WorldWideScience

Sample records for factors emission factors

  1. AP-42 Emissions Factors (WebFIRE)

    Data.gov (United States)

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

  2. CO2 Emission Factors for Coals

    Directory of Open Access Journals (Sweden)

    P. Orlović-Leko

    2015-03-01

    Full Text Available Emission factors are used in greenhouse gas inventories to estimate emissions from coal combustion. In the absence of direct measures, emissions factors are frequently used as a quick, low cost way to estimate emissions values. Coal combustion has been a major contributor to the CO2 flux into the atmosphere. Nearly all of the fuel carbon (99 % in coal is converted to CO2 during the combustion process. The carbon content is the most important coal parameter which is the measure of the degree of coalification (coal rank. Coalification is the alteration of vegetation to form peat, succeeded by the transformation of peat through lignite, sub-bituminous, bituminous to anthracite coal. During the geochemical or metamorphic stage, the progressive changes that occur within the coal are an increase in the carbon content and a decrease in the hydrogen and oxygen content resulting in a loss of volatiles. Heterogeneous composition of coal causes variation in CO2 emission from different coals. The IPCC (Intergovernmental Panel on Climate Change has produced guidelines on how to produce emission inventories which includes emission factors. Although 2006 IPCC Guidelines provided the default values specified according to the rank of the coal, the application of country-specific emission factors was recommended when estimating the national greenhouse gas emissions. This paper discusses the differences between country-specific emission factors and default IPCC CO2 emission factors, EF(CO2, for coals. Also, this study estimated EF(CO2 for two different types of coals and peat from B&H, on the basis fuel analyses. Carbon emission factors for coal mainly depend on the carbon content of the fuel and vary with both rank and geographic origin, which supports the idea of provincial variation of carbon emission factors. Also, various other factors, such as content of sulphur, minerals and macerals play an important role and influence EF(CO2 from coal. Carbonate minerals

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

    Science.gov (United States)

    de Haan, Peter; Keller, Mario

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

  4. Temperature Dependence of Factors Controlling Isoprene Emissions

    Science.gov (United States)

    Duncan, Bryan N.; Yoshida, Yasuko; Damon, Megan R.; Douglass, Anne R.; Witte, Jacquelyn C.

    2009-01-01

    We investigated the relationship of variability in the formaldehyde (HCHO) columns measured by the Aura Ozone Monitoring Instrument (OMI) to isoprene emissions in the southeastern United States for 2005-2007. The data show that the inferred, regional-average isoprene emissions varied by about 22% during summer and are well correlated with temperature, which is known to influence emissions. Part of the correlation with temperature is likely associated with other causal factors that are temperature-dependent. We show that the variations in HCHO are convolved with the temperature dependence of surface ozone, which influences isoprene emissions, and the dependence of the HCHO column to mixed layer height as OMI's sensitivity to HCHO increases with altitude. Furthermore, we show that while there is an association of drought with the variation in HCHO, drought in the southeastern U.S. is convolved with temperature.

  5. Factors Affecting Methane Emission from Rice Paddies

    Institute of Scientific and Technical Information of China (English)

    于心科; 王卫东; 等

    1995-01-01

    A comparative study of rice paddies and the uncovered water field in Taoyuan(Hunan) showed that methane emission from rice-vegetated paddy fields in 1993 was different from that in 1992(I,e,lower in rates and irregular in pattern).Climate has obvious influence on methane emission .And ebullition made a considerable contribution to the total flux of methane emission from rice paddies (45%).This implies that the intensification of paddy cultivation of rice might not be,as was proposed,the main con-tributor to the observed gradual increasing of atmospheric methane.24-hour automatic measurements of atmospheric temperature,air temperature and methane concentration in the static sampling boxes revealed that temperature,in addition to fertilization and irrigation style,is one of the most important factors that control the emission of methane from rice paddies.

  6. NOx and SO2 emission factors for Serbian lignite Kolubara

    Directory of Open Access Journals (Sweden)

    Jovanović Vladimir V.

    2012-01-01

    Full Text Available Emission factors are widely accepted tool for estimation of various pollutants emissions in USA and EU. Validity of emission factors is strongly related to experimental data on which they are based. This paper is a result of an effort to establish reliable NOx and SO2 emission factors for Serbian coals. The results of NOx and SO2 emissions estimations based on USA and EU emission factors from thermal power plants Nikola Tesla Obrenovac A and B utilizing the Serbian lignite Kolubara are compared with experimental data obtained during almost one decade (2000-2008 of emissions measurements. Experimental data are provided from regular annual emissions measurement along with operational parameters of the boiler and coal (lignite Kolubara ultimate and proximate analysis. Significant deviations of estimated from experimental data were observed for NOx, while the results for SO2 were satisfactory. Afterwards, the estimated and experimental data were plotted and linear regression between them established. Single parameter optimization was performed targeting the ideal slope of the regression line. Results of this optimization provided original NOx and SO2 emission factors for Kolubara lignite.

  7. Development of South African vehicle emission factors

    CSIR Research Space (South Africa)

    Forbes, P

    2009-10-01

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

  8. Factors Leading to Variability of Emission Factors, Single Scattering Albedo, and Elemental Carbon Fraction from Biofuel Emissions

    Science.gov (United States)

    Roden, C. A.; Bond, T. C.; Conway, S.; Osorto Pinel, B.; Maccarty, N.

    2006-12-01

    In a three-year study of field and laboratory emissions of traditional and improved biofuel cookstoves, we found that field measured particulate emissions of actual cooking events average 2.5 times those of reproduced lab emissions. Emission factors are highly dependent on the care and skill of the operator, and the resulting combustion; these do not appear to be accurately reproduced in the lab. The single scatter albedo (SSA) of the emissions is very low in both lab and field measurements, averaging about 0.3 for lab tests and around 0.5 for field tests, indicating that the primary particles are climate warming. In Honduras, improved stoves generally had lower emission factors than traditional stoves. Over the course of 3 summers we have measured field emissions from traditional cookstoves, relatively-new improved cookstoves, and "broken-in" improved cookstoves. For improved stoves, the presence of a chimney generally resulted in lower emission factors but left the SSA unaffected. Traditional cookstoves had an average PM emission factor of 8.5 g/kg significantly larger than previous studies. Particulate emission factors for improved cookstoves without and with chimneys averaged about 5.7 g/kg and 3.5 g/kg respectively. The elemental carbon (EC) fraction of PM varied significantly between individual tests, but averaged about 25% for each of the categories. Wood type affects on the PM emission factor, the SSA of the emissions and EC fraction. During our 2006 field measurements, we performed multiple emission measurements on the same stove while varying the fuel. Pine wood generally produced more PM than oak per kilogram of fuel. Additionally, Ocote, a resinous pitch pine often used in Central America for lighting fires, produces emissions which have a very low SSA and high EC fraction. We present the elemental carbon fraction and mass emission factors for different type of stoves and testing conditions. We summarize the characteristics of the particles emitted

  9. Revisiting factors controlling methane emissions from high-Arctic tundra

    DEFF Research Database (Denmark)

    Mastepanov, M.; Sigsgaard, Charlotte; Tagesson, Håkan Torbern;

    2013-01-01

    controlling methane emission, i.e. temperature and water table position. Late in the growing season CH4 emissions were found to be very similar between the study years (except the extremely dry 2010) despite large differences in climatic factors (temperature and water table). Late-season bursts of CH4...... short-term control factors (temperature and water table). Our findings suggest the importance of multiyear studies with a continued focus on shoulder seasons in Arctic ecosystems....

  10. Emission Factor from Small Scale Tropical Peat Combustion

    Science.gov (United States)

    Setyawati, W.; Damanhuri, E.; Lestari, P.; Dewi, K.

    2017-03-01

    Peatfire in Indonesia recently had become an important issue regarding its global warming impact of green house gases emitted. Emission factor is one of important variables to determine total emission of carbon released by peatfire. But currently there were only a few studies about Indonesian peat fire emission factors. The previous studies of Indonesian peat fire emission factor reported the results from a very limited number of samples and during smoldering combustion stages only. Therefore this study attempts to quantify carbon dioxide (CO2) and methane (CH4) emission factors from laboratory peat combustion based on higher number of samples and taken both of combustion stages (flaming and smoldering) into consideration. Peats were sampled from five different districts in Pontianak, West Kalimantan. Ultimate analysis showed that pure peat composed of relatively high carbon content (52.85 - 59.43% dry basis). Laboratory experiments were carried out by burning small amout of peats in a mini furnace and measuring their CO2 and CH4 emission concentration during flaming and smoldering. CO2, CO and CH4 average emission factors and their related average MCE for flaming were found to be 2,088 ± 21 g/kg (n = 17), 3.104 ± 7.173 g/kg (n = 17), 0.143 ± 0.132 g/kg (n = 17) and 0.998 ± 0.005 (n = 17), respectively, while for smoldering were 1,831 ± 131 g/kg (n = 17), 138 ± 72 g/kg (n = 17), 17 ± 12 g/kg (n = 17) and 0.894 ± 0.055 g/kg (n = 17), respectively. This emission factors based on the laboratory combustion experiment can be conveniently used to estimate CO2 and CH4 emission from Indonesian peat fire. Equation models to correlate between MCE and emission factors for both flaming and smoldering were developed. MCE and CO2 emission factor during flaming was relatively higher than smoldering. On the contrary, CO and CH4 emission factors were relatively smaller during flaming than smoldering.

  11. Effect of Environmental Factors on Sulfur Gas Emissions from Drywall

    Energy Technology Data Exchange (ETDEWEB)

    Maddalena, Randy

    2011-08-20

    Problem drywall installed in U.S. homes is suspected of being a source of odorous and potentially corrosive indoor pollutants. The U.S. Consumer Product Safety Commission's (CPSC) investigation of problem drywall incorporates three parallel tracks: (1) evaluating the relationship between the drywall and reported health symptoms; (2) evaluating the relationship between the drywall and electrical and fire safety issues in affected homes; and (3) tracing the origin and the distribution of the drywall. To assess the potential impact on human health and to support testing for electrical and fire safety, the CPSC has initiated a series of laboratory tests that provide elemental characterization of drywall, characterization of chemical emissions, and in-home air sampling. The chemical emission testing was conducted at Lawrence Berkeley National Laboratory (LBNL). The LBNL study consisted of two phases. In Phase 1 of this study, LBNL tested thirty drywall samples provided by CPSC and reported standard emission factors for volatile organic compounds (VOCs), aldehydes, reactive sulfur gases (RSGs) and volatile sulfur compounds (VSCs). The standard emission factors were determined using small (10.75 liter) dynamic test chambers housed in a constant temperature environmental chamber. The tests were all run at 25 C, 50% relative humidity (RH) and with an area-specific ventilation rate of {approx}1.5 cubic meters per square meter of emitting surface per hour [m{sup 3}/m{sup 2}/h]. The thirty samples that were tested in Phase 1 included seventeen that were manufactured in China in 2005, 2006 and 2009, and thirteen that were manufactured in North America in 2009. The measured emission factors for VOCs and aldehydes were generally low and did not differ significantly between the Chinese and North American drywall. Eight of the samples tested had elevated emissions of volatile sulfur-containing compounds with total RSG emission factors between 32 and 258 micrograms per square

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

    Science.gov (United States)

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

    2016-09-01

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

  13. Environmental factors controlling methane emissions from peatlands in northern Minnesota

    Science.gov (United States)

    Dise, Nancy B.; Gorham, Eville; Verry, Elon S.

    1993-01-01

    The environmental factors affecting the emission of methane from peatlands were investigated by correlating CH4 emission data for two years, obtained from five different peatland ecosystems in northern Minnesota, with peat temperature, water table position, and degree of peat humification. The relationship obtained between the CH4 flux and these factors was compared to results from a field manipulation experiment in which the water table was artificially raised in three experimental plots within the driest peatland. It was found that peat temperature, water table position, and degree of peat humification explained 91 percent of the variance in log CH4 flux, successfully predicted annual CH4 emission from individual wetlands, and predicted the change in flux due to the water table manipulation. Raising the water table in the bog corrals by an average of 6 cm in autumn 1989 and 10 cm in summer 1990 increased CH4 emission by 2.5 and 2.2 times, respectively.

  14. Measurements of air pollution emission factors for marine transportation

    Science.gov (United States)

    Alföldy, B.; Balzani Lööv, J.; Lagler, F.; Mellqvist, J.; Berg, N.; Beecken, J.; Weststrate, H.; Duyzer, J.; Bencs, L.; Horemans, B.; Cavalli, F.; Putaud, J.-P.; Janssens-Maenhout, G.; Pintér Csordás, A.; Van Grieken, R.; Borowiak, A.; Hjorth, J.

    2012-12-01

    The chemical composition of the plumes of seagoing ships was investigated during a two weeks long measurement campaign in the port of Rotterdam, Hoek van Holland, The Netherlands, in September 2009. Altogether, 497 ships were monitored and a statistical evaluation of emission factors (g kg-1 fuel) was provided. The concerned main atmospheric components were SO2, NO2, NOx and the aerosol particle number. In addition, the elemental and water-soluble ionic composition of the emitted particulate matter was determined. Emission factors were expressed as a function of ship type, power and crankshaft rotational speed. The average SO2 emission factor was found to be roughly half of what is allowed in sulphur emission control areas (16 vs. 30 g kg-1 fuel), and exceedances of this limit were rarely registered. A significant linear relationship was observed between the SO2 and particle number emission factor. The intercept of the regression line, 0.5 × 1016 (kg fuel)-1, gives the average number of particles formed during the burning of 1 kg zero sulphur content fuel, while the slope, 2 × 1018, provides the average number of particles formed with 1 kg sulphur burnt with the fuel. Water-soluble ionic composition analysis of the aerosol samples from the plumes showed that ~144 g of particulate sulphate was emitted from 1 kg sulphur burnt with the fuel. The mass median diameter of sulphate particles estimated from the measurements was ~42 nm.

  15. DEVELOPING SPEED DEPENDENT EMISSION FACTORS USING ON-BOARD EMISSION MEASURING EQUIPMENT IN INDIA

    Directory of Open Access Journals (Sweden)

    Sushant Sharma

    2016-09-01

    Full Text Available Vehicular emission models are important tools in several environmental impact studies. Although several studies have been conducted for emission control purposes, few attempts have been made on the planning side. For instance, long-term transportation network capacity improvement models do not explicitly consider emission in the objective function. Incorporating vehicular emission into the objective function is effective only if speed dependent emission factor is used in the estimation of emission. Although this issue is well addressed in the developed countries, owing to the heterogeneity of vehicles and absence of speed dependent emission factors the benefit from network investment is often underestimated in developing countries like India. Therefore, an attempt is made to explore the possibility of developing speed dependent emission factor for Indian conditions and vehicles. For accurate measurement an onboard test is conducted on typical vehicles; namely, a passenger car, a sports utility vehicle, and a truck. On board test equipment collected the data while the vehicle traversed with different speed ranges. The data obtained is processed and used for developing emission factor in the form of second degree polynomial with speed as the dependent variable. The emission factors for the three types of vehicles and for CO, CO2, NOX, and HC are developed. The results have been compared with Indian driving cycle based emission factors as well as UK based speed dependent emission factors for car in particular. The study gave a preliminary insight into the behaviors of pollutants with respect to speed. However, there is a need to develop such factor using large spectrum of vehicles and diverse driving conditions.

  16. Inorganic acid emission factors of semiconductor manufacturing processes.

    Science.gov (United States)

    Chein, HungMin; Chen, Tzu Ming; Aggarwal, Shankar Gopala; Tsai, Chuen-Jinn; Huang, Chun-Chao

    2004-02-01

    A huge amount of inorganic acids can be produced and emitted with waste gases from integrated circuit manufacturing processes such as cleaning and etching. Emission of inorganic acids from selected semiconductor factories was measured in this study. The sampling of the inorganic acids was based on the porous metal denuders, and samples were then analyzed by ion chromatography. The amount of chemical usage was adopted from the data that were reported to the Environmental Protection Bureau in Hsin-chu County according to the Taiwan Environmental Protection Agency regulation. The emission factor is defined as the emission rate (kg/month) divided by the amount of chemical usage (L/month). Emission factors of three inorganic acids (i.e., hydrofluoric acid [HF], hydrochloric acid [HCl], and sulfuric acid [H2SO4]) were estimated by the same method. The emission factors of HF and HCl were determined to be 0.0075 kg/L (coefficient of variation [CV] = 60.7%, n = 80) and 0.0096 kg/L (CV = 68.2%, n = 91), respectively. Linear regression equations are proposed to fit the data with correlation coefficient square (R2) = 0.82 and 0.9, respectively. The emission factor of H2SO4, which is in the droplet form, was determined to be 0.0016 kg/L (CV = 99.2%, n = 107), and its R2 was 0.84. The emission profiles of gaseous inorganic acids show that HF is the dominant chemical in most of the fabricators.

  17. Accuracy of exhaust emission factor measurements on chassis dynamometer

    NARCIS (Netherlands)

    Joumard, R.; Laurikko, J.; Han, T.L.; Geivanidis, S.; Samaras, Z.; Merétei, T.; Devaux, P.; André, J.-M.; Cornelis, E.; Lacour, S.; Prati, M.V.; Vermeulen, R.; Zallinger, M.

    2009-01-01

    The influence of 20 parameters on the measurement of light-vehicle emission factors on chassis dynamometer based on driving patterns, vehicle-related parameters, vehicle sampling, and laboratory-related parameters, was studied. The results were based on literature synthesis, ≈ 2700 specific tests

  18. Greenhouse gas emission factors associated with rewetting of organic soils

    Directory of Open Access Journals (Sweden)

    D. Wilson

    2016-04-01

    Full Text Available Drained organic soils are a significant source of greenhouse gas (GHG emissions to the atmosphere. Rewetting these soils may reduce GHG emissions and could also create suitable conditions for return of the carbon (C sink function characteristic of undrained organic soils. In this article we expand on the work relating to rewetted organic soils that was carried out for the 2014 Intergovernmental Panel on Climate Change (IPCC Wetlands Supplement. We describe the methods and scientific approach used to derive the Tier 1 emission factors (the rate of emission per unit of activity for the full suite of GHG and waterborne C fluxes associated with rewetting of organic soils. We recorded a total of 352 GHG and waterborne annual flux data points from an extensive literature search and these were disaggregated by flux type (i.e. CO2, CH4, N2O and DOC, climate zone and nutrient status. Our results showed fundamental differences between the GHG dynamics of drained and rewetted organic soils and, based on the 100 year global warming potential of each gas, indicated that rewetting of drained organic soils leads to: net annual removals of CO2 in the majority of organic soil classes; an increase in annual CH4 emissions; a decrease in N2O and DOC losses; and a lowering of net GHG emissions. Data published since the Wetlands Supplement (n = 58 generally support our derivations. Significant data gaps exist, particularly with regard to tropical organic soils, DOC and N2O. We propose that the uncertainty associated with our derivations could be significantly reduced by the development of country specific emission factors that could in turn be disaggregated by factors such as vegetation composition, water table level, time since rewetting and previous land use history.

  19. Parastatistical Factors for Cascade Emission of a Pair of Paraparticles

    CERN Document Server

    Nelson, Charles A; Mera, Calvin S; Shapiro, Alanna M

    2013-01-01

    The empirical absence to date of particles obeying parastatistics in high energy collider experiments might be due to their large masses and lack of gauge couplings. If there is a portal to such particles, they might be cascade emitted as a pair of para-Majorana neutrinos or as a pair of scalar paraparticles. In this paper, for an assumed portal Lagrangian, the associated parastatistical factors are obtained for the case of order p=2 parastatistics and the, in general differing factors, for the cases of emission of a non-degenerate or a degenerate pair of particles which obey normal statistics.

  20. [Emission factors of polycyclic aromatic hydrocarbons (PAHs) in residential coal combustion and its influence factors].

    Science.gov (United States)

    Hai, Ting-Ting; Chen, Ying-Jun; Wang, Yan; Tian, Chong-Guo; Lin, Tian

    2013-07-01

    As the emission source of polycyclic aromatic hydrocarbons (PAHs), domestic coal combustion has attracted increasing attention in China. According to the coal maturity, combustion form and stove type associated with domestic coal combustion, a large-size, full-flow dilution tunnel and fractional sampling system was employed to collect the emissions from five coals with various maturities, which were burned in the form of raw-coal-chunk (RCC)/honeycomb-coal-briquettes (HCB) in different residential stoves, and then the emission factors of PAHs (EF(PAHs)) were achieved. The results indicate that the EF(PAHs) of bituminous coal ranged from 1.1 mg x kg(-1) to 3.9 mg x kg(-1) for RCC and 2.5 mg x kg(-1) to 21. 1 mg x kg(-1) for HCB, and the anthracite EF(PAH8) were 0.2 mg x kg(-1) for RCC and 0.6 mg x kg(-1) for HCB, respectively. Among all the influence factors of emission factors of PAHs from domestic coal combustion, the maturity of coal played a major role, the range of variance reaching 1 to 2 orders of magnitude in coals with different maturity. Followed by the form of combustion (RCC/HCB), the EF(PAHs) of HCB was 2-6 times higher than that of RCC for the same geological maturity of the coal. The type of stove had little influence on EF(PAHs).

  1. Revisiting factors controlling methane emissions from high-Arctic tundra

    DEFF Research Database (Denmark)

    Mastepanov, M.; Sigsgaard, C.; Tagesson, T.;

    2013-01-01

    with measurements made outside the growing season, are underrepresented in the literature. Here we present results of 5 yr (2006-2010) of automatic chamber measurements at a high-Arctic location in Zackenberg, NE Greenland, covering both the growing seasons and two months of the following freeze-in periods...... explained by high seasonality of both variables, and weakly correlated with the water table. The greatest variability in fluxes between the study years was observed during the first part of the growing season. Somewhat surprisingly, this variability could not be explained by commonly known factors...... controlling methane emission, i.e. temperature and water table position. Late in the growing season CH4 emissions were found to be very similar between the study years (except the extremely dry 2010) despite large differences in climatic factors (temperature and water table). Late-season bursts of CH4...

  2. Revisiting factors controlling methane emissions from high-Arctic tundra

    Directory of Open Access Journals (Sweden)

    M. Mastepanov

    2013-07-01

    Full Text Available The northern latitudes are experiencing disproportionate warming relative to the mid-latitudes, and there is growing concern about feedbacks between this warming and methane production and release from high-latitude soils. Studies of methane emissions carried out in the Arctic, particularly those with measurements made outside the growing season, are underrepresented in the literature. Here we present results of 5 yr (2006–2010 of automatic chamber measurements at a high-Arctic location in Zackenberg, NE Greenland, covering both the growing seasons and two months of the following freeze-in periods. The measurements show clear seasonal dynamics in methane emission. The start of the growing season and the increase in CH4 fluxes were strongly related to the date of snowmelt. Within each particular growing season, CH4 fluxes were highly correlated with the soil temperature (R2 > 0.75, which is probably explained by high seasonality of both variables, and weakly correlated with the water table. The greatest variability in fluxes between the study years was observed during the first part of the growing season. Somewhat surprisingly, this variability could not be explained by commonly known factors controlling methane emission, i.e. temperature and water table position. Late in the growing season CH4 emissions were found to be very similar between the study years (except the extremely dry 2010 despite large differences in climatic factors (temperature and water table. Late-season bursts of CH4 coinciding with soil freezing in the autumn were observed during at least three years. The cumulative emission during the freeze-in CH4 bursts was comparable in size with the growing season emission for the year 2007, and about one third of the growing season emissions for the years 2009 and 2010. In all three cases the CH4 burst was accompanied by a corresponding episodic increase in CO2 emission, which can compose a significant contribution to the annual CO2

  3. 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)

  4. Development of database of real-world diesel vehicle emission factors for China.

    Science.gov (United States)

    Shen, Xianbao; Yao, Zhiliang; Zhang, Qiang; Wagner, David Vance; Huo, Hong; Zhang, Yingzhi; Zheng, Bo; He, Kebin

    2015-05-01

    A database of real-world diesel vehicle emission factors, based on type and technology, has been developed following tests on more than 300 diesel vehicles in China using a portable emission measurement system. The database provides better understanding of diesel vehicle emissions under actual driving conditions. We found that although new regulations have reduced real-world emission levels of diesel trucks and buses significantly for most pollutants in China, NOx emissions have been inadequately controlled by the current standards, especially for diesel buses, because of bad driving conditions in the real world. We also compared the emission factors in the database with those calculated by emission factor models and used in inventory studies. The emission factors derived from COPERT (Computer Programmer to calculate Emissions from Road Transport) and MOBILE may both underestimate real emission factors, whereas the updated COPERT and PART5 (Highway Vehicle Particulate Emission Modeling Software) models may overestimate emission factors in China. Real-world measurement results and emission factors used in recent emission inventory studies are inconsistent, which has led to inaccurate estimates of emissions from diesel trucks and buses over recent years. This suggests that emission factors derived from European or US-based models will not truly represent real-world emissions in China. Therefore, it is useful and necessary to conduct systematic real-world measurements of vehicle emissions in China in order to obtain the optimum inputs for emission inventory models.

  5. Evaluation of an Odour Emission Factor (OEF) to estimate odour emissions from landfill surfaces

    Science.gov (United States)

    Lucernoni, Federico; Tapparo, Federica; Capelli, Laura; Sironi, Selena

    2016-11-01

    Emission factors are fundamental tools for air quality management. Odour Emission Factors (OEFs) can be developed in analogy with the emission factors defined for other chemical compounds, which relate the quantity of a pollutant released to the atmosphere to a given associated activity. Landfills typically represent a common source of odour complaint; for this reason, the development of specific OEFs allowing the estimation of odour emissions from this kind of source would be of great interest both for the landfill design and management. This study proposes an up-to-date methodology for the development of an OEF for the estimation of odour emissions from landfills, thereby focusing on the odour emissions related to the emissions of landfill gas (LFG) from the exhausted landfill surface. The proposed approach is an "indirect" approach based on the quantification of the LFG emissions from methane concentration measurements carried out on an Italian landfill. The Odour Emission Rate (OER) is then obtained by multiplying the emitted gas flow rate by the LFG odour concentration. The odour concentration of the LFG emitted through the landfill surface was estimated by means of an ad hoc correlation investigated between methane concentration and odour concentration. The OEF for the estimation of odour emissions from landfill surfaces was computed, considering the landfill surface as the activity index, as the product between the mean specific LFG flux emitted through the surface resulting from the experimental campaigns, equal to 0.39 l/m2/h, and its odour concentration, which was estimated to be equal to 105‧000 eq. ouE/m3, thus giving an OEF of 0.011 ouE/m2/s. This value, which is considerably lower than those published in previous works, should be considered as an improved estimation based on the most recent developments of the research in the field of odour sampling on surface sources.

  6. Development of emission factors for particulate matter in a school

    Energy Technology Data Exchange (ETDEWEB)

    Scheff, P.A.; Paulius, V.; Conroy, L.M.

    1999-07-01

    Schools have complex indoor environments which are influenced by many factors such as number of occupants, building design, office equipment, cleaning agents, and school activities. Like large office buildings, school environments may be adversely influenced by deficiencies in ventilation which may be due to improper operation of HVAC systems, attempts at energy efficiency that limit the supply of outdoor air, or remodeling of building components. Most importantly, children spend up to a third of their time in these structures, and thus it is desirable to better understand the environmental quality in these buildings. A middle school (grades 6 to 8) in a residential section of Springfield, IL was selected for this baseline indoor air quality survey. The school was characterized as having no health complaints, good maintenance schedules, and did not contain carpeting within the classrooms or hallways. The focus of this paper is on the measurements of air quality in the school. The development of emission factors for particulate matter is also discussed. Four indoor locations including the Cafeteria, a Science Classroom, an Art Classroom, and the Lobby outside of the main office, and one outdoor location were sampled for various environmental comfort and pollutant parameters for one week in February of 1997. Integrated samples (8 hour sampling time) for respirable and total particulate matter, and short-term measurements of bioaerosols (two minute samples, three times per day) on three consecutive days were collected at each of the indoor and outdoor sites. Continuous measurements of carbon dioxide, carbon monoxide, temperature and humidity were logged at all locations for five days. Continuous measurements of respirable particulate matter were also collected in the Lobby area. Detailed logs of occupant activity were also collected at each indoor monitoring location throughout the study. Total particle concentrations ranged from 29 to 177 {micro}g/m{sup 3} in the art

  7. 75 FR 26904 - Mandatory Reporting of Greenhouse Gases: Notice of Data Availability; Default Emission Factors...

    Science.gov (United States)

    2010-05-13

    ... Emission Factors for Semiconductor Manufacturing Refined Process Categories AGENCY: Environmental... Protection Agency (EPA) is making available to the public draft default emission factors for semiconductor... specifically, as one option for monitoring and reporting, EPA proposed semiconductor manufacturers...

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

    Science.gov (United States)

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

    2017-02-01

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

  9. Changes in agricultural carbon emissions and factors that influence agricultural carbon emissions based on different stages in Xinjiang, China

    Science.gov (United States)

    Xiong, Chuanhe; Yang, Degang; Xia, Fuqiang; Huo, Jinwei

    2016-11-01

    Xinjiang’s agricultural carbon emissions showed three stages of change, i.e., continued to rise, declined and continued to rise, during 1991–2014. The agriculture belonged to the “low emissions and high efficiency” agriculture category, with a lower agricultural carbon emission intensity. By using the logarithmic mean divisia index decomposition method, agricultural carbon emissions were decomposed into an efficiency factor, a structure factor, an economy factor, and a labour factor. We divided the study period into five stages based on the changes in efficiency factor and economy factor. Xinjiang showed different agricultural carbon emission characteristics at different stages. The degree of impact on agricultural carbon emissions at these stages depended on the combined effect of planting-animal husbandry carbon intensity and agricultural labour productivity. The economy factor was the critical factor to promote the increase in agricultural carbon emissions, while the main inhibiting factor for agricultural carbon emissions was the efficiency factor. The labour factor became more and more obvious in increasing agricultural carbon emissions. Finally, we discuss policy recommendations in terms of the main factors, including the development of agricultural science and technology (S&T), the establishment of three major mechanisms and transfer of rural labour in ethnic areas.

  10. Relationship between CH4 and N2O emissions from rice field and its impacting factors

    Institute of Scientific and Technical Information of China (English)

    HOUAixin; CHENGuanxiong; WUJie; WANGZhengping

    1998-01-01

    To find out the relationship between CH4 and N2O emissions from rice field and determine the key factors affecting the emissions, and give a scientifie basis for working out mitigation options of their emissions from flooded rice field, we measured the emissions and their impacting environmental factors systematically and simultaneously from Mar to Dee in 1995-1996 in northern China.

  11. Satellite observations indicate substantial spatiotemporal variability in biomass burning NOx emission factors for South America

    Directory of Open Access Journals (Sweden)

    P. Castellanos

    2013-08-01

    Full Text Available Biomass burning is an important contributor to global total emissions of NOx (NO + NO2. Generally bottom-up fire emissions models calculate NOx emissions by multiplying fuel consumption estimates with static biome specific emission factors, defined in units of grams of NO per kilogram of dry matter consumed. Emission factors are a significant source of uncertainty in bottom-up fire emissions modeling because relatively few observations are available to characterize the large spatial and temporal variability of burning conditions. In this paper we use NO2 tropospheric column observations from the Ozone Monitoring Instrument (OMI from the year 2005 over South America to calculate monthly NOx emission factors for four fire types: deforestation, savanna/grassland, woodland, and agricultural waste burning. In general, the spatial trends in NOx emission factors calculated in this work are consistent with emission factors derived from in situ measurements from the region, but are more variable than published biome specific global average emission factors widely used in bottom up fire emissions inventories such as the Global Fire Emissions Database (GFED v3. Satellite based NOx emission factors also indicate substantial temporal variability in burning conditions. Overall, we found that deforestation fires have the lowest NOx emission factors, on average 30 % lower than the emission factors used in GFED v3. Agricultural fire NOx emission factors were the highest, on average a factor of 2 higher than GFED v3 values. For savanna, woodland, and deforestation fires early dry season NOx emission factors were a factor of ~1.5–2.0 higher than late dry season emission factors. A minimum in the NOx emission factor seasonal cycle for deforestation fires occurred in August, the time period of severe drought in South America in 2005. Our results support the hypothesis that prolonged dry spells may lead to an increase in the contribution of smoldering combustion

  12. [Estimation of average traffic emission factor based on synchronized incremental traffic flow and air pollutant concentration].

    Science.gov (United States)

    Li, Run-Kui; Zhao, Tong; Li, Zhi-Peng; Ding, Wen-Jun; Cui, Xiao-Yong; Xu, Qun; Song, Xian-Feng

    2014-04-01

    On-road vehicle emissions have become the main source of urban air pollution and attracted broad attentions. Vehicle emission factor is a basic parameter to reflect the status of vehicle emissions, but the measured emission factor is difficult to obtain, and the simulated emission factor is not localized in China. Based on the synchronized increments of traffic flow and concentration of air pollutants in the morning rush hour period, while meteorological condition and background air pollution concentration retain relatively stable, the relationship between the increase of traffic and the increase of air pollution concentration close to a road is established. Infinite line source Gaussian dispersion model was transformed for the inversion of average vehicle emission factors. A case study was conducted on a main road in Beijing. Traffic flow, meteorological data and carbon monoxide (CO) concentration were collected to estimate average vehicle emission factors of CO. The results were compared with simulated emission factors of COPERT4 model. Results showed that the average emission factors estimated by the proposed approach and COPERT4 in August were 2.0 g x km(-1) and 1.2 g x km(-1), respectively, and in December were 5.5 g x km(-1) and 5.2 g x km(-1), respectively. The emission factors from the proposed approach and COPERT4 showed close values and similar seasonal trends. The proposed method for average emission factor estimation eliminates the disturbance of background concentrations and potentially provides real-time access to vehicle fleet emission factors.

  13. Evaluation the Amount of Emission and Sulfur Dioxide Emission Factor from Tehran Oil Refinery

    Directory of Open Access Journals (Sweden)

    Chavoshi B.

    2011-06-01

    Full Text Available Bachgrounds and Objectives: Oil, gas and petrochemical are known as important sources of air pollutants and emission of green house gases. About 99 percent of sulfur dioxide in the air is produced from human resources. Although several samples have been taken from industries and refineries' output by environmental experts and private companies, but accurate assessment is not available based on pollutant emissions on product levels (emission coefficients and on the total amount of the annual emission which, can be used as basic modeling of air pollution and planning.Materials and Methods: This study was cross sectional and the output of the chimney measured with Testo 350 XL system. Performance standard was determined based on ASTM D6522 EPACTMO30-41. The amounts of sulfur dioxide were measured from Tehran oil refinery's outlet from the beginning of the march 2007 till the year 2008 for 20 months. Sampling was carried out on averaged range (9 am to 14 pm.Results: The results showed that Northern Distillation unit produced pollutants' concentration more than 3 times in the southern Distillation unit. An emission of pollutants from Northern unit was, 2.8 times higher than the Southern unit. The northern emission factor was 5.6 times higher than the value obtained from southern unit. The Concentration, emissions and coefficient of sulfur dioxide in North catalyst convert unit were more than 2 times in comparison with the same South unit. These three factors in northern concentration breakers unit were 3, 2.6 and 2.6 times higher than the Southern concentration breakers unit‚ respectively.Discussion: Emission rate in all northern units is 2 to 3 times more than similar southern units. The production volumes in northern units are higher than the southern units and the southern units designed properly to remove more pollutants .The use of new technologies in production processes and application of the latest scientific resources can play a major role

  14. Factors Affecting Regional Per-Capita Carbon Emissions in China Based on an LMDI Factor Decomposition Model

    OpenAIRE

    Dong, Feng; Long, Ruyin; Chen, Hong; Li, Xiaohui; Yang, Qingliang

    2013-01-01

    China is considered to be the main carbon producer in the world. The per-capita carbon emissions indicator is an important measure of the regional carbon emissions situation. This study used the LMDI factor decomposition model–panel co-integration test two-step method to analyze the factors that affect per-capita carbon emissions. The main results are as follows. (1) During 1997, Eastern China, Central China, and Western China ranked first, second, and third in the per-capita carbon emissions...

  15. Pre-Harvest Sugarcane Burning: Determination of emission factors through laboratory measurements and quantification of emissions

    Science.gov (United States)

    de Azeredo Franca, D.; Maria Longo, K.; Gomes Soares Neto, T.; Carlos dos Santos, J.; Rudorf, B. F.; Alves de Aguiar, D.; Freitas, S.; Vieira Cortez, E.; Stockler S. Lima, R.; S. Gacita, M.; Anselmo, E.; A. Carvalho, J., Jr.

    2011-12-01

    Sugarcane is a relevant crop to Brazilian economy and roughly 50% of its production is used to produce ethanol. São Paulo state is the largest producer of sugarcane in Brazil being responsible for almost 60% of its production in a cultivated area of 4.5 Mha in 2010. Sugarcane harvest practice can be performed either with green harvest or with pre-harvest burning. A "Green Ethanol" Protocol is underway to eliminate the pre-harvest burning practice by 2014 in most of the sugarcane cultivated land in São Paulo state. During the last five years close to 2 Mha were annually harvested with the pre-harvest burning practice. This practice emits particulate material, greenhouse gases, and tropospheric ozone precursors to the atmosphere. Even with policies to eliminate the burning practice in the near future there is still a significant environmental damage due to the pre-harvest burning practice of sugarcane. Thus the generation of reliable inventories of emissions due to this activity is crucial in order to assess the environmental impact. Presently the official Brazilian emissions inventories do not include the sugarcane pre-harvest burning contribution. Therefore, this work aims to estimate the annual emissions (from 2006 to 2010) associated with pre-harvest sugarcane burning practice in São Paulo state, including the determination of emission factors for some trace gases and particulate material smaller than 2.5 μm. Annual remote sensing based mappings of burned sugarcane fields throughout the harvest season in each crop year made in the context of Canasat Project (http://www.dsr.inpe.br/laf/canasat/en/) were added to the Brazilian Biomass Burning Emission Model (3BEM) in order to estimate trace gases and aerosols emissions. Two laboratory combustion experiments were carried out to determine the emission factors estimation. Samples of different varieties of sugarcane were harvested in dry weather conditions and in distinct sites in the state of São Paulo to assure

  16. Aromatic compound emissions from municipal solid waste landfill: Emission factors and their impact on air pollution

    Science.gov (United States)

    Liu, Yanjun; Lu, Wenjing; Guo, Hanwen; Ming, Zhongyuan; Wang, Chi; Xu, Sai; Liu, Yanting; Wang, Hongtao

    2016-08-01

    Aromatic compounds (ACs) are major components of volatile organic compounds emitted from municipal solid waste (MSW) landfills. The ACs emissions from the working face of a landfill in Beijing were studied from 2014 to 2015 using a modified wind tunnel system. Emission factors (EFs) of fugitive ACs emissions from the working face of the landfill were proposed according to statistical analyses to cope with their uncertainty. And their impacts on air quality were assessed for the first time. Toluene was the dominant AC with an average emission rate of 38.8 ± 43.0 μg m-2 s-1 (at a sweeping velocity of 0.26 m s-1). An increasing trend in AC emission rates was observed from 12:00 to 18:00 and then peaked at 21:00 (314.3 μg m-2 s-1). The probability density functions (PDFs) of AC emission rates could be classified into three distributions: Gaussian, log-normal, and logistic. EFs of ACs from the working face of the landfill were proposed according to the 95th percentile cumulative emission rates and the wind effects on ACs emissions. The annual ozone formation and secondary organic aerosol formation potential caused by AC emissions from landfills in Beijing were estimated to be 8.86 × 105 kg year-1 and 3.46 × 104 kg year-1, respectively. Toluene, m + p-xylene, and 1,3,5-trimethylbenzene were the most significant contributors to air pollution. Although ACs pollutions from landfills accounts for less percentage (∼0.1%) compared with other anthropogenic sources, their fugitive emissions which cannot be controlled efficiently deserve more attention and further investigation.

  17. Zero Emission Building And Conversion Factors Between Electricity Consumption And Emissions Of Greenhouse Gases In A Long Term Perspective

    Science.gov (United States)

    Graabak, Ingeborg; Bakken, Bjørn Harald; Feilberg, Nicolai

    2014-12-01

    The CO2 emissions from a building's power system will change over the life time of the building, and this need to be taken into account to verify whether a building is Zero Emission (ZEB) or not. This paper describes how conversion factors between electricity demand and emissions can be calculated for the European power system in a long term perspective through the application of a large scale electricity market model (EMPS). Examples of two types of factors are given: a conversion factor for average emissions per kWh for the whole European power system as well as a marginal factor for a specific region.

  18. Human factors engineering for the TERF (Tritium Emissions Reduction Facility) project. [Tritium Emissions Reduction Facility

    Energy Technology Data Exchange (ETDEWEB)

    Hedley, W.H.; Adams, F.S. (EG and G Mound Applied Technologies, Miamisburg, OH (USA)); Wells, J.E. (Lawrence Livermore National Lab., CA (USA))

    1990-12-14

    The Tritium Emissions Reduction Facility (TERF) is being built by EG G Mound Applied Technologies to provide improved control of the tritium emissions from gas streams being processed. Mound handles tritium in connection with production, development, research, disassembly, recovery, and surveillance operations. During these operations, a small fraction of the tritium being processed escapes from its original containment. The objective of this report is to describe the human factors engineering as performed in connection with the design, construction, and testing of the TERF as required in DOE Order 6430.1A, section 1300-12. Human factors engineering has been involved at each step of the process and was considered during the preliminary research on tritium capture before selecting the specific process to be used. Human factors engineering was also considered in determining the requirements for the TERF and when the specific design work was initiated on the facility and the process equipment. Finally, human factors engineering was used to plan the specific acceptance tests that will be made during TERF installation and after its completion. These tests will verify the acceptability of the final system and its components. 16 refs., 8 figs.

  19. Emission factor development for the malt beverage, wine, and distilled spirits industries

    Energy Technology Data Exchange (ETDEWEB)

    Lapp, T.; Shrager, B. [Midwest Research Institute, Cary, NC (United States); Safriet, D. [Environmental Protection Agency, Research Triangle Park, NC (United States)

    1996-12-31

    Midwest Research Institute is currently developing emission factors for inclusion in AP-42 Chapter 9, Food and Agricultural Industries. Three of the sections cover the production of malt beverages, wine, and distilled spirits. The malt beverage segment focuses on the development of ethanol emission factors for filling operations, which were recently identified as the large source of brewery ethanol emissions. The discussion includes a description of the production process and emissions factors for breweries, a history of emission factories for breweries, a description of emission testing conducted at two large breweries, and a presentation of some of the emission factors for malt beverage production. The wine industry segment focuses on emissions from the fermentation stage for red and white wines, the pomace screen and pomace press for red wines, and bottling of white wine. Emission factors are presented for ethanol emissions from each of these sources as well as other VOC emissions from the fermentation process. A discussion of the wine production process is presented. A discussion of the emission sources and available emission factors is presented for the distilled spirits industry segment. Factors are presented for the fermentation and aging stages. A process description is presented for the production of Bourbon whisky.

  20. VOC emission rates and emission factors for a sheetfed offset printing shop.

    Science.gov (United States)

    Wadden, R A; Scheff, P A; Franke, J E; Conroy, L M; Javor, M; Keil, C B; Milz, S A

    1995-04-01

    Emission rates were determined during production for a sheetfed offset printing shop by combining the measured concentrations and ventilation rates with mass balance models that characterized the printing space. Air samples were collected simultaneously on charcoal tubes for 12 separate 1-hour periods at 6 locations. Air samples and cleaning solvents were analyzed by gas chromatography for total volatile organic compounds (VOC) and 13 hydrocarbons. The average VOC emission rate was 470 g/hr with a range of 160-1100 g/hr. These values were in good agreement with the amounts of VOC, hexane, toluene, and aromatic C9s determined from estimated solvent usage and measured solvent compositions. Comparison of the emission rates with source activities indicated an emission factor of 30-51 g VOC/press cleaning. Based on the test observations it was estimated that this typical small printing facility was likely to release 1-2 T VOC/year. The methodology also may be useful for the surface coating industry, as emission rates in this study were determined without recourse to a temporary total enclosure and without interfering with worker activities, increasing worker exposure, or increasing safety and explosion hazards.

  1. Empirical Study of Decomposition of CO2 Emission Factors in China

    Directory of Open Access Journals (Sweden)

    Yadong Ning

    2013-01-01

    Full Text Available China’s CO2 emissions increase has attracted world’s attention. It is of great importance to analyze China’s CO2 emission factors to restrain the CO2 rapid growing. The CO2 emissions of industrial and residential consumption sectors in China during 1980–2010 were calculated in this paper. The expanded decomposition model of CO2 emissions was set up by adopting factor-separating method based on the basic principle of the Kaya identities. The results showed that CO2 emissions of industrial and residential consumption sectors increase year after year, and the scale effect of GDP is the most important factor affecting CO2 emissions of industrial sector. Decreasing the specific gravity of secondary industry and energy intensity is more effective than decreasing the primary industry and tertiary industry. The emissions reduction effect of structure factor is better than the efficiency factor. For residential consumption sector, CO2 emissions increase rapidly year after year, and the economy factor (the increase of wealthy degree or income is the most important factor. In order to slow down the growth of CO2 emissions, it is an important way to change the economic growth mode, and the structure factor will become a crucial factor.

  2. Estimating end-use emissions factors for policy analysis: the case of space cooling and heating.

    Science.gov (United States)

    Jacobsen, Grant D

    2014-06-17

    This paper provides the first estimates of end-use specific emissions factors, which are estimates of the amount of a pollutant that is emitted when a unit of electricity is generated to meet demand from a specific end-use. In particular, this paper provides estimates of emissions factors for space cooling and heating, which are two of the most significant end-uses. The analysis is based on a novel two-stage regression framework that estimates emissions factors that are specific to cooling or heating by exploiting variation in cooling and heating demand induced by weather variation. Heating is associated with similar or greater CO2 emissions factor than cooling in all regions. The difference is greatest in the Midwest and Northeast, where the estimated CO2 emissions factor for heating is more than 20% larger than the emissions factor for cooling. The minor differences in emissions factors in other regions, combined with the substantial difference in the demand pattern for cooling and heating, suggests that the use of overall regional emissions factors is reasonable for policy evaluations in certain locations. Accurately quantifying the emissions factors associated with different end-uses across regions will aid in designing improved energy and environmental policies.

  3. Satellite observations indicate substantial spatiotemporal variability in biomass burning NOx emission factors for South America

    NARCIS (Netherlands)

    Castellanos, P.; Boersma, K.F.; Werf, van de G.R.

    2014-01-01

    Biomass burning is an important contributor to global total emissions of NOx (NO+NO2). Generally bottom-up fire emissions models calculate NOx emissions by multiplying fuel consumption estimates with static biome-specific emission factors, defined in units of grams of NO per kilogram of dry matter

  4. Satellite observations indicate substantial spatiotemporal variability in biomass burning NOx emission factors for South America

    NARCIS (Netherlands)

    Castellanos, P.; Boersma, K.F.; Werf, van de G.R.

    2014-01-01

    Biomass burning is an important contributor to global total emissions of NOx (NO+NO2). Generally bottom-up fire emissions models calculate NOx emissions by multiplying fuel consumption estimates with static biome-specific emission factors, defined in units of grams of NO per kilogram of dry matter c

  5. Factors affecting regional per-capita carbon emissions in China based on an LMDI factor decomposition model.

    Directory of Open Access Journals (Sweden)

    Feng Dong

    Full Text Available China is considered to be the main carbon producer in the world. The per-capita carbon emissions indicator is an important measure of the regional carbon emissions situation. This study used the LMDI factor decomposition model-panel co-integration test two-step method to analyze the factors that affect per-capita carbon emissions. The main results are as follows. (1 During 1997, Eastern China, Central China, and Western China ranked first, second, and third in the per-capita carbon emissions, while in 2009 the pecking order changed to Eastern China, Western China, and Central China. (2 According to the LMDI decomposition results, the key driver boosting the per-capita carbon emissions in the three economic regions of China between 1997 and 2009 was economic development, and the energy efficiency was much greater than the energy structure after considering their effect on restraining increased per-capita carbon emissions. (3 Based on the decomposition, the factors that affected per-capita carbon emissions in the panel co-integration test showed that Central China had the best energy structure elasticity in its regional per-capita carbon emissions. Thus, Central China was ranked first for energy efficiency elasticity, while Western China was ranked first for economic development elasticity.

  6. Factors affecting regional per-capita carbon emissions in China based on an LMDI factor decomposition model.

    Science.gov (United States)

    Dong, Feng; Long, Ruyin; Chen, Hong; Li, Xiaohui; Yang, Qingliang

    2013-01-01

    China is considered to be the main carbon producer in the world. The per-capita carbon emissions indicator is an important measure of the regional carbon emissions situation. This study used the LMDI factor decomposition model-panel co-integration test two-step method to analyze the factors that affect per-capita carbon emissions. The main results are as follows. (1) During 1997, Eastern China, Central China, and Western China ranked first, second, and third in the per-capita carbon emissions, while in 2009 the pecking order changed to Eastern China, Western China, and Central China. (2) According to the LMDI decomposition results, the key driver boosting the per-capita carbon emissions in the three economic regions of China between 1997 and 2009 was economic development, and the energy efficiency was much greater than the energy structure after considering their effect on restraining increased per-capita carbon emissions. (3) Based on the decomposition, the factors that affected per-capita carbon emissions in the panel co-integration test showed that Central China had the best energy structure elasticity in its regional per-capita carbon emissions. Thus, Central China was ranked first for energy efficiency elasticity, while Western China was ranked first for economic development elasticity.

  7. Air pollution emission factors. (Latest citations from the NTIS bibliographic database). Published Search

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    1997-02-01

    The bibliography contains citations concerning emission factors for a variety of industrial, stationary, and mobile sources. Emissions inventories are discussed in terms of specific compounds, as well as by source type. Computer simulations utilizing emission factors in air pollution impact studies are also included. Excluded are NAPA Emissions Inventories and Toxic Release Inventories by state.(Contains 50-250 citations and includes a subject term index and title list.) (Copyright NERAC, Inc. 1995)

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

    Energy Technology Data Exchange (ETDEWEB)

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

    2012-10-15

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

  9. Trend Prediction and Decomposed Driving Factors of Carbon Emissions in Jiangsu Province during 2015–2020

    Directory of Open Access Journals (Sweden)

    Decai Tang

    2016-10-01

    Full Text Available According to the economic and energy consumption statistics in Jiangsu Province, we combined the GM (1, 1 grey model and polynomial regression to forecast carbon emissions. Historical and projected emissions were decomposed using the Logarithmic Mean Divisia Index (LMDI approach to assess the relative contribution of different factors to emission variability. The results showed that carbon emissions will continue to increase in Jiangsu province during 2015–2020 period and cumulative carbon emissions will increase by 39.5487 million tons within the forecast period. The growth of gross domestic product (GDP per capita plays the greatest positive role in driving carbon emission growth. Furthermore, the improvement of energy usage efficiency is the primary factor responsible for reducing carbon emissions. Factors of population, industry structure adjustment and the optimization of fuel mix also help to reduce carbon emissions. Based on the LMDI analysis, we provide some advice for policy-makers in Jiangsu and other provinces in China.

  10. Development of emission factors and emission inventories for motorcycles and light duty vehicles in the urban region in Vietnam.

    Science.gov (United States)

    Tung, H D; Tong, H Y; Hung, W T; Anh, N T N

    2011-06-15

    This paper reports on a 2-year emissions monitoring program launched by the Centre for Environmental Monitoring of the Vietnam Environment Administration which aimed at determining emission factors and emission inventories for two typical types of vehicle in Hanoi, Vietnam. The program involves four major activities. A database for motorcycles and light duty vehicles (LDV) in Hanoi was first compiled through a questionnaire survey. Then, two typical driving cycles were developed for the first time for motorcycles and LDVs in Hanoi. Based on this database and the developed driving cycles for Hanoi, a sample of 12 representative test vehicles were selected to determine vehicle specific fuel consumption and emission factors (CO, HC, NOx and CO(2)). This set of emission factors were developed for the first time in Hanoi with due considerations of local driving characteristics. In particular, it was found that the emission factors derived from Economic Commission for Europe (ECE) driving cycles and adopted in some previous studies were generally overestimated. Eventually, emission inventories for motorcycles and LDVs were derived by combining the vehicle population data, the developed vehicle specific emission factors and vehicle kilometre travelled (VKT) information from the survey. The inventory suggested that motorcycles contributed most to CO, HC and NOx emissions while LDVs appeared to be more fuel consuming.

  11. Review of NO/sub x/ emission factors for stationary fossil fuel combustion sources. Final report

    Energy Technology Data Exchange (ETDEWEB)

    Milligan, R.J.; Sailor, W.C.; Wasilewski, J.; Kuby, W.C.

    1979-09-01

    A review of recent NOx test data was performed, and summaries of emission factors presented for various types of stationary source combustion and for various fossil fuels. The effects of combustion modifications on NOx emissions are quantified. Background data are given to help the user determine the reliability of each factor in particular applications.

  12. EMISSION FACTORS FOR IRON AND STEEL SOURCES: CRITERIA AND TOXIC POLLUTANTS

    Science.gov (United States)

    The report provides a comprehensive set of emission factors for sources of both criteria and toxic air pollutants in integrated iron and steel plants and specialty electric arc shops (minimills). Emission factors are identified for process sources, and process and open source fug...

  13. Investigation on emission factors of particulate matter and gaseous pollutants from crop residue burning

    Institute of Scientific and Technical Information of China (English)

    2008-01-01

    Emission factors of particulate matter (PM), element carbon (EC), organic carbon (OC), SO2, NOx, CO, CO2, and ten ions (Na+, NH4+, K+, Mg2+, Ca2+, F-, Cl-, NO2-, NO3-, SO42-) were estimated from the domestic burning of four types of commonly produced crop residues in rural China: rice straw, wheat straw, corn stover, and cotton stalk, which were collected from the representative regions across China. A combustion tower was designed to simulate the cooking conditions under which the peasants burned their crop residues in rural China, to measure the emission factors. Results show that wheat straw has the highest emission factor for the total PM (8.75 g/kg) among the four crop residues, whereas, corn stover and wheat straw have the highest emission factor for EC (0.95 g/kg) and OC (3.46 g/kg), respectively. Corn stover also presents as having the highest emission factors of NO, NOx, and CO2 whereas, wheat straw, rice straw, and cotton stalk have the highest emission factors of NO2, SO2, and CO, respectively. The water-soluble ions, K+ and Cl-, have the highest emission factors from all the crops. Wheat straw has a relatively higher emission factor of cation species and F-, Cl-, NO2- than other residues.

  14. Emission factors of carbonaceous particulate matter and polycyclic aromatic hydrocarbons from residential solid fuel combustions

    Energy Technology Data Exchange (ETDEWEB)

    Shen, Guofeng [Jiangsu Academy of Environmental Science, Nanjing (China). Inst. of Atmospheric Sciences

    2014-07-01

    Emission inventory is basic for the understanding of environmental behaviors and potential effects of compounds, however, current inventories are often associated with relatively high uncertainties. One important reason is the lack of emission factors, especially for the residential solid fuel combustion in developing countries. In the present study, emission factors of a group of pollutants including particulate matter, organic carbon, elemental carbon (sometimes known as black carbon) and polycyclic aromatic hydrocarbons were measured for a variety of residential solid fuels including coal, crop straw, wood, and biomass pellets in rural China. The study provided a large number of emission factors that can be further used in emission estimation. Composition profiles and isomer ratios were investigated and compared so as to be used in source apportionment. In addition, the present study identified and quantified the influence of factors like fuel moisture, volatile matter on emission performance.

  15. 78 FR 64496 - Acid Rain Program: Notice of Annual Adjustment Factors for Excess Emissions Penalty

    Science.gov (United States)

    2013-10-29

    ... AGENCY Acid Rain Program: Notice of Annual Adjustment Factors for Excess Emissions Penalty AGENCY.... SUMMARY: The Acid Rain Program under title IV of the Clean Air Act provides for automatic excess emissions penalties in dollars per ton of excess emissions for sources that do not meet their annual Acid...

  16. 76 FR 71559 - Acid Rain Program: Notice of Annual Adjustment Factors for Excess Emissions Penalty

    Science.gov (United States)

    2011-11-18

    ... AGENCY Acid Rain Program: Notice of Annual Adjustment Factors for Excess Emissions Penalty AGENCY.... SUMMARY: The Acid Rain Program under title IV of the Clean Air Act provides for automatic excess emissions penalties in dollars per ton of excess emissions for sources that do not meet their annual Acid...

  17. 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)

  18. CO2 emission factors for waste incineration: Influence from source separation of recyclable materials

    DEFF Research Database (Denmark)

    Larsen, Anna Warberg; Astrup, Thomas

    2011-01-01

    CO2-loads from combustible waste are important inputs for national CO2 inventories and life-cycle assessments (LCA). CO2 emissions from waste incinerators are often expressed by emission factors in kg fossil CO2 emitted per GJ energy content of the waste. Various studies have shown considerable...... variations between emission factors for different incinerators, but the background for these variations has not been thoroughly examined. One important reason may be variations in collection of recyclable materials as source separation alters the composition of the residual waste incinerated. The objective...... of this study was to quantify the importance of source separation for determination of emission factors for incineration of residual household waste. This was done by mimicking various source separation scenarios and based on waste composition data calculating resulting emission factors for residual waste...

  19. Measurement of Black Carbon and Particle Number Emission Factors from Individual Heavy-Duty Trucks

    Energy Technology Data Exchange (ETDEWEB)

    Ban-Weiss, George A.; Lunden, Melissa M.; Kirchstetter, Thomas W.; Harley, Robert A.

    2009-02-02

    Emission factors for black carbon (BC) and particle number (PN) were measured from 226 individual heavy-duty (HD) diesel-fueled trucks driving through a 1 km-long California highway tunnel in August 2006. Emission factors were based on concurrent increases in BC, PN, and CO{sub 2}B concentrations (measured at 1 Hz) that corresponded to the passage of individual HD trucks. The distributions of BC and PN emission factors from individual HD trucks are skewed, meaning that a large fraction of pollution comes from a small fraction of the in-use vehicle fleet. The highest-emitting 10% of trucks were responsible for {approx} 40% of total BC and PN emissions from all HD trucks. BC emissions were log-normally distributed with a mean emission factor of 1.7 g kg {sup -1} and maximum values of {approx} 10 g kg{sup -1}. Corresponding values for PN emission factors were 4.7 x 10{sup 15} and 4 x 10{sup 16} kg{sup -1}. There was minimal overlap among high-emitters of these two pollutants: only 1 of the 226 HD trucks measured was found to be among the highest 10% for both BC and PN. Monte Carlo resampling of the distribution of BC emission factors observed in this study revealed that uncertainties (1{sigma}) in extrapolating from a random sample of n HD trucks to a population mean emission factor ranged from {+-} 43% for n = 10 to {+-} 8% for n = 300, illustrating the importance of sufficiently large vehicle sample sizes in emissions studies. Studies with low sample sizes are also more easily biased due to misrepresentation of high-emitters. As vehicles become cleaner on average in future years, skewness of the emissions distributions will increase, and thus sample sizes needed to extrapolate reliably from a subset of vehicles to the entire in-use vehicle fleet are expected to become more of a challenge.

  20. Measurement of black carbon and particle number emission factors from individual heavy-duty trucks.

    Science.gov (United States)

    Ban-Weiss, George A; Lunden, Melissa M; Kirchstetter, Thomas W; Harley, Robert A

    2009-03-01

    Emission factors for black carbon (BC) and particle number (PN) were measured from 226 individual heavy-duty (HD) diesel trucks driving through a 1-km-long California highway tunnel in August 2006. Emission factors were based on concurrent increases in BC, PN, and CO2 concentrations (measured at 1 Hz) that corresponded to the passage of individual HD trucks. The distributions of BC and PN emission factors from individual HD trucks are skewed, meaning that a large fraction of pollution comes from a small fraction of the in-use vehicle fleet. The highest-emitting 10% of trucks were responsible for approximately 40% of total BC and PN emissions from all HD trucks. BC emissions were log-normally distributed with a mean emission factor of 1.7 g kg(-1) and maximum values of approximately 10 g kg(-1). Corresponding values for PN emission factors were 4.7 x 10(15) and 4 x 10(16) # kg(-1). There was minimal overlap among high-emitters of these two pollutants: only 1 of the 226 HD trucks measured was found to be among the highest 10% for both BC and PN. Monte Carlo resampling of the distribution of BC emission factors observed in this study revealed that uncertainties (1sigma) in extrapolating from a random sample of n HD trucks to a population mean emission factor ranged from +/- 43% for n=10 to +/- 8% for n=300, illustrating the importance of vehicle sample sizes in emissions studies. When n=10, sample means are more likely to be biased due to misrepresentation of high-emitters. As vehicles become cleaner on average in the future, skewness of the emissions distributions will increase, and thus sample sizes needed to extrapolate reliably from a subset of vehicles to the entire in-use vehicle fleet will become more of a challenge.

  1. Source Energy and Emission Factors for Energy Use in Buildings (Revised)

    Energy Technology Data Exchange (ETDEWEB)

    Deru, M.; Torcellini, P.

    2007-06-01

    This document supports the other measurement procedures and all building energy-monitoring projects by providing methods to calculate the source energy and emissions from the energy measured at the building. Energy and emission factors typically account for the conversion inefficiencies at the power plant and the transmission and distribution losses from the power plant to the building. The energy and emission factors provided here also include the precombustion effects, which are the energy and emissions associated with extracting, processing, and delivering the primary fuels to the point of conversion in the electrical power plants or directly in the buildings.

  2. Vehicle emission factors of solid nanoparticles in the laboratory and on the road using Portable Emission Measurement Systems (PEMS

    Directory of Open Access Journals (Sweden)

    Barouch eGiechaskiel

    2015-12-01

    Full Text Available Emission inventories are used to quantify sources and identify trends in the emissions of air pollutants. They use vehicle-specific emission factors that are typically determined in the laboratory, through remote-sensing, vehicle chasing experiments and, more recently, on-board Portable Emission Measurement Systems (PEMS. Although PEMS is widely applied to measure gaseous pollutants, their application to Solid Particle Number (SPN emissions is new. In this paper, we discuss the current status of determining SPN emission factors both on the chassis dynamometer and on-road using PEMS-SPN. First, we determine the influence of the measurement equipment, ambient temperature, driving style and cycle characteristics, and the extra mass of the PEMS equipment on the SPN emissions. Afterward, we present the SPN emissions under type-approval conditions as well as on the road of two heavy-duty diesel vehicles equipped with Diesel Particulate Filter (DPF (one Euro VI, two light-duty diesel vehicles equipped with DPF, one light-duty vehicle equipped with a Port Fuel Injection engine (PFI, and seven Gasoline Direct Injection (GDI passenger cars (two Euro 6. We find that cold-start and strong accelerations tend to substantially increase SPN emissions. The two heavy-duty vehicles showed emissions around 2×10^13 p/km (Euro V truck and 6×10^10 p/km (Euro VI truck, respectively. One of the DPF-equipped light-duty vehicles showed emissions of 8×10^11 p/km, while the other one had one order of magnitude lower emissions. The PFI car had SPN emissions slightly higher than 1×10^12 p/km. The emissions of GDI cars spanned approximately from 8×10^11 p/km to 8×10^12 p/km. For the cars without DPF, the SPN emissions remained within a factor of two of the laboratory results. This factor was on average around 0.8 for the Euro 6 and 1.6 for the Euro 5 GDIs. The DPF equipped vehicles showed a difference of almost one order of magnitude between laboratory and on-road tests

  3. The Tropical Forest and Fire Emissions Experiment: overview and airborne fire emission factor measurements

    Directory of Open Access Journals (Sweden)

    R. J. Yokelson

    2007-10-01

    Full Text Available The Tropical Forest and Fire Emissions Experiment (TROFFEE used laboratory measurements followed by airborne and ground based field campaigns during the 2004 Amazon dry season to quantify the emissions from pristine tropical forest and several plantations as well as the emissions, fuel consumption, and fire ecology of tropical deforestation fires. The airborne campaign used an Embraer 110B aircraft outfitted with whole air sampling in canisters, mass-calibrated nephelometry, ozone by UV absorbance, Fourier transform infrared spectroscopy (FTIR, and proton-transfer mass spectrometry (PTR-MS to measure PM10, O3, CO2, CO, NO, NO2, HONO, HCN, NH3, OCS, DMS, CH4, and up to 48 non-methane organic compounds (NMOC. The Brazilian smoke/haze layers extended to 2–3 km altitude, which is much lower than the 5–6 km observed at the same latitude, time of year, and local time in Africa in 2000. Emission factors (EF were computed for the 19 tropical deforestation fires sampled and they largely compare well to previous work. However, the TROFFEE EF are mostly based on a much larger number of samples than previously available and they also include results for significant emissions not previously reported such as: nitrous acid, acrylonitrile, pyrrole, methylvinylketone, methacrolein, crotonaldehyde, methylethylketone, methylpropanal, "acetol plus methylacetate," furaldehydes, dimethylsulfide, and C1-C4 alkyl nitrates. Thus, we recommend these EF for all tropical deforestation fires. The NMOC emissions were ~80% reactive, oxygenated volatile organic compounds (OVOC. Our EF for PM10 (17.8±4 g/kg is ~25% higher than previously reported for tropical forest fires and may reflect a trend towards, and sampling of, larger fires than in earlier studies. A large fraction of the total burning for 2004 likely occurred during a two-week period of very low humidity. The

  4. The Tropical Forest and fire emissions experiment: overview and airborne fire emission factor measurements

    Directory of Open Access Journals (Sweden)

    R. J. Yokelson

    2007-05-01

    Full Text Available The Tropical Forest and Fire Emissions Experiment (TROFFEE used laboratory measurements followed by airborne and ground based field campaigns during the 2004 Amazon dry season to quantify the emissions from pristine tropical forest and several plantations as well as the emissions, fuel consumption, and fire ecology of tropical deforestation fires. The airborne campaign used an Embraer 110B aircraft outfitted with whole air sampling in canisters, mass-calibrated nephelometry, ozone by uv absorbance, Fourier transform infrared spectroscopy (FTIR, and proton-transfer mass spectrometry (PTR-MS to measure PM10, O3, CO2, CO, NO, NO2, HONO, HCN, NH3, OCS, DMS, CH4, and up to 48 non-methane organic compounds (NMOC. The Brazilian smoke/haze layers extended to 2–3 km altitude, which is much lower than the 5–6 km observed at the same latitude, time of year, and local time in Africa in 2000. Emission factors (EF were computed for the 19 tropical deforestation fires sampled and they largely compare well to previous work. However, the TROFFEE EF are mostly based on a much larger number of samples than previously available and they also include results for significant emissions not previously reported such as: nitrous acid, acrylonitrile, pyrrole, methylvinylketone, methacrolein, crotonaldehyde, methylethylketone, methylpropanal, "acetol plus methylacetate," furaldehydes, dimethylsulfide, and C1-C4 alkyl nitrates. Thus, we recommend these EF for all tropical deforestation fires. The NMOC emissions were ~80% reactive, oxygenated volatile organic compounds (OVOC. Our EF for PM10 (17.8±4 g/kg is ~25% higher than previously reported for tropical forest fires and may reflect a trend towards, and sampling of, larger fires than in earlier studies. A large fraction of the total burning for 2004 likely occurred during a two-week period of very low humidity. The combined output of these

  5. Determination of OB/OD/SF Emission Factors using Unmanned Aerial Systems

    Science.gov (United States)

    Instrumented, unmanned aerial systems (UASs) have been used successfully in eight campaigns since 2010 to determine emission factors from open burning (OB), open detonation (OD), and static firing (SF) demilitarization activities. These systems have sampled directly from the plu...

  6. Research on Spatial-Temporal Characteristics and Driving Factor of Agricultural Carbon Emissions in China

    Institute of Scientific and Technical Information of China (English)

    TIAN Yun; ZHANG Jun-biao; HE Ya-ya

    2014-01-01

    Macroscopic grasp of agricultural carbon emissions status, spatial-temporal characteristics as well as driving factors are the basic premise in further research on China’s agricultural carbon emissions. Based on 23 kinds of major carbon emission sources including agricultural materials inputs, paddy ifeld, soil and livestock breeding, this paper ifrstly calculated agricultural carbon emissions from 1995 to 2010, as well as 31 provinces and cities in 2010 in China. We then made a decomposed analysis to the driving factors of carbon emissions with logarithmic mean Divisia index (LMDI) model. The results show:(1) The amount of agricultural carbon emissions is 291.1691 million t in 2010. Compared with 249.5239 million t in 1995, it increased by 16.69%, in which, agricultural materials inputs, paddy ifeld, soil, enteric fermentation, and manure management accounted for 33.59, 22.03, 7.46, 17.53 and 19.39%of total agricultural carbon emissions, respectively. Although the amount exist ups and downs, it shows an overall trend of cyclical rise; (2) There is an obvious difference among regions:the amount of agricultural carbon emissions from top ten zones account for 56.68%, while 9.84%from last 10 zones. The traditional agricultural provinces, especially the major crop production areas are the main source regions. Based on the differences of carbon emission rations, 31 provinces and cities are divided into ifve types, namely agricultural materials dominant type, paddy ifeld dominant type, enteric fermentation dominant type, composite factors dominant type and balanced type. The agricultural carbon emissions intensity in west of China is the highest, followed by the central region, and the east zone is the lowest; (3) Compared with 1995, efifciency, labor and structure factors cut down carbon emissions by 65.78, 27.51 and 3.19%, respectively;while economy factor increase carbon emissions by 113.16%.

