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Full-Text Articles in Engineering
Simultaneous Measurement Of Isotope-Free Tracer And Interdiffusion Coefficients In Sandwich Type Diffusion Couples, Esin Schulz
Simultaneous Measurement Of Isotope-Free Tracer And Interdiffusion Coefficients In Sandwich Type Diffusion Couples, Esin Schulz
Electronic Theses and Dissertations
The experimental determination of the tracer or self-diffusion coefficient as a function of composition can be quite burdensome in alloys since separate measurements must be carried out for each alloy composition. A new formalism recently developed by I.V. Belova, N.S. Kulkarni, Y.H. Sohn and G.E. Murch, based on linear response theory combined with the Boltzmann–Matano method allows determination of tracer and interdiffusion coefficients simultaneously from a single, isotope-free solid to solid diffusion couple experiment. In this study, for the first time, an experimental investigation with an analytical approach based on the new formalism has been carried out in the binary …
Regolith-Based Construction Materials For Lunar And Martian Colonies, Kevin Grossman
Regolith-Based Construction Materials For Lunar And Martian Colonies, Kevin Grossman
Electronic Theses and Dissertations
Humankind's ambitions of exploring our solar system and parts beyond depend heavily on our ability to collect resources from local environments at our destinations rather than bringing materials on the journey. This is a concept known as in-situ resource utilization (ISRU) and it is one that has been understood by every explorer and settler in the history of humankind. Regolith on the moon and Mars has been shown to be a particularly useful resource and has the ability to provide humans with resources including water, oxygen, construction material, fabric, radiation shielding, metals, and may more. This dissertation focuses on construction …
The Formation And Characterization Of Mesoscopic J- And H-Aggregates With Controlled Morphologies By The Co- And Templated Assembly Of Cyanine Dyes, Samuel Rhodes
Electronic Theses and Dissertations
The supramolecular aggregates of π-conjugated molecules have become an area of great interest to the scientific community in recent years for their promise in biosensors and optoelectronic devices. Among various supramolecular aggregates, J- and H-aggregates of πconjugated dye molecules are particularly interesting because of their unique optical and excitonic properties that are not given by individual molecules. H-aggregates are composed of dye molecules in a face-to-face stacking, giving rise to a blue-shifted absorption band compared with the monomer band and a strong emission quenching. In contrast, J-aggregates represent an edge-toedge stacking of dye molecules, showing a red-shifted absorption band with …
Influence Of Chitosan-Alginate Scaffold Stiffness On Bone Marrow Stromal Cell Differentiation, Isabel Arias Ponce
Influence Of Chitosan-Alginate Scaffold Stiffness On Bone Marrow Stromal Cell Differentiation, Isabel Arias Ponce
Electronic Theses and Dissertations
Tissue grafts are the gold standard for replacing large volume tissue defects. Yet, they present several risks, including infection, low functional outcomes, and reduced graft integrity. Tissue engineering (TE) combines cells and biomaterial scaffolds to foster tissue growth and remodeling. Bone marrow stromal cells (BMSCs) have been shown to respond to the stiffness of their microenvironment, resulting in differentiation into different lineages. 3D porous chitosan-alginate (CA) scaffolds have been previously demonstrated for bone TE with osteoblasts and BMSCs; however, only a single scaffold composition (4 wt%) was studied. Three CA scaffold compositions (2, 4, 6 wt% CA) were produced. Scanning …
Advanced Nanoscale Characterization Of Plants And Plant-Derived Materials For Sustainable Agriculture And Renewable Energy, Mikhael Soliman
Advanced Nanoscale Characterization Of Plants And Plant-Derived Materials For Sustainable Agriculture And Renewable Energy, Mikhael Soliman
Electronic Theses and Dissertations
The need for nanoscale, non-invasive functional characterization has become more significant with advances in nano-biotechnology and related fields. Exploring the ultrastructure of plant cell walls and plant-derived materials is necessary to access a more profound understanding of the molecular interactions in the systems, in view of a rational design for sustainable applications. This, in turn, relates to the pressing requirements for food, energy and water sustainability experienced worldwide. Here we will present our advanced characterization approach to study the effects of external stresses on plants, and resulting opportunities for biomass valorization with an impact on the food-energy-water nexus. First, the …
Cell Printing: An Effective Advancement For The Creation Of Um Size Patterns For Integration Into Microfluidic Biomems Devices, Megan Aubin
Electronic Theses and Dissertations
The Body-on-a-Chip (BoaC) is a microfluidic BioMEMs project that aims to replicate major organs of the human body on a chip, providing an in vitro drug testing platform without the need to resort to animal model testing. Using a human model also provides significantly more accurate drug response data, and may even open the door to personalized drug treatments. Microelectrode arrays integrated with human neuronal or human cardiac cells that are positioned on the electrodes are essential components for BoaC systems. Fabricating these substrates relies heavily on chemically patterned surfaces to control the orientation and growth of the cells. Currently, …
Assessment Of Microstructure And Mechanical Behavior Of Materials And Phases Observed In Low-Enriched Uranium Monolithic Fuel Plates After Fabrication, Ryan Newell
Electronic Theses and Dissertations
Low enriched uranium (LEU) fuels are being developed to reduce the use of highly enriched uranium in power generation to reduce proliferation risks. Challenges arise in providing sufficient fissile U in LEU without reactor redesign. As such, a novel monolithic fuel plate design employs LEU alloyed with 10 wt. % Mo. Throughout fabrication of these fuel plates, metallurgical transformations and reactions take place as a result of elevated temperatures during processing. The transformations include decomposition of the metastable body-centered cubic γ phase in the fuel and metallurgical interactions at interfaces between fuel plate components. This work aims to provide further …
Graphene Induced Formation Of Nanostructures In Composites, Chen Shen
Graphene Induced Formation Of Nanostructures In Composites, Chen Shen
Electronic Theses and Dissertations
Graphene induced nanostructures in graphene-based composites and the performance of these composites have been explored in this study. For the metallic nanoparticles decorated graphene aerogels composites, the fabrication of hierarchically structured, reduced graphene oxide (rGO) aerogels with heavily metallic nanoparticles was realized. Higher loading of palladium nanoparticles in graphene aerogels leads to improved hydrogen gas sensing performance. For polymer derived ceramics (PDCs) composites with anisotropic electrical properties, the fabrication of composites was realized by embedding anisotropic reduced graphene oxide aerogels (rGOAs) into the PDCs matrix. Raman spectroscopy and X-ray diffraction studies of PDCs composites with and without graphene indicate that …