In this thesis the lateral resolution limits of the Laser Induced Forward Transfer (LIFT) technique are being investigated. LIFT is a laser direct write process with micron and below resolution and is suitable for modifying, repairing and prototyping micro-devices. Single laser pulses with wavelength of 800 nm and duration of 130 fs from a Ti:Sapphire laser system were focused onto a transparent donor substrate coated with thin film to transfer the thin film material in the form of micro-disks through a small air gap onto an acceptor substrate. In this thesis, donor glass substrate coated with 80nm continuous Cr film and also Cr disks array patterned by photolithography or e-beam lithography were used as targets. The ablation threshold and transfer threshold were determined experimentally and compared to results from two-temperature model (TTM) simulations and reasonably agreement was obtained. For the continuous film target, the size of the LIFT disks depend on the laser fluences and the smallest sizes of around 700 nm were obtained near the transfer threshold. For the pre-patterned disks array targets, initially 1.3m Cr disks were fabricated on the donor substrates by photolithography. Small focused, larger defocused and large top-hat laser beams were used to transfer the pre-patterned Cr disks. The morphology of the transferred material and reliability of transfer were studied. It was found that the large top-hat beam gave the most reliable and high quality transfer results, resulting in mostly intact LIFT disks on the acceptor substrate. To push the resolution limit further, 500nm Cr disks fabricated on the donor substrate by e-beam lithography were used. The successful transfer of these 500 nm Cr disks gives a positive indication that LIFT can potentially be extended further to the nano-scale regime (usually defined as having sub-100 nm resolution).

Thesis (M.S.P.H.)--University of South Florida, 2008. / Title from PDF of title page. Document formatted into pages; contains 45 pages. Includes bibliographical references.

Thesis (MEng)--Stellenbosch University, 2014. / ENGLISH ABSTRACT: Neck pain is a common phenomenon that occurs in a large percentage of the population every day. While many occurrences are not deemed critical such as those from muscle strain which can be treated with rest and pain medication, others due to sports injuries, whiplash from car accidents, bad posture or degeneration of the intervertebral disc can be quite severe. In extreme cases failure of the vertebra(e) or the intervertebral disc requires surgery and possibly the use of cervical implants. Where intervertebral discs fail due to herniation or Degenerative Disc Disease (DDD), Anterior Cervical Discectomy and Fusion (ACDF) is a common surgical method used to remove the a ected disc and replace it with a cervical cage implant. These implants are designed to restore the height between the vertebrae, allowing bone from both vertebrae to grow through them and mineralise. Additive Manufacturing (AM) technologies can produce parts with complex geometries not possible using conventional manufacturing methods. This design freedom, coupled with CT scans of a patient, allow for tailoring an implant to the speci c anatomy of the a ected vertebrae using CAD software. Such an approach must be regulated and shown to be technically and commercially feasible before it can be implemented in industry. This study sought to develop a framework for manufacturing customized cervical cage implants using additive manufacturing. The e cacy of customization to reduce the risk of subsidence was investigated by means of non-destructive and destructive mechanical testing on six cadaver specimens, using readily available PEEK cage implants as a benchmark. The results showed that the customized implant was comparable to the PEEK, with no statistically signi cant di erence between the two. In extreme cases, where PEEK implants cannot be used, customized implants could be a suitable alternative to reduce the risk of subsidence. A manufacturing cost analysis was conducted to determine economic feasibility. The estimated cost and selling price of the customized implants under various utilization scenarios and mark-ups was compared to readily available PEEK implants. The estimated selling prices of the customized implants compared favourably to the PEEK verifying the economic viability of using AM. / AFRIKAANSE OPSOMMING: Nek pyn is 'n algemene verskynsel wat daagliks na tevore kom in die bevolking. Baie gevalle word nie as krities geklasi seer nie soos byvoorbeeld spier pyn wat behandel kan word deur genoegsame rus en pyn medikasie. Pyn wat deur sportbeserings, sweepslag beserings 'whiplash' tydens motor ongelukke, verkeerde postuur, of deur slytasie van 'n intervertebrale skyf veroorsaak is, word dikwels as ernstig geklasi seer. In ekstreme gevalle waar die werwel(s) of die inervertebrale skyf(we) faal, sal chirurgie en servikale inplantate moontlik nodig wees. Waneer intervertebrale skywe faal weens herniatie of Degeneratiewe Skyf Siekte (DDD) kan 'n algemene chirurgiese metode, Anterieure Servikale Discectomie en Fusie (ACDF), gebruik word om die gea ekteerde skyf te verwyder en dit te vervang met 'n servikale samesmelting implantaat. Hierdie implantate herstel die hoogte tussen rugwerwels en is ontwerp sodat die been deur dit kan groei en mineraliseer. Komplekse geometrieë kan vervaardig word deur toevoegingsvervaardiging (AM) tegnologieë. Die ontwerp vryheid, gepaard met CT-skanderings en CAD-sagteware stel mens in staat om die geometrie van die implantaat aan te pas tot die spese eke anatomie van die gea ekteerde vertebra. So 'n benadering moet gereguleer word en eers tegnies en kommersieel uitvoerbaar bewys word voordat dit in die bedryf geïmplementeer kan word. Hierdie studie poog verder om 'n raamwerk vir die vervaardiging van persoonlike servikale implantate deur middel van toevoegingsvervaardiging te ontwikkel. Die doeltre endheid van persoonlike implantate om te verhoed dat die chirurg die eind-plaat beskadig, en sodoende die risiko van insakking te verminder, is ondersoek deur middel van meganiese toetse op ses kadawer monsters. Hierdie toetse is gedoen met behulp van geredelik beskikbaar PEEK servikale implantate as 'n maatstaf. Die resultate het getoon dat die persoonlike- en PEEK implantate vergelykbaar is. In moontlike gevalle waar PEEK implantate nie geskik sou wees nie, kan persoonlike implantate 'n alternatiewe opsie wees om die risiko van insakking te verminder.

