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Quasi-Static And Impact Load Response Of Bfrp-Reinforced Concrete Beams And Post-Terrorist-Attack Sub-Assemblages, José Luis Carrasquillo

Civil & Environmental Engineering Theses & Dissertations

This dissertation presents the outcome of a theoretical and experimental study of Basalt Fiber Reinforced Polymer (BFRP) reinforced concrete beams and post-terrorist-attack subassemblages subjected to either quasi-static or impact load. Both BFRP reinforcement as well as BFRP fabric are used in this investigation. The sub-assemblage consists of an otherwise two-span beam converted to a fixed-end single-span one owing to the loss of a middle column blasted off during the terrorist attack. The simply supported beams are subjected to a midspan quasistatic or an impact load. However, each sub-assemblage is subjected to a quasi-static load up to collapse to simulate the …

Thermo-Elasto-Plastic Stability Of Biaxially Loaded Hollow Rectangular Section Steel Beam-Columns With Applied Torsion, George Adomako Kumi

Civil & Environmental Engineering Theses & Dissertations

Presented herein is an experimental and theoretical study of biaxially loaded hollow rectangular section steel beam-columns with applied torsion at elevated temperatures. The theoretical analysis is based on a system of simultaneous materially nonlinear differential equations of equilibrium for which an iterative semi-analytic solution approach is formulated. Although the primary goal of this research is to study the influence of elevated temperatures on the steel member with the complex loading, rigorous analysis is also conducted of the member at ambient temperature for comparison. The experimental part of the study involves conducting tests on the members at both ambient and high …

Stability And Strength Of Glass Frp Beam-Columns With Biaxial Bending And Torsion Including Shear And Warping Deformations, Emad M. Amin

Civil & Environmental Engineering Theses & Dissertations

Presented herein is a study of the stability and strength of pultruded glass fiber reinforced polymer (Glass FRP) beam-columns with an I-shaped cross section subjected to biaxial bending and torsion including shear and warping deformations. Three coupled differential equations of equilibrium including second-order effects and geometric imperfections are formulated and solved using a finite-difference scheme. Laboratory experiments are also conducted on glass FRP members with applied torsion; axial load; combined axial load with biaxial bending; and combined axial load, biaxial bending and torsional moment, respectively, for comparison to the theoretical predictions. The theoretical results agreed well with the experiments for …

Modeling The Impact Of Connected And Automated Vehicles On Driving Behaviors And Safety: A Driving Simulator Study, Abdalziz Alruwaili

Civil & Environmental Engineering Theses & Dissertations

Connected vehicles (CVs), equipped with advanced sensors, can communicate safety messages to drivers. Automated vehicles (AVs), designed with the ability to automate safety critical control functions, will redefine the traditional role of drivers. This dissertation aims to investigate the impact of connected and automated vehicles (CAVs) on driving behaviors and safety outcomes using data from driving simulator experiments. More specifically, the research objectives include:

1. Modeling the impacts of CVs on driving aggressiveness and situational awareness in highway crash scenarios.

2. Modeling the impacts of CV technologies on driving behaviors and safety outcomes in highway crash scenarios under diverse weather …

Dynamic Soil-Structure Response And Failure Of Wood Utility Poles Under Hurricane-Force Wind And Non-Linear Cable Loads, Ramani Ayakannu

Civil & Environmental Engineering Theses & Dissertations

This dissertation presents the outcome of a study of the dynamic soil-structure interaction response of tapered wood utility poles embedded in various foundation soils subject to quasi-static and dynamic wind loads. The study includes the effects of nonlinear soil behavior with varying quantities of moisture and nonlinear cable tension loads on a class H1 wood pole. The natural frequency response of the pole is determined using a finite element formulation. The dynamic response in the presence of wind-induced forcing function is studied using a SAP2000 finite element scheme with wind speeds up to 220 mph. The natural frequency of the …

Biochar For Heavy Metal Removal In Water: Opportunities, Challenges, And Sustainable Solutions, Pushpita Kumkum

