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- Title
- 2012-2013 Program Review Physics.
- Creator
- Florida Atlantic University, Department of Physics, Charles E. Schmidt College of Science
- Abstract/Description
-
Florida Atlantic University Departmental Dashboard Indicators. Department program reviews for Charles E. Schmidt College of Science, Florida Atlantic University.
- Date Issued
- 2012-2013
- PURL
- http://purl.flvc.org/fau/fd/FA00007691
- Format
- Document (PDF)
- Title
- 2010-2011 Program Review Physics.
- Creator
- Florida Atlantic University, Department of Physics, Charles E. Schmidt College of Science
- Abstract/Description
-
Florida Atlantic University Departmental Dashboard Indicators. Department program reviews for Charles E. Schmidt College of Science, Florida Atlantic University.
- Date Issued
- 2010-2011
- PURL
- http://purl.flvc.org/fau/fd/FA00007684
- Format
- Document (PDF)
- Title
- 2014-2015 Program Review Physics.
- Creator
- Florida Atlantic University, Department of Physics, Charles E. Schmidt College of Science
- Abstract/Description
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Florida Atlantic University Departmental Dashboard Indicators. Department program reviews for Charles E. Schmidt College of Science, Florida Atlantic University.
- Date Issued
- 2014-2015
- PURL
- http://purl.flvc.org/fau/fd/FA00007705
- Format
- Document (PDF)
- Title
- 2016-2017 Program Review Physics.
- Creator
- Florida Atlantic University, Department of Physics, Charles E. Schmidt College of Science
- Abstract/Description
-
Florida Atlantic University Departmental Dashboard Indicators. Department program reviews for Charles E. Schmidt College of Science, Florida Atlantic University.
- Date Issued
- 2016-2017
- PURL
- http://purl.flvc.org/fau/fd/FA00007719
- Format
- Document (PDF)
- Title
- 2009-2010 Program Review Physics.
- Creator
- Florida Atlantic University, Department of Physics, Charles E. Schmidt College of Science
- Abstract/Description
-
Florida Atlantic University Departmental Dashboard Indicators. Department program reviews for Charles E. Schmidt College of Science, Florida Atlantic University.
- Date Issued
- 2009-2010
- PURL
- http://purl.flvc.org/fau/fd/FA00007677
- Format
- Document (PDF)
- Title
- 2015-2016 Program Review Physics.
- Creator
- Florida Atlantic University, Department of Physics, Charles E. Schmidt College of Science
- Abstract/Description
-
Florida Atlantic University Departmental Dashboard Indicators. Department program reviews for Charles E. Schmidt College of Science, Florida Atlantic University.
- Date Issued
- 2015-2016
- PURL
- http://purl.flvc.org/fau/fd/FA00007712
- Format
- Document (PDF)
- Title
- 2013-2014 Program Review Physics.
- Creator
- Florida Atlantic University, Department of Physics, Charles E. Schmidt College of Science
- Abstract/Description
-
Florida Atlantic University Departmental Dashboard Indicators. Department program reviews for Charles E. Schmidt College of Science, Florida Atlantic University.
- Date Issued
- 2013-2014
- PURL
- http://purl.flvc.org/fau/fd/FA00007698
- Format
- Document (PDF)
- Title
- Anisotropic physical properties of SC-15 epoxy reinforced with magnetic nanofillers under uniform magnetic field.
- Creator
- Malkina, Olga, Charles E. Schmidt College of Science, Department of Physics
- Abstract/Description
-
SC-15 epoxy is used in many industrial applications and it is well known that the mechanical and viscoelastic properties of epoxy can be signicantly enhanced when reinforced with nanofillers. In this work, SC-15 epoxy is reinforced by loading with magnetically-active nanofillers and cured in a modest magnetic field. Because of the signicant magnetic response of the nanofillers, this is a low cost and relatively easy technique for imposing a strong magnetic anisotropy to the system without the...
