Engineering Commons^™

Development Of Semi-Circular Bending (Scb) Fracture Test For Bituminous Mixtures, Gabriel Nsengiyumva

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

Granted that most distresses in asphalt (flexible) concrete (AC) pavements are directly related to fracture, it becomes clear that identifying and characterizing fracture properties of AC mixtures is a critical step towards a better pavement design. This thesis examines the testing variables of a reliable and practical semicircular bending (SCB) test for evaluating the fracture characteristics of asphalt concrete mixtures at intermediate service temperature conditions. The first part of this thesis investigates the repeatability of the SCB fracture test method by integrating a statistical-experimental approach to identify testing variables of the SCB test that result in repeatable test results. Toward …

Development Of A Semicircular Bend (Scb) Test Method For Performance Testing Of Nebraska Asphalt Mixtures, Gabriel Nsengiyumva, Yong-Rak Kim, Taesun You

Nebraska Department of Transportation: Research Reports

No abstract provided.

Mitigating Pavement Edge Drop Off, Wayne Jensen, Niles Uerling

Nebraska Department of Transportation: Research Reports

The objective of this research was to investigate and document practices currently being used by the Nebraska Department of Roads (NDOR) districts and other State DOTs to mitigate pavement edge drop off. The NDOR has developed (or borrowed) and is currently incorporating into its standard practices several procedures that significantly decrease the incidence and magnitude of pavement edge-drop off. As these practices become more fully integrated into highway reconstruction projects, pavement edge drop off is expected to decrease dramatically. Localized areas of pavement edge drop off along paved lanes with bare or vegetated shoulders were noted as posing particular problems …

Feasibility Of Using Raman-Based Techniques For Breast Cancer Detection, Sara Mollamohammada

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

Breast cancer is one of the common types of cancer among women all over the world. Early diagnosis is an effective way that improve the treatment process and gives the patients a better chance of survival. Many of the patients infected by breast cancer choose breast conservation surgery (BCS). However, some of those will be subjected to mastectomy, and many will have tumor recurrence as there is no precise technique to show the tumor margins. Raman-based methods are powerful techniques with potential to rapidly differentiate normal from tumor tissues and provides a solution to detect tumor margin. This is because …

Subjective Perception Of Varying Reflection Densities In Room Impulse Responses, Hyun Hong

Durham School of Architectural Engineering and Construction: Dissertations, Thesis, and Student Research

Reverberation time (RT) is a metric commonly used to describe room acoustic conditions, but different rooms which have the same reverberation time can have different reflection densities. Much less is known about how humans perceive different reflection densities and how sensitive humans are to changes in reflection density. Previous investigations in the existing literature have studied the upper limit of distinguishable reflection density using artificial impulse responses, but not with more realistic impulse responses simulated in room acoustic software or measured from real rooms. The aim of this dissertation is to investigate methods for quantifying reflection density from measured impulse …

Methodology For Selecting The Column Configuration With Lowest Media Replacement Cost For Small Adsorption Systems, Artem Bausk

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

The relative performance of three column configurations often used for adsorption systems serving small communities was evaluated in terms of which results in the lowest overall replacement cost. Replacement cost is the cost of fresh media and the transportation, labor, and material costs to replace the media. Both the adsorption capacity and the media replacement costs were modeled. The pore and surface diffusion model was utilized to simulate the fixed-bed adsorption and obtain the breakthrough curves, which were then normalized using the target effluent to influent concentration ratio (C/C_o) and the mass transfer zone fraction (%MTZ_BT). …

Viscoelastic, Fatigue Damage, And Permanent Deformation Characterization Of High Rap Bituminous Mixtures Using Fine Aggregate Matrix (Fam), Hesamaddin Nabizadeh

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

Performance characteristics of bituminous mixtures play the most influential role in designing flexible pavement. These asphaltic mixtures can be considered as heterogeneous mixtures which composed of two primary components: fine aggregate matrix (FAM) phase and aggregate phase. The FAM phase acts as a critical phase in evaluating the performance characteristics including viscoelastic, fatigue damage, and permanent deformation characteristics of entire asphalt mixtures. This study evaluates the viscoelastic, fatigue damage and permanent deformation characteristics of bituminous mixtures containing 65% reclaimed asphalt pavement (RAP) by performing oscillatory torsional shear tests of cylindrical bars of FAM using a dynamic mechanical analyzer. Moreover, this …

