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Full-Text Articles in Physical Sciences and Mathematics

Myfoodrx: A Personalized Food-As-Medicine Mhealth Application For Food-Insecure Adults With Chronic Conditions, Jay Hiteshkumar Jariwala Oct 2025

Myfoodrx: A Personalized Food-As-Medicine Mhealth Application For Food-Insecure Adults With Chronic Conditions, Jay Hiteshkumar Jariwala

USF Tampa Graduate Theses and Dissertations

Food insecurity (FI) remains a persistent public health challenge in the United States, disproportionately affecting underserved populations and contributing to higher rates of chronic conditions such as diabetes, hypertension, and obesity. Traditional Food-as-Medicine programs have emerged as promising interventions, but often follow a generalized, non-personalized approach that limits long-term effectiveness, especially among diverse, high-risk communities. This thesis presents MyFoodRx, a personalized mobile health (mHealth) application designed to address the intersection of food insecurity and chronic disease through tailored nutritional guidance, real-time pantry integration, and adaptive educational content.

Developed through a User-Centered Design (UCD) process, MyFoodRx leverages a modular client–server architecture, …


The Orange Glow In The Sunshine State: Three Visions Of Plato In Florida (1970-1990), Ryan Mcgahan Oct 2025

The Orange Glow In The Sunshine State: Three Visions Of Plato In Florida (1970-1990), Ryan Mcgahan

USF Tampa Graduate Theses and Dissertations

The PLATO network, a collection of mainframe computers, terminals, and educational software, has received an increasing amount of scholarly attention in the last decade as a social precursor to the modern internet. Existing histories have neglected to investigate the ways in which PLATO and its related business enterprise worked to accelerate the shift in university governance away from classical liberal ideas centering the public good and towards a more profit-centered neoliberal rationality. By tracing the rise of PLATO in Florida universities, this paper argues that PLATO aided and was aided by the shifting priorities of American universities in the 1970s …


Microclimatic Conditions In Shulgan-Tash Cave (Southern Ural, Russia): Implications For The Preservation Of Eastern Europe’S Largest Paleolithic Art Collection, Olga Chervyatsova, Rayan Akhmedyanovb, Nailya Saifullina, Ludmila Kuzmina, Mihael Kotov, Yuri Dublyansky Oct 2025

Microclimatic Conditions In Shulgan-Tash Cave (Southern Ural, Russia): Implications For The Preservation Of Eastern Europe’S Largest Paleolithic Art Collection, Olga Chervyatsova, Rayan Akhmedyanovb, Nailya Saifullina, Ludmila Kuzmina, Mihael Kotov, Yuri Dublyansky

International Journal of Speleology

This study presents the results of a long-term investigation of the microclimatic conditions in Shulgan-Tash Cave (Southern Urals, Russia), which hosts the largest assemblage of Upper Paleolithic paintings (ca. 16.3–19.6 ka) in Eastern Europe. The cave exhibits two distinct seasonal ventilation regimes – winter and summer – differentially influence its two levels of galleries. In the Lower Level, which contains 83% of the images, near-atmospheric CO2 concentrations persist year-round, and temperature variations associated with seasonal infiltration events are minimal (1.0–1.3°C). By contrast, the Upper Level, including the decorated Hall of Paintings, is affected by downdrafts of CO2-rich …


Barriers To Machine Learning Adoption In Regulated Electric Utilities, Donald R. Shiflet Jr. Oct 2025

Barriers To Machine Learning Adoption In Regulated Electric Utilities, Donald R. Shiflet Jr.

