Engineering Commons^™

A New Approach To Safety Assessment At Gated Highway–Rail Grade Crossings, Zheng Luo

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

A significant number of pedestrians and bicyclists (i.e., non-motorists) use the roadway system in the U.S. Research pertaining to the safety of them, especially their safety at highway-rail grade crossings (HRGCs), has drawn much attention in the past decade, and remains an important issue of safety research. Yet, the majority of existing research has examined non-motorist safety at intersections or motorist safety at HRGCs separately. Such research has related primarily to exploring relationships between safety countermeasures (e.g., engineering devices, education, enforcement, etc.) and crash frequency/severity, using different quantitative analysis approaches. A primary limitation of these studies is that few have …

The Nebraska Water Leaders Academy: Blending Water Policy And Science With Leadership Theory, Mark E. Burbach, Connie I. Reimers-Hild

Nebraska Water Leaders Academy: Publications and Materials

Water Challenges are Growing
Population Continues to Grow
New and Innovative Leadership is Needed
Nebraska Water Leaders Academy (NWLA) was born!

NWLA Objectives
•Develop scientific, social and political knowledge about water and related natural resources
• Examine the economical and beneficial uses of Nebraska’s water resources
• Develop and enhance leadership and critical thinking skills
• Develop interpersonal skills to become actively involved with water policy issues at the local, regional, state, and national levels
• Develop life-long water resources management skills
• Challenge traditional paradigms while encouraging critical thinking and creative solutions.

Acuta Enews November 2012 Vol. 41, No. 11

ACUTA Newsletters

In this issue...

Hurricane Sandy Arrives on Campus

Hurricanes, Seminar & Toy Phones

Webinar: The Future of Emergency Communication in Higher Ed

Getting Ready for HD Voice

ACUTA Member Benefit: Free Corporate Webinar Webpage

Every Desk a Drafting Table: The Power of a Design Mindset

Info Links

Fall 2012 Seminar Exhibitors and Sponsors

Board Report

Bring 8 Fall Seminar Exhibitors and Sponsors

Welcome New Members

Check It Out

Vibrations Of Crystal Plates With Surface Structures For Resonator And Sensor Applications, Nan Liu

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

This dissertation is mainly on the theoretical analysis of vibrating crystal plates for acoustic wave resonator and sensor applications. The frequency and mode effects of different surface structures on either or both sides of the crystal plates are the main concerns in this dissertation. These effects are fundamental to the improvement of existing acoustic wave devices, or to the design of new acoustic wave devices, especially new sensors based on these effects.

At first, two-dimensional equations of motion for an anisotropic crystal plate with two thin films on its surfaces are derived by reduction from the three-dimensional equations of anisotropic …

Power Electronics-Enabled Self-X Multicell Batteries: A Design Toward Smart Batteries, Taesic Kim, Wei Qiao, Liyan Qu

Department of Electrical and Computer Engineering: Faculty Publications

The traditional multicell battery design usually employs a fixed configuration to connect multiple cells in series and in parallel during operation in order to achieve the required voltage and current. However, this fixed configuration results in low reliability, low fault tolerance, and non-optimal energy conversion efficiency. This paper proposes a novel power electronics-enabled self-X, multicell battery design. The proposed multicell battery can automatically configure itself according to the dynamic load/storage demand and the condition of each cell. The proposed battery can self-heal from failure or abnormal operation of single or multiple cells, self-balance from cell state variations, and self-optimize to …

Evaluation Of A Non-Proprietary, High-Tension, Four-Cable Median Barrier On Level Terrain, Karla A. Lechtenberg, Robert W. Bielenberg, Ronald K. Faller, Dean L. Sicking, Scott K. Rosenbaugh, Daniel M. Homan, Leah R. Kampschnieder, John D. Reid

Nebraska Department of Transportation: Research Reports

No abstract provided.

