Engineering Commons^™

Soil Moisture Dependent Runoff In A Dryland Region: An Investigation Of The Role Of Antecedent Conditions, Monitoring, And Modeling Strategies, Gerhard Schoener

Civil Engineering ETDs

Approximately 30% of the Earth’s land surface is characterized as arid or semiarid, including much of the western United States. Accurate runoff predictions are important for informed watershed management, particularly in rapidly urbanizing areas. Infiltration excess overland flow is the dominant mechanism for runoff generation in many dryland basins, and event-based infiltration or loss models are commonly used to estimate runoff. However, predictions are associated with considerable uncertainty due to the role antecedent soil moisture, an initial condition that must be set by the modeler. The objectives of my research were to (1) evaluate the impact of antecedent soil moisture …

The Effect Of Ph On Organic Carbon Uptake And Biological Phosphorus Removal By Tetrasphaera Polyphosphate Accumulating Organisms, Derek Belka

Civil Engineering ETDs

Tetrasphaera polyphosphate accumulating organisms (PAOs) have been found in greater abundance and may remove more P in full-scale enhanced biological phosphorus removal (EBPR) water resource recovery facilities (WRRF) worldwide than the more extensively studied Accumulibacter PAO. Understanding the effect that environmental conditions, such as pH, have on Tetrasphaera metabolisms is critical to understanding EBPR WRRF process upsets, achieving consistent low effluent P concentrations, and formulating optimization strategies. The objective of this study was to determine pH effects over the range from 5.5 to 8.5 on anaerobic amino acid uptake, P release, and cation release in a Tetrasphaera-enriched culture from …

An Investigation Of Phosphorus Removal By Purple Bacteria In Dairy Wastewater Lagoons, Lauren M. Gomez, Andrew J. Schuler, Jose M. Cerrto, David T. Hanson

Civil Engineering ETDs

The objective of this study was to determine whether the polyphosphate metabolism in purple photosynthetic bacteria (PPB) is similar to that of wastewater polyphosphate-accumulating organisms (PAOs) such as Accumulibacter. Dairy lagoon samples were studied in continuous and batch laboratory tests to evaluate whether cyclic light and dark conditions for PPB are similar to aerobic and anaerobic conditions for PAOs in domestic wastewater treatment systems. 16s rRNA gene amplicon sequencing indicated the presence of the purple sulfur bacterium Thiolamprovum (53.92%) in one lagoon source, and Thiodictyon (3.50%) in a second lagoon. Phosphorus contents were at least 0.7% higher than the …

Cognizant Composites: Seamless Integration Of Circuitry And Sensors Into Structural Composites, Reuben Fresquez

Computer Science ETDs

This thesis describes a set of novel techniques for embedding sensors, circuitry, and electronics into structural composites. I leverage recent developments in human computer interaction to create sensors and circuitry that are seamlessly incorporated into structural composites. I fabricate bend and compression sensors, along with circuitry, from textiles, which enables me to add electronic capabilities without impacting the composite’s structural integrity. I describe the construction of these “cognizant composites” and demonstrate their functionality. I also explore techniques for embedding standard electronic components, including microcontrollers, into structural composites. Potential applications of this technology include buildings that can warn occupants if load-bearing …

Measurement Of Resilience Performance For Infrastructure Construction Project Delivery, Fei Han

Civil Engineering ETDs

In the past decade, infrastructure resilience in the U.S. has become critical due to increasing disruptions to the built environment and the resultant consequences on economic, social, and environmental goals. This attention to resilience research is drawn to investigating the ability of existing structures and facilities to resist and recover from natural and human-caused hazards. From a broader view, resilience also applies to processes, such as infrastructure project delivery processes. During these processes, a project often suffers inevitable threats and disruptions, which can significantly delay or derail the project if the process is not resilient.