USF Tampa Graduate Theses and Dissertations

Machine learning (ML) technologies have the potential to revolutionize regulated electric utilities by improving operational efficiency, enabling predictive maintenance, and optimizing energy management. Despite these advantages, the adoption of ML in this sector lags other industries due to technical, organizational, and regulatory barriers. This research, grounded in the Technology-Organization-Environment (TOE) framework, explores these barriers to uncover actionable solutions for integration. The study identifies key challenges, including explainability, cybersecurity, workforce resistance, and regulatory ambiguity to ML adoption in electric utilities. Utilizing an exploratory qualitative methodology, this approach integrates insights from the literature and industry interviews to rank barriers by frequency, severity, …


An Integrated Pcb-Based Heating And Auto-Ranging Platform For Volatile Organic Compound (Voc) Detection Using Carbon Nanotube Based Sensors, Thomas Kalach Oct 2025

An Integrated Pcb-Based Heating And Auto-Ranging Platform For Volatile Organic Compound (Voc) Detection Using Carbon Nanotube Based Sensors, Thomas Kalach

USF Tampa Graduate Theses and Dissertations

This thesis presents the development, characterization, and integration of a novel low-cost, high-dynamic-range sensor platform for the detection of volatile organic compounds (VOCs), leveraging the unique electrical properties of carbon nanotube (CNT) thin films. The platform introduces a fully integrated auto-ranging analog front-end circuit capable of real-time resistance measurement spanning over eight orders of magnitude ranging from tens of ohms to hundreds of megaohms, without compromising signal resolution or precision. This was achieved through a digitally controlled, multi-path feedback architecture and controllable current source.

To further enhance sensor performance, the system incorporates a copper trace heater beneath the sensor array, …


Introductory Chemistry Student Success: Investigating Study Strategies And Evaluating An Informative Utility Value Intervention, Pallavi Nayyar Oct 2025

Introductory Chemistry Student Success: Investigating Study Strategies And Evaluating An Informative Utility Value Intervention, Pallavi Nayyar

USF Tampa Graduate Theses and Dissertations

Improving retention in STEM (science, technology, engineering, and mathematics) programs is essential to meet the growing demand for skilled professionals in the domestic workforce. To achieve this, it is critical to understand and address the factors that influence student persistence in STEM degrees. Gateway courses such as general chemistry often serve as early barriers to STEM degree completion, with high rates of attrition that impact not only individual students but also institutions and society. Therefore, the aim of this work was to examine and influence the factors that contribute to student withdrawal from introductory chemistry courses in order to promote …


Investigating Factors Influencing Organic Chemistry Learners' Explanation Sophistication And Representational Competence, Caroline J. Crowder Oct 2025

Investigating Factors Influencing Organic Chemistry Learners' Explanation Sophistication And Representational Competence, Caroline J. Crowder

USF Tampa Graduate Theses and Dissertations

The research presented in this dissertation has two themes: organic chemistry learners’ written explanations and representational competence. Chapters 3 and 4 explore how organic chemistry learners construct explanations of reaction mechanisms, specifically focusing on electrophile and nucleophile components. Chapter 5 investigates organic chemistry learners’ representational competence skills and the relationship between these skills and their performance in the course.

Understanding reaction mechanisms is critical for success in organic chemistry, yet learners often struggle to reason beyond explicit, surface-level features. Constructed-response prompts that ask learners to explain what is happening in a reaction mechanism and why it occurs can provide insight …


The Taxonomy And Origins Of Folia: A Brief Review, Donald G. Davis, Louise D. Hose, Harvey R. Duchene Oct 2025

The Taxonomy And Origins Of Folia: A Brief Review, Donald G. Davis, Louise D. Hose, Harvey R. Duchene

International Journal of Speleology

All folia demonstrate a few common elements: folia (singular, folium) are planar or sub-planar speleothems, slanting downward and away from cave walls and ceilings, and genetically associated with fluctuating environmental interfaces. They were first identified and named from examples in western USA hypogenic caves but have since been identified elsewhere in the world. Folia shelves are typically composed of calcite and interweave smoothly along sub-horizontal contours. Calcite accretion, both chemical and mechanical from suspended particles, follows water-surface fluctuations to form protrusions in arrays along walls and ceilings where new accretion tends to follow the water-surface downward during descending phases, gradually …


Nomina Ignota: Dinosaurios, Dinosauroides Y Otros Animales Del Pasado Que Nunca Existieron, Charlie Charmer, Iván Narváez Sep 2025

