Engineering Commons^™

Development Of A Colorimetric Test For Quantification Of Uranium In Drinking Water, Amy Ratliff

All Theses

A new method was developed for the determination of uranium in groundwater above 30µg/L (30ppb). This concentration is the maximum contaminant level (MCL) for uranium in drinking water, which was set in December 2003 by the US EPA under the provisions of the Safe Drinking Water Act. The method is rapid and requires little technical training to conduct, allowing it to be used by consumers, in the laboratory, or in the field. The two-step technique involves preconcentrating uranium using a U/TEVA-2 extraction chromatographic resin followed by complexation with a pyridylazo indicator dye, Br-PADAP. At neutral pH, a counter ion is …

Evaluation Of Laboratory Durability Tests For Stabilized Subgrade Soils, John Wesley Parker

Theses and Dissertations

The Portland Cement Association commissioned a research project at Brigham Young University to compare selected laboratory durability tests available for assessing stabilized subgrade materials. Improved understanding of these tests is needed to enable more objective selection of durability tests by design engineers and to facilitate more meaningful comparisons of data obtained for different stabilizer treatments using different evaluation procedures. The laboratory research associated with this project involved two subgrade materials, four stabilizers at three concentrations each, and three durability tests in a full-factorial experimental design. The two subgrade soils used were a silty sand and a lean clay, while the …

Chemisorption Of Oxygen Onto Activated Carbon Can Enhance The Stability Of Biological Perchlorate Reduction In Fixed Bed Biofilm Reactors, Young Chul Choi, Xu Li, Lutgarde Raskin, Eberhard Morgenroth

Department of Civil and Environmental Engineering: Faculty Publications

Fixed bed biofilm reactors with granular activated carbon (GAC) or glass beads as support media were used to evaluate the influence of short-term (12 h) and long-term (23 days) increases of influent dissolved oxygen (DO) concentrations on biological perchlorate removal. The goal was to evaluate the extent by which chemisorption of oxygen to GAC can enhance the stability of biological perchlorate reduction. Baseline influent concentrations were 50 μg/L of perchlorate, 2 mg/L of acetate as C, and 1 mg/L of DO. Perchlorate removal in the glass bead reactor seized immediately after increasing influent DO concentrations from 1 to 4 mg/L …

The Role Of Space In Education: Pajaro High School, Robert J. Twiggs

Robert "Bob" Twiggs STEM Education Collection

A PowerPoint Presentation created by Professor Bob Twiggs titled "The Role of Space In Education: Pajaro High School" from May 15, 2008.

Ice Nucleation And Overseeding Of Ice In Volcanic Clouds, Adam J. Durant, R. A. Shaw, William I. Rose, Y. Mi, G. G. J. Ernst

Department of Geological and Mining Engineering and Sciences Publications

Water is the dominant component of volcanic gas emissions, and water phase transformations, including the formation of ice, can be significant in the dynamics of volcanic clouds. The effectiveness of volcanic ash particles as ice-forming nuclei (IN) is poorly understood and the sparse data that exist for volcanic ash IN have been interpreted in the context of meteorological, rather than volcanic clouds. In this study, single-particle freezing experiments were carried out to investigate the effect of ash particle composition and surface area on water drop freezing temperature. Measured freezing temperatures show only weak correlations with ash IN composition and surface …

Sticky Gecko Feet: The Role Of Temperature And Humidity, Peter H. Niewiarowski, Stephanie Lopez, Liehui Ge, Emily Hagan, Ali Dhinojwala

College of Polymer Science and Polymer Engineering

Gecko adhesion is expected to be temperature insensitive over the range of temperatures typically experienced by geckos. Previous work is limited and equivocal on whether this expectation holds. We tested the temperature dependence of adhesion in Tokay and Day geckos and found that clinging ability at 12 degrees C was nearly double the clinging ability at 32 degrees C. However, rather than confirming a simple temperature effect, our data reveal a complex interaction between temperature and humidity that can drive differences in adhesion by as much as two-fold. Our findings have important implications for inferences about the mechanisms underlying the …

