Civil and Environmental Engineering Commons^™

In-Vehicle Evaluation Of Milled Rumble Strips At Pre- And Post-Chip Sealed Maintenance Periods, Ernest Tufuor, Laurence Rilett, Christopher Lefrois

Nebraska Department of Transportation: Research Reports

Driver fatigue and drowsiness can have a profound impact on safety. Centerline and shoulder rumble strips (RS) are popular countermeasures designed to produce audible and tactile warning when vehicles deviate from the travel lane onto the RS. This reduces the risk of lane departure crashes. Studies show that the noise produced by RS is a function of many variables. RS depth is known to have the greatest impact on alerting drivers. However, chip-seal pavement maintenance operations have the tendency to reduce the original RS design depth, which may have an impact on the functional effectiveness of the RS. The purpose …

Nebraska Public Water Supply Program Summary Report 2017

Nebraska Department of Environmental Quality: Reports

The United States Environmental Protection Agency (EPA) established the Public Water System Supervision (PWSS) Program under the authority of the 1974 Safe Drinking Water Act (SDWA). Under the SDWA and the 1986 Amendments, EPA sets national limits on contaminant levels in drinking water to ensure that the water is safe for human consumption. These limits are known as Maximum Contaminant Levels (MCLs) and Maximum Residual Disinfectant Levels (MRDLs). For some regulations, EPA establishes treatment techniques in lieu of an MCL to control unacceptable levels of contaminants in water.

2017 Nebraska Groundwater Quality Monitoring Report

Nebraska Department of Environmental Quality: Reports

The 2001 Nebraska Legislature passed LB329 (Neb. Rev. Stat. §46-1304) which, in part, directed the Nebraska Department of Environmental Quality (NDEQ) to report on groundwater quality monitoring in Nebraska. Reports have been issued annually since December 2001. The text of the statute applicable to this report follows: “The Department of Environmental Quality shall prepare a report outlining the extent of ground water quality monitoring conducted by natural resources districts during the preceding calendar year. The department shall analyze the data collected for the purpose of determining whether or not ground water quality is degrading or improving and shall present the …

Compensatory Response Of Fathead Minnow Larvae Following A Pulsed In-Situ Exposure To A Seasonal Agricultural Runoff Event, Jonathan M. Ali, John Sangster, Daniel D. Snow, Shannon L. Bartelt-Hunt, Alan S. Kolok

Nebraska Water Center: Faculty Publications

Agriculturally-dominated waterways such as those found throughout the Midwestern United States often experience seasonal pulses of agrichemical contaminants which pose a potential hazard to aquatic organisms at varying life stages. The objective of this study was to characterize the developmental plasticity of fathead minnow larvae in a natural environment subject to a seasonal episodic perturbation in the form of a complex mixture of agricultural stressors. Fathead minnow larvae were maintained at the Elkhorn River Research Station for a 28-d in situ exposure to an agrichemical pulse event.Minnow larvae were sampled after 14 and 28 days to characterize developmental plasticity through …

Effect Of Operating Conditions And Ion Contaminations On Electro Coagulation And Oxidation Processes For Water Quality Improvement, Vouchlay Theng

Chulalongkorn University Theses and Dissertations (Chula ETD)

The objective of this study is to investigate the effect of ion contaminations and operating conditions on Electro Coagulation (EC) and Oxidation (EO) in turbidity and natural organic matter (NOM) removal. The experiments were conducted in 4 liters column. Ferrous and calcium were chosen as contaminated ions. The operating condition was varied in terms of initial pH and current density. 100 NTU turbidity and 70 mg/L NOM were synthesized from bentonite and humic acid (HA), respectively. The results showed that bipolar arrangement of electrodes with 2 cm gap was the optimal condition in terms of gas flow rate and electrode …

Analysis Of Mechanical Properties Of Alternative Timber Beams For A Native American Earth Lodge, Freddy E. Moran

Electronic Theses and Dissertations

To fill a gap in the literature, this thesis explored the mechanical properties for alternative roof beams of a historic Native American Hidatsa earth lodge. The research demonstrates that in those alternative beams, when Moisture Content (MC) increases, Modulus of Elasticity (E) decreases and deflection increases. The procedure included obtaining dimensions for alternative beams from scaled sketches created by ethnographers and informants who recorded an actual Hidatsa earth lodge in the early 1800s (confirmed by other sources) although no material properties studies have resulted. After calculating loads, the variations in the E were determined using an equation. Using linear analysis, …

