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Full-Text Articles in Physical Sciences and Mathematics

Ecological Impacts Of Restoring Fire-Grazing Interaction In Sandhills Prairie Through Patch-Burn Grazing, Nolan P. Sipe Dec 2023

Ecological Impacts Of Restoring Fire-Grazing Interaction In Sandhills Prairie Through Patch-Burn Grazing, Nolan P. Sipe

School of Natural Resources: Dissertations, Theses, and Student Research

A Collaborative Adaptive Management (CAM) Project was started at the University of Nebraska in 2020 to address some of the key uncertainties related to the management of grasslands in the Nebraska Sandhills through stakeholder driven experiments and the adaptive management cycle. Patch-burn grazing was selected by CAM as a management tool to generate heterogeneity across the landscape and promote biodiversity while balancing economic and ecological trade-offs. The patch-burn grazing system was implemented with controlled burns in May of 2022 and March of 2023. Other parties in CAM will be examining the impact that patch-burn grazing has on forage and livestock …


Occurrence Of Emerging Contaminants In Greater Houston Watersheds, Risk Assessment, And Toxicological Effects, Sekinat Oluwakemi Atobiloye Dec 2023

Occurrence Of Emerging Contaminants In Greater Houston Watersheds, Risk Assessment, And Toxicological Effects, Sekinat Oluwakemi Atobiloye

Dissertations (2016-Present)

Rapid industrialization and urbanization within the Greater Houston area have driven a surge in anthropogenic activities that affects the burgeoning population. This region stands as one of the most densely inhabited metropolises in the United States, experiencing a substantial population growth of 9.8% from 2010 to 2020, with the population expanding from 5.92 million to 7.14 million. This population boom has been accompanied by an increased reliance on modern conveniences, leading to escalated production and utilization of chemicals such as personal care products, pharmaceuticals, pesticides, and heavy metals, all of which pose potential threats to the environment. Although these products …


Northern Neck Regional Shallow Draft Channel Dredging Plan: Feasibility Phase, Donna A. Milligan, Cameron W. Green, C. Scott Hardaway Jr., Christine A. Wilcox, Claire M. Rae, Scott Lerberg, Alex Demeo, George Brooks, Mark Mansfield Dec 2023

Northern Neck Regional Shallow Draft Channel Dredging Plan: Feasibility Phase, Donna A. Milligan, Cameron W. Green, C. Scott Hardaway Jr., Christine A. Wilcox, Claire M. Rae, Scott Lerberg, Alex Demeo, George Brooks, Mark Mansfield

Reports

The Initial Phase of the project (Phase 1), used remote sensing and other data collection to develop a method for determining which waterbodies on the Northern Neck of Virginia need dredging. The analysis included most of the waterbodies in the counties of Lancaster, Northumberland, Richmond, and Westmoreland. From this analysis, 19 waterbodies emerged as potentially needing dredged based on physical parameters and residential and economic usage (Milligan et al., 2023).

In this Feasibility Phase (Phase 2), more detailed site data were collected to provide data to the localities for consideration. These tasks were included in the analysis:

1. Historic shore …


Northern Neck Regional Shallow Draft Channel Dredging Plan: Initial Phase, Donna A. Milligan, Grace M. Massey, C. Scott Hardaway Jr., Christine A. Wilcox, Cameron W. Green, Mark Mansfield Dec 2023

Northern Neck Regional Shallow Draft Channel Dredging Plan: Initial Phase, Donna A. Milligan, Grace M. Massey, C. Scott Hardaway Jr., Christine A. Wilcox, Cameron W. Green, Mark Mansfield

Reports

The purpose of this project is to develop a regional dredging program for the localities of the Northern Neck. This report encompasses Phase 1 of the project, which included creating a database of waterbodies in Lancaster, Northumberland, Richmond, and Westmoreland Counties and the Town of Colonial Beach along the Potomac and Rappahannock Rivers and Chesapeake Bay. Generally, these waterbodies can be categorized into three basic types of shallow draft channels: federally-authorized to include aids to navigation (ATONS), non-federal with ATONS, and non-federal without ATONs. Along the Northern Neck, presently identified, are 13 federal channels, 37 non-federal channels in creeks with …


