Tag: Spring 2010

Ceramic Matrix Composite Insertion into Nozzles for Gas Turbine Engines

Thursday, May 20, 2010 11:00 am – 12:00 pm
Room 610, M&M Building

Greg C. Ojard
Advanced Materials Group
Pratt & Whitney
East Hartford, CT

Abstract

Ceramic matrix composites (ceramic fiber in a ceramic matrix) have the promise ofproviding significant efficiency and durability improvements for gas turbine enginesbecause the material has essentially constant strength with temperature.  Thisallows higher engine operating temperatures without the need for cooling air.  Forany material, the characterization of the material and its resulting performance iskey in determining its usefulness for a given application.  Additionally, long termtesting and resulting residual capability is critical to understanding the durability ofthe material.  Such results will be shown for a characterization effort on novelSiC/SiC and C/SiC material systems.  Results from engine testing will also beshown as well as limited flight testing information.

Biography

Greg Ojard is the Discipline Chief for the Advanced Materials Group in Materials &Processes Engineering at Pratt & Whitney.  He has 18 years of experience in characterizingmaterials for aerospace applications.  He spent his first 5 years developing and performingultrasonic inspections on a wide range of development material and aerospace hardware.  Forthe last 13 years he has worked on characterizing ceramic matrix composites, ceramics andceramic coatings for hot sections in gas turbine engines.  He has been the lead engineer onseveral ceramic matrix composite characterization efforts leading to insertion and flight testopportunities. He holds 2 patents and has over 45 publications. He is also an Adjunct Professorat the University of New Haven teaching materials selection courses.  He earned his PhD fromIowa State University in Metallurgy in 1991.  He has his BS and MS degrees in MetallurgicalEngineering from Michigan Technological University in 1986 and 1988.


Mixed Conducting Ceramic Membrane Reactors

Friday, April 23, 2010 11:00 am – 12:00 pm
Room 610, M&M Building

Susan M. Stagg-Williams
University of Kansas
Lawrence, Kansas

Abstract

Mixed oxygen ionic-electronic conductive (O-MIEC) perovskites have gainedsignificant attention as desirable materials for catalytic reactors because of theirability to separate oxygen from air without the use of an external circuit.  Themembranes have an infinite theoretical oxygen separation factor and can be usedfor staged addition of oxygen to reactors.  One specific application of interest isthe production of synthesis gas (H2 and CO) via simultaneous oxygen separationand hydrocarbon conversion.  However, many of the perovskite or perovskite-likemembranes being investigated suffer from low oxygen flux or mechanicalinstability.  Work at the University of Kansas is focused on the production of highflux oxygen permeable membranes with the mechanical integrity to be used ashigh temperature reactors and in highly reducing environments.  This seminar willoutline strategies for increasing oxygen flux through ceramic membranes andshow examples of reactor applications using these high flux membranes.


Nanogenerators for Self-Powered Nanosystems

Thursday, April 22, 2010 10:00 am – 11:00 am
Room G06, Rekhi Hal

Rusen Yang
School of Materials Science and Engineering
Georgia Institute of Technology
Atlanta, GA

Abstract

A self-powered nanosystem that harvests its operating energy from the environment isan attractive proposition for sensing, medical science, defense technology, and evenpersonal electronics. Therefore, it is essential to explore innovative nanotechnologies forconverting mechanical energy (such as body movement), vibration energy (such asacoustic/ultrasonic wave), and hydraulic energy (such as blood flow) into electric energythat will be used to power nanodevices without using battery. Piezoelectric zinc oxidenanowire (NW) arrays have been successfully demonstrated to convert nano-scalemechanical energy into electric energy. The operation mechanism of the electricgenerator relies on the unique coupling of piezoelectric and semiconducting dualproperties of ZnO as well as the elegant rectifying function of the Schottky barrier formedbetween the metal electrode and the NW. This mechanism resulted in the DCnanogenerator driven by ultrasonic wave. Recently we achieved a new breakthroughwith laterally-packaged single wire generator, which solved the transient contact issue inDC nanogenerator and produced power output from low frequency and irregularmechanical disturbance, such as finger tapping and running hamster. This presentationwill introduce the fundamental principle of nanogenerator and its potential applications.


