Engineering Commons^™

Effects From Filtration, Capping Agents, And Presence/Absence Of Food On The Toxicity Of Silver Nanoparticles To Daphnia Magna, H. Joel Allen, Christopher A. Impellitteri, Dana A. Macke, J. Lee Heckman, Helen C. Poynton, James M. Lazorchak, Shekar Govindaswamy, Deborah L. Roose, Mallikarjuna N. Nadagouda

United States Environmental Protection Agency: Publications

Relatively little is known about the behavior and toxicity of nanoparticles in the environment. Objectives of work presented here include establishing the toxicity of a variety of silver nanoparticles (AgNPs) to Daphnia magna neonates, assessing the applicability of a commonly used bioassay for testing AgNPs, and determining the advantages and disadvantages of multiple characterization techniques for AgNPs in simple aquatic systems. Daphnia magna were exposed to a silver nitrate solution and AgNPs suspensions including commercially available AgNPs (uncoated and coated), and laboratory-synthesized AgNPs (coated with coffee or citrate). The nanoparticle suspensions were analyzed for silver concentration (microwave acid digestions), size …

Persistent Organic Pollutants In Fish Tissue In The Mid-Continental Great Rivers Of The United States, Karen A. Blocksom, David M. Walters, Terri M. Jicha, James M. Lazorchak, Theodore R. Angradi, David W. Bolgrien

United States Environmental Protection Agency: Publications

Great rivers of the central United States (Upper Mississippi, Missouri, and Ohio rivers) are valuable economic and cultural resources, yet until recently their ecological condition has not been well quantified. In 2004– 2005, as part of the Environmental Monitoring and Assessment Program for Great River Ecosystems (EMAPGRE), we measured legacy organochlorines (OCs) (pesticides and polychlorinated biphenyls, PCBs) and emerging compounds (polybrominated diphenyl ethers, PBDEs) in whole fish to estimate human and wildlife exposure risks from fish consumption. PCBs, PBDEs, chlordane, dieldrin and dichlorodiphenyltrichloroethane (DDT) were detected in most samples across all rivers, and hexachlorobenzene was detected in most Ohio River …

Biological Opinion On The Operation Of The Missouri River Main Stem System, Operation And Maintenance Of The Missouri River Bank Stabilization And Navigation Project, And Operation Of The Kansas River Reservoir System

United States Army Corps of Engineers, Omaha District

This Annual Report summarizes implementation efforts in response to the Biological Opinion on the Operation of the Missouri River Main Stem System, Operation and Maintenance of the Missouri River Bank Stabilization and Navigation Project, and Operation of the Kansas River Reservoir System. The document improves upon the previous annual Biological Opinion (BiOp) compliance reports by incorporating:

• The first combined U.S. Fish and Wildlife (USFWS) and U.S. Army Corps of Engineers (Corps) report documenting recovery efforts on the Missouri River satisfying reporting requirements of the 2003 Amended BiOp on the Operation of the Missouri River Main Stem System (System), Operation …

Bottom Flange Reinforcement In Nu I-Girders, George Morcous Ph.D., Kromel Hanna Ph.D., Maher K. Tadros Ph.D., P.E.

Mid-America Transportation Center: Final Reports and Technical Briefs

The 1996 edition of AASHTO Standard Specifications for Highway Bridges stated that nominal confinement reinforcement be placed to enclose prestressing steel in the bottom flange of bridge girders from girder ends to at least a distance equal to the girder’s height. The 2004 edition of AASHTO LRFD Bridge Design Specifications changed the distance over which the confinement reinforcement was to be distributed from 1.0h to 1.5h, and gave minimum requirements for the amount of steel to be used, No.3 bars, and their maximum spacing, not to exceed 6.” Research was undertaken to study what impact, if any, confinement reinforcement had …

Load Rating Of Complex Bridges, George Morcous Ph.D., Kromel Hanna Ph.D., Maher K. Tadros Ph.D., P.E.

