Category Archives: Seminars

ME-EM Graduate Seminar: Cavitation-Induced Damage in Brain Tissue and Surrogates: Relevance to TBI

oct30The ME-EM Graduate Seminar speaker on Thursday, October 30th at 4:00 in 103 EERC will be Dr. Ghatu Subhash from the University of Florida, Gainesville.

The title of his presentation will be ‘Cavitation-Induced Damage in Brain Tissue and Surrogates: Relevance to TBI’.

Traumatic brain injury (TBI) has reached epidemic proportions in US. Around 1.7 million people are diagnosed with TBI each year. While a majority of these injuries are due to physical blows that may occur because of a fall or during an athletic activity, blast-induced mild traumatic brain injury (bmTBI) is specific to soldiers who are exposed to frequent improvised explosive device (IED) blasts in a hostile environment. A blast wave consists of a high pressure front followed by a negative pressure tail. It is commonly believed that only the high pressure front causes significant damage to the brain tissue. In recent years, new evidence has emerged revealing that extensive cavitation indeed occurs in brain tissue due to the negative pressure that immediately follows the high pressure front in the blast wave. The negative pressure initiates cavitation bubbles which collapse and release shock waves, and cause significant local neuronal and astrocyte damage in sensitive areas of the brain. The current research focusses on investigating this specific phenomena in brain tissue and surrogates (e.g., gels). The first goal of this research is to develop an experimental facility to characterize cavitation in a simulated brain environment and measure associated deformation during bubble growth and collapse on a tissue surrogate. The second goal is to quantify the neuronal and astrocyte injury when a brain tissue is exposed to blast waves. A novel experimental facility has been developed to visualize controlled cavitation under high-rate stress wave loading, whose pressure profile mimics that of a blast shock wave, i.e., it contains a high pressure component followed by a negative pressure component. Highly sensitive pressure sensor measures the pressure inside the fluid filled chamber where a single air bubble is introduced at a specified location. Upon arrival of the pressure wave the bubble grows rapidly and collapses. Negative pressure magnitude, which dictates bubble growth rate and its final size, can be controlled. A high speed digital camera with frame rates up to 300,000 per second was employed to capture the tissue deformation characteristics. Digital Image Correlation (DIC) technique was employed on the gel tissue to capture the time varying strain field during the bubble growth, collapse, and subsequent generation of local shock wave. The relationships between the incident pressure, cavitation bubble dynamics, and induced deformation within a tissue surrogate during shock loading are investigated. In the next step, live brain tissue slices extracted from rats were tested with specified areas (e.g. Hippocampus) exposed to single bubble cavitation. Postmortem histological studies have been performed to quantify neuronal and astrocyte damage as a function of shock pressure. Our experiments have shown that the shock-induced cavitation bubble growth and collapse can be captured using this experimental facility and the results indicate that sensitive tissue damage indeed occurs due to the shock wave generated by cavitation bubble collapse.

Professor Subhash obtained his MS and PhD degrees from University of California San Diego and conducted post-doctoral research at California Institute of Technology, Pasadena, CA. He joined the faculty of Michigan Technological University (MTU) in 1993 and then moved to University of Florida (UF) in 2006. He has received numerous awards for excellence in teaching, research and professional service, including the ‘Significant Contribution Award’ American Nuclear Society – Materials Science and Technology Division (2014), Fellow of Society of Experimental Mechanics (2014) ‘Technology Innovator Award’ University of Florida (2014), UF Research Foundation Professor (2013), College of Engineering Teacher/Scholar of the year (2013), ‘2011 Researcher of the Year’ Mechanical and Aerospace Engineering Department, Second Place of the Best paper Awards at the 31st Annual American Ceramic Society meeting (2008), Michigan Tech Distinguished Research Award (2005), ASME Fellow (2004), ASME Student Section Advisor Award (2003), Society of Automotive Engineers (SAE) Ralph R. Teetor Educational Award (2000), American Society of Engineering Education (ASEE) Outstanding New Mechanics Educator Award(1996), and Distinguished Teaching Award at MTU (1994). He is an Associate Editor of Mechanics of Materials, Journal of the American Ceramic Society, Experimental Mechanics and ASME Journal of Engineering Materials and Technology. He has graduated 21 PhD students and is currently advising 12 PhD students in various fields related to processing, microstructural characterization and multiaxial behavior of advanced materials including ceramics, metals, composites, gels and brain tissue. He has authored around 150 peer reviewed journal papers and 70 conference proceedings. He has filed for 8 patent applications in various fields of material processing, mechanical testing, food packaging, and protective helmet design. His recent invention on fluid filled energy absorbing cushions for protective equipment has received widespread attention from major TV networks (Fox , CBS and 40 other local TV channels), and radio stations (including NPR) and articles by Reuters, ASEE morning bell and many local newspapers. He has given numerous invited lectures and seminars at many universities and international conferences.