Temporal Data Mining Of Uncertain Water Reservoir Data, Abhinaya Mohan, Peter Revesz

School of Computing: Conference and Workshop Papers

This paper describes the challenges of data mining uncertain water reservoir data based on past human operations in order to learn from them reservoir policies that can be automated for the future operation of the water reservoirs. Records of human operations of water reservoirs often contain uncertain data. For example, the recorded amounts of water released and retained in the water reservoirs are typically uncertain, i.e., they are bounded by some minimum and maximum values. Moreover, the time of release is also uncertain, i.e., typically only monthly or weekly amounts are recorded. To increase the effectiveness of data mining of …

Long-Term Trends In Air Temperature Distribution And Extremes, Growing Degree-Days, And Spring And Fall Frosts For Climate Impact Assessments On Agricultural Practices In Nebraska, Kari E. Skaggs, Suat Irmak

Department of Agricultural and Biological Systems Engineering: Faculty Publications

Air temperature influences agricultural practices and production outcomes, making detailed quantifications of temperature changes necessary for potential positive and negative effects on agricultural management practices to be exploited or mitigated. Temperature trends of long-term data for five agricultural locations, ranging from the subhumid eastern to the semiarid western parts of Nebraska, were studied to determine local temperature changes and their potential effects on agricultural practices. The study quantified trends in annual and monthly average maximum and minimum air temperature (T_max and T_min), daily temperature range (DTR), total growing degree-days, extreme temperatures, growing-season dates and lengths, and …

Fiber-Tip Fabry–Perot Interferometric Sensor Based On A Thin Silver Film, Fawen Guo

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

Fiber-optic sensors have many advantages, including small size, light weight, immunity to electromagnetic interference, and the capability of remote sensing. Fiber- tip sensors are fabricated on a fiber tip and are the smallest type of fiber-optic sensor. The fiber-tip sensors have attracted a great deal of attention in past years for pressure, temperature, and acoustic sensing.

In this thesis, a fiber-tip sensor based on an ultra-thin silver film was proposed and demonstrated for highly sensitive and high frequency ultrasonic detection. The film is prepared by the vacuum thermal deposition method and then transferred to the fiber tip. The sensor has …

Cost-Effective Treatment Of Existing Guardrail Systems, Mitchell J. Wiebelhaus

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

A cost-effective means for upgrading existing barrier systems, which have deviations from standard practice (i.e., low-rail heights, antiquated end treatments, and improper installation) does not exist. As a result these systems remain on U.S. highways. Barrier systems with deviations from current practice may not perform as intended, thus resulting in fatalities and serious injuries from impacts with these safety devices. It is not plausible to eliminate fatalities and serious injuries from all guardrail impacts; but these numbers could be significantly reduced with the proper design, testing, installation, and maintenance of guardrail systems.

This report offers recommendations for upgrading W-beam guardrails …

Transport Of Engineered Nanomaterials In Porous Media: Groundwater Remediation Application And Effects Of Particle Shape, Megan Seymour

Department of Environmental Engineering: Theses and Other Student Research

Nanotechnology, referring to any science which utilizes particles at the nanoscale, has substantially grown in recent years for its wide spectrum of potential uses. Many theories and models have been developed around the transport of spherical particles; however nanoparticles can be found in various shapes which could greatly affect the predicted transport and retention in the subsurface.

This research explores the beneficial use of carbon nano-onions (CNOs) for environmental remediation and investigates the transport of CNOs in saturated porous media. Surface oxidized CNOs possessed 10 times higher sorption capacity compared to C₆₀ for heavy metal ions including Pb^{2+ …}

Lifecycle Energy Consumption Prediction Of Residential Buildings By Incorporating Longitudinal Uncertainties, Endong Wang, Zhigang Shen

Durham School of Architectural Engineering and Construction: Faculty Publications

Accurate prediction of buildings’ lifecycle energy consumption is a critical part in lifecycle assessment of residential buildings. Longitudinal variations in building conditions, weather conditions and building’s service life can cause significant deviation of the prediction from the real lifecycle energy consumption. The objective is to improve the accuracy of lifecycle energy consumption prediction by properly modelling the longitudinal variations in residential energy consumption model using Markov chain based stochastic approach. A stochastic Markov model considering longitudinal uncertainties in building condition, degree days, and service life is developed: 1) Building’s service life is estimated through Markov deterioration curve derived from actual …

Optimization Of Biodiesel Production Plants, Nghi T. Nguyen

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

A conventional biodiesel plant utilizing two distillation columns to purify unreacted reactants and products is considered in this study. Thermodynamic analyses are used to assess the performance of the existing distillation columns, and reduce the costs of operation by appropriate retrofits in a biodiesel production plant. After the retrofits, the overall exergy loss for the two columns has decreased from 2430.87 kW to 1674.12 kW.