Mid-America Transportation Center: Final Reports and Technical Briefs

The National Bridge Inspection Standards require highway departments to inspect, evaluate, and determine load ratings for structures defined as bridges located on all public roads. Load rating of bridges is performed to determine the live load that structures can safely carry at a given structural condition. Bridges are rated for three types of loads, design loads, legal loads, and permit loads, which is a laborious and time-consuming task as it requires the analysis of the structure under different load patterns. Several tools are currently available to assist bridge engineers to perform bridge rating in a consistent and timely manner. However, …

Study Of Rf Propagation Characteristics For Wireless Sensor Networks In Railroad Environments, Hamid Sharif, Michael Hempel

Mid-America Transportation Center: Final Reports and Technical Briefs

The freight railroad industry in North America is exerting efforts to leverage Wireless Sensor Networks to monitor systems and components on railcars. This allows fault detection and accident prevention even while a train is moving. Railcars, constructed mostly of ferrous materials such as steel, are expected to severely impact signal propagation. To better understand this effect we first evaluated the signal characteristics when sensor nodes are placed in various locations around railcars. We used EM-Field modeling and evaluation techniques to obtain these results and found that node placement selection is critical for the node’s communication distance. As a second research …

Performance Measures Of Warm Asphalt Mixtures For Safe And Reliable Freight Transportation, Hosin "David" Lee Ph.D., P.E., Yongjoo "Thomas" Kim

Mid-America Transportation Center: Final Reports and Technical Briefs

Warm mix asphalt (WMA) is an emerging technology that can allow asphalt to flow at a lower temperature for mixing, placing and compaction. The advantages of WMA include reduced fuel consumption, less carbon dioxide emission, longer paving season, longer hauling distance, reduced oxidation of asphalt, early opening to traffic and a better working environment in the field. In the United States, WMA has become popular in recent years. However, to provide a safe and reliable highway for heavier truck traffic with a high tire pressure, WMA mixtures must meet requirements for strength, stiffness, rutting, and moisture resistance.

WMA mixtures with …

Extending Asphalt Pavement Life Using Thin Whitetopping, Mustaque Hossain, Sharmin Sultana

Mid-America Transportation Center: Final Reports and Technical Briefs

Due to budget constraints, many highway agencies are becoming interested in pavement preservation or rehabilitation rather than reconstruction to ensure pavement is in serviceable condition. Thin whitetopping (TWT) is the process of rehabilitating distressed asphalt concrete (AC) pavements by using a concrete overlay. This study was done to develop a design catalog for existing AC pavements to be overlaid with TWT. The finite element (FE) analysis was performed with SolidWorks, which is the 3-D FE software program used to develop this design catalog. The design considered different TWT thicknesses, existing AC layer thickness and modulus, the bonding condition between TWT …

Assessing The Damage Potential In Pretensioned Bridges, Caused By Increased Truck Loads Due To Freight Movements (Phase I), Robert J. Peterman, Steven Hammerschmidt

Mid-America Transportation Center: Final Reports and Technical Briefs

When evaluating the condition of existing bridges determining in situ stresses in the members provides valuable information about the condition of the structures. In this study, a method of surface strain relief was investigated whereby the change in strain at the surface of concrete members is used to determine the in situ stress. The method involved mounting a linear electrical-resistance strain gage along the axis of maximum stress, coring around the gage, and then relating the change in strain to the corresponding stress in the member. Members were fabricated and varying stresses were applied in order to determine the accuracy …

Characteristics And Contributory Causes Related To Large Truck Crashes (Phase I) -Fatal Crashes, Sundanda Dissanayake Ph.D., P.E.

Mid-America Transportation Center: Final Reports and Technical Briefs

One-ninth of all traffic fatalities in the United States have involved large trucks in the past five years, although large trucks contributed to only 3% of registered vehicles and 7% of vehicle miles travelled. This contrasting proportion indicates that truck crashes in general tend to be more severe than other crashes though they constitute a smaller sector of vehicles on the road. To study this issue, fatal crash data from the FARS was used to analyze characteristics and factors contributing to truck-involved crashes. Driver, vehicle, and crash-related contributory causes were identified, and as an extension the likelihood of occurrence of …

Improving Freight Fire Safety: Assessment Of The Effectiveness Of Mist-Controlling Additives In Mitigating Crash-Induced Diesel Fires, Albert Ratner Ph.D.

