Engineering Commons^™

An Assessment Of Delivery Risks In Transportation Projects, Velvet Fitzpatrick, Kumares C. Sinha

JTRP Technical Reports

A large number of uncertainties exist in the delivery of highway projects, and it is important to describe the extent so that budgeting and programming can be carried out in a manner that duly accounts for such uncertainties. The study investigates the sources of delivery variability (risk factors) that occur in the period between project proposed date and the letting date. Data on 366 highway projects were collected from the Indiana Department of Transportation Management Information Portal. Using statistical and econometric techniques, the data was analyzed to identify the potential risk factors and to determine the magnitude and direction of …

Facilitating Teaching And Research On Open Ended Problem Solving Through The Development Of A Dynamic Computer Tool, Matthew Verleger, Heidi Diefes-Dux

School of Engineering Education Graduate Student Series

Model Eliciting Activities (MEAs) are realistic open-ended problems set in engineering contexts; student teams draw on their diverse experiences both in and out of the classroom to develop a mathematical model explicated in a memo to the client. These activities have been implemented in a required first-year engineering course with enrollments of as many as 1700 students in a given semester. The earliest MEA implementations had student teams write a single solution to a problem in the form of a memo to the client and receive feedback from their TA. For research purposes, a simple static online submission form, a …

Developing A Global Real Time Assessment Tool For The Teaching Enhancement Of Engineering Graduate Teaching Assistants, Nathan Mcneill, Jeeyeon Hahn, Asawaree Ajit Kulkarni, Monica F. Cox

School of Engineering Education Graduate Student Series

No abstract provided.

2010 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.

Strain-Stiffening In Synthetic And Biopolymer Networks, Kendra Erk, Kevin J. Henderson, Kenneth R. Shull

School of Materials Engineering Faculty Publications

Strain-stiffening behavior common to biopolymer networks is difficult to reproduce in synthetic networks. Physically associating synthetic polymer networks can be an exception to this rule and can demonstrate strain-stiffening behavior at relatively low values of strain. Here, the stiffening behavior of model elastic networks of physically associating triblock copolymers is characterized by shear rheometry. Experiments demonstrate a clear correlation between network structure and strain-stiffening behavior. Stiffening is accurately captured by a constitutive model with a single fitting parameter related to the midblock length. The same model is also effective for describing the stiffening of actin, collagen, and other biopolymer networks. …

On Momentum Conservation And Thermionic Emission Cooling, Raseong Kim, Changwook Jeong, Mark S. Lundstrom

Department of Electrical and Computer Engineering Faculty Publications

The possibility of increasing the performance of thermionic cooling devices by relaxing lateral momentum conservation is examined. Upper limits for the ballistic emission current are established. It is then shown that for most cases, nonconserved lateral momentum model produces a current that exceeds this upper limit. For the case of heterojunctions with a much heavier effective mass in the barrier and with a low barrier height, however, relaxing lateral momentum may increase the current. These results can be simply understood from the general principle that the current is limited by the location, well or barrier, with the smallest number of …

Model Of Students' Success: Important Factors Of Student Persistence In Engineering, Jien-Jou Lin, Qu Jin, P.K. Imbrie

School of Engineering Education Graduate Student Series

No abstract provided.

Fieldmanager® – Construction Management Software, Purdue Ect Team

ECT Fact Sheets Archive

The FieldManager® software is a construction management system jointly owned by the Michigan Department of Transportation (MDOT) and Info Tech, Inc. Designed for any size organization that manages construction projects, FieldManager software wraps up contract documentation and reporting, contract modifications, and pay estimates into one neat package for use on multiple hardware platforms, increasing productivity and accountability by implementing a standard business practice across the organization.

Appia® – Construction Management Web Application, Purdue Ect Team

ECT Fact Sheets Archive

The Appia® software is a hosted web application for construction program administration. The Appia system can manage the business processes in the major functional areas of the project life-cycle – estimation, bid management and construction – due to its flexible configuration and customizable business rules, providing organizations the opportunity to simplify and standardize their processes.

Automated Tank Surface Finishing System, Purdue Ect Team

ECT Fact Sheets Archive

The current finishing techniques are costly and laborious, and they expose workers to significant health and safety risks. The automated tank surface finishing system uses a computer-controlled motion module to refinish the vertical exterior walls of a tank. The module is configurable for both blasting and painting and utilizes conventional surface finishing equipment for these processes. An overspray hood is included to reduce contamination of the surrounding environment during painting. The module attaches to a tank’s wind girts with steel cables, and its position and velocity are controlled by servo-driven hoists.

