938 resultados para ENVIRONMENTAL APPLICATIONS


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Thesis (Ph.D.)--University of Washington, 2016-08

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This book presents research in the field of Geophysics, particularly referring to principles, applications and emerging technologies. Table of Contents: Preface pp. i-xxi Environmental Geophysics: Techniques, advantages and limitations (Pantelis Soupios and Eleni Kokinou, Department of Environmental and Natural Resources Engineering, Technological Educational Institute of Crete, Dynamics of the Ocean Floor, Helmholtz Centre for Ocean Research Kiel, Geomar)pp i-xxi Application of Innovative Geophysical Techniques in Coastal Areas (V. Di Fiore, M. Punzo, D. Tarallo, and G. Cavuoto, Institute for Marine Coastal Environment, National Research Council, Naples)pp. i-xxi Marine Geophysics of the Naples Bay (Southern Tyrrhenian sea, Italy): Principles, Applications and Emerging Technologies (Gemma Aiello and Ennio Marsella, Institute for Marine Coastal Environment, National Research Council, Naples)pp. i-xxi Oceanic Oscillation Phenomena: Relation to Synchronization and Stochastic Resonance (Shinya Shimokawa and Tomonori Matsuura, National Research Institute for Earth Science and Disaster Prevention, Univ. of Toyama)pp. i-xxi Assessment of ocean variability in the Sicily Channel from a numerical three-dimensional model using EOFs decomposition (R. Sorgente, A. Olita, A.F. Drago, A. Ribotti, L. Fazioli, and C. Tedesco, Institute for Marine Coastal Environment, National Research Council, Oristano)pp. i-xxi Monitoring Test of Crack Opening in Volcanic Tuff (Coroglio Cliff. Italy) Using Distributed Optical Fiber Sensor (A. Minardo, A. Coscetta, M. Caccavale, G. Esposito, F. Matano, M. Sacchi, R. Somma, G. Zeni, and L. Zeni, Department of Industrial and Information Eng., Second University of Naples Aversa, Institute for Marine Coastal Environment, National Research Council Naples, National Institute for Geophysics and Volcanology, Osservatorio Vesuviano Naples, Institute for Electromagnetic Sensing of the Environment, National Research Council Naples)pp. i-xxi

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Microalgae have a wide range of application fields, from food to fuels, to pharmaceuticals & fine chemicals, aquaculture and environmental bioremediation, among others. Spirulina and Chlorella have been used as food sources since ancient times, due to their high and balanced nutritional value. Our research group in Lisbon has developed a range of food products (emulsions, gelled desserts, biscuits and pastas) enriched with freshwater and marine microalgae (Spirulina, Chlorella, Haematococcus, Isochrysis and Diacronema). The developed products presented attractive and stable colours, high resistance to oxidation and enhanced rheological properties. Some of these products will be prepared at the Post-Congress Course “Functional Foods Development” at the University of Antofagasta. More recently, a great interest has arisen on using microalgae for biofuel production. The same group has also been exploring several marine and freshwater species for biofuel production (e.g., biodiesel, bioethanol, biohydrogen and biomethane) within a biorefinery approach, in order to obtain high and low-value co-products using integral biomass maximizing the energy revenue. Namely, supercritical fluid extraction of Nannochloropsis sp. allowed the recovery of valuable carotenoids and lipids, prior to bioH2 production through dark fermentation of the residual biomass. Also, Scenedesmus obliquus residues after sugars (for bioethanol) and lipids (for biodiesel) extraction has been anaerobically digested attaining high biomethane yields. Regarding sustainability issues, the current trend of our group is now focused on using liquid effluents and high CO2 levels for low cost microalgae growth, contributing to a lower water demand, primary energy consumption and global warming potential by reducing the need for potable water and fertilizers (P, N) and increasing CO2 mitigation. Microalgae biomass has been successfully used for urban wastewater treatment with subsequent bioH2 production, in a biorefinery approach. Presently, ammonium-rich raw effluents from piggeries and poultry industry are being effectively used for microalgae growth avoiding any pre-treatment step.

