We analyze the modifications of the transport behavior of electrons in dense media due to the presence of a strong Coulomb field generated by an ion moving initially in close phase-space correlation with the electrons. These modifications play a profound role in convoy electron emission in ion-solid collisions. The transport behavior is studied within the framework of a classical phase-space master equation. The nonseparable master equation is solved numerically using test-particle discretization and Monte Carlo sampling. In the limit of vanishing Coulomb forces the master equation becomes separable and can be reduced to standard one-dimensional kinetic equations for free-electron transport that can be solved exactly. The comparison to free-electron transport is used to gauge both the reliability of test-particle discretization and the significance of Coulomb distortion of the distribution functions. Applications to convoy-electron emission are discussed

Emissions of Sesquiterpenes from Spruce Sawdust During Drying

International Nuclear Information System (INIS)

Granstroem, K.M.

2006-01-01

Large amounts of sawdust are dried for production of particleboard and Pellets. During processing of wood (i.e. drying, densification), volatile organic compounds are emitted. These contribute in the presence of nitrogen oxides and sunlight to the formation of ground level ozone and other harmful photo-oxidants. In this study sesquiterpene emissions from the drying of fresh Norway Spruce (Picea abies) sawdust in a continuous spouted bed steam dryer at 140-200 deg C have been investigated, and patterns of covariation between sesquiterpene emissions and drying parameters elucidated. Sesquiterpene emissions was about 20% of the monoterpene emissions. Drying in 200 deg C caused markedly larger sesquiterpene emissions than in 140 deg C or 170 deg C. Whereas a change in moisture content had no notable effect on the amount of sesquiterpenes emitted at high wood moisture contents (25-40%), the sesquiterpene emissions increased considerably as drying proceeded at low wood moisture contents (5-15%). While it has long been known that monoterpenes are a dominant VOC emitted during processing of wood, this study shows that sesquiterpenes are of considerable importance

Presence

Directory of Open Access Journals (Sweden)

Pamela Renee Boeck

2014-03-01

Full Text Available Healthy therapeutic relationships enhance wholeness and healing; they are the key to effective health promotion. Therapeutic nursing presence demonstrates caring, empathy, and connection, qualities required to build rapport and trust between nurse and patient. This concept analysis’ purpose was to illuminate the various forms of the meanings of presence and the value placed on them. The science of nursing often precedes the art and spirituality of nursing. This is due to focusing primarily on the high acuity of the patients being seen in conjunction with shortage of personnel and resources. Patient dissatisfaction continues to be a growing concern. The nursing shortage crisis continues along with more nurses experiencing moral distress, compassion fatigue, and/or burnout. In nurses’ haste to complete their duties, are we facing the risk of overlooking one of the original gifts of the nursing profession? This would be the gift of genuine presence. This concept analysis aims to identify the attributes that are essential to the concept of presence, and to clarify its nursing usage, by following the strategy suggested by Walker and Avant. It is important to reflect on various ways of providing presence in the clinical setting. By exploring the spiritual, literary, psychological, and nursing literature, there is a diverse yet similar interconnectivity of what presence may represent. Observations and experiences of a range of sensatory and kinesthetic perceptions are revealed to ascertain the attributes discerning commonalities and themes of presence. Nursing presence is considered to be an essential state of holistic nursing as well as a core competency in contemporary nursing. Clarifying the significance of presence in nursing invites the prospect of additional evidence-based research that may place the intrinsic value of presence as a continuing theoretical foundation.

Ion induced high energy electron emission from copper

Energy Technology Data Exchange (ETDEWEB)

Ruano, G. [Instituto de Desarrollo Tecnologico para la Industria Quimica, Consejo Nacional de Investigaciones Cientificas y Tecnicas and Universidad Nacional del Litoral Gueemes 3450 CC 91, 3000 Santa Fe (Argentina)], E-mail: gdruano@ceride.gov.ar; Ferron, J. [Instituto de Desarrollo Tecnologico para la Industria Quimica, Consejo Nacional de Investigaciones Cientificas y Tecnicas and Universidad Nacional del Litoral Gueemes 3450 CC 91, 3000 Santa Fe (Argentina); Departamento de Ingenieria de Materiales, Facultad de Ingenieria Quimica, Consejo Nacional de Investigaciones Cientificas y Tecnicas and Universidad Nacional del Litoral Gueemes 3450 CC 91, 3000 Santa Fe (Argentina)

2008-11-15

We present measurements of secondary electron emission from Cu induced by low energy bombardment (1-5 keV) of noble gas (He{sup +}, Ne{sup +} and Ar{sup +}) and Li{sup +} ions. We identify different potential and kinetic mechanisms and find the presence of high energetic secondary electrons for a couple of ion-target combinations. In order to understand the presence of these fast electrons we need to consider the Fermi shuttle mechanism and the different ion neutralization efficiencies.

Gamma-ray emission profile measurements during JET ICRH discharges

Energy Technology Data Exchange (ETDEWEB)

Howarth, P.J.A. [Birmingham Univ. (United Kingdom); Adams, J.M.; Bond, D.S.; Watkins, N. [AEA Technology, Harwell (United Kingdom); Jarvis, O.N.; Marcus, F.B.; Sadler, G.; Belle, P. van [Commission of the European Communities, Abingdon (United Kingdom). JET Joint Undertaking

1994-12-31

Ion Cyclotron Resonant Heating (ICRH) that is tuned to minority fuel ions can induce an energy diffusion of the heated species and create high energy tail temperatures of {approx} 1 MeV. The most energetic of these accelerated minority ions can undergo nuclear reactions with impurity Be and C that produces {gamma}-ray emission from the decay of the excited product nuclei. This RF-induced {gamma}-ray emission has been recorded using the JET neutron emission profile diagnostic which is capable of distinguishing neutrons and {gamma}-rays. Appropriate data processing has enabled the RF-induced {gamma}-ray emission signals to be isolated from the {gamma}-ray emission signals associated with neutron interactions in the material surrounding the profile monitor. The 2-d {gamma}-ray emission profiles show that virtually all the radiation originates from the low field side of the RF resonance layer, as expected from RF-induced pitch angle diffusion. The emission profiles indicate the presence of a small population of resonant {sup 3}He ions that possess orbits lying near the passing-trapped boundary. (author) 6 refs., 4 figs.

Pre-equilibrium complex particle emission

International Nuclear Information System (INIS)

Bĕták, E.

2002-01-01

Semi-classical (phenomenological) pre-equilibrium emission of clusters of nucleons (complex particles) such as deuterons, tritons, helions and α particles from reactions induced by light projectiles (nucleons to α’s) is addressed. The main attention is given to the hard components in the emission energetic spectra, which play an increasing role at incident energies above 20 MeV, and are currently attributed to a presence of some kind of pre-equilibrium processes. In addition, the mechanisms of cluster reactions show special features such as the competition between pickup and knockout processes and the contributions of several successive steps in the reaction. The main frame used here to illustrate the processes and interplays of the competing mechanisms of pre-equilibrium cluster formation and emission, namely the coalescence, pick-up and knock-out, is the pre-equilibrium exciton model. It obviously contains the process of clusterization itself as its organic part. The most important case of complex particles with the largest amount of experimental data is that of alpha emission, which therefore naturally attracts most of the attention and where the widest range of possible mechanisms is available on the market. The loosely bound ejectiles, on the other side, are usually not able to demonstrate all features of the whole spectrum of contributing mechanisms, but they are nevertheless an important link between the nucleon emission and the cluster one.

Game Theoretic Analysis of Carbon Emission Reduction and Sales Promotion in Dyadic Supply Chain in Presence of Consumers’ Low-Carbon Awareness

Directory of Open Access Journals (Sweden)

Liangjie Xia

2014-01-01

Full Text Available The paper studies how the combination of the manufacturer’s carbon emission reduction and the retailer’s emission reduction relevant promotion impacts the performances of a dyadic supply chain in low-carbon environment. We consider three typical scenarios, that is, centralized and decentralized without or with side-payment. We compare measures of supply chain performances, such as profitabilities, emission reduction efficiencies, and effectiveness, in these scenarios. To improve chain-wide performances, a new side-payment contract is designed to coordinate the supply chain and numerical experiments are also conducted. We find the following. (1 In decentralized setting, the retailer will provide emission cutting allowance to the manufacturer only if their unit product profit margin is higher enough than the manufacturer’s, and the emission reduction level of per unit product is a monotonically increasing function with respect to the cost pooling proportion provided by the retailer; (2 the new side-payment contract can coordinate the dyadic supply chain successfully due to its integrating sales promotion effort and emission reduction input, which results in system pareto optimality under decentralized individual rationality but achieves a collective rationality effect in the centralized setting; (3 when without external force’s regulation, consumers’ low-carbon awareness is to enhance consumers’ utility and decrease profits of supply chain firms.

[Influence of impurities on waste plastics pyrolysis: products and emissions].

Science.gov (United States)

Zhao, Lei; Wang, Zhong-Hui; Chen, De-Zhen; Ma, Xiao-Bo; Luan, Jian

2012-01-01

The study is aimed to evaluate the impact of impurities like food waste, paper, textile and especially soil on the pyrolysis of waste plastics. For this purpose, emissions, gas and liquid products from pyrolysis of waste plastics and impurities were studied, as well as the transfer of element N, Cl, S from the substrates to the pyrolysis products. It was found that the presence of food waste would reduce the heat value of pyrolysis oil to 27 MJ/kg and increase the moisture in the liquid products, therefore the food residue should be removed from waste plastics; and the soil, enhance the waste plastics' pyrolysis by improving the quality of gas and oil products. The presence of food residue, textile and paper leaded to higher gas emissions.

Defect studies in quartz: Composite nature of the blue and UV emissions

Energy Technology Data Exchange (ETDEWEB)

Martini, Marco, E-mail: m.martini@unimib.it [Dipartimento di Scienza dei Materiali, Università degli Studi di Milano Bicocca, via R. Cozzi 55, I-20125 Milano (Italy); INFN, Sezione di Milano Bicocca, Piazza della Scienza 1, I-20126 Milano (Italy); Fasoli, Mauro; Villa, Irene [Dipartimento di Scienza dei Materiali, Università degli Studi di Milano Bicocca, via R. Cozzi 55, I-20125 Milano (Italy)

2014-05-01

Quartz is an extremely diffused natural luminescence dosimeter. Thanks to the presence of traps and luminescence centres, its TSL and OSL (Thermally and Optically Stimulated Luminescence) properties have been extensively exploited. Quartz is then used for archaeological and geological dating and is one of the most useful materials for accident dosimetry. Many luminescence emissions are known to be present in the OSL and TSL of quartz. Three main emission bands are always reported, as the red, blue and UV bands, centred at around 650, 470, and 360–380 nm, respectively. Although the assignment of the luminescence emissions to specific defect centres in quartz is still undefined, a thorough analysis of the radioluminescence emissions and their response to irradiation and thermal treatments turned out to be very useful in understanding many features. Specifically, the presence of the same emission bands in natural and synthetic quartz and their dependence on the presence of extrinsic impurities is a common characteristic. The main impurities involve Al ions substituting Si ones and charge compensated by nearby either alkali ions, H{sup +}, or a hole. The emission spectra dynamics evidenced in our experiment confirm the role of Al-related centres in the luminescence properties of quartz. From the measurements presented in this paper the composite nature of the “blue” emission is confirmed. Two bands labelled as A at 2.5 eV and B at 2.8 eV contribute to the emission in this region, their behaviour being different as a function of irradiation. More complex is the picture in the UV region, where, besides the already detected C and D bands at 3.4 eV and 3.9 eV, respectively, two further emissions have been detected at 3.1 eV and 3.7 eV. Despite both the 3.4 eV and the 3.7 eV bands are shown to be affected by thermal treatments, the annealing temperature dependence of their intensity is markedly different. In fact, whereas the C band intensity, at 3.4 eV, increases

Defect studies in quartz: Composite nature of the blue and UV emissions

International Nuclear Information System (INIS)

Martini, Marco; Fasoli, Mauro; Villa, Irene

2014-01-01

Quartz is an extremely diffused natural luminescence dosimeter. Thanks to the presence of traps and luminescence centres, its TSL and OSL (Thermally and Optically Stimulated Luminescence) properties have been extensively exploited. Quartz is then used for archaeological and geological dating and is one of the most useful materials for accident dosimetry. Many luminescence emissions are known to be present in the OSL and TSL of quartz. Three main emission bands are always reported, as the red, blue and UV bands, centred at around 650, 470, and 360–380 nm, respectively. Although the assignment of the luminescence emissions to specific defect centres in quartz is still undefined, a thorough analysis of the radioluminescence emissions and their response to irradiation and thermal treatments turned out to be very useful in understanding many features. Specifically, the presence of the same emission bands in natural and synthetic quartz and their dependence on the presence of extrinsic impurities is a common characteristic. The main impurities involve Al ions substituting Si ones and charge compensated by nearby either alkali ions, H + , or a hole. The emission spectra dynamics evidenced in our experiment confirm the role of Al-related centres in the luminescence properties of quartz. From the measurements presented in this paper the composite nature of the “blue” emission is confirmed. Two bands labelled as A at 2.5 eV and B at 2.8 eV contribute to the emission in this region, their behaviour being different as a function of irradiation. More complex is the picture in the UV region, where, besides the already detected C and D bands at 3.4 eV and 3.9 eV, respectively, two further emissions have been detected at 3.1 eV and 3.7 eV. Despite both the 3.4 eV and the 3.7 eV bands are shown to be affected by thermal treatments, the annealing temperature dependence of their intensity is markedly different. In fact, whereas the C band intensity, at 3.4 eV, increases after

Biodiesel unsaturation degree effects on diesel engine NOx emissions and cotton wick flame temperature

Directory of Open Access Journals (Sweden)

Abdullah Mohd Fareez Edzuan

2017-01-01

Full Text Available As compared with conventional diesel fuel, biodiesel has better lubricity and lower particulate matter (PM emissions however nitrogen oxides (NOx emissions generally increase in biodiesel-fuelled diesel engine. Strict regulation on NOx emissions is being implemented in current Euro 6 standard and it is expected to be tighter in next standard, thus increase of NOx cannot be accepted. In this study, biodiesel unsaturation degree effects on NOx emissions are investigated. Canola, palm and coconut oils are selected as the feedstock based on their unsaturation degree. Biodiesel blends of B20 were used to fuel a single cylinder diesel engine and exhaust emissions were sampled directly at exhaust tailpipe with a flue gas analyser. Biodiesel flame temperature was measured from a cotton wick burned in simple atmospheric conditions using a thermocouple. Fourier transform infrared (FTIR spectrometer was also used to identify the functional groups presence in the biodiesel blends. Oxygen content in biodiesel may promote complete combustion as the NOx emissions and flame temperatures were increased while the carbon monoxide (CO emissions were decreased for all biodiesel blends. It is interesting to note that the NOx emissions and flame temperatures were directly proportional with biodiesel unsaturation degree. It might be suggested that apart from excess oxygen and free radical formation, higher NOx emissions can also be caused by the elevated flame temperatures due to the presence of double bonds in unsaturated biodiesel.

Biochemistry Applied to Everyday Life: Chemical Equilibrium and the Transporting Function of the Hemoglobin

Directory of Open Access Journals (Sweden)

Carlos Mario Echeverría Palacio

2006-12-01

Full Text Available The hemoglobin is a blood protein which cantransport oxygen, a gas insoluble in water, todifferent organs where it is required for the properfunction; this protein also transports themetabolic products, CO2 and H+ for theirexcretion. This process depends on pH, the BPGconcentration, pO2 and pCO2. The cooperativebinding between hemoglobin and those compoundsand the conformational changes necessaryfor oxygen and CO2 uptake and release inthe specific place where they are required. Abruptchanges of atmospheric pressure associatedwith height and the exposure to other gases suchas CO present in vehicles and closed roomscould compromise the normal functioning of theorganism because their presence affects thetransport function of the hemoglobin. In thispaper, we will explain everyday phenomenarelated to the transport of gases through hemoglobinas a demonstration that a knowledge ofbiochemistry begins to be useful from now on to understand everyday situations and give usan expectation of their value to comprehendmany health problems that would be faced inthe future

NEBULAR EMISSION-LINES IN IRAS 10215-5916

NARCIS (Netherlands)

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

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

Particle Emissions from Domestic Gas Cookers

DEFF Research Database (Denmark)

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

2010-01-01

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

A model for energy pricing with stochastic emission costs

International Nuclear Information System (INIS)

Elliott, Robert J.; Lyle, Matthew R.; Miao, Hong

2010-01-01

We use a supply-demand approach to value energy products exposed to emission cost uncertainty. We find closed form solutions for a number of popularly traded energy derivatives such as: forwards, European call options written on spot prices and European Call options written on forward contracts. Our modeling approach is to first construct noisy supply and demand processes and then equate them to find an equilibrium price. This approach is very general while still allowing for sensitivity analysis within a valuation setting. Our assumption is that, in the presence of emission costs, traditional supply growth will slow down causing output prices of energy products to become more costly over time. However, emission costs do not immediately cause output price appreciation, but instead expose individual projects, particularly those with high emission outputs, to much more extreme risks through the cost side of their profit stream. Our results have implications for hedging and pricing for producers operating in areas facing a stochastic emission cost environment. (author)

LORINE: Neutron emission Locator by SOI detectors

Energy Technology Data Exchange (ETDEWEB)

Hamrita, H.; Kondrasovs, V.; Borbotte, J. M.; Normand, S. [CEA, LIST, Laboratoire Capteurs et Architectures Electronique, F-91191 Gif-sur-Yvette Cedex (France); Saurel, N. [CEA, DAM, VALDUC, F-21120 Is sur Tille (France)

2009-07-01

The aim of this work is to develop a fast Neutron Emission Locator based on silicon on Insulator detector (LORINE). This locator can be used in the presence of significant flux of gamma radiation. LORINE was developed to locate areas containing a significant amount of actinide during the dismantling operations of equipment. From the results obtained in laboratory, we have proposed the prototype of neutron emission locator as follows: the developed design consists of 5 SOI (Silicon-on-insulator) detectors (1*1 cm{sup 2}) with their charge preamplifiers and their respective converters. All are installed on 5 faces of a boron polyethylene cube (5*5*5 cm{sup 3}). This cube plays the role of neutron shielding between the several detectors. The design must be so compact for use in glove boxes. An electronic card based on micro-controller has been made to control sensors and to send the necessary information to the computer. Location of fast neutron sources does not yet exist in a so compact design and it can be operated in the presence of very important gamma radiation flux

PET/MRI in the presence of metal implants: Completion of the attenuation map from PET emission data

DEFF Research Database (Denmark)

Fuin, Niccolo; Pedemonte, Stefano; Catalano, Onofrio A.

2017-01-01

of radioactivity and attenuation from the emission data to determine the position, shape, and linear attenuation coefficient (LAC) of metallic implants. Methods: The initial estimate of the attenuation map was obtained using the MR Dixon method currently available on the Siemens Biograph mMR scanner...

Jean’s instability in a complex plasma in presence of secondary electrons and nonthermal ions

International Nuclear Information System (INIS)

Sarkar, Susmita; Maity Saumyen

2013-01-01

In this paper we have investigated the effect of secondary electron emission and nonthermality of ion velocity distribution simultaneously on Jean’s instability in a complex plasma in presence of negatively charged dust grains. Primary and secondary electron temperatures are assumed to be equal. Thus plasma under consideration consists of Boltzmann distributed electrons, nonthermal ions and negatively charged dust grains. The dust grain component is modeled by continuity and momentum equations. From the linear dispersion relation we have calculated the real frequency and growth rate of the Jean’s mode. Numerically it is found that for lower values of the nonthermal parameter Jean’s instability is higher for higher secondary electron emission whereas the effect of secondary electron emission on Jean’s instability becomes insignificant for higher values of the nonthermal parameter. (author)

Energy use, emissions, economic growth and trade: A Granger non-causality evidence for Malaysia

OpenAIRE

Ismail, Mohd Adib; Mawar, Murni Yunus

2012-01-01

This paper investigates the relationship among energy, emissions and economic growth in Malaysia with the presence of trade activities. We employ Johansen’s (1995) approach to investigate the relationship. Using annual data from 1971 to 2007, the empirical results shows that there are long-run causalities among energy, emission and economic growth, and among energy, emissions, export and capital, while the short-run Granger non-causality test shows that there are unidirectional causalities ru...

Electron-photon and electron-electron interactions in the presence of strong electromagnetic fields

International Nuclear Information System (INIS)

Surzhykov, A.; Fritzsche, S.; Stoehlker, Th.

2010-01-01

During the last decade, photon emission from highly-charged, heavy ions has been in the focus of intense studies at the GSI accelerator and storage ring facility in Darmstadt. These studies have revealed unique information about the electron-electron and electron-photon interactions in the presence of extremely strong nuclear fields. Apart from the radiative electron capture processes, characteristic photon emission following collisional excitation of projectile ions has also attracted much interest. In this contribution, we summarize the recent theoretical studies on the production of excited ionic states and their subsequent radiative decay. We will pay special attention to the angular and polarization properties of Kα emission from helium-like ions produced by means of dielectronic recombination. The results obtained for this (resonant) capture process will be compared with the theoretical predictions for the characteristic X-rays following Coulomb excitation and radiative recombination of few-electron, heavy ions. Work is supported by Helmholtz Association and GSl under the project VH-NG--421. (author)

Carbon stars with alpha-C:H emission

Science.gov (United States)

Gerbault, Florence; Goebel, John H.

1989-01-01

Many carbon stars in the IRS low resolution spectra (LRS) catalog were found which display emission spectra that compare favorable with the absorption spectrum of alpha-C:H. These stars have largely been classified as 4X in the LRS which has led to their interpretation by others in terms of displaying a mixture of the UIRF's 8.6 micron band and SiC at 11.5 microns. It was also found that many of these stars have a spectral upturn at 20+ microns which resembles the MgS band seen in carbon stars and planetary nebulae. It was concluded that this group of carbon stars will evolve into planetary nebulae like NGC 7027 and IC 418. In the presence of hard ultraviolet radiation the UIRF's will light up and be displayed as narrow emission bands on top of the broad alpha-C:H emission bands.

Time-resolved measurement of emission profiles in pulsed radiofrequency glow discharge optical emission spectroscopy: Investigation of the pre-peak

International Nuclear Information System (INIS)

Alberts, D.; Horvath, P.; Nelis, Th.; Pereiro, R.; Bordel, N.; Michler, J.; Sanz-Medel, A.

2010-01-01

Radiofrequency glow discharge coupled to optical emission spectroscopy has been used in pulsed mode in order to perform a detailed study of the measured temporal emission profiles for a wide range of copper transitions. Special attention has been paid to the early emission peak (or so-called pre-peak), observed at the beginning of the emission pulse profile. The effects of the important pulse parameters such as frequency, duty cycle, pulse width and power-off time, have been studied upon the Cu pulse emission profiles. The influence of discharge parameters, such as pressure and power, was studied as well. Results have shown that the intensity observed in the pre-peak can be 10 times as large as the plateau value for resonant lines and up to 5 times in case of transitions to the metastable levels. Increasing pressure or power increased the pre-peak intensity while its appearance in time changed. The pre-peak decreased when the discharge off-time was shorter than 100 μs. According to such results, the presence of the pre-peak could be probably due to the lack of self-absorption during the first 50 μs, and not to the ignition of the plasma. Under the selected operation conditions, the use of the pre-peak emission as analytical signals increases the linearity of calibration curves for resonant lines subjected to self-absorption at high concentrations.

Time-resolved measurement of emission profiles in pulsed radiofrequency glow discharge optical emission spectroscopy: Investigation of the pre-peak

Energy Technology Data Exchange (ETDEWEB)

Alberts, D. [Department of Physical and Analytical Chemistry, Faculty of Chemistry, University of Oviedo, Julian Claveria 8, 33006 Oviedo (Spain); Horvath, P. [Swiss Federal Laboratories for Materials Testing and Research (EMPA), Feuerwerkerstrasse 39, 3602 Thun (Switzerland); Nelis, Th. [LAPLACE, Universite Paul Sabatier, 118 rte de Narbonne, Bat3R2, 31062 Toulouse Cedex (France); CU Jean Francois Champollion, Place de Verdun 81012 Albi Cedex 9 (France); Pereiro, R. [Department of Physical and Analytical Chemistry, Faculty of Chemistry, University of Oviedo, Julian Claveria 8, 33006 Oviedo (Spain); Bordel, N. [Department of Physics, Faculty of Science, University of Oviedo, Calvo Sotelo, 33007 Oviedo (Spain); Michler, J. [Swiss Federal Laboratories for Materials Testing and Research (EMPA), Feuerwerkerstrasse 39, 3602 Thun (Switzerland); Sanz-Medel, A., E-mail: asm@uniovi.e [Department of Physical and Analytical Chemistry, Faculty of Chemistry, University of Oviedo, Julian Claveria 8, 33006 Oviedo (Spain)

2010-07-15

Radiofrequency glow discharge coupled to optical emission spectroscopy has been used in pulsed mode in order to perform a detailed study of the measured temporal emission profiles for a wide range of copper transitions. Special attention has been paid to the early emission peak (or so-called pre-peak), observed at the beginning of the emission pulse profile. The effects of the important pulse parameters such as frequency, duty cycle, pulse width and power-off time, have been studied upon the Cu pulse emission profiles. The influence of discharge parameters, such as pressure and power, was studied as well. Results have shown that the intensity observed in the pre-peak can be 10 times as large as the plateau value for resonant lines and up to 5 times in case of transitions to the metastable levels. Increasing pressure or power increased the pre-peak intensity while its appearance in time changed. The pre-peak decreased when the discharge off-time was shorter than 100 {mu}s. According to such results, the presence of the pre-peak could be probably due to the lack of self-absorption during the first 50 {mu}s, and not to the ignition of the plasma. Under the selected operation conditions, the use of the pre-peak emission as analytical signals increases the linearity of calibration curves for resonant lines subjected to self-absorption at high concentrations.

Highly charged ion based time-of-flight emission microscope

International Nuclear Information System (INIS)

Hamza, Alex V.; Barnes, Alan V.; Magee, Ed; Newman, Mike; Schenkel, Thomas; McDonald, Joseph W.; Schneider, Dieter H.

2000-01-01

An emission microscope using highly charged ions as the excitation source has been designed, constructed, and operated. A novel ''acorn'' objective lens has been used to simultaneously image electron and secondary ion emission. A resistive anode-position sensitive detector is used to determine the x-y position and time of arrival of the secondary events at the microscope image plane. Contrast in the image can be based on the intensity of the electron emission and/or the presence of particular secondary ions. Spatial resolution of better than 1 μm and mass resolution m/Δm of better than 400 were demonstrated. Background rejection from uncorrelated events of greater than an order of magnitude is also achieved. (c) 2000 American Institute of Physics

The Teaching Methods of Cultural Factors in The Classroom

Institute of Scientific and Technical Information of China (English)

Jia Mengyang

2014-01-01

Culture knowledge plays an important role in linguistic proficiency and currently most teaching activities are stil happened inthe traditionalclassroom. So this paper introducedsome ofthe practicalteachingmethods ofChinese culture inthe Chinese language classroom.

The contribution of single photon emission computed tomography in the clinical assessment of Alzheimer type dementia

International Nuclear Information System (INIS)

Boudousq, V.; Collombier, L.; Kotzki, P.O.

1999-01-01

Interest of brain single-photon emission computed tomography to support clinical diagnosis of Alzheimer-type dementia is now established. Numerous studies have reported a decreased perfusion in the association cortex of the parietal lobe and the posterior temporal regions. In patients with mild cognitive complaints, the presence of focal hypoperfusion may increase substantially the probability of the disease. In addition, emission tomography emerges as a helpful tool in situation in which there is diagnostic doubt. In this case, the presence of temporo-parietal perfusion deficit associated with hippocampal atrophy on MRI or X-ray computed tomography contributes to diagnostic accuracy. However, some studies suggest that emission tomography may be useful for preclinical prediction of Alzheimer's disease and to predict cognitive decline. (author)

Use of real options in nuclear power plant valuation in the presence of uncertainty with CO2 emission credit

International Nuclear Information System (INIS)

Kiriyama, Eriko; Suzuki, Atsuyuki

2004-01-01

The purpose of this study is to analyze the value of an investment in power generation assets that do not emit CO 2 , by using a real option model. This study evaluates the effects of future uncertainty on investment decision-making, by focusing on the uncertainty of CO 2 emission credits [yen/t-CO 2 ] in the fairly near future in Japan. Electric utilities are required to keep plans to prepare for various future uncertainties such as the price of CO 2 emission credits. The real option approach can evaluate the option value of decision-making under uncertainty. This study examined the option value of a power plant [yen/KW] to evaluate the effects of an externality under uncertainty. The results showed that nuclear power would have the most value under the forthcoming CO 2 emission limitations. In order to secure the effectiveness of measures against global warming, we should reconsider the roles of nuclear power plants in Japan. Finally, the real option model is shown to be an effective candidate for a decision-making support tool to deal with problems in energy environmental policy. (author)

Microcracking in ceramics and acoustic emission

International Nuclear Information System (INIS)

Subbarao, E.C.

1991-01-01

One of the limitations in the use of ceramics in critical applications is due to the presence of microcracks, which may arise from differential thermal expansion and phase changes, among others. Acoustic emission signals occur when there are abrupt microdeformations in a material and thus offer a convenient means of non-destructive detection of microcracking. Examples of a study of acoustic emission from microcracking due to anisotropic thermal expansion in low thermal expansion single phase ceramics such as niobia and sodium zirconium phosphate ceramics and due to phase changes in zirconia and superconducting YBa 2 Cu 3 Osub(7-x) ceramics are presented, together with the case of lead titanate ceramics, which exhibits both a phase change (paraelectric to ferroelectric) and an anisotropic thermal expansion. The role of grain size on the extent of microcracking is illustrated in the case of niobia ceramics. Some indirect evidence of healing of microcracks on heating niobia and lead titanate ceramics is presented from the acoustic emission results. (author). 69 refs., 9 figs

DISCOVERY OF C IV EMISSION FILAMENTS IN M87

International Nuclear Information System (INIS)

Sparks, W. B.; Pringle, J. E.; Cracraft, M.; Donahue, M.; Voit, M.; Carswell, R.; Martin, R. G.

2009-01-01

Gas at intermediate temperatures between the hot X-ray-emitting coronal gas in galaxies at the centers of galaxy clusters and the much cooler optical line emitting filaments yields information on transport processes and plausible scenarios for the relationship between X-ray cool cores and other galactic phenomena such as mergers or the onset of an active galactic nucleus. Hitherto, detection of intermediate temperature gas has proven elusive. Here, we present FUV imaging of the 'low excitation' emission filaments of M87 and show strong evidence for the presence of C IV 1549 A emission which arises in gas at temperature ∼10 5 K co-located with Hα+[N II] emission from cooler ∼10 4 K gas. We infer that the hot and cool phases are in thermal communication, and show that quantitatively the emission strength is consistent with thermal conduction, which in turn may account for many of the observed characteristics of cool-core galaxy clusters.

NON-THERMAL EMISSION FROM CATACLYSMIC VARIABLES: IMPLICATIONS ON ASTROPARTICLE PHYSICS

Directory of Open Access Journals (Sweden)

Vojtech Šimon

2013-12-01

Full Text Available We review the lines of evidence that some cataclysmic variables (CVs are the sources of non-thermal radiation. It was really observed in some dwarf novae in outburst, a novalike CV in the high state, an intermediate polar, polars, and classical novae (CNe during outburst. The detection of this radiation suggests the presence of highly energetic particles in these CVs. The conditions for the observability of this emission depend on the state of activity, and the system parameters. We review the processes and conditions that lead to the production of this radiation in various spectral bands, from gamma-rays including TeV emission to radio. Synchrotron and cyclotron emissions suggest the presence of strong magnetic fields in CV. In some CVs, e.g. during some dwarf nova outbursts, the magnetic field generated in the accretion disk leads to the synchrotron jets radiating in radio. The propeller effect or a shock in the case of the magnetized white dwarf (WD can lead to a strong acceleration of the particles that produce gamma-ray emission via pi0 decay; even Cherenkov radiation is possible. In addition, a gamma-ray production via pi0 decay was observed in the ejecta of an outburst of a symbiotic CN. Nuclear reactions during thermonuclear runaway in the outer layer of the WD undergoing CN outburst lead to the production of radioactive isotopes; their decay is the source of gamma-ray emission. The production of accelerated particles in CVs often has episodic character with a very small duty cycle; this makes their detection and establishing the relation of the behavior in various bands difficult.

Foreign Direct Investment, Environmental INGO Presence and Carbon Dioxide Emissions in Less-Developed Countries, 1980-2000 La inversión extranjera directa, la presencia de ONG internacionales medioambientales y las emisiones de dióxido de carbono en los países menos adelantados, 1980-2000

Directory of Open Access Journals (Sweden)

Christopher Dick

2010-10-01

Full Text Available The authors engage foreign investment dependence and world society theories to examine environmental harms in less-developed countries. Results of cross-national random effects panel regression models indicate that foreign investment in manufacturing contributes to total carbon dioxide emissions and emissions per unit of production. World society integration in the context of environmental international non-governmental organization presence does not directly suppress emissions. However, a stronger presence of such organizations in some less-developed nations appears to mitigate the impacts of foreign investment on anthropogenic emissions. These results hold, net of population, level of development, and other structural factors.Los autores abordan la dependencia de inversión extranjera y las teorías de la sociedad mundial para examinar los daños medioambientales en los países menos desarrollados. Los resultados de los modelos de regresión de panel con efectos aleatorios nacionales indican que la inversión extranjera en el sector manufacturero contribuye al total de emisiones de dióxido de carbono y las emisiones por unidad de producción. La integración de la sociedad mundial en el contexto presencia de organizaciones medioambientales internacionales no gubernamentales no reprime directamente las emisiones. Sin embargo, una  mayor presencia de esas organizaciones en algunos países naciones menos desarrolladas parece mitigar los impactos de la inversión extranjera en las emisiones antropogénicas. Los resultados  son en forma de datos netos de la población, nivel de desarrollo y otros factores estructurales.

Wolf-Rayet stars featured in emission-line galaxies

International Nuclear Information System (INIS)

Kunth, D.

1982-01-01

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

Isoprene in poplar emissions: effects on new particle formation and OH concentrations

Science.gov (United States)

Kiendler-Scharr, A.; Andres, S.; Bachner, M.; Behnke, K.; Broch, S.; Hofzumahaus, A.; Holland, F.; Kleist, E.; Mentel, T. F.; Rubach, F.; Springer, M.; Steitz, B.; Tillmann, R.; Wahner, A.; Schnitzler, J.-P.; Wildt, J.

2012-01-01

Stress-induced volatile organic compound (VOC) emissions from transgenic Grey poplar modified in isoprene emission potential were used for the investigation of photochemical secondary organic aerosol (SOA) formation. In poplar, acute ozone stress induces the emission of a wide array of VOCs dominated by sesquiterpenes and aromatic VOCs. Constitutive light-dependent emission of isoprene ranged between 66 nmol m-2 s-1 in non-transgenic controls (wild type WT) and nearly zero (plants (line RA22), respectively. Nucleation rates of up to 3600 cm-3 s-1 were observed in our experiments. In the presence of isoprene new particle formation was suppressed compared to non-isoprene containing VOC mixtures. Compared to isoprene/monoterpene systems emitted from other plants the suppression of nucleation by isoprene was less effective for the VOC mixture emitted from stressed poplar. This is explained by the observed high efficiency of new particle formation for emissions from stressed poplar. Direct measurements of OH in the reaction chamber revealed that the steady state concentration of OH is lower in the presence of isoprene than in the absence of isoprene, supporting the hypothesis that isoprenes' suppressing effect on nucleation is related to radical chemistry. In order to test whether isoprene contributes to SOA mass formation, fully deuterated isoprene (C5D8) was added to the stress-induced emission profile of an isoprene free poplar mutant. Mass spectral analysis showed that, despite the isoprene-induced suppression of particle formation, fractions of deuterated isoprene were incorporated into the SOA. A fractional mass yield of 2.3% of isoprene was observed. Future emission changes due to land use and climate change may therefore affect both gas phase oxidation capacity and new particle number formation.

Global Occurrence and Emission of Rotaviruses to Surface Waters

Directory of Open Access Journals (Sweden)

Nicholas M. Kiulia

2015-05-01

Full Text Available Group A rotaviruses (RV are the major cause of acute gastroenteritis in infants and young children globally. Waterborne transmission of RV and the presence of RV in water sources are of major public health importance. In this paper, we present the Global Waterborne Pathogen model for RV (GloWPa-Rota model to estimate the global distribution of RV emissions to surface water. To our knowledge, this is the first model to do so. We review the literature to estimate three RV specific variables for the model: incidence, excretion rate and removal during wastewater treatment. We estimate total global RV emissions to be 2 × 1018 viral particles/grid/year, of which 87% is produced by the urban population. Hotspot regions with high RV emissions are urban areas in densely populated parts of the world, such as Bangladesh and Nigeria, while low emissions are found in rural areas in North Russia and the Australian desert. Even for industrialized regions with high population density and without tertiary treatment, such as the UK, substantial emissions are estimated. Modeling exercises like the one presented in this paper provide unique opportunities to further study these emissions to surface water, their sources and scenarios for improved management.

Evidence of different red emissions in irradiated germanosilicate materials

Energy Technology Data Exchange (ETDEWEB)

Alessi, A., E-mail: antonino.alessi@univ-st-etienne.fr [Univ-Lyon, Laboratoire H. Curien, UMR CNRS 5516, Université Jean Monnet, 18 rue du Pr. Benoît Lauras, 42000 Saint-Etienne (France); Di Francesca, D. [Univ-Lyon, Laboratoire H. Curien, UMR CNRS 5516, Université Jean Monnet, 18 rue du Pr. Benoît Lauras, 42000 Saint-Etienne (France); Agnello, S. [Dipartimento di Fisica e Chimica, Università di Palermo, I-90123 Palermo (Italy); Girard, S. [Univ-Lyon, Laboratoire H. Curien, UMR CNRS 5516, Université Jean Monnet, 18 rue du Pr. Benoît Lauras, 42000 Saint-Etienne (France); Cannas, M. [Dipartimento di Fisica e Chimica, Università di Palermo, I-90123 Palermo (Italy); Richard, N. [CEA, DAM, DIF, F91297 Arpajon (France); Boukenter, A.; Ouerdane, Y. [Univ-Lyon, Laboratoire H. Curien, UMR CNRS 5516, Université Jean Monnet, 18 rue du Pr. Benoît Lauras, 42000 Saint-Etienne (France)

2016-09-15

This experimental investigation is focused on a radiation induced red emission in Ge doped silica materials, elaborated with different methods and processes. The differently irradiated samples as well as the pristine ones were analyzed with various spectroscopic techniques, such as confocal microscopy luminescence (CML), time resolved luminescence (TRL), photoluminescence excitation (PLE) and electron paramagnetic resonance (EPR). Our data prove that irradiation induces a red luminescence related to the presence of the Ge atoms. Such emission features a photoexcitation spectrum in the UV-blue spectral range and, TRL measurements show that its decrease differs from a single exponential law with a lifetime of tens of nanoseconds. CML measurements under laser at 633 nm evidenced the lack of correlation of the emission here reported with that of the Ge- or Si- non bridging oxygen hole centers. Moreover, our EPR experiments highlighted the lack of correlation between the red emitting defect with other radiation induced paramagnetic centers such as the E′Ge and Ge(2). The relation of the investigated emission with the H(II) defects, previously considered as responsible for a red emission, can not be totally excluded. - Highlights: • Composite nature of the red emission in Ge-doped doped silica materials. • Experimental study with various spectroscopic techniques and on different samples. • Time resolved and stationary characterization of an new red emission. • Study of the spatial distributions of diverse red emissions in optical fibers.

Stability of field emission current from porous n-GaAs(110)

Science.gov (United States)

Tondare, V. N.; Naddaf, M.; Bhise, A. B.; Bhoraskar, S. V.; Joag, D. S.; Mandale, A. B.; Sainkar, S. R.

2002-02-01

Field electron emission from porous GaAs has been investigated. The emitter was prepared by anodic etching of n-GaAs (110) in 0.1 M HCl solution. The as-etched porous GaAs shows nonlinear Fowler-Nordheim (FN) characteristics, with a low onset voltage. The emitter, after operating for 6 h at the residual gas pressure of 1×10-8 mbar, shows a linear FN characteristics with a relatively high onset voltage and poor field emission current stability as compared to the as-etched emitter. The change in the behavior was attributed to the residual gas ion bombardment during field electron emission. X-ray photoelectron spectroscopic investigations were carried out on as-etched sample and the one which was studied for field emission. The studies indicate that the as-etched surface contains As2O3 and the surface after field electron emission for about 6 h becomes gallium rich. The presence of As2O3 seems to be a desirable feature for the stable field emission current.

An emissions trading scheme design for power industries facing price regulation

International Nuclear Information System (INIS)

Kim, Yong-Gun; Lim, Jong-Soo

2014-01-01

The electricity market, monopolistic in nature, with government price regulation, poses a serious challenge for policy makers with respect to the cost-effectiveness of emissions trading, particularly in Asian countries. This paper argues that a cap-and-trade regulatory system for indirect emissions combined with a rate-based allocation system for direct emissions can achieve market efficiency even in the presence of price and quantity controls in the electricity market. This particular policy mix could provide appropriate incentives for industries to reduce their electricity consumption while inducing power producers to reduce their direct carbon emissions cost-effectively in conditions where there is strict government control of electricity prices. Another advantage of the suggested policy mix is that it allows carbon leakage in cross-border power trades to be effectively eliminated. - Highlights: • A rate-based allocation induces power producers to minimize direct emissions. • A cap-and-trade on indirect emission induces firms to reduce electricity consumption. • These two can jointly achieve market efficiency even in the regulated power market

Transparency and spontaneous emission in a densely doped photonic band gap material

Energy Technology Data Exchange (ETDEWEB)

Singh, Mahi R [Department of Physics and Astronomy, University of Western Ontario, London N6A 3K7 (Canada)

2006-12-28

The susceptibility has been calculated for a photonic crystal in the presence of spontaneous cancellation and dipole-dipole interaction. The crystal is densely doped with an ensemble of four-level nano-particles in Y-type configuration. Probe and a pump laser fields are applied to manipulate the absorption coefficient of the system. The expression of the susceptibility has been calculated in the linear response regime of the probe field but nonlinear terms are included for the pump field. It is found that in the presence of spontaneous emission cancellation there is an increase in the height of the two absorption peaks however the phenomenon of electromagnetically induced transparency (EIT) is not affected. On the other hand, there is a change in the height and location of the two peaks in the presence of dipole-dipole interactions. For certain values the particle density of the system can be switched from the EIT state to the non-EIT state. It is also found that when the resonance energies for two spontaneous emission channels lie close to the band edge, the EIT phenomenon disappears.

Emissions impacts of wind and energy storage in a market environment.

Science.gov (United States)

Sioshansi, Ramteen

2011-12-15

This study examines the emissions impacts of adding wind and energy storage to a market-based electric power system. Using Texas as a case study, we demonstrate that market power can greatly effect the emissions benefits of wind, due to most of the coal-fired generation being owned by the two dominant firms. Wind tends to have less emissions benefits when generators exercise market power, since coal-fired generation is withheld from the market and wind displaces natural gas-fired generators. We also show that storage can have greater negative emissions impacts in the presence of wind than if only storage is added to the system. This is due to wind increasing on- and off-peak electricity price differences, which increases the amount that storage and coal-fired generation are used. We demonstrate that this effect is exacerbated by market power.

Investigations of the Impact of Biodiesel Metal Contaminants on Emissions Control Devices

Energy Technology Data Exchange (ETDEWEB)

Brookshear, D. W.; Lance, M. J.; McCormick, Robert L.; Toops, T. J.

2017-02-27

Biodiesel is a renewable fuel with the potential to displace a portion of petroleum use. However, as with any alternative fuel, in order to be a viable choice it must be compatible with the emissions control devices. The finished biodiesel product can contain up to 5 ppm Na+K and 5 ppm Ca+Mg, and these metal impurities can lead to durability issues with the devices used to control emissions in diesel vehicles. Significant work has been performed to understand how the presence of these metals impacts each individual component of diesel emissions control systems, and this chapter summarizes the findings of these research efforts.

Biodiesel emissions profile in modern diesel vehicles. Part 2: Effect of biodiesel origin on carbonyl, PAH, nitro-PAH and oxy-PAH emissions.

Science.gov (United States)

Karavalakis, Georgios; Boutsika, Vasiliki; Stournas, Stamoulis; Bakeas, Evangelos

2011-01-15

In the present study, the effects of different biodiesel blends on the unregulated emissions of a Euro 4 compliant passenger car were examined. Two fresh and two oxidized biodiesel fuels of different source materials were blended with an ultra low sulphur automotive diesel fuel at proportions of 10, 20, and 30% v/v. Emission measurements were conducted on a chassis dynamometer with a constant volume sampling (CVS) technique, over the New European Driving Cycle (NEDC) and the Artemis driving cycles. The experimental results revealed that the addition of biodiesel led to important increases in most carbonyl compounds. Sharp increases were observed with the use of the oxidized biodiesel blends, especially those prepared from used frying oil methyl esters. Similar to carbonyl emissions, most PAH compounds increased with the addition of the oxidized biodiesel blends. It can be assumed that the presence of polymerization products and cyclic acids, along with the degree of unsaturation were the main factors that influenced carbonyl and PAH emissions profile. Copyright © 2010 Elsevier B.V. All rights reserved.

Boundary conditions on the plasma emitter surface in the presence of a particle counter flow: I. Ion emitter

Energy Technology Data Exchange (ETDEWEB)

Astrelin, V. T., E-mail: V.T.Astrelin@inp.nsk.su; Kotelnikov, I. A. [Russian Academy of Sciences, Budker Institute of Nuclear Physics, Siberian Branch (Russian Federation)

2017-02-15

Emission of positively charged ions from a plasma emitter irradiated by a counterpropagating electron beam is studied theoretically. A bipolar diode with a plasma emitter in which the ion temperature is lower than the electron temperature and the counter electron flow is extracted from the ion collector is calculated in the one-dimensional model. An analog of Bohm’s criterion for ion emission in the presence of a counterpropagating electron beam is derived. The limiting density of the counterpropagating beam in a bipolar diode operating in the space-charge-limited-emission regime is calculated. The full set of boundary conditions on the plasma emitter surface that are required for operation of the high-current optics module in numerical codes used to simulate charged particle sources is formulated.

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

Anti-3-[(18)F]FACBC positron emission tomography-computerized tomography and (111)In-capromab pendetide single photon emission computerized tomography-computerized tomography for recurrent prostate carcinoma: results of a prospective clinical trial.

Science.gov (United States)

Schuster, David M; Nieh, Peter T; Jani, Ashesh B; Amzat, Rianot; Bowman, F Dubois; Halkar, Raghuveer K; Master, Viraj A; Nye, Jonathon A; Odewole, Oluwaseun A; Osunkoya, Adeboye O; Savir-Baruch, Bital; Alaei-Taleghani, Pooneh; Goodman, Mark M

2014-05-01

We prospectively evaluated the amino acid analogue positron emission tomography radiotracer anti-3-[(18)F]FACBC compared to ProstaScint® ((111)In-capromab pendetide) single photon emission computerized tomography-computerized tomography to detect recurrent prostate carcinoma. A total of 93 patients met study inclusion criteria who underwent anti-3-[(18)F]FACBC positron emission tomography-computerized tomography plus (111)In-capromab pendetide single photon emission computerized tomography-computerized tomography for suspected recurrent prostate carcinoma within 90 days. Reference standards were applied by a multidisciplinary board. We calculated diagnostic performance for detecting disease. In the 91 of 93 patients with sufficient data for a consensus on the presence or absence of prostate/bed disease anti-3-[(18)F]FACBC had 90.2% sensitivity, 40.0% specificity, 73.6% accuracy, 75.3% positive predictive value and 66.7% negative predictive value compared to (111)In-capromab pendetide with 67.2%, 56.7%, 63.7%, 75.9% and 45.9%, respectively. In the 70 of 93 patients with a consensus on the presence or absence of extraprostatic disease anti-3-[(18)F]FACBC had 55.0% sensitivity, 96.7% specificity, 72.9% accuracy, 95.7% positive predictive value and 61.7% negative predictive value compared to (111)In-capromab pendetide with 10.0%, 86.7%, 42.9%, 50.0% and 41.9%, respectively. Of 77 index lesions used to prove positivity histological proof was obtained in 74 (96.1%). Anti-3-[(18)F]FACBC identified 14 more positive prostate bed recurrences (55 vs 41) and 18 more patients with extraprostatic involvement (22 vs 4). Anti-3-[(18)F]FACBC positron emission tomography-computerized tomography correctly up-staged 18 of 70 cases (25.7%) in which there was a consensus on the presence or absence of extraprostatic involvement. Better diagnostic performance was noted for anti-3-[(18)F]FACBC positron emission tomography-computerized tomography than for (111)In-capromab pendetide single

Isoprene in poplar emissions: effects on new particle formation and OH concentrations

Directory of Open Access Journals (Sweden)

A. Kiendler-Scharr

2012-01-01

Full Text Available Stress-induced volatile organic compound (VOC emissions from transgenic Grey poplar modified in isoprene emission potential were used for the investigation of photochemical secondary organic aerosol (SOA formation. In poplar, acute ozone stress induces the emission of a wide array of VOCs dominated by sesquiterpenes and aromatic VOCs. Constitutive light-dependent emission of isoprene ranged between 66 nmol m⁻² s⁻¹ in non-transgenic controls (wild type WT and nearly zero (<0.5 nmol m⁻² s⁻¹ in isoprene emission-repressed plants (line RA22, respectively. Nucleation rates of up to 3600 cm⁻³ s⁻¹ were observed in our experiments. In the presence of isoprene new particle formation was suppressed compared to non-isoprene containing VOC mixtures. Compared to isoprene/monoterpene systems emitted from other plants the suppression of nucleation by isoprene was less effective for the VOC mixture emitted from stressed poplar. This is explained by the observed high efficiency of new particle formation for emissions from stressed poplar. Direct measurements of OH in the reaction chamber revealed that the steady state concentration of OH is lower in the presence of isoprene than in the absence of isoprene, supporting the hypothesis that isoprenes' suppressing effect on nucleation is related to radical chemistry. In order to test whether isoprene contributes to SOA mass formation, fully deuterated isoprene (C₅D₈ was added to the stress-induced emission profile of an isoprene free poplar mutant. Mass spectral analysis showed that, despite the isoprene-induced suppression of particle formation, fractions of deuterated isoprene were incorporated into the SOA. A fractional mass yield of 2.3% of isoprene was observed. Future emission changes due to land use and climate change may therefore affect both gas phase oxidation capacity and new particle number formation.

FLARE-LIKE VARIABILITY OF THE Mg II {lambda}2800 EMISSION LINE IN THE {gamma}-RAY BLAZAR 3C 454.3

Energy Technology Data Exchange (ETDEWEB)

Leon-Tavares, J. [Finnish Centre for Astronomy with ESO (FINCA), University of Turku, Vaeisaelaentie 20, FI-21500 Piikkioe (Finland); Chavushyan, V.; Patino-Alvarez, V.; Carraminana, A.; Carrasco, L. [Instituto Nacional de Astrofisica Optica y Electronica (INAOE), Apartado Postal 51 y 216, 72000 Puebla (Mexico); Valtaoja, E. [Tuorla Observatory, Department of Physics and Astronomy, University of Turku, FI-20100 Turku (Finland); Arshakian, T. G. [I. Physikalisches Institut, Universitaet zu Koeln, Zuelpicher Str. 77, D-50937 Koeln (Germany); Popovic, L. C. [Astronomical Observatory, Volgina 7, 11160 Belgrade 74 (Serbia); Tornikoski, M.; Laehteenmaeki, A. [Aalto University Metsaehovi Radio Observatory, Metsaehovintie 114, FI-02540 Kylmaelae (Finland); Lobanov, A. [Max-Planck-Institut fuer Radioastronomie, Auf dem Huegel 69, D-53121 Bonn (Germany)

2013-02-01

We report the detection of a statistically significant flare-like event in the Mg II {lambda}2800 emission line of 3C 454.3 during the outburst of autumn 2010. The highest levels of emission line flux recorded over the monitoring period (2008-2011) coincide with a superluminal jet component traversing through the radio core. This finding crucially links the broad emission line fluctuations to the non-thermal continuum emission produced by relativistically moving material in the jet and hence to the presence of broad-line region clouds surrounding the radio core. If the radio core were located at several parsecs from the central black hole, then our results would suggest the presence of broad-line region material outside the inner parsec where the canonical broad-line region is envisaged to be located. We briefly discuss the implications of broad emission line material ionized by non-thermal continuum in the context of virial black hole mass estimates and gamma-ray production mechanisms.

Field emission studies of silver nanoparticles synthesized by electron cyclotron resonance plasma

International Nuclear Information System (INIS)

Purohit, Vishwas; Mazumder, Baishakhi; Bhise, A.B.; Poddar, Pankaj; Joag, D.S.; Bhoraskar, S.V.

2011-01-01

Field emission has been studied for silver nanoparticles (25-200 nm), deposited within a cylindrical silver target in an electron cyclotron resonance (ECR) plasma. Particle size distribution was controlled by optimum biasing voltages between the chamber and the target. Presence of non-oxidized silver was confirmed from the X-Ray diffraction analysis; however, thin protective layer of oxide was identified from the selective area electron diffraction pattern obtained with transmission electron microscopy. The silver nanoparticles were seen to exhibit hilly pointed like structures when viewed under the atomic force microscopy (AFM). The emissive properties of these particles were investigated by field emission microscopy. It is found that this technique of deposition is ideal for formation of nanoparticles films on different substrate geometries with size controllability as well as its application to emission devices.

