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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.
31

Disrupting white representation/speaking back to seventeenth-, eighteenth- and nineteenth-century travel literature a decolonial history of Santa Fe /

Gonzales, Tanya Ana. January 2009 (has links) (PDF)
Thesis (Ph. D. in american studies)--Washington State University, December 2009. / Title from PDF title page (viewed on Jan. 22, 2010). "Department of American Studies." Includes bibliographical references (p. 159-190).
32

Three-dimensional nonlinear finite element model for single and multiple dowel-type wood connections

Hong, Jung-Pyo 05 1900 (has links)
A new three-dimensional finite solid element (3D FE) model for dowel-type wood connections was developed using the concept of a beam on a nonlinear wood foundation, which addresses the intricate wood crushing behaviour under the connector in a dowel type connection. In order to implement the concept of wood foundation with solid elements, a 3D FE wood foundation model was defined within a prescribed foundation zone surrounding the dowel. Based on anisotropic plasticity material theory, the material model for the foundation zone was developed using effective foundation material constants that were defined from dowel-embedment test data. New 3D FE single nail connection models were developed that incorporated the wood foundation model. The 3D wood foundation model was justified and validated using dowel-embedment test data with a range of dowel diameters, from a 2.5-mm nail to a 25.4-mm bolt. The connection models provided successful results in simulating the characteristics of load-slip behaviour that were experimentally observed. Based on the success of the single nail connection models, several applications of the 3D FE connection models were investigated including statistical wood material models, bolted connection models and a multiple nail connection model. Throughout the application studies, discussion of the benefits and limitations of the new model approach using the 3D FE wood foundation are presented. Also, future areas of study are proposed in order to improve the 3D FE dowel-type wood connections models.
33

Accounting for help-seeking : why are some students reluctant to approach lecturers for help?

Grayson, Andrew January 1993 (has links)
No description available.
34

Three-dimensional nonlinear finite element model for single and multiple dowel-type wood connections

Hong, Jung-Pyo 05 1900 (has links)
A new three-dimensional finite solid element (3D FE) model for dowel-type wood connections was developed using the concept of a beam on a nonlinear wood foundation, which addresses the intricate wood crushing behaviour under the connector in a dowel type connection. In order to implement the concept of wood foundation with solid elements, a 3D FE wood foundation model was defined within a prescribed foundation zone surrounding the dowel. Based on anisotropic plasticity material theory, the material model for the foundation zone was developed using effective foundation material constants that were defined from dowel-embedment test data. New 3D FE single nail connection models were developed that incorporated the wood foundation model. The 3D wood foundation model was justified and validated using dowel-embedment test data with a range of dowel diameters, from a 2.5-mm nail to a 25.4-mm bolt. The connection models provided successful results in simulating the characteristics of load-slip behaviour that were experimentally observed. Based on the success of the single nail connection models, several applications of the 3D FE connection models were investigated including statistical wood material models, bolted connection models and a multiple nail connection model. Throughout the application studies, discussion of the benefits and limitations of the new model approach using the 3D FE wood foundation are presented. Also, future areas of study are proposed in order to improve the 3D FE dowel-type wood connections models.
35

Vida de fe en familia en estudiantes de una institución educativa del distrito de Santa Rosa 2016

Rafael Perez, Neire, Diaz Delgado, Marino January 2018 (has links)
El presente trabajo de investigación tiene como determinar las características de la vivencia de la fe en familia según dimensiones, en estudiantes de la I.E. José Olaya Balandra del distrito de Santa Rosa en el año 2016. Esta investigación se ha realizado con un enfoque cuantitativo, perteneciendo a un tipo de investigación descriptivo, puesto que solo se ha pretendido conocer la realidad en torno a la vida de fe en familia de los estudiantes encuestados. Se trabajó con una muestra de 578 estudiantes a quienes se aplicó un diagnóstico (cuestionario). Los resultados de la investigación se puede resumir en que la mayoría de familias no viven su fe de manera activa, especialmente en lo que se refiere a prácticas relacionadas con los sacramentos o devociones relacionadas con la Virgen María y los santos. / Tesis
36

