Thesis (PhD)--University of South Australia, 1997

Thesis (PhD)--University of South Australia, 2001

Thesis (M.S.)--Ohio University, March, 2000. / Title from PDF t.p.

Thesis (M.S.)--Ohio University, June, 1999. / Title from PDF t.p.

Thesis (M.S.)--Virginia Polytechnic Institute and State University, 1992. / Vita. Abstract. Includes bibliographical references (leaves 87-91). Also available via the Internet.

Thesis (M.Phil.)--Hong Kong University of Science and Technology, 2006. / Includes bibliographical references (leaves 83-89). Also available in electronic version.

Thesis (Ph. D.)--City University of Hong Kong, 2005. / "Submitted to Department of Manufacturing Engineering and Engineering Management in partial fulfillment of the requirements for the degree of Doctor of Philosophy." Includes bibliographical references (leaves 164-175).

Dissertação (mestrado) - Universidade Federal de Santa Catarina, Florianópolis, 1989. / Made available in DSpace on 2013-12-05T20:04:23Z (GMT). No. of bitstreams: 1 79635.pdf: 8397322 bytes, checksum: 74de2feee7922e6efd0b29ea6856aab9 (MD5) Previous issue date: 1989 / O presente trabalho descreve o desenvolvimento de um sistema gráfico interativo para a elaboração de desenhos e programas de comando numérico, visando dar apoio ao projeto e a fabricação de matrizes para solados planos injetados, com auxílio de estações gráficas e máquinas de comando numérico (CNC). O referido sistema é composto de módulos que foram desenvolvidos para ajuste de curvas, escalonamento automático dos vários números de um modelo e geração automática de curvas eqüidistantes. Esses módulos, juntamente com a implementação de primitivas geométricas, arquivo gráfico e um ambiente gráfico interativo, assistem ao usuário na criação das diferentes geometrias, que apresentam trajetórias de ferramentas no momento da usinagem. Adicionalmente é apresentado um processador que traduz a geometria criada e os dados tecnológicos introduzidos, para o programa de comando numérico. Finalmente são analisados os resultados no projeto e da usinagem de uma matriz protótipo, que foi totalmente planejada e executada pelo sistema desenvolvido.

Orientador : Manuel de Jesus Mendes / Tese (doutorado) - Universidade Estadual de Campinas, Faculdade de Engenharia de Campinas / Made available in DSpace on 2018-07-15T13:30:53Z (GMT). No. of bitstreams: 1 Tozzi_ClesioLuis_D.pdf: 2880248 bytes, checksum: 4e6d33c3da27b0b41911857f8b6897d3 (MD5) Previous issue date: 1979 / Resumo: O trabalho trata do desenvolvimento de um terminal gráfico interativo baseado na tecnologia do 'TV Raster', com estrutura dinâmica da 'picture memory' e conversão em tempo real do 'display file', possibilitando a rápida atualização da imagem, requisito necessário às aplicações interativas como: controle de processos, CAD, etc / Abstract: Not informed / Doutorado / Doutor em Engenharia Elétrica

OBJECTIVES: To evaluate the mechanical and physical properties of three glass-ceramic CAD/CAM systems; Vita Suprinity PC (Vita ZahnFabrik), Cerrec Tessera (Dentsply-Sirona), and IPS e.max CAD (Ivoclar Vivadent). MATERIALS AND METHODS: For each material, CAD/CAM blocks were sectioned into a total of N=108 (n=12 per group) test discs with a diameter of 11.3 mm core drill and used the precision saw machine. Specimens were divided into three groups (1) glaze control, (2) polish only, and (3) ground after manufacturer glaze. Specimens were randomly assigned for the biaxial flexural strength test then each group was tested under three conditions post-treatment: (1) static, (2) thermal cycling for 5000 cycles, and (3) cyclic loading at 200,000 cycles. The biaxial flexural strength test was preformed according to ISO 6872-2015 using an Instron universal testing machine. Thermal artificial aging cycling was from 5° to 55°C, while fatigue was used for about 20% of the static failure load for 200,000 cycles. Vickers indentation was performed to test microhardness and fracture toughness. Also, surface roughness was measured for each group using a stylus contact profilometer. Additionally, surface topography and crystal microstructure analysis by SEM and crystallographic structural analysis by X-ray diffraction were done. Data were analyzed using one-way ANOVA test or least square regression (α = 0.05) and the post hoc Tukey HSD test. RESULTS: Significant differences were observed in the mean of biaxial flexural strength between the three glass-ceramics materials. The highest mean flexural strength for static was IPS e.max CAD 385.91 ± 46.23 MPa, then Vita Suprinity PC glazed 355.72 ± 72.44 MPa, followed by CEREC Tessera glazed 323.40 ± 61.01 MPa. After thermal cycling and fatiguing, there were no significant effects in flexural strength for CEREC Tessera; however, there was an increase in flexural strength for IPS e.max CAD and Vita Suprinity PC. Vickers Hardness was highest for CEREC Tessera with 7.19 ± 0.47 GPa, then Vita Suprinity PC at 7.05 ± 0.73 GPa, followed by IPS e.max CAD 5.79 ± 0.77 GPa. The fracture toughness for IPS e.max CAD was the highest with 1.97 ± 0.12 MPa.m1/2, CEREC Tessera 0.93 ± 0.05 MPa.m1/2, and Vita Suprinity PC 0.85 ± 0.08 MPa.m1/2. CONCLUSIONS: IPS e.max CAD polished outperformed Vita Suprinity PC and CEREC Tessera with respect to flexural strength under different aging conditions. In contrast, Vita Suprinity PC had the highest strength in every aging condition among the glazing group. Clinically Significant: Although all three materials might be suitable for single restorations, caution is needed when choosing material, especially as the rough surface from clinical adjustments may reduce its strength.