Civil and Environmental Engineering Commons^™

Climate Change Impacts The Subsurface Transport Of Atrazine And Estrone Originating From Agricultural Production Activities, Renys Enrique Barrios, Simin Akbariyeh, Chuyang Liu, Khalid Muzamil Gani, Margarita T. Kovalchuk, Xu Li, Yusong Li, Daniel D. Snow, Zhenghong Tang, John Gates, Shannon L. Bartelt-Hunt

Nebraska Water Center: Faculty Publications

Climate change will impact soil properties such as soil moisture, organic carbon and temperature and changes in these properties will influence the sorption, biodegradation and leaching of trace organic contaminants to groundwater. In this study, we conducted a modeling case study to evaluate atrazine and estrone transport in the subsurface under current and future climate conditions at a field site in central Nebraska. According to the modeling results, in the future, enhanced evapotranspiration and increased average air temperature may cause drier soil conditions, which consequently reduces the biodegradation of atrazine and estrone in the water phase. On the other hand, …

Constitutive Model Of Lateral Unloading Creep Of Soft Soil Under Excess Pore Water Pressure, Wei Huang, Kejun Wen, Xiaojia Deng, Junjie Li, Zhijian Jiang, Yang Li, Lin Li, Farshad Amini

Civil and Architectural Engineering Faculty Research

Presented in this paper is a study on the lateral unloading creep tests under different excess pore water pressures. The marine sedimentary soft soil in Shenzhen, China, was selected in this study. The results show that the excess pore water pressure plays a significant role in enhancing the unloading creep of soft soil. Higher excess pore water pressure brings more obvious creep deformation of soft soil and lower ultimate failure load. Meanwhile, the viscoelastic and the viscoplastic modulus of soft soil were found to exponentially decline with creep time. A modified merchant model and a combined model of the modified …

Recent Shrinkage And Fragmentation Of Bluegrass Landscape In Kentucky, Bo Tao, Yanjun Yang, Jia Yang, S. Ray Smith, James F. Fox, Alex C. Ruane, Jinze Liu, Wei Ren

Plant and Soil Sciences Faculty Publications

The Bluegrass Region is an area in north-central Kentucky with unique natural and cultural significance, which possesses some of the most fertile soils in the world. Over recent decades, land use and land cover changes have threatened the protection of the unique natural, scenic, and historic resources in this region. In this study, we applied a fragmentation model and a set of landscape metrics together with the satellite-derived USDA Cropland Data Layer to examine the shrinkage and fragmentation of grassland in the Bluegrass Region, Kentucky during 2008–2018. Our results showed that recent land use change across the Bluegrass Region is …

Developing Open Source Software Using Version Control Systems: An Introduction To The Git Language For Documenting Your Computational Research, Jared D. Smith, Jonathan D. Herman

All ECSTATIC Materials

Version control systems track the history of code as it is committed (saved) by any number of developers. Have you made a coding error and cannot debug it? Version control systems allow for resetting code back to when it worked, and show what code has changed since previous commits.

The contents of this lecture provide an introduction to the git version control language, GitHub for cloud hosting open source code repositories, and tutorials that demonstrate common and useful git and GitHub practices. This lecture is intended to be coupled with a discussion on creating reproducible computational research.

The zipped folder …

Risk Assessment In Waste Sampling Activity For A Selected Food Industry, Razali Nurul Syazreen

Student Works (2020-2029)

Waste sampling is one of the main activities during environmental audit. This activity has been estimated as a non-risky activity and lead to inadequate risk assessment in the activity. The purpose of this study is to create a safer workplace for enforcement body in general and DOE officer in specific during waste sampling activity. Main objectives are to identify the hazards, further assess the hazards and determine the control measure to reduce the hazards. Observation and on-the-job training have been conducted to three food industry located in Shah Alam to identify the hazards. Structured surveys were conducted with 293 participants …

Optimal Distribution Of Best Management Practices (Bmps) For Urban Stormwater Runoff Quantity And Quality Control, Rezaei Abdul Razaq

Student Works (2020-2029)

The vast development of urban areas throughout the world has substantially impacted the natural landscapes, leading to more imperviousness. Urbanization typically results in a larger amount of runoff volume, increase in flow frequency, duration and peak runoff, faster time of concentration as well as lower infiltration which will affect groundwater recharge. The stormwater runoff quality is also adversely affected in urban areas due to the pollutant loads in stormwater runoff. Best Management Practices (BMPs) and Low Impact Development (LID) have been widely applied to urban impervious surfaces to reduce urban stormwater runoff and improve water quality. In order to achieve …