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Driven by the global trend in the sustainable economy development and environmental concerns, the exploring of plant-derived biomaterials or biocomposites for potential biomedical and/or pharmaceutical applications has received tremendous attention. Therefore, the work of this thesis is dedicated to high-value and high-efficiency utilization of plant-derived materials, with the focus on cellulose and hemicelluloses in the field of biomedical applications in a novel biorefinery concept. The residual cellulose of wood processing waste, sawdust, was converted into cellulose nanofibrils (CNFs) with tunable surface charge density and geometric size through 2,2,6,6-tetramethylpiperidinyloxy (TEMPO)-mediated oxidation and mechanical defibrillation. The sawdust-based CNFs and its resultant free-standing films showed comparable or even better mechanical properties than those from a commercial bleached kraft pulp at the same condition, demonstrating the feasibility of producing CNFs and films thereof with outstanding mechanical properties from birch sawdust by a process incorporated into a novel biorefinery platform recovering also polymeric hemicelluloses for other applications. Thus, it is providing an efficient route to upgrade sawdust waste to valuable products. The surface charge density and geometric size of the CNFs were found to play key roles in the stability of the CNF suspension, as well as the gelling properties, swelling behavior, mechanical stiffness, morphology and microscopic structural properties, and biocompatibility of CNF-based materials (i.e. films, hydrogels, and aerogels). The CNFs with tunable surface chemistry and geometric size was found promising applications as transparent and tough barrier materials or as reinforcing additive for production of biocomposites. The CNFs was also applied as structural matrices for the preparation of biocomposites possessing electrical conductivity and antimicrobial activity by in situ polymerization and coating of polypyrrole, and incorporation of silver nanoparticles, which make the material possible for potential wound healing application. The CNF-based matrices (films, hydrogels, and aerogels) with tunable structural and mechanical properties and biocompatibility were further prepared towards an application as 3D scaffolds in tissue engineering. The structural and mechanical strength of the CNF matrices could be tuned by controlling the charge density of the nanocellulose, as well as the pH and temperature values of the hydrogel formation conditions. Biological tests revealed that the CNF scaffolds could promote the survival and proliferation of tumor cells, and enhance the transfection of exogenous DNA into the cells, suggesting the usefulness of the CNF-based 3D matrices in supporting crucial cellular processes during cell growth and proliferation. The CNFs was applied as host materials to incorporate biomolecules for further biomedical application. For example, to investigate how the biocompatibility of a scaffold is influenced by its mechanical and structural properties, these properties of CNF-based composite matrices were controlled by incorporation of different hemicelluloses (O-acetyl galactoglucomanan (GGM), xyloglucan (XG), and xylan) into CNF hydrogel networks in different ratios and using two different approaches. The charge density of the CNFs, the incorporated hemicellulose type and amount, and the swelling time of the hydrogels were found to affect the pore structure, the mechanical strength, and thus the cells growth in the composite hydrogel scaffolds. The mechanical properties of the composite hydrogels were found to have an influence on the cell viability during the wound healing relevant 3T3 fibroblast cell culture. The thusprepared CNF composite hydrogels may work as promising scaffolds in wound healing application to provide supporting networks and to promote cells adhesion, growth, and proliferation.

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Improved agricultural productivity, and reduction of environmental impacts, require studies of the interactions between different soil components. Fertilizers marketed as "organic" or "natural", such as peats or humic substances (HS) extracted from peats, are enriched with macro and micronutrients that, according to the manufacturers, are released to the plant in accordance with its needs. This work investigates the complexation capacity of HS for macro and micronutrient metal species, considering the competition, for HS complexation sites, between non-essential metals (aluminium and lead), present in the soil, and the nutrients. Humic substances were found to possess strong affinities for Pb(II) and Al(III), forming stable complexes, with concomitant release of complexed nutrients. Although HS are already used commercially as organic fertilizers, further studies of methods of HS enrichment, aimed at avoiding losses, are highly desirable from environmental and economic perspectives. (C) 2009 Elsevier B.V. All rights reserved.

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The atomic-level structure and chemistry of materials ultimately dictate their observed macroscopic properties and behavior. As such, an intimate understanding of these characteristics allows for better materials engineering and improvements in the resulting devices. In our work, two material systems were investigated using advanced electron and ion microscopy techniques, relating the measured nanoscale traits to overall device performance. First, transmission electron microscopy and electron energy loss spectroscopy (TEM-EELS) were used to analyze interfacial states at the semiconductor/oxide interface in wide bandgap SiC microelectronics. This interface contains defects that significantly diminish SiC device performance, and their fundamental nature remains generally unresolved. The impacts of various microfabrication techniques were explored, examining both current commercial and next-generation processing strategies. In further investigations, machine learning techniques were applied to the EELS data, revealing previously hidden Si, C, and O bonding states at the interface, which help explain the origins of mobility enhancement in SiC devices. Finally, the impacts of SiC bias temperature stressing on the interfacial region were explored. In the second system, focused ion beam/scanning electron microscopy (FIB/SEM) was used to reconstruct 3D models of solid oxide fuel cell (SOFC) cathodes. Since the specific degradation mechanisms of SOFC cathodes are poorly understood, FIB/SEM and TEM were used to analyze and quantify changes in the microstructure during performance degradation. Novel strategies for microstructure calculation from FIB-nanotomography data were developed and applied to LSM-YSZ and LSCF-GDC composite cathodes, aged with environmental contaminants to promote degradation. In LSM-YSZ, migration of both La and Mn cations to the grain boundaries of YSZ was observed using TEM-EELS. Few substantial changes however, were observed in the overall microstructure of the cells, correlating with a lack of performance degradation induced by the H2O. Using similar strategies, a series of LSCF-GDC cathodes were analyzed, aged in H2O, CO2, and Cr-vapor environments. FIB/SEM observation revealed considerable formation of secondary phases within these cathodes, and quantifiable modifications of the microstructure. In particular, Cr-poisoning was observed to cause substantial byproduct formation, which was correlated with drastic reductions in cell performance.

