Engineering Commons^™

A Morphological Analysis Of A Hybrid Swarm Of Native Ulmus Rubra And Introduced U. Pumila (Ulmaceae) In Southeastern Nebraska, Christian Elowsky, Ingrid E. Jordon-Thaden, Robert B. Kaul

Nebraska Center for Biotechnology: Faculty and Staff Publications

The parental species and hybrid swarm of native Ulmus rubra Muhl. and the introduced, naturalized and weedy U. pumila L. were investigated in a 65-km transect in Lancaster, Saunders, and Butler counties in Nebraska. Thirty-two trees of U. rubra, 32 of U. pumila, and 50 of the hybrid swarm were sampled for leaves and buds and subsampled for flowers and fruits. Leaves were measured for petiole length, blade length, width, primary and secondary teeth per cm, number of secondary teeth per primary tooth, and texture. Buds were scored for color and distribution of trichomes. Flowers were sampled for stamen counts …

Narrow Grass Hedge Effects On Nutrient Transport Following Swine Slurry Application, John E. Gilley, Shannon L. Bartelt-Hunt, Seth J. Lamb, Xu Li, David B. Marx, Daniel D. Snow, David B. Parker, Brian L. Woodbury

Department of Agricultural and Biological Systems Engineering: Faculty Publications

The effectiveness of a narrow grass hedge in reducing runoff nutrient loads following swine slurry application was examined. Slurry was applied to 0.75 m wide by 4.0 m long plots established on an Aksarben silty clay loam soil located in southeast Nebraska. Manure treatments consisted of no manure application and manure application to meet the 1, 2, or 3 year nitrogen (N) requirements for corn. Runoff water quality was measured during three 30 min simulated rainfall events. The grass hedge did not significantly reduce runoff nutrient transport after the swine slurry, which contained relatively small amounts of manure, was applied. …

Fabrication And Modeling Of Electrochemical Double-Layer Capacitors Using Carbon Nano-Onion Electrode Structures, Fabio Parigi

Department of Electrical and Computer Engineering: Dissertations, Theses, and Student Research

Electrochemical capacitors or ultracapacitors (UCs) that are commercially available today overcome battery limitations in terms of charging time (from tens of minutes to seconds) and limited lifetime (from a few thousand cycles up to more than one million) but still lack specific energy and energy density (2-5% of a lithium ion battery). The latest innovations in carbon nanomaterials, such as carbon nanotubes as an active electrode material for UCs, can provide up to five times as much energy and deliver up to seven times more power than today’s activated carbon electrodes. Further improvements in UC power density have been achieved …

Driver Fatigue Enforcement Techniques And Their Effect On Crashes, Carrie Mohlman

Department of Civil and Environmental Engineering: Dissertations, Theses, and Student Research

Fatigued driving is a type of driver impairment caused by a lack of sleep, sleep disorders, long drive times, etc. Fatigued driving enforcement aims to improve safety by removing impaired drivers from the roadway. While fatigued driving is detrimental to safety, there exists the issue of identifying fatigue. There is a range between being awake and asleep and, in order to improve safety, enforcement officers must be able to identify the point at which drivers are impaired.

This thesis investigates potentially effective fatigued driving enforcement techniques for use by enforcement officers. These techniques were investigated through three primary means: a …

Assessing The Impact Of Speed Limit Reduction Near Signalized High Speed Intersections Equipped With Advance Warning Flashers: A Case Study In Nebraska, Shefang Wang

Department of Civil and Environmental Engineering: Dissertations, Theses, and Student Research

This thesis evaluated the effects of 5 mph and 10 mph speed limit reductions in the vicinity of high-speed, signalized intersections equipped with Advance Warning Flashers (AWF). The selected methodology involved a field study of the impact of speed limit reduction at 7 high-speed, signalized intersections with AWF, using quantile regression models developed for speed. The quantile regression models for speed indicated that reduction of the speed limit from 60 mph to 55 mph did not have significant impact on observed speed during the green time. However, it was found that speed limit reduction from 65 mph to 55 mph …

