Synthesis of Soy-Polyol by Two Step Continuous Route and Development of Soy-Based Polyurethane Foam

Soy-polyol has been synthesized via a low energy two-step continuous route thus avoiding intermediate steps and chemicals. The functional groups of soy-polyol thus produced were identified by Fourier transform infrared (FTIR) spectroscopy which confirmed the cleavage of the double bonds, the formation of new epoxy linkages and the presence of hydroxyl groups. The change in chemical structure and physical properties of the soy polyol was further characterized and the results indicated a successful conversion with reduced unsaturation, increased hydroxyl number and increased viscosity. Polyurethane foam was prepared from soy-polyol using isocyanate and thermogravimetric analysis was used to study its thermal decomposition behaviour. Multiple transitions were identified in relation to depolymerization and bond dissociation. Density and compressive strength of the soy-foam were found to be satisfactory. An investigation of microstructure of soy foam by scanning electron microscope and X-ray computed tomography revealed the internal cell morphology and cell structure.     

Phytoremediation of arsenic in mining‐contaminated areas: The future of transgenic technology

A considerable number of contaminated mining sites in Europe and other parts of the world pose environmental hazards. Given the multifaceted benefits of phytoremediation, screening of plant communities grown in contaminated areas is being conducted to identify hyperaccumulating plant species. A few arsenic (As) hyperaccumulating plants are found in tropical countries; however, generally, they are not grown in contaminated mining sites of cold and temperate countries (Europe and other parts of the world). The transgenic plants identified to date are not believed to be suitable for commercial use of phytoremediation. A few tolerant plant species in mining sites that are found to have elevated As levels primarily concentrate As in their roots. The remediation potential of many of these tolerant plants is limited because of their slow growth and low biomass. Therefore, phytostabilization of contaminated mining sites using tolerant plant species with high biomass and a more extensive root system is the only solution to date in Europe and some other parts of the world. © 2010 Wiley Periodicals, Inc.     

Electrical resistance heating of volatile organic compounds in Sedimentary rock

Electrical resistance heating (ERH) has become a common method of remediation for volatile organic compounds (VOCs) in unconsolidated soils, both above and below the water table. Recently, use of ERH has expanded to include treatment of contaminated sedimentary bedrock. This article describes the implementation issues for rock remediation and provides case studies of three sites remediated by ERH in Maryland, New Jersey, and Indiana. With proper design, remediation of bedrock can be as effectively completed as remediation of overburden materials. © 2010 Wiley Periodicals, Inc.     

Properties of alkali-activated systems with stone powder sludge

This article investigates the effects of stone powder sludge on the microstructure and strength development of alkali-activated fly ash and blast furnace slag mixes. Stone powder sludge produced from a crushed aggregate factory was used to replace fly ash and granulated blast furnace slag at replacement ratios of 0%, 10%, 20%, and 30% by mass. The unit weight and compressive strength of the samples were measured, and scanning electron microscopy/energy dispersive spectroscopy and X-ray diffraction (XRD) analyses were performed. The test results indicated that the compressive strength of alkali-activated blast furnace slag mixes using stone powder sludge was higher than that of the alkali-activated blast furnace slag control mix, but the compressive strength of alkali-activated fly ash mixes decreased with increasing replacement ratio of stone powder sludge. Microscopy results indicated that for alkaliactivated blast furnace slag samples, broken surfaces were more evident than for the alkali-activated fly ash samples. For all XRD diagrams, broad and diffuse peaks were observed around 2θ = 35° (d = 2.96–3.03 Å), implying amorphous or short-ordering structure phases.     

