Engineering Commons^™

The Success, Morphology, And Performance Of Oxygenic Photogranules Under Light-Induced Stress Conditions, Samuel Downes

Environmental & Water Resources Engineering Masters Projects

No abstract provided.

Biofiltration Of Volatile Organic Compounds Emitted At Ethanol Plants, Christopher Arthur Duerschner

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

Ethanol manufacturing is an important and growing sector in the biofuels marketplace. At ethanol plants, the control of volatile organic compound containing emissions from fermentation tanks and distillers dried grains with solubles driers is accomplished through the use of air scrubbers and regenerative thermal oxidizers. The operation of these control units imposes substantial operating costs for the ethanol plant. Biotrickling filters have the ability to replace scrubbers and regenerative thermal oxidizers resulting in significant economic and environmental benefits. Two biotrickling filters were operated in parallel under acetaldehyde loadings ranging from 4 to 136 gm^-3hr^-1. To examine …

Theoretical Model For Shields Diagram And Its Application, Jichao Jiang

Department of Environmental Engineering: Theses and Student Research

The transition from the condition of “no motion” to initial sediment moment, defined as sediment initiation, has been related to practical engineering (channel degradation, stable channel design), oceanographic (dredging, pipelines, cables), sedimentologic (sediment mobility, transport rates), geologic (the hydraulic interpretation of paleoenvironments), geochemical (pollutant transport), and gained considerable interest since nineteenth century.

Shields diagram for sediment initiation in terms of critical shear stress is a classic problem in sediment transport, but it is still an empirical law without a simple and practical theory despite extensive research since the 1930s. Hence, this research presents a simple theoretical model for critical shear …

Urban Underground Infrastructure Monitoring Iot: The Path Loss Analysis, Abdul Salam, Syed Shah

Faculty Publications

The extra quantities of wastewater entering the pipes can cause backups that result in sanitary sewer overflows. Urban underground infrastructure monitoring is important for controlling the flow of extraneous water into the pipelines. By combining the wireless underground communications and sensor solutions, the urban underground IoT applications such as real time wastewater and storm water overflow monitoring can be developed. In this paper, the path loss analysis of wireless underground communications in urban underground IoT for wastewater monitoring has been presented. It has been shown that the communication range of up to 4 kilometers can be achieved from an underground …

Unl-Cc Outdoor Education Center Master Plan, Marie Wagner

Honors Theses

The following report contains the work done by the group Griswold Engineering in completion of the Senior Design requirements for Civil Engineering and the Honors Requirements of the Project Manager. As the project manager, my job was to organize the project as a whole and to work alongside the Structural Engineer on the project. One of the main problems to overcome was the division of labor amongst the group. The project was originally conceived as a group project with one project manager and five other students to serve as the project engineers in each subdiscipline. Since this group only had …

Using A Balloon-Launched Unmanned Glider To Validate Real-Time Wrf Modeling, Travis J. Schuyler, S. M. Iman Gohari, Gary Pundsack, Donald Berchoff, Marcelo I. Guzman

Chemistry Faculty Publications

The use of small unmanned aerial systems (sUAS) for meteorological measurements has expanded significantly in recent years. SUAS are efficient platforms for collecting data with high resolution in both space and time, providing opportunities for enhanced atmospheric sampling. Furthermore, advances in mesoscale weather research and forecasting (WRF) modeling and graphical processing unit (GPU) computing have enabled high resolution weather modeling. In this manuscript, a balloon-launched unmanned glider, complete with a suite of sensors to measure atmospheric temperature, pressure, and relative humidity, is deployed for validation of real-time weather models. This work demonstrates the usefulness of sUAS for validating and improving …

An Underground Radio Wave Propagation Prediction Model For Digital Agriculture, Abdul Salam

Faculty Publications

Underground sensing and propagation of Signals in the Soil (SitS) medium is an electromagnetic issue. The path loss prediction with higher accuracy is an open research subject in digital agriculture monitoring applications for sensing and communications. The statistical data are predominantly derived from site-specific empirical measurements, which is considered an impediment to universal application. Nevertheless, in the existing literature, statistical approaches have been applied to the SitS channel modeling, where impulse response analysis and the Friis open space transmission formula are employed as the channel modeling tool in different soil types under varying soil moisture conditions at diverse communication distances …

Civil Engineering Design Of Cornhusker Council's Outdoor Education Center, Kelly Weiler

