Civil Engineering Commons^™

Driver Comprehension Of Permissive Right-Turns With A Flashing Yellow Arrow (Fya), Christopher Monsere, David Hurwitz

PSU Transportation Seminars

This research explored driver comprehension and behaviors with respect to right-turn signal displays with a focus on the Flashing Yellow Arrow (FYA) in a driving simulator and a comprehension survey. Flashing yellow arrows are used in place of other turn signals, such as solid green or flashing yellow or red circles, to indicate that drivers may turn after yielding to oncoming traffic. These turns are considered “permissive.” Turns where no conflicting traffic is present, such as those indicated with a green arrow, are “protected” turns. The flashing yellow arrow’s inclusion in the 2009 Manual on Uniform Traffic Control Devices sped …

Numerical Analysis Of Leakage Through Defective Geomembrane Liners In Embankment Dams, Sarper Demirdogen

USF Tampa Graduate Theses and Dissertations

Placing a geomembrane liner in the core of a dam is an alternative construction technique to traditional clay core types. This study aims to assess the performance of such internal geomembrane sealing systems in an earthen dam. Two-dimensional (2D) numerical analysis was performed to evaluate leakage through defective seams within an earthen dam. Five possible applications of internal geomembrane systems were initially modeled to locate the zero-pressure lines in an earthen dam. Then, another application where the geomembrane is placed on the upstream face was modeled to compare the upstream and internal geomembrane systems. The results of this study show …

Groundwater Modeling For Mississippi River Alluvial Aquifer Of Northeastern Louisiana, Ramazan Karakullukcu

LSU Master's Theses

The Mississippi River Alluvial Aquifer (MRAA) locates in northeastern Louisiana, extending from the north border of Louisiana and Arkansas to south central Louisiana and underlies the Mississippi River Valley. The MRAA is the second most used groundwater source with about 390 million gallons per day in 2010, which accounts for 25% of all groundwater withdrawals in Louisiana. The groundwater uses are mainly for irrigation, public supply and industries. The excessive groundwater pumping and the economic importance of the MRAA have drawn attention to build a groundwater model to study future water resources management and sustainability plans. The model is the …

Strain Monitoring Of Concrete Components Using Embedded Carbon Nanofibers/Epoxy Sensors, Yanlei Wang, Yongshuai Wang, Baoguo Han, Baolin Wan, Gaochuang Cai, Zhizheng Li

Civil and Environmental Engineering Faculty Research and Publications

In this study, embedded strain sensors based on the principle of piezoresistivity were fabricated by epoxy-based composites filled with different contents of carbon nanofibers (CNFs). The piezoresistive performances and relevant parameters including gauge factor, linearity, repeatability and hysteresis of these sensors were investigated. A compensation circuit was proposed to eliminate the influence of temperature on sensing signals of the sensors. The CNFs/epoxy sensors were embedded into concrete cylinders to monitor their compressive strains under monotonic and cyclic loadings, thereby assessing practical applications of the CNFs/epoxy sensors as strain sensors for monitoring concrete structures. The results indicate that the sensors containing …

A New Thickness-Based Accelerated Aging Test Methodology For Resin Materials: Theory And Preliminary Experimental Study, Yanlei Wang, Xue Zhang, Gaochuang Cai, Baolin Wan, Danièle Waldmann, Yuan Qu

Civil and Environmental Engineering Faculty Research and Publications

This paper proposes a novel accelerated test method based on the thickness of resin materials. This method is to overcome the adverse influence of high temperature on the reliability of experimental results of the accelerated tests widely adopted in the current practice. To verify the proposed thickness-based accelerated method (ThAM), an experimental investigation was conducted focusing on the water absorption and tensile properties of epoxy resin. The results suggest that the existing temperature-based accelerated method (TAM) cannot be applied when the test temperature is high as in this case the degradation mechanism of materials is probably changed. The acceleration factor …

