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  • About
  • The Global ETD Search service is a free service for researchers to find electronic theses and dissertations. This service is provided by the Networked Digital Library of Theses and Dissertations.
    Our metadata is collected from universities around the world. If you manage a university/consortium/country archive and want to be added, details can be found on the NDLTD website.
151

Gestão da informação e do conhecimento e repositórios digitais: construindo um contexto para o surgimento das competências organizacionais / -

Daniele Cristina Gonçalves Brene Pires 30 September 2015 (has links)
A gestão da informação e do conhecimento (GIC) emerge em um contexto socioeconômico no qual a informação e o conhecimento são reconhecidos como um recurso. Um bem imaterial, inesgotável e com alto potencial para geração da sustentabilidade organizacional. Assim, vislumbra-se que este modelo gerencial atende as demandas de um novo comportamento organizacional, que busca compreender os impactos da criação e do uso da informação sobre a vantagem competitiva. Nessa linha, e tendo como objeto de estudo a relação entre a GIC e as competências organizacionais, buscou-se verificar o impacto da GIC sobre o surgimento de competências organizacionais, especialmente considerando a utilização do Dspace, um repositório digital. Por meio da aplicação da metodologia exploratória-descritiva, elaborou-se um estudo sobre a experiência do uso da plataforma Dspace em um Tribunal da Justiça Trabalhista. A análise da literatura e do relato de experiência permitiu identificar que as técnicas de GIC colaboram para o estabelecimento das competências organizacionais, especialmente quando estas são consideradas a partir de uma visão holística que integra a necessidade informacional, os fluxos informacionais, a cultura informacional, o comportamento informacional e o uso da informação. Também identificou-se que os repositórios digitais podem ser um fator de influência para o desenvolvimento das competências organizacionais, uma vez que sua principal função é estruturar os ciclos informacionais para a geração de novos conhecimentos e, finalmente, constatou-se que o Dspace é uma ferramenta que apoia o desenvolvimento das competências organizacionais, pois permite criar um estoque de informações e/ou conhecimentos produzidos ou adquiridos pelas organizações, favorecendo o estabelecimento de um contexto capacitante ideal para aquisições de novas capacidades de agir. / The information and knowledge management emerges in a socioeconomic context in which information and knowledge are recognized as a resource. An immaterial and inexhaustible asset that has a high potential for generating organizational sustainability. Probably, this management tool meets the demands of a new organizational behavior, which seeks to understand the impact of the information creation and use on competitive advantage. Thus, and having as object of study the relationship between the information and knowledge and core competence, we sought to verify its impact on the emergence of core competence, especially considering the use of DSpace, a digital repository. Through the application of exploratory-descriptive methodology, a study about the experience of using the DSpace platform in a court of Labor Justice was done. The analysis of literature and experience report identifies that the techniques of information and knowledge management collaborates to establish the core competence, especially considering an integration between the informational needs, the information flows, the informational culture, information behavior and the use of information. In addition, it was found that digital repositories can be a factor of influence for the development of core competence, especially because its main function is structuring the informational cycle for generating new knowledge and, finally, it was found that the DSpace is an important tool, which supports the development of core competence. It allows creating a stock of information and/or knowledge produced or acquired by organizations, better supporting the establishment of an optimal enabling environment for acquisition of new capabilities to act.
152

The effect of scholarly communication practices on engagement with open access: An Australian study of three disciplines

Kingsley, Danny Abigail, danny.kingsley@anu.edu.au January 2009 (has links)
This dissertation addresses a specific aspect of the broad area of communication systems used among researchers. This research has undertaken to establish a broader view of the communication practices of scholars to understand the motivations behind their publication choices. Open access offers a solution to issues with the scholarly publication system such as delays in publication and restricted visibility of research due to high subscription costs. The principle of open access is to enable maximum access to findings from publicly funded research to maximise social returns on public investments. Despite the apparent benefits of open access, the uptake has been limited. ¶ This thesis research takes a holistic view of the researcher as a communicator to uncover the reasons why researchers are making the publishing decisions they are. In-depth interviews were conducted with 43 researchers in three disciplines at two institutions, the Australian National University and the University of New South Wales. The disciplines, Chemistry, Sociology and Computer Science, were known to have different publication practices, The questions asked about all aspects of researcher communication including researching, authoring, informal communication, article submission, refereeing, mentoring and data storage. ¶ The findings show that traditional arguments for open access are ineffective. The Reward function of scholarly publishing is central to managing academic careers and supports traditional publishing systems. While having work openly accessible increases an academic’s exposure and possibly therefore their citation counts, unless alternative internet-based forms of metrics are adopted, the open access option will not directly appeal to researchers. ¶ Information-seeking behaviour demonstrates how disciplinary differences affect researcher’s interaction with technology. The disciplines showed marked differences in almost all the areas explored, and the behavioural norms expressed in each discipline have direct bearing on the likelihood of members of that discipline embracing open access. The ‘institutional/disciplinary divide’ means that researchers must publish in ways that run counter to their disciplinary norms in order to satisfy institutional and grant funding requirements. ¶ Until governments, and particularly university administrations, recognise the need to consider the discipline and the need to consider the individual and respond to these needs, and until there is a realisation that different disciplines may require radically different approaches, there will not be a large-scale adoption by individual researchers of the current open access tools. Either institutional repositories need to adapt dramatically to offer work practice benefits or the broader academic population will only use institutional repositories under duress, which is not the situation envisaged by open access advocates. The alternative is for communities to develop their own subject-based repositories, a development that again is likely to be highly dependent on communication norms in different disciplines.
153