Diverse Impacts Of Commercial Ev Charging Load Infrastructure On Electric Power Grid, Antonio Avila Dec 2023

Diverse Impacts Of Commercial Ev Charging Load Infrastructure On Electric Power Grid, Antonio Avila

Open Access Theses & Dissertations

With the rising prominence of electric vehicles (EVs) in the transportation sector, this thesis delves into the critical nexus between commercial EVs, charging infrastructure, and their consequential impacts on the power grid. As commercial EVs, particularly medium and heavy-duty variants, gain traction as viable alternatives in the commercial transportation landscape, understanding the intricacies of their charging requirements becomes paramount. This thesis critically examines the technological and logistical dimensions of the charging infrastructure for supporting commercial EVs, evaluating the consequential implications on the power grid and proposing strategies for mitigation through the utilization of Distributed Energy Resources (DERs). In tandem with …


Movement Patterns Of A Federally Endangered Minnow In A Fragmented Desert River, Martinique J. Chavez Dec 2023

Movement Patterns Of A Federally Endangered Minnow In A Fragmented Desert River, Martinique J. Chavez

All Graduate Theses and Dissertations, Fall 2023 to Present

Fishes are unified in their need to move within the systems they occupy, and their movement patterns can be fundamental to their ecology and survival. Many large rivers in North America are fragmented by dams that modify natural flow regimes, compromise connectivity, and imperil freshwater fishes dependent on unrestricted movement in order to complete their life history. Coincident with widespread river fragmentation, are the declines of numerous endemic desert fishes in the American southwest. The Rio Grande Silvery Minnow (Hybognathus amarus, RGSM), has experienced a 95% reduction in its historical range and is now restricted to a highly …


Reimagining Large River Management Using The Resist–Accept–Direct (Rad) Framework In The Upper Mississippi River, Nicole K. Ward, Abigail J. Lynch, Erik A. Beever, Joshua Booker, Kristen L. Bouska, Holly Embke, Jeffrey N. Houser, John F. Kocik, Joshua Kocik, David J. Lawrence, Mary Grace Lemon, Doug Limpinsel, Madeline R. Magee, Bryan M. Maitland, Owen Mckenna, Andrew Meier, John M. Morton, Jeffrey D. Muehlbauer, Robert Newman, Devon C. Oliver, Heidi M. Rantala, Greg G. Sass, Aaron Shultz, Laura M. Thompson, Jennifer L. Wilkening Dec 2023

Reimagining Large River Management Using The Resist–Accept–Direct (Rad) Framework In The Upper Mississippi River, Nicole K. Ward, Abigail J. Lynch, Erik A. Beever, Joshua Booker, Kristen L. Bouska, Holly Embke, Jeffrey N. Houser, John F. Kocik, Joshua Kocik, David J. Lawrence, Mary Grace Lemon, Doug Limpinsel, Madeline R. Magee, Bryan M. Maitland, Owen Mckenna, Andrew Meier, John M. Morton, Jeffrey D. Muehlbauer, Robert Newman, Devon C. Oliver, Heidi M. Rantala, Greg G. Sass, Aaron Shultz, Laura M. Thompson, Jennifer L. Wilkening

School of Natural Resources: Faculty Publications

Background: Large-river decision-makers are charged with maintaining diverse ecosystem services through unprecedented social-ecological transformations as climate change and other global stressors intensify. The interconnected, dendritic habitats of rivers, which often demarcate jurisdictional boundaries, generate complex management challenges. Here, we explore how the Resist–Accept–Direct (RAD) framework may enhance large-river management by promoting coordinated and deliberate responses to social-ecological trajectories of change. The RAD framework identifies the full decision space of potential management approaches, wherein managers may resist change to maintain historical conditions, accept change toward different conditions, or direct change to a specified future with novel conditions. In the Upper Mississippi …


Environment And Sustainability: December 2023, Environment And Sustainability, Office Of The President Dec 2023

Environment And Sustainability: December 2023, Environment And Sustainability, Office Of The President