Visualization And Assessment Of Arterial Progression Quality Using High Resolution Signal Event Data And Measured Travel Time, Christopher M. Day, Ross Haseman, Hiromal Premachandra, Thomas M. Brennan Jr, Jason S. Wasson, James R. Sturdevant, Darcy M. Bullock

Lyles School of Civil Engineering Faculty Publications

No abstract provided.

On Landauer Versus Boltzmann And Full Band Versus Effective Mass Evaluation Of Thermoelectric Transport Coefficients, Changwook Jeong, Raseong Kim, Mathieu Luisier, Supriyo Datta

Department of Electrical and Computer Engineering Faculty Publications

Using a full band description of electronic bandstructure, the Landauer approach to diffusive transport is mathematically related to the solution of the Boltzmann transport equation, and expressions for the thermoelectric parameters in both formalisms are presented. Quantum mechanical and semiclassical techniques to obtain from a full description of the bandstructure, E(k)E(k), the density of modes in the Landauer approach or the transport distribution in the Boltzmann solution are compared and thermoelectric transport coefficients are evaluated. Several example calculations for representative bulk materials are presented and the full band results are related to the more common effective mass formalism. Finally, given …

Simulation Of Spin Field Effect Transistors: Effects Of Tunneling And Spin Relaxation On Performance, Yunfei Gao, Tony Low, Mark S. Lundstrom, Dmitri E. Nikonov

Department of Electrical and Computer Engineering Faculty Publications

numerical simulation of spin-dependent quantum transport for a spin field effect transistor is implemented in a widely used simulator, nanoMOS. This method includes the effect of both spin scattering in the channel and the tunneling barrier between the source/drain and the channel. Accounting for these factors permits setting more realistic performance limits for the transistor, especially the magnetoresistance, which is found to be lower compared to earlier predictions. The interplay between tunneling and spin scattering is elucidated by numerical simulation. Insertion of the tunneling barrier leads to an increased magnetoresistance. Simulations are used to explore the tunneling barrier design issues.

Universality Of Non Ohmic Shunt Leakage In Thin Film Solar Cells, Sourabh Dongaonkar, J. D. Sevaites, G. M. Ford, S. Loser, J. Moore, R. M. Gelfand, H. Mohseni, H. W. Hillhouse, R. Agrawal, M. A. Ratner, T. J. Marks, Mark S. Lundstrom, Muhammad A. Alam

Department of Electrical and Computer Engineering Faculty Publications

http://dx.doi.org/10.1063/1.3518509

Abstract can be found at the above link

Growing Pains: Chinese Engineering Education During The Late Qing Dynasty, Nathan Mcneill, Sensen Li, Junqiu Wang

School of Engineering Education Graduate Student Series

No abstract provided.

Anterior-Posterior Impedance Cardiography: A New Approach To Accurate, Non-Invasive Monitoring Of Cardiac Function, Charles F. Babbs

Weldon School of Biomedical Engineering Faculty Publications

The conventional impedance cardiogram is a record of pulsatile changes in the electrical impedance of the chest with each heartbeat. The signal seems intuitively related to cardiac stroke volume. However doubts persist about the validity of stroke volume measurements based on electrical impedance. This paper presents a new electrical axis for impedance cardiography that is perpendicular to the conventional head-to-foot axis in an anterior-posterior direction. Dual chest and back electrodes are concentric, permitting tetrapolar technique. A relatively simple analytical model is developed, and this model is validated in a three-dimensional finite element model of current flow through the human chest. …

Asee Student Members’ Needs Analysis: Implications For The Asee Student Constituent Committee, Daniel Bumblauskas, Ana Torres-Ayala, Matthew Verleger

School of Engineering Education Graduate Student Series

No abstract provided.