Show moreSC-15 epoxy is used in many industrial applications and it is well known that the mechanical and viscoelastic properties of epoxy can be signicantly enhanced when reinforced with nanofillers. In this work, SC-15 epoxy is reinforced by loading with magnetically-active nanofillers and cured in a modest magnetic field. Because of the signicant magnetic response of the nanofillers, this is a low cost and relatively easy technique for imposing a strong magnetic anisotropy to the system without the need of a superconducting magnet. It is also found that this method is an effective way of enhancing the mechanical properties of epoxy. Three systems were prepared and studied. The first is a dilute system of various concentrations of Fe2O3 nanoparticles in SC-15 epoxy. The second system is a combination of Fe2O3 nanoparticles and chemically-functionalized single-walled carbon nanotubes (SWCNT(COOH)s) in SC-15 epoxy. The third is a dilute system of SWCNT(COOH)s decorated with Fe3O4 particles t hrough a sonochemical oxidation process in SC-15 epoxy. Samples have an initial cure of 6 hrs in a magnetic led of 10 kOe followed by an additional 24 hours of post curing at room temperature. These are compared to the control samples that do not have initial field curing. Tensile and compressive stress-strain analysis of the prepared systems shows that mechanical properties such as tensile strength, tensile modulus and compressive strength are enhanced with the inclusion of these nanofillers. It is also found that there is an anisotropic enhancement of these properties with respect to the imposed curing field. An interesting phenomenon is observed with the increase in modulus of toughness and fracture strain with nanotube inclusion., These parameters are drastically enhanced after curing the systems in a magnetic field. While there is a modest shift in glass transition temperature during viscoelastic analysis, the thermal stability of the created systems is not compromised. Results of these mechanical enhancements will be compared with other nanoloading techniques from literature.
Show less - Date Issued
- 2011
- PURL
- http://purl.flvc.org/FAU/3332722
- Subject Headings
- Nanostructured materials, Epoxy resins, Composite materials, Design
- Format
- Document (PDF)
- Title
- A dosimetric study of a heterogeneous phantom for lung stereotactic body radiation therapy comparing Monte Carlo and pencil beam calculations to dose distributions measured with a 2-d diode array.
- Creator
- Curley, Casey Michael, Ouhib, Zoubir, Florida Atlantic University, Charles E. Schmidt College of Science, Department of Physics
- Abstract/Description
-
Monte Carlo (MC) and Pencil Beam (PB) calculations are compared to their measured planar dose distributions using a 2-D diode array for lung Stereotactic Body Radiation Therapy (SBRT). The planar dose distributions were studied for two different phantom types: an in-house heterogeneous phantom and a homogeneous phantom. The motivation is to mimic the human anatomy during a lung SBRT treatment and incorporate heterogeneities into the pre-treatment Quality Assurance process, where measured and...
Show moreMonte Carlo (MC) and Pencil Beam (PB) calculations are compared to their measured planar dose distributions using a 2-D diode array for lung Stereotactic Body Radiation Therapy (SBRT). The planar dose distributions were studied for two different phantom types: an in-house heterogeneous phantom and a homogeneous phantom. The motivation is to mimic the human anatomy during a lung SBRT treatment and incorporate heterogeneities into the pre-treatment Quality Assurance process, where measured and calculated planar dose distributions are compared before the radiation treatment. Individual and combined field dosimetry has been performed for both fixed gantry angle (anterior to posterior) and planned gantry angle delivery. A gamma analysis has been performed for all beam arrangements. The measurements were obtained using the 2-D diode array MapCHECK 2™.
Show less - Date Issued
- 2015
- PURL
- http://purl.flvc.org/fau/fd/FA00004360
- Subject Headings
- Cancer -- Radiotherapy, Drug development -- Computer simulation, Image guided radiation therapy, Ion bombardment, Lung cancer -- Treatment, Medical physics, Monte Carlo method, Proton beams
- Format
- Document (PDF)
- Title
- CONSISTENCY OF CT NUMBER AND ELECTRON DENSITY IN TREATMENT PLANNING SYSTEM VERSUS CT SCANNER, AND DOSIMETRIC CONSEQUENCES.
- Creator
- Hana, Evan Makdasy, Pella, Silvia, Leventouri, Theodora, Florida Atlantic University, Charles E. Schmidt College of Science, Department of Physics
- Abstract/Description
-
The Computer Tomography (CT) scanned images are very important for the Treatment Planning System (TPS) to provide the electron density of the different types of tissues that the radiation penetrates in the path to the tumor to be treated. This electron density is converted to an attenuation coefficient, which varies with tissue for each structure and even varies by the tissue volume. The purpose of this research is to evaluate the CT numbers, and convert them into relative electron densities....
