Other Environmental Sciences Commons^™

Evaluation Of Dredged Sediments As A Partial Replacement For Fine Aggregate In Mortar And Concrete, Ashish Gautam

Graduate Theses and Dissertations (2019 - present)

The feasibility of using dredged sediment from the Mobile River as a partial replacement for fine aggregate in mortar and concrete was investigated through a series of laboratory characterization and performance evaluation. Three dredged sediment samples (A, B and C) were initially examined, and Sample A was selected for further evaluation due to its closer resemblance to natural fine aggregate. This sample exhibited lower moisture content, higher sand equivalent values, higher specific gravity, and lower absorption. Mortar mixtures with 0, 10, 20, 30, 50, 75 and 100% dredged sediment replacement showed decreasing workability as the replacement level increased. The 20% …

Machine Learning For Predictive Energy And Emissions Modeling Of Vehicles And Power Grids In The United States, S M Tanvir Faysal Alam Chowdhoury

Dissertations

The environmental benefits of electric vehicle (EV) adoption depend on more than replacing internal combustion engine vehicles with electric powertrains. EV adoption reshapes electricity demand, interacts with regional generation mixes, and influences travel behavior and congestion, creating a coupled transportation-energy system in which vehicle and power-plant emissions must be evaluated together. This dissertation develops machine-learning frameworks for predicting energy consumption and emissions from vehicles and power grids under rising EV adoption. The first component forecasts grid emissions from EV charging. Using simulation data from NREL's Cambium database, a Prophet-based time-series framework predicts carbon dioxide, nitrous oxide, and methane emission rates …

The Exergy Of Materials With Application To Socio-Economic Metabolisms And Industrial Ecology, Matthew Kuperus Heun, Erin Schuman, Sofie Schumerth, Tânia Sousa

University Faculty Publications and Creative Works

2026 International Society for Industrial Ecology Socio-Economic Metabolism (ISIE-SEM) Conference Cabridge University, Cambridge, England

Concealed History Of Microplastic Pollution In The Msimbazi Estuary, Dar Es Salaam, Tanzania, Dativa J. Shilla

Tanzania Journal of Science

This study reconstructed the historical deposition of microplastics in sediments of the Msimbazi Estuary, Tanzania, using a radiometrically dated sediment core. Sediment chronology established using ²¹⁰Pb and the Constant Initial Concentration (CIC) model provided an approximately 83-year depositional record. The ²¹⁰Pb age model suggested marked temporal variability in sedimentation rates, with peaks around 1961, 1998, 2013, and 2015, potentially reflecting hydrological extremes and catchment disturbances. Anthropogenic microparticles were detected throughout most of the sediment core, with concentrations ranging from below detection limit (BDL) to 34 items kg⁻¹ dry weight (mean 8.5 ± 3.2 items kg⁻¹), and their abundance generally increased …

Effects Of Changing Fire Regimes On Black Huckleberry Habitat Suitability, Emily Labarge

University Honors Theses

Black huckleberries are a significant cultural, ecological, and economic species in the Pacific Northwest. Historically, black huckleberries were tended with cultural fire by Indigenous peoples, and now also hold importance as a resource in the non-timber forest product economy. Research has begun on the impacts of climate change on suitable black huckleberry habitat and on changing fire regimes, but not in relation to each other. To address this gap, I examined the area of overlap between suitable black huckleberry habitat and fire burn probability into mid-century climate projections. I determined the current ownership entities with management jurisdiction in areas with …

Exploring The Relationship Between Tree Dbh And Lichen Cover On Coast Redwood, Grace M. Personeus, Sierra Gittleman, Alisa A. Zarattini

IdeaFest: Interdisciplinary Journal of Creative Works and Research from Cal Poly Humboldt

We investigated the relationship between Diameter at Breast Height (DBH) and lichen cover on coast redwood (Sequoia sempervirens) to see if larger trees had higher percentages of cover. We measured cover using 10 cover classes on the southeastern and southwestern sides of trees in a secondary growth forest. We found a significant relationship between DBH and cover, yet no significant difference between the two sides measured. We suggest that further research with a larger sample size and more varied age classes will provide further insight into the relationship.