Mid-America Transportation Center: Final Reports and Technical Briefs

Adding long chained polymers to diesel has been proposed as a method to prevent crash fires by arresting the break-up of diesel fuel into a fine mist in transportation related accidents. The effect of such additives on the flow properties of diesel was investigated by studying the impact of poly-butadiene and diesel blend drops on a solid surface using high speed imaging. The addition of the polymer imparted shear-thinning behavior to diesel, and the base viscosities increased rapidly with polymer concentration. Four concentrations of the polymer were tested at three different impact speeds under atmospheric pressure. Maximum spread factors and …

Proposed Implementation Of A Cottonwood Management Plan Along Six Priority Segments Of The Missouri River

United States Army Corps of Engineers, Omaha District

The Missouri River originates in the Rocky Mountains of south-central Montana and flows approximately 2,341 miles through seven states, ending at its confluence with the Mississippi River near St. Louis, Missouri. The plains cottonwood (Populus deltoides) was once the dominant floodplain vegetation in the Missouri River ecosystem (Corps 2006a). Natural cottonwood regeneration has largely ceased along the Missouri River following the construction of the Missouri River Mainstem Reservoir System (System) and Bank Stabilization and Navigation Project (BSNP). The reduction in the number of young cottonwoods to replace older cottonwoods concerns biologists because a variety of plant and wildlife …

Discrete Coordinate Transformation For Designing All-Dielectric Flat Antennas, Wenxuan Tang, Christos Argyropoulos, Efthymios Kallos, Wei Song, Yang Hao

Department of Electrical and Computer Engineering: Faculty Publications

Transformation electromagnetics provides a practical approach to control electromagnetic fields at will. Based on this principle, novel devices such as the invisible cloak have been proposed. Here we examine the extension of this technique as applied to the design of flat devices in antenna systems. A method using discrete coordinate transformation is proposed, which allows the conversion of conventional devices with curved shapes into flat systems, while preserving their non-dispersive, isotropic, broadband, and lossless properties. Two specific design examples, a flat reflector and a flat lens embedded in free space, are presented. To avoid the loss and narrow bandwidth issues …

Clustering Of Protein Families Into Functional Subtypes Using Relative Complexity Measure With Reduced Amino Acid Alphabets, Aydin Albayrak, Hasan H. Otu, Ugur O. Sezerman

Department of Electrical and Computer Engineering: Faculty Publications

Background: Phylogenetic analysis can be used to divide a protein family into subfamilies in the absence of experimental information. Most phylogenetic analysis methods utilize multiple alignment of sequences and are based on an evolutionary model. However, multiple alignment is not an automated procedure and requires human intervention to maintain alignment integrity and to produce phylogenies consistent with the functional splits in underlying sequences. To address this problem, we propose to use the alignment-free Relative Complexity Measure (RCM) combined with reduced amino acid alphabets to cluster protein families into functional subtypes purely on sequence criteria. Comparison with an alignment-based approach was …

Bioinformatic Identification And Characterization Of Human Endothelial Cell-Restricted Genes, Manoj Bhasin, Lei Yuan, Derin B. Keskin, Hasan H. Otu, Towia A. Libermann, Peter Oettgen

Department of Electrical and Computer Engineering: Faculty Publications

Background: In this study, we used a systematic bioinformatics analysis approach to elucidate genes that exhibit an endothelial cell (EC) restricted expression pattern, and began to define their regulation, tissue distribution, and potential biological role.

Results:Using a high throughput microarray platform, a primary set of 1,191 transcripts that are enriched in different primary ECs compared to non-ECs was identified (LCB >3, FDR

Conclusion: The study provides an initial catalogue of EC-restricted genes most of which are ubiquitously expressed in different endothelial cells.

Numerical And Analytical Verification Of A Multiscale Computational Model For Impact Problems In Heterogeneous Viscoelastic Materials With Evolving Damage, Bruno Bachiega Araujo

Department of Engineering Mechanics: Dissertations, Theses, and Student Research

Composites are engineered materials that take advantage of the particular properties of each of its two or more constituents. They are designed to be stronger, lighter and to last longer which can lead to the creation of safer protection gear, more fuel efficient transportation methods and more affordable materials, among other examples.

This thesis proposes a numerical and analytical verification of an in-house developed multiscale model for predicting the mechanical behavior of composite materials with various configurations subjected to impact loading. This verification is done by comparing the results obtained with analytical and numerical solutions with the results found when …

Magneto-Optical Properties Of Cobalt Slanted Columnar Thin Films, Daniel Schmidt, Tino Hofmann, Craig M. Herzinger, Eva Schubert, Mathias Schubert

Department of Electrical and Computer Engineering: Faculty Publications

Magneto-optical properties of ferromagnetic slanted columnar thin films from cobalt made by electron-beam glancing angle deposition are reported. Magneto-optic ellipsometry in the polar Kerr effect configuration was employed to determine the field- and wavelength-dependent complex magneto-optic polarizability parameter within the spectral range from 0.74 to 3.0 eV. Kerr effect measurements and calculations reveal a strong azimuthal dependence for the incident linear polarization with peak Kerr rotation one order of magnitude larger than what has been reported for solid Co thin films.