  7. Mutagenicity and Pollutant Emission Factors of Solid-Fuel Cookstoves: Comparison with Other Combustion Sources

    Science.gov (United States)

    Mutlu, Esra; Warren, Sarah H.; Ebersviller, Seth M.; Kooter, Ingeborg M.; Schmid, Judith E.; Dye, Janice A.; Linak, William P.; Gilmour, M. Ian; Jetter, James J.; Higuchi, Mark; DeMarini, David M.

    2016-01-01

    Background: Emissions from solid fuels used for cooking cause ~4 million premature deaths per year. Advanced solid-fuel cookstoves are a potential solution, but they should be assessed by appropriate performance indicators, including biological effects. Objective: We evaluated two categories of solid-fuel cookstoves for eight pollutant and four mutagenicity emission factors, correlated the mutagenicity emission factors, and compared them to those of other combustion emissions. Methods: We burned red oak in a 3-stone fire (TSF), a natural-draft stove (NDS), and a forced-draft stove (FDS), and we combusted propane as a liquified petroleum gas control fuel. We determined emission factors based on useful energy (megajoules delivered, MJd) for carbon monoxide, nitrogen oxides (NOx), black carbon, methane, total hydrocarbons, 32 polycyclic aromatic hydrocarbons, PM2.5, levoglucosan (a wood-smoke marker), and mutagenicity in Salmonella. Results: With the exception of NOx, the emission factors per MJd were highly correlated (r ≥ 0.97); the correlation for NOx with the other emission factors was 0.58–0.76. Excluding NOx, the NDS and FDS reduced the emission factors an average of 68 and 92%, respectively, relative to the TSF. Nevertheless, the mutagenicity emission factor based on fuel energy used (MJthermal) for the most efficient stove (FDS) was between those of a large diesel bus engine and a small diesel generator. Conclusions: Both mutagenicity and pollutant emission factors may be informative for characterizing cookstove performance. However, mutagenicity emission factors may be especially useful for characterizing potential health effects and should be evaluated in relation to health outcomes in future research. An FDS operated as intended by the manufacturer is safer than a TSF, but without adequate ventilation, it will still result in poor indoor air quality. Citation: Mutlu E, Warren SH, Ebersviller SM, Kooter IM, Schmid JE, Dye JA, Linak WP, Gilmour MI, Jetter

  8. Particulate Matter Emissions Factors for Dust from Unique Military Activities

    Science.gov (United States)

    2010-06-01

    good assumption for desert dust in the absence of iron oxides, especially hematite (Fe2O3)). In the SI-1400 method, particle size distribution is...shear stress imparted to the surface. The PI-SWERL is being used increasingly as a primary tool to evaluate windblown dust emissions from natural and...surface, so the amount of charge should be the primary control on emission strength for a given surface. 26 Table 3. Minimum, maximum, mean and

  9. Toxic volatile organic compounds in environmental tobacco smoke: Emission factors for modeling exposures of California populations

    Energy Technology Data Exchange (ETDEWEB)

    Daisey, J.M.; Mahanama, K.R.R.; Hodgson, A.T. [Lawrence Berkeley Lab., CA (United States)

    1994-10-01

    The primary objective of this study was to measure emission factors for selected toxic air contaminants in environmental tobacco smoke (ETS) using a room-sized environmental chamber. The emissions of 23 volatile organic compounds (VOCs), including, 1,3-butadiene, three aldehydes and two vapor-phase N-nitrosamines were determined for six commercial brands of cigarettes and reference cigarette 1R4F. The commercial brands were selected to represent 62.5% of the cigarettes smoked in California. For each brand, three cigarettes were machine smoked in the chamber. The experiments were conducted over four hours to investigate the effects of aging. Emission factors of the target compounds were also determined for sidestream smoke (SS). For almost all target compounds, the ETS emission factors were significantly higher than the corresponding SS values probably due to less favorable combustion conditions and wall losses in the SS apparatus. Where valid comparisons could be made, the ETS emission factors were generally in good agreement with the literature. Therefore, the ETS emission factors, rather than the SS values, are recommended for use in models to estimate population exposures from this source. The variabilities in the emission factors ({mu}g/cigarette) of the selected toxic air contaminants among brands, expressed as coefficients of variation, were 16 to 29%. Therefore, emissions among brands were Generally similar. Differences among brands were related to the smoked lengths of the cigarettes and the masses of consumed tobacco. Mentholation and whether a cigarette was classified as light or regular did not significantly affect emissions. Aging was determined not to be a significant factor for the target compounds. There were, however, deposition losses of the less volatile compounds to chamber surfaces.

  10. A fuel-based approach for emission factor development for highway paving construction equipment in China.

    Science.gov (United States)

    Li, Zhen; Zhang, Kaishan; Pang, Kaili; Di, Baofeng

    2016-12-01

    The objective of this paper is to develop and demonstrate a fuel-based approach for emissions factor estimation for highway paving construction equipment in China for better accuracy. A highway construction site in Chengdu was selected for this study with NO emissions being characterized and demonstrated. Four commonly used paving equipment, i.e., three rollers and one paver were selected in this study. A portable emission measurement system (PEMS) was developed and used for emission measurements of selected equipment during real-world highway construction duties. Three duty modes were defined to characterize the NO emissions, i.e., idling, moving, and working. In order to develop a representative emission factor for these highway construction equipment, composite emission factors were estimated using modal emission rates and the corresponding modal durations in the process of typical construction duties. Depending on duty mode and equipment type, NO emission rate ranged from 2.6-63.7mg/s and 6.0-55.6g/kg-fuel with the fuel consumption ranging from 0.31-4.52 g/s correspondingly. The NO composite emission factor was estimated to be 9-41mg/s with the single-drum roller being the highest and double-drum roller being the lowest and 6-30g/kg-fuel with the pneumatic tire roller being the highest while the double-drum roller being the lowest. For the paver, both time-based and fuel consumption-based NO composite emission rates are higher than all of the rollers with 56mg/s and 30g/kg-fuel, respectively. In terms of time-based quantity, the working mode contributes more than the other modes with idling being the least for both emissions and fuel consumption. In contrast, the fuel-based emission rate appears to have less variability in emissions. Thus, in order to estimate emission factors for emission inventory development, the fuel-based emission factor may be selected for better accuracy.

  11. Use of portable emissions measurement system (PEMS) for the development and validation of passenger car emission factors

    Science.gov (United States)

    Kousoulidou, Marina; Fontaras, Georgios; Ntziachristos, Leonidas; Bonnel, Pierre; Samaras, Zissis; Dilara, Panagiota

    2013-01-01

    This paper discusses the development and validation of passenger car emission factors, using real world operation data. In total, six passenger cars of different technologies were studied. The tested vehicles were operated under various driving conditions and over two different routes in the region of Lombardia, Italy. These routes were specifically defined in order to provide a range of driving conditions, including urban, rural and highway driving. Tailpipe emissions and exhaust gas flows were measured on-board the vehicle, using a portable emissions measurement system (PEMS). In addition, all vehicles were tested over the European type-approval driving cycle (NEDC) with the same PEMS equipment. The testing of gasoline vehicles showed that emissions are well below the emission standards and do not raise any concern. However, the testing of diesel vehicles both under real-world driving conditions and over the NEDC brought to the surface important concerns regarding the actual NOx emissions of modern diesel vehicles, since they seem to comply with the corresponding emission standard over the type-approval cycle, but they constantly exceed the specified limit when tested under real-world driving conditions. Results from real-world operation revealed that there is a significant deviation from the NOx emission standard limit (especially for the newly introduced Euro 5 technology). These observations raise concerns regarding the actual NOx emissions of modern vehicles and their impact on urban air-quality. The emission factors originally measured on the road are also compared to the corresponding COPERT average speed emission factors. In general, emissions of CO2, THC and CO correlate fairly well with COPERT, for all vehicles. In the case of NOx emissions, emission levels of the two tested Euro 5 diesel passenger cars are consistently higher in urban, rural, and highway driving compared to the corresponding COPERT emission factor. Thus, leading to the conclusion that

  12. Characterization factors for water consumption and greenhouse gas emissions based on freshwater fish species extinction.

    Science.gov (United States)

    Hanafiah, Marlia M; Xenopoulos, Marguerite A; Pfister, Stephan; Leuven, Rob S E W; Huijbregts, Mark A J

    2011-06-15

    Human-induced changes in water consumption and global warming are likely to reduce the species richness of freshwater ecosystems. So far, these impacts have not been addressed in the context of life cycle assessment (LCA). Here, we derived characterization factors for water consumption and global warming based on freshwater fish species loss. Calculation of characterization factors for potential freshwater fish losses from water consumption were estimated using a generic species-river discharge curve for 214 global river basins. We also derived characterization factors for potential freshwater fish species losses per unit of greenhouse gas emission. Based on five global climate scenarios, characterization factors for 63 greenhouse gas emissions were calculated. Depending on the river considered, characterization factors for water consumption can differ up to 3 orders of magnitude. Characterization factors for greenhouse gas emissions can vary up to 5 orders of magnitude, depending on the atmospheric residence time and radiative forcing efficiency of greenhouse gas emissions. An emission of 1 ton of CO₂ is expected to cause the same impact on potential fish species disappearance as the water consumption of 10-1000 m³, depending on the river basin considered. Our results make it possible to compare the impact of water consumption with greenhouse gas emissions.

  13. Factors Affecting Mitigation of Methane Emission from Ruminants: Management Strategies

    Directory of Open Access Journals (Sweden)

    Afshar Mirzaei-Aghsaghali

    2015-06-01

    Full Text Available Nowadays, greenhouse gas emission which results in elevating global temperature is an important subject of worldwide ecological and environmental concern. Among greenhouse gases, methane is considered a potent greenhouse gas with 21 times more global warming potential than carbon dioxide. Worldwide, ruminant livestock produce about 80 million metric tons of methane each year, accounting for about 28% of global emissions from human related activities. Therefore it is impelling animal scientists to finding solutions to mitigate methane emission from ruminants. It seems that solutions can be discussed in four topics including: nutrition (feeding, biotechnology, microbiology and management strategies. We have already published the first review article on feeding strategies. In the current review, management strategies such as emphasizing on animals - type and individual variability, reducing livestock numbers, improving animal productivity and longevity as well as pasture management; that can be leads to decreasing methane production from ruminant animal production are discussed.

  14. Factor Decomposition Analysis of Energy-Related CO2 Emissions in Tianjin, China

    Directory of Open Access Journals (Sweden)

    Zhe Wang

    2015-07-01

    Full Text Available Tianjin is the largest coastal city in northern China with rapid economic development and urbanization. Energy-related CO2 emissions from Tianjin’s production and household sectors during 1995–2012 were calculated according to the default carbon-emission coefficients provided by the Intergovernmental Panel on Climate Change. We decomposed the changes in CO2 emissions resulting from 12 causal factors based on the method of Logarithmic Mean Divisia Index. The examined factors were divided into four types of effects: energy intensity effect, structure effect, activity intensity effect, scale effect and the various influencing factors imposed differential impacts on CO2 emissions. The decomposition outcomes indicate that per capita GDP and population scale are the dominant positive driving factors behind the growth in CO2 emissions for all sectors, while the energy intensity of the production sector is the main contributor to dampen the CO2 emissions increment, and the contributions from industry structure and energy structure need further enhancement. The analysis results reveal the reasons for CO2 emission changes in Tianjin and provide a solid basis upon which policy makers may propose emission reduction measures and approaches for the implementation of sustainable development strategies.

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

    Directory of Open Access Journals (Sweden)

    Farzad Taheripour

    2013-01-01

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

  16. On-Road Measurement of Exhaust Emission Factors for Individual Diesel Trucks

    Science.gov (United States)

    Dallmann, T. R.; DeMartini, S.; Harley, R. A.; Kirchstetter, T. W.; Wood, E. C.; Onasch, T. B.; Herndon, S. C.

    2011-12-01

    Diesel trucks are an important source of primary fine particulate matter (PM2.5) that includes black carbon (BC) as a major component. More stringent exhaust emission standards for new engines, effective starting in 2007, considerably reduce allowable emissions and have led to use of after-treatment control devices such as diesel particle filters. The state of California is also implementing programs to accelerate replacement or retrofit of older trucks. In light of these changes, measurements of emissions from in-use heavy-duty diesel trucks are timely and needed to understand the impact of new control technologies on emissions. PM2.5, BC mass, particle light absorption, and particle light extinction emission factors for hundreds of individual diesel trucks were measured in this study. Emissions were measured in July 2010 from trucks driving through the Caldecott tunnel in the San Francisco Bay area. Gas-phase emissions including nitric oxide, nitrogen dioxide, carbon monoxide, and carbon dioxide (CO2) were also measured. Pollutants were measured using air sampling inlets located directly above the vertical exhaust stacks of heavy-duty trucks driving by on the roadway below. All of these measurements were made using fast time response (1 Hz) sensors. Particle optical properties were simultaneously characterized with direct measurements of absorption (babs) and extinction (bext) coefficients. Emission factors for individual trucks were calculated using a carbon balance method in which emissions of PM2.5, BC, babs, and bext in each exhaust plume were normalized to emissions of CO2. Emission factor distributions and fleet-average values are quantified. Absorption and extinction emission factors are used to calculate the aerosol single scattering albedo and BC mass absorption efficiency for individual truck exhaust plumes.

  17. 40 CFR 63.5890 - How do I calculate an organic HAP emissions factor to demonstrate compliance for continuous...

    Science.gov (United States)

    2010-07-01

    ... emissions factor to demonstrate compliance for continuous lamination/casting operations? 63.5890 Section 63...) NATIONAL EMISSION STANDARDS FOR HAZARDOUS AIR POLLUTANTS FOR SOURCE CATEGORIES National Emissions Standards for Hazardous Air Pollutants: Reinforced Plastic Composites Production Testing and Initial...

  18. Developing spatially stratified N{sub 2}O emission factors for Europe

    Energy Technology Data Exchange (ETDEWEB)

    Leip, Adrian, E-mail: adrian.leip@jrc.ec.europa.eu [European Commission-Joint Research Centre, Institute for Environment and Sustainability, Ispra (Italy); Busto, Mirko [International Institute for Applied Systems Analysis, Laxenburg (Austria); Winiwarter, Wilfried [International Institute for Applied Systems Analysis, Laxenburg (Austria); AIT Austrian Institute of Technology, Vienna (Austria)

    2011-11-15

    We investigate the possibility to replace the - so-called - Tier 1 IPCC approach to estimate soil N{sub 2}O emissions with stratified emissions factors that take into account both N-input and the spatial variability of the environmental conditions within the countries of the European Union, using the DNDC-Europe model. Spatial variability in model simulations is high and corresponds to the variability reported in literature for field data. Our results indicate that (a) much of the observed variability in N{sub 2}O fluxes reflects the response of soils to external conditions, (b) it is likely that national inventories tend to overestimate the uncertainties in their estimated direct N{sub 2}O emissions from arable soils; (c) on average over Europe, the fertilizer-induced emissions (FIE) coincide with the IPCC factors, but they display large spatial variations. Therefore, at scales of individual countries or smaller, a stratified approach considering fertilizer type, soil characteristics and climatic parameters is preferable. - Highlights: > Stratified modelling improves estimates of direct N2O emissions from arable soils. > Large variability between strata (expressed as countries) becomes evident. > Fertilizer-induced emissions of N{sub 2}O differ by N input (manure or mineral fertilizer). > National inventories likely overestimate the uncertainties for direct N2O emissions - Model simulations suggest that stratified country-specific N{sub 2}O emission factors are useful to better describe the soil emission behaviour of the European Union countries.

  19. Geographical Detector Model for Influencing Factors of Industrial Sector Carbon Dioxide Emissions in Inner Mongolia, China

    Directory of Open Access Journals (Sweden)

    Rina Wu

    2016-02-01

    Full Text Available Studying the influencing factors of carbon dioxide emissions is not only practically but also theoretically crucial for establishing regional carbon-reduction policies, developing low-carbon economy and solving the climate problems. Therefore, we used a geographical detector model which is consists of four parts, i.e., risk detector, factor detector, ecological detector and interaction detector to analyze the effect of these social economic factors, i.e., GDP, industrial structure, urbanization rate, economic growth rate, population and road density on the increase of energy consumption carbon dioxide emissions in industrial sector in Inner Mongolia northeast of China. Thus, combining with the result of four detectors, we found that GDP and population more influence than economic growth rate, industrial structure, urbanization rate and road density. The interactive effect of any two influencing factors enhances the increase of the carbon dioxide emissions. The findings of this research have significant policy implications for regions like Inner Mongolia.

  20. Source Apportionment of Stack Emissions from Research and Development Facilities Using Positive Matrix Factorization

    Energy Technology Data Exchange (ETDEWEB)

    Ballinger, Marcel Y. [Pacific Northwest National Lab. (PNNL), Richland, WA (United States); Larson, Timothy V. [Univ. of Washington, Seattle, WA (United States)

    2014-08-19

    Emissions from research and development (R&D) facilities are difficult to characterize due to the wide variety of processes used, changing nature of research, and large number of chemicals. Positive matrix factorization (PMF) was applied to volatile organic compounds (VOCs) concentrations measured in the main exhaust stacks of four different R&D buildings to identify the number and composition of major contributing sources. PMF identified from 9-11 source-related factors contributing to the stack emissions depending on the building. The factors that were similar between buildings were major contributors to trichloroethylene (TCE), acetone, and ethanol emissions. Several other factors had similar profiles for two or more buildings but not for all four. One factor for each building was a combination of p/m-xylene, o-xylene and ethylbenzene. At least one factor for each building was identified that contained a broad mix of many species and constraints were used in PMF to modify the factors to resemble more closely the off-shift concentration profiles. PMF accepted the constraints with little decrease in model fit. Although the PMF model predicted the profiles of the off-shift samples, the percent of total emissions was under-predicted by the model versus the measured data.

  1. Time trend of polycyclic aromatic hydrocarbon emission factors from motor vehicles

    Science.gov (United States)

    Tao, Shu; Shen, Huizhong; Wang, Rong; Sun, Kang

    2010-05-01

    Motor vehicle is an important emission source of polycyclic aromatic hydrocarbons (PAHs) and this is particularly true in urban areas. Motor vehicle emission factors (EFs) for individual PAH compound reported in the literature varied for 4 to 5 orders of magnitude, leading to high uncertainty in emission estimation. In this study, the major factors affecting EFs were investigated and characterized by regression models. Based on the model developed, a motor vehicle PAH emission inventory at country level was developed. It was found that country and model year are the most important factors affecting EFs for PAHs. The influence of the two factors can be quantified by a single parameter of per capita gross domestic production (purchasing power parity), which was used as the independent variables of the regression models. The models developed using randomly selected 80% of measurements and tested with the remained data accounted for 28 to 48% of the variations in EFs for PAHs measured in 16 countries over 50 years. The regression coefficients of the EF prediction models were molecular weight dependent. Motor vehicle emission of PAHs from individual countries in the world in 1985, 1995, 2005, 2015, and 2025 were calculated and the global emission of total PAHs were 470, 390, and 430 Gg in 1985, 1995, and 2005 and will be 290 and 130 Gg in 2015 and 2025, respectively. The emission is currently passing its peak and will decrease due to significant decrease in China and other developing countries.

  2. Pre-Harvest Sugarcane Burning: Determination of Emission Factors through Laboratory Measurements

    Directory of Open Access Journals (Sweden)

    João Andrade Carvalho

    2012-02-01

    Full Text Available Sugarcane is an important crop for the Brazilian economy and roughly 50% of its production is used to produce ethanol. However, the common practice of pre-harvest burning of sugarcane straw emits particulate material, greenhouse gases, and tropospheric ozone precursors to the atmosphere. Even with policies to eliminate the practice of pre-harvest sugarcane burning in the near future, there is still significant environmental damage. Thus, the generation of reliable inventories of emissions due to this activity is crucial in order to assess their environmental impact. Nevertheless, the official Brazilian emissions inventory does not presently include the contribution from pre-harvest sugarcane burning. In this context, this work aims to determine sugarcane straw burning emission factors for some trace gases and particulate material smaller than 2.5 μm in the laboratory. Excess mixing ratios for CO2, CO, NOX, UHC (unburned hydrocarbons, and PM2.5 were measured, allowing the estimation of their respective emission factors. Average estimated values for emission factors (g kg−1 of burned dry biomass were 1,303 ± 218 for CO2, 65 ± 14 for CO, 1.5 ± 0.4 for NOX, 16 ± 6 for UHC, and 2.6 ± 1.6 for PM2.5. These emission factors can be used to generate more realistic emission inventories and therefore improve the results of air quality models.

  3. Incineration of different types of medical wastes: emission factors for gaseous emissions

    Science.gov (United States)

    Alvim-Ferraz, M. C. M.; Afonso, S. A. V.

    Previous research works showed that to protect public health, the hospital incinerators should be provided with air pollution control devices. As most hospital incinerators do not possess such equipment, efficient methodologies should be developed to evaluate the safety of incineration procedure. Emission factors (EF) can be used for an easy estimation of legal parameters. Nevertheless, the actual knowledge is yet very scarce, mainly because EF previously published do not include enough information about the incinerated waste composition, besides considering many different waste classifications. This paper reports the first EF estimated for CO, SO 2, NO x and HCl, associated to the incineration of medical waste, segregated in different types according to the classification of the Portuguese legislation. The results showed that those EF are strongly influenced by incinerated waste composition, directly affected by incinerated waste type, waste classification, segregation practice and management methodology. The correspondence between different waste classifications was analysed comparing the estimated EF with the sole results previously published for specific waste types, being observed that the correspondence is not always possible. The legal limit for pollutant concentrations could be obeyed for NO x, but concentrations were higher than the limit for CO (11-24 times), SO 2 (2-5 times), and HCl (9-200 times), confirming that air pollution control devices must be used to protect human health. The small heating value of medical wastes with compulsory incineration implied the requirement of a bigger amount of auxiliary fuel for their incineration, which affects the emitted amounts of CO, NO x and SO 2 (28, 20 and practically 100% of the respective values were related with fuel combustion). Nevertheless, the incineration of those wastes lead to the smallest amount of emitted pollutants, the emitted amount of SO 2 and NO x reducing to 93% and the emitted amount of CO

  4. Seasonal variations in terpene emission factors of dominant species in four ecosystems in NE Spain

    Science.gov (United States)

    Llusia, Joan; Peñuelas, Josep; Guenther, Alex; Rapparini, Francesca

    2013-05-01

    We studied the daily patterns in the rates of foliar terpene emissions by four typical species from the Mediterranean region in two days of early spring and two days of summer in 4 localities of increasing biomass cover in Northern Spain. The species studied were Thymelaea tinctoria (in Monegros), Quercus coccifera (in Garraf), Quercus ilex (in Prades) and Fagus sylvatica (in Montseny). Of the total 43 VOCs detected, 23 were monoterpenes, 5 sesquiterpenes and 15 were not terpenes. Sesquiterpenes were the main terpenes emitted from T. tinctoria. Total VOC emission rates were on average about 15 times higher in summer than in early spring. The maximum rates of emission were recorded around midday. Emissions nearly stopped in the dark. No significant differences were found for nocturnal total terpene emission rates between places and seasons. The seasonal variations in the rate of terpene emissions and in their chemical composition can be explained mainly by dramatic changes in emission factors (emission capacity) associated in some cases, such as for beech trees, with very different foliar ontogenical characteristics between spring and summer. The results show that temperature and light-standardised emission rates were on average about 15 times higher in summer than in early spring, which, corroborating other works, calls to attention when applying the same emission factor in modelling throughout the different seasons of the year.

  5. Factors Affecting Transportation Sector CO2 Emissions Growth in China: An LMDI Decomposition Analysis

    Directory of Open Access Journals (Sweden)

    Yi Liang

    2017-09-01

    Full Text Available China has now become the largest country in carbon emissions all over the world. Furthermore, with transportation accounting for an increasing proportion of CO2 emissions year by year, the transportation sector has turned out to be one of the main sectors which possesses a high growth speed in CO2 emissions. To accurately analyze potentially influencing factors which accelerate the process of CO2 emissions of transportation sector in China, based on carbon accounting by the checklists method of Intergovernmental Panel on Climate Change’s (IPCC, in this paper, we propose a decomposition model using Logarithmic Mean Divisia Index (LMDI decomposition analysis technology and modified fixed growth rate method. Then effects of six influencing factors including energy structure, energy efficiency, transport form, transportation development, economic development and population size from 2001 to 2014 were quantitatively analyzed. Consequently, the results indicate that: (1 economic development accounts most for driving CO2 emissions growth of the transportation sector, while energy efficiency accounts most for suppressing CO2 emissions growth; (2 the pulling effects of natural gas, electricity and other clean energy consumption on CO2 emissions growth offset the inhibitory effects of traditional fossil fuels, making energy structure play a significant role in promoting CO2 emissions growth; (3 the inhibitory effects of railways and highways lead to inhibitory effects of transport form on CO2 emissions growth; (4 transportation development plays an obvious role in promoting CO2 emissions, while the effects of population size is relatively weaker compared with those of transportation development. Furthermore, the decomposition model of CO2 emissions factors in transport industry constructed in this paper can also be applied to other countries so as to provide guidance and reference for CO2 emissions analysis of transportation industry.

  6. Integral emission factors for methane determined using urban flux measurements and local-scale inverse models

    Science.gov (United States)

    Christen, Andreas; Johnson, Mark; Molodovskaya, Marina; Ketler, Rick; Nesic, Zoran; Crawford, Ben; Giometto, Marco; van der Laan, Mike

    2013-04-01

    The most important long-lived greenhouse gas (LLGHG) emitted during combustion of fuels is carbon dioxide (CO2), however also traces of the LLGHGs methane (CH4) and nitrous oxide (N2O) are released, the quantities of which depend largely on the conditions of the combustion process. Emission factors determine the mass of LLGHGs emitted per energy used (or kilometre driven for cars) and are key inputs for bottom-up emission modelling. Emission factors for CH4 are typically determined in the laboratory or on a test stand for a given combustion system using a small number of samples (vehicles, furnaces), yet associated with larger uncertainties when scaled to entire fleets. We propose an alternative, different approach - Can integrated emission factors be independently determined using direct micrometeorological flux measurements over an urban surface? If so, do emission factors determined from flux measurements (top-down) agree with up-scaled emission factors of relevant combustion systems (heating, vehicles) in the source area of the flux measurement? Direct flux measurements of CH4 were carried out between February and May, 2012 over a relatively densely populated, urban surface in Vancouver, Canada by means of eddy covariance (EC). The EC-system consisted of an ultrasonic anemometer (CSAT-3, Campbell Scientific Inc.) and two open-path infrared gas analyzers (Li7500 and Li7700, Licor Inc.) on a tower at 30m above the surface. The source area of the EC system is characterised by a relative homogeneous morphometry (5.3m average building height), but spatially and temporally varying emission sources, including two major intersecting arterial roads (70.000 cars drive through the 50% source area per day) and seasonal heating in predominantly single-family houses (natural gas). An inverse dispersion model (turbulent source area model), validated against large eddy simulations (LES) of the urban roughness sublayer, allows the determination of the spatial area that

  7. Calculation of nitrous oxide emission from agriculture in the Netherlands : update of emission factors and leaching fraction

    NARCIS (Netherlands)

    Velthof, G.L.; Mosquera Losada, J.

    2011-01-01

    A study was conducted to update the NO2 emission factors for nitrogen (N) fertilizer and animal manures applied to soils, based on results of Dutch experiments, and to derive a country specific methodology to calculate nitrate leachting using a leaching fraction (FracLEACH). It is recommended to use

  8. Exploring the impact of determining factors behind CO2 emissions in China: A CGE appraisal.

    Science.gov (United States)

    Xiao, Bowen; Niu, Dongxiao; Wu, Han

    2017-03-01

    Along with the arrival of the post-Kyoto Protocol era, the Chinese government faces ever greater pressure to reduce greenhouse gases (GHGs). Hence, this paper aims to discuss the drivers of carbon dioxide (CO2) emissions and their impact on society as a whole. First, we analyzed the background and overall situations of CO2 emissions in China. Then, we reviewed previous studies to explore the determinants behind China's CO2 emissions. It is widely acknowledged that energy efficiency, energy mix, and economy structure are three key factors contributing to CO2 emissions. To explore the impacts of those three factors on the economy and CO2 emissions, we established a computable general equilibrium (CGE) model. The following results were found: (1) The decline of a secondary industry can cause an emission reduction effect, but this is at the expense of the gross domestic product (GDP), whereas the development of a tertiary industry can boost the economy and help to reduce CO2 emissions. (2) Cutting coal consumption can contribute significantly to emission reduction, which is accompanied by a great loss in the whole economy. (3) Although the energy efficiency improvement plays a positive role in promoting economic development, a backfire effect can weaken the effects of emission reduction and energy savings.

  9. Tailpipe, resuspended road dust, and brake-wear emission factors from on-road vehicles

    Science.gov (United States)

    Abu-Allaban, Mahmoud; Gillies, John A.; Gertler, Alan W.; Clayton, Russ; Proffitt, David

    Intensive mass and chemical measurements were performed at roadside locations in Reno, Nevada, and Durham/Research Triangle Park), North Carolina to derive tailpipe, resuspended road dust, and brake-wear emission factors from in-use vehicles. Continuous particulate matter (PM) data were utilized to derive total emission factors while integrated PM data were used to attribute the calculated emission factors to different mechanisms using chemical mass balance receptor modeling and scanning electron microscopy techniques. Resuspended road dust and tailpipe emissions were found to be the dominant mechanisms that contribute significantly to the total PM 10 and PM 2.5 emission factors, respectively. Small contributions from brake-wear were observed at locations where strong braking occurs, but no tire-wear was seen at any sampling location. PM 10 emission rates from light-duty spark ignition (LDSI) vehicles ranged from 40 to 780 mg/km, 10 to 70 mg/km, and 0 to 80 mg/km per vehicle for road dust, tailpipe, and brake-wear, respectively. PM 10 emission rates from heavy-duty vehicles ranged from 230 to 7800 mg/km, 60 to 570 mg/km, and 0 to 610 mg/km per vehicle for road dust, tailpipe, and brake-wear, respectively. PM 2.5 emission rates from LDSI vehicles ranged from 2 to 25 mg/km, 10 to 50 mg/km, and 0 to 5 mg/km per vehicle for road dust, tailpipe, and brake-wear, respectively. PM 2.5 emission rates from heavy-duty vehicles ranged from 15 to 300 mg/km, 60 to 480 mg/km, and 0 to 15 mg/km per vehicle for road dust, tailpipe, and brake-wear, respectively.

  10. Impact of Bulldozer's Engine Load Factor on Fuel Consumption, CO2 Emission and Cost

    Directory of Open Access Journals (Sweden)

    V. Kecojevic

    2011-01-01

    Full Text Available Problem statement: Bulldozers consume a large amount of diesel fuel and consequently produce a significant quantity of CO2. Environmental and economic cost issues related to fuel consumption and CO2 emission represent a substantial challenge to the mining industry. Approach: Impact of engine load conditions on fuel consumption and the subsequent CO2 emission and cost was analyzed for Caterpillar bulldozers. Results were compared with the data on bulldozers' fuel consumption from an operating coal surface mine in the United States. Results: There is a strong linear correlation among power, fuel consumption and engine load factor. Reduction in load factor by 15% may significantly reduce the fuel consumption and the CO2 emission. Conclusion/Recommendation: Application of appropriate bulldozer's load factor may help mine operators manage fuel consumption, cost and environmental burden.

  11. Evaluations of in-use emission factors from off-road construction equipment

    Science.gov (United States)

    Cao, Tanfeng; Durbin, Thomas D.; Russell, Robert L.; Cocker, David R.; Scora, George; Maldonado, Hector; Johnson, Kent C.

    2016-12-01

    Gaseous and particle emissions from construction engines contribute an important fraction of the total air pollutants released into the atmosphere and are gaining increasing regulatory attention. Robust quantification of nitrogen oxides (NOx) and particulate matter (PM) emissions are necessary to inventory the contribution of construction equipment to atmospheric loadings. Theses emission inventories require emissions factors from construction equipment as a function of equipment type and modes of operation. While the development of portable emissions measurement systems (PEMS) has led to increased studies of construction equipment emissions, emissions data are still much more limited than for on-road vehicles. The goal of this research program was to obtain accurate in-use emissions data from a test fleet of newer construction equipment (model year 2002 or later) using a Code of Federal Requirements (CFR) compliant PEMS system. In-use emission measurements were made from twenty-seven pieces of construction equipment, which included four backhoes, six wheel loaders, four excavators, two scrapers (one with two engines), six bulldozers, and four graders. The engines ranged in model year from 2003 to 2012, in rated horsepower (hp) from 92 to 540 hp, and in hours of operation from 24 to 17,149 h. This is the largest study of off-road equipment emissions using 40 CFR part 1065 compliant PEMS equipment for all regulated gaseous and particulate emissions.

  12. New estimates of direct N2O emissions from Chinese croplands from 1980 to 2007 using localized emission factors

    Directory of Open Access Journals (Sweden)

    F. S. Zhang

    2011-10-01

    Full Text Available Nitrous oxide (N2O is a long-lived greenhouse gas with a large radiation intensity and it is emitted mainly from agricultural land. Accurate estimates of total direct N2O emissions from croplands on a country scale are important for global budgets of anthropogenic sources of N2O emissions and for the development of effective mitigation strategies. The objectives of this study were to re-estimate direct N2O emissions using localized emission factors and a database of measurements from Chinese croplands. We obtained N2O emission factors for paddy fields (0.41 ± 0.04% and uplands (1.05 ± 0.02% from a normalization process through cube root transformation of the original data. After comparing the results of normalization from the original values, Logarithmic and cube root transformations were used because the frequency of the original data was not normally distributed. Direct N2O emissions from Chinese croplands from 1980 to 2007 were estimated using IPCC (2006 guidelines combined with separate localized emission factors for paddy fields and upland areas. Direct N2O emissions from paddy fields showed little change, increasing by 10.5% with an annual rate of increase of 0.4% from 32.3 Gg N2O-N in 1980 to 35.7 Gg N2O-N in 2007. In contrast, emissions from uplands changed dramatically, increasing by 308% with an annual rate of 11% from 68.0 Gg N2O-N in 1980 to 278 Gg N2O-N in 2007. Total direct N2O emissions from Chinese croplands increased by 213% with an annual rate of 7.6% from 100 Gg N2O-N in 1980 to 313 Gg N2O-N in 2007, and were determined mainly by upland emissions (accounting for 67.8–88.6% of total emissions from 1980 to 2007. Synthetic N fertilizers played a major role in N2O emissions from agricultural land, and the magnitude of the contributions to total direct N2O emissions made by different amendments was synthetic N fertilizer > manure > straw, representing about 78, 15, and 6% of total direct N2O emissions, respectively, between

  13. New estimates of direct N2O emissions from Chinese croplands from 1980 to 2007 using localized emission factors

    Directory of Open Access Journals (Sweden)

    F. S. Zhang

    2011-07-01

    Full Text Available Nitrous oxide (N2O is a long-lived greenhouse gas with a large radiation intensity and it is emitted mainly from agricultural land. Accurate estimates of total direct N2O emissions from croplands on a country scale are important for global budgets of anthropogenic sources of N2O emissions and for the development of effective mitigation strategies. The objectives of this study were to re-estimate direct N2O emissions using localized emission factors and a database of measurements from Chinese croplands. We obtained N2O emission factors for paddy fields (0.41 % and uplands (1.05 % from a normalization process through cube root transformation of the original data after comparing the results of normalization from the original values, logarithmic and cube root transformations because the frequency of the original data was not normally distributed. Direct N2O emissions from Chinese croplands from 1980 to 2007 were estimated using IPCC (2006 guidelines combined with separate localized emission factors for paddy fields and upland areas. Direct N2O emissions from paddy fields showed little change, increasing by 11 % with an annual rate of increase of 0.4 % from 29.8 Gg N2O-N in 1980 to 33.1 Gg N2O-N in 2007. In contrast, emissions from uplands changed dramatically, increasing by 296 % with an annual rate of 10.9 % from 64.4 Gg N2O-N in 1980 to 255.3 Gg N2O-N in 2007. Total direct N2O emissions from Chinese croplands increased by 206 % with an annual rate of 7.6 % from 94.2 Gg N2O-N in 1980 to 288.4 Gg N2O-N in 2007, and were determined mainly by upland emissions (accounting for 68.4–88.5 % of total emissions from 1980 to 2007. Synthetic nitrogen fertilizers played a major role in N2O emissions from agricultural land, and the magnitude of the contributions to total direct N2O emissions made by different amendments was synthetic N fertilizer > manure > straw, representing about 77, 16, and 6.5 % of total direct N2O emissions, respectively, between 2000

  14. New estimates of direct N2O emissions from Chinese croplands from 1980 to 2007 using localized emission factors

    Science.gov (United States)

    Gao, B.; Ju, X. T.; Zhang, Q.; Christie, P.; Zhang, F. S.

    2011-10-01

    Nitrous oxide (N2O) is a long-lived greenhouse gas with a large radiation intensity and it is emitted mainly from agricultural land. Accurate estimates of total direct N2O emissions from croplands on a country scale are important for global budgets of anthropogenic sources of N2O emissions and for the development of effective mitigation strategies. The objectives of this study were to re-estimate direct N2O emissions using localized emission factors and a database of measurements from Chinese croplands. We obtained N2O emission factors for paddy fields (0.41 ± 0.04%) and uplands (1.05 ± 0.02%) from a normalization process through cube root transformation of the original data. After comparing the results of normalization from the original values, Logarithmic and cube root transformations were used because the frequency of the original data was not normally distributed. Direct N2O emissions from Chinese croplands from 1980 to 2007 were estimated using IPCC (2006) guidelines combined with separate localized emission factors for paddy fields and upland areas. Direct N2O emissions from paddy fields showed little change, increasing by 10.5% with an annual rate of increase of 0.4% from 32.3 Gg N2O-N in 1980 to 35.7 Gg N2O-N in 2007. In contrast, emissions from uplands changed dramatically, increasing by 308% with an annual rate of 11% from 68.0 Gg N2O-N in 1980 to 278 Gg N2O-N in 2007. Total direct N2O emissions from Chinese croplands increased by 213% with an annual rate of 7.6% from 100 Gg N2O-N in 1980 to 313 Gg N2O-N in 2007, and were determined mainly by upland emissions (accounting for 67.8-88.6% of total emissions from 1980 to 2007). Synthetic N fertilizers played a major role in N2O emissions from agricultural land, and the magnitude of the contributions to total direct N2O emissions made by different amendments was synthetic N fertilizer > manure > straw, representing about 78, 15, and 6% of total direct N2O emissions, respectively, between 2000 and 2007. The

  15. Factors controlling regional differences in forest soil emission of nitrogen oxides (NO and N2O)

    DEFF Research Database (Denmark)

    Pilegaard, K.; Skiba, U.; Ambus, P.;

    2006-01-01

    Soil emissions of NO and N2O were measured continuously at high frequency for more than one year at 15 European forest sites as part of the EU-funded project NOFRETETE. The locations represent different forest types (coniferous/deciduous) and different nitrogen loads. Geoaphically they range from...... to a compact and moist litter layer lead to N2O production and NO consumption in the soil. The two factors soil moisture and soil temperature are often explaining most of the temporal variation within a site. When comparing annual emissions on a regional scale, however, factors such as nitrogen deposition...

  16. GHG emission factors developed for the recycling and composting of municipal waste in South African municipalities.

    Science.gov (United States)

    Friedrich, Elena; Trois, Cristina

    2013-11-01

    GHG (greenhouse gas) emission factors for waste management are increasingly used, but such factors are very scarce for developing countries. This paper shows how such factors have been developed for the recycling of glass, metals (Al and Fe), plastics and paper from municipal solid waste, as well as for the composting of garden refuse in South Africa. The emission factors developed for the different recyclables in the country show savings varying from -290kg CO2 e (glass) to -19111kg CO2 e (metals - Al) per tonne of recyclable. They also show that there is variability, with energy intensive materials like metals having higher GHG savings in South Africa as compared to other countries. This underlines the interrelation of the waste management system of a country/region with other systems, in particular with energy generation, which in South Africa, is heavily reliant on coal. This study also shows that composting of garden waste is a net GHG emitter, releasing 172 and 186kg CO2 e per tonne of wet garden waste for aerated dome composting and turned windrow composting, respectively. The paper concludes that these emission factors are facilitating GHG emissions modelling for waste management in South Africa and enabling local municipalities to identify best practice in this regard.

  17. Measurements of air pollution emission factors for marine transportation in SECA

    Science.gov (United States)

    Alföldy, B.; Lööv, J. B.; Lagler, F.; Mellqvist, J.; Berg, N.; Beecken, J.; Weststrate, H.; Duyzer, J.; Bencs, L.; Horemans, B.; Cavalli, F.; Putaud, J.-P.; Janssens-Maenhout, G.; Csordás, A. P.; Van Grieken, R.; Borowiak, A.; Hjorth, J.

    2013-07-01

    The chemical composition of the plumes of seagoing ships was measured during a two week long measurement campaign in the port of Rotterdam, Hoek van Holland The Netherlands, in September 2009. Altogether, 497 ships were monitored and a statistical evaluation of emission factors (g kg-1 fuel) was provided. The concerned main atmospheric components were SO2, NO2, NOx and the aerosol particle number. In addition, the elemental and water-soluble ionic composition of the emitted particulate matter was determined. Emission factors were expressed as a function of ship type, power and crankshaft rotational speed. The average SO2 emission factor was found to be roughly half of what is allowed in sulphur emission control areas (16 vs. 30 g kg-1 fuel), and exceedances of this limit were rarely registered. A significant linear relationship was observed between the SO2 and particle number emission factors. The intercept of the regression line, 4.8 × 1015 (kg fuel)-1, gives the average number of particles formed during the burning of 1 kg zero sulphur content fuel, while the slope, 2 × 1018, provides the average number of particles formed with 1 kg sulphur burnt with the fuel. Water-soluble ionic composition analysis of the aerosol samples from the plumes showed that ~144 g of particulate sulphate was emitted from 1 kg sulphur burnt with the fuel. The mass median diameter of sulphate particles estimated from the measurements was ~42 nm.

  18. Measurements of air pollution emission factors for marine transportation in SECA

    Directory of Open Access Journals (Sweden)

    B. Alföldy

    2013-07-01

    Full Text Available The chemical composition of the plumes of seagoing ships was measured during a two week long measurement campaign in the port of Rotterdam, Hoek van Holland The Netherlands, in September 2009. Altogether, 497 ships were monitored and a statistical evaluation of emission factors (g kg−1 fuel was provided. The concerned main atmospheric components were SO2, NO2, NOx and the aerosol particle number. In addition, the elemental and water-soluble ionic composition of the emitted particulate matter was determined. Emission factors were expressed as a function of ship type, power and crankshaft rotational speed. The average SO2 emission factor was found to be roughly half of what is allowed in sulphur emission control areas (16 vs. 30 g kg−1 fuel, and exceedances of this limit were rarely registered. A significant linear relationship was observed between the SO2 and particle number emission factors. The intercept of the regression line, 4.8 × 1015 (kg fuel−1, gives the average number of particles formed during the burning of 1 kg zero sulphur content fuel, while the slope, 2 × 1018, provides the average number of particles formed with 1 kg sulphur burnt with the fuel. Water-soluble ionic composition analysis of the aerosol samples from the plumes showed that ~144 g of particulate sulphate was emitted from 1 kg sulphur burnt with the fuel. The mass median diameter of sulphate particles estimated from the measurements was ~42 nm.

  19. Use of AERMOD to Determine a Hydrogen Sulfide Emission Factor for Swine Operations by Inverse Modeling.

    Science.gov (United States)

    O'Shaughnessy, Patrick T; Altmaier, Ralph

    2011-08-01

    This study was conducted to determine both optimal settings applied to the plume dispersion model, AERMOD, and a scalable emission factor for accurately determining the spatial distribution of hydrogen sulfide concentrations in the vicinity of swine concentrated animal feeding operations (CAFOs). These operations emit hydrogen sulfide from both housing structures and waste lagoons. With ambient measurements made at 4 stations within 1 km of large swine CAFOs in Iowa, an inverse-modeling approach applied to AERMOD was used to determine hydrogen sulfide emission rates. CAFO buildings were treated as volume sources whereas nearby lagoons were modeled as area sources. The robust highest concentration (RHC), calculated for both measured and modeled concentrations, was used as the metric for adjusting the emission rate until the ratio of the two RHC levels was unity. Utilizing this approach, an average emission flux rate of 0.57 µg/m(2)-s was determined for swine CAFO lagoons. Using the average total animal weight (kg) of each CAFO, an average emission factor of 6.06 × 10(-7) µg/yr-m(2)-kg was calculated. From studies that measured either building or lagoon emission flux rates, building fluxes, on a floor area basis, were considered equal to lagoon flux rates. The emission factor was applied to all CAFOs surrounding the original 4 sites and surrounding an additional 6 sites in Iowa, producing an average modeled-to-measured RHC ratio of 1.24. When the emission factor was applied to AERMOD to simulate the spatial distribution of hydrogen sulfide around a hypothetical large swine CAFO (1M kg), concentrations 0.5 km from the CAFO were 35 ppb and dropped to 2 ppb within 6 km of the CAFO. These values compare to a level of 30 ppb that has been determined by the State of Iowa as a threshold level for ambient hydrogen sulfide levels.

  20. Development of Particulate Matter and Heavy Metal Emission Factors for Kerman Copper Industries

    Directory of Open Access Journals (Sweden)

    N Mansouri

    2004-06-01

    Full Text Available An emission factor is a tool that is used to estimate air pollutant emissions to the atmosphere. It relates the quantity of pollutants released from a source to some activities associated with those emissions. To determine the quantity of pollutant released from copper and its alloys smelting furnaces, 63 samples from emission gases were collected on cellulose ester membrane filters in three 8-hour-shifts within 24 hours during a week at three locations. Samples were weighed and analyzed to measure the heavy metal content by flame atomic absorption spectrometry. The emission factors for location 1, without control equipment, for total particulate matter (TPM, Cu, Zn, Pb, Cr, Ni, and Cd were 87.689, 2.076, 37.071, 0.917, 0.023, 0.074, and 0.021 g/Mg of products respectively. Emission factors for location 3, with dedusting unit as control equipment, were 8.139, 0.152, 3.921, 0.055, 0.003, 0.008, and 0.007 g/Mg for the above-mentioned parameters respectively. Finally those were 95.828, 2.228, 40.992, 0.972, 0.026, 0.082, and 0.028 g/Mg as a whole set respectively. Samples of location 2 were collected from inlet of dedusting unit and their results were used only for dedusting unit efficiency calculation.

  1. An instantaneous approach for determining the infrared emissivity of swine surface and the influencing factors.

    Science.gov (United States)

    Zhang, Kun; Jiao, Leizi; Zhao, Xiande; Dong, Daming

    2016-04-01

    Infrared thermal imaging technology has been widely employed in temperature measurements of human and animals and its accuracy relies on the determination process of the emissivity of the target to a large extent. However, common used methods were unable to determine the emissivity of the surface of living animals and thus lower the accuracy. In this paper, we suggested a new approach to acquire the infrared emissivity of living swine in real time. In the approach, the surface temperature of swine and reference body were measured to compute the emissivity and the measurement process was completed in a non-contact and non-invasive manner. We changed the surface reflection energy of animals and reference body by changing the ambient radiant energy and obtain the surface emissivity in real time without confirming the actual temperature of animal surface. In this way, the infrared emissivity of the animal surface can be determined instantaneously and without knowing the real temperature. Both swine specimen and a living swine were used in this study. Using this method, we measured the emissivity of different body sites of the swine. The results showed that the emissivity values at different body sites show the significant differences. The emissivity values at trotter and eye were respectively 0.895 and 0.930 and the emissivity on swine surface varied from 0.945 to 0.978. More important, the distribution of the infrared emissivity on a living swine was explored and the detailed differences of the emissivity on a swine surface can be cleanly seen. Furthermore, we studied the influencing factors on the emissivity of animal surface, through measuring the emissivity distribution on swine surface when pig specimens were sprayed with water on the surface or heated using this method. This study is of great significance for the accurate measurement of swine surface temperature.

  2. Ammonia and methane emissions from two naturally ventilated dairy cattle buildings and the influence of climatic factors on ammonia emissions

    Science.gov (United States)

    Wu, Wentao; Zhang, Guoqiang; Kai, Peter

    2012-12-01

    Based on the requirement of the international conventions, there is a pressing need for inventory of NH3, CH4, CO2 and N2O emissions from livestock buildings. The main aim of this study was to quantify the gas emissions and investigate the influence of the climatic factors on ammonia emissions. The measurements were carried out in two naturally ventilated dairy cattle buildings with different layouts, floor types and manure management systems during three periods covering winter and summer time. Air temperature and the three dimensional air velocities inside and outside the buildings were recorded over the course of summer period. Emission rates were determined by CO2 production model. The results showed that the internal concentrations of NH3, CH4 and CO2 were increased or decreased simultaneously. Low concentration of N2O was measured outside and inside the buildings; the difference of the concentrations were also very low. The variation of CH4 and CO2 concentrations showed a strong correlation. The NH3 emission rates varied from 32 to 77 g HPU-1 d-1 in building 1 and varied from 18 to 30 g HPU-1 d-1 in building 2. The average emission of CH4 was 290 and 230 g HPU-1 d-1 from building 1 and 2, respectively. Diurnal pattern was found for NH3 and CH4 emission rates. From multiple linear regression models, there was a significant linear relationship between NH3 emission rates and climatic factors including the external wind speed as well as the air temperature (P 0.05).

  3. Determination of fleet hourly emission and on-road vehicle emission factor using integrated monitoring and modeling approach

    Science.gov (United States)

    Kim Oanh, N. T.; Martel, M.; Pongkiatkul, P.; Berkowicz, R.

    Roadside air quality and vehicle emission are important and challenging issues in urban air quality management which need to be adequately characterized. This study involves designing a monitoring program that produces suitable data to determine the on-road hourly fleet emission and emission factors of individual vehicles in a street canyon. Simultaneous hourly monitoring of roadside gaseous pollutants (both windward and leeward sides), traffic volume and speed, and wind in a busy street of Bangkok was conducted in the rainy season when traffic emission was predominant in the city. Higher pollutant concentrations often occurred at midday (11:00 to 14:00h) when higher traffic density (3700-3800vehicles h - 1, weekdays) was observed. The levels of toluene and xylenes found in this study are higher than the roadside levels reported in other Asian cities. Hourly maximum concentrations reached 258ppb for toluene, 51ppb for m, p-xylenes, 15ppb for o-xylene, 526ppb for NO x, and 10.5ppm for CO. Hourly monitoring data during the periods when the street canyon effects were pronounced were selected for determination of the fleet hourly emission and vehicle emission factors by back calculation using a street canyon model (Operational Street Pollution Model). The average fleet hourly emission at daytime of NO x (6.2kg km - 1 h - 1), CO (54kg km - 1 h - 1), toluene (2.1kg km - 1 h - 1), m, p-xylenes (0.73kg km - 1 h - 1) and o-xylene (0.27kg km - 1 h - 1) did not vary much. However, the emission rates were substantially reduced at nighttime following the traffic pattern. The obtained pollutant emission factors varied within each group of vehicles with the average values agreed reasonably with the chassis dynamometer results for NO x but somewhat higher for CO and TX. The model estimated results are, however, considered to better represent the real driving conditions in the street at the average vehicle travel speed of around 20km h - 1. A statistical sampling design is proposed

  4. Determining size-specific emission factors for environmental tobacco smoke particles

    Energy Technology Data Exchange (ETDEWEB)

    Klepeis, Neil E.; Apte, Michael G.; Gundel, Lara A.; Sextro, Richard G.; Nazaroff, William W.

    2002-07-07

    Because size is a major controlling factor for indoor airborne particle behavior, human particle exposure assessments will benefit from improved knowledge of size-specific particle emissions. We report a method of inferring size-specific mass emission factors for indoor sources that makes use of an indoor aerosol dynamics model, measured particle concentration time series data, and an optimization routine. This approach provides--in addition to estimates of the emissions size distribution and integrated emission factors--estimates of deposition rate, an enhanced understanding of particle dynamics, and information about model performance. We applied the method to size-specific environmental tobacco smoke (ETS) particle concentrations measured every minute with an 8-channel optical particle counter (PMS-LASAIR; 0.1-2+ micrometer diameters) and every 10 or 30 min with a 34-channel differential mobility particle sizer (TSI-DMPS; 0.01-1+ micrometer diameters) after a single cigarette or cigar was machine-smoked inside a low air-exchange-rate 20 m{sup 3} chamber. The aerosol dynamics model provided good fits to observed concentrations when using optimized values of mass emission rate and deposition rate for each particle size range as input. Small discrepancies observed in the first 1-2 hours after smoking are likely due to the effect of particle evaporation, a process neglected by the model. Size-specific ETS particle emission factors were fit with log-normal distributions, yielding an average mass median diameter of 0.2 micrometers and an average geometric standard deviation of 2.3 with no systematic differences between cigars and cigarettes. The equivalent total particle emission rate, obtained integrating each size distribution, was 0.2-0.7 mg/min for cigars and 0.7-0.9 mg/min for cigarettes.

  5. Decreasing emission factor of pollutants in an oil refinery by renovating the furnace design

    Directory of Open Access Journals (Sweden)

    A. Zabihi

    2016-05-01

    Full Text Available The significant consumption of gas in the World results in the emission of greenhouse gases into atmosphere. Abadan refinery has always been the biggest and oldest oil refinery in the Middle East and has a variety of refined products. After six months of collecting data about pollutant concentration emitted from a stack of old furnaces of units 75 and new unit 200, the emission factor of the pollutant was calculated. The result showed that the emission factor of some hazardous pollutants emitted from old unit 75 was tremendously higher than that of unit 200. This study suggests the installation of a forced fan to provide the excess air and a feed temperature controlling system to control fuel gas consumption. These would make the fuel combustion complete and decrease its consumption. Meanwhile, further results showed that the renovation of unit 75 could lead to a significant annual reduction of some pollutants such as CO, H2S, and CxHx to 66 ton, 3 ton, and 800 kg, respectively; this would increase the emission rate of pollutant SO2 up to 150 ton annually. Finally, the new data of pollution coming from unit 75 were compared to pollution standard at American refineries. Results showed that the emission factor of most pollutants were below the American standard limits. However, the emission factor of sulfur dioxide emitted from upgraded furnace of unit 75 surpassed the American standard values. Fuel gas needs to be free of hydrogen sulfide in order to decrease SO2 emission in unit 75. It is predicted that the renovation of other 11 old furnaces belonging to Abadan refinery will result in significant decrease of pollutants CO, CxHx and H2S up to 320, 94 and 76 ton annually.

  6. Nitrous oxide emission factors from N-fertilizer in sugarcane production in Brazil

    Science.gov (United States)

    Galdos, M. V.; Siqueira Neto, M.; Feigl, B. J.; Carvalho, J. L.; Cerri, C. E.; Cerri, C. C.

    2013-12-01

    The Brazilian sugarcane production is rapidly expanding due to the increase of global demand for ethanol. Concurrently the necessary inputs to culture, especially N-fertilizer, are growing, since N is one of the key element to maintain sugarcane productivity. However, it is known that N-fertilizer is responsible for the largest share of N2O emissions from agricultural soils. The Intergovernmental Panel on Climate Changes (IPCC) estimated that under favorable climatic conditions approximately 1% of the N-fertilizer applied can be emitted as N2O. Our goal was to estimate N2O emission factors from N-fertilizer used in the sugarcane ratoon for ethanol production. A field study was conducted at the Capuava Mill, located in southeastern Brazil. The experimental design was completely randomized, with four replications in a factorial scheme (2 x 2): two N sources (urea and ammonium nitrate), two application rates (80 and 120 kg ha-1), and a control treatment. N2O concentrations were determined by gas chromatography using a Shimadzu© GC-mini. N2O fluxes were calculated from linear regressions of concentration versus incubation time in the soil static chambers. The N2O emission factor of N-fertilizer was calculated according to the methodology described in the Guidelines for National Greenhouse Gas Inventories (IPCC). Comparatively, ammonium nitrate emitted 45 to 75% less N2O than urea application. There was no significant difference in N2O emission between the two applied rates of urea. Also the N2O emission factor of ammonium nitrate (0.3×0.2%) was lower than that of urea (1.1×0.4%). Our results indicated that on average the N fertilization of sugarcane plantation has an emission factor of 0.7×0.5% suggesting that N-fertilizer management can be used to reduce greenhouse gas emissions in order to improve the sustainability of bioethanol from sugarcane.

  7. Metal toxicity characterization factors for marine ecosystems: considering the importance of the estuary for freshwater emissions

    DEFF Research Database (Denmark)

    Dong, Yan; Rosenbaum, Ralph K.; Hauschild, Michael Zwicky

    2017-01-01

    CFs for emission to seawater are 1–4 orders of magnitude lower except for Pb. The new site-generic marine CFs for emission to freshwater lie within two orders of magnitude difference from USES-LCA 2.0 CFs. The comparative contribution share analysis shows a poor agreement of metal toxicity ranking......The study develops site-dependent characterization factors (CFs) for marine ecotoxicity of metals emitted to freshwater, taking their passage of the estuary into account. To serve life cycle assessment (LCA) studies where emission location is often unknown, site-generic marine CFs were developed...... for metal emissions to freshwater and coastal seawater, respectively. The new CFs were applied to calculate endpoint impact scores for the same amount of metal emission to each compartment, to compare the relative ecotoxicity damages in freshwater and marine ecosystems in LCA. Site-dependent marine CFs...

  8. Effect of face fracturing on shear wave coda quality factor estimated from acoustic emission events

    CSIR Research Space (South Africa)

    Kgarume, T

    2013-10-01

    Full Text Available The dependency of the quality factor derived from S wave coda (Q(subc)) on frequency is analysed in order to understand the effect of fracturing ahead of a mining stope. Micro seismic events recorded using acoustic emission sensors in a mining...

  9. Consideration of Real World Factors Influencing Greenhouse Gas Emissions in ALPHA

    Science.gov (United States)

    Discuss a variety of factors that influence the simulated fuel economy and GHG emissions that are often overlooked and updates made to ALPHA based on actual benchmarking data observed across a range of vehicles and transmissions. ALPHA model calibration is also examined, focusin...

  10. Emission factors for open and domestic biomass burning for use in atmospheric models

    Science.gov (United States)

    S. K. Akagi; R. J. Yokelson; C. Wiedinmyer; M. J. Alvarado; J. S. Reid; T. Karl; J. D. Crounse; P. O. Wennberg

    2010-01-01

    Biomass burning (BB) is the second largest source of trace gases and the largest source of primary fine carbonaceous particles in the global troposphere. Many recent BB studies have provided new emission factor (EF) measurements. This is especially 5 true for non methane organic compounds (NMOC), which influence secondary organic aerosol (SOA) and ozone formation. New...

  11. Development of net energy ratio and emission factor for quad-generation pathways

    DEFF Research Database (Denmark)

    Rudra, Souman; Rosendahl, Lasse; Kumar, Amit

    2014-01-01

    of this study was to evaluate the energy performance, reduce GHG and acid rain precursor emission, and use of biomass for different outputs based on demand. Finally, a sensitivity analysis and a comparative study ar conducted for expected technological improvements and factors that could increase the energy...

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

    NARCIS (Netherlands)

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

    2016-01-01

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

  13. Real-time emission factor measurements of isocyanic acid from light duty gasoline vehicles.

    Science.gov (United States)

    Brady, James M; Crisp, Timia A; Collier, Sonya; Kuwayama, Toshihiro; Forestieri, Sara D; Perraud, Véronique; Zhang, Qi; Kleeman, Michael J; Cappa, Christopher D; Bertram, Timothy H

    2014-10-07

    Exposure to gas-phase isocyanic acid (HNCO) has been previously shown to be associated with the development of atherosclerosis, cataracts and rheumatoid arthritis. As such, accurate emission inventories for HNCO are critical for modeling the spatial and temporal distribution of HNCO on a regional and global scale. To date, HNCO emission rates from light duty gasoline vehicles, operated under driving conditions, have not been determined. Here, we present the first measurements of real-time emission factors of isocyanic acid from a fleet of eight light duty gasoline-powered vehicles (LDGVs) tested on a chassis dynamometer using the Unified Driving Cycle (UC) at the California Air Resources Board (CARB) Haagen-Smit test facility, all of which were equipped with three-way catalytic converters. HNCO emissions were observed from all vehicles, in contrast to the idealized laboratory measurements. We report the tested fleet averaged HNCO emission factors, which depend strongly on the phase of the drive cycle; ranging from 0.46 ± 0.13 mg kg fuel(-1) during engine start to 1.70 ± 1.77 mg kg fuel(-1) during hard acceleration after the engine and catalytic converter were warm. The tested eight-car fleet average fuel based HNCO emission factor was 0.91 ± 0.58 mg kg fuel(-1), within the range previously estimated for light duty diesel-powered vehicles (0.21-3.96 mg kg fuel(-1)). Our results suggest that HNCO emissions from LDGVs represent a significant emission source in urban areas that should be accounted for in global and regional models.

  14. Small-Chamber Measurements of Chemical-Specific Emission Factors for Drywall

    Energy Technology Data Exchange (ETDEWEB)

    Maddalena, Randy; Russell, Marion; Apte, Michael G.

    2010-06-01

    Imported drywall installed in U.S. homes is suspected of being a source of odorous and potentially corrosive indoor pollutants. To support an investigation of those building materials by the Consumer Products Safety Commission (CPSC), Lawrence Berkeley National Laboratory (LBNL) measured chemical-specific emission factors for 30 samples of drywall materials. Emission factors are reported for 75 chemicals and 30 different drywall samples encompassing both domestic and imported stock and incorporating natural, synthetic, or mixed gypsum core material. CPSC supplied all drywall materials. First the drywall samples were isolated and conditioned in dedicated chambers, then they were transferred to small chambers where emission testing was performed. Four sampling and analysis methods were utilized to assess (1) volatile organic compounds, (2) low molecular weight carbonyls, (3) volatile sulfur compounds, and (4) reactive sulfur gases. LBNL developed a new method that combines the use of solid phase microextraction (SPME) with small emission chambers to measure the reactive sulfur gases, then extended that technique to measure the full suite of volatile sulfur compounds. The testing procedure and analysis methods are described in detail herein. Emission factors were measured under a single set of controlled environmental conditions. The results are compared graphically for each method and in detailed tables for use in estimating indoor exposure concentrations.

  15. The development of seasonal emission factors from a Canadian commercial laying hen facility

    Science.gov (United States)

    Morgan, Robert J.; Wood, David J.; Van Heyst, Bill J.

    2014-04-01

    Pollutants emitted from poultry housing facilities are a concern from a human health, bird welfare, and environmental perspective. Development of emission factors for these aerial pollutants is difficult due to variable climatic conditions, the number and type of poultry, and the wide range of management practices used. To address these concerns, a study was conducted to develop emission factors for ammonia and particulate matter over a period of one year from a commercial poultry laying hen facility in Wellington County, Ontario, Canada. Instruments housed inside an on-site mobile trailer were used to monitor in-house concentrations of ammonia and size fractionated particulate matter via a heated sample line. Along with a ventilation profile, emission factors were developed for the facility. Average emissions of 19.53 ± 19.97, 2.55 ± 2.10, and 1.10 ± 1.52 g day-1 AU-1 (where AU is defined as an animal unit equivalent to 500 kg live mass) for ammonia, PM10, PM2.5, respectively, were observed. All emissions peaked during the winter months, with the exception of PM2.5 which increased in the summer.

  16. Real-world vehicle emission factors in Chinese metropolis city--Beijing

    Institute of Scientific and Technical Information of China (English)

    WANG Qi-dong; HE Ke-bin; HUO Hong; James Lents

    2005-01-01

    The dynamometer tests with different driving cycles and the real-world tests are presented. Results indicated the pollutants emission factors and fuel consumption factor with ECE15 + EUDC driving cycle usually take the lowest value and with real world driving cycle occur the highest value, and different driving cycles will lead to significantly different vehicle emission factors with the same vehicle.Relative to the ECE15 + EUDC driving cycle, the increasing rate of pollutant emission factors of CO, NOx and HC are - 0.42-2.99,- 0.32-0.81 and - 0.11-11 with FTP75 testing, 0.11-1.29, - 0.77-0.64 and 0.47-10.50 with Beijing 1997 testing and 0.25-1.83,0.09-0.75 and - 0.58-1.50 with real world testing. Compared to the carburetor vehicles, the retrofit and MPI + TWC vehicles' pollution emission factors decrease with different degree. The retrofit vehicle (Santana) will reduce 4.44%-58.44% CO, - 4.95%-36.79% NOx, - 32.32%-33.89% HC, and - 9.39%-14.29% fuel consumption, and especially that the MPI + TWC vehicle will decrease CO by 82.48%-91.76%, NOx by 44.87%-92.79%, HC by 90.00%-93.89% and fuel consumption by 5.44%-10.55%. Vehicles can cause pollution at a very high rate when operated in high power modes; however, they may not often operate in these high power modes.In analyzing vehicle emissions, it describes the fraction of time that vehicles operate in various power modes. In Beijing, vehicles spend 90% of their operation in low power modes or decelerating.

  17. Factors affecting temporal H2S emission at construction and demolition (C&D) debris landfills.

    Science.gov (United States)

    Xu, Qiyong; Townsend, Timothy

    2014-02-01

    Odor problems associated with H2S emissions often result in odor complaints from nearby residents of C&D debris landfills, especially in the early morning. As part of a field study conducted on H2S removal ability using different cover materials, daily and seasonal H2S emissions through a soil cover layer were monitored at a C&D debris landfill to investigate factors affecting H2S emissions. H2S emission rates were not a constant, but varied seasonally, with an average emission rate of 4.67×10(-6)mgm(-2)s(-1). During a the 10-month field study, as the H2S concentration increased from 140ppm to about 3500ppm underneath the cover soil in the testing cell, H2S emissions ranged from zero to a maximum emission rate of 1.24×10(-5)mgm(-2)s(-1). Continuous emission monitoring indicated that H2S emissions even changed over time throughout the day, generally increasing from morning to afternoon, and were affected by soil moisture and temperature. Laboratory experiments were also conducted to investigate the effects of H2S concentration and cover soil moisture content on H2S emissions. The results showed that increased soil moisture reduced H2S emissions by retarding H2S migration through cover soil and dissolving H2S into soil water. The field study also indicated that due to atmospheric dispersion, high H2S emissions may not cause odor problems.

  18. Estimating carbon dioxide emission factors for the California electric power sector

    Energy Technology Data Exchange (ETDEWEB)

    Marnay, Chris; Fisher, Diane; Murtishaw, Scott; Phadke, Amol; Price, Lynn; Sathaye, Jayant

    2002-08-01

    The California Climate Action Registry (''Registry'') was initially established in 2000 under Senate Bill 1771, and clarifying legislation (Senate Bill 527) was passed in September 2001. The Ernest Orlando Lawrence Berkeley National Laboratory (Berkeley Lab) has been asked to provide technical assistance to the California Energy Commission (CEC) in establishing methods for calculating average and marginal electricity emissions factors, both historic and current, as well as statewide and for sub-regions. This study is exploratory in nature. It illustrates the use of three possible approaches and is not a rigorous estimation of actual emissions factors. While the Registry will ultimately cover emissions of all greenhouse gases (GHGs), presently it is focusing on carbon dioxide (CO2). Thus, this study only considers CO2, which is by far the largest GHG emitted in the power sector. Associating CO2 emissions with electricity consumption encounters three major complications. First, electricity can be generated from a number of different primary energy sources, many of which are large sources of CO2 emissions (e.g., coal combustion) while others result in virtually no CO{sub 2} emissions (e.g., hydro). Second, the mix of generation resources used to meet loads may vary at different times of day or in different seasons. Third, electrical energy is transported over long distances by complex transmission and distribution systems, so the generation sources related to electricity usage can be difficult to trace and may occur far from the jurisdiction in which that energy is consumed. In other words, the emissions resulting from electricity consumption vary considerably depending on when and where it is used since this affects the generation sources providing the power. There is no practical way to identify where or how all the electricity used by a certain customer was generated, but by reviewing public sources of data the total emission burden of a

  19. Real-time black carbon emission factor measurements from light duty vehicles.

    Science.gov (United States)

    Forestieri, Sara D; Collier, Sonya; Kuwayama, Toshihiro; Zhang, Qi; Kleeman, Michael J; Cappa, Christopher D

    2013-11-19

    Eight light-duty gasoline low emission vehicles (LEV I) were tested on a Chassis dynamometer using the California Unified Cycle (UC) at the Haagen-Smit vehicle test facility at the California Air Resources Board in El Monte, CA during September 2011. The UC includes a cold start phase followed by a hot stabilized running phase. In addition, a light-duty gasoline LEV vehicle and ultralow emission vehicle (ULEV), and a light-duty diesel passenger vehicle and gasoline direct injection (GDI) vehicle were tested on a constant velocity driving cycle. A variety of instruments with response times ≥0.1 Hz were used to characterize how the emissions of the major particulate matter components varied for the LEVs during a typical driving cycle. This study focuses primarily on emissions of black carbon (BC). These measurements allowed for the determination of BC emission factors throughout the driving cycle, providing insights into the temporal variability of BC emission factors during different phases of a typical driving cycle.

