Jonathan Reyes - Academia.edu (original) (raw)

Papers by Jonathan Reyes

Concussion

Aim: To explore soft-shell padded headgear (HG) use, player behavior and injuries associated with... more Aim: To explore soft-shell padded headgear (HG) use, player behavior and injuries associated with HG in junior Australian football. Methods: Prospective case-crossover with head impact measurement, injury surveillance and video review. Results: 40 players (mean age: 12.43 years, standard deviation: 1.36) across 15 matches were observed. Frequency of head/neck (p = 0.916) or body (p = 0.883) contact events, and match incidents were similar between HG and no HG conditions. Without HG, females had higher frequency of body contacts compared with males (p = 0.015). Males sustained more body contacts with HG than without HG (p = 0.013). Conclusion: Use of HG in junior football was not associated with injury or head contact rate. Associations between HG use and body contact may differ across sexes. (ID: ACTRN12619001165178).

Pilot and Feasibility Studies

Background Up to 25% of concussed individuals experience persistent post-concussion symptoms (PPC... more Background Up to 25% of concussed individuals experience persistent post-concussion symptoms (PPCSs) which may interfere with the return to pre-injury activities and cause significant stress. Given that multiple etiological factors are thought to contribute to PPCSs, an interdisciplinary approach is recommended. This pilot study aims to primarily investigate the feasibility of a novel interdisciplinary treatment for PPCSs. Given this intervention is novel, uncertainty exists in terms of potential recruitment and retention rates, adverse events, and treatment adherence and fidelity. These factors will be explored to inform the feasibility of a phase-2 randomised controlled trial. Preliminary efficacy of this intervention will also be explored. Methods Fifteen individuals with mild traumatic brain injury and PPCSs will receive up to 12 weeks of interdisciplinary treatments including psychology, physiotherapy, and medical interventions. Primary feasibility outcomes including data on re...

The American Journal of Sports Medicine, 2020

Background: Exposure to head acceleration events (HAEs) has been associated with player sex, play... more Background: Exposure to head acceleration events (HAEs) has been associated with player sex, player position, and player experience in North American football, ice hockey, and lacrosse. Little is known of these factors in professional Australian football. Video analysis allows HAE verification and characterization of important determinants of injury. Purpose: To characterize verified HAEs in the nonhelmeted contact sport of professional Australian football and investigate the association of sex, player position, and player experience with HAE frequency and magnitude. Study Design: Descriptive epidemiology study. Methods: Professional Australian football players wore a nonhelmeted accelerometer for 1 match, with data collected across 14 matches. HAEs with peak linear accelerations (PLAs) ≥30 g were verified with match video. Verified HAEs were summarized by frequency and median PLA and compared between the sexes, player position, and player experience. Characterization of match-relat...

Cureus, 2021

Lisinopril is an angiotensin-converting enzyme (ACE) inhibitor that is used as one of the first-l... more Lisinopril is an angiotensin-converting enzyme (ACE) inhibitor that is used as one of the first-line antihypertensive medications. Necrotizing pancreatitis induced by the use of ACE inhibitors is an extremely rare occurrence. Although an uncommon risk factor, our aim is to further highlight that patients with chronic use of lisinopril can develop such complications and should be considered among the list of differential diagnoses for pancreatitis. A 53-year-old Caucasian male with a history of hypertension treated with lisinopril presented with a oneday history of nausea, vomiting, and severe epigastric pain. On physical examination, there was tenderness to palpation in the epigastric region and left lower quadrant without rebound tenderness or guarding. A complete blood count showed a slight increase in white blood cell count to 12,000 cells/mm 3 and serum lipase level was elevated at 1028 U/L. A subsequent CT scan of the abdomen with contrast revealed findings supporting necrotizing pancreatitis. The patient was treated with conservative medical management with goal-directed intravenous fluid support, early enteral feeding, and pain control. His condition resolved, and he was found doing well on follow-up visits.

American Journal of Gastroenterology, 2021

Cureus, 2021

Whiting et al. This is an open access article distributed under the terms of the Creative Commons... more Whiting et al. This is an open access article distributed under the terms of the Creative Commons Attribution License CC-BY 4.0., which permits unrestricted use, distribution, and reproduction in any medium, provided the original author and source are credited.