Constituting the managerial subject : an investigation into middle-management in FE

Fort, Anthony January 2015 (has links)
This doctoral study draws upon interviews with nine curriculum-based FE college middle-managers, and three college strategic plan documents, to critically analyse middle-management identity. Through the use of an analytical framework based on Foucault’s archaeological and genealogical ‘method’ the study shows that when middle-managers talk about their professional practice they are preoccupied with data-metrics. Consequently, they are recognised as ‘disciplined subjects’; disciplined by those data-metrics materially inscribed within the discursive regimes of their college strategic plan documents. The study additionally indicates that the more hierarchically senior the middle-manager the greater the intensity of focus upon data-metrics at the expense of institutional social relations, whereby their preoccupations with data-metrics yield de-socialising effects between themselves and key institutional participants such as teachers, learners and support staff. The study further suggests that while the middle-managers within this study were curriculum-based they were not curriculum-focused; findings which were consistent through the range of middle-management levels: senior-middle, lower-middle and middle-middle, and at separate college sites. Considered together these findings raise a number of important questions for the crucial role of curriculum-based middle-managers, particularly where middle-management as a function is recognised as the means by which policy implementation is secured yet where curriculum-based work, when understood as necessarily tied to pedagogic practices, requires a focus around ‘the learner’; a learner not ontologically foregrounded as data, but in authentically social terms.
37

Three-dimensional nonlinear finite element model for single and multiple dowel-type wood connections

Hong, Jung-Pyo 05 1900 (has links)
A new three-dimensional finite solid element (3D FE) model for dowel-type wood connections was developed using the concept of a beam on a nonlinear wood foundation, which addresses the intricate wood crushing behaviour under the connector in a dowel type connection. In order to implement the concept of wood foundation with solid elements, a 3D FE wood foundation model was defined within a prescribed foundation zone surrounding the dowel. Based on anisotropic plasticity material theory, the material model for the foundation zone was developed using effective foundation material constants that were defined from dowel-embedment test data. New 3D FE single nail connection models were developed that incorporated the wood foundation model. The 3D wood foundation model was justified and validated using dowel-embedment test data with a range of dowel diameters, from a 2.5-mm nail to a 25.4-mm bolt. The connection models provided successful results in simulating the characteristics of load-slip behaviour that were experimentally observed. Based on the success of the single nail connection models, several applications of the 3D FE connection models were investigated including statistical wood material models, bolted connection models and a multiple nail connection model. Throughout the application studies, discussion of the benefits and limitations of the new model approach using the 3D FE wood foundation are presented. Also, future areas of study are proposed in order to improve the 3D FE dowel-type wood connections models. / Forestry, Faculty of / Graduate
38

The Effects of Gamma (γ-) Sterilization on the Redox Stability, Minerology, and Physicochemical Properties of the Synthetic Iron Oxides Ferrihydrite, Lepidocrocite, and Goethite

Khan, Brandon Sajad January 2017 (has links)
Laboratory analyses were conducted on synthetic iron oxides to assess the use of gamma (γ-) irradiation as an efficient sterilization technique to remove microorganisms present in natural bacteriogenic iron oxides (BIOS) and to determine if the technique induces mineralogical changes within the Fe-rich minerals. Fe-oxides (ferrihydrite, lepidocrocite, and goethite) were synthesized with and without alginate (as a proxy for exopolysaccharides) and microbial reductions were carried out using the bacterium Shewanella putrefaciens CN32. A total of 18 Fe-oxide minerals were subjected to microbial reduction to assess redox stability, alteration due to varying levels of gamma irradiation (0, 5, and 28 kGy), and the addition of the exopolysaccharide alginate. Iron reduction rates varied for each Fe-oxide with faster Fe (III) reduction rates observed for the amorphous poorly-sorted 2-line ferrihydrite and slower Fe (III) reduction for the more crystalline Fe-oxides lepidocrocite and goethite. There was no significant impact to the Fe (III) reduction rates due to gamma irradiation (p> 0.05), which was confirmed using a t-test for statistical variance between gamma irradiated samples. However, the addition of alginate enabled lepidocrocite and goethite to achieve maximum Fe (III) reduction by an average of 7 days faster when compared to the Fe-oxides synthesized without the exopolysaccharide.
39

