Civil and Environmental Engineering Commons^™

Co-Removal Of Atrazine And Nitrate From Groundwater Using A Mulch Biofilm, Allison L. Cole

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

The popular broadleaf herbicide atrazine is often found in contaminated groundwater along with other agricultural chemicals, such as nitrate. Mulch biowalls, a passive treatment placed in situ, can inexpensively remediate groundwater by intercepting and treating a contaminant plume. Three types of organic mulch: cedar, cypress, and hardwood were evaluated for their ability to act as supporting materials for a biowall to simultaneously remove atrazine and nitrate from groundwater. Physical and chemical properties of the mulch were characterized. Cedar mulch had the highest organic carbon content, 996 mg/g. The adsorptive capacity of the mulch for atrazine and nitrate, in mono …

Legacy Effects In Material Flux: Structural Catchment Changes Predate Long-Term Studies, Daniel J. Bain, Mark B. Green, John L. Campbell, John F. Chamblee, Sayo Chaoka, Jennifer M. Fraterrigo, Sujay S. Kaushal, Sherry L. Martin, Thomas E. Jordan, Anthony J. Parolari, William V. Sobczak, Donald E. Weller, Wilfred M. Wollheim, Emery R. Boose, Jonathan M. Duncan, Gretchen M. Gettel, Brian R. Hall, Praveen Kumar, Jonathan R. Thompson, James M. Vose, Emily M. Elliott, David S. Leigh

Civil and Environmental Engineering Faculty Research and Publications

Legacy effects of past land use and disturbance are increasingly recognized, yet consistent definitions of and criteria for defining them do not exist. To address this gap in biological- and ecosystem-assessment frameworks, we propose a general metric for evaluating potential legacy effects, which are computed by normalizing altered system function persistence with duration of disturbance. We also propose two distinct legacy-effect categories: signal effects from lags in transport and structural effects from physical landscape changes. Using flux records for water, sediment, nitrogen, and carbon from long-term study sites in the eastern United States from 1500 to 2000, we identify gaps …

Short Term Monitoring Of Suspender Cables On An In-Service Highway Bridge, Gannon Stromquist-Levoir

Master's Theses

No abstract provided.

Micrometeorological Measurement Of Hexachlorobenzene And Polychlorinated Biphenyl Compound Air-Water Gas Exchange In Lake Superior And Comparison To Model Predictions, M. D. Rowe, J A Perlinger

Michigan Tech Publications, Part 1

Air-water exchange fluxes of persistent, bioaccumulative and toxic (PBT) substances are frequently estimated using the Whitman two-film (W2F) method, but micrometeorological flux measurements of these compounds over water are rarely attempted. We measured air-water exchange fluxes of hexachlorobenzene (HCB) and polychlorinated biphenyls (PCBs) on 14 July 2006 in Lake Superior using the modified Bowen ratio (MBR) method. Measured fluxes were compared to estimates using the W2F method, and to estimates from an Internal Boundary Layer Transport and Exchange (IBLTE) model that implements the NOAA COARE bulk flux algorithm and gas transfer model. We reveal an inaccuracy in the estimate of …

Near Surface Hydrometeorology For Sustainable Water Management, V. Sridhar, W. T. A. Jaksa

Civil Engineering Faculty Publications and Presentations

Due to strong interactions between the land and atmosphere and the resulting feedbacks as altered by the anthropogenic changes, it is critical to quantify the surface fluxes and boundary layer properties that has direct implications on the regional evolution of hydrometeorology. This study evaluates the impact of irrigation using the Weather Research and Forecasting (WRF) numerical weather prediction (NWP) model in the Snake River Basin in Idaho. Our simulation extends for the period in the growing season and compares the control and irrigation runs to assess the irrigation induced cooling on the surface energy balance. Understanding this near surface cooling …

Approaches To Control Nitrate Pollution In The San Joaquin Watershed, Misgana K. Muleta, Stephen Clayton

Civil and Environmental Engineering

No abstract provided.

Evaluating Alternative Hydraulic Solutions To Limit Nutrient Contamination Of An Aquifer In Southern California, Jake M. Perry, Misgana K. Muleta

Civil and Environmental Engineering

Many small communities depend on groundwater sources for drinking water and they often use septic tanks for wastewater treatment and disposal. Nitrate and other pollutants leaking from poorly designed septic tank systems can percolate to the aquifers and alter quality of the groundwater. This study describes a groundwater model developed using Visual MODFLOW for an aquifer that is used as a water supply source for the communities of Beaumont and Cherry Valley, CA. The aquifer has been contaminated by nitrates leaking from septic tank systems. The model will assist in clarifying the extent of interactions between nitrate pollutants, percolation from …

A Formal Bayesian Approach For Uncertainty Analysis Of A Watershed Model, Misgana K. Muleta