Environment and Sustainability

• AKU’s Honourable Mention at the 2023 IHF Awards

• 7% energy savings at Stadium Road

• FMIC’s new solar water heater

• 2 Electric Shuttles for campus commuting

• AKU at COP28

• And much more…


A Control Study Analysis Application Of Unoccupied Aerial Systems (Drones) To Monitor Eutrophication, Chrystal Mata Dec 2023

A Control Study Analysis Application Of Unoccupied Aerial Systems (Drones) To Monitor Eutrophication, Chrystal Mata

Water Resources Science and Technology Theses and Graduate Research Reports

Unmanned Aircraft systems (UAS) can offer a valuable perspective for detecting and monitoring for eutrophication in bodies of water by providing high-resolution images and data assignments for algal blooms and nutrient levels. Eutrophication, the process by which water bodies become enriched with nutrients, has emerged as a critical factor in evaluating and maintaining water quality. In this study, we use DJI Inspire Pro 1 equipped with a Zenmuse X3 camera, attached with a Parrot Sequoia multispectral sensor was used to in conjunction with algorithms to retrieve Chlorophyll parameters for monitoring eutrophication. Although water quality parameters such as pH, nitrate, phosphate, …


Trashed: A Review Of Anthropogenic Litter In An Urban Watershed, John D. Hamilton Dec 2023

Trashed: A Review Of Anthropogenic Litter In An Urban Watershed, John D. Hamilton

Water Resources Science and Technology Theses and Graduate Research Reports

Urban creeks, streams and rivers have become an unfortunate destination for trash pollution. Within an urban watershed trash pollution is harmful to fish, wildlife, public health, contributes to microplastic proliferation, and aesthetically tarnishes an otherwise unscathed ecosystem. With lots of attention focused on trash in marine and coastal ecosystems, this study aims to contribute to the growing research on inland urban watersheds and their involvement. This study highlights issues associated with trash pollution, and investigates the associated vectors, origins, behaviors, and contributing factors that create trash ladened urban watersheds. Datasets and site surveys from repeated trash cleanups in three creekside …


Coastal Wetland Restoration Through The Lens Of Odum's Theory Of Ecosystem Development, Friedrich W. Keppeler, Annette S. Engel, Linda M. Hooper-Bùi, Paola C. López-Duarte, Charles W. Martin, Jill A. Olin, Katelyn J. Lamb, Michael J. Polito, Nancy N. Rabalais, Multiple Additional Authors Dec 2023

Coastal Wetland Restoration Through The Lens Of Odum's Theory Of Ecosystem Development, Friedrich W. Keppeler, Annette S. Engel, Linda M. Hooper-Bùi, Paola C. López-Duarte, Charles W. Martin, Jill A. Olin, Katelyn J. Lamb, Michael J. Polito, Nancy N. Rabalais, Multiple Additional Authors

Environmental Science and Management Faculty Publications and Presentations

Advancing ecological restoration assessments requires a more detailed consideration of species interactions and ecosystem processes. Most restoration projects rely on a few metrics not always directly linked with ecological theory. Here, we used Odum's theory of ecosystem development to assess and compare the ecosystem structure and services of created marshes (4–6 years old) with preexisting, reference marshes in a brackish water region of the Mississippi River Delta. We built ecosystem models for created and reference marshes that integrated large datasets of stomach contents, stable isotopes, and taxa abundances. Despite strong resemblance in community structure, created marshes were at an earlier …


Vertical Free-Swinging Photovoltaic Racking Energy Modeling: A Novel Approach To Agrivoltaics, Koami Soulemane Hayibo, Joshua M. Pearce Dec 2023

Vertical Free-Swinging Photovoltaic Racking Energy Modeling: A Novel Approach To Agrivoltaics, Koami Soulemane Hayibo, Joshua M. Pearce

Electrical and Computer Engineering Publications

To enable lower-cost building materials, a free-swinging bifacial vertical solar photovoltaic (PV) rack has been proposed, which complies with Canadian building codes and is the lowest capital-cost agrivoltaics rack. The wind force applied to the free-swinging PV, however, causes it to have varying tilt angles depending on the wind speed and direction. No energy performance model accurately describes such a system. To provide a simulation model for the free-swinging PV, where wind speed and direction govern the array tilt angle, this study builds upon the open-source System Advisor Model (SAM) using Python. After the SAM python model is validated, a …


