The interfacial mass transfer resistances of the ozone dry deposition over the field soil of Taichung County in Taiwan

This study aims to design a dry deposition chamber and to measure ozone depletion over the Taichung field soil. This study seeks to verify the phenomena by an experimental and mathematical model. It is demonstrated that interfacial mass transfer resistances of ozone dry deposition involve reactive resistance (R(sr)) and kinetic resistance (R(sk)). It reveals the chemical reaction (O3 + NO --> NO2) to produce the reactive resistance, and verifies that the interfacial mass transfer resistances depend on nitrogen oxide emission and soil temperature. It shows that the interfacial mass transfer resistances are reduced with increasing soil temperature (T(S)). The model profiles are smaller than the observed data within a relative error of 15%. The reactive resistance decreases exponentially with increasing soil temperature; R(sr)(-1) (cm x sec(-1)) = 0.0001 exp (0.1455T(S)). The kinetic resistance decreases linearly with increasing soil temperature; R(sk)(-1)(cm x sec(-1)) = 0.0108T(S) + 1.4012. This model is more accurate with higher soil temperature and larger ozone concentration. Results are consistent with thermodynamics and reaction kinetics. Ozone dry deposition over agricultural soil causes conversion of nitrogen oxide (NO) to nitrogen dioxide (NO2).     

Technique for aerosol generation with controllable micrometer size distribution

The purpose of this study is to develop an aerosol generating system that can produce particles of micrometer size in a convenient and efficient way. This system is comprised of an ultrasonic atomizer, potassium sodium tartrate tetrahydrate (PST) as solute and a program-controlled solute feeding unit with different PST concentrations. Both the aerosol concentration and size distribution pattern can be easily controlled and reproduced in the developed system. While the initial size of droplets generated from atomizer may remain unchanged, the size of residual dry aerosols was controlled by the solute concentration adjusted by the mixing ratio of solute and water. In addition, PST concentration could be alternatively adjusted in any cyclic way to provide particles with relatively mono-disperse, bimodal, varying size as well as skew distribution to meet requirements for various applications. The main advantage of the generating system is to generate particles of specific size distribution in order to simulate aerosols in ambient air or working places.     

Comparative Toxicity of Copper and Zinc to Isolated Eel Hepatocytes

Attempts were made to elucidate lethal responses of hepatocytes of Japanese eel (Anguilla japonica) exposed to Krebs-HEPES buffer at different concentrations of Cu⁺⁺ and Zn⁺⁺. It was found that the 2-hr LC₅₀ value of Cu⁺⁺ and Zn⁺⁺ on eel hepatocytes was 490 and 1576 μM for Cu⁺⁺ and Zn⁺⁺ in single solution, and 1734 and 5200 μM in mixed solution. the toxic effects of Cu⁺⁺ and Zn⁺⁺ on eel hepatocytes were characteristic of antagonistic interaction. After 2-hr exposure, the amount of accumulated metal on the hepatocytes and the mortality of hepatocytes were increased with increasing metal concentration in Krebs-HEPES buffer. the accumulated amount of both metals was significantly decreased when the eel hepatocytes were exposed to mixed metals than to single metal.     

Earthquake insurance pricing: a risk‐based approach

Flat earthquake premiums are ‘uniformly’ set for a variety of buildings in many countries, neglecting the fact that the risk of damage to buildings by earthquakes is based on a wide range of factors. How these factors influence the insurance premiums is worth being studied further. Proposed herein is a risk‐based approach to estimate the earthquake insurance rates of buildings. Examples of application of the approach to buildings located in Taipei city of Taiwan were examined. Then, the earthquake insurance rates for the buildings investigated were calculated and tabulated. To fulfil insurance rating, the buildings were classified into 15 model building types according to their construction materials and building height. Seismic design levels were also considered in insurance rating in response to the effect of seismic zone and construction years of buildings. This paper may be of interest to insurers, actuaries, and private and public sectors of insurance.