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Sustainable development has only recently started examining the existing infrastructure, and a key aspect of this is hazard mitigation. To examine buildings under a sustainable perspective requires an understanding of a building's life-cycle environmental costs, including the consideration of associated environmental impacts induced by earthquake damage. Damage repair costs lead to additional material and energy consumption, leading to harmful environmental impacts. Merging results obtained from a seismic evaluation and life-cycle analysis for buildings will give a novel outlook on sustainable design decisions. To evaluate the environmental impacts caused by buildings, long-term impacts accrued throughout a building's lifetime and impacts associated with damage repair need to be quantified. A method and literature review for completing this examination has been developed and is discussed. Using software Athena and HAZUS-MH, this study evaluated the performance of steel and concrete buildings considering their life-cycle assessments and earthquake resistance. It was determined that code design-level greatly effects a building repair and damage estimations. This study presented two case study buildings and found specific results that were obtained using several premade assumptions. Future research recommendations were provided to make this methodology more useful in real-world applications. Examining cost and environmental impacts that a building has through, a cradle-to-grave analysis and seismic damage assessment will help reduce material consumption and construction activities from taking place before and after an earthquake event happens.

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Alginate polysaccharide is a promising biosorbent for metal uptake. Dry protonated calcium alginate beads for biosorption applications were prepared, briefly characterized and tested for lead uptake. Several advantages of this biosorbent are reported and discussed in comparison with other alginate-based sorbents. The alginate beads contained 4.7 mmol/g of COOH groups, which suffered hydrolysis near pH 4. The Weber and Morris model, applied to kinetic results of lead uptake, showed that intraparticle diffusion was the rate-controlling step in lead sorption by dry alginate beads. Equilibrium experiments were performed and the data were fitted with different isotherm models. The Langmuir equation was the most adequate to model lead sorption. The maximum uptake capacity (qmax) was estimated as 339 mg/g and the Langmuir constant (b) as 0.84 l/mg. These values were compared with that of other sorbents found in the literature, indicating that dry protonated calcium alginate beads are among the best biosorbents for the treatment and recovery of heavy metals from aqueous streams.

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Alginate polysaccharide is a promising biosorbent for metal uptake. Dry protonated calcium alginate beads for biosorption applications were prepared, briefly characterized and tested for lead uptake. Several advantages of this biosorbent are reported and discussed in comparison with other alginate-based sorbents. The alginate beads contained 4.7 mmol/g of COOH groups, which suffered hydrolysis near pH 4. The Weber and Morris model, applied to kinetic results of lead uptake, showed that intraparticle diffusion was the rate-controlling step in lead sorption by dry alginate beads. Equilibrium experiments were performed and the data were fitted with different isotherm models. The Langmuir equation was the most adequate to model lead sorption. The maximum uptake capacity (qmax) was estimated as 339 mg/g and the Langmuir constant (b) as 0.84 l/mg. These values were compared with that of other sorbents found in the literature, indicating that dry protonated calcium alginate beads are among the best biosorbents for the treatment and recovery of heavy metals from aqueous streams.

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Species occurrence and abundance models are important tools that can be used in biodiversity conservation, and can be applied to predict or plan actions needed to mitigate the environmental impacts of hydropower dams. In this study our objectives were: (i) to model the occurrence and abundance of threatened plant species, (ii) to verify the relationship between predicted occurrence and true abundance, and (iii) to assess whether models based on abundance are more effective in predicting species occurrence than those based on presence–absence data. Individual representatives of nine species were counted within 388 randomly georeferenced plots (10 m × 50 m) around the Barra Grande hydropower dam reservoir in southern Brazil. We modelled their relationship with 15 environmental variables using both occurrence (Generalised Linear Models) and abundance data (Hurdle and Zero-Inflated models). Overall, occurrence models were more accurate than abundance models. For all species, observed abundance was significantly, although not strongly, correlated with the probability of occurrence. This correlation lost significance when zero-abundance (absence) sites were excluded from analysis, but only when this entailed a substantial drop in sample size. The same occurred when analysing relationships between abundance and probability of occurrence from previously published studies on a range of different species, suggesting that future studies could potentially use probability of occurrence as an approximate indicator of abundance when the latter is not possible to obtain. This possibility might, however, depend on life history traits of the species in question, with some traits favouring a relationship between occurrence and abundance. Reconstructing species abundance patterns from occurrence could be an important tool for conservation planning and the management of threatened species, allowing scientists to indicate the best areas for collection and reintroduction of plant germplasm or choose conservation areas most likely to maintain viable populations.

