SEAS Seminars - Fall 2012

 


EMSE Seminar: "Human and Modeling Approaches for Humanitarian Transportation Planning"

Date: Thursday, September 6
Time: 12:00 - 1:30 pm
Location: EMSE Conference Room (1776 G Street, NW)
Presenter: Prof. Erica Gralla, EMSE

Abstract:

Recent disasters have highlighted the importance of supply chain management in emergency response, and sparked interest in translating insights from commercial logistics models to the humanitarian context. However, human experts may be better suited than models to making decisions in the dynamic, information-poor, multi-objective context of humanitarian response. This research explores the strengths and weaknesses of human decision-making in humanitarian logistics, to identify ways to improve both models and human decision-making. I describe an ethnographic study designed to discover how humanitarian experts plan aid deliveries for emergency response. Based on observations of 10 teams of experienced logisticians responding to a simulated emergency, I use grounded theory and visual mapping methods to discover and describe their decision-making processes. Next, I model these decision-making processes to evaluate their performance, in comparison with traditional optimization models.

 

CEE Seminar: "Uncertainty Analysis in Groundwater Dating with Environmental Tracers Using Markov Chain Monte Carlo Method"

Date: Monday, September 17
Time: 2:00 - 3:00 pm
Location: 640 Phillips Hall
Presenter: Professor Arash Massoudieh, The Catholic University of American

Abstract:

The estimation of groundwater age has received increasing attention due to its applications in assessing the sustainability of water withdrawal from the aquifers and evaluating the vulnerability of groundwater resources to near surface or recharge water contamination. In most of the works done in the past, whether a single or multiple tracers used for groundwater dating, the uncertainties in observed concentrations of the tracers and their decay rate constants have been neglected. Furthermore, tracers have been assumed to move at the same speed as the groundwater. In reality some of the radio-tracers or anthropogenic chemicals used for groundwater dating might undergo adsorption and desorption and move with a slower velocity than the groundwater. Also there are uncertainties in the decay rates of synthetic chemicals such as CFCs commonly used for groundwater dating. In this presentation development of a Bayesian modeling approach using Markov Chain Monte Carlo method for estimation of age distribution is described. The model considers the uncertainties in the measured tracer concentrations as well as the parameters affecting the concentration of tracers in the groundwater and provides the frequency distributions of the parameters defining the groundwater age distribution. The model also incorporates the effect of the contribution of dissolution of aquifer minerals in diluting the 14C signature and the uncertainties associated with this process on inferred age distribution parameters. The results of application of the method to data collected at Laselva Biological Station -- Costa Rica will also be presented. In this demonstration application, eight different forms of presumed groundwater age distributions have been tested including four single-peak forms and four double-peaked forms assuming the groundwater consisting distinct young and old fractions. The performance of these presumed groundwater age forms have been evaluated in terms of their capability in predicting tracer concentration close to the observed values and also the level of certainty they provide in estimation of the age-distribution of parameters.

Speakers Bio:

Professor Arash Massoudieh received his B.S. in Civil Engineering from the Sharif University of Technology, Tehran, Iran, his M.S. in Civil Engineering from the University of Tehran and his Ph.D. in Environmental Engineering in University of California, Davis. He worked as a postdoctoral scholar in University of California, Davis for two years, and then was appointed as an Assistant Professor of Civil Engineering in the Catholic University of America in 2008. Professor Massoudieh's research is in the area of modeling contaminant fate and transport surface and subsurface, inverse modeling, storm water quality and management, and sediment-contaminant interactions. Dr. Massoudieh's research is currently funded by National Science Foundation (NSF) and DC Water Resources Research Institute.

 

MAE Seminar: "Secrets of Fish Swimming"

Date: Wednesday, September 26
Time: 2:00 pm
Location: 736 Phillips Hall
Presenter: Prof. Chui-Jie Wu, Dalian University of Technology, China

Abstract:

The lecture consists of the following three parts:

1. The mechanism of swimming and control of self-propelled fish school is investigated with the method of computational fluid dynamics.

2. The optimal shape of caudal fin of three-dimensional self-propelled fish is investigated with the help of method of computational fluid dynamics with moving boundary and topology optimization algorithms.

3. Methods of elimination of vortical wakes with moving boundaries (cylinder and fish) are discussed, and some results are shown.

Some interesting novel results are obtained. In the lecture, we will guide audience to find out and reveal the secrets of fish swimming.

Speaker Bio:

Professor Chui-Jie Wu's research interests cover theoretical, computational, and experimental fluid mechanics. He has served as the dean of School of Aeronautics and Astronautics at Dalian University of Technology, since January 2008. Prior to this appointment, he was promoted directly from lecturer to professor in December 1992, and he was a visiting professor at Johns Hopkins University, a professor and director of Center of Numerical Simulation of Turbulence, State Key Laboratory of Turbulence Study at Peking University, and chair professor at PLA University of Science. He is also an associate editor of Advances in Applied Mathematics and Mechanics and Science in China. Professor Wu has published over 170 scientific papers and four books.