Presence of Social Presence during Disasters

DEFF Research Database (Denmark)

Mukkamala, Alivelu Manga; Beck, Roman

2017-01-01

During emergencies, affected people use social media platforms for interaction and collaboration. Social media is used to ask for help, provide moral support, and to help each other, without direct face-to-face interactions. From a social presence point of view, we analyzed Twitter messages...... to understand how people cooperate and collaborate with each other during heavy rains and subsequent floods in Chennai, India. We conducted a manual content analysis to build social presence classifiers comprising intimacy and immediacy concepts which we used to train a machine learning approach to subsequently...

Hole emission mechanism in Ge/Si quantum dots

Energy Technology Data Exchange (ETDEWEB)

Kaniewska, M.; Zaremba, G.; Kaczmarczyk, M.; Wzorek, M.; Czerwinski, A. [Institute of Electron Technology, Al. Lotnikow 32/46, 02-668 Warsaw (Poland); Engstroem, O. [Institute of Electron Technology, Al. Lotnikow 32/46, 02-668 Warsaw (Poland); Chalmers University of Technology, Kemivaegen 9, 412 96 Goeteborg (Sweden); Karmous, A.; Kirfel, O.; Kasper, E. [Institute for Semiconductor Engineering, University of Stuttgart, Pfaffenwaldring 47, 70569 Stuttgart (Germany); Raeissi, B.; Piscator, J. [Chalmers University of Technology, Kemivaegen 9, 412 96 Goeteborg (Sweden); Surma, B.; Wnuk, A. [Institute of Electronic Materials Technology, Wolczynska 133, 01-919 Warsaw (Poland)

2011-02-15

The mechanisms determining emission of holes in self-assembled Ge quantum dots (QDs) embedded in the p-type Si matrix have been investigated. Specimens were prepared by molecular beam epitaxy (MBE). Electrical methods such as deep level transient spectroscopy (DLTS) and capacitance versus voltage (C-V) measurements were used for the study. The emission mechanisms were identified by measuring a QD-related signal as a function of the repetition frequency of the filling pulses with the reverse voltage and the pulse voltage as a parameter. An observed shift of the signal position or its absence versus the voltage parameters was interpreted in terms of thermal, tunnelling and mixed processes and attributed to the presence of a Coulomb barrier formed as a result of the charging effect. Thermal emission properties of the QDs were characterized under such measurement conditions that tunnelling contributions to the DLTS spectra could be neglected (copyright 2011 WILEY-VCH Verlag GmbH and Co. KGaA, Weinheim) (orig.)

Preferential emission into epsilon-near-zero metamaterial [Invited

International Nuclear Information System (INIS)

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

2015-01-01

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

An emission inventory of sulfur from anthropogenic sources in Antarctica

Directory of Open Access Journals (Sweden)

S. V. Shirsat

2009-05-01

Full Text Available This paper presents first results of a comprehensive emission inventory of chemical species from anthropogenic activities (power generation, vehicles, ships and aircraft in Antarctica, covering the 2004–2005 period.

The inventory is based on estimated emission rates of fuel consumption provided by some of the Antarctic research stations. Since the emission sources have different modes of operation and use a variety of fuel, the emission flux rate of chemical species is calculated by multiplying the fuel consumption value with the density of fuel and appropriate emission factors. A separate inventory is prepared for each anthropogenic emission source in Antarctica.

Depending on the type of operation, emission rates of SO₂, and BC (Black Carbon, from shipping only have been calculated using the above technique. However, only results of SO₂ emissions from each source are presented here. Emission inventory maps of SO₂ depicting the track/path taken by each mobile source are shown. The total annual SO₂ is 158 Mg from power generation and vehicle operations, 3873 Mg from ships and 56 Mg from aircraft for 2004–2005 and these values undergo strong seasonality following the human activity in Antarctica. Though these figures are small when compared to the emissions at most other regions of the world, they are an indication that human presence in Antarctica leads to at least local pollution. The sources are mainly line and point sources and thus the local pollution potentially is relatively strong.

The dynamic relationship between structural change and CO2 emissions in Malaysia: a cointegrating approach.

Science.gov (United States)

Ali, Wajahat; Abdullah, Azrai; Azam, Muhammad

2017-05-01

The current study investigates the dynamic relationship between structural changes, real GDP per capita, energy consumption, trade openness, population density, and carbon dioxide (CO 2 ) emissions within the EKC framework over a period 1971-2013. The study used the autoregressive distributed lagged (ARDL) approach to investigate the long-run relationship between the selected variables. The study also employed the dynamic ordinary least squared (DOLS) technique to obtain the robust long-run estimates. Moreover, the causal relationship between the variables is explored using the VECM Granger causality test. Empirical results reveal a negative relationship between structural change and CO 2 emissions in the long run. The results indicate a positive relationship between energy consumption, trade openness, and CO 2 emissions. The study applied the turning point formula of Itkonen (2012) rather than the conventional formula of the turning point. The empirical estimates of the study do not support the presence of the EKC relationship between income and CO 2 emissions. The Granger causality test indicates the presence of long-run bidirectional causality between energy consumption, structural change, and CO 2 emissions in the long run. Economic growth, openness to trade, and population density unidirectionally cause CO 2 emissions. These results suggest that the government should focus more on information-based services rather than energy-intensive manufacturing activities. The feedback relationship between energy consumption and CO 2 emissions suggests that there is an ominous need to refurbish the energy-related policy reforms to ensure the installations of some energy-efficient modern technologies.

Neutron-Activated Gamma-Emission: Technology Review

Science.gov (United States)

2012-01-01

in Be9 + α  C12 + n and Be9 + α  3He4 + n. Chadwick (5) made use of the naturally occurring α-emitter polonium - 210 , which decays to lead-206 with...emission, the variation of gamma attenuation with distance and the presence of organic clutter (in food , fertilizer, dirt road, etc.) makes it 8...a neutron source by mixing a radioisotope that emits alpha particles, such as radium or polonium , with a low atomic weight isotope, usually in the

Otoacoustic emissions as an instrument of epidemiological surveillance in the health of the workers

Directory of Open Access Journals (Sweden)

Oliveira, Priscila Feliciano de

2011-10-01

Full Text Available Introduction: The noise is a harmful agent to the hearing, being frequent in urban and work environments. Among the structures of the hearing system, the outer hair cells are the first to be injured, and otoacoustic emissions identify minimal cochlear alterations. Objective: Analyze cochlear alterations with otoacoustic emissions transient evoked in individuals exposed to combined risk: noise and chemical products. Method: 49 workers of a cement company participated of the research, aged between 19 and 49 years old, exposure time of at least two years and normal hearing thresholds. Was performed an anamnesis and otoacoustic emissions before and post work activity. The results of the exam were related with the variable: time of exposure to the noise, age, exposure to chemical products and sound habits. The statistical tests used were: T of Student, chi-squared Pearson test and Fisher's exact test and is characterized by a prospective clinical study. Results: At the first testing, had presence of emissions in all of the workers. The average of amplitude is of 10,22 dBSPL in the right ear and 9,48 dBSPL in the left ear. In the second testing there were a variation of 0,69 dBSPL in the lef ear and 0,42 dBSPL in the right ear, of which 79,6% of individuals had presence of emission bilaterally and 20,4% absence in at least one ear. Analyzing the relation between variations of emissions with the variable was not observed statistically significant data. Conclusion: The otoacoustic emissions in the workers health search to prevent the damage to the hearing system through cochlear changings.

Using natural beta emission for detecting concealed tobacco in parcels

International Nuclear Information System (INIS)

Myers, Jeremy; Hussein, Esam M.A.

2007-01-01

It is suspected that postal systems are used for the illegal shipment of tobacco products to circumvent taxation and excise payments. This paper demonstrates that beta-particle emission from the potassium-40 contained in tobacco can be used to passively detect its presence in paperboard postal parcels. The same concept can be utilized for the detection of marijuana, whose leaves are also rich in 40 K. The combination of high beta activity and a low weight is a good indicator of the presence of these two contraband materials

Using natural beta emission for detecting concealed tobacco in parcels

Energy Technology Data Exchange (ETDEWEB)

Myers, Jeremy [Laboratory for Threat Material Detection, Department of Mechanical Engineering, University of New Brunswick, Fredericton, New Brunswick, E3B 5A3 (Canada); Hussein, Esam M.A. [Laboratory for Threat Material Detection, Department of Mechanical Engineering, University of New Brunswick, Fredericton, New Brunswick, E3B 5A3 (Canada)], E-mail: hussein@unb.ca

2007-10-15

It is suspected that postal systems are used for the illegal shipment of tobacco products to circumvent taxation and excise payments. This paper demonstrates that beta-particle emission from the potassium-40 contained in tobacco can be used to passively detect its presence in paperboard postal parcels. The same concept can be utilized for the detection of marijuana, whose leaves are also rich in {sup 40}K. The combination of high beta activity and a low weight is a good indicator of the presence of these two contraband materials.

SEARCH FOR GAMMA-RAY EMISSION FROM MAGNETARS WITH THE FERMI LARGE AREA TELESCOPE

International Nuclear Information System (INIS)

Abdo, A. A.; Ackermann, M.; Ajello, M.; Allafort, A.; Blandford, R. D.; Bloom, E. D.; Borgland, A. W.; Bouvier, A.; Baldini, L.; Bellazzini, R.; Bregeon, J.; Ballet, J.; Barbiellini, G.; Baring, M. G.; Bastieri, D.; Bonamente, E.; Brigida, M.; Bruel, P.; Burnett, T. H.; Caliandro, G. A.

2010-01-01

We report on the search for 0.1-10 GeV emission from magnetars in 17 months of Fermi Large Area Telescope (LAT) observations. No significant evidence for gamma-ray emission from any of the currently known magnetars is found. The most stringent upper limits to date on their persistent emission in the Fermi energy range are estimated between ∼10 -12 and10 -10 erg s -1 cm -2 , depending on the source. We also searched for gamma-ray pulsations and possible outbursts, also with no significant detection. The upper limits derived support the presence of a cutoff at an energy below a few MeV in the persistent emission of magnetars. They also show the likely need for a revision of current models of outer-gap emission from strongly magnetized pulsars, which, in some realizations, predict detectable GeV emission from magnetars at flux levels exceeding the upper limits identified here using the Fermi-LAT observations.

The effect of magnesium-based additives on particulate emissions from oil-fired power plants

Energy Technology Data Exchange (ETDEWEB)

Martinez, L.S.; Galeano, V.C.; Pena, E.S.; Caballero, P.G.

1986-02-01

To improve present knowledge of characteristics of particulate emissions from large-size boilers, in particular the role played by magnesium-oxide slurries, research was carried out with the following main objectives in mind: To identify the elementary chemical composition of emissions from a large boiler burning heavy fuel-oil; To define the differences caused by the use of MgO slurries regarding both quantity and characteristics of emissions; To study the boiler's transient response to sudden changes in additive dosage. The use of different fuel-oil during the experiments has given cause to discuss the following aspects: The joint presence of carbon and sulfur in particulate matter; The influence of certain characteristics of fuel-oil in emissions.

Physical and chemical characterization of residential oil boiler emissions.

Science.gov (United States)

Hays, Michael D; Beck, Lee; Barfield, Pamela; Lavrich, Richard J; Dong, Yuanji; Vander Wal, Randy L

2008-04-01

The toxicity of emissions from the combustion of home heating oil coupled with the regional proximity and seasonal use of residential oil boilers (ROB) is an important public health concern. Yet scant physical and chemical information about the emissions from this source is available for climate and air quality modeling and for improving our understanding of aerosol-related human health effects. The gas- and particle-phase emissions from an active ROB firing distillate fuel oil (commonly known as diesel fuel) were evaluated to address this deficiency. Ion chromatography of impactor samples showed that the ultrafine ROB aerosol emissions were approximately 45% (w/w) sulfate. Gas chromatography-mass spectrometry detected various n-alkanes at trace levels, sometimes in accumulation mode particles, and out of phase with the size distributions of aerosol mass and sulfate. The carbonaceous matter in the ROB aerosol was primarily light-adsorbing elemental carbon. Gas chromatography-atomic emission spectroscopy measured a previously unrecognized organosulfur compound group in the ROB aerosol emissions. High-resolution transmission electron microscopy of ROB soot indicated the presence of a highly ordered primary particle nanostructure embedded in larger aggregates. Organic gas emissions were measured using EPA Methods TO-15 and TO-11A. The ROB emitted volatile oxygenates (8 mg/(kg of oil burned)) and olefins (5 mg/(kg of oil burned)) mostly unrelated to the base fuel composition. In the final analysis, the ROB tested was a source of numerous hazardous air pollutants as defined in the Clean Air Act Amendments. Approximations conducted using emissions data from the ROB tests show relatively low contributions to a regional-level anthropogenic emissions inventory for volitile organic compounds, PM2.5, and SO2 mass.

Simulations of Galactic polarized synchrotron emission for Epoch of Reionization observations

Science.gov (United States)

Spinelli, M.; Bernardi, G.; Santos, M. G.

2018-06-01

The detection of the redshifted cosmological 21 cm line signal requires the removal of the Galactic and extragalactic foreground emission, which is orders of magnitude brighter anywhere in the sky. Foreground cleaning methods currently used are efficient in removing spectrally smooth components. However, they struggle in the presence of not spectrally smooth contamination that is, therefore, potentially the most dangerous one. An example of this is the polarized synchrotron emission, which is Faraday rotated by the interstellar medium and leaks into total intensity due to instrumental imperfections. In this work we present new full-sky simulations of this polarized synchrotron emission in the 50 - 200 MHz range, obtained from the observed properties of diffuse polarized emission at low frequencies. The simulated polarized maps are made publicly available, aiming to provide more realistic templates to simulate the effect of instrumental leakage and the effectiveness of foreground separation techniques.

Fluxon induced surface resistance and field emission in niobium films at 1.5 GHz

CERN Document Server

Benvenuti, Cristoforo; Darriulat, Pierre; Peck, M A; Valente, A M; Van't Hof, C A

2001-01-01

The surface resistance of superconducting niobium films induced by the presence of trapped magnetic flux, presumably in the form of a pinned fluxon lattice, is shown to be modified by the presence of a field emitting impurity or defect. The modification takes the form of an additional surface resistance proportional to the density of the fluxon lattice and increasing linearly with the amplitude of the microwave above a threshold significantly lower than the field emission threshold. Such an effect, a precursor of electron emission, is observed for the first time in a study using radiofrequency cavities operating at their fundamental 1.5 GHz frequency. The measured properties of the additional surface resistance severely constrain possible explanations of the observed effect. (23 refs).

Role of spontaneous and stimulated emission in photon correlations

International Nuclear Information System (INIS)

Chopra, S.; Bohidar, H.; Harwalkar, V.

1984-01-01

Photon correlations have been alternately attributed to either spontaneous or stimulated emission by various authors. In this paper, the authors interpret, on the basis of available experimental data, the contribution of each emission form to the evolution of photon statistics. The laser is used as an example of a source which exhibits different statistical characteristics depending on the level of excitation, which is governed by the pump parameter a. From the data, it is evident that the transition from below to above threshold is accompanied by a significant drop in the magnitude of correlation and an increase in decay time. It may be noted that this transition causes a substantial increase in the coherent output which emphasizes the predominance of stimulated emission. In the case of a laser below threshold, however, photon correlations arise due to superposition of the more dominant spontaneously emitted wavetrains. Exact solutions of quantized systems do not exist in the presence of saturation effects. This implies that factorization and identification of terms with spontaneous or stimulated emission has not yet been done. This does not preculde a physical and intuitive interpretation of photon statistics within the framework of a standard model, and it is therefore argued that spontaneous emission is responsible for photon correlations while stimulated emission shows up in the dynamics as the coherence time

Behaviour of fluoropolymers in presence of tritiated water

International Nuclear Information System (INIS)

Bubueanu, Gh.; Postolache, C.; Tuta, C.

2011-01-01

Complete text of publication follows. One of the most used methods for tritium recovery from tritiated water relies on combined electrolysis with catalytic isotope exchange techniques. The electrolytic cell converts the tritiated water or tritiated heavy water into a hydrogen, deuterium and tritium mixture. The mixture is purified and then tritium is recovered by catalytic isotopic separation techniques. Tritium presence in the system induces an intense radiation field especially at aqueous solution interface. This can generate significant structural modifications with potentially negative effects. In this paper work it is followed the study of radiolytic phenomena in Pt/C/PTFE isotopic exchange catalyst, NAFION membranes and VITON fluoroelastomer in presence of tritiated water with high radioactive concentration. Radiolytical processes were analyzed by: Exposure of fluoropolymers samples immersed in H 2 O at gamma radiation field (60-Co source) in vacuum, at liq. Nitrogen temperature and at ambient temperature respectively; Immersing of NAFION, Pt/C/PTFE catalyst and VITON samples in tritiated water with high activity (3.7 and 37 TBq/L) for different time period. In both cases the samples were characterized by FT IR ATR, and fluoride ions emission from polymeric matrix. Experimental results were correlated with quantum-chemical simulations.

An Empirical Ultraviolet Template for Iron Emission in Quasars as Derived from I Zw 1

DEFF Research Database (Denmark)

Vestergaard, Marianne; Wilkes, B. J.

2001-01-01

contaminant in optical--UV spectra of AGNs. Its presence complicates and limits the accuracy of measurements of both strong and weak emission lines and the continuum emission, affecting studies of line and continuum interrelations, the ionization structure, and elemental abundances in AGNs. Despite the wealth...... iron spectrum make the template particularly suitable for use with most AGN spectra. The iron emission spectrum and the line identifications and measurements are presented and compared with the work of Laor et al. We illustrate the application of the derived FeII and FeIII templates by fitting...

Contribution of Metal Defects in the Assembly Induced Emission of Cu Nanoclusters

KAUST Repository

Wu, Zhennan

2017-03-20

Aggregation/assembly induced emission (AIE) has been observed for metal nanoclusters (NCs), but the origin of the enhanced emission is not fully understood, yet. In this work, the significant contribution of metal defects on AIE is revealed by engineering the self-assembly process of Cu NCs using ethanol. The presence of ethanol leads to a rapid assembly of NCs into ultrathin nanosheets, promoting the formation of metal defects-rich surface. Detailed studies and computer simulation confirm that the metal defects-rich nanosheets possess increased Cu(I)-to-Cu(0) ratio, which greatly influences ligand-to-metal-metal charge transfer and therewith facilitates the radiative relaxation of excitons. Consequently, the Cu NCs self-assembly nanosheets exhibit obvious emission enhancement.

Sinterable Ceramic Powders from Laser-Heated Gases.

Science.gov (United States)

1988-02-01

zone can be calculated from the Planck radi- The number density of particles as a func- ation law. At X - 4 pim . and 1100°C. the tion of position in...the reaction zone is pre- emission rate is about 3 W/cn2 /gtm. If the 250 • ZScs (wh-ztt Ottes ) - 0 2W0 *.04$5, 03 ,,oo, scte-etao rai for I i,, I t i...71997.12971. ynesolino.r Al 1 , uad L&,O,.-’ Nocha’. Ges. Wain. GotnuWa. Moar.. Pim KI..171FPudy. o em meSurfas Tensione. pp. 110- 12 i Surface md

Analysis of recent results of electron cyclotron emission measurements on T.F.R

International Nuclear Information System (INIS)

1977-05-01

Recently reported measurements of the electron cyclotron emission from the TFR Tokamak plasma are analyzed and compared to theoretical predictions. The line shape of an optically thick harmonic in a vertical observation is explained by wall reflections, plasma-detector arrangement and reabsorption. Non thermal emission at the electron plasma frequency is related to the presence of a high energy tail in the electron distribution function and might be the cause of the observed reduced runaway creation rate

Iron solubility related to particle sulfur content in source emission and ambient fine particles.

Science.gov (United States)

Oakes, M; Ingall, E D; Lai, B; Shafer, M M; Hays, M D; Liu, Z G; Russell, A G; Weber, R J

2012-06-19

The chemical factors influencing iron solubility (soluble iron/total iron) were investigated in source emission (e.g., biomass burning, coal fly ash, mineral dust, and mobile exhaust) and ambient (Atlanta, GA) fine particles (PM2.5). Chemical properties (speciation and mixing state) of iron-containing particles were characterized using X-ray absorption near edge structure (XANES) spectroscopy and micro-X-ray fluorescence measurements. Bulk iron solubility (soluble iron/total iron) of the samples was quantified by leaching experiments. Major differences were observed in iron solubility in source emission samples, ranging from low solubility (iron solubility did not correspond to silicon content or Fe(II) content. However, source emission and ambient samples with high iron solubility corresponded to the sulfur content observed in single particles. A similar correspondence between bulk iron solubility and bulk sulfate content in a series of Atlanta PM2.5 fine particle samples (N = 358) further supported this trend. In addition, results of linear combination fitting experiments show the presence of iron sulfates in several high iron solubility source emission and ambient PM2.5 samples. These results suggest that the sulfate content (related to the presence of iron sulfates and/or acid-processing mechanisms by H(2)SO(4)) of iron-containing particles is an important proxy for iron solubility.

Analysis of cubic and orthorhombic C3A hydration in presence of gypsum and lime

KAUST Repository

Kirchheim, A. P.; Fernà ndez-Altable, V.; Monteiro, P. J. M.; Dal Molin, D. C. C.; Casanova, I.

2009-01-01

Field emission scanning electron microscopy (FE-SEM) and X-ray diffraction (XRD) have been used to study the microstructural changes and phase development that take place during the hydration of cubic (pure) and orthorhombic (Na-doped) tricalcium aluminate (C3A) and gypsum in the absence and presence of lime. The results demonstrate that important differences occur in the hydration of each C3A polymorph and gypsum when no lime is added; orthorhombic C3A reacts faster with gypsum than the cubic phase, forming longer ettringite needles; however, the presence of lime slows down the formation of ettringite in the orthorhombic sample. Additional rheometric tests showed the possible effects on the setting time in these cementitious mixes.

Analysis of cubic and orthorhombic C3A hydration in presence of gypsum and lime

KAUST Repository

Kirchheim, A. P.

2009-02-26

Field emission scanning electron microscopy (FE-SEM) and X-ray diffraction (XRD) have been used to study the microstructural changes and phase development that take place during the hydration of cubic (pure) and orthorhombic (Na-doped) tricalcium aluminate (C3A) and gypsum in the absence and presence of lime. The results demonstrate that important differences occur in the hydration of each C3A polymorph and gypsum when no lime is added; orthorhombic C3A reacts faster with gypsum than the cubic phase, forming longer ettringite needles; however, the presence of lime slows down the formation of ettringite in the orthorhombic sample. Additional rheometric tests showed the possible effects on the setting time in these cementitious mixes.

Carbon dioxide emission and economic growth of China-the role of international trade.

Science.gov (United States)

Boamah, Kofi Baah; Du, Jianguo; Bediako, Isaac Asare; Boamah, Angela Jacinta; Abdul-Rasheed, Alhassan Alolo; Owusu, Samuel Mensah

2017-05-01

This study investigates the role of international trade in mitigating carbon dioxide emission as a nation economically advances. This study disaggregated the international trade into total exports and total imports. A multivariate model framework was estimated for the time series data for the period of 1970-2014. The quantile regression detected all the essential relationship, which hitherto, the traditional ordinary least squares could not capture. A cointegration relationship was confirmed using the Johansen cointegration model. The findings of the Granger causality revealed the presence of a uni-directional Granger causality running from energy consumption to economic growth; from import to economic growth; from imports to exports; and from urbanisation to economic growth, exports and imports. Our study established the presence of long-run relationships amongst carbon dioxide emission, economic growth, energy consumption, imports, exports and urbanisation. A bootstrap method was further utilised to reassess the evidence of the Granger causality, of which the results affirmed the Granger causality in the long run. This study confirmed a long-run N-shaped relationship between economic growth and carbon emission, under the estimated cubic environmental Kuznet curve framework, from the perspective of China. The recommendation therefore is that China as export leader should transform its trade growth mode by reducing the level of carbon dioxide emission and strengthening its international cooperation as it embraces more environmental protectionisms.

Fluorescence spectral studies of Gum Arabic: Multi-emission of Gum Arabic in aqueous solution

Energy Technology Data Exchange (ETDEWEB)

Dhenadhayalan, Namasivayam, E-mail: ndhena@gmail.com [Department of Chemistry, National Taiwan University, Taipei, Taiwan (China); Mythily, Rajan, E-mail: rajanmythily@gmail.com [Department of Chemistry, Dwaraka Doss Goverdhan Doss Vaishnav College (Autonomous), 833, Gokul Bagh, E.V.R. Periyar Road, Arumbakkam, Chennai 600 106 (India); Kumaran, Rajendran, E-mail: kumaranwau@rediffmail.com [Department of Chemistry, Dwaraka Doss Goverdhan Doss Vaishnav College (Autonomous), 833, Gokul Bagh, E.V.R. Periyar Road, Arumbakkam, Chennai 600 106 (India)

2014-11-15

Gum Arabic (GA), a food hydrocolloid is a natural composite obtained from the stems and branches of Acacia Senegal and Acacia Seyal trees. GA structure is made up of highly branched arabinogalactan polysaccharides. Steady-state absorption, fluorescence, and time-resolved fluorescence spectral studies of acid hydrolyzed GA solutions were carried out at various pH conditions. The fluorescence in GA is predominantly attributed to the presence of tyrosine and phenylalanine amino acids. The presence of multi-emissive peaks at different pH condition is attributed to the exposure of the fluorescing amino acids to the aqueous phase, which contains several sugar units, hydrophilic and hydrophobic moieties. Time-resolved fluorescence studies of GA exhibits a multi-exponential decay with different fluorescence lifetime of varying amplitude which confirms that tyrosine is confined to a heterogeneous microenvironment. The existence of multi-emissive peaks with large variation in the fluorescence intensities were established by 3D emission contour spectral studies. The probable location of the fluorophore in a heterogeneous environment was further ascertained by constructing a time-resolved emission spectrum (TRES) and time-resolved area normalized emission spectrum (TRANES) plots. Fluorescence spectral technique is used as an analytical tool in understanding the photophysical properties of a water soluble complex food hydrocolloid containing an intrinsic fluorophore located in a multiple environment is illustrated. - Highlights: • The Manuscript deals with the steady state absorption, emission, fluorescence lifetime and time-resolved emission spectrum studies of Gum Arabic in aqueous medium at various pH conditions. • The fluorescence emanates from the tyrosine amino acid present in GA. • Change in pH results in marked variation in the fluorescence spectral properties of tyrosine. • Fluorescence spectral techniques are employed as a tool in establishing the

Natural gas consumption, income, urbanization, and CO2 emissions in China and India.

Science.gov (United States)

Solarin, Sakiru Adebola; Lean, Hooi Hooi

2016-09-01

The objective of this study is to examine the impact of natural gas consumption, output, and urbanization on CO2 emission in China and India for the period, 1965-2013. A cointegraton test, which provides for endogenously determined structural breaks, has been applied to examine the long-run relationship and to investigate the presence of environmental Kuznets curve (EKC) in the two countries. The presence of causal relationship between the variables is also investigated. The findings show that there is a long-run relationship in the variables and natural gas, real GDP, and urbanization have long-run positive impact on emission in both countries. There is no evidence for EKC in China and India. The findings further suggest that there is a long-run feedback relationship between the variables. The policy inferences of these findings are discussed.

Line emissions from sonoluminescence in aqueous solutions of halide salts without noble gases

Energy Technology Data Exchange (ETDEWEB)

Liang, Jinfu, E-mail: liang.shi2007@163.com [The Key Laboratory of Modern Acoustics, Ministry of Education, Institution of Acoustics, Nanjing University, Nanjing 210093 (China); School of Physics and Electronic Science, Guizhou Normal University, Guiyang 550001 (China); Chen, Weizhong, E-mail: wzchen@nju.edu.cn [The Key Laboratory of Modern Acoustics, Ministry of Education, Institution of Acoustics, Nanjing University, Nanjing 210093 (China); Zhou, Chao; Cui, Weicheng; Chen, Zhan [The Key Laboratory of Modern Acoustics, Ministry of Education, Institution of Acoustics, Nanjing University, Nanjing 210093 (China)

2015-02-20

Line emissions of trivalent terbium (Tb{sup 3+}) ion were observed from single-bubble sonoluminescence (SL) in an aqueous solution of terbium chloride (TbCl{sub 3}) that contained no noble gas. In addition, sodium (Na) lines were observed in multi-bubble SL in aqueous solutions of various halide salts that contained no noble gas. These observations show that the halide ions, such as Cl{sup −}, Br{sup −}, and I{sup −}, help for line emissions as the noble gases. The intensity of a line emission depends on both the chemical species produced by cavitation bubbles and the temperature of SL bubble that responds to the driving ultrasound pressure. With the increase of driving pressure, some line emissions attached to the continuous spectrum may become increasingly clear, while other line emissions gradually become indistinct. - Highlights: • Line emissions of Tb(III) ions were observed without the presence of noble gases. • The halide ions help to generate a line emission during sonoluminescence. • The intensity of a line emission mainly depends on the bubble's temperature. • The definition of a line emission is related to the temperature of caviation bubble and the kind of host liquid.

Upconversion emission study of Er3+/Yb3+ doped barium titanate phosphor prepared by co-precipitation method

International Nuclear Information System (INIS)

Mahata, M.K.; Dey, R.; Kumar, K.; Rai, V.K.; Rai, S.B.

2012-01-01

In the present work we have successfully synthesized the Er 3+ , Yb 3+ doped barium titanate phosphor via co-precipitation synthesis method. Under 980 nm excitation, tri-color upconversion fluorescence has been observed. The Fourier Transform Infrared measurement was done to check the presence of organic impurities. In order to find out how many photons are involved in each emission band, the variation of UC emission intensity of the codoped phosphor is studied with increase in excitation power. Upconversion emission spectra show that as the annealing temperature of the powder is increased, intensity of red emission decreases and intensity of green emission increases due to the decrease in maximum phonon frequency of the host material. (author)

Analysis of the carbon monoxide emission by internal combustion engines using LPG as a fuel

International Nuclear Information System (INIS)

Dimitrovski, Mile

2002-01-01

In this paper a description of the toxic emission reduction as well as a reduction of the toxic components presence in exhaust gases is presented. The analysis of the alternative gaseous fuels application as one of the possibilities for a toxic emission reduction is given. In addition, the results of the CO concentration measurements for two cases: first using gasoline, than liquefied petrol gas (LPG) as a fuel are presented. (Author)

Global warming and its implication to emission reduction strategies for residential buildings

Energy Technology Data Exchange (ETDEWEB)

Wang, Xiaoming; Chen, Dong; Ren, Zhengen [CSIRO Climate Adaptation Flagship and CSIRO Ecosystem Sciences, Commonwealth Scientific and Industrial Research Organisation (CSIRO), P.O. Box 56, Graham Road, Highett, Victoria 3190 (Australia)

2011-04-15

Carbon emission reduction schemes by improving residential building energy performance are often developed and assessed upon the assumption of current or stationary climates. This study investigated the heating and cooling (H-C) energy requirements and corresponding carbon emissions of residential houses in different climatic conditions in relation to global warming. This included assessing and quantifying the efficacy of emission reduction schemes based on emission reduction capacity (ERC). ERC represents the percentage of projected carbon emission reduction under changing climate in a specific year compared to the expected reduction by a scheme at current or stationary climates. It is shown that in a heating-dominated region with a cold climate or temperate climate with cold winter, ERC is projected to increase (or the projected emission reduction is higher than the expected reduction under the emission reduction scheme) in the presence of global warming. In contrast, in a cooling-dominated region with a hot dry or hot humid climate or an H-C balanced temperate climate, ERC is projected to decline. This implies that emission reductions will be lower than those initially targeted by the emission reduction scheme without consideration of global warming. Additionally, to reflect the changing carbon emission over years due to climate change, the average emission reduction capacity (AERC) was also proposed for the assessment of reduction schemes. It was concluded that the design and assessment of carbon emission reduction schemes for residential buildings need to move beyond its assumptions of a current or stationary climate to take into account climate change impacts. (author)

Closed string emission from unstable D-brane with background electric field

International Nuclear Information System (INIS)

Nagami, Kenji

2004-01-01

We study the closed string emission from an unstable Dp-brane with constant background electric field in bosonic string theory. The average total number density and the average total energy density of emitted closed strings are explicitly calculated in the presence of electric field. It is explicitly shown that the energy density in the UV region becomes finite whenever the background electric field is switched on. The energy density converted into closed strings in the presence of electric field is negligibly small compared with the D-brane tension in the weak string coupling limit. (author)

Presence Management and Merging Presence Information for NGN Services

Science.gov (United States)

Schumann, Sebastian; Mikoczy, Eugen; Podhradsky, Pavol; Muruchi, Feliciano; Maruschke, Michael

This paper describes an approach for interworking scenarios between Session Initiation Protocol (SIP) based and non SIP based frameworks (e.g. web services) in case of the presence management service. The characteristics of the concept of a centralized presence management will be introduced.

Carbon emissions, energy consumption and output: A threshold analysis on the causal dynamics in emerging African economies

International Nuclear Information System (INIS)

Mensah, Justice Tei

2014-01-01

Following the recent global economic downturn, attention has gradually shifted towards emerging economies which have experienced robust growth amidst sluggish growth of the world economy. A significant number of these emerging economies are in Africa. Rising growth in these economies is associated with surging demand for energy to propel the engines of growth, with direct implications on emissions into the atmosphere. Further, these economies are constantly being shaped by series of structural reforms with direct and indirect effects on growth, demand for energy, etc. To this end, this paper examines the causal dynamics among energy use, real GDP and CO 2 emissions in the presence of regime shifts in six emerging African economies using the Gregory and Hansen (1996a). J. Econ. 70, 99–126 threshold cointegration and the Toda and Yamamoto (1995). J. Econometrics. 66, 225–250 Granger causality techniques. Results confirm the presence of regime shift effects in the long run inter-linkages among energy use, real GDP and CO 2 emissions in the countries considered, thus indicating that structural changes have both economic and environmental effects. Hence, integration of energy and environmental policies into development plans is imperative towards attaining sustainable growth and development. - Highlights: • The paper examines the causal dynamics among output, energy demand and carbon emissions in the presence of regime shifts. • Regime shift have significant effects on the nexus among energy use, real GDP and CO 2 emissions. • Results suggest that structural changes in selected countries have both economic and environmental effects. • Integration of energy and environmental policies into development plans is desirable

Methane oxidation in presence of sulfur dioxide

International Nuclear Information System (INIS)

Mantashyan, A.A.; Avetisyan, A.M.; Makaryan, E.M.; Wang, H.

2006-01-01

The emission of sulfurous gases including SO 2 from stationary power generation remains to be a serious environmental and ecological problem. Sulfurous gases are almost entirely produced from the combustion of sulfur-containing fuels. While fuel desulfurization and flue gas scrubbing is a viable solution, in the developing countries it remains to be an economical challenge to implement these SO x reduction technologies. The oxidation of methane in presence of sulfurous gas (SO 2 ) addition was studied experimentally. Te experiments were conducted in a static reactor at temperature of 728-786 K, and for mixture of C 4 /O 2 ≡ 1/2 at a pressure of 117 Torr with varying amount of SO 2 addition. It was observed that SO 2 addition accelerated the oxidation process, reduced the induction period and increased the extent of methane consumption. At the relatively short resident time (less than 50 sec) SO 3 was detected, but at longer residence time SO 3 was reduced spontaneously to SO 2

Evolution of on-road vehicle exhaust emissions in Delhi

Science.gov (United States)

Goel, Rahul; Guttikunda, Sarath K.

2015-03-01

For a 40-year horizon (1990-2030), on-road vehicle exhaust emissions were evaluated, retrospectively and prospectively, for the largest urban agglomeration in India - the Greater Delhi region with a combined population of 22 million in 2011 (Delhi along with Ghaziabad, Noida, Greater Noida, Faridabad and Gurgaon). Emissions of particulate matter, sulfur dioxide, carbon monoxide and volatile organic compounds (VOCs) reached their peak during late 1990s through early 2000s after which they reduced significantly through year 2012. On the other hand, nitrogen oxides (NOx) and carbon dioxide show an increasing trend. The most reduction in emissions between 1998 and 2012 occurred as a result of implementation of four sets of vehicular emission standards, removal of lead, reduction of sulfur content, mandatory retirement of older commercial vehicles, and conversion of diesel and petrol run public transport vehicles to compressed natural gas. In addition, changes in the vehicular technology have also contributed to controlling emissions especially in case of auto-rickshaws and motorized two-wheelers, which changed from two-stroke to four-stroke. The rising trend of NOx along with the presence of VOCs indicates increasing tendency to form ground-level ozone and as a result, smog in the region. We predict that the current regime of vehicle technology, fuel standards, and high growth rate of private vehicles, is likely to nullify all the past emission reductions by the end of 2020s.

47 CFR 78.103 - Emissions and emission limitations.

Science.gov (United States)

2010-10-01

... 47 Telecommunication 4 2010-10-01 2010-10-01 false Emissions and emission limitations. 78.103... CABLE TELEVISION RELAY SERVICE Technical Regulations § 78.103 Emissions and emission limitations. (a) A CARS station may be authorized to employ any type of emission, for which there are technical standards...

Acoustic emission test on a 25mm thick mild steel pressure vessel with inserted defects

International Nuclear Information System (INIS)

Bentley, P.G.; Dawson, D.G.; Hanley, D.J.; Kirby, N.

1976-12-01

Acoustic emission measurements have been taken on an experimental mild steel vessel with 4 inserted defects ranging in severity up to 90% of through thickness. The vessel was subjected to a series of pressure excursions of increasing magnitude until failure occurred by extension of the largest inserted defect through the vessel wall. No acoustic emission was detected throughout any part of the tests which would indicate the presence of such serious defects or of impending failure. Measurements of acoustic emission from metallurgical specimens are included and the results of post test inspection using conventional NDT and metallographic techniques are reported. (author)

Acoustic emission

International Nuclear Information System (INIS)

Nichols, R.W.

1976-01-01

The volume contains six papers which together provide an overall review of the inspection technique known as acoustic emission or stress wave emission. The titles are: a welder's introduction to acoustic emission technology; use of acoustic emission for detection of defects as they arise during fabrication; examples of laboratory application and assessment of acoustic emission in the United Kingdom; (Part I: acoustic emission behaviour of low alloy steels; Part II: fatigue crack assessment from proof testing and continuous monitoring); inspection of selected areas of engineering structures by acoustic emission; Japanese experience in laboratory and practical applications of acoustic emission to welded structures; and ASME acoustic emission code status. (U.K.)

Does Financial Development Reduce CO2 Emissions in Malaysian Economy? A Time Series Analysis

OpenAIRE

Shahbaz, Muhammad; Solarin, Sakiru Adebola; Mahmood, Haider

2012-01-01

This study deals with the question whether financial development reduces CO2 emissions or not in case of Malaysia. For this purpose, we apply the bounds testing approach to cointegration for long run relations between the variables. The study uses annual time series data over the period 1971-2008. Ng-Perron stationarity test is applied to test the unit root properties of the series. Our results validate the presence of cointegration between CO2 emissions, financial development, energy co...

Consumo de combustíveis no Brasil e Mato Grosso: estimativa do custo ecológico da emissão de gases de efeito estufa

Directory of Open Access Journals (Sweden)

Vallência Maíra Gomes

2012-01-01

Full Text Available O principal objetivo deste trabalho foi estimar o nível da emissão de gases deefeito estufa (GEE a partir do consumo de combustíveis fósseis e renováveis noBrasil e no estado de Mato Grosso entre os anos de 2003 e 2010. Uma vezreconhecido o quantum de emissão de GEE, calculou-se o custo ecológico destaemissão a partir dos preços da tonelada de carbono comercializada na BolsaEuropeia do Clima e na Bolsa do Clima de Chicago. A partir deste exercício,estimou-se o peso deste custo ecológico sobre o Produto Interno Bruto do Brasil ede Mato Grosso no período analisado, considerando hipoteticamente a incorporaçãodestes custos externos na matriz produtiva de ambas as referências espaciais.Utilizando a base de dados de consumo de combustíveis do Brasil e de Mato Grossoda Agência Nacional de Petróleo, Gás Natural e Biocombustíveis, foi empregado oMétodo “Top-Down” ou método de referência do IPCC para estimar as emissões dedióxido de carbono. Atrelou-se o preço do carbono nas Bolsas da Europa e dosEstados Unidos à emissão de gases do efeito estufa, para se estimar os custosexternos, chamados aqui também de custos ecológicos. Os resultados mostram queos custos ecológicos estão tendendo a redução neste período, tanto pela contençãoda emissão de GEE frente ao PIB quanto pela tendência negativa dos preços docarbono nas bolsas internacionais.Abstract The main objective of this study was to estimate the level of greenhouse gasesemission (GHG from the consumption of fossil and renewable fuels in Brazil and inthe state of Mato Grosso between the years 2003 and 2010. Once recognized thequantum of GHG emission, was calculated the ecological cost of this emission asfrom the prices of the ton of carbon traded on the European Climate Exchange andon the Chicago Climate Exchange. From this exercise, was estimated the weight ofthis ecological cost on Gross Domestic Product (GDP of the Brazil and of MatoGrosso in the period

Role of Active Listening and Listening Effort on Contralateral Suppression of Transient Evoked Otoacousic Emissions

OpenAIRE

Kalaiah, Mohan Kumar; Theruvan, Nikhitha B; Kumar, Kaushlendra; Bhat, Jayashree S

2017-01-01

Background and Objectives The present study aimed to investigate the effect of active listening and listening effort on the contralateral suppression of transient evoked otoacoustic emissions (CSTEOAEs). Subjects and Methods Twenty eight young adults participated in the study. Transient evoked otoacoustic emissions (TEOAEs) were recorded using ?linear? clicks at 60 dB peSPL, in three contralateral noise conditions. In condition 1, TEOAEs were obtained in the presence of white noise in the con...

Considering the potential of IAR emissions for ionospheric sounding

Science.gov (United States)

Potapov, A. S.; Polyushkina, T. N.; Tsegmed, B.; Oinats, A. V.; Pashinin, A. Yu.; Edemskiy, I. K.; Mylnikova, A. A.; Ratovsky, K. G.

2017-11-01

develop a method for evaluating the ionosphere critical frequency using the IAR emission observations. Such a method may prove to be useful as an additional alternative to the basic method for probing the ionosphere using digisondes. This is especially important for auroral regions, where the presence of strong absorption, shielding by a lower layer, stratification, the presence of echoes, etc. make the sounding difficult.

Improved field emission from indium decorated multi-walled carbon nanotubes

Energy Technology Data Exchange (ETDEWEB)

Sreekanth, M.; Ghosh, S., E-mail: santanu1@physics.iitd.ernet.in; Biswas, P.; Kumar, S.; Srivastava, P.

2016-10-15

Graphical abstract: Improved field emission properties have been achieved for Indium (In) decorated MWCNTs and are shown using the schematic of field emission set up with In/CNT cathode, and a plot of J-E characteristics for pristine and In decorated CNTs. - Highlights: • Field emission (FE) properties have been studied for the first time from Indium (In) decorated MWCNT films. • Observed increased density of states near the Fermi level for In decorated films. • Superior field emission properties have been achieved for In decorated CNT films. - Abstract: Multi-walled carbon nanotube (MWCNT) films were grown using thermal chemical vapor deposition (T-CVD) process and were decorated with indium metal particles by thermal evaporation technique. The In metal particles are found to get oxidized. The In decorated films show 250% enhancement in the FE current density, lower turn-on and threshold fields, and better temporal stability as compared to their undecorated counterpart. This improvement in field emission properties is primarily attributed to increased density of states near the Fermi level. The presence of O 2p states along with a small contribution from In 5s states results in the enhancement of density of states in the vicinity of the Fermi level.

A wavelet phase filter for emission tomography

International Nuclear Information System (INIS)

Olsen, E.T.; Lin, B.

1995-01-01

The presence of a high level of noise is a characteristic in some tomographic imaging techniques such as positron emission tomography (PET). Wavelet methods can smooth out noise while preserving significant features of images. Mallat et al. proposed a wavelet based denoising scheme exploiting wavelet modulus maxima, but the scheme is sensitive to noise. In this study, the authors explore the properties of wavelet phase, with a focus on reconstruction of emission tomography images. Specifically, they show that the wavelet phase of regular Poisson noise under a Haar-type wavelet transform converges in distribution to a random variable uniformly distributed on [0, 2π). They then propose three wavelet-phase-based denoising schemes which exploit this property: edge tracking, local phase variance thresholding, and scale phase variation thresholding. Some numerical results are also presented. The numerical experiments indicate that wavelet phase techniques show promise for wavelet based denoising methods

Generation of biogas from coffee-pulp and cow-dung co-digestion: Infrared studies of postcombustion emissions

International Nuclear Information System (INIS)

Corro, Grisel; Paniagua, Laura; Pal, Umapada; Bañuelos, Fortino; Rosas, Minerva

2013-01-01

Graphical abstract: Batch digester with coffee pulp/cow dung produced high amounts of methane for 8 months. The FTIR gas spectroscopy analysis revealed the presence of over 70 chemical compounds in biogas generated after 4 months of coffee pulp and cow dung mixture co-digestion, several being hazardous to environment and human and animal health (e.g. isocyanic acid, bromomethane). Biogas produced was burned in a laboratory combustor. The FTIR gas spectroscopy analysis showed that combustion emissions contained: CH 4 , C 3 H 8 , CO, SO 2 , HI, and probably Br 2 which are strongly harmful to human and animal health. - Highlights: • Batch digester with coffee pulp/cow dung produced high amounts of methane for 8 months. • Biogas from coffee pulp/cow dung codigestion contained 60% methane and 20% propane. • Biogas FTIR analysis revealed the presence of isocyanic acid and bromomethane. • Biogas FTIR analysis showed also the presence of HI. • Biogas combustion emissions contained CH 4 , HI, SO 2 and probably Br 2 . - Abstract: Biogas could be produced by the co-digestion of coffee-pulp and cow-dung mixture under solar radiation. Gas chromatography and FTIR spectroscopy were used to analyze the chemical compositions of the generated biogas and its postcombustion emissions. From the first month of co-digestion at mesophylic conditions, methane content in the biogas attains 50% of the yield. This content increased up to 60% and remained almost constant for at least 8 months of further digestion. The FTIR gas spectroscopy analysis revealed the presence of over 70 chemical compounds in the biogas generated after 4 months of co-digestion along with several compounds hazardous to environment and animal health like isocyanic acid, and bromomethane. Combustion emission of the biogas contained several components like CH 4 , C 3 H 8 , CO, SO 2 , HI, and probably Br 2 which are strongly harmful to human and animal health. Results presented in this work indicate that if the

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....

Regulated and unregulated emissions from highway heavy-duty diesel engines complying with U.S. Environmental Protection Agency 2007 emissions standards.

Science.gov (United States)

Khalek, Imad A; Bougher, Thomas L; Merritt, Patrick M; Zielinska, Barbara

2011-04-01

As part of the Advanced Collaborative Emissions Study (ACES), regulated and unregulated exhaust emissions from four different 2007 model year U.S. Environmental Protection Agency (EPA)-compliant heavy-duty highway diesel engines were measured on an engine dynamometer. The engines were equipped with exhaust high-efficiency catalyzed diesel particle filters (C-DPFs) that are actively regenerated or cleaned using the engine control module. Regulated emissions of carbon monoxide, nonmethane hydrocarbons, and particulate matter (PM) were on average 97, 89, and 86% lower than the 2007 EPA standard, respectively, and oxides of nitrogen (NOx) were on average 9% lower. Unregulated exhaust emissions of nitrogen dioxide (NO2) emissions were on, average 1.3 and 2.8 times higher than the NO, emissions reported in previous work using 1998- and 2004-technology engines, respectively. However, compared with other work performed on 1994- to 2004-technology engines, average emission reductions in the range of 71-99% were observed for a very comprehensive list of unregulated engine exhaust pollutants and air toxic contaminants that included metals and other elements, elemental carbon (EC), inorganic ions, and gas- and particle-phase volatile and semi-volatile organic carbon (OC) compounds. The low PM mass emitted from the 2007 technology ACES engines was composed mainly of sulfate (53%) and OC (30%), with a small fraction of EC (13%) and metals and other elements (4%). The fraction of EC is expected to remain small, regardless of engine operation, because of the presence of the high-efficiency C-DPF in the exhaust. This is different from typical PM composition of pre-2007 engines with EC in the range of 10-90%, depending on engine operation. Most of the particles emitted from the 2007 engines were mainly volatile nuclei mode in the sub-30-nm size range. An increase in volatile nanoparticles was observed during C-DPF active regeneration, during which the observed particle number was

Secondary Electron Emission from Dust and Its Effect on Charging

Science.gov (United States)

Saikia, B. K.; Kakati, B.; Kausik, S. S.; Bandyopadhyay, M.

2011-11-01

Hydrogen plasma is produced in a plasma chamber by striking discharge between incandescent tungsten filaments and the permanent magnetic cage [1], which is grounded. The magnetic cage has a full line cusped magnetic field geometry used to confine the plasma elements. A cylindrical Langmuir probe is used to study the plasma parameters in various discharge conditions. The charge accumulated on the dust particles is calculated using the capacitance model and the dust current is measured by the combination of a Faraday cup and an electrometer at different discharge conditions. It is found Secondary electron emission from dust having low emission yield effects the charging of dust particles in presence of high energetic electrons.

Secondary Electron Emission from Dust and Its Effect on Charging

International Nuclear Information System (INIS)

Saikia, B. K.; Kakati, B.; Kausik, S. S.; Bandyopadhyay, M.

2011-01-01

Hydrogen plasma is produced in a plasma chamber by striking discharge between incandescent tungsten filaments and the permanent magnetic cage [1], which is grounded. The magnetic cage has a full line cusped magnetic field geometry used to confine the plasma elements. A cylindrical Langmuir probe is used to study the plasma parameters in various discharge conditions. The charge accumulated on the dust particles is calculated using the capacitance model and the dust current is measured by the combination of a Faraday cup and an electrometer at different discharge conditions. It is found Secondary electron emission from dust having low emission yield effects the charging of dust particles in presence of high energetic electrons.

Enhanced flashover strength in polyethylene nanodielectrics by secondary electron emission modification

Directory of Open Access Journals (Sweden)

Weiwang Wang

2016-04-01

Full Text Available This work studies the correlation between secondary electron emission (SEE characteristics and impulse surface flashover in polyethylene nanodielectrics both theoretically and experimentally, and illustrates the enhancement of flashover voltage in low-density polyethylene (LDPE through incorporating Al2O3 nanoparticles. SEE characteristics play key roles in surface charging and gas desorption during surface flashover. This work demonstrates that the presence of Al2O3 nanoparticles decreases the SEE coefficient of LDPE and enhances the impact energy at the equilibrium state of surface charging. These changes can be explained by the increase of surface roughness and of surface ionization energy, and the strong interaction between nanoparticles and the polymer dielectric matrix. The surface charge and flashover voltage are calculated according to the secondary electron emission avalanche (SEEA model, which reveals that the positive surface charges are reduced near the cathode triple point, while the presence of more nanoparticles in high loading samples enhances the gas desorption. Consequently, the surface flashover performance of LDPE/Al2O3 nanodielectrics is improved.

X-ray emission from comets

International Nuclear Information System (INIS)

Dennerl, Konrad

1999-01-01

When comet Hyakutake (C/1996 B2) encountered Earth in March 1996 at a minimum distance of only 15 million kilometers (40 times the distance of the moon), x-ray and extreme ultraviolet emission was discovered for the first time from a comet. The observations were performed with the astronomy satellites ROSAT and EUVE. A systematic search for x-rays from comets in archival data, obtained during the ROSAT all-sky survey in 1990/91, resulted in the discovery of x-ray emission from four additional comets. They were detected at seven occasions in total, when they were optically 300 to 30 000 times fainter than Hyakutake. These findings indicated that comets represent a new class of celestial x-ray sources. Subsequent detections of x-ray emission from additional comets with the satellites ROSAT, EUVE, and BeppoSAX confirmed this conclusion. The x-ray observations have obviously revealed the presence of a process in comets which had escaped attention until recently. This process is most likely charge exchange between highly charged heavy ions in the solar wind and cometary neutrals. The solar wind, a stream of particles continuously emitted from the sun with ≅ 400 km s -1 , consists predominantly of protons, electrons, and alpha particles, but contains also a small fraction (≅0.1%) of highly charged heavier ions, such as C 6+ ,O 6+ ,Ne 8+ ,Si 9+ ,Fe 11+ . When these ions capture electrons from the cometary gas, they attain highly excited states and radiate a large fraction of their excitation energy in the extreme ultraviolet and x-ray part of the spectrum. Charge exchange reproduces the intensity, the morphology and the spectrum of the observed x-ray emission from comets very well

Prediction of HS Soderberg plant PAH emissions from a laboratory evaluation of a pitch

Energy Technology Data Exchange (ETDEWEB)

Castonguay, L.; Mirtchi, A. A.; Proulx, A. L.; Savard, G.; Simard, E.; Steward, N.; Tremblay, C. [Alcan International Ltd., Arvida Research and Development Centre, Jonquiere, PQ (Canada)

1998-12-31

The presence of certain polycyclic aromatic hydrocarbons (PAHs) in coal tar pitch has been identified as a possible limit to the long-term viability of horizontal stud (HS) Soderberg technology, a technology of importance in the aluminum industry. This paper presents the results of a comparative study of pitch PAH content and HS Soderberg cell emissions. Laboratory results are compared with plant emissions for two regular and low PAH pitches with the same softening points. The results indicate the existence of a correlation between pitch PAH content and cell emission, which is valid for regular tar pitches, low tar pitches, as well as for hybrid pitches. These findings make it possible to predict the quantity and distribution of HS Soderberg cell PAH emissions from the analysis of PAHs in the pitch. The results also justify the conclusion that the emission of genotoxic compounds from pitch in the HS Soderberg technology can be decreased by using a pitch with low PAH content. 4 refs., 5 tabs., 5 figs.