A reactive distillation is developed for esterification of lauric acid with methanol using equilibrium and nonequilibrium models. Equilibrium modeling dominated during last few decades due to their straightforward mathematical modeling. In reality, separation depends on …

Using Slow-Release Permanganate Candles To Remove Tce From A Low Permeable Aquifer At A Former Landfill, Mark D. Christenson, Ann Kambhu, Steve D. Comfort

School of Natural Resources: Faculty Publications

Past disposal of industrial solvents into unregulated landfills is a significant source of groundwater contamination. In 2009, we began investigating a former unregulated landfill with known trichloroethene (TCE) contamination. Our objective was to pinpoint the location of the plume and treat the TCE using in situ chemical oxidation (ISCO). We accomplished this by using electrical resistivity imaging (ERI) to survey the landfill and map the subsurface lithology. We then used the ERI survey maps to guide direct push groundwater sampling. A TCE plume (100-600 µg L^-1) was identified in a low permeable silty-clay aquifer (K_h = 0.5 …

Acuta Enews October 2012 Vol. 41, No. 10

ACUTA Newsletters

In this issue...

A New Mission, A New Vision & a New Seminar

ACUTA Staff Changes

Institutional Excellence Award Deadline Nears

How to Be a Hero When You Roll Out UC

What's on Your Desk?

ACUTA Member Benefit: Website Press Room

New Media Literacy Brings Life to Digital Age 2.0

Info Links

Board Report

Welcome New Members

Check It Out

Developing A Restorable Wetland Index For Rainwater Basin Wetlands In South-Central Nebraska: A Multi-Criteria Spatial Analysis, Zhenghong Tang, Xu Li, Nan Zhao, Ruopu Li, F. Edwin Harvey

Community and Regional Planning Program: Faculty Scholarly and Creative Activity

It is always challenging for decision makers to prioritize wetland conservation programs at the landscape scale. This study employed a GIS-based multi-criteria spatial decision support tool that identified locations with the highest restoration potential for wetland conservation programs in the Rainwater Basin in south-central Nebraska. Five indicators were considered to assess wetland restoration potential: (1) Vegetation characteristics; (2) Soil characteristics; (3) Water volume released from hydrological modification of agricultural irrigation pits; (4) Topographical depression status; and (5) Habitat condition. The results suggested 192 (1.6% of the total) hydric soil footprints as the highest prioritized locations for future wetland restoration programs. …

Initial Changes In Species Cover Following Savanna Restoration Treatments In Western Iowa, David A. Mckenzie, Thomas B. Bragg, David M. Sutherland

Great Plains Research: A Journal of Natural and Social Sciences (through 2013)

Study areas in the Iowa Loess Hills were used to evaluate short-term responses of understory species to three treatment methods designed to facilitate restoration of Quercus macrocarpa savanna. Treatments included burning alone, burning with thinning, and burning with clear-cutting. Plant abundance and diversity were compared before treatment and one year after treatment. Ninety-nine plant species were identified during the study, of which 40 were new following treatment, although most of these were forest associates. Increases in diversity of understory species were observed after treatment, particularly in plots with combined burning and thinning. The forb group was most consistent in response …

Nebraska Blueprint – Fall/Winter 2012

Nebraska Blueprint (Student Publication)

Table of Contents:

From the Editor

Future Engineers Meet at N.U.B.E. Camp – "Nebraska Undergraduates Becoming Engineers (N.U.B.E.) Camp is an annual event organized by the College of Engineering for newly enrolled engineering students."

