Other Civil and Environmental Engineering Commons^™

Evaluation Of Flood Damage On Cross Laminated Timber Wall Configurations, Mustafa Nezih Kaya

Theses and Dissertations

Greenhouse gas emissions are one of the critical factors that affect climate change, increasing flooding risk and threatening human life. The use of traditional construction materials is responsible for a higher percentage of global greenhouse gas emissions when compared to the use of sustainable materials in the construction industry. The substitution of current building materials with sustainable materials is essential to reduce greenhouse gas emissions and positively influence climate change when the current construction demand in the world is considered. Wood is one of the primary environmentally friendly construction materials in regard to high carbon storage and low carbon emissions. …

Use Of A Trial Function Method To Semi-Analytically Simulate Matrix Diffusion In Heterogeneous And Fractured Media, Kien Trung Pham

All Dissertations

A semi-analytic trial function model is applied to simulate matrix diffusion in systems of parallel fractures, 2-D/3-D discrete fracture networks, and in 3-D heterogeneous media. The trial function model gives low normalized root mean square error (NRMSE) when compared to the parallel fracture analytical solution over a range of fracture spacing, with considerations for retardation and decay. The semi-analytic trial function model is efficient in time and maintains less than 6% NRMSE when it simulates matrix diffusive transport in 2-D/3-D discrete fracture networks (DFN). The model can predict DFN plume within a few meters of accuracy compared to fine-grid DFN …

Efficiency Of Bank Filtration In The Removal Of Cyanotoxins Under Different Levels Of Nutrients, Luke Walkenhorst

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

Harmful Algal Blooms (HABs) are an increasing concern not only in Nebraska, but across the world. Increasing global temperatures in conjunction with overuse of synthetic fertilizers are leading causes to the increasing frequency and concern of HABs. In the present work, the effectiveness of simulated bank filtration (BF), as an economical water treatment option, to remove cyanotoxins under different levels of nutrients (nitrates and phosphates) was investigated. Vertical flow-through columns pre-acclimated with two levels of nutrients (e.g., nitrate and phosphate—10 vs. 50 mg/L) were exposed to two different levels of cyanotoxins (10 vs. 75 μg/L). Results from the study confirmed …

Wetland Soil Development Along Salinity And Hydrogeomorphic Gradients In Active And Inactive Deltaic Basins Of Coastal Louisiana, Amanda Fontenot

LSU Master's Theses

Coastal wetlands provide an abundance of ecosystem services that benefit society, such as essential habitat for commercial species, storm protection, nutrient cycling, and carbon storage. Louisiana faces rapid rates of relative sea level rise (natural subsidence and eustatic sea levels) that threaten wetland survival, which are amplified by a reduction of riverine sediment input. An important determining factor of marsh survival is the formation of wetland platform elevation, known as vertical accretion, which is determined by several processes including sediment deposition & erosion, below ground biomass (BGB) productivity, decomposition of organic matter, shallow & deep subsidence, and soil compaction. Feldspar …

Development An Edge-Computing Sensing Unit For Continuous Measurement Of Canopy Cover Percentage Of Dry Edible Beans, Wei-Zhen Liang, Joseph Oboamah, Xin Qiao, Yufeng Ge, Robert M. Harveson, Daran R. Rudnick, Jun Wang, Haishun Yang, Angie Gradiz

Department of Agricultural and Biological Systems Engineering: Faculty Publications

Canopy cover (CC) is an important indicator for crop development. Currently, CC can be estimated indirectly by measuring leaf area index (LAI), using commercially available hand-held meters. However, it does not capture the dynamics of CC. Continuous CC monitoring is essential for dry edible beans production since it can affect crop water use, weed, and disease control. It also helps growers to closely monitor “yellowness”, or senescence of dry beans to decide proper irrigation cutoff to allow the crop to dry down for harvest. The goal of this study was to develop a device – CanopyCAM, containing software and hardware …

Effect Of Bromoform And Linseed Oil On Greenhouse Gas Emissions From Stored Beef Manure, Andrew Ortiz Balsero, Mara Zelt, Amy Millmier Schmidt, Miguel Fudolig, Daniel N. Miller

Department of Agricultural and Biological Systems Engineering: Faculty Publications

Emissions of carbon dioxide, methane, and nitrous oxide – potent greenhouse gases - from stored beef feedlot manure are a significant concern relative to climate change. Research on methane reduction strategies for enteric emissions has identified the application of organic additives, such as bromoform and linseed oil, to ruminant diets as potential solutions for reducing enteric emissions and pathogenic bacteria in excreted manure. The objective of this study was to determine the effect of bromoform and linseed oil on greenhouse gas emissions from beef feedlot manure, and on E. coli concentration in beef cattle manure, during a 5-week storage period. …

Study On Strength And Volume Stability Of Coral Mortar, Qingzong Xue

International Conference on Durability of Concrete Structures

No abstract provided.

