Engineering Commons^™

Are Simulation Tools Developed And Used By Experts Appropriate Experimentation Tools For Educational Contexts?, Alejandra De Jesus Magana De Leon, George Bodner, Sean B. Brophy

School of Engineering Education Graduate Student Series

No abstract provided.

Rube Goldbergineering: Lessons In Teaching Engineering Design To Future Engineers, Shawn Jordan, Nielsen Pereira

School of Engineering Education Graduate Student Series

Hands-on learning experiences and interactive learning environments can be effective in teaching K-12 students. Design, in essence, is an interactive, hands-on experience. Engineering design can be taught in the classroom using innovative hands-on projects, such as designing and building serve to teach design, promote creativity, and provide opportunities for hands-on problem solving, in addition to giving students experience working in cooperative teams. In turn, these experiences could encourage students to consider future careers in engineering and science.

This paper explores findings from data collected during the authors’ recent experience teaching a group of fifteen 4th – 6th grade students enrolled …

Lean Six Sigma Principles In Capstone Aeronautical Engineering Technology Courses, Sergey Dubikovsky, Mary E. Johnson

School of Engineering Education Graduate Student Series

No abstract provided.

2009 Enacted Wheel Tax Rates (Lohut), Indiana Ltap

Indiana Local Technical Assistance Program (LTAP) Publications

This publication is a compilation of wheel tax rates using data provided by the Indiana Bureau of Motor Vehicles.

Modeling Of Subcontinuum Thermal Transport Across Semiconductor-Gas Interfaces, Dhruv Singh, Xiaohui Guo, Alina A. Alexeenko, Jayathi Y. Murthy, Timothy S. Fisher

School of Aeronautics and Astronautics Faculty Publications

A physically rigorous computational algorithm is developed and applied to calculate subcontinuum thermal transport in structures containing semiconductor-gas interfaces. The solution is based on a finite volume discretization of the Boltzmann equation for gas molecules (in the gas phase) and phonons (in the semiconductor). A partial equilibrium is assumed between gas molecules and phonons at the interface of the two media, and the degree of this equilibrium is determined by the accommodation coefficients of gas molecules and phonons on either side of the interface. Energy balance is imposed to obtain a value of the interface temperature. The classic problem of …

Numerical Investigation Of Power Transmission Efficiency In A Rf Plasma, Akshay Ashok, William Stein, Alina A. Alexeenko

School of Aeronautics and Astronautics Faculty Publications

Capacitively coupled radio frequency discharges are used in a variety of applications in which the power transmission efficiency of the discharge is an important performance parameter. While previous research addressed the discharge properties and discharge modeling, little analysis has been done on the dependence of the power transmission efficiency on main discharge paremeters such as applied voltage, operating frequency and pressure. To investigate the effects of a dual frequency waveform on the power transmission efficiency, Particle-InCell/Monte-Carlo Collison (PIC/MCC) methods are used to simulate RF co-axial plasma discharge. Plasma characteristics are studied for a range of operating pressures and radii, as …

Simulations And Measurements Of Gas-Droplet Flows In Supersonic Jets Expanding Into Vacuum, A Venkattraman, Alina A. Alexeenko

School of Aeronautics and Astronautics Faculty Publications

Simulations and measurements of gas-droplet multiphase flows in application to supersonic expansions into vacuum have been considered and compared with each other. The experiments involved exposing a control surface to a supersonic plume from two different nozzles and measuring the size distribution of droplets at various locations. The simulations are based on the direct simulation Monte Carlo modeling of vapor-phase flow with a one-way coupling of droplet momentum and energy. The droplet trajectories are computed for the experimental conditions for droplets originating at the throat and lip of two different nozzles. The maximum droplet radius reaching the control surface and …

Decision Making In First Year Engineering: Exploring How Students Decide About Future Studies And Career Pathways, Ida Ngambeki, Odesma Dalrymple, Demetra Evangelou Dr

School of Engineering Education Graduate Student Series

The number of students enrolling in engineering has declined steadily over the last fifteen years, and the number of engineers joining certain fields in engineering has decreased even more drastically. A number of studies have demonstrated a strong relationship between students’ interests and abilities and their persistence in engineering. It is therefore logical to assume that students who choose a major which makes the best use of their skills and engages their interest, are more likely to not only stay, but also thrive in the field of engineering which they choose. Students who make a poor choice, because of incomplete …

Unified Theory Of Gas Damping Of Flexible Microcantilevers At Low Ambient Pressures, Rahul A. Bidkar, Ryan C. Tung, Alina A. Alexeenko, Hartono Sumali, Arvind Raman

School of Aeronautics and Astronautics Faculty Publications

No abstract provided.