Non-Destructiveapproachto Ellipsometric Monitoring Of A Film Coating On The Inner Surface Of A Tube Shaped Sample, Gregory K. Prilbil, John A. Woollam, Martin M. Liphardt, James D. Welch

Department of Electrical and Computer Engineering: Faculty Publications

Disclosed is the use of a focused electromagnetic beam which is caused to impinge on the top surface of a tube shaped sample, to investigate a film coating on inner surface during fabrication thereof and/or thereafter.

Valence-Shell Photoionization Of The Chlorinelike Ca3+ Ion, Ghassan A. Alna’Washi, M. Lu, M. Habibi, R. A. Phaneuf, A. L. D. Kilcoyne, A. S. Schlachter, C. Cisneros, B. M. Mclaughlin

United States Department of Energy: Publications

Absolute photoionization measurements were performed for a mixture of ²P^o_3/2 ground-state and ²P^o_1/2 metastable-state Ca³⁺ ions over the photon energy range 65.7–104.6 eV by merging an ion beam with a beam of monochromatized synchrotron radiation. The ionization threshold energy of the ²P^o_3/2 ground state was measured to be 67.063 ± 0.015 eV, which is 0.207 eV lower than the value tabulated in the NIST database. Most of the observed resonances associated with multiple Rydberg series of autoionizing states have been assigned spectroscopically using the quantum defect form of the Rydberg …

Kitab Al-Hadaya Wa Al-Tuhaf: A Unique Window On Islamic Textiles, Wendy Landry

Textile Society of America: Symposium Proceedings

During the first millennium, a rare kind of literature evolved in the Islamic world that provides a fascinating window on the interest and importance of material objects. A unique example of this literature, entitled Kitab al-Hadaya wa al-Tuhaf [Book of Gifts and Rarities] was translated into English, annotated and published in 1996 by Kuwaiti curator and scholar Ghada al Hijjawi al-Qaddumi. It is an anthology of anecdotes referring to the period between the sixth century and the twelfth century, probably compiled in the late twelfth century by an official in the Islamic Egyptian government.

Although the historical veracity of the …

Figured Velvets From Simple Looms: Velvet Pick-Up And Related Techniques For Handweavers, Wendy Landry

Textile Society of America: Symposium Proceedings

Much historical velvet was designed to be figural, often in elaborate curvilinear floral motifs, and multiple colours. These complex patterns could be efficiently designed for and executed on the available drawlooms and their successors, the jacquard looms. Faced with such complexity, and the unavailability of jacquard looms and drawlooms, few handweavers have attempted to add velvet technique to their repertoire. However, the basic principles and weave structures of velvet are relatively simple and can be executed on simpler handlooms. Pick-up techniques and simple loom modifications make figured velvet accessible for weavers without access to complex jacquard velvet looms, allowing them …

Infrared Thermography-Driven Flaw Detection And Evaluation Of Hot Mix Asphalt Pavements, Yong K. Cho, Thaddaeus Bode, Yong-Rak Kim

Nebraska Department of Transportation: Research Reports

No abstract provided.

Nebraska Water And Energy Flux Measurement, Modeling, And Research Network (Nebflux), Suat Irmak

Department of Agricultural and Biological Systems Engineering: Faculty Publications

Surface energy and water vapor fluxes play a critical role in understanding the response of agro‐ecosystems to changes in environmental and atmospheric parameters. These fluxes play a crucial role in exploring the dynamics of water and energy use efficiencies of these systems. Quantification of the fluxes is also necessary for assessing the impact of land use and management changes on water balances. Accomplishing these goals requires measurement of water vapor and energy exchanges between various vegetation surfaces and microclimates for long‐enough periods to understand the behavior and dynamics involved with the flux transfer so that robust models can be developed …

Nebraska Blueprint- Winter 2010

Nebraska Blueprint (Student Publication)

Table of Content:

3 From the Editor

4 Early Learning to Understand Engineering

6 Whittier Hall

8 The Engineering Library: A Special Resource

10 Engineering Fees

12 Student Accomplishments

Infrared Thermography-Driven Flaw Detection And Evaluation Of Hot Mix Asphalt Pavements, Yong K. Cho, Yong-Rak Kim, Thaddaeus Bode