Civil & Environmental Engineering Theses & Dissertations

The presence of heavy metals in drinking water is a significant concern due to the harmful impacts it can have on human health. Biochar has emerged as a low-cost alternative to activated carbon for lead (Pb) adsorption due to its porous structure and high surface-to-volume ratio. The last 10 years of studies have been reviewed to investigate the biochar production, activation methods, kinetic, adsorption isotherms, mechanism, regeneration, and adsorption capacities to guide future researchers and practitioners in using biochar to remove Pb from water. However, several challenges hinder the actual application of biochar as an adsorbent. These challenges include variability …

Combine Effects Of Heavy Storm, Sea Level Rise, And Wind-Induced Surge On Flooding In A Low-Gradient Coastal Watershed In Eastern Virginia, Rutvik Rajendrabhai Patel

Civil & Environmental Engineering Theses & Dissertations

This dissertation examines and presents mechanisms of flooding in a low-gradient coastal watershed, located in Virginia Beach, Virginia, USA. The watershed comprises the North Landing River watershed and the West Neck Creek watershed, both characterized by a low topographic gradient. The analysis relied on examining simulations generated using one-dimensional and two-dimensional HEC-RAS models. These models were developed using a 1-m digital elevation model (DEM) obtained from the U.S. Geological Survey (USGS). To calibrate and validate the models, unsteady flows resulting from historical hurricanes (e.g., Matthew, Sandy, and Isabel), southern winds, and/or rising sea levels were utilized. Some flows were caused …

A Review On Biochar As An Adsorbent For Pb(Ii) Removal From Water, Pushpita Kumkum, Sandeep Kumar

Civil & Environmental Engineering Faculty Publications

Heavy metal contamination in drinking water is a growing concern due to its severe health effects on humans. Among the many metals, lead (Pb), which is a toxic and harmful element, has the most widespread global distribution. Pb pollution is a major problem of water pollution in developing countries and nations. The most common sources of lead in drinking water are lead pipes, faucets, and plumbing fixtures. Adsorption is the most efficient method for metal removal, and activated carbon has been used widely in many applications as an effective adsorbent, but its high production costs have created the necessity for …

Small-Strain Site Response Of Soft Soils In The Sacramento-San Joaquin Delta Region Of California Conditioned On Vₛ₃₀ And Mhvsr, Tristan E. Buckreis, Jonathan P. Stewart, Scott J. Brandenberg, Pengfei Wang

Civil & Environmental Engineering Faculty Publications

Sites located in the Sacramento-San Joaquin Delta region of California typically have peaty-organic soils near the ground surface, which are characteristically soft, with shear wave velocities as low as 30 m/s. These unusually soft geotechnical conditions, which are outside the range of applicability of existing ergodic site amplification models, can be anticipated to produce significant site effects during earthquake shaking. We evaluate site response for 36 seismic stations in the Delta region using non-ergodic methods with low-amplitude ground motion data. We model first-order site effects using a period-dependent relation conditioned on the 30 m time-averaged shear wave velocity (V …

Urban Flood Extent Segmentation And Evaluation From Real-World Surveillance Camera Images Using Deep Convolutional Neural Network, Yidi Wang, Yawen Shen, Behrouz Salahshour, Mecit Cetin, Khan Iftekharuddin, Navid Tahvildari, Guoping Huang, Devin K. Harris, Kwame Ampofo, Jonathan L. Goodall

Civil & Environmental Engineering Faculty Publications

This study explores the use of Deep Convolutional Neural Network (DCNN) for semantic segmentation of flood images. Imagery datasets of urban flooding were used to train two DCNN-based models, and camera images were used to test the application of the models with real-world data. Validation results show that both models extracted flood extent with a mean F1-score over 0.9. The factors that affected the performance included still water surface with specular reflection, wet road surface, and low illumination. In testing, reduced visibility during a storm and raindrops on surveillance cameras were major problems that affected the segmentation of flood extent. …

De-Risking Pretreatment Of Microalgae To Produce Fuels And Chemical Co-Products, Jacob S. Kruger, Skylar Schutter, Eric P. Knoshaug, Bonnie Panczak, Hannah Alt, Alicia Sowell, Stafanie Van Wychen, Matthew Fowler, Kyoko Hirayama, Anuj Thakkar, Sandeep Kumar

