Materials Science and Engineering Commons^™

Carbon 1d/2d Nanoelectronics : Integration And Device Applications, Zhaoying Hu

Legacy Theses & Dissertations (2009 - 2024)

Graphene is a one-atom thick planar monolayer of sp2-bonded carbon atoms organized in a hexagonal crystal lattice. A single walled carbon nanotube (CNT) can be thought of as a graphene sheet rolled up into a seamless hollow cylinder with extremely high length-to-diameter ratio. Their ultra-thin body, large surface area, and exceptional electronic, optical and mechanical properties make these low-dimensional carbon materials ideal candidates for electronic applications. However, adopting low-dimensional carbon materials into semiconductor industry faces significant material and integration challenges. There is an urgent need for research at fundamental and applicative levels to find a roadmap for carbon nanomaterial to …

Design And Development Of Stress Engineering Techniques For Iii-Nitride Epitaxy On Si, Jeff Leathersich

Legacy Theses & Dissertations (2009 - 2024)

III-Nitrides have been a heavily researched material system for decades. Their material properties are favorable for a number of applications, most commonly in the optoelectronic and power device industry. Currently a majority of commercialized devices are fabricated on sapphire and SiC substrates but these are expensive and limit the widespread commercialization of the technology. There is substantial ongoing research geared toward the development of GaN on Si substrates because of the significant cost saving that would be realized through the inexpensive, large wafer and maturity of Si fabrication. Significant challenges with the deposition of GaN on Si have, thus far, …

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. …

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 …

First-Principles Point Defect Models In Zr7ni10 And Zr2ni7 Binary Intermetallic Compounds And Their Implications In Nickel-Metal Hydride Batteries, Diana Felicia Wong

Wayne State University Theses

Zr-Ni-based alloys as nickel-metal hydride battery anode materials offer low-cost, flexible and tunable battery performance. Zr7Ni10 is an important secondary phase found in multi-phased AB2 Laves-phase-based metal hydride alloys, and the synergetic effect between the Zr-Ni and the Laves phases allows access to the high hydrogen storage of the Zr-Ni phases despite the lower absorption/desorption kinetics. Zr7Ni10 displays a small solubility window for Zr-rich compositions, while Zr2Ni7, with no solubility window, shows poor capacity with good kinetics. Stability of point defects within the crystal structure allows Zr7Ni10 to maintain the same structure at off-stoichiometric compositions, thus it is theorized that …

Temporally And Spatially Resolved Plasma Spectroscopy In Pulsed Laser Deposition Of Ultra-Thin Boron Nitride Films, Nicholas R. Glavin, Christopher Muratore, Michael L. Jespersen, Jianjun Hu, Timothy S. Fisher, Andrey A. Voevodin

Chemical and Materials Engineering Faculty Publications

Physical vapor deposition (PVD) has recently been investigated as a viable, alternative growth technique for two-dimensional materials with multiple benefits over other vapor deposition synthesis methods. The high kinetic energies and chemical reactivities of the condensing species formed from PVD processes can facilitate growth over large areas and at reduced substrate temperatures. In this study, chemistry, kinetic energies, time of flight data, and spatial distributions within a PVD plasma plume ablated from aboron nitride (BN) target by a KrF laser at different pressures of nitrogen gas were investigated. Time resolved spectroscopy and wavelength specific imaging were used to identify and …

Processing And Property Evaluation Of Tungsten-Based Mixed Oxides For Photovoltaics And Optoelectronics, Mirella Vargas

Open Access Theses & Dissertations

Tungsten Oxide (WO3) films and low-dimensional structures have proven to be promising candidates in the fields of photonics and electronics. WO3 is a well-established n-type semiconductor characterized by unique electrochromic behavior, an ideal optical band gap that permits transparency over a wide spectral range, and high chemical integrity. The plethora of diverse properties endow WO3 to be highly effective in applications related to electrochromism, gas sensing, and deriving economical energy. Compared to the bulk films, a materials system involving WO3 and a related species (elements or metal oxides) offer the opportunity to tailor the electrochromic response, and an overall enhancement …

Moisture Susceptibility Of Dense Graded Asphalt Concrete Using Cyclic Moistue Induced Stress Tester, Sarvesh Dip Dhakal

