Digital Commons Network^™

Electromagnetic Simulations Of The Lansce Chopper Structure, Yusuf Sahin

Electrical and Computer Engineering ETDs

Particle accelerators are important for basic research as well as in applications such as ion implantation and cancer therapy. One important accelerator is the Los Alamos Neutron Science Center (LANSCE) located at Los Alamos National Laboratory (LANL) that primarily produces neutrons for research. The beam chopper simulation described here is a study to provide better modeling of this subsystem of LANSCE. A chopper is a device in which particles are intermittently sliced and directed to a target and/or experiment. The simulations in this thesis are used to analyze the correct operating parameters of the chopper. A good chopper model can …

Myeloid Fth1 Deficiency Protects Mice From Colitis And Colitis-Associated Colorectal Cancer Via Reducing Dmt1-Imported Iron And Stat3 Activation, Zhaoli Liu, Mariella Arcos, David R. Martin, Xiang Xue

Pathology Research and Scholarship

BACKGROUND: Myeloid cells are critical for iron and immune homeostasis. Ferritin heavy chain (FTH1) is essential for intracellular iron storage. Myeloid FTH1 is important in the pathogenesis of many inflammatory diseases. However, the role of myeloid FTH1 in colitis and colitis-associated cancer has not been determined.

METHODS: Myeloid FTH1 deficient and wild-type mice were treated with dextran sodium sulfate (DSS) or azoxymethane (AOM)-DSS to compare their susceptibility to acute colitis or colitis-associated cancer.

RESULTS: Myeloid FTH1-deficient mice fed with a high-iron diet were less susceptible to DSS-induced acute colitis than wild type mice. Mechanistic studies showed that myeloid FTH1 deficiency …

Immigrational Trauma: An Assessment Of Dental Phobia And Access To Care In Undocumented Individuals, Nora J. Vences Ortiz

Dental Hygiene ETDs

The purpose of this study is to assess immigrational trauma as it relates to dental phobia in accessing care from undocumented individuals. Immigrating from a country to the United States presents with unique challenges. These challenges include language barriers, traumatic experiences and cultural factors. These individuals also have perceived notions regarding their treatment with a physician or dentist as their immigration status may or may not be revealed during their care. If reported, they face deportation to their country of origin placing them in the danger they originally fled from. Survey data was collected using REDCap and distributed to students …

Alcohol Consumption And Measures Of Sarcopenic Muscle Risk: Cross-Sectional And Prospective Associations Within The Uk Biobank Study, Jane Skinner, Lee Shepstone, Mary Hickson, Ailsa A. Welch

School of Health Professions

Alcohol intake is a major modifiable risk factor for many diseases. Alcohol can also damage skeletal muscle health during ageing which in turn increases risk of sarcopenia, frailty and falls but this relationship is understudied. The aim of this study was to model the relationship between a full range of alcohol consumption and components of sarcopenic risk, skeletal muscle mass and function, in middle-aged and younger older-aged men and women. A cross-sectional analyses was undertaken of 196,561 white participants from the UK Biobank with longitudinal analysis also in 12,298 of these participants, with outcome measures for the latter repeated after …

An Extended Mtdna Phylogeography For The Alpine Newt Illuminates The Provenance Of Introduced Populations, J Robbemont, Veldhuijzen S Van, J.R. A Steven, J Ambu, R Boyle, D Canestrelli, M Cvijanović, C Dufresnes, C Ennis, R Gandola, D Jablonski, A Julian, D Kranželić, S Lukanov, I Martínez-Solano, R Montgomery, B Naumov, M O’Neill, N Alexandra, M Pabijan, R Puschendorf, D Salvi, B Schmidt, K Sotiropoulos, F Stanescu, D Stanković, S Stapelton, E Šunje, M Szabolcs, E Vacheva, D Willis, A Zimić, J France, Wrm Meilink, T Stark, Rpjh Struij, A Theodoropoulos, Visser1 Mc De, B Wielstra

School of Biological and Marine Sciences

Many herpetofauna species have been introduced outside of their native range. MtDNA barcoding is regularly used to determine the provenance of such populations. The alpine newt has been introduced across the Netherlands, the United Kingdom and Ireland. However, geographical mtDNA structure across the natural range of the alpine newt is still incompletely understood and certain regions are severely undersampled. We collect mtDNA sequence data of over seven hundred individuals, from both the native and the introduced range. The main new insights from our extended mtDNA phylogeography are that 1) haplotypes from Spain do not form a reciprocally monophyletic clade, but …

