All machined surfaces inherently have roughness. The level of control of this surface is dependeat on the specifications outlined for its intended use. In strictly controlled situatiom, the monitoring and characterization of these surfaces becomes increasingly important to ensure that each component conforms to specifications. For this reason, the need for in-situ monitoring systems has increased in order to optimize manufacturing time and minimize generated scrap for companies to remain competitive in industry. Current in-situ roughness monitoring systems, such as optical methods, are limited by the harsl: environments in which these systems are required to operate and the requirement for highly reflective materials. Accordingly, the need to develop a more robust system is required. The objective of this work was to develop and test a noncontact surface roughness characterization system which can be implemented into a machining center in order to provide in-situ measurements where currently available methods are rendered inappropriate. Through the use of a pneumatic technique, a non-contact surface assessment tool has been developed and tested for use in a machining center. The development began offline for characterization of surfaces created by different machining operations and was then introduced in to a turning center for in-situ evaluation. The developed system is capable of distinguishing surfaces created from different machining operations with the same Ra values, characterize milled and turned surfaces down to R^a values of 0.8 μm that are comparable with stylus measurements, impervious to external influences on the measurement process such as cutting fluid, capable of characterizing moving surfaces with surface speeds up to 100 m/min, provides surface characterization around the entire workpiece instead of along a single line, and can be operated in-process to monitor the entire workpiece or be used to make spot checks for important surface features. The developed system is capable of providing a method for in-situ monitoring of machined surfaces where currently available techniques fall short. The limitations caused by the harsh environment in which these in-situ monitoring devices operate and the limitations of workpiece materials have been eliminated and the developed system has been proven to provide results comparable to stylus measurements that are the industrial standard. This work is the basis for the development of a non-contact, in-situ surface roughness assessment tool. Limitations of the current device are also presented. Further research and development avenues are identified to expand the operating envelope of the developed pneumatic system. / Thesis / Master of Applied Science (MASc)

No / Various Partial Differential Equations (PDE) have been used in computer graphics for approximating surfaces of geometric shapes by finding solutions to PDEs subject to suitable boundary conditions. The PDE boundary conditions are defined as 3D curves on the surface of the shapes. We propose how to automatically derive these curves as boundaries of curved patches on the surface of the original polygon mesh. The analytic solution to the PDE used throughout this work is fully determined by finding a set of coefficients associated with parametric functions according to the particular set of boundary conditions. The PDE coefficients require an order of magnitude smaller space compared to the original polygon data and can be interactively rendered with different level of detail. It allows for an efficient exchange of the PDE shapes in 3D Cyber worlds and their web visualization. In this paper we analyze and formulate the requirements for extracting suitable boundary conditions, describe the algorithm for the automatic deriving of the boundary curves, and present its implementation as a part of the function-based extension of VRML and X3D.

Superhydrophobic (SH) surfaces equipped on the skins of natural living beings give them trumps of self-cleaning, anti-bacterial, water harvest, and directional liquid transport, etc., to survive in harsh environments. Bioinspired Superhydrophobic (SH) surfaces have developed many emerging functions, such as self-cleaning, anti-bacterial, water harvest, anti-icing, anti-corrosion, oil-water separation, and many other fascinating functions. However, the implementations of SH coating in real world are still in its infancy, due to (i) the poor performance in the harsh real-world environment and industrial process application, where a multi-level robustness including the mechanical, chemical, and thermal robustness, as well as the strong adherent strength to substrates, is strictly required; (ii) the lack of a technology for facile and mass production. In the light of that any non-perfluorinated component in the formula of an SH coating inevitably generates vulnerable points to the external invasions and the functional applications of SH coatings require control surface topography, we here propose an SH coating entirely made of perfluorinated materials (referred to as Teflon). To achieve this goal, we developed a complete strategy involving material, fabrication, and applications. Firstly, we developed a feasible dynamic soft molding method for the fabrication of three-dimensional (3D) structures. This method paves a road not only to the fabrication of whole-Teflon SH coatings but also to the practical adoption of many other important technologies based on 3D structures. Secondly, we generated whole-Teflon and multi-resist SH coatings by using this method and tightly attached them to different substrates with superior adhering strength surpassing the conventional work. Thirdly, we performed a proof-of-concept demonstration of a roll-to-roll (R2R) hot molding process, which has the potential of translating the lab-scale and plate-to-plate fabrication to industrial mass production. Finally, some fundamental mechanisms and problems of the multifunctional applications in self-cleaning, anti-bacterial fouling, and anti-icing are studied. The outcomes are expected to provide insight understandings on the multifunctional SH coating and move SH coatings toward real-world application.

Includes bibliographical references (p. 78-89).

No description available.

Thesis (M.S.)--Ohio State University, 2005. / Includes bibliographical references (leaves 81-85). Available online via OhioLINK's ETD Center

Thesis (doctoral)--Bonn, 1997. / "Oktober 1997"--T.p. Includes bibliographical references (p. 150-153).

This dissertation addresses atomic-level structure and related properties of the (100) surfaces of Vanadium and Niobium. The primary motivation of the surface structure experiments is based on an observation by P.J. Feibelman [[superscript 3,4]] that ab-initio calculations of surface relaxation (interplanar separation of near-surface planes) exhibit significant and consistent deviation from corresponding experimental relaxation values obtained through LEED crystallography. The deviation is much larger than the accepted accuracy of both the theoretical and experimental techniques. Resolving this dilemma is the primary objective for this systematic investigation of multilayer relaxation at transition metal surfaces. This research also addresses important secondary issues. Closely related to the surface relaxation issue for Nb(100) are experiments that provide an experimentallydetermined structural basis for the "sub-surface valve" model that has been proposed to explain the novel hydrogen uptake kinetics in Niobium. Definitive experiments that address the longstanding search for ferromagnetic order at the surface of V(100) is another important issue.

No description available.

No description available.