Natural Hazards - Groups that are unable to prepare for disasters, or to recover from damage on their own, have a high dependency on government services, which inevitably leads to more government... 相似文献
Understanding contaminant transport in clay-containing soils is critical for accurate prediction of the travel distances of contaminants and for the design and implementation of corresponding remediation plans. This study examined the breakthrough behavior of methylene blue (MB) through sand-illite mixtures using laboratory soil-column experiments at five inlet concentrations, three flow rates, and five illite contents. Kinetic and equilibrium adsorption tests were performed to evaluate the maximum adsorption capacities of the sand and illite used in the soil-column experiments. In addition, the bed efficiency, MB saturation, and adsorption rate were calculated to quantitatively describe the observed breakthrough curves. The observed breakthrough curves, bed efficiencies, MB saturations, and adsorption rates in this study demonstrated the presence of a threshold illite content of ~10% for the adsorption efficiency of contaminants. This implies the need to evaluate the threshold clay content for accurate predictions of contaminant transport through gap-graded clay-containing soils.
Most countries implementing an emissions trading system (ETS), such as EU member states, California in the US, or South Korea, are generally targeting large sized companies, which consume energy above a specific threshold. However, previous studies using computable general equilibrium (CGE) models have analyzed climate policies without considering company size. This may have led to inaccurate results because the impacts of climate policy would differ depending on the coverage of regulated companies. Accordingly, this study examines the environmental and economic impacts of greenhouse gas emission reduction policies, assuming policy results vary by firm size, as covered by the Korean emission trading system. To this end, a CGE model with a separate social accounting matrix based on company size is used to compare three scenarios that reflect different types of carbon pricing methods. The results show that greenhouse gases will be reduced to a lower extent and utility will decrease more if mitigation policies are only imposed to large companies.
Key policy insights
Carbon pricing policies should consider the different impacts on companies of different sizes and industry sectors.
Without considering the different sizes of companies covered by an ETS, the expected carbon price and its economic impact will be underestimated.
Small and medium-sized companies will face more negative impacts than large companies in some industry sectors under an ETS, even if the mitigation burden is only faced by large companies.
In this study, we identified and cloned the sea urchin Hemicentrotus pulcherrimus MT (Hp-MT) mRNA. We examined the gameto- and embryo-toxic effects and the expression of Hp-MT mRNA at various concentrations of phenol in H. pulcherrimus. We found that the normal embryogenesis rate was significantly inhibited when H. pulcherrimus was exposed to phenol (EC50 = 1565.86 ppb, 95% Cl = 1183.47-2037.84 ppb). The no observed effective concentration (NOEC) and the lowest observed effective concentration (LOEC) of the normal embryogenesis rate were < 10 ppb and 100 ppb, respectively. Hp-MT cDNA is 651 bp in length and encodes a protein of 64 amino acids. We found that the expression of Hp-MT mRNA was significantly increased with phenol treatment in a concentrationdependent manner. These results suggest that phenol at greater than 100 ppb has a toxic effect during the early embryonic stages of H. pulcherrimus, and MT mRNA may be used as a biomarker for risk assessment of phenol contamination. 相似文献
Ocean Science Journal - Using a mooring package comprising an acoustic Doppler current profiler (ADCP) and holographic imaging system, a 1-day ice camp study was performed under the Arctic sea ice... 相似文献