Cureus, 2021

Impaired thermoregulation and heat intolerance may be intrinsic to autonomic dysfunction in Parki... more Impaired thermoregulation and heat intolerance may be intrinsic to autonomic dysfunction in Parkinson’s disease due to disturbances in perspiration regulation. Thermoregulatory impairment leading to hyperthermia/heatstroke can be accentuated with the usage of anticholinergics, which block the ability to sweat. Oxybutynin chloride is one of the most used anticholinergic agents in clinical practice for the management of detrusor hyperreflexia secondary to neurogenic bladder dysfunction and is often used in the setting of Parkinson’s disease. We present a rare instance of oxybutynin-induced heatstroke in an elderly patient with Parkinson’s disease.

Performing non-intrusive measurements is the key to acquiring accurate information representative... more Performing non-intrusive measurements is the key to acquiring accurate information representative of what is being observed. The act of measuring often changes the environment being observed altering the information that is being obtained. Due to this, the community of fluid scientists have gravitated towards using laser-based measurements to observe the phenomena occurring in their experiments. The study of fluids has advanced since this point, utilizing techniques such as planar laser induced florescence (PLIF), particle image velocimetry (PIV), laser doppler velocimetry (LDV), particle doppler anemometry (PDA), etc. to acquire chemical species information and velocity information. These techniques, though, are inherently two-dimensional and cannot fully describe a flow field. In the area of reacting flow fields (combustion) acquiring the local fuel to air ratio information is increasingly important. Without it, scientist must rely on global one-dimensional metering techniques to correlate the fuel to air ratio of their flow field of interest. By knowing the fuel to air ratio locally and spatially across a flame, the location of products and reactants can be deduced, giving insight into any inefficiencies associated with a burner. Knowing the spatial fuel air field also gives insights into the density gradient associated with the flow field. Discussed in this work will be the development of a non-intrusive local fuel-air measurement technique and an expansion of the PIV technique into the third dimension, tomographic PIV, utilizing only one camera to do so for each measurement. The local fuel-air measurement is performed by recording two species (C2* and CH*) simultaneously and calibrating their ratio to the known fuel-air field. Tomographic PIV is performed by utilizing fiber coupling to acquire multiple viewpoints utilizing a single camera. iv I dedicate this dissertation to the hard-working students at the Center for Advanced Turbomachinery and Energy Research (CATER) and the Propulsion and Energy Research Laboratory (PERL) at the University of Central Florida (UCF). Day in and day out all of you are there helping push my research forward as I help you better your understanding for yours. This research belongs just as much to you as it does to me. It is my hope that we can be proud of what we have accomplished, big and small, together. May our hard work in that small laboratory produce great changes for the scientific community. v ACKNOWLEDGMENTS I must first acknowledge the creator of the sciences, The Triune God. His ability to breathe science into existence and allowing us to explore and subdue it in manners known and unknown is what allows us to function as a society whether we acknowledge or deny His existence. Without His constant guidance and continual support, I could not have achieved such feats. Johanna Divina Reyes, my wife, I thank you. You have endured much in my quest for deeper knowledge, and I cannot seem to create the words to describe how amazing you are. You have been my hands and feet during this time of my life, feeding me, reminding me to relax, pushing me to my limits, and reminding me of my Savior. Johanna, I love you with all that I am, as imperfect as it may be sometimes. To my parents, Ismael and Rosa Reyes, your instruction in my upbringing is what has allowed me to stand in this time and place today. Just know, that God's promise to you for me is continually being fulfilled. This is only another portion of His blessing because of your faithfulness. To my brothers, Joshua and Jason Reyes, thanks for always reaching out to me. You guys have never stopped believing in me and I will try my hardest to do the same in return. To my extended family members, I thank you for always providing guidance and support. I cannot thank my entire family enough for their immense support system. To my family by law, our bond goes deeper than blood. You have all shown me what it means to acquire a higher education and to never stop pursuing the better character that awaits in the future. Don Juan,

American Journal of Gastroenterology

Gastroenterology, 2020

associated with mean respiratory LES pressure (r=-0.31, p=0.006), and esophageal length (r=-0.38,... more associated with mean respiratory LES pressure (r=-0.31, p=0.006), and esophageal length (r=-0.38, p=0.234). Conclusions: This study describes several known associations with HH, including gender, kyphosis/scoliosis, and GERD symptoms such as chest pain. Moreover, our study describes several associations with less substantial presence in the literature, including relationships between larger HH with detection on straight-leg testing and panesophageal pressurization as well as associations between HH with esophageal length and mean respiratory LES pressure. Thus, the symptomatology and pathogenesis of HH is more complex and multifactorial than previously understood, and indicates areas for future study.

