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Title: Liver Cancer Risk Quantification through an Artificial Neural Network based on Personal Health Data.
Creator: Ataei, Afrouz, Muhammad, Wazir, Florida Atlantic University, Department of Physics, Charles E. Schmidt College of Science
Abstract/Description: Liver cancer is the sixth most common type of cancer worldwide and is the third leading cause of cancer related mortality. Several types of cancer can form in the liver. Hepatocellular carcinoma (HCC) makes up 75%-85% of all primary liver cancers and it is a malignant disease with limited therapeutic options due to its aggressive progression. While the exact cause of liver cancer may not be known, habits/lifestyle may increase the risk of developing the disease. Several risk prediction models...
Show moreLiver cancer is the sixth most common type of cancer worldwide and is the third leading cause of cancer related mortality. Several types of cancer can form in the liver. Hepatocellular carcinoma (HCC) makes up 75%-85% of all primary liver cancers and it is a malignant disease with limited therapeutic options due to its aggressive progression. While the exact cause of liver cancer may not be known, habits/lifestyle may increase the risk of developing the disease. Several risk prediction models for HCC are available for individuals with hepatitis B and C virus infections who are at high risk but not for general population. To address this challenge, an artificial neural network (ANN) was developed, trained, and tested using the health data to predict liver cancer risk. Our results indicate that our ANN can be used to predict liver cancer risk with changes with lifestyle and may provide a novel approach to identify patients at higher risk and can be bene ted from early diagnosis.
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Date Issued: 2021
PURL: http://purl.flvc.org/fau/fd/FA00013742
Subject Headings: Liver--Cancer, Artificial neural networks, Neural networks (Computer science), Cancer--Risk assessment
Format: Document (PDF)

Title: THE INFLUENCE OF THE SPACE SHUTTLE PROGRAM ON LAND USE/LANDCOVER AND POPULATION DYNAMICS IN BREVARD COUNTY.
Creator: Insalaco, Stephanie, Xie, Zhixiao, Florida Atlantic University, Department of Physics, Charles E. Schmidt College of Science
Abstract/Description: The Space Shuttle Program at the John F. Kennedy Space Center (KSC) in Brevard County made a significant impact on the aerospace industry, but what is unknown is how it impacted the county surrounding it, specifically through land use/land cover (LU/LC) change and population dynamics. This research collected land cover and population data throughout the program to determine the impact, while also creating a record of the state of LU/LC and population in Brevard County in general during the...
Show moreThe Space Shuttle Program at the John F. Kennedy Space Center (KSC) in Brevard County made a significant impact on the aerospace industry, but what is unknown is how it impacted the county surrounding it, specifically through land use/land cover (LU/LC) change and population dynamics. This research collected land cover and population data throughout the program to determine the impact, while also creating a record of the state of LU/LC and population in Brevard County in general during the same period. Urbanization and tourism were also evaluated as possible catalysts for change when analyzing the LU/LC maps created in ArcMap and the population graphs from Microsoft Excel. Calculated area for different LU/LC classes were the main focus of this research, which led to the finding that urbanization has been a major factor of change in Brevard County through expanding residential areas rather than tourism and change from the Space Shuttle Program was centered in cities closest to the KSC.
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Date Issued: 2021
PURL: http://purl.flvc.org/fau/fd/FA00013744
Subject Headings: Land use, Land cover, Population Dynamics, Brevard County (Fla.), John F. Kennedy Space Center
Format: Document (PDF)

Title: Electronic structure calculations for alloys using the polymorphous coherent potential approximation.
Creator: Pella, Silvia, Florida Atlantic University, Charles E. Schmidt College of Science, Department of Physics
Abstract/Description: The Polymorphous Coherent Approximation (PCPA) plays the central role in this study. The PCPA represents an extension of the Coherent Potential Approximation (CPA) in the sense that it treats an alloy model in which all of the atoms are allowed to have distinct charges and potentials. It makes use of the supercells that contain hundreds of atoms. The Madelung potentials at all sites are calculated exactly. The present calculations demonstrate the advantages of the PCPA over the CPA in...
Show moreThe Polymorphous Coherent Approximation (PCPA) plays the central role in this study. The PCPA represents an extension of the Coherent Potential Approximation (CPA) in the sense that it treats an alloy model in which all of the atoms are allowed to have distinct charges and potentials. It makes use of the supercells that contain hundreds of atoms. The Madelung potentials at all sites are calculated exactly. The present calculations demonstrate the advantages of the PCPA over the CPA in explaining experiments that depend critically on the charge transfer in an alloy.
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Date Issued: 2003
PURL: http://purl.flvc.org/fau/fd/FADT12029
Subject Headings: Physics, Condensed Matter
Format: Document (PDF)

