Open Access. Powered by Scholars. Published by Universities.®

Mechanical Engineering Commons

Open Access. Powered by Scholars. Published by Universities.®

Selected Works

2017

Discipline
Keyword
Publication
File Type

Articles 1 - 30 of 92

Full-Text Articles in Mechanical Engineering

Automatic Compact Disc Transfer For Quality Assurance Testing, Ravi P. Ramachandran, John Chen, Linda M. Head, John L. Schmalzel, Hampton C. Gabler Dec 2017

Automatic Compact Disc Transfer For Quality Assurance Testing, Ravi P. Ramachandran, John Chen, Linda M. Head, John L. Schmalzel, Hampton C. Gabler

John L. Schmalzel

The purpose of this project was to design, build and test a low cost prototype that transfers compact discs (CDs) from a spindle to a computer based testing station. This will speed up the CD production/testing interface and eliminate the need for manual operation. Along with a heavy product design technical component, the project included a real life educational experience for the four students who got credit for a one year advanced senior project. Various designs were considered and the optimal design (based on cost and performance) was prototyped.


A Virtual Reality Environment For Multi-Sensor Data Integration, Scott Papson, Joseph Oagaro, Robi Polikar, John Chen, John L. Schmalzel, Shreekanth Mandayam Dec 2017

A Virtual Reality Environment For Multi-Sensor Data Integration, Scott Papson, Joseph Oagaro, Robi Polikar, John Chen, John L. Schmalzel, Shreekanth Mandayam

John L. Schmalzel

Virtual reality (VR) has typically found applications in industrial design, rapid prototyping and advanced scientific visualization. In this paper, we investigate the use of VR for multi-sensor data integration. We attempt to demonstrate that multiple data types-graphical, functional and measurement can be effectively combined inside of a VR environment. This platform allows the user to rapidly sift through large and complex data sets and isolate features of interest. Furthermore, VR environments can be made to evolve based on system data and user input-this provides the ability to develop scenarios that can be used to make informed decisions. Results demonstrating the ...


A Venture Capital Fund For Undergraduate Engineering Students At Rowan University, Anthony J. Marchese, John C. Chen, John L. Schmalzel Dec 2017

A Venture Capital Fund For Undergraduate Engineering Students At Rowan University, Anthony J. Marchese, John C. Chen, John L. Schmalzel

John L. Schmalzel

All engineering students at Rowan University are required to take the 8-semester Engineering Clinic sequence wherein multidisciplinary student teams engage in semester-long design projects. In addition to projects that are funded by local industry, faculty research grants or departmental budgets, a Venture Capital Fund has been created, which is specifically ear-marked for the development of original student inventions. Funding of up to $2500 per student team per semester is competitively awarded based on student-generated proposals to the Venture Capital Fund, which has been created through a series of grants from the National Collegiate Inventors and Innovators Alliance (NCIIA). To qualify ...


Automatic Compact Disc Transfer For Quality Assurance Testing, Ravi P. Ramachandran, John Chen, Linda M. Head, John L. Schmalzel, Hampton C. Gabler Dec 2017

Automatic Compact Disc Transfer For Quality Assurance Testing, Ravi P. Ramachandran, John Chen, Linda M. Head, John L. Schmalzel, Hampton C. Gabler

Ravi Ramachandran

The purpose of this project was to design, build and test a low cost prototype that transfers compact discs (CDs) from a spindle to a computer based testing station. This will speed up the CD production/testing interface and eliminate the need for manual operation. Along with a heavy product design technical component, the project included a real life educational experience for the four students who got credit for a one year advanced senior project. Various designs were considered and the optimal design (based on cost and performance) was prototyped.


Multidisciplinary Game-Based Approach For Generating Student Enthusiasm For Addressing Critical Infrastructure Challenges, John F. Gardner Nov 2017

Multidisciplinary Game-Based Approach For Generating Student Enthusiasm For Addressing Critical Infrastructure Challenges, John F. Gardner

John Gardner

Building upon experiences from past course offering,1 several universities across the United States (U.S) have incorporated a critical infrastructure educational game platform as a unifying platform to integrate different disciplines to a common goal. The critical infrastructure backbones of the world provide the delivery mechanisms for energy and other utilities that provide the lifestyle we have come to expect in our society. As these critical infrastructure systems have evolved, the complexity of their integration has generated numerous challenges as a side effect of increased automation that are more pronounced as the infrastructure ages. Although still a modern technological ...