Modeling And Simulation Of 6-Pulse And 12-Pulse Rectifiers Under Balanced And Unbalanced Conditions With Impacts To Input Current Harmonics, Arief Hernandi, Taufik, Makbul Anwari

Electrical Engineering

This paper discusses the impact of using 6-pulse and 12-pulse rectifier circuit commonly found in Adjustable Speed Drives. The 12-pulse topology is known to be more expensive, but produce the least input current harmonics. However, the latter statement is completely true under balanced line conditions. In practice, the lines are inherently unbalanced. Hence, the question of whether the 12-pulse rectifier will indeed perform better in terms of the harmonics injected to the line is still under on-going discussions. This paper presents the modeling and simulation of both rectifier topologies to compare their input current harmonics. The rectifiers are modeled using …

Modeling And Simulation Of Paralleled Series-Loaded-Resonant Converter, Alejandro Polleri, Taufik, Makbul Anwari

Electrical Engineering

This paper presents the development of a circuit modeling for paralleled Series Loaded Resonant (SLR) converter used in an experimental power supply to drive high voltage and high frequency medical equipment. The circuit model for each individual converter is first described. Once the complete model of an individual converter is achieved, the model is then extended to include the parallel connection. To verify the validity of model, the design of paralleled SLR using the model is explained. The component values obtained are then being used in Pspice simulations to further prove the validity of the model.

Modeling And Simulation Of Current Ripple In Dc Link Connecting Two Pwm Inverters Using Matlab/Simulink, Taufik, Makbul Anwari

Electrical Engineering

In this paper, the impacts of PWM carrier signals to DC bus current ripple in a PWM-based generator-load system will be investigated. The study is crucial to aid in the determination of the dc bus capacitor in a real-world inverter system. A Simulink model depicting the contribution of the generator current and the load current to the total DC bus current will be described. Results of the computer simulations will also be discussed.

Ceas E-News 05.13.2008, College Of Engineering And Applied Sciences

College of Engineering and Applied Sciences News

Five inducted into 2007 Alumni Excellence Academy

Catalytic Wet Oxidation Of Lactose, Joseph Holles

Michigan Tech Patents

A process for converting lactose into carbon dioxide and/or carbon monoxide using catalytic wet oxidation. Oxygen gas and an aqueous solution of lactose are fed to a reactor comprising a Pt/Al203 catalyst, a Mn/Ce catalyst or a Pt/Mn—Ce catalyst, and the lactose is oxidized in the reactor at elevated temperature and pressure to produce at least one of small organic acids, carbon dioxide, carbon monoxide, water and combinations thereof. The small organic acids may be further degraded by feeding the small organic acids and oxygen gas into a reactor containing a Mn/Ce catalyst and oxidizing the small organic acids to …

Transient And Localized Processes In The Magnetotail: A Review, A. S. Sharma, R. Nakamura, A. Runov, E. E. Grigorenko, H. Hasegawa, M. Hoshino, P. Louarn, C. J. Owen, A. Petrukovich, J.A. Sauvaud, V. S. Semenov, V. A. Sergeev, J. A. Slavin, B.U. O. Sonnerup, L. M. Zelenyi, G. Fruit, S. Haaland, H. Malova, K. Snekvik

Dartmouth Scholarship

Many phenomena in the Earth's magnetotail have characteristic temporal scales of several minutes and spatial scales of a few Earth radii (R_E). Examples of such transient and localized mesoscale phenomena are bursty bulk flows, beamlets, energy dispersed ion beams, flux ropes, traveling compression regions, night-side flux transfer events, and rapid flappings of the current sheet. Although most of these observations are linked to specific interpretations or theoretical models they are inter-related and can be the different aspects of a physical process or origin. Recognizing the inter-connected nature of the different transient and localized phenomena in the magnetotail, …