Implications Of Rarefied Gas Damping For Rf Mems Reliability, Alina A. Alexeenko, Sruti Chigullapalli

School of Aeronautics and Astronautics Faculty Publications

Capacitive and ohmic RF MEMS switches are based on micron‐sized structures moving under electrostatic force in a gaseous environment. Recent experimental measurements [4, 5] point to a critical role of gas‐phase effects on the lifetime of RF MEMS switches. In this paper, we analyze rarefied flow effects on the gas‐damping behavior of typical capacitive switches. Several damping models based on Reynolds equation [7, 8] and on Boltzmann kinetic equation [9, 6] are applied to quantify the effects of uncertainties in fabrication and operating conditions on the impact velocity of switch contact surfaces for various switch configurations. Implications of rarefied flow …

Experimental Determination Of The Key Heat Transfer Mechanisms In Pharmaceutical Freeze Drying, Arnab Ganguly, Steven L. Nail, Alina A. Alexeenko

School of Aeronautics and Astronautics Faculty Publications

Freeze-drying is often used in manufacture of pharmaceuticals to remove a solvent in such a way that the sensitive molecular structure of the active substance of a drug is least disturbed, and to provide a sterile powder that can be quickly and completely rehydrated. In this work heat transfer rates in a laboratory-scale freeze-dryer have been measured to investigate the contribution of different heat transfer modes. Pure water was partially dried under low-pressure conditions and sublimation rates were determined gravimetrically. The heat transfer rates were observed to be independent of the separation distance between a product vial and a dryer …

Direct Simulation Monte Carlo Modeling Of E-Beam Metal Deposition, A Venkattraman, Alina A. Alexeenko

School of Aeronautics and Astronautics Faculty Publications

Three-dimensional direct simulation Monte Carlo (DSMC) method is applied here to model the electron-beam physical vapor deposition of copperthin films. Various molecular models for copper-copper interactions have been considered and a suitable molecular model has been determined based on comparisons of dimensional mass fluxes obtained from simulations and previous experiments. The variable hard sphere model that is determined for atomic copper vapor can be used in DSMC simulations for design and analysis of vacuum deposition systems, allowing for accurate prediction of growth rates, uniformity, and microstructure.

What Determines Knudsen Force At The Microscale, Jeremy S. Nabeth, Sruti Chigullapalli, Alina A. Alexeenko

School of Aeronautics and Astronautics Faculty Publications

Knudsen forces arise in microscale systems when there is a thermal gradient with a characteristic length scale comparable to the molecular mean free path of the ambient gas. These forces are sometimes referred as radiometric or thermo‐molecular forces [1] and have been recently measured experimentally in a microscale configuration using heated atomic force microscopy (AFM) probes [2]. The Knudsen force on microstructures with thermal gradients can provide a novel actuation mechanism for mass detection, thermogravimetry, and very high‐resolution heat flux measurements. While measuring such forces precisely at microscale can be an arduous task especially since only limited analytical results exist, …

Molecular Models For Dsmc Simulations Of Metal Vapor Deposition, A Venkattraman, Alina A. Alexeenko

School of Aeronautics and Astronautics Faculty Publications

The direct simulation Monte Carlo (DSMC) method is applied here to model the electron‐beam (e‐beam) physical vapor deposition of copper thin films. A suitable molecular model for copper‐copper interactions have been determined based on comparisons with experiments for a 2D slit source. The model for atomic copper vapor is then used in axi‐symmetric DSMC simulations for analysis of a typical e‐beam metal deposition system with a cup crucible. The dimensional and non‐dimensional mass fluxes obtained are compared for two different deposition configurations with non‐uniformity as high as 40% predicted from the simulations.

Flowfield Uncertainty Analysis For Hypersonic Cfd Simulations, A B. Weaver, Alina A. Alexeenko, R B. Greendyke, J A. Camberos

School of Aeronautics and Astronautics Faculty Publications

Uncertainty quantification (UQ) in the hypersonic flow regime offers valuable information to determine physical models in need of improvement and to assist in design of vehicles and flight experiments. Here we present results of UQ analysis based on polynomial chaos method to determine flowfield and surface heat flux uncertainty under typical blunt-body re-entry conditions. The NASA Langley code, LAURA, was used for axisymmetric CFD calculations of chemically reacting hypersonic flow over FIRE-II configuration. A third order polynomial chaos (PC) method using the Gauss-Hermite quadrature was applied for determining probability density functions and moments of output quantities. Input parameters such as …

Knudsen Force Modeling In Application To Microsystems, Jeremy S. Nabeth, Sruti Chigullapalli, Alina A. Alexeenko

School of Aeronautics and Astronautics Faculty Publications

At the microscale, even moderate temperature differences can result in significant Knudsen forces generated by the energy exchange between gas molecules and solids immersed in a gas. Creating, controlling and measuring Knudsen forces in microsystems can be an arduous task since only limited theory exists at present. This present study investigates the mechanism of Knudsen forces in detail based on numerical solution of the Boltzmann kinetic equation. The Knudsen force is shown, in general, to be a result of thermal nonequilibrium between gas and solid. The simulations are validated by comparison with experimental measurements that have been reported by Passian …