  20. Emission factors for gaseous and particulate pollutants from offshore diesel engine vessels in China

    Science.gov (United States)

    Zhang, Fan; Chen, Yingjun; Tian, Chongguo; Lou, Diming; Li, Jun; Zhang, Gan; Matthias, Volker

    2016-05-01

    Shipping emissions have significant influence on atmospheric environment as well as human health, especially in coastal areas and the harbour districts. However, the contribution of shipping emissions on the environment in China still need to be clarified especially based on measurement data, with the large number ownership of vessels and the rapid developments of ports, international trade and shipbuilding industry. Pollutants in the gaseous phase (carbon monoxide, sulfur dioxide, nitrogen oxides, total volatile organic compounds) and particle phase (particulate matter, organic carbon, elemental carbon, sulfates, nitrate, ammonia, metals) in the exhaust from three different diesel-engine-powered offshore vessels in China (350, 600 and 1600 kW) were measured in this study. Concentrations, fuel-based and power-based emission factors for various operating modes as well as the impact of engine speed on emissions were determined. Observed concentrations and emission factors for carbon monoxide, nitrogen oxides, total volatile organic compounds, and particulate matter were higher for the low-engine-power vessel (HH) than for the two higher-engine-power vessels (XYH and DFH); for instance, HH had NOx EF (emission factor) of 25.8 g kWh-1 compared to 7.14 and 6.97 g kWh-1 of DFH, and XYH, and PM EF of 2.09 g kWh-1 compared to 0.14 and 0.04 g kWh-1 of DFH, and XYH. Average emission factors for all pollutants except sulfur dioxide in the low-engine-power engineering vessel (HH) were significantly higher than that of the previous studies (such as 30.2 g kg-1 fuel of CO EF compared to 2.17 to 19.5 g kg-1 fuel in previous studies, 115 g kg-1 fuel of NOx EF compared to 22.3 to 87 g kg-1 fuel in previous studies and 9.40 g kg-1 fuel of PM EF compared to 1.2 to 7.6 g kg-1 fuel in previous studies), while for the two higher-engine-power vessels (DFH and XYH), most of the average emission factors for pollutants were comparable to the results of the previous studies, engine type was

  1. Black carbon particulate matter emission factors for buoyancy-driven associated gas flares.

    Science.gov (United States)

    McEwen, James D N; Johnson, Matthew R

    2012-03-01

    Flaring is a technique used extensively in the oil and gas industry to burn unwanted flammable gases. Oxidation of the gas can preclude emissions of methane (a potent greenhouse gas); however, flaring creates other pollutant emissions such as particulate matter (PM) in the form of soot or black carbon (BC). Currently available PM emissionfactors for flares were reviewed and found to be questionably accurate, or based on measurements not directly relevant to open-atmosphere flares. In addition, most previous studies of soot emissions from turbulent diffusion flames considered alkene or alkyne based gaseous fuels, and few considered mixed fuels in detail and/or lower sooting propensity fuels such as methane, which is the predominant constituent of gas flared in the upstream oil and gas industry. Quantitative emission measurements were performed on laboratory-scale flares for a range of burner diameters, exit velocities, and fuel compositions. Drawing from established standards, a sampling protocol was developed that employed both gravimetric analysis of filter samples and real-time measurements of soot volume fraction using a laser-induced incandescence (LII) system. For the full range of conditions tested (burner inner diameter [ID] of 12.7-76.2 mm, exit velocity 0.1-2.2 m/sec, 4- and 6-component methane-based fuel mixtures representative of associated gas in the upstream oil industry), measured soot emission factors were less than 0.84 kg soot/10(3) m3 fuel. A simple empirical relationship is presented to estimate the PM emission factor as a function of the fuel heating value for a range of conditions, which, although still limited, is an improvement over currently available emission factors.

  2. Seasonal variability of monoterpene emission factors for a ponderosa pine plantation in California

    Directory of Open Access Journals (Sweden)

    R. Holzinger

    2006-01-01

    Full Text Available Monoterpene fluxes have been measured over an 11 month period from June 2003 to April 2004. During all seasons ambient air temperature was the environmental factor most closely related to the measured emission rates. The monoterpene flux was modeled using a basal emission rate multiplied by an exponential function of a temperature, following the typical practice for modelling temperature dependent biogenic emissions. A basal emission of 1.0 μmol h−1 m−2 (at 30°C, based on leaf area and a temperature dependence (β of 0.12°C−1 reproduced measured summer emissions well but underestimated spring and winter measured emissions by 60–130%. The total annual monoterpene emission may be underestimated by ~50% when using a model optimized to reproduce monoterpene emissions in summer. The long term dataset also reveals an indirect connection between non-stomatal ozone and monoterpene flux beyond the dependence on temperature that has been shown for both fluxes.

  3. Emission Laws and Influence Factors of Greenhouse Gases in Saline-Alkali Paddy Fields

    Directory of Open Access Journals (Sweden)

    Jie Tang

    2016-02-01

    Full Text Available The study of greenhouse gas emissions has become a global focus, but few studies have considered saline-alkali paddy fields. Gas samples and saline-alkali soil samples were collected during the green, tillering, booting, heading and grain filling stages. The emission fluxes of CO2, CH4, and N2O as well as the pH, soil soluble salt, available nitrogen, and soil organic carbon contents were detected to reveal the greenhouse gas (GHG emission laws and influence factors in saline-alkali paddy fields. Overall, GHG emissions of paddy soil during the growing season increased, then decreased, and then increased again and peaked at booting stage. The emission fluxes of CO2 and CH4 were observed as having two peaks and a single peak, respectively. Both the total amount of GHG emission and its different components of CO2, CH4, and N2O increased with the increasing reclamation period of paddy fields. A positive correlation was found between the respective emission fluxes of CO2, CH4, and N2O and the available nitrogen and SOC, whereas a negative correlation was revealed between the fluxes of CO2, CH4, and N2O and soil pH and soil conductivity. The study is beneficial to assessing the impact of paddy reclamation on regional greenhouse gas emissions and is relevant to illustrating the mechanisms concerning the carbon cycle in paddy soils.

  4. Influencing Factors of Energy-Related CO2 Emissions in China: A Decomposition Analysis

    Directory of Open Access Journals (Sweden)

    Guokui Wang

    2015-10-01

    Full Text Available China is the largest CO2 emitter in the world and is still reliant on energy consumption for economic growth. Research has focused on effective approaches of reducing and mitigating CO2 emissions. This paper undertakes a decomposition study of energy-related CO2 emissions from the industrial and household sectors during the period 1996–2012, with the objectives of investigating trends of the changes in energy-related CO2 emissions, the driving forces of these changes, and approaches of mitigating CO2 emission. Results show the following: (1 the expansion of economic activity is the dominant stimulatory factor of the increase of CO2 emissions in China and that a sustained increase in CO2 emissions can be expected; (2 the decline in energy intensity and the adjustment of energy mix and industrial structure effectively mitigate CO2 emissions; and (3 the government should give more attention to enhancing the energy utility efficiency and reducing CO2 emissions in rural households.

  5. Emission factors for CH{sub 4}, NO{sub x}, particulates and black carbon for domestic shipping in Norway, revision 1

    Energy Technology Data Exchange (ETDEWEB)

    Nielsen, Joergen Bremnes; Stenersen, Dag

    2010-11-15

    In this report new and updated emission factors for diesel, HFO and gas fuelled ships are presented and discussed as follows; NO{sub x} reduction factors from ships with NO{sub x} reduction measures; NO{sub x} emission factor from gas operated vessels; Methane emission factors for gas operated vessels; Updated emission factors for particulate emissions (PM) with a specific factor for the black carbon (BC) fraction of particulate emissions; A discussion on how low sulfur fuel will affect emissions of PM emissions and the BC fraction of PM is also included. (Author)

  6. Major factors controlling nitrous oxide emission and methane uptake from forest soil

    Institute of Scientific and Technical Information of China (English)

    2001-01-01

    Soil samples were taken from depth of 0-12 cm in virgin broad-leaved Korean pine mixed forest in Changbai Mountain in July 2000. The effects of temperature, soil water content, pH, NH4+ and NO3- on N2O emission and CH4 uptake of a forest soil were studied in laboratory by the method of orthogonal design. It was observed under laboratory conditions in this study that there were significant correlations between N2O emission rate, CH4 oxidation rate, soil pH and temperature. Nevertheless, N2O emission rate also showed a significant positive correlation with CH4 oxidation rate. The results suggested that pH and tem-perature were important factors controlling N2O emission and CH4 oxidation under this experiment conditions.

  7. Atmospheric number size distributions of soot particles and estimation of emission factors

    Directory of Open Access Journals (Sweden)

    D. Rose

    2006-01-01

    Full Text Available Number fractions of externally mixed particles of four different sizes (30, 50, 80, and 150 nm in diameter were measured using a Volatility Tandem DMA. The system was operated in a street canyon (Eisenbahnstrasse, EI and at an urban background site (Institute for Tropospheric Research, IfT, both in the city of Leipzig, Germany as well as at a rural site (Melpitz (ME, a village near Leipzig. Intensive campaigns of 3–5 weeks each took place in summer 2003 as well as in winter 2003/04. The data set thus obtained provides mean number fractions of externally mixed soot particles of atmospheric aerosols in differently polluted areas and different seasons (e.g. at 80 nm on working days, 60% (EI, 22% (IfT, and 6% (ME in summer and 26% (IfT, and 13% (ME in winter. Furthermore, a new method is used to calculate the size distribution of these externally mixed soot particles from parallel number size distribution measurements. A decrease of the externally mixed soot fraction with decreasing urbanity and a diurnal variation linked to the daily traffic changes demonstrate, that the traffic emissions have a significant impact on the soot fraction in urban areas. This influence becomes less in rural areas, due to atmospheric mixing and transformation processes. For estimating the source strength of soot particles emitted by vehicles (veh, soot particle emission factors were calculated using the Operational Street Pollution Model (OSPM. The emission factor for an average vehicle was found to be (1.5±0.4·1014 #(km·veh. The separation of the emission factor into passenger cars ((5.8±2·1013} #(km·veh and trucks ((2.5±0.9·1015 #(km·veh yielded in a 40-times higher emission factor for trucks compared to passenger cars.

  8. Impact of some field factors on inhalation exposure levels to bitumen emissions during road paving operations.

    Science.gov (United States)

    Deygout, François; Auburtin, Guy

    2015-03-01

    Variability in occupational exposure levels to bitumen emissions has been observed during road paving operations. This is due to recurrent field factors impacting the level of exposure experienced by workers during paving. The present study was undertaken in order to quantify the impact of such factors. Pre-identified variables currently encountered in the field were monitored and recorded during paving surveys, and were conducted randomly covering current applications performed by road crews. Multivariate variance analysis and regressions were then used on computerized field data. The statistical investigations were limited due to the relatively small size of the study (36 data). Nevertheless, the particular use of the step-wise regression tool enabled the quantification of the impact of several predictors despite the existing collinearity between variables. The two bitumen organic fractions (particulates and volatiles) are associated with different field factors. The process conditions (machinery used and delivery temperature) have a significant impact on the production of airborne particulates and explain up to 44% of variability. This confirms the outcomes described by previous studies. The influence of the production factors is limited though, and should be complemented by studying factors involving the worker such as work style and the mix of tasks. The residual volatile compounds, being part of the bituminous binder and released during paving operations, control the volatile emissions; 73% of the encountered field variability is explained by the composition of the bitumen batch.

  9. Urban Household Carbon Emission and Contributing Factors in the Yangtze River Delta, China

    Science.gov (United States)

    Xu, Xibao; Tan, Yan; Chen, Shuang; Yang, Guishan; Su, Weizhong

    2015-01-01

    Carbon reduction at the household level is an integral part of carbon mitigation. This study analyses the characteristics, effects, contributing factors and policies for urban household carbon emissions in the Yangtze River Delta of China. Primary data was collected through structured questionnaire surveys in three cities in the region – Nanjing, Ningbo, and Changzhou in 2011. The survey data was first used to estimate the magnitude of household carbon emissions in different urban contexts. It then examined how, and to what extent, each set of demographic, economic, behavioral/cognitive and spatial factors influence carbon emissions at the household level. The average of urban household carbon emissions in the region was estimated to be 5.96 tonnes CO2 in 2010. Energy consumption, daily commuting, garbage disposal and long-distance travel accounted for 51.2%, 21.3%, 16.0% and 11.5% of the total emission, respectively. Regulating rapidly growing car-holdings of urban households, stabilizing population growth, and transiting residents’ low-carbon awareness to household behavior in energy saving and other spheres of consumption in the context of rapid population aging and the growing middle income class are suggested as critical measures for carbon mitigation among urban households in the Yangtze River Delta. PMID:25884853

  10. Urban household carbon emission and contributing factors in the Yangtze River Delta, China.

    Directory of Open Access Journals (Sweden)

    Xibao Xu

    Full Text Available Carbon reduction at the household level is an integral part of carbon mitigation. This study analyses the characteristics, effects, contributing factors and policies for urban household carbon emissions in the Yangtze River Delta of China. Primary data was collected through structured questionnaire surveys in three cities in the region--Nanjing, Ningbo, and Changzhou in 2011. The survey data was first used to estimate the magnitude of household carbon emissions in different urban contexts. It then examined how, and to what extent, each set of demographic, economic, behavioral/cognitive and spatial factors influence carbon emissions at the household level. The average of urban household carbon emissions in the region was estimated to be 5.96 tonnes CO2 in 2010. Energy consumption, daily commuting, garbage disposal and long-distance travel accounted for 51.2%, 21.3%, 16.0% and 11.5% of the total emission, respectively. Regulating rapidly growing car-holdings of urban households, stabilizing population growth, and transiting residents' low-carbon awareness to household behavior in energy saving and other spheres of consumption in the context of rapid population aging and the growing middle income class are suggested as critical measures for carbon mitigation among urban households in the Yangtze River Delta.

  11. USEtox fate and ecotoxicity factors for comparative assessment of toxic emissions in Life Cycle Analysis

    DEFF Research Database (Denmark)

    Andrew D, Henderson; Hauschild, Michael Zwicky; Van de Meent, Dik;

    2011-01-01

    The USEtox model was developed in a scientific consensus process involving comparison of and harmonization between existing environmental multimedia fate models. For freshwater ecosystem toxicity, it covers the entire impact pathway, i.e., transforming a chemical emission into potential impacts......, the effect factor, which is obtained from laboratory measurements of substance toxicity to different phyla, strongly controls freshwater ecotoxicity, with a range of up to 10 orders of magnitude. Chemical-specific differences in multimedia transfer influence the CF for freshwater emissions by less than two...

  12. Emissions, activity data, and emission factors of fluorinated greenhouse gases (F-Gases) in Germany 1995-2002

    Energy Technology Data Exchange (ETDEWEB)

    Schwarz, Winfried [Oeko-Recherche, Buero fuer Umweltforschung und -beratung GmbH, Frankfurt am Main (Germany)

    2005-06-15

    Before the 1997 Kyoto Protocol on Climate Protection, the fluorinated greenhouse gases HFCs, PFCs, and SF6 (F-gases) aroused little public attention. Since then, the standards on surveying and reporting on national emissions have been rising constantly. Amongst others, the annual reporting to the UNFCCC secretariat makes detailed declarations on use and emissions of F-gases necessary, which have to be filled in specified formats for submission (Common Reporting Format = CRF). The scientific basis has been set out by the UNFCCC guidelines on reporting, in accordance with the instructions laid down in IPCC good practice guidance. Additionally, in Germany the Centralised System of Emissions (ZSE) shall provide a suitable tool to satisfy any quality needs of both activity data and emission factors. From 1995 onwards, activity data and emissions of each individual application sector shall be presented in a comprehensible and transparent way. Therefore, the way of data collection as well as the estimation methods applied must be well documented. Moreover, data has to be prepared for appropriate importation into ZSE. It is the objective of this study to provide the transparency demanded within 40 national application sectors of F-gases, for the period between 1995 and 2002. - Firstly, all the activity data as well as the emissions related to them are presented and commented. This applies to manufacturing of products, F-gases banked in operating systems, and decommissioning. - Secondly, the methodologies applied to calculate the emissions are described and all sources of information are revealed, e.g. literature, names of experts from the manufacturing industry, users, trade, and academia. - Thirdly, reliability and safety of data are discussed. - Fourthly, possible deviations from the IPCC default values are stated and given reasons for. Wherever this intensive reviewing of 40 sectors through eight years of reporting uncovers gaps or inconsistencies in previous reports

  13. The effects of deterioration and technological levels on pollutant emission factors for gasoline light-duty trucks.

    Science.gov (United States)

    Zhang, Qingyu; Fan, Juwang; Yang, Weidong; Chen, Bixin; Zhang, Lijuan; Liu, Jiaoyu; Wang, Jingling; Zhou, Chunyao; Chen, Xuan

    2017-07-01

    Vehicle deterioration and technological change influence emission factors (EFs). In this study, the impacts of vehicle deterioration and emission standards on EFs of regulated pollutants (carbon monoxide [CO], hydrocarbon [HC], and nitrogen oxides [NOx]) for gasoline light-duty trucks (LDTs) were investigated according to the inspection and maintenance (I/M) data using a chassis dynamometer method. Pollutant EFs for LDTs markedly varied with accumulated mileages and emission standards, and the trends of EFs are associated with accumulated mileages. In addition, the study also found that in most cases, the median EFs of CO, HC, and NOx are higher than those of basic EFs in the International Vehicle Emissions (IVE) model; therefore, the present study provides correction factors for the IVE model relative to the corresponding emission standards and mileages. Currently, vehicle emissions are great contributors to air pollution in cities, especially in developing countries. Emission factors play a key role in creating emission inventory and estimating emissions. Deterioration represented by vehicle age and accumulated mileage and changes of emission standards markedly influence emission factors. In addition, the results provide collection factors for implication in the IVE model in the region levels.

  14. Research on impacts of population-related factors on carbon emissions in Beijing from 1984 to 2012

    Energy Technology Data Exchange (ETDEWEB)

    Yang, Yayun; Zhao, Tao; Wang, Yanan, E-mail: wyn3615@126.com; Shi, Zhaohui

    2015-11-15

    Carbon emissions related to population factors have aroused great attention around the world. A multitude of literature mainly focused on single demographic impacts on environmental issues at the national level, and comprehensive studies concerning population-related factors at a city level are rare. This paper employed STIRPAT (Stochastic Impacts by Regression on Population, Affluence and Technology) model incorporating PLS (Partial least squares) regression method to examine the influence of population-related factors on carbon emissions in Beijing from 1984 to 2012. Empirically results manifest that urbanization is the paramount driver. Changes in population age structure have significantly positive impacts on carbon emissions, and shrinking young population, continuous expansion of working age population and aging population will keep on increasing environmental pressures. Meanwhile, shrinking household size and expanding floating population boost the discharge of carbon emissions. Besides, per capita consumption is an important contributor of carbon emissions, while industry energy intensity is the main inhibitory factor. Based upon these findings and the specific circumstances of Beijing, policies such as promoting clean and renewable energy, improving population quality and advocating low carbon lifestyles should be enhanced to achieve targeted emissions reductions. - Highlights: • We employed the STIRPAT model to identify population-related factors of carbon emissions in Beijing. • Urbanization is the paramount driver of carbon emissions. • Changes in population age structure exert significantly positive impacts on carbon emissions. • Shrinking household size, expanding floating population and improving consumption level increase carbon emissions. • Industry energy intensity decreases carbon emissions.

  15. Quantifying baseline emission factors of air pollutants in China's regional power grids.

    Science.gov (United States)

    Cai, Wenjia; Wang, Can; Jin, Zhugang; Chen, Jining

    2013-04-16

    Drawing lessons from the clean development mechanism (CDM), this paper developed a combined margin methodology to quantify baseline emission factors of air pollutants in China's regional power grids. The simple average of baseline emission factors of SO2, NOX, and PM2.5 in China's six power grids in 2010 were respectively 1.91 kg/MWh, 1.83 kg/MWh and 0.32 kg/MWh. Several low-efficient mitigation technologies, such as low nitrogen oxide burner (LNB), were suggested to be replaced or used together with other technologies in order to virtually decrease the grid's emission factor. The synergies between GHG and air pollution mitigation in China's power sector was also notable. It is estimated that in 2010, that every 1% CO2 reduction in China's power generation sector resulted in the respective coreduction of 1.1%, 0.5%, and 0.8% of SO2, NOX, and PM2.5. Wind is the best technology to achieve the largest amount of coabatement in most parts of China. This methodology is recommended to be used in making comprehensive air pollution control strategies and in cobenefits analysis in future CDM approval processes.

  16. Nitrous oxide emissions from intensive agricultural systems: Variations between crops and seasons, key driving variables, and mean emission factors

    Science.gov (United States)

    Dobbie, K. E.; McTaggart, I. P.; Smith, K. A.

    1999-11-01

    Emissions of nitrous oxide from intensively managed agricultural fields were measured over 3 years. Exponential increases in flux occurred with increasing soil water- filled pore space (WFPS) and temperature; increases in soil mineral N content due to fertilizer application also stimulated emissions. Fluxes were low when any of these variables was below a critical value. The largest fluxes occurred when WFPS values were very high (70-90%), indicating that denitrification was the major process responsible. The relationships with the driving variables showed strong similarities to those reported for very different environments: irrigated sugar cane crops, pastures, and forest in the tropics. Annual emissions varied widely (0.3-18.4 kg N2O-N ha-1). These variations were principally due to the degree of coincidence of fertilizer application and major rainfall events. It is concluded therefore that several years' data are required from any agricultural ecosystem in a variable climate to obtain a robust estimate of mean N2O fluxes. The emissions from small-grain cereals (winter wheat and spring barley) were consistently lower (0.2-0.7 kg N2O-N per 100 kg N applied) than from cut grassland (0.3-5.8 kg N2O- N per 100 kg N). Crops such as broccoli and potatoes gave emissions of the same order as those from the grassland. Although these differences between crop types are not apparent in general data comparisons, there may well be distinct regional differences in the relative and absolute emissions from different crops, due to local factors relating to soil type, weather patterns, and agricultural management practices. This will only be determined by more detailed comparative studies.

  17. The leaf-level emission factor of volatile isoprenoids: caveats, model algorithms, response shapes and scaling

    Directory of Open Access Journals (Sweden)

    Ü. Niinemets

    2010-06-01

    Full Text Available In models of plant volatile isoprenoid emissions, the instantaneous compound emission rate typically scales with the plant's emission potential under specified environmental conditions, also called as the emission factor, ES. In the most widely employed plant isoprenoid emission models, the algorithms developed by Guenther and colleagues (1991, 1993, instantaneous variation of the steady-state emission rate is described as the product of ES and light and temperature response functions. When these models are employed in the atmospheric chemistry modeling community, species-specific ES values and parameter values defining the instantaneous response curves are often taken as initially defined. In the current review, we argue that ES as a characteristic used in the models importantly depends on our understanding of which environmental factors affect isoprenoid emissions, and consequently need standardization during experimental ES determinations. In particular, there is now increasing consensus that in addition to variations in light and temperature, alterations in atmospheric and/or within-leaf CO2 concentrations may need to be included in the emission models. Furthermore, we demonstrate that for less volatile isoprenoids, mono- and sesquiterpenes, the emissions are often jointly controlled by the compound synthesis and volatility. Because of these combined biochemical and physico-chemical drivers, specification of ES as a constant value is incapable of describing instantaneous emissions within the sole assumptions of fluctuating light and temperature as used in the standard algorithms. The definition of ES also varies depending on the degree of aggregation of ES values in different parameterization schemes (leaf- vs. canopy- or region-scale, species vs. plant functional type levels and various

  18. Interpreting broad emission-line variations I : Factors influencing the emission-line response

    CERN Document Server

    Goad, M R

    2014-01-01

    We investigate the sensitivity of the measured broad emission-line responsivity dlog f_line/dlog f_cont to continuum variations in the context of straw-man BLR geometries of varying size with fixed BLR boundaries, and for which the intrinsic emission-line responsivity is known a priori. We find for a generic emission-line that the measured responsivity, delay and maximum of the cross-correlation function are correlated for characteristic continuum variability timescales T_char less than the maximum delay for that line tau_max(line) for a particular choice of BLR geometry and observer orientation. The above correlations are manifestations of geometric dilution arising from reverberation effects within the spatially extended BLR. When present, geometric dilution reduces the measured responsivity, delay and maximum of the cross-correlation function. We also find that the measured responsivity and delay show a strong dependence on light-curve duration, with shorter campaigns resulting in smaller than expected val...

  19. Stress distribution and effective stress intensity factor of a blunt crack after dislocation emission

    Institute of Scientific and Technical Information of China (English)

    2000-01-01

    The stress fields induced by a dislocation and its image dislocations around a narrow elliptic void are formulated. Based on the solution, the stress distribution and effective stress intensity factor of a blunt (elliptic) crack were calculated under mode I constant loading. The results show that a dislocation-free zone (DFZ) is formed after dislocation emission. There exists a second stress peak in the DFZ except a stress peak at the blunt crack tip. With an increase in the applied stress intensity factor KIa or the friction stress τf of the material, the DFZ size and the peak stress at the crack tip decrease, but the peak stress in the DFZ and the effective stress intensity factor KIf presiding at the crack tip increase. Because of dislocation shielding effects, shielding ratio KIa/KIf increases with increasing KIa}, but it decreases with increasing τf.

  20. Stress distribution and effective stress intensity factor of a blunt crack after dislocation emission

    Institute of Scientific and Technical Information of China (English)

    钱才富; 乔利杰; 褚武扬

    2000-01-01

    The stress fields induced by a dislocation and its image dislocations around a narrow elliptic void are formulated. Based on the solution, the stress distribution and effective stress intensity factor of a blunt (elliptic) crack were calculated under mode I constant loading. The results show that a dislocation-free zone (DFZ) is formed after dislocation emission. There exists a second stress peak in the DFZ except a stress peak at the blunt crack tip. With an increase in the applied stress intensity factor Kla or the friction stress T, of the material, the DFZ size and the peak stress at the crack tip decrease, but the peak stress in the DFZ and the effective stress intensity factor Klf presiding at the crack tip increase. Because of dislocation shielding effects, shielding ratio Kla/Klf increases with increasing Kla, but it decreases with increasing Tf.

  1. [Experimental study on the size spectra and emission factor of ultrafine particle from coal combustion].

    Science.gov (United States)

    Sun, Zai; Yang, Wen-jun; Xie, Xiao-fang; Chen, Qiu-fang; Cai, Zhi-liang

    2014-12-01

    The emission characteristics of ultrafine particles released from pulverized coal combustion were studied, the size spectra of ultrafine particles (5.6-560 nm) were measured with FMPS (fast mobility particle sizer) on a self-built aerosol experiment platform. Meanwhile, a particle dynamic evolution model was established to obtain the particle deposition rate and the emission rate through the optimized algorithm. Finally, the emission factor was calculated. The results showed that at the beginning of particle generation, the size spectra were polydisperse and complex, the initial size spectra was mainly composed of three modes including 10 nm, 30-40 nm and 100-200 nm. Among them, the number concentration of mode around 10 nm was higher than those of other modes, the size spectrum of around 100-200 nm was lognormal distributed, with a CMD (count median diameter) of around 16 nm. Then, as time went on, the total number concentration was decayed by exponential law, the CMD first increased and then tended to be stable gradually. The calculation results showed that the emission factor of particles from coal combustion under laboratory condition was (5.54 x 10(12) ± 2.18 x 10(12)) unit x g(-1).

  2. High Q-factor micro-cavity laser: Fabrication and lasing emission properties

    Energy Technology Data Exchange (ETDEWEB)

    Pham Van Hoi; Ha Xuan Vinh; Chu Thi Thu Ha; Tran Thi Cham [Institute of Materials Science, Vietname Academy of Science and Technology 18 Hoang Quoc Viet Road, Cau Giay District, Hanoi (Viet Nam); Bui Van Thien [Faculty of Natural Science, College of Medicine, Thai Nguyen (Viet Nam); Gruzintsev, A N [Institute of Microelectronics Technology and High Purity Materials, Russian Academy of Sciences (IPMT-RAS) (Russian Federation)], E-mail: hoipv@ims.vast.ac.vn

    2009-09-01

    In this article the fabrication method and lasing emission properties of High-Q micro-cavity lasers based on High-concentration Erbium-doped silica-alumina glasses are presented in detail. The configurations of micro-cavities were spherical and/or modified toroidal forms. The lasing threshold of micro-cavity laser pumped by laser diodes was of hundred micro-watts and Q-factor of cavity had been achieved up-to 10{sup 8} in experiment. The emission power of one whispering-gallery-mode (WGM) lasing from micro-cavity laser was of 0.05-0.5 mW that would be enough for applying in the quantum information and optical sensor techniques. The modified toroidal micro-cavity permits to decrease the polar-mode of WGMs, which help to obtain the single-mode emission from micro-cavity lasers.

  3. Driving factors of carbon dioxide emissions and the impact from Kyoto Protocol

    Energy Technology Data Exchange (ETDEWEB)

    Grunewald, Nicole [Goettingen Univ. (Germany). Dept. of Economics; Martinez-Zarzoso, Inmaculada [Jaume I Univ. (Spain). International Economics Institute

    2009-08-15

    In the last two decades increasing attention has been paid to the relationship between environmental degradation and economic development. According to the Environmental Kuznets Curve (EKC) hypothesis this relationship may be described by an inverted-U curve. However, recent evidence rejects the EKC hypothesis for GHG emissions in a broad sense. In this paper we aim to investigate whether the EKC behavior for CO2 emissions could be proved on the behalf of institutional regulations. We analyze the driving factors of CO2 for developed and developing countries to test the theory of the EKC in the context of environmental regulations using a static and dynamic panel data model. We consider the Kyoto Protocol and the Clean Development Mechanism (CDM). The results from this study indicate that the Kyoto obligations have a reducing effect on CO2 emissions in developed and developing countries. (orig.)

  4. The emission factor of volatile isoprenoids: stress, acclimation, and developmental responses

    Directory of Open Access Journals (Sweden)

    Ü. Niinemets

    2010-07-01

    Full Text Available The rate of constitutive isoprenoid emissions from plants is driven by plant emission capacity under specified environmental conditions (ES, the emission factor and by responsiveness of the emissions to instantaneous variations in environment. In models of isoprenoid emission, ES has been often considered as intrinsic species-specific constant invariable in time and space. Here we analyze the variations in species-specific values of ES under field conditions focusing on abiotic stresses, past environmental conditions and developmental processes. The reviewed studies highlight strong stress-driven, adaptive (previous temperature and light environment and growth CO2 concentration and developmental (leaf age variations in ES values operating at medium to long time scales. These biological factors can alter species-specific ES values by more than an order of magnitude. While the majority of models based on early concepts still ignore these important sources of variation, recent models are including some of the medium- to long-term controls. However, conceptually different strategies are being used for incorporation of these longer-term controls with important practical implications for parameterization and application of these models. This analysis emphasizes the need to include more biological realism in the isoprenoid emission models and also highlights the gaps in knowledge that require further experimental work to reduce the model uncertainties associated with biological sources of variation.

  5. Definition of yearly emission factor of dust and greenhouse gases through continuous measurements in swine husbandry

    Science.gov (United States)

    Costa, Annamaria; Guarino, Marcella

    The object of this study was to develop an accurate estimation method to evaluate the contribution of the various compartments of swine husbandry to dust and GHG (greenhouse gases, CO 2, CH 4 and N 2O) emission into the atmosphere during one year of observation. A weaning, a gestation, a farrowing and a fattening room in an intensive pig house were observed in three different periods (Autumn-Winter, Springtime and Summer, monitoring at least 60% of each period (20% at the beginning, in the middle and at the end) of each cycle). During monitoring, live weight, average live weight gain, number of animals and its variation, type of feed and feeding time were taken into account to evaluate their influence on PM 10, or the fraction of suspended particulate matter with an aerodynamic diameter less than or equal to 10 μm [Emission Inventory Guidebook, 2007. B1100 Particle Emissions from Animal Husbandry Activities. Available from: (accessed October 2008)] and to define GHG emission. The selected piggery had a ventilation control system using a free running impeller to monitor continuously real-time environmental and management parameters with an accuracy of 5%. PM 10 concentration was monitored by a sampler (Haz Dust EPAM 5000), either continuously or through traditional gravimetric technique, and the mean value of dust amount collected on the membranes was utilized as a correction factor to be applied to continuously collected data. PM 10 concentration amount incoming from inlets was removed from PM 10 emission calculation, to estimate the real contribution of pig house dust pollution into atmosphere. Mean yearly emission factor of PM 10 was measured in 2 g d -1 LU -1 for the weaning room, 0.09 g d -1 LU -1 for the farrowing room, 2.59 g d -1 LU -1 for the fattening room and 1.23 g d -1 LU -1 for the gestation room. The highest PM 10 concentration and emission per LU was recorded in the fattening compartment while the lowest value was recorded in the farrowing room. CO

  6. Analysis of energy-related CO2 emissions and driving factors in five major energy consumption sectors in China.

    Science.gov (United States)

    Cui, Erqian; Ren, Lijun; Sun, Haoyu

    2016-10-01

    Continual growth of energy-related CO2 emissions in China has received great attention, both domestically and internationally. In this paper, we evaluated the CO2 emissions in five major energy consumption sectors which were evaluated from 1991 to 2012. In order to analyze the driving factors of CO2 emission change in different sectors, the Kaya identity was extended by adding several variables based on specific industrial characteristics and a decomposition analysis model was established according to the LMDI method. The results demonstrated that economic factor was the leading force explaining emission increase in each sector while energy intensity and sector contribution were major contributors to emission mitigation. Meanwhile, CO2 emission intensity had no significant influence on CO2 emission in the short term, and energy consumption structure had a small but growing negative impact on the increase of CO2 emissions. In addition, the future CO2 emissions of industry from 2013 to 2020 under three scenarios were estimated, and the reduction potential of CO2 emissions in industry are 335 Mt in 2020 under lower-emission scenario while the CO2 emission difference between higher-emission scenario and lower-emission scenario is nearly 725 Mt. This paper can offer complementary perspectives on determinants of energy-related CO2 emission change in different sectors and help to formulate mitigation strategies for CO2 emissions.

  7. Particulate emission factors for mobile fossil fuel and biomass combustion sources.

    Science.gov (United States)

    Watson, John G; Chow, Judith C; Chen, L-W Antony; Lowenthal, Douglas H; Fujita, Eric M; Kuhns, Hampden D; Sodeman, David A; Campbell, David E; Moosmüller, Hans; Zhu, Dongzi; Motallebi, Nehzat

    2011-05-15

    PM emission factors (EFs) for gasoline- and diesel-fueled vehicles and biomass combustion were measured in several recent studies. In the Gas/Diesel Split Study (GD-Split), PM(2.5) EFs for heavy-duty diesel vehicles (HDDV) ranged from 0.2 to ~2 g/mile and increased with vehicle age. EFs for HDDV estimated with the U.S. EPA MOBILE 6.2 and California Air Resources Board (ARB) EMFAC2007 models correlated well with measured values. PM(2.5) EFs measured for gasoline vehicles were ~two orders of magnitude lower than those for HDDV and did not correlate with model estimates. In the Kansas City Study, PM(2.5) EFs for gasoline-powered vehicles (e.g., passenger cars and light trucks) were generally fuel, corresponding to 0.3 and 2 g/mile, respectively. These values are comparable to those of on-road HDDV. EFs for biomass burning measured during the Fire Laboratory at Missoula Experiment (FLAME) were compared with EFs from the ARB Emission Estimation System (EES) model. The highest PM(2.5) EFs (76.8±37.5 g/kg) were measured for wet (>50% moisture content) Ponderosa Pine needles. EFs were generally fuels with low moisture content but underestimated measured EFs for fuel with moisture content >40%. Average EFs for dry chamise, rice straw, and dry grass were within a factor of three of values adopted by ARB in California's San Joaquin Valley (SJV). Discrepancies between measured and modeled emission factors suggest that there may be important uncertainties in current PM(2.5) emission inventories.

  8. Traffic induced particle resuspension in Paris: Emission factors and source contributions

    Science.gov (United States)

    Amato, F.; Favez, O.; Pandolfi, M.; Alastuey, A.; Querol, X.; Moukhtar, S.; Bruge, B.; Verlhac, S.; Orza, J. A. G.; Bonnaire, N.; Le Priol, T.; Petit, J.-F.; Sciare, J.

    2016-03-01

    Gaining knowledge on the process of particle resuspension from urban paved roads is of particular importance considering the increasing relevance of this source in urban air quality management and the lack of basic information on emission factors and source contributions. In this study we performed extensive field measurements for the quantification of the emission factors from different types of road in the city of Paris, and investigated the causes of their variability and the contributions to the ambient air PM10 observed across one year at one traffic monitoring site in the ring road of Paris. Results show agreement between lower road dust loadings (RD10: 0.7-2.2 mg m-2) and emission factors (5.4-9.0 mg vehicle-1 km-1) at inner-roads of Paris, compared to the ring road (2.4 mg m-2 and 17 mg vehicle-1 km-1, respectively), where the two parameters are estimated independently. The higher values in the ring road were likely caused by the poor state of pavement and higher share of heavy duty vehicles. Road wear, brake wear and a carbonaceous source, were almost equally responsible for 96% of RD10. At the traffic monitoring site located at the ring road (220,000 vehicle/day), the contributions of road dust emissions were estimated by receptor modeling to be 13% of PM10 on an annual mean (6.3 μg m-3), while the sum of vehicle exhaust and wear accounted for 47% resulting in a total traffic contribution of 60% of PM10. Road salting resulted to be a minor contributor (1% of annual mean) also in winter time (2%).

  9. Direct Nitrous Oxide Emissions From Tropical And Sub-Tropical Agricultural Systems - A Review And Modelling Of Emission Factors

    Science.gov (United States)

    Albanito, Fabrizio; Lebender, Ulrike; Cornulier, Thomas; Sapkota, Tek B.; Brentrup, Frank; Stirling, Clare; Hillier, Jon

    2017-03-01

    There has been much debate about the uncertainties associated with the estimation of direct and indirect agricultural nitrous oxide (N2O) emissions in developing countries and in particular from tropical regions. In this study, we report an up-to-date review of the information published in peer-review journals on direct N2O emissions from agricultural systems in tropical and sub-tropical regions. We statistically analyze net-N2O-N emissions to estimate tropic-specific annual N2O emission factors (N2O-EFs) using a Generalized Additive Mixed Model (GAMM) which allowed the effects of multiple covariates to be modelled as linear or smooth non-linear continuous functions. Overall the mean N2O-EF was 1.2% for the tropics and sub-tropics, thus within the uncertainty range of IPCC-EF. On a regional basis, mean N2O-EFs were 1.4% for Africa, 1.1%, for Asia, 0.9% for Australia and 1.3% for Central & South America. Our annual N2O-EFs, estimated for a range of fertiliser rates using the available data, do not support recent studies hypothesising non-linear increase N2O-EFs as a function of applied N. Our findings highlight that in reporting annual N2O emissions and estimating N2O-EFs, particular attention should be paid in modelling the effect of study length on response of N2O.

  10. Savanna burning methodology for fire management and emissions reduction: a critical review of influencing factors.

    Science.gov (United States)

    Maraseni, Tek Narayan; Reardon-Smith, Kathryn; Griffiths, Greg; Apan, Armando

    2016-12-01

    Savanna fire is a major source of global greenhouse gas (GHG) emissions. In Australia, savanna fire contributes about 3% of annual GHG emissions reportable to the Kyoto Protocol. In order to reduce GHG emissions from savanna burning, the Australian government has developed and approved a Kyoto compliant savanna controlled burning methodology-the first legal instrument of this kind at a global level-under its Emission Reduction Fund. However, this approved methodology is currently only applicable to nine vegetation fuel types across northern parts of Australia in areas which receive on average over 600 mm rainfall annually, covering only 15.4% of the total land area in Australia. Savanna ecosystems extend across a large proportion of mainland Australia. This paper provides a critical review of ten key factors that need to be considered in developing a savanna burning methodology applicable to the other parts of Australia. It will also inform discussion in other countries intent on developing similar emissions reduction strategies.

  11. Magnetic Field Emission Comparison at Different Quality Factors with Series-Parallel Compensation Network for Wireless Power Transfer to Vehicles

    DEFF Research Database (Denmark)

    Batra, Tushar; Schaltz, Erik

    2014-01-01

    Input current of wireless power transfer system is limited by current rating of power converter on the primary side. Power rating of wireless power transfer system increases linearly with the quality factor for series-parallel topology of the system at a given primary current. Magnetic emissions...... increase in the power rating with the quality factor. This paper signifies that at fixed primary current, operation of wireless power transfer system at higher quality factor is favorable with respect to the magnetic emissions....... to the surroundings also increase with increase in the quality factor. In this paper, first analytical expressions are developed for comparing magnetic emissions at different quality factors. Theoretical and simulation (Comsol) results show comparatively lower increase for the magnetic field emissions to the linear...

  12. Are emissions of black carbon from gasoline vehicles overestimated? Real-time, in situ measurement of black carbon emission factors.

    Science.gov (United States)

    Wang, Yang; Xing, Zhenyu; Zhao, Shuhui; Zheng, Mei; Mu, Chao; Du, Ke

    2016-03-15

    Accurately quantifying black carbon (BC) emission factors (EFs) is a prerequisite for estimation of BC emission inventory. BC EFs determined by measuring BC at the roadside or chasing a vehicle on-road may introduce large uncertainty for low emission vehicles. In this study, BC concentrations were measured inside the tailpipe of gasoline vehicles with different engine sizes under different driving modes to determine the respective EFs. BC EFs ranged from 0.005-7.14 mg/kg-fuel under the speeds of 20-70 km/h, 0.05-28.95 mg/kg-fuel under the accelerations of 0.5-1.5m/s(2). Although the water vapor in the sampling stream could result in an average of 12% negative bias, the BC EFs are significantly lower than the published results obtained with roadside or chasing vehicle measurement. It is suggested to conduct measurement at the tailpipe of gasoline vehicles instead of in the atmosphere behind the vehicles to reduce the uncertainty from fluctuation in ambient BC concentration. Copyright © 2015 Elsevier B.V. All rights reserved.

  13. Post-disturbance dust emissions in dry lands: the role of anthropogenic and climatic factors

    Science.gov (United States)

    Ravi, S.; Zobeck, T. M.; Sankey, J. B.

    2012-12-01

    Disturbances, which cause a temporary reduction in vegetation cover, can greatly accelerate soil erosion by wind and subsequent dust emissions from desert grasslands and shrublands. These ecosystems worldwide are threatened by contemporary shifts in vegetation composition (e.g. encroachment by shrubs, invasion by exotic grasses) and climatic changes (e.g. increase in aridity, droughts), which alter the frequency and intensity of disturbances and dust emissions. Considering the deleterious impact of dust-borne contaminants on regional air quality and human health, accelerated post-disturbance aeolian transport is an increasingly serious concern for ecosystem management and risk assessment. Here, using extensive wind tunnel studies, field experiments (in grasslands and shrublands of North America) and modeling, we investigated the role of disturbances (fires, grazing) and changes in hydroclimatic factors (air humidity, soil moisture) in altering aeolian processes in desert grassland and shrublands. Our results indicate that the degree of post-disturbance aeolian transport and its attenuation with time was found to be strongly affected by the antecedent vegetation type and post-disturbance climatic conditions. The interactions among sediment transport processes, disturbances and hydroclimatic factors are explored from patch to landscape scales and their roles in dust emissions and land degradation are discussed.

  14. Field Derived Emission Factors For Formaldehyde and other Volatile Organic Compounds in FEMA Temporary Housing Units

    Energy Technology Data Exchange (ETDEWEB)

    Parthasarathy, Srinandini; Maddalena, Randy L.; Russell, Marion L.; Apte, Michael G.

    2010-10-01

    Sixteen previously occupied temporary housing units (THUs) were studied to assess emissions of volatile organic compounds. The whole trailer emission factors wereevaluated for 36 VOCs including formaldehyde. Indoor sampling was carried out in the THUs located in Purvis staging yard in Mississippi, USA. Indoor temperature andrelative humidity (RH) were also measured in all the trailers during sampling. Indoor temperatures were varied (increased or decreased) in a selection of THUs using theheating, ventilation and air conditioning (HVAC) systems. Indoor temperatures during sampling ranged from 14o C to 33o C, and relative humidity (RH) varied between 35percentand 74percent. Ventilation rates were increased in some trailers using bathroom fans and vents during some of the sampling events. Ventilation rates measured during some aselection of sampling events varied from 0.14 to 4.3 h-1. Steady state indoor formaldehyde concentrations ranged from 10 mu g-m-3 to 1000 mu g-m-3. The formaldehyde concentrations in the trailers were of toxicological significance. The effects of temperature, humidity and ventilation rates were also studied. A linearregression model was built using log of percentage relative humidity, inverse of temperature (in K-1), and inverse log ACH as continuous independent variables, trailermanufacturer as a categorical independent variable, and log of the chemical emission factors as the dependent variable. The coefficients of inverse temperature, log relativehumidity, log inverse ACH with log emission factor were found to be statistically significant for all the samples at the 95percent confidence level. The regression model wasfound to explain about 84percent of the variation in the dependent variable. Most VOC concentrations measured indoors in the Purvis THUs were mostly found to be belowvalues reported in earlier studies by Maddalena et al.,1,2 Hodgson et al.,3 and Hippelein4. Emissions of TMPB-DIB (a plasticizer found in vinyl products) were found

  15. Magnetic field emission comparison at different quality factors with series-series compensation network for inductive power transfer to vehicles

    DEFF Research Database (Denmark)

    Batra, Tushar; Schaltz, Erik

    2014-01-01

    Inductive power transfer is non-contact transfer of energy by means of magnetic fields. A higher secondary side quality factor at fixed input current ensures a linear increase in power transfer across the air gap. But also at the same time magnetic emissions to the surroundings increase. First...... of all in this paper an analytic expression for comparing the magnetic emissions at different quality factors is introduced. It is shown with help of simulations on Comsol that emissions have a lower increase as compared to linear increase in the power transferred with the quality factor as suggested...

  16. Magnetic field emission comparison at different quality factors with series-series compensation network for inductive power transfer to vehicles

    DEFF Research Database (Denmark)

    Batra, Tushar; Schaltz, Erik

    2014-01-01

    Inductive power transfer is non-contact transfer of energy by means of magnetic fields. A higher secondary side quality factor at fixed input current ensures a linear increase in power transfer across the air gap. But also at the same time magnetic emissions to the surroundings increase. First...... of all in this paper an analytic expression for comparing the magnetic emissions at different quality factors is introduced. It is shown with help of simulations on Comsol that emissions have a lower increase as compared to linear increase in the power transferred with the quality factor as suggested...

  17. Emission-factor uncertainties in maritime transport in the Strait of Gibraltar, Spain

    Directory of Open Access Journals (Sweden)

    J. Moreno-Gutiérrez

    2012-08-01

    Full Text Available A reliable and up-to-date maritime emission inventory is essential for atmospheric scientists quantifying the impact of shipping. The objective of this study is to estimate the atmospheric emissions of SO2, NOx, CO2 and PM10 by international merchant shipping in 2007 in the Strait of Gibraltar, Spain, including the Algeciras Bay by two methods.

    Two methods (both bottom-up have been used in this study:

    1. Establishing engine power-based emission factors (g kWh−1, EPA or the mass of pollutant per work performed by the engine for each of the relevant components of the exhaust gas from diesel engines and power for each ship.

    2. Establishing fuel-based emission factors (kg emitted/t of fuel or mass of pollutant per mass of combusted fuel for each of the relevant components of the exhaust gas and a fuel-consumption inventory (IMO.

    In both methods, the means to estimate engine power and fuel-consumption inventories are the same. The exhaust from boilers and incinerators is regarded as a small contributor and excluded. In total, an estimated average of 1 389 111.05 t of CO2, 23 083.09 t of SO2, 32 005.63 t of NOx and 2972 t of PM10 were emitted from January 2007 until December 2007 by international and domestic shipping. The estimated total fuel consumption amounts to 437 405.84 t. The major differences between the estimates generated by the two methods are for NOx (16% in certain cases and CO (up to 23%.

    A total difference for all compounds of 3038 t (approximately 2% has been found between the two methods but it is not areasonable estimate of uncertainty.

    Therefore, the results for both methods may be considered acceptable because the actual uncontrolled deviations appear in the changes in emission factors that occur for a given engine with age. These deviations are often difficult to

  18. Influence of natural and anthropogenic factors on the dynamics of CO2 emissions from chernozems soil

    Science.gov (United States)

    Syabruk, Olesia

    2017-04-01

    Twentieth century marked a significant expansion of agricultural production. Soil erosion caused by human activity, conversion of forests and grasslands to cropland, desertification, burning nutrient residues, drainage, excessive cultivation led to intense oxidation of soil carbon to the atmosphere and allocation of additional amounts of CO2. According to the UN Intergovernmental Panel on Climate Change, agriculture is one of the main sources of greenhouse gases emissions to the atmosphere. The thesis reveals main patterns of the impact of natural and anthropogenic factors on CO2 emissions in the chernozems typical and podzolized in a Left-bank Forest-Steppe of Ukraine, seasonal and annual dynamics. New provisions for conducting monitoring CO2 emissions from soil were developed by combining observations in natural and controlled conditions, which allows isolating the impact of hydrological, thermal and trophic factors. During the research, the methods for operational monitoring of emission of carbon losses were improved, using a portable infrared gas analyzer, which allows receiving information directly in the field. It was determined that the volumes of emission losses of carbon chernozems typical and podzolized Left-bank Forest-Steppe of Ukraine during the growing season are 480-910 kg/ha and can vary depending on the soil treatment ±( 4,0 - 6,0) % and fertilizer systems ± (3,8 - 7,1) %. The significant impact of long application of various fertilizer systems and soil treatment on the intensity of carbon dioxide emissions was investigated. It was found that most emission occurs in organic- mineral fertilizers systems with direct seeding. The seasonal dynamics of the potential capacity of the soil to produce CO2 were researched. Under identical conditions of humidity and temperature it has maximum in June and July and the gradual extinction of the autumn. It was determined that the intensity of the CO2 emission from the surface of chernozem fluctuates daily from

  19. Comparison of road traffic emission factors and testing by comparison of modelled and measured ambient air quality data.

    Science.gov (United States)

    Peace, H; Owen, B; Raper, D W

    2004-12-01

    This paper describes a comparison of three different sets of road traffic emission factors released by the UK government for use in air quality review and assessment. The air quality management process of review and assessment began in 1997 in the UK. During this period of ongoing review and assessment, a number of changes have been made to the emission factors provided by the government. The use of different sets of emission factors during the assessment process has lead to some inconsistencies between results from neighbouring local authorities and also between different modelling exercises undertaken by the same local authorities. One purpose of this study has been to compare three different sets of emission factors, including the most recent set, and to some degree highlight the uncertainty associated with the use of factors, such as the shift of emphasis in terms of emissions from cars to heavy goods vehicles. The most recently released emission factors are the most comprehensive to date, and theoretically more accurate than previous sets due to the larger database of emission measurements that they have been based on. Therefore, the most recent set of emission factors have been additionally used in a validation exercise between modelled and monitored data. Comparison has been undertaken with monitoring data at a variety of urban background, urban centre and roadside sites. This work has shown some differences between the predicted trends in emission factors and measured trends in ambient air pollution levels, especially at roadside sites, indicating an under-prediction of the air pollution contribution from road traffic.

  20. Real-world traffic emission factors of gases and particles measured in a road tunnel in Stockholm, Sweden

    Science.gov (United States)

    Kristensson, Adam; Johansson, Christer; Westerholm, Roger; Swietlicki, Erik; Gidhagen, Lars; Wideqvist, Ulla; Vesely, Vaclav

    Measurements in a road tunnel in Stockholm, Sweden give the real-world traffic emission factors for a number of gaseous and particle pollutants. These include 49 different polycyclic aromatic hydrocarbons (PAH), CO, NO X, benzene, toluene, xylenes, aldehydes, elements and inorganic/organic carbon contained in particles, the sub-micrometer aerosol number size distribution, PM 2.5 and PM 10. The exhaust pipe emission factors are divided with the help of automated traffic counts into the two pollutant sources, the heavy-duty vehicles (HDV) and light-duty vehicles (LDV). The LDV fleet contains 95% petrol cars and the total fleet contains about 5% HDV. When data permitted, the emission factors were further calculated at different vehicle speeds. The current work shows that average CO, NO X and benzene emission factors amounted to 5.3, 1.4 and 0.017 g veh -1 km -1, respectively. Since the mid-90s CO and benzene decreased by about 15%, carbonyls by about a factor 2, whereas NO X did not change much. PAH emission factors were 2-15 times higher than found during dynamometer tests. Most particles are distributed around 20 nm diameter and the LDV fleet contributes to about 65% of both PM and particle number. In general, the gaseous emissions are higher in Sweden than in USA and Switzerland, foremost due to the lower fraction catalytic converters in Sweden. The PM and number emissions of particles are also slightly higher in the Swedish tunnel.

  1. The Covering Factor of Warm Dust in Weak Emission-Line Active Galactic Nuclei

    CERN Document Server

    Zhang, Xudong

    2016-01-01

    Weak emission-line active galactic nuclei (WLAGNs) are radio-quiet active galactic nuclei (AGNs) that have nearly featureless optical spectra. We investigate the ultraviolet to mid-infrared spectral energy distributions of 73 WLAGNs (0.4factor of warm dust of these 73 WLAGNs. No significant difference is indicated by a KS test between the covering factor of WLAGNs and normal AGNs in the common range of bolometric luminosity. The implication for several models of WLAGNs is discussed. The super-Eddington accretion is unlikely the dominant reason for the featureless spectrum of a WLAGN. The present results favor the evolution scenario, i.e., WLAGNs are in a special stage of AGNs.

  2. Behavioral analysis of EPA`s MOBILE emission factor model. Discussion paper

    Energy Technology Data Exchange (ETDEWEB)

    Harrington, W.; McConnell, V.D.; Cannon, M.

    1998-06-01

    This report provides a review and assessment of several important aspects of the MOBILE model, EPA`s computer model for estimating emission factors for mobile sources. Inventory models like MOBILE have many uses, but the authors focus primarily on the Model`s role for estimation of emission reduction credits from I/M [Inspection/Maintenance] programs. The authors concentrate on how the model incorporates behavioral responses to I/M regulations. The effectiveness of I/M programs in practice are likely to be strongly influenced by the behavior of motorists, mechanics and even state regulatory authorities. In addition to an examination of model structure and assumptions, the authors examine the empirical data used to calibrate the model, much of which is hard coded and not amenable to change by users. Finally, the authors test the sensitivity of MOBILE results to certain assumptions with behavioral content.

  3. Risk factors for distortion product otoacoustic emissions in young men with normal hearing.

    Science.gov (United States)

    Torre, Peter; Dreisbach, Laura E; Kopke, Richard; Jackson, Ron; Balough, Ben

    2007-10-01

    The purpose of this study was to evaluate the possible effects of risk factors on distortion product otoacoustic emissions (DPOAEs) in young adult men with normal hearing. Four hundred thirty-six United States Marine recruit men (mean age = 19.2 years +/- 1.8 years; age range = 17-29 years) participated in this study. Questionnaires were given to each recruit to obtain demographic data and history of noise exposure, solvent exposure, smoking history, and hearing-related histories. Otoscopy, tympanometry, pure-tone air-conduction audiometry (2.0-8.0 kHz) and DPOAEs (2.3-8.0 kHz) were measured. DPOAE levels were lower in Not Hispanic or Latino recruits, in heavy smokers, in recruits who reported loud live music exposure and ringing in their ears after noise exposure. These differences were not statistically significant at all frequencies. Recruits with multiple risk factors had the lowest DPOAEs as compared to recruits with fewer, or no, risk factors; these differences were not statistically significant. Obtaining risk factor data as part of an audiometric evaluation is important even though the individual may have normal hearing.

  4. Field Measurements of Gasoline Direct Injection Emission Factors: Spatial and Seasonal Variability.

    Science.gov (United States)

    Zimmerman, Naomi; Wang, Jonathan M; Jeong, Cheol-Heon; Ramos, Manuel; Hilker, Nathan; Healy, Robert M; Sabaliauskas, Kelly; Wallace, James S; Evans, Greg J

    2016-02-16

    Four field campaigns were conducted between February 2014 and January 2015 to measure emissions from light-duty gasoline direct injection (GDI) vehicles (2013 Ford Focus) in an urban near-road environment in Toronto, Canada. Measurements of CO2, CO, NOx, black carbon (BC), benzene, toluene, ethylbenzene-xylenes (BTEX), and size-resolved particle number (PN) were recorded 15 m from the roadway and converted to fuel-based emission factors (EFs). Other than for NOx and CO, the GDI engine had elevated emissions compared to the Toronto fleet, with BC EFs in the 73rd percentile, BTEX EFs in the 80-90th percentile, and PN EFs in the 75th percentile during wintertime measurements. Additionally, for three campaigns, a second platform for measuring PN and CO2 was placed 1.5-3 m from the roadway to quantify changes in PN with distance from point of emission. GDI vehicle PN EFs were found to increase by up to 240% with increasing distance from the roadway, predominantly due to an increasing fraction of sub-40 nm particles. PN and BC EFs from the same engine technology were also measured in the laboratory. BC EFs agreed within 20% between the laboratory and real-world measurements; however, laboratory PN EFs were an order of magnitude lower due to exhaust conditioning.

  5. Emission factors of polycyclic aromatic hydrocarbons from domestic coal combustion in China.

    Science.gov (United States)

    Geng, Chunmei; Chen, Jianhua; Yang, Xiaoyang; Ren, Lihong; Yin, Baohui; Liu, Xiaoyu; Bai, Zhipeng

    2014-01-01

    Domestic coal stove is widely used in China, especially for countryside during heating period of winter, and polycyclic aromatic hydrocarbons (PAHs) are important in flue gas of the stove. By using dilution tunnel system, samples of both gaseous and particulate phases from domestic coal combustion were collected and 18 PAH species were analyzed by GC-MS. The average emission factors of total 18 PAH species was 171.73 mg/kg, ranging from 140.75 to 229.11 mg/kg for bituminous coals, while was 93.98 mg/kg, ranging from 58.48 to 129.47 mg/kg for anthracite coals. PAHs in gaseous phases occupied 95% of the total of PAHs emission of coal combustion. In particulate phase, 3-ring and 4-ring PAHs were the main components, accounting for 80% of the total particulate PAHs. The total toxicity potency evaluated by benzo[a]pyrene-equivalent carcinogenic power, sum of 7 carcinogenic PAH components and 2,3,7,8-tetrachlorodibenzodioxin had a similar tendency. And as a result, the toxic potential of bituminous coal was higher than that of anthracite coal. Efficient emission control should be conducted to reduce PAH emissions in order to protect ecosystem and human health.

  6. Emission factors and source apportionment for abrasion particles produced by road traffic

    Science.gov (United States)

    Bukowiecki, N.; Lienemann, P.; Figi, R.; Hill, M.; Richard, A.; Furger, M.; Rickers, K.; Cliff, S. S.; Baltensperger, U.; Gehrig, R.

    2009-04-01

    Particle emissions of road traffic are generally associated with fresh exhaust emissions only. However, recent studies identified a clear contribution of non-exhaust emissions to the PM10 load of the ambient air. These emissions consist of particles produced by abrasion from brakes, road wear, tire wear, as well as resuspension of deposited road dust. For many urban environments, quantitative information about the contributions of the individual abrasion processes is still scarce. For effective PM10 reduction scenarios it is of particular interest to know whether road wear, resuspension or fresh abrasion from vehicles is dominating the non-exhaust PM10 contribution. In Switzerland, the emissions of road traffic abrasion particles into the ambient air were characterized in the project APART (Abrasion Particles produced by Road Traffic). The project aimed at finding the contribution of the non-exhaust sources to total traffic-related PM10 and PM2.5 for different traffic conditions, by determining specific elemental fingerprint signatures for the various sources. This was achieved by hourly elemental mass concentration measurements in three size classes (2.5-10, 1-2.5 and 0.1-1 micrometers) with a rotating drum impactor (RDI) and subsequent synchrotron radiation X-ray fluorescence spectrometry (SR-XRF). The elemental fingerprint measurements were embedded into a large set of aerosol, gas phase, meteorological and traffic count measurements. To identify traffic related emissions, measurements were performed upwind and downwind of selected roads. For a better investigation of road wear, a road wear simulator was applied in additional experiments. This allows for the identification and quantification of the different source contributions by means of source-receptor modeling, and for the calculation of real-world emission factors for the individual abrasion sources. The preliminary analysis of hourly resolved trace element measurements in a street canyon in Zürich showed

  7. Field determination of multipollutant, open area combustion source emission factors with a hexacopter unmanned aerial vehicle

    Science.gov (United States)

    Aurell, J.; Mitchell, W.; Chirayath, V.; Jonsson, J.; Tabor, D.; Gullett, B.

    2017-10-01

    An emission sensor/sampler system was coupled to a National Aeronautics and Space Administration (NASA) hexacopter unmanned aerial vehicle (UAV) to characterize gases and particles in the plumes emitted from open burning of military ordnance. The UAV/sampler was tested at two field sites with test and sampling flights spanning over 16 h of flight time. The battery-operated UAV was remotely maneuvered into the plumes at distances from the pilot of over 600 m and at altitudes of up to 122 m above ground level. While the flight duration could be affected by sampler payload (3.2-4.6 kg) and meteorological conditions, the 57 sampling flights, ranging from 4 to 12 min, were typically terminated when the plume concentrations of CO2 were diluted to near ambient levels. Two sensor/sampler systems, termed ;Kolibri,; were variously configured to measure particulate matter, metals, chloride, perchlorate, volatile organic compounds, chlorinated dioxins/furans, and nitrogen-based organics for determination of emission factors. Gas sensors were selected based on their applicable concentration range, light weight, freedom from interferents, and response/recovery times. Samplers were designed, constructed, and operated based on U.S. Environmental Protection Agency (EPA) methods and quality control criteria. Results show agreement with published emission factors and good reproducibility (e.g., 26% relative standard deviation for PM2.5). The UAV/Kolibri represents a significant advance in multipollutant emission characterization capabilities for open area sources, safely and effectively making measurements heretofore deemed too hazardous for personnel or beyond the reach of land-based samplers.

  8. Emission factors for carbonaceous particles and polycyclic aromatic hydrocarbons from residential coal combustion in China.

    Science.gov (United States)

    Chen, Yingjun; Sheng, Guoying; Bi, Xinhui; Feng, Yanli; Mai, Bixian; Fu, Jiamo

    2005-03-15

    Emission factors of carbonaceous particles, including black carbon (BC) and organic carbon (OC), and polycyclic aromatic hydrocarbons (PAHs) were determined for five coals, which ranged in maturity from sub-bituminous to anthracite. They were burned in the form of honeycomb briquettes in a residential coalstove, one of the most common fuel/stove combinations in China. Smoke samples were taken through dilution sampling equipment, with a high volume sampler that could simultaneously collect emissions in both particulate and gaseous phases, and a cascade impactor that could segregate particles into six fractions. Particulate BC and OC were analyzed by a thermal-optical method, and PAHs in emissions of both phases were analyzed by GC-MS. Burning of bituminous coals produced the highest emission factors of particulate matter (12.91 g/kg), BC (0.28 g/kg), OC (7.82 g/kg), and 20 PAHs (210.6 mg/kg) on the basis of burned dry ash-free (daf) coal, while the anthracite honeycomb-briquette was the cleanest household coal fuel. The size-segregated results show that more than 94% of the particles were submicron, and calculated mass median aerodynamic diameters (MMAD) of all particles were under 0.3 microm. Based on the coal consumption in the residential sector of China, 290.24 Gg (gigagrams) of particulate matter, 5.36 Gg of BC, 170.33 Gg of OC, and 4.72 Gg of 20 PAHs mass were emitted annually from household honeycomb-briquette burning during 2000. Anthracite coal should be selected preferentially and more advanced burning conditions should be applied in domestic combustion, from the viewpoint of both climate change and adverse health effects.

  9. [Mercury Distribution Characteristics and Atmospheric Mercury Emission Factors of Typical Waste Incineration Plants in Chongqing].

    Science.gov (United States)

    Duan, Zhen-ya; Su, Hai-tao; Wang, Feng-yang; Zhang, Lei; Wang, Shu-xiao; Yu, Bin

    2016-02-15

    Waste incineration is one of the important atmospheric mercury emission sources. The aim of this article is to explore the atmospheric mercury pollution level of waste incineration industry from Chongqing. This study investigated the mercury emissions from a municipal solid waste incineration plant and a medical waste incineration plant in Chongqing. The exhaust gas samples in these two incineration plants were obtained using USA EPA 30B method. The mercury concentrations in the fly ash and bottom ash samples were analyzed. The results indicated that the mercury concentrations of the municipal solid waste and medical waste incineration plant in Chongqing were (26.4 +/- 22.7) microg x m(-3) and (3.1 +/- 0.8) microg x m(-3) in exhaust gas respectively, (5279.2 +/- 798.0) microg x kg(-1) and (11,709.5 +/- 460.5) microg x kg(-1) in fly ash respectively. Besides, the distribution proportions of the mercury content from municipal solid waste and medical waste in exhaust gas, fly ash, and bottom ash were 34.0%, 65.3%, 0.7% and 32.3%, 67.5%, 0.2% respectively; The mercury removal efficiencies of municipal solid waste and medical waste incineration plants were 66.0% and 67.7% respectively. The atmospheric mercury emission factors of municipal solid waste and medical waste incineration plants were (126.7 +/- 109.0) microg x kg(-1) and (46.5 +/- 12.0) microg x kg(-1) respectively. Compared with domestic municipal solid waste incineration plants in the Pearl River Delta region, the atmospheric mercury emission factor of municipal solid waste incineration plant in Chongqing was lower.

  10. Nitrous oxide emissions from soils amended by cover-crops and under plastic film mulching: Fluxes, emission factors and yield-scaled emissions

    Science.gov (United States)

    Kim, Gil Won; Das, Suvendu; Hwang, Hyun Young; Kim, Pil Joo

    2017-03-01

    Assessment of nitrous oxide (N2O) emission factor (EF) for N2O emission inventory from arable crops fertilized with different nitrogen sources are under increased scrutiny because of discrepancies between the default IPCC EFs and low EFs reported by many researchers. Mixing ratio of leguminous and non-leguminous cover crop residues incorporation and plastic film mulching (PFM) in upland soil has been recommended as a vital agronomic practice to enhance yield and soil quality. However, how these practices together affect N2O emissions, yield-scaled emissions and the EFs remain uncertain. Field experiments spanning two consecutive years were conducted to evaluate the effects of PFM on N2O emissions, yield-scaled emissions and the seasonal EFs in cover crop residues amended soil during maize cultivation. The mixture of barley (Hordeum vulgare) and hairy vetch (Vicia villosa) seeds with 75% recommended dose (RD 140 kg ha-1) and 25% recommended dose (RD 90 kg ha-1), respectively, were broadcasted during the fallow period and 0, 25, 50 and 100% of the total aboveground harvested biomass that correspond to 0, 76, 152 and 304 kg N ha-1 were incorporated before maize transplanting. It was found that the mean seasonal EFs from cover crop residues amended soil under No-mulching (NM) and PFM were 1.13% (ranging from 0.81 to 1.23%) and 1.49% (ranging from 1.02 to 1.63%), respectively, which are comparable to the IPCC (2006) default EF (1%) for emission inventories of N2O from crop residues. The emission fluxes were greatly influenced by NH4+sbnd N, NO3--N, DOC and DON contents of soil. The cumulative N2O emissions markedly increased with the increase in cover crop residues application rates and it was more prominent under PFM than under NM. However, the yield-scaled emissions markedly decreased under PFM compared to NM due to the improved yield. With relatively low yield-scaled N2O emissions, 25% biomass mixing ratio of barley and hairy vetch (76 kg N ha-1) under PFM could be

  11. 40 CFR 63.5796 - What are the organic HAP emissions factor equations in Table 1 to this subpart, and how are they...

    Science.gov (United States)

    2010-07-01

    ... Emissions Factors for Open Molding and Centrifugal Casting § 63.5796 What are the organic HAP emissions... factors. Equations are available for each open molding operation and centrifugal casting operation...

