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Title: DATA-DRIVEN IDENTIFICATION AND CONTROL OF TURBULENT STRUCTURES USING DEEP NEURAL NETWORKS.
Creator: Jagodinski, Eric, Verma, Siddhartha, Florida Atlantic University, Department of Ocean and Mechanical Engineering, College of Engineering and Computer Science
Abstract/Description: Wall-bounded turbulent flows are pervasive in numerous physics and engineering applications. Such flows tend to have a strong impact on the design of ships, airplanes and rockets, industrial chemical mixing, wind and hydrokinetic energy, utility infrastructure and innumerable other fields. Understanding and controlling wall bounded turbulence has been a long-pursued endeavor yielding plentiful scientific and engineering discoveries, but there is much that remains unexplained from a...
Show moreWall-bounded turbulent flows are pervasive in numerous physics and engineering applications. Such flows tend to have a strong impact on the design of ships, airplanes and rockets, industrial chemical mixing, wind and hydrokinetic energy, utility infrastructure and innumerable other fields. Understanding and controlling wall bounded turbulence has been a long-pursued endeavor yielding plentiful scientific and engineering discoveries, but there is much that remains unexplained from a fundamental viewpoint. One unexplained phenomenon is the formation and impact of coherent structures like the ejections of slow near-wall fluid into faster moving ow which have been shown to correlate with increases in friction drag. This thesis focuses on recognizing and regulating organized structures within wall-bounded turbulent flows using a variety of machine learning techniques to overcome the nonlinear nature of this phenomenon. Deep Learning has provided new avenues of analyzing large amounts of data by applying techniques modeled after biological neurons. These techniques allow for the discovery of nonlinear relationships in massive, complex systems like the data found frequently in fluid dynamics simulation. Using a neural network architecture called Convolutional Neural Networks that specializes in uncovering spatial relationships, a network was trained to estimate the relative intensity of ejection structures within turbulent flow simulation without any a priori knowledge of the underlying flow dynamics. To explore the underlying physics that the trained network might reveal, an interpretation technique called Gradient-based Class Activation Mapping was modified to identify salient regions in the flow field which most influenced the trained network to make an accurate estimation of these organized structures. Using various statistical techniques, these salient regions were found to have a high correlation to ejection structures, and to high positive kinetic energy production, low negative production, and low energy dissipation regions within the flow. Additionally, these techniques present a general framework for identifying nonlinear causal structures in general three-dimensional data in any scientific domain where the underlying physics may be unknown.
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Date Issued: 2022
PURL: http://purl.flvc.org/fau/fd/FA00014119
Subject Headings: Turbulent flow, Turbulence, Neural networks (Computer science), Deep learning (Machine learning)
Format: Document (PDF)

Title: APPLICATIONS OF DIGITAL HOLOGRAPHIC IMAGING TOWARDS CHARACTERIZATION OF MARINE PLANKTON DISTRIBUTIONS AND BIOPHYSICAL INTERACTIONS.
Creator: Barua, Ranjoy, Nayak, Aditya R., Florida Atlantic University, Department of Ocean and Mechanical Engineering, College of Engineering and Computer Science
Abstract/Description: Characterization of the distribution and biophysical interactions of oceanic planktonic organisms is crucial to address fundamental science questions associated with climate change, marine ecology, pollution, and ocean optics. Thus, development of instrumentation techniques for monitoring plankton at high spatial and temporal resolutions is important. This dissertation deals with the advancements made in applying digital holography – a 3-D non-intrusive, freestream imaging technique – to...
Show moreCharacterization of the distribution and biophysical interactions of oceanic planktonic organisms is crucial to address fundamental science questions associated with climate change, marine ecology, pollution, and ocean optics. Thus, development of instrumentation techniques for monitoring plankton at high spatial and temporal resolutions is important. This dissertation deals with the advancements made in applying digital holography – a 3-D non-intrusive, freestream imaging technique – to address three different applications associated with marine plankton monitoring and ecology. In the first project, an autonomous in-line digital holographic microscope was successfully deployed for rapid in situ detection of the harmful dinoflagellate, Karenia brevis in the coastal Gulf of Mexico. Monitoring K. brevis abundance and distribution are crucial for early warning systems and implementing preventative measures to limit potential damage. The holographic system was successfully paired with a convolutional neural network for automated data processing to ensure rapid and accurate K. brevis detection.
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Date Issued: 2022
PURL: http://purl.flvc.org/fau/fd/FA00014096
Subject Headings: Marine plankton, Holography, Digital holographic microscopy
Format: Document (PDF)

