Civil and Environmental Engineering, 2000-2025
Permanent URI for this collectionhttps://theses-dissertations.princeton.edu/handle/88435/dsp014m90dv552
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Modeling Streamflow and Nitrogen Dynamics in an Urban Watershed: A Mechanistic Approach
(2025) Musa, Mohammed A.; Porporato, Amilcare Michele M.This thesis develops and tests a process based model of streamflow and nitrogen concentration in the urban stream network of the Bassett Creek watershed. The model treats the watershed as a control volume. This allows for a simplified but physically grounded representation of nitrogen inputs, transformations, and losses. Streamflow is used as the primary control variable. Hydrologic variability is modeled as a key factor shaping nitrogen export over time. This model uses a forward Euler method for two differential equations of streamflow and nitrogen dynamics. These equations are implemented manually in MATLAB to emphasize clarity and sensitivity to parameter changes. The model is calibrated using long term data on rainfall, streamflow, and nitrogen concentrations. Sensitivity analyses are used to identify which parameters most strongly influence outcomes. Results show that the streamflow model captures general runoff behavior with moderate accuracy. The nitrogen model reveals useful qualitative trends but struggles with predictive power due to limited data and the complexity of underlying processes. By grounding the model in first principles and real world observations, this thesis offers an accessible alternative to black box models. It is particularly well suited for environments with limited data and exploratory research in urban watershed systems.
Plants on the Peak: Field and Remote Sensing Variables in Alpine Biodiversity Models
(2025-04-12) Beers, Brooke; Maxwell, Reed MailerThis thesis investigated the ability of field-based and remote sensing variables from an unmanned aerial vehicle (UAV) to predict plant species diversity in an alpine ecosystem on Snodgrass Hillslope, located adjacent to Mount Crested Butte, Colorado. Using multiple linear regression models across 88 field plots, soil moisture and slope aspect were the most consistent predictors of species diversity. Other variables in models included slope angle, soil texture, soil temperature, and infrared temperature. Field-based models explained between 37% and 77% of the variance in plant species diversity, with the strongest performance in the upper forested grid. The incorporation of remote sensing variables, including Normalized Difference Vegetation Index (NDVI) and estimated percent vegetation coverage, improved model performance in most cases and most significantly improved performance when modeling the combined lower and upper plots. Remote-only models using NDVI minimum and slope aspect provided a visualization for species diversity across the entire grids but explained less site-level variance with R2 values of 0.6663 (Adj. R2 = 0.555) for the upper grid and an R2 of 0.4123 (Adj. R2 = 0.2227) for the lower grid. These results highlight both the advantages and limitations of solely UAV-based modelling in mountainous terrain. Future projections using SnowClim v1.0 climate projections demonstrated that areas such as Snodgrass Hillslope will become warmer and more stressed for late-season moisture as snowpack decreases, snowmelt timing advances, and summer temperatures rise. These climate shifts may reduce species diversity in water-limited habitats and alter plant community composition in alpine landscapes. Keywords: alpine plant species diversity, multiple linear models, volumetric water content (VWC), slope aspect, soil texture, remote sensing, unmanned aerial vehicles (UAVs), SnowClim v1.0
Analysis of the Use of Reinforced Polyethylene in Transparent Roof Design
(2025-04-14) Xaviera, Nal; Mandal, JyotirmoyWith global warming induced rising temperatures heavily affecting populations in the global South, it is becoming increasingly important that low-cost and energy efficient methods are developed to cool structures. Passive radiative coolers are an ideal solution because they cool without an external energy source and are able to achieve subambient internal temperatures. However, the extent of internal cooling is limited to how low of a temperature the passive radiative cooling surface is able to reach. Ideally, internal heat would dissipate without a barrier—most commonly a roof—and escape to space through the atmosphere’s longwave infrared window. Polyethylene is a commonly available and low-cost plastic with high transmittance in the longwave infrared spectrum, making it ”transparent” in the range of 8-13µm. However, it does not possess mechanical properties that make it suitable for use as a building material. This thesis explored the thermal performance of various types of polyethylene in a thermally transparent roof design. Reinforcement for the polyethylene and applications of these designs at large scales was also studied.