Nanoscale Research Letters, 2010

In this work, cobalt-doped Cadmium oxide thin films are prepared by sol-gel spin coating techniqu... more In this work, cobalt-doped Cadmium oxide thin films are prepared by sol-gel spin coating technique on the glass substrate. The effects of annealing temperature and Co concentration on Structural, optical properties of the thin films are studied. XRD pattern indicates that a CdO single phase with a cubic polycrystalline structure is formed in all the samples. Prepared thin film samples were revealed by EDX analysis. Optical measurements show that the optical transmission of the layer is reduced and the optical-band gap decreases due to the increase in molar concentrations. The optical-band gap is decreasing while increasing of Co concentration and annealing temperature.

2018 AIAA Aerospace Sciences Meeting

This study describes three-dimensional (3D) quantitative visualization of density field in a supe... more This study describes three-dimensional (3D) quantitative visualization of density field in a supersonic flow around a cone spike. A measurement of the density gradient is conducted within a supersonic wind tunnel facility at the Propulsion and Energy Research Laboratory at the University of Central Florida utilizing Structured Light-Field Focusing Schlieren (SLLF). In conventional schlieren and Shadowgraph techniques, it is widely known that a complicated optical system is needed and yet visualizable area depends on an effective diameter of lenses and mirrors. Unlike these techniques, SLLF is yet one of the same family as schlieren photography, it is capable of non-intrusive turbulent flow measurement with relatively low cost and easy-to-setup instruments. In this technique, cross-sectional area in the flow field that is parallel to flows can be observed while other schlieren methods measure density gradients in line-of-sight, meaning that it measures integrated density distribution caused by discontinuous flow parameters. To reconstruct a 3D model of shock structure, two-dimensional (2D) images are pictured to process in MATLAB. The ultimate goal of this study is to introduce a novel technique of SLLF and quantitative 3D shock structures generated around a cone spike to reveal the interaction between free-stream flow and the high-pressure region. iv ACKNOWLEDGMENTS The author would like to acknowledge foremost my family. Without their continuous support and help during the pursuit of this endeavor, this work would not be possible. Miki Ozawa and Toshiko Ozawa, who raised me and contributed in enriching my career, I will be in debt for my entire life. Yuunosuke Ozawa, who shaped or formed my character, your advice and action taught me to keep my ambition. If not for Annalee Liao, who inspired and motivated me to keep pushing the limits of my ability to excel in life, this couldn't be accomplished. To my lab coworkers who dedicated their support through this, I cannot thank you enough. Last, the author also wishes to acknowledge my facilitator who guided me in this project, Dr. Kareem Ahmed. Your extensive knowledge of the subject has stimulated me to pursue my career in aerospace engineering. Thank you all. v

Journal of Energy Resources Technology

The present work explores a novel flow-independent liquid injection scheme, incorporating solid o... more The present work explores a novel flow-independent liquid injection scheme, incorporating solid obstructions to alter the key mechanisms controlling the liquid breakup and trajectory. These obstructions, designated pintiles, minimize the variability of fuel injection dynamics over a range of operational conditions. To better understand these mechanisms, a variety of solid pintile obstructions are designed and incorporated into a liquid jet in crossflow experiment. The design parameters of interest include the fraction of the liquid jet orifice blocked by the pintile (orifice coverage), the vertical height of the pintile in the liquid stream, and the angle of the obstruction with respect to the injection plate. All pintiles are tested at non-reacting ambient temperature and pressure conditions over a range of engine relevant Reynolds numbers (Re = 171,500–343,000), momentum flux ratios (Q = 4–45), and Weber numbers (We = 20–80) to understand the leading order effects the solid–liquid...

Journal of Fluids Engineering

Tomographic particle image velocimetry (Tomo-PIV) has become a standard tool for capturing a thre... more Tomographic particle image velocimetry (Tomo-PIV) has become a standard tool for capturing a three-dimensional (3D) velocity fields in nonreacting flows. However, the diagnostic approach can become costly and challenging to implement when extended to applications which require high-speed cameras. This limitation has led to the use of fiber wound bundles to allow for multiple views to be captured on a single camera sensor. Additionally, employing this diagnostic approach on reacting flow-fields becomes more complex as the introduction of the flame causes additional luminosity and optical distortion which impacts the particle field reconstruction. This work seeks to validate and determine the limitations when utilizing a single sensor fiber-coupled approach for capturing Tomo-PIV data on a reacting flow-field. A premixed propane (C3H8) and air Bunsen burner flame is utilized to examine if the single sensor approach can meet the parameters for acceptable reconstruction based on previou...

