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Taipei, Taiwan

Ceramic matrix composites (CMCs) are being designed and developed for engine and exhaust components in commercial aviation, because they offer higher temperature capabilities, weight savings, and improved durability compared to metals. The United States Federal Aviation Administration (FAA) issues and enforces regulations and minimum standards covering the safe manufacture, operation, and maintenance of civil aircraft. As new materials, these ceramic composite components will have to meet the certification regulations of the FAA for "airworthiness". The FAA certification process is defined in the Federal Aviation Regulations (Title 14 of the Code of Federal Regulations), FAA policy statements, orders, advisory circulars, technical standard orders, and FAA airworthiness directives. These regulations and documents provide the fundamental requirements and guidelines for design, testing, manufacture, quality assurance, registration, operation, inspection, maintenance, and repair of aircraft systems and parts. For metallic parts in aircraft, the FAA certification and compliance process is wellestablished for type and airworthiness certification, using ASTM and SAE standards, the MMPDS data handbook, and FAA advisory circulars. In a similar manner for polymer matrix composites (PMC), the PMC industry and the FAA have jointly developed and are refining parallel guidelines for polymer matrix composites (PMCs), using guidance in FAA circulars and the CMH-17 PMC handbook. These documents discuss design methods and codes, material testing, property data development, life/durability assessment, production processes, QA procedures, inspection methods, operational limits, and repairs for PMCs. For ceramic composites, the FAA and the CMC and aerospace community are working together (primarily through the CMH-17 CMC handbook) to define and codify key design, production, and regulatory issues that have to be addressed in the certification of CMC components in civil aircraft. © 2015 Owned by the authors, published by EDP Sciences. Source

Ong H.B.,University of Dundee | Sienkiewicz N.,University of Dundee | Sienkiewicz N.,Prospect Technology | Wyllie S.,University of Dundee | And 2 more authors.
Molecular Microbiology | Year: 2013

Summary: African trypanosomes are capable of both de novo synthesis and salvage of pyrimidines. The last two steps in de novo synthesis are catalysed by UMP synthase (UMPS) - a bifunctional enzyme comprising orotate phosphoribosyl transferase (OPRT) and orotidine monophosphate decarboxylase (OMPDC). To investigate the essentiality of pyrimidine biosynthesis in Trypanosoma brucei, we generated a umps double knockout (DKO) line by gene replacement. The DKO was unable to grow in pyrimidine-depleted medium in vitro, unless supplemented with uracil, uridine, deoxyuridine or UMP. DKO parasites were completely resistant to 5-fluoroorotate and hypersensitive to 5-fluorouracil, consistent with loss of UMPS, but remained sensitive to pyrazofurin indicating that, unlike mammalian cells, the primary target of pyrazofurin is not OMPDC. The null mutant was unable to infect mice indicating that salvage of host pyrimidines is insufficient to support growth. However, following prolonged culture in vitro, parasites regained virulence in mice despite retaining pyrimidine auxotrophy. Unlike the wild-type, both pyrimidine auxotrophs secreted substantial quantities of orotate, significantly higher in the virulent DKO line. We propose that this may be responsible for the recovery of virulence in mice, due to host metabolism converting orotate to uridine, thereby bypassing the loss of UMPS in the parasite. © 2013 The Authors. Molecular Microbiology published by John Wiley & Sons Ltd. Source

Carrere G.,Prospect Technology
9th Conference and Exhibition of the SMPTE Australia Section | Year: 2016

Data broadcasting represents in the world a real market because of many factors (diversity of contents, more sensibility of people to the consumption of information, Internet fast increase, diversity of networks, good penetration of PCs, availability of receivers,⋯) © 1999 Society of Motion Picture and Television Engineers, Inc. Source

Smith T.,Prospect Technology
Chemical Engineering Progress | Year: 2012

The impacts of shale gas development on land, air and water resources must be managed through sustainable operating practices. When a well is no longer capable of production, concrete is pumped down the wellbore to seal it from atmospheric pressure, and production equipment is removed from the site. The entire pad is then revegetated and fully restored. The US Environmental Protection Agency has released new air quality rules for hydraulically fractured wells. This requires drillers to use technologies and practices that limit emissions and result in green completions. After a well has been fracture-treated, it is cleaned up, which involves removing the water that was used for fracturing. Growth in the development and production of shale gas resources will require greater sourcing of water and management of water, solid waste, and other byproducts. When procuring water for hydraulic fracturing, it is essential to protect water quality and to ensure adequate water resources for other watershed stakeholders, including residential, commercial and industrial users. Source

Fu G.,Prospect Technology | Fu G.,Princeton University | Soboyejo W.O.,Prospect Technology
Materials Science and Engineering C | Year: 2011

The thermo-sensitive properties of poly (N-isopropylacrylamide) (PNIPA) hydrogels are modified by the addition of hydrophilic acrylamide comonomers and an interpenetrating network of sodium alginate for drug delivery applications near 37 °C. A mathematical model is presented to describe the mass transport kinetics during the hydrogel drug delivery process, which is accompanied by a volume change during phase transition. In this model, the transport in the polymer matrix is described by Fick's second law in cylindrical coordinates, with concentration dependent diffusion coefficients. The moving boundary problems caused by the polymer matrix swelling are also solved by numerical simulation. The models show that the Trypan blue release from the modified PNIPA-based hydrogels is strongly concentration dependent. The sodium alginate component is also shown to effectively facilitate the diffusion process. The results from the simulation are in good agreement with the measurements of diffusion and swelling observed from in vitro experiments. The implications of this work are also discussed for practical drug delivery systems. © 2011 Elsevier B.V. All rights reserved. Source

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