Open Access Theses & Dissertations

Moisture damage in asphalt concrete causes loss in mechanical properties of asphalt material due to the presence of moisture in its microstructures in a liquid or a vapor state. Some of the common types of distress observed in asphalt pavements due to moisture damage are stripping (separation of asphalt binder and aggregate), raveling (dislodgement of aggregate particles in asphalt mixture from surface), and hydraulic scour (a process that occurs on a saturated surface by which the pavement material is eroded due to dynamic action of tires in the presence of water). This Thesis focuses on the research on the effects …

Thermodynamic Grain Size Stabilization Models: An Overview, Mostafa Saber, Carl C. Koch, Ronald O. Scattergood

Mechanical and Materials Engineering Faculty Publications and Presentations

Grain boundaries in a nanocrystalline microstructure produce an increase in the excess free energy of the system. Grain growth is a consequence of the thermodynamic driving force reducing this excess. Thermodynamic stabilization is an approach based on eliminating the driving force by suitable alloy additions that can produce a metastable equilibrium state at the nanoscale grain size, as opposed to kinetic stabilization where the grain growth mobility is restricted by pinning and/or drag mechanisms. The present paper reviews and compares various models proposed for thermodynamic stabilization.

Influence Of Calcium Sulfoaluminate Cement On The Pullout Performance Of Reinforcing Fibers: An Evaluation Of The Micro-Mechanical Behavior, Robert B. Jewell

Theses and Dissertations--Civil Engineering

The objective of this research was to determine the influence of calcium sulfoaluminate (CSA) cement on reinforcing fibers by evaluating the fiber pullout behavior, and bonding characteristics, of a single fiber embedded in a cementitious paste matrix. Four types of fibers commonly used in industry were evaluated: 1) Polyvinyl alcohol; 2) Polypropylene; 3) Coated Steel; and 4) Plain Steel.

Upward trends in energy costs and potential greenhouse gas regulations favor an increased use of construction materials that require lower energy and lower CO₂ emissions to fabricate, such as CSA cement, as opposed to the production of ordinary portland cement …

Effects Of Magnetic Field On The Shape Memory Behavior Of Single And Polycrystalline Magnetic Shape Memory Alloys, Ali S. Turabi

Theses and Dissertations--Mechanical and Aerospace Engineering

Magnetic Shape Memory Alloys (MSMAs) have the unique ability to change their shape within a magnetic field, or in the presence of stress and a change in temperature. MSMAs have been widely investigated in the past decade due to their ability to demonstrate large magnetic field induced strain and higher frequency response than conventional shape memory alloys (SMAs). NiMn-based alloys are the workhorse of metamagnetic shape memory alloys since they are able to exhibit magnetic field induced phase transformation. In these alloys, martensite and austenite phases have different magnetization behavior, such as the parent phase can be ferromagnetic and martensite …

Shape Memory Behavior Of Single Crystal And Polycrystalline Ni-Rich Nitihf High Temperature Shape Memory Alloys, Sayed M. Saghaian

Theses and Dissertations--Mechanical and Aerospace Engineering

NiTiHf shape memory alloys have been receiving considerable attention for high temperature and high strength applications since they could have transformation temperatures above 100 °C, shape memory effect under high stress (above 500 MPa) and superelasticity at high temperatures. Moreover, their shape memory properties can be tailored by microstructural engineering. However, NiTiHf alloys have some drawbacks such as low ductility and high work hardening in stress induced martensite transformation region. In order to overcome these limitations, studies have been focused on microstructural engineering by aging, alloying and processing.

Shape memory properties and microstructure of four Ni-rich NiTiHf alloys (Ni50.3Ti29.7Hf20, Ni50.7Ti29.3Hf20, …

Development Of Multifunctional Shape Memory Polymer And Shape Memory Polymer Composites, Sesha Spandana Pulla

Theses and Dissertations--Mechanical and Aerospace Engineering

Shape memory polymers (SMPs) are an emerging class of active polymers that can be used on a wide range of reconfigurable structures and actuation devices. The present study comprehensively examines the unconstrained shape recovery abilities of an epoxy-based SMP. In doing so, epoxy based SMP is synthesized and thermo-mechanically characterized. Results show that the present SMP exhibits excellent shape recoveries under unconstraint conditions, for a range of fixing strains and temperatures. Additionally, the stress-strain behavior of the SMP is determined to be nonlinear, finite deformation at all regions. The strain energy based models have been used to capture the complicate …

