Engineering Commons^™

Diagnosis Of Systemic Inflammation Using Transendothelial Electrical Resistance And Low-Temperature Co-Fired Ceramic Materials, William L. Mercke

Theses and Dissertations--Chemical and Materials Engineering

Systemic inflammation involves a complex array of cytokines that can result in organ dysfunction. Mortality remains high despite the vast amount of research conducted to find an effective biomarker. The cause of systemic inflammation can be broad and non-specific; therefore, this research investigates using transendothelial electrical resistance (TEER) measurements to better define systemic inflammatory response syndrome (SIRS)/sepsis within a patient. Results show a difference in TEER measurements between healthy individuals and SIRS-rated patients. This research also displays correlations between TEER measurements and biomarkers currently studied with systemic inflammation (tumor necrosis factor-α, C- reactive protein, procalcitonin). Furthermore, this research also presents …

Structural Tailoring Of Nanoporous Metals And Study Of Their Mechanical Behavior, Lei Wang

Theses and Dissertations--Chemical and Materials Engineering

Nanoporous (np) metals and alloys are the subject of increasing research attention due to their high surface-area-to-volume ratio. Numerous methods exist to create np metals, with dealloying being a common approach. By dissolving one or more elements from certain alloy systems, porous structure can be generated. Utilizing this method, multiple np metals, including np-Ni, np-Ir, and np-Au were created. By carefully adjusting precursor type and dealloying conditions for each system, nanoporous Ni/Ir/Au with different morphologies and even controllable ligament/pore size were achieved.

The mechanical behavior of porous materials is related to their fully dense counterparts by scaling equations. Established scaling …

Electromechanical Interaction On The Deformation Behavior Of Metallic Materials, Guangfeng Zhao

Theses and Dissertations--Chemical and Materials Engineering

Metallic materials play important roles in providing electrical, thermal, and mechanical functions in electronic devices and systems. The understanding of the electrical-thermal-mechanical interaction caused by the passage of electric current with high density is important to improve the performance and reliability of electronic assembly and packaging. The electromechanical interaction on the deformation behavior of copper and tin is studied in this work.

The electromechanical response of Cu strips was studied by passing a DC electric current. The electric resistance linearly increased with time before the occurrence of electric fusing. The electrothermal interaction led to the buckling of the Cu strips …

A Three-Dimensional Quantitative Understanding Of Short Fatigue Crack Growth In High Strength Aluminum Alloys, Wei Wen

Theses and Dissertations--Chemical and Materials Engineering

The behaviors of short fatigue crack (SFC) propagation through grain boundaries (GBs) were monitored during high cycle fatigue in an Al-Li alloy AA8090. The growth behaviors of SFCs were found to be mainly controlled by the twist components (α) of crack plane deflection across each of up to first 20 GBs along the crack path. The crack plane twist at the GB can result in a resistance against SFC growth; therefore SFC propagation preferred to follow a path with minimum α at each GB. In addition to the grain orientation, the tilting of GB could also affect α.

An experiment …

Copper Indium Diselenide Nanowire Arrays In Alumina Membranes Deposited On Molybdenum And Other Back Contact Substrates, Bhavananda R. Nadimpally

Theses and Dissertations--Electrical and Computer Engineering

Heterojunctions of CuInSe₂ (CIS) nanowires with cadmium sulfide (CdS) were fabricated demonstrating for the first time, vertically aligned nanowires of CIS in the conventional Mo/CIS/CdS stack. These devices were studied for their material and electrical characteristics to provide a better understanding of the transport phenomena governing the operation of heterojunctions involving CIS nanowires. Removal of several key bottlenecks was crucial in achieving this. For example, it was found that to fabricate alumina membranes on molybdenum substrates, a thin interlayer of tungsten had to be inserted. A qualitative model was proposed to explain the difficulty in fabricating anodized aluminum oxide …

Numerical Modeling And Characterization Of Vertically Aligned Carbon Nanotube Arrays, Johnson Joseph

Theses and Dissertations--Mechanical Engineering

Since their discoveries, carbon nanotubes have been widely studied, but mostly in the forms of 1D individual carbon nanotube (CNT). From practical application point of view, it is highly desirable to produce carbon nanotubes in large scales. This has resulted in a new class of carbon nanotube material, called the vertically aligned carbon nanotube arrays (VA-CNTs). To date, our ability to design and model this complex material is still limited. The classical molecular mechanics methods used to model individual CNTs are not applicable to the modeling of VA-CNT structures due to the significant computational efforts required. This research is to …

Characterization Of And Controlling Morphology Of Ultra-Thin Nanocomposites, Guy C. Laine

Theses and Dissertations--Chemical and Materials Engineering

Ultrathin film nanocomposites are becoming increasingly important for specialized performance of commercial coatings. Critical challenges for ultrathin film nanocomposites include their synthesis and characterization as well as their performance properties, including surface roughness, optical properties (haze, refractive index as examples), and mechanical properties. The objective of this work is to control the surface roughness of ultrathin film nanocomposites by changing the average particle size and the particle volume fraction (loading) of monomodal particle size distributions. This work evaluated one-layer and two-layer films for their surface properties. Monodispersed colloidal silica nanoparticles were incorporated into an acrylate-based monomer system as the model …

Influence Of Surface Modification On Properties And Applications Of Complex Engineered Nanoparticles, Binghui Wang

Theses and Dissertations--Chemical and Materials Engineering

Complex engineered nanoparticles (CENPs) are being used on various applications. Their properties are different from those of neat nanoparticles. The dissertation explores these differences from four aspects: 1) Modify carbon nanomaterials’ inert surfaces and investigate the effect on thermal and rheological behavior of their dispersions; 2) Generate self-assembly bi-layer structure of oxide nanoparticles via surface modification; 3) Study interaction between lysozyme and different surface-charged ceria nanoparticles; 4) Investigate the biodistribution and transformations of CENPs in biological media.

An environment-friendly surface modification was developed to modify surfaces of carbon nanomaterials for increasing their affinity to non-polar fluid. It can offset formation …