Evaluating Wildfire Mitigation And Wildfire “Hot Spots” In The Northern Bay Area, Nicholas W. Jones

Master's Projects and Capstones

Wildfire risk in the Northern Bay Area is increasingly shaped by climate driven vegetation dryness, expansion of the Wildland Urban Interface (WUI) and the fragmentation of environmental policy making. This paper investigates how Alameda, Contra Costa, and Sonoma Counties differ in their wildfire exposure and asks whether county level policies align with the areas of highest hazard and human exposure overlap. This project uses a Geographic Information Systems (GIS) overlay to overlay CAL FIRE Fire Hazard Severity Zones (FHSZ), and WUI data to identify wildfire hot spots where WUI areas intersect with High or Very High FHSZ classifications. This spatial …

Deforestation Dynamics In The Amazon: Impacts, Socio-Environmental Drivers And Restoration Pathways, Maria Natalia Rodriguez

Master's Projects and Capstones

The Amazon, which is the largest tropical rainforest in the world, experienced 542,581 km² of forest loss between the years 2000 and 2020. The process of deforestation endangers the ecological system results which maintain ecosystem connectivity and the Earth's climate system. The Amazon rainforest supplies essential ecological services which include maintaining soil fertility, storing carbon, purifying water and climate stability. The fundamental ecosystem of this area faces new threats because of increasing forest destruction. The research study adopts a combined methodology that uses Geographic Information Systems (GIS) with a comprehensive literature review to study Amazon deforestation patterns and its driving …

The Legacy Of Lead: Lead Exposure's Harmful Effects And Its Concentration In Poc Communities, Layla Sophronia Barber

Student Theses 2015-Present

This thesis examines the disproportionate burden of lead exposure carried by low income, POC communities. The systemic nature of this problem is a symptom of a longstanding legacy of environmental injustice in the United States. Decades of federal neglect are reflected in the higher statistics of lead exposure and poisoning in predominantly black communities. While it is understood that lead exposure poses a serious threat to physical health and early cognitive development, there is a discouraging lack of urgency to remove the toxin from non-wealthy communities. The material covered by this thesis aims to identify and correct the discriminatory social …

Solid Waste Management In Greater Khartoum City, Sudan, Roba Mahmoud

Student Theses 2015-Present

This study investigates the rising solid waste management (SWM) dilemma in Greater Khartoum City (GKC), a critical environmental and public health issue caused by fast urbanization and inadequate infrastructure, with historical linkages to Sudan's colonial and postcolonial growth. Chapter 1 describes the current problem using quantitative and qualitative data, demonstrating that GKC produces approximately 3,340 tons of waste each day, with 56% organic matter, 8% plastics, and 16% paper. Collection efficiency remains severely poor, at 31.5%. Informal recyclers known as Nakasha or Barkata collect approximately 7% of total waste, supporting roughly 3,900 people, whereas filthy open dumps and unsorted medical …

Bottles, Butterflies, And Biomass: Recycled Glass Sand, Microbial Additions, And Herbivory Effects On Milkweed Growth, Kealey Skinner

Honors Theses

Plant-soil-microbe interactions are integral components of ecological networks and drive ecosystem function from the bottom-up. Whereas herbivores regulate ecosystem function from the top-down, having opposing and potentially complementary effects on ecosystem function. My thesis sought to understand how below-ground microbial communities contribute to herbivore preference and plant biomass across varied soil substrates. My thesis asked: how do substrate and soil microbial communities influence herbivore preference and plant biomass accumulation on swamp milkweed (Asclepias incarnata)? To address this question, seedlings of A. incarnata were sown in 2.5 cm wide × 10 cm deep pots filled with either natural beach sand or …

Evaluating The Rural/Urban Divide In Conservation: Methods Of Improvement In Conservation Programming Across Kentucky, Lauren Tackett

Honors College Theses

Kentucky’s lands and waterways have always defined the state. Our unique karst landscape, combined with the Appalachian Mountains and Ohio River, help characterize the state and its identity. However, across Kentucky conservation efforts within recent years have been under attack. Through legislation changes and policy challenges, various bills have sought to repeal Kentucky’s conservation efforts regarding water, soil, and land use. Furthermore, there has been a rise in environmental disasters within the state that cause long term issues for both rural and urban communities to contend with. The responsibility of land stewardship falls on a variety of entities but weighs …

Assessment Of Mississippi Landfill Capacity In Relation To Waste Generation And Land-Use Constraints, Jason C. Anderson

Master's Theses

Municipal solid waste (MSW) management presents a growing challenge in Mississippi as population trends, socioeconomic change and regional development continue to place pressure on existing landfill capacity. This thesis examines waste generation and disposal patterns from 2000 through 2022 across Mississippi counties, with projections extending to 2050. Historical landfill tonnage data was gathered and compiled from the Mississippi Department of Environmental Quality (MDEQ) and analyzed using regression models in Excel and RStudio, with forecasts generated for both in-state and out-of-state waste flow. Results highlight significant variations among landfills, including differing closure timelines, changing county service areas and notable shifts in …

On The Paleontology Of Belize, Alson Ovando

Electronic Theses and Dissertations

Paleontology can be considered an underrepresented and emerging area of science in Belize. A primary aim of this thesis is to provide a background of paleontology in Belize and present the first comprehensive study of Quaternary vertebrate fossils known from the country. Quaternary fossil sites across Belize include caves, rivers, and sinkholes. In addition to reviewing and assessing material from known sites, this thesis presents new information and discoveries that were made while investigating Belize’s Quaternary fossil record. This thesis also includes a geospatial model depicting ecoregions in Belize during the last glacial maximum. Overall, the results presented here demonstrate …

