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 Title
 The effect of sea level rise on Juncus Roemerianus in a high nutrient environment.
 Creator
 Abbott, Cara J., Berry, Leonard, Florida Atlantic University, Charles E. Schmidt College of Science, Center for Environmental Studies
 Abstract/Description

As sea levels continue to rise, the projected damage that will ensue presents a great challenge for conservation and management of coastal ecosystems in Florida. Since Juncus roemerianus is a common marsh plant throughout Florida with unique growing characteristics that make it a popular restoration plant, this study implemented a 20 week greenhouse split plot experiment to examine the effects of sea level rise on J. roemerianus and ultimately determine its tolerance ranges to salinity and...
Show moreAs sea levels continue to rise, the projected damage that will ensue presents a great challenge for conservation and management of coastal ecosystems in Florida. Since Juncus roemerianus is a common marsh plant throughout Florida with unique growing characteristics that make it a popular restoration plant, this study implemented a 20 week greenhouse split plot experiment to examine the effects of sea level rise on J. roemerianus and ultimately determine its tolerance ranges to salinity and inundation in a high nutrient environment. Overall, salinity level and the interaction effect of salinity level and water level had the greatest effects on measured growth parameters including average mature height, maximum height, density, basal area, root length, and biomass. An inverse relationship between increasing salinity and the measured growth variables was observed with the greatest growth and survivability in 0 ppt water, survivability and reduced growth in 20 ppt water, survivability and little growth in 30 ppt water, and nearly complete senesce in 40 ppt water. This was the first laboratory study to determine the effect of 40 ppt water on J. roemerianus. Elevated water levels resulted in higher growth variables in the 20 ppt, 30 ppt, and 40 ppt treatments while inundated water levels produced higher growth variables in the 0 ppt treatment despite previous research finding inundation to have completely adverse effects on J. roemerianus. It is likely that the high nutrient environment provided for this study is the cause for this anomaly. The results of this study have major implications for the future of coastal ecosystems that are dominated by stands of J. roemerianus in South Florida and can be used in conjunction with studies on bordering marsh plants to predict shifts in the ecosystems of Florida that are responding to sea level rise scenarios.
Show less  Date Issued
 2015
 PURL
 http://purl.flvc.org/fau/fd/FA00004426
 Subject Headings
 Coastal ecology, Coastal zone management, Jucus roemerianus, Plant ecophysiology, Salt marsh ecology, Sea level
 Format
 Document (PDF)
 Title
 Human presence and sexual activity of West Indian manatees (Trichechus manatus) at Crystal River, Florida.
 Creator
 Abernathy, Barbara E., Florida Atlantic University, Adams, Ralph M., Charles E. Schmidt College of Science, Department of Biological Sciences
 Abstract/Description

Freeranging manatees wintering in the warm water of Kings Spring, Crystal River, Florida, were studied to determine the relationships between human presence and their sexual behaviors. The manatees of Crystal River are unique because of frequent exposure to large numbers of snorkelers and divers. Quantitative knowledge of such relationships are becoming increasingly important as preservation measures are reviewed to ensure that the human activity at the Spring does not pose a threat to...
Show moreFreeranging manatees wintering in the warm water of Kings Spring, Crystal River, Florida, were studied to determine the relationships between human presence and their sexual behaviors. The manatees of Crystal River are unique because of frequent exposure to large numbers of snorkelers and divers. Quantitative knowledge of such relationships are becoming increasingly important as preservation measures are reviewed to ensure that the human activity at the Spring does not pose a threat to manatee reproduction. Focal animal sampling provided sexual behavioral data of manatees during randomly selected 30 min sampling periods. Frequencies of four of the eight observed sexual behaviors increased significantly in the presence of humans. Differences were also found between the types of sexual behaviors manatees exhibited while interacting with conspecifics, and the behaviors displayed with humans. Manatees appeared to be hyperstimulated in the presence of humans. No conclusions could be made about the effects of human interaction on manatee reproductive success because of the relatively short duration of the study.
Show less  Date Issued
 1995
 PURL
 http://purl.flvc.org/fcla/dt/15159
 Subject Headings
 West Indian manateeSexual behaviorFlorida, ManateesSexual behaviorFlorida
 Format
 Document (PDF)
 Title
 Bayesian approach to an exponential hazard regression model with a change point.
 Creator
 Abraha, Yonas Kidane, Qian, Lianfen, Florida Atlantic University, Charles E. Schmidt College of Science, Department of Mathematical Sciences
 Abstract/Description