  12. Emission factors for PCDD/PCDF and dl-PCB from open burning of biomass.

    Science.gov (United States)

    Black, R R; Meyer, C P Mick; Touati, A; Gullett, B K; Fiedler, H; Mueller, J F

    2012-01-01

    The Stockholm Convention on Persistent Organic Pollutants includes in its aims the minimisation of unintentional releases of polychlorinated dibenzo-dioxins and dibenzofurans (PCDD/PCDF) and dioxin like PCB (dl-PCB) to the environment. Development and implementation of policies to achieve this aim require accurate national inventories of releases of PCDD/PCDF/dl-PCB. To support this objective, the Conference of Parties established a process to review and update the UNEP Standardized Toolkit for Identification and Quantification of Dioxin and Furan Releases. An assessment of all emission inventories was that for many countries open burning of biomass and waste was identified as the major source of PCDD/PCDF releases. However, the experimental data underpinning the release estimates used were limited in number and, consequently, confidence in the accuracy of the emissions predictions was low. There has been significant progress in measurement technology since the last edition of the Toolkit in 2005. In this paper we reassess published emission factors for release of PCDD/PCDF and dl-PCB to land and air. In total, four types of biomass and 111 emission factors were assessed. It was found that there are no systematic differences in emission factors apparent between biomass types or fire classes. The data set is best described by a lognormal distribution. The geometric mean emission factors (EFs) for releases of PCDD/PCDF to air for the four biomass classes used in the Toolkit (sugarcane, cereal crops, forest and savannah/grass) are 1.6μg TEQ (t fuel)(-1), 0.49μg TEQ (t fuel)(-1), 1.0μg TEQ (t fuel)(-1) and 0.4μg TEQ (t fuel)(-1), respectively. Corresponding EFs for release of PCDD/PCDF to land are 3.0ng TEQ (kg ash)(-1), 1.1ng TEQ (kg ash)(-1), 1.1ng TEQ (kg ash)(-1) and 0.67ng TEQ (kg ash)(-1). There are now also sufficient published data available to evaluate EFs for dl-PCB release to air for sugarcane, forest and grass/savannah; these are 0.03μg TEQ (t fuel)(-1

  13. Emission factors and light absorption properties of brown carbon from household coal combustion in China

    Science.gov (United States)

    Sun, Jianzhong; Zhi, Guorui; Hitzenberger, Regina; Chen, Yingjun; Tian, Chongguo; Zhang, Yayun; Feng, Yanli; Cheng, Miaomiao; Zhang, Yuzhe; Cai, Jing; Chen, Feng; Qiu, Yiqin; Jiang, Zhiming; Li, Jun; Zhang, Gan; Mo, Yangzhi

    2017-04-01

    Brown carbon (BrC) draws increasing attention due to its effects on climate and other environmental factors. In China, household coal burned for heating and cooking purposes releases huge amounts of carbonaceous particles every year; however, BrC emissions have rarely been estimated in a persuasive manner due to the unavailable emission characteristics. Here, seven coals jointly covering geological maturity from low to high were burned in four typical stoves as both chunk and briquette styles. The optical integrating sphere (IS) method was applied to measure the emission factors (EFs) of BrC and black carbon (BC) via an iterative process using the different spectral dependence of light absorption for BrC and BC and using humic acid sodium salt (HASS) and carbon black (CarB) as reference materials. The following results have been found: (i) the average EFs of BrC for anthracite coal chunks and briquettes are 1.08 ± 0.80 and 1.52 ± 0.16 g kg-1, respectively, and those for bituminous coal chunks and briquettes are 8.59 ± 2.70 and 4.01 ± 2.19 g kg-1, respectively, reflecting a more significant decline in BrC EFs for bituminous coals than for anthracites due to briquetting. (ii) The BrC EF peaks at the middle of coal's geological maturity, displaying a bell-shaped curve between EF and volatile matter (Vdaf). (iii) The calculated BrC emissions from China's residential coal burning amounted to 592 Gg (1 Gg = 109 g) in 2013, which is nearly half of China's total BC emissions. (iv) The absorption Ångström exponents (AAEs) of all coal briquettes are higher than those of coal chunks, indicating that the measure of coal briquetting increases the BrC / BC emission ratio and thus offsets some of the climate cooling effect of briquetting. (v) In the scenario of current household coal burning in China, solar light absorption by BrC (350-850 nm in this study) accounts for more than a quarter (0.265) of the total absorption. This implies the significance of BrC to climate

  14. Toxic Volatile Organic Compounds in Environmental Tobacco Smoke:Emission Factors for Modeling Exposures of California Populations

    Energy Technology Data Exchange (ETDEWEB)

    Daisey, J.M.; Mahanama, K.R.R.; Hodgson, A.T.

    1994-10-01

    The primary objective of this study was to measure emission factors for selected toxic air in environmental tobacco smoke (ETS) using a room-sized environmental chamber. The emissions of 23 volatile organic compounds (VOCs), including 1,3-butadiene, three aldehydes and two vapor-phase N-nitrosarnines were determined for six commercial brands of cigarettes and reference cigarette 1R4F. The commercial brands were selected to represent 62.5% of the cigarettes smoked in California. For each brand, three cigarettes were machine smoked in the chamber. The experiments were conducted over four hours to investigate the effects of aging. Emission factors of the target compounds were also determined for sidestream smoke (SS). For almost all target compounds, the ETS emission factors were significantly higher than the corresponding SS values probably due to less favorable combustion conditions and wall losses in the SS apparatus. Where valid comparisons could be made, the ETS emission factors were generally in good agreement with the literature. Therefore, the ETS emission factors, rather than the SS values, are recommended for use in models to estimate population exposures from this source. The variabilities in the emission factors (pgkigarette) of the selected toxic air contaminants among brands, expressed as coefficients of variation, were 16 to 29%. Therefore, emissions among brands were generally similar. Differences among brands were related to the smoked lengths of the cigarettes and the masses of consumed tobacco. Mentholation and whether a cigarette was classified as light or regular did not significantly affect emissions. Aging was determined not to be a significant factor for the target compounds. There were, however, deposition losses of the less volatile compounds to chamber surfaces.

  15. Fire environment effects on particulate matter emission factors in southeastern U.S. pine-grasslands

    Science.gov (United States)

    Robertson, Kevin M.; Hsieh, Yuch P.; Bugna, Glynnis C.

    2014-12-01

    Particulate matter (PM) emission factors (EFPM), which predict particulate emissions per biomass consumed, have a strong influence on event-based and regional PM emission estimates and inventories. PM regulated for its impacts to human health and visibility, is of special concern. Although wildland fires vary widely in their fuel conditions, meteorology, and fire behavior which might influence combustion reactions, the EFPM2.5 component of emission estimates is typically a constant for the region or general fuel type being assessed. The goal of this study was to use structural equation modeling (SEM) to identify and measure effects of fire environment variables on EFPM2.5 in U.S. pine-grasslands, which contribute disproportionately to total U.S. PM2.5 emissions. A hypothetical model was developed from past literature and tested using 41 prescribed burns in northern Florida and southern Georgia, USA with varying years since previous fire, season of burn, and fire direction of spread. Measurements focused on EFPM2.5 from flaming combustion, although a subset of data considered MCE and smoldering combustion. The final SEM after adjustment showed EFPM2.5 to be higher in burns conducted at higher ambient temperatures, corresponding to later dates during the period from winter to summer and increases in live herbaceous vegetation and ambient humidity, but not total fine fuel moisture content. Percentage of fine fuel composed of pine needles had the strongest positive effect on EFPM2.5, suggesting that pine timber stand volume may significantly influence PM2.5 emissions. Also, percentage of fine fuel composed of grass showed a negative effect on EFPM2.5, consistent with past studies. Results of the study suggest that timber thinning and frequent prescribed fire minimize EFPM2.5 and total PM2.5 emissions on a per burn basis, and that further development of PM emission models should consider adjusting EFPM2.5 as a function of common land use variables, including pine timber

  16. Particle number concentration near road traffic in Amsterdam (the Netherlands): Comparison of standard and real-world emission factors

    Science.gov (United States)

    Keuken, M. P.; Moerman, M.; Voogt, M.; Zandveld, P.; Verhagen, H.; Stelwagen, U.; Jonge de, D.

    2016-05-01

    In this study, NOx and particle number concentration (PNC) at an urban background and a traffic location were measured in the city of Amsterdam (the Netherlands). Modelled and measured contributions to NOx and PNC at the traffic location were used to derive real-world PN emission factors for average urban road traffic. The results for NOx were applied to validate our approach. The real-world PN emission factors (#.km-1) were 2.9E+14 (urban road) and 3E+14 (motorway). These values were at least a factor eight higher than dynamometer-based PN emission factors from COPERT 4 and HBEFA databases. The real-world PN emission factors were used to model the contribution to PNC near road traffic in 2014. This was two to three times higher than the PNC urban background along urban roads over 20,000 vehicles per day and near motorways. The discrepancy between dynamometer-based and real-world emission factors demonstrates the need for more PNC observations to assess actual PN emissions from road traffic.

  17. Exhaust constituent emission factors of printed circuit board pyrolysis processes and its exhaust control.

    Science.gov (United States)

    Chiang, Hung-Lung; Lin, Kuo-Hsiung

    2014-01-15

    The printed circuit board (PCB) is an important part of electrical and electronic equipment, and its disposal and the recovery of useful materials from waste PCBs (WPCBs) are key issues for waste electrical and electronic equipment. Waste PCB compositions and their pyrolysis characteristics were analyzed in this study. In addition, the volatile organic compound (VOC) exhaust was controlled by an iron-impregnated alumina oxide catalyst. Results indicated that carbon and oxygen were the dominant components (hundreds mg/g) of the raw materials, and other elements such as nitrogen, bromine, and copper were several decades mg/g. Exhaust constituents of CO, H2, CH4, CO2, and NOx, were 60-115, 0.4-4.0, 1.1-10, 30-95, and 0-0.7mg/g, corresponding to temperatures ranging from 200 to 500°C. When the pyrolysis temperature was lower than 300°C, aromatics and paraffins were the major species, contributing 90% of ozone precursor VOCs, and an increase in the pyrolysis temperature corresponded to a decrease in the fraction of aromatic emission factors. Methanol, ethylacetate, acetone, dichloromethane, tetrachloromethane and acrylonitrile were the main species of oxygenated and chlorinated VOCs. The emission factors of some brominated compounds, i.e., bromoform, bromophenol, and dibromophenol, were higher at temperatures over 400°C. When VOC exhaust was flowed through the bed of Fe-impregnated Al2O3, the emission of ozone precursor VOCs could be reduced by 70-80%. Copyright © 2013 Elsevier B.V. All rights reserved.

  18. Diagrams and Parastatistical Factors for Cascade Emission of a Pair of Paraparticles

    CERN Document Server

    Nelson, Charles A; Mera, Calvin S; Shapiro, Alanna M

    2015-01-01

    The empirical absence to date of particles obeying parastatistics in high energy collider experiments might be due to their large masses, weak scale couplings, and lack of gauge couplings. Paraparticles of order p=2 must be pair produced, so the lightest such particles are absolutely stable and so are excellent candidates to be associated with dark matter and/or dark energy. If there is a portal to such particles, from a new scalar A1 boson they might be cascade emitted as a pair of para-Majorana neutrinos as in A1 ---> A2 para-nu para-nu or as a pair of neutral spin-zero paraparticles such as in A1 ---> A2 para-A para-B, where para-B is the anti-paraparticle to para-A. In this paper, for an assumed supersymmetric-like "statistics portal" Lagrangian, the associated connected tree diagrams and their parastatistical factors are obtained for the case of order p=2 parastatistics. These factors are compared with the corresponding statistical factors for the analogous emission of a non-degenerate or a 2-fold degene...

  19. Many-body approach to proton emission and the role of spectroscopic factors

    CERN Document Server

    Al-Khalili, J S; Escher, J; Jennings, B K; Sparenberg, J M; Al-Khalili, Jim; Barbieri, Carlo; Escher, Jutta; Jennings, Byron K.; Sparenberg, Jean-Marc

    2003-01-01

    The process of proton emission from nuclei is studied by utilizing the two-potential approach of Gurvitz and Kalbermann in the context of the full many-body problem. A time-dependent approach is used for calculating the decay width. Starting from an initial many-body quasi-stationary state, we employ the Feshbach projection operator approach and reduce the formalism to an effective one-body problem. We show that the decay width can be expressed in terms of a one-body matrix element multiplied by a normalization factor. We demonstrate that the traditional interpretation of this normalization as the square root of a spectroscopic factor is only valid for one particular choice of projection operator. This causes no problem for the calculation of the decay width in a consistent microscopic approach, but it leads to ambiguities in the interpretation of experimental results. In particular, spectroscopic factors extracted from a comparison of the measured decay width with a calculated single-particle width may be af...

  20. X-ray absorption, nuclear infrared emission and dust covering factors of AGN: testing Unification Schemes

    CERN Document Server

    Mateos, S; Alonso-Herrero, A; Hernán-Caballero, A; Barcons, X; Ramos, A Asensio; Watson, M G; Blain, A; Caccianiga, A; Ballo, L; Braito, V; Almeida, C Ramos

    2016-01-01

    We present the distributions of geometrical covering factors of active galactic nuclei (AGNs) dusty tori (f2) using an X-ray selected complete sample of 227 AGN drawn from the Bright Ultra-hard XMM-Newton Survey. The AGN have z from 0.05 to 1.7, 2-10 keV luminosities between 10^42 and 10^46 erg/s and Compton-thin X-ray absorption. Employing data from UKIDSS, 2MASS and the Wide-field Infrared Survey Explorer in a previous work we determined the rest-frame 1-20 microns continuum emission from the torus which we model here with the clumpy torus models of Nenkova et al. Optically classified type 1 and type 2 AGN are intrinsically different, with type 2 AGN having on average tori with higher f2 than type 1 AGN. Nevertheless, ~20 per cent of type 1 AGN have tori with large covering factors while ~23-28 per cent of type 2 AGN have tori with small covering factors. Low f2 are preferred at high AGN luminosities, as postulated by simple receding torus models, although for type 2 AGN the effect is certainly small. f2 in...

  1. [An investigation of the CH4 and N2O emission factors of light-duty gasoline vehicles].

    Science.gov (United States)

    He, Li-qiang; Song, Jing-hao; Hu, Jing-nan; Xie, Shu-xia; Zu, Lei

    2014-12-01

    In China, most of the studies of vehicular greenhouse gas (GHG) emissions have been focused on CO2 emissions. The investigation of non-CO2 GHGs, e.g. CH4 and N2O, are mainly carried out based on models developed in Europe and the US, and there are few vehicle emission tests for CH4 and N2O. In this study, 22 light-duty gasoline vehicles (LDGVs) were selected for tailpipe CH4 and N2O tests using chassis dynamometer, and their emission factors were obtained based on the NEDC driving cycle. The results showed that the CH4 emission factors of China I to China IV LDGVs were 0.048 g x km(-1), 0.048 g x km(-1), 0.038 g x km(-1) and 0.028 g x km(-1), respectively. For N2O, the emission factors of China I to China IV were 0.045 g x km(-1), 0.039 g x km(-1), 0.026 g x km(-1) and 0.021 g x km(-1), respectively. In the GHGs emissions (in terms of CO2 Eq.) per LDGV, the percentage of CH4 and N2O emissions decreased gradually with tightening of emission standards. The contribution of CH4 emissions was lower than 0.5% in the total emissions, and N2O share rate was between 3.03% and 6.35%. Therefore, tightening emission standards can effectively reduce the CH4 and N2O emissions, to mitigate the greenhouse effects caused by vehicle emissions.

  2. Updated greenhouse gas and criteria air pollutant emission factors and their probability distribution functions for electricity generating units

    Energy Technology Data Exchange (ETDEWEB)

    Cai, H.; Wang, M.; Elgowainy, A.; Han, J. (Energy Systems)

    2012-07-06

    Greenhouse gas (CO{sub 2}, CH{sub 4} and N{sub 2}O, hereinafter GHG) and criteria air pollutant (CO, NO{sub x}, VOC, PM{sub 10}, PM{sub 2.5} and SO{sub x}, hereinafter CAP) emission factors for various types of power plants burning various fuels with different technologies are important upstream parameters for estimating life-cycle emissions associated with alternative vehicle/fuel systems in the transportation sector, especially electric vehicles. The emission factors are typically expressed in grams of GHG or CAP per kWh of electricity generated by a specific power generation technology. This document describes our approach for updating and expanding GHG and CAP emission factors in the GREET (Greenhouse Gases, Regulated Emissions, and Energy Use in Transportation) model developed at Argonne National Laboratory (see Wang 1999 and the GREET website at http://greet.es.anl.gov/main) for various power generation technologies. These GHG and CAP emissions are used to estimate the impact of electricity use by stationary and transportation applications on their fuel-cycle emissions. The electricity generation mixes and the fuel shares attributable to various combustion technologies at the national, regional and state levels are also updated in this document. The energy conversion efficiencies of electric generating units (EGUs) by fuel type and combustion technology are calculated on the basis of the lower heating values of each fuel, to be consistent with the basis used in GREET for transportation fuels. On the basis of the updated GHG and CAP emission factors and energy efficiencies of EGUs, the probability distribution functions (PDFs), which are functions that describe the relative likelihood for the emission factors and energy efficiencies as random variables to take on a given value by the integral of their own probability distributions, are updated using best-fit statistical curves to characterize the uncertainties associated with GHG and CAP emissions in life

  3. Updated greenhouse gas and criteria air pollutant emission factors and their probability distribution functions for electricity generating units

    Energy Technology Data Exchange (ETDEWEB)

    Cai, H.; Wang, M.; Elgowainy, A.; Han, J. (Energy Systems)

    2012-07-06

    Greenhouse gas (CO{sub 2}, CH{sub 4} and N{sub 2}O, hereinafter GHG) and criteria air pollutant (CO, NO{sub x}, VOC, PM{sub 10}, PM{sub 2.5} and SO{sub x}, hereinafter CAP) emission factors for various types of power plants burning various fuels with different technologies are important upstream parameters for estimating life-cycle emissions associated with alternative vehicle/fuel systems in the transportation sector, especially electric vehicles. The emission factors are typically expressed in grams of GHG or CAP per kWh of electricity generated by a specific power generation technology. This document describes our approach for updating and expanding GHG and CAP emission factors in the GREET (Greenhouse Gases, Regulated Emissions, and Energy Use in Transportation) model developed at Argonne National Laboratory (see Wang 1999 and the GREET website at http://greet.es.anl.gov/main) for various power generation technologies. These GHG and CAP emissions are used to estimate the impact of electricity use by stationary and transportation applications on their fuel-cycle emissions. The electricity generation mixes and the fuel shares attributable to various combustion technologies at the national, regional and state levels are also updated in this document. The energy conversion efficiencies of electric generating units (EGUs) by fuel type and combustion technology are calculated on the basis of the lower heating values of each fuel, to be consistent with the basis used in GREET for transportation fuels. On the basis of the updated GHG and CAP emission factors and energy efficiencies of EGUs, the probability distribution functions (PDFs), which are functions that describe the relative likelihood for the emission factors and energy efficiencies as random variables to take on a given value by the integral of their own probability distributions, are updated using best-fit statistical curves to characterize the uncertainties associated with GHG and CAP emissions in life

  4. PARTICULATE MATTER CONCENTRATION AND EMISSION FACTOR IN THREE DIFFERENT LAYING HEN HOUSING SYSTEMS

    Directory of Open Access Journals (Sweden)

    Annamaria Costa

    2009-09-01

    Full Text Available The aim of this study was to evaluate PM10 concentration in three different laying hens houses (traditional battery cages with aerated open manure storage, aviary system and vertical tiered cages with manure belts with forced air drying and to evaluate particulate matter emission into atmosphere during one year of observation. Internal and external temperature and relative humidity, ventilation rate, PM10 concentration have been continuously monitored in order to evaluate particulate matter concentration changes during the day and the season and to define PM10 emission factors. PM10 concentration was corrected by gravimetric technique to lower measurements error. In the aviary system house, TSP and fine particulate matter (particles smaller than 2.5 micron concentration was measured. Average yearly PM10 concentration was remarkably higher in the aviary system house with 0.215 mg m-3 vs 108 mg m-3 for the ventilated belt house and vs 0.094 mg m-3 for the traditional battery cages house. In the Aviary system housing, TSP concentration was 0.444 mg m-3 and PM2.5 was 0.032 mg m-3, highlighting the existence of a severe working environment for men and animals. Recorded values for PM10 emission were 0.433 mg h-1 hen-1 for battery cages housing type, 0.081 mg h-1 hen-1 for ventilated belt cages house, values lower than those available in literature, while the aviary system housing type showed the highest PM10 emission (1.230 mg h-1 hen-1 with appreciable peaks during the morning, together with the increased animal activity and daily farmer operations, as feed administration, cleaning and droppings removal.

  5. Emission factors of gaseous carbonaceous species from residential combustion of coal and crop residue briquettes

    Institute of Scientific and Technical Information of China (English)

    Qin WANG; Chunmei GENG; Sihua LU; Wentai CHEN; Min SHAO

    2013-01-01

    Experiments were performed to measure the emission factors (EFs) of gaseous carbonaceous species, such as CO2, CO, CH4, and non-methane volatile organic compounds (NMVOCs), from the combustion of five types of coal of varying organic maturity and two types of biomass briquettes under residential burning conditions. Samples were collected in stainless steel canisters and 2,4- dinitrophenylhydrazine (DNPH) cartridges and were analyzed by GC FID/MS and HPLC, respectively. The EFs from crop residue briquette burning were generally higher than those from coals, with the exception of CO2. The dominant NMVOC species identified in coal smoke were carbonyls (41.7%), followed by C2 unsaturated hydrocarbons (29.1%) and aromatics (12.1%), while C2 unsaturated hydrocarbons were the dominant species (68.9%) emitted from the combustion of crop residue briquettes, followed by aromatics (14.4%). A comparison of burning normal crop residues in stoves and the open field indicated that briquettes emitted a larger proportion of ethene and acetylene. Both combustion efficiency and coal organic maturity had a significant impact on NMVOC EFs from burning coal: NMVOC emissions increased with increasing coal organic maturity but decreased as the combustion efficiency improved. Emissions from the combustion of crop residue briquettes from stoves occurred mainly during the smoldering process, with low combustion efficiency. Therefore, an improved stove design to allow higher combustion efficiency would be beneficial for reducing emissions of carbonaceous air pollutants.

  6. Identification of main influencing factors of life cycle CO{sub 2} emissions from the integrated steelworks using sensitivity analysis

    Energy Technology Data Exchange (ETDEWEB)

    Zhijia Huang; Xiao Ding; Hao Sun; Siyue Liu [Anhui University of Technology, Maanshan (China)

    2010-07-15

    The amount of CO{sub 2} emissions from steelworks accounts for a great share of the total CO{sub 2} emissions from industry in China. Thus, reducing CO{sub 2} emissions from steelworks is urgent for China's environmental protection and sustainable development. This study aims at identifying factors that influence CO{sub 2} emissions from steelworks and proposing measures to reduce CO{sub 2} emissions. The life cycle inventory (LCI) of iron and steel products implies the relationship between the CO{sub 2} emissions of the steelworks and the input variables of the LCI. The Tornado Chart Tool is utilized to calculate the variation of CO{sub 2} emissions caused by the change of each input variables of LCI. Then, mean sensitivity of each input variable is calculated and the ranking criterion developed is used to identify the main factors influencing the integrated steelworks. Subsequently, measures for reducing CO{sub 2} emissions are proposed. The results indicate that the very important influencing factors of CO{sub 2} emissions in steelworks are the CO{sub 2} emission factor of Blast Furnace Gas (BFG), liquid steel unit consumption of continuous casting, continuous casting slab unit consumption of hot rolling and hot metal ratio of steel making. Consequently, many efficient measures for reducing CO{sub 2} emissions have been proposed, such as removing CO{sub 2} contained in BFG, decreasing the hot metal ratio of Basic Oxygen Furnace (BOF), recycling BFG, optimizing the products' structure, etc.

  7. Fate factors and emission flux estimates for emerging contaminants in surface waters

    Directory of Open Access Journals (Sweden)

    Hoa T. Trinh

    2016-01-01

    Full Text Available Pharmaceuticals, personal care products, hormones, and wastewater products are emerging environmental concerns for manifold reasons, including the potential of some compounds found in these products for endocrine disruption at a very low chronic exposure level. The environmental occurrences and sources of these contaminants in the water, soil, sediment and biota in European nations and the United States are well documented. This work reports a screening-level emission and fate assessment of thirty compounds, listed in the National Reconnaissance of the United States Geological Survey (USGS, 1999–2000 as the most frequently detected organic wastewater contaminants in U.S. streams and rivers. Estimations of the surface water fate factors were based on Level II and Level III multimedia fugacity models for a 1000 km2 model environment, the size of a typical county in the eastern United States. The compounds are categorized into three groups based upon the sensitivity of their predicted surface water fate factors to uncertainties in their physicochemical property values and the landscape parameters. The environmental fate factors, mass distributions, and loss pathways of all of the compounds are strongly affected by their assumed modes of entry into the environment. It is observed that for thirteen of the thirty organic wastewater contaminants most commonly detected in surface waters, conventional treatment strategies may be ineffective for their removal from wastewater effluents. The surface water fate factors predicted by the fugacity models were used in conjunction with the surface water concentrations measured in the USGS reconnaissance to obtain emission flux estimates for the compounds into U.S. streams and rivers. These include estimated fluxes of 6.8 × 10−5 to 0.30 kg/h km2 for the biomarker coprostanol; 1.7 × 10−5 to 6.5 × 10−5 kg/h km2 for the insect repellent N,N-diethyltoluamide; and 4.3 × 10−6 to 3.1 × 10−5 kg/h km2 for

  8. Policies for Promotion of Electric Vehicles and Factors Influencing Consumers’ Purchasing Decisions of Low Emission Vehicles

    Directory of Open Access Journals (Sweden)

    Matjaz Knez

    2017-06-01

    Full Text Available Recently different studies of green transport have become interesting for policy makers,car manufacturers, customers and energy suppliers. Many stakeholders from the publicand private sectors are investing a lot of effort to identify consumer behaviour for futureimprovements in development of green products and effective strategies, which couldaccelerate the transition to sustainable future. This paper presents the effects of electricvehicle promotional policies and customer preferences about alternative fuel vehicles.This study has shown that the electric vehicle promotional policies adopted in Sloveniahave been unsuccessful, as the share of first-time registered electric vehicles in 2013 wasbelow 1%. For different segments of people whose opinions about low emission vehiclesdiffer, different measures must be adopted. When designing promotional policies focusmust be on the most relevant factors such as the total vehicle price and fuel economy.

  9. Half-lives and cluster preformation factors for various cluster emissions in trans-lead nuclei

    Science.gov (United States)

    Ni, Dongdong; Ren, Zhongzhou

    2010-08-01

    The generalized density-dependent cluster model (GDDCM) is extended to study cluster radioactivity in even-even and odd-A nuclei decaying to the doubly magic nucleus Pb208 or its neighboring nuclei. The microscopic cluster-daughter potential is numerically constructed in the double-folding model with M3Y nucleon-nucleon interactions plus proton-proton Coulomb interactions. Instead of the WKB barrier penetration probability, the exact solution of the Schrödinger equation with outgoing Coulomb wave boundary conditions is presented. The cluster preformation factor is well taken into account based on some available experimental cases. The calculated half-lives are found to be in good agreement with the experimental data. This indicates that a unified description of α decay and cluster radioactivity has been achieved by the GDDCM. Predictions of cluster emission half-lives are made for promising emitters, which may guide future experiments.

  10. Emission of Methane From Enteric Fermentation: National Contribution and Factors Affecting it in Livestock

    Directory of Open Access Journals (Sweden)

    Budi Haryanto

    2009-12-01

    Full Text Available Changing in atmosphere condition is affected by the quantity of gases produced from all activities on the earth. Gases that have effects on global warming are CO2, N2O, H2O, and CH4 (methane. Among other sources of methane are enteric fermentation of organic material from ruminants and feces decomposition. Methane production from ruminants is affected by several factors such as breed/type of animal, feed quality, environmental temperature and physiological status of the animal. Energy as methane in ruminants may reach 2 to 15% of the total energy consumption. To reduce the emission of methane from ruminants, it is necessary to apply a strategic feeding system for more efficient utilization of feed.

  11. High-power laser arrays with 100% fill factor emission facet

    Science.gov (United States)

    Yanson, Dan A.; McDougall, Stewart D.; Qiu, Bocang; Loyo-Maldonado, Valentin; Bacchin, Gianluca; Robertson, Stephen; Bon, Sébastien; Marsh, John H.

    2008-02-01

    Novel types of laser diode array with a 100% filling factor at the emission facet are reported. The arrays utilize both parallel and tapered cavity emitters that are connected via a common Laterally Unconfined Non-Absorbing Mirror (LUNAM) defined with quantum-well intermixing technology at 808 nm wavelength. Two LUNAM array types are considered: incoherent (weakly coupled) and coherent (diffraction coupled). Incoherent LUNAM arrays benefit from a reduced power density at the facet, improving reliability, and a near-uniform intensity distribution across the array aperture. Stacked laser diode arrays built with LUNAM bars deliver 950 W power under QCW operation with monolithically integrated LUNAM Talbot cavity. The devices produce a single-lobed horizontal far-field pattern over a limited current range with <10% slope efficiency penalty compared to an uncoupled case. The LUNAM arrays are promising candidates for high-power, high-brightness and high-reliability operation.

  12. Site specific diel methane emission mechanisms in landfills: A field validated process based on vegetation and climate factors.

    Science.gov (United States)

    Xin, Danhui; Hao, Yongxia; Shimaoka, Takayuki; Nakayama, Hirofumi; Chai, Xiaoli

    2016-11-01

    Diel methane emission fluxes from a landfill that was covered by vegetation were investigated to reveal the methane emission mechanisms based on the interaction of vegetation characteristics and climate factors. The methane emissions showed large variation between daytime and nighttime, and the trend of methane emissions exhibited clear bimodal patterns from both Setaria viridis- and Neyraudia reynaudiana-covered areas. Plants play an important role in methane transportation as well as methane oxidation. The notable decrease in methane emissions after plants were cut suggests that methane transportation via plants is the primary way of methane emissions in the vegetated areas of landfill. Within plants, the methane emission fluxes were enhanced due to a convection mechanism. Given that the methane emission flux is highly correlated with the solar radiation during daytime, the convection mechanism could be attributed to the increase in solar radiation. Whereas the methane emission flux is affected by a combined impact of the wind speed and pedosphere characteristics during nighttime. An improved understanding of the methane emission mechanisms in vegetated landfills is expected to develop a reliable model for landfill methane emissions and to attenuate greenhouse gas emissions from landfills.

  13. Development of welding emission factors for Cr and Cr(VI) with a confidence level.

    Science.gov (United States)

    Serageldin, Mohamed; Reeves, David W

    2009-05-01

    Knowledge of the emission rate and release characteristics is necessary for estimating pollutant fate and transport. Because emission measurements at a facility's fence line are generally not readily available, environmental agencies in many countries are using emission factors (EFs) to indicate the quantity of certain pollutants released into the atmosphere from operations such as welding. The amount of fumes and metals generated from a welding process is dependent on many parameters, such as electrode composition, voltage, and current. Because test reports on fume generation provide different levels of detail, a common approach was used to give a test report a quality rating on the basis of several highly subjective criteria; however, weighted average EFs generated in this way are not meant to reflect data precision or to be used for a refined risk analysis. The 95% upper confidence limit (UCL) of the unknown population mean was used in this study to account for the uncertainty in the EF test data. Several parametric UCLs were computed and compared for multiple welding EFs associated with several mild, stainless, and alloy steels. Also, several nonparametric statistical methods, including several bootstrap procedures, were used to compute 95% UCLs. For the nonparametric methods, a distribution for calculating the mean, standard deviation, and other statistical parameters for a dataset does not need to be assumed. There were instances when the sample size was small and instances when EFs for an electrode/process combination were not found. Those two points are addressed in this paper. Finally, this paper is an attempt to deal with the uncertainty in the value of a mean EF for an electrode/process combination that is based on test data from several laboratories. Welding EFs developed with a defined level of confidence may be used as input parameters for risk assessment.

  14. EXploring non road TRansport EMISsions in Europe. Development of a Reference System on Emissions Factors for Rail, Maritime and Air Transport. Annex to Final Report

    Energy Technology Data Exchange (ETDEWEB)

    Chiffi, C.; Fiorello, D. [Trasporti e Territorio TRT, Milan (Italy); Schrooten, L.; De Vlieger, I. [Flemish Institute for Technological Research VITO, Mol (Belgium)

    2008-06-15

    EX-TREMIS brings together the most comprehensive and up-to-date information on non-road transport vehicle emission factors and activity statistics, which together make it possible to estimate the energy consumption and emissions resulting from different transport operations. The database covers four main data types: fleet data, transport activity data, emission and energy consumption factors, total energy consumption and emissions data, where total emissions and emission factors are calculated for CO2, NOX, SOX, CO, VOC, CH4, NMVOC and PM. All the related datasets are made available on the project website www.ex-tremis.eu. The report illustrates the final resulting datasets and presents the development of some selected transport activity units and pollutant emissions. On a separate annex, the methodologies related to the three domains are described in detail together with the references to the relevant sources used and the activities for homogenising data from different sources and filling gaps to cover the whole set of information required.

  15. EXploring non road TRansport EMISsions in Europe. Development of a Reference System on Emissions Factors for Rail, Maritime and Air Transport. Final Report

    Energy Technology Data Exchange (ETDEWEB)

    Chiffi, C.; Fiorello, D. [Trasporti e Territorio TRT, Milan (Italy); Schrooten, L.; De Vlieger, I. [Flemish Institute for Technological Research VITO, Mol (Belgium)

    2008-06-15

    EX-TREMIS brings together the most comprehensive and up-to-date information on non-road transport vehicle emission factors and activity statistics, which together make it possible to estimate the energy consumption and emissions resulting from different transport operations. The database covers four main data types: fleet data, transport activity data, emission and energy consumption factors, total energy consumption and emissions data, where total emissions and emission factors are calculated for CO2, NOX, SOX, CO, VOC, CH4, NMVOC and PM. All the related datasets are made available on the project website www.ex-tremis.eu. The report illustrates the final resulting datasets and presents the development of some selected transport activity units and pollutant emissions. On a separate annex, the methodologies related to the three domains are described in detail together with the references to the relevant sources used and the activities for homogenising data from different sources and filling gaps to cover the whole set of information required.

  16. Modelling site-specific N2O emission factors from Austrian agricultural soils for targeted mitigation measures (NitroAustria)

    Science.gov (United States)

    Amon, Barbara; Zechmeister-Boltenstern, Sophie; Kasper, Martina; Foldal, Cecilie; Schiefer, Jasmin; Kitzler, Barbara; Schwarzl, Bettina; Zethner, Gerhard; Anderl, Michael; Sedy, Katrin; Gaugitsch, Helmut; Dersch, Georg; Baumgarten, Andreas; Haas, Edwin; Kiese, Ralf

    2016-04-01

    Results from a previous project "FarmClim" highlight that the IPCC default emission factor is not able to reflect region specific N2O emissions from Austrian arable soils. The methodology is limited in identifying hot spots and hot moments of N2O emissions. When estimations are based on default emission factors no recommendations can be given on optimisation measures that would lead to a reduction of soil N2O emissions. The better the knowledge is about Nitrogen and Carbon budgets in Austrian agricultural managed soils the better the situation can be reflected in the Austrian GHG emission inventory calculations. Therefore national and regionally modelled emission factors should improve the evidence for national deviation from the IPCC default emission factors and reduce the uncertainties. The overall aim of NitroAustria is to identify the drivers for N2O emissions on a regional basis taking different soil types, climate, and agricultural management into account. We use the LandscapeDNDC model to update the N2O emission factors for N fertilizer and animal manure applied to soils. Key regions in Austria were selected and region specific N2O emissions calculated. The model runs at sub-daily time steps and uses data such as maximum and minimum air temperature, precipitation, radiation, and wind speed as meteorological drivers. Further input data are used to reflect agricultural management practices, e.g., planting/harvesting, tillage, fertilizer application, irrigation and information on soil and vegetation properties for site characterization and model initialization. While at site scale, arable management data (crop cultivation, rotations, timings etc.) is obtained by experimental data from field trials or observations, at regional scale such data need to be generated using region specific proxy data such as land use and management statistics, crop cultivations and yields, crop rotations, fertilizer sales, manure resulting from livestock units etc. The farming

  17. How the user can influence particulate emissions from residential wood and pellet stoves: Emission factors for different fuels and burning conditions

    Science.gov (United States)

    Fachinger, Friederike; Drewnick, Frank; Gieré, Reto; Borrmann, Stephan

    2017-06-01

    For a common household wood stove and a pellet stove we investigated the dependence of emission factors for various gaseous and particulate pollutants on burning phase, burning condition, and fuel. Ideal and non-ideal burning conditions (dried wood, under- and overload, small logs, logs with bark, excess air) were used. We tested 11 hardwood species (apple, ash, bangkirai, birch, beech, cherry, hickory, oak, olive, plum, sugar maple), 4 softwood species (Douglas fir, pine, spruce, spruce/fir), treated softwood, beech and oak wood briquettes, paper briquettes, brown coal, wood chips, and herbaceous species (miscanthus, Chinese silver grass) as fuel. Particle composition (black carbon, non-refractory, and some semi-refractory species) was measured continuously. Repeatability was shown to be better for the pellet stove than for the wood stove. It was shown that the user has a strong influence on wood stove emission behavior both by selection of the fuel and of the burning conditions: Combustion efficiency was found to be low at both very low and very high burn rates, and influenced particle properties such as particle number, mass, and organic content in a complex way. No marked differences were found for the emissions from different wood species. For non-woody fuels, much higher emission factors could be observed (up to five-fold increase). Strongest enhancement of emission factors was found for burning of small or dried logs (up to six-fold), and usage of excess air (two- to three-fold). Real world pellet stove emissions can be expected to be much closer to laboratory-derived emission factors than wood stove emissions, due to lower dependence on user operation.

  18. Fertiliser-induced nitrous oxide emissions from vegetable production in the world and the regulating factors: A review

    Science.gov (United States)

    Rezaei Rashti, Mehran; Wang, Weijin; Moody, Phil; Chen, Chengrong; Ghadiri, Hossein

    2015-07-01

    The emission of nitrous oxide (N2O) from vegetable fields contributes to the global greenhouse gases budget. However, reliable estimation of N2O emissions from vegetable production in the word has been lack. Vegetable cropping systems are characterised with high N application rates, irrigation, intensive production and multiple planting-harvest cycles during the year. Improved understanding of the key factors controlling N2O production is critical for developing effective mitigation strategies for vegetable cropping systems under different climate, soil type and management practices. Based on a comprehensive literature review and data analysis, we estimated the global N2O emission from vegetable production using seasonal fertiliser-induced emission factors (EFs) and examined the relationship of the seasonal emissions and EFs to possible controlling factors. The global average seasonal EF for vegetable fields is around 0.94% of applied N fertiliser, which is very similar to the Intergovernmental Panel on Climate Change (IPCC) annual emission factor of 1.0% for all cropping systems. The total N2O emission from global vegetable production is estimated to be 9.5 × 107 kg N2O-N yr-1, accounting for 9.0% of the total N2O emissions from synthetic fertilisers. Stepwise multiple regression analysis on the relationships of soil properties, climatic factors and N application rates to seasonal N2O emissions and N2O EFs showed that N fertiliser application rate is the main regulator of seasonal N2O emission from vegetable fields but the seasonal EFs are negatively related to soil organic carbon (SOC) content. In fields receiving ≥250 kg ha-1 N fertiliser, 67% (n = 23, P ≤ 0.01) of the variation in seasonal emissions can be explained by the combined effects of N application rate, mean water-filled pore space (WFPS) and air temperature, while 59% (n = 23, P ≤ 0.01) of the variation in seasonal EFs relates to temperature, mean WFPS and soil pH. The result also shows that in

  19. Development of Methane and Nitrous Oxide Emission Factors for the Biomass Fired Circulating Fluidized Bed Combustion Power Plant

    Directory of Open Access Journals (Sweden)

    Chang-Sang Cho

    2012-01-01

    Full Text Available This study makes use of this distinction to analyze the exhaust gas concentration and fuel of the circulating fluidized bed (CFB boiler that mainly uses wood biomass, and to develop the emission factors of Methane (CH4, Nitrous oxide (N2O. The fuels used as energy sources in the subject working sites are Wood Chip Fuel (WCF, RDF and Refused Plastic Fuel (RPF of which heating values are 11.9 TJ/Gg, 17.1 TJ/Gg, and 31.2 TJ/Gg, respectively. The average concentrations of CH4 and N2O were measured to be 2.78 ppm and 7.68 ppm, respectively. The analyzed values and data collected from the field survey were used to calculate the emission factor of CH4 and N2O exhausted from the CFB boiler. As a result, the emission factors of CH4 and N2O are 1.4 kg/TJ (0.9–1.9 kg/TJ and 4.0 kg/TJ (2.9–5.3 kg/TJ within a 95% confidence interval. Biomass combined with the combustion technology for the CFB boiler proved to be more effective in reducing the N2O emission, compared to the emission factor of the CFB boiler using fossil fuel.

  20. Development of methane and nitrous oxide emission factors for the biomass fired circulating fluidized bed combustion power plant.

    Science.gov (United States)

    Cho, Chang-Sang; Sa, Jae-Hwan; Lim, Ki-Kyo; Youk, Tae-Mi; Kim, Seung-Jin; Lee, Seul-Ki; Jeon, Eui-Chan

    2012-01-01

    This study makes use of this distinction to analyze the exhaust gas concentration and fuel of the circulating fluidized bed (CFB) boiler that mainly uses wood biomass, and to develop the emission factors of Methane (CH(4)), Nitrous oxide (N(2)O). The fuels used as energy sources in the subject working sites are Wood Chip Fuel (WCF), RDF and Refused Plastic Fuel (RPF) of which heating values are 11.9 TJ/Gg, 17.1 TJ/Gg, and 31.2 TJ/Gg, respectively. The average concentrations of CH(4) and N(2)O were measured to be 2.78 ppm and 7.68 ppm, respectively. The analyzed values and data collected from the field survey were used to calculate the emission factor of CH(4) and N(2)O exhausted from the CFB boiler. As a result, the emission factors of CH(4) and N(2)O are 1.4 kg/TJ (0.9-1.9 kg/TJ) and 4.0 kg/TJ (2.9-5.3 kg/TJ) within a 95% confidence interval. Biomass combined with the combustion technology for the CFB boiler proved to be more effective in reducing the N(2)O emission, compared to the emission factor of the CFB boiler using fossil fuel.

  1. The causal factors of international inequality in co2 emissions per capita: a regression-based inequality decomposition analysis

    OpenAIRE

    Duro Moreno, Juan Antonio; Teixidó-Figueras, Jordi; Padilla, Emilio

    2014-01-01

    This paper uses the possibilities provided by the regression-based inequality decomposition (Fields, 2003) to explore the contribution of different explanatory factors to international inequality in CO2 emissions per capita. In contrast to previous emissions inequality decompositions, which were based on identity relationships (Duro and Padilla, 2006), this methodology does not impose any a priori specific relationship. Thus, it allows an assessment of the contribution to inequality of differ...

  2. A Factor Decomposition on China’s Carbon Emission from 1997 to 2012 Based on IPAT-LMDI Model

    Directory of Open Access Journals (Sweden)

    Wei Li

    2015-01-01

    Full Text Available We probe into the key factors that possess significant effects on China’s CO2 emissions during 1997–2012 on the basis of IPAT-LMDI model. Carbon dioxide emissions are specifically decomposed into CO2 emission intensity, energy structure, energy intensity, industrial structure, economic output, and population scale effects. Results indicate that the paramount driving factors that resulted in the growth of CO2 emissions are economic output, population scale, and energy structure. In contrast, energy intensity and industrial structure generally play an outstanding role in reducing emissions. This paper constructs a new weight assessment system by introducing “contribution value-significant factor-effect coefficient” to replace “contribution value-contribution rate” in the previous literature. According to the most significant positive effect and the most negative effect from the conclusion, we point out the effective policies that can not only accelerate the target of “China’s carbon emissions per unit of GDP could be cut down by 40–45% by 2020, from 2005 levels,” but also have crucial significance on the low-carbon economic development strategy of China.

  3. Variability in Light-Duty Gasoline Vehicle Emission Factors from Trip-Based Real-World Measurements.

    Science.gov (United States)

    Liu, Bin; Frey, H Christopher

    2015-10-20

    Using data obtained with portable emissions measurements systems (PEMS) on multiple routes for 100 gasoline vehicles, including passenger cars (PCs), passenger trucks (PTs), and hybrid electric vehicles (HEVs), variability in tailpipe emission rates was evaluated. Tier 2 emission standards are shown to be effective in lowering NOx, CO, and HC emission rates. Although PTs are larger, heavier vehicles that consume more fuel and produce more CO2 emissions, they do not necessarily produce more emissions of regulated pollutants compared to PCs. HEVs have very low emission rates compared to tier 2 vehicles under real-world driving. Emission factors vary with cycle average speed and road type, reflecting the combined impact of traffic control and traffic congestion. Compared to the slowest average speed and most congested cycles, optimal emission rates could be 50% lower for CO2, as much as 70% lower for NOx, 40% lower for CO, and 50% lower for HC. There is very high correlation among vehicles when comparing driving cycles. This has implications for how many cycles are needed to conduct comparisons between vehicles, such as when comparing fuels or technologies. Concordance between empirical and predicted emission rates using the U.S. Environmental Protection Agency's MOVES model was also assessed.

  4. Study on Influencing Factors of Carbon Emissions from Energy Consumption of Shandong Province of China from 1995 to 2012

    Directory of Open Access Journals (Sweden)

    Jiekun Song

    2014-01-01

    Full Text Available Carbon emissions from energy consumption of Shandong province from 1995 to 2012 are calculated. Three zero-residual decomposition models (LMDI, MRCI and Shapley value models are introduced for decomposing carbon emissions. Based on the results, Kendall coordination coefficient method is employed for testing their compatibility, and an optimal weighted combination decomposition model is constructed for improving the objectivity of decomposition. STIRPAT model is applied to evaluate the impact of each factor on carbon emissions. The results show that, using 1995 as the base year, the cumulative effects of population, per capita GDP, energy consumption intensity, and energy consumption structure of Shandong province in 2012 are positive, while the cumulative effect of industrial structure is negative. Per capita GDP is the largest driver of the increasing carbon emissions and has a great impact on carbon emissions; energy consumption intensity is a weak driver and has certain impact on carbon emissions; population plays a weak driving role, but it has the most significant impact on carbon emissions; energy consumption structure is a weak driver of the increasing carbon emissions and has a weak impact on carbon emissions; industrial structure has played a weak inhibitory role, and its impact on carbon emissions is great.

  5. The spatial distribution of commuting CO2 emissions and the influential factors: A case study in Xi'an, China

    Directory of Open Access Journals (Sweden)

    Yuan-Yuan Liu

    2015-03-01

    Full Text Available As the transport sector is a major source of greenhouse gas emissions, the effect of urbanization on transport CO2 emissions in developing cities has become a key issue under global climate change. Examining the case of Xi'an, this paper aims to explore the spatial distribution of commuting CO2 emissions and influencing factors in the new, urban industry zones and city centers considering Xi'an's transition from a monocentric to a polycentric city in the process of urbanization. Based on household survey data from 1501 respondents, there are obvious differences in commuting CO2 emissions between new industry zones and city centers: City centers feature lower household emissions of 2.86 kg CO2 per week, whereas new industry zones generally have higher household emissions of 3.20 kg CO2 per week. Contrary to previous research results, not all new industry zones have high levels of CO2 emissions; with the rapid development of various types of industries, even a minimum level of household emissions of 2.53 kg CO2 per week is possible. The uneven distribution of commuting CO2 emissions is not uniformly affected by spatial parameters such as job–housing balance, residential density, employment density, and land use diversity. Optimum combination of the spatial parameters and travel pattern along with corresponding transport infrastructure construction may be an appropriate path to reduction and control of emissions from commuting.

  6. Study on influencing factors of carbon emissions from energy consumption of Shandong Province of China from 1995 to 2012.

    Science.gov (United States)

    Song, Jiekun; Song, Qing; Zhang, Dong; Lu, Youyou; Luan, Long

    2014-01-01

    Carbon emissions from energy consumption of Shandong province from 1995 to 2012 are calculated. Three zero-residual decomposition models (LMDI, MRCI and Shapley value models) are introduced for decomposing carbon emissions. Based on the results, Kendall coordination coefficient method is employed for testing their compatibility, and an optimal weighted combination decomposition model is constructed for improving the objectivity of decomposition. STIRPAT model is applied to evaluate the impact of each factor on carbon emissions. The results show that, using 1995 as the base year, the cumulative effects of population, per capita GDP, energy consumption intensity, and energy consumption structure of Shandong province in 2012 are positive, while the cumulative effect of industrial structure is negative. Per capita GDP is the largest driver of the increasing carbon emissions and has a great impact on carbon emissions; energy consumption intensity is a weak driver and has certain impact on carbon emissions; population plays a weak driving role, but it has the most significant impact on carbon emissions; energy consumption structure is a weak driver of the increasing carbon emissions and has a weak impact on carbon emissions; industrial structure has played a weak inhibitory role, and its impact on carbon emissions is great.

  7. Study on Influencing Factors of Carbon Emissions from Energy Consumption of Shandong Province of China from 1995 to 2012

    Science.gov (United States)

    Song, Jiekun; Song, Qing; Zhang, Dong; Lu, Youyou; Luan, Long

    2014-01-01

    Carbon emissions from energy consumption of Shandong province from 1995 to 2012 are calculated. Three zero-residual decomposition models (LMDI, MRCI and Shapley value models) are introduced for decomposing carbon emissions. Based on the results, Kendall coordination coefficient method is employed for testing their compatibility, and an optimal weighted combination decomposition model is constructed for improving the objectivity of decomposition. STIRPAT model is applied to evaluate the impact of each factor on carbon emissions. The results show that, using 1995 as the base year, the cumulative effects of population, per capita GDP, energy consumption intensity, and energy consumption structure of Shandong province in 2012 are positive, while the cumulative effect of industrial structure is negative. Per capita GDP is the largest driver of the increasing carbon emissions and has a great impact on carbon emissions; energy consumption intensity is a weak driver and has certain impact on carbon emissions; population plays a weak driving role, but it has the most significant impact on carbon emissions; energy consumption structure is a weak driver of the increasing carbon emissions and has a weak impact on carbon emissions; industrial structure has played a weak inhibitory role, and its impact on carbon emissions is great. PMID:24977216

  8. Techniques for Estimating Emissions Factors from Forest Burning: ARCTAS and SEAC4RS Airborne Measurements Indicate which Fires Produce Ozone

    Science.gov (United States)

    Chatfield, Robert B.; Andreae, Meinrat O.

    2016-01-01

    Previous studies of emission factors from biomass burning are prone to large errors since they ignore the interplay of mixing and varying pre-fire background CO2 levels. Such complications severely affected our studies of 446 forest fire plume samples measured in the Western US by the science teams of NASA's SEAC4RS and ARCTAS airborne missions. Consequently we propose a Mixed Effects Regression Emission Technique (MERET) to check techniques like the Normalized Emission Ratio Method (NERM), where use of sequential observations cannot disentangle emissions and mixing. We also evaluate a simpler "consensus" technique. All techniques relate emissions to fuel burned using C(burn) = delta C(tot) added to the fire plume, where C(tot) approximately equals (CO2 = CO). Mixed-effects regression can estimate pre-fire background values of C(tot) (indexed by observation j) simultaneously with emissions factors indexed by individual species i, delta, epsilon lambda tau alpha-x(sub I)/C(sub burn))I,j. MERET and "consensus" require more than emissions indicators. Our studies excluded samples where exogenous CO or CH4 might have been fed into a fire plume, mimicking emission. We sought to let the data on 13 gases and particulate properties suggest clusters of variables and plume types, using non-negative matrix factorization (NMF). While samples were mixtures, the NMF unmixing suggested purer burn types. Particulate properties (b scant, b abs, SSA, AAE) and gas-phase emissions were interrelated. Finally, we sought a simple categorization useful for modeling ozone production in plumes. Two kinds of fires produced high ozone: those with large fuel nitrogen as evidenced by remnant CH3CN in the plumes, and also those from very intense large burns. Fire types with optimal ratios of delta-NOy/delta- HCHO associate with the highest additional ozone per unit Cburn, Perhaps these plumes exhibit limited NOx binding to reactive organics. Perhaps these plumes exhibit limited NOx binding to

  9. Fire Radiative Power (FRP)-based Emission Factors of PM2.5, CO and NOX for Remote Sensing of Biomass Burning Emissions

    Science.gov (United States)

    Karandana Gamalathge, T. D.; Chen, L. W. A.

    2015-12-01

    Large-scale biomass burning such as forest fires represents an important and yet uncertain source of air pollutants and greenhouse gases on a global scale. Due to the highly accidental nature of forest fires, satellite remote sensing could be a promising method to develop regional and global fire emission inventories on a real-time basis. Reliable fire radiative power (FRP)-based fuel consumption and emission factors are critical in this approach. In an attempt to obtain the information, laboratory combustion experiments were conducted to simultaneously monitor FRP, fuel consumption, and emissions of fine particulate matter (PM2.5), carbon monoxide (CO), and reactive nitrogen oxides (NO and NO2). FRP were quantified using temperature-resolved values from a thermal imager instead of conventionally used average temperature, as the former provides more realistic estimates. For dry Ponderosa pine branches, a common fuel in the Sierra Nevada, a strong correlation (r2 ~ 0.8) between FRP and the mass reduction rate (MRR) was found. This led to a radiative energy yield (REY) of 8.5 ± 1.2 MJ/kg, assuming blackbody radiation and a flame emissivity of 0.5. Mass-based emission factors were determined with the carbon balance approach. Considering the ratio of mass-based emission factors and the REY, FRP-based emission factors: PM2.5: 11 g/MJ, CO: 8.0 g/MJ, NO: 0.33 g/MJ, and NO2: 0.07 g/MJ were quantified. The application of this approach to other fuel types and uncertainties in the measurements will be discussed.

  10. Spatial estimation of air PM2.5 emissions using activity data, local emission factors and land cover derived from satellite imagery

    Directory of Open Access Journals (Sweden)

    H. P. Gibe

    2017-09-01

    Full Text Available Exposure to particulate matter (PM is a serious environmental problem in many urban areas on Earth. In the Philippines, most existing studies and emission inventories have mainly focused on point and mobile sources, while research involving human exposures to particulate pollutants is rare. This paper presents a method for estimating the amount of fine particulate (PM2.5 emissions in a test study site in the city of Cabanatuan, Nueva Ecija, in the Philippines, by utilizing local emission factors, regionally procured data, and land cover/land use (activity data interpreted from satellite imagery. Geographic information system (GIS software was used to map the estimated emissions in the study area. The present results suggest that vehicular emissions from motorcycles and tricycles, as well as fuels used by households (charcoal and burning of agricultural waste, largely contribute to PM2.5 emissions in Cabanatuan. Overall, the method used in this study can be applied in other small urbanizing cities, as long as on-site specific activity, emission factor, and satellite-imaged land cover data are available.

  11. Spatial estimation of air PM2.5 emissions using activity data, local emission factors and land cover derived from satellite imagery

    Science.gov (United States)

    Gibe, Hezron P.; Cayetano, Mylene G.

    2017-09-01

    Exposure to particulate matter (PM) is a serious environmental problem in many urban areas on Earth. In the Philippines, most existing studies and emission inventories have mainly focused on point and mobile sources, while research involving human exposures to particulate pollutants is rare. This paper presents a method for estimating the amount of fine particulate (PM2.5) emissions in a test study site in the city of Cabanatuan, Nueva Ecija, in the Philippines, by utilizing local emission factors, regionally procured data, and land cover/land use (activity data) interpreted from satellite imagery. Geographic information system (GIS) software was used to map the estimated emissions in the study area. The present results suggest that vehicular emissions from motorcycles and tricycles, as well as fuels used by households (charcoal) and burning of agricultural waste, largely contribute to PM2.5 emissions in Cabanatuan. Overall, the method used in this study can be applied in other small urbanizing cities, as long as on-site specific activity, emission factor, and satellite-imaged land cover data are available.

  12. Evaluation of carbon dioxide emission factor from urea during rice cropping season: A case study in Korean paddy soil

    Science.gov (United States)

    Kim, Gil Won; Jeong, Seung Tak; Kim, Gun Yeob; Kim, Pil Joo; Kim, Sang Yoon

    2016-08-01

    Fertilization with urea can lead to a loss of carbon dioxide (CO2) that was fixed during the industrial production process. The extent of atmospheric CO2 removal from urea manufacturing was estimated by the Industrial Processes and Product Use sector (IPPU sector). On its basis, the Intergovernmental Panel on Climate Change (IPCC) has proposed a value of 0.2 Mg C per Mg urea (available in 2006 revised IPCC guidelines for greenhouse gas inventories), which is the mass fractions of C in urea, as the CO2 emission coefficient from urea for the agricultural sector. Notably, due to the possibility of bicarbonate leaching to waters, all C in urea might not get released as CO2 to the atmosphere. Hence, in order to provide an accurate value of the CO2 emission coefficient from applied urea in the rice ecosystem, the CO2 emission factors were characterized under different levels of 13C-urea applied paddy field in the current study. The total CO2 fluxes and rice grain yields increased significantly with increasing urea application (110-130 kg N ha-1) and thereafter, decreased. However, with increasing 13C-urea application, a significant and proportional increase of the 13CO2sbnd C emissions from 13C-urea was also observed. From the relationships between urea application levels and 13CO2sbnd C fluxes from 13C-urea, the CO2sbnd C emission factor from urea was estimated to range between 0.0143 and 0.0156 Mg C per Mg urea. Thus, the CO2sbnd C emission factor of this study is less than that of the value proposed by IPCC. Therefore, for the first time, we propose to revise the current IPCC guideline value of CO2sbnd C emission factor from urea as 0.0143-0.0156 Mg C per Mg urea for Korean paddy soils.

  13. Development of an improved urban emissivity model based on sky view factor for retrieving effective emissivity and surface temperature over urban areas

    Science.gov (United States)

    Yang, Jinxin; Wong, Man Sing; Menenti, Massimo; Nichol, Janet; Voogt, James; Krayenhoff, E. Scott; Chan, P. W.

    2016-12-01

    This study aims to evaluate the effects of urban geometry on retrieval of emissivity and surface temperature in urban areas. An improved urban emissivity model based on sky view factor (IUEM-SVF) was further enhanced to consider all radiance contributions leaving the urban canopy, including (i) emission by all facets within an instantaneous field of view (IFOV); (ii) reflection by all facets of emission from surrounding facets; and (iii) propagation of emitted and reflected radiation with multiple reflections (scattering) within a complex 3D array of urban objects. The effective emissivity derived from IUEM-SVF was evaluated with a microscale radiative transfer and energy balance model: Temperatures of Urban Facets in 3-D (TUF-3D). IUEM-SVF performs well when urban facets have uniform emissivity and temperature; e.g., root mean square deviations (RMSD) are less than 0.005 when material emissivity is larger than 0.80 (ɛ ⩾ 0.80). However, when material emissivities are variable within the observed target, differences of effective emissivity between IUEM-SVF and TUF-3D become larger, e.g., RMSD of 0.010. When the effect of geometry is not considered and a mixed pixel emissivity is defined, the difference is even much larger (i.e. 0.02) and this difference increases with the decrease of sky view factor. Thus, the geometry effect should be considered in the determination of effective emissivity. Effective emissivity derived from IUEM-SVF was used to retrieve urban surface temperature from a nighttime ASTER thermal infrared image. Promising results were achieved in comparison with standard LST products retrieved with the Temperature and Emissivity Separation (TES) algorithm. IUEM-SVF shows promise as a means to improve the accuracy of urban surface temperature retrieval. The effect of thermal heterogeneity on the effective emissivity was also evaluated by TUF-3D, and results show that the thermal heterogeneity cannot be neglected since the RMSD between the effective

  14. [Perinatal factors affecting the detection of otoacoustic emissions in vaginally delivered, healthy newborns, during the first 48 hours of life].

    Science.gov (United States)

    Sequi-Canet, José M; Sala-Langa, María J; Collar Del Castillo, José I

    2014-01-01

    Most hospitals perform neonatal hearing screening because it is a very useful procedure. Otoacoustic emissions are an ideal technique for this screening. We analyse the possible influence on screening results of some perinatal factors. We collected retrospective data from 8,239 healthy newborns delivered vaginally at the maternity ward of our hospital. We compared multiple perinatal factors vs the results of otoacoustic emissions performed within the first 48 h of life, before discharge. A total of 6.4% of newborns had an abnormal response and failed the screening. Univariate and multivariate analysis showed a significant (P<.0001) positive relationship between breastfeeding and normal otoacoustic emissions (OR: 0.65). Another, less significant factor was female gender. The remaining variables, including origin, education or employment status of the mother, maternal smoking, dystocic delivery, presentation, need for resuscitation, preterm labour (34-36 weeks), weight, length and frequent maternal pathology, such as streptococcus detection, hypothyroidism, hypertension or diabetes, were not significant. Breastfeeding was the most important factor related to a normal response in otoacoustic emissions. It may improve final results and reduce the number of neonates who need to be rescheduled for a repeated test, as well as the associated anxiety and the possibility of losing patients during follow-up. These are major problems in neonatal hearing screening. Copyright © 2013 Elsevier España, S.L. All rights reserved.

  15. Monitoring organic loading to swimming pools by fluorescence excitation–emission matrix with parallel factor analysis (PARAFAC)

    DEFF Research Database (Denmark)

    Seredynska-Sobecka, Bozena; Stedmon, Colin; Boe-Hansen, Rasmus

    2011-01-01

    Fluorescence Excitation–Emission Matrix spectroscopy combined with parallel factor analysis was employed to monitor water quality and organic contamination in swimming pools. The fluorescence signal of the swimming pool organic matter was low but increased slightly through the day. The analysis...... loading in swimming pool water. The fluorescence at 420nm gradually increased during opening hours and represented material accumulating through the day....

  16. Magnetic Field Emission Comparison at Different Quality Factors with Series-Parallel Compensation Network for Wireless Power Transfer to Vehicles

    DEFF Research Database (Denmark)

    Batra, Tushar; Schaltz, Erik

    2014-01-01

    Input current of wireless power transfer system is limited by current rating of power converter on the primary side. Power rating of wireless power transfer system increases linearly with the quality factor for series-parallel topology of the system at a given primary current. Magnetic emissions...

  17. Field Studies Show That In Situ Greenhouse Gas Emission Factors for East African Agriculture Are Less Than IPCC Values

    Science.gov (United States)

    Pelster, D.; Butterbach-Bahl, K.; Rufino, M.; Rosenstock, T. S.; Wanyama, G.

    2015-12-01

    Greenhouse gas (GHG) emissions from African agricultural systems are thought to comprise a large portion of total emissions from the continent, however these estimates have been calculated using emission factors (EF) from other regions due to the lack of field studies in Africa, which results in large uncertainties for these estimates. Field measurements from western Kenya calculating emissions over a year in 59 different sites found that GHG emissions from typical smallholder farms ranged from 2.8 to 15.0 Mg CO2-C ha-1, -6.0 to 2.4 kg CH4-C ha-1 and -0.1 to 1.8 kg N2O-N ha-1, and were not affected by management intensity. The lack of a response in N2O emissions to N fertilization suggests that the EF currently used in national inventories overestimates N2O emissions from typical smallholder agriculture. Another study measuring N2O and CH4 emissions from manure deposited by grazing cattle found that the N2O EF ranged from 0.1 to 0.2%, while the CH4 EF ranged from 0.04 to 0.14 Kg CH4-C per 173 kg animal. These suggest that the current IPCC EF overestimate agricultural soil and manure GHG emissions for Kenya, and likely for much of East Africa.

  18. Factors influencing CO2 and CH4 emissions from coastal wetlands in the Liaohe Delta, Northeast China

    Directory of Open Access Journals (Sweden)

    L. Olsson

    2015-02-01

    Full Text Available Many factors are known to influence greenhouse gas emissions from coastal wetlands, but it is still unclear which factors are most important under field conditions when they are all acting simultaneously. The objective of this study was to assess the effects of water table, salinity, soil temperature and vegetation on CH4 emissions and ecosystem respiration (Reco from five coastal wetlands in the Liaohe Delta, northeast China: two Phragmites australis (common reed wetlands, two Suaeda salsa (sea blite marshes and a rice (Oryza sativa paddy. Throughout the growing season, the Suaeda wetlands were net CH4 sinks whereas the Phragmites wetlands and the rice paddy were net CH4 sources emitting 1.2–6.1 g CH4 m−2 y−1. The Phragmites wetlands emitted the most CH4 per unit area and the most CH4 relative to CO2. The main controlling factors for the CH4 emissions were water table, temperature and salinity. The CH4 emission was accelerated at high and constant (or managed water tables and decreased at water tables below the soil surface. High temperatures enhanced CH4 emissions, and emission rates were consistently low (4 m−2 h at soil temperatures 18 ppt, the CH4 emission rates were always low (4 m−2 h−1 probably because methanogens were outcompeted by sulphate reducing bacteria. Saline Phragmites wetlands can, however, emit significant amounts of CH4 as CH4 produced in deep soil layers are transported through the air-space tissue of the plants to the atmosphere. The CH4 emission from coastal wetlands can be reduced by creating fluctuating water tables, including water tables below the soil surface, as well as by occasional flooding by high-salinity water. The effects of water management schemes on the biological communities in the wetlands must, however, be carefully studied prior to the management in order to avoid undesirable effects on the wetland communities.

  19. Factors influencing CO2 and CH4 emissions from coastal wetlands in the Liaohe Delta, Northeast China

    Science.gov (United States)

    Olsson, L.; Ye, S.; Yu, X.; Wei, M.; Krauss, K. W.; Brix, H.

    2015-08-01

    Many factors are known to influence greenhouse gas emissions from coastal wetlands, but it is still unclear which factors are most important under field conditions when they are all acting simultaneously. The objective of this study was to assess the effects of water table, salinity, soil temperature and vegetation on CH4 emissions and ecosystem respiration (Reco) from five coastal wetlands in the Liaohe Delta, Northeast China: two Phragmites australis (common reed) wetlands, two Suaeda salsa (sea blite) marshes and a rice (Oryza sativa) paddy. Throughout the growing season, the Suaeda wetlands were net CH4 sinks whereas the Phragmites wetlands and the rice paddy were net CH4 sources emitting 1.2-6.1 g CH4 m-2 yr-1. The Phragmites wetlands emitted the most CH4 per unit area and the most CH4 relative to CO2. The main controlling factors for the CH4 emissions were water table, temperature, soil organic carbon and salinity. The CH4 emission was accelerated at high and constant (or managed) water tables and decreased at water tables below the soil surface. High temperatures enhanced CH4 emissions, and emission rates were consistently low ( 18 ppt, the CH4 emission rates were always low (bacteria. Saline Phragmites wetlands can, however, emit significant amounts of CH4 as CH4 produced in deep soil layers are transported through the air-space tissue of the plants to the atmosphere. The CH4 emission from coastal wetlands can be reduced by creating fluctuating water tables, including water tables below the soil surface, as well as by occasional flooding by high-salinity water. The effects of water management schemes on the biological communities in the wetlands must, however, be carefully studied prior to the management in order to avoid undesirable effects on the wetland communities.

  20. Corruption Factors

    OpenAIRE

    Polterovich, Victor

    1998-01-01

    Among the factors that give rise to corruption, it is suggested that three groups be distinguished: fundamental factors rooted in the imperfection of economic institutions and economic policy, organizational factors ("weakness of the government"), and societal factors that depend on the prehistory and are connected with the mass culture and norms of bureaucratic behavior. A model in which corruption equilibrium is supported by non-optimum tax policy or by slow technical progress is compared w...

  1. Mobility as a territorial key factor in the emission of greenhouse gases; La movilidad como factor territorial dominante en la emision de gases de efecto invernadero

    Energy Technology Data Exchange (ETDEWEB)

    Crespo Garcia, L.; Montane Lopez, M. M.; Garcia Cortes, A.; Jimenez Arroyo, F.

    2011-07-01

    Transport and energy generation are the two dominant sectors in the overall balance of energy consumption, and thus of greenhouse gases emissions. Placement of energy generation plants responds to strategic reasons relate to energy supply in the Spanish territory, while transport is an economic activity tightly related to the productive structure and territorial characteristics: density of populations, geographic situation, efficient space organization, etc. The analysis of these factors enables to prioritize different strategies according the their energetic efficiency in order to pursue an economy less dependent of fossil fuels, focused in activities of higher added value and that keeps in mind limits and strengths of Spanish reality. (Author) 9 refs.

  2. Driving factors of carbon dioxide emissions in China: an empirical study using 2006-2010 provincial data

    Science.gov (United States)

    Liu, Yu; Chen, Zhan-Ming; Xiao, Hongwei; Yang, Wei; Liu, Danhe; Chen, Bin

    2016-04-01

    The rapid urbanization of China has increased pressure on its environmental and ecological well being. In this study, the temporal and spatial profiles of China's carbon dioxide emissions are analyzed by taking heterogeneities into account based on an integration of the extended stochastic impacts using a geographically and temporally weighted regression model on population, affluence, and technology. Population size, urbanization rate, GDP per capita, energy intensity, industrial structure, energy consumption pattern, energy prices, and economy openness are identified as the key driving factors of regional carbon dioxide emissions and examined through the empirical data for 30 provinces during 2006-2010. The results show the driving factors and their spillover effects have distinct spatial and temporal heterogeneities. Most of the estimated time and space coefficients are consistent with expectation. According to the results of this study, the heterogeneous spatial and temporal effects should be taken into account when designing policies to achieve the goals of carbon dioxide emissions reduction in different regions.

  3. Driving factors of carbon dioxide emissions in China: an empirical study using 2006-2010 provincial data

    Science.gov (United States)

    Liu, Yu; Chen, Zhan-Ming; Xiao, Hongwei; Yang, Wei; Liu, Danhe; Chen, Bin

    2017-03-01

    The rapid urbanization of China has increased pressure on its environmental and ecological well being. In this study, the temporal and spatial profiles of China's carbon dioxide emissions are analyzed by taking heterogeneities into account based on an integration of the extended stochastic impacts using a geographically and temporally weighted regression model on population, affluence, and technology. Population size, urbanization rate, GDP per capita, energy intensity, industrial structure, energy consumption pattern, energy prices, and economy openness are identified as the key driving factors of regional carbon dioxide emissions and examined through the empirical data for 30 provinces during 2006‒2010. The results show the driving factors and their spillover effects have distinct spatial and temporal heterogeneities. Most of the estimated time and space coefficients are consistent with expectation. According to the results of this study, the heterogeneous spatial and temporal effects should be taken into account when designing policies to achieve the goals of carbon dioxide emissions reduction in different regions.

  4. GHG emission factors developed for the collection, transport and landfilling of municipal waste in South African municipalities.

