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Search theses and dissertations gathered from participating repositories worldwide. Every result links back to the library that holds it. No account is needed.
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Showing 1 to 17 of 17 for “"preceramic"”.
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Preceramic procurement patterns at Krum Bay, Virgin Islands
… of investigation, the deposit is a small, preceramic period stratified shell midden that is composed predominantly of pearl oysters. Radiocarbon results indicate its utilization between approximately 2900 and 1700 years ago, overlapping somewhat with ceramic-bearing sites of the area. It …
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Comparative Tensile Strengths of Preceramic and Postceramic Solder Connectors Using High-Palladium Alloy
… alloys on soldered connectors under simulated preceramic and postceramic soldering conditions. Materials and methods: Eighty cylindrical castings were fabricated (40 using Rx Naturelle Plus alloy and 40 using Option alloy). The 40 castings for each alloy were subdivided into 2 groups of 20 …
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From Turkeys To Tamales: Paleoindian To Preclassic Period Faunal Use At Maya Hak Cab Pek Rockshelter In Southern Belize
… use in the rockshelter and how it changed from preceramic and to ceramic periods. A change in species diversity that includes more than thirty vertebrate animal species, and 1,651 bones, suggests that the introduction of ceramics altered the use of specific species. Statistical analysis using …
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Fibre Production Among the Coastal Hunter-gatherers of South America’s West Coast: New Narratives from Plant Fibre Technologies
… among the people of the coastal Andean Preceramic Period (10,000 – 3,500 BP) by studying the technological production of bast fibre artefacts from six archaeological sites in Peru and Chile. The raw materials, technological processes and manufacturing techniques were identified through …
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Patterns in glass : obsidian and economic specialisation in the Admiralty Islands
… change we must expand our view to encompass the preceramic period. Obsidian is one of the few archaeologically visible materials which was distributed in both preceramic and ceramic times. This material is chosen as a “measuring device” to map variation in production and distribution patterns in …
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Patterns in glass : obsidian and economic specialisation in the Admiralty Islands
… change we must expand our view to encompass the preceramic period. Obsidian is one of the few archaeologically visible materials which was distributed in both preceramic and ceramic times. This material is chosen as a “measuring device” to map variation in production and distribution patterns in …
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Advanced covalent ceramics from organosilicon polymers for sustainable energy and environment
… polysilazane and hafnium-modified polysilazane preceramic polymer solutions were investigated using a lab-scale, cost-effective drop coating technique. After the successful infiltration of the fibers was confirmed, the infiltrated fibers were heat-treated at different temperatures to complete …
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Manufacturing of advanced continuous fiber reinforced composites for high temperature applications
… fiber reinforced ceramic materials from a preceramic polymer. The first was a vacuum forming process developed using the out-of-autoclave polymer composite manufacturing technique in conjunction with the polymer infiltration and pyrolysis process to produce ceramic composite material of …
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Testbeds for Advancement of Powder Bed Additive Manufacturing with Application to Reactive Binder Jetting of Ceramics
… production of reactive metal salt binders for preceramic binder jetting, and (4) fabricates alumina ceramic components through BJAM and compares the efficacy of polymer and reactive binders in microstructural and dimensional control during post-process sintering. The powder spreading and BJAM …
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Nanostructured Polymer-Derived Ceramic Aerogels for Environmental and Energy Applications
… functionalities after controlled pyrolysis of preceramic polymers. Besides, Polymer-Derived Ceramic routes can be implemented with many processing solutions, such as the outgrowing fields of 3D printing and ceramic matrix composites. Among these, porous and cellular ceramics can be synthesized …
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Synthesis and Characterization of Luminescent Nanostructured SiOC Thin Films
… parameters like the composition of the preceramic gel and the heat treatment conditions. Thus, this new processing method seems very well suited for the production of white emitting materials since the Si- and C-based emission can be tuned across the visible spectral range from UV-blue …
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Nanostructured Porous High Surface Area Ceramics for Catalytic Applications
… low molecular weight polycarbosilane used as a preceramic precursor was converted at 1300 oC to silicon carbide inside the SBA-15, and after subsequent silica removal by HF, a highly ordered mesoporous material was obtained. Ordered mesoporous silicon carbide prepared by the methods reported …
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Design of Robust Heterogeneous Catalysts for Sustainable Chemistry
… complexes for the chemical modification of the preceramic polymer (commercially known as HTT 1800, Clariant Advanced Materials GmbH, Sulzbach, Germany) by the transfer of metal to its nitrogen functions. The modified polymer was transformed to an amorphous SiCN material containing metal NPs by …
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JOINING OF CERAMIC COMPOSITES AND ADVANCED CERAMICS
… joining , solid state displacement reactions, preceramic polymer routes, reaction forming, brazing. Adhesive joining materials (e.g. epoxy resins) are used to join ceramics only for applications at temperature lower than 150 °C, i.e. adhesively bonded joints are widely used for automotive, …
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Mikrostrukturierung präkeramischer Polymere mit Hilfe der UV- und Röntgentiefenlithographie
Aufgrund ihrer herausragenden physikalischen und chemischen Eigenschaften gewinnt die Herstellung von Mikrokomponenten aus keramischen Materialien zunehmend an Bedeutung. Verschiedene Formgebungsverfahren wie das Hoch- und Niederdruck-Mikrospritzgießen keramischer Feedstocks sind etabliert. …