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Pages
- Title
- Computer controlled long-term cyclic fatigue testing of pressure vessels.
- Creator
- Brenn, C. B., Clark, A. M., Harbor Branch Oceanographic Institute
- Date Issued
- 1986
- PURL
- http://purl.flvc.org/fau/fd/FA00007437
- Subject Headings
- Pressure vessels, Hydrostatic pressure, Oceanography
- Format
- Document (PDF)
- Title
- Detailed stress analysis of a spherical acrylic submersible by 3-D finite element modeling.
- Creator
- Das, Partha S., Harbor Branch Oceanographic Institute
- Date Issued
- 1999
- PURL
- http://purl.flvc.org/fau/fd/FA00007504
- Subject Headings
- Pressure vessels, Finite element method, Pressure vessels--Cracking
- Format
- Document (PDF)
- Title
- Wall Pressure Fluctuation in a Turbulent Channel Flow.
- Creator
- Denissova, Lyubov, Glegg, Stewart, Florida Atlantic University, Department of Ocean and Mechanical Engineering, College of Engineering and Computer Science
- Abstract/Description
-
Turbulent flow is a complex three dimensional system of velocity and pressure fluctuations in a fluid that creates vorticity, eddies and other flow structures. In this study we are specifically concerned with the surface pressure fluctuations below a turbulent boundary layer which is one of the primary sources of panel vibration on aircraft fuselages and ship hulls as well a major issue in ship hydrodynamics. The most accepted analytical approaches to describe the surface pressure...
Show moreTurbulent flow is a complex three dimensional system of velocity and pressure fluctuations in a fluid that creates vorticity, eddies and other flow structures. In this study we are specifically concerned with the surface pressure fluctuations below a turbulent boundary layer which is one of the primary sources of panel vibration on aircraft fuselages and ship hulls as well a major issue in ship hydrodynamics. The most accepted analytical approaches to describe the surface pressure fluctuations are the Chase model [1] for the surface pressure wavenumber spectrum and Goody’s model [2] for the pressure spectrum at a point. The most accurate numerical approach to use is Direct Numerical Simulations (DNS) [3]. In this study we compared Chase and Goody’s models against DNS of a turbulent channel flow in the space–time and wavenumber-frequency domains and estimated regions of convergence between the analytical models and the DNS data.
Show less - Date Issued
- 2022
- PURL
- http://purl.flvc.org/fau/fd/FA00014034
- Subject Headings
- Turbulence, Turbulent boundary layer, Pressure
- Format
- Document (PDF)
- Title
- Suppression of the highpressure nervous syndrome (HPNS) in human dives to 720 ft. and 1000 ft. by use of N2/He/O2.
- Creator
- Bennett, P. B., Blenkarn, G. D., Roby, J., Youngblood, D., Harbor Branch Oceanographic Institute
- Date Issued
- 1974
- PURL
- http://purl.flvc.org/fau/fd/FA00007363
- Subject Headings
- Deep diving, High Pressure Neurological Syndrome
- Format
- Document (PDF)
- Title
- AN INVESTIGATION OF ENERGY FLOW AND ACOUSTIC RADIATION OF FLUID-LOADED PANELS USING THE ENERGY ACCOUNTANCY CONCEPT.
- Creator
- MAILLET, PHILIPPE LOUIS., Florida Atlantic University, Dunn, Stanley E., Cuschieri, Joseph M., College of Engineering and Computer Science, Department of Ocean and Mechanical Engineering
- Abstract/Description
-
The energy flow and the acoustic radiation of fluid-loaded panels are investigated using the Energy Accountancy Concept. The various energy components of the systems are defined and studied. Each component is a function of the excitation, the structure, the medium and their coupling. An energy balance equation is written for the system. This method is applied to study the acoustic radiation from a point-excited clamped plate placed on the free surface of a water tank. The radiation efficiency...
Show moreThe energy flow and the acoustic radiation of fluid-loaded panels are investigated using the Energy Accountancy Concept. The various energy components of the systems are defined and studied. Each component is a function of the excitation, the structure, the medium and their coupling. An energy balance equation is written for the system. This method is applied to study the acoustic radiation from a point-excited clamped plate placed on the free surface of a water tank. The radiation efficiency of the plate is measured and compared to previous works. The energy balance equation gives very good results at frequencies between 50 Hz and 12 kHz. An undefined source of energy dissipation is observed in one experiment. The results of this study have shown that the Energy Accountancy Concept can be used to describe the energy flow in a vibrating structure under water-loading.
