Physical Sciences and Mathematics Commons^™

Optimization Of A Water Gas Shift Reaction, Ali Albuloushi

Undergraduate Journal of Mathematical Modeling: One + Two

The optimum flow rate of steam (H₂0) to the reactor for the purpose of producing hydrogen gas for sale is determined.

Trend Analysis And Completion Prediction Of The Section Project, Ronald Jones

Undergraduate Journal of Mathematical Modeling: One + Two

Creating an accurate prediction of the completion timeline of a software development project is complicated and error prone. Developers will gain a natural intuition as to how long a task should take then. However, this prediction can end up being wrong in many cases due to many factors. This paper will attempt to determine a formula which allows a more accurate prediction to be created.

Creating an accurate prediction of the completion timeline of a software development project is complicated and error prone. Developers will gain a natural intuition as to how long a task should take then. However, this …

Stratigraphic Evaluation Of Trinity Aquifers In Hays And Western Travis County And Implications For Groundwater Availability, Nicholas Soto-Kerans, B. Hunt, B. Smith

School of Geosciences Student Publications

Trinity Aquifers are very important groundwater resources in central Texas. However, they show signs of hydrologic stress and depletion in some areas. This study focused on detailed stratigraphic evaluations to better understand hydrologic variations in the Trinity Aquifer system. The study consisted of seven wells located throughout the Western Travis and Northern Hays County area spanning XX miles. All the wells had cuttings and geophysical logs. Two of the wells are multiport monitor wells providing detailed hydrologic data. Geophysical logs, cuttings, thin sections (where available), and outcrop descriptions were compiled, integrated and correlated. Stratigraphic cross sections were constructed and hydrologic …

Organic Agricultural Analysis: Efficiency Of Common Practices, Bradley Biega

Undergraduate Journal of Mathematical Modeling: One + Two

To analyze the efficiency of common watering practices in an organic agriculture setting we use Sweetwater Organic Farm’s conventional methods for irrigation and land allotment as well as some algebra and calculus technique. Sweetwater’s operation is limited to their largest growing field. A mathematical model is built to determine the current efficiency of the rotary head sprinkler system. Then the efficiency of this system is compared to a new drip line system. Several variables like soil porosity, absorption rates, and areas where no plants are located, are taken into consideration. Our results show that the current irrigation in place wastes …

Geochemical Modeling Of Fractional Magma Crystallization, Luke Varner

Undergraduate Journal of Mathematical Modeling: One + Two

Modern day geologists use many different modeling programs such as Geospatial Information Systems in addition to R (programming language) for a wide array of applications such as: projecting collected data for mapping, visualization, and trend prediction. Computational power for these modeling programs is derived from Calculus, Probability, and Statistics. The purpose of this paper is to provide a site-specific geochemical analysis of an igneous rock formation composed of two specific compositions allowing for the predictions of rock formation derived from the resultant geochemical model.

Design Of Nozzle For High-Powered Solid Rocket Propellant, Jackson Stephenson

Undergraduate Journal of Mathematical Modeling: One + Two

This paper presents a preliminary nozzle design for a high-altitude rocket to be built by SOAR, the Society of Aeronautics and Rocketry. The equations and methods used for analysis came from professional sources via text or informational videos. The equations in focus will look at the temperature/pressure/area-Mach relationships for isentropic flow, pressure expansions in selected materials, and finding other characteristic properties using safe chemical property assumptions using CEARUN. The equations were used under the assumption of an isentropic flow under sea level conditions. If the design and the projected results look promising, they will be implemented soon for machining and …

Comparing Two Flywheel-Piston Linkages, Anthony Sanchez

Undergraduate Journal of Mathematical Modeling: One + Two

The main idea of this paper is to compare two different ways of linking a flywheel to a piston: the Scotch Yoke linkage and the Eccentric linkage. The Scotch Yoke linkage is a way to convert the linear motion of a piston into rotational motion by using a flywheel, or vice versa. The Eccentric mechanism, on the other hand, consists of a circular wheel that is fixed to a rotating axle that makes it rotate. We compare two methods by expressing both motions as functions of three variables (R, L and θ) and use these functions to …