Structural Reliability Analysis Of Corroded Steel Girder Bridge, Mohammed Shaalan Al Badran

Department of Civil and Environmental Engineering: Dissertations, Theses, and Student Research

The natural aging, environmental impact, and appropriate design are certainly playing a serious role in safety of the bridges function. The functional safety of bridge constitutes a prime element of the transportation system serving commuters, passengers and freight. According to Federal Highway Administration, the steel bridges share represents a large amount of the United States’ bridges. In last century, the collapse of both the Silver Bridge at Point Pleasant, West Virginia over the Ohio River on December 15, 1967 and over the Mianus River Bridge in Connecticut on June 28, 1983 showed that steel corrosion has been the leading reason …

Velocity Measurements Of The Flow Over A Gate-Controlled Weir Structure, Mohamed M. Jalloh

Department of Civil and Environmental Engineering: Dissertations, Theses, and Student Research

The South Florida Water Management District (SFWMD) uses G304 control structures to manage flow into and out of a large storm-water treatment area (STA). These structures consist of a lateral unsuppressed weir, a sluice gate and a corrugated culvert for flow control and transfer through an embankment. For better flow control in the STAs, it is imperative to accurately measure the discharge through the G304 control structures and to determine the approach velocity over the weir for different field scenarios.

Flow behavior of the G304 structure was examined in a prototype during two days of testing for two canal headwater …

Cable Median Barrier Failure Analysis And Remediation Phase Ii, Cody S. Stolle, Dean L. Sicking, Ronald K. Faller, John D. Reid

Nebraska Department of Transportation: Research Reports

Cable median barrier crashes from a total of 12 states were analyzed. Crash data included scene diagrams, photographs, and field measurements, crash narratives, although the availability of data in each crash varied.

Major contributors to penetration crash propensity were identified: diving underride, in which the front end of the vehicle dropped below the bottom cable; prying, in which the vehicle profile caused cable separation or lifting; override; bouncing override, in which the vehicle rebounded after contact with the back slope and bounced over the top of the barrier; system failure, in which one component failure or design failure prevented the …

Rating Low Levels Of Ambient Noise In Performing Arts Facilities, Lily M. Wang, Brent A. Kraay

Durham School of Architectural Engineering and Construction: Faculty Publications

Previous studies have indicated that common indoor noise rating metrics, such as Noise Criteria NC and Room Criteria RC, do not best correlate to human perceptions of annoyance and distraction in typical office environments. Based on investigations conducted at the University of Nebraska using noise levels between 30 – 60 dBA, the author has proposed that an effective indoor noise rating method should begin with a rating of level (either dBA or sones), then an assessment of spectral quality, tones, and fluctuations. How well would such a system work at very low levels of ambient noise, though, as found in …

Quantifying The Just Noticeable Difference Of Reverberation Time With Band-Limited Noise Centered Around 1000 Hz Using A Transformed Up-Down Adaptive Method, Matthew G. Blevins, Adam T. Buck, Zhao Peng, Lily M. Wang

Durham School of Architectural Engineering and Construction: Faculty Publications

This study seeks to quantify the just noticeable difference (JND) of reverberation time (RT) using band-limited noise. ISO 3382-1 lists the JND of reverberation metrics at 5% based on work by Seraphim (1958). However, others have found the JND of RT to be higher from 6% to 39%. Many of these studies utilized band-limited stimuli, e.g. speech, music motifs and bandlimited noise. A previous study by the authors conducted on 30 subjects using white noise demonstrated a JND of RT at 22%. To further verify these results and investigate potential upward frequency masking, the present study was conducted following the …

Effects Of Background Noise Alternating Between Two Levels At Varying Time Intervals On Human Perception And Performance, Andrew Hathaway, Lily M. Wang

Durham School of Architectural Engineering and Construction: Faculty Publications