Civil & Environmental Engineering Faculty Publications

Conversion of microalgae to renewable fuels and chemical co-products by pretreating and fractionation holds promise as an algal biorefinery concept, but a better understanding of the pretreatment performance as a function of algae strain and composition is necessary to de-risk algae conversion operations. Similarly, there are few examples of algae pretreatment at scales larger than the bench scale. This work aims to de-risk algal biorefinery operations by evaluating the pretreatment performance across nine different microalgae samples and five different pretreatment methods at small (5 mL) scale and further de-risk the operation by scaling pretreatment for one species to the 80 …

Contribution Of High Turbidity To Tidal Dynamics In A Curved Channel In Zhoushan Islands, China, Li Li, Fangzhou Shen, Zhiguo He, Gangfeng Ma, Jiachen Wang, Kailong Huangfu

Civil & Environmental Engineering Faculty Publications

The curved tidal channel, Luotou Deep-water Navigational Channel, is the main channel of the Ningbo Zhoushan Port, which is ranked first in the world. Tidal dynamics in the channel are spatially and temporally asymmetric. In this study, the three-dimensional tidal dynamics in the channel were analyzed using field data and simulated using FVCOM. The results show that the tides in the channel flood/ebb along the northern/southern bank near the bottom/surface layer and these asymmetries are due to the imbalanced Coriolis force, centrifugal force, sea-level gradient, and density gradient. Residual current velocity peaks (0.7 m/s) in the middle of the channel …

Ethical Decision-Making In Older Drivers During Critical Driving Situations: An Online Experiment, Amandeep Singh, Sarah Yahoodik, Yovela Murzello, Samuel Petkac, Yusuke Yamani, Siby Samuel

Psychology Faculty Publications

The present study examined the impact of aging on ethical decision-making in simulated critical driving scenarios. 204 participants from North America, grouped into two age groups (18–30 years and 65 years and above), were asked to decide whether their simulated automated vehicle should stay in or change from the current lane in scenarios mimicking the Trolley Problem. Each participant viewed a video clip rendered by the driving simulator at Old Dominion University and pressed the space-bar if they decided to intervene in the control of the simulated automated vehicle in an online experiment. Bayesian hierarchical models were used to analyze …

Biocrude Production From Lignin In Hydrothermal Medium: Effect Of Rapid Heating And Short Residence Time, Kyoko Hirayama

Civil & Environmental Engineering Theses & Dissertations

This study aims to address knowledge gaps in the production of valuable products from waste streams generated during lignocellulosic biofuel production. The primary objective is to develop a process that converts lignin, a byproduct of bioethanol refineries, into a sustainable biolubricant.

The first chapter examines recent advancements in synthesizing biolubricants and investigates their scalability. It explores innovative materials, catalysts, chemical modification approaches, and additives that have emerged in the field. A particular hurdle is the oxidative stability of biolubricants derived from plant oils, which are prone to autooxidation due to their C=C bonds. To overcome this, the study aims to …

Evaluating Direct Filtration As An Alternative To Conventional Carbon-Based Advanced Treatment For Indirect Potable Reuse, Savannah M. Flemmer

Civil & Environmental Engineering Theses & Dissertations

Hampton Roads Sanitation District (HRSD) is recharging purified wastewater into the Potomac Aquifer via the Sustainable Water Initiative for Tomorrow (SWIFT) project. Conventional SWIFT treatment applies coagulation, flocculation, sedimentation, ozonation, biofiltration, granular activated carbon (GAC) adsorption, and ultraviolet disinfection to secondary effluent to produce water that meets drinking water standards for managed aquifer recharge. HRSD is considering implementing direct filtration as an alternative to conventional treatment for two additional SWIFT facilities. Direct filtration presents an opportunity for significant cost savings by eliminating sedimentation, shortening flocculation detention time, and reducing coagulant usage. Without upstream removal of solids and organics, however, biofilters …

Optimal Domain-Partitioning Algorithm For Real-Life Transportation Networks And Finite Element Meshes, Jimesh Bhagatji, Sharanabasaweshwara Asundi, Eric Thompson, Duc T. Nguyen