Phase I Evaluation Of Selected Concrete Material Models In Ls-Dyna, Bradley J. Winkelbauer

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

Numerous roadside safety systems are configured with reinforced concrete materials, such as bridge railings, median barriers, and roadside parapets. These protective barrier systems are intended to safely contain and redirect errant vehicles as well as prevent impacts into hazardous fixed objects or other geometric features. The analysis and design of these structures may involve impact simulation with finite element software, like LS-DYNA, which includes multiple concrete material models. For such investigations, limited guidance is available for selecting preferred concrete material models and determining appropriate values for specific parameters. This Phase I study investigated the viability and performance of existing concrete …

Nebraska Data Collection, Keyvan Zare Rami, Yong-Rak Kim

Nebraska Department of Transportation: Research Reports

Automated pavement performance data collection is a method that uses advanced technology to collect detailed road surface distress information at traffic speed. Agencies are driven to use automated survey techniques to enhance or replace their current manual distress survey because of the advantages of objective measurements, safety benefits, and reduced measurement time. As agencies move toward the transition to fully automated data collection methods, there are common concerns regarding how the output of the new method will match the current manual survey ratings and how they will be adopted into the existing Pavement Management System (PMS). This study evaluates the …

Sustainability Assessment For Energy Systems And Chemical Process Industries, Michael J. Matzen

Department of Chemical and Biomolecular Engineering: Theses and Student Research

Sustainability has become an important factor in the chemical process and energy industries with a strong drive for process improvements towards more environmentally conscious solutions. However, there are many ways of defining sustainability and even more ways of trying to determine how sustainable a process is. This work looks into applying a conjunction of tools including; process simulation, multi-criteria decision matrices and life-cycle assessment to more quantitatively determine sustainability metrics. We have applied these tools for the production of electricity, methanol and dimethyl ether. A novel method of electricity production, in chemical looping combustion (CLC), was used that inherently involves …

Effects Of Sediments On Bmps For Highway Runoff Control, Matthew Garder

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

Numerous studies conducted on highway stormwater runoff and its control with Best Management Practices (BMPs) indicate that sediment is the major pollutant that affects performance and longevity of BMPs. Currently, there are several knowledge gaps related to the effects of sediments on highway BMPs: a) how much sediment will be generated by a construction site by a section of highway with its surrounding watershed under different conditions; b) how sediment is intercepted by different BMPs with or without pretreatment sections; and c) what are the effects of these sediments on BMPs’ hydraulic behavior, longevity, and pollutants removal or release. The …

Mash Tl-4 Crash Testing And Evaluation Of The Restore Barrier, Jennifer D. Schmidt, Tyler L. Schmidt, Ronald K. Faller, Robert W. Bielenberg, John D. Reid, James C. Holloway, Karla A. Lechtenberg

Nebraska Department of Transportation: Research Reports

Three full-scale vehicle crash tests were conducted according to the MASH Test Level 4 (TL-4) safety performance criteria on a restorable and reusable energy-absorbing roadside/median barrier, designated the RESTORE barrier. The system utilized for test nos. SFH-1 through SFH-3 was 240 ft (73.2 m) long with a nominal height of 38⅝ in. (981 mm). The barrier consisted of an upper steel tube rail attached to the top of 20-ft (6.1-m) long x 22.-in. (565-mm) wide precast concrete beams connected with wedge-shaped joints and supported by 11⅝-in. (295-mm) tall rubber posts and steel skids.