On the Genesis of Nuclei and Phase Separation on an Atomic Scale

Tuesday, April 13, 2010 1:00 – 2:00 pm
Room 610, M&M Building

Professor David N. Seidman
Department of Materials Science and Engineering
Northwestern University
Evanston, Illinois

Abstract

Phase separation in the condensed state of matter is of general scientific interestas well as being technologically important.  It commences with the formation ofsubnanometer diameter nuclei, which subsequently evolve temporally by growingand coarsening.  Hence, it is the kinetics of phase separation that ultimately leadsa system to its equilibrium thermodynamic state.  In this colloquium I will showhow atom-probe tomography is utilized to follow, on an atomic scale, the kineticsof phase separation in ternary alloys, Ni-Al-Cr, beginning with the clustering ofatoms to form nuclei that evolve into a precipitates that have an ordered crystalstructure.  In parallel with the experiments lattice kinetic Monte Carlo simulationsare performed, whose results help in obtaining a detailed atomistic understandingof the underlying mechanisms by which phase separation occurs.  The atomprobe tomographic results taken in concert with the lattice kinetic Monte Carlosimulations yield a physical portrait that provide a deeper physical understandingof phase separation in a concentrated multicomponent alloy than has heretoforebeen possible.


Enhancing Hydrogen Storage Properties through Nanoscale LiBH4

Friday, April 9, 2010 11:00 am – 12:00 pm
Room 610, M&M Building

Professor Leon L. Shaw
Department of Chemical, Materials and Biomolecular Engineering
University of Connecticut, Storrs, CT

Abstract

LiBH4 is one of the materials that have the highest gravimetric hydrogen density at roomtemperature known today. However, LiBH4 has been dehydrogenated and re-hydrogenated athigh temperatures (e.g., > 400ºC) because of its high chemical stability. In this study we reportthat nanoscale LiBH4 can release H2 at temperatures as low as 35ºC with the completion ofreleasing all the hydrogen below 400ºC. These H2 release temperatures are the lowest everreported in the open literature. Furthermore, nanoscale LiBH4 can also alter the reactionpathway of the LiBH4+MgH2 mixture and reduce the hydrogen release temperature of MgH2 tobelow 150ºC – the lowest temperature ever observed for MgH2. We believe that theunprecedented enhancement in the dehydriding behavior of LiBH4 and its mixture with MgH2 isdue to the substantially increased thermodynamic driving force and reaction kinetics derivedfrom the nanoscale of LiBH4. The reaction product from the nanoscale LiBH4, in turn, triggers thehydrogen release from MgH2. The alteration of the reaction pathway of the LiBH4+ MgH2 mixtureopens up the opportunity to make this material system a strong contender for on-boardhydrogen storage applications.

Biography

Dr. Leon L. Shaw is a professor of Chemical, Materials and Biomolecular Engineering, University ofConnecticut. Dr. Shaw received a B.S. in Materials Engineering and a Master of Engineering in MechanicalEngineering from Fuzhou University (China), as well as a Master of Science and a Ph.D. in Materials Science andEngineering with a Minor in Mechanics and Engineering Science from the University of Florida. Dr. Shaw’s researchinterests are in processing and mechanical properties of nanostructured materials, solid freeform fabrication, andenergy materials for hydrogen storage and fuel cell applications. He was the interim head of the Department ofMaterials Science and Engineering from 2004 to 2005. He is a Fellow of ASM International, a Fellow of theAcademy of Materials and Manufacturing Engineering, Poland, and a Member of the Connecticut Academy ofScience and Engineering. Dr. Shaw has over 200 archival technical publications including 3 editorial volumes, 6book chapters, and 132 refereed journal articles. His awards include ASM/TMS Chapters of Excellence forTechnical Programming in 1999 and 2001 and the First Place Winner of the ASM, ISS, TMS World MaterialsOutreach Award in 2003 and 2004.