Data-Driven Prioritization And Empirical Predictions For Bridge Scour In Nebraska, Awgku Ahmad Hashim Awg Bolhasan

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

The effect of scour at the bridge substructure results in an increase in the vulnerability of the overall bridge stability. Previous studies have found that current guidelines are often overly-conservative with respect to scour. This project aims to provide guidance on hydraulic modeling parameters and reasonable scour estimates specific to Nebraska conditions. This will enable engineers to assess bridge sites for scour more precisely for efficient and effective design and countermeasures.

Four sites were surveyed for scour changes between the period of December 9, 2020, to April 20, 2021. At these four sites, overland and bathymetry survey data were collected. …

Mechanical And Durability Properties Of Geopolymer Concrete – A Review, Lelian Elkhatib, Fadi Al Aridi, Adel Elkordi, Jamal Khatib

BAU Journal - Science and Technology

Owing to the ongoing increase in human population, there is a need for more construction projects including residential buildings and other amenities. Concrete is by far the dominant material used in construction and cement is a main ingredient. Cement manufacture is an energy intensive process and emit large amounts of carbon dioxide into the atmosphere. A reduction in the amount of cement used in construction is greatly beneficial. The use of geopolymer or alkali activated materials can serve this purpose as it attempts to totally replace cement in concrete. Geopolymers are materials that consist mainly of silica and alumina materials …

Axial Hypersensitivity Is Associated With Aberrant Nerve Sprouting In A Novel Model Of Disc Degeneration In Female Sprague Dawley Rats, David J. Lillyman, Fei San Lee, Evie C. Barnett, Tyler J. Miller, Moreno Lozano Alvaro, Henry C. Drvol, Rebecca A. Wachs

Department of Agricultural and Biological Systems Engineering: Faculty Publications

Chronic low back pain is a global socioeconomic crisis and treatments are lacking in part due to inadequate models. Etiological research suggests that the predominant pathology associated with chronic low back pain is intervertebral disc degeneration. Various research teams have created rat models of disc degeneration, but the clinical translatability of these models has been limited by an absence of robust chronic painlike behavior. To address this deficit, disc degeneration was induced via an artificial annular tear in female Sprague Dawley rats. The subsequent degeneration, which was allowed to progress for 18-weeks, caused a drastic reduction in disc volume. Furthermore, …

A Segmentation-Guided Deep Learning Framework For Leaf Counting, Xijian Fan, Rui Zhou, Tardi Tjahjadi, Sruti Das Choudhury, Qiaolin Ye

Department of Agricultural and Biological Systems Engineering: Faculty Publications

Deep learning-based methods have recently provided a means to rapidly and effectively extract various plant traits due to their powerful ability to depict a plant image across a variety of species and growth conditions. In this study, we focus on dealing with two fundamental tasks in plant phenotyping, i.e., plant segmentation and leaf counting, and propose a two-steam deep learning framework for segmenting plants and counting leaves with various size and shape from two-dimensional plant images. In the first stream, a multi-scale segmentation model using spatial pyramid is developed to extract leaves with different size and shape, where the fine-grained …

Towards A Cybersecurity Testbed For Agricultural Vehicles And Environments, Mark Freyhof, George Grispos, Santosh Pitla, Cody Stolle

Department of Agricultural and Biological Systems Engineering: Faculty Publications

In today’s modern farm, an increasing number of agricultural systems and vehicles are connected to the Internet. While the benefits of networked agricultural machinery are attractive, this technological shift is also creating an environment that is conducive to cyberattacks. While previous research has focused on general cybersecurity concerns in the farming and agricultural industries, minimal research has focused on techniques for identifying security vulnerabilities within actual agricultural systems that could be exploited by cybercriminals. Hence, this paper presents STAVE – a Security Testbed for Agricultural Vehicles and Environments – as a potential solution to assist with the identification of cybersecurity …

A Physical Model Of Deadmans Run, Quinn Brandt

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

A physical model of Deadmans Run and a pair of railroad bridges was constructed to assess the impacts of the bridges on flood flows. Lower Platte South Natural Resources District is planning a series of improvements to Deadmans Run to improve flood conveyance capacity and remove approximately 500 homes and businesses from the floodplain. The rail bridges are located less than a mile from the confluence of Deadmans Run and Salt Creek, meaning the bridges present a significant bottleneck to the planned improvements. The physical model was used to characterize the drag effects caused by the bridges, which was used …

Development Of A Next-Generation Non-Proprietary Portable Concrete Barrier, Riley Ruskamp

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

Portable concrete barriers (PCBs) are segmented barriers made of precast concrete units that are connected by various load-bearing hardware. PCBs are typically used to shield work zones by redirecting errant vehicles upon impact with the barrier system. Most commonly-available PCBs have demonstrated performance issues arising from the sloped face of the barrier, which encourages vehicles to pitch and roll during impact, potentially resulting in vehicle rollover. Concerns also exist regarding the large dynamic deflections exhibited by these systems that can encroach upon the protected work zone or require anchoring to prevent large displacements. In addition to these concerns, the American …