Wavelet Compression As An Observational Operator In Data Assimilation Systems For Sea Surface Temperature, Bradley J. Sciacca Dec 2023

Wavelet Compression As An Observational Operator In Data Assimilation Systems For Sea Surface Temperature, Bradley J. Sciacca

University of New Orleans Theses and Dissertations

The ocean remains severely under-observed, in part due to its sheer size. Containing nearly billion of water with most of the subsurface being invisible because water is extremely difficult to penetrate using electromagnetic radiation, as is typically used by satellite measuring instruments. For this reason, most observations of the ocean have very low spatial-temporal coverage to get a broad capture of the ocean’s features. However, recent “dense but patchy” data have increased the availability of high-resolution – low spatial coverage observations. These novel data sets have motivated research into multi-scale data assimilation methods. Here, we demonstrate a new assimilation approach …


Measuring The Lengths Of Sperm Whales Of The Northern Gulf Of Mexico By Wavelet Analysis Of Their Usual Clicks, George Drouant Dec 2023

Measuring The Lengths Of Sperm Whales Of The Northern Gulf Of Mexico By Wavelet Analysis Of Their Usual Clicks, George Drouant

University of New Orleans Theses and Dissertations

Abstract

Acoustic recordings of underwater sounds produced by marine mammals present an attractive alternative to costly and logistically complex ship based visual surveys for collecting population data for various species.

The first reported use of underwater acoustic recordings in the long-term monitoring of sperm whale populations was by Ackleh et al. (Ackleh et al., 2012). The paper describes counting sperm whale clicks at different locations to track population changes over time.

Analysis of sperm whale clicks offers additional insight into sperm whale populations. The echo location clicks (usual clicks) of sperm whales can be used to give an estimate of …


The Tidal Prism, Viable Eelgrass Habitat, And The Effects Of Sea Level Rise In Morro Bay, Kaden A. Caliendo Dec 2023

The Tidal Prism, Viable Eelgrass Habitat, And The Effects Of Sea Level Rise In Morro Bay, Kaden A. Caliendo

Master's Theses

The tidal prism, or the volume of water exchanged from the sea to an estuary from mean low to mean high tide, influences system hydrodynamics and ecological functioning. Since 1884, the tidal prism in Morro Bay, California has been estimated to be decreasing over time due to sedimentation from upstream practices. What is the current tidal prism in Morro Bay and how will that change with sea level rise? How will eelgrass respond to rising sea levels?

For this study, inexpensive tidal gauges were deployed at four locations in Morro Bay from March to August 2023 to measure spatially varying …


Including The Human Dimension Into Resilience Planning For Maine’S Lobster Fishery, Katherine Maltby, Katherine E. Mills Dec 2023

Including The Human Dimension Into Resilience Planning For Maine’S Lobster Fishery, Katherine Maltby, Katherine E. Mills

Maine Policy Review

The American lobster fishery is one of the most valuable in the US but is being affected by climate-driven shifts in lobster availability, impacting people’s ability to harvest the resource and sparking broader adaptation challenges. Since the late 1990s, lobster landings in the Gulf of Maine (GOM) have climbed to record levels while those in Southern New England (SNE) have experienced significant declines. The experiences of SNE lobstermen during these declines can offer important lessons for both individual lobstermen and communities in the GOM, where lobster abundance is currently at high levels but facing future uncertainty given continuing climate trends. …


The Surprising Oceanography Of The Gulf Of Maine, Nicholas R. Record, Benjamin Tupper, Johnathan Evanilla, Kyle Oliveira, Camille Ross, Logan Ngai, Karen Stamieszkin Dec 2023

The Surprising Oceanography Of The Gulf Of Maine, Nicholas R. Record, Benjamin Tupper, Johnathan Evanilla, Kyle Oliveira, Camille Ross, Logan Ngai, Karen Stamieszkin

Maine Policy Review

The oceanography of the Gulf of Maine has changed in ways that have not been seen previously but that are likely to be more common in the future–changes like extreme rapid warming and declines in primary productivity. The changing oceanography has underpinned surprising losses in commercial stocks and endangered species. Because of the rapid rate of change, some have viewed the Gulf of Maine as a window into the ocean’s future, with the idea that lessons learned can be applied in places that have yet to experience similar rapid changes. We can examine the dynamics, origin, and implications of surprising …


