Materials Science and Engineering Commons^™

Methods Of Extrusion On Demand For High Solids Loading Ceramic Paste In Freeform Extrusion Fabrication, Wenbin Li, Amir Ghazanfari, Ming Leu, Robert Landers

Faculty Publications, Mechanical Engineering

Fabrication of highly dense parts with complex geometry by paste-extrusion-based solid freeform fabrication processes requires a precise control of the extrusion flow rate to dispense material on demand, which is often referred as Extrusion-On-Demand (EOD). The extrusion process for aqueous ceramic pastes is complex and difficult to control due to their non-Newtonian behavior, compressibility and inhomogeneity. In this study, three methods of EOD (based on ram extruder, needle valve, and auger valve) are introduced and investigated for the extrusion of high solids loading (i.e., >50%, volumetric) aqueous alumina paste. Optimal extrusion process parameters for these methods are determined through printing …

A New Approach To Digital Generation Of Spherical Void Phase Porous Media Microstructures, Nolan J. Dyck, Anthony G. Straatman

Mechanical and Materials Engineering Publications

No abstract provided.

Development Of Scaffold Architectures And Heterotypic Cell Systems For Hepatocyte Transplantation, Dalia Alzebdeh

Wayne State University Dissertations

In vitro assembly of functional liver tissue is needed to enable the transplantation of tissue-engineered livers. In addition, there is an increasing demand for in vitro models that replicate complex events occurring in the liver. However, tissue engineering of sizable implantable liver systems is currently limited by the difficulty of assembling three dimensional hepatocyte cultures of a useful size, while maintaining full cell viability, an issue which is closely related to the high metabolic rate of hepatocytes. In this study, we first compared two designs of highly porous chitosan-heparin scaffolds seeded with hepatocytes in dynamic perfusion bioreactor systems. The aim …

Development Of High Strength High Toughness Third Generation Advanced High Strength Steels., Codrick John Martis

Wayne State University Dissertations

Third generation advanced high strength steels (AHSS's) are emerging as very important engineering materials for structural applications. These steels have high specific strength and thus will contribute significantly to weight reduction in automotive and other structural component. In this investigation two such low carbon low alloy steels (LCLA) with high silicon content (1.6-2wt %) has been developed. These two steel alloys were subjected to single step and two step austempering in the temperature range of 260-399oC to obtain desired microstructures and mechanical properties. Austempering heat treatment was carried out for 2 hours in a molten salt bath. The microstructures were …

Multifunctional Nanomaterials For Biomedical Engineering: Unique Properties, Fabrications, And Diverse Applications, Jen-Jie Chieh, Sharmila M. Mukhopadhyay, Yali Cui

Mechanical and Materials Engineering Faculty Publications

Nanomaterials possess many unique properties useful for biomedical applications ranging from preoperative and intraoperative imaging to coatings, assays, and cell scaffolds. Their popularity and production value are full of competitiveness. Their related methodologies and instruments are also created or emphasized as the mainstream. Since multifunctional nanomaterials attract interests and attention of researchers, engineers, and businessmen in biomedical engineering, this journal is set up to publish a special issue devoted to this topic. The result is a collection of five original research articles, whose authors belong to academic or research institutions of five different countries from Asia, Europe, and America. Papers …

Enhanced Mechanical Stability Of Interlayer Dielectrics With Self-Organized Molecular Pores, Akanksha Pandey

Material Science and Engineering Theses - Archive

In order to reduce resistance-capacitance delays in interconnect structures, ultralow-k films are used as interlayer dielectric materials. In most cases the preferred method to achieve the lower dielectric constant is the use of porous carbon doped silicon oxide (p-SiCOH) dielectrics. A downside of porosity in a dielectric layer during device fabrication is that it reduces the mechanical reliability of the dielectric and increases the susceptibility to adsorption of damaging materials. To overcome this and produce a material which can sustain the rigorous processes of fabrication, it is necessary to optimize the mechanical, thermal and chemical properties along with the electrical …

Enhanced Photocatalytic Performance Of Titania Nanobelts Decorated With Gold Particles Synthesized Using Stirring-Assisted Hydrothermal Method, Yi Shen

