Engineering Commons^™

Synoptic Assessment Of Wetland Function: A Planning Tool For Protection Of Wetland Species Biodiversity, E. William Schweiger, Scott Leibowitz, Jeffrey Hyman, Walt E. Foster, Marla C. Downing

United States Environmental Protection Agency: Publications

We present a synoptic assessment intended to maximize the benefits to wetland species biodiversity gained through Clean Water Act regulatory efforts within 225 sub-basins in Missouri, Iowa, Nebraska and Kansas (US Environmental Protection Agency, Region 7), USA. Our assessment provides a method for prioritizing sub-basins potentially critical for supporting wetland species biodiversity and may assist environmental managers and conservationists constrained by limited resources. We prioritize sub-basins based on the projected increase in the risk of wetland species extirpation across Region 7 that would be avoided by applying a unit of regulatory protection effort within a sub-basin. Because the projected increase …

Synoptic Assessment Of Wetland Function: A Planning Tool For Protection Of Wetland Species Biodiversity, E. William Schweiger, Scott G. Leibowitz, Jeffrey B. Hyman, Walt E. Foster, Marla C. Downing

United States Environmental Protection Agency: Publications

We present a synoptic assessment intended to maximize the benefits to wetland species biodiversity gained through Clean Water Act regulatory efforts within 225 sub-basins in Missouri, Iowa, Nebraska and Kansas (US Environmental Protection Agency, Region 7), USA. Our assessment provides a method for prioritizing sub-basins potentially critical for supporting wetland species biodiversity and may assist environmental managers and conservationists constrained by limited resources. We prioritize sub-basins based on the projected increase in the risk of wetland species extirpation across Region 7 that would be avoided by applying a unit of regulatory protection effort within a sub-basin. Because the projected increase …

Using Mussel Isotope Ratios To Assess Anthropogenic Nitrogen Inputs To Freshwater Ecosystems, R. A. Mckinney, J.L. Lake, M. A. Charpentier, S. Ryba

United States Environmental Protection Agency: Publications

Stable nitrogen isotope ratios (δ¹⁵N) of freshwater mussels from a series of lakes and ponds were related to watershed land use characteristics to assess their utility in determining the source of nitrogen inputs to inland water bodies. Nitrogen isotope ratios measured in freshwater mussels from 19 lakes and ponds in Rhode Island, U.S.A., ranged from 4.9–12.6% and were found to significantly correlate with the fraction of residential development in 100 and 200 m buffer zones around the ponds. Mussel δ¹⁵N values in 12 of the 19 ponds also showed significant correlation with average dissolved nitrate concentrations, …

Implementation Of The Biological Opinion For The Missouri River Main Stem System, Missouri River Bank Stabilization And Navigation Project, Kansas River Reservoir System

United States Army Corps of Engineers, Omaha District

The Endangered Species Act (ESA) requires that the Corps of Engineers (Corps), in coordination with the appropriate resource agencies, will ensure that any action authorized, funded, or carried out is not likely to jeopardize the continued existence of any federally listed threatened or endangered species or result in the destruction or adverse modification of critical habitat. Formal consultation between the U.S. Fish and Wildlife Service (Service) and the Corps under Section 7 of the ESA culminated with the "Biological Opinion on the Operation of the Missouri River Main Stem System, Operation and Maintenance of the Missouri River Bank Stabilization and …

Effect Of Exposure Time On The Fatigue Crack Growth Behavior Of Aircraft Skin Material, Kathryn Lemasters, Tarun Goswami

Biomedical, Industrial & Human Factors Engineering Faculty Publications

The objective of this research project is to identify the effects of service exposure on aircraft materials. The senior author participated in the KC-135 Corrosion Prevention Program conducted by the University of Utah, Salt Lake City. Data from this research program was analyzed to compare the fatigue crack growth rates of aged aircraft materials with those of virgin materials. 2024-T3(clad) Middle Tension (M(T)) specimens were machined from the fuselage and upper wing skins of a retired aircraft. Fatigue crack growth rate (da/dN) and mode 1 stress intensity factor range (Δ K) plots were generated for both sets of data. The …