This thesis contains two parts. The first part derives the Bayesian estimator of the parameters in a piecewise exponential Cox proportional hazard regression model, with one unknown change point for a right censored survival data. The second part surveys the applications of change point problems to various types of data, such as longterm survival data, longitudinal data and time series data. Furthermore, the proposed method is then used to analyse a real survival data.
 Date Issued
 2014
 PURL
 http://purl.flvc.org/fau/fd/FA00004013
 Subject Headings
 Bayesian statistical decision theory, Mathematical statistics, Multivariate analysis  Data processing
 Format
 Document (PDF)
 Title
 On the spectrum of positive operators.
 Creator
 Acharya, Cheban P., Charles E. Schmidt College of Science, Department of Mathematical Sciences
 Abstract/Description

Spectral theory, mathematical system theory, evolution equations, differential and difference equations [electronic resource] : 21st International Workshop on Operator Theory and Applications, Berlin, July 2010.It is known that lattice homomorphisms and Gsolvable positive operators on Banach lattices have cyclic peripheral spectrum (See [17]). In my thesis I prove that positive contractions whose spectral radius is 1 on Banach lattices with increasing norm have cyclic peripheral point...
Show moreSpectral theory, mathematical system theory, evolution equations, differential and difference equations [electronic resource] : 21st International Workshop on Operator Theory and Applications, Berlin, July 2010.It is known that lattice homomorphisms and Gsolvable positive operators on Banach lattices have cyclic peripheral spectrum (See [17]). In my thesis I prove that positive contractions whose spectral radius is 1 on Banach lattices with increasing norm have cyclic peripheral point spectrum. I also prove that if the Banach lattice is a K B space satisfying the growth conditon and º is an eigenvalue of a positive contraction T such that [º] = 1, then 1 is also an eigenvalue of T as well as an eigenvalue of T¨, the dual of T. I also investigate the conditions on contraction operators on Hilbert lattices and ALspaces which guanantee that 1 is an eigenvalue. As we know from [17], if T : EE is a positive ideal irreducible operator on E such the r (T) = 1 is a pole of the resolvent R(º, T), then r (T) is simple pole with dimN (T r(T)I) and ºper(T) is cyclic. Also all points of ºper(T) are simple poles of the resolvent R(º,T). SInce band irreducibility and ºorder continuity do not imply ideal irreducibility [2], we prove the analogous results for band irreducible, ºorder continuous operators.
Show less  Date Issued
 2012
 PURL
 http://purl.flvc.org/FAU/3359288
 Subject Headings
 Operator theory, Evolution equations, Banach spaces, Linear topological spaces, Functional analysis
 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 meanfield 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 meanfield 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 oneloop 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 oneloop 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 oneloop 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
 Curve shortening in secondorder lagrangian.
 Creator
 Adams, Ronald Edward, Kalies, William D., Florida Atlantic University, Charles E. Schmidt College of Science, Department of Mathematical Sciences
 Abstract/Description

