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O presente estudo teve o objetivo de avaliar o efeito da Terapia Laser de Baixa Potência (TLBP) na estabilidade e no deslocamento de mini-implantes (MIs) submetidos a carga. A hipótese nula testada foi que a irradiação laser e o tipo de carga aplicada (imediata ou mediata) não influenciam na estabilidade e no deslocamento de MIs. Foram avaliados 48 dispositivos para a estabilidade e 35 para o deslocamento, os quais foram implantados em pacientes da clínica de pós graduação em Ortodontia da Faculdade de Odontologia de Ribeirão Preto da Universidade de São Paulo. Os MIs foram divididos em 4 grupos segundo a intervenção recebida: 1- TLBP + CI (carga imediata), 2- TLBP + CM (carga mediata / após 4 semanas da implantação), 3- CI (sem TLBP) e 4- CM (após 4 semanas da implantação / sem TLBP). Carga de 150 gF foi aplicada por período de 3 meses para todos os dispositivos. A TLBP foi aplicada usando emissão laser vermelha com comprimento de onda de 660 nm e potência de 100 mW, imediatamente após implantação (densidade de energia: 4 J/cm&sup2; ). Nos dias posteriores foram aplicadas emissões laser infravermelhas com comprimento de onda de 808 nm a cada 48 horas durante duas semanas após colocação dos dispositivos (densidade de energia: 8 J/cm&sup2; para cada aplicação). A estabilidade dos dispositivos foi avaliada pela Análise de Freqüência de Ressonância (AFR) em três momentos: T0 no dia da implantação; T1 antes da aplicação da carga, somente nos grupos 2 e 4; e T2 após três meses de aplicação de carga. Para a avaliação do deslocamento dos dispositivos foram utilizadas imagens de Tomografias Computadorizadas de Feixe Cônico (TCFC). Planos tridimensionais foram criados a partir de pontos de referência identificados na maxila e mandibula para medir e comparar as diferenças entre as distâncias inicial (TC0) e final (TC1) da cabeça do MI ao plano tridimensional. Os resultados demonstraram que o grupo 2 apresentou a menor perda de estabilidade de todos os grupos (p= 0.0161). Os dispositivos que receberam TLBP (Grupos 1 e 2) apresentaram menor perda de estabilidade quando comparados aos grupos que não receberam irradiação laser (p= 0.0372). Os MIs que receberam CI (Grupos 1 e 3) apresentaram maior perda de estabilidade quando foi avaliado o tempo efetivo de aplicação da carga (p< 0.0001). Todos os dispositivos apresentaram deslocamento sem diferenças estatisticamente significantes entre os grupos. A hipótese nula foi parcialmente rejeitada. Os MIs que receberam TLBP e CM tiveram menor perda de estabilidade. O deslocamento não foi influenciado pela irradiação laser e pelo protocolo de aplicação da carga / The present study aimed to evaluate the effect of Low-level Laser Therapy (LLLT) on stability and displacement of mini-implants (MIs) submitted to loading. The null hypothesis tested was that laser irradiation and the applied loading protocol (immediate or mediate) do not influence the stability and displacement of MIs. Forty-eight devices were assessed for stability and 35 for displacement. They were implanted in patients from the graduate clinic of Orthodontics of the School of Dentistry of Ribeirão Preto, University of São Paulo. MIs were divided in four groups according to received intervention: 1- LLLT + IL (immediate loading), 2- LLLT + ML (mediate loading / 4 weeks after implantation), 3- IL (without LLLT) and 4- ML (4 weeks after implantation / without LLLT). Loading of 150 gF was applied during 3 months for all devices. LLLT was implemented using red laser emission with wavelength of 660 nm and potency of 100 mW, immediately after implantation (energy density: 4 J/cm2). In the later days they were applied infrared laser emissions with wavelength of 808 nm every 48 hours during two weeks after placement of devices (energy density: 8 J/cm2 for each application). MIs stability assessment was performed by Resonance Frequency Analysis (RFA) at three moments: T0 on the day of implantation; T1 before loading, for groups 2 and 4; and, T2 after three months of loading application. For displacement analysis, images from Cone-beam Computed Tomography (CBCT) scans were used. Threedimensional planes were created based on landmarks identified on maxilla and mandible to measure and compare differences of initial (TC0) and final (TC1) distances from the MIs head to the plane. Results demonstrated that group 2 presented the lowest loss of stability of all groups (p= 0.0161). Devices that received LLLT (Groups 1 and 2) showed lower loss of stability when they were compared with the groups that did not receive LLLT (p= 0.0372). MIs that received IL (Groups 1 and 3) presented greater loss of stability when the effective time of loading application was assessed (p< 0.0001). All groups showed displacement of the devices without significant differences between them. The null hypothesis was partially rejected. MIs that received LLLT and ML had lower loss of stability. Displacement was not influenced by laser irradiation or loading protocol