Modelling water and solute flows at land-sea and land-atmosphere interfaces under data limitations

Shibuo, Yoshihiro January 2007 (has links)
<p>Water and vapour flows from land to sea and the atmosphere are important for water resources, coastal ecosystems and climate. This thesis investigates possible methods for modelling these flows under often encountered unmonitored hydrological conditions and data limitations. Two contrasting types of drainage basin and associated data limitation/availability cases are considered: the Swedish unmonitored near-coastal catchment areas Forsmark and Simpevarp, for which detailed spatial but not much temporal variability data is available; and the much larger Aral Sea Drainage Basin (ASDB), for which spatial hydrological information is limited, while there is relatively well-known temporal change occurring in the Aral Sea itself and in the land and water use of the region over the last 50 years.</p><p>The hydrologic modelling for the Forsmark and Simpevarp catchment areas showed that the relatively large focused stream flows, and the mean values and total sums of the diffuse small stream-groundwater flow fields in between the large stream flows from land to sea are largely constrained by the catchment hydrological balances and relatively robust and certain to estimate. The ASDB hydrologic modelling indicated an evapotranspiration return flow to the atmosphere from the irrigation water input on irrigated land that is much higher than previous estimates in atmospheric modelling, implying possible considerably larger than previously estimated non-local water and climate effects of the world’s irrigated areas. The more detailed groundwater-seawater dynamics modelling carried out for the coastal parts of the ASDB showed that regional topography and bathymetry largely influence coastal water fluxes during sea level lowering, with the Aral Sea shrinkage decreasing the seawater intrusion risk into the coastal groundwater considerably more for steeper than for flatter coastal topography parts of the region.</p>
154

Modelling water and solute flows at land-sea and land-atmosphere interfaces under data limitations

Shibuo, Yoshihiro January 2007 (has links)
Water and vapour flows from land to sea and the atmosphere are important for water resources, coastal ecosystems and climate. This thesis investigates possible methods for modelling these flows under often encountered unmonitored hydrological conditions and data limitations. Two contrasting types of drainage basin and associated data limitation/availability cases are considered: the Swedish unmonitored near-coastal catchment areas Forsmark and Simpevarp, for which detailed spatial but not much temporal variability data is available; and the much larger Aral Sea Drainage Basin (ASDB), for which spatial hydrological information is limited, while there is relatively well-known temporal change occurring in the Aral Sea itself and in the land and water use of the region over the last 50 years. The hydrologic modelling for the Forsmark and Simpevarp catchment areas showed that the relatively large focused stream flows, and the mean values and total sums of the diffuse small stream-groundwater flow fields in between the large stream flows from land to sea are largely constrained by the catchment hydrological balances and relatively robust and certain to estimate. The ASDB hydrologic modelling indicated an evapotranspiration return flow to the atmosphere from the irrigation water input on irrigated land that is much higher than previous estimates in atmospheric modelling, implying possible considerably larger than previously estimated non-local water and climate effects of the world’s irrigated areas. The more detailed groundwater-seawater dynamics modelling carried out for the coastal parts of the ASDB showed that regional topography and bathymetry largely influence coastal water fluxes during sea level lowering, with the Aral Sea shrinkage decreasing the seawater intrusion risk into the coastal groundwater considerably more for steeper than for flatter coastal topography parts of the region.
155

Oxidative Dissolution of Spent Fuel and Release of Nuclides from a Copper/Iron Canister : Model Developments and Applications

