Association Between Diurnal Temperature Range and Respiratory Tract Infections

Objective This study aimed to assess the association between emergency-room visits for respiratory tract infection （RTI） with diurnal temperature range （DTR）, a weather parameter closely associated with urbanization and global climate change. Methods We conducted a semiparametric time-series analysis to estimate the percentage increase in emergency-room visits for RTI associated with changes in DTR after adjustment for daily weather conditions （temperature and relative humidity） and outdoor air pollution. Results DTR was significantly associated with daily emergency-room visits for RTI. An increase of 1 ~C in the current-day （LO） and in the 2-day moving average （L01） DTR corresponded to a 0.94% [95% confidence interval （CI）, 0.34%-1.55%] and 2.08% （95% CI, 1.24%-2.93%） increase in emergency-room visits for RTI, respectively. Conclusion DTR was associated with increased risk of RTI. More studies are needed to understand the impact of DTR on respiratory health.

Conversion of NO with a catalytic packedbed dielectric barrier discharge reactor

This paper discusses the conversion of nitric oxide（NO） with a low-temperature plasma induced by a catalytic packed-bed dielectric barrier discharge（DBD） reactor. Alumina oxide（Al2O3）,glass（SiO2） and zirconium oxide（ZrO2）, three different spherical packed materials of the same size, were each present in the DBD reactor. The NO conversion under varying input voltage and specific energy density, and the effects of catalysts（titanium dioxide（TiO2） and manganese oxide（Mn Ox） coated on Al2O3） on NO conversion were investigated. The experimental results showed that NO conversion was greatly enhanced in the presence of packed materials in the reactor, and the catalytic packed bed of Mn Ox/Al2O3 showed better performance than that of TiO2/Al2O3. The surface and crystal structures of the materials and catalysts were characterized through scanning electron microscopy analysis. The final products were clearly observed by a Fourier transform infrared spectrometer and provided a better understanding of NO conversion.

NO reduction using low-temperature SCR assisted by a DBD method

This paper discusses the removal of nitric oxide （NO） with low-temperature selective catalytic reduction driven by a dielectric barrier discharge with ammonia （NH3） as a reductant. We explored the effects of NH3, O2, temperature and water under different applied voltage on NO removal at atmospheric pressure. The results showed that when the gas concentration ration of NH3/NO was 0.23-0.67, the NO removal efficiency and the energy consumption was acceptable. The NO removal efficiency reached 84% under an applied voltage of 7 kV, 400 ppm NO and 90 ppm NH3 at a temperature of 150 ℃. Water vapor had a negative effect because NO formation reactions were strengthened and NH3 was oxidized directly rather than reduced NO molecules. The outlet gas components were observed via Fourier transform infrared spectroscopy for revealing the decomposition process and mechanism.

Optical properties and chemical composition of PM_(2.5) in Shanghai in the spring of 2012

The semi-diurnal mean aerosol mass concentration, chemical composition, and optical properties of PM2.s were investigated in Shanghai during the spring of 2012. Slight pollution was observed during the study period. The average PM2.s concentration was 64.11± 22.83μg/m3. The mean coefficients of extinction, scattering, and absorption at 532 nm were 125.9 ± 78.5, 91.1 ± 56.3, and 34.9 ±23.6 Mm-1, respectively. A relatively low mean single scattering alhedo at 532 nm （0.73 ±0.04） and low level of elemental carbon （EC, 2.67± 1.96 μg/m3） suggested that the light absorption was enhanced due to the internal mixing of the EC. Sulfate contributed the most to aerosol light scattering in Shanghai. The chemical composition of PM2.5 was dominated by particulate organic matter, sulfate, nitrate, ammonium, and EC. Anthropogenic sources made a significant contribution to the emission and loading of the particulate pollutants. A relatively good correlation between the aerosol chemical composition and the cloud condensation nuclei （CCN） activation indicated that aerosol chemistry is an important factor that influences the saturated hygroscopicity and growth of the aerosol.