Composite Scaffolds for Bone Tissue Engineering: A Biomimetic Approach

Monday, March 22, 2010 3:00 – 4:00 pm
Room G06, Rekhi Hall

Ian O. Smith
Postdoctoral Research Fellow
University of Michigan School of Dentistry

Abstract

Biomimetics is a useful approach for Tissue Engineering applications, in which wemimic the naturally occurring ECM to positively affect biologic response and tissue formation using scaffolds, which promote cell differentiation, provide biologicalcues, allow nutrient transfer and provide sufficient mechanical properties. Onearea of interest is bone tissue engineering, where ECM collagen is mimicked byfabrication of polymer nanofibers, which are subsequently mineralized through abiomimetic process. The techniques that are currently available to create such ascaffold system have shown promise, but have inherent limitations. My researchaims to combine these existing techniques with what we can learn though ourunderstanding of the surface sciencerelated interactions which occur during earlystage mineralization in order to build upon the processes currently used tofabricate these scaffolds to develop new techniques. We can then expand thecurrent limits and build a scaffold that promotes more effective biologic responseand tissue formation.


Recycling of Copper Stamp Sand in Keweenaw Peninsula

Friday, March 19, 2010 3:00 – 4:00 pm
Room 610, M&M Building

Dr. Bowen Li
Institute of Materials Processing
Michigan Technological University

Abstract

In the region of Keweenaw Peninsula of Michigan, approximately 0.5 billion tons ofcopper tailing waste, called stamp sand, was dumped in the interior waterwaysand along the shorelines of Lake Superior.  The large quantities of mine tailingswith high concentration of copper (0.2-0.6 wt %) have been a threat to theecosystem of Lake Superior. U.S. EPA and the State of Michigan have takenseveral regulatory actions in this Area of Concern (AOC). To reduce heavy metalcontamination in the Lake Superior ecosystem, the best way is to completelyremove the stamp sand from the waterways and the lake.

Research conducted by Michigan Technological University and Lesktech Ltd. haveverified that the stamp sand located in the Gay area has excellent antimicrobialactivity (antibacterial, antifungal, and mold resistance), because of the high coppercontent in the copper tailing matrix. The research has demonstrated that particlessized between 8 and 40 mesh of this copper tailing are ideal material formanufacturing of antimicrobial roofing shingles. As a result of this application, theundesirable waste and contamination source will become a resource for valueadded products.

Biography

Dr. Bowen Li is a Research Assistant Professor in the MaterialsScience and Engineering/Institute of Materials Processing. He earned a PhDdegree in Materials Science and Engineering from Michigan Tech in 2008. He hasbeen involved in research on the evaluation and application of stamp sand since2006.


Manipulation of Surface Tension and Wettability for Microfluidic Devices

Friday, February 26, 2010 3:00 – 4:00 pm
Room 610, M&M Building

Dr. Dennis Desheng Meng
Multi-Scale Energy System (MuSES) Laboratory
Department of Mechanical Engineering – Engineering Mechanics
Michigan Technological University

Abstract

Microfluidic technology has inspired significant scientific interest and shown promising applications in health care,energy, and national security. Manipulation of surface tension and wettability is regard as a core technology ofmicrofluidics. The unique interfacial phenomena at microscale both formed a foundation of this emerging researchfield and offered many powerful tools to implement microfluidic devices. This seminar will discuss the followingthree examples:

  • Self-regulated microfluidic management for microfuel cells are achieved by hydrophobic venting andbubble-driven micropumping, which are based on nanoporous membrane and microchannels with designedwetting/nonwetting patterns respectively. An embedded self-pumping mechanism is demonstrated to deliverthe liquid fuel of micro direct methanol fuel cells (μDMFCs) by employing the CO2 gas bubbles generated bythe fuel cell reactions without any power consumption. On-demand gas generators are also developed tosupply hydrogen and oxygen to a micro polymer electrolyte membrane (PEM) fuel cell, which is automaticallyregulated according to the need of the fuel cell current output.
  • Superhydrophilic surfaces are obtained and tested to investigate their antifogging, antifoulingproperties for microfluidic devices. After hydrophilic treatments, both polyester film and ITO glassdemonstrated reduced adhesion with florescent particles. The superhydrophilicity and its degradation areattributed to the surface functional groups.
  • Self-assembly of bubble/droplet arrays is introduced as a promising microfabrication method. Theaffinity of bubbles/droplets to surfaces in liquid environments is quantified by bubble capturing potential “Fbc”.Self-assembly of low melting-point alloy droplets is employed to fabricate self-adaptive thermal switch array forthermal management of micro power sources.The presentation will also give brief introductions on other on-going projects in the speaker’s group (MuSES lab),including high voltage electrophoretic deposition of nanoforests and microfluidic fabrication of self-healingmaterials.