Elapsed Time Of Vehicle Acceleration, Jensen Mctighe

Undergraduate Journal of Mathematical Modeling: One + Two

Newton’s Second Law states that force is equal to the mass of an object multiplied by its acceleration. More specifically, force is the mass times the instantaneous change in velocity over time of an object. By rearranging this equation, it can be determined that the time elapsed of the acceleration of an object is equal to the integral of the inverse value of the force relative to change in velocity (dv). In the context of real world application, this method can be used to calculate the time taken for a vehicle to accelerate from its minimum to maximum speed, given …

Using The Entropy Rate Balance To Determine The Heat Transfer And Work In An Internally Reversible, Polytropic, Steady State Flow Process, Savannah Griffin

Undergraduate Journal of Mathematical Modeling: One + Two

The entropy rate equation for internally reversible steady state flow process has been used to calculate the heat transfer and work in an internally reversible, polytropic, steady state flow process.

Model Function Of Women’S 1500m World Record Improvement Over Time, Annie Allmark

Undergraduate Journal of Mathematical Modeling: One + Two

We give an example of simple modeling of the known sport results that can be used for athletes’ self-improvement and estimation of future achievements.

This project compares the women’s 1500-meter world record times to the time elapsed between when they were run. The function of time which describes this comparison is found through graphing the data and interpreting the graphs. Then the obtained model function is compared to the real time data. The conclusions drawn from the result include that the calculated function of time lacks in accuracy as time elapsed increases, but the model could be used to estimate …

Minimizing Container Weight, Ibrahim Alomran

Undergraduate Journal of Mathematical Modeling: One + Two

Increased globalization has resulted in increased competition in the shipping industry. Since large carriers control over 70% of the total shipping industry, small carriers are left with only 30% of the market share to compete for. Ultimately, profit margins for small carriers have become very minimal. There is, therefore, need to develop a strategy that will aid in optimizing the profits of carriers. The goal of this paper is to develop a model that will help determine the minimum weight for a particular container design. The validity of the model is important in the sense that minimum container weight will …

A Modeling Toolbox For Permafrost Landscapes, Irina Overeem, Elchin Jafarov, Kang Wang, Kevin Schaefer, Scott Stewart, Gary Clow, Mark Piper, Yasin Elshorbany

USF St. Petersburg campus Faculty Publications

No abstract provided.

A New Approach To Probabilistic Lava Flow Hazard Assessments, Applied To The Idaho National Laboratory, Eastern Snake River Plain, Idaho, Usa, Elisabeth Gallant, Jacob Richardson, Charles Connor, Paul Wetmore, Laura Connor

School of Geosciences Faculty and Staff Publications

We present a new probabilistic lava flow hazard assessment for the U.S. Department of Energy’s Idaho National Laboratory (INL) nuclear facility that (1) explores the way eruptions are defined and modeled, (2) stochastically samples lava flow parameters from observed values for use in MOLASSES, a lava flow simulator, (3) calculates the likelihood of a new vent opening within the boundaries of INL, (4) determines probabilities of lava flow inundation for INL through Monte Carlo simulation, and (5) couples inundation probabilities with recurrence rates to determine the annual likelihood of lava flow inundation for INL. Results show a 30% probability of …

Land Use, Microclimate, And Surface Runoff Linkages: Space-Time Modeling From Rockel-Seli River Basin, Sierra Leone, C. Wilson, B. Liang, S. Wilson, Fenda A. Akiwumi

School of Geosciences Faculty and Staff Publications

This study mainly utilized the Soil and Water Assessment Tool (SWAT) together with SWAT-CUP, both free and open source software (FOSS), to construct a distributed hydrologic flow model for the Rokel-Seli River basin, Sierra Leone, in a bid to spatiotemporally evaluate the role of changes in land use/land cover (LULC) and microclimate on streamflow regimes. The model was informed by LULC data derived from three Landsat satellite images collected in 2002, 2010, and 2016. The LULC data was generated with the aid of several python libraries accessed through the FOSS Anaconda Navigator. LULC change analysis demonstrated that between 2002 and …