AIAA Scitech 2020 Forum, 2020

Flow, Turbulence and Combustion, 2021

Bluff-body flame instabilities are experimentally investigated under varying turbulence condition... more Bluff-body flame instabilities are experimentally investigated under varying turbulence conditions during lean blowout. For all turbulence conditions, the blowout process is induced through a temporal reduction of the fuel flow rate to capture the flame-flow dynamics approaching blowout. Simultaneous high-speed particle image velocimetry (PIV), stereoscopic PIV, and C 2 */CH* chemiluminescence imaging are employed, along with an independent CH* imaging system, to capture flame-flow instabilities. Proper orthogonal decomposition (POD) and dynamic mode decomposition (DMD) techniques are used to identify prominent flame oscillations and evaluate recurring spatiotemporal modes during blowout. The results reveal that the dominant flame oscillations and wrinkling characteristics are directly dependent on the turbulence conditions in the combustor. Specifically, the flame-flow oscillations are strongly coupled with the integral length scales, which were able to collapse the oscillation frequencies to a unified value. The turbulence-driven flameflow oscillations are shown to largely impact the magnitude, temporal evolution, and oscillatory behavior of the flame strain rate. As the turbulence intensity is increased, the oscillation of the flame strain rate increases in frequency, making it more likely for localized extinctions to occur. Additionally, the magnitude of the flame strain rate increases at high turbulence intensities and accelerates the lean blowout process.

AIAA Scitech 2020 Forum, 2020

Applied Optics, 2021

Chemiluminesence is one of the most common reacting flow visualization techniques, in which a nar... more Chemiluminesence is one of the most common reacting flow visualization techniques, in which a narrowband wavelength associated with species radicals is captured on an image sensor. This technique can provide key insights into flame physics, particularly when a full 3D field can be extracted. Tomographic imaging can capture 3D instantaneous information, but becomes impractical to use when the technique is extended to larger, heavier high-speed imaging equipment. This has resulted in many researchers using fiber-based endoscopes (FBE) to capture multiple views on a single image sensor. However, the introduction of the fiber bundle and corresponding equipment to image specific combustion radicals results in a low SNR imaging environment when captured at high repetition rates. Additionally, when varying equivalence ratios, the signal can become further diminished because the combustion radicals signal weakens at fuel rich and fuel lean conditions. Therefore, this work determines the eff...

Journal of Clinical Neuroscience, 2022

Micro riboneucleic acids (miRNAs) may be transcribed after brain injury and be detectable in plas... more Micro riboneucleic acids (miRNAs) may be transcribed after brain injury and be detectable in plasma. This study aimed to assess the discriminative ability of seven miRNAs in plasma to differentiate between patients with mild traumatic brain injury (mTBI) and healthy controls. Changes in miRNA levels over 28 days were compared to changes in self-reported symptom profile. This was a prospective cohort study with longitudinal measurements of miRNA levels and symptom self-report. The Rivermead Post-Concussion Symptom Questionnaire (RPQ) was used to determine symptom severity. Mean normalised expression ratios (NER) of miRNAs at day 0 between mTBI and healthy controls were compared. An analysis of response profiles compared the response over time of miRNA species with RPQ symptom severity. miRNA levels of subjects who were defined to have "recovered" on Day 7 and 28 were compared to "non-recovered" subjects. There were 28 mTBI patients and 30 healthy controls included for analysis. Symptom severity was significantly higher on the day of injury among mTBI subjects (p < 0.001), and miRNA 32-5p levels were also higher (p = 0.009). Change of miRNA levels were similar to RPQ change at Day 7, but significantly different at Day 28. Differences were observed among miRNA levels of recovered subjects. This study demonstrated differences in miRNA levels among mTBI subjects compared to healthy controls and different miRNA levels among those who had recovered compared to those reporting symptoms. The change in profiles of miRNAs was different to symptom severity, suggesting that the two measures reflect different aspects of brain injury and recovery.