Adsorption Behaviour Of Polyacrylic Acid On Cerium Oxide Nanostructures: Experimental And Predictive Model, Ali Haghighat Mesbahi

Electronic Theses and Dissertations

Cerium oxide-based slurries are crucial for chemical mechanical polishing (CMP) in electronic industry. For these slurry systems, poly(acrylic acid) (PAA) is heavily utilized to provide colloidal stability. Some of the important parameters in the colloid stability are molecular weight (MW) and concentration of stabilizer, size of the nanoparticle in the slurry and the pH of system. By determining the colloidal stability of a discrete number of slurry formulations and relating these to certain slurry component parameters, a possible model can be produced to predict the influence of these parameters on the particle stability. Direct quantification of colloidal stability is difficult, …

Porosity Removal Of Cm247 Ni-Base Superalloy Using Thermal Heat Treatment Without Applied Pressure, Chad Heinrich

Electronic Theses and Dissertations

Blade and vane components made with Ni-base superalloys play a vital role in hot section of gas turbine engines. Removal of porosity in cast Ni-base superalloys is a critical process consideration since porosity from casting process can have deleterious effects on the performance and integrity of superalloy component. Still, the cost-efficient processing of Ni-base superalloys that are technologically acceptable, or superior, can contribute significantly to the life-cycle cost of gas turbine engines. The purpose of this thesis was to explore the possibility of eliminating the hot isostatic pressing cycle in a CM247 Ni-base superalloy processing. For cast CM247, conventional processing …

Phase Transformations And Microstructural Evolution In The U-10 Wt.% Mo Alloy With Various Zr Additions At 900c And 650c, Nicholas Eriksson

Electronic Theses and Dissertations

The Reduced Enrichment for Research and Test Reactor (RERTR) now known as the Material Minimization and Management Reactor Control program (MMMRC) seeks to replace the use of highly enriched uranium (HEU) fuels used in research and test nuclear reactors around the world. The low enriched uranium (LEU) fuels must have fissionable uranium densities comparable to the HEU fuels. After extensive investigation by various researchers around the world, the U-Mo alloys were selected as a promising candidate. The Mo alloyed with U allows for the stabilization of the face-centered cubic ?-U phase, which demonstrated favorable irradiation behavior. However, deleterious diffusional interaction …

Comparison Of Lock-In And Pulse-Phase Thermography For Defect Characterization In Frp Composites Applied To Concrete, Jeff Brown, Sai Harsha Chittineni

Publications

Thermal imaging is a well-established technique for the non-destructive evaluation of FRP composites applied to reinforced concrete. Defect characterization using IR thermography, however, remains a topic of on-going research, and there are currently no universally accepted standards for data collection or interpretation. This research involved large scale thermography inspection of two FRP strengthened bridge girders that were removed from service after approximately 10 years of service in a potentially corrosive marine environment. Trial inspections were performed on test areas where defects could be identified using sounding methods. Two procedures showed the most promise for identifying and characterizing defects: sinusoidal (lock-in …

The Ph Sensing Properties Of Rf Sputtered Ruo2 Thin-Film Prepared Using Different Ar/O2 Flow Ratio, Ali Sardarinejad, Devendra Kumar Maurya, Kamal Alameh

Research outputs 2014 to 2021

The influence of the Ar/O₂ gas ratio during radio frequency (RF) sputtering of the RuO₂ sensing electrode on the pH sensing performance is investigated. The developed pH sensor consists in an RF sputtered ruthenium oxide thin-film sensing electrode, in conjunction with an electroplated Ag/AgCl reference electrode. The performance and characterization of the developed pH sensors in terms of sensitivity, response time, stability, reversibility, and hysteresis are investigated. Experimental results show that the pH sensor exhibits super-Nernstian slopes in the range of 64.33-73.83 mV/pH for Ar/O₂ gas ratio between 10/0-7/3. In particular, the best pH sensing performance, in …

Simulation Study Of Hemt Structures With Hfo2 Cap Layer For Mitigating Inverse Piezoelectric Effect Related Device Failures, Deepthi Nagulapally, Ravi P. Joshi, Aswini Pradhan