Compound Flooding In Coastal Areas Emanating From Inland And Offshore Events, Hamed Behzad Koochaksaraii

Dissertations

The vulnerability of urban populations to natural hazards and climate change is a major theme in many reports on coastal cities with flooding ranking highly among the climate change concerns. Flooding could occur as a result of runoff for inland rainfall that accumulates at the mouth of the estuary to the sea or it could occur due to a storm surge emanating from the ocean. The techniques for modeling the flooding from these events are very different, as they were developed in different scientific fields: hydrology and hydraulic engineering for inland rainfall versus coastal oceanography and coastal engineering for offshore …

Stress-State And Injection-Rate Dependent Damage Processes During The Hydraulic Fracturing Of Granite, Gayani Sasendrika Gunarathna

Dissertations

Hydraulic fracturing is a well-stimulation technique that is employed in field applications, such as enhanced geothermal systems (EGS) and shale oil/gas extraction. This research experimentally investigates the effect of the state of stress and injection rate on the hydraulic fracturing processes. In addition, a displacement discontinuity method (DDM) code, FROCK, is used to model the crack initiation and propagation in a granite specimen under hydraulic fracturing conditions. In order to conduct the experimental work, a test setup capable of applying a triaxial state of stress and water pressure inside pre-fabricated flaws cut in prismatic granite specimens is developed. Additionally, the …

Numerical And Analytical Methods To Predict Behavior Of Reinforced Ductile Concrete Composites, Mandeep Pokhrel

Dissertations

Structural components constructed with ductile concrete composites, such as high-performance fiber-reinforced cementitious composites (HPFRCC), are known to perform exceptionally well under extreme mechanical and environmental loading conditions compared to traditional concrete. HPFRCC flexural components exhibit enhanced performance in terms of displacement ductility, energy dissipation capacity, and damage tolerance capacity. However, recent research suggests that the flexural behavior of reinforced HPFRCCs in terms of crack progression, reinforcement plasticity, and failure mechanism is significantly different than conventional reinforced concrete. Specifically, the failure mode of flexural members is found to be predominantly through the fracture of longitudinal reinforcement rather than compression crushing of …

Modeling Of Distributary Channels Formed By A Large Sediment Diversion In Broken Marshland, Dylan Blaskey

LSU New Orleans Theses and Dissertations

A 2-D DELFT3D model was developed to address the morphological response of Barataria Bay, the sediment deposition rate in the receiving basin, and the impact on the existing distributary channels within the broken marsh system due to the proposed Mid-Barataria Sediment Diversion. The model had a mesh size sufficient to accurately represent the development of the distributary channels, localized flooding, erosion, and salinity in the basin. The model predicts that the receiving basin will experience extensive erosion during the first year the diversion is open creating three major distributary pathways which flood much of the basin in freshwater. Most locations …

Determination Of The Optimal Location For Constructing Solar Photovoltaic Farms Based On Multi-Criteria Decision System And Dempster–Shafer Theory, Marzieh Mokarram, Mohammad J. Mokarram, Mohammad R. Khosravi, Ali Saber, Akbar Rahideh

Civil and Environmental Engineering and Construction Faculty Research

Considering environmental concerns regarding air pollution which is induced by burning fossil fuels to generate electrical power, utilizing solar energy as a green and sustainable energy source is of great interest. This study proposes a novel framework to determine the optimal location for constructing solar photovoltaic (PV) farms. To locate the suitable areas for PV farms, firstly, a fuzzy-based method is utilized to homogenize the input parameters, thereafter, the analytical hierarchy process (AHP) and Dempster-Shafer (DS) methods are independently used. In the AHP method, the proper weight for each input parameter is generated utilizing a pairwise comparison matrix. However, the …

Space And Depth-Resolved Naturally Occurring Toxic Groundwater Species In Bangladesh And Rwanda: Origination And Risk Analysis, Kenneth Hamilton

Civil and Environmental Engineering Theses and Dissertations

Access to safe potable water is a necessity for all. Groundwater is a commonly relied upon drinking water source for many areas around the world. This is especially true for communities in high density, rural settings. Such is the case for populations near Cox’s Bazaar, Bangladesh, and in the Bugesera region of Rwanda. Sediment and groundwater contamination, through toxic dissolved species, represents a significant public health risk to exposed populations. Tropical soils, such as the soil profiles in Bangladesh and Rwanda, often contain higher concentrations of heavy metals (Rieuwerts, 2007). Additionally, nitrate from fertilizers, are widely used on the soils …

