Engineering Commons^™

Digital Human Models For Ergonomics, Jeffrey C. Woldstad

Department of Industrial and Management Systems Engineering: Faculty Publications

Digital human models in the context of this section are computer-generated representations of human beings used in computer-aided design (CAD) or similar programs. These models are increasingly being used by ergonomists and other engineers to design both equipment and work environments to meet the needs of human operators. They have the advantage of allowing the designer to explore the potential advantages and disadvantages of different design configurations without requiring the construction of expensive physical mock-ups used in the past.

Using a digital human model, design engineers can position and manipulate operators of varying anthropometry within the simulated work environment. A …

Quality Inspection Task In Modern Manufacturing, J. A. Pesante-Santana, Jeffrey C. Woldstad

Department of Industrial and Management Systems Engineering: Faculty Publications

The development of numerically controlled machines, group technology, cellular manufacturing and just-in-time (JIT) production systems have revolutionized the way products are designed and manufactured. These technological and strategic advances have changed the role of human operators in the manufacturing environment. The highly specialized work force of the low-tech manufacturing system has evolved into the multi-skilled work force of the high- tech manufacturing system. Among the multiple tasks that an operator is expected to perform in advance manufacturing systems (AMS) are job scheduling, inventory planning, machine set-up, problem-solving and quality inspection.

Throughout this evolution, human sensory detection capabilities have been a …

Doppler Estimation Using A Coherent Ultrawide-Band Random Noise Radar, Ram M. Narayanan, Muhammad Dawood

Department of Electrical and Computer Engineering: Faculty Publications

The University of Nebraska has developed an ultrawide- band (UWB) coherent random noise radar operating over the 1–2 GHz frequency range. The system achieves phase coherence by using heterodyne correlation of the received signal with a time-delayed frequency-shifted replica of the transmit waveform. Knowledge of the phase of the received signal and its time dependence due to target motion permits the extraction of the mean Doppler frequency from which the target speed can be inferred. Theoretical analysis, simulation studies, and laboratory measurements using a microwave delay line showed that it was possible to estimate the Doppler frequency from targets with …

Sar Imaging Using Fully Random Bandlimited Signals, Dmitriy S. Garmatyuk, Ram M. Narayanan

Department of Electrical and Computer Engineering: Faculty Publications

A coherent ultrawideband (UWB) random noise synthetic aperture radar (SAR) has been developed and tested at the University of Nebraska. It has been experimentally shown that this type of radar is capable of extracting the phase and the amplitude of the backscattered signal, thus enabling us to create target profiles in the frequency domain. The use of fully random waveforms (bandlimited noise) as the transmit signal is analyzed in this paper. A UWB signal model is developed and radar signal processing is simulated to yield statistical characteristics of image formation using stochastic waveforms. The influence of UWB signal characteristics on …

Low Coherence Fiber Optics For Random Noise Radar, Ruixiang Jiang, Kyle W. Wolfe, Lim Nguyen

Department of Electrical and Computer Engineering: Faculty Publications (to 2015)

Coherent random noise radar has been developed at the University of Nebraska for the detection and identification of shallow subsurface objects such as land mines. Other application ranges from remote sensing, synthetic aperture radar and high-resolution interferometer, to covert target tracking. in this paper, we describe the experimental investigation of a novel applicntion of superfluorescent fiber or erbium doped fiber amplifier (EDFA) light sources(SFS) for random noise radar. The ultra-wide band noise coupled with the use of optical fiber delay lines makes SFS ideally suited for random noise radar applications. Optical fiber- makes long and multiple-step delay lines of a …

Baseline Assessment Of The Use Of A Small Missouri River Backwater By Fish At Ponca State Park In Dixon County, Nebraska, A. Luke Wallace

United States Army Corps of Engineers, Omaha District

Ponca State Park is located adjacent to the Missouri River near the town of Ponca in Dixon County, Nebraska between river miles 753.8 and 755.3. This portion of the river is a 59-mile, unchannelized segment that has been designated as the Missouri National Recreational River under the Wild and Scenic Rivers Act. The majority of the park is situated high on bluffs that overlook the Missouri River. Until recently, the park had only a small amount of easily accessible river frontage. In 1999, the Nebraska Game and Parks Commission (NGPC) acquired an additional 295 acres of river bottomland on the …