Effect Of Ga Content On Defect States In Cuin1-XGaXSe2 Photovoltaic Devices, Jennifer T. Heath, J. David Cohen, William N. Shafarman, Dongxiang Liao, Angus Rockett

Faculty Publications

Defects in the band gap of CuIn_1-xGa_xSe₂ have been characterized using transient photocapacitance spectroscopy. The measured spectra clearly show response from a band of defects centered around 0.8 eV from the valence band edge as well as an exponential distribution of band tail states. Despite Ga contents ranging from Ga/(In+Ga)=0.0 to 0.8, the defect bandwidth and its position relative to the valence band remain constant. This defect band may act as an important recombination center, contributing to the decrease in device efficiency with increasing Ga content.

Implementation And Validation Of Range Imaging On A Uhf Radar Wind Profiler, P. B. Chilson, Tian-You Yu, Richard G. Strauch, Andreas Muschinski, Robert D. Palmer

Department of Electrical and Computer Engineering: Faculty Publications

The available range resolution of pulsed radar wind profilers is usually limited by bandwidth restrictions. Range imaging (RIM) has recently been developed as a means of mitigating these limitations by operating the wind profilers over a small set of distinct transmitter frequencies. A constrained optimization method can then be used to generate high-resolution maps of the reflectivity field as a function of range. This paper presents a description of how the RIM technique has been recently implemented on the Platteville 915-MHz tropospheric profiler, the first such implementation at UHF. Examples of data collected during a two-part experiment on 10 April …

Field Analyses Of Rdx And Tce In Groundwater During A Gcw Pilot Study, Andrew Curtis Elmore, Lisa A. Travaglin, Jennifer L. Triplett

Geosciences and Geological and Petroleum Engineering Faculty Research & Creative Works

Contaminant concentrations in groundwater are typically analyzed using traditional laboratory analytical procedures approved by the Environmental Protection Agency (EPA) or state regulatory agencies. The use of off-site laboratories provides very high-quality water quality data at a relatively high cost in terms of time and money. Yet there are many instances when it is desirable to have water quality data measured in the field. The field methods for measuring water quality typically cost much less than the corresponding laboratory methods. However, the usability of the field data may be uncertain when the results are qualitatively compared to duplicate laboratory results. Groundwater …

Extraction Of Silymarin Compounds From Milk Thistle (Silybum Marianum) Seed Using Hot, Liquid Water As The Solvent, J.F. Alvarez Barreto

Inquiry: The University of Arkansas Undergraduate Research Journal

High value specialty chemicals are usually obtained from natural products by extracting with generally regarded as safe (GRAS) solvents. Because organic solvents are quite often used, high operating and disposal costs often occur. When compared to traditional solvents, water can be viewed as an interesting alternative because of its low operating and disposal costs. Milk thistle contains compounds (taxifolin, silychristin, silydianin, silybinin A and silybinin B) that display hepatoxic protection properties. This paper examines the batch extraction of silymarin compounds from milk thistle seed meal in 50'C, 70'C, 85'C and 100'C water as a function of time. For taxifolin, silychristin, …

Automatic Referencing Of Multi-Spectral Images, Roberto Araiza, Hongjei Xie, Scott A. Starks, Vladik Kreinovich

Departmental Technical Reports (CS)

No abstract provided.

Non-Destructive Testing Of Aerospace Structures: Granularity And Data Mining Approach, Roberto Osegueda, Vladik Kreinovich, Lakshmi Potluri, Richard Alo

Departmental Technical Reports (CS)

For large aerospace structures, it is extremely important to detect faults, and non-destructive testing is the only practical way to do it. Based on measurements of ultrasonic waves, Eddy currents, magnetic resonance, etc., we reconstruct the locations of the faults. The best (most efficient) known statistical methods for fault reconstruction are not perfect. We show that the use of expert knowledge-based granulation improves the quality of fault reconstruction.

