Category: Seminars

The ME-EM Graduate Seminar speaker on Thursday, October 23rd at 4:00 in 103 EERC will be Dr. Dong Hwan Shin a post doc in the Mechanical Engineering Department at Michigan Tech.

The title of his presentation will be ‘Local Aggregation Characteristics and Visualization of Intermediate Layers during Evaporation of Nanofluid Droplets’.

Recently, nanofluids (NF) are of substantial interest because of their potentials in exhibiting improved thermal performance. Thus, nanofluids are expected as the next generation of cooling fluids for automobiles and electronic devices. One of Dr. Shin’s research interests is about characterization of nanofluid droplet evaporation by using confocal and regular inverted microscopic systems. This presentation will introduce his recent work regarding the nanofluid droplet evaporation: Evaporation characteristics of nanofluid droplets with various volume fractions of 50 nm alumina (Al2O3) particles are experimentally examined. The effect of particle concentrations on droplet evaporation rates is examined. The corresponding wettability changes and the total evaporation time are also examined. Besides, he will also introduce the spatial non-uniformity of suspended nanoparticles in the droplet caused by the local aggregation visualized by using the inverted microscope system. The results show that the effective thermal conductivity should be changed according to the non-uniform distribution of nanoparticles inside a droplet on the surface. Next, the contact lines of nanofluids droplets during evaporation are visualized using a high-speed reflected mode slit-confocal. The present work deals with a challenging issue on the experimental visualization of the intermediate layer because the conventional optical approach cannot visualize this layer due to the optical limitation. The intermediate layer thickness varies with time during evaporation, which is observed based on the fringe pattern analysis. Those results show the feasibility of using fringe patterns of contact lines can provide instability of a contact-line region in the thin film and further explain heat and mass transfer in this region.

Dr. Dong Hwan (DH) Shin is a post-doctoral research scholar of Mechanical Engineering-Engineering Mechanics at Michigan Technological University. He received his B.S., M.S. and Ph.D in Mechanical Engineering in Chung-Ang University (CAU) in 2008, 2010 and 2014, respectively. He has already been to MTU as a visiting scholar three times in 2010, 2012 and 2013. His research interests are nanofluids and its applications, micro-droplet evaporation and its applications, flame spray and its applications, and computational fluid dynamics. He has published 17 journal papers and 22 proceedings.

The ME-EM Graduate Seminar speaker on Thursday, October 16 at 4:00 in 103 EERC
will be Dr. Chen-Fang Chang of GM Global Research & Development.

The title of his presentation will be ‘Automotive Powertrain Control: Opportunities and Challenges’.

Advanced powertrain systems are being introduced into passenger vehicles to meet regulatory and customer demands, simultaneously increasing fuel economy, reducing emissions and enhancing driveability. As the powertrain systems become more sophisticated, it will force a dramatic increase in control complexity and calibration effort. This presentation will detail the challenges facing automotive control community and the approaches a control engineer can take to confront these challenges. IC engine controls will be used to exemplify a whole engine controller development cycle. Future outlook will also be provided.

Dr. Chang is currently the Lab Group Manager of the Propulsion Control Systems Group at GM Global R&D. Since joining GM in 1994, he has worked on cylinder-pressure-based engine controls, diesel aftertreatment controls, HCCI engine controls, and, most recently, information-rich propulsion controls. Dr. Chang received his Ph.D. degree in Mechanical Engineering with minor in Electrical Engineering from Stanford University. He holds 43 US patents and has numerous technical publications. He is the recipient of 2013 ASME Rudolf Kalman Award and 2001 SAE Arch T. Coldwell Merit Award.

The ME-EM Graduate Seminar speaker on Thursday, October 9 at 4:00 in 103 EERC will be Dr. Nestor Voronka, Principal, M42 Technologies.

The title of his presentation will be ‘Space Tethers, Small Satellites, and System Engineering’.