Empirical Models For Predicting Water And Heat Flow Properties Of Permafrost Soils, Michael T. O'Connor, M. Bayani Cardenas, Stephen B. Ferencz, Yue Wu, Bethany T. Neilson, Jingyi Chen, George W. Kling

Publications

Warming and thawing in the Arctic are promoting biogeochemical processing and hydrologic transport in carbon‐rich permafrost and soils that transfer carbon to surface waters or the atmosphere. Hydrologic and biogeochemical impacts of thawing are challenging to predict with sparse information on arctic soil hydraulic and thermal properties. We developed empirical and statistical models of soil properties for three main strata in the shallow, seasonally thawed soils above permafrost in a study area of ~7,500 km² in Alaska. The models show that soil vertical stratification and hydraulic properties are predictable based on vegetation cover and slope. We also show that …

Development Of Novel Instrumentation And Methods To Investigate The Composition And Phase Partitioning Of Semivolatile And Intermediately Volatile Organic Compounds In Atmospheric Organic Aerosol, Claire Fortenberry

McKelvey School of Engineering Graduate Student Theses & Dissertations

Atmospheric particulate matter (PM) is ubiquitous in both indoor and outdoor air and is generally detrimental to human health. PM composed of particles with aerodynamic diameters less than 2.5 um (PM2.5) are related to adverse health outcomes including heart disease and respiratory disease. Fundamentally, particle physical properties such as size and hygroscopicity are dictated by chemical composition, which can be highly complex, particularly for organic aerosol (OA). In both outdoor and indoor air, OA is composed substantially of intermediately volatile and semivolatile organic compounds (I/SVOCs), which exist in both gas and particle phases under typical atmospheric conditions. The distribution of …

Chemistry Of Nanoscale Solids And Organic Matter In Sustainable Water Management Systems, Xuanhao Wu

McKelvey School of Engineering Graduate Student Theses & Dissertations

To alleviate global water scarcity and improve public health, engineered water treatment and management systems have been developed for purifying contaminated water and desalinating brackish or ocean water. These engineered systems provide substantial amounts of potable water and lessen environmental concerns about the release of contaminated water. Wastewater treatment plants (WWTPs), water desalination plants (WDPs), and managed aquifer recharge systems (MARs) are three representative sustainable water management (SWM) systems. But the operation of all three poses two fundamental questions: (1) What is the fate of nanoscale solids (e.g., engineered nanomaterials, naturally occurring nanoparticles) in SWM systems and how will their …

College Of Engineering Senior Design Competition Spring 2020, University Of Nevada, Las Vegas

Fred and Harriet Cox Senior Design Competition Projects

Part of every UNLV engineering student’s academic experience, the senior design project stimulates engineering innovation and entrepreneurship. Each student in their senior year chooses, plans, designs, and prototypes a product in this required element of the curriculum. A capstone to the student’s educational career, the senior design project encourages the student to use everything learned in the engineering program to create a practical, real world solution to an engineering challenge. The senior design competition helps focus the senior students in increasing the quality and potential for commercial application for their design projects. Judges from local industry evaluate the projects on …

On The Seismic Performance Of Skewed Special Moment Frame Reduced Beam Section Connections, Damaso Daniel Dominguez

Graduate Theses and Dissertations

Special Moment Frames (SMFs) are frequently used in high seismic areas for architecturally constrained designs, as they provide lateral system stiffness without the use of braces which often obstruct views and architectural features. Reduced beam section (RBS) connections are popular SMF connection details developed following the Northridge earthquake to limit brittle fractures within connection welds. Current American Institute of Steel Construction (ASIC) provisions (i.e. AISC 341-16) provide prequalified SMF RBS connection details (including welding requirements); however, all prequalified details only consider orthogonal connections between the beam and column. This dissertation investigates the effect of adding skew within SMF RBS connections …

Development Of Vs Profiles And Site Periods In The Mexico City Basin, Landon Joel Woodfield

Graduate Theses and Dissertations

This study presents dynamic site characterization measurements at 25 sites within the Mexico City Basin. The primary focus of the testing was along the western edge of the Mexico City Basin. At each site, active source Multi-channel Analysis of Surface Waves (MASW) arrays and passive source Microtremor Array Measurements (MAM) L-arrays and circular arrays were used to acquire dispersion data. Horizontal to Vertical Spectral Ratio (HVSR) data was collected to determine site periods at each location. These experimental dispersion data and site periods were fit using a joint inversion of Rayleigh and Love wave dispersion data and HVSR site period …