Title: UNDERSTANDING GRAVITY DRIVEN PARTICLE SETTLING AND DISTRIBUITION IN FRACTURES.
Creator: Hafez, Mazen, Kim, Myeongsub, Florida Atlantic University, Department of Ocean and Mechanical Engineering, College of Engineering and Computer Science
Abstract/Description: The elevated energy demand and high dependency on fossil fuels have directed researchers’ attention to promoting and advancing hydraulic fracturing (HF) operations for a sustainable energy future. Previous studies have demonstrated that the particle suspension and positioning in slick water play a vital role during the injection and shut-in stages of the HF operations. A significant challenge to HF is the premature particle settling and uneven particle distribution in a formation. Even though...
Show moreThe elevated energy demand and high dependency on fossil fuels have directed researchers’ attention to promoting and advancing hydraulic fracturing (HF) operations for a sustainable energy future. Previous studies have demonstrated that the particle suspension and positioning in slick water play a vital role during the injection and shut-in stages of the HF operations. A significant challenge to HF is the premature particle settling and uneven particle distribution in a formation. Even though various research was conducted on the topic of particle transport, there still exist gaps in the fundamental particle-particle interaction mechanisms. This dissertation utilizes both experimental and numerical approaches to advance the state of the art in particle-particle interactions in various test conditions. Experimentally, the study utilizes high-speed imaging coupled with particle tracking velocimetry (PTV) and particle image velocimetry (PIV) to provide a space and time-resolved investigation of both two-particle and multi-particle interactions during gravitational settling, respectively.
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Date Issued: 2022
PURL: http://purl.flvc.org/fau/fd/FA00014095
Subject Headings: Hydraulic fracturing, Particle image velocimetry, Particle tracking velocimetry, Fluid mechanics research
Format: Document (PDF)

Title: DEVELOPMENT OF MULTIFUNCTIONAL BETA-TRICALCIUM PHOSPHATE SCAFFOLDS FOR ANGIOGENESIS AND OSTEOGENESIS.
Creator: Qian, Enze, Kang, Yunqing, Florida Atlantic University, Department of Ocean and Mechanical Engineering, College of Engineering and Computer Science
Abstract/Description: Rapid and efficient vascularization is still a considerable challenge of a tissue engineered β-tricalcium phosphate (β-TCP) scaffold. To overcome this challenge, branched channels were created in the porous scaffold to stimulate the instant flow of blood supply. The branched channeled porous β-TCP scaffold was fabricated using 3D printing and template-casting method. Human bone mesenchymal stem cells (hBMSC) and human umbilical vein endothelial cells (HUVEC) were seeded in the scaffolds and...
Show moreRapid and efficient vascularization is still a considerable challenge of a tissue engineered β-tricalcium phosphate (β-TCP) scaffold. To overcome this challenge, branched channels were created in the porous scaffold to stimulate the instant flow of blood supply. The branched channeled porous β-TCP scaffold was fabricated using 3D printing and template-casting method. Human bone mesenchymal stem cells (hBMSC) and human umbilical vein endothelial cells (HUVEC) were seeded in the scaffolds and characterized through double-stranded DNA (dsDNA) assay, alkaline phosphatase (ALP) assay and cell migration. Scaffolds were then implanted in the subcutaneous pockets in mice. Hematoxylin and eosin staining and Immunohistochemical staining on vascularization, bone-related markers were carried out. Results showed that branched channels significantly promoted HUVECs’ infiltration, migration, proliferation, and angiogenesis and also promote the proliferation and osteogenesis differentiation of hBMSCs. Scaffolds did not show significant pro-inflammatory effects. In vivo results showed that in the early stage after implantation, cells significantly migrated into branched channeled scaffolds compared to non-channeled and straight channeled scaffolds. More and matured blood vessels formed in the branched channeled scaffolds compared to in non-channeled and straight channeled scaffolds. Besides promoting vascularization, the branched channels also stimulated the infiltration of bone-related cells into the scaffolds. These results suggested that the geometric design of branched channels in the porous β-TCP scaffold promoted rapid vascularization and potentially stimulated bone cell recruitment. To further enhance the function of the scaffold to promote the MSCs differentiation, MnO2 hollow and solid nanoparticles were doped into the scaffold with different concentrations.
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Date Issued: 2023
PURL: http://purl.flvc.org/fau/fd/FA00014193
Subject Headings: Tissue engineering, Bone Regeneration, Beta-tricalcium phosphate
Format: Document (PDF)

Title: A NEW DECELLULARIZED MATRIX FOR ENGINEERING AN ESOPHAGEAL CANCER MODEL IN A PERFUSION BIOREACTOR.
Creator: Brennan, Jordan Michael, Kang, Yunqing, Florida Atlantic University, Department of Ocean and Mechanical Engineering, College of Engineering and Computer Science
Abstract/Description: The lack of physiologically relevant human esophageal cancer models has as a result that many esophageal cancer studies are encountering major bottleneck challenges in achieving breakthrough progress. To address the issue, here a 3D esophageal tumor tissue model was engineered using a biomimetic decellularized esophageal matrix in a customized bioreactor. To obtain a biomimetic esophageal matrix, a detergent-free, rapid decellularization method was developed to decellularize porcine esophagus...
Show moreThe lack of physiologically relevant human esophageal cancer models has as a result that many esophageal cancer studies are encountering major bottleneck challenges in achieving breakthrough progress. To address the issue, here a 3D esophageal tumor tissue model was engineered using a biomimetic decellularized esophageal matrix in a customized bioreactor. To obtain a biomimetic esophageal matrix, a detergent-free, rapid decellularization method was developed to decellularize porcine esophagus. The decellularized esophageal matrix (DEM) was characterized and the DEM was utilized for the growth of esophageal cancer cell KYSE30 in well plates and the bioreactor. Then the expression of cancerrelated markers of KYSE30 cells was analyzed and compared with formalin-fixed, paraffin-embedded (FFPE) esophageal squamous cell carcinoma (ESCC) tissue biospecimens. Results show that the detergent-free decellularization method preserved the esophageal matrix components and effectively removed cell nucleus. KYSE30 cancer cells proliferated well on and inside the DEM. KYSE30 cells cultured on the DEM in the dynamic bioreactor show different cancer marker expressions than those in the static well plate, and also share some similarities to the FFPE-ESCC biospecimens.
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Date Issued: 2023
PURL: http://purl.flvc.org/fau/fd/FA00014206
Subject Headings: Cancer, Esophageal Neoplasms, Biomimetics
Format: Document (PDF)