This research experiment aims to better quantify human perception and performance under increased background noise levels of varying intervals. Twenty-seven participants were tested over five 30 minute sessions where they were subjected to RC-29(H) and RC-47(RV) conditions created by broadband noise fluctuating on different time intervals. These intervals varied from two minutes to ten minutes, simulating the conditions of a noisy HVAC system turning on and off. The performance results of an arithmetic test dealing with short-term memory and a subjective questionnaire will be presented and compared to a similar test using broadband noise bursts and correlated to noise metrics …

Effects Of Reverberation And Noise On Speech Comprehension By Native And Non-Native English-Speaking Listeners, Zhao Peng, Lily M. Wang, Siu Kit Lau, Adam M. Steinbach

Durham School of Architectural Engineering and Construction: Faculty Publications

Previous studies have demonstrated the negative impact of adverse signal-to-noise-ratios on non-native English-speaking listeners' performance on speech recognition using recall tasks, as well as implied that comprehension skills were more impaired than recognition skills under reverberation and noise. The authors have themselves previously conducted a pilot study on three native and three non-native Englishspeaking listeners to examine the effects of reverberation and noise using speech comprehension tasks. Those results suggested that speech comprehension performance is worse under longer reverberation times (RT), and that a longer RT is more detrimental to speech comprehension by non-native listeners than native listeners. This paper …

Acuta Enews June 2013 Vol. 42, No. 6

ACUTA Newsletters

In this Issue,.,

1 Building on the Conference

2 Evaluating Emergency Notification Systems i

Next Generation 9-l-l

3 Results of the 2013 Forum Competition

i ACUTA Discount for SIP Certification

4 Info Links

5 Ddjd Vu All Over Again: Can We Please Pttf SDNs in Context?

6 Do You ROCKZi?

6 Fall Seminar

6 Have You Paid Your Dues for 2013- 14?

7 Welcome New Members

7 Check It Out

Pavement Quality Indicators, Connor Villanueva, Wayne Jensen

Nebraska Department of Transportation: Research Reports

No abstract provided.

Thickness-Shear And Thickness-Twist Vibrations Of Circular At-Cut Quartz Resonators, Huijing He, Jiashi Yang, Qing Jiang

Department of Mechanical and Materials Engineering: Faculty Publications

Exact solutions for free vibration frequencies and modes are obtained for thickness-shear and thickness-twist vibrations of unelectroded circular AT-cut quartz plates governed by the two-dimensional scalar differential equation derived by Tiersten and Smythe. Comparisons are made with experimental results and the widely-used perturbation solution by Tiersten and Smythe under the assumption of weak in-plane anisotropy. Our solution is found to be much closer to the experimental results than the perturbation solution . For the frequency of the fundamental thickness- shear mode, the error of the perturbation method is 0.4549%, significant in resonator applications.

Electrospun Plant Protein Scaffolds With Fibers Oriented Randomly And Evenly In Three-Dimensions For Soft Tissue Engineering Applications, Shaobo Cai

Department of Textiles, Merchandising and Fashion Design: Dissertations, Theses, and Student Research

In this work, electrospinnable and water stable soyprotein was extracted by using a reducing agent in mild alkaline condition, and novel 3D zein and 3D pure soyprotein electrospun scaffolds with three-dimensionally and randomly oriented fibers and large interconnected pores were successfully fabricated by reducing surface resistivity of materials. This unique structure is different from most electrospun scaffolds with fibers oriented mainly in one direction. The structure of novel 3D scaffolds could more closely mimic the 3D randomly oriented fibrous architectures in many native extracellular matrixes (ECM). Confocal laser scanning microscope shows that instead of becoming flattened cells when cultured in …

Optimized Aggregates Gradations For Portland Cement Concrete Mix Designs Evaluation, Wally Heyen, Lieska Halsey, Robert Rea, Mick Syslo

Nebraska Department of Transportation: Research Reports

No abstract provided.