Habitat Erosion Protection Analysis Missouri National Recreational River Nebraska And South Dakota

United States Army Corps of Engineers, Omaha District

The Corps was tasked by the National Park Service to detennine if erosion protection measures were needed to prevent further decline in cottonwood forest within the Missouri National Recreational River. The 1990's had three unusually high water years resulting in increased runoff and dam discharges, with resultant increased erosion. Concern about erosion of cottonwood forests was expressed by the public during public meetings held by the National Park Service and the Corps during 1999. Severe erosion was also evident in the comparison of aerial maps from 1985 to those from 1997. Forested habitat is considered a "wildlife value" for the …

The State And Future Of Mars Polar Science And Exploration, Stephen M. Clifford, David Crisp, David A. Fisher, Ken E. Herkenhoff, Suzanne E. Smrekar, Peter C. Thomas, David D. Wynn-Williams, Richard W. Zurek, Jeffrey R. Barnes, Bruce G. Bills, Erik W. Blake, Wendy M. Calvin, Jonathan M. Cameron, Michael H. Carr, Philip R. Christensen, Benton C. Clark, Gary D. Clow, James A. Cutts, Dorthe Dahl-Jensen, William B. Durham, Fraser P. Fanale, Jack D. Farmer, Francois Forget, Kumiko Gotto-Azuma, Rejean Grard, Robert M. Haberle, William Harrison, Ralph Harvey, Alan D. Howard, Andy P. Ingersoll, Philip B. James, Jeffrey S. Kargel, Hugh H. Kieffer, Janus Larsen, Kenneth Lepper, Michael C. Malin, Daniel J. Mccleese, Bruce Murray, John F. Nye, David A. Paige, Stephen R. Platte, Jef F J. Plaut, Niels Reeh, James W. Rice, David E. Smith, Carol R. Stoker, Kenneth L. Tanaka, Ellen Mosley-Thompson, Thorsteinn Thorsteinsson, Stephen E. Wood, Aaron Zent, Maria T. Zuber, H. Jay Zwally

Department of Mechanical and Materials Engineering: Faculty Publications

As the planet's principal cold traps, the martian polar regions have accumulated extensive mantles of ice and dust that cover individual areas of ~10⁶ km² and total as much as 3-4 km thick. From the scarcity of superposed craters on their surface, these layered deposits are thought to be comparatively young-preserving a record of the seasonal and climatic cycling of atmospheric CO₂, H₂O, and dust over the past ~10⁵-10⁸ years. For this reason, the martian polar deposits may serve as a Rosetta Stone for understanding the geologic and climatic history of …

Fractional Composition Of Grain Sorghum (Sorghum Bicolor) After Wet-Peeling In A Centrifugal Pump, K. R. Lochte-Watson, Curtis L. Weller, Kent M. Eskridge

Department of Agricultural and Biological Systems Engineering: Faculty Publications

Use of a centrifugal pump to peel and facilitate separation of grain sorghum kernels into three fractions was investigated. Special emphasis was given to separating fractions to achieve a high concentration of wax in one fraction and a high concentration of starch in another. Trials were conducted to determine the effects of both soak time and recirculation time on wet-peeling. After peeling, three fractions, peeled kernel, bran, and suspended solids, were collected. Together, the bran and suspended solids fractions contained 12.7% of the initial total dry solids, 90% of initial wax, and 8.1% of the initial starch. Peeled kernel fraction …

Narrow Grass Hedge Effects On Phosphorus And Nitrogen In Runoff Following Manure And Fertilizer Application, B. Eghball, John E. Gilley, L. A. Kramer, T. B. Moorman

Department of Agricultural and Biological Systems Engineering: Faculty Publications