Nomina Ignota: Dinosaurios, Dinosauroides Y Otros Animales Del Pasado Que Nunca Existieron, Charlie Charmer, Iván Narváez

Alambique. Revista académica de ciencia ficción y fantasía / Jornal acadêmico de ficção científica e fantasía

Aunque desaparecieron hace 66 millones de años, los dinosaurios no avianos y otros grandes reptiles con los que convivieron son un reclamo habitual en las historias de ficción del cómic, cine, literatura u otros medios de expresión artística y/o entretenimiento. A menudo, sirven también de inspiración para introducir criaturas inexistentes cuya imagen y denominación parten de referentes conocidos. En el presente trabajo se analizan los diferentes métodos utilizados para bautizar a estas criaturas, así como las características y funciones que sus nombres pueden tener en los mundos de ficción, acuñando una nueva categoría para la nomenclatura científica, aplicable exclusivamente en …


Bayes In The Brain: A Review Of Everything Is Predictable: How Bayesian Statistics Explain Our World, (2024) By Tom Chivers., Michael T. Catalano Jul 2025

Bayes In The Brain: A Review Of Everything Is Predictable: How Bayesian Statistics Explain Our World, (2024) By Tom Chivers., Michael T. Catalano

Numeracy

Tom Chivers’ Everything is Predictable: How Bayesian Statistics Explain Our World, is an interesting and wide-ranging narrative on Bayesian thinking, its history, and its applicability to both our everyday lives and the pursuit of scientific truth. Although appropriate for the non-expert, afficionados and teachers of quantitative literacy should find the plethora of examples, links to psychology as it applies to how people reason about probabilities, and even Chivers’ philosophical musings informative and thought-provoking.


Teaching Ai Ethics And Skepticism: The Impact Of Instruction On Ethical Usage On Students’ Perceptions, Jenna D. Justin Jul 2025

Teaching Ai Ethics And Skepticism: The Impact Of Instruction On Ethical Usage On Students’ Perceptions, Jenna D. Justin

Journal of Practitioner Research

This study investigates the ethical implications of artificial intelligence (AI) in K-12 education, focusing on how explicit instruction influences students' perceptions of AI tools like ChatGPT. Conducted with 80 sixth-grade students at A.D. Henderson University School and FAU High School, the research tracks changes in student understanding and skepticism of AI following a World History unit. Pre- and post-instruction surveys revealed a decline in comfort with AI as students became more aware of its ethical concerns, including plagiarism, bias, and misinformation. The findings suggest integrating AI ethics into the middle school curriculum to foster responsible AI usage among students.


Concentration And Composition Of Organic Contaminants In Blackfin Tuna, Yellowfin Tuna, And The Common Clubhook Squid In The Western Gulf Of Mexico, Lisa Rose-Mann Jul 2025

Concentration And Composition Of Organic Contaminants In Blackfin Tuna, Yellowfin Tuna, And The Common Clubhook Squid In The Western Gulf Of Mexico, Lisa Rose-Mann

USF Tampa Graduate Theses and Dissertations

Cephalopods are an important component of pelagic food webs. They play ecological roles not only as predators but also as prey. However, their role as prey in the trophic transfer of organic contaminants to apex predators such as tunas in the Gulf of Mexico (GoM) is not well known. To investigate the importance of cephalopods in tuna diets, stomach samples were collected in February 2020 from tunas caught by rod and reel aboard the F/V Gulf Eagle near two large offshore floating oil/gas platforms in the northwestern GoM. Cephalopod samples were obtained from gut content analysis of 41 tunas caught …


Exploring System Identification Of Non-Linear Dynamics Using The Weighted Composition Operator And The Liouville Operator, Chukwuebuka Amagwula Jul 2025

Exploring System Identification Of Non-Linear Dynamics Using The Weighted Composition Operator And The Liouville Operator, Chukwuebuka Amagwula

USF Tampa Graduate Theses and Dissertations

System identification is the process of determining mathematical models that describe the dynamics of a system from data. Dynamic Mode Decomposition (DMD) and Sparse Identification of Nonlinear Dynamical Systems (SINDy) are two distinct approaches used for this purpose.