Mobilizing the PFAS-Degrading Gene from Acidimicrobium Sp. Strain A6: A Strategy for Breaking Down PFAS in Anaerobic Digesters
(2025-04-14) van Wachem, Emma; Atkinson, JoshPer- and polyfluoroalkyl substances (PFAS) are persistent contaminants that have been associated with adverse health effects. While Acidimicrobium sp. strain A6 demonstrates the ability to degrade PFAS, it is unsuitable for industrial applications. This thesis is focused on investigating whether a gene from Acidimicrobium sp. strain A6, encoding a reductive dehalogenation enzyme capable of degrading per- and polyfluoroalkyl substances (PFAS), can be successfully transformed into a faster reproducing microbial host. The long-term aim is to design a plasmid that can be transferred into the bacteria Shewanella oneidensis, enabling the gene to propagate through horizontal gene transfer within diverse microbial communities. PFAS pose significant challenges to remediation efforts as they are energy-intensive and expensive to degrade. Here, we show that expression of the A6-derived gene in S. oneidensis resulted in enhanced bacterial growth in PFAS-containing environments, indicating a possible functional response to PFAS exposure. With the insert, S. oneidensis was able to grow in high concentrations of PFOA, a response not observed in strains lacking the gene. While PFAS did not serve as a sole electron acceptor, the enhanced anaerobic growth suggests that its presence may supplement metabolism. These findings demonstrate the potential of harnessing faster-growing microbial hosts for PFAS bioremediation through gene mobilization. I anticipate this research to be a starting point for designing diverse microbial communities capable of degrading PFAS, with the ability to disseminate the degradation gene through horizontal gene transfer.
Evaluating Percolation Ponds for Managed Aquifer Recharge in California’s Central Valley Using a Soil Moisture Balance Model
(2025-04-14) Nyakea, Shalyn M.; Porporato, Amilcare Michele M.Structural Analysis of Domical Vaults: Preserving the Church of St. Michael and Gabriel in Voskopojë, Albania
(2025-04-14) Neznamova, Anna D.; Moini, RezaThis thesis aims to assess the structural behavior of the main domical vault system in the Church of St. Michael and Gabriel in Voskopojë, Albania. Built in the 18th century during the era of Enlightenment in the Balkans, this church displays the cultural significance of Voskopojë during its peak of intellectual and religious development. The Church of St. Michael is one of five remaining masonry churches out of the twenty-six originally constructed in the village. The impacts of seismic activity and the World Wars have made the preservation of its magnificent post-Byzantine fresco art and basilica-style architecture all the more critical. By analyzing the flow of forces in the vault system, this study gives a better understanding of the structural behavior of this valuable architectural site, supporting ongoing efforts in heritage conservation worldwide.
An extensive visual assessment of the church was conducted on-site in Voskopojë, along with aerial and terrestrial photogrammetry to document the structure’s geometry. Information on historical crack patterns, the thickness of the dome, and the condition of the timber ties was obtained from an interview with the site engineer. In addition, the Masonry Quality Index (MQI) was used to estimate the mechanical properties of the masonry following a qualitative analysis of the building material. A model of the domical vault system was created using data from the site survey and interior laser scans of the church elevations and floor plan as a guide. A linear Finite Element Analysis (FEA) of the completed geometric model with appropriate material properties was performed for six cases, including different tie arrangements and vault geometries. This was done to determine the effect of the shape of the vault and the presence of the upper and lower rows of timber ties on the flow of forces in the structure. The models were analyzed under both gravity and lateral loading conditions to simulate the effect of the structure’s self-weight and seismic activity, respectively.
The results of the FEA provide insight into the behavior of the timber ties and the unique vault geometry used in the construction of the church. It was found that the lower row of timber ties may not be structurally necessary to resist the gravity and lateral loading acting on the vault system, except as redundancy for the upper row of ties. The results also indicate that the ties are more important in dissipating stress due to the masonry’s self-weight rather than that imposed by lateral loading. Additionally, the original vault geometry appears to be more effective than the idealized hemispherical dome in transferring stress to the arches under gravity loading. However, the latter may be more efficient for resisting lateral loading due to its uniform shape. The results of this study can inform future work on the preservation of this and similar masonry churches, which will help protect the historical significance of towns such as Voskopojë.
