Engineering Commons^™

Multi-Type Assessment Of Global Droughts And Teleconnections, Zahir Nikraftar, Abdorrahman Mostafaie, Mojtaba Sadegh, Javad Hatami Afkueieh, Biswajeet Pradhan

Civil Engineering Faculty Publications and Presentations

Several drought indices have been developed based on various processes (e.g., precipitation, soil moisture, vegetation health) that respond differently to modes of climate variability, shadowing their relatability to teleconnections, which in turn, limits drought forecasting. In this study, we advanced the multivariate analysis of droughts by using long-term Terrestrial Water Storage estimates, soil moisture and precipitation data along with normalized difference vegetation index. To this end, we employed a Vine copula approach using Archimedean and Elliptical copula families to generate two novel multivariate drought indices called Combined Standardized Drought Index (CSDI), based on agricultural, meteorological, hydrological and ecological univariate indices …

Double Averaging Analysis Applied To A Large Eddy Simulation Of Coupled Turbulent Overlying And Porewater Flow, Yan Ping Lian, Jonathan Dallman, Benjamin Sonin, Kevin R. Roche, Aaron I. Packman, Wing Kam Liu, Gregory J. Wagner

Civil Engineering Faculty Publications and Presentations

Freestream turbulence in rivers is a key contributor to the flux of dissolved nutrients, carbon, and other ecologically important solutes into porewater. To advance understanding of turbulent hyporheic exchange and porewater transport, we investigate flow over and through a rough bed of spheres using large eddy simulation (LES). We apply double averaging (combined space and time averaging) to the LES results to determine the mean velocity distribution, momentum balance, and drag forces. Our simulations show large-scale freestream structures interacting strongly with vortices generated at the surfaces of individual spheres to control turbulent momentum fluxes into the bed. The transition between …

Polar Ice As An Unconventional Water Resource: Opportunities And Challenges, Zahra Karimidastenaei, Björn Klöve, Mojtaba Sadegh, Ali Torabi Haghighi

Civil Engineering Faculty Publications and Presentations

Global water resources are under pressure due to increasing population and diminishing conventional water resources caused by global warming. Water scarcity is a daunting global problem which has prompted efforts to find unconventional resources as an appealing substitute for conventional water, particularly in arid and semiarid regions. Ice is one such unconventional water resource, which is available mainly in the Arctic and Antarctic. In this study, opportunities and challenges in iceberg utilization as a source of freshwater were investigated on the basis of a systematic literature review (SLR). A search in three databases (Scopus, Web of Science, and ProQuest) yielded …

Energy Harvesting For Self-Powered Sensors For Smart Transportation Infrastructures, Anil K. Agrawal, Mohsen Amjadian, Hani Nassif

Civil Engineering Faculty Publications and Presentations

In this research project, an Electromagnetic Energy Harvesting System (EMEHS) is developed for harvesting the kinetic energy of ambient and traffic-induced vibrations and carry out a detailed feasibility study and impacts of such system for application on transportation infrastructures. The proposed EMEHS utilizes the innovative concept of creating array of large number of small permanent magnets through certain optimization criteria to achieve strong and focused magnetic field in a particular orientation. When these magnets are attached to a flexible sub-system and placed close to the copper coil, ambient and traffic-induced vibration of the sub-system induces eddy current in copper the …

Development Of A Cyberinfrastructure For Assessment Of The Lower Rio Grande Valley North And Central Watersheds Characteristics, Linda Navarro, Ahmed Mahmoud, Andrew Ernest, Abdoul Oubeidillah, Jessica Johnstone, Ivan Rene Santos Chavez, Christopher Fuller

Civil Engineering Faculty Publications and Presentations

Lower Laguna Madre (LLM) is designated as an impaired waterway for high concentrations of bacteria and low dissolved oxygen. The main freshwater sources to the LLM flow from the North and Central waterways which are composed of three main waterways: Hidalgo/Willacy Main Drain (HWMD), Raymondville Drain (RVD), and International Boundary & Water Commission North Floodway (IBWCNF) that are not fully characterized. The objective of this study is to perform a watershed characterization to determine the potential pollution sources of each watershed. The watershed characterization was achieved by developing a cyberinfrastructure, and it collects a wide inventory of data to identify …

Effects Of Air-Injection Pressure On Airflow Pattern Of Air Sparging, Arvin Farid, Atena Najafi, Jim Browning, Elisa Barney Smith