Title: Epitaxial bain paths and metastable phases of tetragonal iron and manganese.
Creator: Ma, Hong, Florida Atlantic University, Charles E. Schmidt College of Science, Department of Physics
Abstract/Description: Epitaxial Bain paths and metastable states of tetragonal Fe and Mn have been studied by first-principles total-energy calculations using the full-potential linearized-augmented-plane-wave method. The main accomplishments are as follows. (1) We have performed the first ever EBP calculation of tetragonal antiferromagnetic (AF) Mn showing that when grown epitaxially on Pd(001), the AF Mn film is strained gamma-Mn, but grown on V(001) the film is strained delta-Mn, which could not be determined...
Show moreEpitaxial Bain paths and metastable states of tetragonal Fe and Mn have been studied by first-principles total-energy calculations using the full-potential linearized-augmented-plane-wave method. The main accomplishments are as follows. (1) We have performed the first ever EBP calculation of tetragonal antiferromagnetic (AF) Mn showing that when grown epitaxially on Pd(001), the AF Mn film is strained gamma-Mn, but grown on V(001) the film is strained delta-Mn, which could not be determined using the available crystallographic and elastic data because they were obtained from unstrained states. (2) We have calculated the EBP's of Fe at zero pressure in four magnetic phases, i.e., ferromagnetic (FM), nonmagnetic (NM), type-I antiferromagnetic (AF1), and type-II antiferromagnetic (AF2), which show that the AF2 is the phase of the bulk of epitaxial Fe films on Cu(001) and it is unstable for [110] and [010] shears in the (001) plane, but it can be stabilized by epitaxy on Cu(001). (3)We have unified and simplified the theory of elasticity under hydrostatic pressure p at zero temperature using the Gibbs free energy G, rather than the energy E. The minima of G, but not E, with respect to strains at the equilibrium structure give the zero temperature elastic constants; the stability of a phase at p is then determined by the same Born stability conditions used at p = 0 when applied to the elastic constants from G. The EBP's of FM Fe under hydrostatic pressure show that the bcc phase exists up to 1500 kbar. A bct phase is shown to come into existence at 1300 kbar and becomes stable at 1825 kbar and above. (4) Based on this dissertation research five papers have been published in refereed journals.
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Date Issued: 2002
PURL: http://purl.flvc.org/fau/fd/FADT12021
Subject Headings: Physics, Condensed Matter
Format: Document (PDF)

Title: Structural, magnetic, and electrical properties of ruthenium oxides.
Creator: Leao, Juscelino Batista, Florida Atlantic University, Neumeier, John, Charles E. Schmidt College of Science, Department of Physics
Abstract/Description: Early reports of antiferromagnetism in CaRuO3 will be discussed within the framework of our recent experiments. We have observed that slight Ru deficiency (∼4%) leads to a weak feature in the magnetic susceptibility. Temperature-dependant time-of-flight (TOF) neutron powder diffraction data revealed no long-range magnetic order in the Ruthenium deficient CaRu 0.96O3 sample. More careful analysis of magnetization data indicates that the feature in chi(T) can be attributed to a weak...
Show moreEarly reports of antiferromagnetism in CaRuO3 will be discussed within the framework of our recent experiments. We have observed that slight Ru deficiency (∼4%) leads to a weak feature in the magnetic susceptibility. Temperature-dependant time-of-flight (TOF) neutron powder diffraction data revealed no long-range magnetic order in the Ruthenium deficient CaRu 0.96O3 sample. More careful analysis of magnetization data indicates that the feature in chi(T) can be attributed to a weak ferromagnetic phase which forms below an ordering temperature of T = 147 K. This phase is destroyed with Lanthanum doping (∼2%) and annealing in reducing conditions dramatically shifts this feature. Measurements of the magnetic susceptibility versus temperature of the series Ca1-xLaxRu 0.96O3 (0 ≤ x ≤ 0.12) led to further study of CaRuO 3 and SrRuO3. The structural parameters of CaRuO 3 and SrRuO3 powder samples, obtained from neutron time-of-flight data analysis via Rietveld refinement, will be compared.
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Date Issued: 2002
PURL: http://purl.flvc.org/fcla/dt/12954
Subject Headings: Ferromagnetism, Ruthenium oxide superconductors, Rietveld method
Format: Document (PDF)

Title: Supernovae neutrinos as a probe for neutrino mass and supernovae explosion mechanism.
Creator: Gross, Robert Jason, Florida Atlantic University, Charles E. Schmidt College of Science, Department of Physics
Abstract/Description: In recent years there have been several neutrino detectors built to detect solar, atmospheric, and cosmic neutrinos. In this dissertation, we used a Monte Carlo approach to model both the SuperKamiokande (SuperK) detector in Japan, and the Sudbury Neutrino Observatory (SNO) in Canada. A neutrino flux produced by a supernova code was implemented to simulate a realistic signal. An analysis of the minimum neutrino mass which could be detected was then performed for SuperK which produced...
Show moreIn recent years there have been several neutrino detectors built to detect solar, atmospheric, and cosmic neutrinos. In this dissertation, we used a Monte Carlo approach to model both the SuperKamiokande (SuperK) detector in Japan, and the Sudbury Neutrino Observatory (SNO) in Canada. A neutrino flux produced by a supernova code was implemented to simulate a realistic signal. An analysis of the minimum neutrino mass which could be detected was then performed for SuperK which produced discrepancies for the zero tau mass case when compared to previous work using a smooth emission spectrum as the incident neutrino source. As a result, we reconstructed the neutrino parameters involved in the supernovae explosion mechanism, to correct this discrepancy and determined the minimum mass for a realistic source. The source reconstruction is also useful for empirically determining the explosion mechanism when the next galactic supernova event occurs, since at present, this mechanism is still not entirely understood.
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Date Issued: 2002
PURL: http://purl.flvc.org/fau/fd/FADT12031
Subject Headings: Physics, Astronomy and Astrophysics
Format: Document (PDF)