Modeling Of Viscous Shock Tube Using Es-Bgk Model Kinetic Equations, S Chigullapalli, A Venkattraman, Alina A. Alexeenko

School of Aeronautics and Astronautics Faculty Publications

The viscous effects on unsteady shock wave propagation are investigated by numerical solution of the Boltzmann model kinetic equations. The kinetic equations are solved for two unsteady non-equilibrium flow problems, namely, the one-dimensional Riemann problem and a two-dimensional viscous shock-tube. The numerical method comprises the discrete velocity method in the velocity space and the finite volume discretization in physical space using various flux schemes. The discrete version of H-theorem is applied for analysis of accuracy of the numerical solution as well as of the onset of non-equilibrium. Simulations show that the maximum entropy generation rate in viscous shock tube occurs …

Stabilizing Switched Linear Systems With Unstabilizable Subsystems, Wei Zhang, Jianghai Hu, Alessandro Abate

Department of Electrical and Computer Engineering Technical Reports

Abstract This paper studies the exponential stabilization problem for discrete-time switched linear systems based on a control-Lyapunov function approach. A number of versions of converse control-Lyapunov function theorems are proved and their connections to the switched LQR problem are derived. It is shown that the system is exponentially stabilizable if and only if there exists a finite integer N such that the N-horizon value function of the switched LQR problem is a control-Lyapunov function. An efficient algorithm is also proposed which is guaranteed to yield a control-Lyapunov function and a stabilizing strategy whenever the system is exponentially stabilizable.

Filterpave Systems, Purdue Ect Team

ECT Fact Sheets Archive

The need for hard-surfaced porous pavements has grown over the past few years as the market accepts PPS technology as a viable solution, as regulations leave few other options and as frequency of use increases. The FilterPave system is a unique porous pavement system that uses post-consumer recycled glass as the open-graded aggregate. Approximately 90 glass beverage bottles are used in just one square foot of pavement, making constructive use of abundant recycled materials that are traditionally sent to the landfill and used as daily cover.

Quantitative Prediction Of Body Surface Potentials From Myocardial Action Potentials Using A Summed Dipole Model, Charles F. Babbs

Weldon School of Biomedical Engineering Faculty Publications

This paper demonstrates quantitatively, using streamlined mathematics, how the transmembrane ionic currents in individual cardiac muscle cells act to produce the body surface potentials of the electrocardiogram (ECG). From fundamental principles of electrostatics, anatomy, and physiology, one can characterize the strength of apparent dipoles along a wavefront of depolarization in a local volume of myocardium. Net transmembrane flow of ionic current in actively depolarizing or repolarizing tissue induces extracellular current flow, which sets up a field of electrical potential that resembles that of a dipole. The local dipole strength depends upon the tissue cross section, the tissue resistivity, the resting …

The Effect Of Polydispersivity On The Thermal Conductivity Of Particulate Thermal Interface Materials, Sasanka Kanuparthi, Ganesh Subbarayan, Thomas Siegmund, Bahgat Sammakia

School of Mechanical Engineering Faculty Publications

A critical need in developing thermal interface materials (TIMs) is an understanding of the effect of particle/matrix conductivities, volume loading of the particles, the size distribution, and the random arrangement of the particles in the matrix on the homogenized thermal conductivity. Commonly, TIM systems contain random spatial distributions of particles of a polydisperse (usually bimodal) nature. A detailed analysis of the microstructural characteristics that influence the effective thermal conductivity of TIMs is the goal of this paper. Random microstructural arrangements consisting of lognormal size-distributions of alumina particles in silicone matrix were generated using a drop-fall-shake algorithm. The generated microstructures were …