AIAA Scitech 2019 Forum, 2019

Concussion

Aim: To explore soft-shell padded headgear (HG) use, player behavior and injuries associated with... more Aim: To explore soft-shell padded headgear (HG) use, player behavior and injuries associated with HG in junior Australian football. Methods: Prospective case-crossover with head impact measurement, injury surveillance and video review. Results: 40 players (mean age: 12.43 years, standard deviation: 1.36) across 15 matches were observed. Frequency of head/neck (p = 0.916) or body (p = 0.883) contact events, and match incidents were similar between HG and no HG conditions. Without HG, females had higher frequency of body contacts compared with males (p = 0.015). Males sustained more body contacts with HG than without HG (p = 0.013). Conclusion: Use of HG in junior football was not associated with injury or head contact rate. Associations between HG use and body contact may differ across sexes. (ID: ACTRN12619001165178).

Pilot and Feasibility Studies

Background Up to 25% of concussed individuals experience persistent post-concussion symptoms (PPC... more Background Up to 25% of concussed individuals experience persistent post-concussion symptoms (PPCSs) which may interfere with the return to pre-injury activities and cause significant stress. Given that multiple etiological factors are thought to contribute to PPCSs, an interdisciplinary approach is recommended. This pilot study aims to primarily investigate the feasibility of a novel interdisciplinary treatment for PPCSs. Given this intervention is novel, uncertainty exists in terms of potential recruitment and retention rates, adverse events, and treatment adherence and fidelity. These factors will be explored to inform the feasibility of a phase-2 randomised controlled trial. Preliminary efficacy of this intervention will also be explored. Methods Fifteen individuals with mild traumatic brain injury and PPCSs will receive up to 12 weeks of interdisciplinary treatments including psychology, physiotherapy, and medical interventions. Primary feasibility outcomes including data on re...

The American Journal of Sports Medicine, 2020

Background: Exposure to head acceleration events (HAEs) has been associated with player sex, play... more Background: Exposure to head acceleration events (HAEs) has been associated with player sex, player position, and player experience in North American football, ice hockey, and lacrosse. Little is known of these factors in professional Australian football. Video analysis allows HAE verification and characterization of important determinants of injury. Purpose: To characterize verified HAEs in the nonhelmeted contact sport of professional Australian football and investigate the association of sex, player position, and player experience with HAE frequency and magnitude. Study Design: Descriptive epidemiology study. Methods: Professional Australian football players wore a nonhelmeted accelerometer for 1 match, with data collected across 14 matches. HAEs with peak linear accelerations (PLAs) ≥30 g were verified with match video. Verified HAEs were summarized by frequency and median PLA and compared between the sexes, player position, and player experience. Characterization of match-relat...

Cureus, 2021

Lisinopril is an angiotensin-converting enzyme (ACE) inhibitor that is used as one of the first-l... more Lisinopril is an angiotensin-converting enzyme (ACE) inhibitor that is used as one of the first-line antihypertensive medications. Necrotizing pancreatitis induced by the use of ACE inhibitors is an extremely rare occurrence. Although an uncommon risk factor, our aim is to further highlight that patients with chronic use of lisinopril can develop such complications and should be considered among the list of differential diagnoses for pancreatitis. A 53-year-old Caucasian male with a history of hypertension treated with lisinopril presented with a oneday history of nausea, vomiting, and severe epigastric pain. On physical examination, there was tenderness to palpation in the epigastric region and left lower quadrant without rebound tenderness or guarding. A complete blood count showed a slight increase in white blood cell count to 12,000 cells/mm 3 and serum lipase level was elevated at 1028 U/L. A subsequent CT scan of the abdomen with contrast revealed findings supporting necrotizing pancreatitis. The patient was treated with conservative medical management with goal-directed intravenous fluid support, early enteral feeding, and pain control. His condition resolved, and he was found doing well on follow-up visits.

American Journal of Gastroenterology, 2021

Cureus, 2021

Whiting et al. This is an open access article distributed under the terms of the Creative Commons... more Whiting et al. This is an open access article distributed under the terms of the Creative Commons Attribution License CC-BY 4.0., which permits unrestricted use, distribution, and reproduction in any medium, provided the original author and source are credited.