Future work could include Distinct Element Modeling (DEM) since this approach takes into account the interactions between the masonry blocks and mortar rather than treating the masonry as a homogeneous material. The Concrete Damage Plasticity (CDP) model could be used to perform a safety analysis, following the establishment of more accurate timber tie connections in the geometry. Furthermore, the use of spring boundary conditions on the arch faces or the expansion of the model to include the full church geometry would be necessary for a realistic safety analysis. This is because the vaults surrounding the dome of interest provide significant additional support under both gravity and lateral loading. Finally, adjusting the boundary conditions to account for foundation settlement and adding concentrated point-loading on the vaults from the timber roof structure would provide a more holistic structural assessment based on historical crack patterns.
Transpiration Across Elevations: Modeling the Impact of Climate Change on Plant Groundwater Use at Mountainous Headwaters
(2025-04-14) Defrates, Ashley; Maxwell, Reed MailerAs temperatures have increased with a changing climate, streamflow in the Upper Colorado River Basin (UCRB) has declined, posing a severe threat to public well-being. Much of this downstream surface water originates as groundwater in mountainous catchments. As conditions warm, plants’ demand for water increases, potentially reducing groundwater's contributions to surface water downstream. Yet this response to warming is complicated by transpiration’s dependence on energy and water limitation, which varies spatially and temporally in topographically complex catchments of the UCRB.
This study quantifies the effect of warming on summer transpiration in the East-Taylor Watershed (ETW), a representative catchment of the UCRB, under conditions of varying energy and water limitation. ParFlow-CLM is used to model hydrologic and land surface processes with meteorological forcing input from a wet year (WY2017) and dry year (WY2018). Baseline temperature forcings are then uniformly increased by 1.5oC to explore the effects of projected warming alongside different precipitation inputs, resulting in four total simulations. Analysis focuses on transpiration and recharge, studying the spatial variation of these fluxes with land cover type and elevation. Results indicate that warming has a more substantial effect on plant groundwater use in the ETW during an energy limited water year. Analysis of daily soil moisture change across each root zone layer further reveals an increased reliance on deeper root zone moisture with warming, which is strongest under hot and dry conditions.
Balancing Enjoyment and Efficiency: Sensory Cognizant Queueing in the Happiest Place on Earth
(2025-04-14) Michicich, Morgan M.; Shkuda, Aaron Peter; Hackl, JurgenThe aim of this project is to create a queueing framework to be implemented in Walt Disney World that maximizes guest enjoyment and efficiency of movement, while also taking into consideration sensory needs of guests with intellectual and developmental disabilities (IDDs). To achieve these goals, this project explores the idea of a “second story” being added to Disney World in the form of queueing spaces to both maximize perceived efficiency and utilize verticality that is currently being wasted. The results from this research include observations from spatial ethnography conducted in Disney World, survey data regarding queueing systems in general and in Disney World, and a framework for a queueing system that meets all of the requirements for efficiency, enjoyment, and accessibility as defined by the survey and spatial ethnography. Drawings of two queueing systems that implement this framework are included to better conceptualize how these queues fit into the space, as well as a representative structural analysis of the typical building an attraction queue adhering to this frame- work would be housed in. This new queueing framework, if implemented and found successful, could be replicated in other facets of life to improve queueing experience for all people, regardless of ability.