Machine Learning Tools For Optimization Of Fuel Consumption At Signalized Intersections In Connected/Automated Vehicles Environment, Saleh Ragab Mousa

LSU Doctoral Dissertations

Researchers continue to seek numerous techniques for making the transportation sector more sustainable in terms of fuel consumption and greenhouse gas emissions. Among the most effective techniques is Eco-driving at signalized intersections. Eco-driving is a complex control problem where drivers approaching the intersections are guided, over a period of time, to optimize fuel consumption. Eco-driving control systems reduce fuel consumption by optimizing vehicle trajectories near signalized intersections based on information of the SpaT (Signal Phase and Timing). Developing Eco-driving applications for semi-actuated signals, unlike pre-timed, is more challenging due to variations in cycle length resulting from fluctuations in traffic demand. …

Optimal And Objective Placement Of Sensors In Water Distribution Systems Using Information Theory, Mohammad S. Khorshidi, Mohammad Reza Nikoo, Mojtaba Sadegh

Civil Engineering Faculty Publications and Presentations

Optimization-based deployment of contamination warning system in water distribution systems has been widely used in the literature, due to their superior performance compared to rule- and opinion-based approaches. However, optimization techniques impose an excessive computational burden, which in turn is compensated for by shrinking the problem’s decision space and/or using faster optimization algorithms with less accuracy. This imposes subjectivity in interpretation of the system and associated risks, and undermines model’s accuracy by not exploring the entire feasible space. We propose a framework that uses information theoretic techniques, including value of information and transinformation entropy, for optimal sensor placement. This can …

A Study Of Pipe Co-Flow Into A Channel, Charles Yalung, Moses Karakouzian

AANAPISI Poster Presentations

This poster was presented in the Fall of 2018. It highlighted an ongoing research project into the effects of co-flow from a pipe feeding into an open flow channel. It used both experimental procedures and simulations, but only the experimental procedures were addressed in this poster.

Unobserved Heterogeneity And Spatial Correlation: Statistical And Econometric Analyses Of Heavy-Vehicle Hard Braking And Crash Frequency, Jason Anderson

PSU Transportation Seminars

In heavy-vehicles (a truck with a gross vehicle weight rating of greater than 10,000 pounds), a hard braking event is described as an event that prompts the vehicle’s “black box” to record an abrupt change in speed. More specifically, this occurs when the driver applies excess force to the vehicle’s brake. These hard braking events can then serve as a proxy for several factors, such as economic impacts, environmental impacts, and impacts on safety. In the context of the present study, being that approximately one-third of all heavy-vehicle-caused crashes in 2014 were attributed to faulty brakes, there is a need …

Hexahydro-1,3,5-Trinitro-1,3,5-Triazine (Rdx) Reduction By Granular Zero-Valent Iron In Continuous Flow Reactor, Amalia Terracciano, Jie Ge, Agamemnon Koutsospyros, Xiaoguang Meng, Benjamin Smolinski, Per Arienti

Civil Engineering Faculty Publications

Wastewater streams containing hexahydro-1, 3, 5-trinitro-1, 3, 5-triazine (RDX) are subject to regulatory discharge regulations that require processing through industrial waste treatment. Thus, the development of easy-to-apply technologies for the treatment of RDX-laden wastewater streams is imperative. In the present study, the reduction of RDX by granular zero valent iron (GZVI) in batch and column experiments was investigated. Preliminary batch tests conducted under both oxic and anoxic conditions showed that after 3.0 hours of reaction with GZVI, RDX was mainly converted to formaldehyde (CH₂O), nitrate (NO₃ ^- ), and ammonium (NH₄ ⁺ ). Column filtration tests …

Modeling The Impact Of Traffic Conditions And Bicycle Facilities On Cyclists' On-Road Stress Levels, Àlvaro Caviedes, Miguel A. Figliozzi

