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Articles 1 - 5 of 5

Full-Text Articles in Mechanical Engineering

Dispersion Of Particles On Liquid Surfaces, Sathishkumar Gurupatham Aug 2011

Dispersion Of Particles On Liquid Surfaces, Sathishkumar Gurupatham

Dissertations

When small particles (e.g., flour, pollen, etc.) come in contact with a liquid surface, they immediately disperse. The dispersion can occur so quickly that it appears explosive, especially for small particles on the surface of mobile liquids like water. This explosive dispersion is the consequence of capillary force pulling particles into the interface causing them to accelerate to a relatively large velocity. The maximum velocity increases with decreasing particle size; for nanometer-sized particles (e.g., viruses and proteins), the velocity on an air-water interface can be as large as 47 m/s. They also oscillate at a relatively high ...


Modeling Of Non-Uniform Hydrodynamics And Catalytic Reaction In A Solids-Laden Riser, Rajeshkumar Patel May 2011

Modeling Of Non-Uniform Hydrodynamics And Catalytic Reaction In A Solids-Laden Riser, Rajeshkumar Patel

Dissertations

The riser reactors are widely used in a variety of industrial applications such as polymerization, coal combustion and petroleum refinery because of the strong mixing of gas and solids that yields high heat and mass transfer rates, and reaction rates. In a Fluid Catalytic Cracking (FCC) process, the performance of riser reactor is strongly dependent on the interaction between the fluid and catalysts, since the reaction takes place on the active surface of the catalysts. This is why, the local coupling between hydrodynamics and reaction kinetics is critical to the development of riser reaction models. The local gas-solids flow structure ...


Benefits Of Cpfr And Vmi Collaboration Strategies In A Variable Demand Environment, Dattaraj Kamalapurkar Jan 2011

Benefits Of Cpfr And Vmi Collaboration Strategies In A Variable Demand Environment, Dattaraj Kamalapurkar

Dissertations

In recent years, practitioners and academic researchers have emphasized that organizations need to collaborate with suppliers and customers to improve their competitive advantage. The availability of cost efficient information technologies like EDI, XML, etc. have made it possible to develop and implement many forms of collaboration strategies. Among them, Vendor Managed Inventory (VMI) and Collaborative Planning, Forecasting and Replenishment (CPFR) are most popular, which are considered for this study. While many studies have identified the benefits of demand information sharing in supply chains; however the benefits gained by implementing collaboration strategies like VMI and CPFR in a variable demand environment ...


Ductile Mode Material Removal Of Ceramics And Semiconductors, Deepak Ravindra Jan 2011

Ductile Mode Material Removal Of Ceramics And Semiconductors, Deepak Ravindra

Dissertations

Ceramics and semiconductors are hard, strong, inert and lightweight. They also have good optical properties, wide energy bandgap and high maximum current density. This combination of properties makes them ideal candidates for tribological, semiconductor, MEMS and optoelectronic applications respectively. Manufacturing these materials without causing surface and subsurface damage is extremely challenging due to their high hardness, brittle characteristics and poor machinability. However, ductile regime machining of these materials is possible due to the high-pressure phase transformation occurring in the material caused by the high compressive stresses induced by the single point diamond tool tip. In this study, to further augment ...


Beading And Dimpling Techniques To Improve The Vibration And Acoustic Characteristics Of Plate Structures, Nabeel Taiseer Alshabtat Jan 2011

Beading And Dimpling Techniques To Improve The Vibration And Acoustic Characteristics Of Plate Structures, Nabeel Taiseer Alshabtat

Dissertations

A method of improving the vibroacoustic characteristics of beams and plates is presented. This method is based on creating dimples or beads on the surface of the structures. The proposed method couples the finite element method with an optimization technique based on the genetic algorithm (GA). The improvement of the vibroacoustic characteristics of beams and plates is achieved by two separate strategies. The first strategy is optimizing the natural frequencies of beams and plates. The second strategy is minimizing the sound radiation from such vibrating structures. Optimizing the natural frequencies of some types of beams and simply supported plates by ...