Nebraska Department of Transportation: Research Reports

This research was conducted to study more realistic explanations of how variables are created and dealt with during hot mix asphalt (HMA) paving construction. Several paving projects across the state of Nebraska have been visited where sensory devices were used to test how the selected variables contribute to temperature differentials including density, moisture content within the asphalt, material surface temperature, internal temperature, wind speed, haul time, and equipment type. Areas of high temperature differentials are identified using an infrared camera whose usefulness was initially confirmed with a penetrating thermometer. A non-nuclear density device was also used to record how the …

Low-Cost Obstacle Detection Sensor Array For Unmanned Agricultural Vehicles, Santosh Pitla, Joe D. Luck, Scott A. Shearer

Department of Agricultural and Biological Systems Engineering: Presentations and White Papers

Mobile robots deployed for agricultural applications must operate in harsh environments where they encounter a variety of both moveable and immovable obstacles. Typically, robots utilize vision sensors to learn about the environment in which they are working. In this study, a low-cost infra-red (IR) sensor array was developed to act as an obstacle detection aid for an unmanned agricultural vehicle (UAgV). The IR sensor array developed consists of six IR sensors mounted on two orthogonal steel plates. The array of sensors was continuously oscillated about the yaw-axis to traverse a 200° field of view in front of the UAgV. Three …

Effects Of A Mass Layer With Gradually Varying Thickness On A Quartz Crystal Microbalance, Nan Liu, Jiashi Yang, Weiqiu Chen

Department of Mechanical and Materials Engineering: Faculty Publications

We study the effects of the nonuniform thickness of a thin mass layer on a quartz crystal microbalance. A theoretical analysis is performed on thickness-shear vibration of an AT-cut quartz plate with a nonuniform mass layer. Mindlin’s two-dimensional equation for thickness-shear vibration of a quartz plate is used. Free vibration frequencies and modes are obtained. The effects of the mass layer nonuniformity are examined. It is shown that resonant frequencies and energy trapping of thickness-shear modes are sensitive to mass layer nonuniformity.

Program And Proceedings: Nebraska Academy Of Sciences 1880–2010, 130th Anniversary Year, One Hundred-Twentieth Annual Meeting

Nebraska Academy of Sciences: Programs and Proceedings

Program

Aeronautics and Space Science

Chemistry and Physics

Collegiate Academy: Biology

Collegiate Academy: Chemistry and Physics

Biological and Medical Sciences

Chemistry and Physics

History and Philosophy of Science

Nebraska Wesleyan University Health and Sciences Graduate School Fair

Junior Academy, Senior High Competition/p>

Aeronautics and Space Science, Poster Session

Teaching of Science and Math

Maiben Memorial Lecture: Mark Greip, Department of Chemistry, University of Nebraska–Lincoln

Aeronautics

Anthropology

Junior Academy, Senior High Competition

Earth Science

Junior Academy, Junior High Competition

Infrared Thermography-Driven Flaw Detection And Evaluation Of Hot Mix Asphalt Pavements, Yong K. Cho, Yong-Rak Kim Ph.D., Thaddaeus Bode

Mid-America Transportation Center: Final Reports and Technical Briefs

This research was conducted to study more realistic explanations of how variables are created and dealt with during hot mix asphalt (HMA) paving construction. Several paving projects across the state of Nebraska have been visited where sensory devices were used to test how the selected variables contribute to temperature differentials including density, moisture content within the asphalt, material surface temperature, internal temperature, wind speed, haul time, and equipment type. Areas of high temperature differentials are identified using an infrared camera whose usefulness was initially confirmed with a penetrating thermometer. A non-nuclear density device was also used to record how the …

Investigating Rfid For Roadside Identification Involving Freight Commercial Vehicle Operators (Cvo), Erick C. Jones Ph.D., Judy Perkins Ph.D.

Mid-America Transportation Center: Final Reports and Technical Briefs

Radio Frequency Identification (RFID) is an emerging technology to track commercial vehicles. This transcript describes research that investigates the ability for RFID technologies to work in license plates. Mile markers are common fixtures on the roadside and may provide infrastructure to support identifying RFID to enabled Commercial Vehicle Operators (CVO). This research considers variables that affect the performance of a RFID License Plate System that uses a scanner located at the mile marker. Mile marker characteristics, such as horizontal distance and vertical height, were evaluated along with RFID tag characteristics, such tag type and license plate location.