Fused Deposition Modelling (FDM) is one of the most widely used Rapid Prototyping processes that uses the technique of depositing a semi-solid material in layers to build up a part and finds application in a variety of situations, be it making a mould for the rapid production of an industrial tool or the production of models for preoperative planning of complex cranial reconstructive surgery. When it comes to directly producing the end products, the process is still in its infancy, using inferior materials and flat layer deposition, bringing forth shortcomings such as poor surface quality, low strength for curved parts, and undesirably higher number of layers. Some of these shortcomings can be overcome if material deposition is modelled in curved layers as against the traditional flat-layer slicing and deposition. While the stair case effect can be significantly minimized, mechanical properties of the parts will also be enhanced due to continuity in fibres and the elimination of the inherent weakness between laminations. However, this being a fairly new idea, there are no existing facilities for practically implementing and experimentally testing this concept of Curved Layered Fused Deposition Modeling (CLFDM). The current research is to develop both hardware and software systems to build a working FDM system and implement CLFDM. The project involves the construction of an FDM system and then development of mathematical models for curved slicing. The numerical data generated from curved slicing algorithms is integrated with the hardware system for the practical implementation of CLFDM. Efficient curved slicing algorithms are developed and successfully used on the FDM system built for the practical implementation of CLFDM. Several case studies involving geometrical complications of increasing complexities have been successfully modelled and physically produced using CLFDM.

Thesis (Ph. D.)--University of Missouri-Columbia, 2004. / Typescript. Vita. Includes bibliographical references (leaves 118-122). Also available on the Internet.

Thesis (Ph. D.)--University of Missouri-Columbia, 2004. / Typescript. Vita. Includes bibliographical references (leaves 118-122). Also available on the Internet.

As one of the most promising solar cell technologies, organic solar cells have unique superiorities distinct from inorganic counterparts, such as semitransparency, flexibility and solution-processability, as well as tunable photophysical properties, which originate from the structural verstailities of organic semiconductors. A major breakthrough in OSCs was the exploration of novel non-fullerene electron acceptor (NFAs): In comparison with traditional fullerene derivative acceptors, NFA possesses several advantages, such as low synthesis cost, tunable absorption range and adjustable energetic level, which effectively provides a wide light-harvesting window with low energetic loss. In recent decades, fused-ring electron acceptors (FREAs) have obtained an irreplaceable status in the development of OSCs. However, there are still initial drawbacks to FREA-based devices including: 1: the degree of molecular packing and the corresponding impact on device performance, which has not been studied in depth; 2: the feasibility of approaches for controlling the bulk heterojunction morphology of the film, which also has not been systemic researched; 3: the presence of bulk (geminate and non-geminate) and surface recombination which significantly affects the efficiency and stability of working devices. In this thesis, I took the above three issues as my main doctoral research subjects. In the first part of the thesis, I shine light onto the strength of π-conjugated backbones in FREA molecular structures, which strongly affect the intramolecular interaction. Herein, two FREA with different conjugated framework (IDT core vs IDTT core) are synthesized and employed as electron acceptors in OSCs. A significantly enhanced power conversion efficiency of 11.2% is obtained from IDTTIC-based devices in comparison with that of IDTIC-based devices (5.6%). After considering the electron-donating part in FREA molecules, I also study the effect of the terminal unit, which has a strong relationship with the intramolecular charge transfer effect and intermolecular interactions. Solvent additives are another powerful strategy to further improve the photovoltaic efficiency. 1-chloronaphthalene (CN) was found to be useful in the PTB7-Th:IEICO-4F system, which show a PCE improvement from 9.5% to 12.8%. Furthermore, by utilizing a small molecule donor, BIT-4F-T, as a third component, an optimum PCE of 14.0% is achieved in the devices based on PTB7-Th:IEICO-4F.

This thesis will address the design and production of the ATC Kolín comapny's logo. Thesis will be supported by the use of CAD/CAM programs. The choice of materials, components and tools will also be specified. Milling strategy will be designed with the PowerMill program. Two different methods of production will be compared. First one is the conventional machining on the FV 25 CNC vertical knee milling plant with the Heidenhain iTNC 530 controlling system. Where as the second one is the additive rapid prototypong technology with the usage of Fused Deposition Modeling method. The thesis is finished by the technical-economic evaluation with analysis and comparison of production alternatives.

Processing of ceramics has always been difficult due to how hard and brittle the material is. Fused Deposition of Ceramics (FDC) is a method of additive manufacturing which allows ceramic parts to be built layer by layer, abetting more complex geometries and avoiding the potential to fracture seen with processes such as grinding and milling. In the process of FDC, a polymeric binder system is mixed with ceramic powder for the printing of the part and then burned out to leave a fully ceramic part. This experiment investigates a new combination of materials, zirconia and acrylic binder, optimizing the process of making the material into a filament conducive to the printer system and then performing trials with the filament in the printer to assess its feasibility. Statistical analysis was used to determine optimal parameter levels using response surface methodology to pinpoint the material composition and temperature yielding the highest quality filament. It was discovered that although the mixture had adequate melting characteristics to be liquefied and printed into a part, the binder system did not provide the stiffness required to act as a piston to be fed through the printer head. Further studies should be completed continuing the investigation of zirconia and acrylic binder, but with added components to increase strength and rigidity of the filament.

Yes / In recent years 3D printing has gained popularity amongst industry professionals and hobbyists alike, with many new types of Fused Filament Fabrication (FFF) apparatus types becoming available on the market. A massively overlooked component of FFF is the requirement for a simple method to calculate the geometries of polymer depositions extruded during the FFF process. Manufacturers have so far achieved adequate methods to calculate tool-paths through so called slicer software packages which calculate the required velocities of extrusion from prior knowledge and data. Presented here is a method for obtaining a series of equations for predicting height, width and cross-sectional area values for given processing parameters within the FFF process for initial laydown on to a glass surface.

Seventeen new dithiophenyl- and napthodithiophenyl- fused porphyrins were synthesized; from these an additional 7 porphyrin oligomers were also synthesized. Additionally freebase 2,7-dimethoxytriphenylene fused porphyrin was also synthesized from a freebase precursor. Aromatic indices NICS and AICD were used to evaluate these new molecules.

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