893 resultados para Environmental Science
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Mode of access: Internet.
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"Series H."
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Thesis (Ph.D.)--University of Washington, 2016-08
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This work assessed the environmental impacts of the production and use of 1 MJ of hydrous ethanol (E100) in Brazil in prospective scenarios (2020-2030), considering the deployment of technologies currently under development and better agricultural practices. The life cycle assessment technique was employed using the CML method for the life cycle impact assessment and the Monte Carlo method for the uncertainty analysis. Abiotic depletion, global warming, human toxicity, ecotoxicity, photochemical oxidation, acidification, and eutrophication were the environmental impacts categories analyzed. Results indicate that the proposed improvements (especially no-til farming-scenarios s2 and s4) would lead to environmental benefits in prospective scenarios compared to the current ethanol production (scenario s0). Combined first and second generation ethanol production (scenarios s3 and s4) would require less agricultural land but would not perform better than the projected first generation ethanol, although the uncertainties are relatively high. The best use of 1 ha of sugar cane was also assessed, considering the displacement of the conventional products by ethanol and electricity. No-til practices combined with the production of first generation ethanol and electricity (scenario s2) would lead to the largest mitigation effects for global warming and abiotic depletion. For the remaining categories, emissions would not be mitigated with the utilization of the sugar cane products. However, this conclusion is sensitive to the displaced electricity sources.
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Brazilian agriculture covers about one-third of the land area and is expected to expand further We assessed the compliance of present Brazilian agriculture with environmental legislation and identified challenges for agricultural development connected to this legislation We found (i) minor illegal land use in protected areas under public administration, (ii) a large deficit in legal reserves and protected riparian zones on private farmland, and large areas of unprotected natural vegetation in regions experiencing agriculture expansion Achieving full compliance with the environmental laws as they presently stand would require drastic changes in agricultural land use, where large agricultural areas are taken out of production and converted back to natural vegetation The outcome of a full compliance with environmental legislation might not be satisfactory due to leakage, where pristine unprotected areas become converted to compensate for lost production as current agricultural areas are reconverted to protected natural vegetation. Realizing the desired protection of biodiversity and natural vegetation, while expanding agriculture to meet food and biofuel demand, may require a new approach to environmental protection New legal and regulatory instruments and the establishment of alternative development models should be considered
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This website is linked to UNESCO.org and is free to download for educational purposes. It contains a database of school science experiments and investigations in physics, chemistry, biology, astronomy, geology, weather studies, agriculture projects for primary and secondary schools; and sexuality education and drugs education. It is based on a revision, updating and expansion of the "New UNESCO source book for science teaching", 1979 edition, UNESCO, Paris. It contains experiments from the "low cost" science teaching movement, simplified versions of classical experiments, experiments using locally available substances and kitchen chemicals, and environmental science. Some experiments anticipate experiments usually done in senior high school or college classes. The experiments should be "student-friendly" and "teacher-friendly" because there is no overwhelming technology. Enough theoretical background is included to remind teachers of the theoretical context of the experiment. Every experiment is based on materials listed in a modern commercial catalogue of chemicals and equipment for use by educational institutions. The procedures and safety standards are consistent with instructions issued by Education Queensland (Ministry of Education), State of Queensland, Australia.
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The development and application of a polyaniline/carbon nanotube (CNT) cyclodextrin matrix (PANI-β-CD/MWCNT)-based electrochemical sensor for the quantitative determination of the herbicide 4-chloro-2-methylphenoxyacetic acid (MCPA) and its main transformation product 4-chloro-2-methylphenol in natural waters are described. A simple cyclic voltammetry-based electrochemical methodology, in phosphate buffer solution at pH 6.0, was used to develop a method to determine both MCPA and 4-chloro-2-methylphenol, without any previous extraction or derivatization steps. A linear concentration range (10 to 50 μmol L−1) and detection limits of 1.1 and 1.9 μmol L−1, respectively, were achieved using optimized cyclic voltammetric parameters. The proposed method was successfully applied to the determination of MCPA and 4-chloro-2-methylphenol in natural water samples with satisfactory recoveries (94 to 107 %) and in good agreement with the results obtained by an established high-performance liquid chromatography technique, no significant differences being found between the methods. Interferences from ionic species and other herbicides used for broad-leaf weed control were shown to be small. The newly developed methodology was also successfully applied to MCPA photodegradation environmental studies.
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Poster at Open Repositories 2014, Helsinki, Finland, June 9-13, 2014
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The delivery of library instruction to students in those areas of the sciences and the social sciences dealing with biology and the environment has a long history (Bowden & Di Benedetto 2001; Kutner 2000; Kutner & Danks 2007; Sapp 2006; Sinn 1998). Often these instruction sessions take the form of a one hour lecture or workshop at the start of a semester before the students have begun their projects or papers. This "one-shot" approach, though popular, has its limitations. It may not be offered at a time when the students will actually start making use of library resources, it may not be tied very specifically to a particular assignment, or it may be too general in nature to be of much use to students later on when they need to look at particular topics in much more depth than can be addressed in one such session. The following article describes another approach: the strategic use of drop-in clinics as a method of instruction in which the students themselves determine how the instruction proceeds.
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Virtual globe technology holds many exciting possibilities for environmental science. These easy-to-use, intuitive systems provide means for simultaneously visualizing four-dimensional environmental data from many different sources, enabling the generation of new hypotheses and driving greater understanding of the Earth system. Through the use of simple markup languages, scientists can publish and consume data in interoperable formats without the need for technical assistance. In this paper we give, with examples from our own work, a number of scientific uses for virtual globes, demonstrating their particular advantages. We explain how we have used Web Services to connect virtual globes with diverse data sources and enable more sophisticated usage such as data analysis and collaborative visualization. We also discuss the current limitations of the technology, with particular regard to the visualization of subsurface data and vertical sections.