Show moreThe Computer Tomography (CT) scanned images are very important for the Treatment Planning System (TPS) to provide the electron density of the different types of tissues that the radiation penetrates in the path to the tumor to be treated. This electron density is converted to an attenuation coefficient, which varies with tissue for each structure and even varies by the tissue volume. The purpose of this research is to evaluate the CT numbers, and convert them into relative electron densities. Twenty-five patients’ data and CT numbers were evaluated in the CT scanner and in Eclipse and were converted into relative electron density and compared with each other. The differences between the relative electron density in the Eclipse was found to be from 0 up to 6% between tissue equivalent materials, the final result for all equivalent tissue materials was about 2%. For the patients’ data, the percentage difference of CT number versus electron density was found to be high for high relative electron density organs, namely the final average result for the spine was 8%, less for pelvis, and less for rib while for the other organs it was even less. The very lowest was 0.3% compared with 1% which is acceptable for clinical standards.
Show less - Date Issued
- 2019
- PURL
- http://purl.flvc.org/fau/fd/FA00013315
- Subject Headings
- Tomography, X-Ray Computed, Electron density, Radiation dosimetry--Evaluation, Tomography Scanners, X-Ray Computed
- Format
- Document (PDF)
- Title
- CHARACTERIZING THE PHYSICAL PROPERTIES OF LIVING CELLS THROUGH MICROFLUIDIC IMPEDANCE SENSING.
- Creator
- Galpayage, Dona Kalpani Nisansala Udeni, Lau, Andy W.C., Du, Sarah E., Florida Atlantic University, Department of Physics, Charles E. Schmidt College of Science
- Abstract/Description
-
The purpose of this research is to explore and investigate the biophysical properties of living cells using microfluidics based electrical impedance sensing (EIS) technique. It provides a non-invasive approach to detect label-free biological markers in the regulation of cellular activities even at a molecular level. We specifically focus on the development, testing, and theoretical modeling of electrical impedance spectroscopy for neuroblastoma cells and endothelial cells. First, we...
Show moreThe purpose of this research is to explore and investigate the biophysical properties of living cells using microfluidics based electrical impedance sensing (EIS) technique. It provides a non-invasive approach to detect label-free biological markers in the regulation of cellular activities even at a molecular level. We specifically focus on the development, testing, and theoretical modeling of electrical impedance spectroscopy for neuroblastoma cells and endothelial cells. First, we demonstrate that the EIS technique can be used to monitor the progressive mitochondrial fission/fusion modification in genetically modified human neuroblastoma cell lines. Our results characterize quantitatively the abnormal mitochondrial dynamics through the variations in cytoplasm conductivity. Secondly, we employ a real time EIS method to determine the biophysical properties of the junctions which join one endothelial cell with one another in a monolayer of endothelial cells. In particular, we examine the role of the protein, c-MYC oncogene, in the barrier function. Our results show that the downregulation of c-MYC oncogene enhances the endothelial barrier dysfunction associated with inflammation. Finally, we measure and find that the electrical admittance (the reciprocal of the impedance) of the monolayer of endothelial cellular networks exhibits an anomalous power law of the form, Y ∝ ωα, over a wide range of frequency, with the value of the exponent, α, depending on the severity of the inflammation. We attribute the power law to the changes of the intercellular electric permeability between neighboring endothelial cells. Thus, the inflammation gives rise to relatively smaller values of α compared to that of the no-inflammation group. Furthermore, we propose a simple percolation model of a large R-C network to confirm the emergent of power law scaling behavior of the complex admittance, suggesting that the endothelial network behaves as a complex microstructural network and its electrical properties may be simulated by a large R-C network.
Show less - Date Issued
- 2020
- PURL
- http://purl.flvc.org/fau/fd/FA00013595
- Subject Headings
- Microfluidics, Impedance spectroscopy, Cells
- Format
- Document (PDF)
- Title
- COMMISSIONING AND ACCEPTANCE TESTING OF A TRUEBEAM LINEAR ACCELERATOR.
- Creator
- Dumitru, Nicolae, Pella, Silvia, Florida Atlantic University, Charles E. Schmidt College of Science, Department of Physics
- Abstract/Description
-
Due to the difficulty of a complex commissioning technique for a multi energetic, multi-modality linear accelerator, I perform all the commissioning and acceptance testing for a TrueBeam linear accelerator with 4 megavoltage (MV) energies of which 2 are flattening filter-free (FFF) and 6 electron energies varying from 6 MeV to 20 MeV. A 2 dimensional (2D) water tank was used for scanning all the required field sizes for all the energies. The one dimensional (1D) water tank was used to collect...