Civil & Environmental Engineering Faculty Publications

For large-scale engineering problems, it has been generally accepted that domain-partitioning algorithms are highly desirable for general-purpose finite element analysis (FEA). This paper presents a heuristic numerical algorithm that can efficiently partition any transportation network (or any finite element mesh) into a specified number of subdomains (usually depending on the number of parallel processors available on a computer), which will result in “minimising the total number of system BOUNDARY nodes” (as a primary criterion) and achieve “balancing work loads” amongst the subdomains (as a secondary criterion). The proposed seven-step heuristic algorithm (with enhancement features) is based on engineering common sense …

A User-Centered Mapping Design For Geomorphological Hazard Thematic Map, Su-Min Shen, Yin-Hsuen Chen, Chia-Ming Lo, Mu-Ti Yu, Si-Chin Lin, Sendo Wang, Chih-Hsin Chang, Sheng-Chi Lin

University Administration Publications

Numerous studies have concentrated on developing user-centered designs for hazard zone maps but rarely for hazard-oriented geomorphological maps, named as Geomorphological Hazard Thematic Maps (GHTMs) in this study, which provide more detailed information about natural hazards. This study developed a user-centered mapping design for GHTMs for nonexperts in geomorphology. We invited civil engineers and high school educators to evaluate a sample GHTM's design in group and focus group panel interviews. The civil engineers preferred maps with more geomorphological features, whereas the educators preferred simple designs. Both groups indicated that the inclusion of essential facilities and road networks is essential. The …

A Simulation Way To Investigate The Reason For Congestion In Urban——A Case Study In Hohhot China, Junqing Wang, Hong Yang, Yuan Zhu, Qingwen Pu, Shunlai Cui

College of Engineering & Technology (Batten) Posters

In the case of high density traffic flow, traditional traffic data statistical analysis methods, which not only have certain errors and lead to inaccurate data, but also have many limitations such as labor consumption, can no longer meet the demand for traffic analysis. Drones for traffic data, based on an aerial bird's-eye view, no offset, and error-free complete statistics of urban road shooting section of all data, while greatly reducing cost consumption. A multi-dimensional simulation model is established for the UAV data to the Hohhot central urban area's road simulation platform. This project will test and explore multidimensional data in …

Investigating The Impacts Of Connected Vehicles On Driving Aggressiveness And Situational Awareness In Highway Crash Scenarios: A Driving Simulator Study, Abdalziz Alruwaili

College of Engineering & Technology (Batten) Posters

Psychological factors such as aggressiveness and situational awareness can impact driving performance. Connected vehicles (CV), equipped with advanced sensors and able to communicate safety messages to drivers, have the potential to influence driving performance by altering drivers’ aggressiveness and situational awareness. This paper aims to investigate the impacts of the CVs on driving aggressiveness and situational awareness in highway crash scenarios where a primary crash has already occurred, and a second crash may occur as a result. To achieve this goal, a driving simulator experiment was conducted, and questionnaires focused on driving aggressiveness and CV effectiveness were distributed. Structural equation …

Production Of Lithium Carbonate From Geothermal Brine By Selective Extraction Of Lithium Using A Novel Ion Sieve Method, Ujjwal Pokharel, Sandeep Kumar

College of Engineering & Technology (Batten) Posters

The project implements a novel approach to extract lithium from a geothermal brine with minimal water loss. Production of high-capacity lithium-ion (Li-ion) batteries for electric vehicles (EV) is believed to be the way to reduce dependence on fossil-fuel based vehicles. Currently, most of the lithium in the world comes from the mining of lithium or the evaporative/concentration of the brine. Mining is not environmentally friendly, and the evaporative process takes 12 months for the completion of the extraction process and results in a large amount of water loss which can lead to scarcity of water. The brines constitute 82% of …

Higher-Order Effects In Biaxial Flexure Of Gfrp I-Section Beams, Zia Razzaq, Faridoon Z. Razzaq