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 …

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 …

Diversification By Dispersal Out Of The Andes Revealed By A Newly Discovered Hummingbird Clade, The ‘True Brilliants’, Marialejandra Castro-Farías

Biology ETDs

We identified a novel clade with striking biogeographic implications. Unsampled genera, Hylonympha and Sternoclyta, were found to be close to the genus Heliodoxa within the Brilliants. Heliodoxa tend to occur in lower montane habitats, such as the tropical, upper tropical, and subtropical elevational zones of the Andes and the Neotropics. Analysis of geographic and elevational zones showed that genus Heliodoxa and related genera diversified by out-of-Andes dispersal to mountain ranges of Central America, coastal Venezuela, the Pantepui, and southeastern Brazil, since the mid-Miocene. Within the Brilliants, reductions in elevation preceded these geographic expansions. Secondary colonization of the lowlands from …

An Investigation Of Freshwater Turtle Ecology Using Stable Isotopes, Jonathan Duran

Biology ETDs

In 2022 I investigated niche partitioning among native and invasive freshwater turtles across three sites in the Middle Rio Grande using bulk stable isotope analysis. I found high degrees of niche partitioning at sites in which Red-eared sliders (Trachemys scripta) have yet to establish. However, at sites in which red-eared sliders are now the most abundant species they overlapped greatly in isotopic niche with all native turtles, in particular the painted turtle (Chrysemys picta). Using these same techniques, I then examined the trophic interactions between red-eared sliders and their acanthocephalan parasites. My results suggest that acanthocephalans …

Post-Fire Plant Community Response In Subalpine Mixed Conifer Forest, Sasha Escamilla

Biology ETDs

Increased wildfire activity may lead to significant shifts in vegetation dynamics in high elevation mixed conifer forests. These changes raise concerns about the resilience of forests following wildfire, prompting the need for a deeper understanding of post-fire plant community response. We analyzed up to 11 years of post-fire vegetation data from Valles Caldera National Preserve in northern New Mexico to determine how burned vegetation sites were recovering following high severity wildfire, and whether or not plant communities were transitioning to montane grassland. We found burned understory herbaceous communities were not transitioning into distinctive montane grasslands and were instead recovering to …

Thermoregulation In Nocturnal Volant Endotherms Occupying Hot Deserts, William A. Talbot

Biology ETDs

The study of thermoregulation is of growing concern in this era of rapid climate change. Earlier studies such as those pioneered by Scholander and Bartholomew directed focus toward the study of endotherm survival in conditions of cold weather adversity. As techniques evolved in the measurement of parameters quantifying thermoregulation, metabolism and energy allocation, the standardization procedures has increased the comparability of data from diverse taxa. We can now search historical records and current research for explanations to the changes in the distribution, migration, extirpation or survival of animal and plant populations through time. It is increasingly common to observe dramatic …

Resolving The Paradox Of Polyploidy: Underexplored Facets Of Polyploid Plants, Benjamin P. Gerstner

Biology ETDs

Polyploidy, or whole genome duplication, is a common phenomenon in plants, but the establishment and persistence of mixed-ploidy populations remains a paradox. This dissertation explores factors that contribute to the persistence and establishment of mixed-ploidy populations in nature. The first chapter investigates the role of unreduced gametes in neopolyploid establishment and finds that variability in their formation rate can have a significant impact on polyploid establishment and persistence. The second chapter searches for evidence of soil microbes exhibiting ploidy-specificity, a pre-condition for microbe-mediated niche differentiation, a possible stabilizing mechanism contributing to ploidy coexistence. Finally, the third chapter tests for microbe-mediated …

Synthetic Biology Enabled Modification Of Bone Cells And Impact On Bone Mineral Resorption, Dulce C. Hayes

