The overall goal of the project was to bridge the gap between our knowledge of small-scale geochemical reaction rates and reaction rates meaningful for modeling transport at core scales. The working hypothesis was that reaction rates, determined from laboratory measurements based upon reactions typically conducted in well mixed batch reactors using pulverized reactive media may be significantly changed in in situ porous media flow due to rock microstructure heterogeneity. Specifically we hypothesized that, generally, reactive mineral surfaces are not uniformly accessible to reactive fluids due to the random deposition of mineral grains and to the variation in flow rates within a pore network. Expected bulk reaction rates would therefore have to be correctly up-scaled to reflect such heterogeneity. The specific objective was to develop a computational tool that integrates existing measurement capabilities with pore-scale network models of fluid flow and reactive transport. The existing measurement capabilities to be integrated consisted of (a) pore space morphology, (b) rock mineralogy, and (c) geochemical reaction rates. The objective was accomplished by: (1) characterizing sedimentary sandstone rock morphology using X-ray computed microtomography, (2) mapping rock mineralogy using back-scattered electron microscopy (BSE), X-ray dispersive spectroscopy (EDX) and CMT, (3) characterizing pore-accessible reactive mineral surface area, and (4) creating network models to model acidic CO(sub 2) saturated brine injection into the sandstone rock samples.

关键词：大气；二氧化碳；温室气体

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We attempted to image atmospheric fluorescence in the short-wave infrared (SWIR) from several radioactive sources. Our detection system was an InGaAs camera, fitted with a 25 mm lens to image the scene. No definitive fluorescence was detected. We also used our system to observe the SWIR emission from a proton beam source and established certain criteria for use as fluorescence diagnostics. For example, we clearly observed an enhancement at 1050 nm relative to 1600 nm, consistent with known emission features of molecular nitrogen and with previously published results. However, even for a high activity cobalt-60 source, our recorded signal was not consistent with these diagnostics. Rather, we hypothesize that the small signal which was recorded may have been due to direct incidence of gamma rays on our detector. Compared with the ultraviolet (UV), the infrared emission is expected to be only 20% as bright. We suggest that to increase the signal to noise in the SWIR may require either a telescope to collect a greater fraction of the emission or to image a more localized source than the gamma emission. Further research should include coincident UV and SWIR observations.

关键词：大气；气候变化；空气治理

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In recent years, attention has been given to the processes controlling the emission of oily effluents and their environmental impact. Many industrial processes generate large volumes of water contaminated with oil, called oily waters. The oily water must be treated before its discard in order to meet the criteria established by environmental agencies (for example in Brazil, 20 mg/L). In present days, the process of separating oil/water with ceramic membranes has attracted the attention of many researchers. In this sense, the aim of this study is to evaluate the influence of the tangential inlet shape in the oil/water separation via ceramic membranes. We use a mathematical multiphase flow model to describe the oil-water separation, based on the particle model. Here oil is the dispersed phase while water the continuous phase. To model the turbulence effect we use the RNG κ-ε model. All simulations were carried out using the Ansys CFX ? commercial code. Results of streamlines and velocity, pressure and volume fraction of phase fields are present and analyzed. The numerical results indicate that no significant difference when using a circular or rectangular pipe with the same cross-sectional area.

关键词：陶瓷膜；分离油/水；数值模拟；CFX

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Sandia National Laboratories/New Mexico's (SNL/NM) Environmental Management System is the integrated approach for members of the workforce to identify and manage environmental risks. Each Fiscal Year (FY) SNL/NM performs an analysis to identify environmental aspects, and the environmental programs associated with them are charged with the task of routinely monitoring and measuring the objectives and targets that are established to mitigate potential impacts of SNL/NMs operations on the environment. An annual summary of the results achieved towards meeting established objectives and targets provides a connection to, and rational for, annually revised environmental aspects. The purpose of this document is to summarize the results achieved and documented in FY2012.

关键词：大气；空气污染；空气健康；空气防护

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In August 2012, the U.S. Environmental Protection Agency (EPA) and the National Highway Traffic Safety Administration (NHTSA) announced the final standard governing new-vehicle fuel economy for model years 2017 through 2025. The new standard maintains the current system of incremental increases in Corporate Average Fuel Economy (CAFE) requirements for new light-duty vehicles each model year, based on targeted decreases averaging approximately 5% per year in CO2 output per mile. This report compares the recent improvements in fuel economy with the projected CAFE performance levels anticipated by NHTSA. Recent trends in CAFE performance, when compared with the performance levels projected to be achieved by NHTSA, indicate that achieved CAFE performance has exceeded these anticipated levels for 2012 and 2013 model years--the two years that the current standard has been in effect. Additionally, achieved CAFE performance has consistently increased annually from model year 2008 through model year 2013. If the current trends in annual improvements continue, future CAFE performance is expected to continue meeting or exceeding the projected performance levels (and desired greenhouse gas reductions) contained in the latest CAFE standards.

关键词：大气；空气污染；空气健康

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A program was initiated in June 2009 to evaluate the potential of porous organosilicate sorbents in the capture or neutralization of light gas threats. Of primary interest were targets identified by the TIC/TIM Task Force as priority threats. A number of approaches were taken for increasing binding capacity and reactivity in the sorbent materials: grafting of metalloporphyrins, incorporation of sites for metal coordination, and incorporation of acidic and basic groups. In addition, the impact of morphological considerations, such as pore size and organization, were evaluated. Target capture by the sorbents was evaluated using microbreakthrough testing completed at the Edgewood Chemical Biological Center. Development of relevant sorbent morphologies was also pursued. Overall, the sorbents show promise, with several offering improvements in target capture and retention over state-of-the-art materials.