Prediction Of Solid Oxide Fuel Cell Performance Using Artificial Neural Network, M. A. Rafe Biswas, Kamwana N. Mwara Oct 2017

Prediction Of Solid Oxide Fuel Cell Performance Using Artificial Neural Network, M. A. Rafe Biswas, Kamwana N. Mwara

M. A. Rafe Biswas

NASA’s Johnson Space Center has recently begun efforts to eventually integrate air-independent Solid Oxide Fuel Cell (SOFC) systems, with landers that can be propelled by LOX-CH4, for long duration missions. Using landers that utilize such propellants, provides the opportunity to use SOFCs as a power option, especially since they are able to process methane into a reactant through fuel reformation. Various lead-up activities, such as hardware testing and computational modelling, have been initiated to assist with this developmental effort.
One modeling approach, currently being explored to predict SOFC behavior, involves the usage of artificial neural networks (ANN). Since SOFC ...


Uncertainty Quantification Integrated To Cfd Modeling Of Synthetic Jet Actuators, Srikanth Adya, Daoru Frank Han, Serhat Hosder Oct 2017

Uncertainty Quantification Integrated To Cfd Modeling Of Synthetic Jet Actuators, Srikanth Adya, Daoru Frank Han, Serhat Hosder

Daoru Frank Han

The Point-Collocation Non-intrusive Polynomial Chaos (NIPC) method has been applied to a stochastic synthetic jet actuator problem used as one of the test cases in the CFDVAL2004 workshop to demonstrate the integration of computationally efficient uncertainty quantification to the high-fidelity CFD modeling of synthetic jet actuators. The test case included the simulation of an actuator generating a synthetic jet issued into quiescent air. The Point-Collocation NIPC method is used to quantify the uncertainty in the long-time averaged u and v-velocities at several locations in the flow field due to the uniformly distributed uncertainty introduced in the amplitude and frequency of ...


The Girl Scout Climbing Wall Multidisciplinary Service-Learning Project, Margaret Pinnell, Corinne M. Daprano, Gabrielle Williamson Oct 2017

The Girl Scout Climbing Wall Multidisciplinary Service-Learning Project, Margaret Pinnell, Corinne M. Daprano, Gabrielle Williamson

Corinne M. Daprano

The Girl Scout Wall (GS Wall) project was implemented in two classes at the University of Dayton (UD): a Mechanical and Aerospace Engineering (MAE) course, and a Health and Sports Science (HSS) course, and Sport Facility Management. The MAE course, Introduction to Materials, is a three-credit, third-year required course where students learn about the basic structure and properties of materials as well as the principles of material selection. The Sport Facility Management course is a three-semester hour, required HSS course where students are introduced to the processes of planning, constructing, equipping, maintaining, and managing sport facilities.


Cfd Simulation Of Passenger Hazard Risk At Railway Station Platforms Due To Explosive Air Blasts, Vivian Lawrence, Sakdirat Kaewunruen, Gianni Bartoli, Charalampos Baniotopoulos Aug 2017

Cfd Simulation Of Passenger Hazard Risk At Railway Station Platforms Due To Explosive Air Blasts, Vivian Lawrence, Sakdirat Kaewunruen, Gianni Bartoli, Charalampos Baniotopoulos

Sakdirat Kaewunruen

Safety is the first priority in operating transportation and transit systems. The public and customers rely on operators to assure them the reliable and safe day-to-day uses of public transports. However, based on recent factual evidences, extreme physical and cyber threats are no longer uncommon and these unpreventable measures are even more dangerous to the public’s daily lives. Such clear examples are the terrorist attacks in Saint Petersburg in 2017, in London in 2017, in Stockholm in 2017, in Brussels in 2016, in Nice in 2016, and so many more. These examples have one thing in common. The transportation ...


