• Refine Query
  • Source
  • Publication year
  • to
  • Language
  • 499
  • 244
  • 116
  • 55
  • 33
  • 23
  • 18
  • 10
  • 8
  • 7
  • 4
  • 4
  • 4
  • 3
  • 3
  • Tagged with
  • 1270
  • 193
  • 163
  • 161
  • 141
  • 132
  • 113
  • 102
  • 102
  • 101
  • 97
  • 90
  • 89
  • 88
  • 80
  • About
  • The Global ETD Search service is a free service for researchers to find electronic theses and dissertations. This service is provided by the Networked Digital Library of Theses and Dissertations.
    Our metadata is collected from universities around the world. If you manage a university/consortium/country archive and want to be added, details can be found on the NDLTD website.
161

Avaliação da forma de preparos cavitários confeccionados a partir do sistema CVDentus /

Josgrilberg, Érika Botelho. January 2005 (has links)
Resumo: Foi avaliado a morfologia de preparos cavitários realizados com o sistema CVDentus® variando-se a potência do ultra-som. As cavidades foram preparadas com a ponta cilíndrica modelo 8.2142, na face vestibular de 15 incisivos bovinos, que foram divididos em 3 grupos: G1 utilizando a potência II do aparelho de ultra-som, G2 a potência III e G3 potência IV do mesmo aparelho, na máquina padronizadora de preparos cavitários durante 1 minuto para cada preparo. Após, os preparos foram seccionados ao meio obtendo-se duas hemi-faces com seus perfis, que foi observado em Lupa Estereoscópica e medidos por meio do programa Leica Qwin. De acordo com os testes estatísticos Kruskal-Wallis e método de Dunn, houve diferença entre a largura e a profundidade dos preparos somente quando comparados às potências III e IV do aparelho de ultrasom, e que a largura da cavidade realizada pela potência III é a mais semelhante ao diâmetro real da ponta. Concluiu-se que a potência III indicada pelo fabricante é de fato a mais apropriada para o uso na clínica diária, pois possibilita a realização de preparos conservadores. / Abstract: This study has evaluated the shape of dental cavities made by CVDentus® system with ultrasound potency variation. The cavities have been made on buccal face of 15 bovine incisors with acylindrical bur (82142). The sample have been divided into three groups: G1, using ultrasound power II; G2, using power II, and G3, using power IV with a standard device. The cavities have been sliced in the middle, allowing thereby the cavity's profile observation with magnifying glasses, and measurement with a Leica Qwin program. The Kruskall-Wallis and Dunn statistical analysis has shown differences between dental cavities shapes when power III and IV were used. However, the cavities who have been made with power III were similar to bur dimension. Therefore, we conclude that the manufacturer indication to use power III is more suitable to clinical use because it allows more conservative cavity preparation. / Orientador: Cyneu Aguiar Pansani / Coorientador: Rita de Cassia Loiola Cordeiro / Banca: Evaldo José Corat / Banca: Silvio Issáo Myaki / Mestre
162

The influence of trailing edge coolant ejection on the loss of transonic turbine blades

Deckers, Mathias January 1996 (has links)
No description available.
163

Uso do laser de COsub(2) ou bisturi a frio para a remoção de pigmento melânico gengival - estudo clínico comparativo em pós-operatório precoce

KOEGLER, VERA L. 09 October 2014 (has links)
Made available in DSpace on 2014-10-09T12:50:17Z (GMT). No. of bitstreams: 0 / Made available in DSpace on 2014-10-09T13:58:47Z (GMT). No. of bitstreams: 1 10828.pdf: 923135 bytes, checksum: 56ecab1b373cf9b110daef6cebfdb5ea (MD5) / Dissertacao (Mestrado Profissionalizante em Lasers em Odontologia) / IPEN/D-MPLO / Instituto de Pesquisas Energeticas e Nucleares - IPEN/CNEN-SP; Faculdade de Odontologia - USP
164

Estudo dos efeitos do laser em baixa intensidade na reparação em mucosa bucal de ratos