Civil and Environmental Engineering

Uncertainty analysis (UA) has received substantial attention in water resources during the last decade. Bayesian approaches are often preferred for UA. This study describes a formal Bayesian approach for the assessment of parameter uncertainty and predictive uncertainty using a spatially distributed hydrologic model and will demonstrate its application using data from a well monitored experimental watershed. A Markov-Chain Monte Carlo (MCMC) scheme has been used to sample posterior parameter distributions. A formal, flexible likelihood function that explicitly accounts for heteroscedasticity, temporal correlation and non-normality of simulation residuals has been used to describe closeness of the simulated and observed streamflow. Performance …

Uncertainty Analysis And Calibration Of Swmm Using A Formal, Bayesian Methodology, Misgana K. Muleta

Civil and Environmental Engineering

Importance of uncertainty analysis (UA) to estimate the degree of reliability associated with model predictions is being understood. Consequently, literature that describes various Bayesian methods for the assessment of parameter and model predictive uncertainty has been steadily rising. Applications dealing with urban stormwater management are, however, very limited. This study demonstrates successful application of a formal Bayesian methodology for UA of the U.S. EPA Stormwater Management Model (SWMM), a widely used urban stormwater management model, and illustrates the methodology using a highly urbanized watershed in southern California. DREAM(ZS), a recently developed effective and efficient sampling algorithm, and a generalized, formal …

Correlation Of Shear Strength Between Longitudial And Transverse Specimens, Erasto A. Fernandez

LSU New Orleans Theses and Dissertations

In this thesis, new methods for shear strength are proposed and backed up through extensive experimentation, ABAQUS models and data analysis of Titanium welds of three different alloys. The results are compared with those obtained by using the procedure outlined by AWS B4 for calculating Shear Strength in the transverse and longitudinal directions; this equation is widely used by the American Welding Society (AWS) and all those in search of more efficient designs involving welding.

It is a well-documented issue that the equation provided by AWS yields a large discrepancy between the values for shear strength of longitudinal and transverse …

Modeling Yield Surfaces Of Various Structural Shapes, Oudam Meas

Honors Theses

This study investigates the possibility of custom fitting a widely accepted approximate yield surface equation (Ziemian, 2000) to the theoretical yield surfaces of five different structural shapes, which include wide-flange, solid and hollow rectangular, and solid and hollow circular shapes. To achieve this goal, a theoretically “exact” but overly complex representation of the cross section’s yield surface was initially obtained by using fundamental principles of solid mechanics. A weighted regression analysis was performed with the “exact” yield surface data to obtain the specific coefficients of three terms in the approximate yield surface equation. These coefficients were calculated to determine the …

Study Of The Compressive Strength Of Aluminum Curved Elements, Christine M. Shepherd

Honors Theses

Currently, the Specification for Aluminum Structures (Aluminum Association, 2010) shows thin-walled aluminum plate sections with radii greater than eight inches have a lower compressive strength capacity than a flat plate with the same width and thickness. This inconsistency with intuition, which suggests any degree of folding a plate should increase its elastic buckling strength, inspired this study. A wide range of curvatures are studied—from a nearly flat plate to semi-circular. To quantify the curvature, a single non-dimensional parameter is used to represent all combinations of width, thickness and radius. Using the finite strip method (CU-FSM), elastic local buckling stresses are …

Sensors For Integrated Monitoring And Mitigation Of Scour, Genda Chen, David Pommerenke, Zhi Zhou, Ying Huang

Civil, Architectural and Environmental Engineering Faculty Research & Creative Works

Systems and methods for detecting scour. Some embodiments provide systems which include a sensor and a signal generator with a combined density equal to or greater than that of water. Optionally, the sensor can be a magnet, magnetic resonator, or accelerometer. In some embodiments, the sensor is adapted to be placed in regions potentially subject to scour and to sense a scour-related condition. The signal generator generates a wireless signal conveying data regarding the as-sensed scour-related. In some embodiments the sensor is the signal generator while a receiver of the wireless signal can include an antenna, a magnetometer, or an …

Using Ground Penetrating Radar Signal Reflection To Model A Highly Transmissive Bedrock Aquifer, Daniel J. Brockmeyer Mr.

Master's Theses

The use of numerical modeling software to characterize groundwater contaminant fate and transport requires an understanding of the distribution of hydraulic properties of the aquifer. As the complexity of this distribution increases, a more sophisticated understanding is required. Modeling contaminant transport in bedrock aquifers requires that the spatial distributions of highly conductive geologic features are characterized along with the hydraulic transmissivities of those features (Shapiro, 2003). The goal of this research is to refine the numerical model of a highly transmissive crystalline aquifer by characterizing the spatial variability of the hydraulic transmissivity using the attenuation of the ground penetrating radar …

Creating A Pedestrian Level-Of-Service Index For Transit Stops: Evidence From Denver’S Light Rail System, Patrick Gallagher

Master's Theses

No abstract provided.