Application Of Pca To Cardiac Optical Mapping, Louis Woodhams Aug 2017

Application Of Pca To Cardiac Optical Mapping, Louis Woodhams

Louis Woodhams

Structural remodeling of the heart due to pathologies such as hypertension and myocardial infarction leads to the appearance of myofibroblasts, a phenotype largely absent in physiologic myocardium. While myofibroblasts are responsible for wound healing and structural repair of damaged myocardium, they are thought to have deleterious effects on electrical and mechanical properties of the heart. Understanding these effects is critical to developing effective treatments, and has motivated the development of a series of in vitro engineered heart tissues and cardiomyocyte-myofibroblast co-cultures whose mechanical and electrophysiological function can be deduced from video analysis. Electrophysiological properties are evident from changes in intensity ...


Induction Heating Of Thin Films, Paul L. Bergstrom, Melissa L. Trombley Aug 2017

Induction Heating Of Thin Films, Paul L. Bergstrom, Melissa L. Trombley

Paul Bergstrom

A method of performing regional heating of a system having a substrate. The method may include applying a thin film to the system, and controllably energizing a coil positioned near the thin film. The energized coils thereby generate a magnetic flux. The method further includes inducing a current in the thin film with the magnetic flux thereby heating the system.


Fully-Packaged Carbon Nanotube Supercapacitors By Direct Ink Writing On Flexible Substrates, Bolin Chen, Yizhou Jiang, Xiaohui Tang, Yayue Pan, Shan Hu Aug 2017

Fully-Packaged Carbon Nanotube Supercapacitors By Direct Ink Writing On Flexible Substrates, Bolin Chen, Yizhou Jiang, Xiaohui Tang, Yayue Pan, Shan Hu

Shan Hu

The ability to print fully packaged integrated energy storage components (e.g., supercapacitors) is of critical importance for practical applications of printed electronics. Due to the limited variety of printable materials, most studies on printed supercapacitors focus on printing the electrode materials but rarely the full-packaged cell. This work presents for the first time the printing of a fully packaged single-wall carbon nanotube-based supercapacitor with direct ink writing (DIW) technology. Enabled by the developed ink formula, DIW setup, and cell architecture, the whole printing process is mask free, transfer free, and alignment free with precise and repeatable control on the ...


Presentation Of Double Inlet Scpp, Nima Fathi, Seyed Sobhan Aleyasin, Patrick Wayne, Peter Vorobieff Jul 2017

Presentation Of Double Inlet Scpp, Nima Fathi, Seyed Sobhan Aleyasin, Patrick Wayne, Peter Vorobieff

Nima Fathi

No abstract provided.


The Effect Of Microencapsulated Phase-Change Material On The Compressive Strength Of Structural Concrete, Chad Norvell, David J. Sailor, Peter Dusicka Jul 2017

The Effect Of Microencapsulated Phase-Change Material On The Compressive Strength Of Structural Concrete, Chad Norvell, David J. Sailor, Peter Dusicka

Peter Dusicka

Latent heat energy storage through phase-change materials (PCMs) is one possible strategy to control interior temperatures in buildings, improve thermal comfort, and passively reduce building energy use associated with heating and cooling. While PCMs integrated into building structure elements have been studied since the 1970s, challenges of integrating PCMs into building materials while maintaining their heat storage benefits have limited their application in practice. The recent introduction of microencapsulated phase-change materials provides the energy storage capability of PCMs in micron-scale, chemically-inert capsules that can be easily integrated into composite materials such as gypsum wallboard and concrete. The size and physical ...


Organizing A Student Poster Session In An Asee Section Conference, Steve Eugene Watkins, Les Kinsler, Julia L. Morse, Douglas R. Carroll Jul 2017

Organizing A Student Poster Session In An Asee Section Conference, Steve Eugene Watkins, Les Kinsler, Julia L. Morse, Douglas R. Carroll

Steve Eugene Watkins

Student poster sessions at conferences can be valuable experiences for undergraduate and graduate students and can enrich the conference program for all participants. Student poster presentations beyond the local campus can provide additional experience in professional communication (especially in preparing succinct abstracts and in effective visual design), can prepare students for future conference participations, and can facilitate student-faculty interaction. Several issues exist when including student poster sessions in engineering education conferences. How can the content of posters be related to an engineering education theme? How are communication principles of audience and purpose incorporated into the session guidelines and review process ...