Spontaneous acoustic emission of a corrugated shock wave in the presence of a reflecting surface

International Nuclear Information System (INIS)

Wouchuk, J.G.; Lopez Cavada, J.

2004-01-01

An analytic model to study perturbation evolution in the space between a corrugated shock and a piston surface is presented. The conditions for stable oscillation patterns are obtained by looking at the poles of the exact Laplace transform. It is seen that besides the standard D'yakov-Kontorovich (DK) mode of oscillation, the shock surface can exhibit an additional finite set of discrete frequencies, due to the interaction with the piston which reflects sound waves from behind. The additional eigenmodes are excited when the shock is launched at t=0 + . The first eigenmode (the DK mode) is always present, if the Hugoniot curve has the correct slope in the V-p plane. However, the additional frequencies could be excited for strong enough shocks. The predictions of the model are verified for particular cases by studying a van der Waals gas, as in the work of Bates and Montgomery [Phys. Fluids 11, 462 (1999); Phys. Rev. Lett. 84, 1180 (2000)]. Only acoustic emission modes are considered

Fusion positron emission/computed tomography underestimates the presence of hilar nodal metastases in patients with resected non-small cell lung cancer.

Science.gov (United States)

Carrillo, Sergio A; Daniel, Vincent C; Hall, Nathan; Hitchcock, Charles L; Ross, Patrick; Kassis, Edmund S

2012-05-01

The 5-year survival for patients with resected stage II (N1) non-small cell lung cancer ranges from 40% to 55%. No data exist addressing the benefit of neoadjuvant therapy for patients with stage II disease. This is largely in part due to the lack of a reliable, minimally invasive method to assess hilar nodes. This study is aimed at determining the ability of fusion positron emission/computed tomography (PET/CT) to identify hilar metastases in patients with resected non-small cell lung cancer. A retrospective review of surgically resected patients with fusion PET/CT within 30 days of resection was performed. The sensitivity, specificity, positive predictive value, and negative predictive value for PET/CT in detecting hilar nodal metastases was calculated for a range of maximum standardized uptake values (SUVmax). Hilar nodes from patients with falsely positive PET/CT scans were analyzed for the presence of histoplasmosis. Additionally, the impact of hilar node size greater than 1 centimeter on the calculated values was assessed. There were 119 patients evaluated. The number of lymph nodes resected ranged from 1 to 12 (X=2.98). There was decreased sensitivity and increased specificity with higher SUVmax cutoff values. At the standard SUVmax value of 2.5, the sensitivity and specificity were only 48.5% and 80.2%. The addition of size of hilar node by CT led to a modest improvement in sensitivity at all SUVmax cutoff values. Fusion PET/CT lacks sensitivity and specificity in identifying hilar nodal metastasis in patients with resected non-small cell lung cancer. Further prospective studies assessing the utility of PET/CT versus alternative sampling techniques are warranted. Copyright © 2012 The Society of Thoracic Surgeons. Published by Elsevier Inc. All rights reserved.

A search for OH emission from symbiotic stars

International Nuclear Information System (INIS)

Norris, R.P.; Haynes, R.F.; Wright, A.E.

1984-01-01

A search was made for OH maser emission from a sample of 16 symbiotic stars. This sample was selected on the basis of infrared optical depth and variability, so that the stars within it have circumstellar shells similar to those seen in OH/IR and OH/Mira stars. There were no significant detections, except for one unassociated background source, and it is concluded that the presence of a hot binary companion inhibits any possible OH maser action

Momentum distribution dependence of induced electron-cyclotron emission

International Nuclear Information System (INIS)

Ziebell, L.F.; Dillenburg, D.

1983-01-01

The dependence of the electron-cyclotron wave amplification in an inhomogeneous plasma slab on the electron momentum distribution is investigated. Two types of distributions are considered, both featuring a loss cone and a Maxwellian component. It is shown that the perpendicular emission at the fundamental frequency is in general greatly reduced by the presence of a Maxwellian component and situations occur in which a layer in the slab very effectively absorbs all the radiation amplified elsewhere. The transition from the pure loss cone to the pure Maxwellian case is accompanied by a peculiar behaviour of the dielectric tensor components, which may invalidate the geometrical optics approximation in the calculation of the emission and the commonly held belief that the real part of the refractive index is insensitive to the shape of the momentum distribution function. (Author) [pt

Leaf surface wax is a source of plant methane formation under UV radiation and in the presence of oxygen

DEFF Research Database (Denmark)

Bruhn, Dan; Mikkelsen, Teis Nørgaard; Rolsted, M. M. M.

2014-01-01

to this, we demonstrated that the UV radiation-induced CH4 emission is independent of leaf area index above unity. Further, we observed that the presence of O2 in the atmosphere was necessary for achieving the highest rates of CH4 emission. Methane formation from leaf surface wax is supposedly a two...... investigated the potential of the leaf surface wax itself as a source of UV radiationinduced leaf aerobic CH4 formation. Isolated leaf surface wax emitted CH4 at substantial rates in response to UV radiation. This discovery has implications for how the phenomenon should be scaled to global levels. In relation...

Comparison of anti-corrosion properties of polyurethane based composite coatings with low infrared emissivity

International Nuclear Information System (INIS)

Wang Yajun; Xu Guoyue; Yu Huijuan; Hu Chen; Yan Xiaoxing; Guo Tengchao; Li Jiufen

2011-01-01

Four polyurethane resins, pure polyurethane (PU), epoxy modified polyurethane (EPU), fluorinated polyurethane (FPU) and epoxy modified fluorinated polyurethane (EFPU), with similar polyurethane backbone structure but different grafting group were used as organic adhesive for preparing low infrared emissivity coatings with an extremely low emissivity near 0.10 at 8-14 μm, respectively. By using these four resins, the effect of different resin matrics on the corrosion protection of the low infrared emissivity coatings was investigated in detail by using neutral salt spray test, SEM and FTIR. It was found that the emissivity of the coatings with different resin matrics changes significantly in corrosion media. And the results indicated that the coating using EFPU as organic adhesive exhibited excellent corrosion resistance property which was mainly attributed to the presence of epoxy group and atomic fluorine in binder simultaneously.

From climate change to emissions trading : a briefing

International Nuclear Information System (INIS)

Marcu, A.

2002-01-01

Global warming is caused by the presence of greenhouse gases (GHGs) in the earth's atmosphere. These gases include, carbon dioxide, nitrous oxides, sulphur dioxide and methane. GHGs trap heat between the earth's atmosphere and the earth's surface to cause an overall warming trend of the Earth. The United Nations Framework Convention on Climate Change was established to address the issue of climate change and to determine the anthropogenic impact on climate change. Evidence from ice cores suggest that global warming has occurred in the past. The current state of global warming was examined by comparing the climate of today with that of the past. It was determined that the current global warming trend surpasses that of any ever observed in the past. The Kyoto Protocol was adopted in 1997 as a policy set to address the need for the world to reduce GHG emissions into the atmosphere. The Kyoto Protocol puts forth 3 sets of mechanisms to help businesses reduce GHG emissions. Emissions trading is one of them: it is a financial flexibility mechanism that allows businesses that have emitted more than their allowed share of GHGs to buy allowances from business that have emitted fewer GHGs than they were allowed. Emissions trading does not create reductions, however, it identifies the most economical solution to reduce GHGs. TransAlta, Ontario Power Generation and Suncor have conducted a few transactions to see how the market will work. There will be a global register to keep track of all assigned allowances. The paper described government action in addressing the climate change issue with reference to actions in the United Kingdom, Netherlands, Denmark and Switzerland. Canada has initiated the Greenhouse Gas Emission Reduction Trading Pilot (GERT) to test the effectiveness of emission reduction trading for GHGs in the Canadian context. GERT is a partnership between the federal government, some provinces, industry, labour and environmental groups. Ontario has established a

A fading-based method for checking the presence of closely overlapping peaks in thermoluminescent (TL) materials

Science.gov (United States)

Furetta, C.

The paper describes a method, based on fading experiment, for determining the presence of a complex structure in the thermoluminescent glow curve emission from herbs, e.g. oregano and nopal. Because of the polymineral content of the inorganic part of these herbs, the emitted glow curve is the result of several overlapping glow peaks, each one corresponding to another mineral. The initial rise method is also used for determining the activation energy of each component.

Can non-point pollutions emissions from agriculture be regulated efficiently using input-output taxes?

DEFF Research Database (Denmark)

Hansen, Line Block; Gårn Hansen, Lars

2014-01-01

In many parts of Europe and North America, phosphorus loss from cultivated fields is threatening natural ecosystems. Though there are similarities to other non-point agricultural emissions like nitrogen that have been studied extensively, phosphorus is often characterized by the presence of large...

In-situ positron emission of CO oxidation

OpenAIRE

Vonkeman, K.A.; Jonkers, G.; Wal, van der, S.W.A.; Santen, van, R.A.

1993-01-01

Using a Neuro ECAT positron tomog., the Positron Emission computed Tomog. (PET) was utilized to image the catalytic oxidn. of CO by using CO and CO2, labeled with short lived positron emitting nuclides. Studies were performed over highly dispersed CeO2/g-Al2O3 supported Pt and Rh catalysts. With a math. model of the reaction kinetics, based on the elementary steps of the catalytic reaction and partially on literature surface science data, the effect of CeO2 promotion and the presence of NO we...

Specific Emissions of Harmful Substances from Small Boilers

Directory of Open Access Journals (Sweden)

Horák Jiøí

1998-09-01

Full Text Available Coal is on of the most important energy source and its significance will increase in a future. In Czech republic coal is except else widely used as a fuel for combustion in a small boilers (up to 50 kW. Low efficiency of the small boilers which is often below 50% together with high emissions of the harmful substances into near surroundings cause in average 40 – 70% of total local air pollution. The research was performed in a scope of the Grant no. 101/98/0820 of Grant Agency of Czech Republic was focused on quality of combustion process related to combustion efficiency and creation of harmful substances at combustion of domestic fuels. Experiments were performed to compare combustion of brown coal, clack coal, coke and black coal slurry. Extremely high creation of harmful substances (CO, NOX, solid particles and organic substances was measured when the black coal slurry was used as a fuel, measured in kg of emissions per GJ of burned fuel. Combustion of brown coal produced significant emissions of solid particles which bond harmful substances as metals, polyaromatic hydrocarbons and others together with high emissions of SO2 . Strong dependence between emissions of CO and low quality of combustion given by low combustion temperature, shortage of combustion air, not suitable design of after-combustion chamber and short duration of fuel presence in a combustion area was found out. Emissions of wide range of metals were investigated. The results of the research grant project describe and explain the combustion process and creation of harmful substances in small boilers plus give suggestions and recommendations leading to rational operation of the small boilers and lowering their negative impact to environment.

Emissions treatment of diesel engines by plasma outside of balance; Tratamiento de emisiones de motores diesel por plasma fuera de equilibrio

Energy Technology Data Exchange (ETDEWEB)

Pacheco P, M.; Pacheco S, J.; Valdivia B, R.; Garcia R, M.; Estrada M, N. [ININ, Carretera Mexico-Toluca s/n, 52750 Ocoyoacac, Estado de Mexico (Mexico); Santana D, A. [Instituto Tecnologico y de Estudios Superiores de Monterrey, Mexico D. F. (Mexico); Lefort, B.; Le Moyne, L.; Zamilpa, C., E-mail: marquidia.pacheco@inin.gob.mx [Institut Superieur d l' Automobile et des Transports, 49 rue Madeimoiselle Bourgeois BP31, 58027 Nevers cedex (France)

2013-07-01

Nowadays, diesel engines are greatly developed in automobiles allowing the reduction of carbon dioxide emissions (CO{sub 2}); however high emissions of particulate matter (Mp) and nitric oxides (NO{sub x}) still remain. A technology based on non-thermal plasma to diminish toxic emissions is exposed in this work. From previous experimental and simulation results, a chemical mechanism is proposed showing a rapidly diminution of Mp and NO{sub x}, in presence of plasma. (Author)

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.

Characterization of trichloroethylene adsorption onto waste biocover soil in the presence of landfill gas.

Science.gov (United States)

He, Ruo; Su, Yao; Kong, Jiaoyan

2015-09-15

Waste biocover soils (WBS) have been demonstrated to have great potential in mitigating trichloroethylene (TCE) emission from landfills, due to the relatively high TCE-degrading capacity. In this study, the characteristics of TCE adsorption on WBS in the presence of the major landfill gas components (i.e., CH4 and CO2) were investigated in soil microcosms. The adsorption isotherm of TCE onto WBS was fitted well with linear model within the TCE concentrations of 7000 ppmv. The adsorption capacity of TCE onto WBS was affected by temperature, soil moisture content and particle size, of which, temperature was the dominant factor. The adsorption capacity of TCE onto the experimental materials increased with the increasing organic matter content. A significantly positive correlation was observed between the adsorption capacity of TCE and the organic matter content of experimental materials that had relatively higher organic content (r = 0.988, P = 0.044). To better understand WBS application in practice, response surface methodology was developed to predict TCE adsorption capacity and emissions through WBS in different landfills in China. These results indicated that WBS had high adsorption capacity of TCE in LFG and temperature should be paid more attention to manipulate WBS to reduce TCE emissions from landfills. Copyright © 2015 Elsevier B.V. All rights reserved.

The political economy of emissions trading; L'economie politique des marches de permis d'emissions negociables

Energy Technology Data Exchange (ETDEWEB)

Hanoteau, J

2004-06-15

This thesis is a positive analysis of emissions trading systems' implementation. We explain why allowances are generally granted for free even though normative economic analysis recommends their sale. We show empirically that free tradable permits, source of windfall profit, motivate rent seeking behaviours. The study focuses on the US market for SO{sub 2} emissions allowances. The initial allocation rule resulted from parliamentary discussions that looked like a zero sum game. We formalize it as an endogenous sharing rule, function of lobbying effort, and we test it using political (money) contributions.We analyse theoretically the behaviour of an influenced regulator that has chosen to organize a market for permits and that must still decide on two policy variables: the whole quantity of permits and the way to allocate them initially. We formalize this decisions making process with the common agency model of politics.We show that the choice of an initial allocation rule is not neutral in presence of political market failures (lobbying). The decision to sell the permits or to grant them for free modifies the shareholders' incentive, in a polluting industry, to pressure for or against the reduction of legal emissions.Then, we analyse the public arbitration between the two policy variables when several industrial lobbies play a partially cooperative game for the free permits. The regulator chooses in priority to grant the rights for free rather than to manipulate their quantity, and this constitutes an efficient answer to the political influence. (author)

Carbon emissions and an equitable emission reduction criterion

International Nuclear Information System (INIS)

Golomb, Dan

1999-01-01

In 1995 the world-wide carbon emissions reached 5.8 billion metric tonnes per year (GTC/y). The Kyoto protocol calls for a reduction of carbon emissions from the developed countries (Annex I countries) of 6-8% below 1990 levels on the average, and unspecified commitments for the less developed (non-Annex I) countries. It is doubtful that the Kyoto agreement will be ratified by some parliaments, especially the USA Congress. Furthermore, it is shown that if the non-Annex I countries will not curtail their carbon emissions drastically, the global emissions will soar to huge levels by the middle of the next century. An equitable emission criterion is proposed which may lead to a sustainable rate of growth of carbon emissions, and be acceptable to all countries of the world. The criterion links the rate of growth of carbon emissions to the rate of growth of the Gross Domestic Product (GDP). A target criterion is proposed R = 0.15 KgC/SGDP, which is the current average for western European countries and Japan. This allows for both the growth of the GDP and carbon emissions. However, to reach the target in a reasonable time, the countries for which R≤ 0.3 would be allowed a carbon emission growth rate of 1%./y, and countries for which R≥ 0.3, 0.75%/y. It is shown that by 2050 the world-wide carbon emissions would reach about 10 GTC/y, which is about 3 times less than the Kyoto agreement would allow. (Author)

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...

An X-ray survey of the central molecular zone: Variability of the Fe Kα emission line

Science.gov (United States)

Terrier, R.; Clavel, M.; Soldi, S.; Goldwurm, A.; Ponti, G.; Morris, M. R.; Chuard, D.

2018-05-01

There is now abundant evidence that the luminosity of the Galactic super-massive black hole (SMBH) has not always been as low as it is nowadays. The observation of varying non-thermal diffuse X-ray emission in molecular complexes in the central 300 pc has been interpreted as delayed reflection of a past illumination by bright outbursts of the SMBH. The observation of different variability timescales of the reflected emission in the Sgr A molecular complex can be well explained if the X-ray emission of at least two distinct and relatively short events (i.e. about 10 yr or less) is currently propagating through the region. The number of such events or the presence of a long-duration illumination are open questions. Variability of the reflected emission all over of the central 300 pc, in particular in the 6.4 keV Fe Kα line, can bring strong constraints. To do so we performed a deep scan of the inner 300 pc with XMM-Newton in 2012. Together with all the archive data taken over the course of the mission, and in particular a similar albeit more shallow scan performed in 2000-2001, this allows for a detailed study of variability of the 6.4 keV line emission in the region, which we present here. We show that the overall 6.4 keV emission does not strongly vary on average, but variations are very pronounced on smaller scales. In particular, most regions showing bright reflection emission in 2000-2001 significantly decrease by 2012. We discuss those regions and present newly illuminated features. The absence of bright steady emission argues against the presence of an echo from an event of multi-centennial duration and most, if not all, of the emission can likely be explained by a limited number of relatively short (i.e. up to 10 yr) events. Images of the Fe Kα emission as FITS files are only available at the CDS via anonymous ftp to cdsarc.u-strasbg.fr (130.79.128.5) or via http://cdsarc.u-strasbg.fr/viz-bin/qcat?J/A+A/612/A102

End point detection in ion milling processes by sputter-induced optical emission spectroscopy

International Nuclear Information System (INIS)

Lu, C.; Dorian, M.; Tabei, M.; Elsea, A.

1984-01-01

The characteristic optical emission from the sputtered material during ion milling processes can provide an unambiguous indication of the presence of the specific etched species. By monitoring the intensity of a representative emission line, the etching process can be precisely terminated at an interface. Enhancement of the etching end point is possible by using a dual-channel photodetection system operating in a ratio or difference mode. The installation of the optical detection system to an existing etching chamber has been greatly facilitated by the use of optical fibers. Using a commercial ion milling system, experimental data for a number of etching processes have been obtained. The result demonstrates that sputter-induced optical emission spectroscopy offers many advantages over other techniques in detecting the etching end point of ion milling processes

Analyais of solar X-ray emission line profiles

International Nuclear Information System (INIS)

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

1981-01-01

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

EVIDENCE FOR NON-STELLAR REST-FRAME NEAR-IR EMISSION ASSOCIATED WITH INCREASED STAR FORMATION IN GALAXIES AT z ∼ 1

International Nuclear Information System (INIS)

Lange, Johannes U.; Van Dokkum, Pieter G.; Momcheva, Ivelina G.; Nelson, Erica J.; Leja, Joel; Brammer, Gabriel; Whitaker, Katherine E.; Franx, Marijn

2016-01-01

We explore the presence of non-stellar rest-frame near-IR (2–5 μm) emission in galaxies at z ∼ 1. Previous studies identified this excess in relatively small samples and suggested that such non-stellar emission, which could be linked to the 3.3 μm polycyclic aromatic hydrocarbons feature or hot dust emission, is associated with an increased star formation rate (SFR). In this Letter, we confirm and quantify the presence of an IR excess in a significant fraction of galaxies in the 3D-HST GOODS catalogs. By constructing a matched sample of galaxies with and without strong non-stellar near-IR emission, we find that galaxies with such emission are predominantly star-forming galaxies. Moreover, star-forming galaxies with an excess show increased mid- and far-IR and Hα emission compared to other star-forming galaxies without. While galaxies with a near-IR excess show a larger fraction of individually detected X-ray active galactic nuclei (AGNs), an X-ray stacking analysis, together with the IR-colors and Hα profiles, shows that AGNs are unlikely to be the dominant source of excess in the majority of galaxies. Our results suggest that non-stellar near-IR emission is linked to increased SFRs and is ubiquitous among star-forming galaxies. As such, the near-IR emission might be a powerful tool to measure SFRs in the era of the James Webb Space Telescope

X-ray emission as a diagnostic from pseudospark-sourced electron beams

Energy Technology Data Exchange (ETDEWEB)

Bowes, D., E-mail: david.bowes@strath.ac.uk [Department of Physics, SUPA, University of Strathclyde, Glasgow G4 0NG (United Kingdom); Yin, H.; He, W.; Zhang, L.; Cross, A.W.; Ronald, K.; Phelps, A.D.R. [Department of Physics, SUPA, University of Strathclyde, Glasgow G4 0NG (United Kingdom); Chen, D.; Zhang, P. [Computed Tomography Lab, School of Mathematical Sciences, Capital Normal University, Beijing 100048 (China); Chen, X.; Li, D. [Department of Electronic Engineering, Queen Mary University of London, London E1 4NS (United Kingdom)

2014-09-15

X-ray emission has been achieved using an electron beam generated by a pseudospark low-pressure discharge and utilised as a diagnostic for beam detection. A 300 A, 34 kV PS-sourced electron beam pulse of 3 mm diameter impacting on a 0.1 mm-thick molybdenum target generated X-rays which were detected via the use of a small, portable X-ray detector. Clear X-ray images of a micro-sized object were captured using an X-ray photodetector. This demonstrates the inducement of proton induced X-ray emission (PIXE) not only as an indicator of beam presence but also as a future X-ray source for small-spot X-ray imaging of materials.

Biogenic volatile organic compound (BVOC) emissions from forested areas in Turkey: determination of specific emission rates for thirty-one tree species.

Science.gov (United States)

Aydin, Yagmur Meltem; Yaman, Baris; Koca, Husnu; Dasdemir, Okan; Kara, Melik; Altiok, Hasan; Dumanoglu, Yetkin; Bayram, Abdurrahman; Tolunay, Doganay; Odabasi, Mustafa; Elbir, Tolga

2014-08-15

Normalized biogenic volatile organic compound (BVOC) emission rates for thirty one tree species that cover the 98% of national forested areas in Turkey were determined. Field samplings were performed at fourteen different forested areas in Turkey using a specific dynamic enclosure system. The selected branches of tree species were enclosed in a chamber consisted of a transparent Nalofan bag. The air-flows were sampled from both inlet and outlet of the chamber by Tenax-filled sorbent tubes during photosynthesis of trees under the presence of sunlight. Several environmental parameters (temperature, humidity, photosynthetically active radiation-PAR, and CO2) were continuously monitored inside and outside the enclosure chamber during the samplings. Collected samples were analyzed using a gas chromatography mass spectrometry (GC/MS) system equipped with a thermal desorber (TD). Sixty five BVOCs classified in five major groups (isoprene, monoterpenes, sesquiterpenes, oxygenated sesquiterpenes, and other oxygenated compounds) were analyzed. Emission rates were determined by normalization to standard conditions (1000 μmol/m(2)s PAR and 30 °C temperature for isoprene and 30 °C temperature for the remaining compounds). In agreement with the literature, isoprene was mostly emitted by broad-leaved trees while coniferous species mainly emitted monoterpenes. Several tree species such as Sweet Chestnut, Silver Lime, and European Alder had higher monoterpene emissions although they are broad-leaved species. High isoprene emissions were also observed for a few coniferous species such as Nordmann Fir and Oriental Spruce. The highest normalized total BVOC emission rate of 27.1 μg/gh was observed for Oriental Plane while South European Flowering Ash was the weakest BVOC emitter with a total normalized emission rate of 0.031 μg/gh. Monoterpene emissions of broad-leaved species mainly consisted of sabinene, limonene and trans-beta-ocimene, while alpha-pinene, beta-pinene and beta

On-board measurements of emissions from light-duty gasoline vehicles in three mega-cities of China

Science.gov (United States)

Huo, Hong; Yao, Zhiliang; Zhang, Yingzhi; Shen, Xianbao; Zhang, Qiang; Ding, Yan; He, Kebin

2012-03-01

This paper is the second in a series of three papers aimed at understanding the emissions of vehicles in China by conducting on-board emission measurements. This paper focuses on light-duty gasoline vehicles. In this study, we measured 57 light-duty gasoline vehicles (LDGVs) in three Chinese mega-cites (Beijing, Guangzhou, and Shenzhen), covering Euro 0 through Euro IV technologies, and generated CO, HC, and NOx emission factors and deterioration rates for each vehicle technology. The results show that the vehicle emission standards have played a significant role in reducing vehicle emission levels in China. The vehicle emission factors are reduced by 47-81%, 53-64%, 46-71%, and 78-82% for each phase from Euro I to Euro IV. Euro 0 vehicles have a considerably high emission level, which is hundreds of times larger than that of Euro IV vehicles. Three old taxis and four other Euro I and Euro II LDGVs are also identified as super emitters with equivalent emission levels to Euro 0 vehicles. Of the measured fleet, 23% super emitters were estimated to contribute 50-80% to total emissions. Besides vehicle emission standards, measures for restricting super emitters are equally important to reduce vehicle emissions. This study is intended to improve the understanding of the vehicle emission levels in China, but some key issues such as emission deterioration rates are yet to be addressed with the presence of a sufficient amount of vehicle emission measurements.

The Comparison Study of Contralateral Transient Evoked Otoacoustic Emission (TEOAE Suppression in Normal Hearing Subjects and Multiple Sclerosis Patients

Directory of Open Access Journals (Sweden)

KH Mohamadkhani

2007-01-01

Full Text Available ABSTRACT: Introduction & Objective: A common auditory complaint of multiple sclerosis patients, is misunderstanding speech in the presence of background noise. Evidence from animal and human studies has suggested that the medial olivocochlear bundle may play an important role in hearing noise. The medial olivocochlear bundle function can be evaluated by the suppression effect of transient otoacoustic emission in response to contralateral acoustic stimulation. The present study was conducted to investigate the suppression effect of transient otoacoustic emission in multiple sclerosis patients. Materials & Methods: This analytical case-control study was conducted on 34 multiple sclerosis patients (24 female, 10 male, aged 20-50 years and 34 controls matched for age and gender in Faculty of Rehabilitation, Tehran University of Medical Sciences in 2006. All cases were selected in simple random manner. The suppression effect of transient otoacoustic emission was evaluated by comparing the transient otoacoustic emission levels with and without contralateral acoustic stimulation. Data were analyzed using SPSS software and independent T- test. Results:There was no significant difference in transient otoacoustic emission levels of two groups, but a significantly reduced suppression effect of transient otoacoustic emission was found in multiple sclerosis patients, in compare with the controls. Conclusion: Outer hair cells activity in multiple sclerosis patients was normal but these patients presented low activity of the medial olivocochlear bundle system which could affect their ability to hear in the presence of background noise.

Surface-plasmon-enhanced lasing emission based on polymer distributed feedback laser

Energy Technology Data Exchange (ETDEWEB)

Zhang, Dingke, E-mail: dingke.zhang@gmail.com, E-mail: shijianchen@gmail.com [School of Physics and Electronic Engineering, Chongqing Normal University, Chongqing 401331 (China); Chen, Shijian, E-mail: dingke.zhang@gmail.com, E-mail: shijianchen@gmail.com; Huang, Yingzhou; Zhang, Zhen [School of Physics, Chongqing University, Chongqing 401331 (China); Wang, Yanping; Ma, Dongge [State Key Laboratory of Polymer Physics and Chemistry, Changchun Institute of Applied Chemistry, Chinese Academy of Sciences, Changchun 130022 (China)

2015-01-14

Optical losses associated with the metallic contacts necessary for charge injection are an obstacle to the development of electrically pumped organic lasers. In this work, we show that it is possible to overcome these losses by introducing surface plasmons (SPs) in a distributed feedback laser to enhance the lasing emission. We perform a detailed study of the SPs influence on the lasing emission. We experimentally show that enhanced lasing emission has been successfully achieved in the presence of a metal electrode. The laser emission is strongly dependent on the thickness of Ag layer. By optimizing the thickness of Ag layer, surface-plasmon-enhanced lasing emission has been achieved with much reduced thresholds and higher intensity. When the thickness of the Ag layer increases to 50 nm, the device exhibits ten-fold emission intensity and a fifth of excitation threshold comparing with Ag-free one. The finite-difference time-domain (FDTD) results show that large field intensity is built at the 4-(dicyanomethylene)-2-i-propyl-6-(1,1,7,7-tetramethyljulolidyl-9-enyl) -4H-pyran:/poly(9-vinylcarbazole)Ag interface, which could lead to a strong coupling between lasing and SPs, and consequently a much enhanced laser emission at the photon energy of around 2.02 eV (615 nm). Our FDTD simulations gave an explanation of the effects of the SPs on lasing operation in the periodic structures. The use of SPs would lead to a new class of highly efficient solid-state laser sources and provide a new path to achieve electrically pumped organic lasers.

Strong water absorption in the dayside emission spectrum of the planet HD 189733b.

Science.gov (United States)

Grillmair, Carl J; Burrows, Adam; Charbonneau, David; Armus, Lee; Stauffer, John; Meadows, Victoria; van Cleve, Jeffrey; von Braun, Kaspar; Levine, Deborah

2008-12-11

Recent observations of the extrasolar planet HD 189733b did not reveal the presence of water in the emission spectrum of the planet. Yet models of such 'hot-Jupiter' planets predict an abundance of atmospheric water vapour. Validating and constraining these models is crucial to understanding the physics and chemistry of planetary atmospheres in extreme environments. Indications of the presence of water in the atmosphere of HD 189733b have recently been found in transmission spectra, where the planet's atmosphere selectively absorbs the light of the parent star, and in broadband photometry. Here we report the detection of strong water absorption in a high-signal-to-noise, mid-infrared emission spectrum of the planet itself. We find both a strong downturn in the flux ratio below 10 microm and discrete spectral features that are characteristic of strong absorption by water vapour. The differences between these and previous observations are significant and admit the possibility that predicted planetary-scale dynamical weather structures may alter the emission spectrum over time. Models that match the observed spectrum and the broadband photometry suggest that heat redistribution from the dayside to the nightside is weak. Reconciling this with the high nightside temperature will require a better understanding of atmospheric circulation or possible additional energy sources.

On estimating probability of presence from use-availability or presence-background data.

Science.gov (United States)

Phillips, Steven J; Elith, Jane

2013-06-01

A fundamental ecological modeling task is to estimate the probability that a species is present in (or uses) a site, conditional on environmental variables. For many species, available data consist of "presence" data (locations where the species [or evidence of it] has been observed), together with "background" data, a random sample of available environmental conditions. Recently published papers disagree on whether probability of presence is identifiable from such presence-background data alone. This paper aims to resolve the disagreement, demonstrating that additional information is required. We defined seven simulated species representing various simple shapes of response to environmental variables (constant, linear, convex, unimodal, S-shaped) and ran five logistic model-fitting methods using 1000 presence samples and 10 000 background samples; the simulations were repeated 100 times. The experiment revealed a stark contrast between two groups of methods: those based on a strong assumption that species' true probability of presence exactly matches a given parametric form had highly variable predictions and much larger RMS error than methods that take population prevalence (the fraction of sites in which the species is present) as an additional parameter. For six species, the former group grossly under- or overestimated probability of presence. The cause was not model structure or choice of link function, because all methods were logistic with linear and, where necessary, quadratic terms. Rather, the experiment demonstrates that an estimate of prevalence is not just helpful, but is necessary (except in special cases) for identifying probability of presence. We therefore advise against use of methods that rely on the strong assumption, due to Lele and Keim (recently advocated by Royle et al.) and Lancaster and Imbens. The methods are fragile, and their strong assumption is unlikely to be true in practice. We emphasize, however, that we are not arguing against

A theoretical model for the control of an enforcement system on emissions of pollutants

International Nuclear Information System (INIS)

Villegas, Clara Ines

2005-01-01

A theoretical proposal for the development of an enforcement strategy is presented on this paper. The proposal guaranties full compliance of an emission charge system with self-report presence. The proposed models are static, and mostly based on those proposed by Strandlund and Chavez (2000) for a transferable permits system with self -report presence. Theoretical models were developed for three possible violations: self-report violation, maximum emission limits violation and payment violation. Based in theoretical results, a simulation was implemented with hypothetical data: 20 regulated firms with different marginal abatement cost functions. The variation in charge amount, Monitory costs, abatement cost, self-report value and total cost are analyzed, with each of the theoretical models under different scenarios. Our results show that the behavior of the different variables remains unchanged under the three static models, and that the only variations occur inside the scenarios. Our results can serve as a tool for the formulation and design of taxing systems

Electron mobility variance in the presence of an electric field: Electron-phonon field-induced tunnel scattering

International Nuclear Information System (INIS)

Melkonyan, S.V.

2012-01-01

The problem of electron mobility variance is discussed. It is established that in equilibrium semiconductors the mobility variance is infinite. It is revealed that the cause of the mobility variance infinity is the threshold of phonon emission. The electron-phonon interaction theory in the presence of an electric field is developed. A new mechanism of electron scattering, called electron-phonon field-induced tunnel (FIT) scattering, is observed. The effect of the electron-phonon FIT scattering is explained in terms of penetration of the electron wave function into the semiconductor band gap in the presence of an electric field. New and more general expressions for the electron-non-polar optical phonon scattering probability and relaxation time are obtained. The results show that FIT transitions have principle meaning for the mobility fluctuation theory: mobility variance becomes finite.

Measurements of dioxin emissions during co-firing in a fluidised bed

Energy Technology Data Exchange (ETDEWEB)

I. Gulyurtlu; A.T. Crujeira; P. Abelha; I. Cabrita [INETI, Lisbon (Portugal). Departamento de Engenharia Energetica e Controle Ambiental

2007-09-15

The emissions of dioxins could be considerable when fuels with high chlorine content are used, particularly in fluidised beds due to constraints to use temperatures in the range 800-900{sup o}C for other considerations. However, mixing of fuels with different characteristics may lead to a reduction in dioxin emissions. Studies are currently being undertaken at the above-mentioned department in mixing fuels of varying chlorine and sulphur contents to monitor the emissions of dioxins both in the gas and solid phases. Furthermore, the influence of certain elements like Cu in the ash in the emissions of dioxins is also studied to verify the catalytic effect. The INETI pilot-scale test facility is used for the combustion work. Two different coals, namely Colombian and Polish, are used as the base fuel. The supplementary fuels for co-firing include MBM and straw pellets. The combustion temperature is maintained at about 800-830{sup o}C range without any limestone addition. The residence time of over 2 s is respected. Results obtained by far suggest that the presence of sulphur in both fuels have a very strong effect on the eventual emissions of dioxins and the synergy regarding to reduce the dioxins below the levels permitted is possible by mixing fuels based on their characteristics. The paper reports the results obtained and evaluates the effect of fuel nature and operating conditions on the emissions of dioxins. 34 refs., 8 figs., 12 tabs.

Emission study of alumina plasma produced by a KrF laser

Energy Technology Data Exchange (ETDEWEB)

Yahiaoui, K., E-mail: kyahiaoui@cdta.dz [Centre de Développement des Technologies Avancées, cité 20 aout 1956, BP 17, Baba Hassen, Alger (Algeria); Abdelli-Messaci, S.; Messaoud-Aberkane, S.; Kerdja, T. [Centre de Développement des Technologies Avancées, cité 20 aout 1956, BP 17, Baba Hassen, Alger (Algeria); Kellou, H. [Université des Sciences et de la Technologie Houari Boumediene, BP 32, El-Allia, 16111 Bab-Ezzouar, Alger (Algeria)

2014-03-01

We report on the plasma emission formed from an α-alumina target when irradiated by laser into vacuum and through oxygen gas. Two diagnostic tools have been used: ICCD camera fast imaging and optical emission spectroscopy. The alumina plasma was induced by a KrF laser beam at a wavelength of 248 nm and pulse duration of 25 ns. The laser fluence was set to 8 J/cm{sup 2} and the oxygen pressure was varied from 0.01 to 5 mbar. By using the ICCD camera, two dimensional images of the plasma expansion were taken at different times. Depending on oxygen pressure and time delay, the expansion behavior of the plasma showed free expansion, plume splitting, shock wave formation, hydrodynamic instability and deceleration of the plume. Using optical emission spectroscopy, the plasma emission revealed the presence of neutral Al I, Al II, Al III into vacuum and under oxygen ambiance. The molecular emission of aluminum oxide (AlO) was detected only in oxygen ambiance. It should be noted that no oxygen lines were observed. Finally, the evolution of the electronic temperature along the normal axis from the target surface, into vacuum, was estimated using the Boltzmann plot method. - Highlights: • Ablated mass measurements of α-alumina target irradiated by a laser in nanosecond regime. • Optical emission spectroscopy of alumina plasma. • Fast imaging diagnostic of alumina plume using ICCD camera.

The political economy of emissions trading

International Nuclear Information System (INIS)

Hanoteau, J.

2004-06-01

This thesis is a positive analysis of emissions trading systems' implementation. We explain why allowances are generally granted for free even though normative economic analysis recommends their sale. We show empirically that free tradable permits, source of windfall profit, motivate rent seeking behaviours. The study focuses on the US market for SO 2 emissions allowances. The initial allocation rule resulted from parliamentary discussions that looked like a zero sum game. We formalize it as an endogenous sharing rule, function of lobbying effort, and we test it using political (money) contributions.We analyse theoretically the behaviour of an influenced regulator that has chosen to organize a market for permits and that must still decide on two policy variables: the whole quantity of permits and the way to allocate them initially. We formalize this decisions making process with the common agency model of politics.We show that the choice of an initial allocation rule is not neutral in presence of political market failures (lobbying). The decision to sell the permits or to grant them for free modifies the shareholders' incentive, in a polluting industry, to pressure for or against the reduction of legal emissions.Then, we analyse the public arbitration between the two policy variables when several industrial lobbies play a partially cooperative game for the free permits. The regulator chooses in priority to grant the rights for free rather than to manipulate their quantity, and this constitutes an efficient answer to the political influence. (author)

Biogenic volatile organic compound (BVOC) emissions from forested areas in Turkey: Determination of specific emission rates for thirty-one tree species

International Nuclear Information System (INIS)

Aydin, Yagmur Meltem; Yaman, Baris; Koca, Husnu; Dasdemir, Okan; Kara, Melik; Altiok, Hasan; Dumanoglu, Yetkin; Bayram, Abdurrahman; Tolunay, Doganay; Odabasi, Mustafa; Elbir, Tolga

2014-01-01

Normalized biogenic volatile organic compound (BVOC) emission rates for thirty one tree species that cover the 98% of national forested areas in Turkey were determined. Field samplings were performed at fourteen different forested areas in Turkey using a specific dynamic enclosure system. The selected branches of tree species were enclosed in a chamber consisted of a transparent Nalofan bag. The air-flows were sampled from both inlet and outlet of the chamber by Tenax-filled sorbent tubes during photosynthesis of trees under the presence of sunlight. Several environmental parameters (temperature, humidity, photosynthetically active radiation-PAR, and CO 2 ) were continuously monitored inside and outside the enclosure chamber during the samplings. Collected samples were analyzed using a gas chromatography mass spectrometry (GC/MS) system equipped with a thermal desorber (TD). Sixty five BVOCs classified in five major groups (isoprene, monoterpenes, sesquiterpenes, oxygenated sesquiterpenes, and other oxygenated compounds) were analyzed. Emission rates were determined by normalization to standard conditions (1000 μmol/m 2 s PAR and 30 °C temperature for isoprene and 30 °C temperature for the remaining compounds). In agreement with the literature, isoprene was mostly emitted by broad-leaved trees while coniferous species mainly emitted monoterpenes. Several tree species such as Sweet Chestnut, Silver Lime, and European Alder had higher monoterpene emissions although they are broad-leaved species. High isoprene emissions were also observed for a few coniferous species such as Nordmann Fir and Oriental Spruce. The highest normalized total BVOC emission rate of 27.1 μg/g h was observed for Oriental Plane while South European Flowering Ash was the weakest BVOC emitter with a total normalized emission rate of 0.031 μg/g h. Monoterpene emissions of broad-leaved species mainly consisted of sabinene, limonene and trans-beta-ocimene, while alpha-pinene, beta-pinene and

Biogenic volatile organic compound (BVOC) emissions from forested areas in Turkey: Determination of specific emission rates for thirty-one tree species

Energy Technology Data Exchange (ETDEWEB)

Aydin, Yagmur Meltem; Yaman, Baris; Koca, Husnu; Dasdemir, Okan; Kara, Melik; Altiok, Hasan; Dumanoglu, Yetkin; Bayram, Abdurrahman [Department of Environmental Engineering, Faculty of Engineering, Dokuz Eylul University, Tinaztepe Campus, Buca, Izmir (Turkey); Tolunay, Doganay [Department of Soil Science and Ecology, Faculty of Forestry, Istanbul University, Bahcekoy, Istanbul (Turkey); Odabasi, Mustafa [Department of Environmental Engineering, Faculty of Engineering, Dokuz Eylul University, Tinaztepe Campus, Buca, Izmir (Turkey); Elbir, Tolga, E-mail: tolga.elbir@deu.edu.tr [Department of Environmental Engineering, Faculty of Engineering, Dokuz Eylul University, Tinaztepe Campus, Buca, Izmir (Turkey)

2014-08-15

Normalized biogenic volatile organic compound (BVOC) emission rates for thirty one tree species that cover the 98% of national forested areas in Turkey were determined. Field samplings were performed at fourteen different forested areas in Turkey using a specific dynamic enclosure system. The selected branches of tree species were enclosed in a chamber consisted of a transparent Nalofan bag. The air-flows were sampled from both inlet and outlet of the chamber by Tenax-filled sorbent tubes during photosynthesis of trees under the presence of sunlight. Several environmental parameters (temperature, humidity, photosynthetically active radiation-PAR, and CO{sub 2}) were continuously monitored inside and outside the enclosure chamber during the samplings. Collected samples were analyzed using a gas chromatography mass spectrometry (GC/MS) system equipped with a thermal desorber (TD). Sixty five BVOCs classified in five major groups (isoprene, monoterpenes, sesquiterpenes, oxygenated sesquiterpenes, and other oxygenated compounds) were analyzed. Emission rates were determined by normalization to standard conditions (1000 μmol/m{sup 2} s PAR and 30 °C temperature for isoprene and 30 °C temperature for the remaining compounds). In agreement with the literature, isoprene was mostly emitted by broad-leaved trees while coniferous species mainly emitted monoterpenes. Several tree species such as Sweet Chestnut, Silver Lime, and European Alder had higher monoterpene emissions although they are broad-leaved species. High isoprene emissions were also observed for a few coniferous species such as Nordmann Fir and Oriental Spruce. The highest normalized total BVOC emission rate of 27.1 μg/g h was observed for Oriental Plane while South European Flowering Ash was the weakest BVOC emitter with a total normalized emission rate of 0.031 μg/g h. Monoterpene emissions of broad-leaved species mainly consisted of sabinene, limonene and trans-beta-ocimene, while alpha-pinene, beta

Influence of suspended particles on the emission of organophosphate flame retardant from insulation boards.

Science.gov (United States)

Lazarov, Borislav; Swinnen, Rudi; Poelmans, David; Spruyt, Maarten; Goelen, Eddy; Covaci, Adrian; Stranger, Marianne

2016-09-01

The influence of the presence of the so-called seed particles on the emission rate of Tris (1-chloroisopropyl) phosphate (TCIPP) from polyisocyanurate (PIR) insulation boards was investigated in this study. Two Field and Laboratory Emission Test cells (FLEC) were placed on the surface of the same PIR board and respectively supplied with clean air (reference FLEC) and air containing laboratory-generated soot particles (test FLEC). The behavior of the area-specific emission rates (SER A ) over a time period of 10 days was studied by measuring the total (gas + particles) concentrations of TCIPP at the exhaust of each FLEC. The estimated SER A of TCIPP from the PIR board at the quasi-static equilibrium were found to be 0.82 μg m(-2) h(-1) in the absence of seed particles, while the addition of soot particles led to SER A of 2.16 μg m(-2) h(-1). This indicates an increase of the SER A of TCIPP from the PIR board with a factor of 3 in the presence of soot particles. The TCIPP partition coefficient to soot particles at the quasi-static equilibrium was 0.022 ± 0.012 m(3) μg(-1). In the next step, the influence of real-life particles on TCIPP emission rates was investigated by supplying the test FLEC with air from a professional kitchen where mainly frying and baking activities took place. Similar to the reference FLEC outcomes, SER A was also found to increase in this real-life experiment over a time period of 20 days by a factor 3 in the presence of particles generated during cooking activities. The median value of estimated particle-gas coefficient for this test was 0.062 ± 0.037 m(3) μg(-1).

On the origin of blue emission from ZnO quantum dots synthesized by a sol–gel route

International Nuclear Information System (INIS)

Han, Li-Li; Cui, Lan; Du, Xi-Wen; Wang, Wei-Hua; Wang, Jiang-Long

2012-01-01

ZnO quantum dots (QDs) with blue emission were synthesized by a sol–gel method. A series of control experiments were conducted to explore the origin of the blue emission. It is found that the blue emission arises from neither the quantum confinement nor intermediate products, and it can be achieved only in the presence of Li + cations and excessive OH − anions. Moreover, the long decay time of the blue emission suggests a defect-related de-excitation process. On the basis of the experimental and calculation results, possible de-excitation paths for light emission were discussed, and the origin of the blue emission was determined as the electron transition from the conduction band to interstitial oxygen defects. Excessive OH − anions are responsible for the formation of interstitial oxygen defects, and Li + ions can stabilize the defects by substituting for Zn atoms. Besides, Li + ions can block the growth of ZnO QDs, broaden their band gap and cause a blue shift of the blue emission. (paper)

COLLISIONLESS SHOCKS IN A PARTIALLY IONIZED MEDIUM. II. BALMER EMISSION

Energy Technology Data Exchange (ETDEWEB)

Morlino, G.; Bandiera, R.; Blasi, P.; Amato, E. [INAF-Osservatorio Astrofisico di Arcetri, Largo E. Fermi 5, I-50125 Firenze (Italy)

2012-12-01

Strong shocks propagating into a partially ionized medium are often associated with optical Balmer lines. This emission is due to impact excitation of neutral hydrogen by hot protons and electrons in the shocked gas. The structure of such Balmer-dominated shocks has been computed in a previous paper, where the distribution function of neutral particles was derived from the appropriate Boltzmann equation including coupling with ions and electrons through charge exchange and ionization. This calculation showed how the presence of neutrals can significantly modify the shock structure through the formation of a neutral-induced precursor ahead of the shock. Here we follow up on our previous work and investigate the properties of the resulting Balmer emission, with the aim of using the observed radiation as a diagnostic tool for shock parameters. Our main focus is on supernova remnant shocks, and we find that, for typical parameters, the H{alpha} emission typically has a three-component spectral profile, where (1) a narrow component originates from upstream cold hydrogen atoms, (2) a broad component comes from hydrogen atoms that have undergone charge exchange with shocked protons downstream of the shock, and (3) an intermediate component is due to hydrogen atoms that have undergone charge exchange with warm protons in the neutral-induced precursor. The relative importance of these three components depends on the shock velocity, on the original degree of ionization, and on the electron-ion temperature equilibration level. The intermediate component, which is the main signature of the presence of a neutral-induced precursor, becomes negligible for shock velocities {approx}< 1500 km s{sup -1}. The width of the intermediate line reflects the temperature in the precursor, while the width of the narrow one is left unaltered by the precursor. In addition, we show that the profiles of both the intermediate and broad components generally depart from a thermal distribution, as a

Data analysis in emission tomography using emission-count posteriors

International Nuclear Information System (INIS)

Sitek, Arkadiusz

2012-01-01

A novel approach to the analysis of emission tomography data using the posterior probability of the number of emissions per voxel (emission count) conditioned on acquired tomographic data is explored. The posterior is derived from the prior and the Poisson likelihood of the emission-count data by marginalizing voxel activities. Based on emission-count posteriors, examples of Bayesian analysis including estimation and classification tasks in emission tomography are provided. The application of the method to computer simulations of 2D tomography is demonstrated. In particular, the minimum-mean-square-error point estimator of the emission count is demonstrated. The process of finding this estimator can be considered as a tomographic image reconstruction technique since the estimates of the number of emissions per voxel divided by voxel sensitivities and acquisition time are the estimates of the voxel activities. As an example of a classification task, a hypothesis stating that some region of interest (ROI) emitted at least or at most r-times the number of events in some other ROI is tested. The ROIs are specified by the user. The analysis described in this work provides new quantitative statistical measures that can be used in decision making in diagnostic imaging using emission tomography. (paper)

Data analysis in emission tomography using emission-count posteriors

Science.gov (United States)

Sitek, Arkadiusz

2012-11-01

A novel approach to the analysis of emission tomography data using the posterior probability of the number of emissions per voxel (emission count) conditioned on acquired tomographic data is explored. The posterior is derived from the prior and the Poisson likelihood of the emission-count data by marginalizing voxel activities. Based on emission-count posteriors, examples of Bayesian analysis including estimation and classification tasks in emission tomography are provided. The application of the method to computer simulations of 2D tomography is demonstrated. In particular, the minimum-mean-square-error point estimator of the emission count is demonstrated. The process of finding this estimator can be considered as a tomographic image reconstruction technique since the estimates of the number of emissions per voxel divided by voxel sensitivities and acquisition time are the estimates of the voxel activities. As an example of a classification task, a hypothesis stating that some region of interest (ROI) emitted at least or at most r-times the number of events in some other ROI is tested. The ROIs are specified by the user. The analysis described in this work provides new quantitative statistical measures that can be used in decision making in diagnostic imaging using emission tomography.

White emission via electroplex emission from two blue materials.

Science.gov (United States)

Li, Junming; Song, Dandan; Zhao, Suling; Zhang, Fujun; Xu, Zheng; Song, Jinglu; Lu, Lifang; Liu, Xiaodong; Wang, Yongsheng

2010-03-01

Influences of electric fields on the emission from organic light-emitting diodes (OLEDs) based on poly (N-vinylcarbazole) (PVK); 2, 9-dimethyl-4, 7-diphenyl-1, 10-phenanthroline (BCP); and tris (8-hydroxyquinoline) aluminum (Alq3) were studied. There are three emission peaks at 420 nm, 520 nm, and 620 nm of the device ITO/PEDOT: PSS/PVK/BCP/LiF/Al under different driving voltages. The emissions at 420 nm and 520 nm should be from the exciton emission of PVK and Alq3, respectively. The last emission at 620 nm could be attributed to electroplex emission at the interface between the PVK and BCP layers. A high intensity white emission via electroplex formation was obtained with Commission International d'Eclairage (CIE) coordinates (0.33, 0.34) at 15 V, which is very close to the equienergy white point (0.33, 0.33).

Quantitative multi-color FRET measurements by Fourier lifetime excitation-emission matrix spectroscopy

Science.gov (United States)

Zhao, Ming; Huang, Run; Peng, Leilei

2012-01-01

Förster resonant energy transfer (FRET) is extensively used to probe macromolecular interactions and conformation changes. The established FRET lifetime analysis method measures the FRET process through its effect on the donor lifetime. In this paper we present a method that directly probes the time-resolved FRET signal with frequency domain Fourier lifetime excitation-emission matrix (FLEEM) measurements. FLEEM separates fluorescent signals by their different phonon energy pathways from excitation to emission. The FRET process generates a unique signal channel that is initiated by donor excitation but ends with acceptor emission. Time-resolved analysis of the FRET EEM channel allows direct measurements on the FRET process, unaffected by free fluorophores that might be present in the sample. Together with time-resolved analysis on non-FRET channels, i.e. donor and acceptor EEM channels, time resolved EEM analysis allows precise quantification of FRET in the presence of free fluorophores. The method is extended to three-color FRET processes, where quantification with traditional methods remains challenging because of the significantly increased complexity in the three-way FRET interactions. We demonstrate the time-resolved EEM analysis method with quantification of three-color FRET in incompletely hybridized triple-labeled DNA oligonucleotides. Quantitative measurements of the three-color FRET process in triple-labeled dsDNA are obtained in the presence of free single-labeled ssDNA and double-labeled dsDNA. The results establish a quantification method for studying multi-color FRET between multiple macromolecules in biochemical equilibrium. PMID:23187535

Are renewable energy policies upsetting carbon dioxide emissions? The case of Latin America countries.

Science.gov (United States)

Fuinhas, José Alberto; Marques, António Cardoso; Koengkan, Matheus

2017-06-01

The impact of renewable energy policies in carbon dioxide emissions was analysed for a panel of ten Latin American countries, for the period from 1991 to 2012. Panel autoregressive distributed lag methodology was used to decompose the total effect of renewable energy policies on carbon dioxide emissions in its short- and long-run components. There is evidence for the presence of cross-sectional dependence, confirming that Latin American countries share spatial patterns. Heteroskedasticity, contemporaneous correlation, and first-order autocorrelation cross-sectional dependence are also present. To cope with these phenomena, the robust dynamic Driscoll-Kraay estimator, with fixed effects, was used. It was confirmed that the primary energy consumption per capita, in both the short- and long-run, contributes to an increase in carbon dioxide emissions, and also that renewable energy policies in the long-run, and renewable electricity generation per capita both in the short- and long-run, help to mitigate per capita carbon dioxide emissions.