Title: AN AUTOMATED ANCHORING SYSTEM FOR AN UNMANNED SURFACE VEHICLE.
Creator: Fosbrook, Amanda, Dhanak, Manhar, Florida Atlantic University, Department of Ocean and Mechanical Engineering, College of Engineering and Computer Science
Abstract/Description: The goal of this thesis is to simulate, design and build an automated device that allows unmanned vessels to anchor themselves in specified locations while being United States Coast Guard Navigation Rules compliant. This is a part of a larger project funded by the U.S. Department of Energy for Florida Atlantic University to build an unmanned platform with an Undershot Water Wheel on it. By simulating the environment of the South Florida Intercoastal Water Ways, forces acting on the line,...
Show moreThe goal of this thesis is to simulate, design and build an automated device that allows unmanned vessels to anchor themselves in specified locations while being United States Coast Guard Navigation Rules compliant. This is a part of a larger project funded by the U.S. Department of Energy for Florida Atlantic University to build an unmanned platform with an Undershot Water Wheel on it. By simulating the environment of the South Florida Intercoastal Water Ways, forces acting on the line, anchor and the vessel are analyzed. These forces are used as the guide for the design and build of a line locking mechanism that takes the tension off the winch and a sensor package to monitor the environment the platform is in as well as control of the system. Based off experimental testing, the system was successful in handling all emulated environments with loads exceeding 150lbs of tension.
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Date Issued: 2021
PURL: http://purl.flvc.org/fau/fd/FA00013810
Subject Headings: Autonomous vehicles, Anchors
Format: Document (PDF)

Title: Optimized Parameters Fitting of a Poro-Elastic Acoustic Model with Ultrasonic Measurements for the Monitoring of Corroding Rebar in Reinforced Concrete.
Creator: Shaffer, Samuel, Beaujean, Pierre-Philippe, Florida Atlantic University, Department of Ocean and Mechanical Engineering, College of Engineering and Computer Science
Abstract/Description: Traditional techniques of observing cracking within reinforced structures can be invasive, leading to an increased risk of added corrosion to structures already undergoing corrosive processes. The research presented in this document improves upon a nondestructive method for detecting early crack formation in reinforced concrete. This method includes using acoustic signaling to add a layer of salt water between the sensor and analyzed sample. Following the collection of surface and rebar echo...
Show moreTraditional techniques of observing cracking within reinforced structures can be invasive, leading to an increased risk of added corrosion to structures already undergoing corrosive processes. The research presented in this document improves upon a nondestructive method for detecting early crack formation in reinforced concrete. This method includes using acoustic signaling to add a layer of salt water between the sensor and analyzed sample. Following the collection of surface and rebar echo responses, an adapted version of the novel Biot-Stoll method is used to model sound propagation for poro-elastic mediums. Testing of model parameters and variables has improved the root mean square error (RMSE) by up to 63.7% when studying the full signal, and up to 62.6% for the rebar echo locations. These improvements signify better curve fitting between simulated and measured responses, which lead to increased accuracy in the model parameter outputs.
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Date Issued: 2023
PURL: http://purl.flvc.org/fau/fd/FA00014265
Subject Headings: Reinforced concrete, Reinforcing bars--Corrosion, Ultrasonic testing
Format: Document (PDF)

Title: UNDERSTANDING BUBBLE GROWTH BEHAVIOR DURING NUCLEATE BOILING.
Creator: Ghazvini, Mahyar, Kim, Myeongsub, Florida Atlantic University, Department of Ocean and Mechanical Engineering, College of Engineering and Computer Science
Abstract/Description: Boiling heat transfer associated with bubble growth is perhaps one of the most efficient cooling methodologies due to its sizeable latent heat during phase change. Despite significant advancement, numerous questions remain regarding the fundamentals of bubble growth mechanisms, a primary source of enhanced heat dissipation. This thesis provides a comprehensive examination of the mechanisms involved in the growth of bubbles during nucleate boiling. By conducting a combination of experiments...
Show moreBoiling heat transfer associated with bubble growth is perhaps one of the most efficient cooling methodologies due to its sizeable latent heat during phase change. Despite significant advancement, numerous questions remain regarding the fundamentals of bubble growth mechanisms, a primary source of enhanced heat dissipation. This thesis provides a comprehensive examination of the mechanisms involved in the growth of bubbles during nucleate boiling. By conducting a combination of experiments and numerical analyses, the goal is to enhance our understanding of bubble growth phenomena and their impact on heat transfer. Initially, the experimental work focuses on comparing the heat transfer performance and parameters related to bubble dynamics between regular and modified fin structures. The findings demonstrate that the modified fin structure, which featured artificial nucleation sites, exhibits superior heat transfer characteristics. This improvement is attributed to changes in the bubble departure diameter, bubble departure frequency, and growth time. Subsequently, an artificial neural network is developed to accurately predict the bubble departure diameter based on the wall superheat and subcooling level. This predictive model provides valuable insights into bubble behavior originating from artificial nucleation sites.
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Date Issued: 2023
PURL: http://purl.flvc.org/fau/fd/FA00014295
Subject Headings: Nucleate boiling, Ebullition, Heat--Transmission
Format: Document (PDF)