Preferential Production And Transport Of Grass-Derived Pyrogenic Carbon In Ne-Australian Savanna Ecosystems, Gustavo Saiz, Iain Goodrick, Christopher Wurster, Paul N. Nelson, Jonathan G. Wynn, Michael Bird

School of Geosciences Faculty and Staff Publications

Understanding the main factors driving fire regimes in grasslands and savannas is critical to better manage their biodiversity and functions. Moreover, improving our knowledge on pyrogenic carbon (PyC) dynamics, including formation, transport and deposition, is fundamental to better understand a significant slow-cycling component of the global carbon cycle, particularly as these ecosystems account for a substantial proportion of the area globally burnt. However, a thorough assessment of past fire regimes in grass-dominated ecosystems is problematic due to challenges in interpreting the charcoal record of sediments. It is therefore critical to adopt appropriate sampling and analytical methods to allow the acquisition …

Flowstone Growth In Gournier River (Vercors, France): A Diachronic Landscape Analysis By 3d Modelling And Photo Draping, Kim Genuite, Yves Perrette, Stéphane Jaillet

International Journal of Speleology

Calcite surface has been reported by cavers and scientists over the last decades. Here, we present a methodological work aimed at quantifying that growth. We suggest a method of draping old photographs of a part of the Gournier Cave onto a 3D model. This work relies on a collection of photographs taken by cavers. We have chosen to study a site for which the maximum number of photographs was available. The series of photographs over time makes it possible to overcome the limitation of calcite crust dating. The acquisition of the 3D model has been achieved using terrestrial LIDAR. Then, …

The Blurred Line Between Photic And Aphotic Environments: A Large Mexican Cave With Almost No Dark Zone, Luis M. Mejía-Ortíz, Tanja Pipan, David C. Culver, Peter Sprouse

International Journal of Speleology

Sistema Muévelo Rico is a 1.2 km long cave in Quintana Roo, less than 2 km from the Caribbean Sea. We measured illuminance to a level of 0.1 lux, organic matter (weight loss on ignition), temperature, and relative humidity. The last two were measured at hourly intervals for nearly one year. Approximately one-third of the cave has illuminance values greater than 0.01 lux, and most of the rest of the cave has light as well. Temperature and relative humidity were relatively constant, but they showed a daily cycle at all stations, albeit with different strengths. Organic matter averaged 8%, intermediate …

Phosphate Speleothems In Caves Developed In Iron Ores And Laterites Of The Carajás Mineral Province (Brazil) And A New Occurrence Of Spheniscidite, Alan R.L. Albuquerque, Rômulo S. Angélica, Daniele F. Gonçalves, Simone P.A. Paz

International Journal of Speleology

The Carajás Mineral Province has one of the largest concentrations of caves in Brazil, and its iron ore is among the country’s main exports. As a result of iron ore intense extraction, new environmental policies have been implemented. In an attempt to balance economic activity and environmental conservation, an inventory and a relevance-based classification of caves were implemented in 2008 as criteria for environmental licensing of mining ventures. This implementation motivated the present study of phosphate speleothems in Carajás’ caves developed in ferriferous rocks. The objectives of this study are to describe the phosphate minerals and their formation processes based …

Assessing Preservation Priorities Of Caves And Karst Areas Using The Frequency Of Endemic Cave-Dwelling Species, Eugen Nitzu, Marius Vlaicu, Andrei Giurginca, Ioana N. Meleg, Ionut Popa, Augustin Nae, Ştefan Baba

International Journal of Speleology

Endemic and rare species as bioindicators of habitat vulnerability were used to develop protection and management plans for biotope prioritization (mainly islands habitats, lava tubes or groundwaters). Due to their narrow distribution, the endemic species (species confined to a restricted geographic area) are more susceptible to ecological disequilibrium and habitat loss than the widespread ones. Consequently, endemics become endangered in the context of ecological disturbance caused by anthropogenic pressure, making them suitable candidates to assess environmental preservation needs. Taking into consideration that most of the stygobitic and troglobitic species are endemic and confined to specific karst areas, based on their …

