Physical Sciences and Mathematics Commons^™

Development Of A Two-Fluid Drag Law For Clustered Particles Using Direct Numerical Simulation And Validation Through Experiments, Ahmadreza Abbasi Baharanchi

FIU Electronic Theses and Dissertations

This dissertation focused on development and utilization of numerical and experimental approaches to improve the CFD modeling of fluidization flow of cohesive micron size particles. The specific objectives of this research were: (1) Developing a cluster prediction mechanism applicable to Two-Fluid Modeling (TFM) of gas-solid systems (2) Developing more accurate drag models for Two-Fluid Modeling (TFM) of gas-solid fluidization flow with the presence of cohesive interparticle forces (3) using the developed model to explore the improvement of accuracy of TFM in simulation of fluidization flow of cohesive powders (4) Understanding the causes and influential factor which led to improvements and …

Models Describing The Sea Level Rise In Key West, Florida, Karm-Ervin Jean

FIU Electronic Theses and Dissertations

Lately, we have been noticing an unusual rise in the sea level near many Floridian cities. By 2060, scientists believe that the sea level in the city of Key West will reach between 22.86 to 60.96 centimeters (Strauss et al. 2012). The consequences of sea level rise are unpleasant by gradually tearing away our beaches and natural resources, destroying our homes and businesses, etc. Definitively, a continual increase of the sea level will affect everyone either directly or indirectly.

In this study, the sea level measurements of four Floridian coastal cities (including Key West) are collected in order to describe …

Online Moving Object Visualization With Geo-Referenced Data, Guangqiang Zhao

FIU Electronic Theses and Dissertations

As a result of the rapid evolution of smart mobile devices and the wide application of satellite-based positioning devices, the moving object database (MOD) has become a hot research topic in recent years. The moving objects generate a large amount of geo-referenced data in different types, such as videos, audios, images and sensor logs. In order to better analyze and utilize the data, it is useful and necessary to visualize the data on a map.

With the rise of web mapping, visualizing the moving object and geo-referenced data has never been so easy. While displaying the trajectory of a moving …

Gis-Integrated Mathematical Modeling Of Social Phenomena At Macro- And Micro- Levels—A Multivariate Geographically-Weighted Regression Model For Identifying Locations Vulnerable To Hosting Terrorist Safe-Houses: France As Case Study, Elyktra Eisman

FIU Electronic Theses and Dissertations

Adaptability and invisibility are hallmarks of modern terrorism, and keeping pace with its dynamic nature presents a serious challenge for societies throughout the world. Innovations in computer science have incorporated applied mathematics to develop a wide array of predictive models to support the variety of approaches to counterterrorism. Predictive models are usually designed to forecast the location of attacks. Although this may protect individual structures or locations, it does not reduce the threat—it merely changes the target. While predictive models dedicated to events or social relationships receive much attention where the mathematical and social science communities intersect, models dedicated to …

Robust Modeling And Predictions Of Greenhouse Gas Fluxes From Forest And Wetland Ecosystems, Khandker S. Ishtiaq

FIU Electronic Theses and Dissertations

The land-atmospheric exchanges of carbon dioxide (CO₂) and methane (CH₄) are major drivers of global warming and climatic changes. The greenhouse gas (GHG) fluxes indicate the dynamics and potential storage of carbon in terrestrial and wetland ecosystems. Appropriate modeling and prediction tools can provide a quantitative understanding and valuable insights into the ecosystem carbon dynamics, while aiding the development of engineering and management strategies to limit emissions of GHGs and enhance carbon sequestration. This dissertation focuses on the development of data-analytics tools and engineering models by employing a range of empirical and semi-mechanistic approaches to robustly …

Gaseous Carbon Emissions (Methane And Carbon Dioxide) From Wetland Soils In A Re-Created Everglades Landscape, Bradley R. Schonhoff

FIU Electronic Theses and Dissertations

Reducing the rates of greenhouse gas (GHG) emissions is critical in combatting global climate change. Carbon dioxide (CO₂) and methane (CH₄) are the two most important carbon-based GHGs, for their atmospheric warming potential. Wetlands such as the Florida Everglades play major roles in the global carbon cycle, as varying hydrologic conditions lead to differential production rates of these two GHGs. This study measured CO₂ and CH₄ emissions in a re-created Everglades ridge-and-slough wetland, where water levels were controlled to reflect natural flood patterns. As expected, lower elevations were flooded longer and produced more CH …