In test no. SFH-1, a 5,021-lb (2,277-kg) …

Integrated 3d Bridge-Condition Visualization (Bcv) To Facilitate Element-Based Bridge Condition Rating (Ebcr), Zhigang Shen, Wayne Jensen

Nebraska Department of Transportation: Research Reports

Routine inspection and maintenance records are essential for bridges to function well throughout their intended lifespan. Although existing bridge management systems are efficient at data storage, it is difficult to conduct comprehensive data analysis and management due to the lack of data integration mechanism. Engineers have to manually put many pieces of bridge drawings and inspection data together to make maintenance or repair/rehab decisions. Building information modeling (BIM) can be applied in bridge asset management area, including bridge inspection/rating to help to integrate the many data pieces. In this project we developed a 3D bridge inspection data management system, using …

Mash Test Nos. 3-17 And 3-11 On A Non-Proprietary Cable Median Barrier, Robert W. Bielenberg, Scott K. Rosenbaugh, Ronald K. Faller, Brandt M. Humphrey, Tyler L. Schmidt, John D. Reid

Nebraska Department of Transportation: Research Reports

No abstract provided.

Review Of Robotic Technology For Strawberry Production, S. G. Defterli, Yeyin Shi, Yunjun Xu

Department of Biological Systems Engineering: Papers and Publications

With an increasing world population in need of food and a limited amount of land for cultivation, higher efficiency in agricultural production, especially fruits and vegetables, is increasingly required. The success of agricultural production in the marketplace depends on its quality and cost. The cost of labor for crop production, harvesting, and post-harvesting operations is a major portion of the overall production cost, especially for specialty crops such as strawberry. As a result, a multitude of automation technologies involving semi-autonomous and autonomous robots have been utilized, with an aim of minimizing labor costs and operation time to achieve a considerable …

Potential Irrigation Reductions From Increasing Precipitation Utilization With Variable Rate Irrigation, Tsz Him Lo, Derek M. Heeren, Luciano Mateos, Joe D. Luck, Derrel L. Martin, Dean E. Eisenhauer

Department of Biological Systems Engineering: Papers and Publications

Much of the previous research quantifying the potential benefits of variable rate irrigation (VRI) consists of case studies with simulations using data from small numbers of intensely sampled fields. In this study, an indicator of the amount of root zone available water capacity that is unutilized by uniform rate irrigation was calculated for 49,224 center pivot irrigated fields in Nebraska using publicly available data exclusively. Based on the values of this indicator, potential seasonal irrigation reductions from increasing precipitation utilization with VRI were estimated to be high for a small fraction of analyzed center pivots but low on a regional …

Evaluation Of A Hybrid Remote Sensing Evapotranspiration Model For Variable Rate Irrigation Management, J. Burdette Barker, Christopher M. U. Neale, Derek M. Heeren

Department of Biological Systems Engineering: Papers and Publications

Accurate generation of spatial irrigation prescriptions is essential for implementation and evaluation of variable rate irrigation (VRI) technology. A hybrid remote sensing evapotranspiration (ET) model was evaluated for use in developing irrigation prescriptions for a VRI center pivot. The model is a combination of a two-source energy balance model and a reflectance based crop coefficient water balance model. Spatial ET and soil water depletion were modeled for a 10 km² area consisting of rainfed and irrigated maize fields in eastern Nebraska for 2013. Multispectral images from Landsat 8 Operational Land Imager and Thermal Infrared Sensor were used as model …

Integration And Delivery Of Interferometric Synthetic Aperture Radar [Insar] Data Into Stormwater Planning Within Karst Terranes, Brian Bruckno, Andrea Vaccari, Edward Hoppe, Scott Acton, Elizabeth Campbell

Department of Earth and Atmospheric Sciences: Faculty Publications

As part of two USDOT-funded studies focused on the development of satellite-based Interferometric Synthetic Aperture Radar (InSAR) technology, the researchers integrated InSAR-derived point cloud data into the transportation design process to optimize the location of a stormwater management system in a karst terrane. After initial validation, the InSAR data (over 1.67 million data points comprising various “scatterers”) were brought into a GIS dataframe and georeferenced to locations of known sinkholes. This dataset was then used to evaluate karst hazard within a 40x40km data frame located in the Valley and Ridge Province of Virginia. The group identified systematic kinematic differences in …

Mitigating The Risk Of Extreme Water Scarcity And Dependency: The Case Of Jordan, Joep F. Schyns, Arwa Hamaideh, Arjen Y. Hoekstra, Mesfin Mekonnen, Marlou Schyns

