Physical Sciences and Mathematics Commons^™

Dispersion Of Artificial Tracers In Ventilated Caves, Claudio Pastore, Eric Weber, Frédéric Doumenc, Pierre-Yves Jeannin, Marc Lütscher

International Journal of Speleology

Artificial CO₂ was used as a tracer along ventilated karst conduits to infer airflow and investigate tracer dispersion. In the karst vadose zone, cave ventilation is an efficient mode of transport for heat, gases and aerosols and thus drives the spatial distribution of airborne particles. Modelling this airborne transport requires geometrical and physical parameters of the conduit system, including the cross-sectional areas, the airflow and average air speed, as well as the longitudinal dispersion coefficient which describes the spreading of a solute. Four gauging tests were carried out in one mine (artificial conduit) and two ventilated caves (natural conduits). …

Rates Of Diagenesis Of Tropical Insectivorous Bat Guano Accumulations: Implications For Potential Paleoenvironmental Reconstruction, Donald A. Mcfarlane, Joyce Lundberg

International Journal of Speleology

Cave guano deposits are increasingly being recognized as valuable repositories of paleo-climatic and paleo-environmental information. However, that value is constrained by rates of guano decomposition, and these rates have not been previously well-studied. Here we show that field and laboratory studies of deep insectivorous bat guano sequences in the caves of Borneo demonstrate the extreme dependence of decomposition rate on guano water content. Under tropical conditions, moist guanos exhibit decomposition coefficients (k) values of ~ 0.01, implying the loss of most of the organic content on decadal timescales. Under similar temperatures but drier conditions, k values drop to …

Subaqueous Carbonate Speleothems As Paleotemperature Archives – Clumped Isotope Thermometry And Stable Isotope Compositions Of Inclusion-Hosted Water, Attila Demeny, Ágnes Berentés, László Rinyu, Ivett Kovács, Gergely Surányi, Magdolna Virág

International Journal of Speleology

Clumped isotope measurements of carbonates and stable isotope analyses of water trapped in fluid inclusions are both promising techniques to determine carbonate formation temperatures. Cave-hosted carbonate deposits (speleothems) are excellent targets for such studies, but kinetic fractionations and diagenetic influences frequently deteriorate the temperature data obtained from these methods. However, subaqueous carbonate deposits may provide reliable data, as kinetic fractionations are less significant in underwater environments. In this study, subaqueous speleothems, whose formation temperatures were directly measured in the water, were investigated. Additionally, temperatures calculated from the oxygen isotope fractionations between calcite and fluid inclusion-hosted water were compared with clumped …

The International Crisis In Numeracy Education, Nathan D. Grawe

Numeracy

The OECD recently released results from the 2022 administration of the Programme for International Student Assessment test. As other studies suggest, pandemic mitigation policies resulted in deep learning loss including in basic mathematics which forms the foundation of numeracy. Perhaps of greater concern, however, in many countries pandemic effects amplify declining performance that dates back a decade or more. Losses of two or more years' worth of mathematics education are not uncommon among developed countries. The editorial makes an urgent call for research that identifies practical steps to reverse these trends.

Infusing Quantitative Reasoning Skills Into A Differential Equation Class In An Urban Public Community College, Tanvir Prince

Numeracy

This research centers on implementing Quantitative Reasoning (QR) within a differential equations course at an urban public community college. As a participant in the Numeracy Infusion for College Educators (NICE) faculty development program, I sought to integrate QR skills into my curriculum. Students in the course were introduced to QR goals using real-world data sets, particularly those related to population growth, which aim to enhance their understanding, sharpen their problem-solving abilities, and cultivate a positive perspective on the real-world relevance of mathematics. Preliminary findings indicate varied levels of QR skill development among students. These results underscore the potential benefits of …

Assessing Compliance To Water Resources And Reconstruction Framework During Post-Conflict Reconstruction Borno State, Muritala Olaniyi Oke Dr

Journal of African Conflicts and Peace Studies

Northeast and northwest of Nigeria have, as a result of activities of Boko Haram, bandit and kidnappers, had their public and private properties destroyed. Governments and other stakeholders, upon some successes of the military, have started post-conflict reconstruction to rebuild the war-torn urban and rural communities with the provision of water taking the center stage. This paper looks at the utilisation of Water Resources and a Reconstruction framework for integrating water projects into reconstruction processes. This paper rests on the argument that water projects during reconstruction should not be handled as “normal” water projects and that a more culturally and …