ME-EM Graduate Seminar: Local Aggregation Characteristics and Visualization of Intermediate Layers during Evaporation of Nanofluid Droplets

oct23The 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.

ME-EM Graduate Seminar: Automotive Powertrain Control: Opportunities and Challenges

oct16The 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.

ME-EM Graduate Seminar: Space Tethers, Small Satellites, and System Engineering

oct9The 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.

ME-EM Graduate Seminar: Human-Centered Monitoring: From Enabling Technology, Human Factor to Computational Diagnosis

oct2The 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.

ME-EM Graduate Seminar: Advances in Decoupling

sep25The ME-EM Graduate Seminar speaker on Thursday, September 25 at 4:00 in 103 EERC will be Dr. Daniel
Kawano from Rose-Hulman Institute of Technology – Mechanical Engineering – Engineering Mechanics Department.

The title of his presentation will be ‘Advances in Decoupling’.

Under certain restrictions on system damping, the equations of motion for a linear vibratory system may be decoupled into independent equations that reveal characteristic vibrational behavior. This seminar presents recent advances in the theory of decoupling that allow a vibratory system with general viscous damping characteristics to be exactly decoupled by a real, time-varying, eigenvalue-preserving transformation that generalizes modal analysis. The underlying physics of this decoupling transformation is explained, and the decoupling methodologies for various vibratory systems are discussed.

Daniel Kawano is an Assistant Professor of Mechanical Engineering at Rose-Hulman Institute of Technology in Terre Haute, Indiana. He received his B.S. degree in Mechanical Engineering from California Polytechnic State University (Cal Poly) in San Luis Obispo. Daniel obtained his M.S. and Ph.D. degrees in Mechanical Engineering, with a focus in dynamical systems, from the University of California at Berkeley. His research and academic interests include modeling, analysis, simulation, and testing of dynamical systems; experimental modal analysis; numerical solution of differential and differential-algebraic equations; and pedagogy in engineering education. Daniel’s current research and activities involve exact decoupling of damped, linear vibratory systems,
and the use of online videos, web-based interactive demonstrations, and online
learning platforms to enhance student learning in dynamics. He is also the faculty advisor for Rose-Hulman’s Formula SAE competition team, Rose Grand Prix Engineering.

 

 

ME-EM Graduate Seminar: Applications of Electron Microscopy to Materials for Energy

sep18The 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.

ME-EM Graduate Seminar: In situ Nanoscale Testing to Validate and Elucidate Mechanism for Predictive Modeling

sep11The 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.

ME-EM Graduate Seminar: From carbon nanotubes to crowd noise: An overview of interesting topics in acoustics

barnardThe ME-EM Graduate Seminar speaker on Thursday, September 4 at 4:00 in 103 EERC will be Dr. Andrew Barnard, Mechanical Engineering – Engineering Mechanics, Michigan Technological University.

The title of his presentation will be ‘From carbon nanotubes to crowd noise: An overview of interesting topics in acoustics’.