TASSINARI, SILVIA C. 09 October 2014 (has links)
Made available in DSpace on 2014-10-09T12:50:01Z (GMT). No. of bitstreams: 0 / Made available in DSpace on 2014-10-09T14:02:03Z (GMT). No. of bitstreams: 1 10430.pdf: 2501583 bytes, checksum: d9bc55d07c6e6e0db459c7c5d10481e7 (MD5) / Dissertacao (Mestrado Profissionalizante em Lasers em Odontologia) / IPEN/D-MPLO / Instituto de Pesquisas Energeticas e Nucleares - IPEN/CNEN-SP
165

Efeito do laser de diodo (808 nm) de alta potência no crescimento de cultura de células de fibroblastos humanos

POLIDO, CRISTIANE B. 09 October 2014 (has links)
Made available in DSpace on 2014-10-09T12:50:15Z (GMT). No. of bitstreams: 0 / Made available in DSpace on 2014-10-09T14:01:54Z (GMT). No. of bitstreams: 1 10826.pdf: 3720317 bytes, checksum: 26d9f64b9d44684f557ae44f37e86002 (MD5) / Dissertação (Mestrado Profissionalizante em Lasers em Odontologia) / IPEN/D-MPLO / Intituto de Pesquisas Energeticas e Nucleares, IPEN/CNEN-SP; Faculdade de Odontologia, Universidade de Sao Paulo
166

Estudo da redução microbiana intracanal utilizando laser de baixa potência associado a fotossensibilizador e laser de alta potência

KAIRALLA, ELENI C. 09 October 2014 (has links)
Made available in DSpace on 2014-10-09T12:54:51Z (GMT). No. of bitstreams: 0 / Made available in DSpace on 2014-10-09T14:06:57Z (GMT). No. of bitstreams: 1 12794.pdf: 2065231 bytes, checksum: 5d277cd94726f9af455400aea420ffe2 (MD5) / Dissertacao (Mestrado Profissionalizante em Lasers em Odontologia) / IPEN/D-MPLO / Instituto de Pesquisas Energeticas e Nucleares - IPEN/CNEN-SP; Faculdade de Odontologia, Universidade de Sao Paulo, Sao Paulo
167

Avaliação in vitro da resistência à tração de um sistema de retenção intracanal em condutos radiculares irradiados com laser de Er:YAG e de Nd:YAG

MELLO, NADIA J.C. 09 October 2014 (has links)
Made available in DSpace on 2014-10-09T12:54:53Z (GMT). No. of bitstreams: 0 / Made available in DSpace on 2014-10-09T14:06:54Z (GMT). No. of bitstreams: 1 12796.pdf: 440348 bytes, checksum: 5d7b85c92d4b0bf453b89e0590595d61 (MD5) / Dissertacao (Mestrado Profissionalizante em Lasers em Odontologia) / IPEN/D-MPLO / Instituto de Pesquisas Energeticas e Nucleares - IPEN/CNEN-SP; Faculdade de Odontologia, Universidade de Sao Paulo, Sao Paulo
168

Codificação de bits quânticos via eletrodinâmica quântica de cavidades em circuitos / Quantum bit encoding in circuit cavity quantum electrodynamics

Sá Neto, Olímpio Pereira de, 1984- 12 April 2009 (has links)
Orientador: Marcos Cesar de Oliveira / Dissertação (mestrado) - Universidade Estadual de Campinas, Instituto de Fisica Gleb Wataghin / Made available in DSpace on 2018-08-14T22:41:50Z (GMT). No. of bitstreams: 1 SaNeto_OlimpioPereirade_M.pdf: 2183642 bytes, checksum: 1db9639afd1e7c5b802c3e8608ea049f (MD5) Previous issue date: 2009 / Resumo: Nesta dissertação de mestrado foi analisada a eficiência de um esquema de codificação específico de bits quânticos em estados de campos eletromagnéticos quânticos em linhas de transmissão coplanares acopladas a um dispositivo supercondutor, o "Átomo Artificial", sob a ação de um banho ôhmico. O objetivo central desta pesquisa é estudar a Eletrodinâmica Quântica de Cavidades, bem como aspectos de implementação de dispositivos para computação quântica. Neste contexto, nossa proposta de pesquisa consiste em estudar um esquema prático de processamento de informação eficiente, explorando recursos físicos de um sistema real / Abstract: In this dissertation we analyse the efficiency of a specific quantum bit encoding in a quantum electromagnetic field state prepared in a coplanar transmission line coupled to a single superconducting device, the "Artificial Atom", under action of external noise sources affecting the efficiency of the device. The central objective is to study the circuit cavity quantum electrodynamics and to propose practical aspects of devices for quantum computation implementation / Mestrado / Física / Mestre em Física
169