Graph-Based Latent Embedding, Annotation And Representation Learning In Neural Networks For Semi-Supervised And Unsupervised Settings, Ismail Ozsel Kilinc

USF Tampa Graduate Theses and Dissertations

Machine learning has been immensely successful in supervised learning with outstanding examples in major industrial applications such as voice and image recognition. Following these developments, the most recent research has now begun to focus primarily on algorithms which can exploit very large sets of unlabeled examples to reduce the amount of manually labeled data required for existing models to perform well. In this dissertation, we propose graph-based latent embedding/annotation/representation learning techniques in neural networks tailored for semi-supervised and unsupervised learning problems. Specifically, we propose a novel regularization technique called Graph-based Activity Regularization (GAR) and a novel output layer modification called …

Investigation Of Sediment Ridges Using Bathymetry And Backscatter Near Clearwater, Florida, Lewis Stewart

USF Tampa Graduate Theses and Dissertations

Changes in sediment morphology on the West Florida Shelf is investigated over a 14-year time period using multibeam bathymetry and backscatter in water depths between 10 m and 20 m, off the coast of Indian Rocks Beach, Pinellas County, Florida. Bathymetric surveys collected in 2002 (Kongsberg EM 3000 at 300 kHz) and 2016 (Reson 7125 at 400 kHz) were processed using CARIS Hips and Sips to create bathymetric maps and backscatter images. These data were then interpreted and compared in order to test hypotheses and answer questions related to sediment migration and sediment volume change.

The following questions prompted this …

Cave Monitoring In The Béke And Baradla Caves (Northeastern Hungary): Implications For The Conditions For The Formation Cave Carbonates, György Czuppon, Attila Demény, Szabolcs Leél-Őssy, Mihály Óvari, Mihály Molnár, József Stieber, Klaudia Kiss, Krisztina Kármán, Gergely Surányi, László Haszpra

International Journal of Speleology

In order to use speleothems in the reconstruction of past climate and environmental changes it is necessary to understand the environmental and hydrological processes that determine the physico-chemical conditions of carbonate precipitation and hence speleothem formation. Therefore, in this study an extended monitoring program was conducted in the Béke and Baradla caves located in the Aggtelek region (Northeastern Hungary). The studied caves are rich in speleothem and flowstone occurrences with great potential for paleoclimatology studies. The monitoring activity included measurements of atmospheric and cave temperatures, CO₂ concentration in cave air, as well as chemical and isotopic compositions of water …

Context-Based Human Activity Recognition Using Multimodal Wearable Sensors, Pratool Bharti

USF Tampa Graduate Theses and Dissertations

In the past decade, Human Activity Recognition (HAR) has been an important part of the regular day to day life of many people. Activity recognition has wide applications in the field of health care, remote monitoring of elders, sports, biometric authentication, e-commerce and more. Each HAR application needs a unique approach to provide solutions driven by the context of the problem. In this dissertation, we are primarily discussing two application of HAR in different contexts. First, we design a novel approach for in-home, fine-grained activity recognition using multimodal wearable sensors on multiple body positions, along with very small Bluetooth beacons …

Design And Simulation Of A Miniature Cylindrical Mirror Auger Electron Energy Analyzer With Secondary Electron Noise Suppression, Jay A. Bieber

USF Tampa Graduate Theses and Dissertations

In the nanoscale metrology industry, there is a need for low-cost instruments, which have the ability to probe the structrure and elemental composition of thin films. This dissertation, describes the research performed to design and simulate a miniature Cylindrical Mirror Analyzer, (CMA), and Auger Electron Spectrometer, (AES). The CMA includes an integrated coaxial thermionic electron source. Electron optics simulations were performed using the Finite Element Method, (FEM), software COMSOL. To address the large Secondary Electron, (SE), noise, inherent in AES spectra, this research also included experiments to create structures in materials, which were intended to suppress SE backgound noise in …

Resolving Chronological And Temperature Constraints On Antarctic Deglacial Evolution Through Improved Dating Methodology, Cristina Subt