Uncertainty In Risk Analysis: Towards A General Second-Order Approach Combining Interval, Probabilistic, And Fuzzy Techniques, Scott Ferson, Lev Ginzburg, Vladik Kreinovich, Hung T. Nguyen, Scott A. Starks

Departmental Technical Reports (CS)

Uncertainty is very important in risk analysis. A natural way to describe this uncertainty is to describe a set of possible values of each unknown quantity (this set is usually an interval), plus any additional information that we may have about the probability of different values within this set. Traditional statistical techniques deal with the situations in which we have a complete information about the probabilities; in real life, however, we often have only partial information about them. We therefore need to describe methods of handling such partial information in risk analysis. Several such techniques have been presented, often on …

Use Of Satellite Image Referencing Algorithms To Characterize Asphaltic Concrete Mixtures, Scott A. Starks, Soheil Nazarian, Vladik Kreinovich, Joseph Adidhela

Departmental Technical Reports (CS)

A natural way to test the structural integrity of a pavement is to send signals with different frequencies through the pavement and compare the results with the signals passing through an ideal pavement. For this comparison, we must determine how, for the corresponding mixture, the elasticity E depends on the frequency f in the range from 0.1 to 10^5 Hz. It is very expensive to perform measurements in high frequency area (above 20 Hz). To avoid these measurements, we can use the fact that for most of these mixtures, when we change a temperature, the new dependence changes simply by …

Extending Direct Manipulation In A Text Editor, David G. Novick, Francisco Romero, Edgar Rene Saenz, Armando Sandoval

Departmental Papers (CS)

This paper describes the implementation of a prototype text editor that incorporates conversation-like features through the direct-manipulation modality. In this way, traditional direct-manipulation interaction techniques such as direct reference via pointing can be extended to include techniques more commonly associated with human conversation, such as negotiation of reference. The paper illustrates the use of the prototype with an extended example, and discusses research issues raised by the implementation.

Nebraska Blueprint – Winter 2002

Nebraska Blueprint (Student Publication)

Table of Contents:

From the Editor

From the Office of College Relations – Restructuring of Dean's Office expands services to students—on all three campuses—and alumni.

College Sees Many Exciting Changes – A letter from Dr. John Ballard, Associate Dean

Coming to America: French Student Experiences NU Culture – Karine Hubert grew up in a small French town with little knowledge about America. Her studies at NU changed all that.

Venturing Out: Students Study Abroad in Germany – Engineering students Mark Dietz and John Prauner learn about more than engineering while studying in Germany.

Ambassadors, Diplomats Take on Leadership Roles

Diversity …

Multiple Model Networks In Non-Linear System Modelling For Control – A Review, Ruiyao Gao, Aidan O'Dwyer

Conference papers

Non-linear processes, by their nature, are non-uniform and invariably require custom designed control schemes to deal with individual characteristics. No general theory deals comprehensively with the wide range of non-linear systems encountered. In an attempt to accurately model non-linear dynamical systems, a wide variety of techniques have been developed such as non-linear auto-regressive moving average with exogeneous inputs (NARMAX) models (Chen and Billings, 1989), Weiner models (Schetzen, 1981), Hammerstein models (Billings and Fakhouri, 1982) and Multiple Layer Perceptron (MLP) neural networks (Narendra and Kannan, 1990). While the accuracy of such models offers a potentially significant improvement over linear models, the …

Uniqueness Of Bilevel Image Degradations, Elisa H. Barney Smith

Electrical and Computer Engineering Faculty Publications and Presentations

Two major degradations, edge displacement and corner erosion, change the appearance of bilevel images. The displacement of an edge determines stroke width, and the erosion ofa corner affects crispness. These degradations are functions of the system parameters: the point spread function (PSF) width and functional form, and the binarization threshold. Changing each of these parameters will affect an image differently. A given amount of edge displacement or amount of erosion of black or white corners can be caused by several combinations of the PSF width and the binarization threshold. Any pair of these degradations are unique to a single PSF …

A Congestion Controlled Logical Topology For Multihop Optical Networks, U. Bhattacharya, D. Datta, Badrul H. Chowdhury, G. C. Saha, B. K. Sikdar

Electrical and Computer Engineering Faculty Research & Creative Works

This paper considers the problem of designing the logical topology for any wavelength routed optical network, given the traffic matrix. An heuristic algorithm is proposed here for designing topologies based on the De-Bruijn graph and we compare our results with those obtained through the deterministic approach. The De-Bruijn graph is selected in this context as the logical topology due to some of its characteristic features like simple routing scheme, low diameter and small degree.

