Because of the exceptional physical, chemical, electric and mechanical properties of hard and brittle materials, such as ceramics, glass and diamond film etc, those are considerably valued in high technology industry. Although those materials can be machined using the ECDM method, its machining mechanism is still indeterminate. In this study, a static electrical pitting tester is employed, the electrolyte is KOH(eq), the workpiece is glass, and we change the parameters, such as supply voltage, supply current and machining gap to investigate the mechanism of static Electrochemical Discharge Machining. From the experimental results, which are SEM pictures of machined glass and variations of current, we can clearly infer the mechanism of static-ECDM. Moreover, the most important reason for damaging glass is supply voltage. Even increasing supply voltage can make glass cleave. And the main factor to make the loop become insulating is supply current. While the supply voltage is 50V, the supply current is 8A, and in different machining gap condition, the results show that it has a certainly gap to discharge during the machining process, and the particular gap is about 49£gm. The results also show that the machining model has two kinds of types. When the machining gap is shorter than 49£gm, the machining model is from ring to circle; contrarily, when it is longer than 49£gm, the machining model is circle directly.

In this thesis, we will firstly study the capacitive surface. By combining it with microstrip antenna, we can understand its effects on the properties of antenna, and investigate its miniature property. Next, we will design an electromagnetic band-gap (EBG) structure without vias to reduce the fabrication cost, and propose a best way of surrounding to combine EBG with antenna. In this way, we can improve the shortcomings of microstrip antenna, such as low gain and back radiation, etc. We will also apply our EBG to MIMO to reduce the mutual coupling and enhance gain. Then we make the MIMO antennas in a mobile device possible by shortening the distance between antennas. Finally, we can effectively shorten the distance and enhance performance even more by using miniature EBG. Both the fabrication and measurement will also be performed.

The academician-practitioner gap has been long discussed within the advertising community. There has been extensive literature published, numerous organizations formed and changes made in the academic and practitioner worlds, all to address and help close the gap. This report is an analysis of the academician-practitioner gap, what it entails, why it exists and what must be in place to begin properly reducing the gap. / text

Dissertation (Ph.D.).--University of Texas Graduate School of Biomedical Sciences at San Antonio, 2007. / Vita. Includes bibliographical references.

Thesis (Ph. D.)--University of Hawaii at Manoa, 2000. / Includes bibliographical references (leaves 77-89). Also available in microform.

Thesis (doctoral)--University of Lund. / Description based on print version record.

Thesis (Ph. D.)--University of Hong Kong, 2006.

Universiẗat, Diss., 2004--Marburg.

Orientador: Nicolao Jannuzzi / Dissertação (mestrado) - Universidade Estadual de Campinas, Instituto de Fisica Gleb Wataghin / Made available in DSpace on 2018-07-23T17:35:41Z (GMT). No. of bitstreams: 1 Scarparo_MarcoAntonioFiori_M.pdf: 1349916 bytes, checksum: a859770f891dc4309784c32e7325dd15 (MD5) Previous issue date: 1973 / Resumo: O presente trabalho consta fundamentalmente do estudo da fotoluminescência nas ligas cristalinas de Ga(As1-xPx) para x = 0,27 e x = 0,41. A luminescência se dá no visível, obtida com a excitação das amostras com a linha 5,145 Angstrons do laser de Argonio. Submetemos as duas amostras a variações de excitação e temperatura. Utilizamos excitações da ordem de 125 microwatts a 800 miliwatts, e temperaturas de 77 K a 293 K. Calculamos, baseado nos trabalhos de M. B. Panish e H. C. Casey, (14) as variações dos "gaps" de energia com a temperatura para as duas composições citadas. Criamos modêlos (V e V') que caracterizam transições radiativas nas ligas de Ga(As1-xPx) para as composições estudadas. Estes modelos propostos evidenciam transições radiativas entre estados doadores, ligados a mínimos diferentes da banda de condução e a banda de valência. Os doadores mais rasos estão ligados aos "gap" direto e os doadores mais profundos estão ligados ao "gap" indireto. Estimamos as posições relativas dos doadores em relação aos "gaps" direto, e indireto para ambas as amostras e mostramos os efeitos da excitação e da temperatura nas transições radiativas entre os estados doadores e a banda de valência / Abstract: Not informed. / Mestrado / Física / Mestre em Física

Orientadores: Nelson de Jesus Parada, L. G. Ferreira / Tese (doutorado) - Universidade Estadual de Campinas, Instituto de Fisica Gleb Wataghin / Made available in DSpace on 2018-07-15T03:44:30Z (GMT). No. of bitstreams: 1 Brescansin_LuizMarco_D.pdf: 1866863 bytes, checksum: eaa13c0981301518740c99f0648bc444 (MD5) Previous issue date: 1978 / Resumo: Neste trabalho estudamos a estrutura eletrônica do Na+Cl-, que é um isolante de "gap" direto relativamente grande (~8eV), através do método SCF-Xa. Propomos uma nova maneira de calcular o potencial do "cluster", impondo que ele tenha as mesmas características do potencial no cristal. Com o potencial autoconsistente calculado no "cluster", resolvemos a equação de Schrödinger no cristal, utilizando o método KKR (ou APW) e comparamos as bandas de energia obtidas com os resultados experimentais disponíveis / Abstract: In the present work we study the electronic structure of Na+Cl-, an insulator with a relatively large direct gap (~8eV), using the SCF-Xa method. A new way of calculating the cluster potential is proposed, by imposing thet it has the same features as the crystal potential. With the calculated self-consistent cluster potential, we solve Schrödinger's equation in the crystal, through the KKR (or APW) method and we compare the resulting energy bands with the available experimental results / Doutorado / Física / Doutor em Ciências