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Showing 1 to 20 of 132 for “"contact angles"”.
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Dynamic Contact Angles And Wetting Front Instability In Soils
Dynamic contact could provide a mechanism for initiating the instability of wetting fronts and the formation of gravity fingers/columns in porous media. To study those dynamic contact angles when gravity effects are present, rectangular capillary tubes are used to facilitate the observation of the …
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Methods for the direct simulation of nanoscale film breakup and contact angles
… simulation of fluids with free surfaces and contact lines, with a focus on capturing nanoscale physics in a continuum based computational framework. Free surfaces and contact lines have long presented some of the most challenging problems in computational fluid dynamics. Extensive progress …
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The Determination of The Wetting Characteristics of Starches and Other Polymers as Measured by Contact Angles
Made available in DSpace on 2014-12-05T19:36:53Z (GMT). No. of bitstreams: 1 5805387.pdf: 4207007 bytes, checksum: 12325efbff29173844cb410c8cc29547 (MD5) Previous issue date: 1958
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Wettability of solid particles in relation to particle-stabilised foams and emulsions
… technique for the direct measurement of the contact angles of micrometer and submicrometer particles in their natural environment. One of the main aims of this work was to develop the Film Calliper Method for measuring contact angles at oil -water interfaces. The FCM was therefore used to …
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Aging Effect in the Wettability of Nickel Nanorod Arrays
… arrays was studied by measuring their water contact angles as a function of "aging" time in air. The nickel nanorod arrays were deposited on silicon substrates by DC magnetron sputtering using an oblique angle of 85° with respect to the substrate normal. By changing the deposition time from …
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A study of bubble wetting on surfaces
… to other models. Dynamic and sessile bubble contact angles and droplet contact angles were measured on smooth acrylic, fluorosilanized silicon, glass, nylon, and silicon. These results were compared to the existing model, and the resulting error showed a strong correlation with a Pearson's …
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Wetting kinetics in forced spreading
<p>"Under dynamic conditions, the dynamic contact angle (the angle that the liquid makes with the solid) of a liquid on a solid surface varies dramatically with substrate velocity from its equilibrium value. Experimental data of the dynamic contact angles for polydimethylsiloxane (PDMS or silicone …
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Hydrophobic nanostructured glass surfaces using metal dewetting process
… of the process. Using this fabrication process, contact angles up to 137 degrees was achieved. Further surface modification resulted in contact angles exceeding 150 degrees. Superhydrophobic surfaces were made with the addition of a secondary roughness feature and the a PDMS coating.
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Ink Transfer Mechanisms in Flexographic Printing
… the anilox rolls were extensively studied using contact angles measurements. Two instruments were used to make the measurements and both equilibrium and advancing contact angles were measured. The contact angle data was used in conjunction with the Wenzel, Shuttleworth and Bailey, and Cassie and …
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Effects of silica nanoparticle surface treatment and average diameter on the physical and mechanical properties of poly(dimethylsiloxane)-silica nanocomposites
… 10 minutes, and advancing and receding water contact angles were measured for each nanocomposite. PDMS-silica nanocomposites containing untreated silica nanoparticles were found to have a higher Young's elastic modulus than nanocomposites containing hexamethyldisilazane-treated silica …
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Micro-textured surfaces for omniphobicity and drag-reduction
When a liquid droplet contacts a surface possessing the appropriate combination of surface texture and solid surface energy, the liquid may not penetrate into the surface texture. Instead, the droplet sits partially on air, forming a solid-liquid-air composite interface. Entrapped air pockets of …
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Basics of detached Bridgman growth of Ge1-xSix crystals
… the growth interface and the ampoule. The contact-free growth reduces mechanical stress in the growing crystal resulting in a better crystal quality with less defect density. <br>High contact angles and high growth angles favor crystal detachment. Therefore, the knowledge of the contact …
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Chemical Surface Modification of Polycarbonate to Increase Hydrophilicity
… hydrophilic, ideally superhydrophilic with a contact angle less than 10°. Many chemicals were tested to see if they could increase the polarity of polycarbonate. Polycarbonate was partially submerged in pure chemicals for 2 hours at room temperature to determine its chemical compatibility. …
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Self-Assembled Monolayers As Models For Silica
… software. Water droplet goiniometry found contact angles of 52o, 53o, and 64o for SAMs prepared from 1, 2, and 3, respectively. SAMs of 1 and 2 were found to be hydrophilic. When SAMs prepared from 1, 2, and 3 were silylated with phenyldimethylchlorosilane, the resulting contact angles were …
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Adhesion Fundamentals in Spotted Gum (Corymbia citriodora)
… the sessile drop method. Initial and equilibrium contact angles, time-dependent wetting, and surface energy were determined. Time-dependent wetting and equilibrium contact angles were most informative. Initial contact angles and surface energy calculated with them were misleading and often …
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Modeling bubble-particle interactions in flotation using hydrophobic solid surfaces
… of conditions. Hydrophobic surfaces exhibiting contact angles ranging from 0 to 109° were prepared by reacting silica with octadecyltrichlorosilane (OTS). Contact angles, AFM images, and infrared transmission spectra showed that OTS forms clusters on the silica surface. The presence of water in …
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Rough-terrain mobile robot planning and control with application to planetary exploration
… A method for on-line estimation of wheel-terrain contact angles is presented. Simulation and experimental results show that wheel-terrain model parameters and contact angles can be estimated on-line with good accuracy. Two rough-terrain planning algorithms are introduced. First, a motion planning …
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Computational Modeling of Droplet Impact Dynamics on Solid Substrates
… this project revolves around modeling the moving contact lines at the interface in a multiphase flow environment. Focusing on research from an aircraft de-icing point of view, this study is considered a prerequisite in understanding the physics of droplet impact. The primary focus is on extending …
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Development of Super Hydrophobic Surfaces using Silica Nanoparticles
… development of surfaces that have high water contact angles and hysteresis has always been of great importance in industrial applications. Various methods and techniques have been introduced to fabricate surfaces at nano-scale to support super hydrophobicity. Some of these techniques are …
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Droplet repellency of microfabricated surfaces in saturated environments
This thesis reports changes in apparent contact angles for droplets of various liquids on microstructured surfaces in saturated environments. Micro scale pillar surfaces maintain the non-wetting Cassie-Baxter regime for drops of water over a range of saturation temperatures while micro scale …
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