Does Renewable Energy Consumption and Health Expenditure Decrease Carbon Dioxide Emissions? Evidence for sub-Saharan Africa Countries

OpenAIRE

Apergis, Nicholas; Ben Jebli, Mehdi

2015-01-01

This paper employs a number of panel methodological approaches to explore the link between per capita carbon dioxide emissions, per capita real income, renewable energy consumption and health expenditures for a panel of 42 sub-Saharan African countries, spanning the period 1995-2011. The empirical findings provide supportive of a long-run relationship among the variables. Granger causality reveals the presence of a short-run unidirectional causality running from real GDP to CO2 emissions, a b...

Enhanced green and red upconversion emissions in Er3+-doped boro-tellurite glass containing gold nanoparticles

Science.gov (United States)

Dousti, M. Reza; Amjad, Raja J.; Mahraz, Zahra Ashur S.

2015-01-01

Increasing the cross-section of upconversion emissions from the rare earth ions doped materials is a challenging issue. In this work, we report on the enhancement of the up-converted emissions of Er3+-doped boro-tellurite glasses containing gold nanoparticles which have been prepared by a conventional melt-quench technique. Seven absorption bands and three emission lines are observed using the UV-Vis-IR and photoluminescence spectroscopic techniques, respectively. Red emission is enhanced up to 30 times in a sample having 1 wt% of Au nanoparticles. The presence of the gold nanoparticles with average size of ∼5.74 nm is confirmed by transmission electron microscopy and corresponding surface plasmon band is observed at 630 nm in a singly-doped Au-nanoparticles embedded glass sample. A model to determine the enhancement factor of the emissions is suggested which could not describe the phenomenon for high concentrations of nanoparticles. Enhancement is attributed to the increased local field around the metal, and the results are discussed in details.

Time-resolved pulse-counting lock-in detection of laser induced fluorescence in the presence of a strong background emission

Science.gov (United States)

Pelissier, B.; Sadeghi, N.

1996-10-01

We describe a time-resolved pulse-counting system well adapted for the detection of continuous laser induced fluorescence (LIF) signals in repetitive phenomena, when a strong background emission is present. It consists of 256 channels coupled to a first in first out memory and interfaced to a 486 DX 33 PC, for data storage. It accepts time-averaged count rates up to 450 kcount/s. Time between channels can be set from 12.5 ns to several μs and the dead time between two consecutive cycles of the physical phenomena is less than 20 ns. In phase with a chopper, which modulates the laser beam, it adds the observed photon signal to the channel memories when the beam is on and substracts it when the beam is stopped, acting like a lock-in amplifier which detect only the modulated part of the signal. The minimum detectivity on the LIF signal is only limited by the shot noise of the plasma induced emission signal. As an application, we studied the time variation of the Ar+*(2G9/2) metastable ions, detected by LIF, in two types of plasmas. Their radiative lifetime and collisional quenching frequencies were deduced from their decay rate in the afterglow of a pulsed Helicon reactor. We also observed the evolution of their density in a 455 kHz capacitively coupled argon discharge.

IR emission and UV extinction in two open clusters

International Nuclear Information System (INIS)

Hackwell, J.A.; Hecht, J.H.

1989-01-01

Recent models of interstellar extinction have shown the importance of understanding both the UV and IR properties of interstellar dust grains. IRAS data have shown variations in 60 and 100 micron emissions presumably due to the presence of IR cirrus, while recent observations in the UV by Fitzpatrick and Massa have identified components in the UV extinction curve which vary in different star regions. A Draine and Anderson model connects these results by proposing that different size variations in interstellar grains would cause distinct changes in both the IR emission and the UV extinction. In order to test this model it is necessary to make observations in well defined locations away from peculiar extinction regions. In the infrared this means looking away from the galactic plane so as to limit non-local sources of IR radiation. Two open clusters that are out of the galactic plane and which contain a number of late B and early A stars suitable for UV extinction studies, and whose IRAS data show variations in the 60/100 micron ratio were studied. Based on the Drain and Anderson model, variations were expected in their UV extinction curves that correlate with the IR cirrus emission

Decoupling Economic Growth From Carbon Dioxide Emissions in the EU Countries

Directory of Open Access Journals (Sweden)

Mariola Piłatowska

2018-03-01

Full Text Available This paper aims to look at the long-run equilibrium relationship between CO2 emissions and economic growth (the EKC hypothesis in an asymmetric framework using the non-linear threshold cointegration. In order to avoid the problem of omitted variables bias, the dynamic relationship between pollutant emissions, economic development and energy consumption are also examined (the extended EKC model. The research hypothesis is that the economic growth decouples from CO2 emissions growth, i.e. the EKC hypothesis holds. The empirical study is carried out for the European Union countries (EU-14 divided into three groups depending on a category of knowledge-advanced economies in order to explain the differences in the dynamic linkage between CO2 emissions and economic growth, as well as in the energy consumption impact on this cointegrating relationship. We have found that the EKC hypothesis is valid for the most high-level and some middle-level knowledge advanced economies. The addition of energy consumption to the standard EKC model has improved the results in terms of the presence of linear or threshold cointegration for all low-level knowledge based economies. Moreover, the causality pattern between CO2 emissions and income has changed after energy consumption adding to the EKC model and some similarities are found in the countries belonging to the same category of knowledge-advanced economies

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...

Eco-Technology Licensing under Emission Tax: Royalty vs. Fixed-Fee

OpenAIRE

Seung-Leul Kim; Sang-Ho Lee

2014-01-01

This article considers the licensing strategies of eco-technology when an innovator provides pollution abatement goods to oligopolistic polluting firms that produce consumption goods and emit environmental pollutants. In the presence of emission tax, two types of licensing contracts, royalty and fixed-fee, are examined to analyze market equilibrium and to compare their welfare consequences. We show that an eco-innovator provides a non-exclusive license under a royalty contract while it might ...

Electrochemical characteristics of coated steel with poly(N-methyl pyrrole) synthesized in presence of ZnO nanoparticles

Energy Technology Data Exchange (ETDEWEB)

Mahmoudian, M.R., E-mail: M_R_mahmoudian@yahoo.com [Department of Chemistry, University of Malaya, Kuala Lumpur 50603 (Malaysia); Department of Chemistry, Masjed-Soleiman Branch, Islamic Azad University, Masjed-Soleiman (Iran, Islamic Republic of); Basirun, W.J.; Alias, Y. [Department of Chemistry, University of Malaya, Kuala Lumpur 50603 (Malaysia); Khorsand Zak, A. [Low Dimensional Materials Research Center, Department of Physics, University of Malaya, 50603 Kuala Lumpur (Malaysia)

2011-10-31

Poly(N-methyl pyrrole) (PMPy) coating was electrodeposited on steel substrates in mixed electrolytes of dodecyl benzene sulphonic acid with oxalic acid in the absence and the presence of ZnO nanoparticles (NPs). The morphology and compositions were characterized by Field Emission Scanning Electron Microscopy (FESEM), Fourier Transform Infrared Spectroscopy and Energy-dispersive X-ray spectroscopy. Electrode/coating/electrolyte system was studied by Electrochemical Impedance Spectroscopy. The comparison between the pore resistance (R{sub po}) of synthesized PMPy in the absence and presence of ZnO NPs indicated that the existence of ZnO increased the R{sub po} of the coating. The FESEM micrographs indicated that the size of micro-spherical grains in the morphology of PMPy is significantly reduced and the surface area of PMPy is increased with the presence of ZnO NPs. The increase of the ability to interact with the ions liberated during the corrosion reaction of steel and the increase of the rate probability for the occurrence of cathodic reduction of oxygen on the PMPy with the increase of the surface area can be considered as reasons for improvement of protective properties of synthesized PMPy in the presence of ZnO NPs.

Relation between gamma-ray emission, radio bursts, and proton fluxes from solar flares

International Nuclear Information System (INIS)

Fomichev, V.V.; Chertok, I.M.

1985-01-01

Data on solar gamma-ray flares, including 24 flares with gamma-ray lines, recorded up to June 1982, are analyzed. It is shown that from the point of view of radio emission the differences between flares with and without gamma-ray lines has a purely quantitative character: the former are accompanied by the most intense microwave bursts. Meter type II bursts are not a distinctive feature of flares with gamma-ray lines. Pulsed flares, regardless of the presence or absence of gamma-ray lines, are not accompanied by significant proton fluxes at the earth. On the whole, contrary to the popular opinion in the literature, flares with gamma-ray lines do not display a deficit of proton flux in interplanetary space in comparison with similar flares without gamma-ray lines. The results of quantitative diagnostics of proton flares based on radio bursts are not at variance with the presence of flares without detectable gamma-ray emission in lines but with a pronounced increase in the proton flux at the earth. 23 references

Directional sound beam emission from a configurable compact multi-source system

KAUST Repository

Zhao, Jiajun

2018-01-12

We propose to achieve efficient emission of highly directional sound beams from multiple monopole sources embedded in a subwavelength enclosure. Without the enclosure, the emitted sound fields have an indistinguishable or omnidirectional radiation directivity in far fields. The strong directivity formed in the presence of the enclosure is attributed to interference of sources under degenerate Mie resonances in the enclosure of anisotropic property. Our numerical simulations of sound emission from the sources demonstrate the radiation of a highly directed sound beam of unidirectional or bidirectional patterns, depending on how the sources are configured inside the enclosure. Our scheme, if achieved, can solve the challenging problem of poor directivity of a subwavelength sound system, and can guide beam forming and collimation by miniaturized devices.

Recombination dominated hydrogenic emission from the detached plasmas in W7-AS

International Nuclear Information System (INIS)

Ramasubramanian, N.; Koenig, R.; Wenzel, U.; Thomsen, H.; McCormick, K.; Grigull, P.; Feng, Y.; Klinger, T.; John, A.

2003-01-01

Beyond a certain threshold average density in the High-Density H-Mode the island divertor plasma in the stellarator W7-AS undergoes partial detachment. The tomographic reconstruction of the radiated power density from the detached pulses show that the radiation profile in the triangular plane is also asymmetric. In the detached phase, the spectrometer viewing tangentially to the target tiles in the top divertor region manifests that the impurity radiation layer is close to the X-points. The spectral analysis also demonstrates the presence of a hydrogen radiation zone dominated by recombination emission close to the target tiles. This papers presents the emission from the deeply detached locations including the volume recombination in a stable discharge. (orig.)

THE PHYSICAL PROPERTIES OF HEARTWOOD AND SAPWOOD OF EUCALYPTUS GRANDIS

Directory of Open Access Journals (Sweden)

Bekir Cihad BAL

2012-12-01

Full Text Available In this study, some of the physical propertiesof heartwood and sapwood of Eucalyptus grandisgrown in Karabucak, Turkey were determined. Thephysical properties determined were air-drieddensity, oven-dried density, basic density, shrinkage,swelling, fiber saturation point, and maximummoisture content. According to the test results, thephysical properties of the heartwood samplesdiffered from those of the sapwood samples due tothe presence of high proportion of juvenile wood inthe heartwood. It can be said that the shrinkage andswelling percentages were better for heartwood thansapwood. Air-dried density, oven-dried density, andbasic density of sapwood were higher than those ofheartwood.

EARLY EMISSION FROM TYPE Ia SUPERNOVAE

International Nuclear Information System (INIS)

Rabinak, Itay; Waxman, Eli; Livne, Eli

2012-01-01

A unique feature of deflagration-to-detonation (DDT) white dwarf explosion models of supernovae of type Ia is the presence of a strong shock wave propagating through the outer envelope. We consider the early emission expected in such models, which is produced by the expanding shock-heated outer part of the ejecta and precedes the emission driven by radioactive decay. We expand on earlier analyses by considering the modification of the pre-detonation density profile by the weak shocks generated during the deflagration phase, the time evolution of the opacity, and the deviation of the post-shock equation of state from that obtained for radiation pressure domination. A simple analytic model is presented and shown to provide an acceptable approximation to the results of one-dimensional numerical DDT simulations. Our analysis predicts a ∼10 3 s long UV/optical flash with a luminosity of ∼1 to ∼3 × 10 39 erg s –1 . Lower luminosity corresponds to faster (turbulent) deflagration velocity. The luminosity of the UV flash is predicted to be strongly suppressed at t > t drop ∼ 1 hr due to the deviation from pure radiation domination.

PAH emissions from old and new types of domestic hot water boilers.

Science.gov (United States)

Horak, Jiri; Kubonova, Lenka; Krpec, Kamil; Hopan, Frantisek; Kubesa, Petr; Motyka, Oldrich; Laciok, Vendula; Dej, Milan; Ochodek, Tadeas; Placha, Daniela

2017-06-01

Five different domestic heating boilers (automatic, over-fire, with down-draft combustion and gasification) and three types of fuel (lignite, wood and mixed fuel) were examined in 25 combustion tests and correlated with the emissions of particulate matter (PM), carbon monoxide (CO), total organic carbon (TOC) and 12 polycyclic aromatic hydrocarbons (PAHs with MW = 178-278 g/mol) focusing on particle phase. However, the distribution of 12 PAHs in gas phase was considered as well due to the presence mainly of lighter PAHs in gas phase. The PAHs, as well as the CO and TOC, are the indicators of incomplete combustion, and in this study PAH emission increased significantly with increasing emissions of CO and TOC. The PAHs were mainly detected on PM 2.5 , their contents were increasing linearly with increasing PM 2.5 emissions. The highest emission factors of PAHs were measured for boilers of old construction, such as over-fire boiler (5.8-929 mg/kg) and boiler with down-draft combustion (3.1-54.1 mg/kg). Modern types of boilers produced much lower emissions of PAHs, in particular, automatic boiler (0.3-3.3 mg/kg) and gasification boilers (0.2-6.7 mg/kg). In general, the inefficient combustion at reduced output of boilers generated 1.4-17.7 times more emissions of PAHs than the combustion at nominal output of boilers. It is recommended to operate boilers at nominal output with sufficient air supply and to use the proper fuel to minimise PAHs emissions from domestic heating appliances. Copyright © 2017 Elsevier Ltd. All rights reserved.

Cross-Correlations in Quasar Radio Emission

Science.gov (United States)

Nefedyev, Yuri; Panischev, Oleg; Demin, Sergey

The main factors forming the complex evolution of the accretive astrophysical systems are nonlinearity, intermittency, nonstationarity and also collective phenomena. To discover the dynamic processes in these objects and to detain understanding their properties we need to use all the applicable analyzing methods. Here we use the Flicker-Noise Spectroscopy (FNS) as a phenomenological approach to analyzing and parameterizing the auto- and cross-correlations in time series of astrophysical objects dynamics. As an example we consider the quasar flux radio spectral density at frequencies 2.7 GHz and 8.1 GHz. Data have been observed by Dr. N. Tanizuka (Laboratory for Complex Systems Analysis, Osaka Prefecture University) in a period of 1979 to 1988 (3 309 days). According to mental habits quasar is a very energetic and distant active galactic nucleus containing a supermassive black hole by size 10-10,000 times the Schwarzschild radius. The quasar is powered by an accretion disc around the black hole. The accretion disc material layers, moving around the black hole, are under the influence of gravitational and frictional forces. It results in raising the high temperature and arising the resonant and collective phenomena reflected in quasar emission dynamics. Radio emission dynamics of the quasar 0215p015 is characterized by three quasi-periodic processes, which are prevalent in considering dynamics. By contrast the 1641p399's emission dynamics have not any distinguish processes. It means the presence of high intermittency in accretive modes. The second difference moment allows comparing the degree of manifesting of resonant and chaotic components in initial time series of the quasar radio emission. The comparative analysis shows the dominating of chaotic part of 1641p399's dynamics whereas the radio emission of 0215p015 has the predominance of resonant component. Analyzing the collective features of the quasar radio emission intensity demonstrates the significant

Experimental and theoretical study on field emission properties of zinc oxide nanoparticles decorated carbon nanotubes

International Nuclear Information System (INIS)

Li Xin; Zhou Wei-Man; Liu Wei-Hua; Wang Xiao-Li

2015-01-01

Field emission properties of zinc oxide (ZnO) nanoparticles (NPs) decorated carbon nanotubes (CNTs) are investigated experimentally and theoretically. CNTs are in situ decorated with ZnO NPs during the growth process by chemical vapor deposition using a carbon source from the iron phthalocyanine pyrolysis. The experimental field emission test shows that the ZnO NP decoration significantly improves the emission current from 50 μA to 275 μA at 550 V and the reduced threshold voltage from 450 V to 350 V. The field emission mechanism of ZnO NPs on CNTs is theoretically studied by the density functional theory (DFT) combined with the Penn–Plummer method. The ZnO NPs reconstruct the ZnO–CNT structure and pull down the surface barrier of the entire emitter system to 0.49 eV so as to reduce the threshold electric field. The simulation results suggest that the presence of ZnO NPs would increase the LDOS near the Fermi level and increase the emission current. The calculation results are consistent with the experiment results. (paper)

Mitigation of gaseous Mercury Emissions from Waste-to-Energy Facilities: Homogeneous and Heterogeneous Hg-Oxidation Pathways in Presence of Fly Ash.

Czech Academy of Sciences Publication Activity Database

Rumayor, Marta; Svoboda, Karel; Švehla, Jaroslav; Pohořelý, Michael; Šyc, Michal

Roč. 206, JAN 15 ( 2018 ), s. 276-283 ISSN 0301-4797 R&D Projects: GA TA ČR TE02000236 Institutional support: RVO:67985858 Keywords : mercury * emission * waste incineration Subject RIV: DI - Air Pollution ; Quality OBOR OECD: Environmental sciences (social aspects to be 5.7) Impact factor: 4.010, year: 2016

Mitigation of gaseous Mercury Emissions from Waste-to-Energy Facilities: Homogeneous and Heterogeneous Hg-Oxidation Pathways in Presence of Fly Ash.

Czech Academy of Sciences Publication Activity Database

Rumayor, Marta; Svoboda, Karel; Švehla, Jaroslav; Pohořelý, Michael; Šyc, Michal

2018-01-01

Roč. 206, JAN 15 (2018), s. 276-283 ISSN 0301-4797 R&D Projects: GA TA ČR TE02000236 Institutional support: RVO:67985858 Keywords : mercury * emission * waste incineration Subject RIV: DI - Air Pollution ; Quality OBOR OECD: Environmental sciences (social aspects to be 5.7) Impact factor: 4.010, year: 2016

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

Autonomous mobile platform for monitoring air emissions from industrial and municipal wastewater ponds.

Science.gov (United States)

Fu, Long; Huda, Quamrul; Yang, Zheng; Zhang, Lucas; Hashisho, Zaher

2017-11-01

Significant amounts of volatile organic compounds and greenhouse gases are generated from wastewater lagoons and tailings ponds in Alberta, Canada. Accurate measurements of these air pollutants and greenhouse gases are needed to support management and regulatory decisions. A mobile platform was developed to measure air emissions from tailings pond in the oil sands region of Alberta. The mobile platform was tested in 2015 in a municipal wastewater treatment lagoon. With a flux chamber and a CO 2 /CH 4 sensor on board, the mobile platform was able to measure CO 2 and CH 4 emissions over two days at two different locations in the pond. Flux emission rates of CO 2 and CH 4 that were measured over the study period suggest the presence of aerobic and anaerobic zones in the wastewater treatment lagoon. The study demonstrated the capabilities of the mobile platform in measuring fugitive air emissions and identified the potential for the applications in air and water quality monitoring programs. The Mobile Platform demonstrated in this study has the ability to measure greenhouse gas (GHG) emissions from fugitive sources such as municipal wastewater lagoons. This technology can be used to measure emission fluxes from tailings ponds with better detection of spatial and temporal variations of fugitive emissions. Additional air and water sampling equipment could be added to the mobile platform for a broad range of air and water quality studies in the oil sands region of Alberta.

Acid emissions monitoring needs in ceramic tile industry: challenges derived from new policy trends

Science.gov (United States)

Celades, Irina; Gomar, Salvador; Romero, Fernando; Chauhan, Amisha; Delpech, Bertrand; Jouhara, Hussam

2017-11-01

The emission of acid compounds during the manufacture of ceramic tiles is strongly related to the presence of precursors in the raw materials and/or fuels used, with some exceptions such as the production of thermal NOX. The stages with the potential to produce significant emissions of these compounds have been identified as the suspension spray drying and tile firing stages. The monitoring of emission levels of acid pollutants in these stages has turned in a great importance issue from a regulatory and industrial aspect. The DREAM project (https://www.spire2030.eu/dream) will tackle the regulation of acidic emissions focusing in the firing stage. The initial stages of the project have made it possible to identify the design requirements for the monitoring system. This will allow the control of acid pollutants emissions and other key parameters such as pressure, flow, temperature and humidity. One of the tasks developed has been the review and compilation of current emissions monitoring systems detailing technical specifications such as: position (in situ or extractive), measurement principle and frequency. The future policy trends in air pollution are encouraging the continuous monitoring across the European industry. The present document assesses the advantages regarding environmental impact control, highlighting the main challenges for the ceramic tile industry.

Objective Characterization of Snow Microstructure for Microwave Emission Modeling

Science.gov (United States)

Durand, Michael; Kim, Edward J.; Molotch, Noah P.; Margulis, Steven A.; Courville, Zoe; Malzler, Christian

2012-01-01

Passive microwave (PM) measurements are sensitive to the presence and quantity of snow, a fact that has long been used to monitor snowcover from space. In order to estimate total snow water equivalent (SWE) within PM footprints (on the order of approx 100 sq km), it is prerequisite to understand snow microwave emission at the point scale and how microwave radiation integrates spatially; the former is the topic of this paper. Snow microstructure is one of the fundamental controls on the propagation of microwave radiation through snow. Our goal in this study is to evaluate the prospects for driving the Microwave Emission Model of Layered Snowpacks with objective measurements of snow specific surface area to reproduce measured brightness temperatures when forced with objective measurements of snow specific surface area (S). This eliminates the need to treat the grain size as a free-fit parameter.

Ten per cent polarized optical emission from GRB 090102.

Science.gov (United States)

Steele, I A; Mundell, C G; Smith, R J; Kobayashi, S; Guidorzi, C

2009-12-10

The nature of the jets and the role of magnetic fields in gamma-ray bursts (GRBs) remains unclear. In a baryon-dominated jet only weak, tangled fields generated in situ through shocks would be present. In an alternative model, jets are threaded with large-scale magnetic fields that originate at the central engine and that accelerate and collimate the material. To distinguish between the models the degree of polarization in early-time emission must be measured; however, previous claims of gamma-ray polarization have been controversial. Here we report that the early optical emission from GRB 090102 was polarized at 10 +/- 1 per cent, indicating the presence of large-scale fields originating in the expanding fireball. If the degree of polarization and its position angle were variable on timescales shorter than our 60-second exposure, then the peak polarization may have been larger than ten per cent.

The political economy of emissions trading; L'economie politique des marches de permis d'emissions negociables

Energy Technology Data Exchange (ETDEWEB)

Hanoteau, J

2004-06-15

This thesis is a positive analysis of emissions trading systems' implementation. We explain why allowances are generally granted for free even though normative economic analysis recommends their sale. We show empirically that free tradable permits, source of windfall profit, motivate rent seeking behaviours. The study focuses on the US market for SO{sub 2} emissions allowances. The initial allocation rule resulted from parliamentary discussions that looked like a zero sum game. We formalize it as an endogenous sharing rule, function of lobbying effort, and we test it using political (money) contributions.We analyse theoretically the behaviour of an influenced regulator that has chosen to organize a market for permits and that must still decide on two policy variables: the whole quantity of permits and the way to allocate them initially. We formalize this decisions making process with the common agency model of politics.We show that the choice of an initial allocation rule is not neutral in presence of political market failures (lobbying). The decision to sell the permits or to grant them for free modifies the shareholders' incentive, in a polluting industry, to pressure for or against the reduction of legal emissions.Then, we analyse the public arbitration between the two policy variables when several industrial lobbies play a partially cooperative game for the free permits. The regulator chooses in priority to grant the rights for free rather than to manipulate their quantity, and this constitutes an efficient answer to the political influence. (author)

Time-resolved pulse-counting lock-in detection of laser induced fluorescence in the presence of a strong background emission

International Nuclear Information System (INIS)

Pelissier, B.; Sadeghi, N.

1996-01-01

We describe a time-resolved pulse-counting system well adapted for the detection of continuous laser induced fluorescence (LIF) signals in repetitive phenomena, when a strong background emission is present. It consists of 256 channels coupled to a first in first out memory and interfaced to a 486 DX 33 PC, for data storage. It accepts time-averaged count rates up to 450 kcount/s. Time between channels can be set from 12.5 ns to several μs and the dead time between two consecutive cycles of the physical phenomena is less than 20 ns. In phase with a chopper, which modulates the laser beam, it adds the observed photon signal to the channel memories when the beam is on and substracts it when the beam is stopped, acting like a lock-in amplifier which detect only the modulated part of the signal. The minimum detectivity on the LIF signal is only limited by the shot noise of the plasma induced emission signal. As an application, we studied the time variation of the Ar + *( 2 G 9/2 ) metastable ions, detected by LIF, in two types of plasmas. Their radiative lifetime and collisional quenching frequencies were deduced from their decay rate in the afterglow of a pulsed Helicon reactor. We also observed the evolution of their density in a 455 kHz capacitively coupled argon discharge. copyright 1996 American Institute of Physics

Emissions Models and Other Methods to Produce Emission Inventories

Science.gov (United States)

An emissions inventory is a summary or forecast of the emissions produced by a group of sources in a given time period. Inventories of air pollution from mobile sources are often produced by models such as the MOtor Vehicle Emission Simulator (MOVES).

Plasma emission mechanisms

International Nuclear Information System (INIS)

Melrose, D.B.

1985-01-01

Only three emission processes are thought to play a role in solar radio emission: plasma emission, gyromagnetic emission and bremsstrahlung. In this chapter plasma emission is discussed and the processes involved in its production are treated, namely, the generation of Langmuir turbulence, the partial conversion into fundamental transverse radiation, production of secondary Langmuir waves and the generation of second-harmonic transverse radiation. (U.K.)

Prompt neutron emission; Emission des neutrons prompts de fission

Energy Technology Data Exchange (ETDEWEB)

Sher, R [Commissariat a l' Energie Atomique, Saclay (France).Centre d' Etudes Nucleaires

1959-07-01

It is shown that Ramanna and Rao's tentative conclusion that prompt fission neutrons are emitted (in the fragment system) preferentially in the direction of fragment motion is not necessitated by their angular distribution measurements, which are well explained by the usual assumptions of isotropic emission with a Maxwell (or Maxwell-like) emission spectrum. The energy distribution (Watt spectrum) and the angular distribution, both including the effects of anisotropic emission, are given. (author) [French] On montre que la conclusion experimentale de Ramanna et Rao selon laquelle les neutrons prompts de fission sont emis (dans le systeme de reference des fragments) preferentiellement dans la direction du mouvement du fragment, ne decoule pas necessairement de leurs mesures de distribution angulaire. Celles-ci sont bien expliquees par l'hypothese classique de l'emission isotrope et d'un spectre d'emission maxwellien (ou quasi-maxwellien). On donne la distribution en energie (ou spectre de Watt) et la distribution angulaire, comprenant toutes les deux les effets d'emission anisotrope. (auteur)

'Presence' of the past in the presence (Hans Ulrich Gumbrecht, Eelco Runia)

NARCIS (Netherlands)

ter Schure, L

2006-01-01

In recent writings historian Eelco Runia (Groningen) and literary theorist Hans Ulrich Gumbrecht (Stanford) have introduced the notion of presence, a new and promising way of thinking about history. Although there are differences between the two authors, both think of presence as the antithesis of

Emissions of chromium (VI) from arc welding.

Science.gov (United States)

Heung, William; Yun, Myoung-Jin; Chang, Daniel P Y; Green, Peter G; Halm, Chris

2007-02-01

The presence of Cr in the +6 oxidation state (Cr[VI]) is still observed in ambient air samples in California despite steps taken to reduce emissions from plating operations. One known source of emission of Cr(VI) is welding, especially with high Cr-content materials, such as stainless steels. An experimental effort was undertaken to expand and update Cr(VI) emission factors by conducting tests on four types of arc-welding operations: gas-metal arc welding (GMAW), shielded metal arc welding (SMAW), fluxcore arc welding, and pulsed GMAW. Standard American Welding Society hood results were compared with a total enclosure method that permitted isokinetic sampling for particle size-cut measurement, as well as total collection of the aerosol. The fraction of Cr(VI) emitted per unit mass of Cr electrode consumed was determined. Consistent with AP-42 data, initial results indicate that a significant fraction of the total Cr in the aerosol is in the +6 oxidation state. The fraction of Cr(VI) and total aerosol mass produced by the different arc welding methods varies with the type of welding process used. Self-shielded electrodes that do not use a shield gas, for example, SMAW, produce greater amounts of Cr(VI) per unit mass of electrode consumed. The formation of Cr(VI) from standard electrode wires used for welding mild steel was below the method detection limit after eliminating an artifact in the analytical method used.

Electromagnetic Ion Cyclotron Waves in the Helium Branch Induced by Multiple Electromagnetic Ion Cyclotron Triggered Emissions

Science.gov (United States)

Shoji, M.; Omura, Y.; Grison, B.; Pickett, J. S.; Dandouras, I. S.; Engebretson, M. J.

2011-12-01

Electromagnetic ion cyclotron (EMIC) triggered emissions with rising tones between the H+ and He+ cyclotron frequencies were found in the inner magnetosphere by the recent Cluster observations. Another type of EMIC wave with a constant frequency is occasionally observed below the He+ cyclotron frequency after the multiple EMIC triggered emissions. We performed a self-consistent hybrid simulation with a one-dimensional cylindrical magnetic flux model approximating the dipole magnetic field of the Earth's inner magnetosphere. In the presence of energetic protons with a sufficient density and temperature anisotropy, multiple EMIC triggered emissions are reproduced due to the nonlinear wave growth mechanism of rising-tone chorus emissions, and a constant frequency wave in the He+ EMIC branch is subsequently generated. Through interaction with the multiple EMIC rising-tone emissions, the velocity distribution function of the energetic protons is strongly modified. Because of the pitch angle scattering of the protons, the gradient of the distribution in velocity phase space is enhanced along the diffusion curve of the He+ branch wave, resulting in the linear growth of the EMIC wave in the He+ branch.

Biomass burning - Combustion emissions, satellite imagery, and biogenic emissions

Science.gov (United States)

Levine, Joel S.; Cofer, Wesley R., III; Winstead, Edward L.; Rhinehart, Robert P.; Cahoon, Donald R., Jr.; Sebacher, Daniel I.; Sebacher, Shirley; Stocks, Brian J.

1991-01-01

After detailing a technique for the estimation of the instantaneous emission of trace gases produced by biomass burning, using satellite imagery, attention is given to the recent discovery that burning results in significant enhancement of biogenic emissions of N2O, NO, and CH4. Biomass burning accordingly has an immediate and long-term impact on the production of atmospheric trace gases. It is presently demonstrated that satellite imagery of fires may be used to estimate combustion emissions, and could be used to estimate long-term postburn biogenic emission of trace gases to the atmosphere.

Strategic partitioning of emission allowances under the EU Emission Trading Scheme

Energy Technology Data Exchange (ETDEWEB)

Boehringer, Christoph [Univ. of Oldenburg, Department of Economics, and Centre for European Economic Research (ZEW) (Germany); Rosendahl, Knut Einar [Statistics Norway, Research Department, Pob. 8131 Dep., N-0033 Oslo (Norway)

2009-08-15

The EU Emission Trading Scheme (ETS) is breaking new ground in the experience with emission trading regimes across multiple jurisdictions. Since the EU ETS covers only some industries, it implies a hybrid emission control scheme where EU member states must apply complementary domestic emissions regulation for the non-trading sectors of their economies in order to comply with their national emission reduction targets. The EU ETS thus opens up for strategic partitioning of national emissions budgets by the member states between trading and non-trading sectors. In this paper we examine the potential effects of such strategic behavior on compliance cost and emissions prices. We show that concerns on efficiency losses from strategic partitioning are misplaced. In turn, our analysis implicitly indicates significant political economy forces behind EU climate policy, as both cost-effective and strategically motivated partitioning of national emission budgets are far off from the actual break-down between trading and non-trading sectors. (author)

Vehicle Emissions Risk Management

International Nuclear Information System (INIS)

Ibrahem, L.G.

2004-01-01

Vehicle emissions are considered as a main source for air pollution. Emissions regulation is now well developed in most countries to meet cleaner air quality. Reducing emissions by using cleaner fuels, which meet certain specification, is not enough to get cleaner air, yet the vehicle technology is not improved. Here we will outline the following: - development in fuel specification and emissions regulation. main facts linking vehicle emissions, fuel properties and air quality. catalytic converter technology. Emissions sources: In modem cities, vehicle traffic is potentially a major source of emissions. However sometimes other sources of emissions from industry and other stationary sources can be equally important and include emissions that are of greater toxicity than those from vehicles

Evidence for involvement of gut-associated denitrifying bacteria in emission of nitrous oxide (N(2)O) by earthworms obtained from garden and forest soils.

Science.gov (United States)

Matthies, C; Griesshammer, A; Schmittroth, M; Drake, H L

1999-08-01

Earthworms (Aporrectodea caliginosa, Lumbricus rubellus, and Octolasion lacteum) obtained from nitrous oxide (N(2)O)-emitting garden soils emitted 0.14 to 0.87 nmol of N(2)O h(-1) g (fresh weight)(-1) under in vivo conditions. L. rubellus obtained from N(2)O-emitting forest soil also emitted N(2)O, which confirmed previous observations (G. R. Karsten and H. L. Drake, Appl. Environ. Microbiol. 63:1878-1882, 1997). In contrast, commercially obtained Lumbricus terrestris did not emit N(2)O; however, such worms emitted N(2)O when they were fed (i.e., preincubated in) garden soils. A. caliginosa, L. rubellus, and O. lacteum substantially increased the rates of N(2)O emission of garden soil columns and microcosms. Extrapolation of the data to in situ conditions indicated that N(2)O emission by earthworms accounted for approximately 33% of the N(2)O emitted by garden soils. In vivo emission of N(2)O by earthworms obtained from both garden and forest soils was greatly stimulated when worms were moistened with sterile solutions of nitrate or nitrite; in contrast, ammonium did not stimulate in vivo emission of N(2)O. In the presence of nitrate, acetylene increased the N(2)O emission rates of earthworms; in contrast, in the presence of nitrite, acetylene had little or no effect on emission of N(2)O. In vivo emission of N(2)O decreased by 80% when earthworms were preincubated in soil supplemented with streptomycin and tetracycline. On a fresh weight basis, the rates of N(2)O emission of dissected earthworm gut sections were substantially higher than the rates of N(2)O emission of dissected worms lacking gut sections, indicating that N(2)O production occurred in the gut rather than on the worm surface. In contrast to living earthworms and gut sections that produced N(2)O under oxic conditions (i.e., in the presence of air), fresh casts (feces) from N(2)O-emitting earthworms produced N(2)O only under anoxic conditions. Collectively, these results indicate that gut

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....

Flooding-related increases in CO2 and N2O emissions from a temperate coastal grassland ecosystem

Science.gov (United States)

Gebremichael, Amanuel W.; Osborne, Bruce; Orr, Patrick

2017-05-01

Given their increasing trend in Europe, an understanding of the role that flooding events play in carbon (C) and nitrogen (N) cycling and greenhouse gas (GHG) emissions will be important for improved assessments of local and regional GHG budgets. This study presents the results of an analysis of the CO2 and N2O fluxes from a coastal grassland ecosystem affected by episodic flooding that was of either a relatively short (SFS) or long (LFS) duration. Compared to the SFS, the annual CO2 and N2O emissions were 1.4 and 1.3 times higher at the LFS, respectively. Mean CO2 emissions during the period of standing water were 144 ± 18.18 and 111 ± 9.51 mg CO2-C m-2 h-1, respectively, for the LFS and SFS sites. During the growing season, when there was no standing water, the CO2 emissions were significantly larger from the LFS (244 ± 24.88 mg CO2-C m-2 h-1) than the SFS (183 ± 14.90 mg CO2-C m-2 h-1). Fluxes of N2O ranged from -0.37 to 0.65 mg N2O-N m-2 h-1 at the LFS and from -0.50 to 0.55 mg N2O-N m-2 h-1 at the SFS, with the larger emissions associated with the presence of standing water at the LFS but during the growing season at the SFS. Overall, soil temperature and moisture were identified as the main drivers of the seasonal changes in CO2 fluxes, but neither adequately explained the variations in N2O fluxes. Analysis of total C, N, microbial biomass and Q10 values indicated that the higher CO2 emissions from the LFS were linked to the flooding-associated influx of nutrients and alterations in soil microbial populations. These results demonstrate that annual CO2 and N2O emissions can be higher in longer-term flooded sites that receive significant amounts of nutrients, although this may depend on the restriction of diffusional limitations due to the presence of standing water to periods of the year when the potential for gaseous emissions are low.

Stepwise multiple regression method of greenhouse gas emission modeling in the energy sector in Poland.

Science.gov (United States)

Kolasa-Wiecek, Alicja

2015-04-01

The energy sector in Poland is the source of 81% of greenhouse gas (GHG) emissions. Poland, among other European Union countries, occupies a leading position with regard to coal consumption. Polish energy sector actively participates in efforts to reduce GHG emissions to the atmosphere, through a gradual decrease of the share of coal in the fuel mix and development of renewable energy sources. All evidence which completes the knowledge about issues related to GHG emissions is a valuable source of information. The article presents the results of modeling of GHG emissions which are generated by the energy sector in Poland. For a better understanding of the quantitative relationship between total consumption of primary energy and greenhouse gas emission, multiple stepwise regression model was applied. The modeling results of CO2 emissions demonstrate a high relationship (0.97) with the hard coal consumption variable. Adjustment coefficient of the model to actual data is high and equal to 95%. The backward step regression model, in the case of CH4 emission, indicated the presence of hard coal (0.66), peat and fuel wood (0.34), solid waste fuels, as well as other sources (-0.64) as the most important variables. The adjusted coefficient is suitable and equals R2=0.90. For N2O emission modeling the obtained coefficient of determination is low and equal to 43%. A significant variable influencing the amount of N2O emission is the peat and wood fuel consumption. Copyright © 2015. Published by Elsevier B.V.

Biogenic emissions of isoprenoids and NO in China and comparison to anthropogenic emissions

International Nuclear Information System (INIS)

Tie Xuexi; Li Guohui; Ying, Zhuming; Guenther, Alex; Madronich, Sasha

2006-01-01

In this study, a regional dynamical model (WRF) is used to drive biogenic emission models to calculate high resolution (10 x 10 km) biogenic emissions of isoprene (C 5 H 8 ), monoterpenes (C 1 H 16 ), and nitric oxide (NO) in China. This high resolution biogenic inventory will be available for the community to study the effect of biogenic emissions on photochemical oxidants in China. The biogenic emissions are compared to anthropogenic emissions to gain insight on the potential impact of the biogenic emissions on tropospheric chemistry, especially ozone production in this region. The results show that the biogenic emissions in China exhibit strongly diurnal, seasonal, and spatial variations. The isoprenoid (including both isoprene and monoterpenes) emissions are closely correlated to tree density and strongly vary with season and local time. During winter (January), the biogenic isoprenoid emissions are the lowest, resulting from lower temperature and solar radiation, and highest in summer (July) due to higher temperature and solar radiation. The biogenic NO emissions are also higher during summer and lower during winter, but the magnitude of the seasonal variation is smaller than the emissions of isoprene and monoterpenes. The biogenic emissions of NO are widely spread out in the northern, eastern, and southern China regions, where high-density agricultural soil lands are located. Both biogenic NO and isoprenoid emissions are very small in western China. The calculated total biogenic emission budget is smaller than the total anthropogenic VOC emission budget in China. The biogenic isoprenoid and anthropogenic VOC emissions are 10.9 and 15.1 Tg year -1 , respectively. The total biogenic and anthropogenic emissions of NO are 5.9 and 11.5 Tg(NO) year -1 , respectively. The study shows that in central eastern China, the estimated biogenic emissions of isoprenoids are very small, and the anthropogenic emissions of VOCs are dominant in this region. However, in

Biogenic emissions of isoprenoids and NO in China and comparison to anthropogenic emissions.

Science.gov (United States)

Tie, Xuexi; Li, Guohui; Ying, Zhuming; Guenther, Alex; Madronich, Sasha

2006-12-01

In this study, a regional dynamical model (WRF) is used to drive biogenic emission models to calculate high resolution (10x10 km) biogenic emissions of isoprene (C(5)H(8)), monoterpenes (C(10)H(16)), and nitric oxide (NO) in China. This high resolution biogenic inventory will be available for the community to study the effect of biogenic emissions on photochemical oxidants in China. The biogenic emissions are compared to anthropogenic emissions to gain insight on the potential impact of the biogenic emissions on tropospheric chemistry, especially ozone production in this region. The results show that the biogenic emissions in China exhibit strongly diurnal, seasonal, and spatial variations. The isoprenoid (including both isoprene and monoterpenes) emissions are closely correlated to tree density and strongly vary with season and local time. During winter (January), the biogenic isoprenoid emissions are the lowest, resulting from lower temperature and solar radiation, and highest in summer (July) due to higher temperature and solar radiation. The biogenic NO emissions are also higher during summer and lower during winter, but the magnitude of the seasonal variation is smaller than the emissions of isoprene and monoterpenes. The biogenic emissions of NO are widely spread out in the northern, eastern, and southern China regions, where high-density agricultural soil lands are located. Both biogenic NO and isoprenoid emissions are very small in western China. The calculated total biogenic emission budget is smaller than the total anthropogenic VOC emission budget in China. The biogenic isoprenoid and anthropogenic VOC emissions are 10.9 and 15.1 Tg year(-1), respectively. The total biogenic and anthropogenic emissions of NO are 5.9 and 11.5 Tg(NO) year(-1), respectively. The study shows that in central eastern China, the estimated biogenic emissions of isoprenoids are very small, and the anthropogenic emissions of VOCs are dominant in this region. However, in

Emission characterization and evaluation of natural gas-fueled cogeneration microturbines and internal combustion engines

International Nuclear Information System (INIS)

Canova, Aldo; Chicco, Gianfranco; Genon, Giuseppe; Mancarella, Pierluigi

2008-01-01

The increasing diffusion of small-scale energy systems within the distributed generation (DG) paradigm is raising the need for studying the environmental impact due to the different DG solutions in order to assess their sustainability. Addressing the environmental impact calls for building specific models for studying both local and global emissions. In this framework, the adoption of natural gas-fueled DG cogeneration technologies may provide, as a consequence of cogeneration enhanced overall energy efficiency and of natural gas relatively low carbon content, a significant reduction of global impact in terms of CO 2 emissions with respect to the separate production of electricity and heat. However, a comprehensive evaluation of the DG alternatives should take into account as well the impact due to the presence of plants spread over the territory that could increase the local pollution, in particular due to CO and NO x , and thus could worsen the local air quality. This paper provides an overview on the characterization of the emissions from small-scale natural gas-fueled cogeneration systems, with specific reference to the DG technologies nowadays most available in the market, namely, microturbines and internal combustion engines. The corresponding local and global environmental impacts are evaluated by using the emission balance approach. A numerical case study with two representative machines highlights their different emission characteristics, also considering the partial-load emission performance

Physical and morphological properties of z ~ 3 Lyman break galaxies: dependence on Lyα line emission

Science.gov (United States)

Pentericci, L.; Grazian, A.; Scarlata, C.; Fontana, A.; Castellano, M.; Giallongo, E.; Vanzella, E.

2010-05-01

Aims: We investigate the physical and morphological properties of Lyman break galaxies (LBGs) at redshift ~2.5 to ~3.5, to determine if and how they depend on the nature and strength of the Lyα emission. Methods: We selected U-dropout galaxies from the z-detected GOODS-MUSIC catalog by adapting the classical Lyman break criteria on the GOODS filter set. We kept only those galaxies with spectroscopic confirmation, mainly from VIMOS and FORS public observations. Using the full multi-wavelength 14-bands information (U to IRAC), we determined the physical properties of the galaxies through a standard spectral energy distribution fitting procedure with the updated Charlot & Bruzual (2009) templates. We also added other relevant observations of the GOODS field, i.e. the 24 μm observations from Spitzer/MIPS and the 2 MSec Chandra X-ray observations. Finally, using non parametric diagnostics (Gini, Concentration, Asymmetry, M20 and ellipticity), we characterized the rest-frame UV morphologies of the galaxies. We then analyzed how these physical and morphological properties correlate with the presence of the Lyα emission line in the optical spectra. Results: We find that unlike at higher redshift, the dependence of physical properties on the Lyα line is milder: galaxies without Lyα in emission tend to be more massive and dustier than the rest of the sample, but all other parameters, ages, star formation rates (SFR), X-ray emission and UV morphology do not depend strongly on the presence of the Lyα emission. A simple scenario where all LBGs have intrinsically high Lyα emission, but where the dust and neutral hydrogen content (which shapes the final appearance of the Lyα) depend on the mass of the galaxies, is able to reproduce the majority of the observed properties at z˜3. Some modification might be needed to account for the observed evolution of these properties with cosmic epoch, which is also discussed.

Suppression of nitrogen oxides emission by carbonaceous reductants

International Nuclear Information System (INIS)

Tomita, A.

2001-01-01

The present status of NO x emission from power stations and automobiles is first summarized, and the controlling regulations in respective areas are reviewed. In spite of much progress, we have to further reduce the NO x emission in all the areas. In order to develop more effective technology, the fundamental understanding of the relevant reactions is essential. The heterogeneous reactions, like NO x and N 2 O formation from coal char, NO x and N 2 O reduction with carbon, and NO x reduction with hydrocarbon gases over heterogeneous catalysts are not well understood yet. This paper briefly summarizes our recent studies on the heterogeneous reactions of NO x formation and destruction. The importance of surface nitrogen species is emphasized in all the reaction systems. The presence of such surface species plays a very important role, not only in NO x destruction on carbon surfaces, but also in the NO x release during coal char combustion. Finally, future research areas are identified, where we need to understand what actually happens under high-temperature reaction conditions

Causality between income and emission. A country group-specific econometric analysis

International Nuclear Information System (INIS)

Coondoo, Dipankor; Dinda, Soumyananda

2002-01-01

Empirical studies of the Environmental Kuznets Curve (EKC) examine the presence or otherwise of an inverted U-shaped relationship between the level of pollution and the level of income. Customarily, in the diagram of EKC the level of income is shown on the horizontal axis and that of pollution on the vertical axis. Thus, it is presumed that the relationship between income and pollution is one of unidirectional causality with income causing environmental changes and not vice versa. The validity of this presumption is now being questioned. It is being asserted that the nature and direction of causality may vary from one country to the other. In this paper, we present the results of a study of income-CO 2 emission causality based on a Granger causality test to cross-country panel data on per capita income and the corresponding per capita CO 2 emission data. Briefly, our results indicate three different types of causality relationship holding for different country groups. For the developed country groups of North America and Western Europe (and also for Eastern Europe) the causality is found to run from emission to income. For the country groups of Central and South America, Oceania and Japan causality from income to emission is obtained. Finally, for the country groups of Asia and Africa the causality is found to be bi-directional. The regression equations estimated as part of the Granger causality test further suggest that for the country groups of North America and Western Europe the growth rate of emission has become stationary around a zero mean, and a shock in the growth rate of emission tends to generate a corresponding shock in the growth rate of income. In contrast, for the country groups of Central and South America, Oceania and Japan a shock in the income growth rate is likely to result in a corresponding shock in the growth rate of emission. Finally, causality being bi-directional for the country groups of Asia and Africa, the income and the emission growth

Causality between income and emission. A country group-specific econometric analysis

Energy Technology Data Exchange (ETDEWEB)

Coondoo, Dipankor [Economic Research Unit, Indian Statistical Institute, 203 B.T. Road, 35 Kolkata (India); Dinda, Soumyananda [S.R. Fatepuria College, Beldanga, West Bengal, Murshidabad (India)

2002-03-01

Empirical studies of the Environmental Kuznets Curve (EKC) examine the presence or otherwise of an inverted U-shaped relationship between the level of pollution and the level of income. Customarily, in the diagram of EKC the level of income is shown on the horizontal axis and that of pollution on the vertical axis. Thus, it is presumed that the relationship between income and pollution is one of unidirectional causality with income causing environmental changes and not vice versa. The validity of this presumption is now being questioned. It is being asserted that the nature and direction of causality may vary from one country to the other. In this paper, we present the results of a study of income-CO{sub 2} emission causality based on a Granger causality test to cross-country panel data on per capita income and the corresponding per capita CO{sub 2} emission data. Briefly, our results indicate three different types of causality relationship holding for different country groups. For the developed country groups of North America and Western Europe (and also for Eastern Europe) the causality is found to run from emission to income. For the country groups of Central and South America, Oceania and Japan causality from income to emission is obtained. Finally, for the country groups of Asia and Africa the causality is found to be bi-directional. The regression equations estimated as part of the Granger causality test further suggest that for the country groups of North America and Western Europe the growth rate of emission has become stationary around a zero mean, and a shock in the growth rate of emission tends to generate a corresponding shock in the growth rate of income. In contrast, for the country groups of Central and South America, Oceania and Japan a shock in the income growth rate is likely to result in a corresponding shock in the growth rate of emission. Finally, causality being bi-directional for the country groups of Asia and Africa, the income and the

Laparoscopic Scar: a mimicker of Sister Mary Joseph's nodule on positron emission tomography/CT

International Nuclear Information System (INIS)

Setty, B.; Blake, M.A.; Holalkere, N.S.; Blaszkowsky, L.S.; Fischman, A.

2006-01-01

Positron emission tomography/CT is an established imaging method in the diagnosis and staging of cancers. 18 F -fluoro-2-deoxy-D-glucose (FDG) is the most commonly used radiotracer in positron emission tomography/CT. It is a tumour viability agent and usually its uptake within a lesion reflects the presence of a viable tumour tissue. However, false-positive FDG uptake is known to occur in benign processes of either inflammatory or infectious aetiology. We describe FDG uptake at the site of laparoscopic scar that mimicked Sister Mary Joseph's nodule in a patient with gastric adenocarcinoma. Here, the knowledge of the patient's history and subtle imaging findings helped in accurate staging of the patient. In this case report, we emphasize the value of the knowledge of the patient history and awareness of different pitfalls of FDG to achieve a correct diagnosis on positron emission tomography/CT

Biogenic volatile emissions from the soil.

Science.gov (United States)

Peñuelas, J; Asensio, D; Tholl, D; Wenke, K; Rosenkranz, M; Piechulla, B; Schnitzler, J P

2014-08-01

Volatile compounds are usually associated with an appearance/presence in the atmosphere. Recent advances, however, indicated that the soil is a huge reservoir and source of biogenic volatile organic compounds (bVOCs), which are formed from decomposing litter and dead organic material or are synthesized by underground living organism or organs and tissues of plants. This review summarizes the scarce available data on the exchange of VOCs between soil and atmosphere and the features of the soil and particle structure allowing diffusion of volatiles in the soil, which is the prerequisite for biological VOC-based interactions. In fact, soil may function either as a sink or as a source of bVOCs. Soil VOC emissions to the atmosphere are often 1-2 (0-3) orders of magnitude lower than those from aboveground vegetation. Microorganisms and the plant root system are the major sources for bVOCs. The current methodology to detect belowground volatiles is described as well as the metabolic capabilities resulting in the wealth of microbial and root VOC emissions. Furthermore, VOC profiles are discussed as non-destructive fingerprints for the detection of organisms. In the last chapter, belowground volatile-based bi- and multi-trophic interactions between microorganisms, plants and invertebrates in the soil are discussed. © 2014 John Wiley & Sons Ltd.

Commentary Relative to the Emission Spectrum of the Solar Atmosphere: Further Evidence for a Distinct Solar Surface

Directory of Open Access Journals (Sweden)

Robitaille P.-M.

2013-07-01

Full Text Available The chromosphere and corona of the Sun represent tenuous regions which are characterized by numerous optically thin emission lines in the ultraviolet and X-ray bands. When observed from the center of the solar disk outward, these emission lines experience modest brightening as the limb is approached. The intensity of many ultraviolet and X-ray emission lines nearly doubles when observation is extended just beyond the edge of the disk. These findings indicate that the solar body is opaque in this frequency range and that an approximately two fold greater region of the solar atmosphere is being sampled outside the limb. These observations provide strong support for the presence of a distinct solar surface. Therefore, the behavior of the emission lines in this frequency range constitutes the twenty fifth line of evidence that the Sun is comprised of condensed matter

Plasmonic enhancement in upconversion emission of La2O3:Er3+/Yb3+ phosphor via introducing silver metal nanoparticles

Science.gov (United States)

Tiwari, S. P.; Kumar, K.; Rai, V. K.