Show less - Date Issued
- 1986
- PURL
- http://purl.flvc.org/fcla/dt/14289
- Subject Headings
- Acoustic radiation pressure, Vibration--Measurement
- Format
- Document (PDF)
- Title
- A MICROPROCESSOR BASED DRUG INFUSION CONTROL SYSTEM, EMPLOYING A MODEL REFERENCE ADAPTIVE CONTROL ALGORITHM, TO REGULATE BLOOD PRESSURE IN INTENSIVE CARE UNIT PATIENTS.
- Creator
- HERNANDEZ, LEO., Florida Atlantic University, Shankar, Ravi
- Abstract/Description
-
This microprocessor based drug infusion control system is intended to aid doctors and nurses in the care of critically ill cardiac patients. The patient's arterial blood pressure is monitored and the infusion rate of the vasodilator sodium nitroprusside is regulated based on a model reference adaptive control algorithm. The algorithm employs a reference model to approximate the patient drug response. The reference model output is compared with the patient blood pressure change and the...
Show moreThis microprocessor based drug infusion control system is intended to aid doctors and nurses in the care of critically ill cardiac patients. The patient's arterial blood pressure is monitored and the infusion rate of the vasodilator sodium nitroprusside is regulated based on a model reference adaptive control algorithm. The algorithm employs a reference model to approximate the patient drug response. The reference model output is compared with the patient blood pressure change and the adaptive controller parameters are changed bringing the patient drug response in closer agreement with the reference model. Drug infusion is digitally controlled by a microprocessor based system and employs a stepper motor driven peristaltic pump. Simulation studies have validated the system. Animal experiments and clinical studies will be conducted later.
Show less - Date Issued
- 1987
- PURL
- http://purl.flvc.org/fcla/dt/14415
- Subject Headings
- Blood pressure--Regulation, Drug infusion pumps
- Format
- Document (PDF)
- Title
- MODEL REFERENCE ADAPTIVE CONTROL OF BLOOD PRESSURE.
- Creator
- STEINMETZ, MICHAEL JOSEPH., Florida Atlantic University, Pajunen, Grazyna, College of Engineering and Computer Science, Department of Computer and Electrical Engineering and Computer Science
- Abstract/Description
-
Several adaptive controllers have been designed to control the infusion of the drug sodium nitroprusside for the purpose of reducing high blood pressure in post surgical patients. Most of these controllers have not considered one or more factors of the controlled system including the stochastic background noise present in the patients, the time varying nature of the patient, and the constraints imposed on the control input and system output. This thesis presents a model reference adaptive...
Show moreSeveral adaptive controllers have been designed to control the infusion of the drug sodium nitroprusside for the purpose of reducing high blood pressure in post surgical patients. Most of these controllers have not considered one or more factors of the controlled system including the stochastic background noise present in the patients, the time varying nature of the patient, and the constraints imposed on the control input and system output. This thesis presents a model reference adaptive controller which takes into account all of these factors. Through simulations on a personal computer, the robustness of the controller is demonstrated in the presence of noise, time varying parameters, and deterministic disturbances. Furthermore, this performance is achieved without requiring any prior knowledge of the system delay.
Show less - Date Issued
- 1987
- PURL
- http://purl.flvc.org/fcla/dt/14408
- Subject Headings
- Blood pressure--Regulation, Adaptive control system
- Format
- Document (PDF)
- Title
- Simultaneous pressure-temperature measurements in a heat pipe.
- Creator
- Jayanth, Madhavan., Florida Atlantic University, Abtahi, Amir
- Abstract/Description
-
When a heat pipe operates with a large temperature difference between the two ends, the vapor liquid combination is not in thermodynamic equilibrium. The experiments showed that the vapor liquid mixture is in a higher state of saturation at the condenser as compared to other sections of the pipe. Correlations were obtained that relate the coefficient of thermal coupling alpha to the evaporator flux and mass of NCG (non-condensable gas). As mass of NCG is increased in the heat pipe, the...