Enginews

Chem-E-Car Success – Nebraska's Chem-E-Car team competed in building a car that runs and stops through use of a chemical reaction

Hsuker Motorsports – Husker Motorspots, the UNL Formula SAE (Society of Automotive Engineers) team, builds a car and competes in eight events

Concrete Canoe – An interview with Brent Ciecior, a senior Civil Engineering student, about his involvement with the Concrete Canoe team, which …

Improving Performance Of Solid State Drives In Enterprise Environment, Jian Hu

School of Computing: Dissertations, Theses, and Student Research

Flash memory, in the form of Solid State Drive (SSD), is being increasingly employed in mobile and enterprise-level storage systems due to its superior features such as high energy efficiency, high random read performance and small form factor. However, SSD suffers from the erase-before-write and endurance problems, which limit the direct deployment of SSD in enterprise environment. Existing studies either develop SSD-friendly on-board buffer management algorithms, or design sophisticated Flash Translation Layers (FTL) to ease the erase-before-write problem. This dissertation addresses the two issues and consists of two parts.

The first part focuses on the white-box approaches that optimize the …

Characterization Of Runoff In Two Urban Watersheds In Lincoln, Nebraska, Michael J. Florek Iii

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

Characterization of runoff water quality and conditions for two urban watersheds in Lincoln, NE, was performed using data collected from 2008-2012. Water quality data from in-stream probes and storm sampling was combined with soil sample data, geographic information system (GIS) modeling, and nutrient isotope composition analysis to provide a more detailed picture of runoff mechanisms in the Taylor Park and Colonial Hills watersheds.

Soil sample data and GIS modeling were used to compare physical characteristics of the urban watersheds. Taylor Park and Colonial Hills are relatively similar, save for Colonial Hills being six times as large. Its time of concentration, …

Whole-Word Recognition From Articulatory Movements For Silent Speech Interfaces, Jun Wang, Ashok Samal, Jordan R. Green, Frank Rudzicz

Department of Special Education and Communication Disorders: Faculty Publications

Articulation-based silent speech interfaces convert silently produced speech movements into audible words. These systems are still in their experimental stages, but have significant potential for facilitating oral communication in persons with laryngectomy or speech impairments. In this paper, we report the result of a novel, real-time algorithm that recognizes whole-words based on articulatory movements. This approach differs from prior work that has focused primarily on phoneme-level recognition based on articulatory features. On average, our algorithm missed 1.93 words in a sequence of twenty-five words with an average latency of 0.79 seconds for each word prediction using a data set of …

Subwavelength Ripples Adjustment Based On Electron Dynamics Control By Using Shaped Ultrafast Laser Pulse Trains, Lan Jiang, Xuesong Shi, Xin Li, Yanping Yuan, Cong Wang, Yongfeng Lu

Department of Electrical and Computer Engineering: Faculty Publications

This study reveals that the periods, ablation areas and orientations of periodic surface structures (ripples) in fused silica can be adjusted by using designed femtosecond (fs) laser pulse trains to control transient localized electron dynamics and corresponding material properties. By increasing the pulse delays from 0 to 100fs, the ripple periods are changed from ~550nm to ~255nm and the orientation is rotated by 90°. The nearwavelength/subwavelength ripple periods are close to the fundamental/second-harmonic wavelengths in fused silica respectively. The subsequent subpulse of the train significantly impacts free electron distributions generated by the previous subpulse(s), which might influence the formation mechanism …

Fiber-Optic Pressure Sensor Based On Π-Phase-Shifted Fiber Bragg Grating On Side-Hole Fiber, Qi Zhang, Nan Liu, Thomas Fink, Hong Li, Wei Peng, Ming Han

Department of Electrical and Computer Engineering: Faculty Publications

We present a fiber-optic pressure sensor based on a π-phase-shifted fiber Bragg grating (πFBG) fabricated on a side hole fiber. Due to the resonance effect of a πFBG, its reflection spectrum features two notches that are dramatically narrower than the line width of a regular FBG of similar length. The narrow spectral notches allow high-resolution measurement of their spectral separation, significantly improving the pressure detection limit (defined herein as the minimum detectable pressure change) compared to sensors based on a regular FBG of a similar length and on the same fiber. The πFBG demonstrated in this letter is 8.3 mm …

Acuta Enews September 2012 Vol. 41, No. 9

ACUTA Newsletters

In this issue....