Climate Monitoring In The Caumont Cave And Quarry System (Northern France) Reveal Near Oxygen Isotopic Equilibrium Conditions For Carbonate Deposition, Ingrid Bejarano-Arias, Carole Nehme, Sebastian Breitenbach, Hanno Meyer, Sevasti Modestou, Damase Mouralis

International Journal of Speleology

The study of modern cave deposits forming under near isotopic equilibrium conditions can potentially help disentangle the processes influencing the oxygen isotope system and suitability of stalagmites as archives of past hydrological or thermal changes. We used cave monitoring to evaluate the impact of kinetic isotope fractionation and assess the conditions under which modern cave carbonates form in the Caumont cave and quarry system, located in Normandy, northwest France. Over 20 months, we collected climatological data, dripwater, and modern carbonate samples at 2–4-week intervals at three different stations inside the Caumont cave and quarry system. We find highly stable (10.4 …

Reverse Pseudo-Gours: A New Sub-Type Of Folia Observed In The Nerja Cave (Se Spain), Cristina Liñán Baena, Concepción Jiménez De Cisneros, Yolanda Del Rosal, Paolo Forti

International Journal of Speleology

A new sub-type of folia named “reverse pseudo-gour” has been observed and described in the Nerja Cave, southern Spain. It consists of fairly vertical, thin barriers (about 5 mm high and 2 mm thick) that develop on the underside of a sub-horizontal surface (shelfstone) and grow in the opposite direction to normal gours (rimstone dams), generating sinuous shapes. Their mineral composition is essentially calcium carbonate, although globular aggregates composed of clay and phosphate minerals have also been identified. The genesis and evolution of these reverse pseudo-gours occur just at the air-water interface and are controlled by (1) the sub-horizontality of …

Brain-Inspired Spatio-Temporal Learning With Application To Robotics, Thiago André Ferreira Medeiros

USF Tampa Graduate Theses and Dissertations

The human brain still has many mysteries and one of them is how it encodes information. The following study intends to unravel at least one such mechanism. For this it will be demonstrated how a set of specialized neurons may use spatial and temporal information to encode information. These neurons, called Place Cells, become active when the animal enters a place in the environment, allowing it to build a cognitive map of the environment. In a recent paper by Scleidorovich et al. in 2022, it was demonstrated that it was possible to differentiate between two sequences of activations of a …

Determining The P-Wave Velocity Structure In The Near-Surface Of Nw Miami, Florida, Using Quarry Blasts, Elham Moslemi

USF Tampa Graduate Theses and Dissertations

The fact that Florida is an earthquake-free region has caused seismologists to pay less attention to it. Few earthquakes in this state mean it is not a usual practice to study the propagation of seismic waves. However, utilizing data from quarry blasts, we studied wave propagation in this region. The primary objective of the project is to investigate the near-surface P-wave velocity structure and factors that may affect it. We also analyzed the amplitude of signals versus distance and blast size. A network of up to 10 Raspberry Shake instruments around the NW Miami-Lakes mining area was deployed where four …

Integration Of Algae And Biomass Processes To Synthesize Renewable Bioproducts For The Circular Economy, Jessica Martin

USF Tampa Graduate Theses and Dissertations

Rapid population growth and global industrialization have substantially heightened the demand for fossil-based fuels and products in various sectors of the global economy, including energy production, transportation fuels, and as raw materials for petrochemicals. The intense consumption of fossil fuels has caused immense environmental impacts, especially pertaining to carbon dioxide emissions. Shifting to renewable feedstocks (raw materials) is expected to reduce these emissions by lowering the carbon footprint of fuels and products compared to traditional fossil-derived alternatives. This transition aligns with the goal of creating a sustainable and circular economy, emphasizing efficient resource use, and reducing waste generation through recycling …

All Quiet On The Digital Front: The Unseen Psychological Impacts On Cybersecurity First Responders, Tammie R. Hollis

