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  • 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

DIGITAL HETERODYNE TOPOGRAPHY (MOIRE, CONTOURING, PROFILOMETRY).

BELL, BERNARD WHITE, JR. January 1985 (has links)
Digital heterodyne methods are employed in conjunction with periodic fringe projection to produce a fast automated surface relief measurement technique. A method of sampling the image with a solid state detector array which produces a moire fringe image free of the noise terms normally present with moire techniques is presented along with an extension to Whittaker-Shannon sampling theory to cover the moire aliasing phenomena. The limitations imposed on the surface slopes by the requirement that the properly moire sampled image spectra must be confined to a moire interval are given. Moire sampling allows an optical processing step (removal of the reference surface tilt), while classical nonaliased sampling produces the same information with respect to a tilted surface. General additive noise is analyzed as regards both integrating bucket and phase stepping algorithms and yields a signal to noise ratio dependent error with twice the frequency of the fringes for some algorithms. A phase averaging technique which eliminates these oscillatory errors as well as those caused by reference phase shift errors in all the algorithms is demonstrated. Both parallel and divergent geometries are discussed. The feasibility is experimentally demonstrated with results for the parallel case based on a system composed of commercially obtainable components.
42

Surface reaction kinetics of molecular beam epitaxial growth of CdTe

Benson, J. David 12 1900 (has links)
No description available.
43

On estimating fractal dimension

Dubuc, Benoit January 1988 (has links)
No description available.
44

Characterization and modeling of a magnetic workholding device

Felix-Angulo, Alejandro 05 1900 (has links)
No description available.
45

Application of a contact potential difference probe to detection of nanometer-scale lubricant on a hard disk

Yano, Daisuke 05 1900 (has links)
No description available.
46

Stability analysis of thin film coating systems

Severtson, Yuan C. 05 1900 (has links)
No description available.
47

Measurement of directional emittance of roughened aluminum surfaces

Bapat, Shrikrishna Ganesh 12 1900 (has links)
No description available.
48

Mechanisms of surface hardness enhancement in ion-implanted amorphous carbon

Lee, Deok-Hyung (Doug) 08 1900 (has links)
No description available.
49

A study of surface metallurgical characteristics of tin coated bearing steels

Erdemir, Ali 05 1900 (has links)
No description available.
50

Chemical, electronic and electrochemical properties of diamond thin films

Lau, Chi Hian January 2002 (has links)
Diamond is of interest as an advanced functional material, since the extreme physical properties of diamond, suggests it is ideally suited to a range of new demanding applications. In this context, the thesis explores basic surface chemical properties of diamond thin films, along with electrochemical, electronic and electron emission processes involving this material. New experiments are reported concerning the nature of surface conductivity on diamond. Measurements clearly show that the conductivity only arises if a hydrogenated diamond surface is exposed to water vapour, in the presence of chemical species capable of acting as electron acceptors. The conduction properties of surface conductive diamond in aqueous solution are also studied, and the first detailed electrochemical investigations of this material are described. Comparative electrochemical studies of nanocrystalline and boron-doped diamond have been performed. Investigations of electrode stability, and the accessible "potential window" are described, as well as the behaviour of a range of 'redox' systems, including transition metal complexes, metal deposition/stripping, and bio-related organic species. Significant differences between the behaviour of nanodiamond and microcrystalline boron-doped material are observed. A range of surface chemical and threshold photoemission studies of diamond thin films are reported. The results indicate that quantum photoyields (QPYs) are insensitive to the diamond "quality", although the wavelength selectivity is dependent on it. The adsorption of oxygen strongly reduces the QPY, although this only occurs slowly in the presence of O<sub>2</sub> because of a low reactive sticking probability. Much more rapid uptake of oxygen and consequent reduction of photoyield is observed in the presence of atomic O or electronically excited dioxygen O<sub>2</sub>*. The presence of alkali metals on the diamond surface increases the QPY, and reduces the sensitivity of the QPY to surface oxygen. Significant differences between the surface chemical properties of Li, and other adsorbed akali metals (K and Cs) are observed.

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