Organometallic Rhenium Dyes For Nitric Oxide Detection And Imaging, Lissette I. Lozano-Lewis

FIU Electronic Theses and Dissertations

The importance of sensing Nitric Oxide (NO) in physiology and medicine has led us to explore the reactivity of NO with organometallic Re dyes. Rhenium complexes were synthesized with the ability to react with NO and sense it under physiological conditions. Fluorescent 1,10-phenantroline complexes (phen)Re(PPh₃)(CO)₂OSO₂CF₃ (1) and (phen)Re(CH₃CN)(CO)₂OSO₂CF₃ (3) can sense NO in the range of 10 - 150 mM showing a decrease in fluorescence response at 514 nm and 532 nm respectively, upon NO-donor addition (l_exc = 360 nm). (phen)Re(THF)(CO)₂OSO₂CF …

Development Of A Maldi-Tof-Ms Method For The Analysis Of Cyanobacterial Neurotoxin Β-N-Methylamino-L-Alanine (Bmaa) In Search Of Bmaa Incorporation In Biological Samples, Laura M. Conklin

FIU Electronic Theses and Dissertations

Beta-N-methylamino-L-alanine (BMAA) is a non-protein amino acid produced by many cyanobacteria, and thought to induce neurotoxic effects through excitotoxicity, contributing to neurodegenerative diseases such as Amyotrophic Lateral Sclerosis/Parkinsonism-dementia complex (ALS-PDC) and Alzheimer’s. The ubiquitous nature of cyanobacteria, and evidence of biomagnification through our food web, creates a dire need for the development of an analytical platform that will provide accurate identification and quantification of BMAA amounts in our ecosystem and potential food supply. The present study evaluated the ability of a MALDI-ToF-MS method to detect and quantify BMAA in a variety of biological matrices. Through validation procedures, it …

Data Verifications For Online Social Networks, Mahmudur Rahman

FIU Electronic Theses and Dissertations

Social networks are popular platforms that simplify user interaction and encourage collaboration. They collect large amounts of media from their users, often reported from mobile devices. The value and impact of social media makes it however an attractive attack target. In this thesis, we focus on the following social media vulnerabilities. First, review centered social networks such as Yelp and Google Play have been shown to be the targets of significant search rank and malware proliferation attacks. Detecting fraudulent behaviors is thus paramount to prevent not only public opinion bias, but also to curb the distribution of malware. Second, the …

The Effect Of Disturbance And Freshwater Availability On Lower Florida Keys’ Coastal Forest Dynamics, Danielle E. Ogurcak

FIU Electronic Theses and Dissertations

Coastal forest retreat in the Florida Keys during the 20^th century has been attributed to a combination of sea level rise and hurricane storm surge impacts, but the interactions between these two disturbances leading to forest decline are not well understood. The goal of my research was to assess their effects over a period spanning more than two decades, and to examine the relationships between these press and pulse disturbances and freshwater availability in pine rockland, hardwood hammock, and supratidal scrub communities. Impacts and recovery from two storm surges, Hurricanes Georges (1998) and Wilma (2005), were assessed with satellite-derived …

Fast Detection And Chemical Characterization Of Gunshot Residues By Cmv-Gc-Ms And Libs, Anamary Tarifa

FIU Electronic Theses and Dissertations

Gunshot residue (GSR) is the term used to describe the particles originating from different parts of the firearm and ammunition during the discharge. A fast and practical field tool to detect the presence of GSR can assist law enforcement in the accurate identification of subjects.

A novel field sampling device is presented for the first time for the fast detection and quantitation of volatile organic compounds (VOCs). The capillary microextraction of volatiles (CMV) is a headspace sampling technique that provides fast results (< 2 min. sampling time) and is reported as a versatile and high-efficiency sampling tool. The CMV device can be coupled to a Gas Chromatography-Mass Spectrometry (GC-MS) instrument by installation of a thermal separation probe in the injection port of the GC.