Este trabalho apresenta uma proposta para o Ensino de Física partindo de aplicações da Física em produtos tecnológicos, e está formatado à luz da pedagogia construtivista de Piaget, Vygotsky e Ausubel. Pretende-se despertar a curiosidade e o interesse dos professores e, como conseqüência, dos alunos, pelos temas da Física, desmistificando equipamentos utilizados no cotidiano. Um dos objetivos do trabalho é contribuir para o preenchimento de lacunas existentes no Ensino de Física no Ensino Médio através da formação continuada de professores. O desenvolvimento do trabalho consistiu na realização de oficinas para professores e estudantes do Ensino Médio focalizadas no estudo de Fenômenos Ondulatórios, Eletromagnetismo e Tópicos de Física Moderna que explicam o funcionamento do forno de microondas e do disco rígido de computador. As oficinas foram oferecidas para professores de Física em seis localidades diferentes do Estado, e para alunos da terceira série do Ensino Médio do Instituto Estadual de Educação Cardeal Pacelli de Três de Maio, e consistiram de uma série de atividades, como a desmontagem de um forno de microondas e do disco rígido de computador, atividades interativas e experimentais. A realização destas atividades está de acordo com a proposta de Piaget, segundo a qual, as ações humanas são a base do comportamento. As atividades são desenvolvidas em pequenos grupos, seguidas por momentos de discussão no grande grupo, pois, conforme Vygotsky, o desenvolvimento cognitivo tem como origem a conversão de relações sociais em funções mentais. Através do conjunto de atividades, seja através das ações ou interações humanas, os conhecimentos prévios dos indivíduos são constantemente confrontados com novos conhecimentos, criando condições para uma aprendizagem significativa, conforme Ausubel. O trabalho foi submetido à avaliação com a aplicação de um pré-teste, antes do início das atividades propostas, e de um pós-teste, aplicado após o encerramento das atividades. Os resultados das avaliações mostraram que novos conceitos foram aprendidos pelos participantes, indicando que a proposta, baseada no ensino de Física a partir de aplicações tecnológicas, é eficiente e indicada para promover a melhoria da qualidade do Ensino de Física. / This work consists in a project for Physics Education starting from the application of Physics in technological products, and it is based on the theory of constructivism from Piaget, Vygotsky and Ausubel. The aim is to instigate the curiosity and the interest of teachers and, as a consequence, of students, by Physics subjects, through experiments based on how domestic equipments work. One of the purposes of this project is to help improving the formation of High School Physics teachers. The project consisted of workshops for teachers and High School students, focused on Wave Phenomena, Electromagnetism and Modern Physics, to explain how the microwave oven and a computer hard disk work. The workshops were held at six towns in the Northeast region of the State and for senior High School students of the Instituto Estadual de Educação Cardeal Pacelli in Três de Maio. They consisted of different kinds of activities like disassembling a microwave oven and a computer hard drive, and interactive and experimental activities. The development of these activities is in agreement with the Piaget´s theory that the actions are the basis of the human behavior. The activities were performed in small groups, followed by discussion breaks with the whole group, since, according to Vygotsky, the cognitive development was created by the conversion of social relations to mental functions. Through the set of activities, involving actions and human interactions, the previews knowledge of the individuals are constantly confronted with new knowledge, making conditions for a meaningful learning, according to Ausubel. The evaluation of the project was based on tests for the participants, before and after the workshops. The results showed that the participants improved their knowledge about Physics concepts, indicating that the project, based on Physics education starting from the technological applications, is efficient and indicated to promote the improvement of the quality of Physics classes at High School.