    Science.gov (United States)

    Friedrich, Elena; Trois, Cristina

    2013-04-01

    Greenhouse gas (GHG) emission factors are used with increased frequency for the accounting and reporting of GHG from waste management. However, these factors have been calculated for developed countries of the Northern Hemisphere and are lacking for developing countries. This paper shows how such factors have been developed for the collection, transport and landfilling of municipal waste in South Africa. As such it presents a model on how international results and methodology can be adapted and used to calculate country-specific GHG emission factors from waste. For the collection and transport of municipal waste in South Africa, the average diesel consumption is around 5 dm(3) (litres) per tonne of wet waste and the associated GHG emissions are about 15 kg CO2 equivalents (CO2 e). Depending on the type of landfill, the GHG emissions from the landfilling of waste have been calculated to range from -145 to 1016 kg CO2 e per tonne of wet waste, when taking into account carbon storage, and from 441 to 2532 kg CO2 e per tonne of wet waste, when carbon storage is left out. The highest emission factor per unit of wet waste is for landfill sites without landfill gas collection and these are the dominant waste disposal facilities in South Africa. However, cash strapped municipalities in Africa and the developing world will not be able to significantly upgrade these sites and reduce their GHG burdens if there is no equivalent replacement of the Clean Development Mechanism (CDM) resulting from the Kyoto agreement. Other low cost avenues need to be investigated to suit local conditions, in particular landfill covers which enhance methane oxidation. Copyright © 2012 Elsevier Ltd. All rights reserved.

  5. Black Carbon Concentrations and Diesel Vehicle Emission Factors Derived from Coefficient of Haze Measurements in California: 1967-2003

    Energy Technology Data Exchange (ETDEWEB)

    Tast, CynthiaL; Kirchstetter, Thomas W.; Aguiar, Jeffery; Tonse, Shaheen; Novakov, T.; Fairley, David

    2007-11-09

    We have derived ambient black carbon (BC) concentrations and estimated emission factors for on-road diesel vehicles from archived Coefficient of Haze (COH) data that was routinely collected beginning in 1967 at 11 locations in the San Francisco Bay Area. COH values are a measure of the attenuation of light by particles collected on a white filter, and available data indicate they are proportional to BC concentrations measured using the conventional aethalometer. Monthly averaged BC concentrations are up to five times greater in winter than summer, and, consequently, so is the population?s exposure to BC. The seasonal cycle in BC concentrations is similar for all Bay Area sites, most likely due to area-wide decreased pollutant dispersion during wintertime. A strong weekly cycle is also evident, with weekend concentrations significantly lower than weekday concentrations, consistent with decreased diesel traffic volume on weekends. The weekly cycle suggests that, in the Bay Area, diesel vehicle emissions are the dominant source of BC aerosol. Despite the continuous increase in diesel fuel consumption in California, annual Bay Area average BC concentrations decreased by a factor of ~;;3 from the late 1960s to the early 2000s. Based on estimated annual BC concentrations, on-road diesel fuel consumption, and recent measurements of on-road diesel vehicle BC emissions, diesel BC emission factors decreased by an order of magnitude over the study period. Reductions in the BC emission factor reflect improved engine technology, emission controls and changes in diesel fuel composition. A new BC monitoring network is needed to continue tracking ambient BC trends because the network of COH monitors has recently been retired.

  6. Development of ammonia emission factors for the land application of poultry manure in the Lower Fraser Valley of British Columbia

    Energy Technology Data Exchange (ETDEWEB)

    Lau, A.K. [British Columbia Univ., Vancouver, BC (Canada). Dept. of Chemical and Biological Engineering; Bittman, S.; Hunt, D.E. [Agriculture and Agri-Food Canada, Agassiz, BC (Canada). Pacific Agricultural Research Centre

    2008-07-01

    An estimated 6 per cent of all Canadian ammonia emissions can be attributed to land application of poultry manure. Poultry production in British Columbia (BC) constitutes 15 per cent of the total production in Canada, most of it concentrated in the Lower Fraser Valley, generating about 300,000 tonnes of manure each year. The losses of ammonia must be quantified in order to predict local deposition, nitrogen balances and impact on air quality, particularly the formation of secondary fine particulate matter less than 2.5 mm which is often composed of ammonium nitrate and ammonium sulfate. This study investigated ammonia emissions associated with manure application from various types of poultry operations. After manure application, ammonia emission rates were determined using wind tunnels, capturing the emitted ammonia with acid traps. For all trials, the highest emissions occurred within the first day, and gradually declined over the next 2-3 weeks. Cumulative ammonia emission in all treatments did not exceed the initial amount of ammonia nitrogen present in manure. Ammonia emission rates were significantly different among the manure types. The percent total loss of ammonia with time was positively correlated with manure pH. Ammonia emission rates were typically higher in the spring trials than the fall trial. These data will be used to update ammonia emission factors for BC and Canada. 26 refs., 4 tabs., 3 figs.

  7. Newborn hearing screening by transient evoked otoacoustic emissions: analysis of response as a function of risk factors.

    Science.gov (United States)

    De Capua, B; De Felice, C; Costantini, D; Bagnoli, F; Passali, D

    2003-02-01

    Hearing loss can be considered as the most common birth defect. Early detection of hearing loss by screening at, or shortly after, birth and appropriate intervention are critical to speech, language and cognitive development. In the present study, the characteristics of Transient Evoked Otoacoustic Emissions have been evaluated as a function of known pre- and perinatal risk factors for hearing loss. All newborns were screened for hearing loss using a physiologic test of hearing function, the Transient Evoked Otoacoustic Emissions. A total of 532 consecutive newborn infants received binaural Transient Evoked Otoacoustic Emission testing (262 males, 270 females; mean gestational age 39.2 +/- 2.1 weeks, range 26-43; birth weight: 3,240 +/- 550 g, range 910-4,780). The population examined comprised 448 control infants and 84 high-risk for hearing loss infants (Joint Committee on Infant Hearing 1994 criteria). All Transient Evoked Otoacoustic Emission recordings were performed at comparable postconceptional ages. Audiological screening by Transient Evoked Otoacoustic Emission recording showed an overall 100% sensitivity, 99.02% specificity, with negative and positive predictive values of 100% and 62.5%, respectively. As compared to controls, high-risk infants showed: 1. increased rates of Fail-1 (Transient Evoked Otoacoustic Emissions absent at first examination, 21.4% vs 9.8%, p = 0.004), Fail-2 (Transient Evoked Otoacoustic Emissions absent on retesting: 8.64% vs 1.37%, p = 0.0014), false positives (Transient Evoked Otoacoustic Emissions absent/V wave present: 3.7% vs 0.46%, p = 0.029) and true positives (Transient Evoked Otoacoustic Emissions absent, V wave absent: 2.47% or 24.5 per 1,000 live births vs 0.22% or 2.2 per 1,000 live births, p = 0.013); 2. significantly reduced Transient Evoked Otoacoustic Emission intensity in the 0.7-1 kHz (right side) and 1-2 kHz (left side) frequency ranges. Multivariate logistic regression analysis showed a significant positive

  8. Emission factors of air pollutants from CNG-gasoline bi-fuel vehicles: Part I. Black carbon.

    Science.gov (United States)

    Wang, Yang; Xing, Zhenyu; Xu, Hui; Du, Ke

    2016-12-01

    Compressed natural gas (CNG) is considered to be a "cleaner" fuel compared to other fossil fuels. Therefore, it is used as an alternative fuel in motor vehicles to reduce emissions of air pollutants in transportation. To quantify "how clean" burning CNG is compared to burning gasoline, quantification of pollutant emissions under the same driving conditions for motor vehicles with different fuels is needed. In this study, a fleet of bi-fuel vehicles was selected to measure the emissions of black carbon (BC), carbon monoxide (CO), hydrocarbon (HC) and nitrogen oxide (NOx) for driving in CNG mode and gasoline mode respectively under the same set of constant speeds and accelerations. Comparison of emission factors (EFs) for the vehicles burning CNG and gasoline are discussed. This part of the paper series reports BC EFs for bi-fuel vehicles driving on the real road, which were measured using an in situ method. Our results show that burning CNG will lead to 54%-83% reduction in BC emissions per kilometer, depending on actual driving conditions. These comparisons show that CNG is a cleaner fuel than gasoline for motor vehicles in terms of BC emissions and provide a viable option for reducing BC emissions cause by transportation. Copyright © 2016 Elsevier B.V. All rights reserved.

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

    NARCIS (Netherlands)

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

    2014-01-01

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

  10. El factoring

    Directory of Open Access Journals (Sweden)

    Alberto Rosenthal

    1988-04-01

    Full Text Available RESUMEN El artículo  presenta, una conceptualización general de lo que es el factoring, el origen del mismo, su evolución y hace una clasificación de los distintos tipos de factoring.

  11. Robust factorization

    DEFF Research Database (Denmark)

    Aanæs, Henrik; Fisker, Rune; Åström, Kalle;

    2002-01-01

    Factorization algorithms for recovering structure and motion from an image stream have many advantages, but they usually require a set of well-tracked features. Such a set is in generally not available in practical applications. There is thus a need for making factorization algorithms deal...... effectively with errors in the tracked features. We propose a new and computationally efficient algorithm for applying an arbitrary error function in the factorization scheme. This algorithm enables the use of robust statistical techniques and arbitrary noise models for the individual features....... These techniques and models enable the factorization scheme to deal effectively with mismatched features, missing features, and noise on the individual features. The proposed approach further includes a new method for Euclidean reconstruction that significantly improves convergence of the factorization algorithms...

  12. Determination of a potential set of factors which influence the situation of methane emission into roadways being driven

    Energy Technology Data Exchange (ETDEWEB)

    Marian Turek [Central Mining Institute, Katowice (Poland)

    2009-12-15

    The currently applied methodology of absolute gassiness forecasting in roadways being driven in Polish hard coal mines is based on the results of investigations over twenty years. The application of 'old' methods of forecasting of methane emission during driving of roadways often brings about great discrepancies between the results of the forecasts and actual situation. It is firstly necessary to determine a potential set of factors which exert an influence on situation regarding methane emission into roadways being driven in order to prepare a verified mathematical model of absolute gassiness forecasting. On the basis of available literature and the investigations conducted by the Central Mining Institute an initial list of factors has been prepared which can have an impact upon methane emission into roadways being driven. A prepared initial set has been scrutinized to be verified on the basis of a conducted expert survey among seventy specialists in this field. After collecting of the results of the survey their statistical elaboration was prepared. The co-efficient of agreement of multiple ordering, the so called concordance co-efficient has been taken advantage of in order to check the competency of experts. The investigations prove that the experts are in agreement in their opinions. The estimation of a collective assessment of all participants of the survey was conducted with the use of the rank sum's test by J. Gren. The results of the conducted analysis allowed determining a potential set of factors which influence the situation of methane emission into roadways being driven. This set, after conductance of further detailed investigations, can constitute a base for elaboration of a function describing methane emission into roadways being driven in hard coal mines. 11 refs., 3 tabs.

  13. Dispersion of traffic-related exhaust particles near the Berlin urban motorway – estimation of fleet emission factors

    Directory of Open Access Journals (Sweden)

    W. Birmili

    2009-04-01

    Full Text Available Atmospheric particle number size distributions of airborne particles (diameter range 10–500 nm were collected over ten weeks at three sites in the vicinity of the A100 urban motorway in Berlin, Germany. The A100 carries about 180 000 vehicles on a weekday. The roadside particle distributions showed a number maximum between 20 and 60 nm clearly related to the motorway emissions. The average total number concentration at roadside was 28 000 cm−3 with a total range of 1200–168 000 cm−3. At distances of 80 and 400 m from the motorway the concentrations decreased to mean levels of 11 000 and 9000 cm−3, respectively. An obstacle-resolving dispersion model was applied to simulate the 3-D flow field and traffic tracer transport in the urban environment around the motorway. By inverse modelling, vehicle emission factors were derived that are representative of a fleet with a relative share of 6% lorry-like vehicles, and driving at a speed of 80 km h−1. Three different calculation approaches were compared, which differ in the choice of the experimental winds driving the flow simulation. The average emission factor per vehicle was 2.1 (±0.2 · 1014 km−1 for particle number and 0.077 (±0.01 · 1014 cm3 km−1 for particle volume. Regression analysis suggested that lorry-like vehicles emit 123 (±28 times more particle number than passenger car-like vehicles, and lorry-like vehicles account for about 91% of particulate number emissions on weekdays. Our work highlights the increasing applicability of 3-D flow models in urban microscale environments and their usefulness for determining traffic emission factors.

  14. Size-Resolved Particle Number and Volume Emission Factors for On-Road Gasoline and Diesel Motor Vehicles

    Energy Technology Data Exchange (ETDEWEB)

    Ban-Weiss, George A.; Lunden, Melissa M.; Kirchstetter, Thomas W.; Harley, Robert A.

    2009-04-10

    Average particle number concentrations and size distributions from {approx}61,000 light-duty (LD) vehicles and {approx}2500 medium-duty (MD) and heavy-duty (HD) trucks were measured during the summer of 2006 in a San Francisco Bay area traffic tunnel. One of the traffic bores contained only LD vehicles, and the other contained mixed traffic, allowing pollutants to be apportioned between LD vehicles and diesel trucks. Particle number emission factors (particle diameter D{sub p} > 3 nm) were found to be (3.9 {+-} 1.4) x 10{sup 14} and (3.3 {+-} 1.3) x 10{sup 15} kg{sup -1} fuel burned for LD vehicles and diesel trucks, respectively. Size distribution measurements showed that diesel trucks emitted at least an order of magnitude more particles for all measured sizes (10 < D{sub p} < 290 nm) per unit mass of fuel burned. The relative importance of LD vehicles as a source of particles increased as D{sub p} decreased. Comparing the results from this study to previous measurements at the same site showed that particle number emission factors have decreased for both LD vehicles and diesel trucks since 1997. Integrating size distributions with a volume weighting showed that diesel trucks emitted 28 {+-} 11 times more particles by volume than LD vehicles, consistent with the diesel/gasoline emission factor ratio for PM{sub 2.5} mass measured using gravimetric analysis of Teflon filters, reported in a companion paper.

  15. Zero Emission Building And Conversion Factors Between Electricity Consumption And Emissions Of Greenhouse Gases In A Long Term Perspective

    Directory of Open Access Journals (Sweden)

    Graabak Ingeborg

    2014-12-01

    Full Text Available The CO2 emissions from a building’s power system will change over the life time of the building, and this need to be taken into account to verify whether a building is Zero Emission (ZEB or not.

  16. Determining gaseous emission factors and driver's particle exposures during traffic congestion by vehicle-following measurement techniques.

    Science.gov (United States)

    Tang, U Wa; Wang, Zhishi

    2006-11-01

    Vehicle gaseous emissions (NO, CO, CO2, and hydrocarbon [HC]) and driver's particle exposures (particulate matter traffic congestion in Macao, Special Administrative Region, People's Republic of China, an urban area having one of the highest population densities in the world. The measurements were taken with high time resolution so that fluctuations in the emissions can be seen readily during vehicle acceleration, cruising, deceleration, and idling. The tests were conducted in close proximity to the vehicles, with the inlet of a five-gas analyzer mounted on the front bumper of the mobile laboratory, and the distance between the vehicles was usually within several meters. To measure the driver's particle exposures, the inlets of the particle analyzers were mounted at the height of the driver's breathing position in the mobile laboratory, with the driver's window open. A total of 178 and 113 vehicles were followed individually to determine the gaseous emission factor and the driver's particle exposures, respectively, for motorcycle, passenger car, taxi, truck, and bus. The gaseous emission factors were used to model the roadside air quality, and good correlations between the modeled and monitored CO, NO2, and nitrogen oxide (NO(x)) verified the reliability of the experiments. Compared with petrol passenger cars and petrol trucks, diesel taxies and diesel trucks emitted less CO but more NO(x). The impact of urban canyons is shown to cause a significant increase in the PM1 peak. The background concentrations contributed a significant amount of the driver's particle exposures.

  17. Advanced REACH Tool : Development and application of the substance emission potential modifying factor

    NARCIS (Netherlands)

    Tongeren, M. van; Fransman, W.; Spankie, S.; Tischer, M.; Brouwer, D.; Schinkel, J.; Cherrie, J.W.; Tielemans, E.

    2011-01-01

    The Advanced REACH Tool (ART) is an exposure assessment tool that combines mechanistically modelled inhalation exposure estimates with available exposure data using a Bayesian approach. The mechanistic model is based on nine independent principal modifying factors (MF). One of these MF is the

  18. Determination of a potential set of factors which influence the situation of methane emission into roadways being driven

    Institute of Scientific and Technical Information of China (English)

    Marian Turek

    2009-01-01

    The currently applied methodology of absolute gassiness forecasting in roadways being driven in Polish hard coal mines is based on the results of investigations from before more than twenty years. At present the roadways are being driven in majority of cases in quite different conditions than those which had been the subject of the said investigations. The application of "old" methods of forecasting of methane emission during driving of roadways often brings about great discrepancies between the results of the forecasts and actual situation. It is firstly necessary to determine a potential set of factors which exert an influence on situation regarding methane emission into roadways being driven in order to prepare a verified mathematical model of absolute gassiness forecasting. On the basis of available literature and the investigations conducted by the Central Mining Institute an initial list of factors has been prepared which can have an impact upon methane emission into roadways being driven. The assumptions of heuristic method have been taken advantage of for selection of parameters and indices describing the phenomenon of methane emission. It has been dictated by the fact that the available literature is lacking a pretty unambiguous viewpoint on the subject under consideration and at the same time it is necessary to perform an a priori assessment of the information contained in a given feature (factor). A prepared initial set has been scrutinized to be verified on the basis of a conducted expert survey among seventy specialists in this field. After collecting of the results of the survey their statistical elaboration was prepared. The co-efficient of agreement of multiple ordering, the so called concordance co-efficient has been taken advantage of in order to check the competency of experts. The investigations prove that the experts are in agreement in their opinions. The estimation of a collective assessment of all participants of the survey was conducted

  19. El factoring

    Directory of Open Access Journals (Sweden)

    Alberto Rosenthal

    2015-04-01

    Full Text Available RESUMEN Se presenta la segunda parte del artículo aparecido en  el número 6 de la revista EAN. Su contenido es complementario a lo expuesto en dicho número, en está aparecen las ventajas del factoring, conveniencias, limitaciones así como la forma  de efectuar un factor en Colombia,  su necesidad, incidencia económica, etc.

  20. Description and History of the MOBILE Highway Vehicle Emission Factor Model

    Science.gov (United States)

    MOBILE is an EPA model for estimating pollution from highway vehicles. It has been superseded by the Motor Vehicle Emission Simulator (MOVES). MOBILE calculates emissions of hydrocarbons (HC), oxides of nitrogen (NOx) and carbon monoxide (CO).

  1. Size-resolved particle number emission patterns under real-world driving conditions using positive matrix factorization.

    Science.gov (United States)

    Domínguez-Sáez, Aida; Viana, Mar; Barrios, Carmen C; Rubio, Jose R; Amato, Fulvio; Pujadas, Manuel; Querol, Xavier

    2012-10-16

    A novel on-board system was tested to characterize size-resolved particle number emission patterns under real-world driving conditions, running in a EURO4 diesel vehicle and in a typical urban circuit in Madrid (Spain). Emission profiles were determined as a function of driving conditions. Source apportionment by Positive Matrix Factorization (PMF) was carried out to interpret the real-world driving conditions. Three emission patterns were identified: (F1) cruise conditions, with medium-high speeds, contributing in this circuit with 60% of total particle number and a particle size distribution dominated by particles >52 nm and around 60 nm; (F2) transient conditions, stop-and-go conditions at medium-high speed, contributing with 25% of the particle number and mainly emitting particles in the nucleation mode; and (F3) creep-idle conditions, representing traffic congestion and frequent idling periods, contributing with 14% to the total particle number and with particles in the nucleation mode (conditions. Differences between real-world emission patterns and regulatory cycles (NEDC) are also presented, which evidence that detecting particle number emissions real-world driving conditions.

  2. Life Cycle Building Carbon Emissions Assessment and Driving Factors Decomposition Analysis Based on LMDI—A Case Study of Wuhan City in China

    Directory of Open Access Journals (Sweden)

    Yuanyuan Gong

    2015-12-01

    Full Text Available Carbon emissions calculation at the sub-provincial level has issues in limited data and non-unified measurements. This paper calculated the life cycle energy consumption and carbon emissions of the building industry in Wuhan, China. The findings showed that the proportion of carbon emissions in the construction operation phase was the largest, followed by the carbon emissions of the indirect energy consumption and the construction material preparation phase. With the purpose of analyzing the contributors of the construction carbon emissions, this paper conducted decomposition analysis using Logarithmic Mean Divisia Index (LMDI. The results indicated that the increasing buidling area was the major driver of energy consumption and carbon emissions increase, followed by the behavior factor. Population growth and urbanization, to some extent, increased the carbon emissions as well. On the contrary, energy efficiency was the main inhibitory factor for reducing the carbon emissions. Policy implications in terms of low-carbon construction development were highlighted.

  3. Escape factors for Paschen 2p-1s emission lines in low-temperature Ar, Kr, and Xe plasmas

    Science.gov (United States)

    Zhu, Xi-Ming; Cheng, Zhi-Wen; Pu, Yi-Kang; Czarnetzki, Uwe

    2016-06-01

    Radiation trapping phenomenon is often observed when investigating low-temperature plasmas. Photons emitted from the upper excited states may be reabsorbed by the lower states before they leave the plasmas. In order to account for this effect in the modelling and optical diagnostics of plasmas, either an ‘escape factor’ of a function of the optical depth or a strict solution of the radiation transfer equation can be employed. However, the former is more convenient in comparison and thus is widely adopted. Previous literatures have provided several simple expressions of the escape factor for the uniform plasmas. The emission line profiles are assumed to be dominated by the Doppler broadening, and the line splitting due to the hyperfine structure is not considered. This kind of expression is only valid for small atoms, e.g. Ar in low-pressure uniform discharges. Actually, the excited state density in many of the low-temperature plasmas is non-uniform and the emission line profile can be significantly influenced by the collisional broadening at medium and high pressures. In these cases, a new escape factor equation should be calculated. In this work, we study the escape factor equations for the often used 2p-1s transitions (Paschen’s notation) of the Ar, Kr, and Xe atoms. Possible non-uniform density profiles are considered. In addition, we include the line splitting due to the hyperfine structure for Kr and Xe. For the low-pressure plasmas, an escape factor expression mainly based on the Gaussian line profile is given and particularly verified by an experiment in a low-pressure capacitive discharge. For the high-pressure plasmas, an equation based on the Voigt line profile is also calculated. In this way, the new escape factor expression is ready for use in the modelling of the Ar, Kr, and Xe plasmas from low to atmospheric pressure.

  4. Compositions and greenhouse gas emission factors of flared and vented gas in the Western Canadian Sedimentary Basin.

    Science.gov (United States)

    Johnson, Matthew R; Coderre, Adam R

    2012-09-01

    A significant obstacle in evaluating mitigation strategies for flaring and venting in the upstream oil and gas industry is the lack of publicly available data on the chemical composition of the gas. This information is required to determine the economic value of the gas, infrastructure and processing requirements, and potential emissions or emissions credits, all of which have significant impact on the economics of such strategies. This paper describes a method for estimating the composition of solution gas being flared and vented at individual facilities, and presents results derived for Alberta, Canada, which sits at the heart of the Western Canadian Sedimentary Basin. Using large amounts of raw data obtained through the Alberta Energy Resources Conservation Board, a relational database was created and specialized queries were developed to link production stream data, raw gas samples, and geography to create production-linked gas composition profiles for approximately half of the currently active facilities. These were used to create composition maps for the entire region, to which the remaining facilities with unknown compositions were geographically linked. The derived data were used to compute a range of solution gas composition profiles and greenhouse gas emission factors, providing new insight into flaring and venting in the region and enabling informed analysis of future management and mitigation strategies. Accurate and transparent determination of environmental impacts of flaring and venting of gas associated with oil production, and potential benefits of mitigation, is severely hampered by the lack of publicly available gas composition data. In jurisdictions within the Western Canadian Sedimentary Basin, frameworks exist for regulating and trading carbon offset credits but current potential for mitigation is limited by a lack of standardized methods for calculating CO2 equivalent emissions. The composition and emission factor data derived in this paper

  5. Aerosol and NOx emission factors and submicron particle number size distributions in two road tunnels with different traffic regimes

    Directory of Open Access Journals (Sweden)

    D. Imhof

    2006-01-01

    Full Text Available Measurements of aerosol particle number size distributions (18–700 nm, mass concentrations (PM2.5 and PM10 and NOx were performed in the Plabutsch tunnel, Austria, and in the Kingsway tunnel, United Kingdom. These two tunnels show different characteristics regarding the roadway gradient, the composition of the vehicle fleet and the traffic frequency. The submicron particle size distributions contained a soot mode in the diameter range D=80–100 nm and a nucleation mode in the range of D=20–40 nm. In the Kingsway tunnel with a significantly lower particle number and volume concentration level than in the Plabutsch tunnel, a clear diurnal variation of nucleation and soot mode particles correlated to the traffic density was observed. In the Plabutsch tunnel, soot mode particles also revealed a diurnal variation, whereas no substantial variation was found for the nucleation mode particles. During the night a higher number concentration of nucleation mode particles were measured than soot mode particles and vice versa during the day. In this tunnel with very high soot emissions during daytime due to the heavy-duty vehicle (HDV share of 18% and another 40% of diesel driven light-duty vehicles (LDV semivolatile species condense on the pre-existing soot surface area rather than forming new particles by homogeneous nucleation. With the low concentration of soot mode particles in the Kingsway tunnel, also the nucleation mode particles exhibit a diurnal variation. From the measured parameters real-world traffic emission factors were estimated for the whole vehicle fleet as well as differentiated into the two categories LDV and HDV. In the particle size range D=18–700 nm, each vehicle of the mixed fleet emits (1.50±0.08×1014 particles km-1 (Plabutsch and (1.26±0.10×1014 particles km-1 (Kingsway, while particle volume emission factors of 0.209±0.008 cm3 km-1 and 0.036±0.004 cm3 km-1, respectively, were obtained. PM1 emission factors of 104±4 mg

  6. Factorization of air pollutant emissions: projections versus observed trends in Europe.

    Science.gov (United States)

    Rafaj, Peter; Amann, Markus; Siri, José G

    2014-10-01

    This paper revisits the emission scenarios of the European Commission's 2005 Thematic Strategy on Air Pollution (TSAP) in light of today's knowledge. We review assumptions made in the past on the main drivers of emission changes, i.e., demographic trends, economic growth, changes in the energy intensity of GDP, fuel-switching, and application of dedicated emission control measures. Our analysis shows that for most of these drivers, actual trends have not matched initial expectations. Observed ammonia and sulfur emissions in European Union in 2010 were 10% to 20% lower than projected, while emissions of nitrogen oxides and particulate matter exceeded estimates by 8% to 15%. In general, a higher efficiency of dedicated emission controls compensated for a lower-than-expected decline in total energy consumption as well as a delay in the phase-out of coal. For 2020, updated projections anticipate lower sulfur and nitrogen oxide emissions than those under the 2005 baseline, whereby the degree to which these emissions are lower depends on what assumptions are made for emission controls and new vehicle standards. Projected levels of particulates are about 10% higher, while smaller differences emerge for other pollutants. New emission projections suggest that environmental targets established by the TSAP for the protection of human health, eutrophication and forest acidification will not be met without additional measures.

  7. Derivation of greenhouse gas emission factors for peatlands managed for extraction in the Republic of Ireland and the United Kingdom

    Science.gov (United States)

    Wilson, D.; Dixon, S. D.; Artz, R. R. E.; Smith, T. E. L.; Evans, C. D.; Owen, H. J. F.; Archer, E.; Renou-Wilson, F.

    2015-09-01

    Drained peatlands are significant hotspots of carbon dioxide (CO2) emissions and may also be more vulnerable to fire with its associated gaseous emissions. Under the United Nations Framework Convention on Climate Change (UNFCCC) and the Kyoto Protocol, greenhouse gas (GHG) emissions from peatlands managed for extraction are reported on an annual basis. However, the Tier 1 (default) emission factors (EFs) provided in the IPCC 2013 Wetlands Supplement for this land use category may not be representative in all cases and countries are encouraged to move to higher-tier reporting levels with reduced uncertainty levels based on country- or regional-specific data. In this study, we quantified (1) CO2-C emissions from nine peat extraction sites in the Republic of Ireland and the United Kingdom, which were initially disaggregated by land use type (industrial versus domestic peat extraction), and (2) a range of GHGs that are released to the atmosphere with the burning of peat. Drainage-related methane (CH4) and nitrous oxide (N2O) emissions as well as CO2-C emissions associated with the off-site decomposition of horticultural peat were not included here. Our results show that net CO2-C emissions were strongly controlled by soil temperature at the industrial sites (bare peat) and by soil temperature and leaf area index at the vegetated domestic sites. Our derived EFs of 1.70 (±0.47) and 1.64 (±0.44) t CO2-C ha-1 yr-1 for the industrial and domestic sites respectively are considerably lower than the Tier 1 EF (2.8 ± 1.7 t CO2-C ha-1 yr-1) provided in the Wetlands Supplement. We propose that the difference between our derived values and the Wetlands Supplement value is due to differences in peat quality and, consequently, decomposition rates. Emissions from burning of the peat (g kg-1 dry fuel burned) were estimated to be approximately 1346 CO2, 8.35 methane (CH4), 218 carbon monoxide (CO), 1.53 ethane (C2H6), 1.74 ethylene (C2H4), 0.60 methanol (CH3OH), 2.21 hydrogen

  8. Analysis of the impact path on factors of China's energy-related CO2 emissions: a path analysis with latent variables.

    Science.gov (United States)

    Chen, Wenhui; Lei, Yalin

    2017-02-01

    Identifying the impact path on factors of CO2 emissions is crucial for the government to take effective measures to reduce carbon emissions. The most existing research focuses on the total influence of factors on CO2 emissions without differentiating between the direct and indirect influence. Moreover, scholars have addressed the relationships among energy consumption, economic growth, and CO2 emissions rather than estimating all the causal relationships simultaneously. To fill this research gaps and explore overall driving factors' influence mechanism on CO2 emissions, this paper utilizes a path analysis model with latent variables (PA-LV) to estimate the direct and indirect effect of factors on China's energy-related carbon emissions and to investigate the causal relationships among variables. Three key findings emanate from the analysis: (1) The change in the economic growth pattern inhibits the growth rate of CO2 emissions by reducing the energy intensity; (2) adjustment of industrial structure contributes to energy conservation and CO2 emission reduction by raising the proportion of the tertiary industry; and (3) the growth of CO2 emissions impacts energy consumption and energy intensity negatively, which results in a negative impact indirectly on itself. To further control CO2 emissions, the Chinese government should (1) adjust the industrial structure and actively develop its tertiary industry to improve energy efficiency and develop low-carbon economy, (2) optimize population shifts to avoid excessive population growth and reduce energy consumption, and (3) promote urbanization steadily to avoid high energy consumption and low energy efficiency.

  9. Factors affecting the emission of monoterpenes from red pine (Pinus densiflora)

    Energy Technology Data Exchange (ETDEWEB)

    Yokouchi, Y.; Ambe, Y.

    1984-08-01

    The mechanism of monoterpene emission from Pinus densiflora was studied using an environmentally controlled gas cabinet. It was found that monoterpene emission rate increases exponentially with temperature and is also influenced by light. These observations were explained reasonably by a mechanism whereby monoterpene emission rate depends on the monoterpene amount in the leaf oil and its saturated vapor pressure. 14 references, 2 figures, 1 table.

  10. Changes in carbon dioxide emissions and LMDI-based impact factor decomposition:the Xinjiang Uygur autonomous region as a case

    Institute of Scientific and Technical Information of China (English)

    Li ZHANG; Jun LEI; Xuan ZHOU; XiaoLei ZHANG; Wen DONG; Yu YANG

    2014-01-01

    Studies on carbon dioxide (CO2) emissions at provincial level can provide a scientific basis for the op-timal use of energy and the formulation of CO2 reduction policies. We studied the variation of CO2 emissions of primary energy consumption and its influencing factors based on data in Xinjiang Uygur autonomous region from 1952 to 2008, which were calculated according to the 2006 IPCC Guidelines for National Greenhouse Gas Inven-tories. Xinjiang’s CO2 emission process from 1952 to 2008 could be divided into five stages according to the growth rates of total amount of CO2 emissions and CO2 emission intensity. The impact factors were quantitatively analyzed using Logarithmic Mean Divisia Index (LMDI) method in each stage. Various factors, including government policies and technological progress related to the role of CO2 emissions, were comprehensively analyzed, and the internal relationships among various factors were clarified. The results show that the contribution rates of various impact factors are different in each stage. Overall, economic growth and energy consumption intensity were the main driving factors for CO2 emissions. Since the implementation of the birth control policy, the driving force of population growth on the increase in CO2 emissions has slowly weakened. The energy consumption intensity was further af-fected by the industrial structure and energy consumption intensity of primary, secondary and tertiary industries, with the energy consumption intensity of the secondary industries and the proportion of secondary industries being the most important factors affecting the energy consumption intensity. Governmental policies and technological progress were also important factors that affected CO2 emissions.

  11. GHG emission factors for bioelectricity, biomethane, and bioethanol quantified for 24 biomass substrates with consequential life-cycle assessment

    DEFF Research Database (Denmark)

    Tonini, Davide; Hamelin, Lorie; Alvarado-Morales, Merlin

    2016-01-01

    Greenhouse gas (GHG) emission savings from biofuels dramatically depend upon the source of energy displaced and the effects induced outside the energy sector, for instance land-use changes (LUC). Using consequential life-cycle assessment and including LUC effects, this study provides GHG emission...... factors (EFs) for bioelectricity, biomethane, and bioethanol produced from twenty-four biomasses (from dedicated crops to residues of different origin) under a fossil and a non-fossil energy system. Accounting for numerous variations in the pathways, a total of 554 GHG EFs were quantified. The results...... showed that, important GHG savings were obtained with residues and seaweed, both under fossil and non-fossil energy systems. For high-yield perennial crops (e.g. willow and Miscanthus), GHG savings were achieved only under fossil energy systems. Biofuels from annual crops and residues that are today used...

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

    Science.gov (United States)

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

    2016-09-15

    The estimation of emission factors (EFs) is the basis of accurate emission inventory. However, the EFs of air pollutants for motor vehicles vary under different operating conditions, which will cause uncertainty in developing emission inventory. Natural gas (NG), considered as a "cleaner" fuel than gasoline, is increasingly being used to reduce combustion emissions. However, information is scarce about how much emission reduction can be achieved by motor vehicles burning NG (NGVs) under real road driving conditions, which is necessary for evaluating the environmental benefits for NGVs. Here, online, in situ measurements of the emissions from nine bi-fuel vehicles were conducted under different operating conditions on the real road. A comparative study was performed for the EFs of black carbon (BC), carbon monoxide (CO), hydrocarbons (HCs) and nitrogen oxides (NOx) for each operating condition when the vehicles using gasoline and compressed NG (CNG) as fuel. BC EFs were reported in part I. The part II in this paper series reports the influence of operating conditions and fuel types on the EFs of CO, HC and NOx. Fuel-based EFs of CO showed good correlations with speed when burning CNG and gasoline. The correlation between fuel-based HC EFs and speed was relatively weak whether burning CNG or gasoline. The fuel-based NOx EFs moderately correlated with speed when burning CNG, but weakly correlated with gasoline. As for HC, the mileage-based EFs of gasoline vehicles are 2.39-12.59 times higher than those of CNG vehicles. The mileage-based NOx EFs of CNG vehicles are slightly higher than those of gasoline vehicles. These results would facilitate a detailed analysis of the environmental benefits for replacing gasoline with CNG in light duty vehicles. Copyright © 2016 Elsevier B.V. All rights reserved.

  13. Modeling CO Emission: II. The Physical Characteristics that Determine the X factor in Galactic Molecular Clouds

    CERN Document Server

    Shetty, Rahul; Dullemond, Cornelis P; Ostriker, Eve C; Harris, Andrew I; Klessen, Ralf S

    2011-01-01

    We investigate how the X factor, the ratio of H_2 column density (NH2) to velocity-integrated CO intensity (W), is determined by the physical properties of gas in model molecular clouds (MCs). We perform radiative transfer calculations on chemical-MHD models to compute X. Using integrated NH2 and W reproduces the limited range in X found in observations, resulting in a mean value X=2\\times10^20 s/cm^2/K^1/km^1 from the Galactic MC model. However, in limited velocity intervals, X can take on a much larger range due to CO line saturation. Thus, X strongly depends on both the range in gas velocities and volume densities. The temperature (T) variations within individual MCs do not strongly affect X, as dense gas contributes most to setting X. For fixed velocity and density structure, gas with higher T has higher W, yielding X ~ T^-1/2 for T~20-100 K. We demonstrate that the linewidth-size scaling relation does not influence the X factor - only the range in velocities is important. Clouds with larger linewidths, r...

  14. Lateral gas transport in soil adjacent to an old landfill: factors governing emissions and methane oxidation

    DEFF Research Database (Denmark)

    Christophersen, Mette; Kjeldsen, Peter; Holst, Helle

    2001-01-01

    Field investigations of lateral gas transport and subsequent emissions in soil adjacent to an old landfill in Denmark have been conducted during a one-year period. A significant seasonal variation in the emissions with high carbon dioxide and low methane fluxes in the summer (May to October...

  15. Cyclone robber system total particulate emission factors and rates for cotton gins

    Science.gov (United States)

    This manuscript is part of a series of manuscripts that characterize cotton gin emissions from the standpoint of stack sampling. The impetus behind this project was the urgent need to collect additional cotton gin emissions data to address current regulatory issues. A key component of this study was...

  16. Cyclone robber system PM10 emission factors and rates for cotton gins

    Science.gov (United States)

    This manuscript is part of a series of manuscripts that characterize cotton gin emissions from the standpoint of stack sampling. The impetus behind this project was the urgent need to collect additional cotton gin emissions data to address current regulatory issues. A key component of this study was...

  17. Mote cyclone robber system PM10 emission factors and rates for cotton gins

    Science.gov (United States)

    This manuscript is part of a series of manuscripts that characterize cotton gin emissions from the standpoint of stack sampling. The impetus behind this project was the urgent need to collect additional cotton gin emissions data to address current regulatory issues. A key component of this study was...

  18. Cyclone robber system total particulate emission factors and rates for cotton gins: Method 17

    Science.gov (United States)

    This manuscript is part of a series of manuscripts that characterize cotton gin emissions from the standpoint of stack sampling. The impetus behind this project was the urgent need to collect additional cotton gin emissions data to address current regulatory issues. A key component of this study was...

  19. Mote cyclone robber system total particulate emission factors and rates for cotton gins

    Science.gov (United States)

    This manuscript is part of a series of manuscripts that characterize cotton gin emissions from the standpoint of stack sampling. The impetus behind this project was the urgent need to collect additional cotton gin emissions data to address current regulatory issues. A key component of this study was...

  20. Mote cyclone robber system total particulate emission factors and rate for cotton gins: Method 17

    Science.gov (United States)

    This manuscript is part of a series of manuscripts that characterize cotton gin emissions from the standpoint of stack sampling. The impetus behind this project was the urgent need to collect additional cotton gin emissions data to address current regulatory issues. A key component of this study was...

  1. Battery condenser system PM10 emission factors and rates for cotton gins

    Science.gov (United States)

    This manuscript is part of a series of manuscripts that to characterize cotton gin emissions from the standpoint of stack sampling. The impetus behind this project was the urgent need to collect additional cotton gin emissions data to address current regulatory issues. A key component of this study ...

  2. Battery condenser system total particulate emission factors and rates for cotton gins: Method 17

    Science.gov (United States)

    This manuscript is part of a series of manuscripts that characterize cotton gin emissions from the standpoint of stack sampling. The impetus behind this project was the urgent need to collect additional cotton gin emissions data to address current regulatory issues. A key component of this study was...

  3. Battery condenser system total particulate emission factors and rates for cotton gins

    Science.gov (United States)

    This manuscript is part of a series of manuscripts that characterize cotton gin emissions from the standpoint of stack sampling. The impetus behind this project was the urgent need to collect additional cotton gin emissions data to address current regulatory issues. A key component of this study was...

  4. Assessing the emission factors of low-pour-fuel-oil and diesel in steam boilers

    Directory of Open Access Journals (Sweden)

    Ohijeagbon, I.O.

    2012-12-01

    Full Text Available The purpose of this study is to examine the emissions effects resulting from the use of low pour fuel oil (LPFO and diesel fuels in industrial steam boilers operation. The method of ultimate analysis of the products of combustion and emissions of pollutant analysis were used to estimate the annual rate of emissions of boilers. The results shows that the levels of uncontrolled boiler emissions on the environment can lead to increased greenhouse effects, global warming, and pollution and toxilogical impacts on human health. Only carbon monoxide emission was found to vary with the levels of oxygen generation in the products of combustion, while other substances were generally in relation to constituents and rates of consumption of fuel.

  5. Derivation of greenhouse gas emission factors for peatlands managed for extraction in the Republic of Ireland and the UK

    Directory of Open Access Journals (Sweden)

    D. Wilson

    2015-05-01

    Full Text Available Drained peatlands are significant hotspots of carbon dioxide (CO2 emissions and may also be more vulnerable to fire with its associated gaseous emissions. Under the United Nations Framework Convention on Climate Change (UNFCCC and the Kyoto Protocol, greenhouse gas (GHG emissions from peatlands managed for extraction are reported on an annual basis. However, the Tier 1 (default emission factors (EFs provided in the IPCC 2013 Wetlands Supplement for this land use category may not be representative in all cases and countries are encouraged to move to higher Tier reporting levels with reduced uncertainty levels based on country or regional specific data. In this study, we quantified (1 CO2-C emissions from 9 peat extraction sites in the Republic of Ireland and the United Kingdom, which were initially disaggregated by land use type (industrial vs. domestic peat extraction, and (2 a range of GHGs that are released to the atmosphere with the burning of peat. CO2-C emissions were strongly controlled by soil temperature at the industrial sites (bare peat, and by soil temperature and leaf area index at the vegetated domestic sites. Our derived EFs of 1.70 (±0.47 and 1.64 (±0.44 t CO2-C ha−1 yr−1 for the industrial and domestic sites respectively, are considerably lower than the Tier 1 EF (2.8 ± 1.7 t CO2-C ha−1 yr−1 provided in the Wetlands Supplement. We propose that the difference between our derived values and the Wetlands Supplement value is due to differences in peat quality and, consequently, decomposition rates. Emissions from burning of the peat (g kg−1 dry fuel burned were estimated to be approximately 1346 (CO2, 8.35 (methane, CH4, 218 (carbon monoxide, CO, 1.53 (ethane, C2H6, 1.74 (ethylene, C2H4, 0.60 (methanol, CH3OH, 2.21 (hydrogen cyanide, HCN and 0.73 (ammonia, NH3 and emphasises the importance of understanding the full suite of trace gas emissions from biomass burning, rather than focussing solely on CO2 and CH4 emissions

  6. Methanol emissions from maize: Ontogenetic dependence to varying light conditions and guttation as an additional factor constraining the flux

    Science.gov (United States)

    Mozaffar, A.; Schoon, N.; Digrado, A.; Bachy, A.; Delaplace, P.; du Jardin, P.; Fauconnier, M.-L.; Aubinet, M.; Heinesch, B.; Amelynck, C.

    2017-03-01

    Because of its high abundance and long lifetime compared to other volatile organic compounds in the atmosphere, methanol (CH3OH) plays an important role in atmospheric chemistry. Even though agricultural crops are believed to be a large source of methanol, emission inventories from those crop ecosystems are still scarce and little information is available concerning the driving mechanisms for methanol production and emission at different developmental stages of the plants/leaves. This study focuses on methanol emissions from Zea mays L. (maize), which is vastly cultivated throughout the world. Flux measurements have been performed on young plants, almost fully grown leaves and fully grown leaves, enclosed in dynamic flow-through enclosures in a temperature and light-controlled environmental chamber. Strong differences in the response of methanol emissions to variations in PPFD (Photosynthetic Photon Flux Density) were noticed between the young plants, almost fully grown and fully grown leaves. Moreover, young maize plants showed strong emission peaks following light/dark transitions, for which guttation can be put forward as a hypothetical pathway. Young plants' average daily methanol fluxes exceeded by a factor of 17 those of almost fully grown and fully grown leaves when expressed per leaf area. Absolute flux values were found to be smaller than those reported in the literature, but in fair agreement with recent ecosystem scale flux measurements above a maize field of the same variety as used in this study. The flux measurements in the current study were used to evaluate the dynamic biogenic volatile organic compound (BVOC) emission model of Niinemets and Reichstein. The modelled and measured fluxes from almost fully grown leaves were found to agree best when a temperature and light dependent methanol production function was applied. However, this production function turned out not to be suitable for modelling the observed emissions from the young plants

  7. Factors Influencing Microbial Carbon Emission Potential from Wetland Sediments and its Relation to Surface- and Plot-Scale Measurements

    Science.gov (United States)

    Brooker, M.; Bohrer, G.; Mouser, P. J.

    2012-12-01

    Wetlands provide valuable ecosystem services by sequestering carbon dioxide from the atmosphere and serving as a sink for atmospheric nitrogen export. They are often constructed as buffers between agriculture lands and drainage channels to improve runoff water quality from elevated nutrient loading (e.g. nitrate-N). Unfortunately, carbon sequestration and denitrification in wetlands come with the tradeoff of increased production of methane, another more potent green house gas. Existing models correlate methane emission rates to increased temperature; however, surface- and plot-scale measurements show little or weak relationships between these factors at the field scale. This study examines the relationship of several environmental factors - temperature, zone location, and microbial community - to methane emissions under controlled laboratory conditions. Water and sediments collected from two depths (0-6" and 6-12") and four distinct biomes (open water and three distinct emergent macrophyte covers) were used to prepare anaerobic microcosms at two different temperatures (20°C and 30°C). Headspace gas (methane, carbon dioxide), water chemistry, and microbial community composition were analyzed over the course of several months. We observed: 1) an increase in methane emission potential with higher temperature; 2) higher levels of methane produced from shallower sediments; 3) differential production of methane versus carbon dioxide depending upon biome; and 4) variations in bacterial and archaeal diversity relating to methane production rates. This data helps provide upper limit estimates for methane emissions from wetlands by methanogenic Archaea and informs our ability to better parameterize biogeochemical and atmospheric models of these systems.

  8. A laboratory comparison of emission factors, number size distributions and morphology of ultrafine particles from eleven different household cookstove-fuel systems

    Data.gov (United States)

    U.S. Environmental Protection Agency — This dataset includes all data used to generate figures in the manuscript and supporting information for the publication entitled "Emission factors, number size...

  9. Trends in black carbon and size-resolved particle number concentrations and vehicle emission factors under real-world conditions

    Science.gov (United States)

    Krecl, Patricia; Johansson, Christer; Targino, Admir Créso; Ström, Johan; Burman, Lars

    2017-09-01

    Kerbside concentrations of NOx, black carbon (BC), total number of particles (diameter > 4 nm) and number size distribution (28-410 nm) were measured at a busy street canyon in Stockholm in 2006 and 2013. Over this period, there was an important change in the vehicle fleet due to a strong dieselisation process of light-duty vehicles and technological improvement of vehicle engines. This study assesses the impact of these changes on ambient concentrations and particle emission factors (EF). EF were calculated by using a novel approach which combines the NOx tracer method with positive matrix factorisation (PMF) applied to particle number size distributions. NOx concentrations remained rather constant between these two years, whereas a large decrease in particle concentrations was observed, being on average 60% for BC, 50% for total particle number, and 53% for particles in the range 28-100 nm. The PMF analysis yielded three factors that were identified as contributions from gasoline vehicles, diesel fleet, and urban background. This separation allowed the calculation of the average vehicle EF for each particle metric per fuel type. In general, gasoline EF were lower than diesel EF, and EF for 2013 were lower than the ones derived for 2006. The EFBC decreased 77% for both gasoline and diesel fleets, whereas the particle number EF reduction was higher for the gasoline (79%) than for the diesel (37%) fleet. Our EF are consistent with results from other on-road studies, which reinforces that the proposed methodology is suitable for EF determination and to assess the effectiveness of policies implemented to reduce vehicle exhaust emissions. However, our EF are much higher than EF simulated with traffic emission models (HBEFA and COPERT) that are based on dynamometer measurements, except for EFBC for diesel vehicles. This finding suggests that the EF from the two leading models in Europe should be revised for BC (gasoline vehicles) and particle number (all vehicles

  10. Fine particulate speciation profile and emission factor of municipal solid waste incinerator established by dilution sampling method.

    Science.gov (United States)

    Yang, Hsi-Hsien; Luo, Shao-Wei; Lee, Kuei-Ting; Wu, Jhin-Yan; Chang, Chun Wei; Chu, Pei Feng

    2016-08-01

    In this study, fine particulate matter (PM2.5) emitted from a municipal solid waste incinerator (MSWI) was collected using dilution sampling method. Chemical compositions of the collected PM2.5 samples, including carbon content, metal elements, and water-soluble ions, were analyzed. Traditional in-stack hot sampling was simultaneously conducted to compare the influences of dilution on PM2.5 emissions and the characteristics of the bonded chemical species. The results, established by a dilution sampling method, show that PM2.5 and total particulate matter (TPM) emission factors were 61.6 ± 4.52 and 66.1 ± 5.27 g ton-waste(-1), respectively. The average ratio of PM2.5/TPM is 0.93, indicating that more than 90% of PM emission from the MSWI was fine particulate. The major chemical species in PM2.5 included organic carbon (OC), Cl(-), NH4(+), elemental carbon (EC) and Si, which account for 69.7% of PM2.5 mass. OC was from the unburned carbon in the exhaust, which adsorbed onto the particulate during the cooling process. High Cl(-) emission is primarily attributable to wastes containing plastic bags made of polyvinyl chloride, salt in kitchen refuse and waste biomass, and so on. Minor species that account for 0.01-1% of PM2.5 mass included SO4(2-), K(+), Na, K, NO3(-), Al, Ca(2+), Zn, Ca, Cu, Fe, Pb, and Mg. The mean ratio of dilution method/in-stack hot method was 0.454. The contents of water-soluble ions (Cl(-), SO4(2-), NO3(-)) were significantly enriched in PM2.5 via gas-to-particle conversion in the dilution process. Results indicate that in-stack hot sampling would underestimate levels of these species in PM2.5. PM2.5 samples from a municipal solid waste incinerator (MSWI) were collected simultaneously by a dilution sampling technique and a traditional in-stack method. PM2.5 emission factors and chemical speciation profiles were established. Dilution sampling provides more reliable data than in-stack hot sampling. The results can be applied to estimate the PM2

  11. Effects of cracks and some key factors on emissions of nitrous oxide in paddy fields

    Institute of Scientific and Technical Information of China (English)

    HUANG Shu-hui; LU Jun; TIAN Guang-ming

    2005-01-01

    Paddy field is a primary agricultural landscape in the south of China and is often regarded as one of main sources emitting nitrous oxide to atmosphere. The nitrous oxide emissions under a variety of paddy field practices, such as fertilization, flooding/draining management were investigated to study on agricultural activities on paddy field affect the dynamic process of the emission. Under no addition of fertilizers the average emission flux of nitrous oxide was 8.55 μg/(m2· h) during the rice( Oryza Sativa L. ) growth season. The results indicated that most of nitrous oxide emissions occurred during the crack forming-and-expansion period when paddy field was being drained. The diurnal emissions peak of nitrous oxide appeared at 20:30 at night in cracked rice fields. The statistical analysis suggested that the correlation of nitrous oxide emissions flux (Y) with soil water content ( X1 ), soil temperature ( X2 ), and Eh ( X3 ), could be described in a regression equation: Y= - 1498.95 + 2895.48 X1 + 50.63 X2 -96.99X1 · X2 + 0.006X2· X3. There were the different power equations to simulate the correlations between the everyday dynamic N2O emissions and the mean surface area of cracks, mean volume and depth of cracks respectively during paddy soil drying by soil columns incubation experiments. Taken all together, the current study presented a dynamic analysis of nitrous oxide emission of paddy field under various conditions, therefore provided a basis for the management to balance between environmental effect and paddy field activities.

  12. Behavioral factors.

    Science.gov (United States)

    Zero, D T; Lussi, A

    2006-01-01

    During and after an erosive challenge, behavioral factors play a role in modifying the extent of erosive tooth wear. The manner that dietary acids are introduced into the mouth (gulping, sipping, use of a straw) will affect how long the teeth are in contact with the erosive challenge. The frequency and duration of exposure to an erosive agent is of paramount importance. Night-time exposure (e.g. baby bottle-feeding) to erosive agents may be particularly destructive because of the absence of salivary flow. Health-conscious individuals tend to ingest acidic drinks and juices more frequently and tend to have higher than average oral hygiene. While good oral hygiene is of proven value in the prevention of periodontal disease and dental caries, frequent toothbrushing with abrasive oral hygiene products may enhance erosive tooth wear. Unhealthy lifestyles such as consumption of designer drugs, alcopops and alcohol abuse are other important behavioral factors.

  13. Factor analysis

    CERN Document Server

    Gorsuch, Richard L

    2013-01-01

    Comprehensive and comprehensible, this classic covers the basic and advanced topics essential for using factor analysis as a scientific tool in psychology, education, sociology, and related areas. Emphasizing the usefulness of the techniques, it presents sufficient mathematical background for understanding and sufficient discussion of applications for effective use. This includes not only theory but also the empirical evaluations of the importance of mathematical distinctions for applied scientific analysis.

  14. Size-resolved aerosol emission factors and new particle formation/growth activity occurring in Mexico City during the MILAGRO 2006 Campaign

    Directory of Open Access Journals (Sweden)

    A. J. Kalafut-Pettibone

    2011-02-01

    Full Text Available Measurements of the aerosol size distribution from 11 nm to 2.5 microns were made in Mexico City in March, 2006, during the MILAGRO field campaign. Observations at the T0 research site could often be characterized by morning conditions with high particle mass concentrations, low mixing heights, and highly correlated particle number and CO2 concentrations, indicative that particle number is controlled by primary emissions. Average size-resolved and total number- and volume-based emission factors for combustion sources impacting T0 have been determined using a comparison of peak sizes in number and CO2 concentration peaks. The number emission and volume emission factors for particles from 11 nm to 494 nm are 1.23 × 1015 particles, and 7.54 × 1011 cubic microns per kg of carbon, respectively. Uncertainty on the number emission factor is approximately a factor of 1.5. The mode of the number emission factor was between 25 and 32 nm, while the mode of the volume factor was between 0.25 and 0.32 microns. These emission factors are reported as log normal model parameters and are compared with multiple emission factors from the literature. In Mexico City in the afternoon, the CO2 concentration drops during ventilation of the polluted layer, and the coupling between CO2 and particle number breaks down, especially during new particle formation events when particle number is no longer controlled by primary emissions. Using measurements of particle number and CO2 taken aboard the NASA DC-8, this emission factor was applied to the MCMA plume; the primary emission factor predicts less than 50% of the total particle number and the surplus particle count is not correlated with photochemical age. Primary particle volume and number in the size range 0.1–2 μm are similarly too low to predict the observed volume distribution. Contrary to the case for number, the apparent secondary

  15. DEVELOPMENT OF FINE PARTICULATE EMISSION FACTORS AND SPECIATION PROFILES FOR OIL AND GAS FIRED COMBUSTION SYSTEMS

    Energy Technology Data Exchange (ETDEWEB)

    Glenn England; Oliver Chang; Stephanie Wien

    2002-02-14

    This report provides results from the second year of this three-year project to develop dilution measurement technology for characterizing PM2.5 (particles with aerodynamic diameter smaller than 2.5 micrometers) and precursor emissions from stationary combustion sources used in oil, gas and power generation operation. Detailed emission rate and chemical speciation tests results for a gas turbine, a process heater, and a commercial oil/gas fired boiler are presented. Tests were performed using a research dilution sampling apparatus and traditional EPA methods. A series of pilot tests were conducted to identify the constraints to reduce the size of current research dilution sampler for future stack emission tests. Based on the test results, a bench prototype compact dilution sampler developed and characterized in GE EER in August 2002.

  16. Using growth and decline factors to project VOC emissions from oil and gas production.

    Science.gov (United States)

    Oswald, Whitney; Harper, Kiera; Barickman, Patrick; Delaney, Colleen

    2015-01-01

    Projecting future-year emission inventories in the oil and gas sector is complicated by the fact that there is a life cycle to the amount of production from individual wells and thus from well fields in aggregate. Here we present a method to account for that fact in support of regulatory policy development. This approach also has application to air quality modeling inventories by adding a second tier of refinement to the projection methodology. Currently, modeling studies account for the future decrease in emissions due to new regulations based on the year those regulations are scheduled to take effect. The addition of a year-by-year accounting of production decline provides a more accurate picture of emissions from older, uncontrolled sources. This proof of concept approach is focused solely on oil production; however, it could be used for the activity and components of natural gas production to compile a complete inventory for a given area.

  17. Environmental data book 2011. Estimated emission factors for fuels, electricity, heat and transport in Sweden; Miljoefaktaboken 2011. Uppskattade emissionsfaktorer foer braenslen, el, vaerme och transporter

    Energy Technology Data Exchange (ETDEWEB)

    Gode, Jenny; Martinsson, Fredrik; Hagberg, Linus; Oeman, Andreas; Hoeglund, Jonas; Palm, David

    2011-04-15

    The environmental data book summarizes current and general emission factors for most fuels and sources of Swedish electricity and heat and to power vehicles. Emission data are compiled for wood fuels, energy crops, bio-oils, waste fuels, fossil fuels and peat, biofuels, wind power, hydro power, nuclear power and solar power

  18. Factor ten emission reductions : the key to sustainable development and economic prosperity for the cement and concrete industry

    Energy Technology Data Exchange (ETDEWEB)

    Horton, R. [Alchemix Corp., Pittsburgh, PA (United States)

    2001-07-01

    This paper proposes that the negative environmental effects of current cement/concrete production can be reduced by a factor of 10 by using cement blends with minimum portland cement and maximum pozzolanic loading. In addition to extending the longevity of concrete, such cement blends also avoid the huge cost of repairs and replacement cycles. Market forces will drive this transition toward sustainable development in the concrete and cement industry. The economic advantages of improving the quality of the concrete are great. Even if improving the concrete doubles the price of the highest quality cement, this would only add 2 per cent to the cost of the overall construction project, but the service life of the structure would give a many-fold return on this added investment. Also, regulations on carbon dioxide emissions in the near future will assume economic importance in the manufacturing of cement and concrete. While portland cements have dominated the construction industry for more than 150 years, new blended cements priced on a performance basis will become the standard in the twenty first century. Currently, the typical cement formulation in the United States, if it contains fly ash, contains 15 to 20 per cent fly ash by weight of the total cementitious material. This paper states that soon the number will be 50 to 60 per cent ash. Fly ash will be widely acknowledged for improving critical performance characteristics of concrete such as workability, impermeability and durability. Carbon dioxide credits will also be a major economic factor that will drive the cement industry toward a factor ten environmental improvement. The Kyoto Protocol calls for the trading of greenhouse gas credits which includes carbon dioxide credits. Under the new system, cement producers will be taxed on excess emissions, while those using pozzolans in their cements will earn credits to offset these penalties. 10 refs.

  19. Evaluating the air quality impacts of the 2008 Beijing Olympic Games: On-road emission factors and black carbon profiles

    Science.gov (United States)

    Wang, Xing; Westerdahl, Dane; Chen, Lung Chi; Wu, Ye; Hao, Jiming; Pan, Xiaochuan; Guo, Xinbiao; Zhang, K. Max

    The aggressive traffic interventions and emission control measures implemented to improve air quality during the 2008 Beijing Olympic Games created a valuable case study to evaluate the effectiveness of these measures on mitigating air pollution and protecting public health. In this paper, we report the results from our field campaign in summer 2008 on the on-road emission factors of carbon monoxide, black carbon (BC) and ultrafine particles (UFP) as well as the ambient BC concentrations. The fleet average emission factors for light-duty gasoline vehicles (LDGV) showed considerable reduction in the Olympic year (2008) compared to the pre-Olympic year (2007). Our measurement of Black Carbon (BC), a primary pollutant, at different elevations at the ambient site suggests consistent decrease in BC concentrations as the height increased near the ground level, which indicates that the nearby ground level sources, probably dominated by traffic, contributed to a large portion of BC concentrations in the lower atmospheric layer in Beijing during summertime. These observations indicate that people living in near ground levels experience higher exposures than those living in higher floors in Beijing. The BC diurnal patterns on days when traffic control were in place during the Olympic Games were compared to those on non-traffic-control days in both 2007 and in 2008. These patterns strongly suggest that diesel trucks are a major source of summertime BC in Beijing. The median BC concentration on Olympic days was 3.7 μg m -3, which was dramatically lower than the value on non-traffic-control days, indicating the effectiveness of traffic control regulations in BC reduction in Beijing.

  20. Daily variation characteristics of CO2 emission fluxes and contributions of environmental factors in semiarid grassland of Inner Mongolia, China

    Institute of Scientific and Technical Information of China (English)

    QI; Yuchun; DONG; Yunshe; LIU; Jiyuan; GENG; Yuanbo; LI; Mi

    2005-01-01

    Fixed field experimental studies are carried out on daily variations of the undisturbed community and soil respiration fluxes in different phenological phases of 2001-2002 in semiarid Aneurolepidium chinense steppe of Inner Mongolia, China using static black chamber method. Corresponding statistical analysis of the contributions of the water-heat factors (air temperature, ground temperature, surface soil water content) and ecological factors (aboveground biomass, underground biomass, litter biomass) to daily variation law of the undisturbed community and soil respiration fluxes as well as differences in daily respiration are also conducted. The results indicate that undisturbed community and soil respiration have apparent daily variation laws, daily variation patterns of respiration fluxes during different phenological phases are basically the same, and the variations of environmental factors only exert effect on CO2 emission intensities, while the effect on daily variation pattern of grassland CO2 emission fluxes is relatively small. The daily total respiration of the undisturbed community in different phenological phases ranges from 1.34-10.13 g·m-2; soil daily total respiration ranges from 0.98-5.17 g·m-2; both daily variations of undisturbed community and soil respiration fluxes are significantly correlated (p < 0.05) or extremely significantly correlated (p < 0.01) with air temperatures and ground surface temperatures, but the correlativity with the soil temperature at 5 and 10 cm depths is relatively weak; multiple regression analysis indicates that about 80% of the difference in daily respiration of the undisturbed community among different phenological phases is induced by the variation of the aboveground biomass, while the variations of the remaining factors can jointly explain around 20% of the daily respiration variations of the whole grassland ecosystem; about 83% of the soil daily respiration variation of the different phenological phases is caused

  1. Land and Water Use, CO2 Emissions, and Worker Radiological Exposure Factors for the Nuclear Fuel Cycle

    Energy Technology Data Exchange (ETDEWEB)

    Brett W Carlsen; Brent W Dixon; Urairisa Pathanapirom; Eric Schneider; Bethany L. Smith; Timothy M. AUlt; Allen G. Croff; Steven L. Krahn

    2013-08-01

    The Department of Energy Office of Nuclear Energy’s Fuel Cycle Technologies program is preparing to evaluate several proposed nuclear fuel cycle options to help guide and prioritize Fuel Cycle Technology research and development. Metrics are being developed to assess performance against nine evaluation criteria that will be used to assess relevant impacts resulting from all phases of the fuel cycle. This report focuses on four specific environmental metrics. • land use • water use • CO2 emissions • radiological Dose to workers Impacts associated with the processes in the front-end of the nuclear fuel cycle, mining through enrichment and deconversion of DUF6 are summarized from FCRD-FCO-2012-000124, Revision 1. Impact estimates are developed within this report for the remaining phases of the nuclear fuel cycle. These phases include fuel fabrication, reactor construction and operations, fuel reprocessing, and storage, transport, and disposal of associated used fuel and radioactive wastes. Impact estimates for each of the phases of the nuclear fuel cycle are given as impact factors normalized per unit process throughput or output. These impact factors can then be re-scaled against the appropriate mass flows to provide estimates for a wide range of potential fuel cycles. A companion report, FCRD-FCO-2013-000213, applies the impact factors to estimate and provide a comparative evaluation of 40 fuel cycles under consideration relative to these four environmental metrics.

  2. Iron ore industry emissions as a potential ecological risk factor for tropical coastal vegetation.

    Science.gov (United States)

    Kuki, Kacilda N; Oliva, Marco A; Pereira, Eduardo G

    2008-07-01

    In the coastal zone of the Espírito Santo state, Brazil, fragments of restinga, which form a natural ecosystem, share their space with an increasing number of iron ore industries. The iron ore dust and SO(2) originating from the industry processing activities can interfere with the vegetation of the adjacent ecosystems at various levels. This study was undertaken in order to evaluate the effects of industry emissions on representative members of the restinga flora, by measuring physiological and phenological parameters. Foliar samples of Ipomoea pes caprae, Canavalia rosea, Sophora tomentosa, and Schinus terebinthifolius were collected at three increasing distances from an ore industry (1.0, 5.0, and 15.0 km), and were assessed for their dust deposition, chlorophyll, and Fe content. Phenological monitoring was focused on the formation of shoots, flowers, and fruits and was also performed throughout the course of a year. The results showed that the edaphic characteristics and the mineral constitutions of the plants were affected by industry emissions. In addition, the chlorophyll content of the four species increased with proximity to the industry. Phenological data revealed that the reproductive effort, as measured by fruit production, was affected by emissions and S. tomentosa was the most affected species. The use of an integrative approach that combines biochemical and ecological data indicates that the restinga flora is under stress due to industry emissions, which on a long-term basis may put the ecosystem at risk.

  3. Emission factors for heavy metals from diesel and petrol used in European vehicles

    NARCIS (Netherlands)

    Pulles, M.P.J.; Denier van der Gon, H.A.C.; Appelman, W.A.J.; Verheul, M.

    2012-01-01

    Abstract: Heavy metals constitute an important group of persistent toxic pollutants occurring in ambient air and other media. One of the suspected sources of these metals in the atmosphere is combustion of transport fuels in road vehicles. However estimates of the emissions of these metals from road

  4. Emission factors for heavy metals from diesel and petrol used in European vehicles

    NARCIS (Netherlands)

    Pulles, M.P.J.; Denier van der Gon, H.A.C.; Appelman, W.A.J.; Verheul, M.

    2012-01-01

    Abstract: Heavy metals constitute an important group of persistent toxic pollutants occurring in ambient air and other media. One of the suspected sources of these metals in the atmosphere is combustion of transport fuels in road vehicles. However estimates of the emissions of these metals from road

  5. Cooking with Fire: The Mutagenicity- and PAH-Emission Factors of Solid-Fuel Cookstoves

    Science.gov (United States)

    Emissions from solid fuels used for cooking cause ~4 million premature deaths per year. Advanced solid-fuel cookstoves are a potential solution, but they should be assessed by appropriate performance indicators, including biological effects. We evaluated two categories of solid...

  6. Speciation Profiles and Toxic Emission Factors for Nonroad Engines: DRAFT REPORT

    Science.gov (United States)

    This document details the research and development behind how MOVES2014a estimates air toxic emissions for nonroad engines and equipment run on conventional gasoline without ethanol (E0) and gasoline blended with 10% ethanol (E10) as well as diesel fuel, compressed natural gas (C...

  7. Iron Ore Industry Emissions as a Potential Ecological Risk Factor for Tropical Coastal Vegetation

    Science.gov (United States)

    Kuki, Kacilda N.; Oliva, Marco A.; Pereira, Eduardo G.

    2008-07-01

    In the coastal zone of the Espírito Santo state, Brazil, fragments of restinga, which form a natural ecosystem, share their space with an increasing number of iron ore industries. The iron ore dust and SO2 originating from the industry processing activities can interfere with the vegetation of the adjacent ecosystems at various levels. This study was undertaken in order to evaluate the effects of industry emissions on representative members of the restinga flora, by measuring physiological and phenological parameters. Foliar samples of Ipomoea pes caprae, Canavalia rosea, Sophora tomentosa, and Schinus terebinthifolius were collected at three increasing distances from an ore industry (1.0, 5.0, and 15.0 km), and were assessed for their dust deposition, chlorophyll, and Fe content. Phenological monitoring was focused on the formation of shoots, flowers, and fruits and was also performed throughout the course of a year. The results showed that the edaphic characteristics and the mineral constitutions of the plants were affected by industry emissions. In addition, the chlorophyll content of the four species increased with proximity to the industry. Phenological data revealed that the reproductive effort, as measured by fruit production, was affected by emissions and S. tomentosa was the most affected species. The use of an integrative approach that combines biochemical and ecological data indicates that the restinga flora is under stress due to industry emissions, which on a long-term basis may put the ecosystem at risk.

  8. Cyclone robber system PM2.5 emission factors and rates for cotton gins

    Science.gov (United States)

    This manuscript is part of a series of manuscripts that detail a project to characterize cotton gin emissions from the standpoint of stack and ambient sampling. The impetus behind the project was the 2006 EPA implementation of a more stringent standard for particulate matter less than or equal to 2....

  9. Mote cyclone robber system particulate emission factors for cotton gins: Particle size distribution characteristics

    Science.gov (United States)

    This report is part of a project to characterize cotton gin emissions from the standpoint of total particulate stack sampling and particle size analyses. In 2013, the U.S. Environmental Protection Agency (EPA) published a more stringent standard for particulate matter with nominal diameter less than...

  10. Cyclone robber system particulate emission factors for cotton gins: Particle size distribution characteristics

    Science.gov (United States)

    This report is part of a project to characterize cotton gin emissions from the standpoint of total particulate stack sampling and particle size analyses. In 2013, U.S. Environmental Protection Agency (EPA) published a more stringent standard for particulate matter with nominal diameter less than or ...

