Excimer laser fragmentation-fluorescence spectroscopy as a method for monitoring ammonium nitrate and ammonium sulfate particles

Excimer laser fragmentation-fluorescence spectroscopy (ELFFS) is shown to be an effective detection strategy for ammonium nitrate and ammonium sulfate particles at atmospheric pressure and room temperature. Following photofragmentation of the ammonium salt particle, fluorescence of the NH fragment is observed at 336 nm. The fluorescence signal is shown to depend linearly on particle surface area for laser intensities varying from 1.2 x 10(8) to 6 x 10(8) W/cm2. The 100 shot (1 s) detection limits for ammonium nitrate range from 20 ppb for 0.2 microm particles to 125 ppb for 0.8 microm particles, where these concentrations are expressed as moles of ammonium ion per mole of air. For ammonium sulfate, the 100 shot (1 s) detection limits vary from 60 ppb for 0.2 microm particles to 500 ppb for 1 microm particles. These detection limits are low enough to measure ammonium salt particles that form in the exhaust of combustion processes utilizing ammonia injection as a nitric oxide control strategy.     

A corporate approach to social monitoring and assessment for development in a fragile environment

The prevailing corporate trend regardingdevelopment of energy resources in the tropics emphasizesfinancial gain over long-term societal benefits. Somecorporations are beginning to find a competitive advantage linkedto proactive relations with host communities and adequateprotection of fragile ecosystems. Herein, we describe a casestudy where an international energy production company workedwith stakeholders to achieve social capital and sustainabledevelopment. The strategies aimed to strengthen local capacity toimprove social welfare and to ensure conservation and wise use ofbiodiversity. We provide examples, discuss lessons learned andmake recommendations for future development projects.     

Water Quality Functions of Riparian Forest Buffers in Chesapeake Bay Watersheds

/ Maryland, Virginia, and Pennsylvania, USA, have agreed to reduce nutrient loadings to Chesapeake Bay by 40% by the year 2000. This requires control of nonpoint sources of nutrients, much of which comes from agriculture. Riparian forest buffer systems (RFBS) provide effective control of nonpoint source (NPS) pollution in some types of agricultural watersheds. Control of NPS pollution is dependent on the type of pollutant and the hydrologic connection between pollution sources, the RFBS, and the stream. Water quality improvements are most likely in areas of where most of the excess precipitation moves across, in, or near the root zone of the RFBS. In areas such as the Inner Coastal Plain and Piedmont watersheds with thin soils, RFBS should retain 50%-90% of the total loading of nitrate in shallow groundwater, sediment in surface runoff, and total N in both surface runoff and groundwater. Retention of phosphorus is generally much less. In regions with deeper soils and/or greater regional groundwater recharge (such as parts of the Piedmont and the Valley and Ridge), RFBS water quality improvements are probably much less. The expected levels of pollutant control by RFBS are identified for each of nine physiographic provinces of the Chesapeake Bay Watershed. Issues related to of establishment, sustainability, and management are also discussed.KEY WORDS: Riparian forest buffers; Chesapeake Bay; Nonpoint source pollution; Nitrogen; Phosphorus; Sediment     

Sorption studies of mixed chromium and chlorinated ethenes at the field and laboratory scales

The sorption and desorption behavior of hexavalent chromium and chlorinated ethenes in a sandy ground water aquifer with a low reduction capacity was evaluated by performing a variety of analyses and experiments at the laboratory (batch and column studies) and field (in situ injection-withdrawal experiment) scales. The partitioning coefficients determined from the field and laboratory experiments are generally similar. Both sets of experiments yielded relatively low partition coefficients for chromium and chlorinated ethenes. The column studies and injection-withdrawal experiment indicate that chromium has the potential to leach from aquifer sediments and act as a secondary source of contamination. However, the magnitude of the secondary source effect is not significant due to low concentrations of leachable contamination. The chromium sorption isotherm data were also simulated using the triple layer surface complexation model (TLM). The isotherm data were modeled using the TLM, illustrating the applicability of geochemical modeling for sorption of chromium to these sediments under variable pE-pH conditions.     