A secondorder Lagrangian system is a generalization of a classical mechanical system for which the Lagrangian action depends on the second derivative of the state variable. Recent work has shown that the dynamics of such systems c:an be substantially richer than for classical Lagrangian systems. In particular, topological properties of the planar curves obtained by projection onto the lowerorder derivatives play a key role in forcing certain types of dynamics. However, the application of...
Show moreA secondorder Lagrangian system is a generalization of a classical mechanical system for which the Lagrangian action depends on the second derivative of the state variable. Recent work has shown that the dynamics of such systems c:an be substantially richer than for classical Lagrangian systems. In particular, topological properties of the planar curves obtained by projection onto the lowerorder derivatives play a key role in forcing certain types of dynamics. However, the application of these techniques requires an analytic restriction on the Lagrangian that it satisfy a twist property. In this dissertation we approach this problem from the point of view of curve shortening in an effort to remove the twist condition. In classical curve shortening a family of curves evolves with a velocity which is normal to the curve and proportional to its curvature. The evolution of curves with decreasing action is more general, and in the first part of this dissertation we develop some results for curve shortening flows which shorten lengths with respect to a Finsler metric rather than a Riemannian metric. The second part of this dissertation focuses on analytic methods to accommodate the fact that the Finsler metric for secondorder Lagrangian system has singularities. We prove the existence of simple periodic solutions for a general class of systems without requiring the twist condition. Further; our results provide a frame work in which to try to further extend the topological forcing theorems to systems without the twist condition.
Show less  Date Issued
 2014
 PURL
 http://purl.flvc.org/fau/fd/FA00004175, http://purl.flvc.org/fau/fd/FA00004175
 Subject Headings
 Critical point theory (Mathematical analysis), Differentiable dynamical systems, Geometry,Differential, Lagrange equations, Lagrangian functions, Mathematical optimization, Surfaces of constant curvature
 Format
 Document (PDF)
 Title
 Computing automorphism groups of projective planes.
 Creator
 Adamski, Jesse Victor, Magliveras, Spyros S., Charles E. Schmidt College of Science, Department of Mathematical Sciences
 Abstract/Description

The main objective of this thesis was to find the full automorphism groups of finite Desarguesian planes. A set of homologies were used to generate the automorphism group when the order of the plane was prime. When the order was a prime power Pa,a ≠ 1 the Frobenius automorphism was added to the set of homologies, and then the full automorphism group was generated. The Frobenius automorphism was found by using the planar ternary ring derived from a coordinatization of the plane.
 Date Issued
 2013
 PURL
 http://purl.flvc.org/fau/fd/FA0004000
 Subject Headings
 Combinatorial group theory, Finite geometrics, Geometry, Projective
 Format
 Document (PDF)
 Title
 Effects of midincubation egg movement on loggerhead (Caretta caretta) turtle hatch success and embryo development.
 Creator
 Ahles, Natasha M., Charles E. Schmidt College of Science, Department of Biological Sciences
 Abstract/Description

Due to an emergency status dune restoration project following Subtropical Storm Andrea in 2007 on Singer Island, Florida, nests needed to be moved during early to midincubation. Nesting success was compared between those moved midincubation, moved within 12h to either a native sand incubation area or a renourished sand incubation area, and those left insitu. Nests moved within 12h to the native sand had a significantly larger proportion of pipped hatchlings. Nests moved midincubation had...
Show moreDue to an emergency status dune restoration project following Subtropical Storm Andrea in 2007 on Singer Island, Florida, nests needed to be moved during early to midincubation. Nesting success was compared between those moved midincubation, moved within 12h to either a native sand incubation area or a renourished sand incubation area, and those left insitu. Nests moved within 12h to the native sand had a significantly larger proportion of pipped hatchlings. Nests moved midincubation had a significantly lower proportion of hatched eggs as well as emergent hatchlings. The stage in which embryonic development was arrested corresponded to the stage the embryos were in during the time of movement; indicating movement was the cause of death. When comparing nests moved within the initial 2.5 weeks of development to those moved after 2.5 weeks of development, there was no significant difference in hatching success.
Show less  Date Issued
 2009
 PURL
 http://purl.flvc.org/FAU/221948
 Subject Headings
 Sea turtles, Embryology, Wildlife conservation
 Format
 Document (PDF)
 Title
 Subjecting the CHIMERA supernova code to two hydrodynamic test problems, (i) Riemann problem and (ii) Point blast explosion.
 Creator
 Ahsan, Abu Salah M., Charles E. Schmidt College of Science, Department of Physics
 Abstract/Description