Honors Theses

A team of geotechnical, structural, hydraulic, environmental, and transportation experts collaborated to provide engineering solutions to the Cornhusker Council in an effort to solve the current problems facing their Outdoor Education Center. This results of this project provided the structural design of three bridges on the property, transportation plans for two parking lots and roadway design, geotechnical recommendations for soil testing and erosion prevention, and an environmental and hydraulic analysis of the property. A major challenge in the design of this project is the consideration of the dangers and regulations that accompany the floodway and floodplain regions on site. Various …

Simulation Of Antimicrobial Resistance Gene Fate In Narrow Grass Hedges, Marzieh Khedmati

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

Vegetative Filter Strips (VFS) are used for controlling the volume of runoff and decreasing the contaminants in runoff before entering the water bodies. Many studies investigated the role of VFS in sediment and nutrient removal, but little is known about their efficiency in the removal of emerging contaminants such as antimicrobial resistance genes (ARGs). VFSMOD was used to simulate the efficiency of VFS in this regard. The objectives of this study were to calibrate the VFSMOD with some experimental data and asses the efficiency of the model in simulating the filter behavior in removing ARGs. The tests were conducted in …

Analysis And Application Of Log-Linear And Quantile Regression Models To Predict Bus Dwell Times, Travis B. Glick, Miguel Figliozzi

Civil and Environmental Engineering Faculty Publications and Presentations

Understanding the key factors that contribute to transit travel times and travel time variability is an essential part of transit planning and research. Delay that occurs when buses service bus stops, dwell time, is one of the main sources of travel time variability and has therefore been the subject of ongoing research to identify and quantify its determinants. Previous research has focused on testing new variables using linear regressions that may be added to models to improve predictions. An important assumption of linear regression models used in past research efforts is homoscedasticity or the equal distribution of the residuals across …

Wheat Strip Effects On Microbial Transport Following Variable Applications Of Beef Cattle Manure, Lisa M. Durso, John E. Gilley, David B. Marx, Chance A. Thayer, Bryan L. Woodbury

Biological Systems Engineering: Papers and Publications

Vegetative filter strips (VFS) consisting of perennial vegetation have been successfully used to reduce the transport of contaminants in runoff from land application areas. The effectiveness of a winter wheat strip, which may be more acceptable to producers, in reducing microbial transport was examined in this study. A 1.4 m wheat strip was used to allow direct comparison with experimental results obtained in previous studies. Beef cattle manure was applied to 0.75 m wide by 4.0 m long plots established on an Aksarben silty clay loam located in southeast Nebraska. Manure was added at rates required to meet the 0- …

Production Of Secondary Organic Aerosol During Aging Of Biomass Burning Smoke From Fresh Fuels And Its Relationship To Voc Precursors, A. T. Ahern, E. S. Robinson, D. S. Tkacik, L. E. Hatch, Kelley Barsanti, C. E. Stockwell, Robert J. Yokelson, Multiple Additional Authors

Civil and Environmental Engineering Faculty Publications and Presentations

After smoke from burning biomass is emitted into the atmosphere, chemical and physical processes change the composition and amount of organic aerosol present in the aged, diluted plume. During the fourth Fire Lab at Missoula Experiment, we performed smog‐chamber experiments to investigate formation of secondary organic aerosol (SOA) and multiphase oxidation of primary organic aerosol (POA). We simulated atmospheric aging of diluted smoke from a variety of biomass fuels while measuring particle composition using high‐resolution aerosol mass spectrometry. We quantified SOA formation using a tracer ion for low‐volatility POA as a reference standard (akin to a naturally occurring internal standard). …

The Quest For Model Uncertainty Quantification: A Hybrid Ensemble And Variational Data Assimilation Framework, Peyman Abbaszadeh, Hamid Moradkhani, Dacian Daescu

Civil and Environmental Engineering Faculty Publications and Presentations

This article presents a novel approach to couple a deterministic four‐dimensional variational (4DVAR) assimilation method with the particle filter (PF) ensemble data assimilation system, to produce a robust approach for dual‐state‐parameter estimation. In our proposed method, the Hybrid Ensemble and Variational Data Assimilation framework for Environmental systems (HEAVEN), we characterize the model structural uncertainty in addition to model parameter and input uncertainties. The sequential PF is formulated within the 4DVAR system to design a computationally efficient feedback mechanism throughout the assimilation period. In this framework, the 4DVAR optimization produces the maximum a posteriori estimate of state variables at the beginning …