2015-11-01

In the present work, authors have synthesized silver (Ag) nanoparticle (NP) embedded La2O3:Er3+/Yb3+ powder phosphor. The synthesis method has resulted in silver oxide-lanthanum oxide composite material. Through subsequent heat treatment of sample in pellet form, the silver metal nanoparticles were formed. The presence of plasmonic Ag NPs in the matrix is confirmed by various techniques. Large enhancement in downconversion as well as upconversion emission intensity of Er3+ ions at various concentrations of Ag NPs is obtained. Large enhancement in the upconversion emission intensity is correlated to the reduction in decay time of 4S3/2 level in the presence of Ag NPs, and possible reasons for intensity enhancement are discussed. The application of phosphor in fingermark detection is demonstrated.

Detection of halogenated flame retardants in polyurethane foam by particle induced X-ray emission

International Nuclear Information System (INIS)

Maley, Adam M.; Falk, Kyle A.; Hoover, Luke; Earlywine, Elly B.; Seymour, Michael D.; DeYoung, Paul A.; Blum, Arlene; Stapleton, Heather M.; Peaslee, Graham F.

2015-01-01

A novel application of particle-induced X-ray emission (PIXE) has been developed to detect the presence of chlorinated and brominated flame retardant chemicals in polyurethane foams. Traditional Gas Chromatography–Mass Spectrometry (GC–MS) methods for the detection and identification of halogenated flame retardants in foams require extensive sample preparation and data acquisition time. The elemental analysis of the halogens in polyurethane foam performed by PIXE offers the opportunity to identify the presence of halogenated flame retardants in a fraction of the time and sample preparation cost. Through comparative GC–MS and PIXE analysis of 215 foam samples, excellent agreement between the two methods was obtained. These results suggest that PIXE could be an ideal rapid screening method for the presence of chlorinated and brominated flame retardants in polyurethane foams

Detection of halogenated flame retardants in polyurethane foam by particle induced X-ray emission

Energy Technology Data Exchange (ETDEWEB)

Maley, Adam M.; Falk, Kyle A.; Hoover, Luke; Earlywine, Elly B.; Seymour, Michael D. [Department of Chemistry, Hope College, 35 E. 12th Street, Holland, MI 49423 (United States); DeYoung, Paul A. [Department of Physics, Hope College, 27 Graves Place, Holland, MI 49423 (United States); Blum, Arlene [Green Science Policy Institute, Box 5455, Berkeley, CA 94705 (United States); Stapleton, Heather M. [Nicholas School of the Environment, Duke University, LSRC Box 90328, Durham, NC 27708 (United States); Peaslee, Graham F., E-mail: peaslee@hope.edu [Department of Chemistry, Hope College, 35 E. 12th Street, Holland, MI 49423 (United States)

2015-09-01

A novel application of particle-induced X-ray emission (PIXE) has been developed to detect the presence of chlorinated and brominated flame retardant chemicals in polyurethane foams. Traditional Gas Chromatography–Mass Spectrometry (GC–MS) methods for the detection and identification of halogenated flame retardants in foams require extensive sample preparation and data acquisition time. The elemental analysis of the halogens in polyurethane foam performed by PIXE offers the opportunity to identify the presence of halogenated flame retardants in a fraction of the time and sample preparation cost. Through comparative GC–MS and PIXE analysis of 215 foam samples, excellent agreement between the two methods was obtained. These results suggest that PIXE could be an ideal rapid screening method for the presence of chlorinated and brominated flame retardants in polyurethane foams.

Strongly Coupled Tin-Halide Perovskites to Modulate Light Emission: Tunable 550-640 nm Light Emission (FWHM 36-80 nm) with a Quantum Yield of up to 6.4.

Science.gov (United States)

Chen, Min-Yi; Lin, Jin-Tai; Hsu, Chia-Shuo; Chang, Chung-Kai; Chiu, Ching-Wen; Chen, Hao Ming; Chou, Pi-Tai

2018-05-01

Colloidal perovskite quantum dots represent one of the most promising materials for applications in solar cells and photoluminescences. These devices require a low density of crystal defects and a high yield of photogenerated carriers, which are difficult to realize in tin-halide perovskite because of the intrinsic instability of tin during nucleation. Here, an enhancement in the luminescent property of tin-halide perovskite nanoplates (TPNPs) that are composed of strongly coupled layered structures with the chemical formula of PEA 2 SnX 4 (PEA = C 6 H 5 (CH 2 ) 2 NH 3 , X = Br, I) is reported. TPNPs (X = I) show an emission at a wavelength of 640 nm, with high quantum yield of 6.40 ± 0.14% and full width at half maximum (FWHM) as small as 36 nm. The presence of aliphatic carboxylic acid is found to play a key role in reducing the tin perovskite defect density, which significantly improves the emission intensity and stability of TPNPs. Upon mixing iodo- and bromo- precursors, the emission wavelength is successfully tuned from 640 nm (PEA 2 SnI 4 ) to 550 nm (PEA 2 SnBr 4 ), with a corresponding emission quantum yield and FWHM of 0.16-6.40% and 36-80 nm, respectively. The results demonstrate a major advance for the emission yield and tunability of tin-halide perovskites. © 2018 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

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.

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

International Nuclear Information System (INIS)

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

Tradable permits of greenhouse gas emission: elements for an economic analysis

International Nuclear Information System (INIS)

Quirion, Philippe

2011-01-01

In this HDR (Accreditation to supervise researches), the author proposes an overview of his research works on tradable emission permits, a topic he addressed in 1999. By referring to his various publications and reports, he comments the choice made between tax and quotas at the national level in presence of international tradable quotas. He discusses whether quotas are more acceptable by enterprises. He comments the determination of emission objectives by using absolute levels or by adopting levels proportional to production: context, model and hypothesis, instruments of public policy (absolute objective, price based instrument, relative objective), role of relative caps, comparison with the Newell and Pizer model. He discusses whether competitiveness can be protected without sacrificing economic efficiency, the commitment of developing countries in climate change mitigation. He finally gives his opinion on the ETS, and discusses new research perspectives [fr

A carbon emissions reduction index: Integrating the volume and allocation of regional emissions

International Nuclear Information System (INIS)

Chen, Jiandong; Cheng, Shulei; Song, Malin; Wu, Yinyin

2016-01-01

Highlights: • We build a carbon emissions reduction index (CERI). • The aim is to quantify the pressure on policymakers to reduce emissions. • Scale-related effects and carbon emissions allocations are included in the CERI. • Different standards of carbon emissions allocations are also considered. • We decompose the Gini coefficient to evaluate the effects of three factors. - Abstract: Given the acceleration of global warming and rising greenhouse gas emissions, all countries are facing the harsh reality of the need to reduce carbon emissions. In this study, we propose an index to quantify the pressure faced by policymakers to reduce such emissions, termed the carbon emissions reduction index. This index allows us to observe the effect of carbon emissions volume on the pressure faced by policymakers and study the impact of optimizing interregional carbon emissions on reducing this pressure. In addition, we account for several carbon emissions standards in constructing the index. We conclude that the variation in the index is likely to be attributable to carbon emissions volume, regional ranking, and population (population can also be replaced by GDP, resource endowment, or other factors). In addition, based on empirical data on the world’s largest emitter of carbon dioxide (China), this study analyzes the evolution of pressure to reduce emissions on a country’s policymakers. The results show that the growing volume and unsuitable allocation of carbon emissions from 1997 to 2012 imposed increasing pressure on the Chinese government in this regard. In addition, reductions in carbon emissions volume and regional ranking are primary factors that impact pressure on policymakers.

Real-time monitoring of emissions from monoethanolamine-based industrial scale carbon capture facilities.

Science.gov (United States)

Zhu, Liang; Schade, Gunnar Wolfgang; Nielsen, Claus Jørgen

2013-12-17

We demonstrate the capabilities and properties of using Proton Transfer Reaction time-of-flight mass spectrometry (PTR-ToF-MS) to real-time monitor gaseous emissions from industrial scale amine-based carbon capture processes. The benchmark monoethanolamine (MEA) was used as an example of amines needing to be monitored from carbon capture facilities, and to describe how the measurements may be influenced by potentially interfering species in CO2 absorber stack discharges. On the basis of known or expected emission compositions, we investigated the PTR-ToF-MS MEA response as a function of sample flow humidity, ammonia, and CO2 abundances, and show that all can exhibit interferences, thus making accurate amine measurements difficult. This warrants a proper sample pretreatment, and we show an example using a dilution with bottled zero air of 1:20 to 1:10 to monitor stack gas concentrations at the CO2 Technology Center Mongstad (TCM), Norway. Observed emissions included many expected chemical species, dominantly ammonia and acetaldehyde, but also two new species previously not reported but emitted in significant quantities. With respect to concerns regarding amine emissions, we show that accurate amine quantifications in the presence of water vapor, ammonia, and CO2 become feasible after proper sample dilution, thus making PTR-ToF-MS a viable technique to monitor future carbon capture facility emissions, without conventional laborious sample pretreatment.

DNA abasic site-selective enhancement of sanguinarine fluorescence with a large emission shift.

Directory of Open Access Journals (Sweden)

Fei Wu

Full Text Available Small molecules that can specifically bind to a DNA abasic site (AP site have received much attention due to their importance in DNA lesion identification, drug discovery, and sensor design. Herein, the AP site binding behavior of sanguinarine (SG, a natural alkaloid, was investigated. In aqueous solution, SG has a short-wavelength alkanolamine emission band and a long-wavelength iminium emission band. At pH 8.3, SG experiences a fluorescence quenching for both bands upon binding to fully matched DNAs without the AP site, while the presence of the AP site induces a strong SG binding and the observed fluorescence enhancement for the iminium band are highly dependent on the nucleobases flanking the AP site, while the alkanolamine band is always quenched. The bases opposite the AP site also exert some modifications on the SG's emission behavior. It was found that the observed quenching for DNAs with Gs and Cs flanking the AP site is most likely caused by electron transfer between the AP site-bound excited-state SG and the nearby Gs. However, the flanking As and Ts that are not easily oxidized favor the enhanced emission. This AP site-selective enhancement of SG fluorescence accompanies a band conversion in the dominate emission from the alkanolamine to iminium band thus with a large emission shift of about 170 nm. Absorption spectra, steady-state and transient-state fluorescence, DNA melting, and electrolyte experiments confirm that the AP site binding of SG occurs and the stacking interaction with the nearby base pairs is likely to prevent the converted SG iminium form from contacting with water that is thus emissive when the AP site neighbors are bases other than guanines. We expect that this fluorophore would be developed as a promising AP site binder having a large emission shift.

Factors affecting ultraviolet-A photon emission from β-irradiated human keratinocyte cells.

Science.gov (United States)

Le, M; Mothersill, C E; Seymour, C B; Ahmad, S B; Armstrong, A; Rainbow, A J; McNeill, F E

2015-08-21

The luminescence intensity of 340±5 nm photons emitted from HaCaT (human keratinocyte) cells was investigated using a single-photon-counting system during cellular exposure to (90)Y β-particles. Multiple factors were assessed to determine their influence upon the quantity and pattern of photon emission from β-irradiated cells. Exposure of 1 x 10(4) cells/5 mL to 703 μCi resulted in maximum UVA photoemission at 44.8 x 10(3)±2.5 x 10(3) counts per second (cps) from live HaCaT cells (background: 1-5 cps); a 16-fold increase above cell-free controls. Significant biophoton emission was achieved only upon stimulation and was also dependent upon presence of cells. UVA luminescence was measured for (90)Y activities 14 to 703 μCi where a positive relationship between photoemission and (90)Y activity was observed. Irradiation of live HaCaT cells plated at various densities produced a distinct pattern of emission whereby luminescence increased up to a maximum at 1 x 10(4) cells/5 mL and thereafter decreased. However, this result was not observed in the dead cell population. Both live and dead HaCaT cells were irradiated and were found to demonstrate different rates of photon emission at low β activities (⩽400 μCi). Dead cells exhibited greater photon emission rates than live cells which may be attributable to metabolic processes taking place to modulate the photoemissive effect. The results indicate that photon emission from HaCaT cells is perturbed by external stimulation, is dependent upon the activity of radiation delivered, the density of irradiated cells, and cell viability. It is postulated that biophoton emission may be modulated by a biological or metabolic process.

Heavy-ion induced secondary electron emission from Mg, Al, and Si partially covered with oxygen

International Nuclear Information System (INIS)

Weng, J; Veje, E.

1984-01-01

We have bombarded Mg, Al, and Si with 80 keV Ar + ions and measured the secondary electron emission yields at projectile incidence angles from 0 0 to 85 0 , with oxygen present at the target as well as under UHV conditions. The total secondary electron emission yields are found to depend fairly much on the amount of oxygen present. The three elements studied show relatively large individual variations. For all three elements, and with as well as without oxygen present, the relative secondary electron emission yield is observed to vary as 1/cos v, where v is the angle of incidence of the projectiles. This seems to indicate that the secondary electron production is initiated uniformly along the projectile path in the solid, in a region close to the surface. The results are discussed, and it is tentatively suggested, that the increase in secondary electron emission, caused by the presence of oxygen, originates from neutralization of sputtered oxygen, which initially is sitting as O 2- ions. (orig.)

Avoided emissions of a fuel-efficient biomass cookstove dwarf embodied emissions

Directory of Open Access Journals (Sweden)

D.L. Wilson

2016-06-01

Full Text Available Three billion people cook their food on biomass-fueled fires. This practice contributes to the anthropogenic radiative forcing. Fuel-efficient biomass cookstoves have the potential to reduce CO2-equivalent emissions from cooking, however, cookstoves made from modern materials and distributed through energy-intensive supply chains have higher embodied CO2-equivalent than traditional cookstoves. No studies exist examining whether lifetime emissions savings from fuel-efficient biomass cookstoves offset embodied emissions, and if so, by what margin. This paper is a complete life cycle inventory of “The Berkeley–Darfur Stove,” disseminated in Sudan by the non-profit Potential Energy. We estimate the embodied CO2-equivalent in the cookstove associated with materials, manufacturing, transportation, and end-of-life is 17 kg of CO2-equivalent. Assuming a mix of 55% non-renewable biomass and 45% renewable biomass, five years of service, and a conservative 35% reduction in fuel use relative to a three-stone fire, the cookstove will offset 7.5 tonnes of CO2-equivalent. A one-to-one replacement of a three-stone fire with the cookstove will save roughly 440 times more CO2-equivalent than it “costs” to create and distribute. Over its five-year life, we estimate the total use-phase emissions of the cookstove to be 13.5 tonnes CO2-equivalent, and the use-phase accounts for 99.9% of cookstove life cycle emissions. The dominance of use-phase emissions illuminate two important insights: (1 without a rigorous program to monitor use-phase emissions, an accurate estimate of life cycle emissions from biomass cookstoves is not possible, and (2 improving a cookstove's avoided emissions relies almost exclusively on reducing use-phase emissions even if use-phase reductions come at the cost of substantially increased non-use-phase emissions.

Hitting emissions targets with (statistical) confidence in multi-instrument Emissions Trading Schemes

International Nuclear Information System (INIS)

Shipworth, David

2003-12-01

A means of assessing, monitoring and controlling aggregate emissions from multi-instrument Emissions Trading Schemes is proposed. The approach allows contributions from different instruments with different forms of emissions targets to be integrated. Where Emissions Trading Schemes are helping to meet specific national targets, the approach allows the entry requirements of new participants to be calculated and set at a level that will achieve these targets. The approach is multi-levelled, and may be extended downwards to support pooling of participants within instruments, or upwards to embed Emissions Trading Schemes within a wider suite of policies and measures with hard and soft targets. Aggregate emissions from each instrument are treated stochastically. Emissions from the scheme as a whole are then the joint probability distribution formed by integrating the emissions from its instruments. Because a Bayesian approach is adopted, qualitative and semi-qualitative data from expert opinion can be used where quantitative data is not currently available, or is incomplete. This approach helps government retain sufficient control over emissions trading scheme targets to allow them to meet their emissions reduction obligations, while minimising the need for retrospectively adjusting existing participants' conditions of entry. This maintains participant confidence, while providing the necessary policy levers for good governance

Health effects of soy-biodiesel emissions: mutagenicity-emission factors.

Science.gov (United States)

Mutlu, Esra; Warren, Sarah H; Matthews, Peggy P; King, Charly; Walsh, Leon; Kligerman, Andrew D; Schmid, Judith E; Janek, Daniel; Kooter, Ingeborg M; Linak, William P; Gilmour, M Ian; DeMarini, David M

2015-01-01

Soy biodiesel is the predominant biodiesel fuel used in the USA, but only a few, frequently conflicting studies have examined the potential health effects of its emissions. We combusted petroleum diesel (B0) and fuels with increasing percentages of soy methyl esters (B20, B50 and B100) and determined the mutagenicity-emission factors expressed as revertants/megajoule of thermal energy consumed (rev/MJ(th)). We combusted each fuel in replicate in a small (4.3-kW) diesel engine without emission controls at a constant load, extracted organics from the particles with dichloromethane, determined the percentage of extractable organic material (EOM), and evaluated these extracts for mutagenicity in 16 strains/S9 combinations of Salmonella. Mutagenic potencies of the EOM did not differ significantly between replicate experiments for B0 and B100 but did for B20 and B50. B0 had the highest rev/MJ(th), and those of B20 and B100 were 50% and ∼85% lower, respectively, in strains that detect mutagenicity due to polycyclic aromatic hydrocarbons (PAHs), nitroarenes, aromatic amines or oxidative mutagens. For all strains, the rev/MJ(th) decreased with increasing biodiesel in the fuel. The emission factor for the 16 EPA Priority PAHs correlated strongly (r(2 )= 0.69) with the mutagenicity-emission factor in strain TA100 + S9, which detects PAHs. Under a constant load, soy-biodiesel emissions were 50-85% less mutagenic than those of petroleum diesel. Without additional emission controls, petroleum and biodiesel fuels had mutagenicity-emission factors between those of large utility-scale combustors (e.g. natural gas, coal, or oil) and inefficient open-burning (e.g. residential wood fireplaces).

Particulate emissions from diesel engines: correlation between engine technology and emissions.

Science.gov (United States)

Fiebig, Michael; Wiartalla, Andreas; Holderbaum, Bastian; Kiesow, Sebastian

2014-03-07

In the last 30 years, diesel engines have made rapid progress to increased efficiency, environmental protection and comfort for both light- and heavy-duty applications. The technical developments include all issues from fuel to combustion process to exhaust gas aftertreatment. This paper provides a comprehensive summary of the available literature regarding technical developments and their impact on the reduction of pollutant emission. This includes emission legislation, fuel quality, diesel engine- and exhaust gas aftertreatment technologies, as well as particulate composition, with a focus on the mass-related particulate emission of on-road vehicle applications. Diesel engine technologies representative of real-world on-road applications will be highlighted.Internal engine modifications now make it possible to minimize particulate and nitrogen oxide emissions with nearly no reduction in power. Among these modifications are cooled exhaust gas recirculation, optimized injections systems, adapted charging systems and optimized combustion processes with high turbulence. With introduction and optimization of exhaust gas aftertreatment systems, such as the diesel oxidation catalyst and the diesel particulate trap, as well as NOx-reduction systems, pollutant emissions have been significantly decreased. Today, sulfur poisoning of diesel oxidation catalysts is no longer considered a problem due to the low-sulfur fuel used in Europe. In the future, there will be an increased use of bio-fuels, which generally have a positive impact on the particulate emissions and do not increase the particle number emissions.Since the introduction of the EU emissions legislation, all emission limits have been reduced by over 90%. Further steps can be expected in the future. Retrospectively, the particulate emissions of modern diesel engines with respect to quality and quantity cannot be compared with those of older engines. Internal engine modifications lead to a clear reduction of the

Presence and fate of priority substances in domestic greywater treatment and reuse systems

DEFF Research Database (Denmark)

Donner, E.; Eriksson, Eva; Revitt, M.

2010-01-01

) or "Priority Hazardous Substances" (PHS). Significant knowledge gaps are identified. A wide range of potential treatment trains are available for greywater treatment and reuse but treatment efficiency data for priority substances and other micropollutants is very limited. Geochemical modelling indicates......A wide range of household sources may potentially contribute to contaminant loads in domestic greywater. The ability of greywater treatment systems to act as emission control barriers for household micropollutants, thereby providing environmental benefits in addition to potable water savings, have...... not been fully explored. This paper investigates the sources, presence and potential fate of a selection of xenobiotic micropollutants in on-site greywater treatment systems. All of the investigated compounds are listed under the European Water Framework Directive as either "Priority Substances" (PS...

Functional diversity of soil invertebrates: a potential tool to explain N2O emission?

Science.gov (United States)

Lubbers, Ingrid; De Deyn, Gerlinde; Drake, Harold; Hunger, Sindy; Oppermann, Timo; van Groenigen, Jan Willem

2017-04-01

Soil biota play a crucial role in the mineralization of nutrients from organic material. However, they can thereby increase emissions of the potent greenhouse gas nitrous oxide (N2O). Our current lack of understanding of the factors controlling N2O production and emission is impeding the development of effective mitigation strategies. It is the challenge to control N2O emissions from production systems without reducing crop yield, and diversity of soil fauna may play a key role. A high functional diversity of soil invertebrates is known to stimulate nitrogen mineralization and thereby plant growth, however, it is unknown whether a high functional diversity of soil invertebrates can concurrently diminish N2O emissions. We hypothesized that increased functional diversity of soil invertebrates reduces faunal-induced N2O emissions by facilitating more complete denitrification through (i) stimulating the activity of denitrifying microbes, and (ii) affecting the distribution of micro and macro pores, creating more anaerobic reaction sites. Using state-of-the-art X-ray tomography and next-generation sequencing, we studied effects of functional diversity on soil structural properties and the diversity of the microbial community (16S rRNA genes and 16S rRNA), and linked these to soil N2O emissions. In a 120-day study we found that the functional composition of the soil invertebrate community determined N2O emissions: earthworm activity was key to faunal-induced N2O emissions (a 32-fold increase after 120 days, Pstructural properties (mean pore size, pore size distribution) were found to be radically altered by earthworm activity. We conclude that the presence of a few functional groups (ecosystem engineers) is more important than overall increased functional diversity in explaining faunal-affected N2O emissions.

Social, economic, and resource predictors of variability in household air pollution from cookstove emissions.

Directory of Open Access Journals (Sweden)

Gautam N Yadama

Full Text Available We examine if social and economic factors, fuelwood availability, market and media access are associated with owning a modified stove and variation in household emissions from biomass combustion, a significant environmental and health concern in rural India. We analyze cross-sectional household socio-economic data, and PM(2.5 and particulate surface area concentration in household emissions from cookstoves (n=100. This data set combines household social and economic variables with particle emissions indexes associated with the household stove. The data are from the Foundation for Ecological Society, India, from a field study of household emissions. In our analysis, we find that less access to ready and free fuelwood and higher wealth are associated with owning a replacement/modified stove. We also find that additional kitchen ventilation is associated with a 12% reduction in particulate emissions concentration (p<0.05, after we account for the type of stove used. We did not find a significant association between replacement/modified stove on household emissions when controlling for additional ventilation. Higher wealth and education are associated with having additional ventilation. Social caste, market and media access did not have any effect on the presence of replacement or modified stoves or additional ventilation. While the data available to us does not allow an examination of direct health outcomes from emissions variations, adverse environmental and health impacts of toxic household emissions are well established elsewhere in the literature. The value of this study is in its further examination of the role of social and economic factors and available fuelwood from commons in type of stove use, and additional ventilation, and their effect on household emissions. These associations are important since the two direct routes to improving household air quality among the poor are stove type and better ventilation.

Thermal and nonthermal electron cyclotron emission by high-temperature tokamak plasmas

International Nuclear Information System (INIS)

Airoldi, A.; Ramponi, G.

1997-01-01

An analysis of the electron cyclotron emission (ECE) spectra emitted by a high-temperature tokamak plasma in the frequency range of the second and third harmonic of the electron cyclotron frequency is made, both in purely Maxwellian and in non-Maxwellian cases (i.e., in the presence of a current-carrying superthermal tail). The work is motivated mainly by the experimental observations made in the supershot plasmas of the Tokamak Fusion Test Reactor (TFTR), where a systematic disagreement is found between the T e measurements by second-harmonic ECE and Thomson scattering. We show that, by properly taking into account the overlap of superthermals-emitted third harmonic with second-harmonic bulk emission, the radiation temperature observed about the central frequency of the second harmonic may be enhanced up to 30%endash 40% compared to the corresponding thermal value. Moreover we show that, for parameters relevant to the International Thermonuclear Experimental Reactor (ITER) with T e (0)>7 keV, the overlap between the second and the downshifted third harmonic seriously affects the central plasma region, so that the X-mode emission at the second harmonic becomes unsuitable for local T e measurements. copyright 1997 American Institute of Physics

Understanding Emissions in East Asia - The KORUS 2015 Emissions Inventory

Science.gov (United States)

Woo, J. H.; Kim, Y.; Park, R.; Choi, Y.; Simpson, I. J.; Emmons, L. K.; Streets, D. G.

2017-12-01

The air quality over Northeast Asia have been deteriorated for decades due to high population and energy use in the region. Despite of more stringent air pollution control policies by the governments, air quality over the region seems not been improved as much - even worse sometimes. The needs of more scientific understanding of inter-relationship among emissions, transport, chemistry over the region are much higher to effectively protect public health and ecosystems. Two aircraft filed campaigns targeting year 2016, MAPS-Seoul and KORUS-AQ, have been organized to study the air quality of over Korea and East Asia relating to chemical evolution, emission inventories, trans-boundary contribution, and satellite application. We developed a new East-Asia emissions inventory, named KORUS2015, based on NIER/KU-CREATE (Comprehensive Regional Emissions inventory for Atmospheric Transport Experiment), in support of the filed campaigns. For anthropogenic emissions, it has 54 fuel classes, 201 sub-sectors and 13 pollutants, including CO2, SO2, NOx, CO, NMVOC, NH3, PM10, and PM2.5. Since the KORUS2015 emissions framework was developed using the integrated climate and air quality assessment modeling framework (i.e. GAINS) and is fully connected with the comprehensive emission processing/modeling systems (i.e. SMOKE, KU-EPS, and MEGAN), it can be effectively used to support atmospheric field campaigns for science and policy. During the field campaigns, we are providing modeling emissions inventory to participating air quality models, such as CMAQ, WRF-Chem, CAMx, GEOS-Chem, MOZART, for forecasting and post-analysis modes. Based on initial assessment of those results, we are improving our emissions, such as VOC speciation, biogenic VOCs modeling. From the 2nditeration between emissions and modeling/measurement, further analysis results will be presented at the conference. Acknowledgements : This subject is supported by Korea Ministry of Environment as "Climate Change

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.)

Limiting nutrient emission from a cut rose closed system by high-flux irrigation and low nutrient concentrations?

NARCIS (Netherlands)

Baas, R.; Berg, van der D.

2004-01-01

A two-year project was aimed at decreasing nutrient emission from closed nutrient systems by using high irrigation rates in order to allow lower EC levels in the presence of accumulated Na and Cl. Experimental variables were growing media, irrigation frequencies, EC and NaCl concentrations for cut

SPATIALLY RESOLVED M-BAND EMISSION FROM IO’S LOKI PATERA–FIZEAU IMAGING AT THE 22.8 m LBT

Energy Technology Data Exchange (ETDEWEB)

Conrad, Albert; Veillet, Christian [LBT Observatory, University of Arizona, 933 N. Cherry Ave., Tucson, AZ 85721 (United States); Kleer, Katherine de; Pater, Imke de [University of California at Berkeley, Berkeley, CA 94720 (United States); Leisenring, Jarron; Defrère, Denis; Hinz, Philip; Skemer, Andy [University of Arizona, 1428 E. University Blvd., Tucson, AZ 85721 (United States); Camera, Andrea La; Bertero, Mario; Boccacci, Patrizia [DIBRIS, University of Genoa, Via Dodecaneso 35, I-16146 Genova (Italy); Arcidiacono, Carmelo [INAF-Osservatorio Astronomico di Bologna, via Ranzani 1, I-40127 Bologna (Italy); Hofmann, Karl-Heinz; Schertl, Dieter; Weigelt, Gerd [Max Planck Institute for Radio Astronomy, Auf dem Hügel 69, D-53121 Bonn (Germany); Kürster, Martin [Max Planck Institute for Astronomy, Königstuhl 17, D-69117 Heidelberg (Germany); Rathbun, Julie [Planetary Science Institute, 1700 E. Fort Lowell, Tucson, AZ 85719 (United States); Skrutskie, Michael [University of Virginia, 530 McCormick Road, Charlottesville, VA 22904 (United States); Spencer, John [Southwest Research Institute, 1050 Walnut Ste. Suite 300, Boulder, CO 80302 (United States); Woodward, Charles E., E-mail: aconrad@lbto.org [Minnesota Institute for Astrophysics, 116 Church St., Minneapolis, MN 55455 (United States)

2015-05-15

The Large Binocular Telescope Interferometer mid-infrared camera, LMIRcam, imaged Io on the night of 2013 December 24 UT and detected strong M-band (4.8 μm) thermal emission arising from Loki Patera. The 22.8 m baseline of the Large Binocular Telescope provides an angular resolution of ∼32 mas (∼100 km at Io) resolving the Loki Patera emission into two distinct maxima originating from different regions within Loki’s horseshoe lava lake. This observation is consistent with the presence of a high-temperature source observed in previous studies combined with an independent peak arising from cooling crust from recent resurfacing. The deconvolved images also reveal 15 other emission sites on the visible hemisphere of Io including two previously unidentified hot spots.

Highly controlled, reproducible measurements of aerosol emissions from combustion of a common African biofuel source

Science.gov (United States)

Haslett, Sophie L.; Thomas, J. Chris; Morgan, William T.; Hadden, Rory; Liu, Dantong; Allan, James D.; Williams, Paul I.; Keita, Sekou; Liousse, Cathy; Coe, Hugh

2018-01-01

Particulate emissions from biomass burning can both alter the atmosphere's radiative balance and cause significant harm to human health. However, due to the large effect on emissions caused by even small alterations to the way in which a fuel burns, it is difficult to study particulate production of biomass combustion mechanistically and in a repeatable manner. In order to address this gap, in this study, small wood samples sourced from Côte D'Ivoire in West Africa were burned in a highly controlled laboratory environment. The shape and mass of samples, available airflow and surrounding thermal environment were carefully regulated. Organic aerosol and refractory black carbon emissions were measured in real time using an Aerosol Mass Spectrometer and a Single Particle Soot Photometer, respectively. This methodology produced remarkably repeatable results, allowing aerosol emissions to be mapped directly onto different phases of combustion. Emissions from pyrolysis were visible as a distinct phase before flaming was established. After flaming combustion was initiated, a black-carbon-dominant flame was observed during which very little organic aerosol was produced, followed by a period that was dominated by organic-carbon-producing smouldering combustion, despite the presence of residual flaming. During pyrolysis and smouldering, the two phases producing organic aerosol, distinct mass spectral signatures that correspond to previously reported variations in biofuel emissions measured in the atmosphere are found. Organic aerosol emission factors averaged over an entire combustion event were found to be representative of the time spent in the pyrolysis and smouldering phases, rather than reflecting a coupling between emissions and the mass loss of the sample. Further exploration of aerosol yields from similarly carefully controlled fires and a careful comparison with data from macroscopic fires and real-world emissions will help to deliver greater constraints on the

Greenhouse gas emission reduction by means of fuel switching in electricity generation: Addressing the potentials

International Nuclear Information System (INIS)

Delarue, Erik; D'haeseleer, William

2008-01-01

Many countries committed themselves in the Kyoto protocol to reduce greenhouse gas (GHG) emissions. Some of these targeted emission reductions could result from a switch from coal-fired to gas-fired electricity generation. The focus in this work lies on Western Europe, with the presence of the European Union Emission Trading Scheme (EU ETS). For the switching to occur, several conditions have to be fulfilled. First, an economical incentive must be present, i.e. a sufficiently high European Union Allowance (EUA) price together with a sufficiently low natural gas price. Second, the physical potential for switching must exist, i.e. at a given load, there must remain enough power plants not running to make switching possible. This paper investigates what possibilities exist for switching coal-fired plants for gas-fired plants, dependent on the load level (the latter condition above). A fixed allowance cost and a variable natural gas price are assumed. The method to address GHG emission reduction potentials is first illustrated in a methodological case. Next, the GHG emission reduction potentials are addressed for several Western European countries together with a relative positioning of their electricity generation. GHG emission reduction potentials are also compared with simulation results. GHG emission reduction potentials tend to be significant. The Netherlands have a very widespread switching zone, so GHG emission reduction is practically independent of electricity generation. Other counties, like Germany, Spain and Italy could reduce GHG emissions significantly by switching. With an allowance cost following the switch level of a 50% efficient gas-fired plant and a 40% efficient coal-fired plant in the summer season (like in 2005), the global GHG emission reduction (in the electricity generating sector) for the eight modeled zones could amount to 19%

Acoustic Emission Stethoscope - Measurements with Acoustic Emission on Wind Turbines

Energy Technology Data Exchange (ETDEWEB)

Krystof Kryniski [AaF Infrastructure, Stockholm (Sweden)

2013-02-15

been designed to offer also audible sound derived from the ultrasound produced by faulty components. Identifying which drive-train parts that are in danger, or require immediate attention, can then, with the developed method, be remotely accessed without any need to travel to and climbing-up the actual wind turbine. The new method for condition monitoring using acoustic emission has been shown to give results comparable to the proven methods using vibration acceleration and shock pulse, but the applications with acoustic emission have the potential to be more cost effective, simpler and more reliable. A warning or notification method has been developed in the project. A reference and disturbance measure is displayed continuously and is compared to normal, warning and alarm levels in the notification system. The reference measure is an average value that varies with the wind dependent load on the rotor and the disturbance is a measure of the instantaneous deviations from the average values. The disturbance measure is used to signal the presence of a defect in the machine. The method has been tested on a number of wind turbines. The alert or warning level is pre-set to a factor three times the standard deviation of the signal and the alarm level to five times the standard deviation. No damage has been encountered yet on the tested turbines, meaning that a full test of the capability to detect faults on a wind turbine has not been proved within the project and remains to be verified in future testing. When experience of the signals has been acquired and compared to observed physical damage, the alert and alarm levels can be modified in each application.

40 CFR Table 3 to Subpart Ffff of... - Emission Limits for Hydrogen Halide and Halogen HAP Emissions or HAP Metals Emissions From...

Science.gov (United States)

2010-07-01

... Halogen HAP Emissions or HAP Metals Emissions From Process Vents 3 Table 3 to Subpart FFFF of Part 63... to Subpart FFFF of Part 63—Emission Limits for Hydrogen Halide and Halogen HAP Emissions or HAP... following table that applies to your process vents that contain hydrogen halide and halogen HAP emissions or...

Atmospheric benzenoid emissions from plants rival those from fossil fuels.

Science.gov (United States)

Misztal, P K; Hewitt, C N; Wildt, J; Blande, J D; Eller, A S D; Fares, S; Gentner, D R; Gilman, J B; Graus, M; Greenberg, J; Guenther, A B; Hansel, A; Harley, P; Huang, M; Jardine, K; Karl, T; Kaser, L; Keutsch, F N; Kiendler-Scharr, A; Kleist, E; Lerner, B M; Li, T; Mak, J; Nölscher, A C; Schnitzhofer, R; Sinha, V; Thornton, B; Warneke, C; Wegener, F; Werner, C; Williams, J; Worton, D R; Yassaa, N; Goldstein, A H

2015-07-13

Despite the known biochemical production of a range of aromatic compounds by plants and the presence of benzenoids in floral scents, the emissions of only a few benzenoid compounds have been reported from the biosphere to the atmosphere. Here, using evidence from measurements at aircraft, ecosystem, tree, branch and leaf scales, with complementary isotopic labeling experiments, we show that vegetation (leaves, flowers, and phytoplankton) emits a wide variety of benzenoid compounds to the atmosphere at substantial rates. Controlled environment experiments show that plants are able to alter their metabolism to produce and release many benzenoids under stress conditions. The functions of these compounds remain unclear but may be related to chemical communication and protection against stress. We estimate the total global secondary organic aerosol potential from biogenic benzenoids to be similar to that from anthropogenic benzenoids (~10 Tg y(-1)), pointing to the importance of these natural emissions in atmospheric physics and chemistry.

Spontaneous emission and gain in a waveguide free-electron laser

International Nuclear Information System (INIS)

Golightly, W.J.; Ride, S.K.

1991-01-01

A free-electron laser enclosed in a waveguide of narrowly spaced parallel plates has been proposed as a compact, coherent source of far-infrared radiation. In this paper, the spontaneous emission and small-signal gain of such a device are analyzed. Maxwell's equations are solved for the fields of a relativistic electron beam passing through a linearly polarized undulator in the presence of a parallel-plane waveguide. The radiation intensity is resolved into its component waveguide modes for the fundamental frequency and for all harmonics. The intensity profile in a given harmonic mode is altered significantly when a parameter involving the undulator period, beam energy, and transverse dimension of the guide is such that the radiation group velocity is close to the electrons' axial velocity. The small-signal gain in the waveguide free-electron laser is calculated and related to the spontaneous emission. Near zero slip, the gain curve is significantly different from that of a free-space free-electron laser with the same parameters

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

International Nuclear Information System (INIS)

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)

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).

Emission and Absorption in the M87 LINER

Science.gov (United States)

Sabra, Bassem M.; Shields, Joseph C.; Ho, Luis C.; Barth, Aaron J.; Filippenko, Alexei V.

2003-02-01

The nucleus of M87 displays a LINER spectrum at optical wavelengths, with a nuclear disk of nebulosity that is resolved by the Hubble Space Telescope (HST). We present new results from optical and ultraviolet spectra of the central ~40 pc as measured by HST. In contrast with previous results for the extended disk, the emission-line spectrum of the central region is best reproduced by a multicomponent photoionization scenario, rather than shock heating. The nebular properties as well as energetic considerations suggest a transition on scales of several tens of parsecs, from predominantly photoionization by a central accretion source to shock ionization within the disk. If this source is at all representative, it suggests that many LINERs may be composite in terms of the energetic processes that give rise to the emission spectrum. We also report measurements of resonance-line absorption for the nucleus. The absorption spectrum, like the emission lines, is characterized by low ionization. The absorption-line measurements coupled with independent constraints suggest a total hydrogen column density of 1019-1020 cm-2, outflowing from the galaxy center with a velocity of ~126 km s-1. The kinematic signature of an outflow, along with evidence that the absorber covers the power-law continuum source but not the emission-line clouds, suggests that the absorbing matter is related to accretion phenomena in the nucleus. The presence of such an outflow resembles similar behavior in luminous active galactic nuclei, although the low ionization that characterizes LINERs is probably indicative of a different mode of accretion in these sources. Based on observations with the NASA/ESA Hubble Space Telescope obtained at the Space Telescope Science Institute, which is operated by the Association of Universities for Research in Astronomy, Inc., under NASA contract NAS5-26555.

Origin of unusual bandgap shift and dual emission in organic-inorganic lead halide perovskites.

Science.gov (United States)

Dar, M Ibrahim; Jacopin, Gwénolé; Meloni, Simone; Mattoni, Alessandro; Arora, Neha; Boziki, Ariadni; Zakeeruddin, Shaik Mohammed; Rothlisberger, Ursula; Grätzel, Michael

2016-10-01

Emission characteristics of metal halide perovskites play a key role in the current widespread investigations into their potential uses in optoelectronics and photonics. However, a fundamental understanding of the molecular origin of the unusual blueshift of the bandgap and dual emission in perovskites is still lacking. In this direction, we investigated the extraordinary photoluminescence behavior of three representatives of this important class of photonic materials, that is, CH 3 NH 3 PbI 3 , CH 3 NH 3 PbBr 3 , and CH(NH 2 ) 2 PbBr 3 , which emerged from our thorough studies of the effects of temperature on their bandgap and emission decay dynamics using time-integrated and time-resolved photoluminescence spectroscopy. The low-temperature (photoluminescence of CH 3 NH 3 PbI 3 and CH 3 NH 3 PbBr 3 reveals two distinct emission peaks, whereas that of CH(NH 2 ) 2 PbBr 3 shows a single emission peak. Furthermore, irrespective of perovskite composition, the bandgap exhibits an unusual blueshift by raising the temperature from 15 to 300 K. Density functional theory and classical molecular dynamics simulations allow for assigning the additional photoluminescence peak to the presence of molecularly disordered orthorhombic domains and also rationalize that the unusual blueshift of the bandgap with increasing temperature is due to the stabilization of the valence band maximum. Our findings provide new insights into the salient emission properties of perovskite materials, which define their performance in solar cells and light-emitting devices.

International aviation emissions to 2025: Can emissions be stabilised without restricting demand?

International Nuclear Information System (INIS)

Macintosh, Andrew; Wallace, Lailey

2009-01-01

International aviation is growing rapidly, resulting in rising aviation greenhouse gas emissions. Concerns about the growth trajectory of the industry and emissions have led to calls for market measures such as emissions trading and carbon levies to be introduced to restrict demand and prompt innovation. This paper provides an overview of the science on aviation's contribution to climate change, analyses key trends in the industry since 1990, projects international civil aviation emissions to 2025 and analyses the emission intensity improvements that are necessary to offset rising international demand. The findings suggest international aviation carbon dioxide (CO 2 ) emissions will increase by more than 110 per cent between 2005 and 2025 (from 416 Mt to between 876 and 1013 Mt) and that it is unlikely emissions could be stabilised at levels consistent with risk averse climate targets without restricting demand

Direct measurements of methane emissions from abandoned oil and gas wells in Pennsylvania.

Science.gov (United States)

Kang, Mary; Kanno, Cynthia M; Reid, Matthew C; Zhang, Xin; Mauzerall, Denise L; Celia, Michael A; Chen, Yuheng; Onstott, Tullis C

2014-12-23

Abandoned oil and gas wells provide a potential pathway for subsurface migration and emissions of methane and other fluids to the atmosphere. Little is known about methane fluxes from the millions of abandoned wells that exist in the United States. Here, we report direct measurements of methane fluxes from abandoned oil and gas wells in Pennsylvania, using static flux chambers. A total of 42 and 52 direct measurements were made at wells and at locations near the wells ("controls") in forested, wetland, grassland, and river areas in July, August, October 2013 and January 2014, respectively. The mean methane flow rates at these well locations were 0.27 kg/d/well, and the mean methane flow rate at the control locations was 4.5 × 10(-6) kg/d/location. Three out of the 19 measured wells were high emitters that had methane flow rates that were three orders of magnitude larger than the median flow rate of 1.3 × 10(-3) kg/d/well. Assuming the mean flow rate found here is representative of all abandoned wells in Pennsylvania, we scaled the methane emissions to be 4-7% of estimated total anthropogenic methane emissions in Pennsylvania. The presence of ethane, propane, and n-butane, along with the methane isotopic composition, indicate that the emitted methane is predominantly of thermogenic origin. These measurements show that methane emissions from abandoned oil and gas wells can be significant. The research required to quantify these emissions nationally should be undertaken so they can be accurately described and included in greenhouse gas emissions inventories.

Multi-tone suppression of distortion-product otoacoustic emissions in humans

OpenAIRE

Sieck, Nicole E.; Rasetshwane, Daniel M.; Kopun, Judy G.; Jesteadt, Walt; Gorga, Michael P.; Neely, Stephen T.

2016-01-01

The purpose of this study was to investigate the combined effect of multiple suppressors. Distortion-product otoacoustic emission (DPOAE) measurements were made in normal-hearing participants. Primary tones had fixed frequencies (f2 = 4000 Hz; f1 / f2 = 1.22) and a range of levels. Suppressor tones were at three frequencies (fs = 2828, 4100, 4300 Hz) and range of levels. Decrement was defined as the attenuation in DPOAE level due to the presence of a suppressor. A measure of suppression calle...

Near Infrared Multispectral Mapping of Venus Supports the Hypothesis that Tessera Plateau Material was Formed in the Presence of Surface Water

Science.gov (United States)

Mueller, N. T.; Tsang, C.; Nunes, D. C.; Helbert, J.; Dyar, M. D.; Smrekar, S. E.

2017-12-01

The VIRTIS instrument on Venus Express observed surface thermal emission from the surface. Studies of 1020nm data showed that tessera plateaus, intensely tectonically deformed highlands that predate most other terrains, have significantly lower thermal emission than other highlands. Lower thermal emission could be due either to lower surface emissivity, supporting the hypothesis that tessera are analogous to continental crust on Earth, or to a bias of Magellan altimetry, which does not fully resolve the topographic relief of tessera terrain. To eliminate this ambiguity, we additionally investigate the spectral windows at 1100 and 1180nm. Data are reduced to surface emissivity using an atmospheric radiative transfer model to account for atmospheric scattering and absorption/emission. Magellan altimetry was used to model atmospheric column height and surface temperature. The model uses a binary (collision-induced) absorption coefficient for each window. It fits absolute radiance and gradient with surface elevation reasonably well, although there are indications that the assumed adiabatic temperature lapse rate is not appropriate globally. The 1100nm band has a relatively low signal-to-noise ratio at the latitudes of the tessera plateaus, but Alpha Regio is visible in both the 1020 and the 1180nm band. The difference in emissivity between Alpha and the adjacent corona Eve, which has a similar elevation as Alpha, is 3.6% at 1020nm, but only 2% at 1180nm. The altimetry bias equivalent to the 1020nm deviation is 230 m, while the equivalent is only 70m at 1180nm. An altimetry bias therefore cannot fully explain the observations, and there must be a real difference in emissivity. The observations are consistent with the hypothesis that Alpha Regio has a more felsic composition. The emissivity spectra of granites at Venus temperatures are lower than those of basalt at 1020nm, but the difference decreases or vanishes towards the 1180nm window. The most plausible explanation

Direct Evidence for Maser Emission from the 36.2 GHz Class I Transition of Methanol in NGC253

Science.gov (United States)

Chen, Xi; Ellingsen, Simon P.; Shen, Zhi-Qiang; McCarthy, Tiege P.; Zhong, Wei-Ye; Deng, Hui

2018-04-01

Observations made with the Jansky Very large Array (JVLA) at an angular resolution of ∼0.″1 have detected class I methanol maser emission from the 36.2 GHz transition toward the starburst galaxy NGC 253. The methanol emission is detected toward four sites which lie within the regions of extended methanol emission detected in previous lower angular resolution (a few arcseconds) observations. The peak flux densities of the detected compact components are in the range 3–9 mJy beam‑1. Combining the JVLA data with single-dish observations from the Shanghai Tianma Radio Telescope (TMRT) and previous interferometric observations with the Australia Telescope Compact Array (ATCA), we show that the 36.2 GHz class I methanol emission consists of both extended and compact structures, with typical scales of ∼6″ (0.1 kpc) and ∼0.″05 (1 pc), respectively. The strongest components have a brightness temperature of >103 K, much higher than the maximum kinetic temperature (∼100 K) of the thermal methanol emission from NGC 253. Therefore, these observations conclusively demonstrate for the first time the presence of maser emission from a class I methanol transition in an external galaxy.

The first full-resolution measurements of Auroral Medium Frequency Burst Emissions

Science.gov (United States)

Bunch, N. L.; Labelle, J.; Weatherwax, A.; Hughes, J.

2008-12-01

"ghosts" behind the main MF burst emission. These data in will additionally allow us to search for the presence of sub-millisecond wave packets, sometimes quasi-periodic, reported by LaBelle et al. [1997, J. Geophys. Res. 102, 22221]. Finally, a search for frequency dispersion or absence thereof will provide a test of theories which speculate that different frequencies originate at different altitudes in the ionosphere.

Air Emission Inventory for the Idaho National Engineering Laboratory: 1992 emissions report

Energy Technology Data Exchange (ETDEWEB)

Stirrup, T.S.

1993-06-01

This report presents the 1992 Air Emission Inventory for the Idaho National Engineering Laboratory. Originally, this report was in response to the Environmental Oversight and Monitoring Agreement in 1989 between the State of Idaho and the Department of Energy Idaho Field Office, and a request from the Idaho Air Quality Bureau. The current purpose of the Air Emission Inventory is to provide the basis for the preparation of the INEL Permit-to-Operate (PTO) an Air Emission Source Application, as required by the recently promulgated Title V regulations of the Clean Air Act. This report includes emissions calculations from 1989 to 1992. The Air Emission Inventory System, an ORACLE-based database system, maintains the emissions inventory.

Air Emission Inventory for the Idaho National Engineering Laboratory: 1992 emissions report

International Nuclear Information System (INIS)

Stirrup, T.S.

1993-06-01

This report presents the 1992 Air Emission Inventory for the Idaho National Engineering Laboratory. Originally, this report was in response to the Environmental Oversight and Monitoring Agreement in 1989 between the State of Idaho and the Department of Energy Idaho Field Office, and a request from the Idaho Air Quality Bureau. The current purpose of the Air Emission Inventory is to provide the basis for the preparation of the INEL Permit-to-Operate (PTO) an Air Emission Source Application, as required by the recently promulgated Title V regulations of the Clean Air Act. This report includes emissions calculations from 1989 to 1992. The Air Emission Inventory System, an ORACLE-based database system, maintains the emissions inventory

Trends in Aggregate Vehicle Emissions: Do We Need To Emissions Test?

OpenAIRE

Matthew Kahn

1995-01-01

Vehicle emissions are falling. As the oldest vehicles in the fleet are scrapped and are replaced by cleaner vehicles, aggregate emissions decline. Given this trend, must costly used car regulation continue? The Clean Air Act of 1990 requires more stringent used car testing without considering the counter-factual of how aggregate emissions would evolve in the absence of more regulation. This paper use data on vehicle scrappage rates, vehicle emissions by model year, and county air quality leve...

State environmental law and carbon emissions: Do public utility commissions use environmental statutes to fight global warming?

Energy Technology Data Exchange (ETDEWEB)

Sautter, John A.

2010-10-15

In many states environmental statutes provide the authority for public utility commissioners to make decisions to reduce greenhouse gases from electricity generation. This article looks at six such laws and how the presence of these laws affected CO{sub 2} emissions during a nine-year period from 1997 to 2005. (author)

Experimental and theoretical study on field emission properties of zinc oxide nanoparticles decorated carbon nanotubes

Science.gov (United States)

Li, Xin; Zhou, Wei-Man; Liu, Wei-Hua; Wang, Xiao-Li

2015-05-01

Field emission properties of zinc oxide (ZnO) nanoparticles (NPs) decorated carbon nanotubes (CNTs) are investigated experimentally and theoretically. CNTs are in situ decorated with ZnO NPs during the growth process by chemical vapor deposition using a carbon source from the iron phthalocyanine pyrolysis. The experimental field emission test shows that the ZnO NP decoration significantly improves the emission current from 50 μA to 275 μA at 550 V and the reduced threshold voltage from 450 V to 350 V. The field emission mechanism of ZnO NPs on CNTs is theoretically studied by the density functional theory (DFT) combined with the Penn-Plummer method. The ZnO NPs reconstruct the ZnO-CNT structure and pull down the surface barrier of the entire emitter system to 0.49 eV so as to reduce the threshold electric field. The simulation results suggest that the presence of ZnO NPs would increase the LDOS near the Fermi level and increase the emission current. The calculation results are consistent with the experiment results. Project supported by the National Natural Science Foundation of China (Grant Nos. 91123018, 61172040, and 61172041) and the Natural Science Foundation of Shaanxi Province, China (Grant No. 2014JM7277).

Low temperature tensile deformation and acoustic emission signal characteristics of AISI 304LN stainless steel

Energy Technology Data Exchange (ETDEWEB)

Barat, K.; Bar, H.N. [Material Science and Technology Division, CSIR-National Metallurgical Laboratory, Jamshedpur 831007 (India); Mandal, D. [Material Processing and Technology Division, CSIR-National Metallurgical Laboratory, Jamshedpur 831007 (India); Roy, H., E-mail: himadri9504@gmail.com [NDT and Metallurgy Group, CSIR-Central Mechanical Engineering Research Institute, Durgapur 713209 (India); Sivaprasad, S.; Tarafder, S. [Material Science and Technology Division, CSIR-National Metallurgical Laboratory, Jamshedpur 831007 (India)

2014-03-01

This investigation examines low temperature tensile deformation behavior of AISI 304LN stainless steel along with synergistic analysis of acoustic emission signals. The tensile tests are done at a range of temperatures starting from 283 K till 223 K. The fracture surfaces of the broken specimens are investigated using scanning electron microscope. The amount of deformation induced martensite is measured using a feritscope. The obtained results reveal that with decrease in test temperature, both strength and ductility increase. The increase in strength and ductility with decreasing temperature is explained in terms of void morphologies and formation of deformation induced martensite. The rapid increment in strength and ductility at 223 K is associated with the burst of martensitic transformation at that temperature; which has been clarified from acoustic emission signals. An additional initiative has been taken to model the evolution of martensite formation from the observed cumulative emission counts using a non linear logarithmic functional form. The fitted curves from the recorded acoustic emission cumulative count data are found to be better correlated compared to earlier obtained results. However, at 223 K normal non-linear logarithmic fit is not found suitable due to presence of burst type signals at intervals, therefore; piecewise logarithmic function to model acoustic emission bursts is proposed.

[Investigation of emission characteristics for light duty vehicles with a portable emission measurement system].

