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A preliminary investigation was carried out by the US Environmental Protection Agency (EPA) on the impact of regional ozone concentrations on climate change in the country. The main objective of the investigation was to enhance the ability of air quality managers to consider global change in their decisions through improved characterization of the potential effects of global change on air quality, including O3, PM, and Hg. An integrated assessment framework was designed that supported the research and development efforts within the EPA and the academic research professionals. This design recognized the challenges of bridging spatial scales, temporal scales, and disciplines that characterize the global change and regional air quality problem. A major component of the assessment approach involved the development and application of global to regional climate and air quality modeling systems.

Magnetoresistive effects were studied in ρ-type heteroepitaxial diamond films with a strip or Corbino disk structure in a magnetic field ranging from 0 to 5 T. The films were grown by microwave plasma chemical vapor deposition and boron doped by cold ion implantation and rapid thermal annealing. The experimental results show that the magnetoresistance (MGR) of ρ-type heteroepitaxial diamond films strongly depends on the geometric form of the samples and the magnetic field. Diamond films are assumed to be an isotropic isothermal solid in which conduction is by holes from light, heavy and split-off bands. Based on the Fuchs and Sondheimer thin-film theory, considering spherical energy surfaces and mixed scattering by lattice vibrations and ionized impurities and surface, a theoretical description of the magnetoresistive effect in diamond films is presented by solving the Boltzmann transport equation in the relaxation time approximation. A relationship between the MGR and the thickness of films, magnetic field, and mobility is shown. [ABSTRACT FROM AUTHOR]

Modeling of soil nitric oxide (NO) emissions is highly uncertain and may misrepresent its spatial and temporal distribution. This study builds upon a recently introduced parameterization to improve the timing and spatial distribution of soil NO emission estimates in the Community Multiscale Air Quality (CMAQ) model. The parameterization considers soil parameters, meteorology, land use, and mineral nitrogen (N) availability to estimate NO emissions. We incorporate daily year-specific fertilizer data from the Environmental Policy Integrated Climate (EPIC) agricultural model to replace the annual generic data of the initial parameterization, and use a 12 km resolution soil biome map over the continental USA. CMAQ modeling for July 2011 shows slight differences in model performance in simulating fine particulate matter and ozone from Interagency Monitoring of Protected Visual Environments (IMPROVE) and Clean Air Status and Trends Network (CASTNET) sites and NO2 columns from Ozone Monitoring Instrument (OMI) satellite retrievals. We also simulate how the change in soil NO emissions scheme affects the expected O3 response to projected emissions reductions. [ABSTRACT FROM AUTHOR]

Wax emulsions were prepared by using paraffin wax and oxidized wax as raw materials, compound Wb-L as emulsifier, and C5petroleum resin as stabilizer. Its performance was studied. The results showed that whenMC5 petroleum resin r/Mwax and oxidized wax= 0.20,Memulsifier/Mwax and oxidized wax= 0.50,Mwater/Mwax and oxidized wax= 2.50, emulsifying time was 30 min, emulsifying temperature was 90–95°C, and stirring speed was 1,100 r/min, wax emulsions with good stability, dispersibility, and monodisperse particle size were obtained, giving a preservative solution in pencil board production. [ABSTRACT FROM AUTHOR]

This paper provides a synthesis of results that have emerged from recent modeling studies of the potential sensitivity of U.S. regional ozone (O3) concentrations to global climate change (ca. 2050). This research has been carried out under the auspices of an ongoing U.S. Environmental Protection Agency (EPA) assessment effort to increase scientific understanding of the multiple complex interactions among climate, emissions, atmospheric chemistry, and air quality. The ultimate goal is to enhance the ability of air quality managers to consider global change in their decisions through improved characterization of the potential effects of global change on air quality, including O3. The results discussed here are interim, representing the first phase of the EPA assessment. The aim in this first phase was to consider the effects of climate change alone on air quality, without accompanying changes in anthropogenic emissions of precursor pollutants. Across all of the modeling experiments carried out by the different groups, simulated global climate change causes increases of a few to several parts per billion (ppb) in summertime mean maximum daily 8-h average O3 concentrations over substantial regions of the country. The different modeling experiments in general do not, however, simulate the same regional patterns of change. These differences seem to result largely from variations in the simulated patterns of changes in key meteorological drivers, such as temperature and surface insolation. How isoprene nitrate chemistry is represented in the different modeling systems is an additional critical factor in the simulated O3 response to climate change., Engineering and Applied Sciences

In this paper, the micro-structure and laser damage threshold of nano-ZrO2 thin films were investigated. High-purity nano-ZrO2 particles as the coating materials of samples were prepared by the electron beams evaporation. The micro-structure and crystallitic size of samples were analyzed by X-ray diffraction, a laser by 1064nm, 10ns, 3Hz Nd:YAG laser damage test each for nano-ZrO2 films. The results showed that oxygen partial pressure has an important influence on the micro-structure of nano-ZrO2 films, also found that the crystallitic size and different micro-structure influenced the laser damage threshold. The obtained results showed that laser damage threshold of polycrystalline structure is obviously higher than that of amorphous structure. [ABSTRACT FROM AUTHOR]