Chemical vapor deposition of Al, Fe and of the Al13Fe4 approximant intermetallic phase : experiments and multiscale simulations / Dépôt chimique en phase vapeur d'Al, Fe et de la phase approximante Al13Fe4 : expériences et simulations multi-échelles

Aviziotis, Ioannis 15 November 2016 (has links)
Des couches minces contenant des phases intermétalliques présent et des propriétés et de combinaisons de propriétés qui ne sont que partiellement explorées. Elles portent des solutions potentielles pour conférer des multifonctionnalités à des matériaux avancés requis par les secteurs industriels et sont source derupture et de l'innovation. Leur élaboration par dépôt chimique en phase vapeur à partir de précurseurs métallo-organiques (MOCVD) permet un dépôt conforme sur, et la fonctionnalisation de surfaces complexes, avec un temps de traitement court et à un coût modéré.Pour ceci, il est nécessaire de contrôler les réactions chimiques complexes et des mécanismes de transport impliqués. La modélisation informatique du procédé, alimentée avec des données obtenues par des expériences de dépôt ciblées, est un outil intégré pour l'étude et la compréhension des phénomènes qui se produisent à différentes échelles,de l’échelle macroscopique à celle nanométrique. La MOCVD de composés intermétalliques Al-Fe est étudiée en tant que paradigme de la mise en oeuvre d'une telle approche combinée, expérimentale et théorique. La phase approximanteAl13Fe4 est particulièrement ciblée,en raison de son intérêt comme alternative peu onéreuse aux catalyseurs à base de métaux noble dans l'industrie chimique. La mise au point du dépôt de la phase Al13Fe4est subordonnée à l'étude des proc /min à 185oC. La simulation du procédé prédit des vitesses de croissance en bon accord avec ces résultats, en particulier dans la gamme 139oC-227oC. La modélisation multi-échelle prédit la rugosité RMS avec précision, permettant ainsi le contrôle des propriétés telles que la résistivité électrique. La possibilité d'obtenir des films MOCVD de Fe à faible contamination en O et C est explorée dans la gamme 130oC-250oC à partir de fer pentacarbonyle, Fe(CO)5. La morphologie de la surface des films dépend fortement de la température de dépôt; elle devient plus lisse au-dessus de200oC, qui correspond aussi à la vitesse de croissance maximale, 60nm/min. La vitesse de dépôt diminue fortement lorsque la pression augmente. Les prédictions de la modélisation macroscopique reproduisent précisément ce comportement. Elles indiquent que la diminution de la vitesse de croissance à des températures et des pressions élevées est due à l’augmentation de la décomposition du précurseur en phase gazeuse et à l'inhibition de la réactivité de surface par le ligand CO. Le modèle multi échelle conduit à des valeurs RMS en bon accord avec les mesures expérimentales, en particulier à des températures plus élevées. Suite à l’étude des deux procédés, des co-dépôts d'Al-Fe effectués à 200oCrésultent en des films riches en Alavec une microstructure poreuse et rugueuse. Ceux-ci ne contiennent pas de phases intermétalliques et sont riches en oxygène dû à la réaction d'Al avec les ligandscarbonyles. Afin d’éliminer la contamination, des dépôts séquentiels d'Al et de Fe sont réalisés, ce dernier dans des conditions modifiées à 140oC, 40Torr et 10 min. Ces films sont exemptes d’hétéroélements et présentent un rapport atomique Al:Fe13:4. Diffraction des rayons X et microscopies électroniques révèlent qu’un recuit in situ à 575oC pendant 1 h conduit à des films à gradient de la composition sur l'épaisseur,composés de la phase approximantem-Al13Fe4 conjointement avec des phases intermétalliques Al-Fesecondaires. Il est ainsi démontré que des procédés MOCVD sont appropriés pour obtenir des films constitués d'alliages intermétalliques.Ces films multifonctionnels,appliqués de façon conforme sur des surfaces complexes sont utiles pour un grand nombre d'applications. / Films containing intermetallic compounds exhibit properties and combination of properties which are only partially explored. They carry potential solutions to confer multifunctionality to advanced materials required by industrial sectors and to become a source of breakthrough and innovation.Metalorganic chemical vapor deposition (MOCVD) potentially allows conformal deposition on, and functionalization of complex surfaces, with high throughput and moderate