Digital Commons Network^™

Physical And Stochiometric Controls On Nutrient Uptake And Ecosystem Respiration In Contrasting Sites, Jancoba K. Dorley

Civil Engineering ETDs

Meteorological, hydrological, and biogeochemical processes naturally control stream ecosystems. These processes define the frequency and distribution of precipitation and the supply and demand of solutes and particles to support aquatic food chains through space and time. Studies have also found that stream ecosystems are also controlled by anthropogenic activities, which occur on a much shorter timescale. These anthropogenic activities affect stream ecosystems' structure and function from local to planetary changes to the environment. It is essential for scientists and engineers to understand the relationships between naturally occurring processes and those created by human activities for a better interpretation of stream …

Early-Age Strength And Failure Characteristics Of 3d Printable Polymer Concrete: Numerical Modelling And Experimental Testing, Mohammad Amin Dehghani Najvani

Civil Engineering ETDs

The time-dependent rheological and early-age strength parameters of Polymer concrete (PC) were investigated. PC flow decreased, and the static yield stress and thixotropy increased as the specimen aged, while the dynamic yield stress remained unchanged. The study found that the Herschel-Bulkley model can accurately describe the PC’s rheological behavior over time. The change in cohesion strength and internal friction angle over time was observed using uniaxial unconfined compression and direct shear tests of fresh PC. A time-dependent MohrCoulomb failure criterion was established. Temperature analysis was used to determine the gel time and explain the evolution of the time-dependent early-age strength …

Modeling Of Asphalt Concrete For Cross-Anisotropic Visco-Elasticity And Heterogeneity, Zafrul Hakim Khan

Civil Engineering ETDs

Asphalt Concrete (AC) is a cross-anisotropic viscoelastic material. This study has developed a methodology to backcalculate the cross-anisotropic properties of the AC layer from the Falling Weight Deflectometer (FWD) sensor and pavement response data from embedded sensors inside a pavement section. This study has also developed a two-way coupled Multiscale Finite Element Model (MsFEM) with Phase Field Fracture (PFF) to study the microstructural heterogeneity and damage of the AC layer based on the actual field loadings. A Finite Difference Time Domain (FDTD) and Machine learning-based backcalculation algorithm were developed to determine the layer thickness and dielectric constant from air-coupled Ground …

Post-Wildfire Export Regimes Of Solutes Along The Gallinas-Pecos River-Santa Rosa Fluvial Network, Asmita Kaphle

Civil Engineering ETDs

Wildfires significantly contribute to water pollution when ash and sediments, including nutrients and metals, are released into fluvial systems, impacting aquatic ecosystems and surrounding communities. This study focuses on the impacts of the Hermits Peak-Calf Canyon Fire on the Gallinas and Pecos watersheds. It employs five monitoring stations along a 190km fluvial network to assess solute export regimes post-fire, where grab samples were collected for nutrient and metal analyses for a period of more than a year. The metrics used for characterizing mobilization, chemostatic, or dilution patterns indicated mobilization for most solutes at all sites upstream of Santa Rosa Lake. …

Performance Evaluation Of E-Ticketing Technologies On Asphalt Paving Projects In New Mexico, Gena C. Robertson

Civil Engineering ETDs

The collection and processing of paper tickets for construction material delivery is an inefficient and antiquated practice that exposes inspectors on highway paving projects to substantial safety risks. An alternative to the collection of paper tickets is e-Ticketing, which uses web-based systems to deliver similar information. This research documented a current paper ticketing process and compared it to an e-Ticketing process that was implemented on several pilot projects. Data were obtained using stakeholder meetings, personnel interviews, and surveys. When compared to a paper ticketing system, e-Ticketing was shown to have fewer opportunities for error, require fewer decision points, and provide …

Role Of Endophytic Fungi On Arsenic Uptake In Solution: Insights For Bioremediation, Taylor Lillian Busch

Civil Engineering ETDs

Hazardous metals mobilized from natural deposits and mining legacy are environmental and human health concerns. The waters of our partner Native American communities affected by uranium and gold mining legacy exceed the EPA MCL of 10 µg/L arsenic (As). Bioremediation is a novel technology that uses native resources to remediate metals in the soil and groundwater. Plant-fungi symbiosis for bioremediation is widely studied, but the role of endophytic fungi in metal uptake is not well understood. The objectives of this study are to 1) determine As uptake by symbiotic endophyte Cadophora sp. and little bluestem grass (Schizachyrium scoparium) …