DMD identifies dominant spatiotemporal modes and eigenvalues that describe the evo lution of a system. It assumes a near-linear representation of dynamics and is closely linked to the Koopman operator, making it ideal for analyzing fluid flows, oscillatory systems, and modal structures. The DMD method uses time series data where each data point is referred to as a snapshot and represents the …


Beyond The Hype: The Fundamental Challenges Of Machine Learning-Based Android Malware Detection In Cybersecurity, Guojun Liu Jun 2025

Beyond The Hype: The Fundamental Challenges Of Machine Learning-Based Android Malware Detection In Cybersecurity, Guojun Liu

USF Tampa Graduate Theses and Dissertations

Machine learning (ML) algorithms have achieved remarkable success across various domains, including cybersecurity. Inspired by these advancements, the academic security community has explored numerous ML-based approaches for Android malware detection. While ML holds significant promise in this domain, its practical deployment faces substantial challenges, including data collection, feature selection, app representation across different models, performance instability across datasets, and inherent limitations of learning-based malware detection. These challenges can lead to overly optimistic detection results and weaken the reliability of malware detection frameworks.

Android malware detection has been extensively studied using both traditional ML and deep learning (DL) approaches. Although many …


Phosphorus: From The Origins Of Life To The Origin Of An Industry, Joshua Abbatiello Jun 2025

Phosphorus: From The Origins Of Life To The Origin Of An Industry, Joshua Abbatiello

USF Tampa Graduate Theses and Dissertations

The element phosphorus is a key biogenic element that is often the limiting reagent for life. Phosphorus is quickly bound by metal divalent cations making it virtually insoluble and inert in water (forming the phosphate mineral apatite). Due to this, it becomes imperative to understand alternative pathways to increase biogenically available phosphorus in environments. To that end, this dissertation involved examining olivine as an alternative source of phosphorus to apatite, analyzing a novel grain of iron silicide found via lightning reduction in a fulgurite, and finally sought to understand the impact of phosphate mining through phosphogypsum stacks. Olivine is a …


The Synthesis Of A Photo-Affinity Probe Library For The Fatty Acid Amide Proteome And The Endocannabinoid System Within, Robert E. Feeney Iii Jun 2025

The Synthesis Of A Photo-Affinity Probe Library For The Fatty Acid Amide Proteome And The Endocannabinoid System Within, Robert E. Feeney Iii

USF Tampa Graduate Theses and Dissertations

Fatty acid amides are a large family of endogenous metabolites with significant biological activity, including that of the endocannabinoid system. Currently little is known about how this system of tightly regulated compounds works within humans. This work lays the foundation to explore the structure-activity relationship driving the selectivity of ligand-protein interactions involved with fatty acid amides. A library of activity-based proteomic profiling probes for fatty acid amides has been synthesized to this end. Additionally, progress towards phytocannabinoid probes has been made as well.


An Exploratory Analysis Of Automated Deception Detection For Mental Health Applications, Sayde Leya King Jun 2025

An Exploratory Analysis Of Automated Deception Detection For Mental Health Applications, Sayde Leya King

USF Tampa Graduate Theses and Dissertations

Deception in mental health settings can undermine therapeutic relationships, compromise treatment efficacy, and impact patient outcomes. Yet, research shows that mental health clinicians often perform no better than chance at detecting deceptive behavior in therapy. Automated deception detection, leveraging artificial intelligence (AI) and multimodal behavioral cues—such as eye gaze, body gestures, and facial expressions—offers a promising alternative. However, most existing research focuses on high-stakes legal contexts, limiting its applicability to mental health settings.