Atmospheric Boundary Layer Processes To Mimic Peak Pressures On Low-Rise Buildings: Cfd Versus Full-Scale And Wind Tunnel Measurements, Hamzeh Gol Zaroudi

LSU Doctoral Dissertations

Realistic prediction of peak wind pressures is indispensable in a safe design of low-rise buildings. For several decades wind tunnel testing was employed to obtain wind loads on buildings and other structures. However, there is still doubt in the wind engineering community regarding the adequacy of wind tunnels to predict accurately full-scale pressures on low-rise buildings and small-size structures. The recommendations of the American Society of Civil Engineers (ASCE) 7-10 standard for external pressure coefficients, for roof components and cladding (C&C) design are also based on published wind tunnel data. Recent field measurements show significant deviation of full-scale pressures from …

In-Situ Assessment Of Concrete Bridge Decks And Pavements Using Stress-Wave Based Methods, Mengxing Li

Doctoral Dissertations

"Concrete infrastructure of United States is aging and deteriorating. Accurate assessment the condition of concrete infrastructure is critical for its maintenance and rehabilitation. Stress-wave based methods, including ultrasonic surface wave (USW) and impact echo (IE), are becoming popular for characterizing defects and mechanical properties of concrete infrastructures. In this dissertation, a comprehensive literature review of seismic wave theory and common types of defects identified in concrete infrastructures, as well as stress-wave based methods used for concrete infrastructure monitoring and characterizing on a selected concrete bridge deck and two concrete pavement segments are present. The utility and reliability of both methods …

Novel Applications Of Pulse Pre-Pump Brillouin Optical Time Domain Analysis For Behavior Evaluation Of Structures Under Thermal And Mechanical Loading, Yi Bao

Doctoral Dissertations

"This study aims to: (1) develop an analytical model for the strain transfer effect of distributed fiber optic sensors in a uniform or non-uniform stress field; (2) develop a measurement approach to monitor strains in concrete and detect damage (e.g. crack and delamination) in bonded and unbonded concrete overlays; (3) characterize the strain and temperature sensitivities of distributed fiber optic sensors at elevated temperatures; (4) develop a thermal annealing approach to enhance the thermal stability and temperature sensitivity of the distributed sensors; and (5) apply the distributed sensors to assess structural behaviors of concrete and steel structures exposed to fire. …

High-Volume Recycled Materials For Sustainable Transportation Infrastructure, Seyedhamed Sadati

Doctoral Dissertations

"The objective of this study is to investigate the feasibility of using high performance concrete made with high-volume of recycled materials in transportation infrastructure. The main focus was to develop mixtures for rigid pavement construction. A variety of fine and coarse recycled concrete aggregates (RCA) were investigated. The feasibility of replacing 50% of Portland cement with industrial by-products and supplementary cementitious materials (SCMs) was also evaluated. Experimental program was conducted to quantify the effect of concrete mixture design and RCA characteristics on mechanical properties, drying shrinkage, cracking potential, and durability of concrete. The development of a database and analysis using …

Smart Rocks For Bridge Scour Monitoring -- Design And Localization Using Electromagnetic Techniques And Embedded Orientation Sensors, Andro Radchenko

Doctoral Dissertations

"River bridge scour is an erosion process in which flowing water removes sediment materials (such as sand, rocks) from a bridge foundation, river beds and banks. As a result, the level of the river bed near a bridge pier is lowering such that the bridge foundation stability can be compromised, and the bridge can collapse. The scour is a dynamic process, which can accelerate rapidly during a flood event. Thus, regular monitoring of the scour progress is necessary to be performed at most river bridges. Present techniques are usually expensive, require large man/hour efforts, and often lack the real-time monitoring …

Remote Sensing And Localization Of Smart Rocks With Orientation-Controlled Magnets For Real-Time Monitoring Of Bridge Scour And Riprap Effectiveness, Yan Tang