A Shock wave as represented by the Riemann problem and a Pointblast explosion are two key phenomena involved in a supernova explosion. Any hydrocode used to simulate supernovae should be subjected to tests consisting of the Riemann problem and the Pointblast explosion. L. I. Sedov's solution of Pointblast explosion and Gary A. Sod's solution of a Riemann problem have been rederived here from one dimensional fluid dynamics equations . Both these problems have been solved by using the idea...
Show moreA Shock wave as represented by the Riemann problem and a Pointblast explosion are two key phenomena involved in a supernova explosion. Any hydrocode used to simulate supernovae should be subjected to tests consisting of the Riemann problem and the Pointblast explosion. L. I. Sedov's solution of Pointblast explosion and Gary A. Sod's solution of a Riemann problem have been rederived here from one dimensional fluid dynamics equations . Both these problems have been solved by using the idea of Selfsimilarity and Dimensional analysis. The main focus of my research was to subject the CHIMERA supernova code to these two hydrodynamic tests. Results of CHIMERA code for both the blast wave and Riemann problem have then been tested by comparing with the results of the analytic solution.
Show less  Date Issued
 2008
 PURL
 http://purl.flvc.org/FAU/172665
 Subject Headings
 Mathematical physics, Continuum mechanics, Number theory, Supernovae, Data processing, Shock waves, Fluid dynamics
 Format
 Document (PDF)
 Title
 New stereoselective reactions to form amido alkyl cn and vinyl triflate co bonds via carbocation intermediates & ultrafast silicon fluorination methodologies for applications in pet imaging.
 Creator
 Alhuniti, Mohammed, Lepore, Salvatore D., Florida Atlantic University, Charles E. Schmidt College of Science, Department of Chemistry and Biochemistry
 Abstract/Description

We report here the development of a Lewis acid catalyzed method for the dehydrative coupling of cyclic alcohols and nitriles to form amides with retention of configuration. By contrast, the formation of amides by nitrile trapping of carbocations (Ritter reaction) usually affords racemic product. The present reaction was accomplished by first converting alcohol starting materials to their corresponding chlorosulfites in situ. Even after an extensive search, only copper (II) salts were able to...
Show moreWe report here the development of a Lewis acid catalyzed method for the dehydrative coupling of cyclic alcohols and nitriles to form amides with retention of configuration. By contrast, the formation of amides by nitrile trapping of carbocations (Ritter reaction) usually affords racemic product. The present reaction was accomplished by first converting alcohol starting materials to their corresponding chlorosulfites in situ. Even after an extensive search, only copper (II) salts were able to produce the desired conversion of these chlorosulfites to amides though with low catalytic turnover. Improving the turnover without deteriorating the stereochemical outcome was eventually accomplished by a careful selection of the reagent addition sequence and through the removal of gaseous byproducts. This Ritterlike coupling reaction proceeds in good yields with secondary cyclic alcohols under mild conditions. The stereochemical outcome likely due to fast nucleophilic capture of a nonplanar carbocations (hyperconjomers) stabilized by ring hyperconjugation.
Show less  Date Issued
 2014
 PURL
 http://purl.flvc.org/fau/fd/FA00004262
 Subject Headings
 Intermediates (Chemistry), Nuclear medicine, Organometallic chemistry, Physical organic chemistry, Reaction mechanisms (Chemistry), Tomography, Emission
 Format
 Document (PDF)
 Title
 tRNA processing and quality control in bacteria.
 Creator
 Alluri, Ravi Kumar, Li, Zhongwei, Charles E. Schmidt College of Science, Department of Biomedical Science
 Abstract/Description

In this work, we report that the only exoribonuclease in M. genitalium, RNase R, is able to generate mature 3'ends. The aminoacylacceptor stem, CCA terminus and discriminator residue plays an important role in stopping RNase R digestion at the mature 3'end. Disruption of the stem causes partial or complete degradation of the pretRNA, whereas extension of the stem results in the formation of a mature 3’end. CC residues in CCA terminus and A or G residues at discriminator position are the...
Show moreIn this work, we report that the only exoribonuclease in M. genitalium, RNase R, is able to generate mature 3'ends. The aminoacylacceptor stem, CCA terminus and discriminator residue plays an important role in stopping RNase R digestion at the mature 3'end. Disruption of the stem causes partial or complete degradation of the pretRNA, whereas extension of the stem results in the formation of a mature 3’end. CC residues in CCA terminus and A or G residues at discriminator position are the most preferred residues for precise stopping of RNase R at mature 3’ end. The significance of this works shows that M. genitalium RNase R generates mature tRNA in a single step by recognizing features in the terminal domains of tRNA, a process requiring multiple RNases in most bacteria.
Show less  Date Issued
 2013
 PURL
 http://purl.flvc.org/fau/fd/FA00004174
 Format
 Document (PDF)
 Title
 EEG in preschool children and the development of empathy.
 Creator
 Almeida, Amanda N., Charles E. Schmidt College of Science, Department of Psychology
 Abstract/Description