The Effects Of Reactant Concentration And Air Flow Rate In The Consumption Of Dissolved O2 During The Photochemistry Of Aqueous Pyruvic Acid, Alexis J. Eugene, Marcelo I. Guzman

Chemistry Faculty Publications

The sunlight photochemistry of the organic chromophore pyruvic acid (PA) in water generates ketyl and acetyl radicals that contribute to the production and processing of atmospheric aerosols. The photochemical mechanism is highly sensitive to dissolved oxygen content, [O₂(aq)], among other environmental conditions. Thus, herein we investigate the photolysis (λ ≥ 305 nm) of 10–200 mM PA at pH 1.0 in water covering the relevant range 0 ≤ [O₂(aq)] ≤ 1.3 mM. The rapid consumption of dissolved oxygen by the intermediate photolytic radicals is monitored in real time with a dissolved oxygen electrode. …

Evaluation Of Wind And Solar Energy Investments In Texas, Byungik Chang, Ken Starcher

Civil Engineering Faculty Publications

The primary objective of the project is to evaluate the benefits of wind and solar energy and determine economical investment sites for wind and solar energy in Texas with economic parameters including payback periods. A 50 kW wind turbine system and a 42 kW PV system were used to collect field data. Data analysis enabled yearly energy production and payback period of the two systems.

The average payback period of a solar PV system was found to be within a range of 2-20 years because the large range of the payback period for PV systems were heavily influenced by incentives. …

Evaluation Of Selected Watershed Characteristics To Identify Best Management Practices To Reduce Nebraskan Nitrate Loads From Nebraska To The Mississippi/Atchafalaya River Basin, Aaron R. Mittelstet, Troy E. Gilmore, Tiffany Messer, Daran Rudnick, Thomas Heatherly

Biological Systems Engineering: Papers and Publications

Nebraskan streams contribute excess nitrogen to the Mississippi/Atchafalaya River Basin and Gulf of Mexico, which results in major water-quality impairments. Reducing the amount of nitrogen (N) exported in these streams requires the use of best management practices (BMPs) within the landscape. However, proper BMP utilization has rarely been statistically connected to potential controls of N export within watersheds, particularly precipitation and soil characteristics. In this study, 19 watershed variables were evaluated in five categories (hydrological, physiographic, point sources, land use, and soil properties) to determine the characteristics that influenced variable nitrate nitrogen (NO₃-N) concentrations in 17 Nebraska watersheds …

Assessing Data Availability And Research Reproducibility In Hydrology And Water Resources, James H. Stagge, David E. Rosenberg, Adel M. Abdallah, Hadia Akbar, Nour A. Atallah, Ryan James

Civil and Environmental Engineering Faculty Publications

There is broad interest to improve the reproducibility of published research. We developed a survey tool to assess the availability of digital research artifacts published alongside peer-reviewed journal articles (e.g. data, models, code, directions for use) and reproducibility of article results. We used the tool to assess 360 of the 1,989 articles published by six hydrology and water resources journals in 2017. Like studies from other fields, we reproduced results for only a small fraction of articles (1.6% of tested articles) using their available artifacts. We estimated, with 95% confidence, that results might be reproduced for only 0.6% to 6.8% …

Quantifying And Correcting For Clay Content Effects On Soil Water Measurement By Reflectometers, Jasreman Singh, Tsz Him Lo, Daran Rudnick, Suat Irmak, Humberto Blanco-Canqui

Biological Systems Engineering: Papers and Publications

The presence of clay particles increases the specific surface area of a soil and can affect the calibration of electromagnetic soil water sensors including reflectometers. To quantify and correct for this effect in two relatively new reflectometers, three TDR315 and three CS655 sensors were installed in each of five soils with clay content ranging from 5 to 49%. As the soils were dried in a temperature controlled room, sensor reported soil volumetric water content (θ_v) according to the factory calibration was compared against reference θ_v determined by weighing the soils. Sensor reported θ_v was similar to …

Modeling Of Grace-Derived Groundwater Information In The Colorado River Basin, Md Mafuzur Rahaman, Balbhadra Thakur, Ajay Kalra, Sajjad Ahmad