Biomedical Sciences ETDs

Development of a cell culture based bone model can contribute to biomedical research by producing a reproducible model system that mimics a bone remodeling disorder and reduces the use of animals in research studies. Synthetic biology was used to engineer osteoblast cell lines to alter a key protein in the RANKL pathway in efforts to control the bone remodeling process. Osteoblast cell lines, K7M2 and MC3T3-E1 Subclone 4 were engineered to express osteoprotegerin (OPG) and inhibit OPG expression, respectively. The upregulation of OPG expression was confirmed with Real Time PCR and Quantikine® Immunoassay. To identify the functionality of the engineered …

Reconsidering Fertility Imagery In The Murals Of Teotihuacan, Grace T.O. Ray

Theses

This thesis explores fertility imagery in the Tepantitla Paradise and Tetitla Goddess murals of ancient Teotihuacan in Mexico. In the beginning of the 1970s, these murals had been utilized as case studies in the assertion for the existence of a central female deity known as the Great Goddess, based on an abundance of fertility imagery within the scenes. Scholarship in the field has since discredited this theory, but the deity in the murals remains unidentified. In addition, the city does not offer surviving written texts to provide context for cosmological beliefs, only Teotihuacan’s vibrant material culture was left behind after …

A Computational Approach For The Discovery And Characterization Of Oligonucleotide Aptamers For Protein Targets, Godfred Sabbih

Masters Theses and Doctoral Dissertations

Aptamers are short polynucleotide chains that can bind with very high affinities to a broad range of chemical and biomolecular targets, including proteins, cells, viruses, microorganisms, toxins, and chemical compounds. They are analogous to antibodies with applications in therapeutic delivery, biosensors, and diagnostics, but possess the advantages of easy production and lower immunogenicity than antibodies. They are produced by the experimental method known as the systematic evolution of ligands by exponential enrichment (SELEX). SELEX is a powerful experimental method for selecting oligonucleotide aptamers for chemical or biomolecular targets of interest. The SELEX protocol has seen several modifications since its development …

Secondary Teachers' Perceptions On Their Competency And Self-Efficacy Levels Associated With An Integrated Professional Development Approach To Teaching United States History, Darwin Anthony Galloway

Masters Theses and Doctoral Dissertations

The study assessed a multifaceted professional development approach and its impact on teacher competency and self-efficacy. The professional development approach considered in this study reflected an integration of Content Immersion Mini-institutes, Public History Field Experiences, and Collaborative Pedagogical workshops offered to middle school and high school United States history teachers. The major focus of the study was scaled exit surveys and free response questions completed by teachers in six school districts in northeastern Tennessee, who were part of a Teaching American History Grant program sponsored by Tennessee’s First Frontier Consortium. These extant exit surveys were used to determine the relationship …

Integrating Human Psychology Into Car-Following Models For Accurate Response Prediction: A Realistic Approach, Faiza Khan

Masters Theses and Doctoral Dissertations

Car-following models traditionally focus on vehicle kinematics or dynamics parameters without considering human psychology. However, recent research has attempted to incorporate psychology into car-following models. Despite these efforts, there are limitations in understanding the psychological triggers that influence individual drivers' responses. To address this gap, we propose a new car-following model based on the Theory of Planned Behavior (TPB), which incorporates a human element by utilizing concepts of psychology. To gather the data pertaining to human input a questionnaire was carefully developed utilizing the Theory of Planned Behavior. Data collection and analysis were done through a survey using google forms. …

Developing A Predictive Geospatial Habitat Model For A Rare Species Of Salamander In Tennessee: A Case Study For The Green Salamander (Aneides Aeneus), Erin Gaylord

Masters Theses and Doctoral Dissertations

Green Salamanders (Aneides aeneus; Cope and Packard 1881) are a secretive and cryptic species of salamander that can be relatively difficult to detect, due to their occupation of arboreal habitats. The incorporation of geospatial tools is critical in developing models that can be used to predict undocumented locations in Tennessee and elsewhere. Locating the species in Tennessee was accomplished through a total of 18 localities and with that, several habitat characteristics were able to be identified including, but not limited to: appropriately shaded and structured rocks, typical fauna co-occurring within the area, and general topography of the area. Of the …

Emotion Recogniton In Students With Social Anxiety: Loving-Kindness As An Intervention, Audrey Darnbush