Risk Assessment Of Hazardous Material Transportation For Small And Tribal Communities, Harrison Redepenning

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

By and large transportation of hazardous materials (HazMat) across the US is increasing, with truck transportation as the most common method of transport. Smaller communities (population <5,000) and Native American communities often lack the economic and political influence to quantify the dangers that HazMat incidents present to the immediate and surrounding areas. Lack of such information is an impediment to adequate preparedness in cases of HazMat incidents. This research focuses on assessing the vulnerability of small and tribal communities in Nebraska to the impacts of highway HazMat incidents. This was done by estimating the expected number and type of HazMat incidents per population in each community. Additionally, statistical analysis was conducted on actual HazMat incidents to determine if small and Native American communities experience a higher rate of incidents per population and per HazMat VMT than large and other small communities respectively. For per population, it was found small versus large is statistically significant while Native American versus other small communities was not significant. For per HazMat VMT, neither comparison was found to be statistically significant. In estimated HazMat incidents, actual HazMat incidents per population, and actual HazMat incidents per HazMat VMT, small communities had higher mean values than their large counterparts. Communities on Native American reservation land experienced a higher estimated and lower actual HazMat incident rate per population than other small communities. For actual HazMat incidents per VMT, Native American communities had a higher rate than other small communities.

Advisor: Aemal Khattak

Experimental And Numerical Analysis Of Soil-Geosynthetic Composite For A Geosynthetic-Reinforced Roadway System, Daniel Robertson

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

The present research conducted tests to evaluate the reinforcing performance of geosynthetics including three geogrids (GG1, GG2, and GG3) and one geotextile (GT) for three different soil types – sand, clay, and red shale. All geosynthetics showed great improvement under the lowest confining pressure. The report concluded that between the Large-Scale Direct Shear test, the Large-Scale Pullout Box, and the FLAC simulation, the three geogrids showed the greatest improvement when conducted with sand. The sand could withstand a much greater normal pressure than either clay or red shale. The biaxial geogrids, GG1 and GG3, had ideal results for lower stress …

Performance Of Concrete With Different Cement Finenesses And Nano-Activators, Brandon Faltin

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

The excessive shrinkage in modern concrete is the result of the construction industry in its quest to complete the job as soon as possible. In order to accomplish this, the fineness of cement was increased significantly in recent decades for a faster rate of strength gain. To combat the cement fineness and reverse the trend of shrinkage, the usage of coarse cements and nanoparticles should be strongly considered. The coarse cement is used to reduce the shrinkage of concrete, while the nanoparticle increases the early strength, alleviating the original concerns of reduced early strength when using coarse cement.

Work in …

Estimation Of Methane Emissions From Beef Cattle Manure In Nebraska, Noe Hernandez

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

The emission of methane from livestock production contributes to climate change. Cattle manure accounts for one-third of the total methane emission over the lifecycle of beef and dairy production and represents an opportunity to lower the environmental footprint of the beef industry. While models have been developed to estimate methane emissions from manure under certain types of manure storage methods, there is a lack of a user-friendly interface that agricultural or environmental engineers can use to estimate the methane emission from manure for specific regions. Therefore, the goal of this study was to build an interface to estimate methane emissions …

Optimizing The Self-Healing Efficiency Of Hydrogel Encapsulated Bacteria In Concrete, Ricardo Hungria

LSU Master's Theses

Calcium carbonate precipitation through microbial means is a promising pathway for concrete self-healing technologies, mainly for its microcrack sealing attributes. The main goal of this project was to study and optimize the crack healing efficiency of hydrogel encapsulated bacteria in concrete. To achieve this purpose, Bacillus pseudiformus was implemented as the bacteria strain at a concentration of 10⁸ cells/ml. This bacterium strain along with yeast extract was combined along with three different mineral precursors corresponding to magnesium acetate, calcium lactate, and sodium lactate. All these three precursors were evaluated at two concentrations (67.76 mM/l and 75 mM/l). For each …

Effects Of Different Crash Data Variables On Ems Response Time For A Rural County In Alabama, Sneha R. Vanga, Phillip M. Ligrani, Mehrnaz Doustmohammadi, Michael Anderson

PRC-Affiliated Research

Response time of Emergency Medical Services (EMS) is an important factor related to preventable deaths in road crash incidents. This study focuses on analyzing the effects of different independent variables on the EMS Response Time (ERT). Independent variables considered for this investigation are travel time, day of the week, crash severity, weather, time of the day, and lighting condition. Understanding outcomes resulting from variations of the considered parameters on ERT is crucial to minimize the possibility of adverse outcomes which are tied to different types of injuries, and vital to limit the prospect of fatalities. Crash data used for this …