Title: Structural, electrical and magnetic properties of transition metal nickel oxides.
Creator: Wu, Guoqing, Florida Atlantic University, Charles E. Schmidt College of Science, Department of Physics
Abstract/Description: Neutron powder diffraction, high pressure, magnetic susceptibility, and heat capacity measurements, as well as x-ray powder diffraction and iodometric titration, have been conducted on transition metal nickel oxides (TMOs), representative Ruddlesden-Popper (RP) phases Lan+1NinO3n+1 (n = 1, 2, ..., infinity) and hole-doped La2-xSr xNiO4 (0
Show moreNeutron powder diffraction, high pressure, magnetic susceptibility, and heat capacity measurements, as well as x-ray powder diffraction and iodometric titration, have been conducted on transition metal nickel oxides (TMOs), representative Ruddlesden-Popper (RP) phases Lan+1NinO3n+1 (n = 1, 2, ..., infinity) and hole-doped La2-xSr xNiO4 (0 < x < 1.2). The first complete study of La 2-xSrxNiO4 (0 < x < 1.2) and La n+1NinO3n+1 (n = 2 and 3) phases under high pressure is produced. Strong direct experimental evidence for polaron dominated electrical conduction in these charge transfer (CT) gap La2-xSr xNiO4 compounds is provided. Temperature evolution of the crystal structure of La2-xSrxNiO4 (x = 1/4 and 1/3) is revealed through neutron powder diffraction, structural relationships among n = 1, 2, and 3 phases are exhibited, and charge density wave (CDW) in multilayer Lan+1NinO3n+1 phases is strongly suggested. No superconductivity is observed at pressures up to 1.6 GPa and temperatures down to 4.2 K.
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Date Issued: 2002
PURL: http://purl.flvc.org/fcla/dt/11997
Subject Headings: Physics, Condensed Matter
Format: Document (PDF)

Title: Statistical physics for materials classification.
Creator: Lassalle, Hugues Jean, Florida Atlantic University, Charles E. Schmidt College of Science, Department of Physics
Abstract/Description: Genetic algorithms (GA) and clustering techniques are used to study and classify materials. An analysis of the convergence speed of GA is carried out using advanced probability theory and random walk concepts. The determination of the ground-state of multicomponent alloys and Ising models with long-range interactions is accomplished using a genetic algorithm. A new GA operator, the domain-flip, is introduced and its efficiency is compared to that of traditional GA operators, crossover and...
Show moreGenetic algorithms (GA) and clustering techniques are used to study and classify materials. An analysis of the convergence speed of GA is carried out using advanced probability theory and random walk concepts. The determination of the ground-state of multicomponent alloys and Ising models with long-range interactions is accomplished using a genetic algorithm. A new GA operator, the domain-flip, is introduced and its efficiency is compared to that of traditional GA operators, crossover and mutation. The domain-flip operator destroys phase-boundaries by flipping all bits of a given domain at the same time. This operator turns out to be crucial in extracting the system from low local minima. Therefore its presence is rather essential to speed up the GA convergence. A study of GA convergence in its last stages, where all chromosomes present in the population are assumed to consist of two well-ordered domains, is performed using random walk theory and probability theory. Exact expressions for the average time needed for at least one chromosome to find the ground-state are derived. Also, the probability for two chromosomes to undergo a successful crossover, meaning the result is the ground-state, are given. Finally, clustering techniques, which belong to the field of Data Mining, are applied to the classification of materials. An improved version of the widely-used clustering algorithm, K-means, is developed. A comparison of the two clustering techniques on a two-dimensional data set shows that the guide-point approach is more powerful than the K-means algorithm. The guide-point algorithm is used successfully to partition a materials data set. This clustering results in extracting useful information from the data set for which no a priori knowledge was assumed.
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Date Issued: 2002
PURL: http://purl.flvc.org/fcla/dt/11998
Subject Headings: Physics, Condensed Matter, Engineering, Materials Science, Computer Science
Format: Document (PDF)

