No abstract available.

关键词：大气；气体成分；气候变化；空气分析

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DOD maintains the evidence is inconclusive regarding whether exposure to burn pit emissions creates a long-term health risk for deployed personnel. Contrary to this position, several military professionals maintain the evidence is clear. An Air Force physician at Balad Air Base concurred with a 2006 memorandum and stated: In my professional opinion, the known carcinogens and respiratory sensitizers released into the atmosphere by the burn pit present both an acute and a chronic health hazard to our troops and the local population. A 2011 memorandum from an Army Officer cited evidence that air quality on Bagram Air Field was 'unhealthy' and concluded that the primary contributor was the burn pit. He also listed potential long-term health risks associated with long-term exposure to air conditions such as those found on Bagram. The 2011 memorandum led to a Congressional inquiry and passage of Public Law 112-260 directing the VA to establish an 'Open Air Burn Pit Registry.' This paper will examine studies on exposure to open-air burn pits, look at the recent legislation and potential ramifications for the VA system, and will conclude with a review of technology that might be implemented to abolish open-air burn pits.

关键词：大气；空气污染；空气健康

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Climate projections are essential in order to extend the case-study impacts and vulnerability assessments to encompass future climate change. Thus climate-model based indicators for the future (to 2050 and for the A1B emissions scenario) are presented for the climate and atmosphere theme (including indices of temperature and precipitation extreme events), together with biogeophysical and socioeconomic indicators encompassing the other case-study themes. For the latter, the specific examples presented here include peri-urban fires, air pollution, human health risks, energy demand, alien marine species and tourism (attractiveness and socio-economic consequences). The primary source of information about future climate is the set of global and regional model simulations performed as part of CIRCE. These have the main novel characteristic of incorporating a realistic representation of the Mediterranean Sea including coupling between sea and atmosphere. These projections are inevitably subject to uncertainties relating to unpredictability, model structural uncertainty and value uncertainty. These uncertainties are addressed by taking a multi-model approach, but problems remain, for example, due to a systematic cold bias in the CIRCE models. In the context of the case-study integrated assessments, there are also uncertainties 'downstream' of climate modeling and the construction of climate change projections - largely relating to the modeling of impacts. In addition, there are uncertainties associated with all socio-economic projections used in the case studies - such as population projections. Thus there are uncertainties inherent to all stages of the integrated assessments and it is important to consider all these aspects in the context of adaptation decision making.

关键词：大气；空气污染；未来气候

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We summarize results from comparative simulations of hybrid electric vehicles with either stoichiometric gasoline or diesel engines. Our simulations utilize previously published models of transient engine-out emissions and models of aftertreatment devices.

关键词：大气；废气排放；节能减排

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Carbon capture and storage (CCS) technologies have tremendous potential for reducing carbon dioxide (CO2) emissions and mitigating global climate change. These technologies encourage economic growth and have manageable influence on energy use. Deploying these technologies on a commercial scale will require expanding the workforce, including geologists, engineers, scientists and technicians, trained in CCS specialties.

关键词：大气；温室气体；气体保护

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This project, CRC E-90-2b, was conducted by Southwest Research Institute (SwRI) in order to assess the impact of E10+ blends on MIL illumination and exhaust emissions compliance. The original objectives of this study were to: (1) Document the change in fuel trim and other engine parameters as vehicles operate on a range of ethanol fuels under real-world conditions. (2) Determine if the MIL would illuminate and/or diagnostic trouble codes (DTCs) would be set on potentially sensitive vehicles when exposed to E15 and/or E20. (3) Determine if a vehicle with an illuminated MIL induced by E15 or E20 still meets its emission category target, using a standard cold-start FTP-75 test.

关键词：大气；燃料气体；废气排放

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One of the primary objectives of the Atmospheric Radiation Measurement (ARM) Programs second ARM Mobile Facility (AMF2) is to obtain reliable measurements of radiation (solar, surface, and atmospheric), cloud, and atmospheric properties from ocean-going vessels. To ensure that these climatic measurements are representative and accurate, many AMF2 instrument systems are designed to collect data in a zenith orientation. A pillar of the AMF2 strategy in this effort is the use of a stable platform. The purpose of the platform is to (1) mitigate vessel motion for instruments that require a truly vertical orientation and keep them pointed in the zenith direction and (2) allow for accurate positioning for viewing or shading of the sensors from direct sunlight. Of the numerous ARM instruments that require a zenith orientation, perhaps the most important are the vertically pointing cloud radars, for which vertical motion is a critical parameter.