Interdisciplinary Graduate Experience: Lessons Learned, Steve Eugene Watkins, V. M. Eller, Josh Corra, M. J. Molander, Bethany Konz, Richard H. Hall, K. Chandrashekhara, Abdeldjelil Belarbi Jul 2017

Interdisciplinary Graduate Experience: Lessons Learned, Steve Eugene Watkins, V. M. Eller, Josh Corra, M. J. Molander, Bethany Konz, Richard H. Hall, K. Chandrashekhara, Abdeldjelil Belarbi

Steve Eugene Watkins

Engineers interact in the workplace with technical peers in other disciplines at all stages of design, development, and application. Awareness of the constraints and needs of the other disciplines can be key in many situations. Such interdisciplinary activity and the associated communication are facilitated if the all participants have a solid knowledge of discipline-specific terminology and an understanding of connecting concepts. Consequently, experience relating to interdisciplinary teamwork is a necessary component of engineering education. The Smart Engineering Group at the University of Missouri-Rolla was established to conduct interdisciplinary research and to create interdisciplinary educational resources. The topical interest area is ...


Intelligent Strain Sensing On A Smart Composite Wing Using Extrinsic Fabry-Perot Interferometric Sensors And Neural Networks, Kakkattukuzhy M. Isaac, Donald C. Wunsch, Steve Eugene Watkins, Rohit Dua, V. M. Eller Jul 2017

Intelligent Strain Sensing On A Smart Composite Wing Using Extrinsic Fabry-Perot Interferometric Sensors And Neural Networks, Kakkattukuzhy M. Isaac, Donald C. Wunsch, Steve Eugene Watkins, Rohit Dua, V. M. Eller

Steve Eugene Watkins

Strain prediction at various locations on a smart composite wing can provide useful information on its aerodynamic condition. The smart wing consisted of a glass/epoxy composite beam with three extrinsic Fabry-Perot interferometric (EFPI) sensors mounted at three different locations near the wing root. Strain acting on the three sensors at different air speeds and angles-of-attack were experimentally obtained in a closed circuit wind tunnel under normal conditions of operation. A function mapping the angle of attack and air speed to the strains on the three sensors was simulated using feedforward neural networks trained using a backpropagation training algorithm. This ...


Detection And Classification Of Impact-Induced Damage In Composite Plates Using Neural Networks, Rohit Dua, Steve Eugene Watkins, Donald C. Wunsch, K. Chandrashekhara, Farhad Akhavan Jul 2017

Detection And Classification Of Impact-Induced Damage In Composite Plates Using Neural Networks, Rohit Dua, Steve Eugene Watkins, Donald C. Wunsch, K. Chandrashekhara, Farhad Akhavan

Steve Eugene Watkins

Artificial neutral networks (ANN) can be used as an online health monitoring systems (involving damage assessment, fatigue monitoring and delamination detection) for composite structures owing to their inherent fast computing speeds, parallel processing and ability to learn and adapt to the experimental data. The amount of impact-induced strain on a composite structure can be found using strain sensors attached to composite structures. Prior work has shown that strain-based ANN can characterize impact energy on composite plates and that strain signatures can be associated with damage types and severity. This paper reports the extension of this approach for damage classification using ...