Title: Some topics related to the vibrations of deterministic and non-deterministic metamaterial structures.
Creator: Li, Yuchen, Elishakoff, Isaac, Challamel, Noël, Florida Atlantic University, Department of Ocean and Mechanical Engineering, College of Engineering and Computer Science
Abstract/Description: In this thesis, we will explore different kinds of metamaterial or architectural structural problems, including structures composed of heterogeneous media with bi periodic sub-structures, discrete structures with sub-elements or continuous structures with discrete attached sub-elements. The thesis is composed of seven parts. After having introduced the specificities of metamaterial mechanics, the second chapter is devoted to the vibration of discrete beam problems called Hencky bar-chain...
Show moreIn this thesis, we will explore different kinds of metamaterial or architectural structural problems, including structures composed of heterogeneous media with bi periodic sub-structures, discrete structures with sub-elements or continuous structures with discrete attached sub-elements. The thesis is composed of seven parts. After having introduced the specificities of metamaterial mechanics, the second chapter is devoted to the vibration of discrete beam problems called Hencky bar-chain model in a stochastic framework. It is shown that the lattice beam behaves as a nonlocal continuous beam problem, both in the deterministic and the non-deterministic analyses. The third chapter considers the vibration of continuous beams with the introduction of shear effects and attached periodically oscillators. A discussion on beam modelling, for example Timoshenko beam models or truncated Timoshenko beam models is included. It is shown that the bandgap phenomenon observed for metamaterial beams can be accurately captured by a truncated Timoshenko beam model which means the last term in the Timoshenko equation is not that important.
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Date Issued: 2023
PURL: http://purl.flvc.org/fau/fd/FA00014289
Subject Headings: Metamaterials, Hencky bar-chain model, Lattice theory, Engineering
Format: Document (PDF)

Title: INVESTIGATING THE ROLE OF BIOMOLECULE/MINERAL INTERACTIONS VIA CALCITE AND CELESTITE MODEL SYSTEMS.
Creator: Martin, Andrienne, Merk, Vivian, Florida Atlantic University, Department of Ocean and Mechanical Engineering, College of Engineering and Computer Science
Abstract/Description: In this research, we use calcite and celestite inorganic model systems to better understand biological crystallization in the presence of organic biomolecules. Our goal is to understand what happens when biomolecules occlude into crystals and how that affects the structural organization. Specifically, we focus on the role the respective biomolecule chemistry plays in regulating the incorporation into a crystal. To visualize and characterize the biomolecule/mineral role in crystallization, a...
Show moreIn this research, we use calcite and celestite inorganic model systems to better understand biological crystallization in the presence of organic biomolecules. Our goal is to understand what happens when biomolecules occlude into crystals and how that affects the structural organization. Specifically, we focus on the role the respective biomolecule chemistry plays in regulating the incorporation into a crystal. To visualize and characterize the biomolecule/mineral role in crystallization, a variety of techniques were used to image and analyze the respective model systems. The synthesized single crystals were characterized by light microscopy (LM). Scanning electron microscopy (SEM) and field-emission SEM (FE-SEM) were used to examine the morphology of the crystals. Structural and topographical analyses were carried out using atomic force microscopy (AFM). Fourier transform infrared spectroscopy (FTIR) and confocal Raman microscopy were both used to characterize functional groups, where Raman spectroscopic mappings provided the region-specific chemical composition of the crystal.
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Date Issued: 2023
PURL: http://purl.flvc.org/fau/fd/FA00014287
Subject Headings: Crystallization, Biomolecules, Calcite, Celestite
Format: Document (PDF)