Masters Theses and Doctoral Dissertations

Deficits in emotion recognition can often be found in individuals who have elevated social anxiety—decreasing positive social interaction and increasing social avoidance. Some possible causes for these deficits include: (1) negative interpretation biases for ambiguous social stimuli and (2) negatively biased self-focused and others-focused attention in social situations— which can impede an accurate appraisal of how one is being evaluated. Mindfulness-based interventions target attentional awareness, and some have empirical support for treating anxiety-related issues. However, little research has been conducted to determine the possible therapeutic effects of loving-kindness meditation for social anxiety disorder. Loving-kindness meditation (LKM) is a specific subtype …

Influence Of Abiotic Drivers And Plant Community Interactions On Bald Cypress (Taxodium Distichum) Seedlings: Implications For Restoration, Victoria Ellis

Biological Sciences Theses & Dissertations

Forested freshwater wetlands are valuable ecosystems that provide habitat for numerous species, sequester carbon, and act as sinks for excess water and nutrients. Historically, these ecosystems have been heavily degraded by anthropogenic activities leading to loss of ecosystem services and a desire to restore freshwater forested wetland habitat. Thus, science-backed approaches for the restoration of freshwater forested wetlands are necessary to ensure restoration goals are met. This body of research employed the Stress Gradient Hypothesis to test whether a multi-species planting approach using Juncus effusus (L.) (soft rush) could facilitate the survival of Taxodium distichum (L.) Rich. (bald cypress) seedlings …

Effects Of Physical Characteristics Of Placebos On Exercise Performance, Owen Sipes

Human Movement Studies & Special Education Theses & Dissertations

Previous research has shown that placebos can impact medical conditions such as irritable bowel syndrome and depression as well as elicit analgesic effects and improvements in certain exercise performances. These placebo responses occur from a variety of alterations to the placebo itself or through verbal suggestion of how helpful the placebo will be. This study aimed to observe whether changing the color and quantity of capsules can induce improvements in both vertical jump and hand grip strength. This deceptive, parallel study consisted of 28 participants, with a mean age of 24.9 (±4.3) years old, that were randomly assigned to receive …

Effects Of Chewing Time On Gastrointestinal Discomfort, Substrate Use, And Performance During Running, Thomas Geaney

Human Movement Studies & Special Education Theses & Dissertations

Previous research has shown that food particle size affects gastric processing. For example, food particles greater than 3 mm may delay gastric emptying under certain conditions. Delays in gastric emptying can be problematic during aerobic exercise, leading to nausea, bloating, fullness, and other gastrointestinal (GI) symptoms. In some cases, symptoms can be severe enough to negatively affect athletic performance. This study investigated the effects of manipulating chewing duration of carbohydrate sports bars on GI discomfort, physiological responses, and performance during endurance running. This crossover study recruited 12 male runners (age: 36.4 ± 7.2 years, VO_2peak: 57.2 ± 4.7 …

Disrupting Whiteness In Education Organizations: Community Testimonios Of Strategy, Resistance, And Perseverance In Educational Justice Organizing, Florence E. Castillo

Sociology ETDs

Through this project, I utilize multiple approaches to disrupt whiteness. I make a case for centering Indigenous and non-Western methods, such as testimonio in sociological studies, to disrupt the academic whiteness of knowledge creation and validation. Whiteness itself is amorphous and looks different depending on circumstances, location, who holds power, and context (Hughey 2016). Utilizing a theory of racialized organizations, I shed light on how whiteness is normalized in education institutions through race-neutral, everyday actions (Ray 2019). This further disrupts whiteness by rendering it visible. Finally, I highlight the different modes of resistance that educational activists use to disrupt whiteness. …

Cross-Cultural Applicability Of Eye-Tracking In Assessing Attention To Emotional Faces In Preschool-Aged Children, Sara S Nozadi, Andrea Aguiar, Ruofei Du, Elizabeth A Enright, Susan L Schantz, Curtis Miller, Brandon Rennie, Mallery Quetawki, Debra Mackenzie, Johnnye L Lewis

Pediatrics Research and Scholarship

Humans show an attention bias toward emotional versus neutral information, which is considered an adaptive pattern of information processing. Deviations from this pattern have been observed in children with socially withdrawn behaviors, with most research being conducted in controlled settings among children from urban areas. The goal of the current study was to examine the cross-cultural applicability of two eye-tracking-based measures in assessing attention biases and their relations to children's symptoms of socially withdrawn behaviors in two independent and diverse samples of preschool children. The cross-cultural comparison was conducted between the Navajo Birth Cohort study (NBCS), an indigenous cohort with …