Empathy has been shown to have many positive outcomes in individuals at every stage throughout life. It promotes sociability, helping behaviors, and can protect against the development of psychopathology. Evolutionary theorists have hypothesized that humans have a biological predisposition for empathic response. Temperament, as well as parental interaction with children, account for individual differences in empathic response levels. Much research has also looked at maternal depression as a...
Show moreEmpathy has been shown to have many positive outcomes in individuals at every stage throughout life. It promotes sociability, helping behaviors, and can protect against the development of psychopathology. Evolutionary theorists have hypothesized that humans have a biological predisposition for empathic response. Temperament, as well as parental interaction with children, account for individual differences in empathic response levels. Much research has also looked at maternal depression as a key factor in children's negative emotional responding. We used EEG to measure individual differences in children's empathic emotional responding, as well as parental interaction and its impact on empathy and prosocial development. Results show that children rated as being more sociable are more likely to show outward expressions of empathy. Also, those with greater right frontal asymmetry are more likely to assist others in a prosocial manner.
Show less  Date Issued
 2009
 PURL
 http://purl.flvc.org/FAU/228771
 Subject Headings
 Emotions in children, Parent and child, Developmental psychology, Socialization, Psychological aspects, Child development, Helping behavior in children
 Format
 Document (PDF)
 Title
 DIRECT AND INDIRECT PATHWAYS FROM LONELINESS TO PEER EXPERIENCES.
 Creator
 Altman, Robert L., Laursen, Brett, Florida Atlantic University, Department of Psychology, Charles E. Schmidt College of Science
 Abstract/Description

Loneliness is a common experience for many people (Rubenstein et al., 1979) and most lonely individuals experience a variety of comorbid disorders (Heinrich & Gullone, 2006). Adolescent loneliness is particularly problematic, due to the rapid changes that take place in the peer social world (Laursen & Hartl, 2013). Prior evidence ties loneliness to low group status and victimization (Asher & Paquette, 2003), but we do not fully understand the transmission mechanisms. A full longitudinal...
Show moreLoneliness is a common experience for many people (Rubenstein et al., 1979) and most lonely individuals experience a variety of comorbid disorders (Heinrich & Gullone, 2006). Adolescent loneliness is particularly problematic, due to the rapid changes that take place in the peer social world (Laursen & Hartl, 2013). Prior evidence ties loneliness to low group status and victimization (Asher & Paquette, 2003), but we do not fully understand the transmission mechanisms. A full longitudinal mediation design (Fritz & MacKinnon, 2012) was used to test the hypotheses that social withdrawal mediates the association from loneliness to changes in peer status and peer difficulties victimization among adolescents. Results indicated that the longitudinal associations between loneliness and peer outcomes were mediated by social withdrawal. Successful engagement with peers is vital to navigating the complex social world of adolescence, thus the results provide an impetus for aiding lonely adolescents in improving their social connections.
Show less  Date Issued
 2020
 PURL
 http://purl.flvc.org/fau/fd/FA00013590
 Subject Headings
 Loneliness, Loneliness in adolescence
 Format
 Document (PDF)
 Title
 Message authentication in an identitybased encryption scheme: 1KeyEncryptThenMAC.
 Creator
 Amento, Brittanney Jaclyn, Charles E. Schmidt College of Science, Department of Mathematical Sciences
 Abstract/Description

We present an IdentityBased Encryption scheme, 1KeyEncryptThenMAC, in which we are able to verify the authenticity of messages using a MAC. We accomplish this authentication by combining an IdentityBased Encryption scheme given by Boneh and Franklin, with an IdentityBased NonInteractive Key Distribution given by Paterson and Srinivasan, and attaching a MAC. We prove the scheme is chosen plaintext secure and chosen ciphertext secure, and the MAC is existentially unforgeable.
 Date Issued
 2010
 PURL
 http://purl.flvc.org/FAU/2796050
 Subject Headings
 Data encryption (Computer science), Public key cryptopgraphy, Public key infrastructure (Computer security)
 Format
 Document (PDF)
 Title
 Quantum Circuits for Cryptanalysis.
 Creator
 Amento, Brittanney Jaclyn, Steinwandt, Rainer, Florida Atlantic University, Charles E. Schmidt College of Science, Department of Mathematical Sciences
 Abstract/Description