USF Tampa Graduate Theses and Dissertations

Driven by the increasing frequency of cyberattacks and the existing talent gap between industry needs and skilled professionals, this research study focused on the crucial human element in the domain of cybersecurity incident response. The objective of this dissertation was to offer a meaningful exploration of the lived experiences encountered by cybersecurity incident responders and an assessment of the subsequent impacts on their well-being. Additionally, this study sought to draw comparisons between the experiences of cybersecurity incident responders and their counterparts in traditional emergency response roles. Semi-structured interviews were conducted with a cohort of 22 individuals with first-hand experience working …

Syntheses, Photophysics, & Application Of Porphyrinic Metal-Organic Frameworks, Zachary L. Magnuson

USF Tampa Graduate Theses and Dissertations

Porphyrins are a group of heterocyclic macrocycles that play crucial roles in various biological processes such as electron transfer, catalysis, and sensing. Hemoglobin, which carries oxygen in the blood of mammals, and chlorophyll, which drives photosynthesis in plants and algae, are both porphyrins. The ability of porphyrins to bind metal ions and their unique electronic and photophysical properties make them an excellent platform for designing functional materials for various applications, often drawing inspiration from their function in nature. Metal-organic frameworks (MOFs) are a class of porous materials that have been extensively studied in recent years due to their high surface …

Synthetic Studies Of Potential New Ketogenic Molecules, Mohammad Nazmus Sakib

USF Tampa Graduate Theses and Dissertations

The ketogenic diet has gained popularity in the past few decades among people and physicians due to its various health benefits. A significant amount of research has been done for the modification of the original ketogenic diet and investigation of its potential health benefits. However, synthesis of novel ketogenic compounds as a dietary supplement has not received the same level of attention. That is the primary objective of this research project. The first chapter of this manuscript describes the synthesis of various short and medium chain esters of different polyols that have been done so far, and areas of their …

Influence Of Thickness And Capping Materials On The Static And Dynamic Properties Of Ferrimagnetic Thin Films, Noha Alzahrani

USF Tampa Graduate Theses and Dissertations

Spintronics traditionally relied on ferromagnetic materials for their strong spin properties but facedissues like large stray magnetic fields. To address these challenges, researchers turned to antiferromagnetic materials with fast spin dynamics, due to their zero net magnetic moment but the lack of a net spin moment complicated operation. In this context, ferrimagnetic materials have emerged as promising alternatives. They combine ferromagnetic and antiferromagnetic traits and feature different magnetic ions in their sublattices. This dissertation explores how film thickness and capping materials affect the properties of ferrimagnetic thin films. Rare-earth transition metal ferrimagnetic amorphous alloys have garnered attention in the realm …

Refining The Machine Learning Pipeline For Us-Based Public Transit Systems, Jennifer Adorno

USF Tampa Graduate Theses and Dissertations

According to the Population Division of the United Nations, in the United States, almost 90% of the population will live in urban areas by the year 2050. As the population in a given area increases, higher traffic congestion follows due to an increase of vehicles in the road. A possible way to alleviate congestion could be with widespread use of public transit. However, according to the US Census Bureau, the percentage of individuals commuting through public transportation has been decreasing steadily over time, and the American Community Survey reports that during 2019, only around five percent of the US population …

Human Vs Machine: Hyper-Realistic Avatars And Their Efficacy As A Communication Channel, Jill S. Schiefelbein

USF Tampa Graduate Theses and Dissertations

Hyper-realistic avatars (HRAs), a form of synthetic media, are custom-created digital embodiments of a human, created by capturing and combining that person’s video and vocal likeness. This is the first known study of the efficacy of videos delivered by hyper-realistic avatars as a communication channel in comparison to videos delivered by their human counterparts. An experiment testing how information retention, engagement, and trust vary between viewers of videos delivered by a real human, videos delivered by the HRA representing that same human, and videos delivered by the HRA that discloses to viewers that it is a hyper-realistic avatar is presented. …

Using Social Network Analysis To Measure And Visualize Student Clustering Within Middle And High Schools, Geoffrey David West