Cureus, 2021

Impaired thermoregulation and heat intolerance may be intrinsic to autonomic dysfunction in Parki... more Impaired thermoregulation and heat intolerance may be intrinsic to autonomic dysfunction in Parkinson’s disease due to disturbances in perspiration regulation. Thermoregulatory impairment leading to hyperthermia/heatstroke can be accentuated with the usage of anticholinergics, which block the ability to sweat. Oxybutynin chloride is one of the most used anticholinergic agents in clinical practice for the management of detrusor hyperreflexia secondary to neurogenic bladder dysfunction and is often used in the setting of Parkinson’s disease. We present a rare instance of oxybutynin-induced heatstroke in an elderly patient with Parkinson’s disease.

Performing non-intrusive measurements is the key to acquiring accurate information representative... more Performing non-intrusive measurements is the key to acquiring accurate information representative of what is being observed. The act of measuring often changes the environment being observed altering the information that is being obtained. Due to this, the community of fluid scientists have gravitated towards using laser-based measurements to observe the phenomena occurring in their experiments. The study of fluids has advanced since this point, utilizing techniques such as planar laser induced florescence (PLIF), particle image velocimetry (PIV), laser doppler velocimetry (LDV), particle doppler anemometry (PDA), etc. to acquire chemical species information and velocity information. These techniques, though, are inherently two-dimensional and cannot fully describe a flow field. In the area of reacting flow fields (combustion) acquiring the local fuel to air ratio information is increasingly important. Without it, scientist must rely on global one-dimensional metering techniques to correlate the fuel to air ratio of their flow field of interest. By knowing the fuel to air ratio locally and spatially across a flame, the location of products and reactants can be deduced, giving insight into any inefficiencies associated with a burner. Knowing the spatial fuel air field also gives insights into the density gradient associated with the flow field. Discussed in this work will be the development of a non-intrusive local fuel-air measurement technique and an expansion of the PIV technique into the third dimension, tomographic PIV, utilizing only one camera to do so for each measurement. The local fuel-air measurement is performed by recording two species (C2* and CH*) simultaneously and calibrating their ratio to the known fuel-air field. Tomographic PIV is performed by utilizing fiber coupling to acquire multiple viewpoints utilizing a single camera. iv I dedicate this dissertation to the hard-working students at the Center for Advanced Turbomachinery and Energy Research (CATER) and the Propulsion and Energy Research Laboratory (PERL) at the University of Central Florida (UCF). Day in and day out all of you are there helping push my research forward as I help you better your understanding for yours. This research belongs just as much to you as it does to me. It is my hope that we can be proud of what we have accomplished, big and small, together. May our hard work in that small laboratory produce great changes for the scientific community. v ACKNOWLEDGMENTS I must first acknowledge the creator of the sciences, The Triune God. His ability to breathe science into existence and allowing us to explore and subdue it in manners known and unknown is what allows us to function as a society whether we acknowledge or deny His existence. Without His constant guidance and continual support, I could not have achieved such feats. Johanna Divina Reyes, my wife, I thank you. You have endured much in my quest for deeper knowledge, and I cannot seem to create the words to describe how amazing you are. You have been my hands and feet during this time of my life, feeding me, reminding me to relax, pushing me to my limits, and reminding me of my Savior. Johanna, I love you with all that I am, as imperfect as it may be sometimes. To my parents, Ismael and Rosa Reyes, your instruction in my upbringing is what has allowed me to stand in this time and place today. Just know, that God's promise to you for me is continually being fulfilled. This is only another portion of His blessing because of your faithfulness. To my brothers, Joshua and Jason Reyes, thanks for always reaching out to me. You guys have never stopped believing in me and I will try my hardest to do the same in return. To my extended family members, I thank you for always providing guidance and support. I cannot thank my entire family enough for their immense support system. To my family by law, our bond goes deeper than blood. You have all shown me what it means to acquire a higher education and to never stop pursuing the better character that awaits in the future. Don Juan,

American Journal of Gastroenterology

Gastroenterology, 2020

associated with mean respiratory LES pressure (r=-0.31, p=0.006), and esophageal length (r=-0.38,... more associated with mean respiratory LES pressure (r=-0.31, p=0.006), and esophageal length (r=-0.38, p=0.234). Conclusions: This study describes several known associations with HH, including gender, kyphosis/scoliosis, and GERD symptoms such as chest pain. Moreover, our study describes several associations with less substantial presence in the literature, including relationships between larger HH with detection on straight-leg testing and panesophageal pressurization as well as associations between HH with esophageal length and mean respiratory LES pressure. Thus, the symptomatology and pathogenesis of HH is more complex and multifactorial than previously understood, and indicates areas for future study.