For more information, contact Prof. Chunlei Liang

 

GW Institute for Biomedical Engineering (IBE) Seminar: "Biomaterials and Bioreactors in Bone Tissue Engineering"

Date: Monday, October 8
Time: 1:00 pm
Location: 736 Phillips Hall
Presenter: Prof. John P. Fisher, University of Maryland, College Park

Abstract:

Soluble signaling molecules determine cell phenotype and thus tissue function. For example, growth factors are well known regulators of cell proliferation, migration, and differentiation, typically leading to anabolic tissue growth. While the role of paracrine signaling has been well examined in normal tissue biology as well as abnormal states, such as the uncontrolled cell proliferation associated with tumor development, there has been a relative lack of investigation of endogenously expressed signaling molecules in engineered tissues. Rather, the development of engineered tissues has largely focused upon the viability of cell populations within artificial matrices, or the augmentation of cell function by the delivery of exogenous signaling molecules. This presentation plans to build upon these well explored strategies by considering the overall hypothesis that cell encapsulation within synthetic scaffolds alters the expression and regulation of endogenous signaling molecules, therefore affecting cell phenotype and tissue function. The engineering of bone is discussed, with an emphasis on the role of biomaterials in regulating paracrine signaling within these engineered tissues. For example, we consider the role of cell density, matrix density, and exogenous signal delivery. In addition, we discuss bioreactor systems where endogenously expressed factors are utilized to induce specific cellular responses, including mesenchymal stem cell differentiation. Finally, we consider the development of cyclic acetal based biomaterials, which have properties specifically, developed for facilitated paracrine signaling. The presentation aims to integrate biomaterials development into cell signaling studies so as to initiate new strategies for the engineering of tissues.

Speaker Bio:

Dr. John P. Fisher is Professor and Associate Chair for Undergraduate Studies in the Fischell Department of Bioengineering at the University of Maryland. Fisher completed a B.S. in chemical engineering at The Johns Hopkins University (1995), M.S. in chemical engineering at the University of Cincinnati (1998), Ph.D. in bioengineering at Rice University (2003), and postdoctoral fellowship in cartilage biology and engineering at the University of California Davis (2003). Fisher, the Director of the Tissue Engineering and Biomaterials Laboratory, investigates biomaterials, stem cells, and bioreactors for the regeneration of lost tissues, particularly bone, cartilage, vasculature, and skeletal muscle. His research focuses on the development of novel, implantable, biocompatible materials that can support the development of both adult progenitor and adult stem cells, and particularly examines how biomaterials affect endogenous molecular signaling among embedded cell populations. Fisher is the author of over 65 publications, 120 scientific presentations, and 4 patents. In 2012 Fisher was elected Fellow of the American Institute for Medical and Biological Engineering. In addition, Fisher has received a NSF CAREER Award (2005), the Arthritis Foundation's Investigator Award (2006), the University of Maryland Invention of the Year Award (2006), the Outstanding Graduate Alumnus Award from the Department of Bioengineering at Rice University (2007), the Engalitcheff Award from the Arthritis Foundation (2008), the University of Maryland Professor Venture Fair Competition (2009), and the Teaching Excellence Award from the Fischell Department of Bioengineering at the University of Maryland (2011). Fisher is currently the Editor-in-Chief of the journal Tissue Engineering, Part B: Reviews.

For more information, contact Prof. Lijie "Grace" Zhang

 

ECE Seminar: "GTID: A Technique for Physical Device and Device Type Fingerprinting"

Date: Wednesday, October 10
Time: 2:30-3:30 p.m.
Location: Phillips Hall 640
Presenter: Dr. A. Selcuk Uluagac

Abstract:

In this talk, I will introduce GTID, a technique that passively fingerprints device and device types. This is accomplished by exploiting the heterogeneity of devices, which is a function of the different device hardware compositions and the innate variation in the chip fabrication process. GTID relies on the use of statistical analysis to measure time variant behavior in network traffic to create unique, reproducible device and device type signatures. This technique is applied to the challenging problem of access control in 802.11 networks. I will discuss the efficacy of GTID on both an isolated testbed and a live campus network. Further, I will show, using a corpus of 30 devices representing a wide range of device classes, that GTID has high accuracy and good recall in identifying previously seen and unknown devices and device types. Finally, I will present the efficacy of GTID under various attacker models and discuss its prototype implementation performance.

Speaker Bio:

A. Selcuk Uluagac is currently a member of the research faculty in the School of Electrical and Computer Engineering at Georgia Institute of Technology affiliated with Communications Systems Center (CSC), Communications Assurance and Performance (CAP) Group, and Georgia Tech Information Security Center (GTISC). He earned his Ph.D. with a concentration in information security and networking from the School of Electrical and Computer Engineering, Georgia Institute of Technology in 2010. He also received an M.Sc. in Information Security from the School of Computer Science, Georgia Institute of Technology and an M.Sc. in Electrical and Computer Engineering from Carnegie Mellon University in 2009 and 2002, respectively. He received his B.S. degree in Computer Engineering from the Turkish Naval Academy in 1997. The focus of his research lies at the intersection of the networking and security fields. Of particular interest to Dr. Uluagac is designing secure and energy efficient communication protocols and architectures. In 2007, he received "2007 Outstanding ECE Graduate Teaching Assistant Award" from the School of ECE at Georgia Institute of Technology. He is a member of IEEE (senior grade), ACM, and ASEE.