Title: The relationship between item difficulty and discrimination indices in multiple-choice tests in a physical science course.
Creator: Hotiu, Angelica, Jordan, Robin G., Florida Atlantic University, Charles E. Schmidt College of Science, Department of Physics
Abstract/Description: We have developed a method of quantifying multiple-choice test items in an introductory physical science course in terms of the various tasks required to solve the problem. We assign a numerical level of difficulty to each task so that any question can be assigned a degree of difficulty, which is the sum of the individual levels of difficulty associated in each steps. Using the questions and results from the tests we have investigated the relationship between the degree of difficulty of each...
Show moreWe have developed a method of quantifying multiple-choice test items in an introductory physical science course in terms of the various tasks required to solve the problem. We assign a numerical level of difficulty to each task so that any question can be assigned a degree of difficulty, which is the sum of the individual levels of difficulty associated in each steps. Using the questions and results from the tests we have investigated the relationship between the degree of difficulty of each question and the corresponding discrimination index. Our results indicate that as the degree of difficulty increases so does the capability of the item to discriminate between students with different abilities. There is a maximum degree of difficulty beyond which the discrimination starts to decrease. At that point, test items become too difficult. Thus, it should be possible in future to design items that will provide optimum discrimination.
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Date Issued: 2006
PURL: http://purl.flvc.org/fau/fd/FA00000766
Subject Headings: Decision making, Curriculum planning, Examinations--Scoring, Educational tests and measurements, Universities and colleges--United States--Examinations--Design and construction
Format: Document (PDF)

Title: ELLIPTICA: A NEW PSEUDOSPECTRAL CODE FOR THE CONSTRUCTION OF INITIAL DATA.
Creator: Rashti, Alireza, Tichy, Wolfgang, Florida Atlantic University, Department of Physics, Charles E. Schmidt College of Science
Abstract/Description: Unveiling the secrets of gravity necessitates numerical relativity simulations of gravitational systems, as observations made by gravitational wave detectors expect an interpretation. In the other hand, these numerical simulations require physical and constraint-satisfying initial data. Therefore, the accuracy of simulations go hand in hand with the accuracy of initial data. As such, constructing accurate initial data is an indispensable task and it is the very subject of this dissertation....
Show moreUnveiling the secrets of gravity necessitates numerical relativity simulations of gravitational systems, as observations made by gravitational wave detectors expect an interpretation. In the other hand, these numerical simulations require physical and constraint-satisfying initial data. Therefore, the accuracy of simulations go hand in hand with the accuracy of initial data. As such, constructing accurate initial data is an indispensable task and it is the very subject of this dissertation. Here, we present the newly developed pseudospectral code Elliptica, an infrastructure for construction of initial data for various binary and single gravitational systems of all kinds. The elliptic equations under consideration are solved on a single spatial hypersurface of the spacetime manifold. Using coordinate maps, the hypersurface is covered by patches whose boundaries can adapt to the surface of the compact objects. To solve elliptic equations with arbitrary boundary condition, Elliptica deploys a Schur complement domain decomposition method with a direct solver. In this version, we use cubed sphere coordinate maps and the fields are expanded using Chebyshev polynomials of the first kind. Here, we explain the building blocks of Elliptica and the initial data construction algorithm for black hole-neutron star binary systems. We perform convergence tests and evolve the data to validate our results. Within our framework, the neutron star can reach spin values close to breakup with arbitrary direction, while the black hole can have arbitrary spin with dimensionless spin magnitude ~ 0.8.
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Date Issued: 2022
PURL: http://purl.flvc.org/fau/fd/FA00014006
Subject Headings: Gravitational waves, Elliptic functions, Neutron stars, Black holes (Astronomy)
Format: Document (PDF)

Title: Radiation Induced Injury of Hepatocellular Carcinoma, IMRT vs SBRT.
Creator: Feghhi, Touhid, Pella, Silvia, Florida Atlantic University, Department of Physics, Charles E. Schmidt College of Science
Abstract/Description: Hepatocellular carcinoma is currently one of the most fatal cancers in the world. The routine treatment for this type of cancer consists of surgery, chemotherapy, and finally radiation therapy. Recent advancements in technology have enabled us to deliver highly conformed dose to planning target volume. Two of these methods are Intensity modulated Radiation Therapy (IMRT) and Stereotactic Body Radiation Therapy (SBRT). The difference between these two methods is that in the SBRT high radiation...
Show moreHepatocellular carcinoma is currently one of the most fatal cancers in the world. The routine treatment for this type of cancer consists of surgery, chemotherapy, and finally radiation therapy. Recent advancements in technology have enabled us to deliver highly conformed dose to planning target volume. Two of these methods are Intensity modulated Radiation Therapy (IMRT) and Stereotactic Body Radiation Therapy (SBRT). The difference between these two methods is that in the SBRT high radiation dose per fraction is delivered, but smaller number of fractions which renders better tumor control probability. However, better tumor control comes at the price of complications and radiation induced liver damage. In this work, we compare the outcome of radiation with regards to the probability of radiation damage to the liver after IMRT and SBRT. For this purpose, we analyzed 10 anonymized patients’ data with liver cancer, and we made two similar treatment plans for them. The difference in two plans is dose per fraction and total dose. After optimizing the treatments and calculating the dose volume histogram, we found the effective volume of the liver being irradiated. Finally, this effective volume and the corresponding dose were used to show that SBRT has the advantage of better tumor control probability at the cost of higher probability of complications.
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Date Issued: 2022
PURL: http://purl.flvc.org/fau/fd/FA00014070
Subject Headings: Carcinoma, Hepatocellular, Radiotherapy--Adverse effects, Radiotherapy, Intensity-Modulated, Stereotactic Body Radiation Therapy
Format: Document (PDF)