Title: MICROFLUIDIC ELECTRICAL IMPEDANCE TECHNOLOGY FOR POINT-OFCARE ASSESSMENT OF SICKLE CELL DISEASE.
Creator: Dieujuste, Darryl, Du, Sarah, Florida Atlantic University, Department of Ocean and Mechanical Engineering, College of Engineering and Computer Science
Abstract/Description: Sickle Cell Disease (SCD) is a genetic disease that affects approximately 100,000 people in the USA and millions worldwide. The disease is defined by a mutation in hemoglobin, the red blood cell’s oxygen carrying component. Under hypoxic (low oxygen) conditions, the mutated hemoglobin (known as HbS) polymerizes into rigid fibers that stretch the cell into a sickle shape. These rigid cells can occlude blood vessels and cause an individual immense pain. Currently, no point-of-care devices exist...
Show moreSickle Cell Disease (SCD) is a genetic disease that affects approximately 100,000 people in the USA and millions worldwide. The disease is defined by a mutation in hemoglobin, the red blood cell’s oxygen carrying component. Under hypoxic (low oxygen) conditions, the mutated hemoglobin (known as HbS) polymerizes into rigid fibers that stretch the cell into a sickle shape. These rigid cells can occlude blood vessels and cause an individual immense pain. Currently, no point-of-care devices exist in the market for assisting those with SCD. Using microfluidics with custom designed portable impedance measuring hardware we can achieve label-free in vitro analyses of SCD rheology. This dissertation presents two impedance-based devices for finger-prick volume blood testing, including a microflow cytometer for SCD diagnostics and a vaso-occlusion tester for monitoring blood flow activities. First, the microflow cytometer is validated by measuring the electrical impedance of individual cells flowing through a narrow microfluidic channel. Cellular impedance is interpreted by changes in subcellular components due to oxygen association-dissociation of hemoglobin, using an equivalent circuit model and Multiphysics simulation. Impedance values of sickle cells exhibit remarkable deviations from normal blood cells. Such deviation is quantified by a conformity score, which allows for measurement of SCD heterogeneity, and potentially disease severity. Findings from this study demonstrate the potential for SCD screening via electrical impedance. Second, a vaso-occlusion tester is validated by measuring the impedance response of blood flow within a microfluidic mimic of capillary bed.
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Date Issued: 2023
PURL: http://purl.flvc.org/fau/fd/FA00014243
Subject Headings: Sickle cell anemia, Microfluidics, Point-of-care testing, Electric Impedance
Format: Document (PDF)

Title: DESIGN AND FAILURE ANALYSIS OF MULTI-COMPONENT MOORING LINES WITH NON-LINEAR POLYMER SPRINGS FOR FLOATING OFFSHORE WIND TURBINES.
Creator: McFadden, Jared, Mahfuz, Hassan, Florida Atlantic University, Department of Ocean and Mechanical Engineering, College of Engineering and Computer Science
Abstract/Description: This research studied the effects of mooring line pretension, spring safe working load, and spring response curve on peak loads and platform surge. The maximum tension load from the optimized assembly was applied to a modelled section of 8-strand multiplait rope to study stress concentrations. The analyses yielded a mooring line pretensioned at 1250 kN with a 4500 kN safe working load degressive spring was optimal. Fatigue damage from 12-hour duration of 50-year storm conditions was 8.04 × 10...
Show moreThis research studied the effects of mooring line pretension, spring safe working load, and spring response curve on peak loads and platform surge. The maximum tension load from the optimized assembly was applied to a modelled section of 8-strand multiplait rope to study stress concentrations. The analyses yielded a mooring line pretensioned at 1250 kN with a 4500 kN safe working load degressive spring was optimal. Fatigue damage from 12-hour duration of 50-year storm conditions was 8.04 × 10−6. Infinite life is predicted at annual average conditions. The peak tension from 50-year storm conditions of 3671 kN and annual average conditions of 1388 kN was applied to the section model, yielding a maximum stress of 3.70 × 108 Pa and 2.01 × 108 Pa, respectively, from friction and longitudinal compression of the rope’s cross section. The maximum stress from the static structural analysis was 33.5% of polyester’s ultimate strength, based on the maximum stress failure criterion.
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Date Issued: 2023
PURL: http://purl.flvc.org/fau/fd/FA00014245
Subject Headings: Wind turbines--Design and construction, Wind turbines--Testing, Deep-sea moorings
Format: Document (PDF)

Title: CORROSION MONITORING AND ANALYSIS OF REINFORCED CONCRETE: CORROSION RESISTANT ALLOYS AFTER LONG TERM EXPOSURE TO CHLORIDES.
Creator: Taylor, Redmayne, Presuel-Moreno, Francisco, Florida Atlantic University, Department of Ocean and Mechanical Engineering, College of Engineering and Computer Science
Abstract/Description: Reinforced concrete (RC) is the building block of modern architecture and industry. The failure of which is costly and dangerous. Typically made with carbon steel rebars, corrosion resistant alloys provide an alternative method of delaying failure. Stainless steels, while more expensive than carbon steels, provide excellent corrosion resistance, but less is known about the long term monitoring of corrosion activity for stainless steel than for carbon steel. This study looks at samples...
Show moreReinforced concrete (RC) is the building block of modern architecture and industry. The failure of which is costly and dangerous. Typically made with carbon steel rebars, corrosion resistant alloys provide an alternative method of delaying failure. Stainless steels, while more expensive than carbon steels, provide excellent corrosion resistance, but less is known about the long term monitoring of corrosion activity for stainless steel than for carbon steel. This study looks at samples prepared between 2005 and 2009 using 304SS, 316SS, and 2304SS rebars, as well as SMI and Stelax stainless steel clad carbon steel reinforcements embedded in three different concrete mixes. These selected samples are split into two exposure environments, inside humidity chambers within the laboratory and outdoor exposure. Measurements reported here were made monthly over the course of 250 plus days using the Galvanostatic Pulse method, Electrochemical Impedance Spectroscopy, and a Gecor 8 device. These methods were used to determine corrosion current, isolated corrosion current density, and solution resistance. Corrosion current density values calculated from measurements by the Galvanostatic Pulse and Electrochemical Impedance Spectroscopy method are too small to indicate corrosion, based on value ranges provided by Andrade. However, Gecor 8 corrosion current density values indicate low levels or moderate levels of corrosion for all samples compared to the Andrade’s value ranges. The area used by the Gecor is unknown, so it’s possible this is driving up the measured values.
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Date Issued: 2023
PURL: http://purl.flvc.org/fau/fd/FA00014258
Subject Headings: Reinforced concrete, Corrosion resistant alloys, Carbon steel, Corrosion
Format: Document (PDF)