Show moreDue to the difficulty of a complex commissioning technique for a multi energetic, multi-modality linear accelerator, I perform all the commissioning and acceptance testing for a TrueBeam linear accelerator with 4 megavoltage (MV) energies of which 2 are flattening filter-free (FFF) and 6 electron energies varying from 6 MeV to 20 MeV. A 2 dimensional (2D) water tank was used for scanning all the required field sizes for all the energies. The one dimensional (1D) water tank was used to collect all the output factors for all the photon fields sizes small to medium electron field sizes. For the large electron fields sizes, we had to use the 2D water tank. All the collected data was converted into a file type accepted by the planning system (Eclipse) and subsequently imported there. Treatment plans were generated using multiple forms of planning to verify the viability and quality of the beam data commissioned.
Show less - Date Issued
- 2019
- PURL
- http://purl.flvc.org/fau/fd/FA00013301
- Subject Headings
- Linear accelerators, Cancer--Treatment, Radiation dosimetry
- Format
- Document (PDF)
- Title
- Binary neutron star mergeres: simulations with arbitrarily spinning stars.
- Creator
- Tsatsin, Petr, Marronetti, Pedro, Charles E. Schmidt College of Science, Department of Physics
- Abstract/Description
-
The starting point of any general relativistic numerical simulation is a solution of the Hamiltonian and momentum constraints that (ideally) represents an astrophysically realistic scenario. This dissertation presents a new method to produce initial data sets for binary neutron stars with arbitrary spins and orbital eccentricities. The method only provides approximate solutions to the constraints. However, it was shown that the corresponding constraint violations subside after a few orbits,...
Show moreThe starting point of any general relativistic numerical simulation is a solution of the Hamiltonian and momentum constraints that (ideally) represents an astrophysically realistic scenario. This dissertation presents a new method to produce initial data sets for binary neutron stars with arbitrary spins and orbital eccentricities. The method only provides approximate solutions to the constraints. However, it was shown that the corresponding constraint violations subside after a few orbits, becoming comparable to those found in evolutions of standard conformally flat, helically symmetric binary initial data. This dissertation presents the first spinning neutron star binary simulations in circular orbits with a orbital eccentricity less then 0.01. The initial data sets corresponding to binaries with spins aligned, zero and anti-aligned with the orbital angular momentum were evolved in time. These simulations show the orbital “hang-up” effect previously seen in binary black holes. Additionally, they show orbital eccentricities that can be up to one order of magnitude smaller than those found in helically symmetric initial sets evolutions.
Show less - Date Issued
- 2013
- PURL
- http://purl.flvc.org/fau/fd/FA0004067
- Subject Headings
- Astrophysics, Black holes (Astronomy), General relativity (Physics), Gravitational waves, Neutron stars, Particles (Nuclear physics)
- Format
- Document (PDF)
- Title
- Binary black hole mergers: alternatives to standard puncture initial data and the impact on gravitational waveforms.
- Creator
- Reifenberger, George C., Charles E. Schmidt College of Science, Department of Physics
- Abstract/Description
-
We study the evolution of binary black hole initial data schemes as alternatives to the standard puncture construction. These alternatives are based on post-Newtonian expansions that contain realistic gravitational waves. The first scheme is based on a second order post-Newtonian expansion in Arnowitt, Deser, and Misner transverse-traceless (ADMTT) gauge that has been re-summed to approach standard puncture data at the black holes. The other schemes are based on asymptotic matching of the 4...
Show moreWe study the evolution of binary black hole initial data schemes as alternatives to the standard puncture construction. These alternatives are based on post-Newtonian expansions that contain realistic gravitational waves. The first scheme is based on a second order post-Newtonian expansion in Arnowitt, Deser, and Misner transverse-traceless (ADMTT) gauge that has been re-summed to approach standard puncture data at the black holes. The other schemes are based on asymptotic matching of the 4-metrics of two tidally perturbed Schwarzschild solutions to post-Newtonian expansions at different orders. The alternatives are encouraging and lead to quasi-circular orbits and show gravitational radiation from the onset, as well as a reduction of spurious radiation. Deficiencies compared to punctures include more eccentricity during inspiral and larger constraint violations, since the alternative data sets only approximate solutions of Einstein's equations.