An analytical method using the CMV device was developed for the detection of 17 compounds commonly found …

The Influence Of The Proximal Amide Hydrogen Bonds And The Proximal Helix Dipole On The Catalytic Activity Of Chloroperoxidase, Armando D. Pardillo

FIU Electronic Theses and Dissertations

Chloroperoxidase (CPO) is a heme-thiolate protein with exceptional versatility and great potential as a biocatalyst. The CPO reactive species, Compound I ( Cpd I) is of particular interest, as well as the Cytochrome P450 (P450) -type monoxygenase catalytic activity, which has significant biotechnological potential. Proximal hydrogen bonding of the axial sulfur with the backbone amides (NH•••S) is a conserved feature of heme-thiolate enzymes. In CPO, the effect of NH•••S bonds is amplified by the dipole moment of the proximal helix. The role of the proximal region has been disputed as to whether it simply protects the axial sulfur, or whether …

Elemental Analysis Of Printing Inks Using Tandem Laser- Induced Breakdown Spectroscopy And Laser Ablation Inductively Coupled Plasma Mass Spectrometry, Kiran Subedi

FIU Electronic Theses and Dissertations

As a consequence of the widespread use of computers coupled to high-quality printers and different types of papers, forgery, counterfeiting, change of wills, anonymous letter writing and felonious use of the documents have become serious problems. Forensic analysts are always seeking methods that can provide reliable information on whether a specimen collected at the crime scene is linked to the crime or to a source of known origin. Sensitive methods that can provide more detailed characterization of natural or man-made materials or even provide information not previously available to forensic examiners.

Recent advances in rapid solid sampling of materials using …

Synthesis And Characterization Of Photochromic Copolymers Containing 3-Indolylfulgides/Indolylfulgimides, Changjun Fan

FIU Electronic Theses and Dissertations

Fulgides and fulgimides are important organic photochromic compounds and can switch between the open forms and the closed forms with light. The 3-indolylfulgides and 3-indolylfulgimides exhibit promising photochromic properties and have great potential in optical memory devices, optical switches and biosensors. Copolymers containing 3-indolylfulgides/indolylfulgimides synthesized via free radical polymerizations increase conformation changes and allow the photochromic compounds to be uniformly distributed in the polymer matrix.

A trifluoromethyl 3-indolylfulgide and two trifluoromethyl 3-indolylfulgimides with one or two polymerizable N-stryryl group(s) were prepared. Copolymerization with methyl methacrylate provided two linear copolymers or a cross-linked copolymer. The properties of the monomeric fulgide/fulgimides …

Modeling, Designing, And Implementing An Ad-Hoc M-Learning Platform That Integrates Sensory Data To Support Ubiquitous Learning, Hien M. Nguyen

FIU Electronic Theses and Dissertations

Learning at any-time, at anywhere, using any mobile computing platform learning (which we refer to as “education in your palm”) empowers informal and formal education. It supports the continued creation of knowledge outside a classroom, after-school programs, community-based organizations, museums, libraries, and shopping malls with under-resourced settings. In doing so, it fosters the continued creation of a cumulative body of knowledge in informal and formal education. Anytime, anywhere, using any device computing platform learning means that students are not required to attend traditional classroom settings in order to learn. Instead, students will be able to access and share learning resources …

Comprehensive Analysis Of Emerging New Psychoactive Substances By Ion Mobility Spectrometry And Mass Spectrometry, Seongshin Gwak

FIU Electronic Theses and Dissertations

In the new era of drug abuse, the proliferation of new psychoactive substances (NPS), commonly referred to as designer drugs or legal highs, has been a global concern. These substances are produced to circumvent current legislation for controlled substances with minor modifications in their chemical structure. Although many efforts have been made previously, the characterization of such substances are still challenging because of (1) the continual emergence of newly identified substances, (2) the lack of a universal screening test for NPS that are structurally similar to each other, and (3) the complex and time-consuming chromatographic techniques currently used. Therefore, it …

Modeling Security And Resource Allocation For Mobile Multi-Hop Wireless Neworks Using Game Theory, Laurent L. Y. Njilla

FIU Electronic Theses and Dissertations

This dissertation presents novel approaches to modeling and analyzing security and resource allocation in mobile ad hoc networks (MANETs). The research involves the design, implementation and simulation of different models resulting in resource sharing and security’s strengthening of the network among mobile devices. Because of the mobility, the network topology may change quickly and unpredictably over time. Moreover, data-information sent from a source to a designated destination node, which is not nearby, has to route its information with the need of intermediary mobile nodes. However, not all intermediary nodes in the network are willing to participate in data-packet transfer of …

Integrating Deep Learning With Correlation-Based Multimedia Semantic Concept Detection, Hsin-Yu Ha