Science.gov (United States)

Wang, Hai-Kun; Fu, Li-Xin; Zhou, Yu; Lin, Xin; Chen, Ai-Zhong; Ge, Wei-hu; Du, Xuan

2008-10-01

Emission from 7 typical light-duty vehicles under actual driving conditions was monitored using a portable emission measurement system to gather data for characterization of the real world vehicle emission in Shenzhen, including the effects of driving modes on vehicle emission, comparison of fuel consumption based emission factors (g x L(-1) with mileage based emission factors (g x km(-1)), and the average emission factors of the monitored vehicles. The acceleration and deceleration modes accounted for 66.7% of total travel time, 80.3% of traveling distance and 74.6%-79.2% of vehicle emission; the acceleration mode contributed more than other driving modes. The fuel based emission factors were less dependent on the driving speed; they may be utilized in building macro-scale vehicle emission inventory with smaller sensitivity to the vehicle driving conditions. The effect of vehicle technology on vehicle emission was significant; the emission factors of CO, HC and NO(x) of carbureted vehicles were 19.9-20.5, 5.6-26.1 and 1.8-2.0 times the more advanced vehicles of Euro II, respectively. Using the ECE + EUDC driving cycle would not produce the desired real-world emission rates of light duty vehicles in a typical Chinese city.

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.)

Evaluation of mobile emissions contributions to Mexico City's emissions inventory using on-road and cross-road emission measurements and ambient data

Science.gov (United States)

Zavala, M.; Herndon, S. C.; Wood, E. C.; Onasch, T. B.; Knighton, W. B.; Marr, L. C.; Kolb, C. E.; Molina, L. T.

2009-09-01

Mobile emissions represent a significant fraction of the total anthropogenic emissions burden in the Mexico City Metropolitan Area (MCMA) and, therefore, it is crucial to use top-down techniques informed by on-road exhaust measurements to evaluate and improve traditional bottom-up official emissions inventory (EI) for the city. We present the measurements of on-road fleet-average emission factors obtained using the Aerodyne mobile laboratory in the MCMA in March 2006 as part of the MILAGRO/MCMA-2006 field campaign. A comparison of our on-road emission measurements with those obtained in 2003 using essentially the same measurement techniques and analysis methods indicates that, in the three year span, NO emission factors remain within the measured variability ranges whereas emission factors of aldehydes and aromatics species were reduced for all sampled driving conditions. We use a top-down fuel-based approach to evaluate the mobile emissions from the gasoline fleet estimated in the bottom-up official 2006 MCMA mobile sources. Within the range of measurement uncertainties, we found probable slight overpredictions of mean EI estimates on the order of 20-28% for CO and 14-20% for NO. However, we identify a probable EI discrepancy of VOC mobile emissions between 1.4 and 1.9; although estimated benzene and toluene mobile emissions in the inventory seem to be well within the uncertainties of the corresponding emissions estimates. Aldehydes mobile emissions in the inventory, however, seem to be underpredicted by factors of 3 for HCHO and 2 for CH3CHO. Our on-road measurement-based estimate of annual emissions of organic mass from PM1 particles suggests a severe underprediction (larger than a factor of 4) of PM2.5 mobile emissions in the inventory. Analyses of ambient CO, NOx and CO/NOx concentration trends in the MCMA indicate that the early morning ambient CO/NOx ratio has decreased at a rate of about 1.9 ppm/ppm/year over the last two decades due to reductions in CO

Characteristics of Biogenic VOCs Emission and its High-Resolution Emission Inventory in China

Science.gov (United States)

Li, L.; Li, Y.; Xie, S.

2017-12-01

Biogenic volatile organic compounds (BVOCs), with high emission and reactivity, can have substantial impacts on the haze and photochemical pollution. It is essential to establish an accurate high-resolution BVOC emission inventory in China for air quality simulation and decision making. Firstly, a semi-static enclosure technique is developed for the field measurements of BVOC emission rates from 50 plant species in China. Using the GC-MS/FID system, 103 VOC species for each plant species are measured. Based on the field measurements in our study and the reported emission rates at home and abroad, a methodology for determining the emission categories of BVOCs is developed using statistical analysis. The isoprene and monoterpene emission rates of 192 plant species/genera in China are determined based on the above emission categories. Secondly, a new vegetation classification with 82 plant functional types (PFTs) is developed based on the most detailed and latest vegetation investigations, China's official statistical data and Vegetation Atlas of China (1:1,000,000). The leaf biomass is estimated based on provincial vegetation volume and production with biomass-apportion models. The WRF model is used to determine meteorological variables at a high spatio-temporal resolution. Using MEAGNv2.1 and the determined emission rates in our study, the high-resolution emission inventories of isoprene, 37 monoterpene species, 32 sesquiterpene species, and other VOCs (OVOCs) from 82 PFTs in China for 1981-2013 are established. The total annual BVOC emissions in 2013 are 55.88 Tg, including 33.87 Tg isoprene, 6.36 Tg monoterpene, 1.29 Tg sesquiterpene, and 14.37 Tg OVOCs. The distribution of isoprene emission fluxes is consistent with the distribution of broadleaf trees, especially tree species with high or higher emission potential. During 1981-2013, China's BVOC emissions have increased by 47.48% at an average rate of 1.80% yr-1. Emissions of isoprene have the largest enhancement

Pre-equilibrium gamma emissions

International Nuclear Information System (INIS)

Ghosh, Sudip

1993-01-01

Together with the direct reaction and the compound nuclear emissions the pre-equilibrium (PEQ) or pre-compound processes give a fairly complete picture of nuclear reactions induced by light ions at energies of some tens of MeV. PEQ particle emissions covering the higher energy continuum spectra have been investigated in detail both experimentally and theoretically. In contrast, very little work has been done on PEQ γ- emissions. The reason is that in spite of extensive work done on PEQ particle emissions, the mechanism is not yet fully understood. Also, the PEQ γ-emission cross-sections (∼ micro barns) are very small compared to the PEQ particle emission cross-sections (∼ milli barns). Yet apart from the academic interest the understanding of PEQ γ-emissions is important for applied fusion research etc. In this paper the PEQ γ-emissions is discussed and the work done in this field is reviewed. (author). 14 refs

Revised emission factors for gas engines including start/stop emissions

Energy Technology Data Exchange (ETDEWEB)

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

2008-06-15

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

Influence of heat treatment on field emission characteristics of boron nitride thin films

International Nuclear Information System (INIS)

Li Weiqing; Gu Guangrui; Li Yingai; He Zhi; Feng Wei; Liu Lihua; Zhao Chunhong; Zhao Yongnian

2005-01-01

Boron nitride (BN) nanometer thin films are synthesized on Si (1 0 0) substrates by RF reactive magnetron sputtering. Then the film surfaces are treated in the case of the base pressure below 5 x 10 -4 Pa and the temperature of 800 and 1000 deg. C, respectively. And the films are studied by Fourier transform infrared spectra (FTIR), atomic force microscopic (AFM) and field emission characteristics at different annealing temperature. The results show that the surface heat treatment makes no apparent influence on the surface morphology of the BN films. The transformations of the sample emission characteristics have to do with the surface negative electron affinity (NEA) of the films possibly. The threshold electric fields are lower for BN samples without heat-treating than the treated films, which possibly ascribed to the surface negative electron affinity effect. A threshold field of 8 V/μm and the emission current of 80 μA are obtained. The surface NEA is still presence at the heat treatment temperature of 800 deg. C and disappeared at temperature of 1000 deg. C

The dynamic intensity of CO 2 emissions: empirical evidence for the 20 th century

Directory of Open Access Journals (Sweden)

DIEGO CARNEIRO

Full Text Available ABSTRACT The debate around the economic growth and environmental degradation is the hot topic among academics. However, up to a point, all of them embrace the uncontroversial view that tells us that anthropic factors have leverage on global climate. It happens that the so-called greenhouse effect is closely related to the accumulation of certain gases in the atmosphere, e.g., carbon dioxide, whose original source comes from productive sectors. Thus, our purpose in this article is to estimate the rate of emission intensity - here we mean the ratio between CO2 emissions and GDP - which has increased since the early part of the 20th century. To support that idea, this study reports on data from 24 different countries. In terms of C02 emission, the results undoubtedly show that United Kingdom and the United States highlight a negative picture, particularly when both are compared to India. It should be noted the presence of structural changes, which coincide with three major historical events: the World War I (1914-1918, the Great Depression in the 1930s, and finally the Oil-price shocks in the 1970s. As the result of the analysis demonstrates, the amount of emission produced by developing countries is surprisingly low. That the technology reveals its relative merit for reducing the overall emission intensity is transparently obvious.

Spectroscopic properties of 1.8 μm emission of thulium ions in germanate glass

Science.gov (United States)

Xu, R. R.; Tian, Y.; Wang, M.; Hu, L. L.; Zhang, J. J.

2011-01-01

A new type host of germanate glass (GeO2- BaO-BaF2-Ga2O3-La2O3) codoped with Tm2O3 has been investigated for application as laser material. It possesses a large emission cross section with the value of 9.3×10-21 cm2 at 1.8 μm. Judd-Ofelt intensity parameters and radiative transition probability are calculated and analyzed by Judd-Ofelt theory and absorption spectra. The infrared emission spectra at 1.8 μm have been obtained by using a 794 nm laser diode as excitation resource. The emission intensity ratio of 1.8 (3F4→3H6) to 1.47 μm (3H4→3F4) increases, while the experimental lifetime of the Tm3+:3H4 level decreases by increasing Tm2O3 concentration, which is attributed to the presence of a cross relaxation process. The most intensive emission at 1.8 μm is achieved from the germanate glass with the concentration of Tm2O3 reaches 1.0 wt%. The extended overlap integral method is used to calculate the microparameter of the energy transfer and the critical distance, which are derived to better understand the energy transfer process of thulium ions in the germanate glass responsible for emission at 1.8 μm.

Cardiological applications of positron emission tomography

International Nuclear Information System (INIS)

Schelbert, H.; Czernin, J.

1994-01-01

Positron emission tomography (PET) expands the diagnostic possibilities of nuclear medicine techniques for the diagnosis of coronary artery disease and, especially, for the identification of myocardial viability. The presence of coronary artery disease can be detected by evaluation of myocardial blood flow at rest and during pharmacologically induced hyperemia with a sensitivity of 84 to 98% and a specificity of 78 to 100% according to recent studies. Comparative investigations in the same patients have demonstrated a significant gain in the diagnostic accuracy of PET as compared with single photon emission computed tomography (SPECT). PET has influenced even more profoundly the identification of myocardial viability. Measured against the functional outcome of regional contractile function after successful revascularization, an increase of glucose utilization relative to regional myocardial blood flow is 77 to 85% accurate in identifying reversibly injured myocardium. Conversely, PET is 78 to 92% accurate in identifying myocardium as irreversibly injured when pre-operative glucose uptake was reduced or absent. Recent studies have indicated that it is possible to predict to some extent post-revascularization improvement in left ventricular function as well as in congestive heart failure related symptoms in patients with ischemic cardiomyopathy. Furthermore, PET can identify patients with an increased risk of mortality and morbidity as a result of ischemic heart disease and, thus, stratify patients to the most appropriate and cost-effective therapeutic approach. (authors)

Study of the emission oxidative reactions of ruthenium (II) complex by cationic compounds in anionic micelles

International Nuclear Information System (INIS)

Bonilha, J.B.S.

1985-01-01

The oxidative quenching of the emission of the tetraanionic complex tris (4,4' dicarboxylate - 2,2' - bipyridine ruthenium (II) in aqueous solution, by both organic and inorganic compounds in presence of anionic detergents, above and below the critical micelle concentration is studied. The organic cations, the inorganic ion and detergents used are shown. (M.J.C.) [pt

PresenceRemote

DEFF Research Database (Denmark)

Sokoler, Tomas; Svensson, Marcus Sanchez

2008-01-01

how these technologies can accommodate the specific challenges related to the everyday life of elderly people. In particular, using an example concept – the PresenceRemote – we will discuss how the stigma associated with being lonely, an inherent part of senior living, can be addressed by leaving room...

Visible sub-band gap photoelectron emission from nitrogen doped and undoped polycrystalline diamond films

Energy Technology Data Exchange (ETDEWEB)

Elfimchev, S., E-mail: sergeyel@tx.technion.ac.il; Chandran, M.; Akhvlediani, R.; Hoffman, A.

2017-07-15

Highlights: • Nitrogen related centers in diamond film are mainly responsible for visible sub-band-gap photoelectron emission. • The influence of film thickness and substrate on the measured photoelectron emission yields was not found. • Nanocrystalline diamonds have low electron emission yields most likely because of high amount of defects. • Visible sub-band gap photoelectron emission may increase with temperature due to electron trapping/detrapping processes. - Abstract: In this study the origin of visible sub-band gap photoelectron emission (PEE) from polycrystalline diamond films is investigated. The PEE yields as a function of temperature were studied in the wavelengths range of 360–520 nm. Based on the comparison of electron emission yields from diamond films deposited on silicon and molybdenum substrates, with different thicknesses and nitrogen doping levels, we suggested that photoelectrons are generated from nitrogen related centers in diamond. Our results show that diamond film thickness and substrate material have no significant influence on the PEE yield. We found that nanocrystalline diamond films have low electron emission yields, compared to microcrystalline diamond, due to the presence of high amount of defects in the former, which trap excited electrons before escaping into the vacuum. However, the low PEE yield of nanocrystalline diamond films was found to increase with temperature. The phenomenon was explained by the trap assisted photon enhanced thermionic emission (ta-PETE) model. According to the ta-PETE model, photoelectrons are trapped by shallow traps, followed by thermal excitation at elevated temperatures and escape into the vacuum. Activation energies of trap levels were estimated for undoped nanocrystalline, undoped microcrystalline and N-doped diamond films using the Richardson-Dushman equation, which gives 0.13, 0.39 and 0.04 eV, respectively. Such low activation energy of trap levels makes the ta-PETE process very

The Interactions between Facilitator Identity, Conflictual Presence, and Social Presence in Peer-Moderated Online Collaborative Learning

Science.gov (United States)

Xie, Kui; Lu, Lin; Cheng, Sheng-Lun; Izmirli, Serkan

2017-01-01

Research has focused on the significance of social presence in online learning. However, peer interaction does not always result in positive emotions and feelings; it can trigger tension, distress, and anger within a learning community. Therefore, conflictual presence, as a carrier of negative valence within presence, is also a critical element…

Effect of gasoline/methanol blends on motorcycle emissions: Exhaust and evaporative emissions

Science.gov (United States)

Li, Lan; Ge, Yunshan; Wang, Mingda; Li, Jiaqiang; Peng, Zihang; Song, Yanan; Zhang, Liwei

2015-02-01

The emission characteristics of motorcycles using gasoline and M15 (consisting of 85% gasoline and 15% methanol by volume) were investigated in this article. Exhaust and evaporative emissions, including regulated and unregulated emissions, of three motorcycles were investigated on the chassis dynamometer over the Urban Driving Cycle (UDC) and in the Sealed Housing for Evaporative Determination (SHED), respectively. The regulated emissions were detected by an exhaust gas analyzer directly. The unregulated emissions, including carbonyls, volatile organic compounds (VOCs) and methanol, were sampled through battery-operated air pumps using tubes coated with 2,4-dintrophenylhydrazine (DNPH), Tenax TA and silica gel, respectively. The experimental results showed that, for exhaust emission, compared with those from gasoline fueled motorcycles, the concentration of total hydrocarbons (THC) and CO from motorcycles fueled with M15 decreased by 11%-34.5% and 63%-84% respectively, while the concentration of NOx increased by 76.9%-107.7%. Compared with those from gasoline fueled motorcycles, BTEX from motorcycles fueled with M15 decreased by 16%-60% while formaldehyde increased by 16.4%-52.5%. For evaporative emission, diurnal losses were more than hot soak losses and turned out to be dominated in evaporative emissions. In addition, compared with gasoline fueling motorcycles, the evaporative emissions of THC, carbonyls and VOCs from motorcycles fueled with M15 increased by 11.7%-37%, 38%-45% and 16%-42%, respectively. It should be noted that the growth rate of methanol was as high as 297%-1429%. It is important to reduce the evaporative emissions of methanol fueling motorcycles.

Extended hard-X-ray emission in the inner few parsecs of the Galaxy

DEFF Research Database (Denmark)

Perez, Kerstin; Hailey, Charles J.; Bauer, Franz E.

2015-01-01

of objects emitting soft X-rays (less than 10 kiloelectronvolts) within the surrounding hundreds of parsecs, as well as the population responsible for unresolved X-ray emission extending along the Galactic plane, is dominated by accreting white dwarf systems. Observations of diffuse hard-X-ray (more than 10...... kiloelectronvolts) emission in the inner 10 parsecs, however, have been hampered by the limited spatial resolution of previous instruments. Here we report the presence of a distinct hard-X-ray component within the central 4 × 8 parsecs, as revealed by subarcminute-resolution images in the 20-40 kiloelectronvolt...... outflows interacting with the surrounding radiation field, dense molecular material or magnetic fields. However, all these interpretations pose significant challenges to our understanding of stellar evolution, binary formation, and cosmic-ray production in the Galactic Centre....

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...

Evaluation of PCDD/Fs emissions during ceramic production: a laboratory study.

Science.gov (United States)

Lu, Mang; Luo, Yi-Jing; Zhang, Zhong-Zhi; Xiao, Meng; Zhang, Min

2012-08-30

Because of the ubiquity of polychlorinated dibenzo-p-dioxins and dibenzofurans (PCDD/Fs) in kaolinitic clays, the ceramic industry is considered to be a potential source of PCDD/Fs. However, studies on the emission of PCDD/Fs from ceramic production are still very scarce. In this study, PCDD/Fs emissions during ceramic production were investigated in an electric laboratory batch kiln. The results showed that the PCDD/Fs were completely removed from the ceramic pieces after 30 min of firing at the peak temperature of 1200°C. Nevertheless, on the mass and international toxic equivalent basis, 27.5% and 46.2% of the total PCDD/Fs amount in the raw clay were released into the atmosphere during firing, respectively. These PCDD/Fs were emitted into the air before the temperature was elevated to a level high enough for their destruction. Dechlorination reactions generated a broad distribution within the PCDD/Fs congeners including a variety of non-2,3,7,8-substituted ones. The emission of PCDD/Fs was decreased to 16.3 wt.% of the total PCDD/Fs amount in the raw clay, when the initial kiln temperature was enhanced to 600°C. The emission of PCDD/Fs could be reduced significantly in the presence of a glaze coating on the ceramic test piece. These results indicated that ceramic production is an un-neglectable source of PCDD/Fs in the environment. Copyright © 2012 Elsevier B.V. All rights reserved.

Experiential study on temperature and emission performance of micro burner during porous media combustion

Science.gov (United States)

Janvekar, Ayub Ahmed; Abdullah, M. Z.; Ahmad, Z. A.; Abas, A.; Ismail, A. K.; Hussien, A. A.; Kataraki, P. S.; Ishak, M. H. H.; Mazlan, M.; Zubair, A. F.

2018-05-01

Addition of porous materials in reaction zone give rise to significant improvements in combustion performance. In this work, a dual layered micro porous media burner was tested for stable flame and emissions. Reaction and preheat layer was made up of discrete (zirconia) and foam (porcelain) type of materials respectively. Three different thickness of reaction zone was tested, each with 10, 20 and 30mm. Interestingly, only 20mm thick layer can able to show better thermal efficiency of 72% as compared to 10 and 30mm. Best equivalence ratio came out to be 0.7 for surface and 0.6 for submerged flame conditions. Moreover, emission was continuously monitored to detect presence of NOx and CO, which were under controlled limits.

Double-peaked Emission Lines Due to a Radio Outflow in KISSR 1219

Energy Technology Data Exchange (ETDEWEB)

Kharb, P.; Vaddi, S. [National Centre for Radio Astrophysics—Tata Institute of Fundamental Research, Postbag 3, Ganeshkhind, Pune 411007 (India); Subramanian, S. [Kavli Institute for Astronomy and Astrophysics, Peking University, 5 Yiheyuan Road, Haidian District, Beijing 100871 (China); Das, M. [Indian Institute of Astrophysics, II Block, Koramangala, Bangalore 560034 (India); Paragi, Z., E-mail: kharb@ncra.tifr.res.in [Joint Institute for VLBI in Europe, Postbus 2, 7990 AA Dwingeloo (Netherlands)

2017-09-01

We present the results from 1.5 and 5 GHz phase-referenced VLBA and 1.5 GHz Karl G. Jansky Very Large Array (VLA) observations of the Seyfert 2 galaxy KISSR 1219, which exhibits double-peaked emission lines in its optical spectrum. The VLA and VLBA data reveal a one-sided core-jet structure at roughly the same position angles, providing evidence of an active galactic nucleus outflow. The absence of dual parsec-scale radio cores puts the binary black-hole picture in doubt for the case of KISSR 1219. The high brightness temperatures of the parsec-scale core and jet components (>10{sup 6} K) are consistent with this interpretation. Doppler boosting with jet speeds of ≳0.55 c to ≳0.25 c , going from parsec to kiloparsec scales, at a jet inclination ≳50° can explain the jet one-sidedness in this Seyfert 2 galaxy. A blueshifted broad emission line component in [O iii] is also indicative of an outflow in the emission line gas at a velocity of ∼350 km s{sup −1}, while the [O i] doublet lines suggest the presence of shock-heated gas. A detailed line ratio study using the MAPPINGS III code further suggests that a shock+precursor model can explain the line ionization data well. Overall, our data suggest that the radio outflow in KISSR 1219 is pushing the emission line clouds, both ahead of the jet and in a lateral direction, giving rise to the double peak emission line spectra.

Estimation of carbon emission from peatland fires using Landsat-8 OLI imagery in Siak District, Riau Province

Science.gov (United States)

Aisyah Fadhillah Hafni, Dinda; Syaufina, Lailan; Puspaningsih, Nining; Prasasti, Indah

2018-05-01

The study was conducted in three land cover conditions (secondary peat forest, shrub land, and palm plantation) that were burned in the Siak District, Riau Province, Indonesia year 2015. Measurement and calculation carbon emission from soil and vegetation of peatland should be done accurately to be implemented on climate change mitigation or greenhouse gases mitigation. The objective of the study was to estimate the carbon emission caused peatland fires in the Siak District, Riau Province, Indonesia year 2015. Estimated carbon emissions were performed using visual method and digital method. The visual method was a method that uses on-screen digitization assisted by hotspot data, the presence of smoke, and fire suppression data. The digital method was a method that uses the Normalized Burn Ratio (NBR) index. The estimated carbon emissions were calculated using the equation that was developed from IPCC 2006 in Verified Carbon Standard 2015. The results showed that the estimation of carbon emissions from fires from above the peat soil surface were higher than the carbon emissions from the peat soil. Carbon emissions above the peat soil surface of 1376.51 ton C/ha were obtained by visual method while 3984.33 ton C/ha were obtained by digital method. Peatland carbon emissions of 6.6 x 10-4 ton C/ha were obtained by visual method, whereas 2.84 x 10-3 ton C/ha was obtained by digital method. Visual method and digital method using remote sensing must be combined and developed in order to carbon emission values will be more accurate.

TOWARD AN EMPIRICAL THEORY OF PULSAR EMISSION. X. ON THE PRECURSOR AND POSTCURSOR EMISSION

International Nuclear Information System (INIS)

Basu, Rahul; Mitra, Dipanjan; Rankin, Joanna 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 analysis we find that PPC components have properties very different from that of outer conal emission. The separation of the PPC components from the main pulse center remains constant with frequency. In addition the beam opening angles corresponding to the separation of PPC components from the pulsar center are much larger than the largest encountered in conal emission. Pulsar radio emission is believed to originate within the magnetic polar flux tubes due to the growth of instabilities in the outflowing relativistic plasma. Observationally, there is strong evidence that the main pulse emission originates at altitudes of about 50 neutron star radii for a canonical pulsar. Currently, the most plausible radio emission model that can explain main pulse emission is the coherent curvature radiation mechanism, wherein relativistic charged solitons are formed in a non-stationary electron-positron-pair plasma. The wider beam opening angles of PPC require the emission to emanate from larger altitudes as compared to the main pulse, if both these components originate by the same emission mechanism. We explore this possibility and find that this emission mechanism is probably inapplicable at the height of the PPC emission. We propose that the PPC emission represents a new type of radiation from pulsars with a mechanism different from that of the main pulse

Estimation of vehicular emissions using dynamic emission factors: A case study of Delhi, India

Science.gov (United States)

Mishra, Dhirendra; Goyal, P.

2014-12-01

The estimation of vehicular emissions depends mainly on the values of emission factors, which are used for the development of a comprehensive emission inventory of vehicles. In this study the variations of emission factors as well as the emission rates have been studied in Delhi. The implementation of compressed natural gas (CNG), in the diesel and petrol, public vehicles in the year 2001 has changed the complete air quality scenario of Delhi. The dynamic emission factors of criteria pollutants viz. carbon monoxide (CO), nitrogen oxide (NOx) and particulate matter (PM10) for all types of vehicles have been developed after, which are based on the several factors such as regulated emission limits, number of vehicle deterioration, vehicle increment, vehicle age etc. These emission factors are found to be decreased continuously throughout the study years 2003-2012. The International Vehicle Emissions (IVE) model is used to estimate the emissions of criteria pollutants by utilizing a dataset available from field observations at different traffic intersections in Delhi. Thus the vehicular emissions, based on dynamic emission factors have been estimated for the years 2003-2012, which are found to be comparable with the monitored concentrations at different locations in Delhi. It is noticed that the total emissions of CO, NOx, and PM10 are increased by 45.63%, 68.88% and 17.92%, respectively up to the year 2012 and the emissions of NOx and PM10 are grown continuously with an annual average growth rate of 5.4% and 1.7% respectively.

Emission Sectoral Contributions of Foreign Emissions to Particulate Matter Concentrations over South Korea

Science.gov (United States)

Kim, E.; Kim, S.; Kim, H. C.; Kim, B. U.; Cho, J. H.; Woo, J. H.

2017-12-01

In this study, we investigated the contributions of major emission source categories located upwind of South Korea to Particulate Matter (PM) in South Korea. In general, air quality in South Korea is affected by anthropogenic air pollutants emitted from foreign countries including China. Some studies reported that foreign emissions contributed 50 % of annual surface PM total mass concentrations in the Seoul Metropolitan Area, South Korea in 2014. Previous studies examined PM contributions of foreign emissions from all sectors considering meteorological variations. However, little studies conducted to assess contributions of specific foreign source categories. Therefore, we attempted to estimate sectoral contributions of foreign emissions from China to South Korea PM using our air quality forecasting system. We used Model Inter-Comparison Study in Asia 2010 for foreign emissions and Clean Air Policy Support System 2010 emission inventories for domestic emissions. To quantify contributions of major emission sectors to South Korea PM, we applied the Community Multi-scale Air Quality system with brute force method by perturbing emissions from industrial, residential, fossil-fuel power plants, transportation, and agriculture sectors in China. We noted that industrial sector was pre-dominant over the region except during cold season for primary PMs when residential emissions drastically increase due to heating demand. This study will benefit ensemble air quality forecasting and refined control strategy design by providing quantitative assessment on seasonal contributions of foreign emissions from major source categories.

Presence While Watching Movies

Directory of Open Access Journals (Sweden)

Tom Troscianko

2011-05-01

Full Text Available “Presence” is the illusion of being in a mediated experience rather than simply being an observer. It is a concept often applied to the question of realism of virtual environments. However, it is equally applicable to the act of watching a movie. A movie provides a markedly different visual environment to that given by the natural world—particularly because of frequent edits. And yet, the audience in a movie achieves high levels of presence. We investigate the relationship between presence and the optical and temporal parameters of movies. We find effects of mean shot length, colour/b&w, and 3D/2D. We find that short shots, while being unnatural, are associated with high levels of presence. We consider why such artificial stimuli should appear so real and immersive.

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.

EU-Type Carbon Emissions Trade and the Distributional Impact of Overlapping Emissions Taxes

OpenAIRE

Thomas Eichner; Rüdiger Pethig

2009-01-01

The European Union fulfills its emissions reductions commitments by means of an emissions trading scheme covering some part of each member state’s economy and by national emissions control in the rest of their economies. The member states also levy energy/emissions taxes overlapping with the trading scheme. Restricting our focus on cost-effective policies, this paper investigates the distributive consequences of increasing the overlapping emissions tax that is uniform across countries. For ...

Thallium and manganese complexes involved in the luminescence emission of potassium-bearing aluminosilicates

Energy Technology Data Exchange (ETDEWEB)

Gomez-Gonzalez, Miguel A., E-mail: miguel.gomez@mncn.csic.es [Museo Nacional de Ciencias Naturales, CSIC, Jose Gutierrez Abascal 2, Madrid E-28006 (Spain); Garcia-Guinea, Javier, E-mail: guinea@mncn.csic.es [Museo Nacional de Ciencias Naturales, CSIC, Jose Gutierrez Abascal 2, Madrid E-28006 (Spain); Garrido, Fernando, E-mail: fernando.garrido@mncn.csic.es [Museo Nacional de Ciencias Naturales, CSIC, Jose Gutierrez Abascal 2, Madrid E-28006 (Spain); Townsend, Peter D., E-mail: pdtownsend@gmail.com [School of Science and Technology, University of Sussex, Brighton BN1 9QH (United Kingdom); Marco, Jose-Francisco, E-mail: jfmarco@iqfr.csic.es [Instituto de Química-Física Rocasolano, CSIC, Calle Serrano 119, Madrid E-28006 (Spain)

2015-03-15

The luminescence emission at 285 nm in natural K-feldspar has been studied by Russian groups and associated with thallium ions in structural positions of K{sup +} sites as artificially thallium-doped feldspars display the same emission band. Here attention is focussed on spectra of CL emission bands centered near 285 and 560 nm from paragenetic adularia, moscovite and quartz micro-inclusions. With accesorial thallium they show clear resemblances to each other. Associated sedimentary and hydrothermal aluminosilicate samples collected from Guadalix (Madrid, Spain) were analyzed with a wide range of experimental techniques including Environmental Scanning Electron Microscopy (ESEM) with an attached X-Ray Energy-Dispersive Spectrometer (EDS) and a cathodoluminescence probe (CL) and Electron Probe Microanalysis (EPMA), X-Ray Fluorescence Spectrometry (XRF), Inductively Coupled Plasma-Optical Emission Spectrometry (ICP-OES), Differential and Thermogravimetric Analyses (DTA-TG), radioluminescence (RL), Mössbauer spectroscopy and X-Ray Photoelectron Spectrometry (XPS). The luminescence emission bands at 285 and 560 nm seem to be associated with hydrous thallium–manganese complexes bonded to potassium-bearing aluminosilicates since various minerals such as K-feldspar, moscovite and quartz micro-inclusions display similar CL spectra, accesorial thallium and hydroxyl groups. The presence of iron introduces a brown color which is attributed to submicroscopic iron oxides detectable in the optical and chemical microanalysis, but this does not contribute to the luminescence emission. The XPS Mn 2p spectrum of the adularia sample at room temperature is composed of a spin–orbit doublet plus clear shake-up satellite structure ∼4 eV above the main photoemision lines and is consistent with Mn{sup 2+} in good agreement with the observed luminescence emission at 560 nm for aluminosilicates produced by a {sup 4}T1({sup 4}G)→{sup 6}A1({sup 6}S) transition in tetrahedrally

Study of the high energy emission of accreting compact objects with SPI/INTEGRAL

International Nuclear Information System (INIS)

Droulans, R.

2011-01-01

The study of the high energy emission is essential for understanding the radiative processes inherent to accretion flows onto compact objects (black holes and neutron stars). The X/γ-ray continuum of these systems is successfully interpreted in terms of two components. The first component corresponds to blackbody emission from a geometrically thin optically thick accretion disk while the second component is generally associated to Compton scattering of the thermal disk flux off hot electrons. Despite considerable advances throughout the years, the heating mechanisms as well as the structure of the hot Comptonizing plasma remain poorly understood. In order to shed light on the physical processes that govern the innermost regions of the accretion flow, we take advantage of the data archive accumulated by the SPI instrument, a high energy spectrometer (20 keV - 8 MeV) developed at the CESR (now IRAP, Toulouse, France) for the INTEGRAL mission. Above 150 keV, SPI combines a unique spectral resolution with unequalled sensitivity, being thus an ideal tool to study the high energy emission of accreting compact objects. The thesis manuscript reports on the results of timing and spectral studies of three particular systems. First, I address the high energy emission of the enigmatic micro-quasar GRS 1915+105, a source characterized by colossal luminosity and strong chaotic variability in X-rays. On a timescale of about one day, the photon index of the 20 - 200 keV spectrum varies between 2.7 and 3.5; at higher energies (≥150 keV), SPI unveils the systematic presence of an additional emission component, extending without folding energy up to ∼ 500 keV. Second, I study the high energy emission of GX 339-4, a source whose spectral properties are representative of black hole transients. The spectrum of the luminous hard state of this system shows a variable high energy tail (≥150 keV), with significant flux changes on a short timescale (several hours). I explain the

Emissions of nitrogen oxides from road traffic - regulations, emissions and effects

International Nuclear Information System (INIS)

Sjoedin, Aake; Pihl-Karlsson, Gunilla; Johansson, Manne; Forsberg, Bertil; Erlandsson, Lennart

2004-10-01

The report is a review that aims to improve the basis for additional measures against the road traffic emissions of, in particular, NO x . An important question in the context is whether health effects of NO 2 should serve as a norm for the actions for emission reductions of NO x , or if the environmental effects of NO x -emissions in the form of acidification, eutrophication and ozone should play this role. WHO notes, in its latest review of health effect research, that one cannot demonstrate that NO 2 alone has any direct effects in concentrations at the current whole-year mean norm (40 μg/m 3 ). Such health effects that has been demonstrated in epidemiologic studies at these concentrations are caused by other traffic related emissions (e. g. particles) for which NO 2 constitutes a good indicator. WHO indicates the need for additional sharpening of the norms for ozone and particles. In this context, it is important to note that emissions of NO x on a regional scale contributes to formation of ozone as well as particles. Therefore there exist reasons to decrease the emissions of NO x in order to reach future recommended values for ozone and particles emissions. In the evaluations that will be done during 2004-2005 of the so called Goeteborg protocol, the EU's Ceiling Directives and the CAFE-programme, it is expected that new emissions objective for NO x will be suggested for 2015-2020, to cope with health and environment objectives in Europe. The report shows that that development that currently happens within the vehicle industry, for engines and exhaust emission control system are pursued to meet future exhaust requirement in the USA gives good conditions for the road traffic sector to contribute to that these objectives will reached

Preparation of hydroxyapatite nanoparticles facilitated by the presence of {beta}-cyclodextrin

Energy Technology Data Exchange (ETDEWEB)

Martinez-Perez, Carlos A., E-mail: camartin@uacj.mx [Institute of Engineering and Technology, Autonomous University of Juarez, UACJ, Ave. del Charro 610 norte, C.P. 32320, Cd. Juarez, Chihuahua (Mexico); Garcia-Montelongo, Jorge; Garcia Casillas, Perla E.; Farias-Mancilla, Jose R. [Institute of Engineering and Technology, Autonomous University of Juarez, UACJ, Ave. del Charro 610 norte, C.P. 32320, Cd. Juarez, Chihuahua (Mexico); Monreal Romero, Humberto [School of Odontology, Autonomous University of Chihuahua, UACH, Ave. Universidad s/n Campus Universitario I, C.P. 31170, Chihuahua (Mexico)

2012-09-25

Highlights: Black-Right-Pointing-Pointer It was found that {beta}-cyclodextrin can control the particle size in the production of nanohydroxyapatite. Black-Right-Pointing-Pointer Particle size in the range of 30-50 nm was obtained. Black-Right-Pointing-Pointer A new simple methodology for the preparation of hydroxyapatite nanoparticles with a well controlled size and narrow particles size distribution was developed. - Abstract: Hydroxyapatite nanoparticles with uniform morphology have been successfully synthesized by a chemical coprecipitation method and facilitated by the presence of the {beta}-cyclodextrin. X-ray diffraction (XRD), field emission scanning electron microscopy (FESEM), transmission electron microscopy (TEM); and Fourier Transformed Infrared Spectroscopy (FT-IR) were used in order to characterize the hydroxyapatite samples. The experimental results indicate that the obtained HA is in the range of 20-50 nm. Also it was found that the content of {beta}-CD has an impact on the purity of the HA as well in the particle size of the hydroxyapatite nanoparticles.

Preparation of hydroxyapatite nanoparticles facilitated by the presence of β-cyclodextrin

International Nuclear Information System (INIS)

Martínez-Pérez, Carlos A.; García-Montelongo, Jorge; Garcia Casillas, Perla E.; Farias-Mancilla, José R.; Monreal Romero, Humberto

2012-01-01

Highlights: ► It was found that β-cyclodextrin can control the particle size in the production of nanohydroxyapatite. ► Particle size in the range of 30–50 nm was obtained. ► A new simple methodology for the preparation of hydroxyapatite nanoparticles with a well controlled size and narrow particles size distribution was developed. - Abstract: Hydroxyapatite nanoparticles with uniform morphology have been successfully synthesized by a chemical coprecipitation method and facilitated by the presence of the β-cyclodextrin. X-ray diffraction (XRD), field emission scanning electron microscopy (FESEM), transmission electron microscopy (TEM); and Fourier Transformed Infrared Spectroscopy (FT-IR) were used in order to characterize the hydroxyapatite samples. The experimental results indicate that the obtained HA is in the range of 20–50 nm. Also it was found that the content of β-CD has an impact on the purity of the HA as well in the particle size of the hydroxyapatite nanoparticles.

Thermal degradation of the vapours of organic nitrogen compounds in the presence of the air

International Nuclear Information System (INIS)

Brault, A.; Chevalier, G.; Kerfanto, M.; Loyer, H.

1983-04-01

Following a quick survey of the literature on the products originated during the thermal degradation of some organic nitrogen compounds, the experimental results obtained by applying a technique previously used for other organic compounds are presented. The compounds investigated include: methyl and ethylamines at the origin of the bad smells of many gaseous wastes, trilaurylamine and tetraethylenediamine sometimes used in nuclear facilities. Attention is brought on the emission of noxious products during thermal degradation in the presence of the air, at various temperatures, viz. either usual combustion gases such as carbon monoxide, or nitro-derivatives such as hydrogen cyanide present whatever the compound investigated when temperatures are below 850 0 C [fr

Emission computed tomography

International Nuclear Information System (INIS)

Ott, R.J.

1986-01-01

Emission Computed Tomography is a technique used for producing single or multiple cross-sectional images of the distribution of radionuclide labelled agents in vivo. The techniques of Single Photon Emission Computed Tomography (SPECT) and Positron Emission Tomography (PET) are described with particular regard to the function of the detectors used to produce images and the computer techniques used to build up images. (UK)

Single photon emission computed tomography of the liver

International Nuclear Information System (INIS)

Makler, P.T. Jr.

1988-01-01

Single photon emission computed tomography (SPECT) of the liver has been introduced in order to improve sensitivity and localization of space-occupying lesions. There have been numerous reports on the usefulness of the technique, as well as extensive analyses of its technical drawbacks. In general, SPECT provides a more accurate estimation of defect size than does conventional planar scintigraphy for cases in which one wishes to evaluate changes in lesion size due to therapy. The presence of a superimposed parenchymal disease, however, remains a major problem, which will only be resolved by a scanning technique that specifically detects the disease process of concern (hot spot imaging) rather than displacement of normal tissue (cold spot imaging)

Shipping emissions in ports

OpenAIRE

Merk, Olaf

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...

Hot Dust! Late-Time Infrared Emission From Supernovae

Science.gov (United States)

Fox, Ori; Skrutskie, M. F.; Chevalier, R. A.

2010-01-01

Supernovae light curves typically peak and fade in the course of several months. Some supernovae , however, exhibit late-time infrared emission that in some cases can last for several years. These supernovae tend to be of the Type IIn subclass, which is defined by narrow hydrogen and helium emission lines arising from a dense, pre-existing circumstellar medium excited by the supernova radiation. Such a late-time ``IR excess'' with respect to the optical blackbody counterpart typically indicates the presence of warm dust. The origin and heating mechanism of the dust is not, however, always well constrained. In this talk, I will explore several scenarios that explain the observed late-time emission. In particular, I will discuss the case of the Type IIn SN 2005ip, which has displayed an ``IR excess'' for over 3 years. The results allow us to interpret the progenitor system and better understand the late stages of stellar evolution. Much of the data used for this analysis were obtained with TripleSpec, a medium-resolution near-infrared spectrograph located at Apache Point Observatory, NM, and FanCam, a JHK imager located at Fan Mountain Observatory, just outside of Charlottesville, VA. These two instruments were designed, fabricated, built, and commissioned by our instrumentation group at the University of Virginia. I will also spend some time discussing these instruments. I would like to thank the following for financial support of this work throughout my graduate career: NASA GSRP, NSF AAG-0607737, Spitzer PID 50256, Achievement Reward for College Scientists (ARCS), and the Virginia Space Grant Consortium.

Characterisation of acid pollutant emissions in ceramic tile manufacture

Directory of Open Access Journals (Sweden)

Monfort, E.

2011-08-01

Full Text Available One of the environmental impacts associated with ceramics manufacture is the air emission of acid compounds stem from the presence of impurities in the raw materials and/or fuels. The present study was undertaken to identify the significant gaseous pollutants of an acid nature, to determine their concentrations, and to obtain the characteristic emission factors in spray dryers and firing kilns. The results show that, in spray dryers, the emission levels of the different acid pollutants are far below the current emission limit values applied in the European Union (EU. In firing kilns, the most significant acid pollutant emissions, compared with the recommended EU emission limit values (ELV-BAT, correspond to HF and HCl emissions, indicating that these emissions need to be corrected by appropriate cleaning systems before such emissions are released into the air. On the other hand, the results indicate that SO₂ and NO_x emissions in the Castellón industrial ceramic sector lie below the ELV–BAT proposed in the European ceramic industry BREF, owing to the widespread use of natural gas as fuel and of raw materials with reduced sulphur contents.

Uno de los impactos medioambientales asociado a la fabricación de productos cerámicos es la emisión a la atmósfera de compuestos ácidos debido a la presencia de impurezas en las materias primas y/o combustibles. Los objetivos del presente estudio son: identificar los contaminantes gaseosos de naturaleza ácida significativos, determinar su concentración y obtener factores de emisión de los secaderos por atomización y los hornos de cocción. Los resultados obtenidos, en el caso de los secaderos por atomización, muestran que los niveles de emisión de los diferentes contaminantes ácidos se encuentran alejados de los valores límite de emisiones aplicados actualmente en la Unión Europea (UE. En cuanto a los hornos de cocción, la emisión más significativa de

Dual fluorescence and laser emissions from fluorescein-Na and eosin-B

International Nuclear Information System (INIS)

Math, N.N.; Naik, L.R.; Suresh, H.M.; Inamdar, S.R.

2006-01-01

Dual laser emissions were observed from fluorescein-Na and eosin-B in ethanolic solutions individually in the concentration range from 10 -2 to 10 -3 mol dm -3 under N 2 laser excitation. The first compound was found to lase at two distinct regions with wavelength maxima around 540, 550 nm, while the second one around 558, 574 nm. Steady-state absorption, fluorescence excitation, fluorescence polarization, fluorescence emission and decays of the dyes in various solvents under varying conditions of excitation and detection systems were carried out to identify the nature of the emitting species responsible for laser emissions in two distinct regions. Both the dyes exhibited concentration and excitation wavelength dependence of fluorescence and the effects were found to be more pronounced in binary solution. The fluorescence decays of dyes were monoexponential in ethanol, while in some other solvents used, the decays showed biexponential behavior. The absorption and excitation studies using thin layers of solutions revealed the formation of dimers with the dye concentration around 1x10 -3 mol dm -3 . Fluorescence polarization and decay studies confirmed the presence of dimers. The two laser bands observed in the shorter and longer wavelengths were respectively ascribed to monomeric and dimeric species

Dual fluorescence and laser emissions from fluorescein-Na and eosin-B

Energy Technology Data Exchange (ETDEWEB)

Math, N.N. [Laser Spectroscopy (DRDO/KU) Programme, Department of Physics, Karnatak University, Dharwad 580 003 (India)]. E-mail: nnm31@rediffmail.com; Naik, L.R. [Laser Spectroscopy (DRDO/KU) Programme, Department of Physics, Karnatak University, Dharwad 580 003 (India); Suresh, H.M. [Laser Spectroscopy (DRDO/KU) Programme, Department of Physics, Karnatak University, Dharwad 580 003 (India); Inamdar, S.R. [Laser Spectroscopy (DRDO/KU) Programme, Department of Physics, Karnatak University, Dharwad 580 003 (India)

2006-12-15

Dual laser emissions were observed from fluorescein-Na and eosin-B in ethanolic solutions individually in the concentration range from 10{sup -2} to 10{sup -3} mol dm{sup -3} under N{sub 2} laser excitation. The first compound was found to lase at two distinct regions with wavelength maxima around 540, 550 nm, while the second one around 558, 574 nm. Steady-state absorption, fluorescence excitation, fluorescence polarization, fluorescence emission and decays of the dyes in various solvents under varying conditions of excitation and detection systems were carried out to identify the nature of the emitting species responsible for laser emissions in two distinct regions. Both the dyes exhibited concentration and excitation wavelength dependence of fluorescence and the effects were found to be more pronounced in binary solution. The fluorescence decays of dyes were monoexponential in ethanol, while in some other solvents used, the decays showed biexponential behavior. The absorption and excitation studies using thin layers of solutions revealed the formation of dimers with the dye concentration around 1x10{sup -3} mol dm{sup -3}. Fluorescence polarization and decay studies confirmed the presence of dimers. The two laser bands observed in the shorter and longer wavelengths were respectively ascribed to monomeric and dimeric species.

Soil CO2 emission as related to incorporation of sugarcane crop residues and aggregate breaking after rotary tiller Emissão de CO2 do solo em função da incorporação de palha de cana-de-açúcar e quebra de agregados após preparo com enxada rotativa

Directory of Open Access Journals (Sweden)

Luis G Teixeira

2011-12-01

Full Text Available Soil tillage is a process that accelerates soil organic matter decomposition transferring carbon to atmosphere, mainly in the CO2 form. In this study, the effect of rotary tillage on soil CO2 emission was investigated, including the presence of crop residues on the surface.Emissions were evaluated during 15 days after tillage in 3 plots: 1 non-tilled and without crop residues on soil surface (NTwo, 2 rotary tiller without the presence of crop residues on soil surface (RTwo, and 3 rotary tiller with the presence of crop residues in soil surface (RTw. Emissions from the RTw plot were higher than the other plots, (0.777 g CO2 m-2 h-1, with the lowest emissions recorded in the NTwo plot (0.414 g CO2 m-2 h-1. Total emission indicates that the difference of C-CO2 emitted to atmosphere corresponds to 3% of the total additional carbon in the crop residues in the RTw plot compared to RTwo. The increase in the RTwo emission in comparison to NTwo was followed by changes in the aggregate size distribution, especially those with average diameter lower than 2 mm. The increase in emission from the RTw plot in relation to RTwo was related to a decrease in crop residue mass on the surface, and its higher fragmentation and incorporation in soil. When the linear correlation between soil CO2 emission, and soil temperature and soil moisture is considered, only the RTw treatment showed significant correlation (pO preparo do solo é um dos processos que aceleram a decomposição da matéria orgânica, transferindo carbono para atmosfera, principalmente na forma de CO2. Neste trabalho, investigou-se o efeito do preparo com enxada rotativa sobre as emissões de CO2 do solo durante 02 semanas após o preparo do solo, incluindo-se a presença de resíduos vegetais sobre a superfície. As emissões foram avaliadas por 15 dias após preparo em 3 parcelas: 1 sem preparo e sem palha superficial (SPs; 2 preparo com enxada rotativa sem a presença de palha na superfície (ERs

Study on Emission and Performance of Diesel Engine Using Castor Biodiesel

Directory of Open Access Journals (Sweden)

Md. Saiful Islam

2014-01-01

performance of diesel engine using the castor biodiesel and its blend with diesel from 0% to 40% by volume. The acid-based catalyzed transesterification system was used to produce castor biodiesel and the highest yield of 82.5% was obtained under the optimized condition. The FTIR spectrum of castor biodiesel indicates the presence of C=O and C–O functional groups, which is due to the ester compound in biodiesel. The smoke emission test revealed that B40 (biodiesel blend with 40% biodiesel and 60% diesel had the least black smoke compared to the conventional diesel. Diesel engine performance test indicated that the specific fuel consumption of biodiesel blend was increased sufficiently when the blending ratio was optimized. Thus, the reduction in exhaust emissions and reduction in brake-specific fuel consumption made the blends of caster seed oil (B20 a suitable alternative fuel for diesel and could help in controlling air pollution.

Air Emission Inventory for the Idaho National Engineering Laboratory, 1993 emissions report

International Nuclear Information System (INIS)

1994-06-01

This report presents the 1993 update of the Air Emission Inventory for the Idaho National Engineering Laboratory (INEL). The purpose of the Air Emission Inventory is to commence the preparation of the permit to operate application for the INEL, as required by the recently promulgated Title V regulations of the Clean Air Act. The report describes the emission inventory process and all of the sources at the INEL and provides emissions estimates for both mobile and stationary sources

Air Emission Inventory for the Idaho National Engineering Laboratory, 1993 emissions report

Energy Technology Data Exchange (ETDEWEB)

1994-06-01

This report presents the 1993 update of the Air Emission Inventory for the Idaho National Engineering Laboratory (INEL). The purpose of the Air Emission Inventory is to commence the preparation of the permit to operate application for the INEL, as required by the recently promulgated Title V regulations of the Clean Air Act. The report describes the emission inventory process and all of the sources at the INEL and provides emissions estimates for both mobile and stationary sources.

A spatially resolved study of the synchrotron emission and titanium in Tycho's supernova remnant using NuSTAR

DEFF Research Database (Denmark)

Lopez, Laura A.; Grefenstette, Brian W.; Reynolds, Stephen P.

2015-01-01

that the hardest (>10 keV) X-rays are concentrated in the southwest of Tycho, where recent Chandra observations have revealed high emissivity “stripes” associated with particles accelerated to the knee of the cosmic-ray spectrum. We do not find evidence of 44Ti, and we set limits on its presence and distribution......We report results from deep observations (~750 ks) of Tycho's supernova remnant (SNR) with NuSTAR. Using these data, we produce narrow-band images over several energy bands to identify the regions producing the hardest X-rays and to search for radioactive decay line emission from 44Ti. We find...

Emission and combustion profile study of unmodified research engine propelled with neat biofuels.

Science.gov (United States)

Devarajan, Yuvarajan; Mahalingam, Arulprakasajothi; Munuswamy, Dinesh Babu; Nagappan, Beemkumar

2018-05-07

The current work focuses on the experimental investigation to analyze the combustion and emission characteristics of a direct injection diesel engine fueled with neat biodiesel (BD100) and different proportions of cyclohexanol blends as a fuel additive in various volume fractions. Cyclohexanol is dispersed into a neat biodiesel in a volume fraction of 10, 20, and 30 vol%. The biodiesel is produced from neem oil by the conventional transesterification process. The experimental results revealed that with the increased cyclohexanol fraction, the combustion was found smooth. The addition of cyclohexanol has a positive influence on various physical and chemical properties of neat biodiesel. The in-cylinder pressure is comparatively low for diesel followed by cyclohexanol and biodiesel blends when compared with neat biodiesel. This is due to shorter ignition delay period. The heat-release rate of neat biodiesel is the highest among all fuels. The overall HC emission of BD70COH30 is 12.19% lower than BD100 and 16.34% lower than diesel. The overall CO 2 emission of BD70COH30 is 13.91% higher than BD100 and 19.5% higher than diesel. The overall NO x emission of BD70COH30 is 5.31% lower than BD100 at all load engine operations. The presence of 10, 20, and 30% of cyclohexanol in biodiesel decreased smoke emissions as compared with neat biodiesel and diesel. The overall smoke emission of BD70COH30 is 19.23% lower than BD100 and 25.51% lower than diesel. The overall CO emission of cyclohexanol blended with biodiesel by 30 vol% (BD70COH30) is 17% lower than neat biodiesel and 21.8% lower than diesel. Based on the outcome of this study, neem oil biodiesel and cyclohexanol blends can be employed as a potential alternative fuel for existing unmodified diesel engines owing to its lesser emission characteristics.

Evaluation of emission of greenhouse gases from soils amended with sewage sludge.

Science.gov (United States)

Paramasivam, S; Fortenberry, Gamola Z; Julius, Afolabi; Sajwan, Kenneth S; Alva, A K

2008-02-01

Increase in concentrations of various greenhouse gases and their possible contributions to the global warming are becoming a serious concern. Anthropogenic activities such as cultivation of flooded rice and application of waste materials, such as sewage sludge which are rich in C and N, as soil amendments could contribute to the increase in emission of greenhouse gases such as methane (CH(4)) and nitrous oxide (N(2)O) into the atmosphere. Therefore, evaluation of flux of various greenhouse gases from soils amended with sewage sludge is essential to quantify their release into the atmosphere. Two soils with contrasting properties (Candler fine sand [CFS] from Florida, and Ogeechee loamy sand [OLS] from Savannah, GA) were amended with varying rates (0, 24.7, 49.4, 98.8, and 148.3 Mg ha(-1)) of 2 types of sewage sludge (industrial [ISS] and domestic [DSS] origin. The amended soil samples were incubated in anaerobic condition at field capacity soil water content in static chamber (Qopak bottles). Gas samples were extracted immediately after amending soils and subsequently on a daily basis to evaluate the emission of CH(4), CO(2) and N(2)O. The results showed that emission rates and cumulative emission of all three gases increased with increasing rates of amendments. Cumulative emission of gases during 25-d incubation of soils amended with different types of sewage sludge decreased in the order: CO(2) > N(2)O > CH(4). The emission of gases was greater from the soils amended with DSS as compared to that with ISS. This may indicate the presence of either low C and N content or possible harmful chemicals in the ISS. The emission of gases was greater from the CFS as compared to that from the OLS. Furthermore, the results clearly depicted the inhibitory effect of acetylene in both soils by producing more N(2)O and CH(4) emission compared to the soils that did not receive acetylene at the rate of 1 mL g(-1) soil. Enumeration of microbial population by fluorescein diacetate

Analysis of sludge using Proton induced X-ray emission

International Nuclear Information System (INIS)

Aspiazu, J.; Moreno, E.; Andrade, E.; Miranda, J.; Citalan, S.; Moeller, G.; Soler, F.