Design And Technologies For A Smart Composite Bridge, K. Chandrashekhara, Prakash Kumar, Steve Eugene Watkins, Antonio Nanni Jul 2017

Design And Technologies For A Smart Composite Bridge, K. Chandrashekhara, Prakash Kumar, Steve Eugene Watkins, Antonio Nanni

Steve Eugene Watkins

An all-composite, smart bridge design for shortspan applications is described. The bridge dimensions are 9.14-m (30-ft.) long and 2.74-m (9-ft.) wide. A modular construction based on assemblies of pultruded fiber-reinforced-polymer (FRP) composite tubes is used to meet American Association of State Highway and Transportation Officials (AASHTO) H20 highway load ratings. The hollow tubes are 76 mm (3 in.) square and are made of carbon/vinyl-ester and glass/vinyl-ester. An extensive experimental study was carried out to obtain and compare properties (stiffness, strength, and failure modes) for a quarter portion of the full-sized bridge. The bridge response was measured ...


Impact Of Window Replacement On Yanke Building Energy Consumption, Sukjoon Oh, John F. Gardner Jul 2017

Impact Of Window Replacement On Yanke Building Energy Consumption, Sukjoon Oh, John F. Gardner

John Gardner

From May to November of 2015, the majority of the windows in the Yanke Family Research Park (i.e. the Yanke Building) were removed and replaced with modern high-quality windows because many of the exiting windows had failed and fogged. While such a retrofit should result in significant energy savings, there remains a possibility that improper integration of the new window systems to the building structure may degrade performance by inadvertently providing paths for infiltration of outside air or by providing “bridges” of relatively high thermal conduction between the conditioned space and the environment. In an effort to assess the ...


Us Patent 9,702,573: Nested Heat Transfer System, Sanza Kazadi Jul 2017

Us Patent 9,702,573: Nested Heat Transfer System, Sanza Kazadi

Sanza Kazadi

A novel nested heat transfer system comprises a plurality of chained enhanced entrochemical cells with nested structures. Each enhanced entrochemical cell includes a first chamber containing desiccant, or a higher concentration solution, and a second chamber containing refrigerant,   or   a   lower   concentration   solution.   Preferably,   the   first   chamber   and   the   second   chamber   are   connected   by   a   conduit.  Furthermore,   a   smaller   chamber   in   an   enhanced   entrochemical   cell   is   encapsulated   by   a   larger   chamber   in   an   adjacent   enhanced entrochemical cell, thus forming a nested structure between the two enhanced entrochemical cells. A chain of enhanced entrochemical cells with a plurality of such nested ...


Us Patent 9,702,633: Entrochemical Energy Transfer System And A Process For Obtaining Work From Environmental Thermal Energy, Sanza Kazadi Jul 2017

Us Patent 9,702,633: Entrochemical Energy Transfer System And A Process For Obtaining Work From Environmental Thermal Energy, Sanza Kazadi

Sanza Kazadi

An entrochemical energy transfer system and a related process for obtaining work from environmental thermal energy are disclosed. In one   example,   a   plurality   of   linked   entrochemical   cells   with   nested   chambers   provides   an   aggregate   thermal   gradient   of   each entrochemical   cell   by   transferring   environmental   thermal   energy   in   and/or   out   of   the   plurality   of   linked   entrochemical   cells.   The aggregate thermal gradient generated from the plurality of linked entrochemical cells can be utilized as an environmentally­ friendly energy source for human needs. The entrochemical energy transfer system and the related process for obtaining work from environmental thermal energy utilize a set of entropy ...


The Influence Of Push-Off Timing In A Robotic Ankle-Foot Prosthesis On The Energetics And Mechanics Of Walking., Philippe Malcolm, Roberto E. Quesada, Joshua M. Caputo, Steven H. Collins Jun 2017

The Influence Of Push-Off Timing In A Robotic Ankle-Foot Prosthesis On The Energetics And Mechanics Of Walking., Philippe Malcolm, Roberto E. Quesada, Joshua M. Caputo, Steven H. Collins

Philippe Malcolm

BACKGROUND: Robotic ankle-foot prostheses that provide net positive push-off work can reduce the metabolic rate of walking for individuals with amputation, but benefits might be sensitive to push-off timing. Simple walking models suggest that preemptive push-off reduces center-of-mass work, possibly reducing metabolic rate. Studies with bilateral exoskeletons have found that push-off beginning before leading leg contact minimizes metabolic rate, but timing was not varied independently from push-off work, and the effects of push-off timing on biomechanics were not measured. Most lower-limb amputations are unilateral, which could also affect optimal timing. The goal of this study was to vary the timing ...


