Materials Science and Engineering Commons^™

Systems Thinking, Jane Qiong Zhang, Linda Vanasupa

Materials Engineering

This document is a set of learning materials to support the teaching of systems thinking issues particularly related to sustainability in engineering. It is designed for the general engineering or science audience. Its design is based on the framework of the Fink Taxonomy of Significant Learning. The document is a fully-editable set of slides in open source format (pptx) that includes references to targeted learning objectives on each slide and annotations in the notes section of each slide.

Water - Learning Objectives, Jane Qiong Zhang, Linda Vanasupa

Materials Engineering

This document is a list of learning objectives based on the framework of Fink’s taxonomy of significant learning: foundational knowledge, application, integration, human dimension, caring, and learning how to learn. It represents the aspirations for learning that the water is based on.

Population - Activities, Jane Qiong Zhang, Linda Vanasupa

Materials Engineering

The document contains activities for students in higher education. These activities are focused on population issues related to sustainability. It is designed for the general engineering or science audience. Its design is based on the framework of the Fink Taxonomy of Significant Learning. Each activity includes a profile that indicates whether the activity involves direct or indirect information sources, whether the experience is doing or observing and whether it involves individual or group reflection. The profile also includes notes for faculty, an estimate of the time investment, a graphic of the developmental aims with respect to the six areas of …

Study Of Novel Materials For Organic Photovoltaics And Organic/Inorganic Hybrid Solar Cells, Viney Saini

Theses and Dissertations

As the human race evolves and continues to progress in the future, we will face some obstacles during the advancement. Challenges like water, food, and poverty crisis, pollution, population explosion, and diseases are impediments in the development of mankind. Above all, with the development arises the need to fulfill the energy requirements. There are number of technologies available to answer the present energy needs, e.g. coal, nuclear, oil/natural gas, hydropower, etc. All these technologies have their advantages and disadvantages, with disadvantages being greenhouse gas emissions and other environmental impacts. One technology which has lagged behind due to high cost is …

Synthesis, Field Emission And Associated Degradation Mechanisms Of Tapered Zno Nanorods, Gregory M. Wrobel Mr.

Master's Theses

Equation 1..... 4

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Equation 3..... 6

Equation 4..... 7

Equation 5..... 9

Equation 6..... 10

Equation 7..... 11

Equation 8..... 12

Equation 9..... 14

Equation 10..... 40

Equation 11..... 51

Synthesis, Field Emission and Associated Degradation Mechanisms of Tapered ZnO Nanorods

Gregory Michael Wrobel, M.S.

University of Connecticut, 2011

Modern development of field emitter arrays (FEA) has been made possible, partly thanks to the synthesis and development of one-dimensional (1D) nanostructures. High aspect ratio 1D nanostructures effectively amplify the electric field at the emitter tips, allowing electrons to be extracted at relatively low electric field. An inexpensive …

Fabrication And Characterization Of Zno/Cuo Core-Shell Nanowire Arrays, Kuo-Ting Liao

Master's Theses

Research into nanomaterials has become more and more popular because of their unique properties compared to bulk materials. Amongst various functional materials, zinc oxide (ZnO), with a direct electron energy band gap of 3.34 eV at room temperature, is an important optoelectronic material with an intrinsically n-type semiconducting property. However, to form a p-type ZnO semiconductor is still a challenge. Copper oxide (CuO), compared to ZnO, has a much smaller band gap, 1.2 eV, and shows an intrinsically p-type semiconducting property. It has been suggested that when CuO is alloyed with ZnO properly, a p-n semiconductor heterojunction can be formed …

Air Plasma Sprayed Thermal Barrier Coatings: Experiments And Finite Element Analysis, Charles H. Thistle

Master's Theses

The purpose of this research was to examine the primary in-service failure mechanism of an air plasma sprayed thermal barrier coating commonly used in combustor applications, and to use that failure mechanism as a basis in developing a life prediction strategy. The research consisted of an experimental phase, in which the failure mechanism was identified and key features of the coating system measured, and a modeling phase, in which the findings of the experimental phase were used to build a system specific finite element model of the coating in order to extract quantitative data relevant to coating life.