Detecting Sophisticated Cyberattacks On Public Water Infrastructure, Ayrton Purdy

Graduate Theses and Dissertations (2019 - present)

In recent years there has been an increasing number of cyberattacks on public water generation and distribution systems. Advanced persistent attackers could usurp sensors and control systems to contaminate public drinking water. In order to conceal their malicious activity, they can manipulate sensor data flows to give the appearance of normal activity. The compromised sensors would report normal chemical levels even though unsafe water is entering the distribution system. In response, this research proposes a multi-sensor, cross-comparison approach to anomaly detection. The proposed approach is designed to detect sophisticated cyberattacks which are not easily detectable using traditional cyber tools. The …

How To Effectively Trap Invasive Crayfish: A Discrete Life Stage Mathematical Model, Rini Pattison

Seaver College Research And Scholarly Achievement Symposium

The red swamp crayfish is an invasive species introduced into several streams within the Santa Monica Mountains (SMM). Crayfish predation decimates native aquatic species. The Mountains Restoration Trust (MRT) has worked to remove crayfish through regular trapping in Malibu Creek.

A prior student created a crayfish life cycle model with trapping, which we expand to better predict the efficacy of crayfish removal efforts in the SMM. We separate crayfish based upon life stages and sizes. We construct and parameterize this discrete crayfish population model with and without trapping. We use literature and crayfish removal data from MRT to fit the …

Prediction Of Future Mushroom Fruiting Success And Dispersion Based On Models Of Changing Surface Air Temperature In Oaxaca, Mexico, Frida Martinez

ATU Scholars Symposium

Mushrooms serve various purposes, including medicinal, culinary, and cultural significance for indigenous groups, as well as recreational and ecosystem services. Oaxaca, Mexico, is a hotspot for mushroom biodiversity including the following varieties: Amanita muscaria, Schizophyllum commune and Coprinellus disseminates. The purpose of this study is to determine if a changing Mean Surface Air Temperature will have an influence on these mushrooms. We obtained, analyzed, and compared historical and future climate data from the World Bank Group Climate Change Knowledge Portal to identify if any of the mushroom species would be impacted. The study revealed a general trend of warming Mean …

Radicals Transforming Organic Matter: Implications For Non-Pyrogenic Black Carbon And Nitrogen Formation, Molecular Dynamics In Tropical Soils, And Lignin Valorization, João Vitor Dos Santos

Chemistry & Biochemistry Theses & Dissertations

Radicals drive the transformation of organic matter in natural and engineered systems, altering its structure, reactivity, and stability. Condensed aromatic carbon (ConAC) and condensed aromatic nitrogen (ConAN) are among the most persistent forms of organic matter in soils and are traditionally interpreted as products of biomass burning. This dissertation challenges the long-standing assumption that these materials are exclusively pyrogenic, showing that iron-mediated radical chemistry can generate condensed aromatic structures under ambient conditions.

Chapters II and III show that Fenton-like radical oxidation of lignin-rich biomass produces condensed aromatic structures compositionally similar to pyrogenic black carbon and black nitrogen when assessed with …

Quantifying Nutrient Fluxes Across The Sediment-Water Interface In The Lafayette River Estuary, Adriana E. Amrhein

OES Theses and Dissertations

The Lafayette River, a shallow, eutrophic tributary of the Chesapeake Bay, experiences seasonal harmful algal blooms (HABs). While management efforts focus on reducing external nutrient inputs, internal loading from benthic sediments remains poorly constrained. This study quantifies spatial and seasonal variability in nutrient and radium isotope fluxes across the sediment–water interface at three sites where HABs are known to initiate and represent contrasting sediment textures and hydrodynamic conditions. Sediment cores and porewater samples were collected in summer 2023 and winter 2024 to measure grain size, porosity, dissolved nutrients (NH₄⁺, NOₓ⁻, PO₄³⁻), and radionuclide activities (²²⁴Ra and ²²⁸Th). Radium isotope disequilibrium …

Analysis Of Traditional Wisdom For Ecological Sustainability In Tanzania: A Case Study Of Metaphorical Source Domains In Pangwa Ritual Texts, Winne Stephen Mtega, Angelus Mnenuka

Journal of Humanities and Social Sciences

Campaigns for ecological sustainability have gained a great currency in the contemporary academic discourse. Nonetheless, from time immemorial, Africans have pushed the ecological sustainability agenda through cultural taboos and regulated resource harvesting. Many African societies have embedded ecological consciousness in daily life expressions, and have intricately expressed it through literary and ritual texts. This study focuses on ecological awareness in the ritual texts of the Pangwa community. It analyses how environmental domains—such as land, seeds, and fruits—serve as the basis for metaphors in the Pangwa community to prove the use of wisdom to promote and sustain ecological practices (ecocriticism). The …