Controls On Sediment Connectivity In Fluvial Networks Impacted By Wildfire Across Utah, Alec Arditti Dec 2023

Controls On Sediment Connectivity In Fluvial Networks Impacted By Wildfire Across Utah, Alec Arditti

All Graduate Theses and Dissertations, Fall 2023 to Present

Flooding and sedimentation caused by wildfire are among the greatest threats to watersheds, fish populations and reservoirs in the western US. Burned landscapes are at risk for increased runoff and erosion and have the potential to transport sediment that may put downstream resources at risk. The ability of the channel to transport sediment downstream, known as the connectivity, is important for determining where impacts may occur. Sediment bottlenecks are locations within the watershed where local conditions produce a persistent decrease in downstream connectivity of sediment, resulting in increased sediment deposition and potentially a substantial modification of the local channel and …


The Impacts Of Tilled-In Biodegradable Plastic Mulch On Soil Microbial Communities, Corissa L. Martin Dec 2023

The Impacts Of Tilled-In Biodegradable Plastic Mulch On Soil Microbial Communities, Corissa L. Martin

Masters Theses

Plastics mulch films are used in agriculture to help increase crop production by regulating soil water retention and soil temperature while also preventing weed growth. Despite these benefits, plastic mulches have led to higher levels of microplastic pollution as weathering occurs. In response to this issue, biodegradable plastic mulches (BDMs) have been introduced to help reduce plastic pollution as they are designed to be tilled into soil after each growing season to continue degradation. Degradation of these mulch films is dependent on climate and, in some areas, complete degradation can take years. Since some biodegradable plastic mulches are made of …


Prospects And Constraints For A Recreational Fishery On East Canyon Creek At The 910 Ranch, S. Bishop, A. Garner, G. Mclaughlin, T. Oman, N. Omer, C. Stewart Dec 2023

Prospects And Constraints For A Recreational Fishery On East Canyon Creek At The 910 Ranch, S. Bishop, A. Garner, G. Mclaughlin, T. Oman, N. Omer, C. Stewart

Watershed Sciences Student Research

Summit County Lands and Natural Resources has retained students from Utah State University’s Management and Restoration of Aquatic Ecosystems program to evaluate current conditions of East Canyon Creek (ECC) in the 910 Ranch and propose prospects, constraints, and potential actions to establish a recreational trout fishery.


Exposure To Climate Change Information Predicts Public Support For Solar Geoengineering In Singapore And The United States, Sonny Rosenthal, Peter J. Irvine, Christopher L. Cummings, Shirley S. Ho Dec 2023

Exposure To Climate Change Information Predicts Public Support For Solar Geoengineering In Singapore And The United States, Sonny Rosenthal, Peter J. Irvine, Christopher L. Cummings, Shirley S. Ho

Research Collection College of Integrative Studies

Solar geoengineering is a controversial climate policy measure that could lower global temperature by increasing the amount of light reflected by the Earth. As scientists and policymakers increasingly consider this idea, an understanding of the level and drivers of public support for its research and potential deployment will be key. This study focuses on the role of climate change information in public support for research and deployment of stratospheric aerosol injection (SAI) in Singapore (n = 503) and the United States (n = 505). Findings were consistent with the idea that exposure to information underlies support for research and deployment. …


Post-Wildfire Effects On A Headwater Stream In The San Bernardino National Forest, Kelley Giron Dec 2023

Post-Wildfire Effects On A Headwater Stream In The San Bernardino National Forest, Kelley Giron

Electronic Theses, Projects, and Dissertations

Southern California has experienced prolonged drought conditions that have supported frequent wildfires that adversely impact ecosystems, natural resources, and human development. A primary consequence of these events is the impact on water quality and quantity. Of equal concern is evaluating how diverse land use configurations within a watershed can alter the physio-chemical properties of headwater reaches where drought and wildfire conditions are prevalent. To better understand the extent to which wildfires impact water quality and quantity across a headwater watershed, this study investigates wildfire impacts from the 2021 South Fire to Lytle Creek, a headwater stream of the Santa Ana …