Observations were …

Fluid Structure And Boundary Slippage In Nanoscale Liquid Films, Nikolai V. Priezjev

Mechanical and Materials Engineering Faculty Publications

The book describes the concerted efforts of a large European research project and the achievements of additional leading research groups. The reported knowledge and expertise should support in the innovation and integration of often separated unitary processes. Sampling, cell lysis and DNA/RNA extraction, DNA hybridisation detection micro- and nanosensors, microfluidics, together also with computational modelling and risk assessment can be integrated in the framework of the current and evolving European regulations and needs. The development and uptake of molecular methods is revolutionizing the field of waterborne pathogens detection, commonly performed with time-consuming cultural methods. The molecular detection methods are enabling …

Freeze-Form Extrusion Fabrication Of Composite Structures, Ming-Chuan Leu, Lie Tang, Bradley K. Deuser, Robert G. Landers, Greg Hilmas, Shi C. Zhang, Jeremy Lee Watts

Mechanical and Aerospace Engineering Faculty Research & Creative Works

A Freeze-form Extrusion Fabrication (FEF) process capable of making three-dimensional (3D) parts and structures with graded composite materials is presented in this paper. The process development includes the design and manufacture of a gantry machine with a triple-extruder mechanism and the associated electronics hardware and computer software for fabricating functionally graded parts from multiple aqueous pastes. A rheological behavior study with Al₂O₃ paste is performed to identify an efficient binder for transforming the paste into a pseudoplastic with a high yield stress. A green part is first fabricated using the triple-extruder FEF machine in a layer-by-layer manner …

Effect Of Particle Size, Binder Content And Heat Treatment On Mechanical Properties Of 13-93 Bioactive Glass Scaffolds, Krishna C. R. Kolan, Ming-Chuan Leu, Greg Hilmas, Mariano Garcia Velez

Mechanical and Aerospace Engineering Faculty Research & Creative Works

Particle size, binder content and the post-processing schedule are important parameters that affect the microstructure, and, hence, the mechanical properties of parts produced using the indirect selective laser sintering process. 13-93 bioactive glass, with mean particle sizes ranging from 10 μm to 44 μm, is mixed with different amounts of stearic acid binder to fabricate green scaffolds. Through the design of the post-processing schedule, the time required for postprocessing the green scaffolds is reduced from the initial 80 hrs to 12 hrs. The compressive strength varies from 41 MPa for a part with~60% porosity to 157 MPa for a part …

High Pressure Structural Studies On Nb5si3 Up To 26.2 Gpa, Brandon Stewart, Ravhi S. Kumar

Undergraduate Research Opportunities Program (UROP)

With the use of synchrotron techniques, we can better understand how crystalline structures behave under extreme conditions. This yields the opportunity to resolve complex crystal structures [1]. Here, we focus on the high pressure crystal structure of Nb5Si3. Refractory metal silicides are an important class of materials as they are used in high temperature applications such as turbines and aerospace modules. As an example, the performance of a jet engine is highly influenced by the maximum internal pressure and temperature possible. Obtaining higher levels of thrust is dependent upon the material's ability to remain structurally sound under extreme temperatures and …

Design, Fabrication, And Characterization Of A Thin-Film Nickel-Titanium Shape Memory Alloy Diaphragm For Use In Micro-Electro-Mechanical Systems, Brian Joel Alvarez

Master's Theses

Previous work done at Cal Poly has shown that thin-film nickel-titanium (NiTi) can be easily sputtered onto silicon wafers and annealed to create a crystallized shape memory alloy (SMA) film. Initial work on creating devices yielded cantilevers that were highly warped due to thin-film stress created during the sputtering process. The objective of this work was to create a thin-film NiTi SMA device that could be better characterized. A membrane was selected due to the simplicity of fabrication and testing which would also oppose the thin-film stress due to the increase in attachment points to the substrate.

Silicon wafers were …

Quantitative Characterization Of Microstructure Features For 1st Generation Advanced High Strength Steels, Margarita Vidrio, Ellen Liu, Donsheng Li, Kyoo Sil Choi, Xin Sun

STAR Program Research Presentations

The role of Advanced High Strength Steels (AHSS) in the automotive industry is important because of its affordability and excellent mechanical properties. The 1st generation of AHSS achieves its preferred combination of strength and ductility by embedding harder martensite grains into softer ferritic matrix. Ductility and strength of these steels are important to safety, formability, application, and life. However, a noticeable degree of inconsistent forming behaviors has been observed in the 1st generation AHSS in production, which seems to be related to the microstructure-level inhomogeneity. The objective of this project is to grain fundamental understandings on how different microstructure level …

Effect Of Au Content On Microstructural Evolution Of Snagcu Solder Joints That Undergo Isothermal Aging And Reliability Testing, Patrick J. Hyland

