Zusammenfassung Der vorliegende Beitrag schlägt eine Auswahlmethode vor, die geeignete Verfahren zur kosteneffizienten Rekonstruktion geometrischer Daten von Baugruppen und Bauteilen aufzeigt. Dabei werden verschiedene objektbezogene Einflussfaktoren wie beispielsweise die Bauteilkomplexität, vorhandene Standardfeatures (z.B. genormte Gewindebohrungen) oder besondere Oberflächengeometrien berücksichtigt. Darüber hinaus werden verschiedene Techniken anhand der Kriterien zeitlicher Aufwand, technologischer Aufwands und erzielbarer Maßgenauigkeit quantitativ verglichen. Dadurch kann der Anwender einen erforderlichen Kompromiss zwischen kostenmäßigem Aufwand und erzielbarer Maßgenauigkeit abschätzen.

Made available in DSpace on 2016-04-27T16:57:07Z (GMT). No. of bitstreams: 1 Maria Lucia Torelli Doria de Andrade.pdf: 1813485 bytes, checksum: d412ceceb706049da015f5eeb9437db2 (MD5) Previous issue date: 2011-05-31 / Coordenação de Aperfeiçoamento de Pessoal de Nível Superior / The objective of the current work is to investigate ownership of Spherical Geometry elementary concepts by students in the second year of high school, from a teaching sequence. In addition, it aimed to solve the activities of this sequence, the subjects carry out research treatments and Semiotic Registers Representation conversions relevant to the mathematical Spherical Geometry objects to be studied. We seek to answer the following question: How a didactic sequence articulating different Registers Representation can evaluate high school students in learning Spherical Geometry concepts? Therefore, we applied to two high school students teaching sequence. We based it on Raymond Duval s Semiotic Registers Representation Theory and Guy Brousseau s Didactic Situations Theory as theoretical foundation of this research. The research approach was qualitative and, as methodology we adopted Engineering Curriculum assumptions. Watching the subjects research production in the course of the activities sequence, we found out these individuals performed conversions and registers treatments by semiotic representation according to Duval (2009), as well as they did the record conversion in natural language (activity statement) to record material (Styrofoam ball), which led them to solve the activity and understand Spherical Geometry straight line concept. In this sense, we could highlight semiotic representation material record, and infer that it contributed to the concepts ownership required by the research subjects / O presente trabalho tem como objetivo investigar a apropriação de conceitos elementares de Geometria Esférica por alunos do 2º ano do Ensino Médio, a partir de uma sequência de ensino. Além disso, objetivava que ao resolver as atividades desta sequência, os sujeitos de pesquisa realizassem os tratamentos e conversões dos Registros de Representação Semiótica pertinentes aos objetos matemáticos da Geometria Esférica a serem estudados. Buscamos responder a seguinte questão de pesquisada: Como uma sequência didática articulando diferentes registros de representação pode avaliar alunos do Ensino Médio na aprendizagem de conceitos de Geometria Esférica? Assim, aplicamos junto a dois alunos do Ensino Médio a sequência de ensino. Nos embasamos na Teoria dos Registros de Representação Semiótica de Raymond Duval e na Teoria das Situações Didáticas de Guy Brousseau como fundamentação teórica dessa pesquisa. A abordagem desta investigação foi qualitativa e, como metodologia adotamos pressupostos da Engenharia Didática. Observando as produções dos sujeitos de pesquisa no decorrer das atividades da sequência, constatamos que esses realizaram as conversões e os tratamentos dos registros de representação semiótica de acordo com Duval (2009), como quando fizeram a conversão do registro em língua natural (enunciado da atividade) para o registro material (bola de isopor), o que os levou a resolver a atividade e compreender o conceito de reta na Geometria Esférica. Nesse sentido, pudemos destacar o registro material de representação semiótica, e inferir que esse contribuiu para a apropriação dos conceitos requeridos por parte dos sujeitos de pesquisa

<p>Adsorption of organic molecules at a surface of titanium dioxide (101) anatase is studied using quantum-chemical density functional theory. Anatase can be used in solar cells. For the clean anatase surface the band gap is so large that only UV-light can excite electrons. Different groups with conjugated systems are attached to obtain a more suitable band gap. </p><p>Phenol was attached in different positions to a cluster of anatase and geometry optimized using the B3LYP-functional. The geometry that was energetically most favorable was used to put in phenylmethanol, phenylethanol, naphthol, 2-phenanthrol, 1-pyrol and 2-perylol. To give a more realistic model of phenol at anatase, a study of a two- dimensional periodic anatase surface was also made. </p><p>Molecular orbitals were calculated to study the overlap between HOMO and LUMO orbitals. The calculation shows that phenol will remain as a molecule and will not dissociate. The band gap gets smaller when molecules are attached at the cluster and with 2-perylol it reaches the energy of visible light. </p><p>The molecular orbitals for HOMO, LUMO and LUMO of the adsorbed molecule were investigated. HOMO was localized at the molecule, LUMO at the cluster and LUMO of the adsorbed molecule move closer to the energy of LUMO when the number of rings increases.</p>