Building Sector Trends and Embodied Emissions in São Paulo: Implications for Decarbonization with Inclusion, Sufficiency, and Dematerialization
(2025-04-14) Pinho Novo Gomes, Isabella; Ramaswami, AnuAs the global building stock expands to accommodate a growing urban population, embodied greenhouse gas (GHG) emissions are expected to represent an increasingly significant share of total urban emissions. This study presents a comprehensive assessment of embodied building emissions in the city of São Paulo, Brazil. Drawing on over 90 years of tax-parcel data, a detailed case study of material intensities for both formal and informal residential typologies, and geographically specific life cycle emission factors, this thesis quantifies the annual embodied carbon associated with new residential and commercial construction. Findings estimate average annual new construction in São Paulo generates approximately 1.46 million tons of CO₂-e/year in embodied emissions, which is equivalent to ~9% of the city’s emission profile (including energy, transport, and waste) and ~30% of emissions from the building sector (including operational emissions from electricity use, heating/cooling, and cooking). The study then evaluates the emission implications of three decarbonization strategies: inclusion (upgrading informal settlements to meet minimum floor area standards), sufficiency (reducing excess floor area per capita), and dematerialization (substituting carbon-intensive materials with lower-emission alternatives). While the inclusion scenario results in a negligible increase in emissions, an ambitious sufficiency scenario could reduce embodied emissions by up to ~23%, and an aggressive dematerialization scenario (modeled on near-optimal cement decarbonization) could cut embodied emissions by ~60%. These findings highlight the importance of integrating material-focused mitigation strategies and inclusive urban design into climate action plans.
Air-based thermosyphon system’s role in reducing building-based carbon emissions
(2025-04-14) Eisenberger, Ben H.; Porporato, Amilcare Michele M.Valorization of Jute Stick as a Novel and Sustainable Material for Thermal Insulation in South Asia
(2025-04-14) Ng, Su Fey; Mandal, JyotirmoyExtreme heat events are increasingly salient in South Asia as a consequence of anthropogenic climate change. However, existing buildings in the region are not equipped to withstand such elevated temperatures, posing a risk to human health. Retrofitting the building envelope with insulation has been proposed as an effective means of improving energy efficiency of cooling. Hence, jute stick is proposed for investigation as a novel resource for creating thermal insulation, representing a sustainable and accessible solution for mitigating heat stress, as well as enabling the valorization of agricultural waste. Expanding upon the existing literature on biomaterial-based insulation, this thesis characterizes the thermal properties of jute stick through imaging and obtaining an experimental value for thermal conductivity. Methods of processing jute stick are explored for the fabrication of insulation panel prototypes, while energy modeling facilitates a comparative analysis of insulation-derived benefits. Ultimately, jute stick emerges as a promising biomaterial for application as thermal insulation.
FBG Sensor Analysis of a Beam with Complex Geometry and Boundary Conditions
(2025-04-14) Le, Elvis H.; Glisic, BrankoThis thesis presents an investigation into the structural behavior of a concrete beam with welded connections in an operational parking garage. Long-gauge fiber Bragg grating (FBG) sensors were installed at strategic locations to measure strain under various loading configurations. The research explores the discrepancies between numerical calculations and measured beam response to understand how the complex geometry and boundary conditions influence structural behavior. Finite element analysis (FEA) simulations were conducted using Abaqus software to establish boundary conditions representing two extreme cases: a simply supported beam and a beam with constrained points. These models served as limit states for interpreting the influence of welded connections on beam strain. Measured strain data was compared with FEA predictions, and the effect of welded connections was quantified using a percent effectiveness metric. Results demonstrate that welded connections exert diverse influences on beam deflection depending on both measurement location and load configuration. The connections' behavior generally falls between that of a simply supported beam and one with fixed constraint points, with the proximity to either extreme end condition varying throughout the beam. FEA models showed particular difficulty in accurately predicting lateral bending behavior. The study was constrained by limitations in sensor placement, load magnitude restrictions, and simplifications in the FEA models. Despite these constraints, the methodology demonstrates an effective approach for analyzing structures with complex geometries and boundary conditions. This research contributes to understanding CarbonCure concrete performance in operational structures and supports the ongoing development of structural health monitoring techniques that can enhance the safety and maintenance of built infrastructure.
