Engineering Commons^™

3-D Terahertz Synthetic-Aperture Imaging And Spectroscopy, Samuel C. Henry

Dissertations and Theses

Terahertz (THz) wavelengths have attracted recent interest in multiple disciplines within engineering and science. Situated between the infrared and the microwave region of the electromagnetic spectrum, THz energy can propagate through non-polar materials such as clothing or packaging layers. Moreover, many chemical compounds, including explosives and many drugs, reveal strong absorption signatures in the THz range. For these reasons, THz wavelengths have great potential for non-destructive evaluation and explosive detection. Three-dimensional (3-D) reflection imaging with considerable depth resolution is also possible using pulsed THz systems. While THz imaging (especially 3-D) systems typically operate in transmission mode, reflection offers the most …

Comparison Between Neural Networks And Multiple Regression Methods In Metallurgical Performance Modeling Of Flotation Column, Fardis Nakhaei, Mehdi Irannajad

Mining Engineering Faculty Research & Creative Works

Artificial neural networks are relatively new computational tools which their inherent ability to learn and recognize highly non-linear and complex relationships makes them ideally suited in solving a wide range of complex real-world problems. In this research, different techniques (Linear regression, Non-linear regression, Back propagation neural network, Radial Basis Function for the estimation of Cu grade and recovery values in flotation column concentrate are studied. Modeling is performed based on 90 datasets at different operating conditions at Sarcheshmeh pilot plant, a copper concentrator in Iran, which include chemical reagents dosage, froth height, air and wash water flow rates, gas holdup …

Insertion Of Lithium Ions Into Tio2 (Rutile) Crystals: An Electron Paramagnetic Resonance Study Of The Li-Associated Ti3+ Small Polaron, A. T. Brant, Nancy C. Giles, Larry E. Halliburton

Faculty Publications

Electron paramagnetic resonance (EPR) and electron-nuclear double resonance (ENDOR) are used to identify a Ti³⁺-Li⁺ complex in TiO₂ crystals having the rutile structure. This defect consists of an interstitial Li⁺ ion adjacent to a substitutional Ti³⁺ ion (the unpaired electron on the Ti³⁺ ion provides charge compensation for the Li⁺ ion). The neutral Ti³⁺-Li⁺ complex is best described as a donor-bound small polaron and is similar in structure to the recently reported neutral fluorine and hydrogen donors in TiO₂ (rutile). Lithium ions are diffused into the crystals at …

A New Method For Online Flow Regime Monitoring In Bubble Column Reactors Via Nuclear Gauge Densitometry, Ashfaq Shaikh, Muthanna H. Al-Dahhan

Chemical and Biochemical Engineering Faculty Research & Creative Works

In the Current Work, Nuclear Gauge Densitometry (NGD), Which is Commercially Available and Industrially Used for Liquid/slurry Level Measurement and Control, Has Been Employed to Identify Fingerprints of the Prevailing Hydrodynamic Flow Regime. Experiments Were Performed using an Air-Water System in 0.1012. M Diameter and 1.2. M Long Bubble Column at Ambient Pressure. the Superficial Gas Velocities Were Varied from 1. Cm/s to 12. Cm/s with an Interval of 0.5. Cm/s Near Transition Region. the Flow Regime Boundaries Were Defined using the Conventional Methods of Flow Regime Demarcation Such as the Change in the Slope of the overall Gas Holdup …

Smaller Spacecraft For Flying Large Clusters Of Biological Space Experiments, Robert J. Twiggs

Robert "Bob" Twiggs STEM Education Collection

A PowerPoint presentation created by Professor Bob Twiggs titled "Smaller spacecraft for flying large clusters of biological space experiments" from February 5, 2013.

