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741.
Andrew Dravnieks Frank Jarke 《Journal of the Air & Waste Management Association (1995)》2013,63(12):1284-1289
Abstract Combustion flue gases of three different industrial boilers firing miscellaneous fuels were monitored for a twoweek period. Nitric oxide (NO), sulfur dioxide (SO2), carbon monoxide (CO), carbon dioxide (CO2), and total hydrocarbons (CxHy) were continuously measured using single-component gas analyzers in parallel with a lowresolution Fourier Transform Infrared (FTIR) gas analyzer. Hydrogen chloride (HCl) was measured continuously using the FTIR analyzer and semi-continuously using a traditional liquid-absorption technique. Nitrous oxide (N2O), nitrogen dioxide (NO2), and water vapor (H2O) were continuously measured using the FTIR analyzer only. Laboratory tests were conducted prior to the field measurements to assess the detection limits of the different measurement methods for each gas component. No significant differences were found between the results of the low-resolution FTIR analyzer and the single-component analyzers or the liquid absorption method. 相似文献
742.
Frank E. Butler Joseph E. Knoll M. Rodney Midgett 《Journal of the Air & Waste Management Association (1995)》2013,63(5):581-584
Techniques were developed to sample and analyze the Cr content of participate samples with emphasis on determining the concentration of the carcinogen Cr+6. Cr+6 is extracted to alkaline solution and analyzed colorimetrically. Residual particles are extracted with acid solution to remove soluble Cr+3, which is determined by atomic absorption spectrometry. This methodology was tested on samples from three diverse types of sources: a ferrochrome smelter, a chemical plant, and a refractory brick plant. Identical quadruplicate samples were collected to determine accuracy and precision of the collection and analysis procedures, and extraction of Cr+6 and Cr+3. A statistical analysis revealed that the precision of Cr+6 analysis is comparable to that of the particulate mass determination. The stability of Cr+6 In particulate form and in solution was determined. Size resolved particulate samples were collected to determine the particle size versus the Cr+6 content. At the ferrochrome smelter and the chemical plant the majority of the Cr+6 was contained in the respirable particles. The accuracy and completeness of the chemical methods employed were verified by neutron activation analysis, x-ray photoelectron spectroscopy, and scanning electron microscopyenergy dispersive x-ray analysis. 相似文献
743.
Soyoung Cha Frank Black Foy King 《Journal of the Air & Waste Management Association (1995)》2013,63(3):252-257
Evaluation of emerging diesel particulate emissions control technology will require analytical procedures capable of continuous or “real-time” measurement of transient organic and elemental carbon emissions. Procedures based on the flame ionlzation properties of organic carbon and the opacity or light extinction properties of elemental carbon are described, and applied for measurement of particulate emissions from diesel engines. The Instrumentation provided adequate sensitivity and time resolution for observation of the transient emissions associated with typical automobile urban driving conditions. Analytical accuracy is evaluated by comparing Integrated average results to measurements using classical gravimetric filtration and solvent extraction procedures. Mass specifc extinction coefficients are evaluated using the Beer-Lambert law. A simplified linear model relating elemental carbon concentration to opacity is also evaluated. 相似文献
744.
Ronald L. Williams Frank Lipari Robert A. Potter 《Journal of the Air & Waste Management Association (1995)》2013,63(5):747-756
Exhaust and evaporative emissions tests were conducted on several methanol- and gasoline-fueled vehicles. Separate samples for chromatographlc analysis of formaldehyde, methanol, and Individual hydrocarbons were collected in each of the three phases of the driving cycle and in each of the two portions of the evaporative emissions test. One vehicle, equipped with an experimental variable-fuel engine, was tested using methanol/gasoline fuel mixtures of 100, 85, 50,15, and 0 percent methanol. Combustion-generated hydrocarbons were lowest using methanol fuel, and increased several-fold as the gasoline fraction was increased. Gasoline components In the exhaust Increased from zero as the gasoline fraction of the fuel was Increased. On the other hand, formaldehyde emissions were several times higher using methanol fuel than they were using gasoline. A dedicated methanol car and the variable-fuel car gave similar emissions patterns when they both were tested using methanol fuel. The organic-carbon composition of the exhaust was 85-90 percent methanol, 5-7 percent formaldehyde, and 3-9 percent hydrocarbons. Several cars that were tested using gasoline emitted similar distributions of hydrocarbons, even through the vehicles represented a broad range of current and developmental engine families and emissions control systems. These vehicles continue the trend of the past twenty years toward less photochemically reactive exhaust, with higher percentages of methane and total alkanes, and correspondingly lower percentages of oleflns and aromatlcs. 相似文献
745.