Computer-Aided Engineering Tools For Structural Health Monitoring Under Operational Conditions, Priscilla O. Mensah-Bonsu

Master's Theses

This thesis presents two different applications of computer-aided non-destructive approaches for structures monitored under operational conditions. The first part of the thesis is the development of a graphical user interface (GUI) software for real-time autonomous assessment of structural health condition based on the signature vibration properties of the structure under study. The program, called ConImote2, operates on the wireless sensor network platform called imote2. ConImote2 is created in the Matlab platform for accessibility and to enable extension of its capabilities by the user. The primary goal of creating the program is to overcome the issue of data inundation from SHM …

Laboratory And Field Evaluation Of Two Warm-Mix Additives In Connecticut And Validation Of An Alternative Moisture Susceptibility Test, Alexander K. Bernier

Master's Theses

The first official state Warm-Mix Asphalt (WMA) pavement project in Connecticut was constructed between July 20th and 22nd, 2010 and it involved three experimental sections, i.e. one section with a conventional HMA (control section) and two WMA sections with different technologies, wax and foamed asphalt. All three sections are located on Route 70 in central Connecticut. The materials were collected in loose form and reheated and compacted in laboratory conditions (laboratory fabricated specimens). This paper discusses the effect of mix type on the results from several tests conducted in the laboratory, such as Semi-Circular Bending, Hamburg Wheel Tracking, Indirect Tensile, …

Prestressed Concrete Wind Turbine Supporting System, Ibrahim Lotfy

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

Wind energy is one of the most commercially developed and quickly evolving renewable energy technologies worldwide. Wind turbines are commonly supported on tubular steel towers. As the turbines are growing and the towers are elevating, an increase in structural strength and stiffness is required to withstand the applied forces. Recent studies established concrete as a more economic and durable alternative to steel especially when the tower height exceed 240ft. Presently, concrete towers are not common due to their perceived heavy weight and assembly complexity. One of the systems that have been mentioned in the literature consists of precast rings that …

College Of Engineering Senior Design Competition Spring 2012, University Of Nevada, Las Vegas

Fred and Harriet Cox Senior Design Competition Projects

Senior Design Experience

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. Working in teams, the senior design project encourages students to use everything learned in the engineering and computer design programs to create a practical, real world solution to an engineering challenge.

Beyond the classroom...

Because of the requirement to work in teams, students also build good communication skills, presentation skills and even business writing skills. They also have to source …

College Of Engineering Senior Design Competition Spring 2018, 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 …

Surface Mass Transfer In Large Eddy Simulation (Les) Of Langmuir Turbulence, Cigdem Akan

USF Tampa Graduate Theses and Dissertations

Over the past century the study of gas exchange rates between the atmosphere and the ocean has received increased attention because of concern about the fate of greenhouse gases such as CO₂ released into the atmosphere. Of interest is the oceanic uptake of CO₂ in shallow water coastal regions as biological productivity in these regions is on average about three times larger than in the open ocean. It is well-known that in the absence of breaking surface waves, the water side turbulence controls gas transfer of sparingly soluble gases such as CO₂ from the air to the …

Evaluation Of Pedestrian Risk On 700 N On Utah State University Campus, Kirk Jackson

Undergraduate Honors Capstone Projects

One of the biggest concerns that highway designers face when designing roadways is how to safely design the interface between highway users and pedestrians. This is never truer than on the Utah State University campus where pedestrian use is much higher than on an average road. Utah State University purchased 700 N, the main collector road which runs through the heart of USU’s campus, from the City of Logan in the summer of 2010. Since then, pedestrian safety on 700 N has become the first priority of USU Facilities in regards to their efforts to improve it. It has come …

Developing A Family Of Curves For The Hec-18 Scour Equation, Timothy Calappi, Carol J. Miller, Donald Carpenter, Travis Dahl

Civil and Environmental Engineering Faculty Research Publications

Accurate pier scour predictions are essential to the safe and efficient design of bridge crossings. Current practice uses empirical formulas largely derived from laboratory experiments to predict local scour depth around single-bridge piers. The resulting formulas are hindered by insufficient consideration of scaling effects and hydrodynamic forces. When applied to full-scale designs, these formula deficiencies lead to excessive over prediction of scour depths and increased construction costs. In an effort to improve the predictive capabilities of the HEC-18 scour model, this work uses field-scale data and nonlinear regression to develop a family of equations optimized for various non-cohesive soil conditions. …

Analyzing Traffic Engineering Applications In The Rhode Island Transportation System To Determine Potential Environmental Sustainability, Michael R. Pezzullo