Influence Of Dimensionality On Thermoelectric Device Performance, Raseong Kim, Supriyo Datta, Mark S. Lundstrom

Department of Electrical and Computer Engineering Faculty Publications

The role of dimensionality on the electronic performance of thermoelectric devices is clarified using the Landauer formalism, which shows that the thermoelectric coefficients are related to the transmission, T(E)T(E), and how the conducting channels, M(E)M(E), are distributed in energy. The Landauer formalism applies from the ballistic to diffusive limits and provides a clear way to compare performance in different dimensions. It also provides a physical interpretation of the “transport distribution,” a quantity that arises in the Boltzmann transport equation approach. Quantitative comparison of thermoelectric coefficients in one, two, and three dimensions shows that the channels are utilized more effectively in …

Remote Sensing Methods By Compressive Sensing, Atul Divekar, Okan Ersoy

Department of Electrical and Computer Engineering Technical Reports

Compressive Sensing is a recently developed technique that exploits the sparsity of naturally occurring signals and images to solve inverse problems when the number of samples is less than the size of the original signal. We apply this technique to solve underdetermined inverse problems that commonly occur in remote sensing, including superresolution, image fusion and deconvolution. We use l1-minimization to develop algorithms that perform as well as or better than conventional methods for these problems. Our algorithms use a library of samples from similar images or a model for the image to be reconstructed to express the image as a …

Neonatal Cpr: Room At The Top—A Mathematical Study Of Optimal Chest Compression Frequency Versus Body Size, Charles F. Babbs, Andrew Meyer, Vinay Nadkarni

Weldon School of Biomedical Engineering Faculty Publications

Objective: To explore in detail the expected magnitude of systemic perfusion pressure during standard CPR as a function of compression frequency for different sized people from neonate to adult. Method: A 7-compartment mathematical model of the human cardiopulmonary system—upgraded to include inertance of blood columns in the aorta and vena cavae—was exercised with parameters scaled to reflect changes in body weight from 1 to 70 kg. Results: Maximal systemic perfusion pressure occurs at chest compression rates near 60, 120, 180, and 250 per minute for subjects weighing 70, 10, 3, and 1 kg, respectively. Such maxima are predicted by analytical …

Simulations Of Aerodynamic Damping For Mems Resonators, Xiaohui Guo, Alina A. Alexeenko

School of Aeronautics and Astronautics Faculty Publications

Aerodynamic damping for MEMS resonators is studied based on the numerical solution of Boltzmann-ESBGK equation. A compact model is then developed based on numerical simulations for a wide range of Knudsen numbers. The damping predictions are compared with both Reynold equation based models and several sets of experimental data. It has been found that the structural damping is dominant at low pressures (high Knudsen numbers). For cases with small length-to-width ratios and large vibration amplitudes, the threedimensionality effects must be taken into account. Finally, an uncertainty quantification approach based on the probability transformation method has been applied to assess the …

A Continuum-Based Model For Analysis Of Laterally Loaded Piles In Layered Soils, D Basu, Rodrigo Salgado, Monica Prezzi

Lyles School of Civil Engineering Faculty Publications

An analysis is developed to calculate the response of laterally loaded piles in multilayered elastic media. The displacement fields in the analysis are taken to be the products of independent functions that vary in the vertical, radial and circumferential directions. The governing differential equations for the pile deflections in different soil layers are obtained using the principle of minimum potential energy. Solutions for pile deflection are obtained analytically, whereas those for soil displacements are obtained using the one-dimensional finite difference method. The input parameters needed for the analysis are the pile geometry, the soil profile, and the elastic constants of …

Numerical Simulation Of Gas-Phonon Coupling In Thermal Transpiration Flows, Xiaohui Guo, Dhruv Singh, Jayathi Murthy, Alina A. Alexeenko