Civil and Environmental Engineering and Construction Faculty Research

Groundwater depletion has been one of the major challenges in recent years. Analysis of groundwater levels can be beneficial for groundwater management. The National Aeronautics and Space Administration’s twin satellite, Gravity Recovery and Climate Experiment (GRACE), serves in monitoring terrestrial water storage. Increasing freshwater demand amidst recent drought (2000–2014) posed a significant groundwater level decline within the Colorado River Basin (CRB). In the current study, a non-parametric technique was utilized to analyze historical groundwater variability. Additionally, a stochastic Autoregressive Integrated Moving Average (ARIMA) model was developed and tested to forecast the GRACE-derived groundwater anomalies within the CRB. The ARIMA model …

Aesthetics, Ethics, And Lose-Lose Dilemmas In The Anthropocen, Adam Liska

Biological Systems Engineering: Papers and Publications

Anthropogenic climate change will cause violence to increase globally, and nonlinear increases in sea level could cause a major escalation in global conflict. After 2100, a 22-meter sea-level rise is estimated here to dislocate two billion people from coastal areas. These impending civilization-changing events require us to again reevaluate our prevalent aesthetic preferences for luxury that produce a significant fraction of anthropogenic greenhouse gas emissions. Due to industrial inertia, a central dilemma discussed here is the contradictions between the goals and impacts of aesthetics and ethics. Either we lose our own well-being (a loss of high-emission aesthetics) for the benefit …

Biomaterial Substrate Modifications That Influence Cell-Material Interactions To Prime Cellular Responses To Nonviral Gene Delivery, Amy Mantz, Angela K. Pannier

Biological Systems Engineering: Papers and Publications

Gene delivery is the transfer of exogenous genetic material into somatic cells to modify their gene expression, with applications including tissue engineering, regenerative medicine, sensors and diagnostics, and gene therapy. Viral vectors are considered the most effective system to deliver nucleic acids, yet safety concerns and many other disadvantages have resulted in investigations into an alternative option, i.e. nonviral gene delivery. Chemical nonviral gene delivery is typically accomplished by electrostatically complexing cationic lipids or polymers with negatively charged nucleic acids. Unfortunately, nonviral gene delivery suffers from low efficiency due to barriers that impede transfection success, including intracellular processes such as …

Deficit Irrigation Management Of Maize In The High Plains Aquifer Region: A Review, Daran Rudnick, Sibel Irmak, C. West, J.L. Chavez, I. Kisekka, T.H. Marek, J.P. Schneekloth, D. Mitchell Mccallister, V. Sharma, K. Djaman, J. Aguilar, M.E. Schipanski, D.H. Rogers, A. Schlegel

Biological Systems Engineering: Papers and Publications

Irrigated agriculture is a major economic contributor of the High Plains Region and it primarily relies on the High Plains Aquifer as a source of water. Over time, areas of the High Plains Aquifer have experienced drawdowns limiting its ability to supply sufficient water to sustain fully irrigated crop production. This among other reasons, including variable climatic factors and differences in state water policy, has resulted in some areas adopting and practicing deficit irrigation management. Considerable research has been conducted across the High Plains Aquifer region to identify locally appropriate deficit irrigation strategies. This review summarizes and discusses research conducted …

Observational Time Series For Lakes Azuei And Enriquillo: Surface Area, Volume, And Elevation, Mahrokh Moknatian, Michael Piasecki

Publications and Research

In this report, we present historical time series of surface area, volume, and elevation for lakes Azuei (Haiti) and Enriquillo (Dominican Republic). The intention is to present a history of the lakes’ levels for both bodies of water as derived from Landsat imagery that is augmented by reports and narratives that reach further back in time. We also summarize lake level time series data collected and developed through various other efforts and compare these data sets to our time series. The time series contains 45 years’ worth of data ranging from 1972 to 2017 which we developed from Landsat imagery …

Commercial Water Claims: City Of London Assessment Of Claims Made By London Residents, Jonathan Abbruzzese, Yousir Aldin, Christine Eagles, Karen Lemon, Alexander Watson

Community Engaged Learning Final Projects

The City of London has a mandate to provide its residents with high grade water and yet there have been complaints concerning the impurities, otherwise known as residuals, and the overall quality. This paper delves into the truth about the contents of the municipal water system and what the effects of its components are to the London populace. A public survey asked residents questions about their concerns and water drinking habits. The survey pointed to concerns about fluoride, residual chlorine and overall taste of water among others. Fluoride is known to reduce tooth decay (CDC, 2018) and any negative consequences …

