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Full-Text Articles in Engineering
Dynamic Modeling Of Soft Robotic Dielectric Elastomer Actuator, Abdullah De Jesus El Atrache Ceballos
Dynamic Modeling Of Soft Robotic Dielectric Elastomer Actuator, Abdullah De Jesus El Atrache Ceballos
Doctoral Dissertations and Master's Theses
Dielectric elastomers actuators (DEAs) are among the preferred materials for developing lightweight, high compliance and energy efficient driven mechanisms for soft robots. Simple DEAs consist mostly of a homogeneous elastomeric materials that transduce electrical energy into mechanical deformation by means of electrostatic attraction forces from coated electrodes. Furthermore, stacking multiple single DEAs can escalate the total mechanical displacement performed by the actuator, such is the case of multilayer DEAs. The presented research proposes a model for the dynamical characterization of multilayer DEAs in the mechanical and electrical domain. The analytical model is derived by using free body diagrams and lumped …
Development Of Synthetic Coal Char Simulant For Microwave Conversion Studies: A Computationally-Driven Approach, Kevin A. Hager
Development Of Synthetic Coal Char Simulant For Microwave Conversion Studies: A Computationally-Driven Approach, Kevin A. Hager
Graduate Theses, Dissertations, and Problem Reports
Recent experimental demonstration of new reaction windows for coal char/methane reactions that are less energy-intensive, provides innovation for modular reactors. However, the correlation of the exact mechanism for the enhancement of these reaction windows is not certain. This study investigates the simplification of these experimental studies by developing a well-characterized coal char simulant. The approach involves using a computational approach to screen macroscopic composition to replicate the dielectric and compositional response of actual char. This study is focused on PRB coal char. A discrete element method (DEM) technique was used to simulate the packing of coal chars to give the …
Electrospinning Approach For The Improvement Of Mechanical And Dielectric Properties Of Anisotropic Nanofiber Mat By Using A Novel Fiber Alignment Technique, Blesson Isaac
Mechanical and Aerospace Engineering Dissertations
Many advanced applications, including aerospace, can benefit from materials with superior mechanical and dielectric properties. For these applications, most fiber alignment electrospinning research has focused on either mechanical property improvement or dielectric property improvement, but not both simultaneously. Through an improved apparatus design and system parameter optimization, this work develops an electrospinning apparatus that produces an increased electrostatic force and more tightly controlled discharged particle path to enable a more uniform distribution and higher degree of alignment in deposited electrospun material, which results in simultaneous improvement of both mechanical and dielectric properties. The current state-of-the-art in aligned electrospinning techniques are …
Development Of A Plasma Arc Manufacturing Process And Machine To Create Metal Oxide Particles In Water From Wire Feedstock, Jonathan Alan George
Development Of A Plasma Arc Manufacturing Process And Machine To Create Metal Oxide Particles In Water From Wire Feedstock, Jonathan Alan George
Theses and Dissertations
A plasma arc erosion process can be used to create metal and metal oxide particles in the ultra-fine size range (<70 µm). An electric arc is struck between two metallic electrodes, submerged in water, melting the surface of the electrodes. When the arc collapses a high energy pressure wave strikes the molten surface of the electrode. When the pressure wave strikes the molten metal, small metallic particles are created from the molten metal and are immediately cooled in the water. Previous research developed a process that used a constant current power supply and electrode motion to create ultra-fine particles. This research improves upon previous research by using a pulsed power supply similar to those used in Electrical Discharge Machining (EDM). The pulsed power supply eliminates the need for electrode motion and improves the rate of particle production, provides control over size of the particles created, and reduces the amount of energy needed to produce the particles. The new process improves the maximum particle production rate from 3.6 g/hr to 14 g/hr, provides a method to control the mean diameter of the particles produced, and reduces the amount of energy needed from 200 kWh/kg(previous constant current process) to 10.6 kWh/kg(using the pulsed power supply).