关键词：大气；气体检测；气候模型

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Increases in the abundance of methane (CH4) in the Earth's atmosphere are responsible for significant radiative forcing of climate change (Forster et al., 2007; Wuebbles and Hayhoe, 2002). Since 1750, a 2.5 fold increase in atmospheric CH4 contributed 0.5 W/m2 to direct radiative forcing and an additional 0.2 W/m2 indirectly through changes in atmospheric chemistry. Next to water and carbon dioxide (CO2), methane is the most abundant greenhouse gas in the troposphere. Additionally, CH4 is significantly more effective as a greenhouse gas on a per molecule basis than is CO2, and increasing atmospheric CH4 has been second only to CO2 in radiative forcing (Forster et al., 2007). The chemical reactivity of CH4 is important to both tropospheric and stratospheric chemistry. Along with carbon monoxide, methane helps control the amount of the hydroxyl radical (OH) in the troposphere where oxidation of CH4 by OH leads to the formation of formaldehyde, carbon monoxide, and ozone.

关键词：大气；甲烷；空气排放

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In April 2012, National Institute for Occupational Safety and Health (NIOSH) researchers and the Silica/Milling-Machines Partnership coordinated by the National Asphalt Pavement Association (NAPA) conducted laboratory testing of a local exhaust ventilation (LEV) system on a Roadtec RX600e cold milling machine. The testing was conducted indoors at the Roadtec manufacturing facility in Chattanooga, Tennessee. All tests were conducted on a stationary milling machine with the cutter drum and conveyor belts moving, but without any reclaimed asphalt pavement (RAP) moving through the system. Smoke and tracer gas were used as surrogates for silica dust to evaluate capture efficiencies of the dust emission-control system in the cutter drum housing of the machine. Smoke was used as an initial qualitative test to visually check for leaks. Sulfur Hexafluoride (SF(6)) was used to quantitatively evaluate capture efficiency of tracer gas released in the cutter drum housing of the machine. Two independent analytical instruments were used to measure the resulting SF(6) concentrations in the LEV exhaust duct, an Innova AirTech Instruments 1412 Photoacoustic field gas-monitor and a Miran SapphIRe infrared spectrometer. Capture efficiency tests were conducted at a single flow rate on the Roadtec cold milling machine. The mean capture efficiency from the Innova AirTech Instruments 1412 Photoacoustic field gas-monitor and Miran SapphIRe data were 98% and 99%, respectively. The lower 95% confidence limits were 97% for both the Innova AirTech Instruments 1412 Photoacoustic field gas-monitor and Miran SapphIRe results. Additional testing during actual milling activities is recommended to document capture efficiency under true field conditions. The testing reported here only evaluated capture efficiency within the cutter drum housing. Other potential dust release locations on the machine such as the transition between the primary and secondary conveyor and the top of the secondary conveyor were not evaluated during this testing but could contribute to silica exposures during actual field operation.

关键词：大气；气体流通；空气健康

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Interest in estimating the air pollutant emissions that occur during highway project construction is increasing. This paper describes a construction emissions modeling framework with companion calculation methodologies. On the basis of bid data and field data collected from a range of highway construction projects, the modeling framework builds linkages between material quantities, equipment in-use hours, and pollutant emissions. The data calculation and processing methodologies can assist project analysts in creating emissions estimates across various construction operations at early environmental assessment stages when, typically, limited data are available for characterizing equipment activity for the future project A hypothetical freeway-widening case study was used to demonstrate the application of the modeling framework and calculation methodologies. The example illustrates the framework's ability to disaggregate emissions by construction operation; in the case analysis, hours of equipment use and emissions were greatest during roadway excavation and foundation work. Project analysts can also vary individual equipment characteristics that affect emissions, such as tier group (emissions certification standards), horsepower rating, equipment deterioration, and other factors in construction emissions analyses. For example, the emissions reduction benefits of shifting the equipment fleet to more stringent (Tier 4) emissions standards, especially as a strategy for reducing particulate emissions, can be quantified.

关键词：大气；空气排放；空气污染

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