Hydraulic Habitat Suitability For The Rio Grande Silvery Minnow At The Los Chavez Irrigation Outfall, New Mexico, Haley A. Ormsbee

Civil Engineering ETDs

It is essential to manage the Middle Rio Grande for aquatic species to preserve the native biodiversity of the river. During periods of low flow, endangered species such as the Rio Grande Silvery Minnow (RGSM) may get trapped in a drying reach without the ability to escape from isolated pools. Very little is known about how areas of refuge, such as irrigational outfall channels, buffer RGSM from stream flow intermittency. Hence, there is a crucial need to quantify available habitat for RGSM in areas of refuge. This study aims to make connections between flow regimes and physical-habitat conditions to help …

Identifying The Required Ecological Flow For Sediment Movement In The Río Chama: Field Data Informed Visual Spatial Model, Cristian Kremer

Civil Engineering ETDs

The continuous alteration of flow regimes in rivers has led to negative impacts on habitats and biotic communities, causing irreversible effects on river biodiversity. Implementing e-flows in management strategies can repair historical mismanagement, prevent further degradation, and restore ecosystem services. In the case of the Rio Chama, damming has altered its hydrological regime, affecting sediment transport. Experts recommend specific e-flow conditions for the Rio Chama to improve ecological conditions, in particular a bankfull discharge of 70 m³s^-1 every 2 years for sediment flushing and channel maintenance. The Río Gallina, a tributary of the Rio Chama, plays a …

Repair Of A Wellbore Microannulus, Serafin Garcia Fernandez

Civil Engineering ETDs

In wellbore systems, the microannulus between the steel and the cement has been shown to be a critical leakage pathway. This microannulus offers unique roughness, aperture distribution, and wetting conditions, which are critical in understanding and explaining the potential sealing efficiency of a repair material. An experimental configuration was developed to better understand how a repair material would displace an existing material in the microannulus, visually evaluate potential instabilities on the flow patterns developed, and how efficient the potential repair would be. For that purpose, the experimental configuration consisted of a planar, rough cement surface and a transparent acrylic plate …

Development Of The Navigator: A Lagrangian Smart Sensing System To Characterize Aquatic Ecosystems., Aashish Sanjay Khandelwal

Civil Engineering ETDs

Most freshwater aquatic studies rely on Eulerian monitoring, i.e., water quality and quantity are monitored using grab samples or semi-continuous sensors deployed at fixed cross-sections. While Eulerian monitoring is practical, it provides a limited understanding of spatial and temporal heterogeneity and their effects on environmental processes. This dissertation summarizes the design and application of The Navigator, an alternative Lagrangian monitoring system that offers cost-effective solutions for in-situ, real-time data collection in lotic and lentic freshwater ecosystems such as streams, rivers, ponds, and reservoirs. The Navigator features a suite of methods – an autonomous surface vehicle (ASV) with GPS and LTE …

Gold Thin Film Electrodes For High Sensitivity & Selectivity Electrochemical Detection Of Arsenite In Water, Tybur Q. Casuse Driovínto

Civil Engineering ETDs

This is partial fulfillment of a dissertation defense on electrochemical detection of Arsenic (As) in water using gold (Au) nanofilms as sensing electrodes. The maximum contaminant level of Arsenic in drinking water is set at 10 g L^-1 by the WHO and USEPA. Electrochemical detection by linear stripping voltammetry has comparable detection limits to more expensive laboratory-based methods but with added benefits of being portable and manufacturable. The work has developed sputtered and crystallographically oriented nanofilms for detection of trace As (III). Ultraflat Au(111) oriented thin films, Au(UTF), were compared to single crystal model electrodes to identify the impacts …

Strength As A Function Of Liquid Water Content In Different Snow Types - Results From Field Experiments Using A Blade Hardness Gauge, Mikael Schlumpf

Civil Engineering ETDs

The rapid weakening of snow layers that locally accumulate infiltrating liquid water is a well-known mechanism for wet slab avalanche formation. To quantify this process and improve the prediction of these destructive avalanches, a blade hardness gauge (BHG, a.k.a thin blade penetrometer) and SLF snow sensor were used to take 349 targeted paired measurements of strength and LWC, respectively, in the snow above 19 artificially wetted capillary barriers. Using a multiple regression analysis, we develop an expression for the blade hardness of manually wetted snow as a function of LWC, crystal form, and blade hardness prior to wetting. To understand …

