From June through August 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 field testing of a vacuum cutting system (VCS) on a Wirtgen W 210i cold milling machine. The tests included 11 total days of air sampling across four different highway construction sites in Wisconsin. At each site, full-shift personal breathing zone sampling for respirable crystalline silica was conducted for the operator and ground man during the course of normal employee work activities. The arithmetic mean respirable crystalline silica exposure for the operator was 0.0071 mg/m3 with an upper 95% confidence limit of 0.011 mg/m3. The arithmetic mean respirable crystalline silica exposure for the ground man was 0.0066 mg/m3 with an upper 95% confidence limit of 0.0093 mg/m3. The geometric mean respirable crystalline silica exposure for the operator was 0.0061 mg/m3 with an upper 95% confidence limit of 0.019 mg/m3. The geometric mean respirable crystalline silica exposure for the ground man was 0.0061 mg/m3 with an upper 95% confidence limit of 0.013 mg/m3. All 22 full-shift personal breathing zone samples collected from the operator and ground man were below currently published regulatory and recommended occupational exposure limits for respirable crystalline silica. Based on the results of this study, NIOSH researchers recommend that Wirtgen should consider making the VCS system a standard feature on all Wirtgen half-lane and larger milling machines. NIOSH researchers also recommend that other manufacturers of half-lane and larger cold milling machines should consider implementing local exhaust ventilation as a control for silica exposures.

关键词：大气；气体防护；气体健康

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Increased demands for cleaner burning energy, coupled with the relatively recent technological advances in accessing unconventional hydrocarbon-rich geologic formations, have led to an intense effort to find and extract natural gas from various underground sources around the country. One of these sources, the Marcellus Shale, located in the Allegheny Plateau, is currently undergoing extensive drilling and production. The technology used to extract gas in the Marcellus Shale is known as hydraulic fracturing and has garnered much attention because of its use of large amounts of fresh water, its use of proprietary fluids for the hydraulic-fracturing process, its potential to release contaminants into the environment, and its potential effect on water resources. Nonetheless, development of natural gas extraction wells in the Marcellus Shale is only part of the overall natural gas story in this area of Pennsylvania. Conventional natural gas wells, which sometimes use the same technique, are commonly located in the same general area as the Marcellus Shale and are frequently developed in clusters across the landscape. The combined effects of these two natural gas extraction methods create potentially serious patterns of disturbance on the landscape. This document quantifies the landscape changes and consequences of natural gas extraction for Somerset County and Westmoreland County in Pennsylvania between 2004 and 2010. Patterns of landscape disturbance related to natural gas extraction activities were collected and digitized using National Agriculture Imagery Program (NAIP) imagery for 2004, 2005/2006, 2008, and 2010. The disturbance patterns were then used to measure changes in land cover and land use using the National Land Cover Database (NLCD) of 2001. A series of landscape metrics is also used to quantify these changes and is included in this publication.

关键词：大气；天然气开采；能源利用

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In 1963, the Atomic Energy Commission (AEC), predecessor to the US Department of Energy (DOE), implemented Operation Roller Coaster on the Tonopah Test Range (TTR) and an adjacent area of the Nevada Test and Training Range (NTTR) (formerly the Nellis Air Force Range (NAFR)). Operation Roller Coaster consisted of four tests in which chemical explosions were detonated in the presence of nuclear devices to assess the dispersal of radionuclides and evaluate the effectiveness of storage structures to contain the ejected radionuclides. These tests resulted in dispersal of plutonium over the ground surface downwind of the test ground zero. Three tests, Clean Slate 1, 2, and 3, were conducted on the TTR in Cactus Flat; the fourth, Double Tracks, was conducted in Stonewall Flat on the NTTR. DOE is working to clean up and close all four sites. Substantial cleaned up has been accomplished at Double Tracks and Clean Slate 1. Cleanup of Clean Slate 2 and 3 is on the DOE planning horizon for some time in the next several years.

关键词：大气；空气检测；气候变化

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The Special Analytical Studies Group at the 222-S Laboratory (222-S) examined the particulate recovered from a series of samples from the annular space of tank 241-AY-102 (AY-102) using solid phase characterization (SPC) methods. These include scanning electron microscopy (SEM) using the ASPEX1 scanning electron microscope, X-ray diffraction (XRD) using the Rigaku2 MiniFlex X-ray diffractometer, and polarized light microscopy (PLM) using the Nikon3 Eclipse Pol optical microscope. The SEM is equipped with an energy dispersive X-ray spectrometer (EDS) to provide chemical information. Gary A. Cooke conducted the SEM analysis, John Pestovich performed the XRD analysis, and Dr. Heinz Huber performed the PLM examination. The results and conclusion of these analyses are presented here.