Electrical & Computer Engineering Faculty Publications

The Inverse Piezoelectric Effect (IPE) is thought to contribute to possible device failure of GaN High Electron Mobility Transistors (HEMTs). Here we focus on a simulation study to probe the possible mitigation of the IPE by reducing the internal electric fields and related elastic energy through the use of high-k materials. Inclusion of a HfO₂ "cap layer" above the AlGaN barrier particularly with a partial mesa structure is shown to have potential advantages. Simulations reveal even greater reductions in the internal electric fields by using "field plates" in concert with high-k oxides

Multi-Platform Arabinoxylan Scaffolds As Potential Wound Dressing Materials, Donald C. Aduba Jr

Theses and Dissertations

Biopolymers are becoming more attractive as advanced wound dressings because of their naturally derived origin, abundance, low cost and high compatibility with the wound environment. Arabinoxylan (AX) is a class of polysaccharide polymers derived from cereal grains that are primarily used in food products and cosmetic additives. Its application as a wound dressing material has yet to be realized. In this two-pronged project, arabinoxylan ferulate (AXF) was fabricated into electrospun fibers and gel foams to be evaluated as platforms for wound dressing materials. In the first study, AXF was electrospun with varying amounts of gelatin. In the second study, AXF …

A Study To Evaluate Non-Uniform Phase Maps In Shape Memory Alloys Using Finite Element Method, Naren Motte

Theses and Dissertations

The unique thermo-mechanical behavior of Shape Memory Alloys (SMAs), such as their ability to recover the original shape upon heating or being able to tolerate large deformations without undergoing plastic transformations, makes them a good choice for actuators.

This work studies their application in the aerospace and defense industries where SMA components can serve as release mechanisms for gates of enclosures that have to be deployed remotely. This work provides a novel approach in evaluating the stress and heat induced change of phase in a SMA, in terms of the transformation strain tensor. In particular, the FEA tool

ANSYS has …

Peracetic Acid Sterilization Of Electrospun Polycaprolactone Scaffolds, Suyog Yoganarasimha

Theses and Dissertations

Sterilization of tissue engineered scaffolds is an important regulatory issue and is at the heart of patient safety. With the introduction of new biomaterials and micro/nano structured scaffolds, it is critical that the mode of sterilization preserve these built-in features. Conventional sterilization methods are not optimal for engineered polymeric systems and hence alternate systems need to be identified and validated. PCL is polyester with a low melting point (heat labile), susceptible to hydrolysis and is popular in tissue engineering. Electrospinning generates some nanoscale features within the scaffold, the integrity of which can be affected by sterilization method. Chapter 1 explores …

Preliminary Investigation Into The Cause Of Pinhole Porosity In Aluminum Metal Castings From Serpentine Impurities In Olivine Sand, Brodie J. Biersner

Dissertations and Theses @ UNI

The problem addressed in this study is how contaminates in the foundry molding aggregate olivine, affect aluminum castings during the casting process. This research will concentrate on hydrated contaminates, specifically the mineral serpentine. The purpose of this research is to better understand how hydrated minerals contribute to the generation of pinhole porosity defects during the casting process. Understanding how impurities in foundry aggregates affect the casting process would aid in the reduction of scrap caused by core and molding sands, ultimately providing savings to the casting manufacturer.

A foundry grade olivine was compared to a new source of olivine to …

The Future Of Carbon-Based Scaffolds In Foot And Ankle Surgery, Jarema S. Czarnecki, Khalid Lafdi, Panagiotis A. Tsonis

Chemical and Materials Engineering Faculty Publications

Autologous grafts have been the gold standard in tissue replacement and the most accurate means of recapitulating both the biological and mechanical properties of tissue. However, autologous grafts have had complications and drawbacks. Skin grafting, a prime example of an autologous tissue graft, has been limited by the size of graft, availability, and secondary donor site morbidity. Use of cadaveric tissues circumvents several limitations of autologous grafts; however, sterilization processes used to reduce the risk of disease transmission potentially weaken tissues and eliminate living cells and some growth factors from scaffolds, making them suboptimal tissue replacements. Chemical cross-linkage of tissue …

Effects Of Disorder State And Interfacial Layer On Thermal Transport In Copper/Diamond System, Vikas Sinha, Jaime J. Gengler, Christopher Muratore, Jonathan E. Spowart

