• Refine Query
  • Source
  • Publication year
  • to
  • Language
  • 403
  • 68
  • 68
  • 31
  • 21
  • 20
  • 17
  • 12
  • 11
  • 3
  • 3
  • 2
  • 2
  • 1
  • 1
  • Tagged with
  • 818
  • 818
  • 818
  • 175
  • 133
  • 113
  • 96
  • 89
  • 88
  • 86
  • 72
  • 66
  • 64
  • 64
  • 59
  • 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.
1

Chemical and electrical modification of polypropylene surfaces

Ebbens, Stephen James January 2000 (has links)
Although many multi-component polymer systems are well characterised, the surface properties of polymers mixed with low surface energy additives have received little attention. In addition, the new branches of scanning probe microscopy that enable high resolution mapping and modification of surface charge distributions have been infrequently applied to polymer surfaces. The surface segregation of a fluorochemical additive directly from a polypropylene host matrix has been investigated by AFM and other surface analysis techniques. The level of surface enrichment was found to be governed by the temperature and duration of annealing. Further investigation revealed that the speed and extent of surface enrichment of the additive increases with polymer molecular weight. The effect of additive structure on surface segregation has also reported. A method of depositing charge onto polypropylene substrates from a high potential scanning AFM tip was developed. The relation between AFM tip- voltage and the level of charge deposited on the substrate suggested that a localised corona discharge was generated. AFM scanning parameters were found to effect the deposition of charge. The charging behavior of fluorochemical doped polypropylene surfaces was investigated on macroscopic scales using a scanning electrometer probe, and on microscopic scales using EFM. Fluorochemical domains at the surface have been found to preferentially accumulate both positive and negative charge. Surface charge distributions were found to become more uniform during annealing. Sub-micron particle capture by charged surfaces was investigated using EFM. In addition, spatially confined amine beads were deposited onto a patch of localised charge and subsequently functionalised to produce a metallic gold coating.
2

Factors and forces involved in the initial events of bacterial adhesion as monitored by atomic force microscopy /

Razatos, Anneta Panagis, January 1999 (has links)
Thesis (Ph. D.)--University of Texas at Austin, 1999. / Vita. Includes bibliographical references (leaves 115-131). Available also in a digital version from Dissertation Abstracts.
3

Single molecule mechanical testing

Lillehei, Peter Thomas 05 1900 (has links)
No description available.
4

Colloidal oxide and sulphide interactions in aqueous electrolyte studied by atomic force microscopy /

Toikka, Gary. Unknown Date (has links)
Thesis (PhD)-- University of South Australia, 1997
5

High-speed nano-precision positioning : theory and application to AFM imaging of soft samples /

Tien, Szu-Chi. January 2007 (has links)
Thesis (Ph. D.)--University of Washington, 2007. / Vita. Includes bibliographical references (p. 74-80).
6

Generating nano-scale features by electro-machining using an atomic force microscope

Alkhaleel, Abdallah H. January 2009 (has links)
Thesis (Ph.D.)--University of Nebraska-Lincoln, 2009. / Title from title screen (site viewed October 13, 2009). PDF text: xiii, 127, 11 p. : ill. (some col.) ; 6 Mb. UMI publication number: AAT 3352608. Includes bibliographical references. Also available in microfilm and microfiche formats.
7

Apparatus to deliver light to the tip-sample interface of an atomic force microscope (AFM)

Thoreson, Erik J. January 2002 (has links)
Thesis (M.S.)--Worcester Polytechnic Institute. / Keywords: purple membrane; photomechanics; photoinduced conformation change; photocycle; photoactive; photoinduced; bimetallic bending; bacteriorhodopsin; atomic force microscope; tip-sample interface; molecular conformation; PLDS; photoreactive; AFM. Includes bibliographical references (p. E-1-E-4).
8

Prediction of steady state response in dynamic mode atomic force microscopy and its applications in nano-metrology

Oh, Yunje, January 2005 (has links)
Thesis (Ph. D.)--Ohio State University, 2005. / Title from first page of PDF file. Includes bibliographical references (p. 182-189).
9

AFM and rheological investigations on colloidal processing of ceramics

Coimbra, David January 2001 (has links)
No description available.
10

Structural Characterization of Micromechanical Properties in Asphalt Using Atomic Force Microscopy

Allen, Robert Grover 2010 December 1900 (has links)
The purpose of this study was to characterize the micromechanical properties of various structural components in asphalt using Atomic Force Microscopy (AFM). The focus of the study was based on nano-indentation experiments performed within a micro-grid of asphalt phases in order to determine micromechanical properties such as stiffness, adhesion and elastic/plastic behavior. The change in microstructure and micromechanical behavior due to oxidative aging of the asphalt was also a primary focus of the study. The experiment was performed with careful consideration of AFM artifacts, which can occur due to factors such as geometry of the cantilever tip, hysteresis, filtering methods and acoustic vibrations. The materials used in this study included asphalts AAB, AAD and ABD from the Materials Reference Library (MRL) of the Strategic Highway Research Program (SHRP), chosen due to variations in crude source, chemical composition and elemental analysis for each asphalt type. The analysis of nano-indentation creep measurements corresponding to phase-separated regions ultimately revealed heterogeneous domains in asphalt with different mechanical properties, and oxidative aging was found to induce substantial microstructural change within these domains, including variations in phase structure, phase properties and phase distribution. The form and extent of these changes, however, were different for each asphalt studied. Data analysis and information collected during this study were used for comparisons to existing models and asphalt data, which validated results and established correlations to earlier, related studies. From these comparisons, it was found that data parallels followed expected trends; furthermore, analogous interpretations and distinctions were made between results from this study and the micellar and microstructural models of asphalt. This study of micromechanical properties that govern asphalt behavior has yielded information essential to the advancement of hot mix asphalt (HMA) performance, including a new asphalt “weak zone” hypothesis and a foundation of data for implementation into new and existing asphalt models.

Page generated in 0.0734 seconds