Utilization Of Wet Corn Distillers Grain For The Production Of Cellulase Enzymes And Value Added Products, Hunter R. Flodman

Department of Chemical and Biomolecular Engineering: Dissertations, Theses, and Student Research

Distillers grain, a byproduct from the dry grind corn ethanol industry, is an industrially available, abundant, preprocessed material comprised primarily of cellulose, hemicellulose, protein, oil, and minerals. This research investigated the utilization of distillers grain as a substrate for solid-state fermentation (SSF). SSF is the growth of microorganisms on a moist, solid substrate in the absence of free water. The substrate acts as both the nutrient source and as a solid support for the microorganisms, typically filamentous fungi. SSF has the unique ability to convert agricultural byproducts into valuable bioproducts such as enzymes and organic acids without hydrolyzing polysaccharides to …

Experimental Assessment Of The Impact Of Asymptomatic Gas Emboli On The Vessel Wall, Linxia Gu, Eric L. Cutler

Department of Mechanical and Materials Engineering: Faculty Publications

Quantitative evaluation of shear stress in the vessel wall due to the presence of asymptomatic gas emboli is lacking. The goal of this work was to assess the impact of chronic asymptomatic gas emboli on the risk of atherosclerosis through a custom-built cardiovascular flow simulator. Gas bubbles were created by forced air from a syringe pump. The influences of embolism injection rate, pulse rate, and time-averaged flow rate on the wall mean shear stress were investigated at resting and elevated heart rate conditions. The recorded pressure and volumetric flow rate from 24 experimental settings with four repetitions each were used …

Laboratory Evaluation Of A Turn Compensation Control System For A Ground Sprayer, Wesley M. Porter, Jorge A. Rascon, Yeyin Shi, Randal K. Taylor, Paul A. Weckler

Department of Agricultural and Biological Systems Engineering: Faculty Publications

The ability to compensate sprayer nozzle flow across a horizontal boom has the potential to mitigate the problem of inaccurate chemical application rate due to lateral speed differences when sprayers are turning. A laboratory testing platform and procedure were developed and tested with a commercial turn compensation control system for a ground sprayer. Virtual paths consisting of simulated GPS signals representing right and left turns separated by straight segments were simulated with four turning radii (75%, 125%, 250%, and 500%) based on boom width. Actual application rates from 11 nozzles spread across the boom were measured using load cells in …

Zone Of Intrusion For Permanent 9.1-Degree Single Slope Concrete Barriers, Cale J. Stolle

Department of Mechanical and Materials Engineering: Dissertations, Theses, and Student Research

Three WDOT 9.1-degree single-slope concrete barriers, with top heights of 36 in. (914 mm), 42 in. (1,067 mm), and 56 in. (1,422 mm) (Standard 14B32), were analyzed for Zone of Intrusion (ZOI)’ and working width using nonlinear finite element analysis (FEA). Tire-barrier friction, vehicle-barrier friction, barrier stiffness, mesh size, tire deflation, and suspension component failures were all found to have effects on simulation results. The zone of intrusion and working width were evaluated for each barrier under varying tire deflation and suspension failure conditions and determined to have a maximum value of 12.2 in. (310 mm) for the front fender …

Individual Articulator's Contribution To Phoneme Production, Jun Wang, Jordan R. Green, Ashok Samal

School of Computing: Conference and Workshop Papers

Speech sounds are the result of coordinated movements of individual articulators. Understanding each articulator’s role in speech is fundamental not only for understanding how speech is produced, but also for optimizing speech assessments and treatments. In this paper, we studied the individual contributions of six articulators, tongue tip, tongue blade, tongue body front, tongue body back, upper lip, and lower lip to phoneme classification. A total of 3,838 vowel and consonant production samples were collected from eleven native English speakers. The results of speech movement classification using a support vector machine indicated that the tongue encoded significantly more information than …

Preliminary Analysis Of Ghg Production From The Lincoln Water System To Determine Operating Energy And Infrastructure Construction Impacts, Martin Gakuria

Department of Environmental Engineering: Theses and Other Student Research

The Lincoln Water System (LWS) provides water to the citizens, industries, and commercial areas within and near the City of Lincoln, Nebraska. The intent of this thesis is to determine if reductions in future per capita water demand will help reduce the building of infrastructure and reduce future pumping costs and uses the computation of greenhouse gasses to compare the effects of different degrees of water conservation.