Civil Engineering Faculty Publications and Presentations

Air sparging is a remediation technology for treating soil/groundwater contaminated with volatile organic compounds (VOCs). VOC removal during air sparging is rendered less effective because of the random formation of air channels, creating preferential paths for airflow, thus limiting remediation to these channels, referred to as a zone of influence (ZOI). Pulsation is a popular method used to improve the effectiveness of air sparging through cyclic operation, with the hope that air channels would form elsewhere. Pulsation makes air sparging more time-consuming. This paper studies the effects of one cycle of pulsation and air pressure on the airflow pattern and …

Avoiding Water Bankruptcy In The Drought-Troubled Southwest: What The Us And Iran Can Learn From Each Other, Mojtaba Sadegh, Ali Mirchi, Amir Aghakouchak, Kaveh Madani

Civil Engineering Faculty Publications and Presentations

The 2021 water year ends on Sept. 30, and it was another hot, dry year in the western U.S., with almost the entire region in drought. Reservoirs vital for farms, communities and hydropower have fallen to dangerous lows.

The biggest blow came in August, when the U.S. government issued its first ever water shortage declaration for the Colorado River, triggering water use restrictions.

In response, farmers and cities across the Southwest are now finding new, often unsustainable ways to meet their future water needs. Las Vegas opened a lower-elevation tunnel to Lake Mead, a Colorado River reservoir where water levels …

Enhanced Flexible Pavement Performance Using Treated Compared To Untreated Aggregate Bases: A Comparative Case Study In The Southern United States, Mena L. Souliman, Hemant Gc, Zabi Mohammed

Civil Engineering Faculty Publications and Presentations

One of the important aspects of highway design is aggregates. Aggregates strength and consistency has an effect on pavement structure's overall performance. The consistency of the base material near the site of the construction doesn't always match the requirements of pavement construction and carrying quality aggregate raises the cost of construction. Stabilizing agents such as asphalt cement, lime, fly ash were used to improve the strength of these materials in order to make greater use of locally available materials. Layer materials present in the pavements and the structure of them influence pavement performance. The compressive strain and the tensile strain …

Catchment Processes Can Amplify The Effect Of Increasing Rainfall Variability, Marc F. Müller, Kevin R. Roche, David N. Dralle

Civil Engineering Faculty Publications and Presentations

By filtering the incoming climate signal when producing streamflow, river basins can attenuate—or amplify—projected increases in rainfall variability. A common perception is that river systems dampen rainfall variability by averaging spatial and temporal variations in their watersheds. However, by analyzing 671 watersheds throughout the United States, we find that many catchments actually amplify the coefficient of variation of rainfall, and that these catchments also likely amplify changes in rainfall variability. Based on catchment-scale water balance principles, we relate that faculty to the interplay between two fundamental hydrological processes: water uptake by vegetation and the storage and subsequent release of water …

Wip: Halting Attrition In Civil Engineering Programs Through Lower-Division Engagement Course Implementation, Briceland Mclaughlin, Nick Hudyma, Robert Hamilton, Bhaskar Chittoori, Mojtaba Sadegh, Sondra M. Miller

Civil Engineering Faculty Publications and Presentations

This work in progress paper will describe how a department of civil engineering has built 1-credit engagement courses into the first two years of a new curriculum design to increase retention rates, create a sense of belonging, showcase civil engineering principles and practicality to non-majors, and begin engaging alumni and local civil engineering professionals.

Retention is a core issue for academic departments in the STEM fields. In civil engineering, we have seen a large number of students depart the major each fall and spring semester for various, preventable reasons. This is true for traditional, non-traditional, and transfer students alike. Students …

Assessing The Impact Of The Lead/Lag Times On The Project Duration Estimates In Highway Construction, Mohamed Abdel-Raheem, Jennifer Reyes, Xiaohui Wang, Grecia Silva Sanchez

Civil Engineering Faculty Publications and Presentations

The literature mentions multiple factors that can affect the accuracy of estimating the project duration in highway construction, such as weather, location, and soil conditions. However, there are other factors that have not been explored, yet they can have significant impact on the accuracy of the project time estimate. Recently, TxDOT raised a concern regarding the importance of the proper estimating of the lead/lag times in project schedules. These lead/lag times are often determined based on the engineer’s experience. However, inaccurate estimates of the lead/lag time can result in unrealistic project durations. In order to investigate this claim, the study …