The first ocean general circulation models developed in the late sixties were based on finite differences schemes on structured grids. Many improvements in the fields of engineering have been achieved since three decades with the developments of new numerical methods based on unstructured meshes. Some components of the first models may now seem out of date and new second generation models are therefore under study, with the aim of taking advantage of the potential of modern numerical techniques such as finite elements. In particular, unstructured meshes are believed to be more efficient to resolve the large range of time and space scales present in the ocean. Besides the classical continuous finite element or finite volume methods, another popular new trend in engineering applications is the Discontinuous Galerkin (DG) method, i.e. discontinuous finite elements presenting many interesting numerical properties in terms of dispersion and dissipation, errors convergence rates, advection schemes, mesh adaptation, etc. The method is especially efficient at high polynomial orders. The motivation for this PhD research is therefore to investigate the use of the high-order DG method for geophysical flow modeling. A first part of the thesis is devoted to the mesh adaptation using the DG method. The inter-element jumps of the fields are used as error estimators. New mesh size fields or polynomial orders are then derived and local h- or p-adaptation is performed. The technique is applied to standard benchmarks and computations in more realistic domains as the Gulf of Mexico. A second part deals with the use of the high order DG method with high-order representation of geometrical features. On one hand, a method is proposed to deal with complex representations of the coastlines. Computations are performed using high-order mappings around the Rattray island, located in the Great Barier Reef. Numerical results are then compared to in-situ measurements. On the other hand, a new method is proposed to deal with curved manifolds in order to represents oceanic or atmospheric flows on the sphere. The approach is based on the use of a local high-order non-orthogonal basis, and is equivalent to the use of vectorial shape and test functions to represent the vectorial conservation laws on the manifold's surface. A method is finally proposed to analyze the dispersion and dissipation properties of any numerical scheme on any kind of grid, possibly unstructured. The DG method is then compared to other techniques as the mixed non-conforming linear elements, and the impact of unstructured meshes is studied.

A new version of the Deforming-Spatial-Domain/Stabilized Space--Time (DSD/SST) formulation of incompressible flows has been introduced recently to have additional subgrid-scale representation features. This is the space--time version of the residual-based variational multiscale (VMS) method. The new version is called DSD/SST-VMST (i.e. the version with the VMS turbulence model) and also Space--Time VMS (ST-VMS). The thesis starts with a brief overview of the ST-VMS method. It continues with a comprehensive set of test computations with 3D airfoil geometries at high Reynolds numbers and comparison with experimental data. The thesis shows that the test computations signal a promising future for the ST-VMS method.

A new version of the Deforming-Spatial-Domain/Stabilized Space--Time (DSD/SST) formulation of incompressible flows has been introduced recently to have additional subgrid-scale representation features. This is the space--time version of the residual-based variational multiscale (VMS) method. The new version is called DSD/SST-VMST (i.e. the version with the VMS turbulence model) and also Space--Time VMS (ST-VMS). The thesis starts with a brief overview of the ST-VMS method. It continues with a comprehensive set of test computations with 3D airfoil geometries at high Reynolds numbers and comparison with experimental data. The thesis shows that the test computations signal a promising future for the ST-VMS method.

Adsorption of organic molecules at a surface of titanium dioxide (101) anatase is studied using quantum-chemical density functional theory. Anatase can be used in solar cells. For the clean anatase surface the band gap is so large that only UV-light can excite electrons. Different groups with conjugated systems are attached to obtain a more suitable band gap. Phenol was attached in different positions to a cluster of anatase and geometry optimized using the B3LYP-functional. The geometry that was energetically most favorable was used to put in phenylmethanol, phenylethanol, naphthol, 2-phenanthrol, 1-pyrol and 2-perylol. To give a more realistic model of phenol at anatase, a study of a two- dimensional periodic anatase surface was also made. Molecular orbitals were calculated to study the overlap between HOMO and LUMO orbitals. The calculation shows that phenol will remain as a molecule and will not dissociate. The band gap gets smaller when molecules are attached at the cluster and with 2-perylol it reaches the energy of visible light. The molecular orbitals for HOMO, LUMO and LUMO of the adsorbed molecule were investigated. HOMO was localized at the molecule, LUMO at the cluster and LUMO of the adsorbed molecule move closer to the energy of LUMO when the number of rings increases.