Liu, Longcheng January 2001 (has links)
Three models have been developed and applied in the performance assessment of a final repository. They are based on accepted theories and experimental results for known and possible mechanisms that may dominate in the oxidative dissolution of spent fuel and the release of nuclides from a canister. Assuming that the canister is breached at an early stage after disposal, the three models describe three sub-systems in the near field of the repository, in which the governing processes and mechanisms are quite different. In the model for the oxidative dissolution of the fuel matrix, a set of kinetic descriptions is provided that describes the oxidative dissolution of the fuel matrix and the release of the embedded nuclides. In particular, the effect of autocatalytic reduction of hexavalent uranium by dissolved H2, using UO2 (s) on the fuel pellets as a catalyst, is taken into account. The simulation results suggest that most of the radiolytic oxidants will be consumed by the oxidation of the fuel matrix, and that much less will be depleted by dissolved ferrous iron. Most of the radiolytically produced hexavalent uranium will be reduced by the autocatalytic reaction with H2 on the fuel surface. It will reprecipitate as UO2 (s) on the fuel surface, and thus very little net oxidation of the fuel will take place. In the reactive transport model, the interactions of multiple processes within a defective canister are described, in which numerous redox reactions take place as multiple species diffuse. The effect of corrosion of the cast iron insert of the canister and the reduction of dissolved hexavalent uranium by ferrous iron sorbed onto iron corrosion products and by dissolved H2 are particularly included. Scoping calculations suggest that corrosion of the iron insert will occur primarily under anaerobic conditions. The escaping oxidants from the fuel rods will migrate toward the iron insert. Much of these oxidants will, however, be consumed by ferrous iron that comes from the corrosion of iron. The nonscavenged hexavalent uranium will be reduced by ferrous iron sorbed onto the iron corrosion products and by dissolved hydrogen. In the transport resistance network model, the transport of reactive actinides in the near field is simulated. The model describes the transport resistance in terms of coupled resistors by a coarse compartmentalisation of the repository, based on the concept that various ligands first come into the canister and then diffuse out to the surroundings in the form of nuclide complexes. The simulation results suggest that carbonate accelerates the oxidative dissolution of the fuel matrix by stabilizing uranyl ions, and that phosphate and silicate tend to limit the dissolution by the formation of insoluble secondary phases. The three models provide powerful tools to evaluate "what if" situations and alternative scenarios involving various interpretations of the repository system. They can be used to predict the rate of release of actinides from the fuel, to test alternative hypotheses and to study the response of the system to various parameters and conditions imposed upon it. / QC 20100521
156

Paleoevolution of Pore Fluids in Glaciated Geologic Settings

Normani, Stefano Delfino January 2009 (has links)
Nuclear power generation is being regarded as a solution to ever increasing demand for electricity, and concerns over global warming and climate change due to the use of fossil fuels. Although nuclear power generation is considered to be reliable, economical, clean, and safe, the wastes produced from the nuclear fuel cycle are not, and can remain hazardous for hundreds of thousands of years. An international consensus has developed over the past several decades that deep geologic disposal of low, intermediate, and high level radioactive wastes is the best option to protect the biosphere. In this thesis, both regional scale and sub-regional scale models are created to simulate groundwater flow and transport for a representative Canadian Shield setting, honouring site-specific topography and surface water features. Sub-surface characteristics and properties are derived from numerous geoscience studies. In addition, a regional scale model is developed, centred on the Bruce Nuclear Power Development (BNPD) site near Tiverton, Ontario, and located within the Michigan Basin. Ontario Power Generation (OPG) has proposed a Deep Geologic Repository (DGR) for low & intermediate level waste (L&ILW) at the BNPD site. Paleoclimate simulations using various combinations of parameters are performed for both the Canadian Shield Sub-Regional model, and the Michigan Basin Regional model. Fracture zone permeability is a very important parameter when modelling crystalline rock settings. Migration of a unit tracer representing glacial recharge water can occur to depth in fractures of high permeability. Representative rock compressibility values are necessary as compressibilities are used to calculate storage coefficients, and the one-dimensional loading efficiency; these affect the subsurface propagation of elevated pore pressures due to glacial loading at surface. Coupled density-dependent flow and transport in paleoclimate simulations affects deep flow systems and provides a measure of flow stability, as well as increasing the mean life expectancy at depth. Finally, hydromechanical coupling is a very important mechanism for reducing vertical hydraulic gradients during a glaciation event when a hydraulic boundary condition equal to the pressure at the base of an ice-sheet is applied at ground surface. Pore water velocities are reduced, thereby retarding migration of surface waters into the subsurface environment.
157