Doctoral Dissertations

"This study aims to develop and implement a novel smart rock technology for real-time monitoring of the maximum scour depth and the effectiveness of riprap mitigation measures. A smart rock is one or more stacked magnets encased in concrete that can automatically roll to the deepest point of a scour hole around a bridge pier and provide its location through remote measurement over time. Once integrated into a riprap measure, the smart rock moves together with natural rocks and is thus a potential indicator of the effectiveness of the riprap measure. Therefore, the localization and movement of smart rocks were …

Environmental Hazard Identification, Assessment And Control For A Sustainable Maritime Transportation System, Lizzette Marie Pérez Lespier

Doctoral Dissertations

"A demand exists to contribute towards the widening awareness of the need for sustainable maritime development and for coordinated maritime policies worldwide. Maritime shipping is considered the most eco-efficient mean of transportation and yet, is responsible for negative environmental impacts.

This dissertation focuses on developing data-driven decision support tools to evaluate the sustainable performance of MTS by focusing on the elements of the MTS that place stress on the environment. The first research contribution is a System Dynamics simulation model that examines the MTS resiliency after an extreme event and determines the sequence needed to restore the ocean-going port to …

Contributing Factors To Child Stunting In Guatemala: A Systems Analysis Focused On Enteric Disease Transmission And Mycotoxin Exposure, Lee Emerson Voth-Gaeddert

Doctoral Dissertations

"Child stunting -- low height-for-age -- is a United Nation's indicator for chronic malnutrition that has been linked to both acute and chronic health problems. Data from Guatemala suggests for children under five years of age, 49% are classified as stunted. This dissertation tests the following hypotheses, among children in Guatemala 1) environmental enteric dysfunction (EED) is correlated with height-for-age, 2) aflatoxin B (AFB) exposure is correlated with height-for-age, and 3) AFB exposure is correlated with EED. A network analysis was conducted on data from the US Agency for International Development (USAID) collected in 2012 to identify trends in a …

Durability Behavior Of Fiber Reinforced Polymer And Steel Reinforced Polymer For Infrastructure Applications, Wei Wang

Doctoral Dissertations

"Crack development in reinforced concrete (RC) structures is common in elements such as bridge decks. However, these cracks can impose significant problems over time, because they allow chlorides from deicing chemicals to infiltrate concrete which will then corrode steel bars as RC structures are exposed to harsh weather. In the last decade, composite reinforcement systems are internally or externally applied to concrete structures instead of traditional steel reinforcing bars, or to strengthen concrete elements in flexure and shear. However, studies regarding the long-term durability performance of composite reinforcement systems is limited. Therefore, in order to popularize the application of these …

Design And Performance Of Cost-Effective Ultra High Performance Concrete For Bridge Deck Overlays, Mahdi Valipour

Doctoral Dissertations

"The main objective of this research is to develop a cost-effective ultra-high performance concrete (UHPC) for bonded bridge deck overlays. The high durability and mechanical properties of such repair material can offer shorter traffic closures and prolong the service life of the pavement. The UHPC was optimized using supplementary cementitious materials (SCMs), proper combinations of sands, and adequate selection of fiber types and contents. Packing density studies included paste, sand, and fiber combinations. The robustness of optimized UHPC mixtures to variations of mixing and curing temperatures was examined. The efficiency of various shrinkage mitigation approaches in reducing autogenous and drying …

Long-Period Fiber Grating Corrosion Sensors For Life-Cycle Monitoring And Assessment Of Reinforced Concrete Structures, Yizheng Chen

Doctoral Dissertations

"This study aims to: (1) explore, develop, calibrate and validate Fe-C coated, long period fiber grating (LPFG) sensors for short-term mass loss measurement of the Fe-C coating; (2) develop, calibrate, and validate steel tube-encapsulated, fiber optic probes and LPFG sensors for long-term mass loss detection of the steel tube; (3) correlate the corrosion process of packaging metal materials with that of steel bars in direct contact with the packaged probe or sensor except for a thin insulation tape; and (4) apply both types of corrosion sensors into reinforced concrete (RC) structures for reinforcing bar corrosion monitoring and structural condition assessment. …

Reducing Model Selection Computational Cost By Metamodeling The Evidence, Ramin Madarshahian

Theses and Dissertations

Modeling is an abstraction of reality that lets a designer or engineer perform simulations with a “real” object or structure without testing it physically. However, the result of simulations is as good as their models. Selecting the best model among many candidates is another challenge.

