962 resultados para Atmospheric pollution
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The current system of controlling oil spills involves a complex relationship of international, federal and state law, which has not proven to be very effective. The multiple layers of regulation often leave shipowners unsure of the laws facing them. Furthemore, nations have had difficulty enforcing these legal requirements. This thesis deals with the role marine insurance can play within the existing system of legislation to provide a strong preventative influence that is simple and cost-effective to enforce. In principle, insurance has two ways of enforcing higher safety standards and limiting the risk of an accident occurring. The first is through the use of insurance premiums that are based on the level of care taken by the insured. This means that a person engaging in riskier behavior faces a higher insurance premium, because their actions increase the probability of an accident occurring. The second method, available to the insurer, is collectively known as cancellation provisions or underwriting clauses. These are clauses written into an insurance contract that invalidates the agreement when certain conditions are not met by the insured The problem has been that obtaining information about the behavior of an insured party requires monitoring and that incurs a cost to the insurer. The application of these principles proves to be a more complicated matter. The modern marine insurance industry is a complicated system of multiple contracts, through different insurers, that covers the many facets of oil transportation. Their business practices have resulted in policy packages that cross the neat bounds of individual, specific insurance coverage. This paper shows that insurance can improve safety standards in three general areas -crew training, hull and equipment construction and maintenance, and routing schemes and exclusionary zones. With crew, hull and equipment, underwriting clauses can be used to ensure that minimum standards are met by the insured. Premiums can then be structured to reflect the additional care taken by the insured above and beyond these minimum standards. Routing schemes are traffic flow systems applied to congested waterways, such as the entrance to New York harbor. Using natural obstacles or manmade dividers, ships are separated into two lanes of opposing traffic, similar to a road. Exclusionary zones are marine areas designated off limits to tanker traffic either because of a sensitive ecosystem or because local knowledge is required of the region to ensure safe navigation. Underwriting clauses can be used to nullify an insurance contract when a tanker is not in compliance with established exclusionary zones or routing schemes.
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The objective of this study is to develop a Pollution Early Warning System (PEWS) for efficient management of water quality in oyster harvesting areas. To that end, this paper presents a web-enabled, user-friendly PEWS for managing water quality in oyster harvesting areas along Louisiana Gulf Coast, USA. The PEWS consists of (1) an Integrated Space-Ground Sensing System (ISGSS) gathering data for environmental factors influencing water quality, (2) an Artificial Neural Network (ANN) model for predicting the level of fecal coliform bacteria, and (3) a web-enabled, user-friendly Geographic Information System (GIS) platform for issuing water pollution advisories and managing oyster harvesting waters. The ISGSS (data acquisition system) collects near real-time environmental data from various sources, including NASA MODIS Terra and Aqua satellites and in-situ sensing stations managed by the USGS and the NOAA. The ANN model is developed using the ANN program in MATLAB Toolbox. The ANN model involves a total of 6 independent environmental variables, including rainfall, tide, wind, salinity, temperature, and weather type along with 8 different combinations of the independent variables. The ANN model is constructed and tested using environmental and bacteriological data collected monthly from 2001 – 2011 by Louisiana Molluscan Shellfish Program at seven oyster harvesting areas in Louisiana Coast, USA. The ANN model is capable of explaining about 76% of variation in fecal coliform levels for model training data and 44% for independent data. The web-based GIS platform is developed using ArcView GIS and ArcIMS. The web-based GIS system can be employed for mapping fecal coliform levels, predicted by the ANN model, and potential risks of norovirus outbreaks in oyster harvesting waters. The PEWS is able to inform decision-makers of potential risks of fecal pollution and virus outbreak on a daily basis, greatly reducing the risk of contaminated oysters to human health.
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Single ownership of natural resources is conunon in many developing countries and socialist economies. The sole owner is usually the .state or society at large, and governments are responsible for either distributing exploitation rights or engaging in exploitation through their own corporations. • Under this circumstance, the notion of externality may not fully explain pollution problems existent in these nations. This paper studies the case where a single agent owns both exhaustible and renewable resources, and attempts to maximize its welfare. The resources are either perfect or imperfect substitutes. Initially, exhaustible resource extraction does not affect the renewable resource, and sustainable growth is attainable. A lactor of pollution flowing from the extraction of the nc.nrenewable resource into the growth of the renewable resource is introduced. The continuous exploitation of the exhaustible resource leads to the " optimal " extinction of the renewable resource, and sustainable growth is no longer reached. Regulation from a supra governmental agency such as an multinational institution may prove to be of utmost importance, if sustainability is to be achieved. The paper is divided into five sections. Section two provides a brief survey of the relevant literature. Section three presents the model without pollution. This factor is introduced in section four. The final section discusses some possible approaches for attaining sustainable growth, and contains the concluding remarks .
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Environmental policy affects the distribution of market shares if intermediate goods are differentiated in their pollution intensity. When innovations are environment-friendly, a tax on emissions skews demand towards new goods which are the most productive. In this case, the tax has to increase along a balanced growth path to keep the market shares of goods of different vintages constant. Comparing balanced growth paths, we find that an increase in the burden of environmental taxation spurs innovation because it increases the market share of recent vintages. As a result the cost of environmental policy in terms of slower growth is weaker and may even be absent.