This seminar will present an overview of space tether technology, its applications, and the
results of space tether missions to date. Space tethers present interesting system engineering challenges and in particular when integrated into small satellites. System engineering challenges
of both large and small spacecraft systems will be discussed along with some lessons learned and recommendations.

Dr. Nestor Voronka is the Principal of M42 Technologies, which develops, advanced technologies, provides alternative and relevant solutions to space and aerospace challenges and is currently focused on developing project solutions and flight systems for the DoD, NASA and commercial space customers. From 2003 to 2013 Mr. Voronka served as the Chief Technologist and VP of Tethers Unlimited, Inc where he led various product and technology development efforts designing space tether systems, nanosatellite components, propulsion systems, RF systems, spacecraft antennas, 3D printable radiation shielding, and UAV towed sensor systems. Mr. Voronka was the lead engineer responsible for the design, development, testing, and delivery, and operations of the MAST 3U CubeSat experiment that launched in April 2007. From 1996 to 2003, Mr. Voronka was Chief Engineer at Cybernet Systems Corp. where he was led the development of products and technologies in a number of areas including computer networking, force feedback devices, motor control, motion capture, machine vision, electro-optics, inertial navigation, aviation systems, and medical devices. While at the UM-Space Physics Research Lab 1991-1996 first as a student and then a staff engineer, Mr. Voronka worked the Tethered Satellite System (TSS-1R) that flew on the Space Shuttle Columbia STS-75 flight in February of 1996. Mr. Voronka has two Master’s degrees from the University of Michigan in Electrical Engineering in the areas of electromagnetics, and Signal/Image Processing.

The ME-EM Graduate Seminar speaker on Thursday, October 2 at 4:00 in 103 EERC will be Dr. Ye (Sarah) Sun from Michigan Tech Mechanical Engineering – Engineering Mechanics Department.

The title of her presentation will be ‘Human-Centered Monitoring: From Enabling Technology, Human Factor to Computational Diagnosis’.

The rapidly growing population ageing is a global phenomenon in the recent decades. The concomitant prevalence of chronic diseases necessitates proactive, human-centered approaches to reduce the high cost and enhance the biocompatibility and operability of the current healthcare systems. For drivers at all ages, drowsiness is one of the most prevalent root causes of accidents. Driver health and state monitoring provides an effective way to reduce the risk of driver related crashes. This study aims to facilitate the development of human-centered monitoring in healthcare and transportation safety. A comprehensive framework for human-centered monitoring has been developed that includes three major components, i.e., enabling technology, human factor and computational diagnosis. In the technology part, this study establishes a non-intrusive and non-contact interface platform for human health and state monitoring. Unlike the conventional clinical bio-potential measurement system, the platform is able to acquire the electrophysiological signals with a gap between the skin and the electrodes that is occupied by hair, cloth, and air. The non-contact platform avoids skin irritation and allergic contact dermatitis and is suitable for long-term monitoring purpose. To increase the flexibility in practical application, a body area network has also been integrated for different scenarios such as driving and home monitoring. The developed enabling technology was validated using simulated driving scenario, since it constitutes a high stress and high risk condition, especially for people with chronic diseases. For the human factor part, analyses were conducted on the physiological data collected from the drivers operating a high fidelity driving simulator. This involves driver state analyses particularly related to drowsiness and mental stress. The computational component involved the development of algorithms to assess the robustness of different physiological indicators for the extent of driver fatigue. Moreover, physiological signals for mental stress were also investigated which will serve as the technical basis for timely assistance.

Dr. Ye (Sarah) Sun is an assistant professor in the Department of
Mechanical Engineering-Engineering Mechanics at Michigan Technological
University. She received her Ph.D. degree in Electrical Engineering
from Case Western Reserve University. Her research is an
interdisciplinary resort that integrates engineering innovation with
human health and human behaviors. The primary focus is on
human-centered smart monitoring technologies that integrate advance
sensor technology and decision support to improve healthcare
and transportation safety.

The ME-EM Graduate Seminar speaker on Thursday, September 18 at 4:00 in 103 EERC will be Dr. Dean Miller from Argonne National Laboratory.