Biography

Dennis Desheng Meng is currently an Assistant Professor at the Department of MechanicalEngineering – Engineering Mechanics of Michigan Tech. He obtained his Ph.D. degree in Mechanical Engineeringfrom the University of California at Los Angeles (UCLA) in 2005 along with the Outstanding Ph.D. Award. After hejoined Michigan Tech in August 2007, Dr. Meng started the Multi-Scale Energy Systems (MuSES) Laboratory towork on micro- and nanotechnology for energy applications. The research of MuSES lab is based upon micro- andnanofabrication, such as novel electrochemical methods, microfluidic fabrication and surface treatment. Particularattentions are given to the design and fabrication of micro power sources, such as micro fuel cells, micro batteries,micro supercapacitors, as well as their thermal management.


Metallurgical Investigation of Medical Device Titanium Alloy Wire Fracture During Forming

Thursday, February 18, 2010 10:00 – 11:00 am
Room 610, M&M Building

Jon Stinson
Boston Scientific
Interventional Cardiology Division
Maple Grove, MN

Abstract

Beta III titanium wires are subjected to a 180 degree bend operation duringmedical device manufacturing. After years of successful processing,Manufacturing started to find cracked or broken wires. An investigation waslaunched to identify the root cause of the failures. Processing and material wereevaluated. This presentation will serve as an example of industrial failure analysisand problem solving, which often has limitations of schedule and funding.

Biography

Jon Stinson is a manager at R&D Materials Analytical Lab, Boston ScientificInterventional Cardiology Division. He received a B.S. degree in Metallurgical Engineering atMTU in 1982 and MBA Management degree at the University of St. Thomas in 1992.  Jon firstworked for 12 years in aerospace and defense (Williams International, Howmet, Honeywell,Alliant Techsystems) as a metallurgical engineer on R&D projects for gas turbine engines andordnance. Then he worked for 14 years in the medical device industry as a metallurgicalengineer and materials lab manager on R&D projects for intraluminal catheter, guidewire, andimplant products.

Capillary Phenomena in Fuel Cells

Friday, February 12, 2010 3:00 – 4:00 pm
Room 610, M&M Building

Dr. Jeffrey S. Allen
Advanced Power Systems Research Center
Department of Mechanical Engineering – Engineering Mechanics
Michigan Technological University

Abstract

Effective water management is critical to deployment of durable, low-temperature fuel cells forautomotive applications. The inability to manage the product water directly affect the durability ofa fuel cell stack; currently limiting the stack lifetime well below commercialization targets.  Itturns out that capillary phenomena is largely responsible for the ineffective water managment.Most engineering efforts directed at fuel cell water management attempt to over powercapillarity.  Much of our research is directed towards utilizing the natural presence of capillarityin order to more effectively manage the product water in low-temperature fuel cells.  Theresearch is a combination of experimental and numerical methods. Recent research results oncharacterizing water transport in the Porous Transport Layer (PTL), also known as the gasdiffusion layer (GDL), and predicting that transport will be discussed.  In addition, recent findingson capillary phenomena which dictates water motion in the reactant flow channels will be presented.

Biography

Dr. Jeffrey Allen is an Associate Professor in the Department of MechanicalEngineering – Engineering Mechanics at Michigan Technological University.  He graduated fromthe University of Dayton in Mechanical and Aerospace Engineering (BME 1988, MSME 1990,Ph.D. 1998).  From 1992 to 2004, Dr. Allen conducted experimental research at the NASAGlenn Research Center in the areas of capillary flow and interfacial transport phenomena asboth a principle investigator and as a project scientist for experiments conducted on the MirSpace Station and the NASA Space Shuttles.  In 2004, he joined Michigan Tech where he hasestablished the Microfluidic & Interfacial Transport Laboratories and is the Associate Director ofthe Advanced Power Systems Research Center.  Current research activities include the study oftwo-phase flow in anisotropic porous layers and microchannels directed towards watermanagement in PEM fuel cells, capillary-driven flows, stability of evaporating/condensing liquidfilms, fluidic flow control, microfluidics and microfluidic measurement techniques.