Phase-Field Modeling Of The Formation Of Lamellar Nanostructures In Diblock Copolymer Thin Films Under Inplanar Electric Fields, Xiang-Fa Wu, Yuris A. Dzenis

Department of Engineering Mechanics: Faculty Publications

Recent experiments show that external inplanar electric field can be employed to guide the molecular self-assembly in diblock copolymer (BCP) thin films to form lamellar nanostructures with potential applications in nanotechnology. We study this self-assembly process through a detailed coarse-grained phase separation modeling. During the process, the free energy of the BCP films is modeled as the Ginzburg-Landau free energy with nonlocal interaction and electrostatic coupling. The resulting Cahn-Hilliard (CH) equation is solved using an efficient semi-implicit Fourier-spectral algorithm. Numerical results show that the morphology of order parameter formed in either symmetric or asymmetric BCP thin films is strongly influenced …

Analysis And Calibration Of Rdii And Design Of Sewer Collection Systems, Misgana K. Muleta, Paul F. Boulos

Civil and Environmental Engineering

Excessive wet weather flow resulting from rainfall-derived inflow and infiltration (RDII) is a major source of sanitary sewer overflows (SSOs). SSOs pose serious problem to the public and the environment by causing back up into basements and sewer overflows to streets and rivers. Control of sewer overflows is, therefore, vital to reducing risks to public health and protecting the environment from water pollution. Computer modeling of sewer collection systems plays an important role in determining sound and economical remedial solutions that reduce RDII, improve system integrity, reliability and performance, and avoid overflows. This paper presents a rigorous and efficient three-step …

Geotechnical Investigations At Three Sites In The South Carolina Coastal Plain That Did Not Liquefy During The 1886 Charleston Earthquake, Ronald Boller

All Theses

Geotechnical investigations were performed at three sites in the South Carolina Coastal Plain where liquefaction is believed to not have occurred in 1886 or during other Holocene earthquakes. The three sites are the Coastal Research and Education Center (CREC) located near Charleston, and the Borrow Pit and Marsh Road sites at Hobcaw Barony near Georgetown. The investigations consisted of nine seismic cone penetration test (SCPT) soundings, three non-seismic cone penetration test (CPT) soundings, one standard penetration test (SPT) boring, and two dilatometer test (DMT) soundings. Shear wave velocities (Vs) were calculated from the SCPTs using pseudo interval measurements at the …

College Of Engineering Senior Design Competition Spring 2008, University Of Nevada, Las Vegas

Fred and Harriet Cox Senior Design Competition Projects

Part of every UNLV engineering student’s academic experience, the senior design project stimulates engineering innovation and entrepreneurship. Each student in their senior year chooses, plans, designs, and prototypes a product in this required element of the curriculum. A capstone to the student’s educational career, the senior design project encourages the student to use everything learned in the engineering program to create a practical, real world solution to an engineering challenge.

The senior design competition helps to focus the senior students in increasing the quality and potential for commercial application for their design projects. Judges from local industry evaluate the projects …

A Simulation Study Of Medium Access Control Protocols Of Wireless Networks, Rohan Uddhav Patel

Morehead State Theses and Dissertations

A thesis presented to the faculty of the College of Science and Technology at Morehead State University in partial fulfillment of the requirements for the Degree of Master of Science by Rohan Uddhav Patel on May 8, 2008.

High-Power Low-Frequency Ultrasound: A Review Of Tissue Dissection And Ablation In Medicine And Surgery, Brendan O'Daly, Edmund Morris, Graham Gavin, John O'Byrne, Garrett Mcguinness

Articles

High-power low-frequency ultrasound in the range 20–60 kHz has wide ranging clinical applications in surgical and medical instruments for biological tissue cutting, ablation or fragmentation, and removal. Despite widespread clinical application and common device operating characteristics, there is an incomplete understanding of the mechanism of tissue failure, removal and damage. The relative contribution of cavitation, direct mechanical impact and thermal effects to each process for specific tissue types remains unclear. Different and distinct mechanisms and rates of tissue removal are observed for interaction with soft and hard tissue types. Device operating parameters known to affect the interaction include frequency, peak–peak …

Improving Steel Cleanliness Through Slag Refining, Sarina Bao, Xinhua Wang, Lifeng Zhang, Shufeng Yang, Kent D. Peaslee

Materials Science and Engineering Faculty Research & Creative Works

No abstract provided.

