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Full-Text Articles in Mechanical Engineering

Motion Coordination And Control In The Development Of A Gait Rehabilitation System, Yazan Ahmad Manna Dec 2009

Motion Coordination And Control In The Development Of A Gait Rehabilitation System, Yazan Ahmad Manna

Dissertations

While most take their ability to walk for granted, some are unable to walk due to any number of pathologies, such as traumatic brain injury (TBI), spinal cord injury (SCI), and Parkinson's disease. Decreased activity has been shown to be associated with rapidly deconditioning. Rehabilitation techniques that afford patients the ability to begin reconditioning through walking sooner may ultimately enhance their return to a better quality of life. To assist the functional recovery of such patients, an appropriate afferent input to the spinal cord will help in the therapy of the patient. Manual training is labor intensive, costly, and ...


Optimal Synthesis Of Planar Adjustable Mechanisms, Chong Peng Dec 2009

Optimal Synthesis Of Planar Adjustable Mechanisms, Chong Peng

Dissertations

Adjustable mechanisms provide degrees of flexibility while retaining desirable features of one degree of freedom close-loop mechanisms, such as simplicity, stability, and high speed capabilities. By adjusting linkage parameters, additional phases of motions can be achieved using the same hardware. However, an adjustment to the mechanism adds only one or two additional design positions and divides desired positions into "phases", each of which contains only a few positions usually insufficient for industrial applications.

In order to extend the design position limitation of adjustable mechanisms, an optimal synthesis method based on link length structural error is developed and applied to kinematic ...


Simulation, Synthesis, And Characterization Of Hydrogels And Nanocomposite Gels., Kamleshkumar J. Suthar Dec 2009

Simulation, Synthesis, And Characterization Of Hydrogels And Nanocomposite Gels., Kamleshkumar J. Suthar

Dissertations

Stimuli-responsive gels are three-dimensional, cross-linked polymeric materials that undergo large physical change in response to the environmental stimuli, like temperature, pH, electrical potential, and irradiation. Ferrogels are colloidaldispersion of magnetic nanoparticles in the hydrogel network. The magnetic nanoparticles are attached to the polymeric network by different adhesive forces; as a result, it becomes sensitive to the applied magnetic field.

The main objective of this research is the simulation, synthesis, and characterization of the hydrogel and ferrogel. Simulation of the hydrogel response was performed for various environmental stimuli using a multiphysics finite element analysis software, COMSOL. The pH and electrical response ...


Electrohydrodynamic Manipulation Of Multiphase Fluids, Sai C. Nudurupati Aug 2009

Electrohydrodynamic Manipulation Of Multiphase Fluids, Sai C. Nudurupati

Dissertations

In microfluidic devices, the fluid can be manipulated either as continuous streams or droplets. The latter is particularly attractive as individual droplets can not only move but also split and fuse, thus offer a greater flexibility in applications such as a laboratory-on- a-chip. In this thesis, a technique is developed that uses an externally applied electric field for manipulating and removing particles trapped on the surface of a drop. The drop is assumed to be immersed in another liquid with which it is immiscible, and the electric field is generated by placing electrodes on the sides of the microdevice. Both ...


Analytical, Computational And Experimental Studies Of Capillary Flow In Complex Geometries, Yongqing Peng Aug 2009

Analytical, Computational And Experimental Studies Of Capillary Flow In Complex Geometries, Yongqing Peng

Dissertations

The dynamic processes of capillary flow in complex geometries have been studied analytically, computationally and experimentally in this research. A general approach for modeling the capillary flow in arbitrary irregular geometries with straight axis of symmetry is proposed. Using this approach, the governing equation to describe the dynamic capillary rising motion in capillaries with nonuniform elliptical cross-section is first derived under the assumptions of parabolic distribution of the axial velocity and constant contact angle. The calculation results for the capillary flow in different tubes with irregular wall show that, in comparison with existing models that have been tested, the present ...


Heterogeneous Flow Structure And Gas-Solid Transport Of Riser, Jun You May 2009

Heterogeneous Flow Structure And Gas-Solid Transport Of Riser, Jun You

Dissertations

This study aims to understand physical mechanisms of gas-solid transport and riser flow, investigate heterogeneous flow structures of gas-solid transport and their formation mechanism of the in riser flows, both in axial and radial directions. It provides sound interpretation for the experimental observation and valuable suggestion to riser reactor design. Chemical reaction is also coupled with flow hydrodynamics to board the industrial applications. This study mainly focuses on mathematical modeling approach based upon physical mechanism, and endeavor to validate model prediction against available experimental data.

First of all, most important physical mechanisms including inter-particle collision force, gas/solid interfacial force ...