Show moreWhen a heat pipe operates with a large temperature difference between the two ends, the vapor liquid combination is not in thermodynamic equilibrium. The experiments showed that the vapor liquid mixture is in a higher state of saturation at the condenser as compared to other sections of the pipe. Correlations were obtained that relate the coefficient of thermal coupling alpha to the evaporator flux and mass of NCG (non-condensable gas). As mass of NCG is increased in the heat pipe, the thermal coupling coefficient alpha decreases. The evaporator heat flux is directly proportional to alpha. The coefficient alpha is related to the pressures and temperatures at the evaporator, condenser and the adiabatic sections. In conclusion, for heat pipes that do not operate in thermodynamic equilibrium, correlations were obtained between the operating conditions of the heat pipe, the evaporator heat flux and the mass of NCG.
Show less - Date Issued
- 1997
- PURL
- http://purl.flvc.org/fcla/dt/15435
- Subject Headings
- Heat pipes, Temperature measurements, Pressure--Measurements
- Format
- Document (PDF)
- Title
- The effect of ingesting a caffeine-enhanced sport drink on resting energy expenditures and blood pressure in females.
- Creator
- Klepacki, Brian, Graves, B. Sue, Hellberg, Peter
- Date Issued
- 2009-07-31
- PURL
- http://purl.flvc.org/fcla/dt/3327168
- Subject Headings
- Caffeine --Administration & Dosage, Energy Metabolism, Rest --Physiology, Blood Pressure, Blood Pressure --Physiology, Female, Dietary Supplements
- Format
- Document (PDF)
- Title
- Responses of photosynthesis, respiration, growth and cellular constituents to hypo-osmotic shock in the red alga Gracilaria tikvahiae.
- Creator
- Lapointe, Brian E., Rice, D. L., Lawrence, J. M.
- Date Issued
- 1984
- PURL
- http://purl.flvc.org/FCLA/DT/3353746
- Subject Headings
- Gracilaria, Algae--Physiology, Photosynthesis, Respiration, Growth, Osmotic Pressure, Salinity
- Format
- Document (PDF)
- Title
- Adolescent alcohol consumption: level of consumption in the friendship group impacts friendship choice and friend influence.
- Creator
- DeLay, Dawn, Laursen, Brett, Burk, William Jay, Kiuru, Noona, Salmela-Aro, Katariina, Nurmi, Jarik-Erik, Graduate College
- Date Issued
- 2011-04-08
- PURL
- http://purl.flvc.org/fcla/dt/3164521
- Subject Headings
- Teenagers --Alcohol use, Peer pressure in adolescence, Group identity
- Format
- Document (PDF)
- Title
- Potential for deep sea invasion by Mediterranean shallow water echinoids: pressure and temperature as stage-specific dispersal barriers.
- Creator
- Young, Craig M., Tyler, Paul A., Fenaux, Lucienne, Harbor Branch Oceanographic Institute
- Date Issued
- 1997
- PURL
- http://purl.flvc.org/FCLA/DT/3350882
- Subject Headings
- Echinoidea, Sea urchins, Pressure, Mediterranean Sea, Vertical distribution (Aquatic biology)
- Format
- Document (PDF)
- Title
- A study of steady state and kinetic regulation of chloride ion and osmotic pressure in hemolymph of oysters, Crassostrea virginica, exposed to tri-n-butyltin.
- Creator
- Bokman, Elizabeth, Laughlin, R. B., Jr., Harbor Branch Oceanographic Institute
- Date Issued
- 1989
- PURL
- http://purl.flvc.org/FCLA/DT/3333173
- Subject Headings
- Crassostrea virginica, American oyster, Hemolymph, Trialkyltin Compounds, Osmotic Pressure, Chlorides
- Format
- Document (PDF)
- Title
- A comparison of tidal harmonic constants computed at and near an inlet.
- Creator
- Smith, Ned P.
- Date Issued
- 1980
- PURL
- http://purl.flvc.org/FCLA/DT/3174482
- Subject Headings
- Inlets, Tides, Convection (Meteorology), Pressure --Measurement, Estuarine oceanography
- Format
- Document (PDF)
- Title
- The rise and fall of the estuarine intertidal zone.
- Creator
- Smith, Ned P.
- Date Issued
- 1986
- PURL
- http://purl.flvc.org/FCLA/DT/3174013
- Subject Headings
- Estuaries, Tides, Atmospheric pressure --Diurnal variations, Sea level, Seasons
- Format
- Document (PDF)
- Title
- Effect of applied periodic strain on coherent structures in a turbulent boundary layer.