Promoting The Sustainable Utilization Of Groundwater Resources In Ethiopia Using The Integrated Groundwater Footprint Index, Xinyu Lin

Honors Scholar Theses

The country of Ethiopia is highly vulnerable to human-caused climate change and is already suffering from the effects. The predominately rural population relies heavily on small-scale agriculture, with 78% of households having at least one member engaged in the field, yet staple crops are highly susceptible to droughts and other weather shocks. Total and agricultural GDP growth in the country have been strongly linked to inter-annual rainfall variability, of which Ethiopia has among the highest in sub-Saharan Africa. A decrease in rainfall since the 1970s has been one of the primary causes of low crop yields, and stresses the immediate …

Impact Of Compactive Effort On Soil Strength Of Glacial Lake Columbia Soils, Alexander M. Navarra, Dwight Hendrickson, Jaremy Shaw

2020 Symposium Posters

Glacial Lake Columbia (GLC) existed from 15,550 (+/- 450) to 13,050 (+/- 650) years ago (Atwater, 1986) as a result of the Okanagan Lobe of the Cordilleran Ice Sheet damming the Columbia River near present-day Grand Coulee Dam. The lake deposited a fine-grained basal layer that had interbeds of coarse Missoula Flood deposits and later lake deposits above. Because these GLC deposits are present around most of the Spokane area, they are important to civil engineering and development. We sampled the basal layer of GLC soils from the Peone Prairie, WA. We performed prerequisite testing before the main experiment, with …

An Evaluation Of Bank Storage At Lake Mead Reservoir In The Southwest United States, Jon Woodrow Wilson

UNLV Theses, Dissertations, Professional Papers, and Capstones

A water balance model is employed at Lake Mead to monitor and verify changing hydrology that affects total volume at the reservoir. Bank storage, which is defined as the volume of water captured in permeable lithologic layers subject to changes induced by contact and proximity to an open waterbody, is one component that is updated regularly and is based upon data and methods that were developed in the 1960’s from observations made within the first 30 years of the reservoir's maturation. Since this period, the reservoir has undergone further development and a current understanding of additional hydrologic affects to bank …

Irrigation Design In Montana: Accommodating Varying Water Accessibility Across The Continental Divide., John Garrett Lampson

Biological and Agricultural Engineering Undergraduate Honors Theses

The design work performed in this project was conducted over two summers (2018, 2019) of internship experience with the Natural Resources Conservation Service (NRCS) across the state of Montana. The first summer’s design work was based out of Glendive, MT, in Dawson County, approximately 50 kilometers from the North Dakota border. The second summer was in Missoula, MT, in Missoula County, near the Idaho border. The two areas differ significantly in topography, weather, and water availability with the main separating geographic influence being the Rocky Mountains.

This paper focuses on the design process and requirements for two farms located outside …

Abiotic, Biotic, And Bio-Enhanced Reduction Of Hexavalent Chromium, Chloroform And Co-Contaminants Using Nano-Scale Zero Valent Iron In Highly Contaminated Groundwater, Eduardo Robleto Martinez

UNLV Theses, Dissertations, Professional Papers, and Capstones

Investigations of groundwater in a former industrial perchlorate manufacturing site have shown high contamination with perchlorate, chlorate, nitrate, hexavalent chromium (Cr (VI)), and chloroform (CF) with levels greater than 3,000, 30,000, 300, 100, and 4 mg/L, respectively. Remediation efforts using biological reduction to desired contaminant levels at this site has been challenging due to high contaminant concentrations, and high total dissolved solids (TDS). Furthermore, removal of Cr(VI) and CF in the presence of nitrate, chlorate, and perchlorate has not been examined at the contaminated site. Nano-scale Zero-Valent-Iron (NZVI) has been effective at reducing groundwater contamination both with and without bacterial …

Sediment Outflow Under Simulated Rainfall Conditions With Varying Geotechnical Properties, Pranjay Joshi, Akhilesh Kumar, P. V. Singh, Jahangeer Jahangeer

Daugherty Water for Food Global Institute: Faculty Publications

The vulnerability of soil toward erosion might be reduced by having a good vegetative cover over the soil surface, slope improvement, and improving soil properties so that it is not easily detached and transported. However, the establishment of proper vegetative cover is a long process because it takes time for seeds to germinate and attain maturity. As an alternative approach, if soil resistance was increased by increasing the shear strength of soil against erosive forces offered by eroding agents, the soil system would become capable of withstanding the detachment of its particles on the application of shear stress. To achieve …