Civil and Environmental Engineering Faculty Publications and Presentations

Past research efforts have shown that cyclists’ safety, stress, and comfort levels greatly affect the routes chosen by cyclists and cycling frequency. Some researchers have tried to categorize cyclists’ levels of traffic stress utilizing data that can be directly measured in the field, such as the number of motorized travel lanes, motorized vehicle travel speeds, and type of bicycle infrastructure. This research effort presents a novel approach: real-world, on-road measurements of physiological stress as cyclists travel across different types of bicycle facilities at peak and off-peak traffic times. By matching videos with stressful events, it was possible to observe the …

Prediction And Rehabilitation Of Highway Embankment Slope Failures In Changing Climate, Navid Jafari, Anand Puppala

Publications

Highway slopes constructed with clayey soil are prone to desiccation cracks due to wetting and drying weather cycle, which allows greater moisture infiltration into the embankment from precipitation. Fissures formed due to extended wetting and drying cycles allow water to seep deeper into the soil than surficial wetting and increase the water content. This increases the moisture content in the soil and results in reduction in shear strength to the fully softened strength. On the other hand, development of desiccation cracks and reduction of the soil matric suction ultimately result in higher hydraulic conductivity value which causes development of higher …

Metagenomics Reveal Triclosan-Induced Changes In The Antibiotic Resistome Of Anaerobic Digesters, M. Fujimoto, Daniel Elliott Carey, Patrick J. Mcnamara

Civil and Environmental Engineering Faculty Research and Publications

Triclosan (TCS) is a broad-spectrum antimicrobial used in a variety of consumer products. While it was recently banned from hand soaps in the US, it is still a key ingredient in a top-selling toothpaste. TCS is a hydrophobic micropollutant that is recalcitrant under anaerobic digestion thereby resulting in high TCS concentrations in biosolids. The objective of this study was to determine the impact of TCS on the antibiotic resistome and potential cross-protection in lab-scale anaerobic digesters using shotgun metagenomics. It was hypothesized that metagenomics would reveal selection for antibiotic resistance genes (ARGs) not previously found in pure culture studies or …

An Environmental Science And Engineering Framework For Combating Antimicrobial Resistance, Amy Pruden, Reinaldo E. Alcalde, Pedro J.J. Alvarez, Nicholas Ashbolt, Heather Bischel, Natalie L. Capiro, Emily Crossette, Dominic Frigon, Kassandra Grimes, Charles N. Haas, Kaoru Ikuma, Anthony D. Kappell, Timothy M. Lapara, Lee K. Kimbell, Mengyan Li, Xu Li, Patrick J. Mcnamara, Youngwoo Seo, Mark D. Sobsey, Emanuele Sozzi, Tala Navab-Daneshmand, Lutgarde Raskin, Maria Virginia Riquelme, Peter Vikesland, Krista Wigginton, Zhi Zhou

Civil and Environmental Engineering Faculty Research and Publications

On June 20, 2017, members of the environmental engineering and science (EES) community convened at the Association of Environmental Engineering and Science Professors (AEESP) Biennial Conference for a workshop on antimicrobial resistance. With over 80 registered participants, discussion groups focused on the following topics: risk assessment, monitoring, wastewater treatment, agricultural systems, and synergies. In this study, we summarize the consensus among the workshop participants regarding the role of the EES community in understanding and mitigating the spread of antibiotic resistance via environmental pathways. Environmental scientists and engineers offer a unique and interdisciplinary perspective and expertise needed for engaging with other …

Accounting For Landscape Heterogeneity Improves Spatial Predictions Of Tree Vulnerability To Drought, Amanda M. Schwantes, Anthony J. Parolari, Jennifer J. Swenson, Daniel M. Johnson, Jean-Christopher Domec, Robert B. Jackson, Norman F. Pelak, Amilcare Porporato

Civil and Environmental Engineering Faculty Research and Publications

As climate change continues, forest vulnerability to droughts and heatwaves is increasing, but vulnerability varies regionally and locally through landscape position. Also, most models used in forecasting forest responses to heat and drought do not incorporate relevant spatial processes.