FIU Electronic Theses and Dissertations

The rapid advances in technologies make the explosive growth of multimedia data possible and available to the public. Multimedia data can be defined as data collection, which is composed of various data types and different representations. Due to the fact that multimedia data carries knowledgeable information, it has been widely adopted to different genera, like surveillance event detection, medical abnormality detection, and many others. To fulfil various requirements for different applications, it is important to effectively classify multimedia data into semantic concepts across multiple domains. In this dissertation, a correlation-based multimedia semantic concept detection framework is seamlessly integrated with the …

Modeling A Phosphorus Credit Trading Program In The Lake Okeechobee Watershed, Juliana Corrales

FIU Electronic Theses and Dissertations

Lake Okeechobee is the largest lake in the southeastern United States and is a central component of the hydrology and environment of the Everglades ecosystem in South Florida. The natural state of the lake has been degraded as wetlands and natural habitats in the Lake Okeechobee watershed have been replaced with farms, urban areas, and dairy operations. Excessive phosphorus loadings from these diverse sources have been identified as the leading causes of the lake’s impairment. For more than four decades, many resources have been allocated to regional and local restoration efforts to reduce phosphorus loadings into the lake. However, phosphorus …

Determination Of Extracellular Molecules Produced By Vibrio Harveyi Using Ms/Ms, Jose G. Roble

FIU Electronic Theses and Dissertations

Quorum sensing (QS) is a process that allows bacteria to sense the population density of cells around them by communicating with each other via autoinducer molecules. This cross-communication is crucial in the regulation of bacterial processes such as bioluminescence, virulence, and biofilm formation. Previous research by Milburn and Makemson on Vibrio harveyi suggested that in addition of the known biosynthesis of three well-characterized autoinducers, dozens of unknown molecules are also produced and released to the environment by V. harveyi. This study was performed using electrospray tandem mass spectrometry with the purpose of detection and characterization of the extracellular molecules …

Mangiferin As A Biomarker For Mango Anthracnose Resistance, Herma Pierre

FIU Electronic Theses and Dissertations

Mangos (Mangifera indica L.) are tropical/subtropical fruits belonging to the plant family Anacardiaceae. Anthracnose is the most deleterious disease of mango both in the field and during postharvest handling. It is most commonly caused by the Colletotrichum gloeosporioides complex. Mangiferin, a xanthanoid compound found in at least twelve plant families worldwide (Luo et al., 2012), is present in large amounts of the leaves and edible mangos. Even though this compound plays a pivotal role in the plant’s defense against biotic and abiotic stressors, no correlations been made between the compound and mango anthracnose resistance.

Mangos were collected, grouped …

Macular Pigment And Lens Optical Density Measurements-Evaluating A Flicker Machine With Novel Features, Anirbaan Mukherjee

FIU Electronic Theses and Dissertations

Age related macular degeneration (AMD) is one of the leading causes of blindness amongst the elderly. Macular pigment (MP) in the retina has been established to protect individuals against AMD. Improving levels of MP by diet or supplements is the constant quest of clinical practitioners and researchers, thus necessitating development of instruments capable of repeatable and reliable MP measurement. Cataract, a consequence of the rising opacity levels of the lens with age is one of the other major causes of blindness in the world. Mapcatsf, a LED-based microprocessor-controlled heterochromatic flicker photometer (HFP) using photopic vision is capable of measuring the …

Investigation Of The Lead Isotope Signatures Of Marine Sediments In Relation To The Lead Isotope Signatures Of Northern Andean Ores, Kimberly D. Beck

FIU Electronic Theses and Dissertations

Lead isotope ratios of ores and igneous rocks in the Central and Southern Andes show a large-scale geographic pattern related to magmatic source processes. This pattern changes in the Northern Andes for reasons that are not well understood; this study is an investigation of potential causes of this change. Deep ocean sediment samples from the Nazca Plate were analyzed for ²⁰⁶Pb/²⁰⁴Pb, ²⁰⁷Pb/²⁰⁴Pb and ²⁰⁸Pb/²⁰⁴Pb, and the data were compared with published data on central Andean ores and ores and igneous rocks from Ecuador. Lead isotopic compositions of the Nazca Plate sediments …

Comparisons Of Estimators Of Small Proportion Under Group Testing, Xing Wei

FIU Electronic Theses and Dissertations

Binomial group testing has been long recognized as an efficient method of estimating proportion of subjects with a specific characteristic. The method is superior to the classic maximum likelihood estimator (MLE), particularly when the proportion is small. Under the group testing model, we assume the testing is conducted without error. In the present research, a new Bayes estimator will be proposed that utilizes an additional piece of information, the proportion to be estimated is small and within a given range. It is observed that with the appropriate choice of the hyper-parameter our new Bayes estimator has smaller mean squared error …