Title: BIOLUMINESCENCE OF THE CTENOPHORE MNEMIOPSIS LEIDYI: FIRST FLASH KINETICS.
Creator: Blackburn, Abigail, Twardowski, Michael, Florida Atlantic University, Department of Ocean and Mechanical Engineering, College of Engineering and Computer Science
Abstract/Description: The ctenophore Mnemiopsis leidyi is an opportunistic species that can be extremely abundant and invasive in many parts of the world. It is well known for its bright bioluminescence, but its light emission response to flow stimulation has not been rigorously quantified. The objective of this study is to determine the luminescent response of M. leidyi to several types of mechanical stimuli, an impeller pump with the Underwater Bioluminescence Assessment Tool (UBAT) bathyphotometer and stirring...
Show moreThe ctenophore Mnemiopsis leidyi is an opportunistic species that can be extremely abundant and invasive in many parts of the world. It is well known for its bright bioluminescence, but its light emission response to flow stimulation has not been rigorously quantified. The objective of this study is to determine the luminescent response of M. leidyi to several types of mechanical stimuli, an impeller pump with the Underwater Bioluminescence Assessment Tool (UBAT) bathyphotometer and stirring as the stimulus within an integrating sphere. Tests were conducted with three day old cydippid larvae, analyzing flash parameters of rise time, peak intensity, decay slope, decay time, total integrated emission, total mechanically stimulable luminescence (TMSL), integrated flash emission, and flash duration. There were four patterns of bioluminescent responses measured with the UBAT, but they did not have statistically different flash kinetics. For the integrating sphere, the average peak intensity and TMSL were much greater than for the UBAT due to the different forms of stimulation. This study provides a well-defined baseline of cydippid larvae flash responses which may be used for identifying this species at this life stage in situ.
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Date Issued: 2023
PURL: http://purl.flvc.org/fau/fd/FA00014341
Subject Headings: Mnemiopsis leidyi, Bioluminescence, Ctenophores
Format: Document (PDF)

Title: ARTIFICIAL INTELLIGENCE (AI) ENABLES SENSORIMOTOR INTEGRATION FOR PROSTHETIC HAND DEXTERITY.
Creator: Abd, Moaed A., Engeberg, Erik D., Florida Atlantic University, Department of Ocean and Mechanical Engineering, College of Engineering and Computer Science
Abstract/Description: Hand amputation is a devastating feeling for amputees, and it is lifestyle changing since it is challenging to perform the basic life activities with amputation. Hand amputation means interrupting the closed loop between sensory feedback and motor control. The absence of sensory feedback requires a significant cognitive effort from the amputee to perform basic daily activities with prosthetic hand. Loss of tactile sensations is a major roadblock preventing amputees from multitasking or using...
Show moreHand amputation is a devastating feeling for amputees, and it is lifestyle changing since it is challenging to perform the basic life activities with amputation. Hand amputation means interrupting the closed loop between sensory feedback and motor control. The absence of sensory feedback requires a significant cognitive effort from the amputee to perform basic daily activities with prosthetic hand. Loss of tactile sensations is a major roadblock preventing amputees from multitasking or using the full dexterity of their prosthetic hands. One of the most significant features lacking from commercial prosthetic hands is sensory feedback, according to amputees. Many amputees abandoned their prosthetic devices due to the lack of tactile feedback. In the field of prosthetics, restoring sensory feedback is the most challenging task due to the complexity of integration between the prosthetic and the peripheral nervous system. A prosthetic hand with sensory feedback that imitates the intact hand would improve the lives of millions of amputees worldwide by inducing the prosthetic hand to be a part of the body image and significant impact the control of the prosthetic. To restore the sensory feedback and improve the dexterity for upper limb amputee, multiple components needed to be integrated together to provide the sensory feedback. Tactile sensors are the first components that needed to be integrated into the sensorimotor loop. In this research two tactile sensors were integrated in the sensory feedback loop. The first tactile sensor is BioTac which is a commercially available sensor. The first novel contribution with BioTac is the development of an ANN classifier to detect the direction a grasped object slips in a dexterous robotic hand in real time, and the second novel aspect of this study is the use of slip direction detection for adaptive robotic grasp reflexes. The second tactile sensor is the liquid metal sensor (LMS), this sensor was developed entirely in our lab (BioRobotics lab). The novel contribution for LMS is to detect and prevent slip in real time application, and to recognize different surface features and different sliding speeds.
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Date Issued: 2022
PURL: http://purl.flvc.org/fau/fd/FA00013875
Subject Headings: Artificial intelligence, Haptic devices, Tactile sensors, Sensorimotor integration, Artificial hands
Format: Document (PDF)