Directional Electric Field Sensing Using Slab Coupled Optical Fiber Sensors, Daniel Theodore Perry

Theses and Dissertations

This thesis provides the details of a multi-axis electric field sensor. The sensing element consists of three slab coupled optical fiber sensors that are combined to allow directional electric field sensing. The packaged three-axis sensor has a small cross-sectional area of 0.5 cm x 0.5 cm achieved by using an x-cut crystal. The method is described that uses a sensitivity-matrix approach to map the measurements to field components. The calibration and testing are described resulting in an average error of 1.5º.This work also includes a description of the packaging method used as well as a thorough analysis of the directional …

Ceas E-News 02.04.2013, College Of Engineering And Applied Sciences

College of Engineering and Applied Sciences News

Faculty/staff awards, Karen Lawrence memorial, Impact Label scholarship.

Optoelectronic Measurement Of X-Ray Synchrotron Pulses: A Proof Of Concept Demonstration, Stephen M. Durbin, Aamer Mahmood, Marc W. Caffee, Sergei Savikhin, Eric M. Dufresne, Haidan Wen, Yuelin Li

Birck and NCN Publications

Optoelectronic detection using photoconductive coplanar stripline devices has been applied to measuring the time profile of x-ray synchrotron pulses, a proof of concept demonstration that may lead to improved time-resolved x-ray studies. Laser sampling of current vs time delay between 12 keV x-ray and 800 nm laser pulses reveal the similar to 50 ps x-ray pulse width convoluted with the similar to 200 ps lifetime of the conduction band carriers. For GaAs implanted with 8 MeV protons, a time profile closer to the x-ray pulse width is observed. The protons create defects over the entire depth sampled by the x-rays, …

Test Advising Framework, Yurong Wang

School of Computing: Dissertations, Theses, and Student Research

Test cases are represented in various formats depending on the process, the technique or the tool used to generate the tests. While different test case representations are necessary, this diversity challenges us in comparing test cases and leveraging strengths among them - a common test representation will help.

In this thesis, we define a new Test Case Language (TCL) that can be used to represent test cases that vary in structure and are generated by multiple test generation frameworks. We also present a methodology for transforming test cases of varying representations into a common format where they can be matched …

Would I Survive In Space?, Robert J. Twiggs

Robert "Bob" Twiggs STEM Education Collection

A PowerPoint presentation created by Professor Bob Twiggs titled "Would I survive in Space?" from February 4, 2013.

Microkinetic Modeling And Analysis Of Ethanol Partial Oxidation And Reforming Reaction Pathways On Platinum At Short Contact Times, Maura A. Koehle

Master's Theses

No abstract provided.

Analysis Of Coal Combustion By-Products Disposal Practices At The San Juan Mine: Hydrologic And Water Quality Issues, Bruce Thomson

Civil Engineering Faculty Publications

Coal Combustion By-Products (CCBs) are generated by the burning of coal for electric power generation and as waste streams from emissions control systems. They consist of bottom ash from the furnaces, fly ash from electrostatic precipitators, and flue gas desulfurization sludge from air pollution scrubbers. Depending on the characteristics of the coal, CCBs may contain high concentrations of metals or other constituents that present a threat to ground or surface water resources if not properly managed. This report describes results of an investigation of CCBs generated by a power plant in northwestern New Mexico. Coal Combustion By-Products from this plant …

Design Of A 2.4 Ghz Horizontally Polarized Microstrip Patch Antenna Using Rectangular And Circular Directors And Reflectors, Yosef Yilak Woldeamanuel

Electrical Engineering Theses

In the urban or indoor wireless environment, after a complicated multiple reflection or scattering effect, the polarization of the propagating radio waves may change significantly. Although many current wireless systems are vertically polarized it has been predicted that using horizontally polarized antenna at both the transmitter and receiver has many advantages. In this thesis, new designs are proposed to develop a horizontally polarized microstrip patch antennas for 2.4 GHz applications using directors and reflectors to guide the radiated power. The radiation characteristics of these designs with respect to various geometrical parameters such as the dimensions of the reflector and directors, …