USF Tampa Graduate Theses and Dissertations

In order to determine the timing of Antarctic ice sheet retreat and advance during the Late Quaternary, various tools are used to measure the age of marginal marine sediments. Carbonate 14C dating is a well-established approach, but requires foraminiferal microfossils, shells or other carbonate materials that are rare in most Antarctic regions, and may also suffer from vital effects, which can result in variability of up to 500 years in living organisms. Bulk acid insoluble organic (AIO) 14C dates are frequently as an alternative, but this approach works best where high productivity and sedimentation rates reign, and not too well …

Bayesian Inference On Quantile Regression-Based Mixed-Effects Joint Models For Longitudinal-Survival Data From Aids Studies, Hanze Zhang

USF Tampa Graduate Theses and Dissertations

In HIV/AIDS studies, viral load (the number of copies of HIV-1 RNA) and CD4 cell counts are important biomarkers of the severity of viral infection, disease progression, and treatment evaluation. Recently, joint models, which have the capability on the bias reduction and estimates' efficiency improvement, have been developed to assess the longitudinal process, survival process, and the relationship between them simultaneously. However, the majority of the joint models are based on mean regression, which concentrates only on the mean effect of outcome variable conditional on certain covariates. In fact, in HIV/AIDS research, the mean effect may not always be of …

Imaging Wetland Hydrogeophysics: Applications Of Critical Zone Hydrogeophysics To Better Understand Hydrogeologic Conditions In Coastal And Inland Wetlands And Waters, Christine Marie Downs

USF Tampa Graduate Theses and Dissertations

This dissertation consists of three projects utilizing electric and electromagnetic (EM) methods to better understand critical-zone hydrogeologic conditions in select Florida wetlands and waters.

First, a time-lapse electrical resistivity (ER) survey was conducted in section of mangrove forest on a barrier island in southeast Florida to image changes in pore-water salinity in the root zone. ER data show the most variability in the root zone over a 24-hour period, and, generally, the ground is more resistive during the day than overnight.

Second, a suite of three-dimensional forward models, based on varying lateral boundaries and conductivities typical of a coastal wetland, …

Investigating Marine Resources In The Gulf Of Mexico At Multiple Spatial And Temporal Scales Of Inquiry, Joshua Paul Kilborn

USF Tampa Graduate Theses and Dissertations

The work in this dissertation represents an attempt to investigate multiple temporal and spatial scales of inquiry relating to the variability of marine resources throughout the Gulf of Mexico large marine ecosystem (Gulf LME). This effort was undertaken over two spatial extents within the greater Gulf LME using two different time-series of fisheries monitoring data. Case studies demonstrating simple frameworks and best practices are presented with the aim of aiding researchers seeking to reduce errors and biases in scientific decision making. Two of the studies focused on three years of groundfish survey data collected across the West Florida Shelf (WFS), …

The Performance Of Multilevel Structural Equation Modeling (Msem) In Comparison To Multilevel Modeling (Mlm) In Multilevel Mediation Analysis With Non-Normal Data, Thanh Vinh Pham

USF Tampa Graduate Theses and Dissertations

The mediation analysis has been used to test if the effect of one variable on another variable is mediated by the third variable. The mediation analysis answers a question of how a predictor influences an outcome variable. Such information helps to gain understanding of mechanism underlying the variation of the outcome. When the mediation analysis is conducted on hierarchical data, the structure of data needs to be taken into account. Krull and MacKinnon (1999) recommended using Multilevel Modeling (MLM) with nested data and showed that the MLM approach has more power and flexibility over the standard Ordinary Least Squares (OLS) …

Metal-Organic Frameworks And Mof-Derived Carbon Materials For Fuel Cell Applications, Kia Williams

USF Tampa Graduate Theses and Dissertations

Rapid industrial globalization and technological development and energy consumption across the globe has significantly increased in response to mounting energy needs. The necessity for alternative and sustainable energy conversion devices has become apparent with the growth of energy utilization. In recent years, many research efforts have been made in the development of low-cost, efficient, environmentally friendly energy conversion devices. One type of energy conversion device, polymer electrolyte membrane fuel cells (PEMFCs), uses hydrogen oxidation at the anode and oxygen reduction at the cathode, with a solid-state proton conducting membrane between to generate energy with water as a by-product. PEMFCs use …