This research aimed to conceptualize …

3d Printed Concrete & Polymer Concrete For Infrastructure Applications, Daniel Heras Murcia

Civil Engineering ETDs

Additive manufacturing technology has been established as one of the fastest-growing building technologies worldwide. Three-dimensional concrete printing (3DCP) has developed an increasing interest in the last decade due to its prospects as a transformative technology for industries such as the concrete precast. Besides the improvements in automation technologies in construction, traditional construction has faced considerable challenges: high accident rates, labor dependency, significant potential for automation, and high costs associated with the use of traditional formwork. In this context, three-dimensional concrete, also referred to as physical prototyping, is a novel construction technique in which the concrete is extruded layer-to-layer. 3DCP is …

Towards Creating Smart Cities In Nepal, Ambika P. Adhikari, Keshav Bhattarai

Himalayan Research Papers Archive

Many urban centers in the world are seeking to become smart cities. Nepali city leaders are also aspiring to make their cities smart. A smart city basically has clever improvements made in three sectors of its operations: technological, human, and institutional. Globally, many cities have recently made impressive enhancements in at least one or more of these areas. Nepal’s National Planning Commission (NPC) in 2016 had released a concept paper on smart cities for Nepal, defining smart cities as sustainable, information and technology-based, with high quality services and replicable (NPC 2016). As most Nepali cities still operate with limited infrastructure, …

Pseudo-Ductile 3d Printed Fiber Reinforced Polymer Composites, Shreya Vemuganti

Civil Engineering ETDs

The use of fiber-reinforced polymer (FRP) composite materials is continuously growing in civil infrastructure owing to its high strength, low weight, and manufacturing flexibility. However, FRP is characterized by sudden failure and lacks ductility. When used in construction, gradual failure of FRP components is desired to avoid catastrophic structural collapse. Due to its mechanical orthotropy, the behavior of FRP relies significantly on fiber orientation and stacking sequence. In this research proposal, investigations showed that novel multi-angled glass fiber reinforced polymer (GFRP) composites with varying fiber orientation angles, stacking sequence, and thickness of laminas can be designed and fabricated using 3D …

Effect Of Degradation Environment And Relative Humidity On Fracture Of Cement, Patience L. Raby

Civil Engineering ETDs

Concrete serves in all forms of humidity conditions (arid climates to submerged conditions) and can be exposed to many different forms of degradation. To better understand the effects that degradation and humidity have on concrete as a composite, the effects on cement alone must first be better understood. This research aims to examine the significance of degradation (calcium leaching or sulfate attack), in addition to relative humidity, on cracking and fracture behavior of cement. Flexure and fracture tests were performed on cement exposed to varying periods of each form of degradation as well as various humidities. Samples were exposed to …

Evaluation Of Fine And Coarse Graded Asphalt Mixes, Md Mehedi Hasan

Civil Engineering ETDs

During the last 20 years, asphalt pavements were built in New Mexico (NM) and around the country using mostly Superpave coarse graded mixes as opposed to fine graded mixes. This is because coarse mix uses larger aggregates with good interlocking and requires less asphalt binder than a fine mix, while both mixes fulfill the Superpave criteria. Recently, it was observed nationally that the Superpave coarse graded mixes have good field rutting performances but poor cracking performances. It is hypothesized that fine graded mix can help improve pavement cracking performances. The idea is, the fine mixes would have less air voids …

Monitoring Damage Occurrence, Post-Peak Crack Propagation And Air Permeability In Concrete Using The Brazilian Indirect Tension Test, Angel M. Padilla

Civil Engineering ETDs

This research aims to investigate the relationship between stress, damage, crack propagation, and permeability evolution in concrete. A novel experimental test method is presented that enables monitoring post-peak cracking behavior of concrete using the Brazilian tension test by slowing crack propagation while concurrently measuring permeability and monitoring damage propagation using acoustic emission techniques. The modified Brazilian test method utilizes spring supports in parallel to the test specimen to off-load the test specimen incrementally to slow down the post-peak crack propagation. A vacuum flow system is attached to the rear side of the concrete during loading to measure apparent air permeability …

Dynamic Hvac Energy Management Using Commercial Building Occupancy Metrics & Neural Networks, Krishna Chaitanya Jagadeesh Simma

Civil Engineering ETDs

With the rise of technology use in buildings, it is now possible to collect data that can be used to improve building energy consumption. One factor that has significant impact on building energy consumption is occupancy. Recent studies have shown promising results in obtaining occupancy information from existing infrastructure such as WiFi router networks. However, these existing frameworks require additional investments through software upgrades, added infrastructure, computational resources, and may raise occupant privacy concerns. Additionally, with occupant thermal comfort statistics being lower than ASHAREA specified standards, a novel approach for indoor climate control is needed. To address the limitations in …