Runoff losses of nitrogen (N) and phosphorus (P) from field applied manure can contribute to surface water pollution. Grass hedges may reduce runoff losses of nutrients and sediment. The objective of this study was to evaluate the effects of narrow switchgrass (,i>Panicum virgatum L.) hedges (~0.75 m wide) on the transport of P and N from a field receiving beef cattle feedlot manure under tilled and n-till conditions. This study was conducted on a steep (12% average slope) Monona silt loam (fine-silty, mixed, superactive, mesic Typic Hapludolls) soil near Treynor, Iowa. The experiment was a split-plot with no-till and …

Performance Tests Of Three-Point Mounted Implement Guidance Systems: Ii. Results, Michael F. Kocher, Michael B. Smith, Robert D. Grisso, Linda J. Young

Department of Agricultural and Biological Systems Engineering: Faculty Publications

Side-shift and disk-steer implement guidance systems were tested for differences in performance during cultivation on fields with 0 and 5% side slope. Test speeds were slow (4.8 km/h, 3 mph) and medium (8.0 km/h, 5 mph). Test path shapes included a tractor ramp, implement ramp, sine and curve. Performance measures included tractor positional error, implement positional error, torque from side forces on the cultivator non-swiveling coulters, and travel speed. Relatively few significant differences between guidance systems were detected, and most of those involved interaction with path shape. Therefore, no clear conclusion could be reached indicating one guidance system was better …

Performance Tests Of Three-Point Mounted Implement Guidance Systems: I. Procedure, Michael F. Kocher, Michael B. Smith, Robert D. Grisso, Leonard L. Bashford

Department of Agricultural and Biological Systems Engineering: Faculty Publications

A procedure is presented for determining the performance of three-point mounted implement guidance systems. A test track with tractor ramp, implement ramp, sine wave, and curve path shapes was used as the desired path to guide the tractor and implement, and as a reference location for measuring implement positional errors. Potentiometers were used with mechanical frames to measure the tractor and implement positional errors (lateral displacement between the intended and actual travel paths). An optoelectronic sensor triggered acquisition of data from all sensors at known locations [15.2 cm (6 in.) intervals] along the track. The accumulated errors for the tractor …

Water Vapor Transport Parameters Of A Cast Wheat Gluten Film, Soumya Roy, Aristippos Gennadios, Curtis Weller, Robert F. Testin

Department of Agricultural and Biological Systems Engineering: Faculty Publications

Understanding the mode of transport of water vapor through the film is important for improving the moisture barrier properties of wheat gluten (WG) films. Effective permeability (P_eff), solubility (S_eff), and diffusion (D_eff) coefficients of a hydrophilic cast WG film were determined at 25°C within the relative humidity (RH) range of 0–84% (with a 9–13% RH gradient between upstream and downstream water vapor flux). P_eff, S_eff, and D_eff increased substantially as the RH gradient moved upwards in the RH spectrum. P_eff increased by four orders of …

Effect Of Sample Complexity On Quantification Of Analytes In Aqueous Samples By Near-Infrared Spectroscopy, Mark R. Riley, Mark A. Arnold, David W. Murhammer

Department of Agricultural and Biological Systems Engineering: Faculty Publications

This study was undertaken to quantitate the impact of increasing sample complexity on near-infrared spectroscopic (NIRS) measurements of small molecules in aqueous solutions with varying numbers of components. Samples with 2, 6, or 10 varying components were investigated. Within the 10-component samples, three analytes were quantified with errors below 6% and seven of the analytes were quantified with errors below 10%. An increase in the number of varying components can substantially increase the error associated with measurement. A comparison of measurement errors across sample sets, as gauged by the standard error of prediction (SEP), reveals that an increase in the …

Production And Purification Of The Heavy Chain Fragment C Of Botulinum Neurotoxin, Serotype A, Expressed In The Methylotrophic Yeast Pichia Pastoris, Karen J. Potter, Wenhui Zhang, Leonard A. Smith, Michael M. Meagher

Michael Meagher Publications

A recombinant Hc fragment of botulinum neurotoxin, serotype A (rBoNTA(Hc)), has been successfully expressed in a Mutt strain of the methylotrophic yeast Pichia pastoris for use as an antigen in a proposed human vaccine. Fermentation employed glycerol batch, glycerol-fed batch, and methanol-fed batch phases to achieve high cell density. Induction times were short to maximize rBoNTA(H_c) production while minimizing proteolytic degradation. Concentration of rBoNTA(H_c) in yeast cell lysates was generally 1-2% of the total protein based on ELISA analysis. The H_c fragment was purified from cell lysates using a multistep ion-exchange (IEC) chromatographic process, including …