Senior Honors Projects

Transportation engineering is the application of technology and scientific principles to the planning, functional design, and management of facilities for any mode of transportation in order to provide for the safe, rapid, comfortable, convenient, economical, and environmentally compatible movement of people and goods. Traffic engineering is a specific segment of transportation engineering that deals with the planning, geometric design, and traffic operations of roads, streets and highways, their networks, terminals, abutting lands, and relationships with other modes of transportation. In the midst of this, is the concern for environmental compatibility, which continues to be of growing interest especially with regard …

Concrete Design For Traffic Application, Marc Shields

All Graduate Plan B and other Reports, Spring 1920 to Spring 2023

Inductive charging of electronic devices is a newer technology that is capable of transferring electrical power without physical contact through wiring. Research is currently being done to find and improve ways to implement this technology on electric cars. If this type of technology pas implemented on a large scale throughout much of the country, electrical or hybrid cars could travel across counties and states without depleting their batteries.

The current problem with electric cars is that they have a limited range of travel. Even with larger batteries with much more capacitance, the range of pure electric cars usually does not …

Evaluation Of An Enrichment Culture That Reductively Dechlorinates Γ-Hexachlorocyclohexane, Christina Anderson

All Theses

In a previous study using microcosms from a site contaminated with γ- hexachlorocyclohexane (γ-HCH), rapid anaerobic biodegradation of γ-HCH to benzene and chlorobenzene was observed. Enrichment cultures were developed and subsequently transferred to an anaerobic sulfate-free HEPES buffered medium without loss of γ-HCH dechlorination, thus suggesting γ-HCH undergoes anaerobic biodegradation via chlororespiration. The overall objective of this thesis was to further characterize the enrichment culture.
To do so, one specific objective was to determine the effect of vancomycin on γ-HCH in an enrichment culture grown in a sulfate-free HEPES buffered medium using hydrogen as the electron donor. This objective would …

Slope Stability Monitoring Using Remote Sensing Techniques, Omar Alberto Conte Robles

Graduate Theses and Dissertations

During the past six years the Arkansas State Highway and Transportation Department (AHTD) has spent over nine million dollars repairing slope failures that have occurred in the state of Arkansas. Specifically, higher than average precipitation in 2004 and 2008 led to large quantities of slides, all of which were repaired. Two highways, within the state of Arkansas, with known historical movements along or across the highways are being monitored using traditional surveying techniques and advanced remote sensing techniques. These slides, both of which are located in fill slopes. One a 500-foot long slide located north of Chester, Arkansas, within the …

Efficacy Of Geosynthetic Separators And Filters: An Evaluation Of Test Sections In Marked Tree, Arkansas, Ashique Ali Boga

Graduate Theses and Dissertations

Field and laboratory tests were conducted on 18 full-scale, geosynthetic reinforced, roadway test sections located in Marked Tree, Arkansas. Base course, geosynthetic, and subgrade samples were collected, and pavement depth, in-situ density and in-situ hydraulic conductivity measurements were obtained during a geotechnical site investigation. The performance of sections containing geotextile products being used for separation and filtration (Carthage Mills FX-66, Mirafi 570, Propex 2006, Propex 2044, and Propex 4553) was investigated.

Moisture content, sieve analysis, Atterberg limits, modified proctor, specific gravity, and hydraulic conductivity tests were performed on the acquired soil samples. Transmissivity and permittivity testing was conducted on the …

Synergy Of Alum And Chlorine Dioxide For Curbing Disinfection Byproduct Formation Potential At Central Arkansas Water, Corey W. Granderson

Graduate Theses and Dissertations

Central Arkansas Water (CAW), the water utility for Little Rock, AR, draws their source water from Lake Maumelle and Lake Winona. To curb disinfection byproduct (DBP) formation, CAW has begun retrofitting their two plants to use chlorine dioxide as an alternative primary disinfectant followed by free chlorine secondary disinfection in the distribution system. In this study, fluorescence parallel factor (PARAFAC) analysis was combined with free chlorine simulated distribution system (SDS) tests and DBP formation potential (DBPFP) tests to study the benefit of chlorine dioxide primary disinfection (CDPD) with alum coagulation. Of the DBPs screened, trichloromethane (TCM) was formed in highest …

Computer Modeling Of The Influence Of Structure Plan Areas On Tornado Forces, Nashmi Hassan M Alrasheedi

Graduate Theses and Dissertations

The study of the conventional Straight Line (SL) wind flow dominates research into wind loads on structures. Most structure design takes into account only research into SL flow. Few researchers have studied tornado forces on buildings and attempted to distinguish between tornadic wind loads and SL flow loads. Using a computer simulation, this research addresses and distinguishes between the tornadic forces and SL forces on structures. In the numerical simulation, tornado forces and SL forces will be compared on large structure plan areas and on thin structure plan areas. Additionally this research investigates how the increase in the vortex strength …