Conferences, Lectures, & Seminars
Events for April
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The Non-Technical Side of Managing Technical People
Mon, Apr 03, 2006 @ 01:00 PM - 02:00 PM
Mork Family Department of Chemical Engineering and Materials Science
Conferences, Lectures, & Seminars
Brian Marcotte, a USC Graduate, served as Unocal Vice President of Public Policy- Environmental Health and Safety and as the President of Unocal Indonesia.
Location: Hedco Pertroleum and Chemical Engineering Building (HED) - CO 116
Audiences: Everyone Is Invited
Contact: iraj ershaghi
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Materials Science Seminar - SCALING PROPERTIES OF FRACTURE SURFACES by Elisabeth Bouchaud
Fri, Apr 07, 2006 @ 02:45 PM - 04:00 PM
Mork Family Department of Chemical Engineering and Materials Science
Conferences, Lectures, & Seminars
SCALING PROPERTIES OF FRACTURE SURFACESElisabeth Bouchaud,
Fracture Group, Division of Physics & Chemistry of Surfaces and Interfaces
CEA-Saclay, FranceFor materials as different as metallic alloys and silicate glasses, the morphology of fracture surfaces has revealed anisotropic scale invariance properties which can be described with two sets of parameters: roughness exponents and characteristic length scales, measured either along the direction of crack propagation, or perpendicularly to it. If characteristic length scales depend on the material, its microstructure, and the external loading, roughness exponents, on the contrary, are "universal". The same roughness exponents are indeed observed for metallic alloys and for glasses, for example, albeit at length scales three orders of magnitude smaller in the latter case.Statistical models describing the quasi-static propagation of an elastic line (the crack front) through an array of randomly distributed obstacles (the microstructure) can reproduce qualitatively these observations. We conjecture that the lack of quantitative agreement is due to the fact that these models do not take damage into account.Damage formation at the crack tip is however a general phenomenon, which is well documented for metallic materials. More recently, our Atomic Force Microscopy experiments on silicate glasses show that damage also forms ahead of a stress corrosion crack tip in glass. This mechanism has several implications at the macro-scale, in terms of nonlinear elastic deformation and sample lifetime.The extension of the process zone is estimated, and it is shown that fracture surface roughness is evaluated within this region. It is argued that the observed exponents reflect in fact damage screening occurring at length scales smaller than the process zone size. "Line models", however, lead to good predictions when measurements are performed at length scales larger than the process zone size.Dr. Elisabeth Bouchaud is the Director of the Division of Physics and Chemistry of Surfaces and Interfaces at CEA-Saclay, France and currently a visiting professor at Caltech. Dr. Bouchaud has started a whole new research area involving the study of the scaling properties of fracture surfaces. Her group has performed seminal experiments on crack propagation and damage evolution in glasses. For her pioneering work on fracture, Dr. Bouchaud recently received the prestigious Ancel award for Condensed Matter Physics from the French Physical Society, and in 1997, she was awarded the European Materials Science Society's Lecturer Award.First Year MASC students are required to attend.