Enhancing Urban Water Quality Through Biological-Chemical Treatment: Aquatic Macroinvertebrate Community And Temporal Chlorophyll-A Response, Matthew Chaffee Dec 2023

Enhancing Urban Water Quality Through Biological-Chemical Treatment: Aquatic Macroinvertebrate Community And Temporal Chlorophyll-A Response, Matthew Chaffee

Department of Biological Systems Engineering: Dissertations and Theses

With a growing human population, urbanization is impeding a plethora of natural waterways. Of these, urban ponds play a vital role in nutrient sequestration, flood prevention, and habitat sanctuaries. However, nutrient loading can reduce habitat effectiveness and promote harmful algae blooms. To reduce internal nutrient loads, a biological-chemical treatment strategy consisting of floating treatment wetlands (FTWs) and lanthanum were applied to two urban retention ponds, Densmore and Wilderness Ridge Ponds. To measure effectiveness, chlorophyll-a samples were collected and correlated with Sentinel-2. A novel band algorithm termed 3BR1 produced a strong correlation (R2 = 0.72) to physical chlorophyll-a …


Evaluation Of Evapotranspiration Estimates Using An Existing Hybrid Machine Learning Model In A Natural And A Managed Dryland Site, Katya Esquivel Herrera Dec 2023

Evaluation Of Evapotranspiration Estimates Using An Existing Hybrid Machine Learning Model In A Natural And A Managed Dryland Site, Katya Esquivel Herrera

Open Access Theses & Dissertations

Evapotranspiration (ET) is a critical component of the hydrologic cycle, encompassing both evaporative water loss from surfaces and transpiration through plant stomata. The environmental factors influencing ET include water and energy availability, atmospheric capacity for water uptake, and various meteorological variables. ET serves as a unique climate variable linking water, energy, and carbon cycles. In agroecosystems, accurate ET quantification is vital for optimizing water use efficiency, irrigation management, and crop yield. Traditional methods for ET estimation involve direct measurements and indirect models, with both presenting limitations.

Recent years have witnessed the integration of remote sensing and machine learning (ML) algorithms …


Bitcoin's Technical Foundation And Its Potential For A Decentralized And Environmentally Friendly Future, Iqtiar Md Siddique Dec 2023

Bitcoin's Technical Foundation And Its Potential For A Decentralized And Environmentally Friendly Future, Iqtiar Md Siddique

Open Access Theses & Dissertations

This research examines a systematic analysis of Bitcoin, employing a Coefficient of Variation (CV) approach to gauge its degree of decentralization. Bitcoin, an innovative decentralized digital currency, has received much attention for its potential to revolutionize traditional financial systems. This study employs the Coefficient of Variation (CV) to acquire insights into the wealth distribution and concentration among Bitcoin users. This research demonstrates how decentralized the network of Bitcoin is. The methodology uses real data on Bitcoin addresses and their holdings to compute the Coefficient of Variation (CV). This approach provides valuable insights into the ongoing discourse surrounding Bitcoin's decentralization, offering …


Effects Of Elevated Temperature On 8-Ohdg Expression In The American Oyster (Crassostrea Virginica): Induction Of Oxidative Stress Biomarkers, Cellular Apoptosis, Dna Damage And Γh2ax Signaling Pathways, Md Faizur Rahman, Mohammad Maruf Billah, Richard Kline, Md Saydur Rahman Dec 2023

Effects Of Elevated Temperature On 8-Ohdg Expression In The American Oyster (Crassostrea Virginica): Induction Of Oxidative Stress Biomarkers, Cellular Apoptosis, Dna Damage And Γh2ax Signaling Pathways, Md Faizur Rahman, Mohammad Maruf Billah, Richard Kline, Md Saydur Rahman

School of Earth, Environmental, and Marine Sciences Faculty Publications and Presentations