An Analysis of the Efficiency and Cost Effectiveness of Geothermal Energy Piles in Newark, New Jersey
(2025-04-14) Haile-Manas, Amalia A.; Sandiford, RaymondA geothermal heat pump (GHP) is a heating and cooling system that uses the Earth as a heat source and sink. GHPs possess the environmental benefits associated with all forms of renewable energy, and further have the benefit of meeting a significant demand—building heating and cooling—by tapping an energy source located on site. Moreover, GHPs are efficient and require minimal maintenance. The main drawback of this technology is its high capital cost, which is largely attributed to borehole drilling and pipe installation. Geothermal energy piles (GEPs) provide a way to decrease that cost. On projects that require foundation piles for structural support, geothermal heat exchange tubing can be installed within the piles without any detrimental effect to the foundation's structural integrity. Geothermal energy piles thus increase the viability of GHPs.
This thesis assesses the feasibility of a geothermal energy pile system on the proposed Newark Liberty International Airport AirTrain stations, which will rest on pile foundations. The analysis addresses both the capacity and cost effectiveness of this system. First, calculations demonstrate that geothermal energy piles can provide sufficient heating and cooling capacity given the energy demand, soil conditions, and proposed pile layout. Second, a cost assessment indicates that this system will save money over time despite a higher installation cost. The installation of GEPs on this project could increase awareness of this beneficial technology, which remains relatively uncommon and unknown.
Cap the Cross-Bronx? Modeling the Air Quality Impacts of the Proposed Highway Cap
(2025-04-14) Qua, Martina; Sandiford, RaymondHighways pose several environmental, health, and social concerns. The air and noise pollution from vehicles pose a health risk to those living near highways, often disproportionately affecting marginalized communities. One solution to mitigate these negative externalities is highway capping—constructing lids above highways for conversion into deck parks. A highway capping project was recently proposed for the Cross-Bronx Expressway, but little research has been done on its environmental impact, as it is still in the ideation phase. Thus, this thesis uses a differential analysis to assess how the proposed Cross-Bronx Expressway cap would impact air quality in the surrounding area. Using a Gaussian equation model and verifying results through AERMOD, the Environmental Protection Agency’s regulatory atmospheric dispersion model, pollutant concentrations were calculated in areas adjacent to the proposed cap for the no-build and build scenarios. The study found that air quality marginally improves in areas directly adjacent to the cap, but worsens in areas close to the cap exits, particularly the east exit. While the cap keeps PM2.5 and CO concentrations within the National Ambient Air Quality Standards (NAAQS), it exacerbates existing high NOx concentrations near the cap exits. These findings reveal that there is high variation in how community members will be impacted, depending on their proximity to the cap exits.
Designing a Floating Platform on Lake Carnegie for Rowing Spectatorship
(2025-04-14) Neill, Connor G.; Garlock, Maria Eugenia MoreyraBridging the Missing Middle in Clean Technology: An Engineering, Finance, and Policy Approach
(2025-04-14) Song, CC; Greig, Chris; Mauzerall, DeniseTo meet internationally agreed upon climate goals, the world must rapidly deploy both mature and next-generation clean technologies over the upcoming decades. Without the widespread deployment of next-generation technologies such as CCUS and green hydrogen, the speed of carbon emission reductions needed to meet net zero goals is simply not realistic. However, to achieve the required speed and scale of deployment, next-generation technologies must be able to overcome a large financing gap between the RD&D phase and the phase of large-scale deployment in the real world. This gap is often termed the “missing middle”. These technologies face a chicken-and-egg problem where they need to attract large amounts of relatively low-cost capital to grow, yet they are perceived as too high-risk for private investors to support. Thus, the target of this thesis is to investigate how government subsidies can help bridge this gap and accelerate the commercial viability of next-generation clean technologies. Drawing on historical case studies of mature clean technologies like solar PV, comparative analysis of key technology characteristics, and insights from industry experts, this thesis estimates the level of subsidization that CCUS and green hydrogen will require in the future to achieve “systemic bankability” and ideates on policy design to enable their successful scale up.