Complex models could translate into more accurate predictions, but they also require larger computational effort. The Bayes factor is often used to compare different models considering the data and analyst’s experience. To obtain the Bayes factor, the Bayesian model evidence is calculated; however, calculating the Bayesian model evidence of computationally expensive models is not a …

Investigating The Feedstock Properties And Process Conditions Influencing The Characteristics Of Products Generated From The Hydrothermal Carbonization Of Organic Feedstocks, Liang Li

Theses and Dissertations

Hydrothermal carbonization (HTC) is a novel environmentally beneficial thermal conversion process for the transformation of organic feedstocks to value-added products. However, little is known about the role of feedstock properties and/or process conditions during carbonization. This study was conducted to determine the parameters most influential during the HTC of organic feedstocks. Experiments and statistical analyses were conducted to: (1) determine the effect of specific feedstocks, feedstock interactions, and process conditions on carbonization product characteristics; (2) understand how initial liquid characteristics influence product characteristics and evaluate the significance of these initial liquid characteristics in predicting product characteristics; and (3) develop statistical …

Towards A Better Understanding Of Indoor Exposure To Air Pollutants: Window Opening Occurrence In U.S. Residences, Gauri Dilip Date

Masters Theses

"Opening a window dramatically alters how we are exposed to air pollutants. Online questionnaire surveys were deployed to assess window-opening occurrence of the occupants of US homes. This information will be used to better quantify population exposure to pollutants of indoor and outdoor origin. Frequency distributions of demographics were generated which showed percentages of respondents who participated in the surveys from categories including gender, race, household income and occupancy. In April 2016, 49.3% of the people surveyed opened their windows for at least 1 hour in a day. This increased to 52.5% in September 2016 and reduced considerably to 24.4% …

Extending Time Series Forecasting Methods Using Functional Principal Components Analysis, Isaac Michael Wagner-Muns

Masters Theses

"Traffic volume forecasts are used by many transportation analysis and management systems to better characterize and react to fluctuating traffic patterns. Most current forecasting methods do not take advantage of the underlying functional characteristics of the time series to make predictions. This paper presents a methodology that uses Functional Principal Components Analysis (FPCA) to create smooth and differentiable daily traffic forecasts. The methodology is validated with a data set of 1,813 days of 15 minute aggregated traffic volume time series. Both the FPCA based forecasts and the associated prediction intervals outperform traditional Seasonal Autoregressive Integrated Moving Average (SARIMA) based methods"--Abstract, …

A Case Study Of Student Veteran Efficacy In The College Of Engineering And Information Technology At Georgia Southern University, Kevin G. Finley

College of Graduate Studies: Theses & Dissertations

This thesis addresses the issues student veterans face in their transition from military to academic life while pursuing an undergraduate degree in the STEM fields (Science, Technology, Engineering, Math) at Georgia Southern University’s College of Engineering and Information Technology (CEIT). Historically this transition has been a difficult one. Through the implementation of a mentorship program comprised of military veterans on the staff and faculty of Georgia Southern University as well as assistance and participation from members of the case study researcher team and primary researcher this program assisted incoming military student veterans as they assimilated into the collegiate atmosphere. The …

Increasing Efficiency In The Construction Industry And Construction Management Classrooms Using Computer Software, Tina T. Bien

Undergraduate Honors Theses

The purpose of this research is to identify the best computer software programs that are the most effective within the construction industry. Companies are gradually shifting from manual practices to various software and technologies to optimize business and communication efficiency. With the plethora of software available, the industry does not fully understand which software are the most effective for addressing the challenges of the industry. As the industry is struggling with integrating these software into their company structure, more money is being spent to tackle the challenges that face the construction industry today. Companies that do not integrate construction technology …

Impact Of Reclaimed Asphalt Pavement And Recycled Asphalt Shingles On Laboratory And Field Performance Of Texas Asphalt Concrete Pavements, Berenice Salaices Gomez

Open Access Theses & Dissertations

The use of recycled materials in Asphalt Concrete (AC) mixes is highly promoted in the transportation industry. Recycled materials minimize the use of virgin materials, reduce the consumption of resources, and cut costs for new construction or rehabilitation projects. The incorporation of Reclaimed Asphalt Pavement (RAP) and Recycled Asphalt Shingles (RAS) in the AC mixture is promoted as long as equal or improved performance is achieved. The Texas Department of Transportation (TxDOT) is currently placing asphaltic concrete (AC) mixes that are lasting less than their expected performance life when recycled materials are used.