New Device Against Non-Thermal Effects from Mobile Telephones

Summary Objectives: The aim of this study is to initiate research in the field of biomedical engineering geared towards a reduction of non-thermal effects on the brain due to the use of mobile telephones. This line of research employs devices attached to the back of cellular-telephone cases. Methods: Under electromagnetic-environment controlled conditions EEG records have been obtained in 16 healthy subjects, with their eyes open at the base-line. These records were compared with the use of the mobile telephone with and without one of these devices for five minutes each, and having them statistically tested with Wilcoxon matched-pairs. Results: Differences between experimental EEG, with and without the use of the device, have been observed. These subtle changes basically affect Delta and Theta wave bands. Their distribution, (changes in the affected areas of the brain), also varies, above all in the frontal areas. Conclusions: The use of this device could reduce non-thermal effects of mobile telephones on the human EEG.     

The cost of floods in developing countries’ megacities: a hedonic price analysis of the Jakarta housing market,Indonesia

Environmental Economics and Policy Studies - Although many megacities in developing countries experience floods annually that affect a large number of people, relatively few empirical studies have...     

Social contrasts and land use conflicts in the context of sustainable development and management needs: a case study from an estuarine area at northeastern Brazil

This paper discusses the misuses of estuaries in Northeast of Brazil and the social contrasts there found. The several kinds of impacts promoted by capitalist enterprises in one side and by traditional population, who uses estuary areas at another side, are in complete disagreement with the ethic of sustainable development. Our intention is to demonstrate how these aspects occur in the River Paraíba do Norte estuary, in the State of Paraíba. Observing the conditions of infrastructure besides the multiple ways to handle along with the extension of the estuary, we could recognize 59 focus of conflict between the incorrect use and sustainable mode. Most of the uses concern to traditional artisan fishing, slums and recreational marinas, reflecting the great social contrast between rich and poor people settled in area studied. Ecological and social implications of these conflicting uses are discussed and measures to improve the situation are suggested.     

Foot model for tracking temperature of safety boot insoles: application to different insole materials in firefighter boots

This research is based on the development of a human foot model to study the temperature conditions of a foot bottom surface under extreme external conditions. This foot model is made by combining different manufacturing techniques to enable the simulation of bones and tissues, allowing the placement of sensors on its surface to track the temperature values of different points inside a shoe. These sensors let researchers capture valuable data during a defined period of time, making it possible to compare the features of different safety boots, socks or soles, among others. In this case, it has been applied to compare different plantar insole materials, placed into safety boots on a high-temperature surface.     

Does predation risk,through moon phase and predator cues,modulate food intake,antipredatory and physiological responses in wood mice (Apodemus sylvaticus)?

Predation influences the ecology and behaviour of prey species and it is well known that the risk of predation affects prey’s decision making. We investigated whether predation risk through moon phase and exposure to the faecal odour of a natural predator, the red fox Vulpes vulpes, affect feeding behaviour and physiological response in wood mice (Apodemus sylvaticus). Antipredatory response was studied by live trapping under new and full moon in odourless control areas and areas experimentally manipulated with red fox fresh faeces. Food intake by individuals was determined as the amount of bait remaining in each trap and the physiological response was measured non-invasively analysing faecal corticosterone metabolites (FCM). Traps treated with faeces of red fox were the most avoided, and this avoidance was more significant during full moon. Food intake by wood mice varied according to the moon phase being significantly lower under full moon nights. We found sex, breeding condition and weight of individuals explaining the variation found in FCM concentrations, but no changes in FCM levels due to moon phase or exposure to red fox faeces were detected. These results indicate that wood mice avoid red fox faecal odour and this antipredatory response as well as feeding behaviour are significantly influenced by moon phase. However, no physiological response was found due to predation risk suggesting that wood mice do not take these predation cues enough reliable to experience physiological changes.