Validation Of The Fall3d Model For The 2008 Chaitén Eruption Using Field And Satellite Data, María Soledad Osores, Arnau Folch, Estela Collini, Gustavo Villarosa, Adam J. Durant, Gloria Pujol, José G. Viramonte

Michigan Tech Publications, Part 1

The 2008 Chaitén Volcano eruption began on 2 May 2008 with an explosive phase that injected large amounts of tephra into the atmosphere. During the first week of the eruption, volcanic ash clouds were transported for hundreds of kilometres over Argentina by the prevailing westerly winds. Tephra deposition extended to the Atlantic Ocean and severely affected the Argentinean Patagonia. Impacts included air and water quality degradation, disruption of ground transportation systems and cancellation of flights at airports more than 1,500 km apart. We use the FALL3D tephra transport model coupled with the Weather Research and Forecasting-Advanced Research Weather (WRF-ARW) meteorological …

A Computational Approach To Optimize Microring Resonators For Biosensing Applications, Justin C. Wirth, B. R. Wenner, M. S. Allen, J. W. Allen, M. Qi

Birck and NCN Publications

Microcavity structures have recently found utility in chemical/biological sensing applications. The appeal of these structures over other refractive index-based sensing schemes, such as those based on surface plasmon resonance, lies in their potential for producing a highly sensitive response to binding events. High-Q devices, characterized by sharp line widths, are extremely attractive for sensing applications because the bound analyte provides an increased optical pathlength, thus shifting the resonant frequency of the device. In this work, we design and simulate resonant microrings using full-wave finite element models. In addition to structure design, integration of the biological recognition element on the resonator …

Sheathing Braced Design Of Wall Studs, B. W. Schafer

American Iron and Steel Institute (AISI) Specifications, Standards, Manuals and Research Reports (1946 - present)

This report was prepared as part of the American Iron and Steel Institute sponsored project: Sheathing Braced Design of Wall Studs. The project also received supplementary support and funding from the Steel Stud Manufacturers Association. Additional project information and documentation is available at www.ce.jhu.edu/bschafer/sheathedwalls. Any opinions, findings, and conclusions or recommendations expressed in this publication are those of the author and do not necessarily reflect the views of the American Iron and Steel Institute, nor the Steel Stud Manufacturers Association.

Ccfss Special Edition Technical Bulletin Spring 2013, Wei-Wen Yu Center For Cold-Formed Steel Structures

CCFSS Technical Bulletins (1993 - 2020)

No abstract provided.

Visual Homing With A Pan-Tilt Based Stereo Camera, Paramesh Nirmal, Damian M. Lyons

Faculty Publications

Visual homing is a navigation method based on comparing a stored image of the goal location and the current image (current view) to determine how to navigate to the goal location. It is theorized that insects, such as ants and bees, employ visual homing methods to return to their nest [1]. Visual homing has been applied to autonomous robot platforms using two main approaches: holistic and feature-based. Both methods aim at determining distance and direction to the goal location. Navigational algorithms using Scale Invariant Feature Transforms (SIFT) have gained great popularity in the recent years due to the robustness of …

Volatility In Mrna Secondary Structure As A Design Principle For Antisense, Erik Johnson, Ranjan Srivastava

Open Access Author Fund Awardees' Articles

Designing effective antisense sequences is a formidable problem. A method for predicting efficacious antisense holds the potential to provide fundamental insight into this biophysical process. More practically, such an understanding increases the chance of successful antisense design as well as saving considerable time, money and labor. The secondary structure of an mRNA molecule is believed to be in a constant state of flux, sampling several different suboptimal states. We hypothesized that particularly volatile regions might provide better accessibility for antisense targeting. A computational framework, GenAVERT was developed to evaluate this hypothesis. GenAVERT used UNAFold and RNAforester to generate and compare …

Using A Gridded Global Dataset To Characterize Regional Hydroclimate In Central Chile, E.M.C. Demaria, Edwin P. Maurer, J. Sheffield, E. Bustos, D. Poblete, S. Vicuña, F. Meza

