Engineering Commons^™

Vortex Generated Rotor Wake Model For Real-Time Simulation, Kenneth S. Graham

Link Foundation Modeling, Simulation and Training Fellowship Reports

The University of Alabama Flight Dynamics Laboratory (UA FDL) has been simulating helicopters since 1981. The real-time, man-in-the-loop, simulator was developed locally and is continuously being upgraded. The hardware, software, architecture and math models are all developed in-house by a team of faculty and graduate students. Since 1994, the UA rotor model has been Bladehelo [2] - a true blade model that numerically integrates the flapping motion of individual blades and the shaft rotation. The approach is physically based. Discrepancies are studied until they are understood. Bladehelo played a key role in the discovery of residual bending [3], [4]. Bladehe!o …

Steel Bridge Protection Policy: Warranty Clauses For Indot Steel Bridge Paint Contracts, Luh M. Chang, Tarek Zayed, Jon D. Fricker

JTRP Technical Reports

The study identifies various painting systems that are successfully used in Indiana’s surrounding states and other industries. The identified systems are further screened and evaluated. After prudently comparing INDOT’s inorganic zinc / vinyl system with the waterborne acrylic system, the moisture cure urethane coating system, and the 3-coat system of zinc-epoxy-urethane, the results show that the new 3-coat system fulfills INDOT’s needs with the most benefits. Therefore, the 3-coat system is recommended to replace INDOT present inorganic zinc / vinyl system. To deal with the problems facing the lead-based paint, a comparison between full-removal and over-coating alternatives is made. Results …

Reconciled Platoon Accommodations At Traffic Signals, Jay Wasson, Montasir Abbas, Darcy M. Bullock, Avery Rhodes, Chong Kang Zhu

JTRP Technical Reports

The use of microprocessor-based traffic signal controllers introduced in the 1960s has allowed for the development of many new strategies to make traffic signal systems more responsive to traffic conditions. Many efforts have focused on the development of real-time, adaptive control strategies. While some of these strategies have been shown to improve intersection performance, there are several factors that have limited their deployment. Some of these include substantial capital cost, complicated calibration procedures, and the reluctance of practicing engineers to deploy strategies radically different from those currently in use. Therefore, lower cost strategies that are compatible with existing infrastructure continue …

Steel Bridge Protection Policy: Evaluation Of Bridge Coating System For Indot Steel Bridges, Luh M. Chang, Tarek Zayed, Jon D. Fricker

JTRP Technical Reports

The study identifies various painting systems that are successfully used in Indiana’s surrounding states and other industries. The identified systems are further screened and evaluated. After prudently comparing INDOT’s inorganic zinc / vinyl system with the waterborne acrylic system, the moisture cure urethane coating system, and the 3-coat system of zinc-epoxy-urethane, the results show that the new 3-coat system fulfills INDOT’s needs with the most benefits. Therefore, the 3-coat system is recommended to replace INDOT present inorganic zinc / vinyl system. To deal with the problems facing the lead-based paint, a comparison between full-removal and over-coating alternatives is made. Results …

Steel Bridge Protection Policy: Metalization Of Steel Bridges: Research And Practice, Luh M. Chang, Tarek Zayed, Jon D. Fricker

JTRP Technical Reports

The study identifies various painting systems that are successfully used in Indiana’s surrounding states and other industries. The identified systems are further screened and evaluated. After prudently comparing INDOT’s inorganic zinc / vinyl system with the waterborne acrylic system, the moisture cure urethane coating system, and the 3-coat system of zinc-epoxy-urethane, the results show that the new 3-coat system fulfills INDOT’s needs with the most benefits. Therefore, the 3-coat system is recommended to replace INDOT present inorganic zinc / vinyl system. To deal with the problems facing the lead-based paint, a comparison between full-removal and over-coating alternatives is made. Results …

Opal: Project Objectives & Development, Robert J. Twiggs

Robert "Bob" Twiggs STEM Education Collection

Project and development objectives for the OPAL Project from 1999.

Opal Update, Robert J. Twiggs

Robert "Bob" Twiggs STEM Education Collection

A PowerPoint Presentation created by Professor Bob Twiggs titled "OPAL Update" from 1999.

A Study Of Factors Affecting The Implementation Of Iso 9000 In Taiwan's Construction Industry, Chuan-Chen Hung

Dissertations and Theses @ UNI

The purpose of this study was to determine the attitude of Taiwanese construction companies regarding the adoption and implementation of ISO 9000. This was accomplished by conducting a survey to investigate the perceived factors affecting the intention to adopt ISO 9000 and its successful implementation.