This thesis examines Dar&uuml / lf&uuml / nun Konferanslari which consists of a series of lectures that were delivered by Salih Zeki in 1914 &ndash / 1915 in Ottoman State. These lectures were on geometry, its history and especially on the discovery of non-Euclidean geometries. And the purpose of this thesis is to propose the sufficiency and the legitimacy of these lectures as an account on the history of geometry. As a preliminary to analyzing Salih Zeki&rsquo / s lectures, different views on geometry&rsquo / s history and progress will be analyzed and compared. The results of this comparison will be the guide by means of which Dar&uuml / lf&uuml / nun Konferanslari will be examined. This thesis also serves as a source that makes Salih Zeki&rsquo / s ideas accessible, by presenting an English summary of his lectures which were originally published in Ottoman Turkish.

Thesis (MEng) -- Stellenbosch University, 2014 / ENGLISH ABSTRACT: The electrodynamics of arbitrary, point-to-plane electrospraying geometries, were investigated in this research both analytically and numerically. Electrospraying is the process during which particles of sizes in the nanometre range are simultaneously generated and charged by means of an applied electrostatic field. A high electrostatic potential is applied to a conductive capillary needle, which overcomes the force exerted by the liquid surface tension. One of the primary limitations of this process are corona discharges. The effect of corona discharges have not been studied quantitatively, even though it is frequently reported in the electrospraying literature. The main objective of this research was to understand the corona discharge thresholds associated with electrospraying. Previously, only one theoretical, and two empirical investigations studied this phenomenon, over a time period of approximately forty years. It was clear that by better understanding these thresholds, electrospraying could be applied much more effectively. A corona discharge threshold model is proposed, using either a numerical or analytical model for the calculation of polarization fields. When compared with the experimental results of other researchers, both these two models have average relative percentage errors of approximately 15%. These are the first models proposed in the literature for the calculation of electrospraying corona thresholds. A new method to determine surface tension using electrospraying is described theoretically. In addition to this method, the calculation of corona discharge thresholds have various applications. For example, the dynamics of electrostatic ion thrusters are much better described, powder production by means of electrospraying can be optimised, and pattern generation using pulsed electrospraying cone-jets can be optimised as well. / AFRIKAANSE OPSOMMING: Die elektrodinamika van arbitrêre, punt-tot-vlak elektrosproei geometrieë was beide analities en numeries ondersoek in hierdie tesis. Dit is die proses waartydens nanodeeltjies gelyktydig gegenereer en elektrostaties gelaai word. Deur 'n hoë elektriese potensiaal aan te lê tot 'n geleidende kapillêr, is dit moontlik om die krag van die oppervlakte spanning te oorkom. Een van die primêre beperkings van elektrosproei is corona ontladings. Die effek van corona ontladings was nog nie kwantitatief bestudeer nie, selfs al word dit dikwels rapporteer in die elektrosproei literatuur. Die primêre doel van hierdie navorsing was om die corona ontlading drempels te verstaan wat geassosieer word met elektrosproei. In die verlede was daar nog net een teoretiese, en twee empiriese ondersoeke gewees wat hierdie verskynsel bestuur het, oor 'n tydperk van ongeveer veertig jaar. Dit was duidelik dat deur 'n beter begrip te hê van hierdie elektrosproei drempels, kan hierdie proses baie meer doeltreffend toegepas word. In hierdie tesis word 'n corona ontlading drempel model voorgestel, wat gebruik maak van 'n analitiese of numeriese model om die polarisasie velde te bereken. Wanneer vergelyk met die resultate van ander navorsers, het beide die modelle 'n gemiddelde relatiewe persentasie fout van ongeveer 15%. Hierdie is die eerste modelle wat voorgestel word vir die berekening van corona ontlading drempels. Deur gebruik te maak van elektrosproei, word 'n nuwe metode ook voorgestel om die oppervlakte spanning te bereken. In byvoeging tot hierdie, het die berekening van corona ontlading drempels vele ander toepassings. As 'n voorbeeld, die dinamika van elektrostatiese ioon stuwers word beter beskryf, en poeier produksie deur middel van elektrosproei kan optimeer word.

