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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.
501

Ultratenké polymerní filmy na pevných površích: studium fyzikálními metodami / Characterization of ultra-thin polymer films on solid substrates using different physical techniques

Pop-Georgievski, Ognen January 2013 (has links)
The presented doctoral research was aimed at preparation and characterization of ultra thin polymer films on solid substrates using different physical techniques. Each of these physical techniques probes selectively different characteristics of the films. While some of the techniques are strong in the predetermination of some unique properties of the layers, they might be limited and give no specific/conclusive information about some other important characteristics. Therefore, only the combination of the techniques provides a profound picture of the thickness, architecture, composition and functionality of the films/layers. This combined characterization approach elucidates in details the physical characteristics and the mechanisms responsible for the unique behavior of different polymer films/layers in the application that they are intended for. In the thesis, of particular interest were films of high biomedical, biotechnological and tissue engineering importance, such as: 1. poly(lactide) films formed by grafting "from-" a silanized alacrite thin films (L605 Co-based super alloy), 2. polydopamine (PDA) films that could serve as substrate independent mod- ification platform for further surface modification steps, 3. poly(ethylene oxide)films formed by "grafting to-" PDA modified surfaces, 4....
502

New modelling and simulation methods to support clean marine propulsion

Grant, Michael 24 August 2021 (has links)
The marine industry has increased its adoption of pure-electric, diesel-electric, and other non-traditional propulsion architectures to reduce ship emissions and fuel consumption. While these technologies can improve performance, the design of a propulsion system becomes challenging, given that no single technology is superior across all vessel types. Furthermore, even identical ships with different operating patterns may be better suited to different propulsion technologies. Addressing this problem, previous research has shown that if key elements of a vessel's operational pro file are known, simulation and optimization techniques can be employed to evaluate multiple propulsion architectures and result in a better propulsion system design and energy management strategy for a given vessel. While these studies have demonstrated the performance improvements that can be achieved from optimizing clean marine propulsion systems, they rely on vessel operational profiles obtained through physical measurement from existing ships. From a practical point of view, the optimization of a vessel's propulsion system needs to occur prior to a vessel's construction and thus precludes physical measurement. To this end, this thesis introduces a marine simulation platform for producing vessel operational profiles which enable propulsion system optimization during the ship design process. Core subsystem modules are constructed for simulating ship motions in 3 degrees of freedom and result in operational profile time-series, including propulsion power. Data is acquired from a benchmark vessel to validate the simulation. Results show the proposed approach strikes a balance between speed, accuracy, and complexity compared with other available tools. / Graduate

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