Improving Satellite-Based Chlorophyll-A Estimating Algorithms In Shallow, Coastal Waters, Tara Blakey

FIU Electronic Theses and Dissertations

This work evaluated the improvement to the accuracy of chlorophyll-a (chl-a) estimating algorithms derived from Sea-Viewing Wide Field-of-View Sensor (SeaWIFS) archives of an optically-shallow, subtropical bay. Preliminary investigation into the in situ chl-a measurements showed that the fine spatial and temporal resolution currently only available through satellite remote sensing are required to adequately understand the dynamics of coastal chl-a. The in situ datasets, however, were found to be useful for developing chl-a algorithms by allowing for 1) identification of appropriate times of year for classifying benthic habitats and 2) the assumption of annually …

Land Use /Land Cover Driven Surface Energy Balance And Convective Rainfall Change In South Florida, Hari P. Kandel

FIU Electronic Theses and Dissertations

Modification of land use/land cover in South Florida has posed a major challenge in the region’s eco-hydrology by shifting the surface-atmosphere water and energy balance. Although drainage and development in South Florida took place extensively between the mid- and late- 20^th century, converting half of the original Everglades into agricultural and urban areas, urban expansion still accounts for a dominant mode of surface cover change in South Florida. Changes in surface cover directly affect the radiative, thermophysical and aerodynamic parameters which determine the absorption and partitioning of radiation into different components at the Earth surface. The alteration is responsible …

Hydrologic Controls Of Coastal Groundwater Discharge In Southern Taylor Slough, Everglades National Park, Florida, Edward Linden

FIU Electronic Theses and Dissertations

This project empirically determined the controls of groundwater discharge potential and surface water chemistry in southern Taylor Slough, Everglades National Park, Florida. Potential for groundwater discharge was calculated as the difference in equivalent freshwater stage between groundwater and surface water on a daily basis for two sites (upland and coastal) along southern Taylor Slough. Upstream water stages were shown to vary most similarly to the timing of groundwater discharge potential in coastal Taylor Slough. Surface water major ion chemistry did not apparently change as a result of groundwater discharge potential. Surface water major ion chemistry at the coastal site was …

Target And Non-Target Techniques For The Quantitation Of Drugs Of Abuse, Identification Of Transformation Products, And Characterization Of Contaminants Of Emergent Concern By High Resolution Mass Spectrometry, Nubia Vanesa Heuett

FIU Electronic Theses and Dissertations

Development and application of target and non-target techniques for routine analysis, identification of transformation products, and characterization of unknown compounds in water matrices using liquid-chromatography high-resolution mass spectrometry (HRMS) were explored in this dissertation. A novel analytical method based on online-SPE-LC-HRMS was developed for the detection of 18 drugs of abuse (DOAs) in raw sewage water from a college campus. Results showed the presence of 14 DOAs for which amphetamine and 11-nor-9-carcoxy-THC (THC metabolite) were the most prevalent and had the highest potential consumption rates.

A second study dedicated to the identification of transformation products (TPs) generated from DOAs was …

Understanding The Challenges Of Expanding Community Forestry In Northwest Cameroon, Caitlin M. Farnung

FIU Electronic Theses and Dissertations

The tropical afro-montane forest of the Northwest region is unique and under direct threat from the high population density of the region. Community-based forestry management is an opportunity to sustainably manage the remaining forest fragments.

Community forestry was introduced to Cameroon with the legislation of the 1994 Forestry Law. Over two decades later little research has been conducted in the Northwest region of Cameroon. Twenty-four semi-structured interviews were conducted, and samples of forestry records were analyzed as exploratory research that would act as a base for further research.

This research found that the tenure of the community over the community …

A Spatial And Temporal Analysis Of Land Use And Water Quality In Southern Miami Dade County, Mario Londono

FIU Electronic Theses and Dissertations

This thesis research employs a multi-pronged analysis approach to contribute to the existing knowledge regarding land use and water quality in southern Miami Dade County. Nutrient concentrations for TP, NOx-N, and NH3-N were evaluated for water quality monitoring stations across seven canals for two time periods: 1990-2003 and 2009-2014. Overall, the sites did not surpass the mandated TP threshold but a number of sites exceeded the NOx-N and NH3-N criteria set by multiple government agencies. Statistical tests demonstrated that the sites had differing distributions, not sharing similar median concentrations. Land use classifications were derived for the area interest for the …