A madeira foi largamente utilizada em edificações no período colonial brasileiro por sua abundância em variadas espécies e a facilidade de obtenção e adaptação aos fins previstos. Muitos destes imóveis ainda existem e abrangem a maior parte do patrimônio histórico e cultural de nossas cidades. Devido à degradação causada pelo tempo e a falta de manutenção adequada destes elementos estruturais, as edificações estão expostas ao risco de colapso. O objetivo deste trabalho foi sugerir um método de reabilitação parcial de vigas estruturais de madeira, pois se notou um problema recorrente nestes elementos em construções antigas pelo fato de acumularem umidade, serem alvos de patologias principalmente na parte superior. Para reabilitação empregamos madeiras de baixa densidade pela facilidade de compra desse material, baixo custo e principalmente por aderir muito bem a tratamento preservativo com CCB, o que garante que a estrutura estará protegida de novos ataques. Além das madeiras de baixa densidade tratadas, parafusos auto atarraxantes foram escolhidos para fazer a união entre as madeiras. Para os ensaios de flexão estática de 3 pontos foram adotados 4 diferentes tipos de parafusos variando o diâmetro e comprimento além disso, o número de parafusos inseridos nos corpos de prova também variou. Este estudo contém a análise de relação entre a quantidade de parafusos auto atarraxantes (que fazem a união das peças) e o produto de rigidez de peças mistas compostas de madeira referência (que simula a viga em estado de degradação) e madeira tratada (substituindo a porção degradada). Para a madeira referencia adotou-se Eucalipto (classe C30 de resistência) e Roxinho (classe C60) e, para madeira tratada adotou-se Pinus e Caxeta (de baixa densidade, ambas da classe C20). Análises estatísticas foram utilizadas para interpretação dos resultados obtidos em laboratório. Estas análises apontaram o crescimento do produto de rigidez das vigas mistas conforme a inserção de parafusos e a partir dai foi possível expressar em formulas a correlação dos dados. Utilizou-se o teste de Tukey para apontar o melhor tratamento para cada tipo de viga mista (Pinus e Eucalipto, Roxinho e Caxeta) além do melhor parafuso a se utilizar. / Wood was widely used in buildings in the Brazilian colonial period because of it is abundant in varied species and the ease of obtaining and adapting to intended purposes. Many of these properties still exist and cover most of historical and cultural heritage of Brazilian cities. Due to the degradation caused by the weather and lack of adequate maintenance of these structural elements, buildings are exposed to risk of collapse. The objective of this work was to suggest a method of partial rehabilitation of structural timber beams, since a recurrent problem was observed in these elements in old constructions due to accumulation of humidity, being targets of pathologies mainly in their upper part. For rehabilitation we use low density wood because of ease to purchasing this material, low cost and mainly for adhering very well to condom treatment with CCB, which ensures that the structure will be protected from further attacks. In addition to the treated low density woods, self-tapping screws were chosen to make union between woods. For tests, 4 different types of screws were used, varying diameter and length, and number of screws inserted in the specimens also varied. This study contains an analysis of relationship between the number of self-tapping screws (which make the joining of pieces) and the rigidity product of composite pieces of reference wood (which simulates beam in degraded state) and treated wood (replacing degraded portion). Eucalyptus (class C30 of resistance) and Roxinho (class C60) were used for reference wood, and Pinus and Caxeta (low density, both of class C20) were used for treated wood. Statistical analyzes were used to interpret results obtained in laboratory. These analyzes indicated growth of product of flexural stiffness according to insertion of screws and from this it was possible to express in formulas a correlation of data. Tukey test was used to indicate the best treatment for each type of mixed beam (Pinus and Eucalyptus, Roxinho and Caxeta) as well as the best screw to be used.