Evaluation Of Two Real Time Methods For Assessing Thm Precursor Concentrations, Griffin Moriarty

Environmental & Water Resources Engineering Masters Projects

Conventional drinking water treatment generally requires maintenance of a disinfectant residual, most commonly free or combined chlorine. Since the discovery of disinfection byproducts (DBPs), utilities have relied on a broad range of water quality parameters to help them achieve compliance with DBP regulations. Most notably, dissolved organic carbon (DOC) and ultraviolet absorbance at 254 nm (UV254) have been used to assess DBP precursor levels in near-real time. These are often compared to actual system DBP concentrations or to results from laboratory DBP precursor tests resulting in a site-specific precursor-DBP model. The DOC or UV254 models are often inaccurate, requiring re-calibration, …

An Assessment Of Lead And Copper In School Drinking Water, Kaavya Raghavan Ram

Environmental & Water Resources Engineering Masters Projects

Metal contamination in drinking water, especially heavy metals such as lead, and corrosion issues, pose a threat to human health and have received increasing attention in recent years. This study reports on the results of ‘The Massachusetts Assistance Program for Lead in School Drinking Water’ and provides a better understanding of the dynamics of sampling protocols, premise plumbing and their influence on lead and copper concentrations. ‘The Massachusetts Assistance Program for Lead in School Drinking Water’ that was announced in April 2016, implemented tap-based water sampling for lead and copper at K-12 public schools and Early Education and Childcare centers …

Developing A Toolkit For Citizen Scientists' Evaluation Of Drinking Water Quality, Leighann D'Andrea

Environmental & Water Resources Engineering Masters Projects

This project evaluated tools for citizen science by assessing the potential to monitor drinking water quality at home with commercially sold, or off the shelf, test kits. The first objective was to compare the results of off the shelf test kits with laboratory-obtained values as performed in a controlled environment by trained laboratory personnel. The second objective was to provide potential citizen scientists with a selection of test kits to determine if they could successfully use the kits. These two objectives contributed to the end goal of understanding whether test kits on the market existed that could be used by …

Modeling Nature-Based Solutions For Climate Resilience, Mason Saleeba

Environmental & Water Resources Engineering Masters Projects

Riparian wetlands can serve as nature-based infrastructure that slow the rapid movement of water during high flow events. As the recurrence of high flow events increases due to global climate change, an improved understanding of the potential of wetland landscapes to provide flood mitigation is needed. This research addresses both the impacts of climate change and land cover on extreme flow events in the Otter Creek watershed in Vermont. The upstream portion of the basin is modeled with the Soil and Water Assessment Tool (SWAT) to investigate the impacts of climate change on extreme flow events. A Hydrologic Engineering Center's …

The Heat Is On: The Capacities Required For The Establishment And Sustainability Of Community-Owned Renewable Energy District Heating Systems In Ireland, Gerard Doyle

Reports

International reviews of countries’ progress at tackling climate change show that Ireland is making small levels of progress on tackling issues associated with climate change. This paper will examine a theoretical framework, referred to as capacity analysis, to explain the capacities that need to be in place for the successful implementation of community-owned renewable energy district heating initiatives. The theoretical framework employed here is based on the ‘conceptual framework’ developed by Pringle which consists of four categories of capacity. The research methodology involves a case study with cases from Austria, Northern Ireland, the Republic of Ireland, Wales and Scotland. The …

Development Of Poly-Vinyl Alcohol Stabilized Silver Nanofluids For Solar Thermal Applications, James Walshe, George Amarandei, Hind Ahmed, Sarah Mccormack, John Doran

Articles

Nanofluids offer the potential to address the low thermal conductivities found in conventional heat transfer fluids, through their unique electrical, optical and thermal properties, but their implementation remains restricted due to absorption and stability limitations. Here, we characterize and exploit the distinctive plasmonic properties exhibited by polyvinyl-alcohol stabilized silver nanostructures by tuning their absorption and thermal properties through controlling the nanoparticle size, morphology and particle-size distribution configuration at the synthesis stage. The photo-thermal efficiency of different water-based silver nanofluids under a standard AM1.5G weighted solar spectrum were explored, the influence of each of these components on the resulting fluids performance …