• Refine Query
  • Source
  • Publication year
  • to
  • Language
  • 164
  • 22
  • 20
  • 16
  • 14
  • 9
  • 6
  • 3
  • 2
  • 2
  • 2
  • 2
  • 2
  • 2
  • 2
  • Tagged with
  • 301
  • 301
  • 42
  • 40
  • 39
  • 37
  • 36
  • 28
  • 28
  • 27
  • 27
  • 26
  • 26
  • 25
  • 25
  • 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.
41

Access to Space without Energy and Propellant on Board

Sasoh, Akihiro, Jeung, In-Seuck, Choi, Jeong-Yeol 04 1900 (has links)
No description available.
42

Condensation and oxidation of laser ablation of titanium under water

Huang, Jun-Jie 22 July 2008 (has links)
none
43

Development of femtosecond laser endoscopic microsurgery

Hoy, Christopher Luk, 1982- 13 July 2012 (has links)
Femtosecond laser microsurgery has emerged as a remarkable technique for precise ablation of biological systems with minimal damage to their surrounding tissues. The combination of this technique with nonlinear optical imaging provides a means of microscopic visualization to guide such surgery in situ. A clinical endoscope capable of image-guided femtosecond laser microsurgery will provide physicians a means for cellular-level microsurgery with the highest precision. This dissertation focuses the development of a miniaturized fiber-coupled probe for image-guided microsurgery, towards future realization as a clinical endoscope. The first part of the dissertation describes the development of an 18-mm diameter probe. This development includes delivery of femtosecond laser pulses with pulse energy in excess of 1 µJ through air-core photonic bandgap fiber, laser beam scanning by a microelectromechanical system scanning mirror, and development of a new image reconstruction methodology for extracting increased temporal information during Lissajous beam scanning. During testing, the 18-mm probe compares favorably with the state-of-the-art as a microscopic imaging tool and we present the first known demonstration of cellular femtosecond laser microsurgery through an optical fiber. The second part of the dissertation explores further refinement of the design into a streamlined package with 9.6 mm diameter and improved imaging resolution. Study of the optical performance through analytical and computer-aided optical design indicates that simple custom lenses can be designed that require only commercial-grade manufacturing tolerances while still producing a fully aberration-corrected microsurgical endoscope. With the 9.6-mm probe, we demonstrate nonlinear optical imaging, including tissue imaging of intrinsic signals from collagen, using average laser powers 2-3× lower than the current state-of-the-art. We also demonstrate the use of the 9.6-mm probe in conjunction with gold nanoparticles for enhanced imaging and microsurgery through plasmonics. Finally, in the third part of this dissertation, we detail bench-top development of a new clinical application for combined femtosecond laser microsurgery and nonlinear optical imaging: the treatment of scarred vocal folds. We show the utility of femtosecond laser microsurgery for creating sub-epithelial voids in vocal fold tissue that can be useful for enhancing localization of injectable biomaterial treatments. We demonstrate that a single compact fiber laser system can be utilized for both microsurgery and imaging. Furthermore, the proposed clinical technique is shown to be achievable with parameters (e.g., pulse energy, focused spot size) that were found to be attainable with fiber-coupled probes while still achieving ablation speeds practical for clinical use. / text
44

Enhancement of high power pulsed laser ablation and biological hard tissue applications

Kang, Hyun Wook 28 August 2008 (has links)
Not available / text
45

Oxide-metal nanoparticles using laser ablation of microparticle aerosols

Nahar, Manuj 16 February 2011 (has links)
We have studied a continuous aerosol process for producing oxide nanoparticles with sizes of 10-60 nm that are decorated with smaller 1-3 nm metallic nanoparticles. Such particles may be useful in a number of areas including catalysis and as contrast enhancement agents in biomarkers. To produce the oxide nanoparticle carriers, an aerosol of 1-10 [micrometer] oxide particles are ablated using an excimer laser. The resulting oxide nanoparticle aerosol is then mixed with 1-2 [micrometer] metallic particles and this mixed aerosol is ablated a second time. The oxide nanoparticles are too small to ablate but act as seeds for the nucleation of metallic nanoparticles on the surface of the oxide. The nanoparticle sizes can be varied by changing the gas type or gas pressure in the aerosol. We demonstrate the feasibility of such an approach using two oxides, SiO₂ and TiO₂, and two metals, Au and Ag. / text
46

Fibre Bragg grating techniques

Barnier, Fabien January 2000 (has links)
No description available.
47

Time and spatially resolved laser induced ablation plumes

Atherton, David Patrick. January 2007 (has links)
Thesis (M.S.)--University of Nevada, Reno, 2007. / "December 2007." Includes bibliographical references (leaves 56-58). Online version available on the World Wide Web.
48

Model polyimide films : synthesis, characterization, and deposition by resonant infrared laser ablation

Dygert, Nicole Leigh. January 2008 (has links)
Thesis (Ph. D. in Interdisciplinary Materials Sciences)--Vanderbilt University, Dec. 2008. / Title from title screen. Includes bibliographical references.
49

Gallium nitride light emitting diodes and a study of etching techniques

Bhattacharya, Smiti. January 1900 (has links)
Thesis (M.S.)--West Virginia University, 2005. / Title from document title page. Document formatted into pages; contains xi, 110 p. : ill. (some col.). Includes abstract. Includes bibliographical references (p. 85-89).
50

Investigation of fabrication process development for integrated optical grating structures

Pisharoty, Divya. January 1900 (has links)
Thesis (M.S.)--West Virginia University, 2005. / Title from document title page. Document formatted into pages; contains x, 114 p. : ill. (some col.). Includes abstract. Includes bibliographical references (p. 112-114).

Page generated in 0.0815 seconds