Location: Vivian Hall of Engineering (VHE) - 217
Audiences: Everyone Is Invited
Contact: Petra Pearce
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Lyman L. Handy Colloquium - A Personal Perspective Of The Changing Nuclear Threat by Dr. S. Hecker
Thu, Apr 13, 2006 @ 12:30 PM - 01:30 PM
Mork Family Department of Chemical Engineering and Materials Science
Conferences, Lectures, & Seminars
Lyman L. Handy Colloquium A Personal Perspective Of The Changing
Nuclear ThreatDr. Siegfried S. Hecker
CISAC/Stanford University
Los Alamos National LaboratoryABSTRACT Presidents Reagan and Gorbachev ushered in the end of the Cold War with a summit meeting at Reykjavik in October 1986. The political changes unleashed altered the nuclear threat from one that could end civilization as we know it to one of securing "loose nukes" in chaotic Russia and other states of the former Soviet Union. Whereas during the Cold War nuclear deterrence brought an uneasy global peace, the dissolution of the Soviet Union resulted in a resurgence of regional and ethnic conflicts, troubling nuclear proliferation developments, and the emergence of international megaterrorism. The gravity of these developments was demonstrated on 9/11. Now, we face the most difficult challenge of how to avoid a nuclear 9/11, which will not only cause horrific destruction, but will also threaten international order and our way of life. Plutonium is a key component of nuclear deterrence and today's nuclear threat. I will touch on what makes plutonium the most complex and fascinating element in the periodic table.Location: Olin Hall of Engineering (OHE) - 122
Audiences: Everyone Is Invited
Contact: Petra Pearce
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Materials Science Seminar-- Thermoelectric Materials for Space Power Generation
Fri, Apr 14, 2006 @ 02:30 PM - 04:00 PM
Mork Family Department of Chemical Engineering and Materials Science
Conferences, Lectures, & Seminars
Presented by:Dr. Thierry Caillat
Principal Scientist
Power Systems and Sensors Section
Jet Propulsion Laboratory/California Institute of TechnologyAbstract:Of the various static energy conversion technologies considered for Radioisotope Power Systems for space applications, thermoelectric (TE) energy conversion has received the most interest. Radioisotope Thermoelectric Generators (RTGs) generate electrical power by converting the heat released from the nuclear decay of radioactive isotopes (typically plutonium-238) into electricity using a thermoelectric converter. RTGs have been successfully used to power a number of space missions including the Appolo lunar missions, the Viking Mars landers, Pioneer 10 and 11, and the Voyager, Ulysses, Galileo, and Cassini outer planet spacecrafts. These generators have demonstrated their reliability over extended period of time (tens of years) and are compact, rugged, radiation resistant, scalable, and produce no noise, vibration or torque during operation. These properties have made RTGs suitable for autonomous missions in the extreme environment of the outer space and on planetary surface. Converter units use TE materials, which, when operating over a temperature gradient, produce a voltage called the Seebeck voltage. System conversion efficiency for state-of-practice RTGs is about 6%. The most widely used TE materials, in order of increasing temperature, are: Bismuth Telluride (Bi2Te3); lead Telluride (PbTe); tellurides of Antimony, Germanium and Silver (TAGS); lead Tin Telluride (PbSnTe); and silicon Germanium (SiGe). All of these materials except Bi2Te3 have been used in RTGs, which have been flown on space missions. A wide variety of physical, thermal, and thermoelectric properties requirements must be met for the design of reliable thermoelectric RTG converters. An overview of various thermoelectric phenomena and materials is provided in this talk. Space applications and requirements for thermoelectric materials are discussed. Current trends in thermoelectric material research are briefly introduced.First year MASC students are required to attend.Location: Vivian Hall of Engineering (VHE) - 217
Audiences: Everyone Is Invited
Contact: Petra Pearce
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Environmental Biotechnology: Challenges and Opportunities for Chemical Engineers
Mon, Apr 17, 2006 @ 12:30 PM - 01:30 PM
Mork Family Department of Chemical Engineering and Materials Science
Conferences, Lectures, & Seminars
Graduate Seminarby Professor Wilfred Chen
Department of Chemical and Environmental Engineering