If there are any questions, please contact Dr. Lan at tlan@gwu.edu.

 

MAE Seminar: "DGEN 380: The Smallest Two Spool, Unmixed Flow Turbofan Jet Engine on the Market"

Date: Monday, October 15
Time: 2:00 pm
Location: 736 Phillips Hall
Presenter: Martin Vivies, Price Induction

Abstract:

Price Induction Inc. has been designing, over the past ten years, a small turbofan engine geared to the "PLJ" segment of the marketplace, the Personal Light Jet. This engine DGEN 380 is modern, compact and very easy to manipulate. It is a twin-spool unmixed flow, high-bypass ratio turbofan engine, weighing only 175 pounds while providing 575 pounds of thrust and it is controlled by FADEC. The DGEN 380 incorporates a number of advanced technologies. First, it is a geared turbofan, which puts a planetary gearbox between the low pressure spool and the fan. This is done to optimize the fan speed given design compromises, which often have to be made with the low pressure turbine when it is spinning at the same RPM.

Secondly the DGEN incorporates an Integral Starter Generator, lowering the weight while making the nacelle diameter potentially smaller, because an output drive shaft and its associated hardware for connection to a generator, is eliminated. The technological innovations don't end there, as the fan and turbines form a "Blisk" ... a combination of blade and disk often machined from a single ingot, which dramatically reduces parts count. The engines are being marketed in tandem with new products, launched in 2010, the WESTT solutions, which are targeting the Aerospace Engineering College Departments. WESTT products have already been installed in various French academies, including the prestigious Toulouse-based Institut Supérieur de l'Aeronautique et de l'Espace.

Speaker Bio:

Martin Vivies graduated from University of Illinois in Urbana-Champaign and SUPELEC (FRANCE) with a master in Electrical Engineering with thesis. He worked two years for MBDA France, as an engineer on active antenna radio technology for fast moving objects. He was recruited in 2011 by Price Induction to work on FADEC and other electronics related issue on the DGEN 380 as part of a Chief Technical Officer position in the American subsidiary.

For more information, contact Prof. Philippe Bardet

 

MAE Seminar: "DGEN 380: The Smallest Two Spool, Unmixed Flow Turbofan Jet Engine on the Market"

Date: Monday, October 15
Time: 2:00 pm
Location: 736 Phillips Hall
Presenter: Martin Vivies, Price Induction

Abstract:

Price Induction Inc. has been designing, over the past ten years, a small turbofan engine geared to the "PLJ" segment of the marketplace, the Personal Light Jet. This engine DGEN 380 is modern, compact and very easy to manipulate. It is a twin-spool unmixed flow, high-bypass ratio turbofan engine, weighing only 175 pounds while providing 575 pounds of thrust and it is controlled by FADEC. The DGEN 380 incorporates a number of advanced technologies. First, it is a geared turbofan, which puts a planetary gearbox between the low pressure spool and the fan. This is done to optimize the fan speed given design compromises, which often have to be made with the low pressure turbine when it is spinning at the same RPM.

Secondly the DGEN incorporates an Integral Starter Generator, lowering the weight while making the nacelle diameter potentially smaller, because an output drive shaft and its associated hardware for connection to a generator, is eliminated. The technological innovations don't end there, as the fan and turbines form a "Blisk" ... a combination of blade and disk often machined from a single ingot, which dramatically reduces parts count. The engines are being marketed in tandem with new products, launched in 2010, the WESTT solutions, which are targeting the Aerospace Engineering College Departments. WESTT products have already been installed in various French academies, including the prestigious Toulouse-based Institut Supérieur de l'Aeronautique et de l'Espace.

Speaker Bio:

Martin Vivies graduated from University of Illinois in Urbana-Champaign and SUPELEC (FRANCE) with a master in Electrical Engineering with thesis. He worked two years for MBDA France, as an engineer on active antenna radio technology for fast moving objects. He was recruited in 2011 by Price Induction to work on FADEC and other electronics related issue on the DGEN 380 as part of a Chief Technical Officer position in the American subsidiary.