Radiation Resistance Testing Of Mosfet And Cmos As A Means Of Risk Management, Akira Tokuhiro, Massimo F. Bertino

Nuclear Engineering and Radiation Science Faculty Research & Creative Works

Whether for military, research (space, accelerator physics) and/or civilian use, risk avoidance against radiation-induced damage is not possible with COTS parts. Thus the sensible approach is risk management. We recommend a sensible risk management approach as follows: 1) know the radiation environment of the intended application to the extent possible; 2) know the effects of ionizing radiation on the component(s) of interest; 3) know the requirements of the application; 4) identify the candidate or chosen components; 5) test the components; 6) design-in safety factor margins to the extent possible.

Second-Order Statistical Properties Of The Wss Jakes' Fading Channel Simulator, Chengshan Xiao, Y. Rosa Zheng, N. C. Beaulieu

Electrical and Computer Engineering Faculty Research & Creative Works

An improved Jakes' (1994) fading channel simulator was proposed by Pop and Beaulieu (see ibid., vol.49, p.699-708, Apr. 2001) to eliminate the stationarity problem occurring in Jakes' original design. In this paper, second-order statistical properties of the improved Jakes' simulator are analyzed. Consistent with Pop and Beaulieu's caution about high-order statistics of the simulator, it is proved that some second-order statistics of both the quadrature components and the envelope do not match the desired ones even if the number of sinusoids approaches infinity. Therefore, care must be taken when the simulator is employed to evaluate algorithms and systems.

Software Engineering As A Business, Ann K. Miller, C. Ebert

Electrical and Computer Engineering Faculty Research & Creative Works

No abstract provided.

Logic Functions From Three-Terminal Quantum Resistor Networks For Electron Wave Computing, Cheng-Hsiao Wu, Diwakar Ramamurthy

Electrical and Computer Engineering Faculty Research & Creative Works

Electron transmission characteristics through a generalized three-terminal clean Aharonov-Bohm ring is investigated with an arbitrary terminal configuration. This three-terminal ring is shown to be the most basic quantum resistor network that is suitable for electron wave computing, as we demonstrate in this work. There are four basic classes of three-terminal rings. The scaling relation in each class is deduced. Thus the transmission characteristics in each class are valid from an atomic-scale-sized ring to a mesoscopic-scale-sized one, limited only by the electron phase-breaking length. The Buttiker symmetry rule is essential when searching for basic logic functions. Logic functions such as IF-THEN, …

Apparatus For Comminution Of Solid Materials Using A Processor-Controlled Liquid Jet, Marian Mazurkiewicz

Mining Engineering Faculty Research & Creative Works

The present invention is directed to a tire comminution apparatus that is of simple construction and that can be operated without excessive maintenance. According to the present invention, a vehicle tire of any size or composition can be comminuted with essentially the same comminution apparatus. The comminution apparatus includes a freely moving lance with a nozzle for transforming a liquid into a high velocity liquid jet. The lance is positioned and controlled such that the liquid jet impacts the tire thereby separating it into its component parts. The comminution apparatus may be computer controlled.