A Relational Model For Environmental And Water Resources Data, Jeffery S. Horsburgh, David G. Tarboton, David R. Maidment, Ilya Zaslavsky

Civil and Environmental Engineering Faculty Publications

Environmental observations are fundamental to hydrology and water resources, and the way these data are organized and manipulated either enables or inhibits the analyses that can be performed. The Observations Data Model presented here provides a new and consistent format for the storage and retrieval of point environmental observations in a relational database designed to facilitate integrated analysis of large data sets collected by multiple investigators. Within this data model, observations are stored with sufficient ancillary information (metadata) about the observations to allow them to be unambiguously interpreted and to provide traceable heritage from raw measurements to useable information. The …

Advanced Algorithms For Vlsi: Statistical Circuit Optimization And Cyclic Circuit Analysis, Osama Neiroukh

Dissertations and Theses

This work focuses on two emerging fields in VLSI. The first is use of statistical formulations to tackle one of the classical problems in VLSI design and analysis domains, namely gate sizing. The second is on analysis of nontraditional digital systems in the form of cyclic combinational circuits.

In the first part, a new approach for enhancing the process-variation tolerance of digital circuits is described. We extend recent advances in statistical timing analysis into an optimization framework. Our objective is to reduce the performance variance of a technology-mapped circuit where delays across elements are represented by random variables which capture …

Test007: Case 20-30, Tractor Museum

Case-New Holland

All tractors tested at the Nebraska Tractor Test Laboratory were certified by their manufacturers as being stock model machines, conforming to specifications filed with the application for test. No special or high-test fuels were used except as recommended by the manufacturer as necessary.

All results within the official tractor test report were actually attained in tests and are without correction or allowances for friction, temperature, altitude, etc. The results were initially accomplished with the tractor in charge of skilled operators employed by the University.

Unless otherwise noted, each tractor was apparently in good condition at the end of the testing …

Validation Of Tropospheric Emission Spectrometer (Tes) Nadir Ozone Profiles Using Ozonesonde Measurements, Ray Nassar, Jennifer A. Logan, Helen M. Worden, Inna A. Megretskaia, Kevin W. Bowman, Gregory B. Osterman, Anne M. Thompson, David W. Tarasick, Shermane Austin, Hans Claude, Manvendra K. Dubey, Wayne K. Hocking, Bryan J. Johnson, Everette Joseph, John Merrill, Gary A. Morris, Mike Newchurch, Samuel J. Oltmans, Françoise Posny, F. J. Schmidlin, Holger Vömel, David N. Whiteman, Jacquelyn C. Witte

Publications and Research

We compare Tropospheric Emission Spectrometer (TES) version 2 (V002) nadir ozone profiles with ozonesonde profiles from the Intercontinental Chemical Transport Experiment Ozonesonde Network Study, the World Ozone and Ultraviolet Data Center, the Global Monitoring Division of the Earth System Research Laboratory, and the Southern Hemisphere Additional Ozonesonde archives. Approximately 1600 coincidences spanning 72.5°S–80.3°N from October 2004 to October 2006 are found. The TES averaging kernel and constraint are applied to the ozonesonde data to account for the TES measurement sensitivity and vertical resolution. TES sonde differences are examined in six latitude zones after excluding profiles with thick high clouds. Values …