Chemical and Materials Engineering Faculty Publications

The characterization of Cu/diamond interface thermal conductance (h_c) along with an improved understanding of factors affecting it are becoming increasingly important, as Cu-diamond composites are being considered for electronic packaging applications. In this study, ∼90 nm thick Cu layers weredeposited on synthetic and natural single crystal diamond substrates. In several specimens, a Ti-interface layer of thickness ≤3.5 nm was sputtered between the diamond substrate and the Cu top layer. The h_c across Cu/diamond interfaces for specimens with and without a Ti-interface layer was determined usingtime-domain thermoreflectance. The h_c is ∼2× higher for similar interfacial layers on …

Containment Materials For Thin-Strip Casting Of Steel, Abhishek Kumar

Doctoral Dissertations

"The focus of this research was to investigate the corrosion behavior of BN-based and ZrO₂-C refractories by molten steel. These refractories are used as side-dam and core-nozzle in the thin-strip casting of steel. The improvement and development of these refractory components will increase the process efficiency by prolonging the refractory service life.

The first part of this study focused on interaction of BN-ZrO₂-SiC side-dams with steel-inclusion system in a laboratory setup under argon gas environment. It was observed that corrosion of this ceramic was severe in contact with steel compared to slag/inclusion.

The second part of …

Laser Surface And Sub-Surface Repair During Metal Additive Manufacturing, Prudvi Teja Ravi

Masters Theses

"This study examines the use of laser surface treatment to repair surface and subsurface defects. Numerical analysis was performed on laser surface melting using Gaussian heat distribution equations to analyze the depth of the melt pool created by the phenomena. Concurrently, a process map was developed with a planned set of experiments by varying the ranges of laser power and travel speed to determine the dimensions of the melt pool across the gamut. The data generated from both the process studies and the numerical analysis was then used to determine the ideal operating ranges of the process parameters to repair …

Evaluation Of Nickel-Titanium Oxide-Niobium Pentoxide Metal Ceramic Composite As Interconnect For Solid Oxide Fuel Cell, Abhijith Budur

Masters Theses

"With increasing importance for clean energy, fuel cells have gained great significance in recent decades. Solid oxide fuel cells are easy to transport due to presence of solid electrolyte and also have requisite electrical properties,but have been obstructed by their limitation to be used at only temperatures greater than 600⁰C and less than 800⁰C. To construct a stack of cells, materials that are good electrical conductors and having necessary mechanical strengths at that temperatures are being considered as interconnects between the cells. Evaluation of Nickel-Titanium dioxide-Niobium pentoxide (NTN) as interconnect and comparison to Stainless Steel 441 alloy has been made …

Formation And Evolution Of Spinel In Aluminum Killed Calcium Treated Linepipe Steels, Obinna Adaba

Masters Theses

"Magnesium aluminate (Spinel) inclusions have been observed to cause hook crack in line pipe steels. These inclusions are typically formed during liquid steel processing at the ladle metallurgy furnace (LMF) and subsequently modified by calcium to form less harmful liquid inclusions. Unfortunately, spinel inclusions are still sometimes observed in samples taken from the tundish and coil after calcium treatment.

The formation and evolution of spinel inclusions during liquid steel processing at two industrial mini mills was investigated by analysis of lollipop samples taken at different stages of the steelmaking process. The effect of reoxidation on the formation of spinels after …

Healing Of Bone Defects In A Rodent Calvarial Defect Model Using Strong Porous Bioactive Glass (13-93) Scaffolds, Yinan Lin

Masters Theses

"The main objective of this project was to evaluate the capacity of strong porous silicate (13-93) bioactive glass scaffolds prepared by a robocasting technique to regenerate bone and stimulate angiogenesis in a rat calvarial defect model. The scaffolds were created with the same grid-like microstructure but in a variety of formulations: (i) as-fabricated, (ii) pretreated in an aqueous phosphate solution to convert the glass surface to hydroxyapatite, (iii) loaded with bone morphogenetic protein-2 (BMP2) (1 µg per scaffold), and (iv) doped with copper (0.4-2.0 wt. % CuO). When compared to the as-fabricated scaffolds, the pretreated scaffolds enhanced bone regeneration at …