Mechanical Engineering Commons^™

Fabrication And Characterization Of Molecular Spintronics Devices, Pawan Tyagi

University of Kentucky Doctoral Dissertations

Fabrication of molecular spin devices with ferromagnetic electrodes coupled with a high spin molecule is an important challenge. This doctoral study concentrated on realizing a novel molecular spin device by the bridging of magnetic molecules between two ferromagnetic metal layers of a ferromagnetic-insulator-ferromagnetic tunnel junction on its exposed pattern edges. At the exposed sides, distance between the two metal electrodes is equal to the insulator film thickness; insulator film thickness can be precisely controlled to match the length of a target molecule. Photolithography and thin-film deposition were utilized to produce a series of tunnel junctions based on molecular electrodes of …

Investigation Of Blast Mitigation Properties Of Carbon And Polyurethane Based Foams, Bradley E. Toon

University of Kentucky Master's Theses

Solid foams have been studied for years for their ability to mitigate damage from sudden impact. Small explosive attacks threaten to damage or destroy key structures in some parts of the world. A newly developed material, carbon foam, may offer the ability to mitigate the effects of such blasts. This project investigates the energy absorbing properties of carbon and polyurethane based foams in dynamic compression to illustrate their viability to protect concrete structures from the damaging effects of pressure waves from a small blast. Cellular solid mechanics fundamentals and a survey of the microscopic cellular structure of each type of …

An Integrated Framework For Applying Lean Manufacturing And Other Strategies In Mass Customization Environments, Gregory Brandon Stump

University of Kentucky Master's Theses

Manufacturing organizations are facing fragmented markets and increased demand of variety from consumers. As a result, many of these firms have adopted mass customization manufacturing strategies in an effort to offer their customers the freedom of choice while maintaining operational efficiency. Lean manufacturing strategies have also seen heavy use in manufacturing environments. This study investigates the possibilities of integrating lean manufacturing principles and practices into mass customization environments in order to improve system performance. The feasibility of other manufacturing strategies such as agility, Quick Response Manufacturing and the Theory of Constraints assisting in the application of lean manufacturing for mass …

Performance Optimization Of A Structured Cfd Code - Ghost On Commodity Cluster Architectures, Pavan K. Kristipati

University of Kentucky Master's Theses

This thesis focuses on optimizing the performance of an in-house, structured, 2D CFD code – GHOST, on commodity cluster architectures. The basic philosophy of the work is to optimize the cache usage of the code by implementing efficient coding techniques without changing the underlying numerical algorithm. Various optimization techniques that were implemented and the resulting changes in performance have been presented. Two techniques, external and internal blocking that were implemented earlier to tune the performance of this code have been reviewed. What follows is further tuning effort in order to circumvent the problems associated with using the blocking techniques. Later, …

Lectures On Computational Numerical Analysis Of Partial Differential Equations, James M. Mcdonough

Mechanical Engineering Textbook Gallery

From Chapter 1:

The purpose of these lectures is to present a set of straightforward numerical methods with applicability to essentially any problem associated with a partial differential equation (PDE) or system of PDEs independent of type, spatial dimension or form of nonlinearity.

A Precision Instrument For Research Into Nanolithographic Techniques Using Field-Emitted Electron Beams, King-Fu Hii

University of Kentucky Doctoral Dissertations

Nanomanufacturing is an active research area in academia and industry due to the ever-growing demands for precision surface modifications of thin films or substrates with nanoscale features. Conventional lithographic techniques face many challenges as they approach their fundamental limits. Consequently, new nanomanufacturing tools, fabrication techniques, and precision instruments are being explored and developed to meet these challenges. It has been hypothesized that direct-write nanolithography might be achieved by using a field-emitted electron beam for nanomachining. This dissertation moves this research one step closer by developing a precision instrument that can enable the integration of direct-write nanolithography by a field-emitted electron …

An Investigation Of Size Effects On Thin Sheet Formability For Microforming Applications, Nasr Abdelrahman Shuaib

University of Kentucky Doctoral Dissertations

The increasing demand for powerful miniaturized products for all industrial applications has prompted the industry to develop new and innovative manufacturing processes to fabricate miniature parts. One of the major challenges facing the industry is the dynamic market which requires continuous improvements in design and fabrication techniques. This means providing products with complex features while sustaining high functionality. As a result, microfabrication has gained a wide interest as the technology of the future, where tabletop machine systems exist. Microforming processes have the capability of achieving mass production while minimizing material waste. Microforming techniques can produce net-shape products with intricacy in …

Elastic-Plastic Indentation Deformation In Homogeneous And Layered Materials: Finite Element Analysis, Siva Naga Venkata Ravi Kiran Kurapati

University of Kentucky Master's Theses

The complex phenomenon of indentation deformation is studied using finite element analysis for both homogeneous and layered materials. For the homogeneous materials, the elastic-plastic deformation at large indentation depth is studied. The variation of the load-displacement curves as well as the variation of the energy ratio with the applied indentation depth for different strain hardening indices is presented. The power law relation between the indentation load and depth for shallow indentation becomes invalid for deep indentation. The ratio of plastic energy to total mechanical work is a linear function of the ratio of residual indentation depth and maximum indentation depth. …