For more information, contact Prof. Philippe Bardet

 

CS Colloquium: "The Battle for Control of Online Communications"

Date: Wednesday, October 24
Time: 11:00 am
Location: 736 Phillips Hall
Presenter: Prof. Nick Feamster, University of Maryland and Georgia Tech

Abstract:

The Internet offers users many opportunities for communicating and exchanging ideas, but emerging threats---ranging from message abuse to censorship---have put free and open communication at risk. For example, recent estimates suggest that spam constitutes about 95% of all email traffic, hundreds of thousands of online scam domains emerge every day, online social networks may be used to spread propaganda, and more than 60 countries around the world perform some form of censorship on Internet traffic. In this talk, I will discuss approaches we have developed to combating these threats, in an effort to preserve free and open communication on the Internet. I will first discuss a 13-month study of the network-level behavior of spammers, and present a spam filtering system we developed that classifies email messages based on the network-level traffic characteristics email, rather than the contents of the email messages (how the messages are sent, rather than what is in them). I will also describe emerging threats concerning domain name registration and mechanisms that we are developing to ascertain the reputation of domain names, sometimes before the attacks even take place. In the second part of the talk, I will turn to the emerging threats of censorship and information control. I will describe the extent and nature of problems involving both censorship and information manipulation and control, and the approaches we are taking to both monitoring and circumventing attempts to restrict and manipulate access to online information.

Speaker Bio:

Nick Feamster is the Darnell-Kanal Associate Professor of Computer Science in the Department of Computer Science at University of Maryland, and an associate professor at Georgia Tech, where he leads the Network Operations and Internet Security Group. He received his Ph.D. in Computer science from MIT in 2005, and his S.B. and M.Eng. degrees in Electrical Engineering and Computer Science from MIT in 2000 and 2001, respectively. His research focuses on many aspects of computer networking and networked systems, including the design, measurement, and analysis of network routing protocols, network operations and security, and anonymous communication systems. In December 2008, he received the Presidential Early Career Award for Scientists and Engineers (PECASE) for his contributions to cybersecurity, notably spam filtering. His honors include the Technology Review 35 "Top Young Innovators Under 35" award, a Sloan Research Fellowship, the NSF CAREER award, the IBM Faculty Fellowship, and award papers at SIGCOMM 2006 (network-level behavior of spammers), the NSDI 2005 conference (fault detection in router configuration), Usenix Security 2002 (circumventing web censorship using Infranet), and Usenix Security 2001 (web cookie analysis).

 

MAE Seminar: "Turbulence Production By Nonbreaking Waves"

Date: Thursday, October 25
Time: 2:00 pm
Location: 736 Phillips Hall
Presenter: Ivan Savelyev, Research Physicist, Remote Sensing Division, US Naval Research Laboratory

Abstract:

This seminar will give a brief overview of several ongoing basic research projects at the Naval Research Lab, which the speaker is directly involved in. These projects include infrared imaging of warm buoyant plumes, turbulent wakes behind steep and breaking surface gravity waves, turbulent wakes behind submerged moving objects, infrared surface signatures of breaking internals waves, and aerosol generation by breaking surface waves. A recent study on turbulence generation by nonbreaking surface waves will be presented in greater detail. The goal of this study was to verify the existence of energy flux from steep, but not breaking waves to subsurface turbulence. The investigation relied on both experimental and numerical approaches. Turbulent velocities at the water surface were measured in a laboratory wave tank with high precision using the thermal marking velocimetry technique. Numerically, a fully nonlinear model for the wave motion was coupled with Large Eddy Simulation for the turbulent motion. The results confirm the turbulence production due to wave motion. The turbulent kinetic energy was found to be a function of time, wave steepness, wave phase, and initial turbulent conditions. Additionally, turbulent motion near the surface was found to be horizontally anisotropic due to the formation of near-surface eddies, elongated in the direction of wave propagation. The seminar will conclude with a brief overview of future research plans, involving a 16-element three-dimensional surface wave generator.

Speaker Bio:

Dr. Ivan Savelyev is a Research Physicist at the Remote Sensing Division of US Naval Research Laboratory (NRL), Washington DC. His research interest is in hydrodynamic processes taking place at the air-sea interface and in the upper ocean. For this purpose he utilizes innovative remote sensing techniques and conducts experiments in laboratory wave tanks and in the ocean. He joined NRL in 2009 after defending his Ph.D. dissertation at the University of Miami, RSMAS, where he conducted various laboratory experiments on air-sea fluxes and wave-coupled processes in high wind conditions. His M.S. degree in Ocean Physics and B.S. degree in Physics are from Moscow State University.

For more information, contact Prof. Philippe Bardet

 

CS Seminar: "Simulation-Based Tools For Evaluating Underactuated Hand Designs"

Date: Thursday, October 25
Time: 4:30 pm
Location: 640 Phillips Hall
Presenter: Dan Aukes, Stanford University

Abstract:

This talk presents a tool aimed at the design of compliant, under-actuated hands. The particular motivation is hands that will be used for an underwater robot to grasp a variety of objects, some of which may be delicate or slippery. The focus of the analysis is the problem of object acquisition. In comparison to many prior grasp analysis tools, the tool presented here models the dynamics of a hand, including actuation mechanisms, compliance and friction in an efficient formulation that permits one to evaluate variations in such quantities as phalange length, finger spacing, transmission ratios, and torsional joint stiffnesses when comparing hand designs. The analysis is demonstrated for an object acquisition problem and leads to the computation of a vector space of three dimensional regions for which the hand will tend to center and stably grasp a compact object.