- Creator
- Neravetla, Bharath Reddy, Florida Atlantic University, Dhanak, Manhar R., College of Engineering and Computer Science, Department of Ocean and Mechanical Engineering
- Abstract/Description
-
The effect of applied periodic straining field on the behavior of coherent vortical structures in the turbulent boundary layer is studied. In particular, the coherent vortical longitudinal structures in the turbulent boundary layer in the form of isolated vortices or in the form of pairs of counter-rotating vortices is considered. The effect on the pressure fluctuations on the wall due to the applied periodic strain is studied. A numerical method using Contour Dynamics technique and...
Show moreThe effect of applied periodic straining field on the behavior of coherent vortical structures in the turbulent boundary layer is studied. In particular, the coherent vortical longitudinal structures in the turbulent boundary layer in the form of isolated vortices or in the form of pairs of counter-rotating vortices is considered. The effect on the pressure fluctuations on the wall due to the applied periodic strain is studied. A numerical method using Contour Dynamics technique and incompressible, inviscid equations of motion is developed to determine the evolution of these structures in time. The pressure fluctuations on the wall are calculated making use of the unsteady Bernoulli's equation. The various parameters associated with the coherent structures in the turbulent boundary layer such as the strength of the vortices, their distance from the wall, separation distance between counter-rotating vortices, the frequency of the applied straining field, the magnitude of the straining field and the stretching rate are varied to study the resultant pressure fluctuations. It is observed that at low applied frequencies, there are high modulations in the surface pressure fluctuations, and at higher applied frequencies of straining field there is reduction in surface pressure fluctuations in the boundary layer.
Show less - Date Issued
- 1994
- PURL
- http://purl.flvc.org/fcla/dt/15020
- Subject Headings
- Vortex-motion, Turbulent boundary layer, Pressure--Measurement
- Format
- Document (PDF)
- Title
- Design of a high signal to noise ratio electrical impedance plethysmograph.
- Creator
- Urso, Alessio Francesco., Florida Atlantic University, Shankar, Ravi, College of Engineering and Computer Science, Department of Computer and Electrical Engineering and Computer Science
- Abstract/Description
-
We have developed a high signal to noise ratio automatically resetting electrical impedance plethysmograph for noninvasive determination of blood pressure in pigeons. Pigeons are finding increased use as an economical and appropriate animal model for the study of human atherosclerosis. The impedance plethysmograph obtains the pulsatile arterial volume change as an impedance pulse. Nyboer's equation may then be used to extract the arterial volume change from the impedance pulse. The designed...
Show moreWe have developed a high signal to noise ratio automatically resetting electrical impedance plethysmograph for noninvasive determination of blood pressure in pigeons. Pigeons are finding increased use as an economical and appropriate animal model for the study of human atherosclerosis. The impedance plethysmograph obtains the pulsatile arterial volume change as an impedance pulse. Nyboer's equation may then be used to extract the arterial volume change from the impedance pulse. The designed impedance plethysmograph has a sensitivity of 430 mV/m$\Omega$ and a noise level of 0.12 m$\Omega$ peak-to-peak, significantly better than systems reported earlier. Refinements to further enhance the performance are also presented.
Show less - Date Issued
- 1990
- PURL
- http://purl.flvc.org/fcla/dt/14609
- Subject Headings
- Impedance plethysmography, Atherosclerosis--Animal models, Blood pressure--Measurement
- Format
- Document (PDF)
- Title
- Base pressure resulting from sudden expansion in cross-sectional area from a conical converging nozzle.
- Creator
- Hwang, Chi-bok., Florida Atlantic University, Chow, Wen L., College of Engineering and Computer Science, Department of Ocean and Mechanical Engineering
- Abstract/Description
-
This research concerns with the determination of the base pressure related to the conical convergent nozzle flow when a sudden enlargement in cross-sectional area occurs. It is recognized at the outset that the problem belongs to the category of strong interaction where inviscid and viscous flows must be considered together before a solution can be established. The viscous flow analyses based on the integral formulations are guided more or less by the boundary layer concept. The inviscid flow...