  11. Battery condenser system PM2.5 emission factors and rates for cotton gins

    Science.gov (United States)

    This manuscript is part of a series of manuscripts that detail a project to characterize cotton gin emissions from the standpoint of stack and ambient sampling. The impetus behind the project was the 2006 EPA implementation of a more stringent standard for particulate matter less than or equal to 2....

  12. Battery condenser system particulate emission factors for cotton gins: Particle size distribution characteristics

    Science.gov (United States)

    This report is part of a project to characterize cotton gin emissions from the standpoint of total particulate stack sampling and particle size analyses. In 2013, the Environmental Protection Agency (EPA) published a more stringent standard for particulate matter with nominal diameter less than or e...

  13. Carbon baseline as limiting factor in managing environmental sound activities in peatland for reducing greenhouse gas emission

    Directory of Open Access Journals (Sweden)

    BAMBANG HERO SAHARJO

    2011-07-01

    Full Text Available Saharjo BH (2011 Carbon baseline as limiting factor in managing environmental sound activities in peatland for reducing greenhouse gas emission. Biodiversitas 12: 182-186. The total carbon stock in Indonesia was estimated to be around 44.5 Gt or about 53.1% of the total carbon stock in tropical areas. Over 1990-2002, it was estimated that around 3.5 Gt of carbon was released in Sumatra and about 0.81-2.56 Gt was released in Central Kalimantan due to the 1997 fire alone. It was recognized that deforestation, high exploitation of peat and peat fire were behind the huge emissions of Greenhouse Gases in Indonesia. Results of a research conducted in Central Kalimantan peatland, showed that the total carbon stock at logged over area was estimated around 413.972 t ha-1 (0-30 cm depth of peat and at burnt area was 411.349 t ha-1 (0-30 cm depth of peat. Meanwhile it had been well recognized that most of opened peatlands had been occupied by Acacia crassicarpa and oil palms. Research carried out in East Kalimantan showed that the carbon stock of 25 years old oil palm planted on mineral soil was about 180 t ha-1, which is less than that of carbon stock produced by peatland clearance. This indicated that although plants occupied peatland, high Greenhouse Gas emissions were still produced, meaning that global climate change would continue and created high risk impacts.

  14. Transportation Energy Futures Series. Effects of the Built Environment on Transportation. Energy Use, Greenhouse Gas Emissions, and Other Factors

    Energy Technology Data Exchange (ETDEWEB)

    Porter, C. D. [National Renewable Energy Lab. (NREL) and Cambridge Systematics, Inc., Golden, CO (United States); Brown, A. [National Renewable Energy Lab. (NREL) and Cambridge Systematics, Inc., Golden, CO (United States); Dunphy, R. T. [National Renewable Energy Lab. (NREL) and Cambridge Systematics, Inc., Golden, CO (United States); Vimmerstedt, L. [National Renewable Energy Lab. (NREL) and Cambridge Systematics, Inc., Golden, CO (United States)

    2013-03-15

    Planning initiatives in many regions and communities aim to reduce transportation energy use, decrease emissions, and achieve related environmental benefits by changing land use. This report reviews and summarizes findings from existing literature on the relationship between the built environment and transportation energy use and greenhouse gas emissions, identifying results trends as well as potential future actions. The indirect influence of federal transportation and housing policies, as well as the direct impact of municipal regulation on land use are examined for their effect on transportation patterns and energy use. Special attention is given to the 'four D' factors of density, diversity, design and accessibility. The report concludes that policy-driven changes to the built environment could reduce transportation energy and GHG emissions from less than 1% to as much as 10% by 2050, the equivalent of 16%-18% of present-day urban light-duty-vehicle travel. This is one of a series of reports produced as a result of the Transportation Energy Futures (TEF) project, a Department of Energy-sponsored multi-agency project initiated to pinpoint underexplored strategies for abating GHGs and reducing petroleum dependence related to transportation.

  15. Transportation Energy Futures Series: Effects of the Built Environment on Transportation: Energy Use, Greenhouse Gas Emissions, and Other Factors

    Energy Technology Data Exchange (ETDEWEB)

    Porter, C. D.; Brown, A.; Dunphy, R. T.; Vimmerstedt, L.

    2013-03-01

    Planning initiatives in many regions and communities aim to reduce transportation energy use, decrease emissions, and achieve related environmental benefits by changing land use. This report reviews and summarizes findings from existing literature on the relationship between the built environment and transportation energy use and greenhouse gas emissions, identifying results trends as well as potential future actions. The indirect influence of federal transportation and housing policies, as well as the direct impact of municipal regulation on land use are examined for their effect on transportation patterns and energy use. Special attention is given to the 'four D' factors of density, diversity, design and accessibility. The report concludes that policy-driven changes to the built environment could reduce transportation energy and GHG emissions from less than 1% to as much as 10% by 2050, the equivalent of 16%-18% of present-day urban light-duty-vehicle travel. This is one of a series of reports produced as a result of the Transportation Energy Futures (TEF) project, a Department of Energy-sponsored multi-agency project initiated to pinpoint underexplored strategies for abating GHGs and reducing petroleum dependence related to transportation.

  16. GHG emission factors for bioelectricity, biomethane, and bioethanol quantified for 24 biomass substrates with consequential life-cycle assessment.

    Science.gov (United States)

    Tonini, Davide; Hamelin, Lorie; Alvarado-Morales, Merlin; Astrup, Thomas Fruergaard

    2016-05-01

    Greenhouse gas (GHG) emission savings from biofuels dramatically depend upon the source of energy displaced and the effects induced outside the energy sector, for instance land-use changes (LUC). Using consequential life-cycle assessment and including LUC effects, this study provides GHG emission factors (EFs) for bioelectricity, biomethane, and bioethanol produced from twenty-four biomasses (from dedicated crops to residues of different origin) under a fossil and a non-fossil energy system. Accounting for numerous variations in the pathways, a total of 554 GHG EFs were quantified. The results showed that, important GHG savings were obtained with residues and seaweed, both under fossil and non-fossil energy systems. For high-yield perennial crops (e.g. willow and Miscanthus), GHG savings were achieved only under fossil energy systems. Biofuels from annual crops and residues that are today used in the feed sector should be discouraged, as LUC GHG emissions exceeded any GHG savings from displacing conventional energy sources.

  17. Size-resolved aerosol emission factors and new particle formation/growth activity occurring in Mexico City during the MILAGRO 2006 Campaign

    Directory of Open Access Journals (Sweden)

    A. J. Kalafut-Pettibone

    2011-09-01

    Full Text Available Measurements of the aerosol size distribution from 11 nm to 2.5 microns were made in Mexico City in March 2006, during the MILAGRO (Megacity Initiative: Local and Global Research Observations field campaign. Observations at the urban supersite, referred to as T0, could often be characterized by morning conditions with high particle mass concentrations, low mixing heights, and highly correlated particle number and CO2 concentrations, indicative that particle number is controlled by primary emissions. Average size-resolved and total number- and volume-based emission factors for combustion sources impacting T0 have been determined using a comparison of peak sizes in particle number and CO2 concentration. Peaks are determined by subtracting the measured concentration from a calculated baseline concentration time series. The number emission and volume emission factors for particles from 11 nm to 494 nm are 1.56 × 1015 particles, and 9.48 × 1011 cubic microns per kg of carbon, respectively. The uncertainty of the number emission factor is approximately plus or minus 50 %. The mode of the number emission factor was between 25 and 32 nm, while the mode of the volume factor was between 0.25 and 0.32 microns. These emission factors are reported as log normal model parameters and are compared with multiple emission factors from the literature. In Mexico City in the afternoon, the CO2 concentration drops during ventilation of the polluted layer, and the coupling between CO2 and particle number breaks down, especially during new particle formation events when particle number is no longer controlled by primary emissions. Using measurements of particle number and CO2 taken aboard the NASA DC-8, the determined primary emission factor was applied to the Mexico City Metropolitan Area (MCMA plume to quantify the degree of secondary particle formation in the plume; the primary emission

  18. Size-resolved aerosol emission factors and new particle formation/growth activity occurring in Mexico City during the MILAGRO 2006 Campaign

    Energy Technology Data Exchange (ETDEWEB)

    Kalafut-Pettibone A. J.; Wang J.; Eichinger, W. E.; Clarke, A.; Vay, S. A.; Blake, D. R.; Stanier, C. O.

    2011-09-01

    Measurements of the aerosol size distribution from 11 nm to 2.5 microns were made in Mexico City in March 2006, during the MILAGRO (Megacity Initiative: Local and Global Research Observations) field campaign. Observations at the urban supersite, referred to as T0, could often be characterized by morning conditions with high particle mass concentrations, low mixing heights, and highly correlated particle number and CO{sub 2} concentrations, indicative that particle number is controlled by primary emissions. Average size-resolved and total number- and volume-based emission factors for combustion sources impacting T0 have been determined using a comparison of peak sizes in particle number and CO{sub 2} concentration. Peaks are determined by subtracting the measured concentration from a calculated baseline concentration time series. The number emission and volume emission factors for particles from 11 nm to 494 nm are 1.56 x 10{sup 15} particles, and 9.48 x 10{sup 11} cubic microns per kg of carbon, respectively. The uncertainty of the number emission factor is approximately plus or minus 50 %. The mode of the number emission factor was between 25 and 32 nm, while the mode of the volume factor was between 0.25 and 0.32 microns. These emission factors are reported as log normal model parameters and are compared with multiple emission factors from the literature. In Mexico City in the afternoon, the CO{sub 2} concentration drops during ventilation of the polluted layer, and the coupling between CO{sub 2} and particle number breaks down, especially during new particle formation events when particle number is no longer controlled by primary emissions. Using measurements of particle number and CO{sub 2} taken aboard the NASA DC-8, the determined primary emission factor was applied to the Mexico City Metropolitan Area (MCMA) plume to quantify the degree of secondary particle formation in the plume; the primary emission factor accounts for less than 50 % of the total particle

  19. Long-Term Emission Factors for Land Application of Treated Organic Municipal Waste

    DEFF Research Database (Denmark)

    Yoshida, Hiroko; Nielsen, Martin P.; Scheutz, Charlotte

    2016-01-01

    The agro-ecosystem model Daisy was used to explore the long-term fate of nitrogen (N) after land application of compost and digestate (based on source separated organic municipal solid waste (MSW)). The cumulative crop N yield response and emissions for mineral fertilizer (MF), anaerobically...... digested organic waste (MSW-D), and composted organic waste (MSW-C) were derived by fitting a linear mixed model to the outcomes of the simulations. The non-linearity of crop N yield responses and emission responses to increasing N fertilizer application was addressed by dividing these responses into high...... response due to high inorganic N content and a gradual increase thereafter, due to the slow mineralization of organic N. Overall, 52–69 % of N applied as MF was up-taken by plant biomass, while plant uptakes of 15–28 % by MSW-D and 19–29 % by MSW-C were measured under high response conditions. When the N...

  20. Combustion efficiency and emission factors for wildfire-season fires in mixed conifer forests of the northern Rocky Mountains, US

    Directory of Open Access Journals (Sweden)

    S. P. Urbanski

    2013-07-01

    Full Text Available In the US, wildfires and prescribed burning present significant challenges to air regulatory agencies attempting to achieve and maintain compliance with air quality regulations. Fire emission factors (EF are essential input for the emission models used to develop wildland fire emission inventories. Most previous studies quantifying wildland fire EF of temperate ecosystems have focused on emissions from prescribed burning conducted outside of the wildfire season. Little information is available on EF for wildfires in temperate forests of the conterminous US. The goal of this work is to provide information on emissions from wildfire-season forest fires in the northern Rocky Mountains, US. In August 2011, we deployed airborne chemistry instruments and sampled emissions over eight days from three wildfires and a prescribed fire that occurred in mixed conifer forests of the northern Rocky Mountains. We measured the combustion efficiency, quantified as the modified combustion efficiency (MCE, and EF for CO2, CO, and CH4. Our study average values for MCE, EFCO2, EFCO, and EFCH4 were 0.883, 1596 g kg−1, 135 g kg−1, 7.30 g kg−1, respectively. Compared with previous field studies of prescribed fires in temperate forests, the fires sampled in our study had significantly lower MCE and EFCO2 and significantly higher EFCO and EFCH4. The fires sampled in this study burned in areas reported to have moderate to heavy components of standing dead trees and down dead wood due to insect activity and previous fire, but fuel consumption data was not available. However, an analysis of MCE and fuel consumption data from 18 prescribed fires reported in the literature indicates that the availability of coarse fuels and conditions favorable for the combustion of these fuels favors low MCE fires. This analysis suggests that fuel composition was an important factor contributing to the low MCE of the fires measured in this study. This study only measured EF for CO2, CO

  1. Factors affecting mitigation of methane emission from ruminants: Microbiology and biotechnology strategies

    Directory of Open Access Journals (Sweden)

    Afshar Mirzaei

    2015-12-01

    Full Text Available Climate change is a subject of global environmental concern. Increased anthropogenic Greenhouse Gas (GHG emissions have increased the global temperature the last 100 to 200 years. Carbon dioxide and methane are the main greenhouse gases related to animal nutrition and methane has greater global warming potential than carbon dioxide. Among greenhouse gases, methane is considered a potent greenhouse gas with 21 times more global warming potential than carbon dioxide. Worldwide, ruminant livestock produce about 80 million metric tons of methane each year, accounting for about 28% of global emissions from human related activities. Therefore it is impelling animal scientists to finding solutions to mitigate methane emission from ruminants. It seems that solutions can be discussed in four topics including: nutrition (feeding, biotechnology, microbiology and management strategies. We have already published the first and second review articles on feeding strategies and management strategies. In the current review, Microbiology and biotechnology such as emphasizing on animal  breeding, genetic merit, bovine somatotropin (BST, unproductive animals, vaccination, immunisation and biological control (bacteriophage, acetogenesis reductive, chemical defaunation that can be leads to decreasing methane production from ruminant animal production are discussed.

  2. Development of real-world driving cycles and estimation of emission factors for in-use light-duty gasoline vehicles in urban areas.

    Science.gov (United States)

    Hwa, Mei-Yin; Yu, Tai-Yi

    2014-07-01

    This investigation adopts vehicle tracking manner to establish real-world driving patterns and estimates emission factors with dynamometers with 23 traffic-driving variables for 384 in-use light-duty passenger vehicles during non-rush hour. Adequate numbers of driving variables were decided with factor analysis and cluster analysis. The dynamometer tests were performed on FTP75 cycle and five local driving cycles derived from real-world speed profiles. Results presented that local driving cycles and FTP75 cycle were completely different in driving characteristic parameters of typical driving cycles and emission factors. The highest values of emission factor ratios of local driving cycle and FTP75 cycle for CO, NMHC, NO x , CH4, and CO2 were 1.38, 1.65, 1.58, 1.39, and 1.14, respectively.

  3. Modelling of NO{sub x} emission factors from heavy and light-duty vehicles equipped with advanced aftertreatment systems

    Energy Technology Data Exchange (ETDEWEB)

    Oliveira, M.L.M., E-mail: monalisa@unifor.br [IDMEC - Institute of Mechanical Engineering, Instituto Superior Tecnico, Technical University of Lisbon, Av. Rovisco Pais, 1049-001 Lisbon (Portugal); Silva, C.M. [IDMEC - Institute of Mechanical Engineering, Instituto Superior Tecnico, Technical University of Lisbon, Av. Rovisco Pais, 1049-001 Lisbon (Portugal); Moreno-Tost, R. [Departamento de Quimica Inorganica, Cristalografia y Mineralogia, Unidad Asociada al Instituto de Catalisis, CSIC, Universidad de Malaga, Campus de Teatinos, 29071 Malaga (Spain); Farias, T.L. [IDMEC - Institute of Mechanical Engineering, Instituto Superior Tecnico, Technical University of Lisbon, Av. Rovisco Pais, 1049-001 Lisbon (Portugal); Jimenez-Lopez, Antonio [IDMEC - Institute of Mechanical Engineering, Instituto Superior Tecnico, Technical University of Lisbon, Av. Rovisco Pais, 1049-001 Lisbon (Portugal); Departamento de Quimica Inorganica, Cristalografia y Mineralogia, Unidad Asociada al Instituto de Catalisis, CSIC, Universidad de Malaga, Campus de Teatinos, 29071 Malaga (Spain); Rodriguez-Castellon, E. [Departamento de Quimica Inorganica, Cristalografia y Mineralogia, Unidad Asociada al Instituto de Catalisis, CSIC, Universidad de Malaga, Campus de Teatinos, 29071 Malaga (Spain)

    2011-08-15

    Highlights: {yields} Alternative SCR materials. {yields} Catalysts used in heavy-duty vehicles are based on V{sub 2}O{sub 5}-WO{sub 3}-TiO{sub 2}. {yields}Zeolites containing transition metal ions as catalysts for urea SCR has increased. {yields} FeZSM5 catalyst can be a possible candidate as far as pollutants regulation is considered. {yields} Regarding N{sub 2}O emissions mordenite based SCR do not emit this pollutant. - Abstract: NO{sub x} emission standards are becoming stringiest over the world especially for heavy-duty vehicles. To comply with current and future regulations some vehicle manufacturers are adopting exhaust aftertreatment systems known as Selective Catalytic Reduction (SCR). The catalysts are based on Vanadium (Va) and the reductant agent based on ammonia. However, Va is listed on the California Proposition 65 List as potentially causing cancer and alternatives are being studied. This paper presents a model based on neural networks that integrated with a road vehicle simulator allows to estimate NO{sub x} emission factors for different powertrain configurations, along different driving conditions, and covering commercial, zeolite and mordenite alternatives as the base monolith for SCR. The research included the experimental study of copper based and iron based zeolites (ZSM5 and Cuban natural mordenite). The response of NO{sub x} conversion efficiency was monitored in a laboratory for varying space velocity, oxygen, sulfur, water, NO{sub x} and SO{sub 2} emulating the conditions of a Diesel engine exhaust along a trip. The experimental data was used for training neural networks and obtaining a mathematical correlation between the outputs and inputs of the SCR system. The developed correlation was integrated with ADVISOR road vehicle simulator to obtain NO{sub x} emission factors and to test each SCR system installed on light-duty and heavy-duty vehicles for standardized driving cycles and real measured driving cycles. Despite having lower NO

  4. Analysis of the Driving Factors and Contributions to Carbon Emissions of Energy Consumption from the Perspective of the Peak Volume and Time Based on LEAP

    Directory of Open Access Journals (Sweden)

    Lei Tian

    2016-05-01

    Full Text Available Studying the driving factors and contributions of carbon emissions peak volume and time is essential for reducing the cumulative carbon emissions in developing countries with rapid economic development and increasing carbon emissions. Taking Jilin Province as a case study, four scenarios were set in this paper respectively: Business as Usual Scenario (BAU, Energy-Saving Scenario (ESS, Energy-Saving and Low-Carbon Scenario (ELS, and Low-Carbon Scenario (LCS. Furthermore, the carbon emissions were predicted according to the energy consumption based on the application of LEAP system. The research result showed that the peak time of carbon emissions would appear in 2045, 2040, 2035 and 2025 under the four different scenarios, respectively. The peak volumes would be 489.8 Mt, 395.2 Mt, 305.3 Mt and 233.6 Mt, respectively. The cumulative emissions by 2050 are respectively 15.632 Bt, 13.321 Bt, 10.971 Bt and 8.379 Bt. According to the forecasting, we analyzed the driving factors of and contributions to carbon emissions peak volume and time. On the premise of moderate economic growth, the “structural emission reduction”, namely the adjustment of industrial structure and energy structure, and “technology emission reduction”, namely the reduction of energy intensity and carbon emission coefficient could make the peak volume reduced by 20%–52% and cumulative carbon emissions (2050 reduced by 15%–46% on the basis of BAU. Meanwhile, controlling the industrial structure, energy structure and energy intensity could make carbon emissions reach the peak 5–20 years ahead of the time on the basis of BAU. Controlling GDP, industrial structure, energy structure, energy intensity and coefficient of carbon emissions is the feasible method to adjust the carbon emissions peak volume and time in order to reduce the cumulative emissions.

  5. Modeling CO Emission: I. CO as a Column Density Tracer and the X-Factor in Molecular Clouds

    CERN Document Server

    Shetty, Rahul; Dullemond, Cornelis P; Klessen, Ralf S

    2010-01-01

    Theoretical and observational investigations have indicated that the abundance of carbon monoxide (CO) is very sensitive to intrinsic properties of the gaseous medium, such as density, metallicity, and the background UV field. In order to accurately interpret CO observations, it is thus important to understand how well CO traces the gas, which in molecular clouds (MCs) is predominantly molecular hydrogen (H2). Recent hydrodynamic simulations by Glover & Mac Low have explicitly followed the formation and destruction of molecules in model MCs under varying conditions, confirming that CO formation strongly depends on the cloud properties. Conversely, the H2 formation is primarily determined by the age of the MC. We apply radiative transfer calculations to these MC models in order to investigate the properties of CO line emission. We focus on integrated CO (J=1-0) intensities emerging from individual clouds, including its relationship to the total, H2, and CO column densities, as well as the "X factor," the r...

  6. DEVELOPMENT OF FINE PARTICULATE EMISSION FACTORS AND SPECIATION PROFILES FOR OIL AND GAS-FIRED COMBUSTION SYSTEMS

    Energy Technology Data Exchange (ETDEWEB)

    Glenn C. England

    2004-10-20

    ambient air to dilute the stack gas sample followed by 80-90 seconds residence time to allow aerosol formation and growth to stabilize prior to sample collection and analysis. More accurate and complete emissions data generated using the methods developed in this program will enable more accurate source-receptor and source apportionment analysis for PM2.5 National Ambient Air Quality Standards (NAAQS) implementation and streamline the environmental assessment of oil, gas and power production facilities. The overall goals of this program were to: (1) Develop improved dilution sampling technology and test methods for PM2.5 mass emissions and speciation measurements, and compare results obtained with dilution and traditional stationary source sampling methods. (2) Develop emission factors and speciation profiles for emissions of fine particulate matter, especially organic aerosols, for use in source-receptor and source apportionment analyses. (3) Identify and characterize PM2.5 precursor compound emissions that can be used in source-receptor and source apportionment analyses.

  7. Factors influencing polychlorinated dibenzo-p-dioxin and polychlorinated dibenzofuran (PCDD/F) emissions and control in major industrial sectors: case evidence from Shandong Province, China.

    Science.gov (United States)

    Wang, Lin; Lu, Yonglong; He, Guizhen; Mol, Arthur P J; Wang, Tieyu; Gosens, Jorrit; Ni, Kun

    2014-07-01

    Analyzing determinants that influence polychlorinated dibenzo-p-dioxin and polychlorinated dibenzofuran (PCDD/F) emissions is helpful for decision-makers to find effective and efficient ways to mitigate PCDD/F emissions. The PCDD/F emissions and the contributions of the scale effect, structure effect and technology effect to emissions from eight main industrial sectors in 2006, 2008 and 2010 in Shandong Province, were calculated in this article. Total PCDD/F emissions in Shandong increased by 52.8% in 2008 (614.1g I-TEQ) and 49.7% in 2010 (601.8 g I-TEQ) based on 2006 (401.9 g I-TEQ). According to the decomposition method, the largest influencing factor on PCDD/F emission changes was the composition effect (contributed 43.4% in 2008 and 120.6% in 2010 based on 2006), which was also an emission-increasing factor. In this case, the present industrial restructuring policy should be adjusted to control the proportion of production capacities with high emission factors, such as iron ore sintering and steel making and the secondary non-ferrous metal sector. The scale effect increased the emissions in 2008 (contributed 21.9%) and decreased the emissions in 2010 (contributed -28.0%). However, as a source control measure, the excess capacity control policy indeed had a significant role in emission reduction. The main reason for the technology effect (contributed 34.7% in 2008 and 7.4% in 2010 based on 2006) having an emission-increasing role was the weakness in implementing policies for restricting industries with outdated facilities. Some specific suggestions were proposed on PCDD/F reduction for local administrators at the end.

  8. A Sheath Collision Model with Thermionic Electron Emission and the Schottky Correction Factor for Work Function of Wall Material

    CERN Document Server

    Pekker, Leonid

    2015-01-01

    This paper proposes a model that expands Godyak's collisional sheath model to the case of hot electrodes (anode or cathode) with thermionic electron emission. In the model, the electrodes are assumed to be made from refractory metals and, consequently, the erosion of the electrodes is small and can be neglected. In the frame of two temperature thermal plasma modeling, this model allows self-consistent calculation of the sheath potential drop, the Schottky correction factor for the work function of the wall material, the thermionic electron current density, and the heat fluxes of the charged particles from the plasma to the wall. The model is applied to the cathode spot at the tungsten cathode in argon. It is shown that the Shottky correction factor plays a crucial role in modeling high-intensity arcs. It is demonstrated that a virtual cathode can be formed in the atmospheric pressure argon plasma at the cathode surface temperature of 4785 K if the cathode current density is sufficiently small. The heat flux t...

  9. Comparison of models for estimating methane emission factor for enteric fermentation of growing-finishing Hanwoo steers.

    Science.gov (United States)

    Jo, Namchul; Kim, Jongnam; Seo, Seongwon

    2016-01-01

    The methodology provided by the Intergovernmental Panel on Climate Change (IPCC) guidelines is widely used for estimating enteric methane (CH4) production by cattle. No attempt other than the default values in the IPCC Tier 1 has been made for estimating CH4 emission from Hanwoo, a dominant beef species in Korea raised in a unique feeding system. The objective of this study was to compare models for estimating the CH4 emission factor (MEF; kg CH4/head/year) for enteric fermentation in Hanwoo steers. The MEF was estimated based on Korea- and Hanwoo-specific data obtained from the literature using several models. The models include the IPCC Tier 1 (T1), the IPCC Tier 2 method (T2), the IPCC Tier 2 methodology with actual dry matter intake (T2DMI), and the Japanese Tier 3 method (JT3). The JT3 was included due to the similarity in the beef cattle production system between the two countries. Estimated MEF using T2 were 43.4, 33.9, and 36.2 kg CH4/head/year for the growing, finishing, and overall period, respectively. The overall MEF estimated using T2 was 23 % lower than the estimate by T1 (47.0 kg CH4/head/year). There were significant differences in the estimated MEF for enteric fermentation of Hanwoo steers among the methods (P cattle production systems.

  10. Development of net energy ratio and emission factor for biohydrogen production pathways.

    Science.gov (United States)

    Kabir, Md Ruhul; Kumar, Amit

    2011-10-01

    This study investigates the energy and environmental aspects of producing biohydrogen for bitumen upgrading from a life cycle perspective. Three technologies are studied for biohydrogen production; these include the Battelle Columbus Laboratory (BCL) gasifier, the Gas Technology Institute (GTI) gasifier, and fast pyrolysis. Three different biomass feedstocks are considered including forest residue (FR), whole forest (WF), and agricultural residue (AR). The fast pyrolysis pathway includes two cases: truck transport of bio-oil and pipeline transport of bio-oil. The net energy ratios (NERs) for nine biohydrogen pathways lie in the range of 1.3-9.3. The maximum NER (9.3) is for the FR-based pathway using GTI technology. The GHG emissions lie in the range of 1.20-8.1 kg CO₂ eq/kg H₂. The lowest limit corresponds to the FR-based biohydrogen production pathway using GTI technology. This study also analyzes the intensities for acid rain precursor and ground level ozone precursor.

  11. Generation rates and emission factors of particulate matter and particle-bound polycyclic aromatic hydrocarbons of incense sticks.

    Science.gov (United States)

    Lung, Shih-Chun Candice; Hu, Shu-Chuan

    2003-02-01

    The generation rates and emission factors of particulate matter and associated polycyclic aromatic hydrocarbons (PAHs) from incense burning were assessed in a laboratory setting. The differences among different segments of the same stick, among different sticks of the same kind of incense, and between two kinds of manually made Chih-Chen incense sticks (A and B) were evaluated. Joss sticks were burned inside a 44 cm long elutriator; personal environmental monitors fitted into the top of the elutriator were used to take PM2.5 and PM10 samples of incense smoke. Samples were analyzed for PAHs by gas chromatography-flame ionization Detector. It was found that particle and associated PAHs were generated approximately at 561 microg/min (geometric standard deviation (GSD) = 1.1) and 0.56 microg/min (GSD = 1.1) from Incense A, and at 661 microg/min (GSD = 1.7) and 0.46 microg/min (GSD = 1.3) from Incense B, respectively. One gram of Incense A emitted about 19.8 mg (GSD = 1.1) particulate matter and 17.1 microg (GSD = 1.2) particulate-phase PAHs, while one gram of Incense B produced around 43.6 mg (GSD = 1.1) of particles and 25.2 microg (GSD = 1.2) of particle-bound PAHs. There were significant differences in emissions between Incenses A and B, although they belong to the same class of incense. A 10-20% variability in emissions was observed in the main part of the manually produced stick, and a larger variation was found at both tips of the combustible part.

  12. Emission factors of gaseous pollutants from recent kerosene space heaters and fuels available in France in 2010.

    Science.gov (United States)

    Carteret, M; Pauwels, J-F; Hanoune, B

    2012-08-01

    Laboratory measurements of the gaseous emission factors (EF) from two recent kerosene space heaters (wick and injector) with five different fuels have been conducted in an 8-m(3) environmental chamber. The two heaters tested were found to emit mainly CO(2), CO, NO, NO(2), and some volatile organic compounds (VOCs). NO(2) is continuously emitted during use, with an EF of 100-450 μg per g of consumed fuel. CO is normally emitted mainly during the first minutes of use (up to 3 mg/g). Formaldehyde and benzene EFs were quantified at 15 and 16 μg/g, respectively, for the wick heater. Some other VOCs, such as 1,3-butadiene, were detected with lower EFs. We demonstrated the unsuitability of a 'biofuel' containing fatty acid methyl esters for use with the wick heater, and that the accumulation of soot on the same heater, whatever the fuel, leads to a dramatic increase in the CO EF, up to 16 mg/g, which could be responsible for chronic and acute CO intoxications. Our results show that in spite of new technologies and emission standards for unvented kerosene space heaters, as well as for the fuels, the use of these heaters in indoor environments still leads to NO(x) levels in excess of current health recommendations. Whereas injection heaters generate more nitrogen oxides than wick heaters, prolonged use of the latter leads to a soot buildup, concomitant with high CO emissions, which could be responsible for acute and chronic intoxications. The use of a biofuel in a wick heater is also of concern. Maintenance of the heaters and adequate ventilation of the room during use of kerosene space heaters are therefore of prime importance to reduce personal exposure. © 2011 John Wiley & Sons A/S.

  13. Emission factor estimation of ca. 160 emerging organic microcontaminants by inverse modeling in a Mediterranean river basin (Llobregat, NE Spain).

    Science.gov (United States)

    Banjac, Zoran; Ginebreda, Antoni; Kuzmanovic, Maja; Marcé, Rafael; Nadal, Martí; Riera, Josep M; Barceló, Damià

    2015-07-01

    Starting from measured river concentrations, emission factors of 158 organic compounds out of 199 analyzed belonging to different groups of priority and emerging contaminants [pesticides (25), pharmaceuticals and hormones (81), perfluoroalkyl substances (PFASs) (18), industrial compounds (12), drugs of abuse (8) and personal care products (14)] have been estimated by inverse modeling. The Llobregat river was taken as case study representative of Mediterranean rivers. Industrial compounds and pharmaceuticals are the dominant groups (range of 10(4) mg·1000 inhab(-1)·d(-1)). Personal care products, pesticides, PFASs and illegal drugs showed a load approximately one order of magnitude smaller. Considered on a single compound basis industrial compounds still dominate (range of ca. 10(3) mg·1000 inhab(-1)·d(-1)) over other classes. Generally, the results are within the range when compared to previously published estimations for other river basins. River attenuation expressed as the percentage fraction of microcontaminants eliminated was quantified. On average they were around 60-70% of the amount discharged for all classes, except for PFASs, that are poorly eliminated (ca. 20% on average). Uncertainties associated with the calculated emissions have been estimated by Monte-Carlo methods (15,000 runs) and typically show coefficients of variation of ca. 120%. Sensitivities associated with the various variables involved in the calculations (river discharge, river length, concentration, elimination constant, hydraulic travel time and river velocity) have been assessed as well. For the intervals chosen for the different variables, all show sensitivities exceeding unity (1.14 to 3.43), tending to amplify the variation of the emission. River velocity and basin length showed the highest sensitivity value. Even considering the limitations of the approach used, inverse modeling can provide a useful tool for management purposes facilitating the quantification of release rates of

  14. Development of methane emission factors for enteric fermentation in cattle from Benin using IPCC Tier 2 methodology.

    Science.gov (United States)

    Kouazounde, J B; Gbenou, J D; Babatounde, S; Srivastava, N; Eggleston, S H; Antwi, C; Baah, J; McAllister, T A

    2015-03-01

    The objective of this study was to develop emission factors (EF) for methane (CH4) emissions from enteric fermentation in cattle native to Benin. Information on livestock characteristics and diet practices specific to the Benin cattle population were gathered from a variety of sources and used to estimate EF according to Tier 2 methodology of the 2006 Intergovernmental Panel on Climate Change (IPCC) Guidelines for National Greenhouse Gas Inventories. Most cattle from Benin are Bos taurus represented by Borgou, Somba and Lagune breeds. They are mainly multi-purpose, being used for production of meat, milk, hides and draft power and grazed in open pastures and crop lands comprising tropical forages and crops. Estimated enteric CH4 EFs varied among cattle breeds and subcategory owing to differences in proportions of gross energy intake expended to meet maintenance, production and activity. EFs ranged from 15.0 to 43.6, 16.9 to 46.3 and 24.7 to 64.9 kg CH4/head per year for subcategories of Lagune, Somba and Borgou cattle, respectively. Average EFs for cattle breeds were 24.8, 29.5 and 40.2 kg CH4/head per year for Lagune, Somba and Borgou cattle, respectively. The national EF for cattle from Benin was 39.5 kg CH4/head per year. This estimated EF was 27.4% higher than the default EF suggested by IPCC for African cattle with the exception of dairy cattle. The outcome of the study underscores the importance of obtaining country-specific EF to estimate global enteric CH4 emissions.

  15. Evaluation of Uncertainties in Measuring Particulate Matter Emission Factors from Atmospheric Fugitive Sources Using Optical Remote Sensing

    Science.gov (United States)

    Yuen, W.; Ma, Q.; Du, K.; Koloutsou-Vakakis, S.; Rood, M. J.

    2015-12-01

    Measurements of particulate matter (PM) emissions generated from fugitive sources are of interest in air pollution studies, since such emissions vary widely both spatially and temporally. This research focuses on determining the uncertainties in quantifying fugitive PM emission factors (EFs) generated from mobile vehicles using a vertical scanning micro-pulse lidar (MPL). The goal of this research is to identify the greatest sources of uncertainty of the applied lidar technique in determining fugitive PM EFs, and to recommend methods to reduce the uncertainties in this measurement. The MPL detects the PM plume generated by mobile fugitive sources that are carried downwind to the MPL's vertical scanning plane. Range-resolved MPL signals are measured, corrected, and converted to light extinction coefficients, through inversion of the lidar equation and calculation of the lidar ratio. In this research, both the near-end and far-end lidar equation inversion methods are considered. Range-resolved PM mass concentrations are then determined from the extinction coefficient measurements using the measured mass extinction efficiency (MEE) value, which is an intensive PM property. MEE is determined by collocated PM mass concentration and light extinction measurements, provided respectively by a DustTrak and an open-path laser transmissometer. These PM mass concentrations are then integrated with wind information, duration of plume event, and vehicle distance travelled to obtain fugitive PM EFs. To obtain the uncertainty of PM EFs, uncertainties in MPL signals, lidar ratio, MEE, and wind variation are considered. Error propagation method is applied to each of the above intermediate steps to aggregate uncertainty sources. Results include determination of uncertainties in each intermediate step, and comparison of uncertainties between the use of near-end and far-end lidar equation inversion methods.

  16. Coupling field and laboratory measurements to estimate the emission factors of identified and unidentified trace gases for prescribed fires

    Science.gov (United States)

    Yokelson, R. J.; Burling, I. R.; Gilman, J. B.; Warneke, C.; Stockwell, C. E.; de Gouw, J.; Akagi, S. K.; Urbanski, S. P.; Veres, P.; Roberts, J. M.; Kuster, W. C.; Reardon, J.; Griffith, D. W. T.; Johnson, T. J.; Hosseini, S.; Miller, J. W.; Cocker, D. R., III; Jung, H.; Weise, D. R.

    2013-01-01

    An extensive program of experiments focused on biomass burning emissions began with a laboratory phase in which vegetative fuels commonly consumed in prescribed fires were collected in the southeastern and southwestern US and burned in a series of 71 fires at the US Forest Service Fire Sciences Laboratory in Missoula, Montana. The particulate matter (PM2.5) emissions were measured by gravimetric filter sampling with subsequent analysis for elemental carbon (EC), organic carbon (OC), and 38 elements. The trace gas emissions were measured by an open-path Fourier transform infrared (OP-FTIR) spectrometer, proton-transfer-reaction mass spectrometry (PTR-MS), proton-transfer ion-trap mass spectrometry (PIT-MS), negative-ion proton-transfer chemical-ionization mass spectrometry (NI-PT-CIMS), and gas chromatography with MS detection (GC-MS). 204 trace gas species (mostly non-methane organic compounds (NMOC)) were identified and quantified with the above instruments. Many of the 182 species quantified by the GC-MS have rarely, if ever, been measured in smoke before. An additional 153 significant peaks in the unit mass resolution mass spectra were quantified, but either could not be identified or most of the signal at that molecular mass was unaccounted for by identifiable species. In a second, "field" phase of this program, airborne and ground-based measurements were made of the emissions from prescribed fires that were mostly located in the same land management units where the fuels for the lab fires were collected. A broad variety, but smaller number of species (21 trace gas species and PM2.5) was measured on 14 fires in chaparral and oak savanna in the southwestern US, as well as pine forest understory in the southeastern US and Sierra Nevada mountains of California. The field measurements of emission factors (EF) are useful both for modeling and to examine the representativeness of our lab fire EF. The lab EF/field EF ratio for the pine understory fuels was not

  17. Coupling field and laboratory measurements to estimate the emission factors of identified and unidentified trace gases for prescribed fires

    Directory of Open Access Journals (Sweden)

    R. J. Yokelson

    2013-01-01

    Full Text Available An extensive program of experiments focused on biomass burning emissions began with a laboratory phase in which vegetative fuels commonly consumed in prescribed fires were collected in the southeastern and southwestern US and burned in a series of 71 fires at the US Forest Service Fire Sciences Laboratory in Missoula, Montana. The particulate matter (PM2.5 emissions were measured by gravimetric filter sampling with subsequent analysis for elemental carbon (EC, organic carbon (OC, and 38 elements. The trace gas emissions were measured by an open-path Fourier transform infrared (OP-FTIR spectrometer, proton-transfer-reaction mass spectrometry (PTR-MS, proton-transfer ion-trap mass spectrometry (PIT-MS, negative-ion proton-transfer chemical-ionization mass spectrometry (NI-PT-CIMS, and gas chromatography with MS detection (GC-MS. 204 trace gas species (mostly non-methane organic compounds (NMOC were identified and quantified with the above instruments. Many of the 182 species quantified by the GC-MS have rarely, if ever, been measured in smoke before. An additional 153 significant peaks in the unit mass resolution mass spectra were quantified, but either could not be identified or most of the signal at that molecular mass was unaccounted for by identifiable species.

    In a second, "field" phase of this program, airborne and ground-based measurements were made of the emissions from prescribed fires that were mostly located in the same land management units where the fuels for the lab fires were collected. A broad variety, but smaller number of species (21 trace gas species and PM2.5 was measured on 14 fires in chaparral and oak savanna in the southwestern US, as well as pine forest understory in the southeastern US and Sierra Nevada mountains of California. The field measurements of emission factors (EF are useful both for modeling and to examine the representativeness of our lab fire EF. The lab EF/field EF ratio for

  18. Coupling field and laboratory measurements to estimate the emission factors of identified and unidentified trace gases for prescribed fires

    Directory of Open Access Journals (Sweden)

    R. J. Yokelson

    2012-08-01

    Full Text Available An extensive program of experiments focused on biomass burning emissions began with a laboratory phase in which vegetative fuels commonly consumed in prescribed fires were collected in the southeastern and southwestern US and burned in a series of 71 fires at the US Forest Service Fire Sciences Laboratory in Missoula, Montana. The particulate matter (PM2.5 emissions were measured by gravimetric filter sampling with subsequent analysis for elemental carbon (EC, organic carbon (OC, and 38 elements. The trace gas emissions were measured by an open-path Fourier transform infrared (OP-FTIR spectrometer, proton-transfer-reaction mass spectrometry (PTR-MS, proton-transfer ion-trap mass spectrometry (PIT-MS, negative-ion proton-transfer chemical-ionization mass spectrometry (NI-PT-CIMS, and gas chromatography with MS detection (GC-MS. 204 trace gas species (mostly non-methane organic compounds – NMOC were identified and quantified with the above instruments. Many of the 182 species quantified by the GC-MS have rarely, if ever, been measured in smoke before. An additional 153 significant peaks in the unit mass resolution mass spectra were quantified, but either could not be identified or most of the signal at that molecular mass was unaccounted for by identifiable species.

    In a second, "field" phase of this program, airborne and ground-based measurements were made of the emissions from prescribed fires that were mostly located in the same land management units where the fuels for the lab fires were collected. A broad variety, but smaller number of species (21 trace gas species and PM2.5 was measured on 14 fires in chaparral and oak savanna in the southwestern US, as well as pine forest understory in the southeastern US and Sierra Nevada mountains of California. The field measurements of emission factors (EF are useful both for modeling and to examine the representativeness of our lab fire EF. The lab EF/field EF ratio for

  19. Air pollution from gas flaring: new emission factor estimates and detection in a West African aerosol remote-sensing climatology

    Science.gov (United States)

    MacKenzie, Rob; Fawole, Olusegun Gabriel; Levine, James; Cai, Xiaoming

    2016-04-01

    Gas flaring, the disposal of gas through stacks in an open-air flame, is a common feature in the processing of crude oil, especially in oil-rich regions of the world. Gas flaring is a prominent source of volatile organic compounds (VOCs), polycyclic aromatic hydrocarbons (PAH), CO, CO2, nitrogen oxides (NOx), SO2 (in "sour" gas only), and soot (black carbon), as well as the release of locally significant amounts of heat. The rates of emission of these pollutants from gas flaring depend on a number of factors including, but not limited to, fuel composition and quantity, stack geometry, flame/combustion characteristics, and prevailing meteorological conditions. Here, we derive new estimated emission factors (EFs) for carbon-containing pollutants (excluding PAH). The air pollution dispersion model, ADMS5, is used to simulate the dispersion of the pollutants from flaring stacks in the Niger delta. A seasonal variation of the dispersion pattern of the pollutant within a year is studied in relation to the movements of the West Africa Monsoon (WAM) and other prevailing meteorological factors. Further, we have clustered AERONET aerosol signals using trajectory analysis to identify dominant aerosol sources at the Ilorin site in West Africa (4.34 oE, 8.32 oN). A 10-year trajectory-based analysis was undertaken (2005-2015, excluding 2010). Of particular interest are air masses that have passed through the gas flaring region in the Niger Delta area en-route the AERONET site. 7-day back trajectories were calculated using the UK Universities Global Atmospheric Modelling Programme (UGAMP) trajectory model which is driven by analyses from the European Centre for Medium-Range Weather Forecasts (ECMWF). From the back-trajectory calculations, dominant sources are identified, using literature classifications: desert dust (DD); Biomass burning (BB); and Urban-Industrial (UI). We use a combination of synoptic trajectories and aerosol optical properties to distinguish a fourth source

  20. Global Factor Trade with Differentiated Factor Prices and Factor Intensities

    OpenAIRE

    Yun-kwong Kwok

    2004-01-01

    Relaxing the assumption of internationally identical factor intensity techniques in the HOV model creates two challenges. First, computing actual factor intensity techniques of different countries requires detailed input-output tables and factor usage data, which are not always available. Second, determinants of the factor intensity technique differences across countries need to be identified. This paper explores the role of relative factor price differences in the determination of factor int...

  1. Coupling field and laboratory measurements to estimate the emission factors of identified and unidentified trace gases for prescribed fires

    Energy Technology Data Exchange (ETDEWEB)

    Yokelson, R. J.; Burling, I. R.; Gilman, J. B.; Warneke, C.; Stockwell, C. E.; de Gouw, J.; Akagi, S. K.; Urbanski, S. P.; Veres, P.; Roberts, J. M.; Kuster, W. C.; Reardon, J.; Griffith, D. W. T.; Johnson, T. J.; Hosseini, S.; Miller, J. W.; Cocker III, D. R.; Jung, H.; Weise, D. R.

    2013-01-01

    Vegetative fuels commonly consumed in prescribed fires were collected from five locations in the southeastern and southwestern U.S. and burned in a series of 77 fires at the U.S. Forest Service Fire Sciences Laboratory in Missoula, Montana. The particulate matter (PM2.5) emissions were measured by gravimetric filter sampling with subsequent analysis for elemental carbon (EC), organic carbon (OC), and 38 elements. The trace gas emissions were measured with a large suite of state-of-the-art instrumentation including an open-path Fourier transform infrared (OP FTIR) spectrometer, proton-transfer-reaction mass spectrometry (PTR-MS), proton-transfer ion-trap mass spectrometry (PIT-MS), negative-ion proton-transfer chemical-ionization mass spectrometry (NI-PT-CIMS), and gas chromatography with MS detection (GC-MS). 204 trace gas species (mostly non-methane organic compounds (NMOC)) were identified and quantified with the above instruments. An additional 152 significant peaks in the unit mass resolution mass spectra were quantified, but either could not be identified or most of the signal at that molecular mass was unaccounted for by identifiable species. As phase II of this study, we conducted airborne and ground-based sampling of the emissions from real prescribed fires mostly in the same land management units where the fuels for the lab fires were collected. A broad variety, but smaller number of species (21 trace gas species and PM2.5) was measured on 14 fires in chaparral and oak savanna in the southwestern US, as well as pine forest understory in the southeastern US and Sierra Nevada mountains of California. These extensive field measurements of emission factors (EF) for temperate biomass burning are useful both for modeling and to examine the representativeness of our lab fire EF. The lab/field EF ratio for the pine understory fuels was not statistically different from one, on average. However, our lab EF for “smoldering compounds” emitted by burning the semi

  2. Decomposition of factors determining the trend of CO{sub 2} emissions from car travel in Great Britain (1970-2000)

    Energy Technology Data Exchange (ETDEWEB)

    Kwon, Tae-Hyeong [The Korea Transport Institute (KOTI), 2311 Daehwa-dong, Ilsan-gu, Goyang-Shi, Gyeonggi-do, 411-701 (Korea, Republic of)

    2005-04-15

    Carbon dioxide (CO{sub 2}) is the most important of the greenhouse gases that are causing global warming. The transport sector currently accounts for more than one-quarter of CO{sub 2} emissions and more importantly its share in total emissions is increasing in most countries. This paper investigates the key factors in the change in CO{sub 2} emissions from car travel in Great Britain over the last 30 years. It attempts to disentangle determinants of growth in CO{sub 2} emissions from car travel, which has the largest share of emissions in road transport. The study is based on various decomposition analyses, starting from the IPAT identity. As summarised in the IPAT identity, the degree of the Impact of human activity on the environment is determined by changes in Population, Affluence (per-capita consumption) and Technology (environmental impact per quantity of consumption). In the case of CO{sub 2} emissions from car travel in Great Britain, the affluence (A) factor (car driving distance per person) was a dominant force for the growth of emissions over the last 30 years. Not only do people travel longer distances by cars than 30 years ago, but car occupancy rates have also decreased, contributing to the growth of car driving distance per person. Although technology (T) factors such as fuel efficiency and fuel substitution to diesel fuel partly cancelled out these growth effects of affluence factors, this contribution was relatively small. However, in the 1990s there emerged a different pattern in the trend. Of the affluence (A) factors, the growth rate of car trip distance per person weakened considerably. As for the technology (T) effect, the carbon intensity of car driving kept decreasing over this period. Therefore, although CO{sub 2} emissions from car travel (I) continued to increase, the growth rate became substantially lower than in the earlier periods. More detailed investigation into the determinants of both affluence (A) factors and technology (T

  3. The spatial distribution of commuting CO2 emissions and the influential factors:A case study in Xi'an, China

    Institute of Scientific and Technical Information of China (English)

    LIU Yuan-Yuan; WANG Yuan-Qing; AN Rui; LI Chao

    2015-01-01

    As the transport sector is a major source of greenhouse gas emissions, the effect of urbanization on transport CO2 emissions in developing cities has become a key issue under global climate change. Examining the case of Xi'an, this paper aims to explore the spatial distribution of commuting CO2 emissions and influencing factors in the new, urban industry zones and city centers considering Xi'an's transition from a monocentric to a polycentric city in the process of urbanization. Based on household survey data from 1501 respondents, there are obvious differences in commuting CO2 emissions between new industry zones and city centers: City centers feature lower household emissions of 2.86 kg CO2 per week, whereas new industry zones generally have higher household emissions of 3.20 kg CO2 per week. Contrary to previous research results, not all new industry zones have high levels of CO2 emissions;with the rapid development of various types of industries, even a minimum level of household emissions of 2.53 kg CO2 per week is possible. The uneven distribution of commuting CO2 emissions is not uniformly affected by spatial parameters such as jobehousing balance, residential density, employment density, and land use diversity. Optimum combination of the spatial parameters and travel pattern along with corresponding transport infrastructure construction may be an appropriate path to reduction and control of emissions from commuting.

  4. Effects of multiple environmental factors on CO2 emission and CH4 uptake from old-growth forest soils

    Directory of Open Access Journals (Sweden)

    M. Cao

    2009-07-01

    Full Text Available To assess contribution of multiple environmental factors to actual carbon exchanges between the atmosphere and forest soils, four old-growth forests referred to as boreal coniferous forest, temperate needle-broadleaved mixed forest, subtropical evergreen broadleaved forest and tropical seasonal rain forest were selected along the eastern China. In each old-growth forest, soil CO2 and CH4 fluxes were measured for three years using the static chamber and gas chromatography technique. Soil temperature and moisture at the 10 cm depth were measured simultaneously with the greenhouse gas measurements. Inorganic N (NH4+-N and NO3--N in the 0–10 cm was determined monthly. From north to south, annual mean CO2 flux ranged from 18.09±0.22 to 35.40±2.24 Mg CO2 ha−1 yr−1 and annual mean CH4 flux ranged from -0.04±0.11 to -5.15±0.96 kg CH4 ha−1 yr−1. Soil CO2 fluxes in the old-growth forests were mainly driven by soil temperature, followed by soil moisture and NO3--N. Based on the gradient theory of exchange of time and space, increase in air temperature in the future would promote soil CO2 emission in the old-growth forests. The responses of soil CH4 uptake to warming were dependent upon the critical temperature in forest. In addition, the NO3--N promotion to CO2 emission could partially attribute to the compound effects of high nitrate stimulation on soil microbe activities and increased decomposability of organic materials. The mechanism of NH4+ inhibition to CH4 uptake included both a competitive inhibition of CH4 mono-oxygenase enzyme and a toxic inhibition by hydroxylamine or nitrite produced via NH4+ oxidation. Overall, increasing in precipitation and nitrogen deposition in eastern China would increase soil CO2 emission, but decrease soil CH4 uptake in the old-growth forests.

  5. Characterizing fluorescent dissolved organic matter in a membrane bioreactor via excitation-emission matrix combined with parallel factor analysis.

    Science.gov (United States)

    Maqbool, Tahir; Quang, Viet Ly; Cho, Jinwoo; Hur, Jin

    2016-06-01

    In this study, we successfully tracked the dynamic changes in different constitutes of bound extracellular polymeric substances (bEPS), soluble microbial products (SMP), and permeate during the operation of bench scale membrane bioreactors (MBRs) via fluorescence excitation-emission matrix (EEM) combined with parallel factor analysis (PARAFAC). Three fluorescent groups were identified, including two protein-like (tryptophan-like C1 and tyrosine-like C2) and one microbial humic-like components (C3). In bEPS, protein-like components were consistently more dominant than C3 during the MBR operation, while their relative abundance in SMP depended on aeration intensities. C1 of bEPS exhibited a linear correlation (R(2)=0.738; pbEPS amounts in sludge, and C2 was closely related to the stability of sludge. The protein-like components were more greatly responsible for membrane fouling. Our study suggests that EEM-PARAFAC can be a promising monitoring tool to provide further insight into process evaluation and membrane fouling during MBR operation.

  6. Estimates of black carbon and size-resolved particle number emission factors from residential wood burning based on ambient monitoring and model simulations.

    Science.gov (United States)

    Olivares, Gustavo; Ström, Johan; Johansson, Christer; Gidhagen, Lars

    2008-06-01

    In this paper we derive typical emission factors for coarse particulate matter (PM(10)), oxides of nitrogen (NO(x)), black carbon (BC), and number particle size distributions based on a combination of measurements and air quality dispersion modeling. The advantage of this approach is that the emission factors represent integrated emissions from several vehicle types and different types of wood stoves. Normally it is very difficult to estimate the total emissions in cities on the basis of laboratory measurements on single vehicles or stoves because of the large variability in conditions. The measurements were made in Temuco, Chile, between April 18 and June 15, 2005 at two sites. The first one was located in a residential area relatively far from major roads. The second site was located in a busy street in downtown Temuco where wood consumption is low. The measurements support the assumption that the monitoring sites represent the impact of different emission sources, namely traffic and residential wood combustion (RWC). Fitting model results to the available measurements, emission factors were obtained for PM(10) (RWC = 2160 +/- 100 mg/kg; traffic = 610 +/- 51 mg/veh-km), NO(x) (RWC = 800 +/- 100 mg/kg; traffic = 4400 +/- 100 mg/veh-km), BC (RWC = 74 +/- 6 mg/kg; traffic = 60 +/- 3 mg/veh-km) and particle number (N) with size distribution between 25 and 600 nm (N(25-600)) (RWC = 8.9 +/- 1 x 10(14) pt/kg; traffic = 6.7 +/- 0.5 x 10(14) pt/veh-km). The obtained emission factors are comparable to results reported in the literature. The size distribution of the N emission factors for traffic was shown to be different than for RWC. The main difference is that although traffic emissions show a bimodal size distribution with a main mode below 30 nm and a secondary one around 100 nm, RWC emissions show the main mode slightly below 100 nm and a smaller nucleation mode below 50 nm.

  7. Evaluation of 4-[18F]fluorobenzoyl-FALGEA-NH2 as a positron emission tomography tracer for epidermal growth factor receptor mutation variant III imaging in cancer

    DEFF Research Database (Denmark)

    Denholt, Charlotte Lund; Binderup, Tina; Stockhausen, Marie-Thérése;

    2011-01-01

    This study describes the radiosynthesis, in vitro and in vivo evaluation of the novel small peptide radioligand, 4-[(18)F]fluorobenzoyl-Phe-Ala-Leu-Gly-Glu-Ala-NH(2,) ([(18)F]FBA-FALGEA-NH(2)) as a positron emission tomography (PET) tracer for imaging of the cancer specific epidermal growth factor...

  8. 40 CFR Table 1 to Subpart Wwww of... - Equations To Calculate Organic HAP Emissions Factors for Specific Open Molding and Centrifugal...

    Science.gov (United States)

    2010-07-01

    ... 40 Protection of Environment 12 2010-07-01 2010-07-01 true Equations To Calculate Organic HAP Emissions Factors for Specific Open Molding and Centrifugal Casting Process Streams 1 Table 1 to Subpart... Specific Open Molding and Centrifugal Casting Process Streams ER25AU05.020 ER25AU05.021...

  9. On-road measurements of NMVOCs and NOx: Determination of light-duty vehicles emission factors from tunnel studies in Brussels city center

    Science.gov (United States)

    Ait-Helal, W.; Beeldens, A.; Boonen, E.; Borbon, A.; Boréave, A.; Cazaunau, M.; Chen, H.; Daële, V.; Dupart, Y.; Gaimoz, C.; Gallus, M.; George, C.; Grand, N.; Grosselin, B.; Herrmann, H.; Ifang, S.; Kurtenbach, R.; Maille, M.; Marjanovic, I.; Mellouki, A.; Miet, K.; Mothes, F.; Poulain, L.; Rabe, R.; Zapf, P.; Kleffmann, J.; Doussin, J.-F.

    2015-12-01

    Emission factors (EFs) of pollutants emitted by light-duty vehicles (LDV) were investigated in the Leopold II tunnel in Brussels city center (Belgium), in September 2011 and in January 2013, respectively. Two sampling sites were housing the instruments for the measurements of a large range of air pollutants, including non-methane volatile organic compounds (NMVOCs), nitrogen oxides (NOx) and carbon dioxide (CO2). The NMVOCs and NOx traffic EFs for LDV were determined from their correlation with CO2 using a single point analysis method. The emission factor of NOx is (544 ± 199) mg vehicle-1 km-1; NMVOCs emission factors vary from (0.26 ± 0.09) mg vehicle-1 km-1 for cis-but-2-ene to (8.11 ± 2.71) mg vehicle-1 km-1 for toluene. Good agreement is observed between the EFs determined in the Leopold II tunnel and the most recent EFs determined in another European roadway tunnel in 2004, with only a slight decrease of the EFs during the last decade. An historical perspective is provided and the observed trend in the NMVOCs emission factors reflect changes in the car fleet composition, the fuels and/or the engine technology that have occurred within the last three decades in Europe.

  10. Factors influencing CO2 and CH4 emissions from coastal wetlands in the Liaohe Delta, Northeast China

    DEFF Research Database (Denmark)

    Olsson, L.; Ye, S.; Wei, M.

    2015-01-01

    to the atmosphere. The CH4 emission from coastal wetlands can be reduced by creating fluctuating water tables, including water tables below the soil surface, as well as by occasional flooding by high-salinity water. The effects of water management schemes on the biological communities in the wetlands must, however......Many factors are known to influence greenhouse gas emissions from coastal wetlands, but it is still unclear which factors are most important under field conditions when they are all acting simultaneously. The objective of this study was to assess the effects of water table, salinity, soil...... temperature and vegetation on CH4 emissions and ecosystem respiration (Reco) from five coastal wetlands in the Liaohe Delta, northeast China: two Phragmites australis (common reed) wetlands, two Suaeda salsa (sea blite) marshes and a rice (Oryza sativa) paddy. Throughout the growing season, the Suaeda...

  11. Measurements of VOC/SVOC emission factors from burning incenses in an environmental test chamber: influence of temperature, relative humidity, and air exchange rate.

    Science.gov (United States)

    Manoukian, A; Buiron, D; Temime-Roussel, B; Wortham, H; Quivet, E

    2016-04-01

    This study investigates the influence of three environmental indoor parameters (i.e., temperature, relative humidity, and air exchange rate) on the emission of 13 volatile organic compounds (VOCs) and semi-volatile organic compounds (SVOCs) during incense burning. Experiments have been carried out using an environmental test chamber. Statistical results from a classical two-level full factorial design highlight the predominant effect of ventilation on emission factors. The higher the ventilation, the higher the emission factor. Moreover, thanks to these results, an estimation of the concentration range for the compounds under study can be calculated and allows a quick look of indoor pollution induced by incense combustion. Carcinogenic substances (i.e., benzene, benzo(a)pyrene, and formaldehyde) produced from the incense combustion would be predicted in typical living indoors conditions to reach instantaneous concentration levels close to or higher than air quality exposure threshold values.

  12. Emission factors of SO2, NOx and particles from ships in Neva Bay from ground-based and helicopter-borne measurements and AIS-based modeling

    Directory of Open Access Journals (Sweden)

    J. Beecken

    2014-10-01

    Full Text Available Emission factors of SO2, NOx and size distributed particle numbers were measured for approximately 300 different ships in the Gulf of Finland and Neva Bay area during two campaigns in August/September 2011 and June/July 2012. The measurements were carried out from a harbor vessel and from an MI-8 helicopter downwind of passing ships. Other measurements were carried out from shore sites near the island of Kronstadt and along the river Neva in the city area of Saint Petersburg. Most ships were running at reduced speed (10 knots, i.e. not at their optimal load. Vessels for domestic and international shipping were monitored. It was seen that the distribution of the SO2 emission factors is bi-modal with averages of 4.6 gSO2 kgfuel−1 and 18.2 gSO2 kgfuel−1 for the lower and the higher mode, respectively. The emission factors show compliance with the 1% fuel sulfur content SECA limit for 90% of the vessels in 2011 and 97% in 2012. The distribution of the NOx emission factor is mono-modal with an average of 58 gNOx kgfuel−1. The corresponding emission related to the generated power yields an average of 12.1 gNOx kWh−1. The distribution of the emission factors for particulate number shows that nearly 90% of all particles in the 5.6 nm to 10 μm size range were below 70 nm in diameter. The distribution of the corresponding emission factors for the mass indicates two separated main modes, one for particles between 30 and 300 nm the other above 2 μm. The average particle emission factors were found to be in the range from 0.7 to 2.7 × 1016 particles kgfuel−1 and 0.2 to 3.4 gPM kgfuel−1, respectively. The NOx and particulate emissions are comparable with other studies. The measured emission factors were compared, for individual ships, to modeled ones using the Ship Traffic Emission Assessment Model (STEAM of the Finnish Meteorological Institute. A reasonably good agreement for gaseous sulfur and nitrogen emissions can be seen for ships in

  13. Application of positive matrix factorization to on-road measurements for source apportionment of diesel- and gasoline-powered vehicle emissions in Mexico City

    Directory of Open Access Journals (Sweden)

    D. A. Thornhill

    2009-12-01

    Full Text Available The goal of this research is to quantify diesel- and gasoline-powered motor vehicle emissions within the Mexico City Metropolitan Area (MCMA using on-road measurements captured by a mobile laboratory combined with positive matrix factorization (PMF receptor modeling. During the MCMA-2006 ground-based component of the MILAGRO field campaign, the Aerodyne Mobile Laboratory (AML measured many gaseous and particulate pollutants, including carbon dioxide, carbon monoxide (CO, nitrogen oxides (NOx, benzene, toluene, alkylated aromatics, formaldehyde, acetaldehyde, acetone, ammonia, particle number, fine particulate mass (PM2.5, and black carbon (BC. These serve as inputs to the receptor model, which is able to resolve three factors corresponding to gasoline engine exhaust, diesel engine exhaust, and the urban background. Using the source profiles, we calculate fuel-based emission factors for each type of exhaust. The MCMA's gasoline-powered vehicles are considerably dirtier, on average, than those in the US with respect to CO and aldehydes. Its diesel-powered vehicles have similar emission factors of NOx and higher emission factors of aldehydes, particle number, and BC. In the fleet sampled during AML driving, gasoline-powered vehicles are responsible for 97% of mobile source emissions of CO, 22% of NOx, 95–97% of aromatics, 72–85% of carbonyls, 74% of ammonia, negligible amounts of particle number, 26% of PM2.5, and 2% of BC; diesel-powered vehicles account for the balance. Because the mobile lab spent 17% of its time waiting at stoplights, the results may overemphasize idling conditions, possibly resulting in an underestimate of NOx and overestimate of CO emissions. On the other hand, estimates of the inventory that do not correctly account for emissions during idling are likely to produce bias in the opposite direction. Nevertheless, the fuel-based inventory suggests that mobile

  14. Quantification of vehicle fleet PM10 particulate matter emission factors from exhaust and non-exhaust sources using tunnel measurement techniques.

    Science.gov (United States)

    Lawrence, Samantha; Sokhi, Ranjeet; Ravindra, Khaiwal

    2016-03-01

    Road tunnels act like large laboratories; they provide an excellent environment to quantify atmospheric particles emission factors from exhaust and non-exhaust sources due to their known boundary conditions. Current work compares the High Volume, Dichotomous Stacked Filter Unit and Partisol Air Sampler for coarse, PM10 and PM2.5 particle concentration measurement and found that they do not differ significantly (p = 95%). PM2.5 fraction contributes 66% of PM10 proportions and significantly influenced by traffic (turbulence) and meteorological conditions. Mass emission factors for PM10 varies from 21.3 ± 1.9 to 28.8 ± 3.4 mg/vkm and composed of Motorcycle (0.0003-0.001 mg/vkm), Cars (26.1-33.4 mg/vkm), LDVs (2.4-3.0 mg/vkm), HDVs (2.2-2.8 mg/vkm) and Buses (0.1 mg/vkm). Based on Lawrence et al. (2013), source apportionment modelling, the PM10 emission of brake wear (3.8-4.4 mg/vkm), petrol exhaust (3.9-4.5 mg/vkm), diesel exhaust (7.2-8.3 mg/vkm), re-suspension (9-10.4 mg/vkm), road surface wear (3.9-4.5 mg/vkm), and unexplained (7.2 mg/vkm) were also calculated. The current study determined that the combined non-exhaust fleet PM10 emission factor (16.7-19.3 mg/vkm) are higher than the combined exhaust emission factor (11.1-12.8 mg/vkm). Thus, highlight the significance of non-exhaust emissions and the need for legislation and abatement strategies to reduce their contributions to ambient PM concentrations.

  15. Effects of Endogenous Factors on Regional Land-Use Carbon Emissions Based on the Grossman Decomposition Model: A Case Study of Zhejiang Province, China

    Science.gov (United States)

    Wu, Cifang; Li, Guan; Yue, Wenze; Lu, Rucheng; Lu, Zhangwei; You, Heyuan

    2015-02-01

    The impact of land-use change on greenhouse gas emissions has become a core issue in current studies on global change and carbon cycle. However, a comprehensive evaluation of the effects of land-use changes on carbon emissions is very necessary. This paper attempted to apply the Grossman decomposition model to estimate the scale, structural, and management effects of land-use carbon emissions based on final energy consumption by establishing the relationship between the types of land use and carbon emissions in energy consumption. It was shown that land-use carbon emissions increase from 169.5624 million tons in 2000 to 637.0984 million tons in 2010, with an annual average growth rate of 14.15 %. Meanwhile, land-use carbon intensity increased from 17.59 t/ha in 2000 to 64.42 t/ha in 2010, with an average annual growth rate of 13.86 %. The results indicated that rapid industrialization and urbanization in Zhejiang Province promptly increased urban land and industrial land, which consequently affected land-use extensive emissions. The structural and management effects did not mitigate land-use carbon emissions. By contrast, both factors evidently affected the growth of carbon emissions because of the rigid demands of energy-intensive land-use types and the absence of land management. Results called for the policy implications of optimizing land-use structures and strengthening land-use management.

  16. Factor II deficiency

    Science.gov (United States)

    ... if one or more of these factors are missing or are not functioning like they should. Factor II is one such coagulation factor. Factor II deficiency runs in families (inherited) and is very rare. Both parents must ...

  17. Factor VII deficiency

    Science.gov (United States)

    ... if one or more of these factors are missing or are not functioning like they should. Factor VII is one such coagulation factor. Factor VII deficiency runs in families (inherited) and is very rare. Both parents must ...

  18. Heart disease - risk factors

    Science.gov (United States)

    Heart disease - prevention; CVD - risk factors; Cardiovascular disease - risk factors; Coronary artery disease - risk factors; CAD - risk ... a certain health condition. Some risk factors for heart disease you cannot change, but some you can. ...

  19. Thyroid Cancer Risk Factors

    Science.gov (United States)

    ... Prevented? Thyroid Cancer Causes, Risk Factors, and Prevention Thyroid Cancer Risk Factors A risk factor is anything that ... Cancer? Can Thyroid Cancer Be Prevented? More In Thyroid Cancer About Thyroid Cancer Causes, Risk Factors, and Prevention ...

  20. Discrimination of marine algal taxonomic groups based on fluorescence excitation emission matrix, parallel factor analysis and CHEMTAX

    Institute of Scientific and Technical Information of China (English)

    CHEN Xiaona; SURongguo; BAIYing; SHI Xiaoyong; YANG Rujun

    2014-01-01

    An in vivo three-dimensional fluorescence method for the determination of algae community structure was developed by parallel factor analysis (PARAFAC) and CHEMTAX. The PARAFAC model was applied to fluo-rescence excitation-emission matrix (EEM) of 60 algae species belonging to five divisions and 11 fluorescent components were identified according to the residual sum of squares and specificity of the composition profiles of fluorescent. By the 11 fluorescent components, the algae species at different growth stages were classified correctly at the division level using Bayesian discriminant analysis (BDA). Then the reference fluo-rescent component ratio matrix was constructed for CHEMTAX, and the EEM–PARAFAC–CHEMTAX method was developed to differentiate algae taxonomic groups. The correct discrimination ratios (CDRs) when the fluorometric method was used for single-species samples were 100% at the division level, except for Bacil-lariophyta with a CDR of 95.6%. The CDRs for the mixtures were above 94.0% for the dominant algae species and above 87.0% for the subdominant algae species. However, the CDRs of the subdominant algae species were too low to be unreliable when the relative abundance estimated was less than 15.0%. The fluorometric method was tested using the samples from the Jiaozhou Bay and the mesocosm experiments in the Xiaomai Island Bay in August 2007. The discrimination results of the dominant algae groups agreed with microscopy cell counts, as well as the subdominant algae groups of which the estimated relative abundance was above 15.0%. This technique would be of great aid when low-cost and rapid analysis is needed for samples in a large batch. The fluorometric technique has the ability to correctly identify dominant species with proper abundance both in vivo and in situ.