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Transferring distribution models between different geographical areas may be problematic, as the performance of models outside their original scope is hard to predict. A modelling procedure is needed that gets the gist of the environmental descriptors of a distribution area, without either overfitting to the training data or overestimating the species’ distribution potential.We tested the transferability power of the favourability function, a generalized linear model, on the distribution of the Iberian desman (Galemys pyrenaicus) in the Iberian territories of Portugal and Spain.We also tested the effects of two of the main potential constraints on model transferability: the analysed ranges of the predictor variables, and the completeness of the species distribution data. We modelled 10 km×10km presence/absence data from Portugal and Spain separately, extrapolated each model to the other country, and compared predictions with observations. The Spanish model, despite arguably containing more false absences, showed good predictive ability in Portugal. The Portuguese model, whose predictors ranged between only a subset of the values observed in Spain, overestimated desman distribution when transferred.We discuss possible reasons for this differential model behaviour, and highlight the importance of this kind of models for prediction and conservation applications

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In Andalusia, southern Spain, each game estate applies its own rules and presents its results in annual hunting reports, which have been mandatory for Spanish game estates since 1989. We used the information about hunting yields, included in 32134 annual hunting reports produced during the period 1993/94 to 2001/02 by 6049 game estates, to determine the current distribution of hunting yields of big and small game species in Andalusia. Using generalised linear models and a geographic information system, we determined the most favourable municipalities to big and small game, respectively, and delimited potential areas to attain good hunting yields for big and small game at a 1-km2 resolution. Municipalities and areas favourable to big game are mainly located in the Sierra Morena and the westernmost fringe of the Betic Range, while those favourable to small game occupy the upper Guadalquivir River valley. There is a clear segregation between big and small game species according to the physiography and land uses of the territory. Big game species are typical of Mediterranean woodland areas, while the most emblematic small game species prefer agricultural areas. Our results provide a territorial ordination of hunting yields in southern Spain and have several potential applications in strategic planning for hunting activities and biodiversity conservation in Andalusia that can be extrapolated to other regions.

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A strategic planning process has been implemented at the Brazilian Agricultural Research Agency (Embrapa) to introduce sustainable development objectives in all steps of agricultural Research and Development. An essential component of the institutional mission statement hence devised has called for the systematic assessment of social and environmental impacts (in addition to the traditionally studied economic ones) of all technology innovations resulting from R&D. The proposed approach emphasizes the interest of promoting close interaction between R&D teams and technology-adopting producers, under actual field contexts, in order to improve both the technology development and the demand probing processes. Given the multiplicity of technological applications ensuing from Embrapa?s very broad research encompassment, and the variety of environmental and productive contexts involved, a customized impact assessment system has been proposed. Directed at the appraisal of agricultural technology development research projects (ex-ante) as well as their ensuing innovations (ex-post), the Ambitec-Agro System comprises a set of integrated socio-environmental indicators, constructed in modules suited to Agricultural, Animal husbandry, and Agro-industrial activities, besides a specific module for Social Impact Assessment. The system has been routinely applied in technology appraisal in all of Embrapa?s Units, as a basis for their institutional performance evaluations, and toward the formulation of the annual Social Balance Report. Following the inception of this institutional technology appraisal initiative, several methodological innovations have been proposed within Embrapa, including technical improvements and applicability adaptations of the Ambitec-Agro system, and approaches to further-reaching objectives, such as the sustainable development of rural communities, and the environmental management of agricultural activities.

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The morphological and chemical changes occurring during the thermal decomposition of weddelite, CaC2O4·2H2O, have been followed in real time in a heating stage attached to an Environmental Scanning Electron Microscope operating at a pressure of 2 Torr, with a heating rate of 10 °C/min and an equilibration time of approximately 10 min. The dehydration step around 120 °C and the loss of CO around 425 °C do not involve changes in morphology, but changes in the composition were observed. The final reaction of CaCO3 to CaO while evolving CO2 around 600 °C involved the formation of chains of very small oxide particles pseudomorphic to the original oxalate crystals. The change in chemical composition could only be observed after cooling the sample to 350 °C because of the effects of thermal radiation.