Speaker Bio:

Dan Aukes is a Ph.D. student studying under Dr. Mark Cutkosky in the Mechanical Engineering Department at Stanford University. He has been designing and building underactuated robotic hands for underwater robots, and more recently for the DARPA ARM-H project. His work focuses on analysis tools and methods for improving the design of underactuated mechanisms. He did his undergraduate work at Northwestern University, focusing on mechatronics and robotics, and consulted with DMC, Inc. in Chicago, before beginning his graduate work at Stanford.

For more information, contact Prof. Evan Drumwright

 

CS Seminar: "Autonomous Agile Aerial Robots"

Date: Wednesday, October 31
Time: 2:30 pm
Location: 205 Tompkins Hall
Presenter: Dr. Vijay Kumar, University of Pennsylvania

Abstract:

Autonomous micro aerial robots can operate in three-dimensional unstructured environments, and offer many opportunities for environmental monitoring, search and rescue, and first response. I will describe the challenges in developing small, agile robots and our recent work in addressing these challenges. I will also discuss the deployment of large numbers of aerial robots, focusing on the control and planning problems with applications to cooperative manipulation and transport, construction, and exploration and mapping.

Speaker Bio:

Dr. Vijay Kumar is the UPS Foundation Professor in the School of Engineering and Applied Science at the University of Pennsylvania. He received his Ph.D. in Mechanical Engineering from The Ohio State University in 1987. He has been on the Faculty in the Department of Mechanical Engineering and Applied Mechanics with a secondary appointment in the Department of Computer and Information Science at the University of Pennsylvania since 1987.

Dr. Kumar is a Fellow of the American Society of Mechanical Engineers (ASME) and the Institution of Electrical and Electronic Engineers (IEEE). He presently serves on the editorial boards of the IEEE Transactions on Automation Science and Engineering, the ASME Journal of Mechanisms and Robotics and the Springer Stracts in Advanced Robotics (STAR). He is the recipient of the National Science Foundation Presidential Young Investigator award (1991), the Lindback Award for Distinguished Teaching (1996), and best paper awards at DARS 2002, ICRA 2004, ICRA 2008, ICRA 2011, RSS 2009, DARS 2010 and RSS 2011. He is a Distinguished Lecturer and the winner of the 2012 Distinguished Service Award in the IEEE Robotics and Automation Society and the winner of the 2012 ASME Mechanisms and Robotics Committee Award.

For more information, contact Prof. Evan Drumwright

 

CANCELLED MAE Seminar: "On the Propagation, Instability and Turbulence of Advancing Material Fronts"

Date: Thursday, November 1
Time: 2:00 pm
Location: 736 Phillips Hall
Presenter: Prof. S. Balachandar, University of Florida

Abstract:

Penetration of one material into another is a fundamental fluid mechanical process that can be observed all around us in many industrial and environmental applications. Filling/emptying pipelines, coating flows, falling films and sedimentation fronts are some industrial applications. Tsunamis, volcanic plumes, lava and pyroclastic flows, dust storms, powder snow avalanches, submarine turbidity currents and supernovae offer fascinating examples of advancing material fronts. This talk will introduce the concept of gravity currents, where the density difference between the propagating and the ambient materials drives the flow. The examples mentioned above include both scalar and particulate gravity currents, where in the former the density difference is due to temperature or salinity, while in the later suspended particles contribute to density difference. Particular attention will be paid to the front velocity and simple theoretical models that attempts to predict it. The propagating fronts undergo Rayleigh-Taylor, Lobe-and-cleft and Kelvin-Helmholtz instabilities, giving rise to fascinating pathways to turbulence. One particular example we will consider in greater detail is the sustained propagation of submarine turbidity currents, whose propagation depends on an interesting interplay between suspended particles and turbulence. The suspended particles drive the flow and are the source of turbulence in a turbidity current, while the flow turbulence enables resuspension of particles from the bed. If resuspension dominates over deposition the intensity of the current can increase, thereby further increasing resuspension and resulting in a runaway current. On the other hand, stable stratification due to suspended sediment concentration can damp and even kill turbulence. Then deposition dominates over resuspension and the current could laminarize resulting in massive deposits. In this talk we present results that indicate the existence of conditions for the total damping of the near-bed turbulence. Under these conditions, sediment in suspension rains out passively on the bed, even though the upper layer may remain turbulent. The above scenario provides a reasonable (but not unique) explanation for the formation of massive turbidities that have recently been reported from field observations.