Material Science and Engineering Theses - Archive

In this thesis, anatase TiO2 nanobelts (TNBs) have been successfully obtained via an optimized stirring-assisted hydrothermal synthesis. The impact of stirring speed has been studied. Difference in morphology caused by stirring speed was observed by high resolution Field-Emission SEM (FE-SEM). Methylene Blue degradation test indicated that at certain stirring speed, i.e., 700 rpm, which was the highest, produced the best photoactivity than commercial P25 TiO2.Furthermore, Au decorated TNBs were obtained by a simple reduction reaction with Au-containing precursor. The Au-TNBs were founded to outperform in MB degradation the commercial P25 TiO2 and the pristine TNBs under both UV and visible …

Organic/Inorganic Guanidinium-Based Hybrid Anion Exchange Membranes For Alkaline Fuel Cells, Shambhavi Raju Sakri

Material Science and Engineering Theses - Archive

Organic-inorganic hybrid membranes are good alternatives to homogeneous ones to overcome the limitations posed by the individual constituent materials. These membranes pose promising applications in fuel cells with the combination of phenomenal functionality of organic polymers and stability of inorganic material. Introduction of inorganic materials into the polymer matrix is usually known to show an increase in mechanical properties of the membrane while, the organic part of the membrane, i.e., the polymer contributes towards the electrochemical properties. The properties of the individual materials combine to enhance the characteristic properties of the hybrid membranes. In this thesis we attempted to develop …

Characterization Of Fracture Toughness In Amorphous Diamond Like Carbon Thin Films And Coatings, Ronaksinh Parmar

Material Science and Engineering Theses - Archive

Any material containing a crack when subjected to a certain amount of load, will eventually fail. This failure of material can be either time consuming (ductile) or instant (brittle) depending on the type of material and amount of load applied. For one to be able to study fracture toughness, it is important to study the material's failure rate and how long it can withstand load without failure once a crack has been initiated. Ductile materials demonstrate high fracture toughness while brittle materials show lower fracture toughness and fail instantly once a crack has been initiated. Characterization of fracture toughness in …

The Effects Of Deposition Conditions On The Mechanical Properties Of Titanium Silicon Nitride Nanocomposite Coatings, Suo Liu

Material Science and Engineering Theses - Archive

Titanium Silicon Nitride has received much attention in recent years for its theoretical super hardness and oxidation resistance at high temperature. In this work, the mechanical properties of TiSiN thin films including hardness, coefficient of friction, wear rate, wear mechanism were studied in detail using nanoindentation, pin-on-disk tribometer, optical profilometer, SEM and XPS. Four deposition conditions were varied to find the optimal conditions that produce the TiSiN film with the highest hardness and the best wear resistance. First, four substrate biases (100V, 200V, 300V, and 500V) were used, respectively. Then, different power (50W, 55W, 60W) and different N2 ratio (20%, …

Study Of The Effect Of Ion Concentration, Ph, And Surface Charge On Single-Particle Placement, Kunhua Yu

Material Science and Engineering Theses - Archive

Supervising Professor: Seong Jin Koh Single particle placement (SPP) in which nanoparticles are placed on exact substrate positions on a single particle level has drawn a lot of attention as it can be used as an effective tool for bottom-up fabrications of nanoscale systems. In SPP, single nanoparticles are electrically guided toward substrate target positions through electrostatic funneling mechanism and once a single nanoparticle is placed on a target position it prevents the other nanoparticles from approaching toward the substrate, leading to placement of exactly one nanoparticle on each target position. This thesis investigates the role of three key parameters …

Nanoarchitectured Energy Storage Devices, Zenan Yu

Electronic Theses and Dissertations

Supercapacitors, the devices that connect the gap between batteries and conventional capacitors, have recently attracted significant attention due to their high specific capacitance, substantially enhanced power and energy densities, and extraordinary cycle life. In order to realize even better performance with supercapacitors, rejuvenated effort towards developing nanostructured electrodes is necessary. In this dissertation, several strategic directions of nanoarchitecturing the electrodes to enhance the performance of supercapacitors are investigated. An introduction and background of supercapacitors, which includes motivation, classification and working principles, recent nanostructured electrode materials studies, and devices fabrication, are initially presented. A facile method, called Spin-on Nanoprinting (SNAP), to …