Nanoscale Research Letters, 2010

In this work, cobalt-doped Cadmium oxide thin films are prepared by sol-gel spin coating techniqu... more In this work, cobalt-doped Cadmium oxide thin films are prepared by sol-gel spin coating technique on the glass substrate. The effects of annealing temperature and Co concentration on Structural, optical properties of the thin films are studied. XRD pattern indicates that a CdO single phase with a cubic polycrystalline structure is formed in all the samples. Prepared thin film samples were revealed by EDX analysis. Optical measurements show that the optical transmission of the layer is reduced and the optical-band gap decreases due to the increase in molar concentrations. The optical-band gap is decreasing while increasing of Co concentration and annealing temperature.

2018 AIAA Aerospace Sciences Meeting

This study describes three-dimensional (3D) quantitative visualization of density field in a supe... more This study describes three-dimensional (3D) quantitative visualization of density field in a supersonic flow around a cone spike. A measurement of the density gradient is conducted within a supersonic wind tunnel facility at the Propulsion and Energy Research Laboratory at the University of Central Florida utilizing Structured Light-Field Focusing Schlieren (SLLF). In conventional schlieren and Shadowgraph techniques, it is widely known that a complicated optical system is needed and yet visualizable area depends on an effective diameter of lenses and mirrors. Unlike these techniques, SLLF is yet one of the same family as schlieren photography, it is capable of non-intrusive turbulent flow measurement with relatively low cost and easy-to-setup instruments. In this technique, cross-sectional area in the flow field that is parallel to flows can be observed while other schlieren methods measure density gradients in line-of-sight, meaning that it measures integrated density distribution caused by discontinuous flow parameters. To reconstruct a 3D model of shock structure, two-dimensional (2D) images are pictured to process in MATLAB. The ultimate goal of this study is to introduce a novel technique of SLLF and quantitative 3D shock structures generated around a cone spike to reveal the interaction between free-stream flow and the high-pressure region. iv ACKNOWLEDGMENTS The author would like to acknowledge foremost my family. Without their continuous support and help during the pursuit of this endeavor, this work would not be possible. Miki Ozawa and Toshiko Ozawa, who raised me and contributed in enriching my career, I will be in debt for my entire life. Yuunosuke Ozawa, who shaped or formed my character, your advice and action taught me to keep my ambition. If not for Annalee Liao, who inspired and motivated me to keep pushing the limits of my ability to excel in life, this couldn't be accomplished. To my lab coworkers who dedicated their support through this, I cannot thank you enough. Last, the author also wishes to acknowledge my facilitator who guided me in this project, Dr. Kareem Ahmed. Your extensive knowledge of the subject has stimulated me to pursue my career in aerospace engineering. Thank you all. v

Journal of Energy Resources Technology

The present work explores a novel flow-independent liquid injection scheme, incorporating solid o... more The present work explores a novel flow-independent liquid injection scheme, incorporating solid obstructions to alter the key mechanisms controlling the liquid breakup and trajectory. These obstructions, designated pintiles, minimize the variability of fuel injection dynamics over a range of operational conditions. To better understand these mechanisms, a variety of solid pintile obstructions are designed and incorporated into a liquid jet in crossflow experiment. The design parameters of interest include the fraction of the liquid jet orifice blocked by the pintile (orifice coverage), the vertical height of the pintile in the liquid stream, and the angle of the obstruction with respect to the injection plate. All pintiles are tested at non-reacting ambient temperature and pressure conditions over a range of engine relevant Reynolds numbers (Re = 171,500–343,000), momentum flux ratios (Q = 4–45), and Weber numbers (We = 20–80) to understand the leading order effects the solid–liquid...

Journal of Fluids Engineering

Tomographic particle image velocimetry (Tomo-PIV) has become a standard tool for capturing a thre... more Tomographic particle image velocimetry (Tomo-PIV) has become a standard tool for capturing a three-dimensional (3D) velocity fields in nonreacting flows. However, the diagnostic approach can become costly and challenging to implement when extended to applications which require high-speed cameras. This limitation has led to the use of fiber wound bundles to allow for multiple views to be captured on a single camera sensor. Additionally, employing this diagnostic approach on reacting flow-fields becomes more complex as the introduction of the flame causes additional luminosity and optical distortion which impacts the particle field reconstruction. This work seeks to validate and determine the limitations when utilizing a single sensor fiber-coupled approach for capturing Tomo-PIV data on a reacting flow-field. A premixed propane (C3H8) and air Bunsen burner flame is utilized to examine if the single sensor approach can meet the parameters for acceptable reconstruction based on previou...