The survey instrument was developed through the review of related literature as well as through validations. One hundred eighty (180) construction companies were randomly sampled from the 1998 Membership Directory of the National Construction Association of the Republic of China (Taiwan), which consisted of 60 Type-A, Type-B, and Type-C construction companies. In total, 62 respondents …

Road Rescue Implements A Continuous Process Improvement Framework, John Olson, Paul Savory

Department of Industrial and Management Systems Engineering: Faculty Publications

Continuous improvement programs traditionally focus on making small incremental improvements to a system. Unfortunately, their success can be limited due to the rapid changing environment within which most small companies operate. Improvement efforts should be flexible enough to capitalize on incremental and radical changes to a system. This paper presents a case analysis of how Road Rescue, an ambulance manufacturer, uses a continuous improvement framework to capitalize on both radical and incremental improvement opportunities. Results include a 10% increase in throughput, reduced cycle time of 44%, increased customer satisfaction, and higher quality.

Doppler Measurements Using A Coherent Ultrawideband Random Noise Radar, Muhammad Dawood, Ram M. Narayanan

Department of Electrical and Computer Engineering: Faculty Publications

The University of Nebraska has developed a random noise radar system which transmits an ultrawideband random noise waveform with a uniform power spectral density (PSD) in the 1-2 GHz frequency range. Simulation studies and controlled laboratory tests confirm the system's ability to preserve the instantaneous phase of the received signal [l, 2]. The potential of the system to characterize the Doppler shift of moving targets exhibiting varying linear and rotational velocities was clearly demonstrated [2]. This paper provides with the results of recent field experiments at a range of about 200 m which confirm the ability of the system to …

Complete Maps Of The Aspect Sensitivity Of Vhf Atmospheric Radar Echoes, R. M. Worthington, R. D. Palmer, S. Fukao

Department of Electrical and Computer Engineering: Faculty Publications

Using the MU radar at Shigaraki, Japan (34.85°N, 136.10°E), we measure the power distribution pattern of VHF radar echoes from the mid-troposphere. The large number of radar beam-pointing directions (320) allows the mapping of echo power from 0° to 40° from zenith, and also the dependence on azimuth, which has not been achieved before at VHF wavelengths. The results show how vertical shear of the horizontal wind is associated with a definite skewing of the VHF echo power distribution, for beam angles as far as 30° or more from zenith, so that aspect sensitivity cannot be assumed negligible at any …

Finding Of No Significant Impact Bank Stabilization Project Ponca State Park, Nebraska Missouri National Recreational River

United States Army Corps of Engineers, Omaha District

An environmental assessment has been prepared that summarizes the expected effects of the proposed project on the existing environment. This is a project proposed by the Omaha District, Corps of Engineers to halt the erosion occurring along the riverfront at Ponca State Park in Dixon County, Nebraska, and protect the access road to the park's public boat ramp. This project is authorized under the Wild and Scenic Rivers Act amendment of 1978 (Public Law 95-625). The proposed project is located along the right bank of the Missouri River between River Miles (RM) 753.9 and 753.5 at Ponca State Park about …

Final General Management Plan Environmental Impact Statement

United States Army Corps of Engineers, Omaha District

This Final General Management Plan / Environmental Impact Statement presents three alternatives for the future of the Missouri National Recreational River: a continuation of existing (conditions (no-action) alternative, a resource protection/recreation (preferred) alternative emphasizing protection and enhancement of biologic values and the history and culture of the area, and a recreational emphasis alternative. In both action alternatives, the Corps of Engineers (COE) and the National Park Service (NPS) would manage the area through a cooperative agreement. The Corps of Engineers would function as the day-la-day manager of the water-related resources, while the National Park Service would administer the land-related resources. …

The Certified Safe Farm Project In Nebraska: The First Year, Jerry Jaspersen, Susanna Von Essen, Pam List, Larry Howard, David Morgan

Department of Agricultural and Biological Systems Engineering: Faculty Publications

Potentially preventable death, disabling injury, and serious illness are very common secondary to work in production agriculture in Nebraska and elsewhere. The traditional approach to farm safety has consisted largely of education designed to prevent traumatic injury. While education is of critical importance, additional incentives may be needed to reduce fatal and non-fatal events to an acceptable level. The Certified Safe Farm concept was developed in collaboration with two Nebraska health insurance companies. The program consists of combining an on-farm safety assessment and occupational health screening with an education program. The incentive to complete this program is to be eligible …