Paleoevolution of Pore Fluids in Glaciated Geologic Settings

Normani, Stefano Delfino January 2009 (has links)
Nuclear power generation is being regarded as a solution to ever increasing demand for electricity, and concerns over global warming and climate change due to the use of fossil fuels. Although nuclear power generation is considered to be reliable, economical, clean, and safe, the wastes produced from the nuclear fuel cycle are not, and can remain hazardous for hundreds of thousands of years. An international consensus has developed over the past several decades that deep geologic disposal of low, intermediate, and high level radioactive wastes is the best option to protect the biosphere. In this thesis, both regional scale and sub-regional scale models are created to simulate groundwater flow and transport for a representative Canadian Shield setting, honouring site-specific topography and surface water features. Sub-surface characteristics and properties are derived from numerous geoscience studies. In addition, a regional scale model is developed, centred on the Bruce Nuclear Power Development (BNPD) site near Tiverton, Ontario, and located within the Michigan Basin. Ontario Power Generation (OPG) has proposed a Deep Geologic Repository (DGR) for low & intermediate level waste (L&ILW) at the BNPD site. Paleoclimate simulations using various combinations of parameters are performed for both the Canadian Shield Sub-Regional model, and the Michigan Basin Regional model. Fracture zone permeability is a very important parameter when modelling crystalline rock settings. Migration of a unit tracer representing glacial recharge water can occur to depth in fractures of high permeability. Representative rock compressibility values are necessary as compressibilities are used to calculate storage coefficients, and the one-dimensional loading efficiency; these affect the subsurface propagation of elevated pore pressures due to glacial loading at surface. Coupled density-dependent flow and transport in paleoclimate simulations affects deep flow systems and provides a measure of flow stability, as well as increasing the mean life expectancy at depth. Finally, hydromechanical coupling is a very important mechanism for reducing vertical hydraulic gradients during a glaciation event when a hydraulic boundary condition equal to the pressure at the base of an ice-sheet is applied at ground surface. Pore water velocities are reduced, thereby retarding migration of surface waters into the subsurface environment.
158

The Mobilization of Actinides by Microbial Ligands Taking into Consideration the Final Storage of Nuclear Waste - Interactions of Selected Actinides U(VI), Cm(III), and Np(V) with Pyoverdins Secreted by Pseudomonas fluorescens and Related Model Compounds (Final Report BMBF Project No.: 02E9985)

Glorius, M., Moll, H., Bernhard, G., Roßberg, A., Barkleit, A. 31 March 2010 (has links) (PDF)
The groundwater bacterium Pseudomonas fluorescens (CCUG 32456) isolated at a depth of 70 m in the Äspö Hard Rock Laboratory secretes a pyoverdin-mixture with four main components (two pyoverdins and two ferribactins). The dominant influence of the pyoverdins of this mixture could be demonstrated by an absorption spectroscopy study. The comparison of the stability constants of U(VI), Cm(III), and Np(V) species with ligands simulating the functional groups of the pyoverdins results in the following order of complex strength: pyoverdins (PYO) > trihydroxamate (DFO) > catecholates (NAP, 6­HQ) > simple hydroxamates (SHA, BHA). The pyoverdin chromophore functionality shows a large affinity to bind actinides. As a result, pyoverdins are also able to complex and to mobilize elements other than Fe(III) at a considerably high efficiency. It is known that EDTA may form the strongest actinide complexes among the various organic components in nuclear wastes. The stability constants of 1:1 species formed between Cm(III) and U(VI) and pyoverdins are by a factor of 1.05 and 1.3, respectively, larger compared to the corresponding EDTA stability constants. The Np(V)-PYO stability constant is even by a factor of 1.83 greater than the EDTA stability constant. The identified Np(V)-PYO species belong to the strongest Np(V) species with organic material reported so far. All identified species influence the actinide speciation within the biologically relevant pH range. The metal binding properties of microbes are mainly determined by functional groups of their cell wall (LPS: Gram-negative bacteria and PG: Gram-positive bacteria). On the basis of the determined stability constants raw estimates are possible, if actinides prefer to interact with the microbial cell wall components or with the secreted pyoverdin bioligands. By taking pH 5 as an example, U(VI)-PYO interactions are slightly stronger than those observed with LPS and PG. For Cm(III) we found a much stronger affinity to aqueous pyoverdin species than to functional groups of the cell wall compartments. A similar behavior was observed for Np(V). This shows the importance of indirect interaction processes between actinides and bioligands secreted by resident microbes.
159

Joint Project: Migration of Actinides in the System Clay, Humic Substance, Aquifer - Migration Behavior of Actinides (Uranium, Neptunium) in Clays: Characterization and Quantification of the Influence of Humic Substances (Final Report BMWi Project No.: 02 E 9673)