Show less - Date Issued
- 2013
- PURL
- http://purl.flvc.org/fcla/dt/3362577
- Subject Headings
- Black holes (Astronomy), General relativity (Physics), Gravitational waves, Inertia (Mechanics), Mass (Physics), Particles (Nuclear physics)
- Format
- Document (PDF)
- Title
- Biogenic gas dynamics in peat soil blocks using ground penetrating radar: a comparative study in the laboratory between peat soils from the Everglades and from two northern peatlands in Minnesota and Maine.
- Creator
- Cabolova, Anastasija., Charles E. Schmidt College of Science, Department of Physics
- Abstract/Description
-
Peatlands cover a total area of approximately 3 million square kilometers and are one of the largest natural sources of atmospheric methane (CH4) and carbon dioxide (CO2). Most traditional methods used to estimate biogenic gas dynamics are invasive and provide little or no information about lateral distribution of gas. In contrast, Ground Penetrating Radar (GPR) is an emerging technique for non-invasive investigation of gas dynamics in peat soils. This thesis establishes a direct comparison...
Show morePeatlands cover a total area of approximately 3 million square kilometers and are one of the largest natural sources of atmospheric methane (CH4) and carbon dioxide (CO2). Most traditional methods used to estimate biogenic gas dynamics are invasive and provide little or no information about lateral distribution of gas. In contrast, Ground Penetrating Radar (GPR) is an emerging technique for non-invasive investigation of gas dynamics in peat soils. This thesis establishes a direct comparison between gas dynamics (i.e. build-up and release) of four different types of peat soil using GPR. Peat soil blocks were collected at peatlands with contrasting latitudes, including the Everglades, Maine and Minnesota. A unique two-antenna GPR setup was used to monitor biogenic gas buildup and ebullition events over a period of 4.5 months, constraining GPR data with surface deformation measurements and direct CH4 and CO2 concentration measurements. The effect of atmospheric pressure was also investigated. This study has implications for better understanding global gas dynamics and carbon cycling in peat soils and its role in climate change.
Show less - Date Issued
- 2010
- PURL
- http://purl.flvc.org/FAU/2974433
- Subject Headings
- Wetland ecology, Wetland ecology, Wetland ecology, Gas dynamics, Soil permeability, Ground penetrating radar, Porous materials, Fluid dynamics
- Format
- Document (PDF)
- Title
- Charge Regulation of a Surface Immersed in an Electrolyte Solution.
- Creator
- Acharya, Pramod, Lau, Andy W. C., Florida Atlantic University, Charles E. Schmidt College of Science, Department of Physics
- Abstract/Description
-
In this thesis, we investigate theoretically a new model of charge regulation of a single charged planar surface immersed in an aqueous electrolyte solution. Assuming that the adsorbed ions are mobile in the charged plane, we formulate a field theory of charge regulation where the numbers of adsorbed ions can be determined consistently by equating the chemical potentials of the adsorbed ions to that of the ions in the bulk. We analyze the mean-field treatment of the model for electrolyte of...
Show moreIn this thesis, we investigate theoretically a new model of charge regulation of a single charged planar surface immersed in an aqueous electrolyte solution. Assuming that the adsorbed ions are mobile in the charged plane, we formulate a field theory of charge regulation where the numbers of adsorbed ions can be determined consistently by equating the chemical potentials of the adsorbed ions to that of the ions in the bulk. We analyze the mean-field treatment of the model for electrolyte of arbitrary valences, and then beyond, where correlation effects are systematically taken into account in a loop expansion. In particular, we compute exactly various one-loop quantities, including electrostatic potentials, ion distributions, and chemical potentials, not only for symmetric (1, 1) electrolyte but also for asymmetric (2, 1) electrolyte, and make use of these quantities to address charge regulation at the one-loop level. We find that correlation effects give rise to various phase transitions in the adsorption of ions, and present phase diagrams for (1, 1) and (2, 1) electrolytes, whose distinct behaviors suggest that charge regulation, at the one-loop level, is no longer universal but depends crucially on the valency of the ions.
Show less - Date Issued
- 2016
- PURL
- http://purl.flvc.org/fau/fd/FA00004560, http://purl.flvc.org/fau/fd/FA00004560
- Subject Headings
- Surface chemistry., Intermolecular forces., Electrodynamics., Quantum field theory.
- Format
- Document (PDF)
- Title
- Central Moments of Squeezed States: A Coincidence Statistics Analogue.