This dissertation addresses this gap by pursuing three key research objectives using a mixed-methods approach. First, we investigate mental health clinicians’ perspectives on AI-assisted deception detection through …


Efficient Methods And Algorithms For Analyzing Stochastic Systems, Mohammad Ahmadi Jun 2025

Efficient Methods And Algorithms For Analyzing Stochastic Systems, Mohammad Ahmadi

USF Tampa Graduate Theses and Dissertations

This dissertation addresses the challenges of stochastic analysis of safety-critical systems with biological components, where unexpected behavior can lead to catastrophic events. Two fundamental challenges hinder the analysis of such systems: their typically large or infinite state spaces, and the extreme rarity of error states of interest. While Monte Carlo simulation can analyze biochemical systems without storing the state space, accurately estimating rare event probabilities becomes computationally prohibitive. Conversely, probabilistic model checking excels at analyzing extremely low probability events but becomes impractical for systems with large or infinite state spaces due to memory constraints.This work proposes two main contributions to …


Isotopic Fingerprints Of The Coastal Margins: Tracing Dissolved Iron Sources From Land To Sea, Hannah R. Hunt Jun 2025

Isotopic Fingerprints Of The Coastal Margins: Tracing Dissolved Iron Sources From Land To Sea, Hannah R. Hunt

USF Tampa Graduate Theses and Dissertations

Dissolved iron (dFe) is an essential micronutrient for sustaining life in the surface ocean. Nearly four decades of research dedicated to understanding sources, cycling and biogeochemical modifications of Fe sources in the global oceans has generated a significant body of research supporting the idea that the concentration of Fe in the surface ocean exerts significant controls on primary production and carbon uptake in the surface ocean. Creation of the GEOTRACES program greatly increased the spatial and temporal resolution of high-quality trace element and trace element isotope data revealing new insights into the global Fe cycle, especially through the use of …


Applications Of Contracting Self-Similar Groups To Cryptography And Scale Groups, Arsalan Akram Malik Jun 2025

Applications Of Contracting Self-Similar Groups To Cryptography And Scale Groups, Arsalan Akram Malik

USF Tampa Graduate Theses and Dissertations

Given their peculiar properties, self-similar groups are of great interest both from applications and theoretical standpoints. In this work we study the scope of their applications in post-quantum cryptography and in constructing scale groups via lifting maps.

We propose self-similar contracting groups as a platform for cryptographic schemes based on simultaneous conjugacy search problem (SCSP). This class of groups admits fast polynomial-time algorithms for the word problem and element multiplication that can be used for effective encryption and decryption of messages. It contains extraordinary examples like the Grigorchuk group, which is known to be non-linear, thus making some of existing …


On Some Hypergraph Coloring Algorithms, Boyoon Lee Jun 2025

On Some Hypergraph Coloring Algorithms, Boyoon Lee

USF Tampa Graduate Theses and Dissertations

Of a given bipartite graph G = (V, E), it is elementary to construct a bipartition in timeO(|V |+|E|). For a given k-graph H = H(k) with k ≥ 3 fixed, Lovász proved that deciding whether H is bipartite is NP-complete. In this thesis, we consider the average running time of this problem. For that, let B_n = (B^(k))_n be the collection (family) of all bipartite k-graphs H on the fixed vertex set [n] = {1, ...., n}. We construct, of a given H ∈ B_n, a bipartition in time averaging O(n^k) over the class B_n. We provide two proofs …


The Only Constant Is Change: The Role Of Genetic Diversification In Cancer And Beyond, Malgorzata Tyczynska Weh Jun 2025

The Only Constant Is Change: The Role Of Genetic Diversification In Cancer And Beyond, Malgorzata Tyczynska Weh

USF Tampa Graduate Theses and Dissertations

Genetic diversification, the process by which genetic variation arises in a population, is fundamental to evolution by natural selection. Mutation, a central diversification process, fuels adaptation across species, including in cancer. Yet most new mutations are neutral or deleterious on cell fitness, raising the question of how mutation-driven adaptation persists. To explore this paradox, I developed a spatial agent-based model (ABM) in which population fitness emerges from individual cells acquiring mutations at varied rates and with diverse fitness effects. I evaluated model behavior across adaptive states, mutation rates, and distributions of fitness effects. The results show that high mutation rates …