Show moreThis research concerns with the determination of the base pressure related to the conical convergent nozzle flow when a sudden enlargement in cross-sectional area occurs. It is recognized at the outset that the problem belongs to the category of strong interaction where inviscid and viscous flows must be considered together before a solution can be established. The viscous flow analyses based on the integral formulations are guided more or less by the boundary layer concept. The inviscid flow field is established from the hodograph transformation, and the method of characteristics. Again the point of reattachment behaves as a saddle point singularity for the system of equations describing the viscous flow recompression process. After the point of reattachment is approached, an overall momentum balance is applied so that the base pressure and the location where recompression starts, may be determined. Experimental studies with specific conical angles and area ratios are also conducted in the laboratory. The results obtained from the theoretical analysis agreed well with the experimental data produced in the laboratory and the data available elsewhere. These evidences lead to the conclusion that the method developed in this investigation is effective in dealing with problems of this type.
Show less - Date Issued
- 1991
- PURL
- http://purl.flvc.org/fcla/dt/12280
- Subject Headings
- Base flow (Aerodynamics), Viscous flow, Aerodynamics, Supersonic, Pressure vessels
- Format
- Document (PDF)
- Title
- Control of response of tall multi-story buildings under wind excitation.
- Creator
- Qiu, Xin., Florida Atlantic University, Lin, Y. K., College of Engineering and Computer Science, Department of Ocean and Mechanical Engineering
- Abstract/Description
-
Theoretical investigation is carried out into the extent to which floor accelerations of a wind-excited tall building can be reduced by increasing damping in those components in a building which are generally regarded to be non-structural elements, and by using active control. The wind loads are modeled as stochastic processes, which are correlation-stationary in time. Only the drag wind forces are considered in the analyses. The spectral densities and cross-spectral densities of two commonly...
Show moreTheoretical investigation is carried out into the extent to which floor accelerations of a wind-excited tall building can be reduced by increasing damping in those components in a building which are generally regarded to be non-structural elements, and by using active control. The wind loads are modeled as stochastic processes, which are correlation-stationary in time. Only the drag wind forces are considered in the analyses. The spectral densities and cross-spectral densities of two commonly used models, proposed by Davenport and by Simiu, are compared. The Davenport spectrum is used in the numerical calculation for illustration purposes. Several structural models are discussed: an ideal spatially periodic model, an ideal piece-wise spatially periodic model, a nominal spatially periodic model with random disorder in periodicity, and an ideal spatially periodic model equipped with an active mass damper control system. The problems are formulated using the transfer matrix approach in the frequency domain. Analytical solutions are obtained for the spectral densities and the mean-square values of the floor accelerations and those of the active control force. Numerical examples are given for illustration.
Show less - Date Issued
- 1997
- PURL
- http://purl.flvc.org/fcla/dt/12495
- Subject Headings
- Tall buildings--Aerodynamics, Wind-pressure, Damping (Mechanics)
- Format
- Document (PDF)
- Title
- Bio-Inspired Modified Turbulent Boundary Layers.
- Creator
- French, Stone A., Glegg, Stewart, Florida Atlantic University, Department of Ocean and Mechanical Engineering, College of Engineering and Computer Science
- Abstract/Description
-
The reduction of drag and sound pressure levels (SPL) are desirable traits in many fluidics’ applications ranging from high-speed transportation to energy generation. Inspiration has been found in some species of owls that possess boundary layer control surface treatments on their wings that appear to reduce SPL while in flight. This modification of the flow over the wings is known as the development of a modified boundary layer (MBL). Virginia Tech is working in collaboration with Florida...
Show moreThe reduction of drag and sound pressure levels (SPL) are desirable traits in many fluidics’ applications ranging from high-speed transportation to energy generation. Inspiration has been found in some species of owls that possess boundary layer control surface treatments on their wings that appear to reduce SPL while in flight. This modification of the flow over the wings is known as the development of a modified boundary layer (MBL). Virginia Tech is working in collaboration with Florida Atlantic University to investigate this reduction in SPL experimentally but requires the assistance of RANS simulation to obtain drag results. This thesis investigates the drag effects of the rod style geometries being evaluated at VT to mimic the MBL of an owl. In doing this it was found that the height of the rods has a direct correlation with the amount of drag induced by the presence of the rods in the flow field.
Show less - Date Issued
- 2021
- PURL
- http://purl.flvc.org/fau/fd/FA00013826
- Subject Headings
- Turbulent boundary layer, Sound pressure, Biomimicry, Drag (Aerodynamics)
- Format
- Document (PDF)