Civil & Environmental Engineering Faculty Publications

A theoretical study of Glass Fiber Reinforced Polymer (GFRP) beams subjected to biaxial bending moments is presented with a focus on the influence of higher-order effects on maximum normal stresses. It is shown that the biaxial bending type of loading causes a dramatic increase in the maximum normal stress for a GFRP beam when induced torsional effects are included. The study demonstrates that the traditional first-order theory can grossly underestimate the maximum normal stress in a GFRP beam. Based on the numerical results presented using a higher-order theory which also accounts for induced warping normal stresses, the maximum normal stress …

Rainwater Catchment System In Public Sector Housing, Araceli Peña, Muhammad Yanzar Sarin

2023 REYES Proceedings

Water is a universal right for all living beings on the planet, but today it has become a commercial good. It costs significantly to extract water from increasingly distant storage sources. For these reasons and many more the fight for water has become increasingly intense. Precisely, an alternative to avoid more dam construction is the implementation of public politic with actions focused on the integral solution of water, that is to say, that it be distributed fairly and equitably to all users, avoiding more concessions to great industries like as soft drinks and breweries, which are the main consumers and …

Elastoplastic Quasi-Static And Impact Load Response Of Steel Structure Sub-Assemblage With Cfrp Strips, Ali Al Aloosi, Zia Razzaq

Civil & Environmental Engineering Faculty Publications

Presented in this paper is the outcome of an experimental investigation of the elastoplastic quasi-static and impact load response of a steel sub-assemblage constructed using a pair of hollow square section members with or without Carbon Fiber Reinforced Polymer (CFRP) strips. The sub-assemblage consists of a long structural member welded to a short member, thus representing a typical combination of a column and a beam on the face of a multi-story steel building frame. The column is subjected to a lateral quasi-static or impact load. Tests are conducted on four separate steel sub-assemblages. The first two tests are conducted with …

Effects Of Salix Psammophila On Groundwater Recharge In A Semiarid Area Of North China, Lizhu Hou, Jingdong Gao, Bill X. Hu, Xixi Wang

Civil & Environmental Engineering Faculty Publications

Study region: The semiarid Mu Us Sandy Land (MUSL) was selected for this study. It is in the farming-pastoral ecotone of north China and functions as an eco-environmental barrier.

Study focus: Afforestation can mitigate desertification and soil erosion by improving hydrologic condition, which is particularly true for semiarid and arid regions. However, little is known about the quantitative response of hydrologic improvement to afforestation level that can be measured by leaf area index (LAI). The objective was to setup and use a physically-based model to quantitatively assess the dynamics of water fluxes from Salix psammophila afforestation in the MUSL.

New …

Numerical Study Of Sediment Suspension Affected By Rigid Cylinders Under Unidirectional And Combined Wave-Current Flows, Sha Lou, Xiaolan Chen, Shengyu Zhou, Gangfeng Ma, Shuguang Liu, Larisa Dorzhievna Radnaeva, Elena Nikitina, Irina Viktorovna Fedorova

Civil & Environmental Engineering Faculty Publications

Sediment transport modeling for flows with cylinders is very challenging owing to the complicated flow–cylinder–sediment interactions, especially under the combined wave-current flows. In this paper, an improved formulation for incipient sediment suspension considering the effect of cylinder density (i.e., solid volume fraction) is employed to simulate the bottom sediment flux in the flow with cylinders. The proposed model is calibrated and validated using laboratory measurements under unidirectional and combined wave-current flows in previous studies. It is proved that the effects of cylinders on sediment suspension can be accounted for through a modified critical Shields number, and the proposed model is …

Modeling The Production Of Microalgal Biomass In Large Water Resource Recovery Facilities And Its Processing Into Various Commodity Bioproducts, James Pierson, Gopi Raju Makkena, Sandeep Kumar, Vinod Kumar, Vivekanand Vivekanand, Hasan Husain, Muhammad Ayser, Venkatesh Balan

Civil & Environmental Engineering Faculty Publications

Algae are capable of sequestering nutrients such as nitrates and phosphates from wastewater in the presence of sunlight and carbon dioxide (CO₂) to build up their body mass and help combat climate change. In the current study, we carried out different case studies to estimate the volume of algal biomass that could be produced annually using the rotating algal biofilm (RAB) method in three large-scale water resource recovery facilities (WRRFs) in Texas: Fort Worth, Dallas, and Houston. We calculated the total amount of lipids, carbohydrates, and proteins that could be fractionated from the algal biomass while using the …

