Estimating Population Exposure to Fine Particulate Matter in the Conterminous U.S. Using Shape Function-Based Spatiotemporal Interpolation Method: A County Level Analysis

This paper investigates spatiotemporal interpolation methods for the application of air pollution assessment. The air pollutant of interest in this paper is fine particulate matter PM2.5. The choice of the time scale is investigated when applying the shape function-based method. It is found that the measurement scale of the time dimension has an impact on the quality of interpolation results. Based upon the result of 10-fold cross validation, the most effective time scale out of four experimental ones was selected for the PM2.5 interpolation. The paper also estimates the population exposure to the ambient air pollution of PM2.5 at the county-level in the contiguous U.S. in 2009. The interpolated county-level PM2.5 has been linked to 2009 population data and the population with a risky PM2.5 exposure has been estimated. The risky PM2.5 exposure means the PM2.5 concentration exceeding the National Ambient Air Quality Standards. The geographic distribution of the counties with a risky PM2.5 exposure is visualized. This work is essential to understanding the associations between ambient air pollution exposure and population health outcomes

Estimating Population Exposure to Fine Particulate Matter in the Conterminous U.S. using Shape Function-based Spatiotemporal Interpolation Method

This paper investigates spatiotemporal interpolation methods for the application of air pollution assessment. The air pollutant of interest in this paper is fine particulate matter PM2.5. The choice of the time scale is investigated when applying the shape function-based method. It is found that the measurement scale of the time dimension has an impact on the quality of interpolation results. Based upon the result of 10-fold cross validation, the most effective time scale out of four experimental ones was selected for the PM2.5 interpolation. The paper also estimates the population exposure to the ambient air pollution of PM2.5 at the county-level in the contiguous U.S. in 2009. The interpolated county-level PM2.5 has been linked to 2009 population data and the population with a risky PM2.5 exposure has been estimated. The risky PM2.5 exposure means the PM2.5 concentration exceeding the National Ambient Air Quality Standards. The geographic distribution of the counties with a risky PM2.5 exposure is visualized. This work is essential to understanding the associations between ambient air pollution exposure and population health outcomes

New potential carbon emission reduction enterprises in China: deep geological storage of CO2 emitted through industrial usage of coal in China

Deep geological storage of carbon dioxide (CO2) could offer an essential solution to mitigate greenhouse gas emissions from the continued use of fossil fuels. Currently, CO2 capture is both costly and energy intensive; it represents about 60% of the cost of the total carbon capture and storage (CCS) chain which is causing a bottleneck in advancement of CCS in China. This paper proposes capturing CO2 from coal chemical plants where the CO2 is high purity and relatively cheap to collect, thus offering an early opportunity for industrial-scale full-chain CCS implementation. The total amount of high concentration CO2 that will be emitted (or is being emitted) by the coal chemical factories approved by the National Development and Reform Commission described in this paper is 42 million tonnes. If all eight projects could utilize CCS, it would be of great significance for mitigating greenhouse gas emissions in China. Basins which may provide storage sites for captured CO2 in North China are characterized by large sedimentary thicknesses and several sets of reservoir-caprock strata. Some oil fields are nearing depletion and a sub-set of these are potentially suitable for CO2 enhanced oil recovery (EOR) and CCS demonstration but all these still require detailed geological characterization. The short distance between the high concentration CO2 sources and potential storage sites should reduce transport costs and complications. The authors believe these high purity sources coupled with EOR or aquifer storage could offer China an opportunity to lead development in this globally beneficial CCS optio

Effect of Bi-B-Si-Zn-Al glass additive on the properties of low-temperature sintered silicon carbide ceramics

In this study, the performance of low-temperature sintered Bi-B-Si-Zn-Al glass/SiC composites by vacuum hot-press sintering between 700°C and 1000°C was investigated. The specimen had a relatively preferable density of 95.5% and thermal conductivity of 8.660 Wm−1K−1 after sintering at 900°C for 2 h. The dielectric constant and dielectric loss tangle of the composite were 32.9 and 0.57 at 20 GHz, respectively. The XRD analysis indicated the formation of Bi, Zn and ZnAl2O4 crystals, and the microstructure showed the low contact angle of the glass and SiC grain. Such low-temperature sintered SiC ceramic may have a promising application in the electronic field