University of California, RiversideAbstractEnvironmental biotechnology refers to the utilization of biomolecules to improve environmental quality. Over the past three decades breakthroughs in molecular genetics have revolutionized our ability to analyze and manipulate the structures and properties of nucleic acids and proteins. However, a major limitation in the applications of biomolecules is the existence of a functional gap between naturally occurring biomolecules and those required by specific practical settings. Therefore, the ability to close this functional gap has become a première intellectual and engineering challenge. In this talk, I will attempt to highlight opportunities available for chemical engineers to make significant contributions in the area of environmental biotechnology and their future challenges. Specially, I will discuss our recent work on the development of new biomolecular engineering tools and their applications in the remediation and detection of toxic pollutants. Examples will include: (1) developing biocatalysts for the detoxification of organophosphorus pesticides, (2) engineering plant-microbe symbiosis for rhizoremediation of heavy metal and TCE, (3) engineering elastin biopolymers for heavy metal remediation and antibody array fabrication, and (4) real-time monitoring of infectious viruses. Monday, April 17, 2006Seminar 12:30 p.m.THH 116The Scientific Community is Cordially Invited
Location: Mark Taper Hall Of Humanities (THH) - 116
Audiences: Everyone Is Invited
Contact: Petra Pearce
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Processing and Characterization of Nanocrystalline Materials with Interesting Physical Properties
Fri, Apr 21, 2006 @ 02:45 PM - 03:30 PM
Mork Family Department of Chemical Engineering and Materials Science
Conferences, Lectures, & Seminars
THE MORK FAMILY DEPARTMENT OF CHEMICAL ENGINEERING AND MATERIALS SCIENCEPRESENTS A SEMINAR
byAmiya K. MukherjeeDepartment of Chemical Engineering & Materials Science
University of California, DavisNanocrystalline materials have been produced by severe plastic deformation, electro-deposition, magnetron sputtering, crystallization from bulk metallic glass, ball milling and powders produced from inert gas condensation. The consolidation of the powder particles in some of these processing routes was achieved by electrical field assisted sintering with capability of superimposing 2 GPa gas pressure. The nanocrystalline metallic materials demonstrated both high strain-rate superplasticity and low-temperature superplasticity with important differences in the mechanistic details from their microcrystalline counterparts. The nanomaterials derived from crystallization of bulk metallic glass demonstrated extreme strength and at elevated temperatures showed superplasticity-like ductility. A three-phase alumina based nanoceramic composite demonstrated superplasticity at a lower temperature and at a higher strain rate. An alumina-carbon nanotube-niobium nanocomposite has a fracture toughness that is five times higher than that of pure alumina and an electrical conductivity that is thirteen orders of magnitude greater than that of pure nanocrystalline alumina. It also has excellent potential for use as a thermoelectric material. An alumina-spinel nanocomposite demonstrated optical transparency in the mid infrared range. A silicon carbide/silicon nitride nanocomposite produced by pyrolysis of liquid polymer precursor has produced one of the lowest creep rates in ceramics at a referred temperature of 1400° C. These structural and functional properties will be discussed in the context of microstructural investigations and recent results from molecular dynamics simulations. This research is supported by NSF, ARO, and ONR.Friday, April 21, 2006, 2:45-3:30 PM
(Refreshments will be served at 2:30 PM)
Location: VHE 217
**ALL FIRST YEAR MATERIALS SCIENCE MAJORS ARE REQUIRED TO ATTEND**
Location: Vivian Hall of Engineering (VHE) - 217
Audiences: Everyone Is Invited
Contact: Petra Pearce
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Materials Science Seminar-- Ultra-High Temperature Ceramics for Hypersonic Flight Vehicles
Fri, Apr 28, 2006 @ 02:45 PM - 03:30 PM
Mork Family Department of Chemical Engineering and Materials Science
Conferences, Lectures, & Seminars
THE MORK FAMILY DEPARTMENT OF CHEMICAL ENGINEERING AND MATERIALS SCIENCEPRESENTS A SEMINAR
BYJochen Marschall
SRI InternationalABSTRACTThe leading edges of hypersonic vehicles experience extreme aerothermal heating in a highly reactive gas environment. The current state-of-the-art thermal protection system for leading edges is SiC-protected carbon/carbon, as used for the nose cap and wing leading edges on the Space Shuttle. This system is rated for reusable operation up to 1500 °C. New hypersonic vehicle designs anticipate the need for leading edges that operate above 2000 °C. Ultra-high temperature ceramic (UHTC) materials based on zirconium and hafnium diborides, carbides and oxides are promising candidates for such applications.
The first part of this seminar will describe the environments experienced by leading edges during hypersonic flight, and the constraints that these flight environments impose on component design and materials selection. The second part will introduce UHTC materials, and describe their properties, manufacture, and testing. The final portion of the seminar will focus on the high temperature oxidation of UHTC materials, the formation of complex oxide scale microstructures, the acceleration of oxidation rates by dissociated oxygen, and the ramifications of UHTC oxidation on performance in flight.April 28, 2006
2:45-3:30 PM
(Refreshments will be served at 2:30 PM)
VHE 217**ALL FIRST YEAR MATERIALS SCIENCE MAJORS ARE REQUIRED TO ATTEND**
Location: Vivian Hall of Engineering (VHE) - 217
Audiences: Everyone Is Invited
Contact: Petra Pearce