3d Printing Of Earthen Materials: Toward The Carbon-Zero Construction, Shiva Bhusal

Civil Engineering ETDs

In recent years, digital manufacturing techniques in the architecture and construction industry have rapidly gained attention, especially with 3D printing, also called additive manufacturing. The use of cement has been common in modern construction and is now being explored for 3D printing. However, due to cement's contribution to approximately 7 percent of global carbon emissions and its high cost, research on sustainable and greener materials has gained attention. Previous studies on alternative construction have examined the mechanical and rheological properties of soil mixes, but not much attention has been given to printability evaluation, shrinkage, and cracking, which can affect the …

Additive Manufacturing Of Lightweight Concrete Mixtures, Kourosh Rashidi

Civil Engineering ETDs

Additive manufacturing, also known as 3D printing, is an innovative technique that is increasing its popularity in many industries including construction. 3D printing is related to the layer wised manufacturing or additive construction of any simple to intricate geometry from a digital file. The construction industry has a high potential for using 3D printing technology. However, one of the critical factors in the adaption of additive manufacturing in the construction industry is achieving a printable concrete mix design. This research aims to design printable mixes of lightweight concrete that could be effectively used in the 3D printing of walls or …

The Impact Of Albuquerque’S Bus Rapid Transit System On Pedestrian Safety, Martina Mercure

Civil Engineering ETDs

This project will explore the impacts of several traffic safety countermeasures and roadway design changes on pedestrian safety along the Central Avenue corridor of Albuquerque, New Mexico. The motivation behind this research is the communities concern for the increase in pedestrian fatalities in the US and specifically New Mexico. The research will have a specific focus on pedestrian safety, but we will also address traffic safety outcomes for motor vehicle users and bicyclists. The City of Albuquerque has taken note of the traffic safety issues on Central Avenue and has implemented or is in the process of implementing several countermeasures …

Additive Manufacturing Of Engineered Cementitious Composites With Ultra-High Tensile Ductility, Amir Bakhshi

Civil Engineering ETDs

One of the critical factors in the development of additive manufacturing in the construction industry is designing suitable materials for 3D printing applications. 3D concrete printing (3DCP) has gained significant attention due to the abundance and availability of concrete. However, concrete is a brittle material and, without proper reinforcement, cannot meet the requirements for structural purposes. Engineered Cementitious Composites (ECC), known for high ductility, and strain-hardening with low fiber contents, can potentially eliminate the need for steel reinforcement in 3D printing without any need for manual placement of reinforcement. A set of systematic tests on ECC mix designs' fresh and …

The Impact Of Murals On Traffic Safety: A Behavior And Crash Analysis, Maria Cecelia Cruz

Civil Engineering ETDs

ABSTRACT

This research analyzed changes in motor vehicle volumes and motor vehicle speeds after the installation of an intersection mural in Albuquerque, NM and changes in crash frequency after mural installations in Philadelphia, PA. Data was collected manually on site for the Albuquerque study and secondary data – including installation dates and physical characteristics – were used for the Philadelphia crash analyses. Statistics were computed to determine trends in motor vehicle speeds and volumes relative to the Albuquerque mural installation. A geographic information system (GIS) spatial analysis and t-test statistical analyses were used to determine which Philadelphia murals saw significant …

An Investigation Of Emerging Technologies To Advance The Understanding Of Dynamics Between The Floodplain And Main Channel Due To Riparian Vegetation, Smriti Chaulagain

Civil Engineering ETDs

Riparian vegetation covers only about 0.4% of the land surface whereas rivers and streams cover about 0.3 to 0.56% but riparian vegetation still provides substantial ecosystem services including many that affect hydrodynamic processes. The ability to estimate the flow resistance caused by vegetation and the consequences for hydrodynamic processes has long been a vexing problem for engineers. Flow resistance is strongly influenced by local hydraulic conditions (water velocity and depth) and vegetation structures, and in turn, vegetation affects mass and momentum exchange processes. However, riparian vegetation conditions change continuously due to external stressors including climate change (e.g., extended drought in …

Thermodynamic And Kinetic Investigation Of U(Vi) And As(V) Reactions: Insights For Risk Assessment And Remediation, Maria Isabel Meza