Modeling Triaxial Testing With Flexible Membrane To Investigate Effects Of Particle Size On Strength And Strain Properties Of Cohesionless Soil, Thang Pham, Md. Wasif Zaman, Thuy Vu

Civil Engineering Faculty Publications and Presentations

A 3D DEM model using Particle Flow Code (PFC3D) software was developed utilizing a bonded-ball flexible membrane approach to study cohesionless soil as a discontinuous discrete material. This approach is not yet widely used because of its complexity and high computational cost, but it allowed the authors to observe the stress-strain curves of triaxial specimens, to single out effects of individual factors on the strength and strain properties, and to observe the formation of the shear band and failure surface. The 3D model was calibrated and verified with experimental data, and a sensitivity analysis was carried out for the microparameters. …

A Practical Framework To Assess The Sustainability And Resiliency Of Civil Infrastructure, Thomas Adam Robbins, Bhaskar C. S. Chittoori

Civil Engineering Faculty Publications and Presentations

Research within civil engineering is focusing on newer ideas and philosophies such as sustainability and resiliency (S&R). This is evident in the development of frameworks for assessing the sustainability or the resiliency of civil infrastructures. Several frameworks have been developed by researchers to quantify the S&R of civil infrastructures. It is evident that the S&R are not mutually exclusive, and it is important to assess these aspects at the same time and that frameworks are able to accommodate simultaneous assessments. While there are other frameworks that follow a unified approach to S&R assessments, they do not account for the risk …

Anthropogenic Drought: Definition, Challenges, And Opportunities, Mojtaba Sadegh

Civil Engineering Faculty Publications and Presentations

Traditional, mainstream definitions of drought describe it as deficit in water-related variables or water-dependent activities (e.g., precipitation, soil moisture, surface and groundwater storage, and irrigation) due to natural variabilities that are out of the control of local decision-makers. Here, we argue that within coupled human-water systems, drought must be defined and understood as a process as opposed to a product to help better frame and describe the complex and interrelated dynamics of both natural and human-induced changes that define anthropogenic drought as a compound multidimensional and multiscale phenomenon, governed by the combination of natural water variability, climate change, human decisions …

Warming Enabled Upslope Advance In Western Us Forest Fires, Mohammad Reza Alizadeh, John T. Abatzoglou, Charles H. Luce, Jan F. Adamowski, Arvin Farid, Mojtaba Sadegh

Civil Engineering Faculty Publications and Presentations

Increases in burned area and large fire occurrence are widely documented over the western United States over the past half century. Here, we focus on the elevational distribution of forest fires in mountainous ecoregions of the western United States and show the largest increase rates in burned area above 2,500 m during 1984 to 2017. Furthermore, we show that high-elevation fires advanced upslope with a median cumulative change of 252 m (−107 to 656 m; 95% CI) in 34 y across studied ecoregions. We also document a strong interannual relationship between high-elevation fires and warm season vapor pressure deficit (VPD). …

Western Fires Are Burning Higher In The Mountains At Unprecedented Rates: It’S A Clear Sign Of Climate Change, Mojtaba Sadegh, John Abatzoglou, Mohammad Reza Alizadeh

Civil Engineering Faculty Publications and Presentations

The Western U.S. appears headed for another dangerous fire season, and a new study shows that even high mountain areas once considered too wet to burn are at increasing risk as the climate warms.

Nearly two-thirds of the U.S. West is in severe to exceptional drought right now, including large parts of the Rocky Mountains, Cascades and Sierra Nevada. The situation is so severe that the Colorado River basin is on the verge of its first official water shortage declaration, and forecasts suggest another hot, dry summer is on the way.

Warm and dry conditions like these are a recipe …

Another Dangerous Fire Season Is Looming In The Western U.S., And The Drought-Stricken Region Is Headed For A Water Crisis, Mojtaba Sadegh, Amir Aghakouchak, John Abatzoglou

Civil Engineering Faculty Publications and Presentations

Just about every indicator of drought is flashing red across the western U.S. after a dry winter and warm early spring. The snowpack is at less than half of normal in much of the region. Reservoirs are being drawn down, river levels are dropping and soils are drying out.