cost. For this reason, it is necessary to control the complex chemical reactions and the transport mechanisms involved in a MOCVD process. In this perspective, computational modeling of the process, fed with experimental information from targeted deposition experiments, provides an integrated tool for the investigation and the understanding of the phenomena occurring at different length scales, from the macro- to the nanoscale. The MOCVD of Al-Fe intermetallic compounds is investigated in the present thesis as a paradigm of implementation of such a combined, experimental and theoretical approach. Processing of the approximant phase Al13Fe4 is particularly targeted, due to its potential interest as low-cost and environmentally benign alternative to noble metal catalysts in the chemical industry. The attainment of the targeted Al13Fe4 intermetallic phase passes through the investigation of the MOCVD of unary Al and Fe films. The MOCVD of Al from dimethylethylamine alane (DMEAA) in the range 139oC-241oC results in pure films. Increase of the deposition temperature yields higher film density and decreased roughness. The Aldeposition rate increases to a maximum of 15.5 nm/min at 185oC and then decreases. Macroscopic simulations of the process predictdeposition rates in sufficient agreement with experimental measurements, especially in the range 139oC-227oC. At higher temperatures, competitive gas phase and surface phenomena cannot be captured by the applied model. Multiscale modeling of the process predicts the RMS roughness of the films accurately, thus allowing the control of properties such as electrical resistivity which depend on the microstructure. The MOCVD of Fe from iron pentacarbonyl, Fe(CO)5, is investigated in the range 130oC-250oC for the possibility toobtain fairly pure Fe films with low Oand C contamination. The surface morphology depends strongly on the temperature and changes are observed above 200oC. The Fe deposition rate increases up to 200oC, to a maximum of 60 nm/min, and then decreases. Moreover, the deposition rate decreases sharply with increasing pressure. Computational predictions capture accurately the experimental behavior and they reveal that the decrease athigher temperatures and pressures is attributed to the high gas phase decomposition rate of the precursor and to inhibition of the surface fromCO. The multiscale model calculates RMS roughness in good agreement with experimental data, especially at higher temperatures. Upon investigation of the two processes, aseries of Al-Fe co-depositions performed at 200oC results in Al-rich films with a loose microstructure. They contain no intermetallic phases and they are O-contaminated due to the reaction of the Al with the carbonyl ligands. Sequential deposition of Al and Fe followed by in situ annealing at 575oC for 1 h is applied to bypass the Ocontamination. The process conditions of Fe are modified to 140oC, 40 Torr and 10 min resulting in O-free films with Al:Fe atomic ratio close to the targeted 13:4 one. Characterization techniques including X-ray diffraction, TEM and
40

Novel pathway for microbial FE(III) reduction: electron shuttling through naturally occurring thiols

Wee, Seng Kew 08 June 2015 (has links)
The g-proteobacterium Shewanella oneidensis MR-1 reduces a wide range of terminal electron acceptors, including solid Fe(III) oxides. Pathways for Fe(III) oxide reduction by S. oneidensis include non-reductive (organic ligand-promoted) solubilization reactions, and either direct enzymatic, or indirect electron shuttling pathways. Results of the present study expand the spectrum of electron acceptors reduced by S. oneidensis to include the naturally occurring disulfide compounds cystine, oxidized glutathione, dithiodiglycolate, dithoidiproponiate and cystamine. Subsequent electron shuttling experiments demonstrated that S. oneidensis employs the reduced (thiol) form of the disulfide compounds (cysteine, reduced glutathione, mercaptoacetate, mercaptopropionate, and 2-nitro-5-thiobenzoate, cystamine) as electron shuttles to transfer electrons to extracellular Fe(III) oxides. The results of the present study indicate that microbial disulfide reduction may represent an important electron-shuttling pathway for electron transfer to Fe(III) oxides in anaerobic marine and freshwater environments.

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