Data analysis was performed on water production statistics and data (1994-2011) collected and provided by the City of Lincoln, Nebraska. Projections in accordance with the Lincoln-Lancaster County 2040 Comprehensive Plan were made to …

Nuts & Bolts, Volume 1, Issue 3

Friends of the Larsen Tractor Museum

Museum Open House
Calling All Tractor Clubs
Allis WC Donation
Tractor Show Information

The Evaluation Of Software Quality, Dhananjay Gade

Department of Industrial and Management Systems Engineering: Dissertations, Theses, and Student Research

Software Quality comprises all characteristics and significant features of a product or an activity which relate to the satisfaction of given requirements. The totality of characteristics of a software product depends upon its ability to satisfy given needs: for example (a) the degree to which software possesses a desired attribute or combination of attributes. (b) The degree to which a customer or user perceives that software meets their expectations, (c) the characteristics of software that determine the degree to which the software in use will meet the customer expectation. This study has three objectives. The first objective is to identify …

Acuta Enews May 2013 Vol. 42, No. 5

ACUTA Newsletters

In this Issue...

1 ACUTA Honors 4 Schools, 3 Individuals

2 Convergence (or when the Stars Are Aligned)

2 View 8 Conference Session

Three Predictions for Higher Ed Residential Networking

3 Get Full Access to eSchool News Online

4 Info Links

5 Mobile Voice Policies Are MIA!

6 Board Report

6 Annual Dues Invoices Mailed May 1

7 Welcome New Members

7 Check It Out

8 Annual Conference Photo Section

Stormwater Pollution Treatment Bmp Discharge Structures, Miles F. Simmons

Department of Civil and Environmental Engineering: Dissertations, Theses, and Student Research

Structural best management practices (BMPs) are used to capture and treat stormwater runoff. Most structural BMPs provide treatment by filtering runoff through a filter media or collecting it in a detention basin and slowly discharging it over an extended period of time to allow suspended solids and associated contaminants to settle out. The purpose of this study is to design an effective outlet structure that provides adequate filtration or slows discharge to 40 hours.

A model detention basin was constructed in the Civil Engineering Hydraulics Laboratory at the University of Nebraska-Lincoln (UNL) and two full scale outlet structures were tested …

Friends Of The Lester F. Larsen Tractor Test & Power Museum Newsletter, Spring 2013

Friends of the Larsen Tractor Museum

Membership renewal

Annual Meeting, May 17, 2013

Honoring William E. Splinter

Environmentally Friendly Sizing Agent From Corn Distillers Dried Grains, Yue Zhang

College of Education and Human Sciences: Dissertations, Theses, and Student Research

Distillers dried grains (DDGS), the coproducts of corn ethanol production, were used as a textile sizing agent on cotton, polyester and polyester/cotton blends in an effort to find inexpensive and biodegradable alternatives to sizing agents such as poly(vinyl alcohol) that are currently used. Although DDGS is an inexpensive, biodegradable and abundant co-product, it has limited industrial applications. DDGS is a mixture of carbohydrates, proteins and oil which are used as sizing agents or as size additives. The effects of DDGS extraction conditions on sizing evaluation parameters such as fiber adhesion, film properties, viscosity and fabric abrasion were studied in comparison …

Precast/Prestressed Concrete Truss-Girder For Roof Applications, Peter S. Samir

Department of Construction Engineering and Management: Dissertations, Theses, and Student Research

Steel trusses are the most popular system for supporting long span roofs in commercial buildings, such as warehouses and aircraft hangars. There are several advantages of steel trusses, such as lightweight, ease of handling and erection, and geometric flexibility. However, they have some drawbacks, such as high material and maintenance cost, and low fire resistance. In this paper, a precast concrete truss is proposed as an alternative to steel trusses for spans up to 160 ft. without intermediate supports. The proposed design is easy to produce and has lower construction and maintenance costs than steel trusses. The proposed design is …