Giardia intestinalis is an anaerobic parasite, that colonizes the small intestine of humans and other vertebrate hosts. This cosmopolitan parasite, which causes diarrhoea, is transmitted by contaminated water or food via a resistant stage, the cyst. The encystation process involves a number of events that lead to a complete reconstruction of the cell into the form of infectious cyst. The aim of this work was to visualize these modifications in vivo by means of enzymatic labelling of proteins. For the purposes of this work, enzymatic tags Y-FAST and HaloTag were chosen, as they enable visualizing live cells under anaerobic conditions. Chimeric protein constructs were created to visualize the dynamics of the encystation vesicles, the structures of endoplasmic reticulum, the adhesive disc and mitosis. Using the developed constructs, we successfully followed the dynamics of the encystation vesicles and the adhesive disc in vivo. Finally, this work has provided novel molecular tools, which will be used to follow the overall redesign of the parasite cell during encystation.

L’étude présentée est consacrée à l’usinabilité de la fonte à graphite vermiculaire. Celle-ci se situe entre la fonte à graphite lamellaire et la fonte à graphite sphéroïdale par rapport à la forme du graphite constituant ce matériau. Elle est utilisée depuis plus de cinq ans dans les blocs moteurs diesel afin d’améliorer les performances et de diminuer les rejets atmosphériques pour respecter les nouvelles normes Européennes. Pour évaluer l’usinabilité d’un matériau, il faut s’étalonner par rapport à un matériau de référence. Dans notre cas, la fonte à graphite vermiculaire a été comparée à la fonte à graphite lamellaire. Des essais de tractions ont permis d’obtenir les propriétés mécaniques du lot de matière utilisé pour la campagne d’essais d’usinage ; ceci, afin de se situer dans la gamme de ce type de fonte. Les plaquettes d’usinage ont été caractérisées par nano-indentation. Les revêtements PVD et CVD ont subit des essais de micro-rayure afin de caractériser leur adhésion sur leurs substrats respectifs. La mise en place d’un plan d’expérience a permis de limiter le nombre de plaquettes d’usinage prototypes à réaliser. Des essais tribologiques de type pion/disque ont révélé des pistes exploitables pour la compréhension des phénomènes de frottement et d’usures mis en jeu lors de l’usinage de la fonte à graphite vermiculaire. / This study deals with machinability of compacted graphite iron. This material is in-between grey cast iron and nodular cast iron due to the graphite particle shape. It is used for manufacturing diesel engine blocks so as to increase performances and reduce carbon emissions to comply with Euro 5 norm. It is necessary to compare one material to a reference material to evalute machinability criterium. In our case, compacted graphite iron has been compared to grey cast iron. Tensile tests have given us mechanical properties of our test pieces batch used for machining tests. It helped us to qualify the material in its own material range. Inserts have been characterized by nanoindentation. PVD and CVD coatings were benchmarked in microscratch way to determine their respective adhesion to theirs substrates A design of experiment has been setted up so as to reduce number of inserts protypes to be manufactured. Pin on disk tribologic tests gave few hints to have a better understanding of friction phenomena and wear during compacted graphite iron machining.

Esta dissertação traz ideias para a inserção de novos conteúdos na matemática escolar. Ela trata da exploração de geometrias não-euclidianas, através de dois ambientes de geometria dinâmica, o "Spherical Easel” e o "Disco de Poincaré". O primeiro é um software livre e o segundo foi desenvolvido utilizando-se o recurso de macro-construção do GeoGebra. Na concepção das atividades tratamos as idéias que correspondem ao mundo não-euclidiano fazendo comparações com aquelas que fazem parte da geometria euclidiana e para cada atividade há um comentário que explica a sua intenção de aprendizagem. É a partir de considerações teóricas sobre a natureza da geometria e sua evolução histórica, bem como sobre o processo de aprendizagem da geometria, que é feita a apresentação da proposta. / This dissertation brings ideas to the inclusion of new contents in school mathematics. They are related to the exploitation of non-Euclidean geometries through two dynamic geometry environments, the "Spherical Easel" and the "Poincaré Disk". The first one is a free software and the second one was developed using the GeoGebra macro-construction. In the design of the activities the approach of ideas that correspond to non-euclidian worlds was made through comparison with the euclidian world and for each activity there is a comment that explain its learning objective. The proposal is supported by theoretical considerations about the nature of geometry and its historical evolution, as well as about the geometry learning process.