It’s only May, and states are already considering water use restrictions to make the supply last longer. California’s governor declared a drought emergency in 41 of 58 counties. In Utah, irrigation water providers are increasing fines for overuse. Some Idaho ranchers are talking about selling off livestock because rivers and reservoirs …

Environmental Geotechnics: Challenges And Opportunities In The Post-Covid-19 World, Arvin Farid

Civil Engineering Faculty Publications and Presentations

The outbreak of the coronavirus disease 2019 (Covid-19) pandemic not only has created a health crisis across the world but is also expected to impact negatively the global economy and societies at a scale that is maybe larger than that of the 2008 financial crisis. Simultaneously, it has inevitably exerted many negative consequences on the geoenvironment on which human beings depend. The current paper articulates the role of environmental geotechnics in elucidating and mitigating the effects of the current pandemic. It is the belief of all authors that the Covid-19 pandemic presents not only significant challenges but also opportunities for …

Compound Extremes Drive The Western Oregon Wildfires Of September 2020, John T. Abatzoglou, David E. Rupp, Larry W. O'Neill, Mojtaba Sadegh

Civil Engineering Faculty Publications and Presentations

Several very large high‐impact fires burned nearly 4,000 km² of mesic forests in western Oregon during September 7–9, 2020. While infrequent, very large high‐severity fires have occurred historically in western Oregon, the extreme nature of this event warrants analyses of climate and meteorological drivers. A strong blocking pattern led to an intrusion of dry air and strong downslope east winds in the Oregon Cascades following a warm‐dry 60‐day period that promoted widespread fuel flammability. Viewed independently, both the downslope east winds and fuel dryness were extreme, but not unprecedented. However, the concurrence of these drivers resulted in compound extremes …

A Magneto-Mechanical Piezoelectric Energy Harvester Designed To Scavenge Ac Magnetic Field From Thermal Power Plant With Power-Line Cables, Quan Wang, Kyung-Bum Kim, Sang-Bum Woo, Yooseob Song, Tae-Hyun Sang

Civil Engineering Faculty Publications and Presentations

Piezoelectric energy harvesters have attracted much attention because they are crucial in portable industrial applications. Here, we report on a high-power device based on a magneto-mechanical piezoelectric energy harvester to scavenge the AC magnetic field from a power-line cable for industrial applications. The electrical output performance of the harvester (×4 layers) reached an output voltage of 60.8 V_max, an output power of 215 mW_max (98 mW_rms), and a power density of 94.5 mW_max/cm³ (43.5 mW_rms/cm³) at an impedance matching of 5 kΩ under a magnetic field of 80 …

A Flexible Piezoelectric Energy Harvester-Based Single-Layer Ws2 Nanometer 2d Material For Self-Powered Sensors, Quan Wang, Kyung-Bum Kim, Sang Bum Woo, Yooseob Song, Tae Hyun Sung

Civil Engineering Faculty Publications and Presentations

A piezoelectric sensor is a typical self-powered sensor. With the advantages of a high sensitivity, high frequency band, high signal-to-noise ratio, simple structure, light weight, and reliable operation, it has gradually been applied to the field of smart wearable devices. Here, we first report a flexible piezoelectric sensor (FPS) based on tungsten disulfide (WS₂) monolayers that generate electricity when subjected to human movement. The generator maximum voltage was 2.26 V, and the produced energy was 55.45 μJ of the electrical charge on the capacitor (capacity: 220 μF) when applying periodic pressing by 13 kg. The generator demonstrated here …

Pooling Data Improves Multimodel Idf Estimates Over Median-Based Idf Estimates: Analysis Over The Susquehanna And Florida, Abhishekh Kumar Srivastava, Richard Grotjahn, Paul Aaron Ullrich, Mojtaba Sadegh

Civil Engineering Faculty Publications and Presentations

Traditional multimodel methods for estimating future changes in precipitation intensity, duration, and frequency (IDF) curves rely on mean or median of models’ IDF estimates. Such multimodel estimates are impaired by large estimation uncertainty, shadowing their efficacy in planning efforts. Here, assuming that each climate model is one representation of the underlying data generating process, i.e., the Earth system, we propose a novel extension of current methods through pooling model data: (i) evaluate performance of climate models in simulating the spatial and temporal variability of the observed annual maximum precipitation (AMP), (ii) bias-correct and pool historical and future AMP data of …