Title: DEVELOPMENT OF BROADBAND QUANTUM TECHNOLOGY AND OPTIMAL DISCRIMINATION OF QUANTUM CORRELATIONS.
Creator: Rezaei, Tahereh, Kwiat, Paul G., Florida Atlantic University, Department of Physics, Charles E. Schmidt College of Science
Abstract/Description: In this effort, we present progress toward demonstrating a Decoy-State Quantum Key Distribution (QKD) source based on a polarization-modulator and a wavelength-stable attenuated pulsed laser. A three-state QKD protocol is achieved by preparing particular quantum polarization states. The polarization-modulator-based QKD source improves security by removing several sources of side-channel attacks that exist when multiple sources are used to generate different QKD states. Here we present a QKD...
Show moreIn this effort, we present progress toward demonstrating a Decoy-State Quantum Key Distribution (QKD) source based on a polarization-modulator and a wavelength-stable attenuated pulsed laser. A three-state QKD protocol is achieved by preparing particular quantum polarization states. The polarization-modulator-based QKD source improves security by removing several sources of side-channel attacks that exist when multiple sources are used to generate different QKD states. Here we present a QKD source design and an evaluation of critical subsystems characterized by the Quantum Bit Error Rate, Quantum State tomography, and achievable Key Rates. The QKD source is intended to operate within compact Size, Weight, and Power constraints. The Polarization-Modulator QKD source has applications in future mobile quantum networks such as Unmanned-Aerial Vehicles (UAV) and autonomous vehicles, as well as fixed fiber-based quantum networks. Quantum mechanics can produce correlations that are stronger than classically allowed. This stronger-than-the-classical correlation is the “fuel” for quantum computing. In 1991 Schumacher forwarded a beautiful geometric approach, analogous to the well-known result of Bell, to capture the non-classicality of this correlation for a singlet state. He used well-established information distance defined on an ensemble of identically–prepared states. He calculated that for certain detector settings used to measure the entangled state, the resulting geometry violated a triangle inequality —a violation that is not possible classically. This provided novel information–based on geometric Bell inequality in terms of a “covariance distance.” Here we experimentally reproduce his construction and demonstrate a definitive violation for a Bell state of two photons based on the usual spontaneous parametric down-conversion in a paired BBO crystal. The state we produced had visibility of Vad = 0.970}0.012. We discuss generalizations to higher dimensional multipartite quantum states.
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Date Issued: 2022
PURL: http://purl.flvc.org/fau/fd/FA00014102
Subject Headings: Quantum cryptography, Quantum optics, Quantum mechanics
Format: Document (PDF)

Title: COMPARATIVE PHARMACOKINETICS, BIODISTRIBUTION AND DOSIMETRY OF 212Pb (ALPHA-EMITTER) LABELED ANTIBODY VS PEPTIDE VS SMALL MOLECULE.
Creator: Moshiri, Nader Sedeh, Leventouri, Theodora, Florida Atlantic University, Department of Physics, Charles E. Schmidt College of Science
Abstract/Description: With the advent of newly and more reliably designed targeted therapy methods in the past several years, targeted radionuclide therapy has attracted more attentions around the world as a more reliable treatment modality in combination with other well established traditional cancer treatments i.e., external beam radiotherapy and chemotherapy. Alpha particles have a high relative biological effectiveness (RBE) due to their high linear energy transfer (LET). However, to utilize them for...
Show moreWith the advent of newly and more reliably designed targeted therapy methods in the past several years, targeted radionuclide therapy has attracted more attentions around the world as a more reliable treatment modality in combination with other well established traditional cancer treatments i.e., external beam radiotherapy and chemotherapy. Alpha particles have a high relative biological effectiveness (RBE) due to their high linear energy transfer (LET). However, to utilize them for therapeutic purposes, precise human body dosimetry calculation is required. The measurement of their uptake and biodistribution can be quite challenging. Also, due to the complex biology of different types of cells, their shapes and functions, there is not a simple and clear understanding of the mechanism of action that fits all. This study aims to estimate and compare the human organ dosimetry of the alpha emitter, 212Pb, from animal data assuming that it is conjugated with three different types of commonly used targeting nanoparticles. For this purpose, the pre-published animal data of three different radionuclide labeled peptide, antibody, and small molecule carriers were selected and converted to human data. Then a compartmental model was designed for each of them to fit the model to the human data with 212Pb, half-life of 10.64 hours. Once each model reached the desired fit, the area under the curves were extracted then the estimated human organ dosimetry calculations took place via the MIRD scheme. The organ dosimetry results for 212Pb + three different carriers are presented in Tables 14, 17, and 20.
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Date Issued: 2023
PURL: http://purl.flvc.org/fau/fd/FA00014215
Subject Headings: Cancer--Treatment, Lead-212, Nuclear Medicine
Format: Document (PDF)