Channel Modeling For Vehicle-To-Vehicle Communications, David W. Matolak

Faculty Publications

Physical layer channel modeling is critical for design and performance evaluation at multiple layers of the communications protocol stack. In this article we describe and provide results for modeling vehicle-to-vehicle (V2V) wireless channels. V2V settings produce some unique conditions, and due to these conditions, V2V channels often exhibit greater dynamics than many conventional channels and, in addition, can also exhibit more severe fading. Thus, new channel models are needed to characterize this setting in order to evaluate contending transmission schemes and aid in V2V communication system design. A brief review of key statistical channel parameters is provided. Then both analytical …

Development Of A Low-Cost Fine Steering Mirror, Steven R. Wassom, Morgan Davidson

Space Dynamics Laboratory Publications

The Space Dynamics Laboratory has used internal funds to develop a prototype low-cost two-axis fine steering mirror (FSM) for space-based and airborne applications. The FSM has a lightweight 75 mm-by- 150-mm high-reflectance mirror, high angular deflection capability for along-track ground motion compensation and cross-track pointing, and a 70-Hertz bandwidth for small amplitudes to help cancel unwanted jitter. It makes use of off-the-shelf components as much as possible. Key performance parameters are: Clear aperture, 75 mm; elevation angle, ±15 deg (mechanical); azimuth angle, ±60 deg (mechanical); slew rate, greater than 75 deg/sec; bandwidth, 70 Hz; steady-state average error, about 1 arcsec; …

An Investigation Of Positive Engagement, Continuously Variable Transmissions, Ryan R. Dalling

Theses and Dissertations

A Positive Engagement, Continuously Variable Transmission (PECVT) allows for a continuously variable transmission ratio over a given range using positively engaged members, such as gear teeth, to transmit torque. This research is an investigation of PECVTs to establish a classification system and governing principles that must be satisfied for an embodiment to overcome the non-integer tooth problem. Results of an external patent search are given as examples of different concepts and PECVT embodiments that have been employed to negate the effects of the non-integer tooth problem. To classify all published and unpublished PECVT embodiments, a classification system is developed, based …

Particle Composition And Size Distributions In And Around A Deep Pit Swine Operation, Randy S. Martin, P. J. Silva, Kori D. Moore, M. Erupe, V. S. Doshi

Civil and Environmental Engineering Faculty Publications

The contribution of emissions from agricultural facilities is rapidly becoming a major concern for local and regional air quality. Characterization of particle properties such as physical size distribution and chemical composition can be valuable in understanding the processes contributing to emissions and ultimate fate of particulate matter from agricultural facilities. A measurement campaign was conducted at an Iowa, deep-pit, three-barn swine finishing facility to characterize near-source ambient particulate matter. Size-specific mass concentrations were determined using minivol samplers, with additional size distribution information obtain using optical particle counters. Particulate composition was determined via ion chromatographic analysis of the collected filters. A …

Ceas E-News 05.06.2008, College Of Engineering And Applied Sciences

College of Engineering and Applied Sciences News

CEAS directs engineering sessions for KAMSC students

The Cubesat Role In New Science And Commercial Applications: International Workshop On Small Satellite, New Missions And New Technologies, Robert J. Twiggs

Robert "Bob" Twiggs STEM Education Collection

A PowerPoint Presentation created by Professor Bob Twiggs titled "The CubeSat Role in new Science and Commercial Applications: International Workshop on Small Satellite, New Missions and New Technologies" from June 6, 2008.

Credit-Based Dynamic Reliability Management Using Online Wearout Detection, John Y. Oliver, Rajeevan Amirtharajah, Venkatesh Akella, Frederic T. Chong

Electrical Engineering

As circuit geometries continue to shrink, and supply voltages remain relatively constant, circuit wearout becomes a concern. We propose that the relative reliability of the circuits of a processor be exposed to the operating system, and be managed by a credit-based wearout monitor. This wearout monitor receives dynamic updates of the reliability of circuits through the use of stability detector circuits that are small enough to be widely deployed. We find that through the combined use of the wearout monitor and stability detectors, we can efficiently and accurately manage the reliability of a processor, and re-coup the performance of a …