The Effects of Angles of Inclination and Incidence on the Aerodynamic Performance of Hyperbolic Paraboloid Kinetic Umbrellas
(2025-04-14) Takahashi, Yoshihiro; Garlock, Maria Eugenia MoreyraAs the risks for coastal hazards increase, traditional countermeasures such as flood walls and storm surge barriers pose a problem, as they hinder access to the beach and diminish coastal beauty. A kinetic hypar umbrella has been proposed as an alternative solution that can provide hybrid benefits of coastal protection and structural art. While hydrostatic and hydrodynamic loads have been tested for the hypar geometry, wind loads have not yet been tested. This thesis seeks to understand the aerodynamic performance of the kinetic umbrellas under varying conditions of inclination and incidence angles. To do so,
(a wind tunnel at the Forrestal Campus of Princeton University) was validated by comparison with data sets collected at a vetted wind tunnel located at the University of Oviedo. Secondly, a velocity profile was measured for to understand the variance in wind across the face of the nozzle. Both tests concluded that the difference between the data sets and the variance in the velocity profile was within the realm of testing errors to vet the wind tunnel, especially to study the behavior trends of the aerodynamic coefficients.The impacts of changing inclination angles on drag and lift coefficients were observed to match the general behavior of airplane wings and its angle of attack. The drag and moment coefficient curves showed a U-shaped curvature with respect to inclination angles, which increased in value as the inclination decreased or increased away from 0 degrees. The lift coefficient showed a more sine-like curvature with a point symmetry about the 0 degrees point. With respect to the angle of incidence, the drag and moment coefficient curves also displayed a U-shaped curvature, increasing in value as the inclination decreased or increased away from 90 degrees. The lift coefficient exhibited a cosine-like curvature where the value decreases as the incidence angle increases from 0 and continues to decrease as the incidence angle increases to 180 degrees. The shape of the curvatures with respect to angle of incidence matches the expected behavior; changing the incidence angle rotation is essentially changing the angle of attack in another axis.
Structural Study of Split Bamboo Hyperbolic Paraboloid Grid Shell
(2025-04-14) Bazalar Alpiste, Brenda S.; Adriaenssens, Sigrid M.Algorithmic Intentions, Material Consequences: Personalization in the Subscription Economy
(2025-04-14) Walsh, Charlotte M.; Bourg, Ian CharlesMany subscription box services market their products as uniquely tailored to each consumer’s individual preferences. This personalization typically begins with an on- boarding quiz where consumers articulate their tastes and preferences, creating the expectation that each subsequent delivery will reflect these stated choices. While 85% of businesses believe they are offering a personalized service, only 60% of consumers agree. This disconnect suggests that “personalization” often functions more as marketing rhetoric than as a substantive product feature. The implications of failed personalization extend beyond poor customer satisfaction; they also drive significant waste: from discarded products and excessive packaging to carbon emissions generated by unnecessary manufacturing and shipping. This thesis investigates whether companies truly deliver on the promise of personalized selection. The research employs a two-part methodology: (1) a controlled 2x2 factorial experiment comparing expert vs. non-expert participants who receive either preference-aligned or preference-misaligned boxes, and (2) qualitative interviews to explore participants’ perceived satisfaction, product fit, and personalization. The experiment was carried out on two different subscription boxes from distinct product categories: IPSY, which delivers a curated beauty box, and MistoBox, which ships subscribers a hand-picked bag of coffee. The findings illuminate the intersection between consumer experience, algorithmic design, and environmental impact, offering ways in which personalization strategies can be optimized to serve consumer and sustainability objectives. Notably, in the experiment, over 80% of IPSY products went unused, highlighting the urgent need for more effective personalization models to reduce waste and improve product relevance.
Sustainable Actuation and Operation of Hybrid Bridge-Barriers
(2025-04-14) Ahdieh, Na'im A.; Garlock, Maria Eugenia MoreyraThis thesis works through the design process for a flood protection barrier falling within a special sub-category that the research team has defined: Sustainable Hybrid Bridge Barriers (SHBB). The design starts with what is known as a visor gate, which has some limited precedent around the world. But this project offers a unique new approach to that basic structure, which not only performs as a barrier in large storms, but also incorporates a pedestrian bridge, functions in a relatively more sustainable fashion, and has aesthetic appeal. The design process for each element of the barrier, including its unique ballast system, are worked through in the paper. Future work to be done to implement such a design in reality is also described systematically. The design on this iteration was unfortunately unsuccessful, but the groundwork has still been laid for next steps.