Title: A Comparative Analysis of Monte Carlo and Collapsed Cone Dose Calculation Algorithms for Monaco 3D Treatment Plans.
Creator: Pereira, Shakeel, Kyriacou, Andreas, Florida Atlantic University, Department of Physics, Charles E. Schmidt College of Science
Abstract/Description: The Monaco treatment planning system offers three different dose calculation algorithms for use in calculating 3D treatment plans. These include Monte Carlo (MC), Collapsed Cone (CC) and the pencil beam algorithms. The aim of this study is an in-depth analysis of Monte Carlo and Collapsed Cone dose calculation methods to find the optimal parameters for clinical use for both algorithms. An end-to-end phantom with inhomogeneities was scanned and the DICOM images were imported into Monaco for...
Show moreThe Monaco treatment planning system offers three different dose calculation algorithms for use in calculating 3D treatment plans. These include Monte Carlo (MC), Collapsed Cone (CC) and the pencil beam algorithms. The aim of this study is an in-depth analysis of Monte Carlo and Collapsed Cone dose calculation methods to find the optimal parameters for clinical use for both algorithms. An end-to-end phantom with inhomogeneities was scanned and the DICOM images were imported into Monaco for contouring and planning. Treatment plans were then created in Monaco for both MC and CC using different permutations of variables for approximately 400 plans. These variables include CT Slice thickness, grid size, statistical uncertainty, and beam energy. Following planning the end-to-end phantom was then irradiated on an Elekta Linac and plans for each beam energy were created. Clinical beam data was then compared to the computed plans for each dose calculation method.
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Date Issued: 2022
PURL: http://purl.flvc.org/fau/fd/FA00014019
Subject Headings: Radiotherapy, Radiotherapy Dosage, Radiation dosimetry
Format: Document (PDF)

Title: NON-RADIOACTIVE ELEMENTS FOR PROMPT GAMMA ENHANCEMENT IN PROTON THERAPY.
Creator: Galanakou, Panagiota, Muhammad, Wazir, Florida Atlantic University, Department of Physics, Charles E. Schmidt College of Science
Abstract/Description: Intensity modulated proton beam scanning therapy allows for highly conformal dose distribution and better sparing of organ-at-risk compared to conventional photon radiotherapy, thanks to the characteristic dose deposition at depth, the Bragg Peak (BP), of protons as a function of depth and energy. However, proton range uncertainties lead to extended clinical margins, at the expense of treatment quality. Prompt Gamma (PG) rays emitted during non- elastic interactions of proton with the matter...
Show moreIntensity modulated proton beam scanning therapy allows for highly conformal dose distribution and better sparing of organ-at-risk compared to conventional photon radiotherapy, thanks to the characteristic dose deposition at depth, the Bragg Peak (BP), of protons as a function of depth and energy. However, proton range uncertainties lead to extended clinical margins, at the expense of treatment quality. Prompt Gamma (PG) rays emitted during non- elastic interactions of proton with the matter have been proposed for in-vivo proton range tracking. Nevertheless, poor PG statistics downgrade the potential of the clinical implementation of the proposed techniques. We study the insertion of the nonradioactive elements 19F, 17O, 127I in a tumor area to enhance the PG production of 4.44 MeV (P1) and 6.15 MeV (P2) PG rays emitted during proton irradiation, both correlated with the distal fall-off of the BP. We developed a novel Monte Carlo (MC) model using the TOPAS MC package. With this model, we simulated incident proton beams with energies of 75 MeV, 100 MeV and 200 MeV in co-centric cylindrical phantoms. The outer cylinder (scorer) was filled with water and the inner cylinder (simulating a tumor region inside water-equivalent body) was filled with water containing 0.1%–20% weight fractions of each of the tested elements.
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Date Issued: 2023
PURL: http://purl.flvc.org/fau/fd/FA00014222
Subject Headings: Proton Therapy, Monte Carlo method--Simulation, Gamma rays
Format: Document (PDF)

Title: A New Mechanical and Radiation Isocenter Adjustment Approach Using the Isopoint.
Creator: Irons, Tristan, Kyriacou, Andreas, Florida Atlantic University, Department of Physics, Charles E. Schmidt College of Science
Abstract/Description: The Winston-Lutz has been the standard test for isocenter convergence, however, any adjustments needed – in case the test fails – are time consuming since the source of error is not readily available from the results. Isopoint by the Aktina Medical company has been developed to address this problem via decoupling the mechanical from the radiation isocenter and providing the user with information that was inaccessible before. The focus of this research is to perform optimization of the...
Show moreThe Winston-Lutz has been the standard test for isocenter convergence, however, any adjustments needed – in case the test fails – are time consuming since the source of error is not readily available from the results. Isopoint by the Aktina Medical company has been developed to address this problem via decoupling the mechanical from the radiation isocenter and providing the user with information that was inaccessible before. The focus of this research is to perform optimization of the isocenter by using the Isopoint and to confirm the validity of its results, as well as to find how much time is saved via this new technology. The data for this project was collected on a 2012 Elekta Synergy, a Varian 21ix, and a 2021 Elekta Versa through partnership with GenesisCare. Our findings indicate that the Isopoint will allow for more accurate and speedy adjustments of the LINAC (Linear Accelerator) and will be integral in the future of this field.
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Date Issued: 2023
PURL: http://purl.flvc.org/fau/fd/FA00014259
Subject Headings: Medical physics
Format: Document (PDF)