Feasibility Of Using A High-Power Electromagnetic Energy Harvester To Power Structural Health Monitoring Sensors And Systems In Transportation Infrastructures, Mohsen Amjadian, Anil K. Agrawal, Hani Nassif

Civil Engineering Faculty Publications and Presentations

This paper investigates the feasibility of an electromagnetism energy harvester (EMEH) for scavenging electric energy from transportation infrastructures and powering of conventional sensors used for their structural health monitoring. The proposed EMEH consists of two stationary layers of three cuboidal permanent magnets (PMs), a rectangular thick aircore copper coil (COIL) attached to the free end of a flexible cantilever beam whose fixed end is firmly attached to the highway bridge oscillating in the vertical motion due to passing traffic. The proposed EMEH utilizes the concept of creating an alternating array of permanent magnets to achieve strong and focused magnetic field …

Machine Learning Methods To Map Stabilizer Effectiveness Based On Common Soil Properties, Amit Gajurel, Bhaskar Chittoori, Partha Sarathi Mukherjee, Mojtaba Sadegh

Civil Engineering Faculty Publications and Presentations

Most chemical stabilization guidelines for subgrade/base use unconfined compressive strength (UCS) of treated soils as the primary acceptance criteria for selecting optimum stabilizer in laboratory testing. Establishing optimal additive content to augment UCS involves a resource-intensive trial-and-error procedure. Also, samples collected from discrete locations for laboratory trials may not be representative of the overall site. This study aims to minimize the number of laboratory trials and help strategize sampling locations by developing spatial maps of UCS at different treatment levels for lime and cement. These spatial maps were developed using machine-learning techniques, and using a database compiled from various reported …

Studying The Relationship Between Indigenous Microbial Communities, Urease Activity, And Calcite Precipitation In Artificial Mixes Of Clay And Sand, Somaye Asghari, Bhaskar C. S. Chittoori, Malcolm Burbank, Nick Hudyma

Civil Engineering Faculty Publications and Presentations

Microbial-induced calcium carbonate precipitation (MICP) is evolving as a new method of improving the mechanical properties of soil. This environmentally friendly technique is a bio-geo-chemical process where microbes play a key role in increasing soil strength through precipitating calcium carbonate. Past studies at Boise State University have indicated that MICP via bio-stimulation could be a viable alternative for expansive clayey soil treatments. However, these studies raised a new question about the relationship between soil composition, urease activity, and calcite precipitation. To answer this question, batch studies were conducted using autoclaved-sterilized sand mixed with different percentages of non-sterile natural clay and …

Northeast Florida: A New Hotspot For Hurricane Damage?, William R. Dally, Raphael Crowley, Nick Hudyma

Civil Engineering Faculty Publications and Presentations

Until recent Hurricanes Matthew and Irma struck northeast Florida, Hurricane Dora had been the first and only hurricane-strength storm in recorded history to strike the region. The area had gradually become regarded as a safe spot as storms at that latitude generally curved away from Jacksonville and northeast Florida, and turned north to make landfall in the Carolinas. Unknown to most, Vilano Beach had been experiencing steady yet chronic beach erosion and was already in a highly vulnerable state in many places when the recent storms struck. The cause of the ongoing background erosion continues to be a source of …

Kinetics And Thermodynamics Of Thermal Inactivation For Recombinant Escherichia Coli Cellulases, Cel12b, Cel8c, And Polygalacturonase, Peh28; Biocatalysts For Biofuel Precursor Production, Eman Ibrahim, Ahmed Mahmoud, Kim D. Jones, Keith E. Taylor, Ebtesam N. Hosseney, Patrick L. Mills, Jean M. Escudero

Civil Engineering Faculty Publications and Presentations

Lignocellulosic biomass conversion using cellulases/polygalacturonases is a process that can be progressively influenced by several determinants involved in cellulose microfibril degradation. The current paper focuses on the kinetics and thermodynamics of thermal inactivation of recombinant E. coli cellulases, cel12B, cel8C, and a polygalacturonase, peh 28, derived from Pectobacterium carotovorum sub sp. carotovorum. Several consensus motifs conferring the enzymes’ thermal stability in both cel12B and peh28 model structures have been detailed earlier, which were confirmed for the three enzymes through the current study of their thermal inactivation profiles over the 20-80 °C range using the respective activities on carboxymethylcellulose and …