Este trabalho apresenta uma proposta para o Ensino de Física partindo de aplicações da Física em produtos tecnológicos, e está formatado à luz da pedagogia construtivista de Piaget, Vygotsky e Ausubel. Pretende-se despertar a curiosidade e o interesse dos professores e, como conseqüência, dos alunos, pelos temas da Física, desmistificando equipamentos utilizados no cotidiano. Um dos objetivos do trabalho é contribuir para o preenchimento de lacunas existentes no Ensino de Física no Ensino Médio através da formação continuada de professores. O desenvolvimento do trabalho consistiu na realização de oficinas para professores e estudantes do Ensino Médio focalizadas no estudo de Fenômenos Ondulatórios, Eletromagnetismo e Tópicos de Física Moderna que explicam o funcionamento do forno de microondas e do disco rígido de computador. As oficinas foram oferecidas para professores de Física em seis localidades diferentes do Estado, e para alunos da terceira série do Ensino Médio do Instituto Estadual de Educação Cardeal Pacelli de Três de Maio, e consistiram de uma série de atividades, como a desmontagem de um forno de microondas e do disco rígido de computador, atividades interativas e experimentais. A realização destas atividades está de acordo com a proposta de Piaget, segundo a qual, as ações humanas são a base do comportamento. As atividades são desenvolvidas em pequenos grupos, seguidas por momentos de discussão no grande grupo, pois, conforme Vygotsky, o desenvolvimento cognitivo tem como origem a conversão de relações sociais em funções mentais. Através do conjunto de atividades, seja através das ações ou interações humanas, os conhecimentos prévios dos indivíduos são constantemente confrontados com novos conhecimentos, criando condições para uma aprendizagem significativa, conforme Ausubel. O trabalho foi submetido à avaliação com a aplicação de um pré-teste, antes do início das atividades propostas, e de um pós-teste, aplicado após o encerramento das atividades. Os resultados das avaliações mostraram que novos conceitos foram aprendidos pelos participantes, indicando que a proposta, baseada no ensino de Física a partir de aplicações tecnológicas, é eficiente e indicada para promover a melhoria da qualidade do Ensino de Física. / This work consists in a project for Physics Education starting from the application of Physics in technological products, and it is based on the theory of constructivism from Piaget, Vygotsky and Ausubel. The aim is to instigate the curiosity and the interest of teachers and, as a consequence, of students, by Physics subjects, through experiments based on how domestic equipments work. One of the purposes of this project is to help improving the formation of High School Physics teachers. The project consisted of workshops for teachers and High School students, focused on Wave Phenomena, Electromagnetism and Modern Physics, to explain how the microwave oven and a computer hard disk work. The workshops were held at six towns in the Northeast region of the State and for senior High School students of the Instituto Estadual de Educação Cardeal Pacelli in Três de Maio. They consisted of different kinds of activities like disassembling a microwave oven and a computer hard drive, and interactive and experimental activities. The development of these activities is in agreement with the Piaget´s theory that the actions are the basis of the human behavior. The activities were performed in small groups, followed by discussion breaks with the whole group, since, according to Vygotsky, the cognitive development was created by the conversion of social relations to mental functions. Through the set of activities, involving actions and human interactions, the previews knowledge of the individuals are constantly confronted with new knowledge, making conditions for a meaningful learning, according to Ausubel. The evaluation of the project was based on tests for the participants, before and after the workshops. The results showed that the participants improved their knowledge about Physics concepts, indicating that the project, based on Physics education starting from the technological applications, is efficient and indicated to promote the improvement of the quality of Physics classes at High School.

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Esta dissertação traz ideias para a inserção de novos conteúdos na matemática escolar. Ela trata da exploração de geometrias não-euclidianas, através de dois ambientes de geometria dinâmica, o "Spherical Easel” e o "Disco de Poincaré". O primeiro é um software livre e o segundo foi desenvolvido utilizando-se o recurso de macro-construção do GeoGebra. Na concepção das atividades tratamos as idéias que correspondem ao mundo não-euclidiano fazendo comparações com aquelas que fazem parte da geometria euclidiana e para cada atividade há um comentário que explica a sua intenção de aprendizagem. É a partir de considerações teóricas sobre a natureza da geometria e sua evolução histórica, bem como sobre o processo de aprendizagem da geometria, que é feita a apresentação da proposta. / This dissertation brings ideas to the inclusion of new contents in school mathematics. They are related to the exploitation of non-Euclidean geometries through two dynamic geometry environments, the "Spherical Easel" and the "Poincaré Disk". The first one is a free software and the second one was developed using the GeoGebra macro-construction. In the design of the activities the approach of ideas that correspond to non-euclidian worlds was made through comparison with the euclidian world and for each activity there is a comment that explain its learning objective. The proposal is supported by theoretical considerations about the nature of geometry and its historical evolution, as well as about the geometry learning process.