Exploring The Relationship Between Vehicular Emissions And Traffic Operations At Isolated Signalized Intersections, Abiral Dulal

Civil Engineering ETDs

Most roadway transportation modes still run on petroleum fuels. Petroleum fuels are major sources of air pollutants, including hydrocarbons (HC), carbon monoxide (CO), carbon dioxide (CO₂), nitrogen oxides (NO and NO₂, which are together called NOx), Volatile Organic Compounds (VOCs), and particulate matter of size(PM10) and2 and BC). Mitigating pollution is a serious issue, and therefore, it is the engineers' and planners' responsibility to study and reduce emissions as much as possible. Emission levels are generally high at street intersections, which are places where vehicles tend to accelerate, decelerate, and idle. Emission levels at intersections are …

A Practical Methodology To Detect, Quantify And Characterize Experimental Uncertainties In The Dynamic Testing Of Structures, James L. Woodall

Civil Engineering ETDs

This thesis investigates the uncertainty in the experimental context of structural dynamics. This thesis proposes a method to estimate both the effect of boundary conditions, as well as two different methods to detect the location of sensors on a specimen. Firstly, this thesis proposes a technique to predict the dynamic behavior of any point along a cantilever beam with an uncertain transverse elastic restraint. Secondly, this thesis investigates the estimation of the location of a sensor given the output data of a physical experiment with two different methods. Small errors in the sensor location may go unnoticed in the frequency …

Nighttime Pedestrian Fatalities Across The United States And Their Relationship With Built Environment And Socioeconomic Factors: Gis-Based Analysis And Assessment, Amir Tarighi

Civil Engineering ETDs

Fatalities from motor vehicle collisions are the fifth leading cause of years of lost life worldwide (Foreman et al., 2018) and are a great concern for all communities. This road safety crisis has been especially pronounced for U.S. pedestrians over the last decade. National records show that between 2010 and 2019, pedestrian fatalities in the U.S. increased 44% while all other traffic fatalities increased only 4% and more than fifty percent of pedestrian fatalities occurred in dark lighting conditions. This study analyzed the relationship between pedestrian fatality locations at night and five demographic characteristics of those locations including population density, …

Development Of A Low-Cost Efficient Wireless Intelligent Sensor For Strain (Lewis-S) And Applications In Measuring Nonlinear Dynamics, Eric Robbins

Civil Engineering ETDs

Nonlinearities exist in all real-life systems and can be caused by behaviors such as large deformations, yielding, contact, etc. which can result in phenomena not found in linear testing. Considering nonlinear behavior in dynamic analyses can be beneficial to increase model predictability and can accurately characterize system responses. Generally, accelerometers are commonly used in linear and nonlinear vibration testing to obtain the acceleration response of a system. However, some systems may render the use of accelerometers problematic, or accelerometers may introduce limitations to measurement capabilities such that it can be beneficial to obtain experimental data using different sensors. In the …

Strength, Fracture Evolution, And Permeability Changes From Confined Brazilian Tests On Sandstone, Tyler Louis Hagengruber

Civil Engineering ETDs

This research reports on confined Brazilian strength tests and concurrent permeability testing on sandstone. The majority of the tests measured permeability during loading to failure in the confined extension region. Additional testing includes unloading and reloading cycles to detect the development of microcracks and the dependence of permeability on mixed stress conditions. Further testing characterizes fracture networks by observing porosity changes due to microcrack interactions before peak load. All tests involve 5 cm diameter disk-shaped, jacketed samples that are subjected to confining stresses while they are diametrically loaded. Specially designed end caps allow for gas flow measurements. The test configuration …

Neural Network Based Occupancy Prediction Using Patterns Detected In Wifi Occupancy, Krishna Chaitanya Jagadeesh Simma, Thomas P. Caudell, Susan M. Bogus

Civil Engineering Faculty Publications

The role of occupants in building energy management is well established. Occupant information from commercial buildings can function as a metric for the heating, ventilation, and air conditioning (HVAC) loads. Predicting these loads ahead in time could aid in setting up HVAC protocols to minimize wasteful energy demand and improve occupant comfort. To this extent, several frameworks were proposed that use occupancy data collected from commercial office buildings and graduate student offices to predict occupancy. However, the occupancy data collected in these frameworks are controlled and have limited complexity compared to larger commercial spaces such as airports, libraries, lecture halls, …