Treatment Guidelines For Pavement Preservation, Jusang Lee, Todd Shields

JTRP Technical Reports

This project presents pavement treatment practice guidelines and a distress identification manual for the purpose of improving the INDOT pavement preservation practices. The treatment guidelines consist of 10 treatment types for asphalt pavements and composite pavements and 8 treatment types for Portland cement concrete pavement (PCCP). The treatment guidelines include treatment descriptions, benefits, applicable pavement conditions, treatment materials, and treatment procedures. The guidelines are based on information obtained mainly from the INDOT Standard Specification, the INDOT Design Manual, and the INDOT Field Operations Handbook for Crew Leaders. The treatments are covered in the guidelines. The distress identification manual presents the …

Automated Pavement Condition Data Collection Quality Control, Quality Assurance, And Reliability, Ghim Ping (Raymond) Ong, Samy Noureldin, Kumares C. Sinha

JTRP Technical Reports

In recent years, state highway agencies have come to understand the need for high quality pavement condition data at both the project and network levels. At the same time, agencies also realize that they have become too dependent on contractors to ensure the quality of the delivered data without any means to independently assure the quality of these delivered data. This research study therefore aims to investigate the inherent variability of the automated data collection processes and proposes guidelines for an automated data collection quality management program in Indiana. In particular, pavement roughness data (in terms of IRI) and pavement …

The Characterization Of Aerosol Particle Contamination As The Result Of Carry-Over And Cross-Over In Enthalpy Wheels, Rodney G. Handy, Kevin Rodgers, Jon Wang, Matt Tumey, Danny Rodriguez, William J. Hutzel

School of Engineering Technology Faculty Publications

This paper provides results from a study that characterized the particle distributions found from variable contaminated airstreams in energy recovery ventilators (ERV) during two different test scenarios. The first scenario involved the measurement of the particulate concentrations during an operational situation when the pressure differential forces cross-flow leakage between the exhaust and intake streams. The second scenario involved the characterization of aerosol particulate concentrations from the carry-over contamination when the wheel was not in operation. The findings from the study concluded that if a source of aerosol particulate matter is present in an environment utilizing an ERV system, then cross-over …

Thermal Conduction In Molecular Materials Using Coarse Grain Dynamics: Role Of Mass Diffusion And Quantum Corrections For Molecular Dynamics Simulations, Ya Zhou, Alejandro Strachan

PRISM: NNSA Center for Prediction of Reliability, Integrity and Survivability of Microsystems

We use a mesodynamical method, denoted dynamics with implicit degrees of freedom DID, to characterize thermal transport in a model molecular crystal below and above its melting temperature. DID represents groups of atoms molecules in this case using mesoparticles and the thermal role of the intramolecular degrees of freedom DoFs are described implicitly using their specific heat. We focus on the role of these intramolecular DoFs on thermal transport. We find that thermal conductivity is independent of intramolecular specific heat for solid samples and a linear relationship between the two quantities in liquid samples with the coefficient of proportionality being …

Stochastic Analysis Of Electrostatic Mems Subjected To Parameter Variations, Nitin Agarwal, Narayana R. Aluru

PRISM: NNSA Center for Prediction of Reliability, Integrity and Survivability of Microsystems

This paper presents an efficient stochastic framework for quantifying the effect of stochastic variations in various design parameters such as material properties, geometrical features, and/or operating conditions on the performance of electrostatic microelectromechanical systems (MEMS) devices. The stochastic framework treats uncertainty as a separate dimension, in addition to space and time, and seeks to approximate the stochastic dependent variables using sparse grid interpolation in the multidimensional random space. This approach can be effectively used to compute important information, such as moments (mean and variance), failure probabilities, and sensitivities with respect to design variables, regarding relevant quantities of interest. The approach …

Frequency-Domain Simulations Of A Negative-Index Material With Embedded Gain, Yonatan Sivan, Shumin Xiao, Uday K. Chettiar, Alexander V. Kildishev, V. M. Shalaev

Birck and NCN Publications

We solve the equations governing light propagation in a negative-index material with embedded nonlinearly saturable gain material using a frequency-domain model. We show that available gain materials can lead to complete loss compensation only if they are located in the regions where the field enhancement is maximal. We study the increased enhancement of the fields in the gain composite as well as in the metal inclusions and show analytically that the effective gain is determined by the average near-field enhancement.