Laboratory And Field Testing Of Seed Spacing Uniformity For Sugarbeet Planters, Jonathan W. Panning, Michael F. Kocher, John A. Smith, Stephen D. Kachman

Department of Agricultural and Biological Systems Engineering: Faculty Publications

Five planter configurations were evaluated for seed spacing uniformity at three field speeds using a seed location method in the field and a laboratory method involving an opto-electronic sensor system. Planter seed spacing uniformity was described using the Coefficient of Precision (CP3) measure. Results showed that CP3 measures determined using the laboratory test method were significantly different from those determined using the field test method. This indicated the laboratory test method cannot be used to predict planter seed spacing uniformity in the field. Seed spacing uniformity determined in laboratory tests was higher than, or equal to, seed spacing uniformity determined …

Lead-Free Interconnection For Electronic Devices, Ravi F. Saraf

Department of Chemical and Biomolecular Engineering: Patents

An electronic device that is equipped with a plurality of bonding pads positioned on the device for making electrical interconnections and electrically conductive composite bumps adhered to the bonding pads wherein the bumps are formed of a composite material consisting of a thermoplastic polymer and at least about 30 volume percent of conductive metal particles based on the total volume of the metal particles and the thermoplastic polymer. The present invention is also directed to a method of making electrical interconnections to an electronic device by pressing a plurality of composite bumps of a polymeric based material against a substrate …

Near-Band-Gap Cupt-Order-Induced Birefringence In Al0.48Ga0.52Inp2, Mathias Schubert, Tino Hofmann, Bernd Rheinlander, Ines Pietzonka, Torsten Sass, Volker Gottschalch, John A. Woollam

Department of Electrical and Computer Engineering: Faculty Publications

The order-induced birefringence in the near-band-gap spectral range (0.75 to 2.5 eV), and its dependence on the degree of ordering η is reported for Al_0.48Ga_0.52InP₂. Transmission and reflection generalized variable angle spectroscopic ellipsometry, dark-field spectroscopy, and cross-polarized reflectance difference spectroscopy (CRDS) are used to determine precisely the room-temperature dielectric functions for polarization parallel and perpendicular to the ordering direction of a series of spontaneously CuPt-ordered samples grown by metalorganic vapor-phase epitaxy. The CRDS technique is introduced as an approach to sense extremely weak anisotropy at oblique angles of incidence. The observed order birefringence is …

United States Patent: Method And System For Estimating The Tenderness Of A Meat Product, Maria Victoria Spadaro, Rosana Moreira, Jimmy Keeton, D. H. Allen

Department of Engineering Mechanics: Faculty Publications

A method for estimating the tenderness of a meat product is provided. The method includes determining the stress relaxation coefficient of a meat sample. One or more physical parameters of the meat sample are then determined from the stress relaxation coefficient. Diagnostic sensory characterization data, such as a numerical estimation of the meat's overall tenderness, is then determined for the meat sample. The physical parameters are then correlated to the diagnostic sensory characterization data, to allow the diagnostic sensory characterization data to be estimated solely from the measured physical parameters.

Method For Providing Discharge Protection Or Shielding, Ravi F. Saraf

Department of Chemical and Biomolecular Engineering: Patents

Electrostatic discharge protection or electromagnetic interference shielding is provided by applying a composition comprising a thermoset or thermoplastic polymeric matrix, and a conductive filler component, where said filler component comprises electrically conductive particles and at least one conducting polymer to a dielectric substrate.

Acuta Enews December 1999, Vol.28, No. 12

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Breakaway Steel Guardrail Post, Dean L. Sicking, John D. Reid, John R. Rohde

Department of Mechanical and Materials Engineering: Faculty Publications

A breakaway guardrail post includes upper and lower post sections spaced apart but connected by a breakaway joint. The joint is attached at one end to the upper post by a first fastener set and connected at a second end by a second fasteners set. Upon impact forces being applied to the upper post section, the first fastener fails and the upper post section rotates downwardly.