Einleitung: Die Verwendung der Hamstringsehnen als Transplantate in der rekonstruktiven Chirurgie des vorderen Kreuzbandes stellt eine wenig invasive Alternative zur herkömmlichen Verwendung des mittleren Patellarsehnendrittels dar. Hier ist jedoch die Transplantatverankerung, die bisher meist extrakortikal, also weit entfernt der nativen Kreuzbandinsertion angelegt wurde problematisch. Hierdurch zeigt das Transplantat-Verankerungs-Konstrukt ein unbefriedigendes elastisches und plastisches Dehnungsverhalten, welches u.A. für eine geringere Kniestabilität und eine gestörte ossäre Transplantatintegration verantwortlich gemacht wird. Eine anatomiegerechte Transplantatverankerung auf Gelenkniveau könnte die mechanischen und biologischen Rahmenbedingungen verbessern, um so die Hamstringsehnen als Alternativtransplantat mit verbesserter klinischer Prognose einsetzten zu können. Eine direkte Verankerung mit Interferenzschrauben erlaubt eine solche anatomische Transplantatverankerung, so dass wir dieses neue Operationsverfahren biomechanisch und tierexperimentell untersucht haben. Methoden: In sechs biomechanischen Teilprojekten und in zwei tierexperimentellen Untersuchungen wurde die Eignung der direkten Verankerung mit biodegradierbaren Interferenzschrauben der Hamstringsehnen im Vergleich zu konventionellen Patellar- und Hamstringsehnen-Techniken untersucht. Ergebnisse: Wir konnten demonstrieren, dass die initiale femorale Verankerungsfestigkeit, auch in Sinne der sog. Hybridfixation ausreichend ist. Die tibiale Verankerung unterliegt jedoch verschiedenen Variablen und bedarf einer differenzierten klinischen Anwendung. Im Vergleich zu konventionellen Techniken der Hamstringsehnen-Verankerung kann das plastische und elastische Dehnungsverhalten durch die Verankerung mit Interferenzschrauben deutlich verbessert werden, wobei jedoch das mechanische Verhalten des Patellarsehnen-Transplantates nicht erreicht wurde. Die tierexperimentelle Analyse zeigt auf, dass die ossäre Integration durch die Kompression des Transplantates auf Gelenkniveau soweit verbessert werden kann, dass sog. Tunnelaufweitungen, als Zeichen einer gestörten Einheilung vermieden werden und, dass das Transplantat mit einer direkten Bandinsertion, entsprechend des nativen vorderen Kreuzbandes, auf Gelenkniveau einheilt. Schlussfolgerung: Die hier vorgelegten Untersuchungen haben erstmals umfassend die Rahmenbedingungen der Interferenzschrauben-Verankerung der Hamstringsehnen beschrieben; einer Technik die inzwischen weltweit verbreitete Anwendung findet. Durch eine anatomische Transplantatverankerung auf Gelenkniveau besteht nun die Möglichkeit, mit optimierten mechanischen und biologischen Rahmenbedingungen eine adäquate Alternativtechnik zur konventionellen Verwendung der Patellarsehnen anzubieten. / Introduction: The use of hamstring tendon grafts as a substitute for anterior cruciate ligament reconstruction presents a less invasive procedure compared to the conventional bone-patellar tendon- bone graft. Current techniques of hamstring tendon anterior cruciate ligament reconstruction utilise an extra-cortical fixation. An extra-cortical fixation, however, shows inferior structural parameters with respect to construct slippage or stiffness. These factors may contribute to less stable knees after reconstruction and a delayed osseous integration of the grafted tissue. An anatomic hamstring tendon graft fixation close to the joint line may overcome these problems and may present an alternative to the conventional bone-patellar tendon-bone graft by means of optimised mechanical and biological boundary conditions. We therefore studied anatomic interference fit fixation of hamstring tendon grafts in different mechanical and animal experimental setups. Methods: In six different biomechanical projects and two animal studies, we studied the capability of hamstring tendon interference fit fixation to be used as a secure and reproducible technique of anterior cruciate ligament reconstruction and compared these data to the bone-patellar tendon-bone graft and other conventional hamstring tendon graft fixation techniques. Results: We could demonstrate that the initial femoral fixation strength, as well as a hybrid fixation is sufficient. However, the tibial fixation presents the weak link and underlies different variables, such as bone density and screw geometry. Compared to conventional extra-cortical fixation techniques, the viscoelastic and viscoplastic deformation behaviour could be optimized, but did not reach comparable data to the bone-patellar tendon-bone graft. Animal experiments could clearly demonstrate that interference fit fixation promotes osseous tendon incorporation and minimises the likely hood of a tunnel enlargement. We further found that in contrast to conventional fixation techniques the use of interference screws resulted in the development of a direct ligament insertion anatomy, directly at the joint line, like it is found with the native anterior cruciate ligament. Conclusion: With the present studies we could first describe the mechanical and biological boundary conditions of hamstring tendon interference fit fixation, a technique which gains increased world wide attention as a standard procedure in cruciate ligament surgery. By using an anatomic joint line fixation of hamstring tendon grafts, there are optimised boundary conditions, which therefore presents an adequate alternative to the conventional bone-patellar tendon-bone graft in cruciate ligament reconstruction.