Title: APPLICATION OF ORGAN-ON-A-CHIP TECHNOLOGY FOR MASS TRANSPORT ANALYSIS IN PHYSIOLOGICAL AND PATHOLOGICAL CONDITIONS.
Creator: Mosavati, Babak, Du, Sarah, Florida Atlantic University, Department of Ocean and Mechanical Engineering, College of Engineering and Computer Science
Abstract/Description: Mass transport is important for all biological functions to protect the cell’s environment and to keep its balance of nutrients, proteins and keep the organism alive. We are motivated to study two different types of mass transport, glucose and oxygen that are critical in human system. Specifically, this study focused on mass and oxygen transport in human placenta and oxygen transport in transfusion of artificial oxygen carriers. Studying these processes in vivo or ex vivo are difficult due to...
Show moreMass transport is important for all biological functions to protect the cell’s environment and to keep its balance of nutrients, proteins and keep the organism alive. We are motivated to study two different types of mass transport, glucose and oxygen that are critical in human system. Specifically, this study focused on mass and oxygen transport in human placenta and oxygen transport in transfusion of artificial oxygen carriers. Studying these processes in vivo or ex vivo are difficult due to ethical or technical challenges. In this dissertation, Organ-on-a-chip devices were used to simulate placental barrier and blood vessels. In first device, 3D placenta–on-a-chip device consists of a polycarbonate membrane and two Poly dimethylsiloxane microchannels was used. Human umbilical vein endothelial cells were cultured in microfluidic devices and mass transport was measured. In the second device, 3-lane OrganoPlate was used to develop the placental barrier model. The human umbilical vein endothelial cells and trophoblast cells cultured in two microchannels compartmented by polycarbonate membrane (first device) and extracellular matrix gel (second device) to mimic the placental barrier in vitro. Finally, the glucose transfer across the placental barrier affected by malaria parasite was investigated. The results of this study can be used for better understanding of placental malaria pathology and drug efficacy testing.
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Date Issued: 2022
PURL: http://purl.flvc.org/fau/fd/FA00013963
Subject Headings: Organs-on-chips, Biomedical engineering
Format: Document (PDF)

Title: HYDRODYNAMIC PERFORMANCE AND SEAKEEPING ANALYSIS OF A CATAMARAN IN TRANSFORMING NEAR-SHORE HEAD AND FOLLOWING SEAS.
Creator: Ulgen, Kayhan, Dhanak, Manhar R., Florida Atlantic University, Department of Ocean and Mechanical Engineering, College of Engineering and Computer Science
Abstract/Description: A computational investigation of the hydrodynamic and seakeeping performance of a catamaran in calm, and in the presence of transforming head and following seas in waters of constant and varying depths is described. Parametric studies were conducted for a selected WAM-V 16 catamaran geometry using OpenFOAM® to uncover the physical phenomena. In the process a methodology has been developed for simulating the interactions between the vehicle and the shallow water environment akin to that in the...
Show moreA computational investigation of the hydrodynamic and seakeeping performance of a catamaran in calm, and in the presence of transforming head and following seas in waters of constant and varying depths is described. Parametric studies were conducted for a selected WAM-V 16 catamaran geometry using OpenFOAM® to uncover the physical phenomena. In the process a methodology has been developed for simulating the interactions between the vehicle and the shallow water environment akin to that in the coastal environment. The multiphase flow around the catamaran, including the six degrees-of-freedom motion of the vehicle, was modeled using a Volume of Fluid (VoF) method and solved using a dynamic mesh. The numerical approach was validated through computing benchmark cases and comparing the results with previous work. It is found that in a calm shallow water environment the total resistance, dynamic trim and sinkage of a catamaran in motion can be significantly impacted by the local water depth. The variations of the impact with depth and length-based Froude numbers are characterized. The impact varies as the vehicle moves from shallow waters to deep water or vice versa. In the presence of head and following small-amplitude seas, interesting interactions between incident waves and those generated by the vehicle are observed and are characterized for their variation with Froude number and water depth.
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Date Issued: 2022
PURL: http://purl.flvc.org/fau/fd/FA00013942
Subject Headings: Seakeeping, Catamarans, Hydrodynamics, Computational fluid dynamics
Format: Document (PDF)