An End-To-End Convolutional Selective Autoencoder Approach To Soybean Cyst Nematode Eggs Detection, Adedotun Akintayo, Nigel Lee, Vikas Chawla, Mark P. Mullaney, Christopher C. Marett, Asheesh K. Singh, Arti Singh, Gregory L. Tylka, Baskar Ganapathysubramanian, Soumik Sarkar Jun 2017

An End-To-End Convolutional Selective Autoencoder Approach To Soybean Cyst Nematode Eggs Detection, Adedotun Akintayo, Nigel Lee, Vikas Chawla, Mark P. Mullaney, Christopher C. Marett, Asheesh K. Singh, Arti Singh, Gregory L. Tylka, Baskar Ganapathysubramanian, Soumik Sarkar

Baskar Ganapathysubramanian

Soybean cyst nematodes (SCNs), Heterodera glycines, are unwanted micro-organisms that reduce yields of a major source of food–soybeans. In the United States alone, approximately $1 billion is lost per annum due to cyst nematode infections on soybean plants. Experts have conceived methods of mitigating the losses through phenotyping techniques via SCN eggs density estimation, and then applying the right control measures. Currently, they rely on labor intensive and time-consuming identification of SCN eggs in soil samples processed onto microscopic frames. However, phenotyping a vast array of fields requires automated high-throughput techniques. From an automation perspective, detection of rarely occurring ...


A Vision For Health Informatics: Introducing The Sked Framework, Elizabeth D. Trippe, Jacob B. Aguilar, Yi H. Yan, Mustafa V. Nural, Jessica A. Brady, Mehdi Assefi, Saeid Safaei, Mehdi Allahyari, Seyedamin Pouriyeh, Mary R. Galinski, Jessica C. Kissinger, Juan B. Gutierrez Jun 2017

A Vision For Health Informatics: Introducing The Sked Framework, Elizabeth D. Trippe, Jacob B. Aguilar, Yi H. Yan, Mustafa V. Nural, Jessica A. Brady, Mehdi Assefi, Saeid Safaei, Mehdi Allahyari, Seyedamin Pouriyeh, Mary R. Galinski, Jessica C. Kissinger, Juan B. Gutierrez

Mehdi Allahyari

The goals of the Triple Aim of health care and the goals of P4 medicine outline objectives that require a significant health informatics component. However, the goals do not provide specifications about how all of the new individual patient data will be combined in meaningful ways and with data from other sources, like epidemiological data, to promote the health of individuals and society. We seem to have more data than ever before but few resources and means to use it efficiently. We need a general, extensible solution that integrates and homogenizes data of disparate origin, incompatible formats, and multiple spatial ...


A Wrf Ensemble For Improved Wind Speed Forecasts At Turbine Height, Adam J. Deppe, William A. Gallus Jr., Eugene S. Takle Jun 2017

A Wrf Ensemble For Improved Wind Speed Forecasts At Turbine Height, Adam J. Deppe, William A. Gallus Jr., Eugene S. Takle

William A. Gallus Jr.

The Weather Research and Forecasting Model (WRF) with 10-km horizontal grid spacing was used to explore improvements in wind speed forecasts at a typical wind turbine hub height (80 m). An ensemble consisting of WRF model simulations with different planetary boundary layer (PBL) schemes showed little spread among the individual ensemble members for forecasting wind speed. A second configuration using three random perturbations of the Global Forecast System model produced more spread in the wind speed forecasts, but the ensemble mean possessed a higher mean absolute error (MAE). A third ensemble of different initialization times showed larger model spread, but ...