1996-01-01

Regulations to control the huge amounts of sludge produced by wastewater are needed. Sludge generated in conventional sedimentators or anaerobic digesters were characterized by Proton Induced X-ray Emission (PIXE). It was possible to determine the presence of macro nutrient elements, such as P and K, and secondary nutrients like Ca, S, and Mg. Moreover, heavy elements like Cu, Zn, and Pb were also found. The sludge treatment in anaerobic digesters increased the amount of certain elements Al, Si, S, Cl, and K; decrease in Ca, Ti, and Cu, and no change in V, Cr, and Zn. Possible uses of this sludge are also suggested

Emission trading: A discussion paper

International Nuclear Information System (INIS)

1992-05-01

Emission trading is a market-based incentive program designed to control air emissions in which a cap is placed on the total quantity of pollutants allowed to be emitted in an airshed. Appropriate shares of this amount are allocated among participating emission sources, and participants can buy or sell their shares. Advantages of emission trading include its potential to achieve air emission targets at a lower cost than the traditional command and control approach, and its ability to accommodate economic growth without compromising environmental quality. A study was conducted to evaluate the potential use of emission trading programs to achieve emission reduction goals set for nitrogen oxides, volatile organic compounds (VOC), and sulfur oxides. Emission trading programs in the USA are reviewed and a set of factors important for the success of emission trading are identified. Key policy and design issues related to an emission trading program are identified, explained, and discussed. Administrative issues are then analyzed, such as legislative authority, monitoring and enforcement requirements, and trading between jurisdictions. A preliminary assessment of emission trading for control of NOx and VOC in the Lower Fraser Valley indicates that emission trading would be feasible, but legislative authority to implement such a program would have to be introduced

Temporal and spatial variation in recent vehicular emission inventories in China based on dynamic emission factors.

Science.gov (United States)

Cai, Hao; Xie, Shaodong

2013-03-01

The vehicular emission trend in China was tracked for the recent period 2006-2009 based on a database of dynamic emission factors of CO, nonmethane volatile organic compounds (NMVOC), NOx, PM10, CO2, CH4, and N2O for all categories of on-road motor vehicles in China, which was developed at the provincial level using the COPERT 4 model, to account for the effects of rapid advances in engine technologies, implementation of improved emission standards, emission deterioration due to mileage, and fuel quality improvement. Results show that growth rates of CO and NMVOC emissions slowed down, but NOx and PM10 emissions continued rising rapidly for the period 2006-2009. Moreover CO2, CH4, and N2O emissions in 2009 almost doubled compared to those in 2005. Characteristics of recent spatial distribution of emissions and emission contributions by vehicle category revealed that priority of vehicular emission control should be put on the eastern and southeastern coastal provinces and northern regions, and passenger cars and motorcycles require stricter control for the reduction of CO and NMVOC emissions, while effective reduction of NOx and PM10 emissions can be achieved by better control of heavy-duty vehicles, buses and coaches, and passenger cars. Explicit provincial-level Monte Carlo uncertainty analysis, which quantified for the first time the Chinese vehicular emission uncertainties associated with both COPERT-derived and domestically measured emission factors by vehicle technology, showed that CO, NMVOC, and NOx emissions for the period 2006-2009 were calculated with the least uncertainty, followed by PM10 and CO2, despite relatively larger uncertainties in N2O and CH4 emissions. The quantified low uncertainties of emissions revealed a necessity of applying vehicle technology- and vehicle age-specific dynamic emission factors for vehicular emission estimation, and these improved methodologies are applicable for routine update and forecast of China's on-road motor vehicle

Pre-compound emission in low-energy heavy-ion interactions

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Kumar Sharma Manoj

2017-01-01

Full Text Available Recent experimental studies have shown the presence of pre-compound emission component in heavy ion reactions at low projectile energy ranging from 4 to 7 MeV/nucleons. In earlier measurements strength of the pre-compound component has been estimated from the difference in forward-backward distributions of emitted particles. Present measurement is a part of an ongoing program on the study of reaction dynamics of heavy ion interactions at low energies aimed at investigating the effect of momentum transfer in compound, precompound, complete and incomplete fusion processes in heavy ion reactions. In the present work on the basis of momentum transfer the measurement of the recoil range distributions of heavy residues has been used to decipher the components of compound and pre-compound emission processes in the fusion of 16O projectile with 159Tb and 169Tm targets. The analysis of recoil range distribution measurements show two distinct linear momentum transfer components corresponding to pre-compound and compound nucleus processes are involved. In order to obtain the mean input angular momentum associated with compound and pre-compound emission processes, an online measurement of the spin distributions of the residues has been performed. The analysis of spin distribution indicate that the mean input angular momentum associated with pre-compound products is found to be relatively lower than that associated with compound nucleus process. The pre-compound components obtained from the present analysis are consistent with those obtained from the analysis of excitation functions.

Pre-compound emission in low-energy heavy-ion interactions

Science.gov (United States)

Sharma, Manoj Kumar; Shuaib, Mohd.; Sharma, Vijay R.; Yadav, Abhishek; Singh, Pushpendra P.; Singh, Devendra P.; Unnati; Singh, B. P.; Prasad, R.

2017-11-01

Recent experimental studies have shown the presence of pre-compound emission component in heavy ion reactions at low projectile energy ranging from 4 to 7 MeV/nucleons. In earlier measurements strength of the pre-compound component has been estimated from the difference in forward-backward distributions of emitted particles. Present measurement is a part of an ongoing program on the study of reaction dynamics of heavy ion interactions at low energies aimed at investigating the effect of momentum transfer in compound, precompound, complete and incomplete fusion processes in heavy ion reactions. In the present work on the basis of momentum transfer the measurement of the recoil range distributions of heavy residues has been used to decipher the components of compound and pre-compound emission processes in the fusion of 16O projectile with 159Tb and 169Tm targets. The analysis of recoil range distribution measurements show two distinct linear momentum transfer components corresponding to pre-compound and compound nucleus processes are involved. In order to obtain the mean input angular momentum associated with compound and pre-compound emission processes, an online measurement of the spin distributions of the residues has been performed. The analysis of spin distribution indicate that the mean input angular momentum associated with pre-compound products is found to be relatively lower than that associated with compound nucleus process. The pre-compound components obtained from the present analysis are consistent with those obtained from the analysis of excitation functions.

Minimal NOx emission by Lysinibacillus sphaericus in nutrient poor soil

Directory of Open Access Journals (Sweden)

Melissa Sánchez

2018-06-01

Full Text Available The aim of this study was to determine whether nitrogen dioxide emissions by Lysinibacillus sphaericus exist in nutrient poor soil. First, we evaluated the presence of two genes involved in denitrification (nosF and nosD by PCR screening of five strains of L. sphaericus (III (37, OT4b.49, OT4b.25, OT4b.31 and CBAM5. We then applied a bacterial consortium made up by L. sphaericus III (37 and OT4b.49 into closed microcosms of soil and with minimum salts medium (MSM supplemented with ammonia to measure the concentration of produced nitrogen dioxide over time. The assays with closed microcosms showed a minimum level of nitrogen dioxide over time. The nosF and nosD primers amplified the expected fragment for the five strains and the sequenced nosF and nosD PCR product showed an ATPase domain and a copper-binding domain respectively, which was consistent with the function of these genes. The basal emission of nitrogen dioxide by L. sphaericus in soil is coupled to its ability to enhance the nitrogen bioavailability for soils deficient in nutrients. Therefore, our results indicate that this microorganism can be considered as a good candidate to validate the low emission of NOx in field and in the future as an alternative for biofertilization.

Acoustic emission and magnification of atomic lines resolution for laser breakdown of salt water in ultrasound field

International Nuclear Information System (INIS)

Bulanov, Alexey V.; Nagorny, Ivan G.

2015-01-01

Researches of the acoustic effects accompanying optical breakdown in a water, generated by the focused laser radiation with power ultrasound have been carried out. Experiments were performed by using 532 nm pulses from Brilliant B Nd:YAG laser. Acoustic radiation was produced by acoustic focusing systems in the form hemisphere and ring by various resonance frequencies of 10.7 kHz and 60 kHz. The experimental results are obtained, that show the sharply strengthens effects of acoustic emission from a breakdown zone by the joint influence of a laser and ultrasonic irradiation. Essentially various thresholds of breakdown and character of acoustic emission in fresh and sea water are found out. The experimental result is established, testifying that acoustic emission of optical breakdown of sea water at presence and at absence of ultrasound essentially exceeds acoustic emission in fresh water. Atomic lines of some chemical elements like a Sodium, Magnesium and so on were investigated for laser breakdown of water with ultrasound field. The effect of magnification of this lines resolution for salt water in ultrasound field was obtained

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

Science.gov (United States)

2012-03-21

... National Emission Standards for Hazardous Air Pollutant Emissions: Group IV Polymers and Resins; Pesticide... Hazardous Air Pollutant Emissions: Group IV Polymers and Resins; National Emission Standards for Hazardous... proposed rule titled, National Emission Standards for Hazardous Air Pollutant Emissions: Group IV Polymers...

Hotspots of soil N2O emission enhanced through water absorption by plant residue

Energy Technology Data Exchange (ETDEWEB)

Kravchenko, A.N.; Toosi, E.R.; Guber, A.K.; Ostrom, N.E.; Yu, J.; Azeem, K.; Rivers, M.L.; Robertson , G.P. (UAF Pakistan); (UC); (Hubei); (MSU)

2017-06-05

N2O is a highly potent greenhouse gas and arable soils represent its major anthropogenic source. Field-scale assessments and predictions of soil N2O emission remain uncertain and imprecise due to the episodic and microscale nature of microbial N2O production, most of which occurs within very small discrete soil volumes. Such hotspots of N2O production are often associated with decomposing plant residue. Here we quantify physical and hydrological soil characteristics that lead to strikingly accelerated N2O emissions in plant residue-induced hotspots. Results reveal a mechanism for microscale N2O emissions: water absorption by plant residue that creates unique micro-environmental conditions, markedly different from those of the bulk soil. Moisture levels within plant residue exceeded those of bulk soil by 4–10-fold and led to accelerated N2O production via microbial denitrification. The presence of large (Ø >35 μm) pores was a prerequisite for maximized hotspot N2O production and for subsequent diffusion to the atmosphere. Understanding and modelling hotspot microscale physical and hydrologic characteristics is a promising route to predict N2O emissions and thus to develop effective mitigation strategies and estimate global fluxes in a changing environment.

Pollutant emissions of commercial and industrial wood furnaces; determination of emissions and emission reducing techniques

International Nuclear Information System (INIS)

Baumbach, G.; Angerer, M.

1993-01-01

Approximately 382.000 t of wood waste from production processes are fired in Baden-Wuerttemberg per year in 4345 furnaces with capacities of less than 1 MW (field of application of the ''1 BImSchV''). This corresponds to an energy consumption of 5600 TJ. The firings with a totally installed capacity of 594 MW are operated mainly by joiners, carpenters, in sawmills and furniture factories. Certainly there are typical differences between the diverse branches concerning the characteristics of the firings such as capacity, kind of firing, of fuel supply and heat generation. Because of lacking established emission factors, at present time the emissions of these furnaces cannot be calculated. Therefore field measurements are carried out at a representative selection of the registered installations. The emissions are measured in consideration of the usual ways of operation and the commonly used fuels. Supplementarily the compound of the emitted hydrocarbons and their dependence on completeness of the combustion as well as the compound and the grain size distribution of the particle emissions are investigated. (orig.) [de

Effect of palm methyl ester-diesel blends performance and emission of a single-cylinder direct-injection diesel engine

Science.gov (United States)

Said, Mazlan; Aziz, Azhar Abdul; Said, Mohd Farid Muhamad

2012-06-01

The purpose of this study is to investigate engine performance and exhaust emission when using several blends of neat palm oil methyl ester (POME) with conventional diesel (D2) in a small direct injection diesel engine, and to compare the outcomes to that of the D2 fuel. Engine performances, exhaust emissions, and some other important parameters were observed as a function of engine load and speed. In addition, the effect of modifying compression ratio was also carried out in this study. From the engine experimental work, neat and blended fuels behaved comparably to diesel (D2) in terms of fuel consumption, thermal efficiency and rate of heat released. Smoke density showed better results than that emitted by D2, operating under similar conditions due to the presence of inherited oxygen and lower sulphur content in the biofuel and its blends. The emissions of CO, CO2, and HC were also lower using blended mixtures and in its neat form. However, NOx concentrations were found to be slight higher for POME and its blends and this was largely due to higher viscosity of POME and possibly the presence of nitrogen in the palm methyl ester. General observation indicates that biofuel blends can be use without many difficulties in this type of engine but for optimized operation minor modifications to the engine and its auxiliaries are required.

The POETICs of industrial carbon dioxide emissions in Japan: an urban and institutional extension of the IPAT identity

Science.gov (United States)

Scholz, Stephan

2006-01-01

Background This study applies the POETICs framework (population, organization, environment, technology, institutions and culture) to an analysis of industrial carbon dioxide emissions in Japanese cities. The inclusion of institutional variables in the form of International Council for Local Environmental Initiatives membership, ISO 14001 implementation, and non-profit sector activity addresses the ecological limitations of the often used IPAT (impact = population × affluence × technology) approach. Results Results suggest the weak existence of an environmental Kuznets curve, in which the wealthiest cities are reducing their emissions through increased efficiency. Significant institutional impacts are also found to hold in the predicted directions. Specifically, panel and cross-sectional regressions indicate that membership in the International Council for Local Environmental Initiatives and non-profit organizational presence have negative effects on industrial carbon dioxide emissions. Conclusion The presence of institutional drivers at the city level provides empirical support for the POETICs rubric, which recasts the ecological framing of the IPAT identity in a more sociological mold. The results also indicate that Japanese civil society has a role to play in carbon mitigation. More refined studies need to take into consideration an expanded set of methods, drivers, and carbon budgets, as applied to a broader range of cases outside of Japan, to more accurately assess how civil society can bridge the issue of scale that separates local level policy concerns from global level climate dynamics. PMID:17005049

The POETICs of industrial carbon dioxide emissions in Japan: an urban and institutional extension of the IPAT identity.

Science.gov (United States)

Scholz, Stephan

2006-09-27

This study applies the POETICs framework (population, organization, environment, technology, institutions and culture) to an analysis of industrial carbon dioxide emissions in Japanese cities. The inclusion of institutional variables in the form of International Council for Local Environmental Initiatives membership, ISO 14001 implementation, and non-profit sector activity addresses the ecological limitations of the often used IPAT (impact = population x affluence x technology) approach. Results suggest the weak existence of an environmental Kuznets curve, in which the wealthiest cities are reducing their emissions through increased efficiency. Significant institutional impacts are also found to hold in the predicted directions. Specifically, panel and cross-sectional regressions indicate that membership in the International Council for Local Environmental Initiatives and non-profit organizational presence have negative effects on industrial carbon dioxide emissions. The presence of institutional drivers at the city level provides empirical support for the POETICs rubric, which recasts the ecological framing of the IPAT identity in a more sociological mold. The results also indicate that Japanese civil society has a role to play in carbon mitigation. More refined studies need to take into consideration an expanded set of methods, drivers, and carbon budgets, as applied to a broader range of cases outside of Japan, to more accurately assess how civil society can bridge the issue of scale that separates local level policy concerns from global level climate dynamics.

Decoupling emissions of greenhouse gas, urbanization, energy and income: analysis from the economy of China.

Science.gov (United States)

Wang, Tianqiong; Riti, Joshua Sunday; Shu, Yang

2018-05-08

The adoption and ratification of relevant policies, particularly the household enrolment system metamorphosis in China, led to rising urbanization growth. As the leading developing economy, China has experienced a drastic and rapid increase in the rate of urbanization, energy use, economic growth and greenhouse gas (GHG) pollution for the past 30 years. The knowledge of the dynamic interrelationships among these trends has a plethora of implications ranging from demographic, energy, and environmental and sustainable development policies. This study analyzes the role of urbanization in decoupling GHG emissions, energy, and income in China while considering the critical contribution of energy use. As a contribution to the extant body of literature, the present research introduces a new phenomenon called "the environmental urbanization Kuznets curve" (EUKC), which shows that at the early stage of urbanization, the environment degrades however, after a threshold point the technique effects surface and environmental degradation reduces with rise in urbanization. Applying the autoregressive distributed lag model and the vector error correction model, the paper finds the presence of inverted U-shaped curve between urbanization and GHG emission of CO 2 , while the same hypothesis cannot be found between income and GHG emission of CO 2 . Energy use in all the models contributes to GHG emission of CO 2 . In decoupling greenhouse gas emissions, urbanization, energy, and income, articulated and well-implemented energy and urbanization policies should be considered.

Biomass burning: Combustion emissions, satellite imagery, and biogenic emissions

International Nuclear Information System (INIS)

Levine, J.S.; Cofer, W.R III; Rhinehart, R.P.; Cahoon, D.R. J.; Winstead, E.L.; Sebacher, S.; Sebacher, D.I.; Stocks, B.J.

1991-01-01

This chapter deals with two different, but related, aspects of biomass burning. The first part of the chapter deals with a technique to estimate the instantaneous emissions of trace gases produced by biomass burning using satellite imagery. The second part of the chapter concerns the recent discovery that burning results in significantly enhanced biogenic emissions of N 2 O, NO, and CH 4 . Hence, biomass burning has both an immediate and long-term impact on the production of trace gases to the atmosphere. The objective of this research is to better assess and quantify the role of this research is to better assess and quantify the role and impact of biomass as a driver for global change. It will be demonstrated that satellite imagery of fires may be used to estimate combustion emissions and may in the future be used to estimate the long-term postburn biogenic emissions of trace gases to the atmosphere

Effects of combustion and operating conditions on PCDD/PCDF emissions from power boilers burning salt-laden wood waste.

Science.gov (United States)

Leclerc, Denys; Duo, Wen Li; Vessey, Michelle

2006-04-01

This paper discusses the effects of combustion conditions on PCDD/PCDF emissions from pulp and paper power boilers burning salt-laden wood waste. We found no correlation between PCDD/PCDF emissions and carbon monoxide emissions. A good correlation was, however, observed between PCDD/PCDF emissions and the concentration of stack polynuclear aromatic hydrocarbons (PAHs) in the absence of TDF addition. Thus, poor combustion conditions responsible for the formation of products of incomplete combustion (PICs), such as PAHs and PCDD/PCDF precursors, increase PCDD/PCDF emissions. PAH concentrations increased with higher boiler load and/or low oxygen concentrations at the boiler exit, probably because of lower available residence times and insufficient excess air. Our findings are consistent with the current understanding that high ash carbon content generally favours heterogeneous reactions leading to either de novo synthesis of PCDD/PCDFs or their direct formation from precursors. We also found that, in grate-fired boilers, a linear increase in the grate/lower furnace temperature produces an exponential decrease in PCDD/PCDF emissions. Although the extent of this effect appears to be mill-specific, particularly at low temperatures, the results indicate that increasing the combustion temperature may decrease PCDD/PCDF emissions. It must be noted, however, that there are other variables, such as elevated ESP and stack temperatures, a high hog salt content, the presence of large amounts of PICs and a high Cl/S ratio, which contribute to higher PCDD/PCDFs emissions. Therefore, higher combustion temperatures, by themselves, will not necessarily result in low PCDD/PCDFs emissions.

Pyrene-Phosphonate Conjugate: Aggregation-Induced Enhanced Emission, and Selective Fe3+ Ions Sensing Properties

Directory of Open Access Journals (Sweden)

Sachin D. Padghan

2017-08-01

Full Text Available A new pyrene-phosphonate colorimetric receptor 1 has been designed and synthesized in a one-step process via amide bond formation between pyrene butyric acid chloride and phosphonate-appended aniline. The pyrene-phosphonate receptor 1 showed aggregation-induced enhanced emission (AIEE properties in water/acetonitrile (ACN solutions. Dynamic light scattering (DLS characterization revealed that the aggregates of receptor 1 at 80% water fraction have an average size of ≈142 nm. Field emission scanning electron microscopy (FE-SEM analysis confirmed the formation of spherical aggregates upon solvent evaporation. The sensing properties of receptor 1 were investigated by UV-vis, fluorescence emission spectroscopy, and other optical methods. Among the tested metal ions, receptor 1 is capable of recognizing the Fe3+ ion selectively. The changes in spectral measurements were explained on the basis of complex formation. The composition of receptor 1 and Fe3+ ions was determined by using Job’s plot and found to be 1:1. The receptor 1–Fe3+ complex showed a reversible UV-vis response in the presence of EDTA.

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

Energy Technology Data Exchange (ETDEWEB)

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

2010-06-15

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

On-line Field Measurements of Speciated PM1 Emission Factors from Common South Asian Combustion Sources

Science.gov (United States)

DeCarlo, P. F.; Goetz, J. D.; Giordano, M.; Stockwell, C.; Maharjan, R.; Adhikari, S.; Bhave, P.; Praveen, P. S.; Panday, A. K.; Jayarathne, T. S.; Stone, E. A.; Yokelson, R. J.

2017-12-01

Characterization of aerosol emissions from prevalent but under sampled combustion sources in South Asia was performed as part of the Nepal Ambient Monitoring and Source Testing Experiment (NAMaSTE) in April 2015. Targeted emission sources included cooking stoves with a variety of solid fuels, brick kilns, garbage burning, crop-residue burning, diesel irrigation pumps, and motorcycles. Real-time measurements of submicron non-refractory particulate mass concentration and composition were obtained using an Aerodyne mini Aerosol Mass Spectrometer (mAMS). Speciated PM1 mass emission factors were calculated for all particulate species (e.g. organics, sulfates, nitrates, chlorides, ammonium) and for each source type using the carbon mass balance approach. Size resolved emission factors were also acquired using a novel high duty cycle particle time-of-flight technique (ePTOF). Black carbon and brown carbon absorption emission factors and absorption Angström exponents were measured using filter loading and scattering corrected attenuation at 370 nm and 880 nm with a dual spot aethalometer (Magee Scientific AE-33). The results indicate that open garbage burning is a strong emitter of organic aerosol, black carbon, and internally mixed particle phase hydrogen chloride (HCl). Emissions of HCl were attributed to the presence chlorinated plastics. The primarily coal fired brick kilns were found to be large emitters of sulfate but large differences in the organic and light absorbing component of emissions were observed between the two kiln types investigated (technologically advanced vs. traditional). These results, among others, bring on-line and field-tested aerosol emission measurements to an area of atmoshperic research dominated by off-line or laboratory based measurements.

Presence : concept, determinants and measurement

NARCIS (Netherlands)

IJsselsteijn, W.A.; Ridder, de H.; Freeman, J.; Avons, S.E.; Rogowitz, B.E.; Pappas, T.N.

2000-01-01

The concept of presence, i.e. the sensation of 'being there' in a mediated environment, has received substantial attention from the virtual reality community, and is becaming increasingly relevant both to broadcasters and display developers. Although research into presence is still at an early stage

Judicial aspects of emission trade. Emission trade in the European Union

International Nuclear Information System (INIS)

Van Beuge, M.J.J.

2004-01-01

Emission trade will start in Europe in 2005. In a series of articles an overview will be given of several juridical aspects with respect to the international and national trade of emission. In part 1 attention was paid to the international judicial basis for the present climate policy. In this article an overview is given of developments with regard to emission trade in the European Union [nl

Inverse constraints for emission fluxes of atmospheric tracers estimated from concentration measurements and Lagrangian transport

Science.gov (United States)

Pisso, Ignacio; Patra, Prabir; Breivik, Knut

2015-04-01

Lagrangian transport models based on times series of Eulerian fields provide a computationally affordable way of achieving very high resolution for limited areas and time periods. This makes them especially suitable for the analysis of point-wise measurements of atmospheric tracers. We present an application illustrated with examples of greenhouse gases from anthropogenic emissions in urban areas and biogenic emissions in Japan and of pollutants in the Arctic. We asses the algorithmic complexity of the numerical implementation as well as the use of non-procedural techniques such as Object-Oriented programming. We discuss aspects related to the quantification of uncertainty from prior information in the presence of model error and limited number of observations. The case of non-linear constraints is explored using direct numerical optimisation methods.

Experimental characterization of nanoparticles emissions during Laser Shock Processing of AA6061, AISI304 and Ti6Al4V

Directory of Open Access Journals (Sweden)

João F. Gomes

2017-11-01

Full Text Available This paper describes an experimental study on the emission of nanometric size particles during laser shock processing of metallic materials: stainless steel, aluminum and titanium alloys which are the most common ones processed by this technique. The emission of nanometric size particles was confirmed to consist of aggregates composed of smaller spherical particles in the range of 10-20 nm, covered by a small concentric “layer” probably of metal oxides. The analysis of the nanoparticles showed the presence of the main elements present in the tested alloys as well as high oxygen content, which is another indication of the presence of oxides of Fe, Al and Ti. The amount of emitted nanoparticles, showed considerable increases over the baseline measured for the working environment, and these increases correspond to the more intense pulses of the laser beam. The material density was seen to highly affect the quantity of emitted nanoparticles. During LSP of aluminium alloy (the lighter material a large quantity of nanoparticles was measured, while in LSP of stainless steel few nanoparticles were observed, and this is the denser material, among the three tested. Titanium alloy results in intermediate values. The study of these emissions is innovative and relevant for industrial environments where the manufacturing process is in use.

A Low-Cost Tele-Presence Wheelchair System

OpenAIRE

Shen, Jiajun; Xu, Bin; Pei, Mingtao; Jia, Yunde

2016-01-01

This paper presents the architecture and implementation of a tele-presence wheelchair system based on tele-presence robot, intelligent wheelchair, and touch screen technologies. The tele-presence wheelchair system consists of a commercial electric wheelchair, an add-on tele-presence interaction module, and a touchable live video image based user interface (called TIUI). The tele-presence interaction module is used to provide video-chatting for an elderly or disabled person with the family mem...

Air Emissions Factors and Quantification

Science.gov (United States)

Emissions factors are used in developing air emissions inventories for air quality management decisions and in developing emissions control strategies. This area provides technical information on and support for the use of emissions factors.

Effect of reed canary grass cultivation on greenhouse gas emission from peat soil at controlled rewetting

DEFF Research Database (Denmark)

Karki, Sandhya; Elsgaard, Lars; Lærke, Poul Erik

2015-01-01

Cultivation of bioenergy crops in rewetted peatland (paludiculture) is considered as a possible land use option to mitigate greenhouse gas (GHG) emissions. However, bioenergy crops like reed canary grass (RCG) can have a complex influence on GHG fluxes. Here we determined the effect of RCG...... and bare soil were measured at weekly to fortnightly intervals with static chamber techniques for a period of 1 year. Cultivation of RCG increased both ER and CH4 emissions, but decreased the N2O emissions. The presence of RCG gave rise to 69, 75 and 85% of total ER at −20, −10 and 0 cm GWL, respectively...... from ER were obviously the dominant RCG-derived GHG flux, but above-ground biomass yields, and preliminary measurements of gross photosynthetic production, showed that ER could be more than balanced due to the photosynthetic uptake of CO2 by RCG. Our results support that RCG cultivation could be a good...

Blue Emission in Proteins

OpenAIRE

Sarkar, Sohini; Sengupta, Abhigyan; Hazra, Partha; Mandal, Pankaj

2014-01-01

Recent literatures reported blue-green emission from amyloid fibril as exclusive signature of fibril formation. This unusual visible luminescence is regularly used to monitor fibril growth. Blue-green emission has also been observed in crystalline protein and in solution. However, the origin of this emission is not known exactly. Our spectroscopic study of serum proteins reveals that the blue-green emission is a property of protein monomer. Evidences suggest that semiconductor-like band struc...

Reducing CO2 Emissions in the Production of Porous Fired Clay Bricksks

Directory of Open Access Journals (Sweden)

Mikuláš ŠVEDA

2017-08-01

Full Text Available A plan to reduce CO2 emissions is a priority these days. Brick industry contributes to the increase of these emissions mainly through the use of combustible pore-forming agents such as sawdust, cellulose, and coal sludge. These agents are used to improve the thermal insulation properties of brick products, and the suppliers regularly increase the prices of these agents based on their high consumption. Therefore, in an effort to reduce raw material expenses and CO2 emissions, brick manufacturers are looking for new possibilities while maintaining the quality of their products. This article discusses the possibility of using industrially manufactured product Vuppor as an additive as a replacement for combustible pore-forming agents. The presence of this additive in the fired clay body increases the proportion of pores, especially with a size range between 0.1 and 5 µm, having a positive impact on the reduction of its thermal conductivity. With a 0.5 wt.% dose of Vuppor additive, the brick production costs and thermal conductivity can be reduced by 20 % and 12 %, respectively, while also achieving reductions in CO2 emissions over 60 %. Consequently, the combustible pore-forming agents can be used in a more environmentally friendly manner, for example in the furniture industry, the biogas production, and the like.DOI: http://dx.doi.org/10.5755/j01.ms.23.2.15103

Carbonyl Emissions in E-cigarette Aerosol: A Systematic Review and Methodological Considerations

Directory of Open Access Journals (Sweden)

Konstantinos E. Farsalinos

2018-01-01

Full Text Available Carbonyl emissions from tobacco cigarettes represent a substantial health risk contributing to smoking-related morbidity and mortality. As expected, this is an important research topic for tobacco harm reduction products, in an attempt to compare the relative risk of these products compared to tobacco cigarettes. In this study, a systematic review of the literature available on PubMed was performed analyzing the studies evaluating carbonyl emissions from e-cigarettes. A total of 32 studies were identified and presented. We identified a large diversity of methodologies, with substantial discrepancies in puffing patterns, aerosol collection and analytical methods as well as reported units of measurements. Such discrepancies make comparisons difficult, and in some cases the accuracy of the findings cannot be determined. Importantly, control for the generation of dry puffs was not performed in the vast majority of studies, particularly in studies using variable power devices, which could result in testing conditions and reported carbonyl levels that have no clinical relevance or context. Some studies have been replicated, verifying the presence of dry puff conditions. Whenever realistic use conditions were ensured, carbonyl emissions from e-cigarettes were substantially lower than tobacco cigarette smoke, while newer generation (bottom-coil, cotton wick atomizers appeared to emit minimal levels of carbonyls with questionable clinical significance in terms of health risk. However, extremely high levels of carbonyl emissions were reported in some studies, and all these studies need to be replicated because of potentially important health implications.

Prompt neutron emission

International Nuclear Information System (INIS)

Sher, R.

1959-01-01

It is shown that Ramanna and Rao's tentative conclusion that prompt fission neutrons are emitted (in the fragment system) preferentially in the direction of fragment motion is not necessitated by their angular distribution measurements, which are well explained by the usual assumptions of isotropic emission with a Maxwell (or Maxwell-like) emission spectrum. The energy distribution (Watt spectrum) and the angular distribution, both including the effects of anisotropic emission, are given. (author) [fr

Embodied greenhouse gas emission by Macao

International Nuclear Information System (INIS)

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

2013-01-01

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

Research on Acoustic Emission and Electromagnetic Emission Characteristics of Rock Fragmentation at Different Loading Rates

Directory of Open Access Journals (Sweden)

Fujun Zhao

2018-01-01

Full Text Available The relationships among the generation of acoustic emission, electromagnetic emission, and the fracture stress of rock grain are investigated, which are based on the mechanism of acoustic emission and electromagnetic emission produced in the process of indenting rock. Based on the relationships, the influence of loading rate on the characteristics of acoustic emission and electromagnetic emission of rock fragmentation is further discussed. Experiment on rock braking was carried out with three loading rates of 0.001 mm/s, 0.01 mm/s, and 0.1 mm/s. The results show that the phenomenon of acoustic emission and electromagnetic emission is produced during the process of loading and breaking rock. The wave forms of the two signals and the curve of the cutter indenting load show jumping characteristics. Both curves have good agreement with each other. With the increase of loading rate, the acoustic emission and electromagnetic emission signals are enhanced. Through analysis, it is found that the peak count rate, the energy rate of acoustic emission, the peak intensity, the number of pulses of the electromagnetic emission, and the loading rate have a positive correlation with each other. The experimental results agree with the theoretical analysis. The proposed studies can lead to an in-depth understanding of the rock fragmentation mechanism and help to prevent rock dynamic disasters.

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...

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,...

Causal nexus between energy consumption and carbon dioxide emission for Malaysia using maximum entropy bootstrap approach.

Science.gov (United States)

Gul, Sehrish; Zou, Xiang; Hassan, Che Hashim; Azam, Muhammad; Zaman, Khalid

2015-12-01

This study investigates the relationship between energy consumption and carbon dioxide emission in the causal framework, as the direction of causality remains has a significant policy implication for developed and developing countries. The study employed maximum entropy bootstrap (Meboot) approach to examine the causal nexus between energy consumption and carbon dioxide emission using bivariate as well as multivariate framework for Malaysia, over a period of 1975-2013. This is a unified approach without requiring the use of conventional techniques based on asymptotical theory such as testing for possible unit root and cointegration. In addition, it can be applied in the presence of non-stationary of any type including structural breaks without any type of data transformation to achieve stationary. Thus, it provides more reliable and robust inferences which are insensitive to time span as well as lag length used. The empirical results show that there is a unidirectional causality running from energy consumption to carbon emission both in the bivariate model and multivariate framework, while controlling for broad money supply and population density. The results indicate that Malaysia is an energy-dependent country and hence energy is stimulus to carbon emissions.

Symbiotic star UV emission and theoretical models

International Nuclear Information System (INIS)

Kafatos, M.

1982-01-01

Observations of symbiotic stars in the far UV have provided important information on the nature of these objects. The canonical spectrum of a symbiotic star, e.g. RW Hya, Z And, AG Peg, is dominated by strong allowed and semiforbidden lines of a variety of at least twice ionized elements. Weaker emission from neutral and singly ionized species is also present. A continuum may or may not be present in the 1200 - 2000 A range but is generally present in the range 2000 - 3200 A range. The suspected hot subdwarf continuum is seen in some cases in the range 1200 - 2000 A (RW Hya, AG Peg, SY Mus). The presence of an accretion disk is difficult to demonstrate and to this date the best candidate for accretion to a main sequence star remains CI Cyg. A number of equations have been derived by the author that can yield the accretion parameters from the observable quantities. Boundary layer temperatures approximately 10 5 K and accretion rates approximately > 10 -5 solar masses/yr are required for accreting main sequence companions. To this date, though, most of the symbiotics may only require the presence of a approximately 10 5 K hot subdwarf. (Auth.)

Detailed EXOSAT and optical observations of the intermediate polar 3A0729+103: discovery of two medium energy X-ray emission regions

International Nuclear Information System (INIS)

McHardy, I.M.; Pye, J.P.; Fairall, A.P.; Menzies, J.W.

1987-01-01

EXOSAT observations of the intermediate polar cataclysmic variable 3A0729+103 reveal a strong orbital modulation, with the 2-4KeV X-rays being significantly more modulated than the 4-6keV X-rays, indicative of photoelectric absorption. The 913 second modulation which is very prominent in the optical light curve, is weakly detected in the medium-energy X-ray light curve, confirming that it represents the white dwarf spin period. These observations are well explained by a combination of two sources of medium-energy X-ray emission. The presence of two emission regions is also clearly seen in the optical spectroscopy, particularly in the intensity of the He II4686 line which has two peaks during the orbit. The authors identify the two optical emission regions with the two X-ray emission regions. (author)

Particle number emissions of gasoline hybrid electric vehicles; Partikelanzahl-Emission bei Hybridfahrzeugen mit Ottomotor

Energy Technology Data Exchange (ETDEWEB)

Porter, Scott [Horiba Instruments Inc., Ann Arbor, MI (United States)

2012-04-15

Hybrid Electric Vehicles (HEV) are commonly reputed to be environmentally friendly. Different studies show that this assumption raises some questions in terms of particle number emissions. Against the background that upcoming emission standards will not only limit particle matter emissions but also particle number emissions for gasoline engines, the exhaust behaviour of downsized gasoline engines used in HEV should be investigated more extensively. A Horiba study compares the particle number emissions of a gasoline vehicle to those of a gasoline powered HEV. (orig.)

Capturing Online Presence

DEFF Research Database (Denmark)

de Bakker, Frank; Hellsten, Lina

2013-01-01

The rise of Internet-mediated communication poses possibilities and challenges for organisation studies, also in the area of corporate social responsibility (CSR) and business and society interactions. Although social media are attracting more and more attention in this domain, websites also remain...... an important channel for CSR debate. In this paper, we present an explorative study of activist groups’ online presence via their websites and propose a combination of methods to study both the structural positioning of websites (hyperlink network analysis) and the meanings in these websites (semantic co...... activist networks’ online presence can provide insights into the tactics these networks apply to achieve institutional change on CSR issues. Meanwhile, we identify some notable differences between styles and word use in the two organisations’ websites. We conclude with a set of suggestions for future...

Cost of lower NO x emissions: Increased CO 2 emissions from heavy-duty diesel engines

Science.gov (United States)

Krishnamurthy, Mohan; Carder, Daniel K.; Thompson, Gregory; Gautam, Mridul

This paper highlights the effect of emissions regulations on in-use emissions from heavy-duty vehicles powered by different model year engines. More importantly, fuel economy data for pre- and post-consent decree engines are compared. The objective of this study was to determine the changes in brake-specific emissions of NO x as a result of emission regulations, and to highlight the effect these have had on brake-specific CO 2 emission; hence, fuel consumption. For this study, in-use, on-road emission measurements were collected. Test vehicles were instrumented with a portable on-board tailpipe emissions measurement system, WVU's Mobile Emissions Measurement System, and were tested on specific routes, which included a mix of highway and city driving patterns, in order to collect engine operating conditions, vehicle speed, and in-use emission rates of CO 2 and NO x. Comparison of on-road in-use emissions data suggests NO x reductions as high as 80% and 45% compared to the US Federal Test Procedure and Not-to-Exceed standards for model year 1995-2002. However, the results indicate that the fuel consumption; hence, CO 2 emissions increased by approximately 10% over the same period, when the engines were operating in the Not-to-Exceed region.

Negative ion emission at field electron emission from amorphous (alpha-C:H) carbon

CERN Document Server

Bernatskij, D P; Ivanov-Omskij, V I; Pavlov, V G; Zvonareva, T K

2001-01-01

The study on the electrons field emission from the plane cathode surface on the basis of the amorphous carbon film (alpha-C:H) is carried out. The methodology, making it possible to accomplish simultaneously the registration of the emission currents and visually observe the distribution of the emission centers on the plane emitter surface is developed. The analysis of the oscillograms indicated that apart from the proper electron constituent the negative ions of hydrogen (H sup - and H sub 2 sup -), carbon (C sup -) and hydrocarbon (CH sub n sup -) are observed. The ions emission is connected with the processes of formation and degradation of the local emission centers

Contribution to the study of stimulated emission in neodymium-doped glass; Contribution a l'etude de l'emission stimulee dans le verre dope au neodyme

Energy Technology Data Exchange (ETDEWEB)

Jego, J M [Commissariat a l' Energie Atomique, Limeil-Brevannes (France). Centre d' Etudes; Faculte des Sciences de Rennes, 35 (France)

1969-07-01

In 1917, Einstein discovered the existence of the stimulated emission of electromagnetic waves by atoms. It is caused by the presence of radiating energy of suitable frequency in a material which is in a non equilibrium state. This discovery held the germ of the idea for the fabrication of generators and waves amplifiers for very short, almost monochromatic wavelengths. forty years elapsed however before these were produced for the first time. A maser operating in the field of micrometric waves appeared in 1954. In the optical field, the first 'Laser' was built by MAIMAN in 1960. The active atom was chromium situated in an alumina matrix (ruby). The fluorescent single crystal was placed between two reflectors which maintained in the medium a provoked inversion of the population until the emission conditions were attained. The laser effect has made it possible to produce several hundred line generators covering the optical range for both gaseous and liquid or solid media. Amongst the latter, neodymium has a transition between the 4 F{sub 3/2} and the 4 I{sub 11/2} levels which has made it possible to obtain very high power lasers. A study has been made during the present work of the conditions in which a pulse can be formed, and of its amplification in neodymium-doped glass. By making accurate measurements of the various yields involved in this process, it has been possible to obtain the value for the population inversion obtained in the medium, and to make a detailed study of stimulated emission in neodymium. (author) [French] En 1917, Einstein annonce l'existence de l'emission stimulee d'ondes electromagnetiques par les atomes. Elle est provoquee par la presence d'energie rayonnante de frequence convenable au sein d'un milieu materiel hors equilibre. Cette decouverte contenait en germe la possibilite de realiser des generateurs puis des amplificateurs d'ondes de tres courtes longueurs d'onde quasi-monochromatiques. Il faut attendre cependant quelques quarante

Permafrost Thaw increases Emissions of Nitrous Oxide from Subarctic Peatlands

Science.gov (United States)

Voigt, C.; Marushchak, M. E.; Lamprecht, R. E.; Jackowicz-Korczynski, M.; Lindgren, A.; Mastepanov, M.; Christensen, T. R.; Granlund, L.; Tahvanainen, T.; Martikainen, P. J.; Biasi, C.

2017-12-01

Permafrost soils in the Arctic are thawing, exposing not only carbon but also large nitrogen stocks. The decomposition of this vast pool of long-term immobile C and N stocks results in the release of greenhouse gases to the atmosphere. Among these, carbon dioxide (CO2) and methane (CH4) are being studied extensively, and gaseous C release from thawing permafrost is known to be substantial. Most recent studies, however, show that Arctic soils may further be a relevant source of the strong greenhouse gas nitrous oxide (N2O). As N2O is almost 300 times more powerful in warming the climate than CO2 based on a 100-yr time horizon, the release of N2O from thawing permafrost could create a significant non-carbon permafrost-climate feedback. To study the effect of permafrost thaw on N2O fluxes, we collected peat mesocosms from a Subarctic permafrost peatland, and subjected these intact soil-plant systems to sequential thawing from the top of the active layer down to the upper permafrost layer. Measurements of N2O fluxes were coupled with detailed soil analyses and process studies. Since N2O fluxes are highly dependent on moisture conditions and vegetation cover, we applied two distinct moisture treatments (dry vs. wet) and simulated permafrost thaw in vegetated as well as in naturally bare mesocosms. Under dry conditions, permafrost thaw clearly increased N2O emissions. We observed the largest post-thaw emissions from bare peat surfaces, a typical landform in subarctic peatlands previously identified as hot spots for Arctic N2O emissions. There, permafrost thaw caused a five-fold increase in emissions (0.56 vs. 2.81 mg N2O m-2 d-1). While water-logged conditions suppressed N2O emissions, the presence of vegetation lowered, but did not prevent post-thaw N2O release. Based on these findings, we show that one fourth of the Arctic land area could be vulnerable for N2O emissions when permafrost thaws. Our results demonstrate that Arctic N2O emissions may be larger than

Hybrid plasmonic nanodevices: Switching mechanism for the nonlinear emission

Energy Technology Data Exchange (ETDEWEB)

Bragas, Andrea V. [Departamento de Física, FCEyN, Universidad de Buenos Aires, IFIBA CONICET, 1428 Buenos Aires (Argentina); Singh, Mahi R. [Department of Physics and Astronomy, Western University, London (Canada)

2014-03-31

Control of the light emission at the nanoscale is of central interest in nanophotonics due to the many applications in very different fields, ranging from quantum information to biophysics. Resonant excitation of surface plasmon polaritons in metal nanoparticles create nanostructured and enhanced light fields around those structures, which produce their strong interaction in a hybrid nanodevice with other plasmonic or non-plasmonic objects. This interaction may in turn also modulate the far field with important consequences in the applications. We show in this paper that the nonlinear emission from semiconductor quantum dots is strongly affected by the close presence of metal nanoparticles, which are resonantly excited. Using a pulsed laser, optical second harmonic is generated in the quantum dot, and it is highly enhanced when the laser is tuned around the nanoparticle plasmon resonance. Even more interesting is the demonstration of a switching mechanism, controlled by an external continuous-wave field, which can enhance or extinguish the SH signal, even when the pulsed laser is always on. Experimental observations are in excellent agreement with the theoretical calculations, based on the dipole-dipole near-field coupling of the objects forming the hybrid system.

Characterization of particulate emissions from Australian open-cut coal mines: Toward improved emission estimates.

Science.gov (United States)

Richardson, Claire; Rutherford, Shannon; Agranovski, Igor

2018-06-01

Given the significance of mining as a source of particulates, accurate characterization of emissions is important for the development of appropriate emission estimation techniques for use in modeling predictions and to inform regulatory decisions. The currently available emission estimation methods for Australian open-cut coal mines relate primarily to total suspended particulates and PM 10 (particulate matter with an aerodynamic diameter available relating to the PM 2.5 (currently available emission estimation techniques, this paper presents results of sampling completed at three open-cut coal mines in Australia. The monitoring data demonstrate that the particulate size fraction varies for different mining activities, and that the region in which the mine is located influences the characteristics of the particulates emitted to the atmosphere. The proportion of fine particulates in the sample increased with distance from the source, with the coarse fraction being a more significant proportion of total suspended particulates close to the source of emissions. In terms of particulate composition, the results demonstrate that the particulate emissions are predominantly sourced from naturally occurring geological material, and coal comprises less than 13% of the overall emissions. The size fractionation exhibited by the sampling data sets is similar to that adopted in current Australian emission estimation methods but differs from the size fractionation presented in the U.S. Environmental Protection Agency methodology. Development of region-specific emission estimation techniques for PM 10 and PM 2.5 from open-cut coal mines is necessary to allow accurate prediction of particulate emissions to inform regulatory decisions and for use in modeling predictions. Development of region-specific emission estimation techniques for PM 10 and PM 2.5 from open-cut coal mines is necessary to allow accurate prediction of particulate emissions to inform regulatory decisions and for

Factors influencing presence in virtual worlds.

Science.gov (United States)

Chow, Meyrick C M

2012-01-01

Virtual worlds are showing potential as an effective platform for a variety of activities, including learning. The concept of presence (the sensation of "being there" in a mediated environment) has received substantial attention from the virtual reality community, and the effectiveness of virtual worlds has often been linked to the feelings of presence reported by their users. The present study examined the effects of attitude and perceived ease of use on sense of presence in Second Life, which is one of the most known and used virtual worlds. Based on data from a survey of 206 nursing students, hypotheses are empirically tested. Findings suggest that users' attitude toward using Second Life and their perceived ease of use of it have a positive effect on their sense of presence in the virtual environment. This study advances our understanding of factors influencing presence in virtual worlds.

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...

Carbon emissions in China

International Nuclear Information System (INIS)

Liu, Zhu

2016-01-01

This study analyzes the spatial-temporal pattern and processes of China's energy-related carbon emissions. Based on extensive quantitative analysis, it outlines the character and trajectory of China's energy-related carbon emissions during the period 1995-2010, examining the distribution pattern of China's carbon emissions from regional and sectoral perspectives and revealing the driving factors of China's soaring emission increase. Further, the book investigates the supply chain carbon emissions (the carbon footprints) of China's industrial sectors. Anthropogenic climate change is one of the most serious challenges currently facing humankind. China is the world's largest developing country, top primary energy consumer and carbon emitter. Achieving both economic growth and environmental conservation is the country's twofold challenge. Understanding the status, features and driving forces of China's energy-related carbon emissions is a critical aspect of attaining global sustainability. This work, for the first time, presents both key findings on and a systematic evaluation of China's carbon emissions from energy consumption. The results have important implications for global carbon budgets and burden-sharing with regard to climate change mitigation. The book will be of great interest to readers around the world, as it addresses a topic of truly global significance.

Laboratory measurements of the x-ray line emission from neon-like Fe XVII

International Nuclear Information System (INIS)

Brown, G V; Beiersdorfer, P; Chen, H; Scofield, J; Boyce, K R; Kelley, R L; Kilbourne, C A; Porter, F S; Gu, M F; Kahn, S M; Szymkowiak, A E

2006-01-01

The authors have conducted a systematic study of the dominant x-ray line emission from Fe XVII. These studies include relative line intensities in the optically thin limit, intensities in the presence of radiation from satellite lines from lower charge states of iron, and the absolute excitation cross sections of some of the strongest lines. These measurements were conducted at the Lawrence Livermore National Laboratory electron beam ion trap facility using crystal spectrometers and a NASA-Goddard Space Flight Center microcalorimeter array

Effect of Al–5Ti–1B grain refiner on the microstructure, mechanical properties and acoustic emission characteristics of Al5052 aluminium alloy

Directory of Open Access Journals (Sweden)

Amulya Bihari Pattnaik

2015-04-01

Full Text Available In the present investigation, the effect of Al–5Ti–1B grain refiner on the microstructure, mechanical properties and acoustic emission characteristics of Al 5052 aluminium alloy have been studied. Microstructural analysis showed the presence of primary α solid solution. No Al–Mg phase was found to be formed due to the presence of magnesium in the solid solution. The results indicated that the addition of Al–5Ti–1B grain refiner into the alloy caused a significant improvement in ultimate tensile strength (UTS and elongation values from 114 MPa and 7.8% to 185 MPa and 18% respectively. The main mechanisms behind this improvement were found to be due to the grain refinement during solidification and segregation of Ti at primary α grain boundaries. Acoustic emission (AE results indicated that intensity of AE signals increased with increase in Al–5Ti–1B master alloy content, which had been attributed to the combined effect of dislocation motion and grain refinement. The field emission scanning electron microscopy (FESEM and energy dispersive X-ray (EDX analysis were used to study the microstructure and fracture surfaces of the samples.

Strong blue and white photoluminescence emission of BaZrO{sub 3} undoped and lanthanide doped phosphor for light emitting diodes application

Energy Technology Data Exchange (ETDEWEB)

Romero, V.H. [Centro de Investigaciones en Optica, A. P. 1-948, Leon Gto., 37160 (Mexico); De la Rosa, E., E-mail: elder@cio.mx [Centro de Investigaciones en Optica, A. P. 1-948, Leon Gto., 37160 (Mexico); Salas, P. [Centro de Fisica Aplicada y Tecnologia Avanzada, Universidad Nacional Autonoma de Mexico, A.P. 1-1010, Queretaro, Qro. 76000 (Mexico); Velazquez-Salazar, J.J. [Department of Physics and Astronomy, The University of Texas at San Antonio One UTSA Circle, San Antonio TX 78249 (United States)

2012-12-15

In this paper, we report the obtained strong broadband blue photoluminescence (PL) emission centered at 427 nm for undoped BaZrO{sub 3} observed after 266 nm excitation of submicron crystals prepared by hydrothermal/calcinations method. This emission is enhanced with the introduction of Tm{sup 3+} ions and is stronger than the characteristic PL blue emission of such lanthanide. The proposed mechanism of relaxation for host lattice emission is based on the presence of oxygen vacancies produced during the synthesis process and the charge compensation due to the difference in the electron valence between dopant and substituted ion in the host. Brilliant white light emission with a color coordinate of (x=0.29, y=0.32) was observed by combining the blue PL emission from the host with the green and red PL emission from Tb{sup 3+} and Eu{sup 3+} ions, respectively. The color coordinate can be tuned by changing the ratio between blue, green and red band by changing the concentration of lanthanides. - Graphical abstract: Strong blue emission from undoped BaZrO{sub 3} phosphor and white light emission by doping with Tb{sup 3+} (green) and Eu{sup 3+} (red) after 266 nm excitation. Highlights: Black-Right-Pointing-Pointer Blue emission from BaZrO{sub 3} phosphor. Black-Right-Pointing-Pointer Blue emission enhanced with Tm{sup 3+}. Black-Right-Pointing-Pointer White light from BaZrO{sup 3+} phosphor.

Use of gradient dilution to flag and overcome matrix interferences in axial-viewing inductively coupled plasma-atomic emission spectrometry

International Nuclear Information System (INIS)

Cheung, Yan; Schwartz, Andrew J.; Hieftje, Gary M.

2014-01-01

Despite the undisputed power of inductively coupled plasma-atomic emission spectrometry (ICP-AES), its users still face serious challenges in obtaining accurate analytical results. Matrix interference is perhaps the most important challenge. Dilution of a matrix-containing sample is a common practice to reduce matrix interference. However, determining the optimal dilution factor requires tedious and time-consuming offline sample preparation, since emission lines and the effect of matrix interferences are affected differently by the dilution. The current study exploits this difference by employing a high-performance liquid chromatography gradient pump prior to the nebulizer to perform on-line mixing of a sample solution and diluent. Linear gradient dilution is performed on both the calibration standard and the matrix-containing sample. By ratioing the signals from two emission lines (from the same or different elements) as a function of dilution factor, the analyst can not only identify the presence of a matrix interference, but also determine the optimal dilution factor needed to overcome the interference. A ratio that does not change with dilution signals the absence of a matrix interference, whereas a changing ratio indicates the presence of an interference. The point on the dilution profile where the ratio stabilizes indicates the optimal dilution factor to correct the interference. The current study was performed on axial-viewing ICP-AES with o-xylene as the solvent

Emissions Trading Resources

Science.gov (United States)

Learn about emissions trading programs, also known as cap and trade programs, which are market-based policy tools for protecting human health and the environment by controlling emissions from a group of sources.