Speaker Bio:

S. "Bala" Balachandar got his undergraduate degree in Mechanical Engineering at the Indian Institute of Technology, Madras in 1983 and his MS and PhD in Applied Mathematics and Engineering at Brown University in 1985 and 1988. From 1990 to 2005 he was at the University of Illinois, Urbana-Champaign, in the Department of Theoretical and Applied Mechanics. From 2005 to 2011 he served as the Chairman of the Department of Mechanical and Aerospace Engineering at the University of Florida. Currently he is the William F. Powers Professor and the Director of College of Engineering Institute for Computational Engineering. Bala received the Francois Naftali Frenkiel Award from American Physical Society (APS) Division of Fluid Dynamics (DFD) in 1996 and the Arnold O. Beckman Award and the University Scholar Award from University of Illinois. In 2003, his student won the Andreas Acrivos Dissertation Award from APS-DFD. He is Fellow of the American Physical Society and ASME. He is currently an associate editor of the International Journal of Multiphase Flow and Theoretical and Computational Fluid Dynamics.

For more information, contact Prof. Kausik Sarkar

 

MAE Seminar: "Molecular Understanding, Design and Development of Ultra Low Fouling Zwitterionic-based Functional Materials"

Date: Thursday, November 8
Time: 10:30 am
Location: 640 Phillips Hall
Presenter: Prof. Shaoyi Jiang, University of Washington, Seattle

Abstract:

An important challenge in many applications, ranging from biomedical devices to ship hulls, is the prevention of nonspecific biomolecular and microorganism attachment on surfaces. To address this challenge, our goals are twofold. First, we strive to provide a fundamental understanding of nonfouling mechanisms at the molecular level using an integrated experimental and simulation approach. Second, we aim to develop biocompatible and environmentally benign ultra low fouling materials based on the molecular principles learned. Over the last several years, we have demonstrated that zwitterionic materials and surfaces are highly resistant to nonspecific protein adsorption, cell adhesion and biofilm formation from complex media. Both simulation and experimental results show that the strong hydration of zwitterionic materials is responsible for their excellent nonfouling properties. In addition to their excellent nonfouling properties, zwitterionic carboxybetaine-based materials have functional groups for direct ligand immobilization while the cationic precursors of zwitterionic materials have self-sterilizing capabilities. Superhydrophilic zwitterionic materials are also shown to have unique advantages for stealth nanoparticles over their amphiphilic poly(ethylene glycol) (PEG) counterparts. Examples will be given to illustrate the application of zwitterionic materials to blood-contact devices, implantable materials, drug/gene delivery carriers, biosensors, antimicrobial coatings, and marine coatings.

Speaker Bio:

Professor Shaoyi Jiang received his Ph.D. degree in chemical engineering from Cornell University in 1993. He was a postdoctoral fellow at UC Berkeley between 1993 and 1994 and a research fellow at Caltech between 1994 and 1996 both in chemistry. He is currently the Boeing-Roundhill Professor of Chemical Engineering at the University of Washington, Seattle. He is a senior editor for Langmuir, a fellow of the American Institute of Chemical Engineers, and a member of the Washington State Academy of Sciences. His research focuses on interfacial phenomena, particularly molecular understanding, design and development of zwitterionic-based functional materials for biomedical and engineering applications.

For more information, contact Prof. Yongsheng Leng

 

Joint CS-ECE Colloquium: "Enhancing Access to the Radio Spectrum"

Date: Friday, November 16
Time: 2:30 - 3:30 pm
Location: 736 Phillips Hall
Presenter: Dr. Zhi (Gerry) Tian, Communications, Circuits and Sensing Systems (CCSS) Program, NSF

Abstract:

This talk has two parts. In the first part, I will discuss several NSF programs related to Communications, Sensing and Cyber-Physical Systems. In particular, I will give an introduction on NSF's new initiative on enhancing access to the radio spectrum (EARS). In the second part, I will present a technical discussion on compressed sensing in statistical signal processing, where compressive sampling of random processes is of interest. In contrast to existing framework of compressed sensing for deterministic signals, our recent results indicate that significant compression can be realized by directing reconstructing useful statistics (second-order statistics, features) rather than the random signals themselves. As an example, I will present a cyclic feature based compressive spectrum sensing approach for wideband cognitive radios. Wideband communication signals possess unique two-dimensional sparsity structures in both the frequency domain and the modulation-dependent cyclic frequency domain. Exploitation of these sparsity elements not only reveals important features of the modulated signals for detection and classification purposes, but also results in fast reconstruction of the cyclic statistics and hence reduced sensing time. Using the new framework of compressed sensing for random processes, compressive spectrum sensing becomes feasible even for (non-sparse) crowded spectrum.

Speaker Bio:

Zhi (Gerry) Tian is a Program Director for the Communications, Circuits and Sensing Systems (CCSS) program in the Division of Electrical, Communications and Cyber Systems (ECCS) of the Engineering Directorate at the NSF. Dr. Tian joined NSF from Michigan Technological University through an IPA assignment. At Michigan Tech, Dr. Tian is a Professor in the Department of Electrical and Computer Engineering. Her research interests lie in digital and wireless communications, wireless sensor networks, and statistical analysis. She delivered technical tutorials on topics related to cognitive radios and compressed sensing in several international conferences. She served as Associate Editor for IEEE Transactions on Wireless Communications and IEEE Transaction on Signal Processing.

