Frankfurt (Main), Univ., Diss., 2005. / Computerdatei im Fernzugriff.

Zugl.: Frankfurt (Main), Univ., Diss., 2005

Universiẗat, Diss., 2005--Frankfurt (Main).

No description available.

In einer vorangegangenen In-vitro-Untersuchung wurden die pallatinalen Wurzeln menschlicher Molaren im Scherversuch (10mm/Min) gebrochen. Zahnfragmente wurden mit Hilfe verschiedener Dentinhaftvermittler (OptiBond FL, Syntac, Adhese, Prompt L-Pop und OptiBond FL in Kombination mit Tetrac Flow) adhäsiv wiederbefestigt. Die so rekonstruierte Zahneinheit wurde erneut an der ursprünglichen Bruchfläche gebrochen und die Bruchfestigkeit ermittelt. In der vorliegenden In-vitro-Untersuchung wurden die Bruchflächen der erneut gebrochenen Zähne digital abfotografiert und lichtmikroskopisch untersucht, um den Frakturmodus zu ermitteln. Die Frakturmodi (Adhäsivfraktur, Kohäsivfraktur im Dentin oder Befestigungsmaterial) wurden absolut und in Relation zur gesamten Bruchfläche ermittelt. Hierzu wurde ein spezielles CAD-Programm verwendet. Mittels statistischer Tests wurden die Adhäsivsysteme auf signifikante Unterschiede hinsichtlich der aufgetretenen Frakturmodi untersucht. Ergebnisse: Keine signifikanten Unterschiede. Kohäsivfrakturen im Befestigungsmaterial traten unabhängig vom Dentinhaftvermittler am häufigsten auf. Vor allem konnte dieser Bruchmodus bei Verwendung von OptiBond FL beobachtet werden. Adhäsivfrakturen traten am zahlreichsten bei Gebrauch von Prompt L-Pop und Kohäsivfrakturen im Dentin bei Verwendung von Syntac auf. / In a preceding in-vitro-investigation roots of human molars were broken in shear-test (10mm/min). Teeth were restored by fragment fixation with different adhesive systems (OptiBond FL, Syntac, Adhese, Prompt L-Pop and OptiBond FL in combination with Tetrac Flow) and shear test was repeated to investigate fracture-toughness. In this in-vitro investigation pictures of the surfaces of the broken roots were taken and they were analysed using light-microscope. Failure-modes (adhesive-fracture, cohesive-fracture in dentine or restaurative material) were calculated absolute and in relation to the whole surface by a special CAD-software. Statistical tests were done to find out significant difference in failure-mode between the tested adhesive systems. Results: No significant differences. In every adhesive system cohesive fracture in restaurative material was the most frequent fracture-mode. Most of them could be observed if OptiBond FL was used. Adhesive fractures especially appeared in the group of Prompt L-Pop, and cohesive fractures in dentine by using syntac.

Heidelberg, Univ., Diss., 2007.

Zugl.: Aachen, Techn. Hochsch., Diss., 2008

This thesis deals with freezy sublimation in cryoattachement Gatan Alto 2500 connected to scanning electron microscope (SEM) JEOL JSM-7401F. The thesis is devided into the theoretical and practical parts. In the theoretical part I focus mainly on physical qualities of water and on problematics of freezy-drying. I also describe qualities of subsidiary substances which are being used when working with cryotechnology. I briefly describe technology used: cryoattachement Alto 2500 and SEM JSM-7401F. In the practical part I deal with the description of the method that I have developed in order to measure weight decrease of frozen specimen owning to its sublimation in vacuum. I provide measurement results of the sublimation of these substances: demineralized water, Dextran, glycerol and phosphate buffer saline.

The purpose of this diploma thesis is to research and compare available wireless communication technologies (frequency, modulation type, transmission speed and consumption). Describe transmission electron microscopes theory and deduce the most sensitive microscope parts to high frequency distortion. Investigate effect of wireless technology on CE standards and come up with, perform and evaluate the influence measurement of chosen technologies on base parameters of transmission electron microscope.

This thesis focuses on the study of the life of a fluorescent dye. It also examines changes in its emission spectrum determined with the aid of development of fluorescence intensity over the long term sensing in several kinds if of cella. The general part of the thesis with the issues of confocal microscopy, fluorescent radiation and maks. Furthermorer, an analysis of methods for measuring fluorescence lifetime is done. In the thesis there is elaborated a description of the program, whitch was designed for the analysis of the collected output of the used confocal microscope. Sebsequently, the results are evaluated.