Production of polyols and polyurethane from biomass: a review

Environmental Chemistry Letters - Depletion of fossil fuels and climate issues are calling for renewable sources of chemicals such as modern biomass, yet converting biomass into chemicals is...     

Study of the Climate Change Impacts on Water Quality in the Upstream Portion of the Cau River Basin,Vietnam

This paper presents simulations of climate change impacts on water quality in the upstream portion of the Cau River Basin in the North of Vietnam. The integrated modeling system GIBSI was used to simulate hydrological processes, pollutant and sediment wash-off in the river basin, and pollutant transport and transformation in the river network. Three projections for climate change based on emission scenarios B1, B2, and A2 of IPCC Special Report on Emission Scenarios (SRES) were considered. By assuming that the input pollution sources and watershed configuration were constant, based on 2008 data, water quality in the river network was simulated up to the terminal year 2050. For each climate change scenario, patterns of precipitation in wet and dry year were considered. The change in annual and monthly trends for dissolved oxygen (DO), biochemical oxygen demand (BOD), and ammonium ions (NH4+) load and concentration for different portions of the watershed have been analyzed. The results of these simulations show that climate change has more impact on changing the seasonal water quality parameters than on altering the average annual load of the pollutants. The percent change and change pattern in water quality parameters are different for wet and dry year, and the changes in wet year are smaller than those in dry year.     

N-methylcarbamate pesticides and their phenolic degradation products: hydrolytic decay,sequestration and metal complexation studies

We report on the rates of decomposition of a group of N-methylcarbamate (NMC) pesticides (carbaryl, carbofuran and propoxur) under pre-determined tropical field conditions. Rates of decomposition for three NMCs were determined at pH 7.08 and T?=?20?°C and pH 7.70 and T = 33?°C respectively, as follows: carbaryl (78?days and 69?days); carbofuran (143?days and 83?days) and propoxur (116?days and 79?days). Investigation on methods for removal of NMCs and their phenolic decomposition products shows that activated charcoal outperforms zeolite, alumina, diatomaceous earth, cellulose and montmorillonite clay in the removal of both NMCs and phenols from aqueous solution. Furthermore, metal complexation studies on the NMCs and phenols showed that Fe (III) forms a complex with isopropoxyphenol (IPP) within which the Fe:IPP ratio is 1:3, indicative of the formation of a metal chelate complex with the formula Fe(IPP)₃.     

Assessing community vulnerability to floods and hurricanes along the Gulf Coast of the United States

Hurricanes and flooding have affected millions of people and generated massive economic losses over the past several decades. Geographic information system (GIS) methods are employed in this paper to analyse coastal communities' vulnerability to these two hazards along the Gulf Coast of the United States. Specifically, two types of quantitative indicators are developed: (i) exposure to hurricanes and flooding, based on information from multiple sources; and a social vulnerability index, constructed using census data. These indices are combined to depict the spatial patterns of overall community vulnerability to hurricanes and flooding along the US Gulf Coast. The results of this study can potentially inform disaster management agencies, county governments, and municipalities in areas at heightened risk. Furthermore, the demonstration of the geographic distribution of community vulnerability can assist decision-makers in prioritising to-do items and designing policies and plans for the more effective allocation of resources. The paper ends by discussing the study's limitations and its practical implications.     

Strain hardening effect of CF8M stainless steel in the environment fatigue test under pressurized water reactor condition

To develop a fatigue design curve of cast stainless steel CF8M that has been used in piping material of nuclear power plants, a low cycle fatigue tests were conducted in the environment of a pressurized water reactor at 15 MPa and 315 °C. Cylindrical solid fatigue specimens were used for the strain-controlled environmental fatigue tests. Fatigue life was measured in terms of the number of cycles with the variation of strain amplitudes at 0.04%/s strain rate. This paper focuses on the characteristics of the cyclic strain hardening effect caused during environment fatigue tests of the CF8M cast stainless steel. The process and method of correcting fatigue test data in this paper would be so useful to produce reliable data of environmental fatigue curves for the material in operating condition of high pressure and high temperature water environments.     

Chemical diversity and biological activities of essential oils from native populations of Clinopodium menthifolium subsp. ascendens (Jord.) Govaerts

Environmental Science and Pollution Research - This study is focused on the analysis of regional variation of the chemical compositions of three Clinopodium menthifolium subsp. ascendens (Jord.)...     

Application of WRF-Chem to simulate air quality over Northern Vietnam

Environmental Science and Pollution Research - The WRF-Chem (Weather Research and Forecasting with Chemistry) model is implemented and validated against ground-based observations for meteorological...     

Production of plant growth–promoting bacteria inoculants from composting leachate to develop durable agricultural ecosystems

Environmental Science and Pollution Research - Composting process of residual organic material generates considerable amounts of liquid leachate which contains high organic load. This waste stream...     

Aerosol Composition Change due to Dust Storm: Measurements between 1992 and 1999 at Gosan,Korea

Aerosol composition change between dust storm and non duststorm periods is studied using the TSP (Total SuspendedParticulate) data measured at Gosan, Korea between 1992 and1999. The concentrations of elements measured between 1993and 1996 and those of ions between 1992 and 1999 duringdust storms are compared with those during non-dust stormperiods in spring (March, April, and May). Among theanalyzed ions, the concentrations of crustal species(potassium, calcium, magnesium, and chloride) andanthropogenic species (nitrate and non-sea salt (nss)-sulfate) increased when dust storm occurs while those ofammonium and sodium did not increase. Among the analyzedelements, the concentrations of crustal species (Fe, Al,Ca, Ti, and Zn) increased when dust storm occurs whilethose of anthropogenic species (Mn, V, Ni, Cu, Cd, and Cr)did not increase. The only anthropogenic element of whichconcentration increased during dust storm periods was Pb.It was found that the concentrations of nitrate and nss-sulfatewere highest during spring. Also, the ratio of theyearly average concentrations of nitrate to nss-sulfateincreases, probably due to the emission trend change innortheast Asia, especially, in China.