While adaptation has received a fair amount of attention in the climate change debate, barriers to adaptation are the focus of a more specific, recent discussion. In this discussion, such barriers are generally treated as having a uniform, negative impact on all actors. However, we argue that the precise nature and impact of such barriers on different actors has so far been largely overlooked. Our study of two drought-prone communities in rural Ethiopia sets out to examine how female- and male-headed households adapt to climate change, particularly focusing on how a variety of barriers influence the choice of adaptation measures to varying extents. To this purpose, we built a conceptual framework based on the Sustainable Livelihood Approach. Data were collected using semi-structured interviews and focus group discussions with male- and female-headed households, community leaders and local extension workers. Our findings suggest that gender-based differences in the choice of adaptation measures at the household level are driven by cultural, social, financial and institutional barriers. Barriers to adaptation—particularly when interacting—have a differentiated impact upon different actors. This outcome hints at the need for donors and policymakers to develop intervention strategies that are sensitive to this fact. 相似文献
746.
Steve Kelling Daniel Fink Frank A. La Sorte Alison Johnston Nicholas E. Bruns Wesley M. Hochachka 《Ambio》2015,44(4):601-611
Data from well-designed experiments provide the strongest evidence of causation in biodiversity studies. However, for many species the collection of these data is not scalable to the spatial and temporal extents required to understand patterns at the population level. Only data collected from citizen science projects can gather sufficient quantities of data, but data collected from volunteers are inherently noisy and heterogeneous. Here we describe a ‘Big Data’ approach to improve the data quality in eBird, a global citizen science project that gathers bird observations. First, eBird’s data submission design ensures that all data meet high standards of completeness and accuracy. Second, we take a ‘sensor calibration’ approach to measure individual variation in eBird participant’s ability to detect and identify birds. Third, we use species distribution models to fill in data gaps. Finally, we provide examples of novel analyses exploring population-level patterns in bird distributions. 相似文献
747.
Julian Adolphs Frank Kleinjung Jorge Numata Hans Mielke Klaus Abraham Helmut Schafft Christine Müller-Graf Matthias Greiner 《Chemosphere》2013
When food producing animals are contaminated with PCDD/F congeners, information on the contaminant’s concentration in the bodies of the animals at time of slaughter is needed for risk management purposes. We have developed a mathematical model for the kinetics of PCDD/Fs in growing pigs in case of contaminated feed fed for a limited duration of time. This model allows the prediction of concentrations in body fat. It considers absorption fractions of PCDD/Fs, clearance by metabolism, dilution by growth and excretion through fecal fat. The model parameters were calibrated by fitting the model to experimental data. On the basis of this toxicokinetic model a probabilistic model has been constructed. The probabilistic model handles the parameters with appropriate probability distributions and Monte-Carlo simulation technique, providing for realistic situations with many animals and a range of contaminations and feeding intervals. We applied the new model to describe the German dioxin incident of winter 2010/2011 and discuss its viability as decision tool. The approach demonstrated here is a showcase how a risk assessment in the case of contaminated feeding can be performed. 相似文献
748.