Civil Engineering ETDs

The goal of this dissertation was to investigate the mechanisms of immobilization of uranium (U) and arsenic (As) in waters nearby to Native American Communities for remediation applications. This work sought to identify the physical or chemical processes affecting the complexation, sorption, and precipitation of U and As with calcium (Ca), carbonates (CO3)2-, and phosphate (PO4)3-. The current knowledge about the mechanisms affecting the reaction of metal mixtures such as U, As, and other co-occurring elements in natural waters with minerals such as limestone1-5 and hydroxyapatite for remediation applications is limited. A better understanding of thermodynamics and kinetics affecting the …

Permeability And Porosity Of Loose Granular Salt, Evan J. Babcock

Civil Engineering ETDs

In this study, permeability and porosity measurements are made and reported for loose granular salt from the Waste Isolation Pilot Plant (WIPP). Measurements are made on a particularly wide range of particle sizes of this salt in a permeameter constructed large enough to fit and represent mixtures containing salt particles up to 25.4 cm in size. Salt samples with different particle size distributions are constructed and tested at varying levels of consolidation due to induced vibrations. Permeability measurements are made at a varying range of porosities for a given sample. Measurements are also compared with a predictive model for permeability …

Interfacial Interactions Of Uranium And Hdpe In Agricultural Soil And Their Bioacummulation In Mentha Arvensis, Casey Miller, Andrew Neidhart, Kendra Hess, Abdul-Mehdi S. Ali, Angelica Benavidez, Michael Spilde, Laura Green, José M. Cerrato, Jorge Gonzalez Estrella, Eliane El Hayek

Civil Engineering ETDs

We investigated the adsorption, precipitation, and phytoavailability of uranium after reactions with soil, high-density polyethylene particles, and Mentha arvensis through the integration of batch experiments, plant exposure, microscopy, and spectroscopy. Soluble U (initially 100 µM) decreased by 98.6% (1.09 µM) at pH 5 and 86.2% (13.81 µM) at pH 7.5 after 0.1 h of reaction with 10 g of soil in solution. Heterogenous U precipitates were observed in weathered HDPE surfaces for experiments without soil at both pH conditions. This suggests the weathering of the microplastic surfaces enhanced the nucleation of the U precipitates. Plants exposed to both U and …

Reactions In The Microannulus Of A Wellbore System With Produced Water From The Permian Basin, Ernesto J. Perea

Civil Engineering ETDs

The objective of this study is to determine the effect of the products from steel corrosion and cement dissolution after reaction with produced water (PW) on the permeability of a wellbore microannulus. The wellbore microannulus is the interface between wellbore cement and steel casing and is often identified as a leakage pathway in wellbore systems. The need to better understand the impact of PW on well integrity aids in the assessment of environmental impacts of energy production. Static batch reactors were used to expose a cement – steel microannulus to two PW solutions, a simulated PW, and a field sampled …

Experimental And Numerical Investigation Of 3d-Printed Viscoelastic Dampers, Mohammed Jaradat

Civil Engineering ETDs

Elastomeric materials are extensively used in energy dissipation applications to mitigate large lateral displacements and attenuate vibrations. One way of exploiting the capabilities of elastomeric materials is using shear-damping mechanisms such as viscoelastic damping devices (VEDs).

In this research the freedom of design offered by additive manufacturing technology is utilized to produce 3D printed elastomeric parts that act as the viscoelastic layer in an energy damping device. A mechanically interlocked viscoelastic damper (MIVED) with a jigsaw-like interlocking mechanism was designed and manufactured. MIVED is composed of a rigid and soft phase. It operates in two modes, modes I and II, …

Co-Occurrence Of Microplastics, Uranium And Arsenic In Heavy Metal-Contaminated Freshwaters And Their Potential Interaction, Jasmine Anne Quiambao

Civil Engineering ETDs

This study identified microplastics and heavy metals in fields sites of freshwater systems in New Mexico and evaluated the interactions of arsenic (As) and uranium (U) with commercial microplastics for acidic and neutral pH in laboratory-controlled conditions. The potential interaction of microplastics with other contaminants is not well-established. Microplastics could interact with heavy metals in ecosystems with naturally elevated background concentrations of metals or affected by anthropogenic activities. Previous studies have found heavy metal contamination in freshwater systems in New Mexico near abandoned mine sites. The objective of this study is (1) to identify and characterize microplastics from metal contaminated …

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 …

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 …

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 …