Engineering Commons^™

Computational Study Of Microstructure-Propertymechanism Relations In Ferroic Composites, Fengde D. Ma

Dissertations, Master's Theses and Master's Reports - Open

Ferroic materials, as notable members of smart materials, have been widely used in applications that perform sensing, actuation and control. The macroscopic property change of ferroic materials may become remarkably large during ferroic phase transition, leading to the fact that the macroscopic properties can be tuned by carefully applying a suitable external field (electric, magnetic, stress). To obtain an enhancement in physical and/or mechanical properties, different kinds of ferroic composites have been fabricated. The properties of a ferroic composite are determined not only by the properties and relative amounts of the constituent phases, but also by the microstructure of individual …

Modeling And Simulation Of Microstructures, Mechanisms, And Diffraction Effects In Energy Materials: Ferroelectrics And Lithium Ion Battery Cathode Materials, Jie Zhou

Dissertations, Master's Theses and Master's Reports - Open

Ferroelectric materials, as a large family exploited for the application of sensors, transducers and random access memories, open up a remarkable ground both for fundamental science and industry. Dielectric and piezoelectric properties are of the most interest in ferroelectric materials, which motivate research to enhance ferroelectric properties based on various application purposes. Among the multitudinous candidates in ferroelectric family, pseudo binary solid solutions with ABO₃ lattice structure attract special attention in virtue of their large strain response when applying external loading. Furthermore, existence of morphological phase boundary (MPB) on their phase diagrams shed light on tuning material compositions to …

Beautiful Forms And Compositions Are Not Made By Chance: Exploring The Efficacy Of Portable X-Ray Fluorescence To Sort And Source English Lead Glazed Ceramics, Steven J. Sarich

Dissertations, Master's Theses and Master's Reports - Open

Advances in portable X-ray fluorescence (pXRF) technology have made it a viable option for the non-destructive exploration of the underlying chemical composition of ceramic artifacts for the purposes of classification. However, because the literature regarding the use of this instrument on historic artifacts is limited, it is necessary to begin with a broad scale exploratory assessment that might act as a jumping off point for future studies on this topic. Toward that end, this research uses a collection of British and Continental European ceramics ranging from 1650-1920, owned and curated by the Chipstone Foundation in Fox Point, WI, to explore …

A Field Investigation Of Composite Mud Brick Compressive Strength, Kevin D. Hale

Dissertations, Master's Theses and Master's Reports - Open

It has been highlighted in numerous publications that in the field of earth construction there is a strong disconnect between experimental work in the laboratory and its application in the field. The current study attempts to help bridge this gap with a field test conducted in Nampula, Mozambique. Mud bricks were made with a simple hand mold and reinforced with bamboo and straw fibers. Fibers were cut into lengths of 3 cm and 6 cm while being mixed in fractions of 0.125%, 0.25% and 0.50% by weight and compressive strength was measured using an application of the 3-point bending test. …

Structures, Properties And Functionalities Of Magnetic Domain Walls In Thin Films, Nanowires And Atomic Chains: Micromagnetic And Ab Initio Studies, Liwei D. Geng

Dissertations, Master's Theses and Master's Reports - Open

Structures, properties and functionalities of magnetic domain walls in thin film, nanowires and atomic chains are studied by micromagnetic simulations and ab initio calculations in this dissertation. For magnetic domain walls in thin films, we computationally investigated the dynamics of one-dimensional domain wall line in ultrathin ferromagnetic film, and the exponent α = 1.24 ± 0.05 is obtained in the creep regime near depinning force, indicating the washboard potential model is supported by our simulations. Furthermore, the roughness, creep, depinning and flow of domain wall line with commonly existed substructures driven by magnetic field are also studied. Our simulation results …

Biological Materials: Part A. Temperature-Responsive Polymers And Drug Delivery And Part B. Polymer Modification Of Fish Scale And Their Nano-Mechanical Properties, Xu Xiang

Dissertations, Master's Theses and Master's Reports - Open

This research has three parts. Two parts deal with novel nanoparticle assemblies for drug delivery, and are described in Part A, while the third part looks at properties of fish scales, an abundant and little-used waste resource, that can be modified to have value in medical and other areas.

Part A describes fundamental research into the affects of block sequence of amphiphilic block copolymers prepared from on a new and versatile class of monomers, oligo(ethylene glycol) methyl ether acrylate (OEGA) and the more hydrophobic di(ethylene glycol) methyl ether methacrylate (DEGMA). Polymers from these monomers are biologically safe and give polymers …

Systematic Study Of The Biological Effects Of Nitric Oxide (No) Using Innovative No Measurement And Delivery Systems, Weilue He

Dissertations, Master's Theses and Master's Reports

Nitric oxide (NO) is recognized as the most important small signaling molecule in the human body. An imbalance of NO is closely associated with many serious diseases such as neurological disorders, cardiovascular diseases, chronic inflammations and cancers. Herein two chemiluminescence-based devices (a real-time NO measurement device and a controllable NO delivery device) were developed to facilitate the NO quantitative study and obtain information for NO related drug design.

The first device used for real-time measuring NO(g) flux from living cells was developed and validated. The principle was to use a two-chamber design, with a cell culture chamber and a gaseous …

3d Printing, Open-Source Technology And Their Applications In Research, Chenlong Zhang

Dissertations, Master's Theses and Master's Reports

Open-source software received tremendous success as it drives down the cost of software and expand the distribution. Open-source hardware, as part of the open-source movement, has just risen into public attention for its potential to further drive down the cost of all kinds of manufacturing goods and reshape the manufacture chain. In this report we explores the history, development and the future of open-source hardware project, summarizing the opportunities, challenges and possible solutions. 3D printing is demonstrated as a booster to assist open-source hardware’s development. Low-cost 3D printer enables at-home and in-time fabrication, the download-print-use-improve-distribute cycle is established to encourage …

Biocorrosion Rate And Mechanism Of Metallic Magnesium In Model Arterial Environments, Patrick Bowen

Dissertations, Master's Theses and Master's Reports

A new paradigm in biomedical engineering calls for biologically active implants that are absorbed by the body over time. One popular application for this concept is in the engineering of endovascular stents that are delivered concurrently with balloon angioplasty. These devices enable the injured vessels to remain patent during healing, but are not needed for more than a few months after the procedure. Early studies of iron- and magnesium-based stents have concluded that magnesium is a potentially suitable base material for such a device; alloys can achieve acceptable mechanical properties and do not seem to harm the artery during degradation. …