Title: COMPUTATIONAL ASPECTS OF QUANTUM GRAVITY: NUMERICAL METHODS IN SPINFOAM MODELS.
Creator: Qu, Dongxue, Han, Muxin, Florida Atlantic University, Department of Physics, Charles E. Schmidt College of Science
Abstract/Description: Quantum Gravity attempts to unify general relativity (GR) and quantum theory, and is one of the challenging research areas in theoretical physics. LQG is a background-independent and non-perturbative approach towards the theory of quantum gravity. The spinfoam formulation gives the covariant path integral formulation of LQG. The spinfoam amplitude plays a crucial role in the spinfoam formulation by defining the transition amplitude of covariant LQG. It is particularly interesting for testing...
Show moreQuantum Gravity attempts to unify general relativity (GR) and quantum theory, and is one of the challenging research areas in theoretical physics. LQG is a background-independent and non-perturbative approach towards the theory of quantum gravity. The spinfoam formulation gives the covariant path integral formulation of LQG. The spinfoam amplitude plays a crucial role in the spinfoam formulation by defining the transition amplitude of covariant LQG. It is particularly interesting for testing the semiclassical consistency of LQG, because of the connection between the semiclassical approximation of path integral and the stationary phase approximation. The recent semiclassical analysis reveals the interesting relation between spinfoam amplitudes and the Regge calculus, which discretizes GR on triangulations. This relation makes the semiclassical consistency of covariant LQG promising. The spinfoam formulation also provides ways to study the n-point functions of quantum-geometry operators in LQG. Despite the novel and crucial analytic results in the spinfoam formulation, the computational complexity has been obstructed further explorations in spinfoam models. Nevertheless, numerical approaches to spinfoams open new windows to circumvent this obstruction. There has been enlightening progress on numerical computation of the spinfoam amplitudes and the two-point function. The numerical technology should expand the toolbox to investigate LQG.
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Date Issued: 2022
PURL: http://purl.flvc.org/fau/fd/FA00013878
Subject Headings: Quantum gravity, Quantum theory, Quantum gravity--Mathematics, Theoretical physics
Format: Document (PDF)

Title: DETECTION AND CATEGORIZATION OF LUNG CANCER USING CONVOLUTIONAL NEURAL NETWORK.
Creator: Mostafanazhad, Shahabeddin Aslmarand, Muhammad, Wazir, Florida Atlantic University, Department of Physics, Charles E. Schmidt College of Science
Abstract/Description: Medical professionals use CT images to get information about the size, shape, and location of any lung nodules. This information will help radiologist and oncologist to identify the type of cancer and create a treatment plan. However, most of the time, the diagnosis regarding the types of lung cancer is error-prone and time-consuming. One way to address these problems is by using convolutional neural networks. In this Thesis, we developed a convolutional neural network that can detect...
Show moreMedical professionals use CT images to get information about the size, shape, and location of any lung nodules. This information will help radiologist and oncologist to identify the type of cancer and create a treatment plan. However, most of the time, the diagnosis regarding the types of lung cancer is error-prone and time-consuming. One way to address these problems is by using convolutional neural networks. In this Thesis, we developed a convolutional neural network that can detect abnormalities in lung CT scans and further categorize the abnormalities to benign, malignant adenocarcinoma and malignant squamous cell carcinoma. Our network is based on DenseNet, which utilizes dense connections between layers (dense blocks), so that all layers are connected. Because of all layers being connected, different layers can reuse features from previous layers which speeds up the process and make this network computationally efficient. To retrain this network we used CT images for 314 patients (over 1500 CT images) consistent of 42 Lung Adenocarcinoma and 78 Squamous Cell Carcinoma, 118 Non cancer and 76 benign were acquired from the National Lung Screening Trial (NLST). These images were divided to two categories of Training and Validation with 70% being training dataset and 30% as validation dataset. We trained our network on Training dataset and then checked the accuracy of our model using the validation dataset. Our model was able to categorize lung cancer with an accuracy of 88%. Afterwards we calculated the the confusion matrix, Precision (Sensitivity), Recall (Positivity) and F1 score of our model for each category. Our model is able to classify Normal CT images with Normal Accuracy of 89% Precision of 94% and F1 score of 93%. For benign nodules Accuracy was 92% precision of 97% and F1 score 86%, while for Adenocarcinoma and squamous cell cancer the Accuracy was 98% and 93%, Precision 85% and 84% and F1 score 92% and 86.9%. The relatively high accuracy of our model shows that convolutional neural networks can be a valuable tool for the classification of lung cancer, especially in a small city or underdeveloped rural hospital settings and can play a role in achieving healthcare equality.
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Date Issued: 2022
PURL: http://purl.flvc.org/fau/fd/FA00013965
Subject Headings: Lungs--Cancer, Neural networks (Computer science), Tomography, X-Ray Computed
Format: Document (PDF)