Civil, Environmental and Sustainable Engineering

Central Chile is facing dramatic projections of climate change, with a consensus for declining precipitation, negatively affecting hydropower generation and irrigated agriculture. Rising from sea level to 6000 m within a distance of 200 km, precipitation characterization is difficult because of a lack of long-term observations, especially at higher elevations. For understanding current mean and extreme conditions and recent hydroclimatological change, as well as to provide a baseline for downscaling climate model projections, a temporally and spatially complete dataset of daily meteorology is essential. The authors use a gridded global daily meteorological dataset at 0.25° resolution for the period 1948–2008, …

Acuta Enews February 2013 Vol. 42, No. 2

ACUTA Newsletters

In this issue...

1 Meeting Member Needs with Excellence

2 Remembering Luther Robb

2 New Phone System for ACUTA Office

3 Info Links

3 Look, Everybody: Lori's Back!

4 What's on Your Desk Today?

5 Why Fax over IP Fails

6 Networks and a Single Point of Failure

7 Turning Big Data into Big ldeas

7 Thanks to Journal Advertisers for 2012

8 Board Report

8 Bring 8 Winter Seminar Sessions to Your Desktop or Tablet

8 Thanks to Winter 2013 Seminar Exhibitors and Sponsors

9 Welcome New Members

9 Check It Out

Fatigue Risks In The Connections Of Sign Support Structures, Christopher M. Foley, Joseph A. Diekfuss, Baolin Wan

Transportation Reports with the Wisconsin Department of Transportation

This research effort develops a reliability-based approach for prescribing inspection intervals for mast-arm sign support structures corresponding to user-specified levels of fatigue-induced fracture risk. The resulting level of risk for a particular structure is dependent upon its geographical location, the type of connection it contains, the orientation of its mast-arm relative to north and the number of years it has been in service. The results of this research effort indicate that implementation of state-of-the-art reliability-based assessment procedures can contribute very valuable procedures for assigning inspection protocols (i.e. inspection intervals) that are based upon probabilities of finding fatigue-induced cracking in these …

Vector Acoustic Intensity Around A Tuning Fork, Daniel A. Russell, Justin Junell, Daniel O. Ludwigsen

Physics Publications

The acoustic intensity vector field around a tuning fork is investigated. Theory for a longitudinal quadrupole source predicts a well-defined transition between near-field and far-field, with significant circulation of sound energy in the near-field. Vector components of the time-averaged intensity were measured using a two-microphone intensity probe and found to agree well with predictions from theory. The vector intensity map is interpreted, and shown to provide useful information about the near-field of an acoustic source.

Research Challenges And Opportunities In Knowledge Representation, Natasha Noy, Deborah Mcguinness, Eyal Amir, Chitta Baral, Michael Beetz, Sean Bechhofer, Craig Boutilier, Anthony Cohn, Johan De Kleer, Michel Dumontier, Tim Finin, Kenneth Forbus, Lise Getoor, Yolanda Gil, Jeff Heflin, Pascal Hitzler, Craig Knoblock, Henry Kautz, Yuliya Lierler, Vladimir Lifschitz, Peter F. Patel-Schneider, Christine Piatko, Doug Riecken, Mark Schildhauer

Computer Science and Engineering Faculty Publications

Modern intelligent systems in every area of science rely critically on knowledge representation and reasoning (KR). The techniques and methods developed by the researchers in knowledge representation and reasoning are key drivers of innovation in computer science; they have led to significant advances in practical applications in a wide range of areas from natural-­‐language processing to robotics to software engineering. Emerging fields such as the semantic web, computational biology, social computing, and many others rely on and contribute to advances in knowledge representation. As the era of “Big Data” evolves, scientists in a broad range of disciplines are increasingly relying …

Flexural And Shear Behavior Of Reinforced Concrete Members Strengthened With A Discrete Fiber-Reinforced Polyurea System, Courtney E. Greene, John J. Myers

Civil, Architectural and Environmental Engineering Faculty Research & Creative Works