关键词：大气；空气污染；颗粒物

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The basic principles of the U.S. Environmental Protection Agencys (EPA) Traceability Protocol for the Assay and Certification of Gaseous Calibration Standards (EPA, 1997) were developed jointly by EPA, the National Bureau of Standards (now National Institute of Standards and Technology (NIST)), and specialty gas producers over 30 years ago. At the time, commercially-prepared calibration gases were perceived as being too inaccurate and too unstable for use in calibrations and audits of continuous source emission monitors and ambient air quality monitors. The protocol was developed to improve their quality by establishing their traceability to NIST Standard Reference Materials (SRMs) and to provide reasonably priced products. This protocol established the gas metrological procedures for measurement and certification of these calibration gases for EPA's Acid Rain Program under 40 Code of Federal Regulations (CFR) Part 75, for the Ambient Air Quality Monitoring Program under 40 CFR Part 58, and for the Source Testing Program under 40 CFR Parts 60, 61, and 68. EPA required monitoring organizations implementing these programs (the regulated community) to use EPA Protocol Gases as their calibration gases. EPA revised the protocol to establish detailed statistical procedures for estimating the total uncertainty of these gases. EPA's Acid Rain Program developed acceptance criteria for the uncertainty estimate.

关键词：大气；气体成分；大气 保护

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This chapter presents the design of a system of fuzzy controllers for a differential mobile robot that was developed to navigate in outdoors environments over a predetermined route from point A to point B without human intervention. The mobile robot has the main features of geo-navigation to obtain its current position during the navigation, obstacles detection and the avoidance of these obstacles in an autonomous form. In this work to achieve the autonomous navigation in real-time, it was necessary to design a system based on fuzzy controllers. The system performs the detection and the analysis of the surrounding environment of the mobile robot to take actions that allow achieving the target point in a safe way. The position and orientation of the mobile robot is achieved with the use of geographical coordinates, through a GPS and the use of a magnetic compass which determines the steering angle. The detection of the environment is through ultrasonic sensors mounted on the mobile robot. All the inputs are taken by the system to compute through fuzzy rules the motion control of the mobile robot, to estimate the position and orientation accurately and to control the speed of the two DC motors to drive the wheels. In this work, the experiments were performed in dynamic outdoors environments, where the mobile robot performed successfully the navigation and the obstacles avoidance. In all the experiments, the mobile robot achieved its mission to reach the target position without human intervention; the results show the validity of the developed system. The experimental framework, experiments and results are explained in terms of performance and accuracy.

关键词：模糊控制器；移动机器人；地理导航

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Owing to industrial and social requirements, but also to technical and scientific progress, the food processing industry is facing new challenges: a wide diversification of processing equipment and the emergence of new food matrices which are more and more complex. In the meantime, the choice of technologies and processes should achieve the following goals: (ⅰ) to ensure the microbiological security of a given product up to a date limit; (ⅱ) to improve product quality through better control and understanding of the process and (ⅲ) to enhance the competitiveness and reliability of the process.

关键词：能源效率；欧姆加热过程；控制器

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After more than a decade of producing a nominal 10 km aerosol product based on the dark target method, the MODIS aerosol team will be releasing a nominal 3 km product as part of their Collection 6 release. The new product differs from the original 10 km product only in the manner in which reflectance pixels are ingested, organized and selected by the aerosol algorithm. Overall, the 3 km product closely mirrors the 10 km product. However, the finer resolution product is able to retrieve over ocean closer to islands and coastlines, and is better able to resolve fine aerosol features such as smoke plumes over both ocean and land. In some situations, it provides retrievals over entire regions that the 10 km product barely samples. In situations traditionally difficult for the dark target algorithm, such as over bright or urban surfaces the 3 km product introduces isolated spikes of artificially high aerosol optical depth (AOD) that the 10 km algorithm avoids. Over land, globally, the 3 km product appears to be 0.01 to 0.02 higher than the 10 km product, while over ocean, the 3 km algorithm is retrieving a proportionally greater number of very low aerosol loading situations. Based on collocations with ground-based observations for only six months, expected errors associated with the 3 km land product are determined to be greater than for the 10 km product: 0.05 0.25 AOD. Over ocean, the suggestion is for expected errors to be the same as the 10 km product: 0.03 0.05 AOD. The advantage of the product is on the local scale, which will require continued evaluation not addressed here. Nevertheless, the new 3 km product is expected to provide important information complementary to existing satellite-derived products and become an important tool for the aerosol community.

关键词：大气；气溶胶；空气治理

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This document consists of eight papers that explore the transport of toxic inhalation hazard materials, carbon dioxide and sulfur oxides emissions from container shipping, transportation asset sensitivity to extreme weather events and climate change, damage to offshore pipeline by ship factors, safety risk analysis of maritime transportation, spatial analysis of maritime accidents, human behavior in vessel maneuver simulations, and mariner near misses and design.

关键词：大气；人类活动；空气变化

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The HHE Program evaluated exposures to volatile organic compounds, mold, airborne particles, and formaldehyde in the autopsy suite, histology laboratory, and toxicology laboratory at a medical examiner's office.

关键词：大气；室内气体；气体健康

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