USF Tampa Graduate Theses and Dissertations

The dominant philosophy of American public schools has been to group students together based on similar characteristics. Known as tracking, high achieving students would take courses on the “college track” while others would take “career track” courses. It was not long until advocates noticed that this process unfairly advantaged affluent and White student over poor and minoritized groups. A new process called “ability grouping” took over where tracking left off, but to the same effect. It is difficult to measure the degree students are grouped together by a certain characteristic, and while a few research papers aim to do so, …

Coupling Chemical And Genomic Data Of Marine Sediment-Associated Bacteria For Metabolite Profiling, Stephanie P. Suarez

USF Tampa Graduate Theses and Dissertations

Marine sediment-associated bacteria house many new and exciting novel secondary metabolites. These metabolites can be tested for bioactivity against various types of cancer and fungal, bacterial, and viral infections. In this thesis, we investigated the combination of biosynthetic gene cluster information with mass spectra to perform a chemical profiling of sediment- associated bacteria. Furthermore, we utilized a scoring technique to provide an identification and confidence score to each annotated compound. The sediment was collected from east Arthur Harbor, Palmer Station, Antarctica, at depths of 20 ft and 60 ft. After plating on agar, 52 unique bacterial strains were isolated, with …

Deciphering Trends And Tactics: Data-Driven Techniques For Forecasting Information Spread And Detecting Coordinated Campaigns In Social Media, Kin Wai Ng Lugo

USF Tampa Graduate Theses and Dissertations

The main objective of this dissertation is to develop models that predict and investigate the spread of information in social media over time. In this context, we consider topics of discussions as the information that spreads. Thus, we are interested in forecasting the number of messages per day in a future interval of time. We take a data-driven approach, in which we compare our results with real datasets from a multitude of socio-political contexts and from multiple social media platforms, specifically, Twitter and YouTube.

We identified a number of challenges related to forecasting social media time series per topic. First, …

Examining Paleoshorelines In The Eastern Gulf Of Mexico: Insights On Sea Level History And Potential Areas Of Interest For Habitat Management, Catalina Rubiano

USF Tampa Graduate Theses and Dissertations

An inventory of multibeam bathymetry containing relict drowned and lithified paleoshorelines has been compiled and analyzed in the first ever shelf-wide investigation of paleo sea level indicators on the west Florida shelf (WFS). On the largest scale, the WFS is a wide and gently sloping terrain that is characterized by a carbonate-rich sediment regime. This framework coupled with the region’s tectonic stability provided a setting in which sea level changes since ~ 20 ka have been recorded to a remarkable degree of resolution in the form of paleoshorelines which formed at sea level and were subsequently drowned and preserved in …

Developing New Strategy Toward Ruthenium And Gold Redox Catalysis, Chenhuan Wang

USF Tampa Graduate Theses and Dissertations

This dissertation mainly contains three parts: 1) The discovery of triazole-modified Ru carbene catalysts for alkene metathesis and dynamic covalent chemistry; 2) The study of ligand assisted gold oxidative addition toward aryl iodide to achieve the alkene difunctionalization; 3) Gold redox catalysis via chiral P,N-chelating ligands. In the first part, the 1,2,3-triazole coordinated ruthenium carbene complexes (TA-Ru) were reported for the first time as a new class of modified Grubbs catalyst to achieve challenging olefin metathesis at higher temperatures without catalyst decomposition. With this new TA-Ru catalyst, cross-metathesis (CM), ring-closing metathesis (RCM) and dynamic covalent chemistry (DCvC) were achieved. The …

Deep Learning-Based Automatic Stereology For High- And Low-Magnification Images, Hunter Morera

USF Tampa Graduate Theses and Dissertations

Quantification of the true number of stained cells in specific brain regions is an important metric in many fields of biomedical research involving cell degeneration, cytotoxicology, cellular inflammation, and drug development for a wide range of neurological disorders and mental illnesses. Unbiased stereology is the current state-of-the-art method for collecting the cell count data from tissue sections. These studies require trained experts to manually focus through a z-stack of microscopy images and count (click) on a hundred or more cells per case, making this approach time consuming (~1 hour per case) and prone to human error (i.e., inter-rater variability). Thus, …

Booker Creek: Wet Season Water Quality Trends In A Florida Urban Stream, Alexandra M. Shostak