- Creator
- Tison, Christopher C., Miller, Warner A., Alsing, Paul M., Florida Atlantic University, Charles E. Schmidt College of Science, Department of Physics
- Abstract/Description
-
As a subset of quantum optics, single photons are one of the competing physical resources for quantum information processing. When used as carriers of quantum information, they have no equal. For the processing of quantum information, single photons have proven difficult to scale beyond the order of ⇠ 10 photons. The lack of single-photon-level interaction has led to creative approaches which rely on postselection to filter the possible measured outcomes to those which appear as though...
Show moreAs a subset of quantum optics, single photons are one of the competing physical resources for quantum information processing. When used as carriers of quantum information, they have no equal. For the processing of quantum information, single photons have proven difficult to scale beyond the order of ⇠ 10 photons. The lack of single-photon-level interaction has led to creative approaches which rely on postselection to filter the possible measured outcomes to those which appear as though interaction occurred. This approach of post-selection leans heavily on the ability to not only generate but also detect scores of single photons simultaneously and with near perfect efficiency. Our work relaxes the emphasis which has been placed on single photons for quantum information processing to that of states with, in principle, an arbitrary number of photons. Central moment expectations on two-mode squeezed states are shown to exhibit post-selection behavior which reflects the single-photon counterpart. These measures are proven to be robust to loss and return entangled state statistics on average. With naive estimation of the central moment, states with ~ 20 modes are within reach with current technology, closing the gap between quantum states which can and cannot be classically simulated.
Show less - Date Issued
- 2018
- PURL
- http://purl.flvc.org/fau/fd/FA00005951
- Subject Headings
- Squeezed states (Optics), Quantum optics, Photons, Integrated optics
- Format
- Document (PDF)
- Title
- Diffusion tensor imaging in mild traumatic brain injuries.
- Creator
- Hotiu, Angelica, Charles E. Schmidt College of Science, Department of Physics
- Abstract/Description
-
Mild traumatic brain injuries (MTBI) are the leading type of head injuries with appreciable risque of sequelae leading to functional and psychological deficits. Although mild traumatic brain injuries are frequently underdiagnosed by conventional imaging modalities, rapidly evolving techniques such as diffusion tensor imaging (DTI) reveal subtle changes in white matter integrity as a result of head trauma and play an important role in refining diagnosis, therapeutic interventions and...
Show moreMild traumatic brain injuries (MTBI) are the leading type of head injuries with appreciable risque of sequelae leading to functional and psychological deficits. Although mild traumatic brain injuries are frequently underdiagnosed by conventional imaging modalities, rapidly evolving techniques such as diffusion tensor imaging (DTI) reveal subtle changes in white matter integrity as a result of head trauma and play an important role in refining diagnosis, therapeutic interventions and management of MTBI. In this dissertation we use diffusion tensor imaging to detect the microstructural changes induced by axonal injuries and to monitor their evolution during the recovery process. DTI data were previously acquired from 11 subjects, football players of age 19-23 years (median age 20 years). Three players had suffered a mild traumatic brain injury during the season and underwent scanning within 24 hours after the injury with follow-ups after one and two weeks. A set of diffusion indices, such as fractional anisotropy, axial, radial and mean diffusivity were derived from the diffusion tensor. Changes in diffusion indices in concussed subjects were analyzed based on two different approaches: whole brain analysis, using tract-based spatial statistics (TBSS) and region of interest analysis (ROI). In both approaches we use a voxelwise analysis to examine group differences in diffusion indices between five controls and three concussed subjects for all DTI scans. Additional statistical analysis was performed between control groups consisting of five and three non-injured players. Both analyses demonstrated that the MTBI group reveals increase in fractional anisotropy and decreases in transversal and mean diffusivity in cortical and subcortical areas within 24 hours after the injury., No changes were detected in TBSS analysis for the follow-up data sets. Furthermore, our ROI approach revealed multiples regions with significantly different voxels, non-uniformly distributed throughout the brain, for all diffusion indices in all three scans. Three of the diffusion indices fractional anisotropy, mean and transversal diffusivity showed higher vulnerability to head trauma in subcortical and cortical areas than in regions in the lower brain. Recovery of white matter pathways occured at different locations in the brain at one and two weeks after head trauma. Strong recovery was observed in mean and transversal diffusivity in subcortical areas that correspond to the corticospinal tract. No recovery was found for fractional anisotropy and axial diffusivity in the same region. Also, decreases in fractional anisotropy and increases in transversal and axial diffusivity were observed in the spleninum of the corpus callosum. As voxelwise analysis performed on DTI data revealed white matter regions, which exhibit changes in diffusion parameters in the concussed group for all three scans, we conclude that diffusion tensor imaging is a powerful technique for early detection of axonal injuries and may serve as an important tool for monitoring microstructural changes during the recovery process.