Geipel, Gerhard, Sachs, Susanne, Brendler, Vinzenz, Mibus, Jens, Krepelova, Adela, Günther, Alix, Schmeide, Katja, Koban, Astrid, Bernhard, Gert 31 March 2010 (has links) (PDF)
Objective of this project was the study of interaction processes between humic substances, U(VI), Np(V) and kaolinite KGa-1b. It contributed to the attainment of a better process understanding, the improvement of the knowledge on the interaction of humic substances and metal ions and the enhancement of the thermodynamic database. With a synthetic humic acid (HA), N-containing functional groups of HA were characterized by 15N-NMR spectroscopy. Based on these results, model studies of the influence of amino groups on the complexation behavior of HA were performed. Spectroscopic studies with amino acids show that the amino group do not contribute to the U(VI) complexation at pH 4. The impact of kaolinite on the formation of HA and humic substance-kaolinite-sorbates was studied in model syntheses. The results exhibit that the presence of kaolinite during the syntheses mainly influences the yields on HA and their elemental compositions. Synthetic humic substance-kaolinite-sorbates were isolated. Under exclusion of CO2, the U(VI) complexation by HA was investigated at pH 7 by means of the conventional time-resolved laser-induced fluorescence spectroscopy (TRLFS) and TRLFS with ultrafast pulses. Complexation parameters for the ternary complex UO2(OH)HA(I) were determined. Studies of the Np(V) reduction in presence of HA with different functionalities under anaerobic conditions have shown that Np(V) is reduced to Np(IV) by HA. The redox capacity depends on the HA functionality. Applying a modified HA it was verified that phenolic/acidic OH groups play a dominating role in the Np(V) reduction. The influence of HA on the U(VI) and Np(V) sorption onto kaolinite was investigated in batch experiments. In dependence on the experimental conditions, HA effects the sorption and consequently the mobility of U(VI) and Np(V). From studies of the U(VI) sorption onto synthetic humic substance-kaolinite-sorbates it was concluded that the structure and functionality of sorbed/associated humic substances considerably influence the sorption behavior of U(VI). The structure of U(VI)-kaolinite-surface complexes in presence of HA was studied by means of X-ray absorption spectroscopy and TRLFS and compared to those of U(VI)-kaolinite-complexes. Investigations of the migration of HA and U(VI) in the laboratory system kaolinite-water were carried out in diffusion experiments. The migration of HA in compacted clay is governed by diffusion and influenced by its colloidal properties. Humic substances exert an immobilizing effect on the U(VI) transport in compacted kaolinite.
160

Influence of Humic Acids on the Migration Behavior of Radioactive and Non-Radioactive Substances Under Conditions Close to Nature -Synthesis, Radiometric Determination of Functional Groups, Complexation-

Nitsche, Heino, Heise, Karl-Heinz, Bernhard, Gert, Schmeide, Katja, Pompe, Susanne, Bubner, Marianne 31 March 2010 (has links) (PDF)
The interaction behavior of humic acids with uranium(VI) and the influence of humic substances on the migration behavior of uranium was investigated. A main focus of this work was the synthesis of four different humic acid model substances and their characterization and comparison to the natural humic acid from Aldrich. A radiometric method for the determination of humic acid functional groups was applied in addition to conventional methods for the determination of the functionality of humic acids. The humic acid model substances show functional and structural properties comparable to natural humic acids. Modified humic acids with blocked phenolic OH were synthesized to determine the influence of phenolic OH groups on the complexation behavior of humic acids. A synthesis method for 14C-labeled humic acids with high specific activity was developed. The complexation behavior of synthetic and natural humic acids with uranium(VI) was investigated by X-ray absorption spectroscopy, laser-induced fluorescence spectroscopy and FTIR spectroscopy. The synthetic model substances show an interaction behavior with uranium(VI) that is comparable to natural humic acids. This points to the fact that the synthetic humic acids simulate the functionality of their natural analogues very well. For the first time the influence of phenolic OH groups on the complexation behavior of humic acids was investigated by applying a modified humic acid with blocked phenolic OH groups. The formation of a uranyl hydroxy humate complex was identified by laserspectroscopic investigations of the complexation of Aldrich humic acid with uranium(VI)at pH 7. The migration behavior of uranium in a sandy aquifer system rich in humic substances was investigated in column experiments. A part of uranium migrates non-retarded through the sediment, bound to humic colloids. The uranium migration behavior is strongly influenced by the kinetically controlled interaction processes of uranium with the humic colloids. The influence of humic acids on the sorption of uranium(VI) onto phyllite was investigated in batch experiments using two different humic acids. The uranium(VI) sorption onto the rock phyllite is influenced by the pH-dependent sorption behavior of the humic acids.

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