Recent research has been conducted to evaluate the benefits provided by externally applied discrete fiber-reinforced polyurea (DFRP) coating systems. This coating was proposed to allow for ease of construction in repair-retrofit situations and to provide multihazard benefits, ranging from blast or impact fragmentation mitigation to seismic reinforcement and general strengthening. This phase of research investigated the flexural and shear reinforcement capabilities of the systems. Testing parameters included type of structural failure, polyurea, and fiber volume fraction. Additionally, the effects of the thickness of the composite system were considered. Concrete beam specimens were fabricated and coated per the designed test matrix …

Sustainable Purchasing Practices: An Investigation Into Current Industry Awareness And Practice, Frank Palisi, Kathryne Newton, Edward Sweeney

Conference papers

This research study illustrates the importance of sustainable purchasing practices for organizations in the U.S. distribution industry and answers several important questions: what is the current awareness of U.S. organizations regarding sustainable purchasing practices; to what extent are U.S. organizations evaluating, selecting, and retaining suppliers based upon sustainable purchasing practices; and to what extent are sustainable purchasing practices being implemented by the U.S. organizations under study? With an ever increasing global economy, is it critically important for organizations to put in place sustainability practices; the biggest impact organizations can make is often in an organization’s purchasing department. The researcher begins …

Smore Revision: Ignition And User Interface, Arash Mehrparvar

Aerospace Engineering

The Static Methanol Oxygen Rocket Engine (SMORE) has undergone several revisions since its inception. This latest revision aimed to increase startup reliability and user safety in the operation of the rocket. The implementation of maintenance procedures, safeguards in the ignition system, as well as construction of a new control box and redesign of the igniter itself have accomplished these goals while keeping costs down and without modifying the current rocket setup. Startup reliability has increased drastically, so long as all other rocket setup procedures are followed properly. 250 subsequent firings of the rocket have proven an igniter reliability of more …

Power And Politics In Organizations, Thomas W. Camm

Mining Engineering

Aristotle made the observation that man is a political animal. Engineers often like to think they are above the fray when it comes to organizational politics, but most organizational theorists believe politics is a fundamental dynamic in any group. This paper examines the various ways that people use power within organizations to negotiate the political interactions in the work place.

Probabilistic Estimates Of Future Changes In California Temperature And Precipitation Usingstatistical And Dynamical Downscaling, David W. Pierce, Tapash Das, Daniel R. Cayan, Edwin P. Maurer, Norman L. Miller, Yan Bao, M. Kanamitsu, Kei Yoshimura, Mark A. Snyder, Lisa C. Sloan, Guido Franco, Mary Tyree

Civil, Environmental and Sustainable Engineering

Sixteen global general circulation models were used to develop probabilistic projections of temperature (T) and precipitation (P) changes over California by the 2060s. The global models were downscaled with two statistical techniques and three nested dynamical regional climate models, although not all global models were downscaled with all techniques. Both monthly and daily timescale changes in T and P are addressed, the latter being important for a range of applications in energy use, water management, and agriculture. The T changes tend to agree more across downscaling techniques than the P changes. Year-to-year natural internal climate variability is roughly of similar …

Pore Geometry Effects On Intrapore Viscous To Inertial Flows And On Effective Hydraulic Parameters, Kuldeep Chaudhary, M. Bayani Cardenas, Wen Deng, Philip C. Bennett

Civil, Architectural and Environmental Engineering Faculty Research & Creative Works

In this article, the effects of different diverging-converging pore geometries were investigated, and the microscale fluid flow and effective hydraulic properties from these pores were compared with that of a pipe from viscous to inertial laminar flow regimes. The flow fields are obtained using computational fluid dynamics, and the comparative analysis is based on a new dimensionless hydraulic shape factor β, which is the "specific surface" scaled by the length of pores. Results from all diverging-converging pores show an inverse pattern in velocity and vorticity distributions relative to the pipe flow. The hydraulic conductivity K of all pores is …