Title: MODIFIED f(R) THEORY OF GRAVITY: AN ALTERNATIVE GRAVITY THEORY.
Creator: Saiedi, Hamidreza, Wille, Luc T., Florida Atlantic University, Department of Physics, Charles E. Schmidt College of Science
Abstract/Description: Through the variational principle, we review the gravitational field equations in Einstein gravity and modified f(R) gravity theories. Metric and Palatini formalisms are two different approaches that are employed to obtain the field equations in the context of f(R) theory of gravity. In this framework, we attempt to investigate the energy conditions in Friedmann-Lemaitre-Robertson-Walker (FLRW) metric using the Raychaudhuri equation. Then, we focus on wormhole geometries and their...
Show moreThrough the variational principle, we review the gravitational field equations in Einstein gravity and modified f(R) gravity theories. Metric and Palatini formalisms are two different approaches that are employed to obtain the field equations in the context of f(R) theory of gravity. In this framework, we attempt to investigate the energy conditions in Friedmann-Lemaitre-Robertson-Walker (FLRW) metric using the Raychaudhuri equation. Then, we focus on wormhole geometries and their thermodynamics behavior in Palatini and metric versions of modified f(R) gravity, separately. To violate the null and the weak energy conditions, wormhole spacetimes need an exotic matter. It has been shown that in f(R) gravity the matter threading the wormholes serves the energy conditions, and it is the derivative terms of the higher order curvature that may be explained as a gravitational fluid, that supports these geometries. Therefore, in f(R) gravity theory it is not required to introduce exotic matter in order to have traversable wormholes. In the framework of metric and Palatini f(R) gravity, we investigate the thermodynamic properties of evolving wormholes. We obtain an expression for the variation of the total entropy to discuss the thermodynamic behavior of wormhole spacetimes. The investigation has been extended to the apparent and event horizons. Eventually, we apply the radius of these horizons to determine the validity of the generalized second law of thermodynamics. This law states that the rate of change of total entropy is positive.
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Date Issued: 2022
PURL: http://purl.flvc.org/fau/fd/FA00013879
Subject Headings: Gravity, Gravitational fields--Mathematics, Wormholes (Physics)
Format: Document (PDF)

Title: SYMMETRY CHARGES ON REDUCED PHASE SPACE AND ASYMPTOTIC FLATNESS.
Creator: Tan, Hongwei, Han, Muxin, Florida Atlantic University, Department of Physics, Charles E. Schmidt College of Science
Abstract/Description: Though general relativity (GR) is proven to be a successful theory in describing the macroscopical nature of our universe, it still has several problems to be resolved. One of them is known as the time problem of GR. GR is a pure constraint theory, and the time evolution of the system is a gauge transformation, without carrying any physical information. One potential resolution to this issue is the relational formalism, which considers the dynamics of a material frame by coupling it to...
Show moreThough general relativity (GR) is proven to be a successful theory in describing the macroscopical nature of our universe, it still has several problems to be resolved. One of them is known as the time problem of GR. GR is a pure constraint theory, and the time evolution of the system is a gauge transformation, without carrying any physical information. One potential resolution to this issue is the relational formalism, which considers the dynamics of a material frame by coupling it to gravity. This approach allows for constructing gauge invariant observables and subsequent quantization. One realization of the relational formalism is the Brown-Kuchaˇr formalism. In this formalism, the gravity couples Brown-Kuchaˇr dust fields, and the Brown-Kuchaˇr dust fields play the roles as a family of observers. Then, one can introduce a gauge fixing scheme to the system and construct gauge invariant observables (Dirac observables) in the reduced phase Space. The probe time of the dust plays the role as the physical time of each point of the spacetime. In this thesis, we consider the Brown-Kuchaˇr formalism in an asymptotically flat background. A set of boundary conditions for the asymptotic flatness are formulated for Dirac observables on the reduced phase space. We compute the boundary term of the physical Hamiltonian, which is identical to the ADM mass. We construct a set of the symmetry charges on the reduced phase space, which encompass both the bulk terms and the boundary terms are conserved by the physical Hamiltonian evolution. The symmetry charges generate transformations preserving the asymptotically flat boundary conditions. Under the reduced-phase space Poisson bracket, the symmetry charges form an infinite dimensional Lie algebra AG after adding a central charge. A suitable quotient of AG is analogous to the BMS algebra at spatial infinity by Henneaux and Troessaert.
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Date Issued: 2024
PURL: http://purl.flvc.org/fau/fd/FA00014398
Subject Headings: General relativity (Physics), Physics, Space and time, Spacetime
Format: Document (PDF)

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