Assessing computer waste generation in Chile using material flow analysis

The quantities of e-waste are expected to increase sharply in Chile. The purpose of this paper is to provide a quantitative data basis on generated e-waste quantities. A material flow analysis was carried out assessing the generation of e-waste from computer equipment (desktop and laptop PCs as well as CRT and LCD-monitors). Import and sales data were collected from the Chilean Customs database as well as from publications by the International Data Corporation. A survey was conducted to determine consumers’ choices with respect to storage, re-use and disposal of computer equipment. The generation of e-waste was assessed in a baseline as well as upper and lower scenarios until 2020.The results for the baseline scenario show that about 10,000 and 20,000 tons of computer waste may be generated in the years 2010 and 2020, respectively. The cumulative e-waste generation will be four to five times higher in the upcoming decade (2010–2019) than during the current decade (2000–2009). By 2020, the shares of LCD-monitors and laptops will increase more rapidly replacing other e-waste including the CRT-monitors. The model also shows the principal flows of computer equipment from production and sale to recycling and disposal. The re-use of computer equipment plays an important role in Chile. An appropriate recycling scheme will have to be introduced to provide adequate solutions for the growing rate of e-waste generation.     

Food Aid and the Famine Relief Argument (Brief Return)

Recent publications by Pogge (Global ethics: seminal essays. St. Paul: Paragon House 2008) and by Singer (The life you can save: acting now to end world poverty. New York: Random House 2009) have resuscitated a debate over the justifiability of famine relief between Singer and ecologist Garrett Hardin in the 1970s. Yet that debate concluded with a general recognition that (a) general considerations of development ethics presented more compelling ethical problems than famine relief; and (b) some form of development would be essential to avoiding the problems of growth noted by Hardin. Better than renewing the debate, we should recognize two points. First, food needs do indeed evoke a moral response that is more direct and compelling than the philosophical positions often generated to rationalize a duty to bring aid. As such the argument for feeding hungry people cannot be generalized into a paradigm for development ethics without distortions that undercut the morally valid elements in Singer’s original argument. Second, contrary to prevailing assumptions in present day development ethics, food aid and famine relief continue to be important priorities for international agencies, notably the World Food Program. Emergency food assistance, the nominal topic of Singer’s original article, thus is an important issue for agricultural as well as development ethics, though one that should indeed be seen as distinct from more complex duties to address the conditions of chronic poverty and underdevelopment.     

Influence of environmental factors on the response of a natural population of Daphnia magna (Crustacea: Cladocera) to spinosad and Bacillus thuringiensis israelensis in Mediterranean coastal wetlands

The present study was undertaken to assess the impact of a candidate mosquito larvicide, spinosad (8, 17 and 33 μg L⁻¹) on a field population of Daphnia magna under natural variations of water temperature and salinity, using Bti (0.16 and 0.50 μL L⁻¹) as the reference larvicide. Microcosms (125 L) were placed in a shallow temporary marsh where D. magna was naturally present. The peak of salinity observed during the 21-day observation period may have been partly responsible for the decrease of daphnid population density in all the microcosms. It is also probably responsible for the absence of recovery in the microcosms treated with spinosad which caused a sharp decrease of D. magna abundance within the first two days following treatment whereas Bti had no effect. These results suggest that it may be difficult for a field population of daphnids to cope simultaneously with natural (water salinity and temperature) and anthropogenic (larvicides) stressors.     

Accumulation and biological cycling of heavy metal in four salt marsh species, from Tagus estuary (Portugal)

Pools of Zn, Cu, Cd and Co in leaf, stem and root tissues of Sarcocornia fruticosa, Sarcocornia perennis, Halimione portulacoides and Spartina maritima were analyzed on a bimonthly basis, in a Tagus estuary salt marsh. All the major concentrations were found in the root tissues, being the concentrations in the aboveground organs neglectable for sediment budget proposes, as seen by the low root-aboveground translocation. Metal annual accumulation, root turnovers and cycling coefficients were also assessed. S. maritima showed the higher root turnovers and cycling coefficients for most of the analyzed metals, making this a phytostabilizer specie. By contrast the low root turnover, cycling coefficient and low root necromass generation makes S. perennis the most suitable specie for phytoremediation processes. Although the high amounts of metal return to the sediments, due to root senescence, salt marshes can still be considered sinks of heavy metals, cycling heavy metals mostly between sediment and root.