School of Aeronautics and Astronautics Faculty Publications

Thermal transpiration is a rarefied gas flow driven by a wall temperature gradient and is a promising mechanism for gas pumping without moving parts, known as the Knudsen pump. Obtaining temperature measurements along capillary walls in a Knudsen pump is difficult due to extremely small length scales. Meanwhile, simplified analytical models are not applicable under the practical operating conditions of a thermal transpiration device, where the gas flow is in the transitional rarefied regime. Here, we present a coupled gas-phonon heat transfer and flow model to study a closed thermal transpiration system. Discretized Boltzmann equations are solved for molecular transport …

Synthesis Of Best Practices In Transportation Security, Volume Ii: Emergency Response, Rodrigo Vargas, Jon D. Fricker

JTRP Technical Reports

Part I of the research focused on developing a methodology to identify and evaluate the most critical and vulnerable INDOT assets. This method aims at obtaining an index that reflects the vulnerability and criticality of an asset on the basis of multiple performance criteria. This methodology was tested on the seven INDOT districts. Because not all the factors that influence the vulnerability do have same weight, the analytical hierarchical process is used to obtain the weights for the criteria. Countermeasures are suggested as a part of the research to reduce the vulnerability of a given asset based on its relevant …

Saw-Cutting Guidelines For Concrete Pavements: Examining The Requirements For Time And Depth Of Saw-Cutting, Kambiz Raoufi, Tony Their, W. Jason Weiss, Jan Olek, Tommy E. Nantung

JTRP Technical Reports

Joints are placed in Portland cement concrete pavements (PCCP) to control random cracking. These joints provide a weakened plane that enables a crack to form in a controlled manner, relieving residual stresses that develop when thermal, hygral, or hydration movements are resisted by sub grade and adjoining pavement. While the concept of creating a weakened plane through saw-cutting is straightforward, determining the time and depth of the saw-cut has proven to be complicated. The goal of this project was to reduce the risk for joint raveling and random cracking. Specifically, this project has focused on: developing a procedure for determining …

Nanoantenna Array-Induced Fluorescence Enhancement And Reduced Lifetimes, Reuben M. Bakker, V. P. Drachev, Zhengtong Liu, Hsiao-Kuan Yuan, Rasmus H. Pedersen, Alexandra Boltasseva, Jiji Chen, Joseph Irudayaraj, Alexander V. Kildishev, V. M. Shalaev

Birck and NCN Publications

Enhanced fluorescence is observed from dye molecules interacting with optical nanoantenna arrays. Elliptical gold dimers form individual nanoantennae with tunable plasmon resonances depending upon the geometry of the two particles and the size of the gap between them. A fluorescent dye, Rhodamine 800, is uniformly embedded in a dielectric host that coats the nanoantennae. The nanoantennae act to enhance the dye absorption. In turn, emission from the dye drives the plasmon resonance of the antennae; the nanoantennae act to enhance the fluorescence signal and change the angular distribution of emission. These effects depend upon the overlap of the plasmon resonance …

Transport-Based Dopant Metrology In Advanced Finfets, Gabriel P. Lansbergen, Rajib Rahman, Cameron J. Wellard, Jaap Caro, Nadine Collaert, Serge Biesemans, Gerhard Klimeck, Lloyd C. L. Hollenberg, Sven Rogge

Other Nanotechnology Publications

Ultra-scaled FinFET transistors bear unique fingerprint-like device-to-device differences attributed to random single impurities. Through correlation of experimental data with multimillion atom simulations in NEMO 3-D, we can identify the impurity’s chemical species and determine their concentration, local electric field and depth below the Si/SiO2 interface. The ability to model the excited states rather than just the ground states is the critical need. We therefore demonstrate a new approach to atomistic impurity metrology and confirm the assumption of tunneling through individual impurity quantum states.