The objective of this Thesis is to …

Modeling The Effects Of Manufacturing Geometric Imperfections In The Buckling Analysis Of Three-Dimensional Structures, Juan Carlos Salcido

Open Access Theses & Dissertations

Reticulated three-dimensional structures follow design practices based on the common assumption that joints are either rigid, or pinned. However, the actual non-linear behavior of the jointing system interaction is required to be incorporated into the analysis of the structure to accurately predict its buckling stability. Besides, currently, there is a concern on how manufacturing imperfections of these jointing systems affect the global behavior of three-dimensional structures. This Dissertation incorporates and captures the effect that manufacturing geometric imperfections in the fir-tree jointing system produce in the non-linear buckling behavior of three-dimensional structures.

To understand the effect that initial manufacturing imperfections of …

Integrating The Macroscopic And Microscopic Traffic Safety Analysis Using Hierarchical Models, Qing Cai

Electronic Theses and Dissertations

Crash frequency analysis is a crucial tool to investigate traffic safety problems. With the objective of revealing hazardous factors which would affect crash occurrence, crash frequency analysis has been undertaken at the macroscopic and microscopic levels. At the macroscopic level, crashes from a spatial aggregation (such as traffic analysis zone or county) are considered to quantify the impacts of socioeconomic and demographic characteristics, transportation demand and network attributes so as to provide countermeasures from a planning perspective. On the other hand, the microscopic crashes on a segment or intersection are analyzed to identify the influence of geometric design, lighting and …

Load Estimation, Structural Identification And Human Comfort Assessment Of Flexible Structures, Ozan Celik

Electronic Theses and Dissertations

Stadiums, pedestrian bridges, dance floors, and concert halls are distinct from other civil engineering structures due to several challenges in their design and dynamic behavior. These challenges originate from the flexible inherent nature of these structures coupled with human interactions in the form of loading. The investigations in past literature on this topic clearly state that the design of flexible structures can be improved with better load modeling strategies acquired with reliable load quantification, a deeper understanding of structural response, generation of simple and efficient human-structure interaction models and new measurement and assessment criteria for acceptable vibration levels. In contribution …

Effect Of Inlet Angle From Tributary Into Main Channel, Artuan Mcgee, Moses Karakouzian

AANAPISI Poster Presentations

Open channel flows play a significant role within major metropolitan areas in the removal of excess surface runoff. Main channels are responsible for the removal of all excess surface runoff which are fed by connecting tributaries. Both main channels and tributaries can occur naturally or be manmade but their orientation must be considered in the removal of excess surface run off. It is believed that the angle in which the tributaries connect to the main channel is an important factor in whether the run off is removed efficiently or a major contributor to flooding. Current practice requires tributaries in flood …

City Of Gresham Stormwater Retrofit Master Plan, Teresa F. Huntsinger

Civil and Environmental Engineering Master's Project Reports

The Stormwater Retrofit Master Plan identifies more than 50 stormwater retrofit project opportunities across three watersheds in the City of Gresham. The retrofit projects are prioritized in a scoring system to evaluate the costs and benefits of diverse project sizes and types. Project types range from bioswales and planters in city parking lots and along arterial roads, to regional end-of-pipe facilities and retrofits of existing detention ponds. Top projects will move forward for further assessment, design and construction, helping the city achieve its water quality improvement goals. The scoring system may be used to evaluate additional projects in the future.

The Impact Of Owner Practices And Procedures On Construction Project Safety Performance, Huang Liu

Theses and Dissertations--Civil Engineering

Construction sites are dangerous work environments. One traditional assumption prevails in the construction industry that construction safety should be the sole responsibility of the contractor. However, some safety researchers gradually begin to challenge this assumption. The elementary research in this field try to validate the existence of relationship of the owner’s practices and safety performance, which indicates that the involvements of the owner have a positive impact on improvement of safety performance. Therefore, the owner can and should take a responsibility of the project safety. Some subsequent research focus on collecting and summarizing the best safety practices and procedures of …