The Impact Of Pev User Charging Behavior In Building Public Charging Infrastructure, Ahmad Almaghrebi

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

Plug-in electric vehicles (PEVs) play a significant role in the development of green cities since they generate less pollution than conventional vehicles. To promote PEV adoption and mitigate range anxiety, charging infrastructure should be deployed at strategic locations that are readily accessible to the public. Nebraska is working on the expansion of charging infrastructure around the state; however, stakeholders face several difficulties in trying to minimize irregular charging behaviors. Most electric vehicle users plug in and leave their vehicles for an extended time at public parking lots designated for PEVs. Some users even leave their vehicles for longer than 24 …

The Siltcatcher: A Sediment-Capture System For Wetland Creation And Coastal Protection In Western Lake Pontchartrain, Andrew M. Wright

LSU Master's Theses

The West Lake Pontchartrain region faces a number of long-term environmental challenges due to anthropogenic climate disturbance and landscape modification, including sea level rise, increased storm surge risk, shoreline erosion, and wetland degradation. In response, this thesis applies recent research in the fields of landscape architecture and civil engineering to propose a dynamic, natural-systems solution for wetland creation and shoreline protection. The project envisions a series of breakwater-like structures in western Lake Pontchartrain positioned to slow water released from the nearby Bonnet Carré Spillway, causing suspended sediment to settle and create self-building and self-sustaining wetlands capable of keeping pace with …

Physical And Biological Factors Controlling The Fate Of Nitrate In A Louisiana Coastal Deltaic Floodplain, Alexandra Christensen

LSU Doctoral Dissertations

The Mississippi River Delta is threatened by a growing pressure to support large human populations in the United States both with food production, navigation systems, and urban development in the Mississippi River Basin. Nitrate-nitrogen load in the Mississippi River, up to 100 Tg N yr^-1 from agricultural and urban runoff, leads to phytoplankton blooms and hypoxia across the Louisiana continental shelf, creating dead zones of low dissolved oxygen threatening a significant commercial fishery. Along the coast and river corridors, floodplain ecosystems have the capacity to retain and remove nitrate. This dissertation explores the role of productive, actively growing coastal …

The Long-Term Outlook Of The Mississippi-Atchafalaya Bifurcation: A Convergence Of Engineering, Economics, And Deltaic Evolution, Thomas Mitchell Andrus

LSU Doctoral Dissertations

The most recent and currently active delta lobe of the Mississippi River (MR) is the Atchafalaya-Wax Lake lobe, which was initiated approximately 400 years ago as a result of MR stream capture by the Atchafalaya River (AR). This capture process accelerated in the early to mid-1900s but further progress was prevented by construction and operation of the Old River Control Structure (ORCS) Complex. Many recent studies indicate that MR system below the ORCS is on a retreating geologic trajectory due to contributing factors such as sea level rise, subsidence, faulting, and declining hydraulic stream power. Diversions along the Lower MR …

Reliability Improvement On Feasibility Study For Selection Of Infrastructure Projects Using Data Mining And Machine Learning, Xi Hu

Theses and Dissertations

With the progressive development of infrastructure construction, conventional analytical methods such as correlation index, quantifying factors, and peer review are no longer satisfactory in support for decision-making of implementing an infrastructure project in the age of big data. This study proposes using a mathematical model named Fuzzy-Neural Comprehensive Evaluation Model (FNCEM) to improve the reliability of the feasibility study of infrastructure projects by using data mining and machine learning. Specifically, the data collection on time-series data, including traffic videos (278 Gigabytes) and historical weather data, uses transportation cameras and online searching, respectively. Meanwhile, the researcher sent out a questionnaire for …

Post-Overlay Flexible Pavement Performance Modeling And Its Application In Sustainable Asphalt Overlay Policy Making, Chunfu Xin

USF Tampa Graduate Theses and Dissertations

Highway pavement is a critical component of the highway transportation infrastructure. After the construction of a pavement system, pavement condition will deteriorate over time due to a combination effect of material aging, traffic loading, and environmental impact. To restore the pavement performance and to reduce its adverse effects on public users and environment, asphalt overlay activities are conducted frequently during the service life of a pavement. As a key component that bridges the overlay policies with future pavement performance, economic cost and environmental impact, the forecast accuracy of post-overlay pavement performance model is extremely important. However, most of previous studies …