Nitrate Leaching In Irrigated Corn And Soybean In A Semi-Arid Climate, N. L. Klocke, Darrell G. Watts, J. P. Schneekloth, Don R. Davison, R. W. Todd, Anne M. Parkhurst

Department of Agricultural and Biological Systems Engineering: Faculty Publications

Nitrate-nitrogen leached from the root zone of land in intensive corn production is a major groundwater contaminant in some of the intensively irrigated regions of the western Cornbelt, including central and western Nebraska. To obtain a clearer understanding of the amount and timing of nitrate leaching losses from irrigated crops, 14 monolithic percolation lysimeters were installed in 1989-1990 in sprinkler irrigated plots at the University of Nebraska’s West Central Research and Extension Center near North Platte, Nebraska. The lysimeters were used to provide a direct measure of leachate depth from continuous corn and a corn-soybean rotation. Both cropping systems were …

Wax Yield Of Grain Sorghum (Sorghum Bicolor) As Affected By Mechanical Harvesting, Threshing, And Handling Methods, K. R. Lochte-Watson, Curtis L. Weller

Department of Agricultural and Biological Systems Engineering: Faculty Publications

Wax is found on the outer layer of the grain sorghum (Sorghum bicolor) kernel. Current harvesting and handling techniques cause abrasion and breakage, thereby potentially reducing wax yield from sorghum kernels. The purpose of this study was to determine wax yield of sorghum after mechanical harvesting and handling and to compare wax yield of whole and broken sorghum kernels. Combine threshing and auger conveying of grain caused abrasion and breakage, which reduced the wax yield by 5%. The monitored process in this experiment included a cleaning system which reduced the amount of broken kernels and sorghum particles, increasing …

Opto-Electronic Sensor System For Laboratory Measurement Of Planter Seed Spacing With Small Seeds, Y. Lan, Michael F. Kocher, John A. Smith

Department of Agricultural and Biological Systems Engineering: Faculty Publications

An opto-electronic sensor system for measuring seed spacing uniformity with different types of seeds is described in this paper. It consisted of a rectangular photogate block (124 × 92 mm) with 24 phototransistors (diameter, 3 mm) receiving light beams from 24 light emitting diodes (diameter, 3 mm) opposite them, a digital input/output board in a personal computer, and power supplies. The opto-electronic system was tested by comparing seed spacing measurements obtained from the opto-electronic system with measurements of the same seed spacings obtained from a grease belt test stand. The tests were conducted with different types of seeds including regular-pelleted …

Belts Vs Tires, Belts Vs Belts, Tires Vs Tires, Leonard L. Bashford, Michael F. Kocher

Department of Agricultural and Biological Systems Engineering: Faculty Publications

Tractive performance comparisons among two different width rubber belt tracks, 46 cm (18 in.) and 81 cm (32 in.) wide, and two different size rear tires, 710/70R38 and 18.4R46, were made on two different surface conditions. The belts were tested on a Caterpillar 55 tractor equipped with the Mobil-trac™ system and the tires on a John Deere 8400 mechanical front-wheel-drive (MFWD) tractor. The performance tests were completed on two surfaces, one being a non-tilled wheat stubble field and the second, the wheat stubble field tilled approximately 23 cm (9 in.) deep with a Noble blade sweep. Performance comparisons using tractive …

Seepage Characteristics And Hydraulic Properties Of A Feedlot Runoff Storage Pond, David B. Parker, Dean E. Eisenhauer, Dennis D. Schulte, John A. Nienaber

Department of Agricultural and Biological Systems Engineering: Faculty Publications

Water and chemical transport were investigated beneath a 22-year-old beef feedlot runoff storage pond. Soil and sludge samples were collected from 14 borings to 6.1-m depths in a cross-section across the pond. The soils consisted of silt loam and clay loam, and the groundwater level was about 30 m beneath the land surface. Soil samples were analyzed for pH, NO₃-N, NH₄-N, Cl, P, K, SO₄-S, TKN, and organic matter. Physical and hydraulic properties were measured on undisturbed samples of soil and sludge to compare saturated hydraulic conductivity, moisture release characteristics, and bulk density. Saturated …

Search For Charged Higgs Bosons In E+E- Collisions At √S = 181-184 Gev, Barate, R.; Et Al., M. Thulasidas

Research Collection School Of Computing and Information Systems

No abstract provided.