USF Tampa Graduate Theses and Dissertations

Booker Creek, a 1.9-mile stream with a 4.9-mi2 watershed, flows southeast through highly urbanized St. Petersburg, Florida, and empties into Bayboro Harbor, which connects with Tampa Bay. This study collected and analyzed water quality data for several parameters (TN, TP, nitrate-nitrite, ammonia, orthophosphate, chl-a, fecal coliform, dissolved oxygen, pH, turbidity, temperature, and salinity) every two weeks, at four different sites, during the 2022 wet season to characterize the current state and geographic variability of Booker Creek. Current creek sampling regimes, though consistent, do not sample at multiple sites along the creek. Urban streams do not display uniform water quality along …

Affordances And Limitations Of Molecular Representations In General And Organic Chemistry, Ayesha Farheen

USF Tampa Graduate Theses and Dissertations

Molecular representations that show chemical bonding are ubiquitous in general and organic chemistry. These help in communicating chemistry concepts that are fundamental to understanding how and why molecules interact. The goal of this dissertation work is to offer an evidence-based report on the affordances and limitations of the variety of molecular representations by chemistry topic. The variety of representations investigated are chemical formula, Lewis dot structure, line-angle diagram, ball and stick, space filling, and electrostatic potential maps. Five studies were conducted with general and organic chemistry students and three key findings emerged. First, affordances and limitations of molecular representations are …

Labile Dissolved Nickel (Ni) Concentrations In The North Pacific, Calyn M. Crawford

USF Tampa Graduate Theses and Dissertations

Nickel (Ni) is an important micronutrient for phytoplankton and bacteria that serves as a required co-factor in several metalloenzymes. Despite these known biological uses, total dissolved Ni concentrations remain elevated in global surface waters, in contrast to the surface depletion commonly observed for macronutrients and other nutrient-type trace elements. A prevailing hypothesis for the muted depletion of dissolved Ni concentrations in surface waters is that dissolved Ni in seawater is not in a bioavailable form. The chemical lability of Ni in seawater provides insight into Ni speciation and bioavailability, but few measurements have been made in the open ocean to …

Understanding Controls On Spring Hydrographs In An Eogenetic Karst Aquifer In North-Central Florida, Ryan Almeqhem

USF Tampa Graduate Theses and Dissertations

Florida has one of the largest karst aquifers in the United States, with a significant portion of its water resources originating from the eogenetic karst system in north central Florida. Despite the importance of this system, eogenetic karst still needs to be studied compared to telogenetic karst. The hydrological behavior of karst aquifers is complex, with numerous factors influencing the timing, magnitude, and shape of spring hydrographs. One hypothesis, by Florea and Vacher (2006), suggests that matrix permeability is the primary control of spring hydrographs in karst systems. However, this thesis challenges this hypothesis by presenting evidence that the recharge …

Tree Planting As An Adaptive Management Tool For Climate Change In Morocco, Stephanie J. Robinson

USF Tampa Graduate Theses and Dissertations

The practice of planting fruit trees to combat climate change impacts in Morocco has been growing in popularity with support from the Moroccan government and non-profit organizations. Although it is often considered a successful adaptive management tool, tree planting initiatives (TPIs) in arid lands have not been thoroughly analyzed, their management is unstandardized, and these initiatives can cause harm when trees are planted in areas that cannot support them. To implement tree planting better these TPIs need to find areas where the trees they are introducing have the best chance of survival without negatively impacting the surrounding ecosystem and human …

Book Review: Australian Caves And Karst Systems, John Webb, Susan White, Garry K. Smith, Jo De Waele

International Journal of Speleology

No abstract provided.

Evaluating Methods For Improving Dnn Robustness Against Adversarial Attacks, Laureano Griffin

USF Tampa Graduate Theses and Dissertations

Deep learning has become more widespread as advances in the field continue. As aresult, making sure deep learning is safe has become a priority. A seemingly normal image with intentional pixel changes can cause a well-trained model to misclassify the image with high confidence. Those kinds of images are called adversarial attacks. Adversarial training has been developed to defend against adversarial attacks. This thesis evaluates different adversarial training methods against a variety of adversarial attacks. The key metrics for evaluation are classification accuracy and training time. This thesis also experiments with an improvement on an existing adversarial training method, the …