First Insight On The Genesis Of Iron Oxide-Hydroxide Biospeleothems In Rancho Chico Lava Tube, Mexico, Rafael López-Martínez, Elizabeth Solleiro-Rebolledo, Rocio Alcántara-Hernández, Teresa Pi Puig, Sergey Sedov, Daisy Valera Fernández, M. Nayeli Luis-Vargas, Yasmany Lima Vera, Jesús Solé, Ramon Espinasa-Pereña Jun 2025

First Insight On The Genesis Of Iron Oxide-Hydroxide Biospeleothems In Rancho Chico Lava Tube, Mexico, Rafael López-Martínez, Elizabeth Solleiro-Rebolledo, Rocio Alcántara-Hernández, Teresa Pi Puig, Sergey Sedov, Daisy Valera Fernández, M. Nayeli Luis-Vargas, Yasmany Lima Vera, Jesús Solé, Ramon Espinasa-Pereña

International Journal of Speleology

Iron is a common element in lava tube systems, typically observed as thin crusts or inferred from the reddish coloration of secondary mineral deposits. In this study, we describe iron oxide-hydroxide biospeleothems discovered in the Rancho Chico Lava Tube, located within the Xalapa Monogenetic Volcanic Field in Mexico. We adopt an integrative approach combining petrography, soil micromorphology, scanning electron microscopy, mineralogy, and 16S rRNA gene metabarcoding. DNA sequencing reveals the presence of microorganisms such as Acidithiobacillus, Gallionella, and members of the Leptospirillaceae family, which may be involved in the oxidation of Fe²⁺ within the lava tube. The source …


Sea Turtle Nesting On Nourished Beaches With Different Construction Designs: A Case Study In Southeast Florida, Usa., Lara Novalvos Hernandez Jun 2025

Sea Turtle Nesting On Nourished Beaches With Different Construction Designs: A Case Study In Southeast Florida, Usa., Lara Novalvos Hernandez

USF Tampa Graduate Theses and Dissertations

This study examines the influences of different beach nourishment designs and subsequent post-nourishment profile adjustments on loggerhead (Caretta caretta) and green (Chelonia mydas) sea turtles nest survival and reproductive success. Data on time-series post-nourishment beach-profile changes, positions and elevations of turtle tracks and nest/false-crawl apices, and sea turtle nest hatch/emergence success were collected on five high density nesting beaches along the east coast of Florida: Melbourne Beach, Jensen Beach, Jupiter Island Beach, Juno Beach, and South Hutchinson Island Beach. The field data collection was conducted in 2018, 2019, 2021, and 2022 with the main goal of documenting and comparing turtle …


Behavior And Land Use Of Eastern Gray Squirrels In Urban And Suburban Environments, Laura F. Engel Jun 2025

Behavior And Land Use Of Eastern Gray Squirrels In Urban And Suburban Environments, Laura F. Engel

USF Tampa Graduate Theses and Dissertations

Urbanization has significantly altered natural habitats, impacting wildlife behavior and distribution. This study examines the behavior and land use of eastern gray squirrels (Sciurus carolinensis) in urban and suburban environments at the University of South Florida. Using a combination of point count surveys and time-activity budgets, squirrel presence was assessed in relation to tree genera, nest locations, human activity, and infrastructure. Results indicate a significant association between squirrel presence and tree genera, with a preference for Quercus species, as well as a strong positive correlation between human infrastructure and squirrel presence. However, no significant relationship was found between human presence …


Quantifying Wellbore Effects During Co2 Sequestration In A Saline Aquifer, Uzoma Johnpaul Ajugwe Jun 2025

Quantifying Wellbore Effects During Co2 Sequestration In A Saline Aquifer, Uzoma Johnpaul Ajugwe

USF Tampa Graduate Theses and Dissertations

Carbon capture and storage (CCS) is a strategy for mitigating climate change by reducing greenhouse gas emissions from large stationary sources like fossil-fuel-fired power stations. One method of CCS involves carbon dioxide (CO2) sequestration in deep saline aquifers, where supercritical CO2 is injected into an aquifer. The success of such projects depends on accurate predictions of CO2 behavior within the subsurface, which are obtained through numerical simulations.