Inside-Out Crosslinked And Commercial-Scale Hydrogels, And Sub-Macromolecular Selective Purification Using The Hyrdogels, William H. Velander, Kevin E. Van Cott

Department of Chemical and Biomolecular Engineering: Patents

Relating to chromatographic processes and ion-exchange and affinity matrices, a spatial installation method for a bifunctional reagent that crosslinks and/or activates a polymer matrix is disclosed, with inside-outside installation of a bifunctional reagent on and within a polymer matrix. The polymer matrix is cellulose, agarose, or chitosan particles. The installation may be followed by inside-outside ligand attachment, by further reacting the matrix with a ligand or ionic group so that a higher concentration of ligand or ionic moiety occurs on the intra-particle volume than the outer matrix surface.

Acuta Enews November 1999, Vol.28, No. 11

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Methods Of Fabricating Plasticized, Antiplasticized And Crystalline Conducting Polymers And Precursors Thereof, Ravi F. Saraf

Department of Chemical and Biomolecular Engineering: Patents

Methods of forming materials containing precursors to electrically conductive polymers and electrically conductive polymers are described which have a high degree of crystallinity. The high degree of crystallinity is achieved by preparing the materials under conditions which provide a high degree of mobility to the polymer molecules permitting them to associate with one another to form a crystalline state. High levels of electrical conductivity are achieved in in the electrically conductive materials without stretch orienting the material. The enhanced electrical conductivity is isotropic as compared to a stretch oriented film which has isotropic electrical conductivity. In the preferred embodiment, additives …

Coulomb Crystals And Glasses For Self-Assembly Of Nanoparticles, P. F. Williams, A. Belolipetski, A. Goussev, M. E. Markes

P. F. (Paul Frazer) Williams Publications

Under proper conditions, small particles may be suspended in a regularly-spaced array called a Coulomb crystal. In this paper we discuss the application of this phenomenon to the self-assembly of nanoparticles in a lattice-lie array on a substrate. Issues associated with depositing the particles, and the size and lattice spacing of the particles are discussed.

Carrier Concentration And Lattice Absorption In Bulk And Epitaxial Silicon Carbide Determined Using Infrared Ellipsometry, Thomas E. Tiwald, John A. Woollam, Stefan Zollner, Jim Christiansen, R. B. Gregory, T. Wetteroth, S. R. Wilson, Adrian R. Powell

Department of Electrical and Computer Engineering: Faculty Publications

We have measured the dielectric function of bulk nitrogen-doped 4H and 6H SiC substrates from 700 to 4000 cm^-1 using Fourier-transform infrared spectroscopic ellipsometry. Photon absorption by transverse optical phonons produces a strong reststrahlen band between 797 and 1000 cm^-1 with the effects of phonon anisotropy being observed in the region of the longitudinal phonon energy (960 to 100 cm^-1). The shape of this band is influenced by plasma oscillations of free electrons, which we describe with a classical Drude equation. For the 6H-SiC samples, we modify the Drude equation to account for the strong effective …

Acuta Enews October 1999, Vol.28, No. 10

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ACUTA Strategizes for the Future

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Introduction To Industrial Engineering: Team Tower, Paul Savory

Department of Industrial and Management Systems Engineering: Instructional Materials

Classroom exercise for IMSE 150 at the University of Nebraska-Lincoln. This goal is to introduce freshman industrial engineering students to various aspects of industrial engineering and being an engineer. One of the key areas of Industrial Engineering is quality control. Quality control is concerned with testing and inspecting a product to confirm that it meets production and customer specifications. To understand some of the basics of quality control, let’s consider the production of M&M candies.

Introduction To Industrial Engineering: Group Resume, Paul Savory

Department of Industrial and Management Systems Engineering: Instructional Materials

Classroom exercise for IMSE 150 at the University of Nebraska-Lincoln. This goal is to introduce freshman industrial engineering students to various aspects of industrial engineering and being an engineer. This ice-breaking exercise has students work in groups to create a group resume to get to know each other better.