For more information, contact Prof. Tian Lan

 

MAE Seminar: "Materials by Design "

Date: Monday, November 19
Time: 11:00 am
Location: 736 Phillips Hall
Presenter: Prof. Markus J. Buehler, Massachusetts Institute of Technology

Abstract:

What if we could design materials that integrate powerful concepts of living organisms -- self-organization, the ability to self-heal, and an amazing flexibility to create astounding material properties from abundant and inexpensive raw materials? This talk will present a comprehensive review of bottom-up design of materials for various purposes -- as structural materials such as bone in our body or for lightweight composites, for applications as coatings, and as multifunctional sensors to measure small changes in temperature or stress, designed from the bottom up and through a close coupling of experiment and powerful computation as we assemble a new generation of materials, atom by atom.

We begin with a discussion of materials in biological systems, which are synthesized, controlled and used for an astonishing variety of purposes -- structural support, force generation, mass transport, catalysis, or energy conversion -- despite severe limitations in available energy, quality and quantity of building blocks. We show how by incorporating concepts from biology and engineering, computational modeling has led the way in identifying the core principles that link the molecular structure of biomaterials at scales of nanometers to physiological scales at the level of tissues, organs, and organisms. As a result a new paradigm of materials design has emerged, based on the insight that the way components are connected at different length-scales defines what material properties can be achieved, how they can be altered to meet functional requirements, and how they fail in disease states; rather than the chemical composition of materials alone.

The use of the world's fastest supercomputers allows us to predict properties of complex materials from first principles, realized in a multiscale modeling approach that spans massive ranges in scale. Combined with experimental studies, such "in silico" models allow us to simulate disease, understand catastrophic failure of tissues and organs, and enable us to translate concepts from the living world into groundbreaking material designs that blur the distinction between the living and non-living systems. We review case studies of joint experimental-computational work of biomimetic materials design, manufacturing and testing for the development of strong, tough and mutable materials for applications as protective coatings, cables and structural materials. We outline challenges and opportunities for technological innovation for biomaterials and beyond, exploiting novel concepts of mathematics based on category theory, which leads to a new way to organize hierarchical structure-property information. Altogether, the use of a new paradigm to design materials from the bottom up plays a critical role in advanced manufacturing, providing flexibility, tailorability and efficiency.

Speaker Bio:

Markus J. Buehler is an Associate Professor in the Department of Civil and Environmental Engineering at the Massachusetts Institute of Technology (MIT), where he directs the Laboratory for Atomistic and Molecular Mechanics (LAMM). He is the Director of the MIT-Germany Program, Co-Director of the MIT Computation for Design and Optimization Program, and leads the Mechanics and Materials Group in the Department of Civil and Environmental Engineering. Buehler has published more than 200 articles on computational materials science, molecular biomechanics and nanotechnology, authored two monographs, and given several hundred invited, keynote and plenary talks.

For more information, contact Prof. James Lee

 

ECE Colloquium: "Chemical, Structural, and Electronic Hybridization of Graphene Films "

Date: Thursday, November 29
Time: 3:30 - 4:30 pm
Location: 309 Tompkins Hall
Presenter: Dr. Jeremy Robinson, Materials Research Scientist, Naval Research Laboratory

Abstract:

Graphene's unique transport properties have motivated intensive research and development to mold it into the electronic material of the future. However, graphene can be much more than an electrical switch. Its high structural integrity and chemical flexibility enable extensive control of its optical, mechanical, and electronic properties. Graphene's atomic thinness also highlights another important property of two-dimensional crystals -- the ability to electronically, chemically, or structurally hybridize with neighboring surfaces. In this talk, I will discuss some basic growth, characterization, and functionalization aspects of graphene, then describe efforts at NRL to broadly engineer graphene materials for applications in sensing, nanomechanics, and nanoelectronics. To begin, I will review the primary synthesis techniques, exfoliation and growth, then highlight the most common characterization tools including optical microscopy and Raman spectroscopy. In the second part of the talk I will first discuss graphene oxide, which has a rich ensemble of functional groups and related defects ideally suited for sensing applications, and the demonstration of sensors with parts-per-billion sensitivities to vapors. Second, I will discuss the chemical hybridization of graphene via the stoichiometric addition of fluorine atoms and the formation of graphene nanoribbons within a fluorographene matrix. Experiments indicate fluorinated graphene derivatives become highly resistive and optically transparent, while DFT calculations show band gaps open depending on the fluorine coverage and ordering. Third, I will describe the structural hybridization of layered chemically modified graphene, enabled by local laser annealing and inter-layer crystallization. By measuring the response of high-quality nanomechanical resonators, we can extract relevant mechanical properties including tension, yield strength, resilience, and modulus. Finally, I will highlight recent results related to the electronic hybridization of two stacked graphene films, where the moire pattern formed by the relative "twist" between layers is responsible for new properties of the bilayer system. Such twisted bilayer systems give rise to properties not intrinsic to a single graphene layer.