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Antimicrobial resistance of marine heterotrophic bacteria to different antimicrobials agents were evaluated in seawater, dry and wet sands from three marine recreational beaches with different pollution levels. In all studied beaches, the greatest frequencies of resistance were found in relation to penicillin. on Gonzaguinha, the most polluted beach, 72.3% of all isolated strains showed simple resistance, whilst 8.33% had multiple resistance. The values found on Ilha Porchat beach, were 70.8% and 6.9% for simple and multiple resistances, respectively. on GuaraA(0), the less polluted beach, only 35.3% of isolated strains had simple resistance. Multiple resistance was not observed. While samples from Gonzaguinha and Ilha Porchat beach showed isolated strains resistant to seven and six different antimicrobial agents, respectively, samples from GuaraA(0) beach were resistant only to penicillin and erytromicin. The positive correlations obtained between the degree of seawater contamination and frequency and variability of bacterial resistance indicate that polluted marine recreational waters and sands are sources of resistant bacteria contributing thus, to the dissemination of bacterial resistance.
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Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)
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Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)
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Discussions about pollution caused by vehicles emission are old and have been developed along the years. The search for cleaner technologies and frequent weather alterations have been inducing industries and government organizations to impose limits much more rigorous to the contaminant content in fuels, which have an direct impact in atmospheric emissions. Nowadays, the quality of fuels, in relation to the sulfur content, is carried out through the process of hydrodesulfurization. Adsorption processes also represent an interesting alternative route to the removal of sulfur content. Both processes are simpler and operate to atmospheric temperatures and pressures. This work studies the synthesis and characterization of aluminophosphate impregnate with zinc, molybdenum or both, and its application in the sulfur removal from the gasoline through the adsorption process, using a pattern gasoline containing isooctane and thiophene. The adsorbents were characterized by x-ray diffraction, differential thermal analysis (DTG), x-ray fluorescence and scanning electron microscopy (SEM). The specific area, volume and pore diameter were determined by BET (Brunauer- Emmet-Teller) and the t-plot method. The sulfur was quantified by elementary analysis using ANTEK 9000 NS. The adsorption process was evaluated as function of the temperature variation and initial sulfur content through the adsorption isotherm and its thermodynamic parameters. The parameters of entropy (ΔS), enthalpy variation (ΔH) and free Gibbs energy (ΔG) were calculated through the graph ln(Kd) versus 1/T. Langmuir, Freundlich and Langmuir-Freundlich models were adjusted to the experimental data, and the last one had presented better results. The thermodynamic tests were accomplished in different temperatures, such as 30, 40 and 50ºC, where it was concluded the adsorption process is spontaneous and exothermic. The kinetic of adsorption was studied by 24 h and it showed that the capability adsorption to the adsorbents studied respect the following order: MoZnPO > MoPO > ZnPO > AlPO. The maximum adsorption capacity was 4.91 mg/g for MoZnPO with an adsorption efficiency of 49%.
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Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)
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Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)
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Several positioning techniques have been developed to explore the GPS capability to provide precise coordinates in real time. However, a significant problem to all techniques is the ionosphere effect and the troposphere refraction. Recent researches in Brazil, at São Paulo State University (UNESP), have been trying to tackle these problems. In relation to the ionosphere effects it has been developed a model named Mod_Ion. Concerning tropospheric refraction, a model of Numerical Weather Prediction(NWP) has been used to compute the zenithal tropospheric delay (ZTD). These two models have been integrated with two positioning methods: DGPS (Differential GPS) and network RTK (Real Time Kinematic). These two positioning techniques are being investigated at São Paulo State University (UNESP), Brazil. The in-house DGPS software was already finalized and has provided very good results. The network RTK software is still under development. Therefore, only preliminary results from this method using the VRS (Virtual Reference Station) concept are presented.
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Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)
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Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)
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Detailed analyses of persistent organic pollutants (POPs) such as organochlorine pesticides (OCPs), hexachlorocyclohexane (HCH) isomers (HCHs), dichlorodiphenyltrichloro ethane (DDT) and its metabolites (DDTs) and congeners of polychlorinated biphenyls (PCBs) in soil and surface water from the northeastern São Paulo, Brazil allowed the evaluation of the contamination status, distribution and possible pollution sources. The pesticides and PCBs demonstrated markedly different distributions, reflecting different agricultural, domestic and industrial usage in each region studied. The ranges of HCH, DDT, and PCBs concentrations in the soil samples were 0.05-0.92, 0.12-11.01, 0.02-0.25 ng g(-1) dry wt, respectively, and in the surface water samples were 0.02-0.6, 0.02-0.58 and 0.02-0.5 ng l(-1), respectively. Overall elevated levels of DDT and PCB were recorded in region 2, a site very close to melting, automotive batteries industries, and agricultural practice regions. High ratios of metabolites of DDT to DDT isomers revealed the recent use of DDT in this environment. The sources of contamination are closely related to human activities, such as domestic and industrial discharge, street runoff, agricultural pesticides and soil erosion, due to deforestation as well as atmospheric transport. (c) 2006 Elsevier Ltd. All rights reserved.