Atomic-Layer-Deposited Al2o3/Gaas Metal-Oxide-Semiconductor Field-Effect Transistor On Si Substrate Using Aspect Ratio Trapping Technique, Y Q. Wu, M Xu, P. D. Ye, Z Cheng, J Li, J Park, J Hydrick, J Bai, M Carroll, J G. Fiorenza, A Lochtefeld

Birck and NCN Publications

High quality GaAs epilayers grown by metal-organic chemical vapor deposition are demonstrated on a SiO2-patterned silicon substrate using aspect ratio trapping technique, whereby threading dislocations from lattice mismatch are largely reduced via trapping in SiO2 trenches during growth. A depletion-mode metal-oxide-semiconductor field-effect transistor (MOSFET) is demonstrated on a n-doped GaAs channel with atomic-layer deposited Al2O3 as the gate oxide. The 10 mu m gate length transistor has a maximum drain current of 88 mA/mm and a transconductance of 19 mS/mm. The surface mobility estimated from the accumulation drain current has a peak value of similar to 500 cm(2)/Vs, which is …

Full-Band And Atomisic Simulation Of Realistic 40 Nm Inas Hemt, Mathieu Luisier, Neophytos Neophytou, Neerav Kharche, Gerhard Klimeck

Other Nanotechnology Publications

A realistic 40 nm InAs high electron mobility transistor is studied using a two-dimensional, full-band, and atomistic Schr¨odinger-Poisson solver based on the sp3d5s∗ tightbinding model. Bandstructure non-parabolicity effects, strain, alloy disorder in the InGaAs and InAlAs barriers, as well as band-to-band tunneling in the transistor OFF-state are automatically included through the full-band atomistic model. The source and drain contact extensions are taken into account a posteriori by adding two series resistances to the device channel. The simulated current characteristics are compared to measured data and show a good quantitative agreement.

From Nemo1d And Nemo3d To Omen: Moving Towards Atomistic 3-D Quantum Transport In Nano-Scale Semiconductors, Gerhard Klimeck, Mathieu Luisier

Other Nanotechnology Publications

Lessons learned in 15 years of NEMO development starting from quantitative and predictive resonant tunneling diode (RTD) to multi-million atom electronic structure modeling and the path for OMEN are laid out. The recent OMEN capabilities enable realistically large 3D atomistic nano-scale device simulation.

Optical Hyperspace For Plasmons: Dyakonov States In Metamaterials, Zubin Jacob, Evgenii E. Narimanov

Birck and NCN Publications

We show that the subdiffraction imaging behavior observed in the magnifying superlens experiment, [Smolyaninov , Science 317, 1699 (2007)] is due to the hyperbolic dispersion of Dyakonov plasmons supported by the device. These states which are a special case of Dyakonov surface waves [Dyakonov, Sov. Phys. JETP 67, 714 (1988)] exist at the interface of a metal and an anisotropic dielectric giving rise to plasmon beams on resonance. Furthermore, we describe how the unique properties of metamaterial Dyakonov plasmons can be tailored for plasmonic devices.

Hydrodynamic Loading Of Microcantilevers Oscillating Near Rigid Walls, Ryan C. Tung, Jana Anirban, Arvind Raman

Birck and NCN Publications

The vibrations of microcantilevers in atomic force microscopes (AFMs) or radio frequency (RF) switches are strongly influenced by the viscous hydrodynamics of the surrounding fluid in the vicinity of a rigid wall. While prior efforts to model this hydrodynamic loading have focused on squeeze film damping effects at high Knudsen and squeeze numbers, the regimes of low Knudsen and squeeze numbers are also very important for which squeeze film models need to be discarded in favor of unsteady Stokes hydrodynamics. We extend the work of Green and Sader [Phys Fluids 17, 073102 (2005); J. Appl. Phys. 98, 114913 (2005)] and …

Trade-Off Analysis Methodology For Asset Management, Qiang Bai, Samuel Labi, Zongzhi Li

JTRP Technical Reports

In an era that is characterized by funding limitations, increased stakeholder participation, and the need for increased accountability and transparency, transportation agencies seek to ensure that comprehensive evaluation processes are identified and used for decision-making. Consistent with such processes is the incorporation of multiple performance criteria from different program areas, optimization of decisions under constrained budgets, and investigation of trade-offs between program areas, performance measures, budgetary levels, risk levels, and performance thresholds. To help INDOT carry out these processes, this study developed theoretical constructs for scaling and amalgamation of the different performance measures, and for analyzing the different kinds of …