Game-Day Football Visualization Experience On Dissimilar Virtual Reality Platforms, Vijay Kalivarapu, Anastacia Maria Macallister, Melynda Tess Hoover, Shubang Sridhar, Jonathan Andrew Schlueter, Anthony Civitate, Phillip Thompkins, Jesse Smith, Janae Hoyle, James H. Oliver, Eliot H. Winer, Gerrit Chernoff Jun 2017

Game-Day Football Visualization Experience On Dissimilar Virtual Reality Platforms, Vijay Kalivarapu, Anastacia Maria Macallister, Melynda Tess Hoover, Shubang Sridhar, Jonathan Andrew Schlueter, Anthony Civitate, Phillip Thompkins, Jesse Smith, Janae Hoyle, James H. Oliver, Eliot H. Winer, Gerrit Chernoff

Vijay K. Kalivarapu

College football recruiting is a competitive process. Athletic administrations attempt to gain an edge by bringing recruits to a home game, highlighting the atmosphere unique to campus. This is however not always possible since most recruiting efforts happen off-season. So, they relate the football game experience through video recordings and visits to football facilities. While these substitutes provide a general idea of a game, they cannot capture the feeling of playing while cheered on by a crowd of 55,000 people. To address this challenge and improve the recruitment process, the Iowa State University (ISU) athletic department and the Virtual ...


Influence Of Aluminum Passivation On The Reaction Mechanism: Flame Propagation Studies, Birce Dikici, Steven W. Dean, Michelle L. Pantoya, Valery I. Levitas, R. Jason Jouet Jun 2017

Influence Of Aluminum Passivation On The Reaction Mechanism: Flame Propagation Studies, Birce Dikici, Steven W. Dean, Michelle L. Pantoya, Valery I. Levitas, R. Jason Jouet

Valery I. Levitas

Currently, two main known mechanisms of aluminum (Al) nanoparticle reaction are discussed in the literature, namely those based on diffusion through an oxide shell and melt-dispersion. The two mechanisms lead to opposite predictions in nanoparticle design. The diffusion mechanism suggests that the reduction or complete elimination of the oxide shell will increase Al reactivity, whereas the meltdispersion mechanism suggests an increase in initial oxide thickness up to an optimal value. The goal of this study is to perform critical experiments in a confined flame tube apparatus to compare these two predictions. Specifically, the flame propagation rates of perfluoroalkyl carboxylic acid ...


Coupled Phase Transformations And Plastic Flows Under Torsion At High Pressure In Rotational Diamond Anvil Cell: Effect Of Contact Sliding, Biao Feng, Valery I. Levitas Jun 2017

Coupled Phase Transformations And Plastic Flows Under Torsion At High Pressure In Rotational Diamond Anvil Cell: Effect Of Contact Sliding, Biao Feng, Valery I. Levitas

Valery I. Levitas

A three-dimensional large-sliding contact model coupled with strain-induced phase transformations (PTs) and plastic flow in a disk-like sample under torsion at high pressure in rotational diamond anvil cell (RDAC) is formulated and studied. Coulomb and plastic friction are combined and take into account variable parameters due to PT. Results are obtained for weaker, equal-strength, and stronger high pressure phases, and for three values of the kinetic coefficient in a strain-controlled kinetic equation and friction coefficient. All drawbacks typical of problem with cohesion are overcome, including eliminating mesh-dependent shear band and artificial plastic zones. Contact sliding intensifies radial plastic flow, which ...


Contaminant Transport At Large Courant Numbers Using Markov Matrices, Anthony D. Fontanini, Umesh Vaidya, Alberto Passalacqua, Baskar Ganapathysubramanian Jun 2017

Contaminant Transport At Large Courant Numbers Using Markov Matrices, Anthony D. Fontanini, Umesh Vaidya, Alberto Passalacqua, Baskar Ganapathysubramanian

Umesh Vaidya

Volatile organic compounds, particulate matter, airborne infectious disease, and harmful chemical or biological agents are examples of gaseous and particulate contaminants affecting human health in indoor environments. Fast and accurate methods are needed for detection, predictive transport, and contaminant source identification. Markov matrices have shown promise for these applications. However, current (Lagrangian and flux based) Markov methods are limited to small time steps and steady-flow fields. We extend the application of Markov matrices by developing a methodology based on Eulerian approaches. This allows construction of Markov matrices with time steps corresponding to very large Courant numbers. We generalize this framework ...