Analysis Of Traffic Conflicts With Right Turning Vehicles At Unsignalized Intersections In Suburban Areas, Abbas Sheykhfard, Farshidreza Haghighi, Sarah Bakhtiari, Sara Moridpour, Kun Xie, Grigorios Fountas

Civil & Environmental Engineering Faculty Publications

Right-turn collisions at intersections are one of the most dominant crash types in suburban areas, especially at unsignalized intersections. There is, however, a lack of comprehensive research on the speed patterns of vehicles during right-turn manoeuvres and their impact on crashes. To provide an in-depth investigation of the factors determining the safety of right-turn manoeuvres, driving behaviour data were collected through an instrumented vehicle study. Using this data, binary logistic regression models were developed to identify the factors affecting the probability of Vehicle-Vehicle (V-V) and Vehicle-Pedestrian (V-P) conflicts at six suburban intersections in Babol, Iran, during right-turn stage manoeuvres. In …

Are Ride-Hailing Services Safer Than Taxis? A Multivariate Spatial Approach With Accomodation Of Exposure Uncertainty, Guocong Zhai, Kun Xie, Hong Yang, Di Yang

Civil & Environmental Engineering Faculty Publications

Despite many research efforts on ride-hailing services and taxis, limited studies have compared the safety performance of the two modes. A major challenge is the need for reliable mode-specific exposure data to model their safety outcomes. Moreover, crash frequencies of the two modes by injury severities tend to be spatially and inherently correlated. To fully address these issues, this study proposes a novel multivariate conditional autoregressive model considering measurement errors in mode-specific exposures (MVCARME). More specially, a classical measurement error structure is used to accommodate the uncertainty of mode-specific exposures estimated, and a multivariate spatial specification is adopted to capture …

Reduced Metal Nanocatalysts For Selective Electrochemical Hydrogenation Of Biomass-Derived 5-(Hydroxymethyl)Furfural To 2, 5-Bis(Hydroxymethyl)Furan In Ambient Conditions, Baleeswaraiah Muchharla, Moumita Dikshit, Ujjwal Pokharel, Ravindranath Garimella, Adetayo Adedeji, Kapil Kumar, Wei Cao, Hani Elsayed-Ali, Kishor Kumar Sadasivuni, Naif Abdullah Al-Dhabi, Sandeep Kumar, Bijandra Kumar

Chemistry & Biochemistry Faculty Publications

Selective electrochemical hydrogenation (ECH) of biomass-derived unsaturated organic molecules has enormous potential for sustainable chemical production. However, an efficient catalyst is essential to perform an ECH reaction consisting of superior product selectivity and a higher conversion rate. Here, we examined the ECH performance of reduced metal nanostructures i.e., reduced Ag (rAg) and reduced copper (rCu) prepared via electrochemical or thermal oxidation and electrochemical reduction process, respectively. Surface morphological analysis suggests formation of nanocoral and entangled nanowire structure formation for rAg and rCu catalysts. rCu exhibits slight enhancement in ECH reaction performance in comparison to the pristine Cu. However, the rAg …

Understanding And Assessing Demographic (In)Equity Resulting From Extreme Heat Exposure Due To Lack Of Tree Canopies In Norfolk, Va Using Agent-Based Modeling, Virginia Zamponi, Kevin O'Brien, Erik Jensen, Brandon Feldhaus, Russell Moore, Christopher J. Lynch, Ross Gore

VMASC Publications

Prolonged exposure to extreme heat can result in illness and death. In urban areas of dense concentrations of pavement, buildings, and other surfaces that absorb and retain heat, extreme heat conditions can arise regularly and create harmful environmental exposures for residents daily during certain parts of the year. Tree canopies provide shade and help to cool the environment, making mature trees with large canopies a simple and effective way to reduce urban heat. We develop a demographically representative 1 (agent): 1 (person) agent-based model to understand the extent to which different demographics of residents in Norfolk, VA are equitably shaded …