Biomimetic Oral Mucin From Polymer Micelle Networks, Sundar Prasanth Authimoolam

Theses and Dissertations--Chemical and Materials Engineering

Mucin networks are formed by the complexation of bottlebrush-like mucin glycoprotein with other small molecule glycoproteins. These glycoproteins create nanoscale strands that then arrange into a nanoporous mesh. These networks play an important role in ensuring surface hydration, lubricity and barrier protection. In order to understand the functional behavior in mucin networks, it is important to decouple their chemical and physical effects responsible for generating the fundamental property-function relationship. To achieve this goal, we propose to develop a synthetic biomimetic mucin using a layer-by-layer (LBL) deposition approach. In this work, a hierarchical 3-dimensional structures resembling natural mucin networks was generated …

Nanohub.Org: A Gateway To Undergraduate Simulation-Based Research In Materials Science And Related Fields, Tanya A. Faltens, Peter A. Bermel, Amanda Buckles, K Anna Douglas, Alejandro H. Strachan, Lynn K. Zentner, Gerhard Klimeck

Birck and NCN Publications

Our future engineers and scientists will likely be required to use advanced simulations to solve many of tomorrow's challenges in nanotechnology. To prepare students to meet this need, the Network for Computational Nanotechnology (NCN) provides simulation-focused research experiences for undergraduates at an early point in their educational path, to increase the likelihood that they will ultimately complete a doctoral program. The NCN summer research program currently serves over 20 undergraduate students per year who are recruited nationwide, and selected by NCN and the faculty for aptitude in their chosen field within STEM, as well as complementary skills such as coding …

Safe Re-Entry Time With In-Cycle Shotcrete For Support Of Underground Excavations, Hla Aye Saw, Ernesto Villaescusa, Christopher Windsor

Shotcrete for Underground Support XII

No abstract provided.

Quality Control For Wet-Mix Fiber Reinforced Shotcrete In Ground Support, Lihe (John) Zhang, Dudley R. Morgan

Shotcrete for Underground Support XII

No abstract provided.

Finite Element Analysis Of System-Level Electronic Packages For Space Applications, Adrien Lambert, Ahsan Mian, Justin Hogan, Todd Kaiser, Brock Lameres

Mechanical and Materials Engineering Faculty Publications

Thermal analysis was required in order to aid in the design and testing of a radiation tolerant computing (RTC) system using a radiation sensor. During development of the system, different test beds were employed in order to characterize the radiation sensor and its supporting electronic systems. The most common preliminary tests are high altitude balloon tests which allow the sensor to experience cosmic radiation at high altitudes, consistent with space flight operations. In this study, finite element analysis (FEA) was used to evaluate primary system architecture, system support structures, and the flight payload in order to determine if the system …

Early-Age Behavior Of Shotcrete Using Expansive Admixture, Kyong-Ku Yun, Kassa B. Abay, Kyeo-Re Lee, Seung-Yeon Han, Kyong Namkung

Shotcrete for Underground Support XII

No abstract provided.

Acoustic Emission Characteristics Of Damage Accumulation In Kevlar® 49 Composites, Eduardo Andrade

Open Access Theses & Dissertations

Acoustic emission (AE) data attained during tensile testing of epoxy impregnated Kevlar® 49 (K/Ep) composite strands were reduced and analyzed to monitor progressive damage accumulation during the approach to tensile failure. The K/Ep material tested in this study was chosen due to its similarity to the material-of-construction used in composite overwrapped pressure vessels (COPVs) used on the NASA Space Shuttle Orbiter. Insight into the progressive microstructural degradation of K/Ep strands was gained by monitoring AE event rate and energy. Source location based on energy attenuation and arrival time data was used to differentiate between significant AE attributable to microstructural damage …

Novel Endohedral Derivatives Of Sc3n@C2n (N = 34, 40) And Unique Tether Controlled Bis-Functionalization Of Fullerenes, Maira Raquel Ceron Hernandez

Open Access Theses & Dissertations

Since the discovery of fullerenes in 1985, their exohedral functionalization has been necessary to increase their solubility and explore their properties and potential applications in materials science and medicinal chemistry. This Thesis provides a short overview of the importance of electronic, size and shape complementarity in determining the structures of specific endohedral fullerene compounds. This is followed by a description of a new method for the separation of scandium nitride endohedral fullerenes Sc3N@C2n (n = 34, 39 and 40), and their monofunctionalization.

We also present the regioselective synThesis of easily isolable bis-derivatives of C60, C70, and M3N@Ih-C80 (M = Sc, …