Spelling suggestions: "subject:"[een] FOULING"" "subject:"[enn] FOULING""
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Reduction of autoxidative fouling rates on aerospace alloys via oleophobic surface modificationsBlair N Francis (14192582) 30 November 2022 (has links)
<p> Demand ever increases for clean-burning, high-efficiency, and power-dense jet engines. This demand raises the thermal requirements and stresses on fuel systems for every new generation of gas turbine engine. Fuel is used to cool subsystems such as engine oil, pumps, electronics, valves, etc. resulting in elevated fuel temperatures upstream of combustor nozzles. Carbonaceous deposits or fouling occurs if the wetted wall temperature is elevated sufficiently, especially at fuel nozzle tips where temperatures are maximized. Fouling within fuel nozzles diminish atomization performance producing incomplete combustion, instability, and polluting byproducts. Therefore, the industry seeks strategies to mitigate carbon deposition without reducing the thermal requirements placed on the fuel. Existing carbon mitigation techniques rely on coating the fuel-wetted surfaces in an inert layer via anodic oxidation, chemical vapor deposition, etc. In this proposal, we aim to investigate a novel approach: inducing the lotus effect (heterogenous wetting) along the walls of fuel passageways. The lotus effect minimizes wetting area along a liquid-solid interface using a highly ordered set of micro or nano features with weak interfacial energy resulting in the liquid only wetting the peaks of said features. We hypothesized that the combination of a chemically inert surface with reduced wetting area diminishes the opportunity for deposit to form. The mitigating effect can be enhanced by the thermal insulation provided by the vapor or gas pockets trapped between the liquid-solid interface, passively reducing the thermal loading of the fuel. As a preliminary step, we produced the lotus effect on multiple aerospace alloys such as Inconel 718, stainless steel 304, and pure titanium via electrochemical etching and surface modification. We then exposed treated tubes to fuel under fouling-favorable conditions to compare their relative deposition rates. Our results indicate that the lotus effect loses stability at pressures well below those used in practical applications. However, the electrochemical etch we developed consistently produced negligible deposit where it would typically be maximized. Depending on if the surface is etched, FAS17 (a perfluoroalkyl silane used to generate superphobicity) can act to encourage or discourage carbon deposition. We determined that the electrochemical etch or FAS17 alone may be a method to mitigate carbon deposition regardless of the wetting behavior </p>
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Strategies for the Prevention and Remediation of Bacterial BiofilmsBojanowski, Caitlin January 2017 (has links)
No description available.
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TWO SURFACE MODIFICATION METHODS TO REDUCE PROTEIN FOULING IN MICROFILTRATION MEMBRANESRAJAM, SRIDHAR 04 April 2007 (has links)
No description available.
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Performance Evaluation and Characterization of an Innovative Membrane Bioreactor in the Treatment of Wastewater and Removal of Pharmaceuticals and PesticidesZhang, Qiang 16 July 2009 (has links)
No description available.
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An Experimental Investigation of High Temperature Particle Rebound and Deposition Characteristics Applicable to Gas Turbine FoulingLawrence, Michael James January 2013 (has links)
No description available.
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Analysis of an aerobic membrane bioreactor with the application of event detection software and variable operational filtration modesLeow, Aaron S. January 2015 (has links)
No description available.
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Quantification of Fouling during UHT Processing in an Indirect Tubular Heat ExchangerFeldman, Ariella 29 December 2016 (has links)
No description available.
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Methacrylic Terpolymer Biomaterials for Cardiovascular ApplicationsHeath, Daniel Edward 15 September 2010 (has links)
No description available.
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Mass Transfer Analysis of Polyether Sulfone and Polyamide Membranes Modified by Ion Beam IrradiationKing, Stanley Wayne 25 May 2004 (has links)
No description available.
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Development of a method to measure “soft particles” in the fuel / Metodutveckling för mätning av "mjuka partiklar" i bränsletCsontos, Botond January 2016 (has links)
As environmental awareness raises the expectations to reduce emission of modern diesel engines are growing as well. Fuel diversity and the advanced injector systems requires even more attention on an ever existing problem which is called nozzle hole fouling. Recent literature and observations at Scania indicate the phenomena is connected to fuel filter plugging caused by metal carboxyl contaminants through the formation of “soft particles”. This report begins with a literature review about the nature of agglomerates in biodiesel. Followed by the evaluation of six particle sizing equipment. This include one ensemble technique based on Brownian motion, namely dynamic light scattering. The remaining five techniques are single particle counters, including a high speed camera system, light blocking system, Nano tracking analysis and two different approaches using light microscope. To characterise the structure and chemical components of the particles SEM, EDX, FT-IR and ICP-OES were used. From the above mentioned methods optical microscopy was chosen to be the best method to evaluate the particle distribution. The main reasons for this is the ability to measure particles in the solution in the desired size range and the possibility to couple it with a Raman spectrometer, providing possibilities for future studies. Besides finding the best technique to measure the particles, a secondary result is the negation of Zinc-neodecanoate creating particles in the fuel. It opposes the assumption made in the literature about filter blocking, and it finds the need for deeper understanding of the nature of soft particles.
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