La fragilité reconnue des fixations mécaniques conduit à limiter leur utilisation à 1000 MPa afin d'éviter les risquesde rupture fragile par hydrogène, que celui-ci soit d'origine interne ou externe. Connue sur des produits plats defaible épaisseur (clips), la microstructure bainitique obtenue lors de la trempe dans un bain de sels ne présente pasde fragilité liée à l'hydrogène. Cette étude vise à apporter aux industriels les connaissances nécessaires àl'application de ce procédé à des pièces massives.Au-delà de sa résistance à l'hydrogène, seule la microstructure constituée de bainite inférieure peut satisfaire auxexigences de propriétés mécaniques attendues dans les fixations. L'outil d'optimisation de la composition chimiquede l'acier créé permet d'intégrer les critères propres à la transformation de l'austénite en bainite inférieure partrempe isotherme dans un bain de sels mais aussi de prendre en compte l'aptitude de l'acier à être déformé à froidaprès un recuit d'adoucissement préalable.La caractérisation de la sensibilité à l'hydrogène faite sur des goujons après chargement à saturation en hydrogènemontre qu'à 1370 MPa, l'acier à structure bainitique ne présente pas de rupture fragile par l'hydrogène comparé aumême acier à structure martensitique revenue qui est systématiquement fragile. En parallèle, parmi les alliagesternaires Al-Zr-Zn déposés par un procédé de dépôt physique en phase vapeur, il a été possible d'identifier unenuance sacrificielle dont l'effet protecteur vis-à-vis des fixations devra encore faire l'objet d'investigations. / In the objective to prevent brittle fracture due to hydrogen (internal or external origins), the usages of mechanicalfastening parts is restricted above 1000 MPa. As already experienced on low-thickness flat products (clips), thebainitic microstructure generated by salt bath quenching is not subjected to hydrogen embrittlement. The target ofthe present study consists in setting up the required knowledge to extend this process to massive parts.In addition to its resistance to hydrogen, only the lower-bainite microstructure is able to meet the mechanicalpropertyspecifications for fasteners. The optimization tool developed in the present framework, has been designedto integrate the particularities of the austenite to lower bainite transformation in salt bath, as well as the ability tosustain cold forming after annealing treatment.A set of mechanical characterizations has been performed on hydrogen saturated bolts. Under a load of 1370 MPa,the bainitic structure has not shown any sign brittle fracture, while it has systematically been the case for thetempered martensitic structure. Furthermore, among the ternary alloys Al-Zr-Zn that can be deposed in vapor phase,a sacrificial grade presenting a protection effect has been identified. However, this effect must be furtherinvestigated, in order to determine the interest for fastening applications.

Diss. (sammanfattning) Linköping : Linköpings universitet, 2007. / Härtill 4 uppsatser.

Diss. (sammanfattning) Linköping : Linköpings universitet, 2007. / Härtill 4 uppsatser.

The diploma thesis deals with the influences on business planning, to which companies adapt in effort to succeed in a dynamic production and market environment. The influencing effect causing changes in the production company and the ability to react flexibly can eliminate possible losses or outages in production. However, adaptation leads to significant interventions throughout the company's value chain. The theoretical part presents the possibilities of business planning, which can have a significantly useful impact on management of the order across the pre-production and production stages. In the practical part, simulation models are demonstrated proofing nagative influencing effects. Then the methodology is compiled, witch leads the future user, how to limit or eliminate both internal and external disturbing effects.

The aim of the thesis is the design machines for laser cutting and plasma workspace 2.0 x1, 8 meters. The work described technology laser cutting and plasma and the resulting demands on the machine. Longer work includes a search of design solutions, then the actual design, including the necessary calculations and drawings.

This diploma thesis designs a small vertical CNC milling machine. The thesis includes selection of suitable structural design of the machine based on market analysis and requirements. The listed components, constructional calculations and 3D model are chosen in order to minimize the costs.