Global temperature is increasing due to anthropogenic activities and the effects of elevated temperature on DNA lesions are not well documented in marine organisms. The American oyster (Crassostrea virginica, an edible and commercially important marine mollusk) is an ideal shellfish species to study oxidative DNA lesions during heat stress. In this study, we examined the effects of elevated temperatures (24, 28, and 32 °C for one-week exposure) on heat shock protein-70 (HSP70, a biomarker of heat stress), 8-hydroxy-2’-deoxyguanosine (8-OHdG, a biomarker of pro-mutagenic DNA lesion), double-stranded DNA (dsDNA), γ-histone family member X (γH2AX, a molecular biomarker of DNA damage), …


Initial Limnology Of Laguna Pozo Verde, Costa Rica: Bathymetry, Water, Sediments, And Diatoms, Sally P Horn, Erik N. Johanson, Mauricio Murillo Herrera, Kurt A. Haberyan, Taber Friedel, Chad S. Lane Dec 2023

Initial Limnology Of Laguna Pozo Verde, Costa Rica: Bathymetry, Water, Sediments, And Diatoms, Sally P Horn, Erik N. Johanson, Mauricio Murillo Herrera, Kurt A. Haberyan, Taber Friedel, Chad S. Lane

Geography Publications and Other Works

ABSTRACT. Introduction: Costa Rica has hundreds of lakes, many of which have never been scientifically studied. Objective: To carry out a first, basic limnological study of Laguna Pozo Verde in Juan Castro Blanco National Park, Costa Rica (~1935m elevation), to provide baseline data for studying future changes. Methods: We measured water depths and temperatures, and Secchi depth; analyzed surface sediments; and examined maps and satellite imagery. Results: Though described by some as formed by volcanic processes, Laguna Pozo Verde likely formed in a landslide, which occur frequently in this rainy area on the steep south slope of the inactive Porvenir …


Development, Voice, And Vulnerability: A Rhetorical Analysis Of The Policy-Making Discourse Regarding The Paris Agreement As An Organizational Response To Climate Change, David Almanza-Canas Dec 2023

Development, Voice, And Vulnerability: A Rhetorical Analysis Of The Policy-Making Discourse Regarding The Paris Agreement As An Organizational Response To Climate Change, David Almanza-Canas

UNLV Theses, Dissertations, Professional Papers, and Capstones

On December 12, 2015, the Paris Agreement was officially ratified by 196 sovereign entities. This treaty represents a global call to action to ameliorate the impact of human activities on our environment, and it creates a means of cooperation through financial support and transparent industrial practices with the goal of promoting accountability across the world. This treaty and the discourse surrounding it present fertile ground for the academic understanding of persuasive practices in policy-making. By examining the rhetorical implications of the Paris Agreement as a global policy, scholars can gain new insight about the communities represented in the conversation as …


An Evaluation Of Lead Concentration In Commercially Available Tiles, Daidre N. Gamboa Dec 2023

An Evaluation Of Lead Concentration In Commercially Available Tiles, Daidre N. Gamboa

UNLV Theses, Dissertations, Professional Papers, and Capstones

Workers in the manufacturing and construction industries are at risk of lead exposure in projects that involve removal or installation of tiles, and other individuals exposed to lead, including children may also be at risk. The concern with lead in tiles is thought to be related to the glazing process or the country where the tile was produced. Multiple regulations are in place in the U.S. to protect people from lead exposure, including through surface coatings or painted surfaces. But these regulations do not cover glazed tiles. This study examined whether there are differences in lead concentration in (1) tiles …


Beyond Corporate Greenwashing: Discourse Of A 'Just' Electric Energy Transition Materialized At The Thacker Pass Lithium Mine, Laekyn Kelley Dec 2023

Beyond Corporate Greenwashing: Discourse Of A 'Just' Electric Energy Transition Materialized At The Thacker Pass Lithium Mine, Laekyn Kelley

UNLV Theses, Dissertations, Professional Papers, and Capstones

Thacker Pass in Northern Nevada is a rich desert ecosystem with spiritual significance to local Indigenous peoples, and it is also the site for what will be, for now, the United States’ largest open-pit lithium mine. Lithium is one mineral constituent of electric batteries which are essential to current U.S. electric energy transition policy, a transition which policymakers and other public groups have called on to be done in a way which is just. However, what exactly a just electric energy transition looks like in places like Thacker Pass is under continued negotiation in theoretical and practical senses. Existing research …