Carbon nanotube (CNT) thin-films are ultra-lightweight, semi-transparent, flexible, and stretchable, films that can create sound through thermoacoustics. CNT thermophones have the potential to replace moving coil transducers and expand the applications of modern loudspeakers through “singing” fabrics. The fundamentals of CNT thermophone operation and key research challenges will be presented.
Underwater acoustics encompasses many disciplines and applications from Navy ships to oil exploration to climate change. Michigan Tech is located in an ideal location, on the shores of Lake Superior, to perform experimental underwater acoustics research through the Great Lakes Research Center (GLRC). Several topics in underwater acoustics will be discussed.
Transducer arrays and wavenumber domain signal processing provide a powerful way to visualize acoustic fields. An overview of techniques including supersonic intensity in reverberant environments (SIRE), and wavenumber processing of panel-to-panel transmission loss will be discussed. Current panel transmission loss (TL) measurement standards are woefully inadequate. Several test facilities can test the same specimen and the results can vary by more than 6 dB. Although panel TL theory is well developed, understanding of the fundamental measurement error is not. Insight into the field diffusivity in the source room will be discussed as well as paths towards an improved measurement standard. Smart controls systems are leading the way towards the realization of cyber-physical systems. An overview of the utility of FPGA-based control systems will be presented. These systems are particularly well suited for safety-critical control applications. Crowd noise is a much discussed topic in the mainstream media. Unfortunately most of the ad-hoc measurements that have been promoted are lacking in scientific rigor. Sound level measurements from Penn State football games will be presented to demonstrate how we can better measure this interesting phenomenon.

Dr. Andrew Barnard is a new assistant professor in the ME-EM department at Michigan Tech. He holds a B.S. and M.S. in mechanical engineering from MTU and a Ph.D. in Acoustics from Penn State. Dr. Barnard is Board Certified by the Institute for Noise Control Engineering and is a Certified LabVIEW Developer.
He spent the last 8 years working as a research faculty member at the Applied Research Laboratory at Penn State, specializing in structural acoustics. Dr. Barnard has general interests in mechanical vibration, noise control, and acoustics.
His specialties include dynamic test and measurement, underwater acoustic intensity, experimental modal analysis, room acoustics, acoustic material characterization, outdoor sound propagation, theoretical acoustics, signal processing, and real-time control systems. Other interests include loudspeaker design and fabrication, architectural acoustics, and engineering education.

ME-EM Graduate Seminar

The ME-EM Graduate Seminar speaker on Thursday, April 24 at 4:00 in 103 EERC will be Dr. Antonio Gauchia from MTU.

The title of his presentation will be ‘Finite Element Modeling of a Real Bus Structure: Effect of Electrified Powertrain’.

Environmental sustainability is driving powertrain design and development towards electrified vehicles. Bus powertrain has evolved from conventional internal combustion engine to hybrid powertrain. However, in terms of lateral vehicle dynamics, this type of vehicle is particularly sensitive to the height of the center of gravity. One of the most severe accidents that involve buses is rollover. Buses are especially prone to rollover due to their high ratio between centre of gravity height and wheel track. Therefore, bus safety must be re-assessed to verify that it still complies with current vehicle standards and regulations, in particular, those related to vehicle lateral dynamics. Bus manufacturers have to overcome these challenges to match standards and provide a reliable, safe and comfortable vehicle. This seminar will present the impact of powertrain design in bus rollover. It will deeply describe how to evaluate this effect from the initial finite element modeling stage of a real bus structure to the final one consisting in the evaluation of powertrain design influence in bus rollover. Two scenarios will be analyzed: a bus structure with conventional internal combustion engine components and a bus structure with hybrid powertrain components. The rollover threshold will be used to evaluate the lateral performance of each powertrain layout.

Dr. Antonio Gauchia finished his studies of General Engineering Degree in 2003 and obtained a PhD in Mechanical Engineering in 2006 at the University Carlos III of Madrid (UC3M). He teaches Vehicle Dynamics and Components, Transportation Engineering and Technical Drawing. During his 10 year experience at UC3M Mechanical Engineering Department, he has also collaborated in projects with industry and administration. His
research interests are vehicle experimental testing, vehicle dynamic simulation and bus safety rollover. He has been a Visiting Researcher at the University of Birmingham (U.K.) in collaboration with Ford. He is currently a Visiting Researcher at the ME-EM Department at Michigan Tech.