  1. Feasibility of Vascular Endothelial Growth Factor Imaging in Human Atherosclerotic Plaque Using 89Zr-Bevacizumab Positron Emission Tomography

    Directory of Open Access Journals (Sweden)

    Reza Golestani

    2013-06-01

    Full Text Available Intraplaque angiogenesis is associated with the occurrence of atherosclerotic plaque rupture. Cardiovascular molecular imaging can be used for the detection of rupture-prone plaques. Imaging with radiolabeled bevacizumab, a monoclonal anti-vascular endothelial growth factor (VEGF-A, can depict VEGF levels corresponding to the angiogenic status in tumors. We determined the feasibility of 89Zr-bevacizumab imaging for the detection of VEGF in carotid endarterectomy (CEA specimens. Five CEA specimens were coincubated with 89Zr-bevacizumab and aspecific 111In-labeled IgG to determine the specificity of bevacizumab accumulation. In 11 CEA specimens, 89Zr-bevacizumab micro-positron emission tomography (PET was performed following 2 hours of incubation. Specimens were cut in 4 mm wide segments and were stained for VEGF and CD68. In each segment, the mean percent incubation dose per gram of tissue (%Inc/g and tissue to background ratio were determined. A 10-fold higher accumulation of 89Zr-bevacizumab compared to 111In-IgG uptake was demonstrated by gamma counting. The mean %Inc/ghot spot was 2.2 ± 0.9 with a hot spot to background ratio of 3.6 ± 0.8. There was a significant correlation between the segmental tissue to background uptake ratio and the VEGF score (ρ = .74, p < .001. It is feasible to detect VEGF tissue concentration within CEA specimens using 89Zr-bevacizumab PET. 89Zr-bevacizumab accumulation in plaques is specific and correlates with immunohistochemistry scores.

  2. Application of positive matrix factorization to on-road measurements for source apportionment of diesel- and gasoline-powered vehicle emissions in Mexico City

    Directory of Open Access Journals (Sweden)

    D. A. Thornhill

    2010-04-01

    Full Text Available The goal of this research is to quantify diesel- and gasoline-powered motor vehicle emissions within the Mexico City Metropolitan Area (MCMA using on-road measurements captured by a mobile laboratory combined with positive matrix factorization (PMF receptor modeling. During the MCMA-2006 ground-based component of the MILAGRO field campaign, the Aerodyne Mobile Laboratory (AML measured many gaseous and particulate pollutants, including carbon dioxide, carbon monoxide (CO, nitrogen oxides (NOx, benzene, toluene, alkylated aromatics, formaldehyde, acetaldehyde, acetone, ammonia, particle number, fine particulate mass (PM2.5, and black carbon (BC. These serve as inputs to the receptor model, which is able to resolve three factors corresponding to gasoline engine exhaust, diesel engine exhaust, and the urban background. Using the source profiles, we calculate fuel-based emission factors for each type of exhaust. The MCMA's gasoline-powered vehicles are considerably dirtier, on average, than those in the US with respect to CO and aldehydes. Its diesel-powered vehicles have similar emission factors of NOx and higher emission factors of aldehydes, particle number, and BC. In the fleet sampled during AML driving, gasoline-powered vehicles are found to be responsible for 97% of total vehicular emissions of CO, 22% of NOx, 95–97% of each aromatic species, 72–85% of each carbonyl species, 74% of ammonia, negligible amounts of particle number, 26% of PM2.5, and 2% of BC; diesel-powered vehicles account for the balance. Because the mobile lab spent 17% of its time waiting at stoplights, the results may overemphasize idling conditions, possibly resulting in an underestimate of NOx and overestimate of CO emissions. On the other hand, estimates of the inventory that do not correctly account for emissions during idling are likely to produce bias in the opposite direction.The resulting fuel

  3. Application of positive matrix factorization to on-road measurements for source apportionment of diesel- and gasoline-powered vehicle emissions in Mexico City

    Science.gov (United States)

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

    2010-04-01

    The goal of this research is to quantify diesel- and gasoline-powered motor vehicle emissions within the Mexico City Metropolitan Area (MCMA) using on-road measurements captured by a mobile laboratory combined with positive matrix factorization (PMF) receptor modeling. During the MCMA-2006 ground-based component of the MILAGRO field campaign, the Aerodyne Mobile Laboratory (AML) measured many gaseous and particulate pollutants, including carbon dioxide, carbon monoxide (CO), nitrogen oxides (NOx), benzene, toluene, alkylated aromatics, formaldehyde, acetaldehyde, acetone, ammonia, particle number, fine particulate mass (PM2.5), and black carbon (BC). These serve as inputs to the receptor model, which is able to resolve three factors corresponding to gasoline engine exhaust, diesel engine exhaust, and the urban background. Using the source profiles, we calculate fuel-based emission factors for each type of exhaust. The MCMA's gasoline-powered vehicles are considerably dirtier, on average, than those in the US with respect to CO and aldehydes. Its diesel-powered vehicles have similar emission factors of NOx and higher emission factors of aldehydes, particle number, and BC. In the fleet sampled during AML driving, gasoline-powered vehicles are found to be responsible for 97% of total vehicular emissions of CO, 22% of NOx, 95-97% of each aromatic species, 72-85% of each carbonyl species, 74% of ammonia, negligible amounts of particle number, 26% of PM2.5, and 2% of BC; diesel-powered vehicles account for the balance. Because the mobile lab spent 17% of its time waiting at stoplights, the results may overemphasize idling conditions, possibly resulting in an underestimate of NOx and overestimate of CO emissions. On the other hand, estimates of the inventory that do not correctly account for emissions during idling are likely to produce bias in the opposite direction.The resulting fuel-based estimates of emissions are lower than in the official inventory for CO and NOx

  4. 北京市机动车尾气排放因子研究%Emission Factors of Vehicle Exhaust in Beijing

    Institute of Scientific and Technical Information of China (English)

    樊守彬; 田灵娣; 张东旭; 曲松

    2015-01-01

    通过调研北京市机动车车型构成﹑车辆行驶工况﹑环境温度﹑油品品质等基础数据,利用 COPERT Ⅳ模型计算了机动车尾气中 CO﹑ NOx﹑ HC 和 PM 的排放因子.应用车载测试系统对典型轻型汽油客车和柴油货车的实际道路排放因子进行测量,并将测量结果与模型计算结果对比,结果发现国Ⅳ标准下,轻型汽油客车的 CO 排放因子的实测数据是模型数据的0.96倍,NOx 的实测数据是模型数据的0.64倍,HC 的实测数据是模型数据的4.89倍.对于国Ⅲ排放标准的柴油货车,轻型﹑中型和重型货车的 CO 排放因子,实测数据分别是模型数据的1.61﹑1.07和1.76倍,NOx 排放因子的实测数据是模型数据的1.04﹑1.21和1.18倍,HC 排放因子的实测数据是模型数据的3.75﹑1.84和1.47倍,PM 排放因子则为模型数据是实测数据的1.31﹑3.42和6.42倍.%Based on the investigation of basic data such as vehicle type composition, driving conditions, ambient temperature and oil quality, etc. , emission factors of vehicle exhaust pollutants including carbon monoxide(CO), nitrogen oxides(NOx ), hydrocarbons (HC) and particulate matter(PM) were calculated using COPERT Ⅳ model. Emission factors of typical gasoline passenger cars and diesel trucks were measured using on-board measurement system on actual road. The measured and modeled emission factors were compared and the results showed that: the measured emission factors of CO, NOx and HC were 0. 96, 0. 64 and 4. 89 times of the modeled data for passenger cars conforming to the national Ⅳ emission standard. For the light, medium and heavy diesel trucks conforming to the national Ⅲ emission standard, the measured data of CO emission factors were 1. 61, 1. 07 and 1. 76 times of the modeled data, respectively, the measured data of NOx emission factors were 1. 04, 1. 21 and 1. 18 times of the modeled data, and the measured data of HC emission factors were 3. 75, 1. 84 and 1. 47

  5. Measuring the Total-Factor Carbon Emission Performance of Industrial Land Use in China Based on the Global Directional Distance Function and Non-Radial Luenberger Productivity Index

    Directory of Open Access Journals (Sweden)

    Wei Wang

    2016-04-01

    Full Text Available Industry is a major contributor to carbon emissions in China, and industrial land is an important input to industrial production. Therefore, a detailed analysis of the carbon emission performance of industrial land use is necessary for making reasonable carbon reduction policies that promote the sustainable use of industrial land. This paper aims to analyze the dynamic changes in the total-factor carbon emission performance of industrial land use (TCPIL in China by applying a global directional distance function (DDF and non-radial Luenberger productivity index. The empirical results show that the eastern region enjoys better TCPIL than the central and western regions, but the regional gaps in TCPIL are narrowing. The growth in NLCPILs (non-radial Luenberger carbon emission performance of industrial land use in the eastern and central regions is mainly driven by technological progress, whereas efficiency improvements contribute more to the growth of NLCPIL in the western region. The provinces in the eastern region have the most innovative and environmentally-friendly production technologies. The results of the analysis of the influencing factors show implications for improving the NLCPIL, including more investment in industrial research and development (R&D, the implementation of carbon emission reduction policies, reduction in the use of fossil energy, especially coal, in the process of industrial production, actively learning about foreign advanced technology, properly solving the problem of surplus labor in industry and the expansion of industrial development.

  6. Factors and characteristics of ammonia, hydrogen sulfide, carbon dioxide, and particulate matter emissions from two manure-belt layer hen houses

    Science.gov (United States)

    Ni, Ji-Qin; Diehl, Claude A.; Chai, Lilong; Chen, Yan; Heber, Albert J.; Lim, Teng-Teeh; Bogan, Bill W.

    2017-05-01

    Manure-belt layer hen houses are a relatively newer design and are replacing the old high-rise layer hen houses for egg production in USA. However, reliable aerial pollutant emission data from comprehensive and long-term on-farm monitoring at manure-belt houses are scarce. This paper reports the emission factors and characteristics of ammonia (NH3), hydrogen sulfide (H2S), carbon dioxide (CO2), and particulate matter (PM10) from two 250,000-bird capacity manure-belt layer hen houses (B-A and B-B) in northern Indiana, USA. The 2-year continuous field monitoring followed the Quality Assurance Project Plan of the National Air Emission Monitoring Study (NAEMS). Only days with more than 18 h (or 75%) of valid data were reported to avoid biased emission calculation. The results of 2-year average daily mean (ADM) gas emissions per hen from the two houses, excluding emissions from their manure shed, were 0.280 g for NH3, 1.952 mg for H2S, and 103.2 g for CO2. They were 67% lower for NH3, 77% higher for H2S, and 10% higher for CO2 compared with reported emissions from high-rise layer hen houses. Emissions of NH3 and CO2 exhibited evident seasonal variations. They were higher in winter than in summer and followed the NH3 and CO2 concentration seasonal patterns. Annual emission differences were observed for all the four pollutants. Reduced emissions of the three gases were shown during periods of layer hen molting and flock replacement. The 2-year ADM PM10 emission from B-B was 25.2 mg d-1 hen-1. A unique weekly PM10 emission pattern was identified for both houses. It was characterized with much lower Sunday emissions compared with the other single-day emissions of the week and was related to the weekly schedule of in-house production operations, including maintenance and cleaning.

  7. High energy emission of GRB 130821A: Constraining the density profile of the circum-burst medium as well as the initial Lorentz factor of the outflow

    Energy Technology Data Exchange (ETDEWEB)

    Liang, Yun-Feng; Zhou, Bei; He, Hao-Ning; Fan, Yi-Zhong; Wei, Da-Ming [Key laboratory of Dark Matter and Space Astronomy, Purple Mountain Observatory, Chinese Academy of Sciences, Nanjing 210008 (China); Tam, Pak-Hin Thomas, E-mail: phtam@phys.nthu.edu.tw [Institute of Astronomy and Department of Physics, National Tsing Hua University, Hsinchu 30013, Taiwan (China)

    2014-02-01

    GRB 130821A was detected by Fermi-GBM/LAT, Konus-WIND, SPI-ACS/INTEGRAL, RHESSI and Mars Odyssey-HEND. Although the data of GRB 130821A are very limited, we show in this work that the high energy γ-ray emission (i.e., above 100 MeV) alone imposes tight constraint on the density profile of the circum-burst medium as well as the initial Lorentz factor of the outflow. The temporal behavior of the high energy γ-ray emission is consistent with the forward shock synchrotron radiation model, and the circum-burst medium likely has a constant-density profile. The Lorentz factor is about a few hundred, similar to other bright GRBs.

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

    Science.gov (United States)

    de Avillez, Miguel A.; Breitschwerdt, Dieter

    2017-09-01

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

  9. Risk Factors and Prevention

    Science.gov (United States)

    ... Factors & Prevention Back to Patient Resources Risk Factors & Prevention Even people who look healthy and free of ... as possible. Share: The Normal Heart Risk Factors & Prevention Heart Diseases & Disorders Substances & Heart Rhythm Disorders Symptoms & ...

  10. Risk Factors for Scleroderma

    Science.gov (United States)

    ... You are here: Home For Patients Risk Factors Risk Factors for Scleroderma The cause of scleroderma is ... what biological factors contribute to scleroderma pathogenesis. Genetic Risk Scleroderma does not tend to run in families ...

  11. Revised (Mixed-Effects) Estimation for Forest Burning Emissions of Gases and Smoke, Fire/Emission Factor Typology, and Potential Remote Sensing Classification of Types for Ozone and Black-Carbon Simulation

    Science.gov (United States)

    Chatfield, Robert B.; Segal Rozenhaimer, M.

    2014-01-01

    We summarize recent progress (a) in correcting biomass burning emissions factors deduced from airborne sampling of forest fire plumes, (b) in understanding the variability in reactivity of the fresh plumes sampled in ARCTAS (2008), DC3 (2012), and SEAC4RS (2013) airborne missions, and (c) in a consequent search for remotely sensed quantities that help classify forest-fire plumes. Particle properties, chemical speciation, and smoke radiative properties are related and mutually informative, as pictures below suggest (slopes of lines of same color are similar). (a) Mixed-effects (random-effects) statistical modeling provides estimates of both emission factors and a reasonable description of carbon-burned simultaneously. Different fire plumes will have very different contributions to volatile organic carbon reactivity; this may help explain differences of free NOx(both gas- and particle-phase), and also of ozone production, that have been noted for forest-fire plumes in California. Our evaluations check or correct emission factors based on sequential measurements (e.g., the Normalized Ratio Enhancement and similar methods). We stress the dangers of methods relying on emission-ratios to CO. (b) This work confirms and extends many reports of great situational variability in emissions factors. VOCs vary in OH reactivity and NOx-binding. Reasons for variability are not only fuel composition, fuel condition, etc., but are confused somewhat by rapid transformation and mixing of emissions. We use "unmixing" (distinct from mixed-effects) statistics and compare briefly to approaches like neural nets. We focus on one particularly intense fire the notorious Yosemite Rim Fire of 2013. In some samples, NOx activity was not so suppressed by binding into nitrates as in other fires. While our fire-typing is evolving and subject to debate, the carbon-burned delta(CO2+CO) estimates that arise from mixed effects models, free of confusion by background-CO2 variation, should provide a

  12. An Analysis of Decoupling and Influencing Factors of Carbon Emissions from the Transportation Sector in the Beijing-Tianjin-Hebei Area, China

    Directory of Open Access Journals (Sweden)

    Xiaoping Zhu

    2017-04-01

    Full Text Available The transport sector is the major green-house gas emitter and most rapidly growing sector in terms of consuming energy in China. Understanding the driving forces behind carbon emission is a prerequisite for reducing carbon emissions and finding a balance between economic growth and carbon emissions. The purpose of this paper is to identify the impact of the factors which influence the level of carbon emissions from the transportation sector in the Beijing-Tianjin-Hebei (BTH area, China, using decomposition model, combined with a decoupling elasticity index. The results of our study indicate that: (1 changes in the level of carbon emissions from the transportation sector are not always synchronized with changes in economic growth. (2 The decoupling state between the carbon emissions and economic growth of Tianjin and Beijing can be roughly divided into two phases. The first phase was during the 2005 to 2009 period, when the decoupling state was pessimistic. The second phase was from 2009 to 2013, when the decoupling state became better overall and was mainly dominated by weak decoupling. Conversely, the decoupling state of Hebei was mainly weak during this period. (3 Economic growth and population size play positive roles in increasing the levels of transportation-related carbon emissions in BTH. However, the energy structure is a negative force. The effect of energy intensity always plays a negative role in Tianjin and Hebei, but positive in Beijing. The industrial structure effect shows a fluctuating trend, but the cumulative effect value is negative, and negative interaction is prominent. Finally, this paper gives some suggestions on how to develop low-carbon transport in BTH area.

  13. Factor V deficiency

    Science.gov (United States)

    ... When certain blood clotting factors are low or missing, your blood does not clot properly. Factor V deficiency is rare. It may be caused by: A defective Factor V gene passed down through families (inherited) An antibody that interferes with normal Factor ...

  14. Foundations of factor analysis

    CERN Document Server

    Mulaik, Stanley A

    2009-01-01

    Introduction Factor Analysis and Structural Theories Brief History of Factor Analysis as a Linear Model Example of Factor AnalysisMathematical Foundations for Factor Analysis Introduction Scalar AlgebraVectorsMatrix AlgebraDeterminants Treatment of Variables as Vectors Maxima and Minima of FunctionsComposite Variables and Linear Transformations Introduction Composite Variables Unweighted Composite VariablesDifferentially Weighted Composites Matrix EquationsMulti

  15. Analysis of Air Toxics From NOAA WP-3 Aircraft Measurements During the TexAQS 2006 Campaign: Comparison With Emission Inventories and Additive Inhalation Risk Factors

    Science.gov (United States)

    Del Negro, L. A.; Warneke, C.; de Gouw, J. A.; Atlas, E.; Lueb, R.; Zhu, X.; Pope, L.; Schauffler, S.; Hendershot, R.; Washenfelder, R.; Fried, A.; Richter, D.; Walega, J. G.; Weibring, P.

    2007-12-01

    Benzene and nine other air toxics classified as human carcinogens by the International Agency for Research on Cancer (IARC) were measured from the NOAA WP-3 aircraft during the TexAQS 2006 campaign. In-situ measurements of benzene, measured with a PTR-MS instrument, are used to estimate emission fluxes for comparison with point source emission inventories developed by the Texas Commission on Environmental Quality. Mean and median mixing ratios for benzene, acetaldehyde, formaldehyde, 1,3-butadiene, carbon tetrachloride, chloroform, 1,2-dichloroethane, dibromoethane, dichloromethane, and vinyl chloride, encountered over the city of Houston during the campaign, are combined with inhalation unit risk factor values developed by the California Environmental Protection Agency and the United States Environmental Protection Agency to estimate the additive inhalation risk factor. This additive risk factor represents the risk associated with lifetime (70 year) exposure at the levels measured and should not be used as an absolute indicator of risk to individuals. However, the results are useful for assessments of changing relative risk over time, and for identifying dominant contributions to the overall air toxic risk.

  16. A new method of determining the initial size and Lorentz factor of gamma-ray burst fireballs using a thermal emission component

    CERN Document Server

    Peér, A; Wijers, R A M J; Mészáros, P; Rees, M J; Pe'er, Asaf; Ryde, Felix; Wijers, Ralph A.M.J.; M\\'esz\\'aros, Peter; Rees, Martin J.

    2007-01-01

    In recent years there is increasing evidence for a thermal component in the gamma- and X-ray spectrum of the prompt emission phase in gamma-ray bursts. The temperature and flux of the thermal component show a characteristic break in the temporal behavior after few seconds. We show here, that measurements of the temperature and flux of the thermal component at early times (before the break) allow the determination of the values of two of the least restricted fireball model parameters: the size at the base of the flow and the outflow bulk Lorentz factor. Relying on the thermal emission component only, this measurement is insensitive to the inherent uncertainties of previous estimates of the bulk motion Lorentz factor. We give specific examples of the use of this method: for GRB970828 at redshift z=0.9578, we show that the physical size at the base of the flow is r_0 = (3.3+-2.1)*10^8 cm and the Lorentz factor of the flow is \\Gamma = 305+-28, and for GRB990510 at z=1.619, r_0=(1.9+-2.0)*10^8 cm and \\Gamma=384+-7...

  17. Determination of emission factors for benzol and particles of passenger cars in urban areas; Ermittlung von Pkw-Emissionsfaktoren fuer Benzol und Partikel im Ballungsraum

    Energy Technology Data Exchange (ETDEWEB)

    Hitzler, G.; Essers, U. [Forschungsinstitut fuer Kraftfahrwesen und Fahrzeugmotoren Stuttgart (FKFS) (Germany)

    1997-10-01

    In this project real velocity curves from the city of Stuttgart are used to investigate the emission behaviour for both benzene and particulates of passenger cars. The driving cycles, which are carried out by the ISV, represent the style of driving for several types of city streets. The types of city streets are chosen in order to describe all occuring common traffic conditions. Vehicles from the passenger car population, both with Otto-engine and Diesel-engine will be selected by the FKFS. By means of these cars the emissions of CO, HC and NO{sub x}, benzene and particulates will be measured on the exhaust gas roller test bench of the Institute. Emissions factors for several groups of engine displacements and different classes of technologies to reduce noxious components in the exhaust gas are developed from the measuring results. By means of these factors it is possible to evaluate the emissions of passenger cars both related to car population and the types of city streets and even ascending routes the vehicles are driving on. The influence of the cold-start phase on the emissions is also taken into account and will be declared as a selfstanding factor. The interpretation of the results shows the great progress of technical research in emission reduction since the begin of the eighties. (orig.) 17 tabs., 30 figs., 17 refs. [Deutsch] In diesem Vorhaben werden reale Fahrprofile des Ballungsraumes Stuttgart fuer die Bestimmung des Emissionsverhaltens von Pkw fuer die Stoffe Benzol und Partikel verwendet. Die vom Institut fuer Strassen- und Verkehrswesen aus Messfahrten ermittelten Fahrprofile geben das Fahrverhalten auf verschiedenen Strassentypen wieder. Die Strassentypen wurden so ausgewaehlt, dass die im Ballungsraum vorkommenden Strassenverkehrsverhaeltnisse damit beschrieben werden koennen. Aus dem Fahrzeugkollektiv der Personenkraftwagen werden vom FKFS repraesentative Fahrzeuge sowohl mit Otto- als auch mit Dieselmotor ausgewaehlt und auf dem

  18. ISS Payload Human Factors

    Science.gov (United States)

    Ellenberger, Richard; Duvall, Laura; Dory, Jonathan

    2016-01-01

    The ISS Payload Human Factors Implementation Team (HFIT) is the Payload Developer's resource for Human Factors. HFIT is the interface between Payload Developers and ISS Payload Human Factors requirements in SSP 57000. ? HFIT provides recommendations on how to meet the Human Factors requirements and guidelines early in the design process. HFIT coordinates with the Payload Developer and Astronaut Office to find low cost solutions to Human Factors challenges for hardware operability issues.

  19. Factors affecting the luminescence emission of InGaN multi-quantum wells grown on (0001) sapphire substrates by MOVPE

    Energy Technology Data Exchange (ETDEWEB)

    Martinez, Oscar; Jimenez, Juan [GdS-Optronlab, Edificio I+D, Univ. de Valladolid, Paseo de Belen 1, 47011 Valladolid (Spain); Avella, Manuel [GdS-Optronlab, Edificio I+D, Univ. de Valladolid, Paseo de Belen 1, 47011 Valladolid (Spain); Parque Cientifico, Edificio I+D, Univ. de Valladolid, Paseo de Belen 1, 47011 Valladolid (Spain); Bosi, Matteo [IMEM-CNR Institute, Area delle Scienze 37/A, 43124 Fontanini, Parma (Italy); Fornari, Roberto [Institute for Crystal Growth (IKZ), Max Born Str. 2, 12489 Berlin (Germany)

    2010-01-15

    The luminescence emission of InGaN/GaN multi-quantum wells (MQW) is affected by several factors, i.e. the composition, the QW thickness, the piezoelectric field and the high density of threading dislocations. In the case of heterostructures containing several QWs piled up, one has to consider the homogeneity of each QW and the thickness of the barrier layers between them, which have influence on the strain. We present herein a cathodoluminescence (CL) study of a series of InGaN QW structures, paying special emphasis to the problem of the lateral distribution of In, and how it influences the emission properties of the QWs. (copyright 2010 WILEY-VCH Verlag GmbH and Co. KGaA, Weinheim) (orig.)

  20. Black carbon, particle number concentration and nitrogen oxide emission factors of random in-use vehicles measured with the on-road chasing method

    Directory of Open Access Journals (Sweden)

    I. Ježek

    2015-06-01

    Full Text Available The chasing method was used in an on-road measurement campaign, and emission factors (EF of black carbon (BC, particle number (PN and nitrogen oxides (NOx were determined for 139 individual vehicles of different types encountered on the roads. The aggregated results provide EFs for BC, NOx and PN for three vehicle categories: goods vehicles, gasoline and diesel passenger cars. This is the first on-road measurement study where BC EFs of numerous individual diesel cars were determined in real-world driving conditions. We found good agreement between EFs of goods vehicles determined in this campaign and the results of previous studies that used either chasing or remote sensing measurement techniques. The composition of the sampled car fleet determined from the national vehicle registry information is reflective of Eurostat statistical data on the Slovenian and European vehicle fleet. The median BC EF of diesel and gasoline cars that were in use for less than 5 years, decreased by 60 and 47% from those in use for 5–10 years, respectively, the median NOx and PN EFs, of goods vehicles that were in use for less than five years, decreased from those in use for 5–10 years by 52 and 67%, respectively. The influence of engine maximum power of the measured EFs showed an increase in NOx EF from least to more powerful vehicles with diesel engines. Finally a disproportionate contribution of high emitters to the total emissions of the measured fleet was found; the top 25% of emitting diesel cars contributed 63, 47 and 61% of BC, NOx and PN emissions respectively. With the combination of relatively simple on-road measurements with sophisticated post processing individual vehicles EF can be determined and useful information about the fleet emissions can be obtained by exactly representing vehicles which contribute disproportionally to vehicle fleet emissions; and monitor how the numerous emission reduction approaches are reflected in on-road driving

  1. Unloading system PM10 emission factors and rates for cotton gins: Method 201A PM10 sizing cyclones

    Science.gov (United States)

    This manuscript is part of a series of manuscripts that characterize cotton gin emissions from the standpoint of stack sampling. The impetus behind this project was the urgent need to collect additional cotton gin emissions data to address current regulatory issues. A key component of this study was...

  2. Combined mote system PM10 emission factors and rates for cotton gins: Method 201A PM10 sizing cyclones

    Science.gov (United States)

    This manuscript is part of a series of manuscripts that characterize cotton gin emissions from the standpoint of stack sampling. The impetus behind this project was the urgent need to collect additional cotton gin emissions data to address current regulatory issues. A key component of this study was...

  3. First stage lint cleaning systems emission factors and rates for cotton gins: Method 201A PM10 sizing cyclones

    Science.gov (United States)

    This manuscript is part of a series of manuscripts that characterize cotton gin emissions from the standpoint of stack sampling. The impetus behind this project was the urgent need to collect additional cotton gin emissions data to address current regulatory issues. A key component of this study was...

  4. Mote trash system PM10 emission factors and rates for cotton gins: Method 201A PM10 sizing cyclones

    Science.gov (United States)

    This manuscript is part of a series of manuscripts that characterize cotton gin emissions from the standpoint of stack sampling. The impetus behind this project was the urgent need to collect additional cotton gin emissions data to address current regulatory issues. A key component of this study was...

  5. Mote cleaner system PM10 emission factors and rates for cotton gins: Method 201A PM10 sizing cyclones

    Science.gov (United States)

    This manuscript is part of a series of manuscripts that characterize cotton gin emissions from the standpoint of stack sampling. The impetus behind this project was the urgent need to collect additional cotton gin emissions data to address current regulatory issues. A key component of this study was...

  6. Overflow system PM10 emission factors and rates for cotton gins: Method 201A PM10 sizing cyclones

    Science.gov (United States)

    This manuscript is part of a series of manuscripts that characterize cotton gin emissions from the standpoint of stack sampling. The impetus behind this project was the urgent need to collect additional cotton gin emissions data to address current regulatory issues. A key component of this study was...

  7. First stage mote system PM10 emission factors and rates for cotton gins: Method 201A PM10 sizing cyclones

    Science.gov (United States)

    This manuscript is part of a series of manuscripts to characterize cotton gin emissions from the standpoint of stack sampling. The impetus behind this project was the urgent need to collect additional cotton gin emissions data to address current regulatory issues. A key component of this study was f...

  8. Battery condenser system PM10 emission factors and rates for cotton gins: Method 201A PM10 sizing cyclones

    Science.gov (United States)

    This manuscript is part of a series of manuscripts that to characterize cotton gin emissions from the standpoint of stack sampling. The impetus behind this project was the urgent need to collect additional cotton gin emissions data to address current regulatory issues. A key component of this study ...

  9. Combined lint cleaning system PM10 emission factors and rates for cotton gins: Method 201A PM10 sizing cyclones

    Science.gov (United States)

    This manuscript is part of a series of manuscripts that characterize cotton gin emissions from the standpoint of stack sampling. The impetus behind this project was the urgent need to collect additional cotton gin emissions data to address current regulatory issues. A key component of this study was...

  10. Master trash system PM10 emission factors and rates for cotton gins: Method 201A PM10 sizing cyclones

    Science.gov (United States)

    This manuscript is part of a series of manuscripts that characterize cotton gin emissions from the standpoint of stack sampling. The impetus behind this project was the urgent need to collect additional cotton gin emissions data to address current regulatory issues. A key component of this study was...

  11. Size-resolved particle number emission patterns under real-world driving conditions using positive matrix factorization

    NARCIS (Netherlands)

    Domínguez-Sáez, A.; Viana, M.; Barrios, C.C.; Rubio, J.R.; Amato, F.; Pujadas, M.; Querol, X.

    2012-01-01

    A novel on-board system was tested to characterize size-resolved particle number emission patterns under real-world driving conditions, running in a EURO4 diesel vehicle and in a typical urban circuit in Madrid (Spain). Emission profiles were determined as a function of driving conditions. Source ap

  12. The molar H: Corg ratio of biochar is a key factor in mitigating N2O emissions from soil

    NARCIS (Netherlands)

    Cayuela, M.L.; Jeffery, S.L.; Zwieten, van L.

    2015-01-01

    A previously published meta-analysis of biochar impacts on soil N2O emissions by Cayuela et al. (2014) found a “grand mean” reduction in N2O emissions of 54 ± 6% following biochar application to soil. Here we update this analysis to include 26 additional manuscripts bringing the total to 56

  13. The molar H: Corg ratio of biochar is a key factor in mitigating N2O emissions from soil

    NARCIS (Netherlands)

    Cayuela, M.L.; Jeffery, S.L.; Zwieten, van L.

    2015-01-01

    A previously published meta-analysis of biochar impacts on soil N2O emissions by Cayuela et al. (2014) found a “grand mean” reduction in N2O emissions of 54 ± 6% following biochar application to soil. Here we update this analysis to include 26 additional manuscripts bringing the total to 56 articles

  14. Mote cyclone robber system PM10 emission factors and rates for cotton gins: Method 201A PM10 sizing cyclones

    Science.gov (United States)

    This manuscript is part of a series of manuscripts that characterize cotton gin emissions from the standpoint of stack sampling. The impetus behind this project was the urgent need to collect additional cotton gin emissions data to address current regulatory issues. A key component of this study was...

  15. Second stage mote system PM10 emission factors and rates for cotton gins: Method 201A PM10 sizing cyclone

    Science.gov (United States)

    This manuscript is part of a series of manuscripts that characterize cotton gin emissions from the standpoint of stack sampling. The impetus behind this project was the urgent need to collect additional cotton gin emissions data to address current regulatory issues. A key component of this study was...

  16. Cyclone robber system PM10 emission factors and rates for cotton gins: Method 201A PM10 sizing cyclones

    Science.gov (United States)

    This manuscript is part of a series of manuscripts that characterize cotton gin emissions from the standpoint of stack sampling. The impetus behind this project was the urgent need to collect additional cotton gin emissions data to address current regulatory issues. A key component of this study was...

  17. Size-resolved polycyclic aromatic hydrocarbon emission factors from on-road gasoline and diesel vehicles: temperature effect on the nuclei-mode.

    Science.gov (United States)

    Eiguren-Fernandez, Arantzazu; Miguel, Antonio H

    2012-03-06

    Motor vehicles are a major source of polycyclic aromatic hydrocarbon (PAH) emissions in urban areas. Motor vehicle emission control strategies have included improvements in engine design, exhaust emission control, and fuel reformulation. Therefore, an updated assessment of the effects of the shifts in fuels and vehicle technologies on PAH vehicular emission factors (EFs) is needed. We have evaluated the effects of ambient temperature on the size-resolved EFs of nine US EPA Priority Pollutant PAH, down to 10 nm diameter, from on-road California gasoline light-duty vehicles with spark ignition (SI) and heavy-duty diesels with compression ignition (CI) in summer 2004 and winter 2005. During the winter, for the target PAH with the lowest subcooled equilibrium vapor pressure --benzo[a]pyrene, benzo[ghi]perylene, and indeno[1,2,3-cd]pyrene-- the mass in the nucleation mode, defined here as particles with dp <32 nm, ranged between 14 and 38% for SI vehicles and 29 and 64% for CI vehicles. Our observations of the effect of temperature on the mass of PAH in the nucleation mode are similar to the observed effect of temperature on the number concentration of diesel exhaust particles in the nucleation mode in a previous report.

  18. Determination of nitrous acid emission factors from a gasoline vehicle using a chassis dynamometer combined with incoherent broadband cavity-enhanced absorption spectroscopy.

    Science.gov (United States)

    Nakashima, Yoshihiro; Kajii, Yoshizumi

    2017-01-01

    Nitrous acid (HONO) is a well-known source of hydroxyl radicals in the troposphere. Vehicle exhaust is considered to be one of the primary emission sources of HONO. In this study, measurements of HONO in gasoline vehicle exhaust were carried out using a chassis dynamometer combined with incoherent broadband cavity-enhanced absorption spectroscopy. When catalysts were warm, concentrations of HONO were higher than those prior to catalysts warming. Other species, such as CO, and total hydrocarbons (THCs), showed the opposite pattern. There were no correlations evident between HONO and other trace species concentrations immediately after emission. The HONO/NOx ratio, a good proxy for the formation of HONO in atmosphere, ranged from 1.1 to 6.8×10(-3), which was consistent with previous studies. HONO emission factors (EFs) were calculated to be 0.01-3.6mgkg(-1) fuel, which was different from the vehicle's specifications and those reported under different driving cycles. Annual HONO emissions in Japan were estimated using the calculated EFs and other statistical data. Copyright © 2016 Elsevier B.V. All rights reserved.

  19. Factors controlling regional differences in forest soil emission of nitrogen oxides (NO and N2O)

    DEFF Research Database (Denmark)

    Pilegaard, K.; Skiba, U.; Ambus, P.

    2006-01-01

    Soil emissions of NO and N2O were measured continuously at high frequency for more than one year at 15 European forest sites as part of the EU-funded project NOFRETETE. The locations represent different forest types (coniferous/deciduous) and different nitrogen loads. Geoaphically they range from...... Finland in the north to Italy in the south and from Hungary in the east to Scotland in the west. The highest NO emissions were observed from coniferous forests, whereas the lowest NO emissions were observed from deciduous forests. The NO emissions from coniferous forests were highly correlated with N...... with the C/N ratio. The difference in N-oxide emissions from soils of coniferous and deciduous forests may partly be explained by differences in N-deposition rates and partly by differences in characteristics of the litter layer and soil. NO was mainly derived from nitrification whereas N2O was mainly...

  20. Load-Dependent Emission Factors and Chemical Characteristics of IVOCs from a Medium-Duty Diesel Engine.

    Science.gov (United States)

    Cross, Eben S; Sappok, Alexander G; Wong, Victor W; Kroll, Jesse H

    2015-11-17

    A detailed understanding of the climate and air quality impacts of mobile-source emissions requires the characterization of intermediate-volatility organic compounds (IVOCs), relatively-low-vapor-pressure gas-phase species that may generate secondary organic aerosol with high yields. Due to challenges associated with IVOC detection and quantification, IVOC emissions remain poorly understood at present. Here, we describe measurements of the magnitude and composition of IVOC emissions from a medium-duty diesel engine. Measurements are made on an engine dynamometer and utilize a new mass-spectrometric instrument to characterize the load dependence of the emissions in near-real-time. Results from steady-state engine operation indicate that IVOC emissions are highly dependent on engine power, with highest emissions at engine idle and low-load operation (≤25% maximum rated power) with a chemical composition dominated by saturated hydrocarbon species. Results suggest that unburned fuel components are the dominant IVOCs emitted at low loads. As engine load increases, IVOC emissions decline rapidly and become increasingly characterized by unsaturated hydrocarbons and oxygenated organics, newly formed from incomplete combustion processes at elevated engine temperatures and pressures. Engine transients, including a cold-start ignition and engine acceleration, show IVOC emission profiles that are different in amount or composition compared to steady-state combustion, underscoring the utility of characterizing IVOC emissions with high time resolution across realistic engine operating conditions. We find possible evidence for IVOC losses on unheated dilution and sampling surfaces, which need to be carefully accounted for in IVOC emission studies.

  1. Field measurement of emission factors of PM, EC, OC, parent, nitro-, and oxy- polycyclic aromatic hydrocarbons for residential briquette, coal cake, and wood in rural Shanxi, China.

    Science.gov (United States)

    Shen, Guofeng; Tao, Shu; Wei, Siye; Chen, Yuanchen; Zhang, Yanyan; Shen, Huizhong; Huang, Ye; Zhu, Dan; Yuan, Chenyi; Wang, Haochen; Wang, Yafei; Pei, Lijun; Liao, Yilan; Duan, Yonghong; Wang, Bin; Wang, Rong; Lv, Yan; Li, Wei; Wang, Xilong; Zheng, Xiaoying

    2013-03-19

    Air pollutants from residential solid fuel combustion are attracting growing public concern. Field measured emission factors (EFs) of various air pollutants for solid fuels are close to the reality and urgently needed for better emission estimations. In this study, emission factors of particulate matter (PM), organic carbon (OC), elemental carbon (EC), and various polycyclic aromatic hydrocarbons (PAHs) from residential combustions of coal briquette, coal cake, and wood were measured in rural Heshun County, China. The measured EFs of PM, OC, and EC were 8.1-8.5, 2.2-3.6, 0.91-1.6 g/kg for the wood burnt in a simple metal stove, 0.54-0.64, 0.13-0.14, 0.040-0.0041 g/kg for the briquette burned in an improved stove with a chimney, and 3.2-8.5, 0.38-0.58, 0.022-0.052 g/kg for the homemade coal cake combusted in a brick stove with a flue, respectively. EFs of 28 parent PAHs, 4 oxygenated PAHs, and 9 nitro-PAHs were 182-297, 7.8-10, 0.14-0.55 mg/kg for the wood, 14-16, 1.7-2.6, 0.64-0.83 mg/kg for the briquette, and 168-223, 4.7-9.5, 0.16-2.4 mg/kg for the coal cake, respectively. Emissions from the wood and coal cake combustions were much higher than those for the coal briquette, especially true for high molecular weight PAHs. Most EFs measured in the field were higher than those measured in stove combustions under laboratory conditions.

  2. Bayesian Exploratory Factor Analysis

    DEFF Research Database (Denmark)

    Conti, Gabriella; Frühwirth-Schnatter, Sylvia; Heckman, James J.;

    2014-01-01

    This paper develops and applies a Bayesian approach to Exploratory Factor Analysis that improves on ad hoc classical approaches. Our framework relies on dedicated factor models and simultaneously determines the number of factors, the allocation of each measurement to a unique factor, and the corr......This paper develops and applies a Bayesian approach to Exploratory Factor Analysis that improves on ad hoc classical approaches. Our framework relies on dedicated factor models and simultaneously determines the number of factors, the allocation of each measurement to a unique factor......, and the corresponding factor loadings. Classical identification criteria are applied and integrated into our Bayesian procedure to generate models that are stable and clearly interpretable. A Monte Carlo study confirms the validity of the approach. The method is used to produce interpretable low dimensional aggregates...

  3. Aerosol and trace gas vehicle emission factors measured in a tunnel using an Aerosol Mass Spectrometer and other on-line instrumentation

    Science.gov (United States)

    Chirico, Roberto; Prevot, Andre S. H.; DeCarlo, Peter F.; Heringa, Maarten F.; Richter, Rene; Weingartner, Ernest; Baltensperger, Urs

    2011-04-01

    In this study we present measurements of gas and aerosol phase composition for a mixed vehicle fleet in the Gubrist tunnel (Switzerland) in June 2008. PM 1 composition measurements were made with a High-Resolution Time-of-Flight Aerosol Mass Spectrometer (AMS) and a Multi Angle Absorption Photometer (MAAP). Gas-phase measurements of CO, CO 2, NO x and total hydrocarbons (THC) were performed with standard instrumentation. Weekdays had a characteristic diurnal pattern with 2 peaks in concentrations for all traffic related species corresponding to high vehicle density (˜300 ± 30 vehicles per 5 min) in the morning rush hour between 06:00 and 09:00 and in the afternoon rush hours from approximately 15:30 to 18:30. The emission factors (EF) of OA were heavily influenced by the OA mass loading. To exclude this partitioning effect, only organic aerosol mass concentrations from 60 μg m -3 to 90 μg m -3 were considered and for these conditions the EF(OA) value for HDV was 33.7 ± 2.3 mg km -1 for a temperature inside the tunnel of 20-25 °C. This value is not directly applicable to ambient conditions because it is derived from OA mass concentrations that are roughly a factor of 10 higher than typical ambient concentrations. An even higher EF(OA) HDV value of 47.4 ± 1.6 mg km -1 was obtained when the linear fit was applied to all data points including OA concentrations up to 120 μg m -3. Similar to the increasing EF, the OA/BC ratio in the tunnel was also affected by the organic loading and it increased by a factor of ˜3 over the OA range 10-120 μg m -3. This means that also the OA emission factors at ambient concentrations of around 5-10 μg m -3 would be 2-3 times lower than the emission factor given above. For OA concentrations lower than 40 μg m -3 the OA/BC mass ratio was below 1, while at an OA concentration of 100-120 μg m -3 the OA/BC ratio was ˜1.5. The AMS mass spectra (MS) acquired in the tunnel were highly correlated with the primary organic aerosol

  4. Influence of spatially-dependent, modeled soil carbon emission factors on life-cycle greenhouse gas emissions of corn and cellulosic ethanol

    Energy Technology Data Exchange (ETDEWEB)

    Qin, Zhangcai; Dunn, Jennifer B.; Kwon, Ho-young; Mueller, Steffen; Wander, Michelle M.

    2016-01-01

    Converting land to biofuel feedstock production incurs changes in soil organic carbon (SOC) that can influence biofuel life-cycle greenhouse gas (GHG) emissions. Estimates of these land use change (LUC) and life-cycle GHG emissions affect biofuels’ attractiveness and eligibility under a number of renewable fuel policies in the U.S. and abroad. Modeling was used to refine the spatial resolution and depth-extent of domestic estimates of SOC change for land (cropland, cropland pasture, grasslands, and forests) conversion scenarios to biofuel crops (corn, corn stover, switchgrass, Miscanthus, poplar, and willow). In most regions, conversions from cropland and cropland pasture to biofuel crops led to neutral or small levels of SOC sequestration, while conversion of grassland and forest generally caused net SOC loss. Results of SOC change were incorporated into the Greenhouse Gases, Regulated Emissions, and Energy use in Transportation (GREET) model to assess their influence on life-cycle GHG emissions for the biofuels considered. Total LUC GHG emissions (g CO2eq MJ-1) were 2.1–9.3 for corn, -0.7 for corn stover, -3.4–12.9 for switchgrass, and -20.1–-6.2 for Miscanthus; these varied with SOC modeling assumptions applied. Extending soil depth from 30 to 100cm affected spatially-explicit SOC change and overall LUC GHG emissions; however the influence on LUC GHG emissions estimates were less significant in corn and corn stover than cellulosic feedstocks. Total life-cycle GHG emissions (g CO2eq MJ-1, 100cm) were estimated to be 59–66 for corn ethanol, 14 for stover ethanol, 18-26 for switchgrass ethanol, and -0.6–-7 for Miscanthus ethanol.

  5. 省域碳排放影响因素比较研究%Comparative Study on the Factors Affecting the Provincial Carbon Emissions

    Institute of Scientific and Technical Information of China (English)

    欧元明; 周少甫

    2014-01-01

    分析碳排放情况,本文发现人均碳排放和碳排放密度之间没有必然联系;碳排放密度存在明显的空间群集效应。基于 LMDI 方法分解,发现人均产出起拉动作用,而能源效率和能源消费碳排放强度则主要是抑制作用。基于 STIRPAT 模型分析,发现人均总产出水平、单位产出的化石能源消耗量、煤炭消费占比均对碳排放有显著的强化作用。建议:大力发展便捷的公共交通、倡导绿色出行,减轻交通对大城市碳排放的压力;通过改变能源结构,通过电力能源生产外迁等方式降低排放密度超高的地区碳排放压力、开发清洁能源,降低二氧化碳高排放能源消费占比;对高能耗产业逐步实施“产能总量控制---限制出口---进口替代”路径的产业优化措施,逐步减轻“输入性碳排放”压力。%Based on descriptive statistics analysis method to analyze the 30 provinces and autonomous regions and the country’s car-bon dioxide emissions ,this paper found : per capita carbon emissions and carbon emissions density are not necessarily linked , secondary energy output region’s per capita carbon emissions are high ,and the density of carbon emissions is low ;carbon emissions density had obvi-ously spatial clustering effect .The LMDI method is used to decompose on the driving factors based on carbon emissions per capita ,found that per capita output has stimulating effect ,while energy efficiency and carbon intensity of energy consumption are inhibited .Based on analysis of influencing factors by STIRPAT model ,we found that per capita output ,fossil energy consumption per unit of output ,coal con-sumption accounted for carbon emissions have a significant strengthening effect .Thus it recommends to vigorously develop the convenient public transportation ,promote green travel ,and reduce traffic pressure on the city carbon emissions ; as supplementary carbon trading ,by changing

  6. N2O emission characteristics and its affecting factors in rain-fed potato fields in Wuchuan County, China

    Science.gov (United States)

    Wang, Liwei; Wang, Cheng; Pan, Zhihua; Xu, Hui; Gao, Lin; Zhao, Peiyi; Dong, Zhiqiang; Zhang, Jingting; Cui, Guohui; Wang, Sen; Han, Guolin; Zhao, hui

    2016-12-01

    Representing an important greenhouse gas, nitrous oxide (N2O) emission from cultivated land is a hot topic in current climate change research. This study examined the influences of nitrogen fertilisation, temperature and soil moisture on the ammonia monooxygenase subunit A (amoA) gene copy numbers and N2O emission characteristics. The experimental observation of N2O fluxes was based on the static chamber-gas chromatographic method. The ammonia-oxidising bacteria (AOB) and ammonia-oxidising archaea (AOA) gene copy numbers in different periods were measured by real-time polymerase chain reaction (PCR). The results indicated that rain-fed potato field was a N2O source, and the average annual N2O emission was approximately 0.46 ± 0.06 kgN2O-N/ha/year. N2O emissions increased significantly with increase in fertilisation, temperatures below 19.6 °C and soil volumetric water content under 15%. Crop rotation appreciably decreases N2O emissions by 34.4 to 52.4% compared to continuous cropping in rain-fed potato fields. The significant correlation between N2O fluxes and AOB copy numbers implied that N2O emissions were primarily controlled by AOB in rain-fed potato fields. The research has important theoretical and practical value for understanding N2O emissions from rain-fed dry farmland fields.

  7. N2O emission characteristics and its affecting factors in rain-fed potato fields in Wuchuan County, China

    Science.gov (United States)

    Wang, Liwei; Wang, Cheng; Pan, Zhihua; Xu, Hui; Gao, Lin; Zhao, Peiyi; Dong, Zhiqiang; Zhang, Jingting; Cui, Guohui; Wang, Sen; Han, Guolin; Zhao, hui

    2017-05-01

    Representing an important greenhouse gas, nitrous oxide (N2O) emission from cultivated land is a hot topic in current climate change research. This study examined the influences of nitrogen fertilisation, temperature and soil moisture on the ammonia monooxygenase subunit A ( amoA) gene copy numbers and N2O emission characteristics. The experimental observation of N2O fluxes was based on the static chamber-gas chromatographic method. The ammonia-oxidising bacteria (AOB) and ammonia-oxidising archaea (AOA) gene copy numbers in different periods were measured by real-time polymerase chain reaction (PCR). The results indicated that rain-fed potato field was a N2O source, and the average annual N2O emission was approximately 0.46 ± 0.06 kgN2O-N/ha/year. N2O emissions increased significantly with increase in fertilisation, temperatures below 19.6 °C and soil volumetric water content under 15%. Crop rotation appreciably decreases N2O emissions by 34.4 to 52.4% compared to continuous cropping in rain-fed potato fields. The significant correlation between N2O fluxes and AOB copy numbers implied that N2O emissions were primarily controlled by AOB in rain-fed potato fields. The research has important theoretical and practical value for understanding N2O emissions from rain-fed dry farmland fields.

  8. 中国水泥生产碳排放系数测算典型研究%Carbon Emission Factors for Cement Plants in China

    Institute of Scientific and Technical Information of China (English)

    赵建安; 魏丹青

    2013-01-01

    The carbon emission coefficient system of cement production is the most important basic parameter when calculating cement carbon emissions. This paper briefly introduces the accuracy and applicability of these methods, most of which contain four aspects: operational boundaries, raw material calcination emission, fuel combustion emissions and indirect emission. We selected two typical NSP clinker production lines form western China and found that the CO2 emissions factor can be reduced by using acetylene sludge, steel slag and pyrite cinder as alternative raw material, because these materials provide CaO, the basic ingredients necessary for production, and no CO2 emissions. As a result, the usual calculation method for raw material calcination emissions will not be applicable. The correct approach is to convert the type and weight ratio of all alternative raw material with CaO and MgO into a corrected parameter. There is a significant difference in classification standards, low calorific value and CO2 emission factors of coal between the IPCC default-value and China's actual use of coal in cement production. Almost all the China' s cement plants using bituminous coal as their production fuel, therefor the fuel combustion CO2 emission factor should be in the range of 250~350 kgCO2 per tonne clinker, which is 27% lower than IPCC default-value. The CO2 emission factor of unit cement is overvalued by 10%, because international researchers believe that the clinker/cement ratio of China' s cement manufacturing plants ranges from 80%~85%, while the practical value is approximately 65%. On this basis of the above, we hold opinion that CO2 emissions of China's cement production will be seriously overvalued using IPCC or WBCSD default calculation factors. Last, four techniques to reduce CO2 emissions from the cement manufacturing industries are reviewed: using alternative raw material, using alternative fuels instead of fossil fuels, reducing electricity consumption, and

  9. Risk Factors for Thrombosis

    Institute of Scientific and Technical Information of China (English)

    包承鑫

    2002-01-01

    @@ Thrombotic disease is a multifactorial disease, multiple interactions between genetic and environmental factors contribute to the development of the disease.This review summarized some risk factors reported for arterial thrombosis and venous thrombosis in recent few years.

  10. Factoring Polynomials and Fibonacci.

    Science.gov (United States)

    Schwartzman, Steven

    1986-01-01

    Discusses the factoring of polynomials and Fibonacci numbers, offering several challenges teachers can give students. For example, they can give students a polynomial containing large numbers and challenge them to factor it. (JN)

  11. Coagulation Factors Test

    Science.gov (United States)

    ... be limited. Home Visit Global Sites Search Help? Coagulation Factors Share this page: Was this page helpful? ... else I should know? How is it used? Coagulation factor testing is performed to determine if a ...

  12. Annual Adjustment Factors

    Data.gov (United States)

    Department of Housing and Urban Development — The Department of Housing and Urban Development establishes the rent adjustment factors - called Annual Adjustment Factors (AAFs) - on the basis of Consumer Price...

  13. Historical Pattern and Future Trajectories of Terrestrial N2O Emission driven by Multi-factor Global Changes

    Science.gov (United States)

    Lu, C.; Tian, H.; Yang, J.; Zhang, B.; Xu, R.

    2015-12-01

    Nitrous oxide (N2O) is among the most important greenhouse gases only next to carbon dioxide (CO2) and methane (CH4) due to its long life time and high radiative forcing (with a global warming potential 265 times as much as CO2 at 100-year time horizon). The Atmospheric concentration of N2O has increased by 20% since pre-industrial era, and this increase plays a significant role in shaping anthropogenic climate change. However, compared to CO2- and CH4-related research, fewer studies have been performed in assessing and predicting the spatiotemporal patterns of N2O emission from natural and agricultural soils. Here we used a coupled biogeochemical model, DLEM, to quantify the historical and future changes in global terrestrial N2O emissions resulting from natural and anthropogenic perturbations including climate variability, atmospheric CO2 concentration, nitrogen deposition, land use and land cover changes, and agricultural land management practices (i.e., synthetic nitrogen fertilizer use, manure application, and irrigation etc.) over the period 1900-2099. We focused on inter-annual variation and long-term trend of terrestrial N2O emission driven by individual and combined environmental changes during historical and future periods. The sensitivity of N2O emission to climate, atmospheric composition, and human activities has been examined at biome-, latitudinal, continental and global scales. Future projections were conducted to identify the hot spots and hot time periods of global N2O emission under two emission scenarios (RCP2.6 and RCP8.5). It provides a modeling perspective for understanding human-induced N2O emission growth and developing potential management strategies to mitigate further atmospheric N2O increase and climate warming.

  14. Ambient air quality measurements from a continuously moving mobile platform: Estimation of area-wide, fuel-based, mobile source emission factors using absolute principal component scores

    Science.gov (United States)

    Larson, Timothy; Gould, Timothy; Riley, Erin A.; Austin, Elena; Fintzi, Jonathan; Sheppard, Lianne; Yost, Michael; Simpson, Christopher

    2017-03-01

    We have applied the absolute principal component scores (APCS) receptor model to on-road, background-adjusted measurements of NOx, CO, CO2, black carbon (BC), and particle number (PN) obtained from a continuously moving platform deployed over nine afternoon sampling periods in Seattle, WA. Two Varimax-rotated principal component features described 75% of the overall variance of the observations. A heavy-duty vehicle feature was correlated with black carbon and particle number, whereas a light-duty feature was correlated with CO and CO2. NOx had moderate correlation with both features. The bootstrapped APCS model predictions were used to estimate area-wide, average fuel-based emission factors and their respective 95% confidence limits. The average emission factors for NOx, CO, BC and PN (14.8, 18.9, 0.40 g/kg, and 4.3 × 1015 particles/kg for heavy duty vehicles, and 3.2, 22.4, 0.016 g/kg, and 0.19 × 1015 particles/kg for light-duty vehicles, respectively) are consistent with previous estimates based on remote sensing, vehicle chase studies, and recent dynamometer tests. Information on the spatial distribution of the concentrations contributed by these two vehicle categories relative to background during the sampling period was also obtained.

  15. Disaggregated N2O emission factors in China based on cropping parameters create a robust approach to the IPCC Tier 2 methodology.

    Science.gov (United States)

    Shepherd, Anita; Yan, Xiaoyuan; Nayak, Dali; Newbold, Jamie; Moran, Dominic; Dhanoa, Mewa Singh; Goulding, Keith; Smith, Pete; Cardenas, Laura M

    2015-12-01

    China accounts for a third of global nitrogen fertilizer consumption. Under an International Panel on Climate Change (IPCC) Tier 2 assessment, emission factors (EFs) are developed for the major crop types using country-specific data. IPCC advises a separate calculation for the direct nitrous oxide (N2O) emissions of rice cultivation from that of cropland and the consideration of the water regime used for irrigation. In this paper we combine these requirements in two independent analyses, using different data quality acceptance thresholds, to determine the influential parameters on emissions with which to disaggregate and create N2O EFs. Across China, the N2O EF for lowland horticulture was slightly higher (between 0.74% and 1.26% of fertilizer applied) than that for upland crops (values ranging between 0.40% and 1.54%), and significantly higher than for rice (values ranging between 0.29% and 0.66% on temporarily drained soils, and between 0.15% and 0.37% on un-drained soils). Higher EFs for rice were associated with longer periods of drained soil and the use of compound fertilizer; lower emissions were associated with the use of urea or acid soils. Higher EFs for upland crops were associated with clay soil, compound fertilizer or maize crops; lower EFs were associated with sandy soil and the use of urea. Variation in emissions for lowland vegetable crops was closely associated with crop type. The two independent analyses in this study produced consistent disaggregated N2O EFs for rice and mixed crops, showing that the use of influential cropping parameters can produce robust EFs for China.

  16. Environmental factors in autism

    OpenAIRE

    Andreas Martin Grabrucker

    2013-01-01

    Autism is a neurodevelopmental disorders characterized by impairments in communication and social behavior, and by repetitive behaviors. Although genetic factors might be largely responsible for the occurrence of autism they cannot fully account for all cases and it is likely that in addition to a certain combination of autism-related genes, specific environmental factors might act as risk factors triggering the development of autism. Thus, the role of environmental factors in autism is an im...

  17. Environmental Factors in Autism

    OpenAIRE

    Andreas M. Grabrucker

    2013-01-01

    Autism is a neurodevelopmental disorders characterized by impairments in communication and social behavior, and by repetitive behaviors. Although genetic factors might be largely responsible for the occurrence of autism they cannot fully account for all cases and it is likely that in addition to a certain combination of autism-related genes, specific environmental factors might act as risk factors triggering the development of autism. Thus, the role of environmental factors in autism is an im...

  18. Residual effects of fertilization history increase nitrous oxide emissions from zero-N controls:Implications for estimating fertilizer-induced emission factors

    Science.gov (United States)

    Agricultural N fertilization is the dominant driver of increasing atmospheric nitrous oxide (N2O) concentrations over the past half century, yet there is considerable uncertainty in estimates of N2O emissions from agriculture. Such estimates are typically based on the amount of N applied and a ferti...

  19. Mesonic Form Factors

    Energy Technology Data Exchange (ETDEWEB)

    Frederic D. R. Bonnet; Robert G. Edwards; George T. Fleming; Randal Lewis; David Richards

    2003-07-22

    We have started a program to compute the electromagnetic form factors of mesons. We discuss the techniques used to compute the pion form factor and present preliminary results computed with domain wall valence fermions on MILC asqtad lattices, as well as Wilson fermions on quenched lattices. These methods can easily be extended to rho-to-gamma-pi transition form factors.

  20. Multilevel Mixture Factor Models

    Science.gov (United States)

    Varriale, Roberta; Vermunt, Jeroen K.

    2012-01-01

    Factor analysis is a statistical method for describing the associations among sets of observed variables in terms of a small number of underlying continuous latent variables. Various authors have proposed multilevel extensions of the factor model for the analysis of data sets with a hierarchical structure. These Multilevel Factor Models (MFMs)…

  1. Influencing Factors Analysis of Greenhouse Gas Emissions in Fujian Province%福建省温室气体排放影响因素分析

    Institute of Scientific and Technical Information of China (English)

    黄洵; 黄民生; 黄飞萍

    2013-01-01

    针对当前温室气体排放影响因素研究中忽视工农业生产排放源的现状,在对福建省2001-2010年各类温室气体排放量进行核算,并统一转换成CO2当量的基础上,通过引入能表达工农业生产过程自身温室气体排放的新指标,建立改进后的对数 Divisia 均值分解模型(LMDI)对福建省温室气体排放的影响因素进行分解分析。研究发现:2001-2010年福建省温室气体排放量不断上升,但环比增长率整体波动下降;产业结构、经济规模、人口规模、能源结构、人均收入、城市化水平、城市居民工业强度等因素的累积效应对温室气体排放增加有正向促进作用,其中城市居民工业强度的贡献率达到了13.66%;能源强度、农业生产强度的累积效应对温室气体排放有负向抑制作用,其中农业生产强度累积效应占负向效应总和的50%以上。研究结果显示:工农业生产过程对福建省温室气体排放有显著的驱动作用,不应忽视。%At present the emissions from agricultural and industrial activities are relatively neglected in the influencing factors analysis of greenhouse gas emissions. In this paper, the method of 2006 IPCC Guidelines for National Greenhouse Gas Inventories is used to calculate the emissions of greenhouse gas of Fujian Province from 2001 to 2010. On the basis of the carbon dioxide equivalent which is converted from greenhouse gases, we have analyzed the influencing factors of greenhouse gas emissions by the model of LMDI, and introduced some new indexes to explain the influence of the emissions from industrial and agricultural activities. The results show that although the total emission of greenhouse gas was increasing during the period of the study, its growth rate was decreasing;The accumulative effects of industrial structure, economic scale, population size, energy structure, per capita income, urbanization level and industrial

  2. Influencing Factors of Ammonia Emissions from Pig Houses and Mitigation Techniques%影响猪场氨气排放的因素及控制措施

    Institute of Scientific and Technical Information of China (English)

    李新建; 吕刚; 任广志

    2012-01-01

    Pig houses are important sources for ammonia (NH3) emissions. For decades, investigations were carried out in determining the influencing factors and to point out opportunities of mitigation. The main factors influencing NH3 production are the floor type, the manure removal system, the climatic conditions inside the building, the diet composition and the feed efficiency of animals. Thus, the aims of this article are to describe the NH3 production process occurring in livestock manure and to specify the factors that impact on emissions from pig buildings, with focus on the effects of the housing and climate conditions, the animals, the diets and the manure removal strategies.%猪舍是环境中氨气排放的重要来源,多年来,许多研究者对影响氨气排放的因素以及减少其排放技术进行了研究.影响氨气排放的主要因素包括地板类型、粪污处理系统、猪舍环境条件、日粮组成以及饲喂技术等.论文主要综述了影响氨气排放的各种因子以及减少氨气排放的各种措施,为生产中减少氨气污染,提高猪的健康,节约资源等提供理论指导.

  3. Influence of fuel mass load, oxygen supply and burning rate on emission factor and size distribution of carbonaceous particulate matter from indoor corn straw burning

    Institute of Scientific and Technical Information of China (English)

    Guofeng Shen; Miao Xue; Siye Wei; Yuanchen Chen; Bin Wang; Rong Wang; Huizhong Shen

    2013-01-01

    The uncertainty in emission estimation is strongly associated with the variation in emission factor (EF),which could be influenced bya variety of factors such as fuel properties,stove type,fire management and even methods used in measurements.The impacts of thesefactors are complicated and often interact with each other.Controlled burning experiments were conducted to investigate the influencesof fuel mass load,air supply and burning rate on the emissions and size distributions of carbonaceous particulate matter (PM) fromindoor corn straw bunting in a cooking stove.The results showed that the EFs of PM (EFpM),organic carbon (EFoc) and elementalcarbon (EFEc) were independent of the fuel mass load.The differences among them under different burning rates or air supply amountswere also found to be insignificant (P > 0.05) in the tested circumstances.PM from the indoor corn straw burning was dominated byfine PM with diameter less than 2.1 μm,contributing 86.4% ± 3.9% of the total.The size distribution of PM was influenced by theburning rate and air supply conditions.On average,EFPM,EFoc and EFEC for corn straw burned in a residential cooking stove were(3.84 ± 1.02),(0.846 ± 0.895) and (0.391 ± 0.350) g/kg,respectively.EFPM,EFoc and EFEc were found to be positively correlatedwith each other (P < 0.05),but they were not significantly correlated with the EF of co-emitted CO,suggesting that special attentionshould be paid to the use of CO as a surrogate for other incomplete combustion pollutants.

  4. Effects of nitrogen conversion and environmental factors on landfill CH4 oxidation and N2O emissions in aged refuse.

    Science.gov (United States)

    Zhang, Houhu; Zhao, Keqiang; Yan, Xiaofei; Sun, Qinfang; Li, Yi; Zhang, Yi; Zun, Zhao; Ke, Fan

    2013-09-15

    We determined the effects of nitrification capacity and environmental factors on landfill methane oxidation potential (MOP) using an aged refuse in laboratory batch assays and compared it with two different types of soils. The nitrogen conversion in the three experimental materials after 120 h incubation yielded first-order reaction kinetics at an initial concentration of 200 mg kg(-1) NH4(+)-N. The net nitrification rate for the aged refuse was 1.50 (p bacteria during CH4 co-oxidation, the average value of the MOP in the aged refuse at a temperature range of 4-45 °C was 2.34 (p landfill can be neglected after applying an aged refuse bio-cover because of the much higher MOP in the aged refuse. The calculated maximum MOP value in the aged refuse was 12.45 μmol g(-1) d.w. h(-1), which was much higher than the documented data.

  5. Modelling nitrous oxide emissions from organic and conventional cereal-based cropping systems under different management, soil and climate factors

    DEFF Research Database (Denmark)

    Doltra, J; Olesen, Jørgen E; Báez, D;

    2015-01-01

    -based cropping systems. Forage maize was grown in a conventional dairy system at Mabegondo (NW Spain) and wheat and barley in organic and conventional crop rotations at Foulum (NW Denmark). These two European sites represent agricultural areas with high and low to moderate emission levels, respectively. Field...

  6. Small marine craft emission factors observed from the NOAA R/V Ronald H. Brown during TexAQS/GoMACCS 2006

    Science.gov (United States)

    Lerner, B. M.; Lack, D.; Murphy, P. C.; Williams, E. J.

    2007-12-01

    During the TexAQS/GoMACCS 2006 field campaign, the NOAA R/V Ronald H. Brown often encountered small marine recreational craft and small fishing vessels while sailing close to the Texas coast, especially in Galveston Bay. Measurement of a suite of trace gases at high time resolution (1 Hz) allowed us to calculate emission factors (EFs), relative to carbon dioxide, for nitrogen oxides (NOx), sulfur dioxide (SO2) and carbon monoxide (CO) for distinct exhaust plumes from these sources. Photoacoustic aerosol absorption spectroscopy (PAS) measurements made concurrently allowed for the first quantification of mass EFs for light-absorbing particles from fishing craft. As previously observed along the New England coast, gasoline-powered recreational vessels showed significantly higher NOx/CO2 and lower CO/CO2 EFs than current emissions inventories predict, although in agreement with the most recent published literature of laboratory studies. These findings imply lower volatile organic compound emissions from these vessels, although this was not directly measured.

  7. Bayesian Exploratory Factor Analysis

    DEFF Research Database (Denmark)

    Conti, Gabriella; Frühwirth-Schnatter, Sylvia; Heckman, James J.

    2014-01-01

    This paper develops and applies a Bayesian approach to Exploratory Factor Analysis that improves on ad hoc classical approaches. Our framework relies on dedicated factor models and simultaneously determines the number of factors, the allocation of each measurement to a unique factor......, and the corresponding factor loadings. Classical identification criteria are applied and integrated into our Bayesian procedure to generate models that are stable and clearly interpretable. A Monte Carlo study confirms the validity of the approach. The method is used to produce interpretable low dimensional aggregates...

  8. DEVELOPMENT OF FINE PARTICULATE EMISSION FACTORS AND SPECIATION PROFILES FOR OIL AND GAS-FIRED COMBUSTION SYSTEMS

    Energy Technology Data Exchange (ETDEWEB)

    Glenn C. England; Stephanie Wien; Mingchih O. Chang

    2002-08-01

    This report provides results from the first year of this three-year project to develop dilution measurement technology for characterizing PM2.5 (particles with aerodynamic diameter smaller than 2.5 micrometers) and precursor emissions from stationary combustion sources used in oil, gas and power generation operations. Detailed emission rate and chemical speciation test results for a refinery gas-fired process heater and plans for cogeneration gas turbine tests and pilot-scale tests are presented. Tests were performed using a research dilution sampling apparatus and traditional EPA methods to compare PM2.5 mass and chemical speciation. Test plans are presented for a gas turbine facility that will be tested in the fourth quarter of 2002. A preliminary approach for pilot-scale tests is presented that will help define design constraints for a new dilution sampler design that is smaller, lighter, and less costly to use.

  9. Life cycle assessment of lignocellulosic ethanol: a review of key factors and methods affecting calculated GHG emissions and energy use.

    Science.gov (United States)

    Gerbrandt, Kelsey; Chu, Pei Lin; Simmonds, Allison; Mullins, Kimberley A; MacLean, Heather L; Griffin, W Michael; Saville, Bradley A

    2016-04-01

    Lignocellulosic ethanol has potential for lower life cycle greenhouse gas emissions compared to gasoline and conventional grain-based ethanol. Ethanol production 'pathways' need to meet economic and environmental goals. Numerous life cycle assessments of lignocellulosic ethanol have been published over the last 15 years, but gaps remain in understanding life cycle performance due to insufficient data, and model and methodological issues. We highlight key aspects of these issues, drawing on literature and a case study of corn stover ethanol. Challenges include the complexity of feedstock/ecosystems and market-mediated aspects and the short history of commercial lignocellulosic ethanol facilities, which collectively have led to uncertainty in GHG emissions estimates, and to debates on LCA methods and the role of uncertainty in decision making.

  10. A Field Program to Identify TRI Chemicals and Determine Emission Factors from DoD Munitions Activities

    Science.gov (United States)

    2006-01-01

    FINAL REPORT to STRATEGIC ENVIROMENTAL RESEARCH AND DEVELOPMENT PROGRAM (SERDP) on A FIELD PROGRAM TO IDENTIFY TRI CHEMICALS...adhere to EPCRA, including the toxic release inventory (TRI) requirements. A particularly difficult reporting issue for DoD concerns air emissions...primarily because of constraints imposed on the physical location of the lidar due to laser safety issues . The lack of flexibility in repositioning

  11. Cross-country polarisation in CO2 emissions per capita in the European Union : changes and explanatory factors

    OpenAIRE

    Duro Moreno, Juan Antonio; Padilla, Emilio

    2011-01-01

    In this study, we analyse the degree of polarisation—a concept fundamentally different from that of inequality—in the international distribution of CO2 emissions per capita in the European Union. It is analytically relevant to examine the degree of instability inherent to a distribution and, in the analysed case, the likelihood that the distribution and its evolution will increase or decrease the chances of reaching an agreement. Two approaches were used to measure polarisation: the endogenou...