Title: Numerical Simulation of Marine Hydrokinetic Turbines in Realistic Operating Conditions.
Creator: Dunlap, Broc, VanZwieten, James, Florida Atlantic University, Department of Ocean and Mechanical Engineering, College of Engineering and Computer Science
Abstract/Description: Marine Hydrokinetic (MHK) energy is an alternative to address the demand for cleaner energy sources. This study advanced numerical modeling tools and uses these to evaluate the performance of both a Tidal Turbine (TT) and an Ocean Current Turbine (OCT) operating in a variety of conditions. Inflow models are derived with current speeds ranging from 1.5 to 3 m/s and Turbulence Intensities (TI) of 5-15% and integrated into a TT simulation. An OCT simulation representing a commercial scale 20 m...
Show moreMarine Hydrokinetic (MHK) energy is an alternative to address the demand for cleaner energy sources. This study advanced numerical modeling tools and uses these to evaluate the performance of both a Tidal Turbine (TT) and an Ocean Current Turbine (OCT) operating in a variety of conditions. Inflow models are derived with current speeds ranging from 1.5 to 3 m/s and Turbulence Intensities (TI) of 5-15% and integrated into a TT simulation. An OCT simulation representing a commercial scale 20 m diameter turbine moored to the seafloor via underwater cable is enhanced with the capability to ingest Acoustic Doppler Current Profiler (ADCP) data and simulate fault conditions. ADCP measurements collected off the coast of Ft. Lauderdale during Hurricanes Irma and Maria were post-processed and used to characterize the OCT performance. In addition, a set of common faults were integrated into the OCT model to assess the system response in fault-induced scenarios.
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Date Issued: 2022
PURL: http://purl.flvc.org/fau/fd/FA00013962
Subject Headings: Turbines, Ocean wave power, Simulations, Mathematical models
Format: Document (PDF)

Title: Numerical Simulation and Performance Characterization of Two Wave Energy Converters.
Creator: DePietro, Abigail R., VanZwieten, James, Florida Atlantic University, Department of Ocean and Mechanical Engineering, College of Engineering and Computer Science
Abstract/Description: This research consists of the numerical model development and simulation of two prototype Wave Energy Convertor designs (WECs) across three simulation types. The first design is an oscillating body WEC called the Platypus designed to capture wave energy as three paddle arms actuate over the surface of the waves. The second design is an overtopping type WEC called the ROOWaC which captures and drains entrained water to generate power. Modeling of these systems was conducted using two...
Show moreThis research consists of the numerical model development and simulation of two prototype Wave Energy Convertor designs (WECs) across three simulation types. The first design is an oscillating body WEC called the Platypus designed to capture wave energy as three paddle arms actuate over the surface of the waves. The second design is an overtopping type WEC called the ROOWaC which captures and drains entrained water to generate power. Modeling of these systems was conducted using two techniques: the Morison load approach implemented using hydrodynamic response coefficients used to model the Platypus and a boundary element method (BEM) frequency-domain approach to model both WEC designs in the time domain. The BEM models included the development of hydrodynamic response coefficients using a discretized panel mesh of the system for calculation of added mass, excitation, and radiation forces. These three model families provided both performance predictions and power output information to WEC developers that supply important data for future full-scale designs. These models were used to predict power generation estimates for both WECs as follows: the Platypus WEC was predicted to have a maximum efficiency range between 14.5-35% and the ROOWaC WEC was predicted to generate a maximum peak average power of 19 W upon preliminary results.
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Date Issued: 2022
PURL: http://purl.flvc.org/fau/fd/FA00013956
Subject Headings: Ocean energy resources--Research, Ocean wave power, Simulations, Mathematical methods and modelling
Format: Document (PDF)

Title: A Design Concept for Launch and Recovery of REMUS 100 AUV from WAM-V 16 USV.
Creator: Palmaccio, Brendan, Dhanak, Manhar, Florida Atlantic University, Department of Ocean and Mechanical Engineering, College of Engineering and Computer Science
Abstract/Description: In this thesis, feasibility of a concept for launch and recovery of the Remus AUV from WAM-V USV is investigated. A modular recovery system which can be added to the WAM-V payload tray was designed, and based on a review of previous literature a CONOPS was developed for the launch and recovery process. The first phase of the CONOPS, which pertains to the position of the REMUS initially on the free surface prior to sling engagement is simulated using ANSYS AQWA. Preprocessing for the...
Show moreIn this thesis, feasibility of a concept for launch and recovery of the Remus AUV from WAM-V USV is investigated. A modular recovery system which can be added to the WAM-V payload tray was designed, and based on a review of previous literature a CONOPS was developed for the launch and recovery process. The first phase of the CONOPS, which pertains to the position of the REMUS initially on the free surface prior to sling engagement is simulated using ANSYS AQWA. Preprocessing for the simulation involved simplification of the model in ANSYS SpaceClaim to achieve a proper mesh as well as theoretical calculations of the input parameters for wave environment and point masses etc. The simulation was evaluated by taking into consideration two wave environment scenarios: beam sea’s (-90 degrees) and head seas (0 degrees). The wave environment was based on a linear frequency range for the waves which considered wavelengths that correspond to half and double the length of the WAM-V 16’. The significance of the simulation is characterized through identifying the ideal direction and wave frequency range for recovery based on the RAOs of the two vehicles.
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Date Issued: 2023
PURL: http://purl.flvc.org/fau/fd/FA00014216
Subject Headings: Autonomous underwater vehicles--Design and construction, Marine engineering, Littoral combat ships
Format: Document (PDF)

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