Frank J. Schenck Vinetta Howard‐King 《Journal of environmental science and health. Part. B》2013,48(1):1-12
Abstract A multiresidue solid‐phase extraction (SPE) method for the isolation and subsequent gas Chromatographie determination of organochlorine and organophosphorus pesticide residues in low‐moisture, nonfatty products is described. Residues are extracted from samples with an acetonitrile/water mixture. Cleanup of the extract is performed using graphitized carbon black and anion exchange SPE columns, and analysis is performed by gas chromatography with Hall electrolytic conductivity and flame photometric detection. Recovery data was obtained by fortifying corn, oats and wheat with pesticides. The average recoveries were 79–123% for eight organochlorine and 51–122% for 28 organophosphorus pesticide residues. The limit of quantitation for chlorpyriphos was 0.05 ppm using the Hall electrolytic conductivity detector and <0.005 ppm using the flame photometric detector. 相似文献
749.
Frank F. Scherr Ajit K. Sarmah 《Journal of environmental science and health. Part. B》2013,48(8):763-772
A simple and robust analytical method was developed to simultaneously detect and quantify 17β-estradiol (E2), estrone (E1), 17β-estradiol-3-sulphate (E2-3S), and estrone-3-sulphate (E1-3S) in aqueous solutions (calcium chloride and artificial urine solutions) and agricultural soils using high performance liquid chromatography and UV detection. The standards for all four compounds were linear in the range of 0.01 to 1.0 μg mL?1 (n = 6) and 1.0 to 20 μg mL?1 (n = 6), respectively, with correlation coefficients > 0.999. The on-column limits of detection at an injection volume of 50 μL and S/N (signal: noise) ratio of 3 were: 9.0 ng mL?1, 10 ng mL?1, 5.0 ng mL?1, and 7.0 ng mL?1 for E2-3S, E1-3S, E2 and E1, respectively. The limit of detection and quantification in artificial urine solution and CaCl2 solution was 1.0 ng mL?1 for all four compounds. Method detection limits for the compounds in the 3 soils ranged from 2 to 2.4 ng g?1 (E2-3S and E1-3S), and 1.0 to 2.9 ng g?1 (E2 and E1), respectively. 相似文献
750.
The Concept of Farm Animal Welfare: Citizen Perceptions and Stakeholder Opinion in Flanders, Belgium
Filiep Vanhonacker Wim Verbeke Els Van Poucke Zuzanna Pieniak Griet Nijs Frank Tuyttens 《Journal of Agricultural and Environmental Ethics》2012,25(1):79-101
Several attempts to conceptualize farm animal welfare have been criticized for diverging reasons, among them often the failure
to incorporate the public concern and opinion. This paper’s objective is to develop a conception of farm animal welfare that
starts from the public’s perception and integrates the opinion of different stakeholder representatives, thus following a
fork-to-farm approach. Four qualitative citizen focus group discussions were used to develop a quantitative questionnaire,
which has been completed by a representative sample of Flemish citizens (n = 459). Exploratory and confirmatory factor analyses were applied to develop a conception of farm animal welfare starting
from an extended list of aspects that relate to animal production and associate with farm animal welfare in the public’s perception.
In depth interviews with stakeholder representatives were used to match and adapt the structure of the animal welfare conception
model. The resulting conception revealed seven dimensions grouped in two different levels. Three dimensions were animal-based:
“Suffering and Stress,” “Ability to Engage in Natural Behavior,” and “Animal Health.” Four dimensions were resource-based:
“Housing and Barn climate,” “Transport and Slaughter,” “Feed and Water,” and “Human-Animal Relationship.” This conception
is distinct from earlier attempts since it is based on public perceptions; it addresses the opinion of different stakeholders,
and it distinguishes empirically between animal-based and resource-based dimensions in the conceptualization of farm animal
welfare. The relevancy of a popular definition is supported by the present demand oriented economy, in which animal welfare
is a non-trade concern, and mainly left to the market where consumers still mainly act as individuals who calculate and weigh
pros and cons. 相似文献