Daugherty Water for Food Global Institute: Faculty Publications

Jordan faces great internal water scarcity and pollution, conflict over trans-boundary waters, and strong dependency on external water resources through trade. This paper analyzes these issues and subsequently reviews options to reduce the risk of extreme water scarcity and dependency. Based on estimates of water footprint, water availability, and virtual water trade, we find that groundwater consumption is nearly double the groundwater availability, water pollution aggravates blue water scarcity, and Jordan’s external virtual water import dependency is 86%. The review of response options yields 10 ingredients for a strategy for Jordan to mitigate the risks of extreme water scarcity and …

Evaluation Of Concrete Grinding Residue (Cgr) Slurry Application On Vegetation And Soil Responses Along Nebraska State Highway 31, Martha Mamo, Dennis L. Mccallister, Walter H. Schacht

Nebraska Department of Transportation: Research Reports

No abstract provided.

Development And Evaluation Of Weak-Post W-Beam Guardrail In Mow Strips, Scott K. Rosenbaugh, Ronald K. Faller, Karla A. Lechtenberg, James C. Holloway

Nebraska Department of Transportation: Research Reports

The objective of this study was to adapt and evaluate a weak-post, W-beam guardrail system for use within mow strips and other pavements. The weak-post guardrail system was originally designed as the MGS bridge rail and has also been adapted for use on culverts. It was envisioned that the weak-post design would absorb the impact forces and prevent damage to the mow strips, thereby minimizing maintenance and repair costs.

Evaluation of the weak posts in mow strips began with three rounds of dynamic bogie testing. Round 1 of bogie testing showed that 4-in. (102-mm) thick concrete would sustain only minor …

Conceptual Development Of An Impact-Attenuation System For Intersecting Roadways, Joseph G. Putjenter, Robert W. Bielenberg, Ronald K. Faller, John D. Reid

Nebraska Department of Transportation: Research Reports

Longitudinal barriers are commonly used to shield hazards, including stiff bridge rail ends and slopes. In some locations, a secondary roadway intersects the primary roadway within the guardrail’s length-of-need (LON). Some intersections may have as little as 15 ft (4.6 m) between the intersection and beginning of the bridge railing, which require short-radius guardrail systems. One short-radius guardrail system has passed several crash tests under AASHTO Manual for Assessing Safety Hardware (MASH) standards.

Site conditions provided by the Nebraska Department of Roads were used to determine the constraints for a new safety treatment for intersecting roadways and include intersection radii, …

Mgs Dynamic Deflections And Working Widths At Lower Speeds, Nicholas A. Weiland, Cody S. Stolle, John D. Reid, Ronald K. Faller, Robert W. Bielenberg, Karla A. Lechtenberg

Nebraska Department of Transportation: Research Reports

The Midwest Guardrail System (MGS) has been full-scale crash tested in many configurations, including installations adjacent to slopes, with different types of wood posts, with and without blockouts, for culvert and bridge applications, and at high flare rates. Although the performance of the MGS and the dynamic deflection and working width of the barrier have been examined, little is known about the dynamic deflection and working width of the MGS when impacted at lower speeds. The MGS is a relatively low-cost barrier, and the Test Level 3 (TL-3) version could be installed for TL-2 and TL-1 applications. The barrier is …

Performance Characteristics Of Posts Embedded In Soil, Brandt M. Humphrey, Karla A. Lechtenberg, John D. Reid, Ronald K. Faller, James C. Holloway

Nebraska Department of Transportation: Research Reports

The primary objective of this research study was to determine the post-soil impact reaction of W6x8.5 (W150x12.6) steel posts and 6-in. x 8-in. (152-mm x 203-mm) Southern Yellow Pine (SYP) posts, specifically along the weak axis. Five bogie tests were conducted on W6x8.5 (W150x12.6) A992 steel posts with a length of 72 in. with embedment depths ranging between of 24 and 40 in. (610 and 1,016 mm). Four bogies tests were conducted on 6-in. x 8-in. (152 mm x 203 mm) SYP posts embedded at depths ranging between 30 and 40 in. (735 and 1,016 mm). The target impact conditions …

Evaluate Students’ Learning Effectiveness Of Hvac System Using 3d Game Animation, Lalitha Devi Nandam