Atmospheric Turbulence Conditions Leading To Focused And Folded Sonic Boom Wave Fronts, Andrew A. Piacsek

All Faculty Scholarship for the College of the Sciences

The propagation and subsequent distortion of sonic booms with rippled wave fronts are investigated theoretically using a nonlinear time-domain finite-difference scheme. This work seeks to validate the rippled wave front approach as a method for explaining the significant effects of turbulence on sonic booms [A. S. Pierce and D. J. Maglieri, J. Acoust. Soc. Am. 51, 702–721 (1971)]. A very simple description of turbulence is employed in which velocity perturbations within a shallow layer of the atmosphere form strings of vortices characterized by their size and speed. Passage of a steady-state plane shock front through such a vortex layer …

Flow Shop Scheduling Problem: A Computational Study, Amr Arisha, Paul Young, Mohie El Baradie

Conference papers

A computational study has been developed to obtain optimal / near optimal solution for the flow shop scheduling problem with make-span minimization as the primary criterion and the minimization of either the mean completion time, total waiting time or total idle time as the secondary criterion. The objective is to determine a sequence of operations in which to process ‘n’ jobs on ‘m’ machines in same order (flow shop environment) where skipping is allowed. The Simulation approach for deterministic and stochastic flow shop scheduling has been developed. It reads and manipulates data for 500 jobs on 500 machines. Different factorial …

Impulse, Dave Graves, Kyle Johnson, Jill Hlavacek

Impulse (Jerome J. Lohr College of Engineering Publication)

Features:
[Page] 2 Yellowstone solar project creates powerful memories
[Page] 4 Crothers contractor on schedule for summer completion
[Page] 6 Engineering Resource Center enhances region's commerce
Students:
[Page] 8 More students remain in state for engineering, technology jobs
[Page] 10 Enrollment booming in 'practical' engineering department
[Page] 12 Job Fair gives students inside track at careers
[Page] 13 Students gain valuable insight as engineering interns
[Page] 14 Electrical engineering staff hails from five different countries
[Page] 15 Finding excellence in FE test
[Page] 16 Even when you fall short, there's much to be gained
[Page] 17 Student marksmen outfire professional …

Holographically Recorded Photopolymer Diffractive Optical Element For Holographic And Electronic Speckle Pattern Interferometry, Sridhar Guntaka, Vincent Toal, Suzanne Martin

Articles

A diffractive optical element is described that can be used to implement a self-aligning electronic speckle apttern interferometer and holographic interferometer requiring only a laser source and a camera in the optical set-up.

Systemic Issues In Asynchronous Delivery Of Graduate Engineering Management Programs, Charles Keating, David Dryer, Andres Sousa-Poza, William Peterson, Robert Safford

Engineering Management & Systems Engineering Faculty Publications

The purpose of this paper is to examine systemic issues that impact the design, delivery, and maintenance of asynchronous engineering management educational products. Asynchronous education continues to rapidly evolve as an alternative to traditional classroom delivery. An asynchronous educational system requires the effective integration of technology, supporting processes, and infrastructure design to prepare, deliver, and maintain asynchronous educational products. Currently, the technological capabilities for delivery of asynchronous education have outstripped the ability to maximize those advanced technologies. To help understand this rift between technology and our ability to deploy that technology this paper examines three critical areas. First, the distinctions …

Engineering Management- The Minor Of Choice, William Peterson, Paul Kauffmann, Charles Keating, Resit Unal

Engineering Management & Systems Engineering Faculty Publications

The minor in engineering management provides several real benefits to undergraduate engineering and engineering technology students, not the least of which can be a substantially larger starting salary. The other benefits it offers students are in the skill sets developed (project management, engineering economics, organization behavior / principles of management, and either statistical concepts or decision techniques), the preparation to start an engineering management graduate degree, and the bridging of the competency gaps identified in several national surveys. This paper addresses the benefits of the minor to engineering management programs.

A Task Process Pre-Experimental Model, Holly A. H. Handley, Alexander H. Lewis

Engineering Management & Systems Engineering Faculty Publications

The Adaptive Architectures for Command and Control (A2C2) program is a multidisciplinary program that employs a scientific basis for designing and analyzing adaptive and reconfigurable organizational structures at the Joint Task Force level. As part of its unique model-driven experimentation method, a pre-experimental model is created to support the formulation of hypotheses, the determination of key variables and parameter values, and the prediction of organizational performance. The pre-experimental model is used to explore the parameters of the experimental design in order to determine the appropriate region to conduct officer-in-the-loop experiments at the Naval Postgraduate School. A pre-experimental model based on …