76 FR 13851 - National Emission Standards for Hazardous Air Pollutants: Mercury Emissions From Mercury Cell...

Science.gov (United States)

2011-03-14

... National Emission Standards for Hazardous Air Pollutants: Mercury Emissions From Mercury Cell Chlor-Alkali...-5] RIN 2060-AN99 National Emission Standards for Hazardous Air Pollutants: Mercury Emissions From Mercury Cell Chlor-Alkali Plants AGENCY: Environmental Protection Agency (EPA). ACTION: Supplemental...

BP's emissions trading system

International Nuclear Information System (INIS)

Victor, David G.; House, Joshua C.

2006-01-01

Between 1998 and 2001, BP reduced its emissions of greenhouse gases by more than 10%. BP's success in cutting emissions is often equated with its use of an apparently market-based emissions trading program. However no independent study has ever examined the rules and operation of BP's system and the incentives acting on managers to reduce emissions. We use interviews with key managers and with traders in several critical business units to explore the bound of BP's success with emissions trading. No money actually changed hands when permits were traded, and the main effect of the program was to create awareness of money-saving emission controls rather than strong price incentives. We show that the trading system did not operate like a 'textbook' cap and trade scheme. Rather, the BP system operated much like a 'safety valve' trading system, where managers let the market function until the cost of doing so surpassed what the company was willing to tolerate

Emission from power plants 1989-1998

International Nuclear Information System (INIS)

Anon.

1999-01-01

Emissions from power plants consist of several substances with different environmental effects. Most important is emission of CO 2 ,SO 2 and NO x . The actual emission of CO 2 declined from 33 million ton in 1997 to 29 million ton in 1998, while the corrected emission of CO 2 declined from 27 million ton to 26 million ton. The primary cause to the decline in the actual emission of CO 2 is the constant changing of the energy consumption from coal towards natural gas. The corrected emission of CO 2 increased a little from 1989 to 1991, but has declined since 1991. The actual emission of CO 2 has been more variable, which especially reflects the fluctuating import and export of electricity. The actual emission of SO 2 has in the period varied, but the tendency is declining emission of SO 2 . In the years 1991 and 1996 the actual emission of SO 2 increased, these being the years where the net export of electricity increased. The corrected emission of SO 2 has generally declined during the period. The actual emission of NO x has varied during the period, but the tendency is declining emission. Emission of NO x has been large this year with large electricity export. Correction the emission for net import and export of electricity the NO x emission has declined during 1989-1998. The corrected emission of NO x has declined 54 % during the period 1989-1998. The reason is primary the usage of low NO x burners. (EHS)

An empirical model to predict road dust emissions based on pavement and traffic characteristics.

Science.gov (United States)

Padoan, Elio; Ajmone-Marsan, Franco; Querol, Xavier; Amato, Fulvio

2018-06-01

The relative impact of non-exhaust sources (i.e. road dust, tire wear, road wear and brake wear particles) on urban air quality is increasing. Among them, road dust resuspension has generally the highest impact on PM concentrations but its spatio-temporal variability has been rarely studied and modeled. Some recent studies attempted to observe and describe the time-variability but, as it is driven by traffic and meteorology, uncertainty remains on the seasonality of emissions. The knowledge gap on spatial variability is much wider, as several factors have been pointed out as responsible for road dust build-up: pavement characteristics, traffic intensity and speed, fleet composition, proximity to traffic lights, but also the presence of external sources. However, no parameterization is available as a function of these variables. We investigated mobile road dust smaller than 10 μm (MF10) in two cities with different climatic and traffic conditions (Barcelona and Turin), to explore MF10 seasonal variability and the relationship between MF10 and site characteristics (pavement macrotexture, traffic intensity and proximity to braking zone). Moreover, we provide the first estimates of emission factors in the Po Valley both in summer and winter conditions. Our results showed a good inverse relationship between MF10 and macro-texture, traffic intensity and distance from the nearest braking zone. We also found a clear seasonal effect of road dust emissions, with higher emission in summer, likely due to the lower pavement moisture. These results allowed building a simple empirical mode, predicting maximal dust loadings and, consequently, emission potential, based on the aforementioned data. This model will need to be scaled for meteorological effect, using methods accounting for weather and pavement moisture. This can significantly improve bottom-up emission inventory for spatial allocation of emissions and air quality management, to select those roads with higher emissions

GHG emissions due to deforestation

International Nuclear Information System (INIS)

Croezen, H.; Van Valkengoed, M.

2009-05-01

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.

Criteria and air-toxic emissions from in-use automobiles in the National Low-Emission Vehicle program.

Science.gov (United States)

Baldauf, Rich W; Gabele, Pete; Crews, William; Snow, Richard; Cook, J Rich

2005-09-01

The U.S. Environmental Protection Agency (EPA) implemented a program to identify tailpipe emissions of criteria and air-toxic contaminants from in-use, light-duty low-emission vehicles (LEVs). EPA recruited 25 LEVs in 2002 and measured emissions on a chassis dynamometer using the cold-start urban dynamometer driving schedule of the Federal Test Procedure. The emissions measured included regulated pollutants, particulate matter, speciated hydrocarbon compounds, and carbonyl compounds. The results provided a comparison of emissions from real-world LEVs with emission standards for criteria and air-toxic compounds. Emission measurements indicated that a portion of the in-use fleet tested exceeded standards for the criteria gases. Real-time regulated and speciated hydrocarbon measurements demonstrated that the majority of emissions occurred during the initial phases of the cold-start portion of the urban dynamometer driving schedule. Overall, the study provided updated emission factor data for real-world, in-use operation of LEVs for improved emissions modeling and mobile source inventory development.

A contribution to the characterisation of natural and industrial crystalline emissions using electron beam and X-ray techniques

International Nuclear Information System (INIS)

Riedel, F.N.

1980-01-01

In this work the composition of dusts of different origin is studied based on the assumption that natural and industrial emissions sources may possibly be differentiated by the emission of characteristic minerals and compounds. Only if some of these compounds or certain groups of compounds can be associated with a distinct emission source, such compounds may be considered as guiding compounds or guiding minerals. In this case the emission sources should be identified unambiguously even over large distances. In the air pollution studies performed in the past, the emphasis has been laid mainly on gases like SO 2 , CO, CO 2 , NOsub(x), and HF, without paying much attention to the crystalline and amorphous components, which are present simultaneously. This study is restricted to the dust-like component of natural and industrial emission sources to get more information on its composition. In part these emissions are less dangerous in the compound state, as for example fluorine in the mica type mineral muskovite (KAl 2 [(OH,F) 2 AlSi 3 O 10 ]. As a working hypothesis it has been assumed that based on a series of investigations these compounds can be identified using electron miscroscopy and electron diffraction. In the presence of larger quantities of emission materials also X-ray techniques as Debye-Scherrer- or gonio methods can be applied. Reliable results can only be obtained by an investigation covering a broad area of industrial production. (orig./RW) [de

Maser Emission Associated with Young High Mass Stars

Science.gov (United States)

Mahmoud, Khaled Abdalla Edris

In this work the maser emission has been used to study the very early stage evolution of the young stars. The maser emission of OH molecule was searched for towards a sample of high mass protostellar objects using the Nançay and GBT telescopes. The sample of objects searched was selected to contain very young forming high mass stars. The results of this survey have been compared with previous H2O and CH3OH masers observations. Then MERLIN has been used to map the OH as well as H2O and CH3OH masers towards one of these sources in high angular resolution. The survey detected OH maser emission towards 63 objects with 37 new detections. There are 56 star forming regions and 7 OH/IR candidates. The detection of OH masers towards 26% of a sample of 217 sources should remove any doubt about the existence of OH maser emission towards these objects of this early evolutionary stage. Nearly half of the detected sources have OH fluxes rates and velocity range support the spatial association of OH and class II CH3OH masers as suggested by Caswell et al. [1995] and modelled by Cragg et al. [2002]. IRAS20126+4104 was mapped in the OH, water and methanol masers using MERLIN. The 1665-MHz OH, 22-GHz H2O and 6.7-GHz CH3OH masers are detected and all originate very close to the central source. The OH and methanol masers appear to trace part of the circumstellar disk around the central source. The positions and velocities of the OH masers are consistent with Keplerian rotation around a central mass of ˜5Msun. The water masers are offset from the OH and CH3OH masers and have significantly changed since they were last observed, but still appear to be associated outflow from the source. All the OH masers components are circular polarized, in some cases reaching 100 percent while some OH components also have low levels of linear polarization. We identified one Zeeman pair and the splitting of this pair indicate the presence of a magnetic field of strength ˜11 mG within ˜0.5" (850 AU

NOx emissions from high swirl turbulent spray flames with highly oxygenated fuels

KAUST Repository

Bohon, Myles

2013-01-01

Combustion of fuels with fuel bound oxygen is of interest from both a practical and a fundamental viewpoint. While a great deal of work has been done studying the effect of oxygenated additives in diesel and gasoline engines, much less has been done examining combustion characteristics of fuels with extremely high mass fractions of fuel bound oxygen. This work presents an initial investigation into the very low NOx emissions resulting from the combustion of a model, high oxygen mass fraction fuel. Glycerol was chosen as a model fuel with a fuel bound oxygen mass fraction of 52%, and was compared with emissions measured from diesel combustion at similar conditions in a high swirl turbulent spray flame. This work has shown that high fuel bound oxygen mass fractions allow for combustion at low global equivalence ratios with comparable exhaust gas temperatures due to the significantly lower concentrations of diluting nitrogen. Despite similar exhaust gas temperatures, NOx emissions from glycerol combustion were up to an order of magnitude lower than those measured using diesel fuel. This is shown to be a result not of specific burner geometry, but rather is influenced by the presence of higher oxygen and lower nitrogen concentrations at the flame front inhibiting NOx production. © 2012 The Combustion Institute.

Emission allowances stall in marketplace

International Nuclear Information System (INIS)

Malec, W.F.

1993-01-01

Misinformation and public misunderstanding have given emissions trading a bad reputation in the public marketplace, says William F. Malec, executive vice president of the Tennessee Valley Authority (TVA), in Knoxville, Tennessee. Media coverage of a May 1992 emissions-allowance trade between TVA and Wisconsin Power and Light open-quotes focused on the agreement's pollution-trading aspects, not its overall potential economic and environmental benefits,close quotes Malec says. Such negative portrayal of TVA's transaction sparked severe public criticism and charges that emissions trading gives utilities the right to pollute. open-quotes The fact is that TVA sought the emissions-trading agreement as a means to reduce overall emissions in the most cost-effective way,close quotes Malec explains. Emissions trading allows a company with emission levels lower than clean-air standards to earn open-quotes credits.close quotes These credits then may be purchased by a company with emission levels that exceed federal standards. Under this arrangement, the environment is protected and companies that buy credits save money because they do not have to purchase expensive emissions-control devices or reduce their production levels. Malec says TVA decided to enter into the emissions-allowance market, not only to cut costs, but also to publicize the existence and benefits of emissions trading. However, TVA's experience proves that open-quotes people will not accept what they do not understand,close quotes concludes Malec, open-quotes especially when complex environmental issues are involved.close quotes

Radio emission from Jupiter

International Nuclear Information System (INIS)

Velusamy, T.

1976-01-01

The basic features of the different radio emissions from the planet Jupiter are reviewed. These radio emissions characterized into three types as thermal, decimetric and decametric, are discussed. The coherent emission mechanism for the origin of the decametric bursts and the acceleration mechanism for relativistic electrons in the decimetric radiation have not been properly understood. The emissions are much related to the magnetic field of Jupiter. The system III rotation period for Jupiter has been calculated as 092 55 m 29.74 S. (A.K.)

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.

An econometric time-series analysis of global CO2 concentrations and emissions

International Nuclear Information System (INIS)

Cohen, B.C.; Labys, W.C.; Eliste, P.

2001-01-01

This paper extends previous work on the econometric modelling of CO 2 concentrations and emissions. The importance of such work rests in the fact that models of the Cohen-Labys variety represent the only alternative to scientific or physical models of CO 2 accumulations whose parameters are inferred rather than estimated. The stimulation for this study derives from the recent discovery of oscillations and cycles in the net biospheric flux of CO 2 . A variety of time series tests is thus used to search for the presence of normality, stationarity, cyclicality and stochastic processes in global CO 2 emissions and concentrations series. Given the evidence for cyclicality of a short-run nature in the spectra of these series, both structural time series and error correction model are applied to confirm the frequency and amplitude of these cycles. Our results suggest new possibilities for determining equilibrium levels of CO 2 concentrations and subsequently revising stabilization policies. (Author)

Is it efficient to co-compost and co-vermicompost green waste with biochar and/or clay to reduce CO2 emissions? A short-term laboratory experiment on (vermi)composts with additives.

Science.gov (United States)

Barthod, Justine; Rumpel, Cornélia; Paradelo, Remigio; Dignac, Marie-France

2016-04-01

Intensive farming practices can lead to a depletion of soil organic matter, negatively impacting important soil properties such as structural stability, fertility and C storage. The addition of organic amendments such as compost and vermicompost, rich in carbon, helps maintaining soil organic matter levels or restoring degraded soils. Composting and vermicomposting are based on stabilization of organic matter through the mineralization of easily decomposable organic matter compounds, therefore releasing greenhouse gases, including CO2. The aim of this study was to evaluate the global potential reduction of such emissions by the use of additives (2:1 clay and/or biochar): during (vermi)composting processes and after use of the final products as soil amendments. We hypothesized that the interactions between the additives and organic matter may lead to carbon stabilization and that such interactions may be enhanced by the presence of worms (Eisenia). We added in different proportions clay (25% or 50%), biochar (10%) and a mixture of biochar (10%) with clay (25%) to pre-composted green waste. The CO2 emissions of the composting and vermicomposting processes were measured during 21 days. After that, the amendments were added to a loamy cambisol soil and the CO2 emissions were monitored during 30 days of a laboratory experiment. The most efficient treatments in terms of reducing global CO2 emissions were the co-vermicomposting process with 25% clay followed by co-composting with 50% clay and with 10% biochar plus 25% clay. In this treatment (vermicompost with 25% clay), the carbon emissions were decreased by up to 44% compared to regular compost. Addition of biochar reduced CO2 emissions only during composting. Co-composting with biochar could be a promising avenue to limit global CO2 emissions whereas in presence of worms clay additions are better suited. These findings suggest that the presence of worms increased the formation of organo-mineral associations and thus C

Highly controlled, reproducible measurements of aerosol emissions from combustion of a common African biofuel source

Directory of Open Access Journals (Sweden)

S. L. Haslett

2018-01-01

Full Text Available Particulate emissions from biomass burning can both alter the atmosphere's radiative balance and cause significant harm to human health. However, due to the large effect on emissions caused by even small alterations to the way in which a fuel burns, it is difficult to study particulate production of biomass combustion mechanistically and in a repeatable manner. In order to address this gap, in this study, small wood samples sourced from Côte D'Ivoire in West Africa were burned in a highly controlled laboratory environment. The shape and mass of samples, available airflow and surrounding thermal environment were carefully regulated. Organic aerosol and refractory black carbon emissions were measured in real time using an Aerosol Mass Spectrometer and a Single Particle Soot Photometer, respectively. This methodology produced remarkably repeatable results, allowing aerosol emissions to be mapped directly onto different phases of combustion. Emissions from pyrolysis were visible as a distinct phase before flaming was established. After flaming combustion was initiated, a black-carbon-dominant flame was observed during which very little organic aerosol was produced, followed by a period that was dominated by organic-carbon-producing smouldering combustion, despite the presence of residual flaming. During pyrolysis and smouldering, the two phases producing organic aerosol, distinct mass spectral signatures that correspond to previously reported variations in biofuel emissions measured in the atmosphere are found. Organic aerosol emission factors averaged over an entire combustion event were found to be representative of the time spent in the pyrolysis and smouldering phases, rather than reflecting a coupling between emissions and the mass loss of the sample. Further exploration of aerosol yields from similarly carefully controlled fires and a careful comparison with data from macroscopic fires and real-world emissions will help to deliver

Sorption and reduction of selenite on chlorite surfaces in the presence of Fe(II) ions.

Science.gov (United States)

Baik, Min Hoon; Lee, Seung Yeop; Jeong, Jongtae

2013-12-01

The sorption and reduction of selenite on chlorite surfaces in the presence of Fe(II) ions were investigated as a function of pH, Se(IV) concentration, and Fe(II) concentration under an anoxic condition. The sorption of Se(IV) onto chlorite surfaces followed the Langmuir isotherm regardless of the presence of Fe(II) ions in the solution. The Se(IV) sorption was observed to be very low at all pH values when the solution was Fe(II)-free or the concentration of Fe(II) ions was as low as 0.5 mg/L. However, the Se(IV) sorption was enhanced at a pH > 6.5 when the Fe(II) concentration was higher than 5 mg/L because of the increased sorption of Fe(II) onto the chlorite surfaces. XANES (X-ray absorption near edge structure) spectra of the Se K-edge showed that most of the sorbed Se(IV) was reduced to Se(0) by Fe(II) sorbed onto the chlorite surfaces, especially at pH > 9. The combined results of field-emission scanning electron microscopy (FE-SEM) and X-ray diffraction (XRD) also showed that elemental selenium and goethite were formed and precipitated on the chlorite surfaces during the sorption of selenite. Consequently it can be concluded that Se(IV) can be reduced to Se(0) in the presence of Fe(II) ions by the surface catalytic oxidation of Fe(II) into Fe(III) and the formation of goethite at neutral and particularly alkaline conditions. Thus the mobility of selenite in groundwater is expected to be reduced by the presence of a relatively higher concentration of Fe(II) in subsurface environments. Copyright © 2013 Elsevier Ltd. All rights reserved.

Effect of magnetic field-aligned currents on VLF emissions in the magnetosphere

International Nuclear Information System (INIS)

Kulkarni, V.H.

1988-01-01

The dispersion relation for the electromagnetic electron cyclotron waves in the presence of magnetic field-aligned currents has been obtained. The kinetic distribution of electrons for the main body of plasma with a temperature anisotropy and a loss cone distribution have been considered. In general, it has been seen that the current moving along the direction of resonant electrons reduce the growth rate. This effect has been analysed in the case of magnetospheric plasma to suggest possible correlations between the Birkeland currents and the emissions of very low frequency (VLF) electromagnetic waves. (author). 19 refs

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

Science.gov (United States)

2010-07-01

... waste landfill emissions. 60.33c Section 60.33c Protection of Environment ENVIRONMENTAL PROTECTION... 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...

Emission intensity in New Zealand manufacturing and the short-run impacts of emissions pricing

International Nuclear Information System (INIS)

Bartleet, Matthew; Iyer, Kris; Numan-Parsons, Elisabeth

2010-01-01

This paper reports the greenhouse gas (GHG) emission intensity of the New Zealand (NZ) manufacturing sector at a combination of industry group and class levels (sub-sectors). The short-run impacts of a price on emissions are investigated with a focus on exporting activities. Sub-sectors that could be materially impacted by an expected range of emissions prices accounted for slightly over 9% of national gross domestic product. It is found that there is much variability of emission intensity within manufacturing and even within sub-sectors. An assessment of trade intensities further indicates that several emissions-intensive activities are also export-intensive. These activities are at most risk of losing competitiveness in the short-run if they are subjected to a price on GHG emissions that their competitors in other countries are not. Emissions reduction policies must take account of trade competitiveness imperatives if NZ is to meet its international GHG emissions target while maintaining manufacturing sector competitiveness. - Research Highlights: →Estimates initial short-term competitiveness impacts of ETS on NZ manufacturing. →Materiality of impacts determined based on firm level emissions and export intensity. →Results suggest that food processing sub-sectors are likely to be most impacted. →Iron and steel processing, and paper and pulp manufacture are impacted as well. →Cumulative GDP share of materially affected sub-sectors slightly over 9%.

Wavelet Based Characterization of Low Radio Frequency Solar Emissions

Science.gov (United States)

Suresh, A.; Sharma, R.; Das, S. B.; Oberoi, D.; Pankratius, V.; Lonsdale, C.

2016-12-01

Low-frequency solar radio observations with the Murchison Widefield Array (MWA) have revealed the presence of numerous short-lived, narrow-band weak radio features, even during quiet solar conditions. In their appearance in in the frequency-time plane, they come closest to the solar type III bursts, but with much shorter spectral spans and flux densities, so much so that they are not detectable with the usual swept frequency radio spectrographs. These features occur at rates of many thousand features per hour in the 30.72 MHz MWA bandwidth, and hence necessarily require an automated approach to determine robust statistical estimates of their properties, e.g., distributions of spectral widths, temporal spans, flux densities, slopes in the time-frequency plane and distribution over frequency. To achieve this, a wavelet decomposition approach has been developed for feature recognition and subsequent parameter extraction from the MWA dynamic spectrum. This work builds on earlier work by the members of this team to achieve a reliable flux calibration in a computationally efficient manner. Preliminary results show that the distribution of spectral span of these features peaks around 3 MHz, most of them last for less than two seconds and are characterized by flux densities of about 60% of the background solar emission. In analogy with the solar type III bursts, this non-thermal emission is envisaged to arise via coherent emission processes. There is also an exciting possibility that these features might correspond to radio signatures of nanoflares, hypothesized (Gold, 1964; Parker, 1972) to explain coronal heating.

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

Fighting against VOC emissions; Lutter contre les emissions de COV

Energy Technology Data Exchange (ETDEWEB)

Fanlo, J.L. [Ecole des Mines d' Ales, 30 (France); Puech, G. [APAVE, 75 - Paris (France); Patoux, R. [Rhodia Rhoditech (France)] [and others

2001-12-01

This document brings together 15 testimonies of experts about the processes used in the industry for the abatement of volatile organic compound (VOC) emissions. The different points approached concern: the first industrial experiments of fight against VOC emissions, how to audit the facilities, how to make a diagnosis, to hierarchized and to measure continuously VOC emissions, how to anticipate the explosion risks linked with VOC treatment processes, the techniques of VOC abatement at the source implemented by industrialists, the implementation of an emission mastery scheme by Crow Cork and Seal company, the implementation of a solvent management plan by Turbomeca company and of a paints strategy by Renault car-making company, the combination of VOC abatement techniques implemented by industrialists, the classification of destruction and recovery processes: the experience feedback of Sanofi Synthelabo and of Air Liquide companies, the combination of upstream and downstream techniques implemented by Pechiney Rhenalu, Ashland Polyester and Quebecor companies. (J.S.)

Carbon emissions in China

Energy Technology Data Exchange (ETDEWEB)

Liu, Zhu [Harvard Univ., Cambridge, MA (United States). Sustainability Science Program

2016-07-01

This study analyzes the spatial-temporal pattern and processes of China's energy-related carbon emissions. Based on extensive quantitative analysis, it outlines the character and trajectory of China's energy-related carbon emissions during the period 1995-2010, examining the distribution pattern of China's carbon emissions from regional and sectoral perspectives and revealing the driving factors of China's soaring emission increase. Further, the book investigates the supply chain carbon emissions (the carbon footprints) of China's industrial sectors. Anthropogenic climate change is one of the most serious challenges currently facing humankind. China is the world's largest developing country, top primary energy consumer and carbon emitter. Achieving both economic growth and environmental conservation is the country's twofold challenge. Understanding the status, features and driving forces of China's energy-related carbon emissions is a critical aspect of attaining global sustainability. This work, for the first time, presents both key findings on and a systematic evaluation of China's carbon emissions from energy consumption. The results have important implications for global carbon budgets and burden-sharing with regard to climate change mitigation. The book will be of great interest to readers around the world, as it addresses a topic of truly global significance.

Dual mode emission and harmonic generation in ZnO-CaO-Al{sub 2}O{sub 3}: Er{sup 3+} nano-composite

Energy Technology Data Exchange (ETDEWEB)

Verma, R.K. [Laser and Spectroscopy Laboratory, Department of Physics, Banaras Hindu University, Varanasi 221005 (India); Kumar, K. [Laser and Spectroscopy Laboratory, Department of Physics, Banaras Hindu University, Varanasi 221005 (India); Nano-technology Application Centre, University of Allahabad, Allahabad (India); Rai, S.B., E-mail: sbrai49@yahoo.co.i [Laser and Spectroscopy Laboratory, Department of Physics, Banaras Hindu University, Varanasi 221005 (India)

2011-05-15

Er{sup 3+} doped ZnO-CaO-Al{sub 2}O{sub 3} nano-composite phosphor has been synthesized through combustion method and its emission and harmonic generation properties have been studied. The X-ray diffraction and thermal analysis techniques have been used to prove the dual phase (ZnO and CaO-Al{sub 2}O{sub 3}) nature of the phosphor. The phosphor has shown up-conversion emission on near-infra-red (976 nm) excitation and down-conversion emission on 355 nm excitation in presence of Er{sup 3+} and thus behaves as a dual mode phosphor. On excitation with 976 nm diode laser, material shows color tunability (calcination of composite material at different temperatures). Formation of ZnO nanocrystals on heat treatment of as-synthesized sample has shown its characteristic emission at 388 nm and also the energy transfer from ZnO to Er{sup 3+} ions. The low temperature emission measurements have been carried out and the results have been discussed. Phosphor has shown strong second harmonic generation (SHG) at 532 nm on 1064 nm and at 266 nm on 532 nm excitation. - Research highlights: {yields} We have synthesized Er{sup 3+} doped composite material by combustion method. The two phases of composites are ZnO and CaO-Al{sub 2}O{sub 3}. {yields} The phosphor has shown up-conversion emission on near-infra-red (976 nm) excitation and down-conversion emission on 355 nm excitation in presence of Er{sup 3+} and thus behaves as a dual mode phosphor. This material also shows colour tenability on excitation of 976 nm diode laser at different temperature calcinations (i.e., As-synthesized to calcinated at 1473 K). {yields} Low temperature effects on Er{sup 3+} as well as ZnO emission have been carried out. We observed that at low temperature the efficiency of Er{sup 3+} increases while in the case of ZnO its intensity increases and also 12 nm shifting observed. {yields} Composite material has shown strong second harmonic generation (SHG) at 532 nm on 1064 nm and at 266 nm on 532 nm

Impacts of Climate Change Induced Vegetation Responses on BVOC Emissions from Subarctic Heath Ecosystems

DEFF Research Database (Denmark)

Valolahti, Hanna Maritta

The role of biogenic volatile organic compounds (BVOCs) affecting Earths’ climate system is one of the greatest uncertainties when modelling the global climate change. BVOCs presence in the atmosphere can have both positive and negative climate feedback mechanisms when they involve atmospheric...... chemistry and physics. Vegetation is the main source of BVOCs. Their production is directly linked to temperature and the foliar biomass. On global scale, vegetation in subarctic and arctic regions has been modeled to have only minor contribution to annual total BVOC emissions. In these regions cold...... temperature has been regulating annual plant biomass production, but ongoing global warming is more pronounced in these regions than what the global average is. This may increase the importance of subarctic and arctic vegetation as a source of BVOC emissions in near future. This thesis aims to increase...

Exhaust emissions and electric energy generation in a stationary engine using blends of diesel and soybean biodiesel

International Nuclear Information System (INIS)

Pereira, Roberto G.; Oliveira, Jorge L.; Oliveira, Paulo Cesar P.; Oliveira, Cesar D.; Fellows, Carlos E.; Piamba, Oscar E.

2007-01-01

The present work describes an experimental investigation concerning the electric energy generation using blends of diesel and soybean biodiesel. The soybean biodiesel was produced by a transesterification process of the soybean oil using methanol in the presence of a catalyst (KOH). The properties (density, flash point, viscosity, pour point, cetane index, copper strip corrosion, conradson carbon residue and ash content) of the diesel and soybean biodiesel were determined. The exhaust emissions of gases (CO, CO 2 ,C x H y ,O 2 , NO, NO x and SO 2 ) were also measured. The results show that for all the mixtures tested, the electric energy generation was assured without problems. It has also been observed that the emissions of CO, C x H y and SO 2 decrease in the case of diesel-soybean biodiesel blends. The temperatures of the exhaust gases and the emissions of NO and NO x are similar to or less than those of diesel. (author)

Acoustic emission during the compaction of brittle UO2 particles

International Nuclear Information System (INIS)

Hegron, Lise

2014-01-01

One of the options considered for recycling minor actinides is to incorporate about 10% to UO 2 matrix. The presence of open pores interconnected within this fuel should allow the evacuation of helium and fission gases to prevent swelling of the pellet and ultimately its interaction with the fuel clad surrounding it. Implementation of minor actinides requires working in shielded cell, reducing their retention and outlawing additions of organic products. The use of fragmentable particles of several hundred micrometers seems a good solution to control the microstructure of the green compacts and thus control the open porosity after sintering. The goal of this study is to monitor the compaction of brittle UO 2 particles by acoustic emission and to link the particle characteristics to the open porosity obtained after the compact sintering. The signals acquired during tensile strength tests on individual granules and compacts show that the acoustic emission allows the detection of the mechanism of fragmentation and enables identification of a characteristic waveform of this fragmentation. The influences of compaction stress, of the initial particle size distribution and of the internal cohesion of the granules, on the mechanical strength of the compact and on the microstructure and open porosity of the sintered pellets, are analyzed. By its ability to identify the range of fragmentation of the granules during compaction, acoustic emission appears as a promising technique for monitoring the compaction of brittle particles in the manufacture of a controlled porosity fuel. (author) [fr

Water vapor emission from H II regions and infrared stars

International Nuclear Information System (INIS)

Cato, B.T.; Ronnang, B.O.; Rydbeck, O.E.H.; Lewin, P.T.; Yngvesson, K.S.; Cardiasmenos, A.G.; Shanley, J.F.

1976-01-01

The spatial structure of water vapor microwave line emission has been investigated with moderate angular resolution in several well-known H II regions. New H 2 O sources have been with infrared (1R) sources. One of these sources, IRC: 20411, has been investigated at optical wavelengths. It is found to be of spectral class M3-M5 and by indirect evidence the luminosity class is preliminarily determined to Ib. The distance is estimated to be approx.2 kpc, and the star must be in front of the dust complex which obscures W28 A2. In NGC 7538 new high-velocity features have been discovered. Two new weak water vapor masers, G30.1: 0.7 and G32.8: 0.3, have been detected in a search among eight class II OH/IR sources. H 2 O emission coinciding with the low-velocity OH features of VY Canis Majoris has also been detected. A search for local thermodynamic equilibrium (LTE) water-vapor line emission in molecular clouds associated with H II regions is also reported. No line was detected with the utilized sensitivity. The physical implications of this are discussed and an upper limit of the H 2 O column density has been estimated. Gaussian analysis of the strong, narrow feature in the spectrum of ON 1 indicates a possible presence of two hyperfine components, viz., F→F'=7→6 and 6→5

Exhaust emissions reduction from diesel engine using combined Annona-Eucalyptus oil blends and antioxidant additive

Science.gov (United States)

Senthil, R.; Silambarasan, R.; Pranesh, G.

2017-03-01

The limited resources, rising petroleum prices and depletion of fossil fuel have now become a matter of great concern. Hence, there is an urgent need for researchers to find some alternate fuels which are capable of substituting partly or wholly the higher demanded conventional diesel fuel. Lot of research work has been conducted on diesel engine using biodiesel and its blends with diesel as an alternate fuel. Very few works have been done with combination of biodiesel-Eucalypts oil without neat diesel and this leads to lots of scope in this area. The aim of the present study is to analyze the performance and emission characteristics of a single cylinder, direct injection, compression ignition engine using eucalyptus oil-biodiesel as fuel. The presence of eucalyptus oil in the blend reduces the viscosity and improves the volatility of the blends. The methyl ester of Annona oil is blended with eucalypts oil in 10, 20, 30, 40 and 50 %. The performance and emission characteristics are evaluated by operating the engine at different loads. The performance characteristics such as brake thermal efficiency, brake specific fuel consumption and exhaust gas temperature are evaluated. The emission constituents measured are Carbon monoxide (CO), unburned hydrocarbons (HC), Oxides of nitrogen (NOx) and Smoke. It is found that A50-Eu50 (50 Annona + 50 % Eucalyptus oil) blend showed better performance and reduction in exhaust emissions. But, it showed a very marginal increase in NOx emission when compared to that of diesel. Therefore, in order to reduce the NOx emission, antioxidant additive (A-tocopherol acetate) is mixed with Annona-Eucalyptus oil blends in various proportions by which NOx emission is reduced. Hence, A50-Eu50 blend can be used as an alternate fuel for diesel engine without any modifications.

Modeling natural emissions in the Community Multiscale Air Quality (CMAQ Model–I: building an emissions data base

Directory of Open Access Journals (Sweden)

S. F. Mueller

2010-05-01

Full Text Available A natural emissions inventory for the continental United States and surrounding territories is needed in order to use the US Environmental Protection Agency Community Multiscale Air Quality (CMAQ Model for simulating natural air quality. The CMAQ air modeling system (including the Sparse Matrix Operator Kernel Emissions (SMOKE emissions processing system currently estimates non-methane volatile organic compound (NMVOC emissions from biogenic sources, nitrogen oxide (NOx emissions from soils, ammonia from animals, several types of particulate and reactive gas emissions from fires, as well as sea salt emissions. However, there are several emission categories that are not commonly treated by the standard CMAQ Model system. Most notable among these are nitrogen oxide emissions from lightning, reduced sulfur emissions from oceans, geothermal features and other continental sources, windblown dust particulate, and reactive chlorine gas emissions linked with sea salt chloride. A review of past emissions modeling work and existing global emissions data bases provides information and data necessary for preparing a more complete natural emissions data base for CMAQ applications. A model-ready natural emissions data base is developed to complement the anthropogenic emissions inventory used by the VISTAS Regional Planning Organization in its work analyzing regional haze based on the year 2002. This new data base covers a modeling domain that includes the continental United States plus large portions of Canada, Mexico and surrounding oceans. Comparing July 2002 source data reveals that natural emissions account for 16% of total gaseous sulfur (sulfur dioxide, dimethylsulfide and hydrogen sulfide, 44% of total NOx, 80% of reactive carbonaceous gases (NMVOCs and carbon monoxide, 28% of ammonia, 96% of total chlorine (hydrochloric acid, nitryl chloride and sea salt chloride, and 84% of fine particles (i.e., those smaller than 2.5 μm in size released into the

Modeling natural emissions in the Community Multiscale Air Quality (CMAQ) Model-I: building an emissions data base

Science.gov (United States)

Smith, S. N.; Mueller, S. F.

2010-05-01

A natural emissions inventory for the continental United States and surrounding territories is needed in order to use the US Environmental Protection Agency Community Multiscale Air Quality (CMAQ) Model for simulating natural air quality. The CMAQ air modeling system (including the Sparse Matrix Operator Kernel Emissions (SMOKE) emissions processing system) currently estimates non-methane volatile organic compound (NMVOC) emissions from biogenic sources, nitrogen oxide (NOx) emissions from soils, ammonia from animals, several types of particulate and reactive gas emissions from fires, as well as sea salt emissions. However, there are several emission categories that are not commonly treated by the standard CMAQ Model system. Most notable among these are nitrogen oxide emissions from lightning, reduced sulfur emissions from oceans, geothermal features and other continental sources, windblown dust particulate, and reactive chlorine gas emissions linked with sea salt chloride. A review of past emissions modeling work and existing global emissions data bases provides information and data necessary for preparing a more complete natural emissions data base for CMAQ applications. A model-ready natural emissions data base is developed to complement the anthropogenic emissions inventory used by the VISTAS Regional Planning Organization in its work analyzing regional haze based on the year 2002. This new data base covers a modeling domain that includes the continental United States plus large portions of Canada, Mexico and surrounding oceans. Comparing July 2002 source data reveals that natural emissions account for 16% of total gaseous sulfur (sulfur dioxide, dimethylsulfide and hydrogen sulfide), 44% of total NOx, 80% of reactive carbonaceous gases (NMVOCs and carbon monoxide), 28% of ammonia, 96% of total chlorine (hydrochloric acid, nitryl chloride and sea salt chloride), and 84% of fine particles (i.e., those smaller than 2.5 μm in size) released into the atmosphere

Year-round simulated methane emissions from a permafrost ecosystem in Northeast Siberia

Science.gov (United States)

Castro-Morales, Karel; Kleinen, Thomas; Kaiser, Sonja; Zaehle, Sönke; Kittler, Fanny; Kwon, Min Jung; Beer, Christian; Göckede, Mathias

2018-05-01

Wetlands of northern high latitudes are ecosystems highly vulnerable to climate change. Some degradation effects include soil hydrologic changes due to permafrost thaw, formation of deeper active layers, and rising topsoil temperatures that accelerate the degradation of permafrost carbon and increase in CO2 and CH4 emissions. In this work we present 2 years of modeled year-round CH4 emissions into the atmosphere from a Northeast Siberian region in the Russian Far East. We use a revisited version of the process-based JSBACH-methane model that includes four CH4 transport pathways: plant-mediated transport, ebullition and molecular diffusion in the presence or absence of snow. The gas is emitted through wetlands represented by grid cell inundated areas simulated with a TOPMODEL approach. The magnitude of the summertime modeled CH4 emissions is comparable to ground-based CH4 fluxes measured with the eddy covariance technique and flux chambers in the same area of study, whereas wintertime modeled values are underestimated by 1 order of magnitude. In an annual balance, the most important mechanism for transport of methane into the atmosphere is through plants (61 %). This is followed by ebullition ( ˜ 35 %), while summertime molecular diffusion is negligible (0.02 %) compared to the diffusion through the snow during winter ( ˜ 4 %). We investigate the relationship between temporal changes in the CH4 fluxes, soil temperature, and soil moisture content. Our results highlight the heterogeneity in CH4 emissions at landscape scale and suggest that further improvements to the representation of large-scale hydrological conditions in the model will facilitate a more process-oriented land surface scheme and better simulate CH4 emissions under climate change. This is especially necessary at regional scales in Arctic ecosystems influenced by permafrost thaw.

Year-round simulated methane emissions from a permafrost ecosystem in Northeast Siberia

Directory of Open Access Journals (Sweden)

K. Castro-Morales

2018-05-01

Full Text Available Wetlands of northern high latitudes are ecosystems highly vulnerable to climate change. Some degradation effects include soil hydrologic changes due to permafrost thaw, formation of deeper active layers, and rising topsoil temperatures that accelerate the degradation of permafrost carbon and increase in CO2 and CH4 emissions. In this work we present 2 years of modeled year-round CH4 emissions into the atmosphere from a Northeast Siberian region in the Russian Far East. We use a revisited version of the process-based JSBACH-methane model that includes four CH4 transport pathways: plant-mediated transport, ebullition and molecular diffusion in the presence or absence of snow. The gas is emitted through wetlands represented by grid cell inundated areas simulated with a TOPMODEL approach. The magnitude of the summertime modeled CH4 emissions is comparable to ground-based CH4 fluxes measured with the eddy covariance technique and flux chambers in the same area of study, whereas wintertime modeled values are underestimated by 1 order of magnitude. In an annual balance, the most important mechanism for transport of methane into the atmosphere is through plants (61 %. This is followed by ebullition ( ∼  35 %, while summertime molecular diffusion is negligible (0.02 % compared to the diffusion through the snow during winter ( ∼  4 %. We investigate the relationship between temporal changes in the CH4 fluxes, soil temperature, and soil moisture content. Our results highlight the heterogeneity in CH4 emissions at landscape scale and suggest that further improvements to the representation of large-scale hydrological conditions in the model will facilitate a more process-oriented land surface scheme and better simulate CH4 emissions under climate change. This is especially necessary at regional scales in Arctic ecosystems influenced by permafrost thaw.

The POETICs of industrial carbon dioxide emissions in Japan: an urban and institutional extension of the IPAT identity

Directory of Open Access Journals (Sweden)

Scholz Stephan

2006-09-01

Full Text Available Abstract Background This study applies the POETICs framework (population, organization, environment, technology, institutions and culture to an analysis of industrial carbon dioxide emissions in Japanese cities. The inclusion of institutional variables in the form of International Council for Local Environmental Initiatives membership, ISO 14001 implementation, and non-profit sector activity addresses the ecological limitations of the often used IPAT (impact = population × affluence × technology approach. Results Results suggest the weak existence of an environmental Kuznets curve, in which the wealthiest cities are reducing their emissions through increased efficiency. Significant institutional impacts are also found to hold in the predicted directions. Specifically, panel and cross-sectional regressions indicate that membership in the International Council for Local Environmental Initiatives and non-profit organizational presence have negative effects on industrial carbon dioxide emissions. Conclusion The presence of institutional drivers at the city level provides empirical support for the POETICs rubric, which recasts the ecological framing of the IPAT identity in a more sociological mold. The results also indicate that Japanese civil society has a role to play in carbon mitigation. More refined studies need to take into consideration an expanded set of methods, drivers, and carbon budgets, as applied to a broader range of cases outside of Japan, to more accurately assess how civil society can bridge the issue of scale that separates local level policy concerns from global level climate dynamics.

Acoustic Emission Technology and Application

International Nuclear Information System (INIS)

Joo, Y. S.; Lim, S. H.; Eom, H. S.; Kim, J. H.; Jung, H. K.

2003-10-01

Acoustic emission is the elastic wave that is generated by the rapid release of energy from the localized sources within a material. After the observation of acoustic emission phenomenon in 1950, the research and further investigation had been performed. Acoustic emission examination becomes a rapidly matured nondestructive testing method with demonstrated capabilities for characterizing material behavior and for detecting the defect. It is of interest as a possible passive monitoring technique for detecting, locating and characterizing the defects in component and structure. Acoustic emission technology has recently strengthened the on-line monitoring application for the detection of incipient failures and the assurance of structural integrity. The field of acoustic emission testing is still growing vigorously and presents many challenges. Especially, acoustic emission has been successfully applied in the leak detection of primary pressure boundary of nuclear power plants. In this state-of-art report, the principle, measurement and field applications of acoustic emission technique is reviewed and summarized. Acoustic emission technology will contribute to the assurance of nuclear safety as the on-line monitoring technique of structural integrity of NSSS components and structures

Membrane potential and microsecond to millisecond delayed light emission after a single excitation flash in isolated chloroplasts

International Nuclear Information System (INIS)

Jursinic, P.; Govindjee; Wraight, C.A.

1978-01-01

The effect of light-induced and salt-jump induced membrane potential on microsecond and millisecond delayed light emission from chloroplasts, following a single 10 ns flash, have been studied. Microsecond delayed light emission is shown to be independent of the membrane potential contrary to proposals that the activation energy for delayed light emission can be modulated by transmembrane electric fields. This result is discussed in terms of the possible origin of this short-lived emission. Millisecond delayed light after a single excitation flash is enhanced by membrane potential only if a proton gradient is present. By measuring changes in ms delayed light caused by simultaneous injection of KCl and Na-benzoate (which creates a proton gradient) in the presence of valinomycin, the light-induced potential generated across the thylakoid membrane by a single excitation flash was calibrated and found to be 128 +- 10 mV in agreement with the recent measurements of Zickler and Witt, (FEBS Lett. 66, 142-148 (1976)), based on voltage-dependent ionophores. It is concluded that the secondary charges that give rise to ms delayed light, after a single flash, do not fully span the membrane. (author)

Effect of Weakly Nonthermal Ion Velocity Distribution on Jeans Instability in a Complex Plasma in Presence of Secondary Electrons

International Nuclear Information System (INIS)

Sarkar, S.; Maity, S.

2013-01-01

In this paper we have investigated the effect of weak nonthermality of ion velocity distribution on Jean’s instability in a complex plasma in presence of secondary electrons and negatively charged dust grains. The primary and secondary electron temperatures are assumed equal. Thus plasma under consideration consists of three components: Boltzman distributed electrons, non-thermal ions and negatively charged inertial dust grains. From the linear dispersion relation we have calculated the real frequency and growth rate of the Jean’s mode. Numerically we have found that secondary electron emission destabilizes Jean’s mode when ion nonthermality is weak. (author)

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.

Emissions from photovoltaic life cycles.

Science.gov (United States)

Fthenakis, Vasilis M; Kim, Hyung Chul; Alsema, Erik

2008-03-15

Photovoltaic (PV) technologies have shown remarkable progress recently in terms of annual production capacity and life cycle environmental performances, which necessitate timely updates of environmental indicators. Based on PV production data of 2004-2006, this study presents the life-cycle greenhouse gas emissions, criteria pollutant emissions, and heavy metal emissions from four types of major commercial PV systems: multicrystalline silicon, monocrystalline silicon, ribbon silicon, and thin-film cadmium telluride. Life-cycle emissions were determined by employing average electricity mixtures in Europe and the United States during the materials and module production for each PV system. Among the current vintage of PV technologies, thin-film cadmium telluride (CdTe) PV emits the least amount of harmful air emissions as it requires the least amount of energy during the module production. However, the differences in the emissions between different PV technologies are very small in comparison to the emissions from conventional energy technologies that PV could displace. As a part of prospective analysis, the effect of PV breeder was investigated. Overall, all PV technologies generate far less life-cycle air emissions per GWh than conventional fossil-fuel-based electricity generation technologies. At least 89% of air emissions associated with electricity generation could be prevented if electricity from photovoltaics displaces electricity from the grid.

Dust emission from wet, low-emission coke quenching process

Science.gov (United States)

Komosiński, Bogusław; Bobik, Bartłomiej; Konieczny, Tomasz; Cieślik, Ewelina

2018-01-01

Coke plants, which produce various types of coke (metallurgical, foundry or heating), at temperatures between 600 and 1200°C, with limited access to oxygen, are major emitters of particulates and gaseous pollutants to air, water and soils. Primarily, the process of wet quenching should be mentioned, as one of the most cumbersome. Atmospheric pollutants include particulates, tar substances, organic pollutants including B(a)P and many others. Pollutants are also formed from the decomposition of water used to quench coke (CO, phenol, HCN, H2S, NH3, cresol) and decomposition of hot coke in the first phase of quenching (CO, H2S, SO2) [1]. The development of the coke oven technology has resulted in the changes made to different types of technological installations, such as the use of baffles in quench towers, the removal of nitrogen oxides by selective NOx reduction, and the introduction of fabric filters for particulates removal. The BAT conclusions for coke plants [2] provide a methodology for the measurement of particulate emission from a wet, low-emission technology using Mohrhauer probes. The conclusions define the emission level for wet quenching process as 25 g/Mgcoke. The conducted research was aimed at verification of the presented method. For two of three quench towers (A and C) the requirements included in the BAT conclusions are not met and emissions amount to 87.34 and 61.35 g/Mgcoke respectively. The lowest particulates emission was recorded on the quench tower B and amounted to 22.5 g/Mgcoke, therefore not exceeding the requirements.

Aspects related to 'emission trading'

International Nuclear Information System (INIS)

Tutuianu, Ovidiu

1999-01-01

The paper presents the aspects of international GHG (greenhouse gases) emission trading, such as: quality of GHG emission data, possible partners, monitoring activity, market mechanisms and difficulties. The following conclusions are drown: - debates on international trade with GHG emissions are currently in a very early stage; - actions are possible and feasible, particularly after Kyoto Conference, as versatile mechanism (besides the Joint Implementation Projects) which have in view the lowering of the global emission costs in different zones of the planet; - difficulties concerning monitoring, reporting and verification, practically preclude implementing a system of emission trading covering all the GHG, all the sources and reservoirs; - an international viable system of emission trading could initiate with a limited number of participants and consideration of only emission categories easy to be confined and surveyed; - existence of a national market and corresponding institutions for monitoring which could booster an international system development

EARLY ULTRAVIOLET/OPTICAL EMISSION OF THE TYPE Ib SN 2008D

Energy Technology Data Exchange (ETDEWEB)

Bersten, Melina C.; Nomoto, Ken' ichi [Kavli Institute for the Physics and Mathematics of the Universe, Todai Institutes for Advanced Study, University of Tokyo, 5-1-5 Kashiwanoha, Kashiwa, Chiba 277-8583 (Japan); Tanaka, Masaomi [National Astronomical Observatory of Japan, 2-21-1 Osawa, Mitaka, Tokyo 181-8588 (Japan); Tominaga, Nozomu [Department of Physics, Faculty of Science and Engineering, Konan University, 8-9-1 Okamoto, Kobe, Hyogo 658-8501 (Japan); Benvenuto, Omar G., E-mail: melina.bersten@ipmu.jp [Facultad de Ciencias Astronomicas y Geofisicas, Universidad Nacional de La Plata, Paseo del Bosque S/N, B1900FWA La Plata (Argentina)

2013-04-20

We propose an alternative explanation for the post-breakout emission of SN 2008D associated with the X-ray transient 080109. Observations of this object show a very small contrast of 0.35 dex between the light-curve minimum occurring soon after the breakout, and the main luminosity peak which is due to radioactive heating of the ejecta. Hydrodynamical models show that the cooling of a shocked Wolf-Rayet star leads to a much greater difference ({approx}> 0.9 dex). Our proposed scenario is that of a jet produced during the explosion which deposits {sup 56}Ni-rich material in the outer layers of the ejecta. The presence of high-velocity radioactive material allows us to reproduce the complete luminosity evolution of the object. Without outer {sup 56}Ni it could be possible to reproduce the early emission purely from cooling of the shocked envelope by assuming a larger progenitor than a Wolf-Rayet star, but that would require an initial density structure significantly different from what is predicted by stellar evolution models. Analytic models of the cooling phase have been proposed reproduce the early emission of SN 2008D with an extended progenitor. However, we found that the models are valid only until 1.5 days after the explosion where only two data of SN 2008D are available. We also discuss the possibility of the interaction of the ejecta with a binary companion, based on published analytic expressions. However, the binary separation required to fit the early emission should be {approx}< 3 R{sub Sun }, which is too small for a system containing two massive stars.

QUASI-QUIESCENT RADIO EMISSION FROM THE FIRST RADIO-EMITTING T DWARF

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Williams, Peter K. G.; Berger, Edo; Zauderer, B. Ashley, E-mail: pwilliams@cfa.harvard.edu [Harvard-Smithsonian Center for Astrophysics, 60 Garden Street, Cambridge, MA 02138 (United States)

2013-04-20

Radio detections of ultracool dwarfs provide insight into their magnetic fields and the dynamos that maintain them, especially at the very bottom of the main sequence, where other activity indicators dramatically weaken. Until recently, radio emission was only detected in the M and L dwarf regimes, but this has changed with the Arecibo detection of rapid polarized flares from the T6.5 dwarf 2MASS J10475385+2124234. Here, we report the detection of quasi-quiescent radio emission from this source at 5.8 GHz using the Karl G. Jansky Very Large Array. The spectral luminosity is L{sub {nu}} = (2.2 {+-} 0.7) Multiplication-Sign 10{sup 12} erg s{sup -1} Hz{sup -1}, a factor of {approx}100 times fainter than the Arecibo flares. Our detection is the lowest luminosity yet achieved for an ultracool dwarf. Although the emission is fully consistent with being steady, unpolarized, and broad band, we find tantalizing hints for variability. We exclude the presence of short-duration flares as seen by Arecibo, although this is not unexpected given estimates of the duty cycle. Follow-up observations of this object will offer the potential to constrain its rotation period, electron density, and the strength and configuration of the magnetic field. Equally important, follow-up observations will address the question of whether the electron cyclotron maser instability, which is thought to produce the flares seen by Arecibo, also operates in the very different parameter regime of the emission we detect, or whether instead this ultracool dwarf exhibits both maser and gyrosynchrotron radiation, potentially originating from substantially different locations.

Neutrino emissivity in the quark-hadron mixed phase of neutron stars

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Spinella, William M. [Computational Science Research Center San Diego State University, San Diego, CA (United States); San Diego State University, Department of Physics, San Diego, CA (United States); Weber, Fridolin [San Diego State University, Department of Physics, San Diego, CA (United States); University of California San Diego, Center for Astrophysics and Space Sciences, La Jolla, CA (United States); Contrera, Gustavo A. [CONICET, Buenos Aires (Argentina); CONICET - Dept. de Fisica, UNLP, IFLP, La Plata (Argentina); Universidad Nacional de La Plata, Grupo de Gravitacion, Astrofisica y Cosmologia, Facultad de Ciencias Astronomicas y Geofisicas, La Plata (Argentina); Orsaria, Milva G. [CONICET, Buenos Aires (Argentina); Universidad Nacional de La Plata, Grupo de Gravitacion, Astrofisica y Cosmologia, Facultad de Ciencias Astronomicas y Geofisicas, La Plata (Argentina)

2016-03-15

Numerous theoretical studies using various equation of state models have shown that quark matter may exist at the extreme densities in the cores of high-mass neutron stars. It has also been shown that a phase transition from hadronic matter to quark matter would result in an extended mixed phase region that would segregate phases by net charge to minimize the total energy of the phase, leading to the formation of a crystalline lattice. The existence of quark matter in the core of a neutron star may have significant consequences for its thermal evolution, which for thousands of years is facilitated primarily by neutrino emission. In this work we investigate the effect a crystalline quark-hadron mixed phase can have on the neutrino emissivity from the core. To this end we calculate the equation of state using the relativistic mean-field approximation to model hadronic matter and a nonlocal extension of the three-flavor Nambu-Jona-Lasinio model for quark matter. Next we determine the extent of the quark-hadron mixed phase and its crystalline structure using the Glendenning construction, allowing for the formation of spherical blob, rod, and slab rare phase geometries. Finally we calculate the neutrino emissivity due to electron-lattice interactions utilizing the formalism developed for the analogous process in neutron star crusts. We find that the contribution to the neutrino emissivity due to the presence of a crystalline quark-hadron mixed phase is substantial compared to other mechanisms at fairly low temperatures (

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

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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.

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.