NY City, the New WTC, and ACUTA

Overheard via eMail: Legacy Systems

UC Cloud Security: Avoiding an Identity Crisis

Board Report

Annual Dues Reminders Mailed July 3

Sense- Making: Why People Won't Be Replaced by Computers Anytime Soon

Young Professionals-- What's in It for You?

Webinar FREE to Members

Info Links

PCI Compliance of Increasing Importance to Higher Ed

ACUTA Member Benefit: Post and Access RFPs Welcome New Members

Check It Out

Maximal Force Characteristics Of The Ca2+-Powered Actuator Of Vorticella Convallaria, Sangjin Ryu, Matthew J. Lang, Paul Matsudaira

Department of Mechanical and Materials Engineering: Faculty Publications

The millisecond stalk contraction of the sessile ciliate Vorticella convallaria is powered by energy from Ca²⁺ binding to generate contractile forces of ~10 nN. Its contractile organelle, the spasmoneme, generates higher contractile force under increased stall resistances. By applying viscous drag force to contracting V. convallaria in a microfluidic channel, we observed that the mechanical force and work of the spasmoneme depended on the stalk length, i.e., the maximum tension (150–350 nN) and work linearly depended on the stalk length (~2.5 nN and ~30 fJ per 1 mm of the stalk). This stalk-length dependency suggests that motor units of …

An Analysis Of The Impacts Of Temperature Segregation On Hot Mix Asphalt, Thaddaeus A. Bode

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

This research was conducted to produce a more realistic picture 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 sensing devices were used to test how the selected variables contribute to temperature differentials. These variables include 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 …

Scalable Distributed Communication Architectures To Support Advanced Metering Infrastructure In Smart Grid, Jian Zhou, Rose Qingyang Hu, Yi Qian

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

In this paper, we investigate the scalability of three communication architectures for advanced metering infrastructure (AMI) in smart grid. AMI in smart grid is a typical cyber-physical system (CPS) example, in which large amount of data from hundreds of thousands of smart meters are collected and processed through an AMI communication infrastructure. Scalability is one of the most important issues for the AMI deployment in smart grid. In this study, we introduce a new performance metric, accumulated bandwidth distance product (ABDP), to represent the total communication resource usages. For each distributed communication architecture, we formulate an optimization problem and obtain …

Optimal Reduction Of Electrical Energy Consumption By Supply Air Ac Motors, Keyhan Rafiee

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

The Nebraska Center for Energy Sciences Research (NCER) at the University of Nebraska-Lincoln (UNL) strives to be energy efficient through Green Energy. Of course, in meeting some of the requirements for different types of Leadership in Energy and Environmental Design (LEED) certification, certain minimum levels of energy efficiency practices must be met. One such level of energy efficiency, in particular, is reduction in the consumption of electrical energy in buildings. This thesis is a study of methods of reducing the consumption of electrical energy (measured in kW of electrical power) in the UNL Jorgensen Hall (JH) air handling unit 2 …

Modeling Of Power Semiconductor Devices, Tanya Kirilova Gachovska

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

One of the requirements for choosing a proper power electronic device for a converter is that it must possess a low specific on-resistance. The specific on-resistance of a bipolar device is related to the base width and doping concentration of the lightly doped drift region. This means that the doping concentration and the width of the low-doped base region in a bipolar device must be carefully considered to achieve a desired avalanche breakdown voltage and on-resistance. In order to determine the technological parameters of a semiconductor device, a one dimensional analysis is used to calculate the minimum depletion layer width, …

Automation Of Landmark Selection For Rodent Brain Mri-Histology Registration Using Thin-Plate Splines, Ayan Sengupta

School of Computing: Dissertations, Theses, and Student Research

Image registration is the process of aligning two different images of the same object taken at different times, at different orientations or using different instruments. This is common in medical applications since multiple modalities are used to image different parts of the body. This is an important early step in many diagnostic procedures such as change detection, monitoring tumor or quantifying spread of a disease. The widely used landmark based registration approach is tedious, time consuming, inconsistent and error prone. Furthermore, the standard schemes based on rigid and affine transformation can only describe global geometric differences between the objects of …