Genomic Analyses In Cornelia De Lange Syndrome And Related Diagnoses: Novel Candidate Genes, Genotype-Phenotype Correlations And Common Mechanisms, Maninder Kaur, Justin Blair, Batsal Devkota, Sierra Fortunato, Dinah Clark, Audrey Lawrence, Jiwoo Kim, Wonwook Do, Benjamin Semeo, Olivia Katz, Devanshi Mehta, Nobuko Yamamoto, Emma Schindler, Zayd Al Rawi, Nina Wallace, Jonathan J Wilde, Jennifer Mccallum, Jinglan Liu, Dongbin Xu, Marie Jackson, Stefan Rentas, Ahmad Abou Tayoun, Zhang Zhe, Omar Abdul-Rahman, Bill Allen, Moris A Angula, Kwame Anyane-Yeboa, Jesús Argente, Pamela H Arn, Linlea Armstrong, Lina Basel-Salmon, Gareth Baynam, Lynne M Bird, Daniel Bruegger, Gaik-Siew Ch'ng, David Chitayat, Robin Clark, Gerald F Cox, Usha Dave, Elfrede Debaere, Michael Field, John M Graham, Karen W Gripp, Robert Greenstein, Neerja Gupta, Randy Heidenreich, Jodi Hoffman, Robert J Hopkin, Kenneth L Jones, Marilyn C Jones, Ariana Kariminejad, Jillene Kogan, Baiba Lace, Julian Leroy, Sally Ann Lynch, Marie Mcdonald, Kirsten Meagher, Nancy Mendelsohn, Ieva Micule, John Moeschler, Sheela Nampoothiri, Kaoru Ohashi, Cynthia M Powell, Subhadra Ramanathan, Salmo Raskin, Elizabeth Roeder, Marlene Rio, Alan F Rope, Karan Sangha, Angela E Scheuerle, Adele Schneider, Stavit Shalev, Victoria Siu, Rosemarie Smith, Cathy Stevens, Tinatin Tkemaladze, John Toimie, Helga Toriello, Anne Turner, Patricia G Wheeler, Susan M White, Terri Young, Kathleen M Loomes, Mary Pipan, Ann Tokay Harrington, Elaine Zackai, Ramakrishnan Rajagopalan, Laura Conlin, Matthew A Deardorff, Deborah Mceldrew, Juan Pie, Feliciano Ramos, Antonio Musio, Antonie D Kline, Kosuke Izumi, Sarah E Raible, Ian D Krantz

Pediatrics Research and Scholarship

Cornelia de Lange Syndrome (CdLS) is a rare, dominantly inherited multisystem developmental disorder characterized by highly variable manifestations of growth and developmental delays, upper limb involvement, hypertrichosis, cardiac, gastrointestinal, craniofacial, and other systemic features. Pathogenic variants in genes encoding cohesin complex structural subunits and regulatory proteins (NIPBL, SMC1A, SMC3, HDAC8, and RAD21) are the major pathogenic contributors to CdLS. Heterozygous or hemizygous variants in the genes encoding these five proteins have been found to be contributory to CdLS, with variants in NIPBL accounting for the majority (>60%) of cases, and the only gene identified to date that results in …

2022 American College Of Rheumatology Guideline For Exercise, Rehabilitation, Diet, And Additional Integrative Interventions For Rheumatoid Arthritis, Bryant R England, Benjamin J Smith, Nancy A Baker, Jennifer L Barton, Carol A Oatis, Gordon Guyatt, Allen Anandarajah, Kristine Carandang, Karmela Kim Chan, Deb Constien, Eileen Davidson, Carole V Dodge, Anita Bemis-Dougherty, Sotiria Everett, Nadine Fisher, Liana Fraenkel, Susan M Goodman, Janet Lewis, Victoria Menzies, Larry W Moreland, Iris Navarro-Millan, Sarah Patterson, Lawrence Rick Phillips, Neha Shah, Namrata Singh, Daniel White, Rawan Alheresh, Kamil E Barbour, Thomas Bye, Dana Guglielmo, Rebecca Haberman, Tate Johnson, Anatole Kleiner, Chris Y Lane, Linda C Li, Hiral Master, Daniel Pinto, Janet L Poole, Kimberly Steinbarger, Daniel Sztubinski, Louise Thoma, Vlad Tsaltskan, Marat Turgunbaev, Courtney Wells, Amy S Turner, Jonathan R Treadwell