In order to improve spatial predictions of tree vulnerability, we employed a nonlinear stochastic model of soil moisture dynamics accounting for landscape differences in aspect, topography and soils. Across a watershed in central Texas we modeled dynamic water stress for a dominant tree species, Juniperus ashei, and projected future dynamic water stress through the 21^st century.

Modeled dynamic water …

Strain And Damage Self-Sensing Of Basalt Fiber Reinforced Polymer Laminates Fabricated With Carbon Nanofibers/Epoxy Composites Under Tension, Yanlei Wang, Yongshuai Wang, Baolin Wan, Baoguo Han, Gaochuang Cai, Ruijuan Chang

Civil and Environmental Engineering Faculty Research and Publications

This study investigated the strain and damage self-sensing capabilities of basalt fiber reinforced polymer (BFRP) laminates fabricated with carbon nanofibers (CNFs)/epoxy composites subjected to tensile loadings. The conduction mechanisms based on the tunnel conduction and percolation conduction theories as well as the damage evolution were also explored. A compensation circuit with a half-bridge configuration was proposed. The results indicated the resistivity of the CNFs/BFRP laminates and CNFs/epoxy composites exhibited similar change rule, indicating that the conductive networks of CNFs/BFRP laminates were governed by CNFs/epoxy composites. With the increase of strain under monotonic tensile loading, the electrical resistance response could be …

Modeling Sulfate Attack In Modern Concrete For Building Sustainable And Resilient Infrastructure, Zachary Grasley

Publications

External sulfate attack is a complex phenomenon and is manifested in the form of large expansion, cracking, and spalling depending on the exposure solution and material constituent properties. Several models were developed in the past to demonstrate sulfate attack mechanisms that account for the diffusion of sulfate ions into the porous concrete and the successive deformation triggered by the chemical reaction and precipitation of expansive agents. However, none of these models accounts for the effect of the migration of solvent water from the low solute concentration solution to high solute concentration solution driven by the osmotic pressure. Osmotic pressure is …

In-Situ Mechanical Characterization For Compacted Aggregates, Douglas Cortes, Paola Bandini

Publications

The evaluation of compacted unbound aggregate layers is perhaps the most common undertaking in transportation-related projects. The assessment of compaction compliance in engineered fills, subgrades, subbases, and bases in roadways and railways is central to ensure longevity of ground transportation infrastructure. In many cases, premature failures in roadways that originate in the unbound aggregate layers can be traced back to inadequate compaction. These failures are preventable, provided the problem areas can be identified by a suitable field test during construction. The most widely used method for compaction assessment during construction is the nuclear density gauge (NDG) test. While the device …

Bridge Inspecting With Unmanned Aerial Vehicles R&D, Paul Darby, Vijaya Gopu

Publications

The project achieves through research including literature, on site interviews, and experimentation: 1) a recommendation for a UAV-based system to practically assist in routine bridge inspection work in the State of Louisiana, 2) the identification and description of advantages, disadvantages, and limitations in the use of UAVs for routing bridge inspection work in Louisiana, and 3) provided recommendations for future work. The Yuneec H520 aircraft and its E90 camera are recommended, as is the need for a boat to be included as part of the system. The recommended system has advantages in reaching portions of the bridge that are difficult …

Development Of Environmentally-Friendly Stabilization Methods For Transportation Infrastructure Based On Geopolymers, Miladin Radovic, Anand Puppala

Publications

Geopolymers (GPs) have received much attention as an eco-friendly and sustainable alternative to conventional chemical additives, since they can be processed at room temperatures from aqueous solutions by utilizing waste materials (e.g. fly ash) or abundant natural sources (e.g. clay). A collaborative research study is carried out by teams from Texas A&M University (TAMU) and University of Texas at Arlington (UTA) to investigate the effectiveness of GPs for stabilizing base and subgrade materials by considering the strength and shrink-swell characteristics. Two types of clay, obtained from the North Dallas area, were mixed with a potassium-based GP synthesized from metakaolin and …