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

An important skill required for students in Construction Engineering and Architecture is to understand what the major components are and how the whole system and its components function. Students typically learn to understand HVAC equipment by reviewing two-dimensional (2D) CAD drawings, images and site visits. With latest developments in 3D game engines for facilitating interactive learning, it is now possible for students to experience three-dimensional (3D) environments of HVAC systems. While this technology is still at an early stage in learning application, it has the potential to significantly enhance the capability of students to study, comprehend and gain experience designing …

Dynamic Characteristics And Seismic Response Analysis Of A Long-Span Steel-Box Basket-Handle Railway Arch Bridge, Xuhui He, Biao Wei, Yunfeng Zou, Dongyang Hu, Daniel G. Linzell

Department of Civil and Environmental Engineering: Faculty Publications

The inside oblique angle between the vertical plane and the arch rib has been shown to be one of the main factors influencing dynamic properties of long-span steel-box basket-handle arch bridges. Details related to the extent, that the inside oblique angle influenced the dynamic characteristics and the seismic response of the arch bridge under the combined longitudinal and vertical seismic excitation and under the combined lateral and vertical seismic excitation, were reported herein. Four oblique angles (0°, 3°, 4.8°, and 6°) were selected based on the arch ribs height and bridge deck width. Findings suggested that a larger inside oblique …

Quantification Of Variable Rate Irrigation Benefits And Spatial Variability In Root Zone Water Holding Capacity, Tsz Him Lo

Department of Biological Systems Engineering: Dissertations and Theses

Variable rate irrigation (VRI) investment decisions require field-specific knowledge of benefits. The objective of this research was to help producers and consultants consider and quantify potential benefits of VRI. First, a conceptual model was developed for evaluating the public and/or private gain from adopting VRI where irrigation water supply is non-restrictive. Potential benefits were classified into three categories and were attributed to ten reasons. In the Central Plains at current prices, a small improvement in corn (maize) yield would make a large contribution to VRI profitability. Second, the potential irrigation withdrawal reduction from adapting VRI to spatial heterogeneity of root …

Land Use And Water And Soil Management Practices Impacts On Potential Groundwater Recharge In Loess Regions Of South Central Nebraska, Gustavo Bosch-Rubia

Department of Biological Systems Engineering: Dissertations and Theses

Sustainability of agro-ecosystems must consider land use and water and soil management effects on groundwater recharge. Water flow beneath the plant root zone through the intermediate vadose zone determines potential groundwater recharge. Different land uses, water and soil management practices control deep percolation as a result of changes on evapotranspiration and infiltration. This study of the impact of surface activities on deep percolation was conducted at six locations across Nebraska: Two center-pivot irrigated no-till planting systems fields were compared with one tilled center-pivot irrigated field, a furrow irrigated field with multiple tillage treatments, an eco-fallow dryland farming system, and a …

Airborne Infection In Healthcare Environments: Implications To Hospital Corridor Design, Ehsan Mousavi

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

Several studies have linked nosocomial transmission airborne diseases to airflow in healthcare settings. Quasi-experimental methods are developed to observe the aerodynamic transport behavior of synthetic respiratory particles in corridors of a hospital. Computational models, validated by experimental results, are then developed to explore the spatial relationships of supply-exhaust air ventilation in patient corridors. The aim of this study is to determine optimal HVAC design strategies to contain and remove airborne contaminants in healthcare environments.

In addition to occupant comfort, hospital HVAC systems are designed to provide ventilation and directional airflow to contain, dilute and remove contaminants including airborne disease. Of …

Implementation Of Sustainability Improvements At The Facility Level: Business Motivations And Impact Of P2 Intern Recommendations, Vincent D. Kuppig

Department of Environmental Engineering: Theses and Student Research

Many sustainability and pollution prevention (P2) technical assistance programs exist across the Unities States. There is a need to quantify the actual impact using various metrics and, in addition, to identify the driving forces behind a company’s decision-making process. The University of Nebraska-Lincoln Partners in Pollution Prevention and the Kansas State University Pollution Prevention Institute intern programs partnered to complete 30 reassessments in 2014 to obtain specific information related to each P2 recommendation. After being reassessed, the clients were surveyed concerning their motivations for implementing and not implementing each recommendation; 23 clients responded to the survey.

The clients surveyed were …