关键词：大气；空气污染；空气净化

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Most climate scientists agree that humans are accelerating a change in the Earths climate through the emission of greenhouse gases (GHG). In response, governments and organizations in the United States at the state, regional, and local levels have been enacting policies aimed at reducing energy consumption and GHG emissions. These policies typically include an overall emissions reduction target for a city, a state, or an agency. To meet reduction targets, some agencies and organizations are developing plans and strategies that are often disaggregated by emissions sources. Transportation, surface transportation in particular, is one of the most significant sources of GHG emissions: About 29% of all U.S. GHG emissions are from transportation, and emissions are expected to increase, as can be seen in Figure 1. So far, the most common transportation-related response to reduce GHG emissions and promote energy security through reduced energy consumption has focused on four core strategies: reduce vehicle miles traveled (VMT), reduce carbon intensity of fuels, improve vehicle efficiency, and improve overall operational efficiency of the surface transportation system. Several of these strategies would require federal policy changes, namely advancements in vehicle technology and further regulation of fuel sources. However, transportation agencies at the state and local levels have more control over reducing VMT and improving the operational efficiency of the surface transportation system since they own, operate, and regulate much of the nations transportation system. Systematically incorporating GHG emissions into transportation planning and decision making can lead to successful strategies and plans for mitigation.

关键词：大气；温室气体；全球变暖

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The greenhouse gas (GHG) nitrous oxide (N2O) is produced by soil microorganisms. Nitrogen (N) inputs, soil moisture and carbon stimulate the production of this gas, which accounts for about one third of all GHGs from Californias agriculture sector. Nitrogen inputs, crop N removal, and cumulative N2O emissions were measured from spring 2011 to fall 2012 in three dairy forage production systems receiving liquid and solid manure, as well as synthetic N fertilizer. The annual N2O emissions ranged from 4.87.4 kg N2O-N (mass of N in the form of N2O) ha-1 from sites with sandy soil (>70% sand) and from 11.416.5 kg N2O-N ha-1 in clayey soils (>40% clay) and were comparable to those of similar systems in other regions (1.213.8 kg N loss as N2O) although the California systems received higher N inputs (694-1281 kg N ha-1) than those systems (150225 kg N ha-1). The periods of N2O release after irrigation events were longer (weeks) in a clayey than in sandy soils (days). Nitrous oxide fluxes up to 1.4 kg N2O-N ha-1 d-1 were recorded after large applications of synthetic N fertilizer (>100 kg N ha-1) whereas moderate additions of liquid manure and/or synthetic N fertilizer supplied together with the irrigation water resulted in lower, albeit consistent, N2O emissions of up to 100 g N2O-N ha-1 d-1. To lower N2O emission potential, applying N incrementally in moderate doses with the irrigation water according to crop N demand is recommended.

关键词：大气；空气污染；空气治理

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The U.S. Consumer Product Safety Commission (CPSC) and others are concerned about the hazard of acute residential carbon monoxide (CO) exposures from portable gasoline powered generators that can result in death or serious adverse health effects in exposed individuals. CPSC databases contain records of 755 deaths from CO poisoning associated with consumer use of generators in the period of 1999 through 2011, with nearly three-quarters of those occurring between 2005 and 2011. The majority of these incidents occur during power outages, or when a generator is used to provide power to a structure that is not wired for electrical power. Typically, these deaths occur when consumers use a generator in an enclosed or partially enclosed space or outdoors near an open door, window or vent. While avoiding the operation of such generators in or near a home is expected to reduce indoor CO exposures significantly, it may not be realistic to expect such usage to be eliminated completely. Another means of reducing these exposures would be to decrease the amount of CO emitted from these devices. In order to support life-safety based analyses of potential CO emission limits, a computer simulation study was conducted to evaluate indoor CO exposures as a function of generator source location and CO emission rate. These simulations employed the multizone airflow and contaminant transport model CONTAM, which was applied to a collection of 87 single-family, detached dwellings that are representative of the U.S. housing stock for that housing type. A total of almost one hundred thousand individual 24-hour simulations were conducted. This report presents the simulation results in terms of the maximum levels of carboxyhemoglobin that would be experienced by occupants in the occupied portions of the dwellings as a function of CO emission rate for different indoor source locations.

关键词：大气；一氧化碳泄露；室内空气健康

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The welding process results in the formation of high concentrations of nano-sized particles loaded with toxic metals such as hexavalent chromium (Cr6+), nickel (Ni), and manganese (Mn). Welding fumes pose serious health risks to welders because fumes can cause respiratory and neurological ailments as well as cancer. Tightened occupational standards require an exposure reduction of at least 90% that is not satisfied by current control technologies. There is also potential public concern about the environmental risks associated with the release of welding fumes into ambient air. The overall objective of this demonstration was to develop an innovative silica precursor technology that can limit the oxidation of chromium by quenching oxygen species and coating metal particles in welding fumes with a thin, amorphous silica layer. An additional objective was to assess the benefit of increased particle size distribution. The demonstration verified the feasibility and practicality of implementing silica precursor technology into DOD welding operations. Silica precursor technology was demonstrated to be an effective means of controlling metal emissions in welding fumes. The two-fold approach of limiting oxidation potential and coating metal particles with an amorphous silica layer goes beyond previous control technologies by addressing all the toxic metals, regardless of their oxidation state. This project demonstrated, through both a laboratory study and field tests, the benefits of adding silica precursor during the welding process.

关键词：大气；空气污染；空气健康

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