Material Balance Modification In One-Dimensional Modeling Of Porous Electrodes, Mukul Jain, John W. Weidner

Faculty Publications

The material balance used previously in one-dimensional mathematical models of porous electrodes is invalid when there is a non-zero volume change associated with the reaction. It is shown here how the material balance should be modified either to account for a loss in volume, or to account for an inflow of electrolyte from the header into the active pores. A one-dimensional mathematical model is used to illustrate the effect of this correction on the prediction of the delivered capacity and the electrolyte concentration in a lithium/thionyl chloride primary battery.

Correlation Of Double-Layer Capacitance With The Pore Structure Of Sol-Gel Derived Carbon Xerogels, Chuan Lin, James A. Ritter, Branko N. Popov

Faculty Publications

Nine different sol-gel derived carbon xerogels were prepared with different pore structures by varying the carbonization temperature (in flowing N₂) and activation time (in 5% CO₂ in N₂). For each of these carbon xerogels, mesopore and micropore size distributions and cumulative surface areas were extracted from a density functional theory analysis. Increasing the carbonization temperature caused a decrease in the number of micropores in the 6 Å range but had little effect on the mesopore size distribution and thus mesopore cumulative surface area. Increasing the CO₂ activation time caused an increase in the number …

A Mathematical Model Of An Electrochemical Capacitor With Double-Layer And Faradaic Processes, Chuan Lin, James A. Ritter, Branko N. Popov, Ralph E. White

Faculty Publications

A mathematical model of an electrochemical capacitor with hydrous ruthenium oxide (RuO₂·xH₂O) electrodes including both double-layer and surface faradaic processes is developed to predict the behavior of the capacitor under conditions of galvanostatic charge and discharge. The effect of RuO₂·xH₂O particle size is studied and shows that the smaller the particles the better the performance because of the increased surface area per unit volume or mass. The model also predicts that the faradaic process increases significantly the energy per unit volume of the capacitor for power densities of …

Development Of Carbon-Metal Oxide Supercapacitors From Sol-Gel Derived Carbon-Ruthenium Xerogels, Chuan Lin, James A. Ritter, Branko N. Popov

Faculty Publications

Sol-gel derived high surface area carbon-ruthenium xerogels were prepared from carbonized resorcinol-formaldehyde resins containing an electrochemically active form of ruthenium oxide. The electrochemical capacitance of these materials increased with an increase in the ruthenium content indicating the presence of pseudocapacitance associated with the ruthenium oxide undergoing reversible faradaic redox reactions. A specific capacitance of 256 F/g (single electrode) was obtained from a carbon xerogel containing 14 wt % Ru, which corresponded to more than 50% utilization of the ruthenium. The double layer accounted for 40% of this capacitance. This material was also electrochemically stable, showing no change in a cyclic …

A Mathematical Model For Electroless Copper Deposition On Planar Substrates, M. Ramasubramanian, Branko N. Popov, Ralph E. White, K. S. Chen

Faculty Publications

A mathematical model for the electroless deposition of copper on a planar electrode is presented and used to make time-dependent predictions on the various quantities in the system. The model takes into account mass transport by diffusion and migration, Butler-Volmer kinetics at the electrode surface, and mixed potential theory. A finite difference approach is used to solve the equations, and the resultant model is used to predict the concentration profiles, potential response, and plating rate as a function of time and concentration of various reactive components.

Mathematical Modeling Of The Lithium Deposition Overcharge Reaction In Lithium‐Ion Batteries Using Carbon‐Based Negative Electrodes, Pankaj Arora, Marc Doyle, Ralph E. White

Faculty Publications

No abstract provided.

Influence Of Some Design Variables On The Thermal Behavior Of A Lithium‐Ion Cell, Gerardine G. Botte, Bradley A. Johnson, Ralph E. White

Faculty Publications

No abstract provided.

A Simple Method For Determining Differential Diffusion Coefficients From Aqueous Electrolyte Diaphragm Cell Data At Temperatures Below 0°C, D. M. See, Ralph E. White

Faculty Publications

No abstract provided.

Methanol Fuel Cell Model: Anode, S. F. Baxter, V. S. Battaglia, Ralph E. White

Faculty Publications

No abstract provided.

Mathematical Modeling Of Electrochemical Capacitors, Venkat Srinivasan, John W. Weidner

Faculty Publications

Analytic solutions to the mathematical model of an electrochemical capacitor (EC) are used to study cell performance under two types of operating conditions: (i) constant current and (ii) electrochemical impedance spectroscopy. The analytic solution under constant-current operation is used to investigate the relative importance of ionic resistance in the separator, and ionic and electronic resistances in the porous electrode in the design and operation of an EC. Model results are presented that show the trade-off between energy and power density, as the physical properties of the cell components are varied (e.g., electrode thickness). The analytic solution …