Pediatrics Research and Scholarship

OBJECTIVE: To develop initial American College of Rheumatology (ACR) guidelines on the use of exercise, rehabilitation, diet, and additional interventions in conjunction with disease-modifying antirheumatic drugs (DMARDs) as part of an integrative management approach for people with rheumatoid arthritis (RA).

METHODS: An interprofessional guideline development group constructed clinically relevant Population, Intervention, Comparator, and Outcome (PICO) questions. A literature review team then completed a systematic literature review and applied the Grading of Recommendations Assessment, Development and Evaluation (GRADE) approach to rate the certainty of evidence. An interprofessional Voting Panel (n = 20 participants) that included 3 individuals with RA achieved consensus …

Examining The Effects Of Iron-Oxide Nanoparticles On Primary Gingival Keratinocytes For The Prevention Of Oral Disease, Jennifer C. Carranza

Dental Hygiene ETDs

Oral plaque biofilm has been identified as the primary contributor to dental conditions such as dental caries and periodontal disease that promotes a diverse and pervasive collection of microbial species to inhabit the oral cavity. Disrupting the plaque matrix early could help combat this global disease burden. This study evaluated the effect of IONPs on primary gingival keratinocytes.

Purpose: This study aimed to examine existing research regarding nanoparticles and determine if IONPs affect the PGK cell membranes with preliminary research to find the maximum lysis possible with PGK cells.

Methods: IONP core/shell syntheses were performed. Considering keratinocyte characteristics, examining data …

Resistance Narratives: Storytelling Of Transnational Insurgencies In 1960-70s Us And Mexico, Tania Libertad Balderas

English Language and Literature ETDs

Resistance Narratives: Storytelling of Transnational Insurgencies in 1960-70s US and Mexico emphasizes how the narratives from the Mexican Insurgency, the American Indian Movement (AIM), and the leftist faction of the Chicana/o Movement in the 1960s and 1970s articulate intersecting notions of resistance, liberation, and transnational solidarity. The comparative analysis of the testimonial novel Las mujeres del alba (2019) by Chihuahuan novelist Carlos Montemayor, the autobiographies Lakota Woman (1991) and Ohitika Woman (1993) by Sičháŋǧu Lakȟóta writer and AIM militant Mary Brave Bird (formerly Crow Dog), and the memoirs and plays by the San Diego-based group Teatro de las Chicanas, collected …

Testing The Niche Center Hypothesis In The Fossil Record Of Atlantic Bivalves, Rhiannon Z. Nolan

Earth and Planetary Sciences ETDs

Paleoecological analyses of six shallow marine bivalves were conducted to test the Abundant Center Hypothesis using data from the fossil record of the Pleistocene through modern day. This hypothesis predicts the highest abundance of a species is at the center of the geographic or environmental range, decreasing toward the edges. In geographic space, distances to a centerline within a geographic range were variably correlated with population abundances, and some species displayed a sharp drop-off in abundance as distance increased. In environmental space, bivalve species showed moderate correlations between abundance and centrality when measured using cumulative data across the last 2.8 …

Hydrothermal Liquefaction Of Wastewater Sludges For Energy Resource Recovery, Carl L. Abadam

Civil Engineering ETDs

This study aims to identify how variabilities in wastewater process configurations impact the biocrude yields from sludges processed and stabilized by hydrothermal liquefaction. Clean and renewable energy sources are vital to ensure a sustainable future. However, the current consumption of fossil fuels limits the ability to achieve this goal. Hydrothermal liquefaction (HTL) is a thermochemical process that converts wet biomass to valuable biocrude oil and biochar while reducing solid masses. Wastewater sludges were sampled across three facilities with varying influent design capacities and biological treatment configurations. Lipids extracted via solvent extraction and biocrudes produced from HTL were determined gravimetrically. Relative …