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Full-Text Articles in Mechanical Engineering

Dem Simulated Radial And Axial Pressure In A Cylindrical Granular Column, Meng Cui Aug 2008

Dem Simulated Radial And Axial Pressure In A Cylindrical Granular Column, Meng Cui

Theses

The study of packed beds of granular spheres and their applications are of great interest to industries, and one of the most important subjects that has been studied is cylindrical beds. In 1895, H. A. Janssen discovered that in a vertical cylinder the pressure measured at the bottom does not depend upon the height of the filling in contrast to Newtonian fluids that possess linear hydrostatic pressure equilibrium. One of assumptions of his theory stated that the horizontal pressure is proportional to the vertical. In this thesis, this physical hypothesis is investigated using Discrete Element Simulations of inelastic with a …


Ignition Of Metal Powder By Electrostatic Discharge Stimulation, Ervin Beloni Jan 2008

Ignition Of Metal Powder By Electrostatic Discharge Stimulation, Ervin Beloni

Theses

Energetic formulations with metal fuel additives are extensively used in propellants, explosives, pyrotechnics, and incendiaries. Currently, replacement of regular metal powders with nanocomposite metal-based materials is being considered. Such nanocomposite reactive materials are capable of very high reaction rates while maintaining the high combustion enthalpies characteristic of metals. However, such novel reactive nano-materials are often highly sensitive to impact, friction, and electrostatic discharge, making them difficult to handle. In particular, their high electrostatic discharge sensitivity (ESD) was reported. While ESD testing is very common and standardized, the mechanisms of powder ignition by electric spark remain unclear. This project is aimed …


Design Of Gait Rehabilitation System, Andriy Pletenetskyy Jan 2008

Design Of Gait Rehabilitation System, Andriy Pletenetskyy

Theses

This thesis describes the conceptual design of an innovative robotic rehabilitation machine whose purpose is to help in the recovery of people with motor function disabilities. The machine is smaller, simpler and cheaper than current solutions on the market yet it delivers same functionality.

The conceptual development of the gait rehabilitation system also features a human model with average anthropometric dimensions that allows better visualization and understanding of the actual machine operation. The human model is kinematically coupled to the machine and the whole assembly presents a complex mechanism that closely simulates gait training session.

Three-dimensional modeling and analysis techniques …


Phase Transfer In A Collision Between A Droplet And Solid Spheres, Zheng Shen Jan 2008

Phase Transfer In A Collision Between A Droplet And Solid Spheres, Zheng Shen

Theses

The hydrodynamics of a liquid droplet impinging on a particle is of direct relevance to many engineering applications. The mechanism of heat and mass transfer during the droplet solid collision is essential to the design and operation of many industrial systems. However, very limited systemic research is available to describe the droplet impact on hot solid spheres.

This paper aims to establish a systematic investigation of phase transfer due to the droplet-solid impact, by both experimental and modeling approaches. The targeted phase transfer includes the surface attachment, mass of vaporization, heat transfer to droplet and its partition between vaporization and …


Fully Dense Aluminum-Rich Aluminum Copper Oxide Powders For Energetic Formulations, Demitrios Stamatis Jan 2008

Fully Dense Aluminum-Rich Aluminum Copper Oxide Powders For Energetic Formulations, Demitrios Stamatis

Theses

The thermite reaction between Al and CuO is well known and highly exothermic. For a conventional thermite mixture comprising mixed metal and oxide powders, this reaction is rate limited by the slow heterogeneous mass transfer at the metal and oxide interface. The relatively low reaction rate and a difficult ignition have restricted practical applications for this reaction. For newly developed, nano-composed thermites, the interface area can be substantially increased resulting in a much higher reaction rate and a new range of possible applications. Nanocomposite Al-CuO materials are produced using a technique referred to as arrested reactive milling. Regular metal and …


Precision Coil Inspection, Karol Murphy Jan 2008

Precision Coil Inspection, Karol Murphy

Theses

Boston Scientific produces the Guglielmi Detachable Coil in their Cork based facility. These are used in a surgical procedure to eliminate aneurysms. The first step in the process is to form a coil by wrapping a platinum wire around a mandrel. These coils have outer diameters ranging from 190 pm to 520pm. This is called the primary wind and is inspected to find any defects introduced into the coil from the winding process. These defects may be the result of wire defects in the raw material or possibly poor handling by the operators. These primary winds are processed further to …


Treatment Of Aqueous Waste Streams At Eli Lilly - Alternatives To Incineration, Barry Hennessy Jan 2008

Treatment Of Aqueous Waste Streams At Eli Lilly - Alternatives To Incineration, Barry Hennessy

Theses

The aim of this project was to investigate the potential to treat liquid waste (secondary) from production processes at Eli Lilly with the emphasis on minimising the volume of waste sent for thermal oxidation. In addition, the project aimed to investigate if the chosen technology was diverse and potentially capable of handling waste streams from different processes. Membrane technology was identified as one of the most suitable technologies and trials were carried out on secondary waste from three production processes. The literature review and practical thrials aswell as assessment of trial results ran from October 2003 to June 2005.

All …