The title of his presentation will be ‘Applications of Electron Microscopy to Materials for Energy’.

Electron microscopy has long been an important tool in understanding the structure and function of materials. Electron microscopy provides powerful capabilities for characterization of microstructure at the nanoscale. Likewise, focused ion beam instruments provide unique capability for preparation and interrogation of materials. In this presentation, several examples of the application of these approaches to energy related materials will presented. In fuel cell materials, quantitative three-dimensional reconstruction of microstructure through focused ion beam – scanning electron microscopy
has provided new insight into cathode performance. For Li-battery materials, we have developed a new way to follow structural evolution in single oxide cathode particles by in situ microscopy during electrochemical cycling that has shed new light on mechanisms for performance degradation. In high temperature superconductors, electron microscopy has revealed how subtle changes in chemistry during processing can have a profound influence on their ultimate performance. These examples illustrate some of the ways electron microscopy can provide unique and practical insight into the behavior of materials.

Dean Miller is a Senior Materials Scientist and Director of the Electron Microscopy Center at Argonne National Laboratory. He received his B.S. in Metallurgical Engineering and Ph.D. in Materials Science, both from the University of Illinois in Champaign-Urbana. His research at Argonne focuses
on the characterization of complex electronic oxides including high-temperature superconductors, magnetic oxides, and advanced battery materials with a particular emphasis on characterization by electron beam methods.

The ME-EM Graduate Seminar speaker on Thursday, September 11 at 4:00 in 103 EERC will be Dr. Kahlid Hattar from Sandia National Laboratory. The title of his presentation will be ‘In situ Nanoscale Testing to Validate and Elucidate Mechanism for Predictive Modeling’.

Topic: In situ Nanoscale Testing to Validate and Elucidate Mechanism for Predictive Modeling

Predicting performance margins of complex systems requires the development of multiscale physics based models that incorporate potential processing, microstructure, and property variations. To create the necessary set of models, a fundamental understanding of the physics governing the associated materials interplay and response in the expected environments of operation is essential. In situ transmission electron microscopy (TEM) experiments validated by welldesigned bulk tests provide an excellent tool to elucidate the underlying mechanisms that govern the properties of materials exposed to various environmental conditions of interest.
This presentation will demonstrate the breadth of in situ TEM research capabilities that are now available to the materials science community. These capabilities will be highlighted through a set of three experimental examples. In the first set, both the detrimental and beneficial effects of ion irradiation in face-centered cubic metal will be demonstrated.
The detrimental effect will be shown through a detailed comparison of displacement damage on the microstructure and mechanical properties of high purity Cu whereas the beneficial effect will be presented for Au electrical contacts. Recent advancements in in situ TEM stages permit studies in gas and liquid environments. To demonstrate the potential of these stages, recent work done at Sandia to understand the uptake and release of hydrogen in nanoporous Pd nanoparticles and the nanoscale mechanisms of corrosion in high purity Fe will be shown. Finally, the presentation will highlight the ability of in situ ion irradiation studies to investigate the structural evolution of advanced nanoscale detectors under controlled radiation environments.
This research was partially funded by the U.S. Department of Energy, Office of Science, Office of Basic Energy Sciences, Division of Materials Sciences and Engineering. Sandia National Laboratories is a multi-program laboratory managed and operated by Sandia Corporation, a wholly owned subsidiary of Lockheed Martin Corporation, for the U.S. Department of Energy’s National Nuclear Security Administration under contract DE-AC04-94AL85000.

Khalid Hattar is a Senior Member of the Technical Staff of Sandia National Laboratories. He
received a B.S. in Chemical Engineering from University of California, Santa Barbara in 2003, and a
Ph.D. in Materials Science and Engineering from University of Illinois, Urbana-Champaign in 2009.
He joined the Radiation-Solids Interaction group at Sandia in December 2008. He specializes in
determining the property-microstructure relationship
for a variety of structural, electrical, and optical
materials through in situ TEM in various extreme
environments.