The effects of scaling and high subsonic cavity flow and control

Thangamani, V 15 August 2014 (has links)
The effects of scaling a cavity with respect to a fixed incoming boundary layer thickness on its flow dynamics and control was studied experimentally. Three cavity models with constant length-to-depth ratio of 5 and length-to-width ratio of 2 and with corresponding linear dimensions in the ratio 0.5 : 1 : 2 were tested at freestream Mach number 0.71. Additionally, the 0.5 and 1 scale models were tested at freestream Mach number of 0.85. The experiments involved timeaveraged pressure measurements, unsteady pressure measurements, and PIV measurements. Time-averaged pressure measurements made at the floor were used to study the ’flow-type’ of the cavities. Unsteady pressure measurements were used to study the acoustic characteristics of the cavity. The cavity length-to-boundary layer thickness ratios tested were 10, 20 and 40. The Cp distribution on the clean cavities indicated a change in the cavity flowtype with change in the cavity scale. Varying the L/δ from 10 to 40 changed the cavity flow-type from open to transitional. Analysis of the frequency spectra of the cavity revealed an increase in tonal amplitudes and OASPL with increasing L/δ . The PIV measurements indicated that this could be caused by an increase in energy exchange between the freestream and the cavity. The velocity magnitudes inside the cavities were found to increase with increase in L/δ . A comparative study of different passive control methods on the largest cavity showed that leading-edge spoilers were superior in cavity tone suppression. Of these, the effectiveness of a sawtooth spoiler on the three cavities of different scales was tested. The results showed that while the spoiler was effective in eliminating tones and suppression of noise for the smaller cavities, it was unable to eliminate the tones completely for the largest cavity. To find the correct method for scaling the spoilers with the cavity dimensions, different spoiler heights were tested on the three cavities. The results showed that the cavity noise suppression for a given cavity attains saturation level at a particular spoiler height, called the critical spoiler height. An increase in spoiler height beyond the critical spoiler height was found to have no effect on the noise suppression. It is also found that this critical spoiler height can be scaled with the length of the cavity (for given L/D, M and spoiler profile) irrespective of the boundary layer thickness.
170

A superconducting RF deflecting cavity for the ARIEL e-linac separator

Storey, Douglas W. 13 March 2018 (has links)
The ARIEL electron linac is a 0.3MW accelerator that will drive the production of rare isotopes in TRIUMF's new ARIEL facility. A planned upgrade will allow a second beam to be accelerated in the linac simultaneously, driving a Free Electron Laser while operating as an energy recovery linac. To not disrupt beam delivery to the ARIEL facility, an RF beam separator is required to separate the interleaved beams after they exit the accelerating cavities. A 650MHz superconducting RF deflecting mode cavity has been designed, built, and tested for providing the required 0.3MV transverse deflecting voltage to separate the interleaved beams. The cavity operates in a TE-like mode, and has been optimized through the use of simulation tools for high shunt impedance with minimal longitudinal footprint. The design process and details about the resulting electromagnetic and mechanical design are presented, covering the cavity's RF performance, coupling to the operating and higher order modes, multipacting susceptibility, and the physical design. The low power dissipation on the cavity walls at the required deflecting field allows for the cavity to be fabricated using non-conventional techniques. These include fabricating from bulk, low purity niobium and the use of TIG welding for joining the cavity parts. A method for TIG welding niobium is developed that achieves minimal degradation in purity of the weld joint while using widely available fabrication equipment. Applying these methods to the fabrication of the separator cavity makes this the first SRF cavity to be built at TRIUMF. The results of cryogenic RF tests of the separator cavity at temperatures down to 2K are presented. At the operating temperature of 4.2K, the cavity achieves a quality factor of 4e8 at the design deflecting voltage of 0.3MV. A maximum deflecting voltage of 0.82MV is reached at 4.2K, with peak surface fields of 26MV/m and 33mT. The cavity's performance exceeds the goal deflecting voltage and quality factor required for operation. / Graduate

Page generated in 0.0275 seconds