Engineering Commons^™

Defect Evolution In High-Temperature Irradiated Nuclear Graphite, Steve Johns

Boise State University Theses and Dissertations

Graphite has historically been used as a moderator material in nuclear reactor designs dating back to the first man-made nuclear reactor to achieve criticality (Chicago Pile 1) in 1942. Additionally, graphite is a candidate material for use in the future envisioned next-generation nuclear reactors (Gen IV); specifically, the molten-salt-cooled (MSR) and very-high-temperature reactor (VHTR) concepts. Gen IV reactor concepts will introduce material challenges as temperature regimes and reactor lifetimes are anticipated to far exceed those of earlier reactors. Irradiation-induced defect evolution is a fundamental response in nuclear graphite subjected to irradiation. These defects directly influence the many property changes of …

Direct Solar Absorption Nanoparticle Doped Membranes For A Hybrid Membrane Distillation And Photovoltaic Cell, Alejandro Espejo Sanchez

Boise State University Theses and Dissertations

The growing demand for clean water supplies is driving the need for an innovative approach of water desalination. Developing a method for treating water with high salinities is possible with membrane distillation (MD). Additionally, MD is very attractive for pairing with solar energy due to the low temperature requirements. The integration of a membrane distillation system with a photovoltaic (PV) system will result in the co-production of electricity and clean water, thereby improving the economics of MD. Such a hybrid system will directly absorb thermal energy in the membrane for desalination while taking advantage of the spectrally selective nature of …

Additive Manufacturing Of Graphene-Based Devices For Flexible Hybrid Electronics, Twinkle Pandhi

Boise State University Theses and Dissertations

In this work, I investigate and enhance the fundamental sensing properties of printed electronic nanomaterials (e.g., graphene) in real-world environments while decreasing weight, cost, and power consumption. The dissertation addresses this issue with the following foci in mind: (1) developing a straightforward and repeatable process to synthesize graphene ink which is also compatible with Inkjet-printing (IJP) and Aerosol Jet printing (AJP). (2) Tuning additive manufacturing printing (IJP and AJP) parameters to establish a repeatable manufacturing process and print high performing (graphene-based) electrodes and interconnects, compatible with the underlying substrate. (3) Investigate power dissipation and electrical breakdown in AJP printed graphene …

Large Displacement J-Integral Double Cantilever Beam (Dcb) Test Method For Mode I Fracture Toughness, Joshua Gunderson

Boise State University Theses and Dissertations

The J-integral is used to develop an alternative double cantilever beam (DCB) test method for the Mode I fracture toughness suitable for both small and large displacements. The current focus is the experimental determination of the Mode I interlaminar fracture toughness of composite materials, but the method is generally applicable to other similar tests and material systems, such as to the Mode I fracture toughness of adhesives. A series of five identical specimens are tested to compare the linear-elastic fracture mechanics method recommended by ASTM, which makes use of linear beam theory with root rotation, large displacement, and end …

Single Molecule Super-Resolution Microscopy Study On The Precision With Which Dna Nanostructures Can Orient Fluorescent Dyes, Brett Michael Ward

Boise State University Theses and Dissertations

DNA nanotechnology enables the rapid, programmable self-assembly of novel structures and devices at the nanoscale. Utilizing the simplicity of Watson-Crick base pairing, DNA nanostructures are capable of assembling a variety of nanoparticles in arbitrary configurations with relative ease. Several emerging opto-electronic systems require a high degree of control of both the position and orientation of component fluorescent molecules, and while DNA nanostructures have demonstrated these capabilities, the precision with which DNA can orient fluorescent molecules is not well understood. Determining these bounds is critical in establishing the viability of DNA nanotechnology as a method of assembling fluorescent molecular networks.

In …

Mxenes As Flow Electrodes For Capacitive Deionization Of Wastewater, Naqsh E. Mansoor

Boise State University Theses and Dissertations

The energy-water nexus poses an integrated research challenge, while opening up an opportunity space for the development of energy efficient technologies for water remediation. Capacitive Deionization (CDI) is an upcoming reclamation technology that uses a small applied voltage applied across electrodes to electrophoretically remove dissolved ionic impurities from wastewater streams. Similar to a supercapacitor, the ions are stored in the electric double layer of the electrodes. Reversing the polarity of applied voltage enables recovery of the removed ionic impurities, allowing for recycling and reuse. Simultaneous materials recovery and water reclamation makes CDI energy efficient and resource conservative, with potential to …

Material Design, Processing, And Engineering Requirements For Magnetic Shape Memory Devices, Andrew Armstrong

Boise State University Theses and Dissertations

For magnetic shape memory (MSM) alloys, a magnetic field stimulates a shape change. We use the shape change to build devices such as micro-actuators, sensors, and microfluidic pumps. Currently, (as a novel technology,) devices suffer from some material and magnetic driver shortcomings. Here we address the issues related to operating temperature, repeatability, failure, and magnetic driver development. To increase the operating temperature of the MSM material, we alloyed Fe and Cu to Ni-Mn-Ga. We showed that the element-specific contribution to the valence electron density as parameter systematically determines the effect of each element on the variation of the martensite transformation …

Diffusion Bonding Of Inconel 600 To Silicon Carbide For Next Generation High Temperature Applications, Yaiza Rodriguez Ortego

Boise State University Theses and Dissertations

Ceramic to metal interfaces are of interest for applications in extreme environments because they allow increased operational temperatures, resulting in greater thermodynamic efficiency in energy conversion processes. Ceramics offer high temperature corrosion resistance while metals offer robust and versatile solutions to assemblies. Understanding the solid-state reactions, the resulting interfacial microstructure, and the properties of the joints produced by diffusion bonding is essential for developing reliable ceramic to metal interfaces.

The combination of silicon carbide (SiC) and a nickel-based alloy (Inconel 600) offers improved strength and resistance to high temperature degradation. This work focuses on the understanding of the solid-state diffusion …

Empirical Modeling Of Structural Distortions In Perovskite Ceramics, Evan Connor Smith

Boise State University Theses and Dissertations

Predictive models for composition-structure-property relationships are essential to realizing the full potential of electroceramic materials; however, the electroceramics industry has largely failed to invest in predictive models in favor of simple rules of thumb or expensive, time-consuming trial-and-error methods. Empirically derived predictive models have the potential to significantly improve and guide future research in a more cost-effective and timely manner. It may even be possible to predict some intrinsic properties (e.g., polarization) on the order of a unit cell using only the charge and size of each chemical component. Scientists and researchers may ultimately be able to use …

An All-Optical Excitonic Switch Templated On A Dna Scaffold Operated In The Liquid And Solid Phases, Donald L. Kellis

Boise State University Theses and Dissertations

The natural excitonic circuitry of photosynthetic organisms, including light harvesting antennas, provides a distinctive example of a highly attractive bio-inspired alternative to electronic circuits. Excitonics, which capitalizes on spatially arranged optically active molecules ability to capture and transfer light energy below the diffraction limit of light has garnered recognition as a potential disruptive replacement for electronic circuits. However, assembly of optically active molecules to construct even simple excitonic devices has been impeded by the limited maturity of suitable molecular scale assembly technologies.

An example of nanophotonic circuitry, natural light harvesting antennas employ proteins as scaffolds to organize and self-assemble light-active …