Speaker Bio:

Jeremy Robinson earned his Bachelor's degree in Physics from Towson University in 2002 and went on to study Materials Science and Engineering at UC Berkeley. Upon finishing his PhD in 2007 he worked for one year as an NRC postdoctoral fellow in the Electronics Science Division at the Naval Research Laboratory in Washington, DC. Dr. Robinson joined the full-time staff at NRL in 2008, where he currently resides. During his short tenure at NRL, Dr. Robinson has been tremendously active in graphene research, publishing over 30 graphene specific journal articles and presenting numerous invited talks at professional meetings. Notable research successes include the discovery of fluorinated graphene derivatives, the first demonstrated chemical sensors using graphene oxide, and the successful development of graphene-based nanomechanical resonators. As a result, Dr. Robinson has one issued graphene patent, a graphene article cited over 300 times and two cited over 100 times, and on two separate occasions was awarded the Alan Berman Research Publication Award at NRL.

For more information, contact Prof. Tian Lan

 

Institute for Nanotechonology and Institute for Biomedical Engineering Seminar: "Biocompatible Nanoparticle Materials In For Cancer Imaging and Therapy "

Date: Friday, November 30
Time: 10:30 am
Location: 771 Rome Hall
Presenter: Dr. Xiaoyuan (Shawn) Chen, Chief and Senior Investigator, National Institutes of Health

Abstract:

Nanoparticles with unique physical and chemical properties can be rendered water-soluble and biocompatible for use in cancer diagnosis, imaging and therapy. This talk will highlight some of the recent advances in using different nanomaterials (both rigid inorganic materials and biodegradable polymeric materials) for multimodality imaging (PET, optical, MRI, photoacoustic, etc.), for drug and gene delivery and for theranostics. The challenges and future perspectives of nanomedicine in cancer research will also be briefly discussed.

Speaker Bio:

Dr. Chen received his Ph.D. in chemistry from the University of Idaho in 1999. After two quick postdocs at Syracuse University and Wash University, he joined USC as an Assistant Professor of Radiology. He then moved to Stanford in 2004 and was promoted to Associate Professor in 2008. In the summer of 2009, he joined NIH as a tenured Senior Investigator and Lab Chief. Dr. Chen has published over 340 papers and numerous books. He is the editor-in-chief a newly launched SCI journal Theranostics and sits on the editorial board of over 10 peer-reviewed journals. His lab focuses on developing molecular imaging probes and nanomedicine with clinical translational potential.

For more information, contact Prof. Lijie Grace Zhang

 

GW Institute for Biomedical Engineering Seminar: "Ultrasound Enhanced Triggered Release of Liposomal Contents"

Date: Thursday, December 6
Time: 1:00 - 2:00 pm
Location: 204 Tompkins Hall
Presenter: Dr. Sanku Mallik, North Dakota State University

Abstract:

Amongst the lipid-based nanoparticles, liposomes are used extensively for targeting and delivery of anticancer and other drugs. However, the liposome based methodology frequently involves the passive release of the encapsulated drugs to the selected tissue sites. Overexpressions of the enzymes matrix metalloproteinases are correlated with many pathological conditions, notably various cancers and cardiovascular diseases. Matrix metalloproteinase-9 (MMP-9) is involved in the progression and metastasis of a large number of cancers. Recently, we have demonstrated that MMP-9 mediated cleavage of substrate lipo-peptides causes lipid demixing, resulting in release of encapsulated contents from liposomes in the extracellular matrix of rapidly-dividing cancer cells. When the liposomes are echogenic, the release of the liposomal contents is further enhanced by the application of diagnostic frequency ultrasound. For release of liposomal contents in the cell cytosol, we have prepared polymer-coated, reduction sensitive, echogenic liposomes presenting the folate groups on the surface. We observed that these liposomes are actively targeted to cervical cancer cells overexpressing the folate receptor and efficiently internalized. The reducing environment of the cytosol rapidly releases the encapsulated anticancer drug from the liposomes, leading to cell death. With further developments, we anticipate that these liposomes will offer unique opportunities for targeting, triggered release of encapsulated drugs and simultaneous imaging employing diagnostic frequency ultrasound.

Speaker Bio:

Sanku Mallik obtained his Ph D in Chemistry from Case Western Reserve University. After postdoctoral research in the California Institute of Technology, he joined the Chemistry faculty at the University of North Dakota in 1995. In 1998, he moved to the Chemistry Department, North Dakota State University (NDSU). In 2006, he joined the Department of Pharmaceutical Sciences at NDSU. His research interests are to design liposomal drug delivery systems, to prepare synthetic polymers for cancer cell subtyping and to synthesize inhibitors for the enzymes histone deacetylases. He has published more than 70 papers and currently a member of the American Chemical Society and the American Association of Pharmaceutical Scientists.