AIAA Scitech 2020 Forum, 2020

Flow, Turbulence and Combustion, 2021

Bluff-body flame instabilities are experimentally investigated under varying turbulence condition... more Bluff-body flame instabilities are experimentally investigated under varying turbulence conditions during lean blowout. For all turbulence conditions, the blowout process is induced through a temporal reduction of the fuel flow rate to capture the flame-flow dynamics approaching blowout. Simultaneous high-speed particle image velocimetry (PIV), stereoscopic PIV, and C 2 */CH* chemiluminescence imaging are employed, along with an independent CH* imaging system, to capture flame-flow instabilities. Proper orthogonal decomposition (POD) and dynamic mode decomposition (DMD) techniques are used to identify prominent flame oscillations and evaluate recurring spatiotemporal modes during blowout. The results reveal that the dominant flame oscillations and wrinkling characteristics are directly dependent on the turbulence conditions in the combustor. Specifically, the flame-flow oscillations are strongly coupled with the integral length scales, which were able to collapse the oscillation frequencies to a unified value. The turbulence-driven flameflow oscillations are shown to largely impact the magnitude, temporal evolution, and oscillatory behavior of the flame strain rate. As the turbulence intensity is increased, the oscillation of the flame strain rate increases in frequency, making it more likely for localized extinctions to occur. Additionally, the magnitude of the flame strain rate increases at high turbulence intensities and accelerates the lean blowout process.

AIAA Scitech 2020 Forum, 2020

Applied Optics, 2021

Chemiluminesence is one of the most common reacting flow visualization techniques, in which a nar... more Chemiluminesence is one of the most common reacting flow visualization techniques, in which a narrowband wavelength associated with species radicals is captured on an image sensor. This technique can provide key insights into flame physics, particularly when a full 3D field can be extracted. Tomographic imaging can capture 3D instantaneous information, but becomes impractical to use when the technique is extended to larger, heavier high-speed imaging equipment. This has resulted in many researchers using fiber-based endoscopes (FBE) to capture multiple views on a single image sensor. However, the introduction of the fiber bundle and corresponding equipment to image specific combustion radicals results in a low SNR imaging environment when captured at high repetition rates. Additionally, when varying equivalence ratios, the signal can become further diminished because the combustion radicals signal weakens at fuel rich and fuel lean conditions. Therefore, this work determines the eff...

Journal of Clinical Neuroscience, 2022

Micro riboneucleic acids (miRNAs) may be transcribed after brain injury and be detectable in plas... more Micro riboneucleic acids (miRNAs) may be transcribed after brain injury and be detectable in plasma. This study aimed to assess the discriminative ability of seven miRNAs in plasma to differentiate between patients with mild traumatic brain injury (mTBI) and healthy controls. Changes in miRNA levels over 28 days were compared to changes in self-reported symptom profile. This was a prospective cohort study with longitudinal measurements of miRNA levels and symptom self-report. The Rivermead Post-Concussion Symptom Questionnaire (RPQ) was used to determine symptom severity. Mean normalised expression ratios (NER) of miRNAs at day 0 between mTBI and healthy controls were compared. An analysis of response profiles compared the response over time of miRNA species with RPQ symptom severity. miRNA levels of subjects who were defined to have "recovered" on Day 7 and 28 were compared to "non-recovered" subjects. There were 28 mTBI patients and 30 healthy controls included for analysis. Symptom severity was significantly higher on the day of injury among mTBI subjects (p < 0.001), and miRNA 32-5p levels were also higher (p = 0.009). Change of miRNA levels were similar to RPQ change at Day 7, but significantly different at Day 28. Differences were observed among miRNA levels of recovered subjects. This study demonstrated differences in miRNA levels among mTBI subjects compared to healthy controls and different miRNA levels among those who had recovered compared to those reporting symptoms. The change in profiles of miRNAs was different to symptom severity, suggesting that the two measures reflect different aspects of brain injury and recovery.

AIAA Scitech 2019 Forum, 2019