Submitted by RITA DE CASSIA IDEM null (ritaipvt@gmail.com) on 2018-01-02T19:57:36Z No. of bitstreams: 1 Dissertação_Rita Idem.pdf: 4181624 bytes, checksum: 24ad8d143f22775db811032ac8bfe18c (MD5) / Approved for entry into archive by Adriana Aparecida Puerta null (dripuerta@rc.unesp.br) on 2018-01-05T10:59:25Z (GMT) No. of bitstreams: 1 idem_rc_me_rcla.pdf: 3718572 bytes, checksum: 8c1dec95d9ecba7c9a2e5d105b406db8 (MD5) / Made available in DSpace on 2018-01-05T10:59:25Z (GMT). No. of bitstreams: 1 idem_rc_me_rcla.pdf: 3718572 bytes, checksum: 8c1dec95d9ecba7c9a2e5d105b406db8 (MD5) Previous issue date: 2017-12-07 / Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq) / Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES) / Esta pesquisa teve como cenário de investigação um curso de extensão universitária, do qual participaram licenciandos em Matemática e professores. O curso se deu por meio de investigações de atividades sobre Geometria Plana e Geometria Espacial com o uso do software GeoGebra e discussões sobre a integração de tecnologias digitais no ensino. Nesse contexto, o objetivo foi identificar e analisar conhecimentos que emergiram durante o curso de extensão universitária, bem como, investigar os contextos em que essa emergência ocorreu. Sendo assim, a pergunta que norteou esta pesquisa foi: Que conhecimentos docentes emergem quando licenciandos em Matemática e professores exploram atividades de Geometria utilizando o GeoGebra? Este estudo apoiou-se teoricamente no Construcionismo, e nos Conhecimentos Docentes, principalmente em relação ao construto teórico Conhecimento Tecnológico Pedagógico de Conteúdo (TPACK). A produção de dados se deu por meio de filmagens dos encontros do curso, da gravação da tela do computador, da coleta de atividades escritas dos participantes, do desenvolvimento de atividades pelos participantes e de entrevistas semiestruturadas com os mesmos. A análise dos dados evidenciou dois momentos distintos: um momento em que ocorriam Ciclos de Ações construcionistas e emergiam Conhecimentos Tecnológicos, de Conteúdo e suas articulações, caracterizado pela exploração das atividades do curso; em outro momento emergiam Conhecimentos Pedagógicos, Tecnológicos Pedagógicos, Tecnológicos Pedagógicos de Conteúdo e conhecimentos referentes ao contexto educacional, caracterizado pelas discussões no curso, pelas entrevistas e pelo desenvolvimento de atividades. Os resultados evidenciaram que durante o curso houve a emergência de conhecimentos necessários à integração das tecnologias digitais no ensino, os quais se relacionaram à experimentação geométrica com o GeoGebra, à aprendizagem construcionista e a possíveis obstáculos à integração das tecnologias digitais no ensino. Dessa maneira, este estudo buscou contribuir com discussões sobre a articulação teórica Construcionismo-TPACK na aprendizagem docente e sobre perspectivas de sua influência na formação de professores de Matemática. / This research had as an investigation scenario a university extension course, which was attended by future Mathematics teachers and teachers. The course took place through investigations of activities about Plane Geometry and Space Geometry with the using of GeoGebra software and discussions about the integration of digital technologies in teaching. In this context, the objective was to identify and analyze knowledge that emerged during the university extension course, as well as to investigate the contexts in which this emergence occurred. Thus, the question that guided this research was: What teaching knowledge emerge when undergraduate Mathematics students and teachers explore Geometry activities using GeoGebra? This study was theoretically based on Constructionism, and on Teaching Knowledge, mainly in relation to the theoretical construct Technological Pedagogical Content Knowledge (TPACK). The production of data took place through the filming of the course meetings, the recording of the computer screen, the collection of written activities of the participants, the development of activities by the participants and semi-structured interviews with them. The analysis of the data revealed two distinct moments: a moment in which constructionist Cycles of Actions occurred and Technological Knowledge, Content Knowledge and their articulations emerged, characterized by the exploration of the activities of the course; In another moment emerged Pedagogical Knowledge, Technological Pedagogical Knowledge, Technological Pedagogical Content Knowledge and knowledge regarding the educational context, characterized by the discussions in the course, the interviews and the development of activities. The results evidenced that during the course there was the emergence of the necessary knowledge to integrate digital technologies in teaching, which were related to geometric experimentation with GeoGebra, constructionist learning and possible constraints to the integration of digital technologies in teaching. In this way, this study sought to contribute with discussions about the theoretical articulation of Constructionism-TPACK in teacher learning and on the perspectives of its influence in the Mathematics Teachers’ Education.