  12. Factors affecting non-tailpipe aerosol particle emissions from paved roads: On-road measurements in Stockholm, Sweden

    Science.gov (United States)

    Hussein, Tareq; Johansson, Christer; Karlsson, Hans; Hansson, Hans-Christen

    A large fraction of urban PM 10 concentrations is due to non-exhaust traffic emissions. In this paper, a mobile measurement system has been used to quantify the relative importance of road particle emission and suspension of accumulated dust versus direct pavement wear, tire type (studded, friction, and summer), pavement type, and vehicle speed. Measurements were performed during May-September on selected roads with different pavements and traffic conditions in the Stockholm region. The highest particle mass concentrations were always observed behind the studded tire and the lowest were behind the summer tire; studded-to-summer ratios were 4.4-17.3 and studded-to-friction ratios were 2.0-6.4. This indicates that studded tires lead to higher emissions than friction and summer tires regardless to the asphalt type. By comparing with measurements in a road simulator, it could be estimated that the pavement wear due to the friction tires was 0.018-0.068 of the suspension of accumulated road dust. Likewise for studded tires road-wear was estimated to be 1.2-4.8 the suspension of accumulated dust. This indicates that wear due to friction tires is very small compared to the suspension of accumulated dust and that suspension due to studded tires may sometimes be as large as the wear of the road. But this will vary depending on, e.g. the amount of dust accumulated on the roads. An important dependence on vehicle speed was also observed. During May, the particle mass concentrations behind the studded tire at vehicle speed 100 km h -1 were about 10 times higher than that at 20 km h -1. The speed dependence was not so pronounced in September, which could be due to less accumulated dust on the roads. The particle number size distribution of the emissions due to road wear by studded tire was characterized by a clear increase in number concentrations of the coarse fraction of aerosol particles, with a geometric mean diameter between 3 and 5 μm. The size distribution of the

  13. `People on the move and goods on the go` behavioral factors driving carbon-dioxide emissions for travel and freight in OECD countries

    Energy Technology Data Exchange (ETDEWEB)

    Schipper, L. [Lawrence Berkeley Laboratory (United States)

    1996-12-01

    Concern has been expressed in many government and private studies over the cost of externalitites from transportation, which include safety, air pollution, noise, competition for urban space, balance of payments associated with oil imports, and risks from importing oil. If the individual (s) benefiting at the time faced those costs, the travel (or shipment) behind the externality might not take place, or technology would be applied to reduce the extent of the problem. For large trucks and busses, the costs (per vehicle-km) are considerably higher. Expressed as per unit of travel (passenger kilometers) or per unit of freight, i.e., taking into account the utilization of the vehicle, the specific cost change because of economics of scale. Transportation is a valuable part of our economy, but it is no free lunch. Emissions of CO{sub 2} or carbon from road transport are also on government agendas is industrialized countries. Not surprisingly, CO{sub 2} emissions from travel and freight have increased in most industrialized countries faster than population, albeit less rapidly than GDP. This paper reviews some of the factors driving that increase. Whatever the `real` external costs of each mode, all studies suggest two important findings: First, these costs are sometimes comparable to, or higher than, direct fuel costs per kilometer at the margin; Second, the value attached to the externality for carbon emissions tends to be low compared to those associated with other problems. Hence this suggests that CO{sub 2} by itself may not `felt` as a strong stimulus for change, but that changes to deal with the other problems may affect traffic, and therefore CO{sub 2} emissions, profoundly. (EG) 51 refs.

  14. Field determination of biomass burning emission ratios and factors via open-path FTIR spectroscopy and fire radiative power assessment: headfire, backfire and residual smouldering combustion in African savannahs

    Directory of Open Access Journals (Sweden)

    M. J. Wooster

    2011-02-01

    Full Text Available Biomass burning emissions factors are vital to quantifying trace gases releases from vegetation fires. Here we evaluate emissions factors for a series of savannah fires in Kruger National Park (KNP, South Africa using ground-based open path Fourier transform infrared (FTIR spectroscopy and an infrared lamp separated by 150–250 m distance. Molecular abundances along the extended open path are retrieved using a spectral forward model coupled to a non-linear least squares fitting approach. We demonstrate derivation of trace gas column amounts for horizontal paths transecting the width of the advected plume, and find, for example, that CO mixing ratio changes of ~0.001 μmol mol−1 (~10 ppbv can be detected across the relatively long optical paths used here. We focus analysis on five key compounds whose production is preferential during the pyrolysis (CH2O, flaming (CO2 and smoldering (CO, CH4, NH3 fire phases. We demonstrate that well constrained emissions ratios for these gases to both CO2 and CO can be derived for the backfire, headfire and residual smouldering combustion stages of these savannah fires, from which stage-specific emission factors can then be calculated. Headfires and backfires in general show similar emission ratios and emission factors, but those of the residual smouldering combustion stage can differ substantially (e.g., ERCH4/CO2 up to ~7 times higher than for the flaming stages. The timing of each fire stage was identified via airborne optical and thermal IR imagery and ground-observer reports, with the airborne IR imagery also used to derive estimates of fire radiative energy, thus allowing the relative amount of fuel burned in each stage to be calculated and the "fire averaged" emission ratios and emission factors to be determined. The derived "fire averaged" emission ratios are dominated by the headfire contribution, since

  15. Greenhouse gas emissions from concrete can be reduced by using mix proportions, geometric aspects, and age as design factors

    Science.gov (United States)

    Miller, Sabbie A.; Horvath, Arpad; Monteiro, Paulo J. M.; Ostertag, Claudia P.

    2015-11-01

    With increased awareness of the emissions of greenhouse gases (GHGs) and the significant contribution from the cement industry, research efforts are being advanced to reduce the impacts associated with concrete production and consumption. A variety of methods have been proposed, one of the most common being the replacement of cement as a binder in concrete with supplementary cementitious materials, such as fly ash (FA), which can have lower environmental effects. The use of FA can change the kinetics of the hydration reactions and, consequently, modify the evolution of the concrete strength over time. Yet the influence of designing structural elements to obtain the required strength at later ages has not been examined in terms of their influence on global warming potential (GWP) of concrete. This research investigates the influence of design age, in addition to mix proportions and geometric aspects, on the GWP associated with making beams, columns, and a concrete building frame. Findings suggest that while the GWP for beams is not highly dependent on concrete mixture strength, the GWP for columns is dependent on strength, thus the influence of required strength at later ages influences GWP of making columns more so than beams. For the concrete frame analyzed, a potential 45% reduction in GWP, depending on mix proportions and design age, was found. Using the findings from this research, the GWP associated with production of concrete in California could be reduced by approximately 1.8 million metric tons of CO2-eq emissions, equivalent to approximately 2% of all industrial GHG emissions in California.

  16. The Impact of Factors Affecting Environmental Pollution with Emphasis on Trade Openness in Different Countries (Case study CO2 emission

    Directory of Open Access Journals (Sweden)

    hosein mohammadi

    2015-05-01

    Full Text Available Urbanization, population growth and moving from traditional manufacturing industry to accelerate the process of economic development and parallel, significant environmental impacts are left. The purpose of this study is to investigate the effect of different variables such as trade openness, comparative advantage, production levels and other important variables affecting the emission of carbon dioxide gas in various countries of the world. Stata11 software was used to estimate the panel data model of 77 countries over the years 2010-1980. The results indicate that propagation environment, and in particular CO2, in all four groups of countries are associated with prior emission, with a per capita income direct link but with the square of it correlates inversely and have direct link with the ratio of capital to labor and with the square of it correlates inversely and trade openness in high-income countries and moderate negative effect in low-income and middle-income countries is directly related to the bottom.

  17. Biomonitoring of VOC emissions from the coating process at DaimlerChrysler - an inside view of motivation factors

    Energy Technology Data Exchange (ETDEWEB)

    Hahn, H.U. [DaimlerChrysler AG, Sindelfingen (Germany); Kostka-Rick, R. [Biologisch Ueberwachen und Bewerten, Echterdingen (Germany)

    2002-07-01

    To reduce ambient air pollution by solvents in the Boeblingen/Sindelfingen area, water-based paints were introduced in the Sindelfingen factory in the early nineties. Effect monitoring using plants was to clarify what effects the coating process had on the environment and to what extent the environmental impact was reduced by water-based paint technology. Depending on the results, the new method was to be optimized. In terms of the environmental liability legislation, the findings were to permit a self-appraisal of production effects. Between 1992 and 1996, a special bio-indication process tailored to the solvent emissions from the paint shop was developed. From 37 different plant species and varieties, nasturtium, different varieties of bush bean and of tomato were selected as bio-indicators, reacting specifically and sensitively to the solvent emissions. The monitoring plants were exposed at 13 different sites on the factory premises and in the urban area of Sindelfingen for air quality monitoring. Since 1992, more than 9,700 plants have been exposed and investigated and some 125,000 injury scores have been recorded. (orig.)

  18. Association between Cerebral Amyloid Deposition and Clinical Factors Including Cognitive Function in Geriatric Depression: Pilot Study Using Amyloid Positron Emission Tomography

    Science.gov (United States)

    Kim, Hye-Geum; Kong, Eun-Jung; Cheon, Eun-Jin; Kim, Hae-Won; Koo, Bon-Hoon

    2016-01-01

    The purpose of this study was to explore the relationship between cerebral amyloid deposition and overall clinical factors including cognitive functions in geriatric depression by using 18F-florbetaben positron emission tomography. Thirteen subjects aged over 60 years who had a history of major depressive disorder and also had subjective memory complaint were included. Of all subjects, 3 subjects judged as amyloid positive, and the others judged as amyloid negative. Their memory, visuospatial functions and attention abilities were negatively correlated with amyloid deposition in specific brain regions, but their language and recognition abilities were not correlated with any region. The amyloid deposition of the whole brain region was significantly negatively correlated with immediate memory. PMID:27776391

  19. Analytic Couple Modeling Introducing Device Design Factor, Fin Factor, Thermal Diffusivity Factor, and Inductance Factor

    Science.gov (United States)

    Mackey, Jon; Sehirlioglu, Alp; Dynys, Fred

    2014-01-01

    A set of convenient thermoelectric device solutions have been derived in order to capture a number of factors which are previously only resolved with numerical techniques. The concise conversion efficiency equations derived from governing equations provide intuitive and straight-forward design guidelines. These guidelines allow for better device design without requiring detailed numerical modeling. The analytical modeling accounts for factors such as i) variable temperature boundary conditions, ii) lateral heat transfer, iii) temperature variable material properties, and iv) transient operation. New dimensionless parameters, similar to the figure of merit, are introduced including the device design factor, fin factor, thermal diffusivity factor, and inductance factor. These new device factors allow for the straight-forward description of phenomenon generally only captured with numerical work otherwise. As an example a device design factor of 0.38, which accounts for thermal resistance of the hot and cold shoes, can be used to calculate a conversion efficiency of 2.28 while the ideal conversion efficiency based on figure of merit alone would be 6.15. Likewise an ideal couple with efficiency of 6.15 will be reduced to 5.33 when lateral heat is accounted for with a fin factor of 1.0.

  20. Explicit correlation factors

    Science.gov (United States)

    Johnson, Cole M.; Hirata, So; Ten-no, Seiichiro

    2017-09-01

    We analyze the performance of 17 different correlation factors in explicitly correlated second-order many-body perturbation calculations for correlation energies. Highly performing correlation factors are found to have near-universal shape and size in the short range of electron-electron distance (0 1.5 a.u.) is insignificant insofar as the factor becomes near constant, leaving an orbital expansion to describe decoupled electrons. An analysis based on a low-rank Taylor expansion of the correlation factor seems limited, except that a negative second derivative with the value of around -1.3 a.u. correlates with high performance.

  1. Identification and quantification of carbamate pesticides in dried lime tree flowers by means of excitation-emission molecular fluorescence and parallel factor analysis when quenching effect exists.

    Science.gov (United States)

    Rubio, L; Ortiz, M C; Sarabia, L A

    2014-04-11

    A non-separative, fast and inexpensive spectrofluorimetric method based on the second order calibration of excitation-emission fluorescence matrices (EEMs) was proposed for the determination of carbaryl, carbendazim and 1-naphthol in dried lime tree flowers. The trilinearity property of three-way data was used to handle the intrinsic fluorescence of lime flowers and the difference in the fluorescence intensity of each analyte. It also made possible to identify unequivocally each analyte. Trilinearity of the data tensor guarantees the uniqueness of the solution obtained through parallel factor analysis (PARAFAC), so the factors of the decomposition match up with the analytes. In addition, an experimental procedure was proposed to identify, with three-way data, the quenching effect produced by the fluorophores of the lime flowers. This procedure also enabled the selection of the adequate dilution of the lime flowers extract to minimize the quenching effect so the three analytes can be quantified. Finally, the analytes were determined using the standard addition method for a calibration whose standards were chosen with a D-optimal design. The three analytes were unequivocally identified by the correlation between the pure spectra and the PARAFAC excitation and emission spectral loadings. The trueness was established by the accuracy line "calculated concentration versus added concentration" in all cases. Better decision limit values (CCα), in x0=0 with the probability of false positive fixed at 0.05, were obtained for the calibration performed in pure solvent: 2.97 μg L(-1) for 1-naphthol, 3.74 μg L(-1) for carbaryl and 23.25 μg L(-1) for carbendazim. The CCα values for the second calibration carried out in matrix were 1.61, 4.34 and 51.75 μg L(-1) respectively; while the values obtained considering only the pure samples as calibration set were: 2.65, 8.61 and 28.7 μg L(-1), respectively.

  2. Real-world automotive particulate matter and PAH emission factors and profile concentrations: Results from an urban tunnel experiment in Naples, Italy

    Science.gov (United States)

    Riccio, A.; Chianese, E.; Monaco, D.; Costagliola, M. A.; Perretta, G.; Prati, M. V.; Agrillo, G.; Esposito, A.; Gasbarra, D.; Shindler, L.; Brusasca, G.; Nanni, A.; Pozzi, C.; Magliulo, V.

    2016-09-01

    On-road particulate matter (PM) mass was measured during a sampling campaign in March of 2015 in the '4 giornate' tunnel in Naples, Italy. Two sets of samples were collected at both sides of the tunnel, each set representing the daily cycle at a 1 h time resolution. Distance-based - mass per kilometer - and fuel-based - mass per burned fuel - emission factors (EFs) were calculated using mass concentrations, traffic flow rates and wind speed as a function of fleet composition. Also, chemical analyses were performed for polycyclic aromatic hydrocarbons (PAHs). Due to the high traffic volume, particle mass concentration at the tunnel exit was always significantly elevated relative to entrance concentration; depending on the hour of the day, PM10 concentration ranged between 300 μg/m3, during the early afternoon, and 600 μg/m3 during rush hours at the tunnel exit. Correspondingly, PAHs achieved concentrations as high as 1450 ng/m3, and benzo(a)pyrene, a surely carcinogenic compound, achieved concentrations as high as 69 ng/m3, raising serious concerns in relation to population exposure close to this urban tunnel. Distance-based and fuel-based emission factors for CO2, PM10 and PAHs were estimated, but while the EF for CO2 was within the range of expected values, the present study found much higher EFs for particulate matter and PAHs. According to the national official statistics from ISPRA (the Italian Institute for the Protection and Research on Environment), derived from the COPERT database, we expected an EF for particulate matter of about 55 mg/km, but the EF estimated from measurements taken at both sides of the tunnel was about four times higher than that expected; also, benzo(a)pyrene achieved an average EF of 2.7 μg/km, about three times higher than that expected from the ISPRA database.

  3. Comparison of carcinogen, carbon monoxide, and ultrafine particle emissions from narghile waterpipe and cigarette smoking: Sidestream smoke measurements and assessment of second-hand smoke emission factors

    Science.gov (United States)

    Daher, Nancy; Saleh, Rawad; Jaroudi, Ezzat; Sheheitli, Hiba; Badr, Thérèse; Sepetdjian, Elizabeth; Al Rashidi, Mariam; Saliba, Najat; Shihadeh, Alan

    2010-01-01

    The lack of scientific evidence on the constituents, properties, and health effects of second-hand waterpipe smoke has fueled controversy over whether public smoking bans should include the waterpipe. The purpose of this study was to investigate and compare emissions of ultrafine particles (UFP, 1.5 air changes per hour (ACH). The chamber was characterized for particle mass and number surface deposition rates. UFP and CO concentrations were measured online using a fast particle spectrometer (TSI 3090 Engine Exhaust Particle Sizer), and an indoor air quality monitor. Particulate PAH and gaseous volatile aldehydes were captured on glass fiber filters and DNPH-coated SPE cartridges, respectively, and analyzed off-line using GC-MS and HPLC-MS. PAH compounds quantified were the 5- and 6-ring compounds of the EPA priority list. Measured aldehydes consisted of formaldehyde, acetaldehyde, acrolein, methacrolein, and propionaldehyde. We found that a single waterpipe use session emits in the sidestream smoke approximately four times the carcinogenic PAH, four times the volatile aldehydes, and 30 times the CO of a single cigarette. Accounting for exhaled mainstream smoke, and given a habitual smoker smoking rate of 2 cigarettes per hour, during a typical one-hour waterpipe use session a waterpipe smoker likely generates ambient carcinogens and toxicants equivalent to 2-10 cigarette smokers, depending on the compound in question. There is therefore good reason to include waterpipe tobacco smoking in public smoking bans.

  4. Field determination of biomass burning emission ratios and factors via open-path FTIR spectroscopy and fire radiative power assessment: headfire, backfire and residual smouldering combustion in African savannahs

    Science.gov (United States)

    Wooster, M. J.; Freeborn, P. H.; Archibald, S.; Oppenheimer, C.; Roberts, G. J.; Smith, T. E. L.; Govender, N.; Burton, M.; Palumbo, I.

    2011-11-01

    Biomass burning emissions factors are vital to quantifying trace gas release from vegetation fires. Here we evaluate emissions factors for a series of savannah fires in Kruger National Park (KNP), South Africa using ground-based open path Fourier transform infrared (FTIR) spectroscopy and an IR source separated by 150-250 m distance. Molecular abundances along the extended open path are retrieved using a spectral forward model coupled to a non-linear least squares fitting approach. We demonstrate derivation of trace gas column amounts for horizontal paths transecting the width of the advected plume, and find for example that CO mixing ratio changes of ~0.01 μmol mol-1 [10 ppbv] can be detected across the relatively long optical paths used here. Though FTIR spectroscopy can detect dozens of different chemical species present in vegetation fire smoke, we focus our analysis on five key combustion products released preferentially during the pyrolysis (CH2O), flaming (CO2) and smoldering (CO, CH4, NH3) processes. We demonstrate that well constrained emissions ratios for these gases to both CO2 and CO can be derived for the backfire, headfire and residual smouldering combustion (RSC) stages of these savannah fires, from which stage-specific emission factors can then be calculated. Headfires and backfires often show similar emission ratios and emission factors, but those of the RSC stage can differ substantially. The timing of each fire stage was identified via airborne optical and thermal IR imagery and ground-observer reports, with the airborne IR imagery also used to derive estimates of fire radiative energy (FRE), allowing the relative amount of fuel burned in each stage to be calculated and "fire averaged" emission ratios and emission factors to be determined. These "fire averaged" metrics are dominated by the headfire contribution, since the FRE data indicate that the vast majority of the fuel is burned in this stage. Our fire averaged emission ratios and factors

  5. Field determination of biomass burning emission ratios and factors via open-path FTIR spectroscopy and fire radiative power assessment: headfire, backfire and residual smouldering combustion in African savannahs

    Directory of Open Access Journals (Sweden)

    M. J. Wooster

    2011-11-01

    Full Text Available Biomass burning emissions factors are vital to quantifying trace gas release from vegetation fires. Here we evaluate emissions factors for a series of savannah fires in Kruger National Park (KNP, South Africa using ground-based open path Fourier transform infrared (FTIR spectroscopy and an IR source separated by 150–250 m distance. Molecular abundances along the extended open path are retrieved using a spectral forward model coupled to a non-linear least squares fitting approach. We demonstrate derivation of trace gas column amounts for horizontal paths transecting the width of the advected plume, and find for example that CO mixing ratio changes of ~0.01 μmol mol−1 [10 ppbv] can be detected across the relatively long optical paths used here. Though FTIR spectroscopy can detect dozens of different chemical species present in vegetation fire smoke, we focus our analysis on five key combustion products released preferentially during the pyrolysis (CH2O, flaming (CO2 and smoldering (CO, CH4, NH3 processes. We demonstrate that well constrained emissions ratios for these gases to both CO2 and CO can be derived for the backfire, headfire and residual smouldering combustion (RSC stages of these savannah fires, from which stage-specific emission factors can then be calculated. Headfires and backfires often show similar emission ratios and emission factors, but those of the RSC stage can differ substantially. The timing of each fire stage was identified via airborne optical and thermal IR imagery and ground-observer reports, with the airborne IR imagery also used to derive estimates of fire radiative energy (FRE, allowing the relative amount of fuel burned in each stage to be calculated and "fire averaged" emission ratios and emission factors to be determined. These "fire averaged" metrics are dominated by the headfire contribution, since the FRE data indicate that the vast majority

  6. The Correlation Between Pre-treatment Fluorodeoxyglucose Positron Emission Tomography/Computed Tomography Parameters and Clinical Prognostic Factors in Pediatric Hodgkin Lymphoma

    Science.gov (United States)

    Tatcı, Ebru; Uslu Biner, İnci; Emir, Suna; Tanyıldız, Hikmet Gülşah; Özmen, Özlem; Alagöz, Engin; Gökçek, Atila; Şahin, Gürses

    2017-01-01

    Objective: To compare standardized uptake values (SUV) derived from pre-treatment 18F-fluorodeoxyglucose (FDG) positron emission tomography/computed tomography (PET/CT) imaging and clinical prognostic factors in pediatric patients with Hodgkin lymphoma (HL). Methods: Pre-treatment FDG PET/CT findings of 28 children with HL were evaluated in this retrospective study. Metabolic tumor volume (MTV), SUVmax normalized by weight (SUVweight), lean body mass (SUVlbm), body surface area (SUVbsa) and plasma glucose levels of tumors (SUVglucose) were calculated using pre-treatment FDG PET/CT scan images. These metabolic parameters were correlated with clinical factors [age, sex, number of lymph node groups, presence of splenic involvement, bulky mediastinal disease, Ann Arbor stage, serum white blood cell (WBC) count, erythrocyte sedimentation rate (ESR), serum albumin and hemoglobin levels]. Results: SUVbsa, SUVlbm, SUVweight, SUVglucose and MTV were higher in patients with stage III-IV disease, bulky tumor and ≥3 lymph node groups (p0.05). SUVbsa and SUVlbm were higher in patients with anemia (p0.05). Conclusion: Metabolic parameters derived from pre-treatment FDG PET/CT may have an important role in predicting high-risk disease in patients with HL. Also, SUVbsa and SUVlbm may be better markers than SUVweight in the quantitative evaluation of FDG PET/CT scans in pediatric patients. PMID:28291005

  7. Factors Affecting Aerosol Radiative Forcing

    Science.gov (United States)

    Wang, Jingxu; Lin, Jintai; Ni, Ruijing

    2016-04-01

    Rapid industrial and economic growth has meant a large amount of aerosols in the atmosphere with strong radiative forcing (RF) upon the climate system. Over parts of the globe, the negative forcing of aerosols has overcompensated for the positive forcing of greenhouse gases. Aerosol RF is determined by emissions and various chemical-transport-radiative processes in the atmosphere, a multi-factor problem whose individual contributors have not been well quantified. In this study, we analyze the major factors affecting RF of secondary inorganic aerosols (SIOAs, including sulfate, nitrate and ammonium), primary organic aerosol (POA), and black carbon (BC). We analyze the RF of aerosols produced by 11 major regions across the globe, including but not limited to East Asia, Southeast Asia, South Asia, North America, and Western Europe. Factors analyzed include population size, per capita gross domestic production (GDP), emission intensity (i.e., emissions per unit GDP), chemical efficiency (i.e., mass per unit emissions) and radiative efficiency (i.e., RF per unit mass). We find that among the 11 regions, East Asia produces the largest emissions and aerosol RF, due to relatively high emission intensity and a tremendous population size. South Asia produce the second largest RF of SIOA and BC and the highest RF of POA, in part due to its highest chemical efficiency among all regions. Although Southeast Asia also has large emissions, its aerosol RF is alleviated by its lowest chemical efficiency. The chemical efficiency and radiative efficiency of BC produced by the Middle East-North Africa are the highest across the regions, whereas its RF is lowered by a small per capita GDP. Both North America and Western Europe have low emission intensity, compensating for the effects on RF of large population sizes and per capita GDP. There has been a momentum to transfer industries to Southeast Asia and South Asia, and such transition is expected to continue in the coming years. The

  8. Rh Factor Blood Test

    Science.gov (United States)

    Tests and Procedures Rh factor blood test By Mayo Clinic Staff Rhesus (Rh) factor is an inherited protein found on the surface of ... If your blood has the protein, you're Rh positive. If your blood lacks the protein, you' ...

  9. Baryon form factors

    CERN Document Server

    Kubis, B; Meißner, Ulf G; Mei{\\ss}ner, Ulf-G.

    1999-01-01

    We calculate the form factors of the baryon octet in the framework of heavy baryon chiral perturbation theory. The calculated charge radius of the show that kaon loop effects can play a significant role in the neutron electric form factor. Furthermore. we derive generalized Caldi-Pagels relations between various charge radii which are free of chiral loop effects.

  10. Overview of environmental factors

    Science.gov (United States)

    Purvis, C. K.

    1989-01-01

    The orbital environment is complex, dynamic, and comprised of both natural and system-induced components. Several environment factors are important for materials. Materials selection/suitability determination requires consideration of each and all factors, including synergisms among them. Understanding and evaluating these effects will require ground testing, modeling, and focused flight experimentation.

  11. The Transcription Factor Encyclopedia

    DEFF Research Database (Denmark)

    Yusuf, Dimas; Butland, Stefanie L; Swanson, Magdalena I

    2012-01-01

    ABSTRACT: Here we present the Transcription Factor Encyclopedia (TFe), a new web-based compendium of mini review articles on transcription factors (TFs) that is founded on the principles of open access and collaboration. Our consortium of over 100 researchers has collectively contributed over 130...

  12. Factors of schizoid personality.

    Science.gov (United States)

    Raine, A; Allbutt, J

    1989-02-01

    The increasing use of schizoid personality scales with normals has led to a number of validation studies, but to date there are no published analyses of the factorial structure of these scales. This study presents results of factor analyses of schizoid personality scales in an initial attempt to delineate their factorial structure. Questionnaires were administered to 114 male and female undergraduates and factor analysed using Varimax, Quartimax, and Oblique rotations. A two-factor varimax solution yielded a first factor accounting for 49 per cent of total unrotated variance with high (0.70 to 0.91) loadings from Hallucinatory predisposition, Perceptual aberration, Schizophrenism, STA and STB scales, and was interpreted as reflecting a general factor of schizoid personality disorder. Psychoticism and Social anhedonia loaded on a second factor accounting for 20 per cent of the variance which was uncorrelated (r = 0.09) with factor 1. This factor solution was closely replicated using quartimax and oblimin rotation criteria. It is concluded that Social anhedonia and Psychoticism represent a separate dimension from other scales which reflect the more positive features of schizoid personality.

  13. Factors Affecting Aerosol Radiative Forcing

    Science.gov (United States)

    Wang, J.; Lin, J.; Ni, R.

    2016-12-01

    Rapid industrial and economic growth has meant large amount of aerosols in the atmosphere with strong radiative forcing (RF) upon the climate system. Over parts of the globe, the negative forcing of aerosols has overcompensated for the positive forcing of greenhouse gases. Aerosol RF is determined by emissions and various chemical-transport-radiative processes in the atmosphere, a multi-factor problem whose individual contributors have not been well quantified. In this study, we analyze the major factors affecting RF of secondary inorganic aerosols (SIOAs, including sulfate, nitrate and ammonium), primary organic aerosol (POA), and black carbon (BC). We analyze the RFof aerosols produced by 11 major regions across the globe, including but not limited to East Asia, Southeast Asia, South Asia, North America, and Western Europe. Factors analyzed include population size, per capita gross domestic production (GDP), emission intensity (i.e., emissionsper unit GDP), chemical efficiency (i.e., mass per unit emissions) and radiative efficiency (i.e., RF per unit mass). We find that among the 11 regions, East Asia produces the largest emissions and aerosol RF, due to relatively high emission intensity and a tremendous population size.South Asia produce the second largest RF of SIOA and BC and the highest RF of POA, in part due to its highest chemical efficiency among all regions. Although Southeast Asia also has large emissions,its aerosol RF is alleviated by its lowest chemical efficiency.The chemical efficiency and radiative efficiency of BC produced by the Middle East-North Africa are the highest across the regions, whereas its RF is loweredbyasmall per capita GDP.Both North America and Western Europe have low emission intensity, compensating for the effects on RF of large population sizes and per capita GDP. There has been a momentum to transfer industries to Southeast Asia and South Asia, and such transition is expected to continue in the coming years. The resulting

  14. Factorized Graph Matching.

    Science.gov (United States)

    Zhou, Feng; de la Torre, Fernando

    2015-11-19

    Graph matching (GM) is a fundamental problem in computer science, and it plays a central role to solve correspondence problems in computer vision. GM problems that incorporate pairwise constraints can be formulated as a quadratic assignment problem (QAP). Although widely used, solving the correspondence problem through GM has two main limitations: (1) the QAP is NP-hard and difficult to approximate; (2) GM algorithms do not incorporate geometric constraints between nodes that are natural in computer vision problems. To address aforementioned problems, this paper proposes factorized graph matching (FGM). FGM factorizes the large pairwise affinity matrix into smaller matrices that encode the local structure of each graph and the pairwise affinity between edges. Four are the benefits that follow from this factorization: (1) There is no need to compute the costly (in space and time) pairwise affinity matrix; (2) The factorization allows the use of a path-following optimization algorithm, that leads to improved optimization strategies and matching performance; (3) Given the factorization, it becomes straight-forward to incorporate geometric transformations (rigid and non-rigid) to the GM problem. (4) Using a matrix formulation for the GM problem and the factorization, it is easy to reveal commonalities and differences between different GM methods. The factorization also provides a clean connection with other matching algorithms such as iterative closest point; Experimental results on synthetic and real databases illustrate how FGM outperforms state-of-the-art algorithms for GM. The code is available at http://humansensing.cs.cmu.edu/fgm.

  15. Risk Factors for Tuberculosis

    Directory of Open Access Journals (Sweden)

    Padmanesan Narasimhan

    2013-01-01

    Full Text Available The risk of progression from exposure to the tuberculosis bacilli to the development of active disease is a two-stage process governed by both exogenous and endogenous risk factors. Exogenous factors play a key role in accentuating the progression from exposure to infection among which the bacillary load in the sputum and the proximity of an individual to an infectious TB case are key factors. Similarly endogenous factors lead in progression from infection to active TB disease. Along with well-established risk factors (such as human immunodeficiency virus (HIV, malnutrition, and young age, emerging variables such as diabetes, indoor air pollution, alcohol, use of immunosuppressive drugs, and tobacco smoke play a significant role at both the individual and population level. Socioeconomic and behavioral factors are also shown to increase the susceptibility to infection. Specific groups such as health care workers and indigenous population are also at an increased risk of TB infection and disease. This paper summarizes these factors along with health system issues such as the effects of delay in diagnosis of TB in the transmission of the bacilli.

  16. Environmental factors in autism.

    Science.gov (United States)

    Grabrucker, Andreas M

    2012-01-01

    Autism is a neurodevelopmental disorders characterized by impairments in communication and social behavior, and by repetitive behaviors. Although genetic factors might be largely responsible for the occurrence of autism they cannot fully account for all cases and it is likely that in addition to a certain combination of autism-related genes, specific environmental factors might act as risk factors triggering the development of autism. Thus, the role of environmental factors in autism is an important area of research and recent data will be discussed in this review. Interestingly, the results show that many environmental risk factors are interrelated and their identification and comparison might unveil a common scheme of alterations on a contextual as well as molecular level. For example, both, disruption in the immune system and in zinc homeostasis may affect synaptic transmission in autism. Thus, here, a model is proposed that interconnects the most important and scientifically recognized environmental factors. Moreover, similarities in how these risk factors impact synapse function are discussed and a possible influence on an already well described genetic pathway leading to the development of autism via zinc homeostasis is proposed.

  17. Environmental factors in autism

    Directory of Open Access Journals (Sweden)

    Andreas Martin Grabrucker

    2013-01-01

    Full Text Available Autism is a neurodevelopmental disorders characterized by impairments in communication and social behavior, and by repetitive behaviors. Although genetic factors might be largely responsible for the occurrence of autism they cannot fully account for all cases and it is likely that in addition to a certain combination of autism-related genes, specific environmental factors might act as risk factors triggering the development of autism. Thus, the role of environmental factors in autism is an important area of research and recent data will be discussed in this review. Interestingly, the results show that many environmental risk factors are interrelated and their identification and comparison might unveil a common scheme of alterations on a contextual as well as molecular level. For example, both, disruption in the immune system and in zinc homeostasis may affect synaptic transmission in autism. Thus, here, a model is proposed that interconnects the most important and scientifically recognized environmental factors. Moreover, similarities in how these risk factors impact synapse function are discussed and a possible influence on an already well described genetic pathway leading to the development of autism via zinc homeostasis is proposed.

  18. Factor V Leiden thrombophilia.

    Science.gov (United States)

    Kujovich, Jody Lynn

    2011-01-01

    Factor V Leiden is a genetic disorder characterized by a poor anticoagulant response to activated Protein C and an increased risk for venous thromboembolism. Deep venous thrombosis and pulmonary embolism are the most common manifestations, but thrombosis in unusual locations also occurs. The current evidence suggests that the mutation has at most a modest effect on recurrence risk after initial treatment of a first venous thromboembolism. Factor V Leiden is also associated with a 2- to 3-fold increased relative risk for pregnancy loss and possibly other obstetric complications, although the probability of a successful pregnancy outcome is high. The clinical expression of Factor V Leiden is influenced by the number of Factor V Leiden alleles, coexisting genetic and acquired thrombophilic disorders, and circumstantial risk factors. Diagnosis requires the activated Protein C resistance assay (a coagulation screening test) or DNA analysis of the F5 gene, which encodes the Factor V protein. The first acute thrombosis is treated according to standard guidelines. Decisions regarding the optimal duration of anticoagulation are based on an individualized assessment of the risks for venous thromboembolism recurrence and anticoagulant-related bleeding. In the absence of a history of thrombosis, long-term anticoagulation is not routinely recommended for asymptomatic Factor V Leiden heterozygotes, although prophylactic anticoagulation may be considered in high-risk clinical settings. In the absence of evidence that early diagnosis reduces morbidity or mortality, decisions regarding testing at-risk family members should be made on an individual basis.

  19. Two-factor authentication

    CERN Document Server

    Stanislav, Mark

    2015-01-01

    During the book, readers will learn about the various technical methods by which two-factor authentication is implemented, security concerns with each type of implementation, and contextual details to frame why and when these technologies should be used. Readers will also be provided with insight about the reasons that two-factor authentication is a critical security control, events in history that have been important to prove why organization and individual would want to use two factor, and core milestones in the progress of growing the market.

  20. Teratogenic factors affect transcription factor expression.

    Science.gov (United States)

    Kojima, Takuya; Asano, Shinya; Takahashi, Naoki

    2013-01-01

    Chemical compounds are produced every day, many with adverse effects on human health, and hence it is vital to predict the risks to humans simply, rapidly, and accurately. Teratogens have a serious impact on fetal development. This has been studied mainly by phenotypic analysis of experimental animals. However, since phenotypes can vary within different species, we established a new evaluation system based on our recent finding that teratogens influence Hox gene expression in mice. Similarly to the Hox gene expression changes, the expression patterns of several transcription factors involved in development, including the Dlx, Irx, Sall, and T-box families, were altered after 6 h of exposure to retinoic acid (RA) or 2,3,7,8-tetrachlorodibenzo-p-dioxin (TCDD). The expression changes in Dlx4, Dlx6, Irx5, Sall2, Sall3, Sall4, Tbx10, and Tbx22 were linked to teratogen-induced phenotypes, and our results indicate that expression changes in developmental transcription factors can help to predict teratogenic risk.

  1. TMDs, universality and factorization

    CERN Document Server

    D'Alesio, Umberto

    2011-01-01

    We present a short overview on transverse momentum dependent parton distribution and fragmentation functions, giving their partonic interpretation and ways to access them. We then discuss the issue of their universality and its connection to factorization in perturbative QCD.

  2. Factor V Leiden

    Science.gov (United States)

    ... increase your chance of developing abnormal blood clots (thrombophilia), usually in your veins. Most people with factor ... sharp tools. References Bauer KA. Management of inherited thrombophilia. http://www.uptodate.com/home. Accessed June 6, ...

  3. New microbial growth factor

    Science.gov (United States)

    Bok, S. H.; Casida, L. E., Jr.

    1977-01-01

    A screening procedure was used to isolate from soil a Penicillium sp., two bacterial isolates, and a Streptomyces sp. that produced a previously unknown microbial growth factor. This factor was an absolute growth requirement for three soil bacteria. The Penicillium sp. and one of the bacteria requiring the factor, an Arthrobacter sp., were selected for more extensive study concerning the production and characteristics of the growth factor. It did not seem to be related to the siderochromes. It was not present in soil extract, rumen fluid, or any other medium component tested. It appears to be a glycoprotein of high molecular weight and has high specific activity. When added to the diets for a meadow-vole mammalian test system, it caused an increased consumption of diet without a concurrent increase in rate of weight gain.

  4. Factors Affecting Wound Healing

    Science.gov (United States)

    Guo, S.; DiPietro, L.A.

    2010-01-01

    Wound healing, as a normal biological process in the human body, is achieved through four precisely and highly programmed phases: hemostasis, inflammation, proliferation, and remodeling. For a wound to heal successfully, all four phases must occur in the proper sequence and time frame. Many factors can interfere with one or more phases of this process, thus causing improper or impaired wound healing. This article reviews the recent literature on the most significant factors that affect cutaneous wound healing and the potential cellular and/or molecular mechanisms involved. The factors discussed include oxygenation, infection, age and sex hormones, stress, diabetes, obesity, medications, alcoholism, smoking, and nutrition. A better understanding of the influence of these factors on repair may lead to therapeutics that improve wound healing and resolve impaired wounds. PMID:20139336

  5. Factor X assay

    Science.gov (United States)

    ... D, Neff AT. Rare coagulation factor deficiencies. In: Hoffman R, Benz EJ Jr, Silberstein LE, Heslop HE, ... Laboratory evaluation of hemostatic and thrombotic disorders. In: Hoffman R, Benz EJ Jr, Silberstein LE, Heslop HE, ...

  6. Factor XII assay

    Science.gov (United States)

    ... D, Neff AT. Rare coagulation factor deficiencies. In: Hoffman R, Benz EJ Jr, Silberstein LE, Heslop HE, ... Laboratory evaluation of hemostatic and thrombotic disorders. In: Hoffman R, Benz EJ Jr, Silberstein LE, Heslop HE, ...

  7. Rheumatoid Factors: Clinical Applications

    Directory of Open Access Journals (Sweden)

    Francesca Ingegnoli

    2013-01-01

    Full Text Available Rheumatoid factors are antibodies directed against the Fc region of immunoglobulin G. First detected in patients with rheumatoid arthritis 70 years ago, they can also be found in patients with other autoimmune and nonautoimmune conditions, as well as in healthy subjects. Rheumatoid factors form part of the workup for the differential diagnosis of arthropathies. In clinical practice, it is recommended to measure anti-cyclic citrullinated peptide antibodies and rheumatoid factors together because anti-cyclic citrullinated peptide antibodies alone are only moderately sensitive, and the combination of the two markers improves diagnostic accuracy, especially in the case of early rheumatoid arthritis. Furthermore, different rheumatoid factor isotypes alone or in combination can be helpful when managing rheumatoid arthritis patients, from the time of diagnosis until deciding on the choice of therapeutic strategy.

  8. Heart Disease Risk Factors

    Science.gov (United States)

    ... Hearts® WISEWOMAN Program Other Chronic Disease Topics Diabetes Nutrition Obesity Physical Activity Stroke Heart Disease Risk Factors Recommend ... Hearts® WISEWOMAN Program Other Chronic Disease Topics Diabetes Nutrition Obesity Physical Activity Stroke File Formats Help: How do ...

  9. Human Factors Laboratory

    Data.gov (United States)

    Federal Laboratory Consortium — Purpose: The purpose of the Human Factors Laboratory is to further the understanding of highway user needs so that those needs can be incorporated in roadway design,...

  10. Factors Affecting Wound Healing

    OpenAIRE

    Guo, S.; DiPietro, L A

    2010-01-01

    Wound healing, as a normal biological process in the human body, is achieved through four precisely and highly programmed phases: hemostasis, inflammation, proliferation, and remodeling. For a wound to heal successfully, all four phases must occur in the proper sequence and time frame. Many factors can interfere with one or more phases of this process, thus causing improper or impaired wound healing. This article reviews the recent literature on the most significant factors that affect cutane...

  11. FGF growth factor analogs

    Science.gov (United States)

    Zamora, Paul O [Gaithersburg, MD; Pena, Louis A [Poquott, NY; Lin, Xinhua [Plainview, NY; Takahashi, Kazuyuki [Germantown, MD

    2012-07-24

    The present invention provides a fibroblast growth factor heparin-binding analog of the formula: ##STR00001## where R.sub.1, R.sub.2, R.sub.3, R.sub.4, R.sub.5, X, Y and Z are as defined, pharmaceutical compositions, coating compositions and medical devices including the fibroblast growth factor heparin-binding analog of the foregoing formula, and methods and uses thereof.

  12. Brain derived neurotrophic factor

    DEFF Research Database (Denmark)

    Mitchelmore, Cathy; Gede, Lene

    2014-01-01

    Brain Derived Neurotrophic Factor (BDNF) is a neurotrophin with important functions in neuronal development and neuroplasticity. Accumulating evidence suggests that alterations in BDNF expression levels underlie a variety of psychiatric and neurological disorders. Indeed, BDNF therapies are curre......Brain Derived Neurotrophic Factor (BDNF) is a neurotrophin with important functions in neuronal development and neuroplasticity. Accumulating evidence suggests that alterations in BDNF expression levels underlie a variety of psychiatric and neurological disorders. Indeed, BDNF therapies...

  13. General Factors in Graphs.

    Science.gov (United States)

    1986-07-01

    conjectured that the general factor problem can be solved in polynomial time when, in each Bi, all the gaps (if any) have length one. We prove this conjecture...exactly bi edges incident with node i, for each i. This problem is well-solved. A polynomial algorithm is known (Edmonds and Johnson (1970)) as well as a...powerful theorem to characterize the existence of solutions ( Tutte (1952)). The following generalization of the factor problem was studied by Lovtsz

  14. Factors Impacting Knowledge Sharing

    DEFF Research Database (Denmark)

    Schulzmann, David; Slepniov, Dmitrij

    The purpose of this paper is to examine various factors affecting knowledge sharing at the R&D center of a Western MNE in China. The paper employs qualitative methodology and is based on the action research and case study research techniques. The findings of the paper advance our understanding...... about factors that affect knowledge sharing. The main emphasis is given to the discussion on how to improve knowledge sharing in global R&D organizations....

  15. Los factores de riesgo

    Directory of Open Access Journals (Sweden)

    Justo Senado Dumoy

    1999-01-01

    Full Text Available Sobre el fundamento filosófico de los conceptos de la Dialéctica Materialista, se presenta un análisis en relación con el concepto e interpretación de los Factores de Riesgo.A analysis on the concept and interpretation of risk factors is presented based on the philosophical foundation of the concepts of materialist dialectics.

  16. Factors affecting emotional divorce

    Directory of Open Access Journals (Sweden)

    Karim Said Shabanlou

    2016-03-01

    Full Text Available Emotional Divorce is the most important factor in the rupture of the most fundamental structures of society, the family.Due to the sensitivity and position of the familyAnd its functions specifically to investigate the factors underlying emotional divorce has of particular importance.Emotional Divorce phenomenon is not a single factor, but rather a set of related factors together led to Emotional Divorce.In this paper the role of psychological factors such as early maladaptive schemas, negative body image, perfectionism is discussed on an emotional divorce.Also quality of life and family relationships of couples with emotional divorce,Such as quality of health, sexual dissatisfaction, ignoring the needs, expectations and opinions of women by men or vice versa,And also social and economic factors such as subcultures families, couples, the quality of social relationships, social networks couple,Economic situation of the families of the couple, financial crisis, unemployment and economic revenues couples studied and some suggestions are presented based on the findings.

  17. New positron emission tomography derived parameters as predictive factors for recurrence in resected stage I non-small cell lung cancer.

    Science.gov (United States)

    Melloni, G; Gajate, A M S; Sestini, S; Gallivanone, F; Bandiera, A; Landoni, C; Muriana, P; Gianolli, L; Zannini, P

    2013-11-01

    The recurrence rate for stage I non-small cell lung cancer is high, with 20-40% of patients that relapse after surgery. The aim of this study was to evaluate new F-18 fluorodeoxyglucose (FDG) positron emission tomography (PET) derived parameters, such as standardized uptake value index (SUVindex), metabolic tumor volume (MTV) and total lesion glycolysis (TLG), as predictive factors for recurrence in resected stage I non-small cell lung cancer. We retrospectively reviewed 99 resected stage I non-small cell lung cancer patients that were grouped by SUVindex, TLG and MTV above or below their median value. Disease free survival was evaluated as primary end point. The 5-year overall survival and the 5-year disease free survival rates were 62% and 73%, respectively. The median SUVindex, MTL and TLG were 2.73, 2.95 and 9.61, respectively. Patients with low SUVindex, MTV and TLG were more likely to have smaller tumors (p ≤ 0.001). Univariate analysis demonstrated that SUVindex (p = 0.027), MTV (p = 0.014) and TLG (p = 0.006) were significantly related to recurrence showing a better predictive performance than SUVmax (p = 0.031). The 5-year disease free survival rates in patients with low and high SUVindex, MTV and TLG were 84% and 59%, 86% and 62% and 88% and 60%, respectively. The multivariate analysis showed that only TLG was an independent prognostic factor (p = 0.014) with a hazard ratio of 4.782. Of the three PET-derived parameters evaluated, TLG seems to be the most accurate in stratifying surgically treated stage I non-small cell lung cancer patients according to their risk of recurrence. Copyright © 2013 Elsevier Ltd. All rights reserved.

  18. 40 CFR 1042.245 - Deterioration factors.

    Science.gov (United States)

    2010-07-01

    ... deterioration factors for an engine family with established technology based on engineering analysis instead of... Certifying Engine Families § 1042.245 Deterioration factors. This section describes how to determine... considered to rely on established technology for control of gaseous emissions, except that this does...

  19. Emission factors of fine particles, carbonaceous aerosols and traces gases from road vehicles: Recent tests in an urban tunnel in the Pearl River Delta, China

    Science.gov (United States)

    Zhang, Yanli; Wang, Xinming; Li, Guanghui; Yang, Weiqiang; Huang, Zhonghui; Zhang, Zhou; Huang, Xinyu; Deng, Wei; Liu, Tengyu; Huang, Zuzhao; Zhang, Zhanyi

    2015-12-01

    Motor vehicles contribute primarily and secondarily to air quality problems due to fine particle (PM2.5) and ozone (O3) pollution in China's megacities. Characterizing vehicle emission with the rapid change of vehicle numbers and fleet compositions is vital for both bottom-up emission survey and top-down source apportioning. To obtain emission factors (EFs) of PM2.5, carbonaceous aerosols and trace gases for road vehicles, in urban Guangzhou we conducted a field campaign in 2014 in the Zhujiang Tunnel, a heavily burdened tunnel with about 40,000 motor vehicles passing through each of its two separated bores per day. PM2.5 and volatile organic compounds (VOCs) were sampled for offline analysis while trace gases including SO2, NOx and CO were measured online and in situ. An eddy covariance system with an integrated 3-D sonic anemometer was also adopted to measure CO2 and winds inside the tunnel. We recorded an average fleet composition of 61% light-duty gasoline vehicles (LDVs) + 12% heavy-duty diesel vehicles (HDVs) + 27% liquefied petroleum gas vehicles (LPGVs), and EFs of 82.7 ± 28.3, 19.3 ± 4.7 and 13.3 ± 3.3 mg veh-1 km-1, respectively, for PM2.5, organic carbon (OC) and elemental carbon (EC). These EFs were respectively 23.4%, 18.3% and 72.3% lower when compared to that measured in the same tunnel in 2004. EFs of PM2.5, OC and EC were higher at night time (148 ± 126, 29 ± 24 and 21 ± 18 mg veh-1 km-1, respectively) due to significantly elevated fractions of HDVs in the traffic fleets. An average ratio of OC to EC 1.45 from this tunnel study was much higher than that of ∼0.5 in previous tunnel studies. The EFs of SO2, NOx, CO, CO2 and NMHCs for road traffic were also obtained from our tunnel tests, and they were 20.7 ± 2.9, (1.29 ± 0.2)E+03, (3.10 ± 0.68)E+03, (3.90 ± 0.49)E+05, and 448 ± 39 mg veh-1 km-1, respectively.

  20. Heterogeneous adsorption behavior of landfill leachate on granular activated carbon revealed by fluorescence excitation emission matrix (EEM)-parallel factor analysis (PARAFAC).

    Science.gov (United States)

    Lee, Sonmin; Hur, Jin

    2016-04-01

    Heterogeneous adsorption behavior of landfill leachate on granular activated carbon (GAC) was investigated by fluorescence excitation-emission matrix (EEM) combined with parallel factor analysis (PARAFAC). The equilibrium adsorption of two leachates on GAC was well described by simple Langmuir and Freundlich isotherm models. More nonlinear isotherm and a slower adsorption rate were found for the leachate with the higher values of specific UV absorbance and humification index, suggesting that the leachate containing more aromatic content and condensed structures might have less accessible sites of GAC surface and a lower degree of diffusive adsorption. Such differences in the adsorption behavior were found even within the bulk leachate as revealed by the dissimilarity in the isotherm and kinetic model parameters between two identified PARAFAC components. For both leachates, terrestrial humic-like fluorescence (C1) component, which is likely associated with relatively large sized and condensed aromatic structures, exhibited a higher isotherm nonlinearity and a slower kinetic rate for GAC adsorption than microbial humic-like (C2) component. Our results were consistent with size exclusion effects, a well-known GAC adsorption mechanism. This study demonstrated the promising benefit of using EEM-PARAFAC for GAC adsorption processes of landfill leachate through fast monitoring of the influent and treated leachate, which can provide valuable information on optimizing treatment processes and predicting further environmental impacts of the treated effluent.

  1. Investigation of the interaction between As and Sb species and dissolved organic matter in the Yangtze Estuary, China, using excitation-emission matrices with parallel factor analysis.

    Science.gov (United States)

    Wang, Ying; Zhang, Di; Shen, Zhen-Yao; Feng, Cheng-Hong; Zhang, Xiao

    2015-02-01

    The interactions between trivalent or pentavalent As/Sb and dissolved organic matter (DOM) in four regions (the river channel, the adjacent coastal area, and the northern and southern nearshore areas) of the Yangtze Estuary, China, were studied using fluorescence quenching titration combined with excitation-emission matrix spectroscopy and parallel factor analysis (PARAFAC). The As/Sb-DOM complexation characteristics were investigated using FTIR and UV absorbance spectroscopy and zeta potential analysis. Four protein-like components and one humic-like component were identified in the DOM from the Yangtze Estuary, China, by PARAFAC analysis. The tryptophan-like substance represented by component 2 was the dominant component and played an important role in the complexation between DOM and As/Sb. The results of complexation modeling demonstrated that the binding capacity of trivalent As/Sb with DOM was higher than that of pentavalent As/Sb with DOM. The DOM from the north nearshore area with the most acidic functional groups and greatest aromaticity possessed the highest binding capacity for trivalent and pentavalent As/Sb. The increase in the UV absorbance and the charge neutralization further indicated the interaction between As/Sb and DOM. The higher binding capacity of Sb(III) with DOM was mainly due to the hydroxyl and carboxyl groups. Our study demonstrates that the use of the advanced EEM-PARAFAC method in fluorescence quenching studies is very useful for evaluating the properties of DOM-pollutant interactions.

  2. CATTELL AND EYSENCK FACTOR SCORES RELATED TO COMREY PERSONALITY FACTORS.

    Science.gov (United States)

    Comrey, A L; Duffy, K E

    1968-10-01

    The Eysenck Personality Inventory, the Cattell 16 PF Inventory, and the Comrey Personality Inventory were administered to 272 volunteers. Eysenck and Cattell factor scores were correlated with scores over homogeneous item groups (FHIDs) which define the Comrey test factors. This matrix was factor analyzed to relate the Eysenck and Cattell factor scores to the factor structure underlying the Comrey test. The Eysenck Neuroticism, Comrey Neuroticism, and Cattell second-order Anxiety factors appeared to match. The Eysenck Introversion and the Comrey Shyness factors also matched. The 16 Cattell primary factors overlapped but did not match with the Comrey factors.

  3. Breast cancer risk factors

    Directory of Open Access Journals (Sweden)

    Marzena Kamińska

    2015-09-01

    Full Text Available Breast cancer is the most frequently diagnosed neoplastic disease in women around menopause often leading to a significant reduction of these women’s ability to function normally in everyday life. The increased breast cancer incidence observed in epidemiological studies in a group of women actively participating in social and professional life implicates the necessity of conducting multidirectional studies in order to identify risk factors associated with the occurrence of this type of neoplasm. Taking the possibility of influencing the neoplastic transformation process in individuals as a criterion, all the risk factors initiating the process can be divided into two groups. The first group would include inherent factors such as age, sex, race, genetic makeup promoting familial occurrence of the neoplastic disease or the occurrence of benign proliferative lesions of the mammary gland. They all constitute independent parameters and do not undergo simple modification in the course of an individual’s life. The second group would include extrinsic factors conditioned by lifestyle, diet or long-term medical intervention such as using oral hormonal contraceptives or hormonal replacement therapy and their influence on the neoplastic process may be modified to a certain degree. Identification of modifiable factors may contribute to development of prevention strategies decreasing breast cancer incidence.

  4. [Prognostic factors in resuscitation].

    Science.gov (United States)

    Bahloul, F; Le Gall, J R; Loirat, P; Alperovitch, A; Patois, E

    1988-10-08

    The outcome from intensive care is known to be influenced by such factors as age, previous health status, severity of the disease and diagnosis. In order to assess the influence of each individual factor, 3,687 patients from 38 French intensive care units were studied. For each patient were recorded: age, simplified acute physiological score (SAPS), previous health status, diagnosis, type of intensive care unit (medicine, scheduled or elective surgery) and immediate outcome. Each of these factors was found to influence the immediate survival rate. A multivariate analysis ranked the factors in the following order: SAPS, age, type of intensive care unit and previous health status. Diagnosis played a role in the prognosis since with a 10-15 points SAPS mortality was nil for drug overdose, 12 per cent for chronic obstructive pulmonary disease and 38 per cent for cardiogenic shock. However, a single diagnosis was made in only 37 per cent of the patients, as against 3 diagnoses in 17 per cent and 4 diagnoses or more in 7 per cent. When the type of intensive care unit was considered, the mean death rate was 20 per cent in medicine, 27 per cent in scheduled surgery and 5 per cent in elective surgery (P less than 0.001). Since this study showed a definite influence of each of the four factors on immediate survival, intensive care patients can be described and classified according to this system. However, it must be stressed that individual prognoses are extremely vague.

  5. Geothermal Plant Capacity Factors

    Energy Technology Data Exchange (ETDEWEB)

    Greg Mines; Jay Nathwani; Christopher Richard; Hillary Hanson; Rachel Wood

    2015-01-01

    The capacity factors recently provided by the Energy Information Administration (EIA) indicated this plant performance metric had declined for geothermal power plants since 2008. Though capacity factor is a term commonly used by geothermal stakeholders to express the ability of a plant to produce power, it is a term frequently misunderstood and in some instances incorrectly used. In this paper we discuss how this capacity factor is defined and utilized by the EIA, including discussion on the information that the EIA requests from operations in their 923 and 860 forms that are submitted both monthly and annually by geothermal operators. A discussion is also provided regarding the entities utilizing the information in the EIA reports, and how those entities can misinterpret the data being supplied by the operators. The intent of the paper is to inform the facility operators as the importance of the accuracy of the data that they provide, and the implications of not providing the correct information.

  6. Multi-factor authentication

    Energy Technology Data Exchange (ETDEWEB)

    Hamlet, Jason R; Pierson, Lyndon G

    2014-10-21

    Detection and deterrence of spoofing of user authentication may be achieved by including a cryptographic fingerprint unit within a hardware device for authenticating a user of the hardware device. The cryptographic fingerprint unit includes an internal physically unclonable function ("PUF") circuit disposed in or on the hardware device, which generates a PUF value. Combining logic is coupled to receive the PUF value, combines the PUF value with one or more other authentication factors to generate a multi-factor authentication value. A key generator is coupled to generate a private key and a public key based on the multi-factor authentication value while a decryptor is coupled to receive an authentication challenge posed to the hardware device and encrypted with the public key and coupled to output a response to the authentication challenge decrypted with the private key.

  7. The focus factor

    DEFF Research Database (Denmark)

    Nicolaisen, Jeppe; Frandsen, Tove Faber

    2015-01-01

    Introduction. We present a new bibliometric indicator to measure journal specialisation over time, named the focus factor. This new indicator is based on bibliographic coupling and counts the percentage of re-citations given in subsequent years. Method. The applicability of the new indicator....... To validate re-citations as caused by specialisation, other possible causes were measured and correlated (obsolescence, journal self-citations and number of references). Results. The results indicate that the focus factor is capable of distinguishing between general and specialised journals and thus...... effectively measures the intended phenomenon (i.e., journal specialisation). Only weak correlations were found between journal re-citations and obsolescence, journal self-citations, and number of references. Conclusions. The focus factor successfully measures journal specialisation over time. Measures based...

  8. La adolescencia: factores criticos

    Directory of Open Access Journals (Sweden)

    Noé Ardila Espinel

    1980-01-01

    Full Text Available Ten factors, tbat are considered by several psychologists as sensitive and characterístíc of the adolescent period, were tested by means of a Lykert type scale of 50 ítems, Seventy-eight subjects divided in three groups (U·13 years, early adolescence; 14·17 years, middle adolescence; 18-22 years, late adolescence answered the scale, Results índicate age differences. The factors that are in conflict duríng the middle adolescente are: emotional control, self control, social behavior, logical thinking, tendeney toward independency, economic índependency, family índependency, relígíous independency, rules conflict,and affective development, The factors change in direction before, during, and after adolescence

  9. Model Correction Factor Method

    DEFF Research Database (Denmark)

    Christensen, Claus; Randrup-Thomsen, Søren; Morsing Johannesen, Johannes

    1997-01-01

    The model correction factor method is proposed as an alternative to traditional polynomial based response surface techniques in structural reliability considering a computationally time consuming limit state procedure as a 'black box'. The class of polynomial functions is replaced by a limit...... statebased on an idealized mechanical model to be adapted to the original limit state by the model correction factor. Reliable approximations are obtained by iterative use of gradient information on the original limit state function analogously to previous response surface approaches. However, the strength...... of the model correction factor method, is that in simpler form not using gradient information on the original limit state function or only using this information once, a drastic reduction of the number of limit state evaluation is obtained together with good approximations on the reliability. Methods...

  10. Orthogonal factorizations of digraphs

    Institute of Scientific and Technical Information of China (English)

    Guizhen LIU

    2009-01-01

    Let G be a digraph with vertex set V(G) and arc set E(G) and let g = (g-,g+) and f = (f-, f+) be pairs of positive integer-valued functions defined on V(G) such that g-(x) ≤ f-(x) and g+(x) ≤ f+(x) for each x ∈ V(G). A (g, f)-factor of G is a spanning subdigraph H of G such that g-(x) ≤ idH(x) ≤ f-(x) and g+(x) ≤ odu(x) ≤ f+(x) for each x ∈ V(H); a (g, f)-factorization of G is a partition of E(G) into arc-disjoint (g, f)-factors. Let = {F1,F2,...,Fm} and H be a factorization and a subdigraph of G, respectively, is called k-orthogonal to H if each FI, 1 ≤ I ≤ m, has exactly k arcs in common with H. In this paper it is proved that every (mg+m-1, mf-m+1)-digraph has a (g, f)-factorization k-orthogonal to any given subdigraph with km arcs if k ≤ min{g-(x),g+(x)} for any x ∈ V(G) and that every (mg, mf)-digraph has a (g, f)-factorization orthogonal to any given directed m-star if 0 ≤ g(x) ≤ f(x) for any x ∈ V(G). The results in this paper are in some sense best possible.

  11. Factores de riesgo psicosocial

    OpenAIRE

    Fernández, Borja

    2012-01-01

    Tras un año de estudio de la Prevención de Riesgos Laborales he podido ir adquiriendo, todavía más, una clara concienciación sobre el estudio, supresión y mejora de los factores de riesgo que afectan a los trabajadores en la ejecución de su trabajo. Algo que es fácil de darse cuenta al entrar en profundidad en estas cuestiones, es de la escasa conciencia que tienen las organizaciones y los trabajadores sobre lo perjudiciales que pueden ser para su salud los factores de riesgo ergonómicos. ...

  12. Graph factors modulo k

    DEFF Research Database (Denmark)

    Thomassen, Carsten

    2014-01-01

    We prove a general result on graph factors modulo k . A special case says that, for each natural number k , every (12k−7)-edge-connected graph with an even number of vertices contains a spanning subgraph in which each vertex has degree congruent to k modulo 2k.......We prove a general result on graph factors modulo k . A special case says that, for each natural number k , every (12k−7)-edge-connected graph with an even number of vertices contains a spanning subgraph in which each vertex has degree congruent to k modulo 2k....

  13. Endodontic surgery prognostic factors.

    Science.gov (United States)

    Azarpazhooh, Amir; Shah, Prakesh S

    2011-01-01

    Medline, (PubMed) and the Cochrane databases together with hand searching of the following journals: Journal of Endodontics, International Endodontic Journal, Oral Surgery Oral Medicine Oral Pathology (name changed to Oral Surgery Oral Medicine Oral Pathology Oral Radiology and Endodontics in 1995), Endodontics and Dental Traumatology (name changed to Dental Traumatology in 2001), Journal of Oral and Maxillofacial Surgery, and International Journal of Oral and Maxillofacial Surgery. Clinical studies evaluating apical surgery with placement of a root-end filling were included. Studies on apical surgery with orthograde root canal filling or about apicectomy alone without root-end filling were excluded, as were experimental and animal studies. Only studies with ≥ ten patients with a minimum six month follow-up period and clearly defined radiographic and clinical healing criteria, with healing reported for at least two categories of a specific prognostic factor were accepted. Studies reporting in English, German, French, Spanish, Italian, Portuguese and Scandinavian languages were included. All studies were assessed separately by two of the three authors, with disagreements resolved by discussion. Prognostic factors were divided into patient related, tooth-related or treatment-related factors. The reported percentages of healed teeth were pooled per category. The statistical method of Mantel-Haenszel was applied to estimate the odds ratios and their 95% confidence intervals. Homogeneity was assessed using Woolf's test. With regard to tooth-related factors, the following were identified as predictors of healing: absence of preoperative pain or signs, good density of the root canal filling and a periapical lesion size of ≤ 5 mm. With regard to treatment-related factors, teeth treated with the use of an endoscope tended to have higher healed rates than teeth treated without the use of an endoscope. Although the clinician may be able to control treatment

  14. STEREOTYPICAL FACTORS IN TOURISM

    Directory of Open Access Journals (Sweden)

    Cristina-Elena ALBU

    2013-06-01

    Full Text Available International tourism has grown rapidly nowdays, contributing to the growth of the global economy. The purpose of this essay is to identify and analyze stereotypical factors in the development of strategies concerning the offer for the tourism industry: the image of a tourist destination, brand, country of origin and customer behaviour. Documentary study was the research method used: representative articles were analysed, as recent as possible, to determine the factors mentioned above. Professionals in the industry of tourism need to understand cultural differences between tourists, as well as those of the host country, to be able to create tourist reception offers that live up to the standards expected by clients.

  15. The transcription factor encyclopedia.

    Science.gov (United States)

    Yusuf, Dimas; Butland, Stefanie L; Swanson, Magdalena I; Bolotin, Eugene; Ticoll, Amy; Cheung, Warren A; Zhang, Xiao Yu Cindy; Dickman, Christopher T D; Fulton, Debra L; Lim, Jonathan S; Schnabl, Jake M; Ramos, Oscar H P; Vasseur-Cognet, Mireille; de Leeuw, Charles N; Simpson, Elizabeth M; Ryffel, Gerhart U; Lam, Eric W-F; Kist, Ralf; Wilson, Miranda S C; Marco-Ferreres, Raquel; Brosens, Jan J; Beccari, Leonardo L; Bovolenta, Paola; Benayoun, Bérénice A; Monteiro, Lara J; Schwenen, Helma D C; Grontved, Lars; Wederell, Elizabeth; Mandrup, Susanne; Veitia, Reiner A; Chakravarthy, Harini; Hoodless, Pamela A; Mancarelli, M Michela; Torbett, Bruce E; Banham, Alison H; Reddy, Sekhar P; Cullum, Rebecca L; Liedtke, Michaela; Tschan, Mario P; Vaz, Michelle; Rizzino, Angie; Zannini, Mariastella; Frietze, Seth; Farnham, Peggy J; Eijkelenboom, Astrid; Brown, Philip J; Laperrière, David; Leprince, Dominique; de Cristofaro, Tiziana; Prince, Kelly L; Putker, Marrit; del Peso, Luis; Camenisch, Gieri; Wenger, Roland H; Mikula, Michal; Rozendaal, Marieke; Mader, Sylvie; Ostrowski, Jerzy; Rhodes, Simon J; Van Rechem, Capucine; Boulay, Gaylor; Olechnowicz, Sam W Z; Breslin, Mary B; Lan, Michael S; Nanan, Kyster K; Wegner, Michael; Hou, Juan; Mullen, Rachel D; Colvin, Stephanie C; Noy, Peter John; Webb, Carol F; Witek, Matthew E; Ferrell, Scott; Daniel, Juliet M; Park, Jason; Waldman, Scott A; Peet, Daniel J; Taggart, Michael; Jayaraman, Padma-Sheela; Karrich, Julien J; Blom, Bianca; Vesuna, Farhad; O'Geen, Henriette; Sun, Yunfu; Gronostajski, Richard M; Woodcroft, Mark W; Hough, Margaret R; Chen, Edwin; Europe-Finner, G Nicholas; Karolczak-Bayatti, Magdalena; Bailey, Jarrod; Hankinson, Oliver; Raman, Venu; LeBrun, David P; Biswal, Shyam; Harvey, Christopher J; DeBruyne, Jason P; Hogenesch, John B; Hevner, Robert F; Héligon, Christophe; Luo, Xin M; Blank, Marissa Cathleen; Millen, Kathleen Joyce; Sharlin, David S; Forrest, Douglas; Dahlman-Wright, Karin; Zhao, Chunyan; Mishima, Yuriko; Sinha, Satrajit; Chakrabarti, Rumela; Portales-Casamar, Elodie; Sladek, Frances M; Bradley, Philip H; Wasserman, Wyeth W

    2012-01-01

    Here we present the Transcription Factor Encyclopedia (TFe), a new web-based compendium of mini review articles on transcription factors (TFs) that is founded on the principles of open access and collaboration. Our consortium of over 100 researchers has collectively contributed over 130 mini review articles on pertinent human, mouse and rat TFs. Notable features of the TFe website include a high-quality PDF generator and web API for programmatic data retrieval. TFe aims to rapidly educate scientists about the TFs they encounter through the delivery of succinct summaries written and vetted by experts in the field. TFe is available at http://www.cisreg.ca/tfe.

  16. The Transcription Factor Encyclopedia

    DEFF Research Database (Denmark)

    Yusuf, Dimas; Butland, Stefanie L; Swanson, Magdalena I

    2012-01-01

    mini review articles on pertinent human, mouse and rat TFs. Notable features of the TFe website include a high-quality PDF generator and web API for programmatic data retrieval. TFe aims to rapidly educate scientists about the TFs they encounter through the delivery of succinct summaries written......ABSTRACT: Here we present the Transcription Factor Encyclopedia (TFe), a new web-based compendium of mini review articles on transcription factors (TFs) that is founded on the principles of open access and collaboration. Our consortium of over 100 researchers has collectively contributed over 130...

  17. Factors stimulating content marketing

    Directory of Open Access Journals (Sweden)

    Naser Azad

    2016-02-01

    Full Text Available This paper presents an empirical investigation to determine factors influencing on content marketing in banking industry. The study designs a questionnaire consists of 40 questions in Likert scale and distributes it among 550 randomly selected regular customers of Bank Mellat in city of Tehran, Iran and 400 properly filled questionnaires are collected. Cronbach alphas for all components of the survey are well above desirable level. Using principle component analysis with Varimax rotation, the study has determined six factors influencing the most on content marketing including organization, details, having new ideas, quality, sensitivity and power while the last component contains only two subcomponents and is removed from the study.

  18. Human factors in network security