Show less - Date Issued
- 2010
- PURL
- http://purl.flvc.org/FAU/2100579
- Subject Headings
- Brain, Magnetic resonance imaging, Brain, Concussion, Diagnosis, Neuropsychology, Diffusion tensor imaging
- Format
- Document (PDF)
- Title
- Evaluation of surface dose outside the treatment area for breast cancer irradiation modalities using thermoluminescence dosimeters (TLDs).
- Creator
- Khanal, Suraj P., Charles E. Schmidt College of Science, Department of Physics
- Abstract/Description
-
The purpose of this research is to compare the surface dose outside the treatment area for different breast cancer irradiation modalities using Thermoluminescence Dosimeters (TLDs). Five different modalities are included in this study: Accuboost, Photon boost, Electron boost, Strut-Adjusted Volume Implant (SAVI), and Mammosite Multi-lumen (ML).Six points of interest (POI) on the breast cancer patients had been selected for the TLDs placement. Data from 25 breast cancer patients at Lynn Cancer...
Show moreThe purpose of this research is to compare the surface dose outside the treatment area for different breast cancer irradiation modalities using Thermoluminescence Dosimeters (TLDs). Five different modalities are included in this study: Accuboost, Photon boost, Electron boost, Strut-Adjusted Volume Implant (SAVI), and Mammosite Multi-lumen (ML).Six points of interest (POI) on the breast cancer patients had been selected for the TLDs placement. Data from 25 breast cancer patients at Lynn Cancer Institute of the Boca Raton Regional Hospital were included in the study. The measured percentage ranges of the averaged doses at the six POIs for the different modalities are: Sternum 0.26% - 3.26%, Shoulder 0.33% - 2.79%, Eye 0.26% - 1.32%, Thyroid 0.20% - 2.75%, CLB 0.2% - 5.46%, Lower Abdomen 0.16% - 2.25%.
Show less - Date Issued
- 2013
- PURL
- http://purl.flvc.org/fcla/dt/3362479
- Subject Headings
- Thermoluminescence, Therapeutic use, Radiation dosimetry, Breast, Cancer, Treatmernt, Radiation, Measurement, Methodology
- Format
- Document (PDF)
- Title
- Empirical beam angle optimization for lung cancer intensity modulated radiation therapy.
- Creator
- Doozan, Brian, Pella, Silvia, Florida Atlantic University, Charles E. Schmidt College of Science, Department of Physics
- Abstract/Description
-
Empirical methods of beam angle optimization (BAO) are tested against the BAO that is currently employed in Eclipse treatment planning software. Creating an improved BAO can decrease the amount of time a dosimetrist spends on making a treatment plan, improve the treatment quality and enhance the tools an inexperienced dosimetrist can use to develop planning techniques. Using empirical data created by experienced dosimetrists from 69 patients treated for lung cancer, the most frequently used...
Show moreEmpirical methods of beam angle optimization (BAO) are tested against the BAO that is currently employed in Eclipse treatment planning software. Creating an improved BAO can decrease the amount of time a dosimetrist spends on making a treatment plan, improve the treatment quality and enhance the tools an inexperienced dosimetrist can use to develop planning techniques. Using empirical data created by experienced dosimetrists from 69 patients treated for lung cancer, the most frequently used gantry angles were applied to four different regions in each lung to gather an optimal set of fields that could be used to treat future lung cancer patients. This method, given the moniker FAU BAO, is compared in 7 plans created with the Eclipse BAO choosing 5 fields and 9 fields. The results show that the conformality index improved by 30% or 3% when using the 5 and 9 fields. The conformation number was better by 12% from the 5 fields and 9% from the 9 fields. The organs at risk (OAR) were overall more protected to produce fewer nonstochastic effects from the radiation treatment with the FAU BAO.
Show less - Date Issued
- 2014
- PURL
- http://purl.flvc.org/fau/fd/FA00004280, http://purl.flvc.org/fau/fd/FA00004280
- Subject Headings
- Cancer -- Radiotherapy, Image guided radiation therapy, Lung cancer -- Treatment, Medical physics, Medical radiology -- Data processing, Medicine -- Mathematical models
- Format
- Document (PDF)