Spatiotemporal Interpolation Methods for Air Pollution Exposure

This paper investigates spatiotemporal interpolation methods for the application of air pollution assessment The air pollutant of interest in this paper is fine particulate matter PM2.5. The choice of the time scale is investigated when applying the shape function-based method. It is found that the measurement scale of the time dimension has an impact on the interpolation results. Based upon the comparison between the accuracies of interpolation results, the most effective time scale out of four experimental ones was selected for performing the PM interpolation. The paper also evaluates the population exposure to the ambient air pollution of PM2.5 at the county-level in the contiguous U.S. in 2009. The interpolated county-level PM has been linked to 2009 population data and the population with a risky PM exposure has been estimated. The risky PM2.5 exposure means the PM2.5 concentration exceeding the National Ambient Air Quality Standards. The geographic distribution of the counties with a risky PM2.5 exposure is visualized. This work is essential to understanding the associations between ambient air pollution exposure and population health outcomes

The effects of polydimethylsiloxane on transparent and hydrophobic waterborne polyurethane coatings containing polydimethylsiloxane

The effects of polydimethylsiloxane (PDMS) on phase separation, optical transmittance and surface properties including surface composition, morphology and wettability of waterborne polyurethane (WPU) containing PDMS were investigated. After the introduction of PDMS into the WPU backbone by polymerization, the large difference in the solubility parameter of the non-polar PDMS segment and the high-polar urethane segments promoted PDMS enrichment at the air-polymer interface and enhanced phase separation, resulting in rough structures. Accordingly, the combination of PDMS enrichment and the rough structures contributed to the high or superhydrophobic surfaces and the highest contact angle with water achieved was 156.5 degrees. The optical transmittance of the highly hydrophobic coatings reached about 78-87% throughout most of the visible light region. Importantly, the highly hydrophobic and transparent properties will greatly broaden the applications of WPU, showing potential for the environmental protection and industrial applications

preparation of eg-g-mwcnts and antistatic poly(ethylene terephthalate) nanocomposites

Antistatic Poly(ethylene terephthalate) (PET) materials had been successfully prepared through solution-blending incorporation of ethylene glycol-graft-Multi-walled carbon nanotubes (EG-g-MWCNTs). MWCNTs were first carboxylated and then esterified with EG to yield EG-g-MWCNTs. The FT-IR spectra, TEM images, Raman spectra, TGA curves and electrical conductivity were investigated, which indicated that the agglomeration degree of MWCNTs has been reduced and the conductivity keeps as high as 4.278 S/cm after the modification of EG. On the other hand, EG-g-MWCNTs dispersed well in EG, which was one of the synthetic monomers for PET, and thus ensured its good compatibility with PET. As a result, the electrical conductivity of PET/EG-g-MWCNTs nanocomposites (0.1 wt%) was seven orders of magnitude higher than pure PET and reached the antistatic level. © (2011) Trans Tech Publications

A novel three-dimensional boron phosphide network for thermal management of epoxy composites

Recently, construction of effective three-dimensional (3D) heat transfer networks inside polymer has emerged as a promising design strategy to improve the isotropic thermal conductivity for electronic packaging materials. Hexagonal boron nitride (BN) sheets are popular carriers for constructing 3D networks. But removing overheat capability of BN was greatly sacrificed due to size limitation when constructing 3D network. Herein, a novel 3D heat-transferring network, interconnected boron phosphide (BP) grains in-situ growing on Ni foam, was designed to alternate 3D BN network. An isotropic 3D-BP@Ni network with high-quality and integrity was successfully fabricated by a simple high temperature treatment. The synthesized 3D-BP@Ni was incorporated into epoxy resin (ER) by infiltration to fabricate composites. ER/3D-BP@Ni composite, with strong interfacial adhesion between epoxy and 3D-BP@Ni, achieved a high thermal conductivity of 2.01 W/(mK), which corresponded to 908.53% and 402.00% enhancement compared to pure epoxy and ER/Ni composite. The coefficient of thermal expansion (CTE) of the composite reached as low as 26.95×10-6/℃, much smaller than epoxy of 60.69×10-6/℃ and ER/Ni composite of 59.42×10-6/℃. The designed ER/3D-BP@Ni composite has distinguished heat removal and CTE with semiconductors from traditional polymer composites containing 3D BN network. This strategy is promising to promote the development of electrical packaging materials with high isotropic thermal conductivity