Master's Theses

Electronics, especially, printed circuit boards (PCBs) are a widespread technology. Metal coatings or “surface finishes” are often added to PCB board pads and component leads during manufacturing to improve their performance. Electroplated nickel/gold over copper is a popular surface finish for printed circuit boards and component leads. The presence of gold in solder joints, however, is known to have detrimental effects referred to as gold embrittlement. It is generally understood that tin-lead solder joints with less than 3 weight percent (wt%) of gold will not experience reliability issues. The acceptable level of gold in lead-free solder joints, however, is less …

Morphology Changes In Pcpdtbt:Pcbm And P3ht:Pcpdtbt:Pcbm And Its Effect On Polymer Solar Cell Performance, Galen David Cauble

Physics

Polymer solar cell morphology is sensitive to both heat and time. By thermally annealing polymer solar cells the morphology of the devices can be altered causing immediate changes in device performance. Blending PCPDTBT:PCBM with P3HT:PCPDTBT combines the absorption characteristics of each to create a more even absorption spectrum. Subjecting PCPDTBT:PCBM, and P3HT:PCPDTBT:PCBM polymer solar cells to thermal annealing as well as recording device performance through time has shown that P3HT:PCPDTBT:PCBM devices react positively to thermal annealing (increasing from 0.8% to 1.4%) while PCPDTBT:PCBM devices have varied reactions. Furthermore, the P3HT:PCPDTBT:PCBM devices have achieved efficiencies of 1.6% in AM 1.5 compared …

Stress Relaxation Of Glass Using A Parallel Plate Viscometer, Guy-Marie Vallet

All Theses

Currently, grinding and polishing is the traditional method for manufacturing optical glass lenses. However, for a few years now, precision glass molding has gained importance for its flexibility in manufacturing aspheric lenses. With this new method, glass viscoelasticity and more specifically stress relaxation are important phenomena in the glass transition region to control the molding process and to predict the final lens shape.
The goal of this research is to extract stress relaxation parameters in shear of Pyrex¨ glass by using a Parallel Plate Viscometer (PPV). The PPV machine was originally created to measure the viscosity of glass solid cylinders …

Substrate Topography Design And Fabrication For Osteoblast And Dental Pulp Stem Cells Studies, Gloria Chen

All Theses

Research for cell guidance based tissue engineering has rapidly grown due to the increasing interest in tissue engineering and reconstructive medicine applications, such as cranial reconstruction. Many research teams have begun the process of identifying what factors influence cell behavior (including cell growth, proliferation, alignment and spreading). Published studies have pointed to the influence of the cell medial pH, substrate stiffness, chemistry and topography. Conclusive results are often hard to identify since researchers often vary many of these factors simultaneously and it is hard to decouple individual factor influence. These reports also points out that the cellular response can be …

Effect Of Accelerated Aging On Mechanical Properties And Structure Of Nano-Scale Composite Systems, David Economy

All Theses

Nano-scale composites are being investigated by academic, industrial, and national laboratories for potential applications such as wear resistant coatings and high strength foils. These structures are of interest due to their as-fabricated mechanical properties, such as high strength for nanolaminates. However, there have only been limited studies of the long-term mechanical stability. A greater understanding of how these systems might respond to sustained use is needed before these systems transition from research laboratories into widespread application. It is the objective of this thesis to clarify the link between accelerated aging using elevated temperatures over time and mechanical properties of two …

Thermoelectric Properties Of Nickel And Titanium Co-Intercalated Titanium Diselenide, Timothy Holgate

All Dissertations

Thermoelectric materials are involved in the direct conversion between thermal and electrical energy. They may be used to generate power from a thermal gradient or to pump heat in or out of a system when driven with DC power. Much of the recent advances in thermoelectric research have been in materials whose thermoelectric efficiency has been optimized at temperatures above room temperature where power generation is the main application.
The question that I seek to answer in this dissertation is to use our standard experimental techniques in order to assess the possibility of a class of transition metal dichalcogenides bases …

Immersion Cooling Of Photovoltaic Cells In Highly Concentrated Solar Beams, Ahmed Darwish

UNLV Theses, Dissertations, Professional Papers, and Capstones

Concentrated solar radiation can be utilized to generate electrical power from photovoltaic cells, but concentrated solar radiation increases the photovoltaic cell’s temperature. This increase in temperature can lead to degradation of the cell efficiency, and too high of a temperature can damage the cell’s integrity. This is particularly important in dish and tower systems where a maximum uniform flux may be difficult to achieve. While a variety of approaches have been used to the keep the cells cool, most are based upon removal of heat from the back (opposite surface of the incident flux exposed surface) of the cell. This …