TOUGHREACT, a renowned simulation tool, models subsurface fluid flow, geochemical interactions, and solute transport, providing insights into the feasibility of CO2 sequestration projects. A critical aspect of these simulations is the apportioning of …


A Community-Based Study To Investigate Persistent Ambient Odors In Childs Park, Fl, Gennaro Saliceto Jun 2025

A Community-Based Study To Investigate Persistent Ambient Odors In Childs Park, Fl, Gennaro Saliceto

USF Tampa Graduate Theses and Dissertations

For many years, residents in Childs Park, Saint Petersburg, Florida, have reported unpleasant odors. Although there have been prior efforts to address the issue, the odors continue to be a concern for the community, who worry about possible health implications. This research aimed to equip residents with information to address the issue by identifying the presence of airborne pollutants that generate odors, quantifying the concentrations of toxic organic pollutants, and exploring the sources and environmental conditions that contribute to odors and their perception.

To accomplish these aims, the study utilized different methods. First, two walking measurement campaigns were conducted to …


Development And Photophysical Characterization Of Bioinspired Materials, Qaisar Maqbool Jun 2025

Development And Photophysical Characterization Of Bioinspired Materials, Qaisar Maqbool

USF Tampa Graduate Theses and Dissertations

Porphyrins are versatile aromatic macrocycles with unique photophysical properties that make them attractive for applications in light harvesting, photocatalysis, and sustainable energy conversion. Incorporating porphyrins into metal-organic frameworks (MOFs) offers a unique opportunity to modulate their photophysical behavior through spatial confinement and host–guest interactions. This thesis explores how structural modifications influence porphyrin excited-state behavior through a multi-stage investigation. The work begins by comparing the photophysical properties of two cationic porphyrins: tetra(N-methylpyridyl) porphyrin(TMPyP) and tetra(4-N,N,N-trimethylanilinium) porphyrin(4TANP). While TMPyP exhibits significant singlet–charge transfer (S₁–CT) state mixing due to charge delocalization onto peripheral pyridinium groups, 4TANP lacks comparable behavior. The localized nature of …


Siliciclastic Cave Or Diamond Mine? Multiapproach Investigation In Igatu Village, Chapada Diamantina, Northeastern Brazil, Raphael Parra, Ricardo G. F. De A. Pereira, Leonardo F. Vieira, Rubson P. Maia Jun 2025

Siliciclastic Cave Or Diamond Mine? Multiapproach Investigation In Igatu Village, Chapada Diamantina, Northeastern Brazil, Raphael Parra, Ricardo G. F. De A. Pereira, Leonardo F. Vieira, Rubson P. Maia

International Journal of Speleology

The territory around Igatu, as that of many villages in southeastern Chapada Diamantina (Bahia, Brazil), was deeply modified by diamond mine activity. Caves were special targets for miners, since they can act as diamond-bearing sediment traps, and the Canal da Fumaça Cave was one of the most important and rich of them. The question that arises is whether the formation is a natural cave or an artificial diamond mine. In order to answer this question, we developed speleological and geological studies with detailed cave surveys, remote sensing and field measurements for structural analysis, optical and electronic microscope for petrographic characterization, …


Temperature-Driven Air Circulation In Caves With Blind Passages, Chris Hendy Dr, David J. Merritt, Shannon Corkill, Cross Cross May 2025

Temperature-Driven Air Circulation In Caves With Blind Passages, Chris Hendy Dr, David J. Merritt, Shannon Corkill, Cross Cross

International Journal of Speleology

Two blind-passage show-caves in the Waitomo district of New Zealand, Ruakuri Cave and Aranui Cave, have been monitored for the impact of visitors on their environment, especially focusing on partial pressures of carbon dioxide because high levels cause speleothem degradation. In Ruakuri Cave, annual cycles of daily mean pCO2 correspond with annual cycles of visitor numbers, both peaking in summer. The origin of the high pCO2 had been assumed to be anthropogenic due to respiration from visitors. Prolonged intervals with no visitation during the Covid-19 pandemic saw the daily mean pCO2 continuing to show the annual cycle, …