Finite elds of the form F2m play an important role in coding theory and cryptography. We show that the choice of how to represent the elements of these elds can have a signi cant impact on the resource requirements for quantum arithmetic. In particular, we show how the Gaussian normal basis representations and \ghostbit basis" representations can be used to implement inverters with a quantum circuit of depth O(mlog(m)). To the best of our knowledge, this is the rst construction with...
Show moreFinite elds of the form F2m play an important role in coding theory and cryptography. We show that the choice of how to represent the elements of these elds can have a signi cant impact on the resource requirements for quantum arithmetic. In particular, we show how the Gaussian normal basis representations and \ghostbit basis" representations can be used to implement inverters with a quantum circuit of depth O(mlog(m)). To the best of our knowledge, this is the rst construction with subquadratic depth reported in the literature. Our quantum circuit for the computation of multiplicative inverses is based on the ItohTsujii algorithm which exploits the property that, in a normal basis representation, squaring corresponds to a permutation of the coe cients. We give resource estimates for the resulting quantum circuit for inversion over binary elds F2m based on an elementary gate set that is useful for faulttolerant implementation. Elliptic curves over nite elds F2m play a prominent role in modern cryptography. Published quantum algorithms dealing with such curves build on a short Weierstrass form in combination with a ne or projective coordinates. In this thesis we show that changing the curve representation allows a substantial reduction in the number of Tgates needed to implement the curve arithmetic. As a tool, we present a quantum circuit for computing multiplicative inverses in F2m in depth O(mlogm) using a polynomial basis representation, which may be of independent interest. Finally, we change our focus from the design of circuits which aim at attacking computational assumptions on asymmetric cryptographic algorithms to the design of a circuit attacking a symmetric cryptographic algorithm. We consider a block cipher, SERPENT, and our design of a quantum circuit implementing this cipher to be used for a key attack using Grover's algorithm as in [18]. This quantum circuit is essential for understanding the complexity of Grover's algorithm.
Show less  Date Issued
 2016
 PURL
 http://purl.flvc.org/fau/fd/FA00004662, http://purl.flvc.org/fau/fd/FA00004662
 Subject Headings
 Artificial intelligence, Computer networks, Cryptography, Data encryption (Computer science), Finite fields (Algebra), Quantum theory
 Format
 Document (PDF)
 Title
 INCREASING THE ACCURACY OF BINARY NEUTRON STARSIMULATIONS WITH AN IMPROVED VACUUM TREATMENT.
 Creator
 Amit Poudel, Tichy, Wolfgang, Florida Atlantic University, Department of Physics, Charles E. Schmidt College of Science
 Abstract/Description

The main purpose of this dissertation is to study the inspiral and merger of binary neutron stars. The inspiral, in such a system, is caused by the loss of energy and angular momentum that is carried away by the emitted gravitational waves. Newlyformed neutron stars, after supernova explosions, are very hot. They cool down during the hundreds of millions of years, which is needed to bring the two stars in a neutron star binary close enough together to start investigating them with numerical...
Show moreThe main purpose of this dissertation is to study the inspiral and merger of binary neutron stars. The inspiral, in such a system, is caused by the loss of energy and angular momentum that is carried away by the emitted gravitational waves. Newlyformed neutron stars, after supernova explosions, are very hot. They cool down during the hundreds of millions of years, which is needed to bring the two stars in a neutron star binary close enough together to start investigating them with numerical relativity simulations. Thus, they can be considered as fluids at zero temperature to very high accuracy, when we start numerical simulations. In this description, the stars also have a welldefined star surface, beyond which there is a true vacuum. This vacuum, outside the stars, will persist until the stars get so close that mass can be ejected due to tidal forces, and later, when they come into contact and eject streams of hot matter. To date, all current numerical relativity programs use an artificial atmosphere from the very beginning. They do this, to avoid numerical problems arising from the sharp transition of the matter region to the vacuum outside the stars. To be more precise, they take the initial data and fill all the vacuum regions with a very lowdensity zero velocity atmosphere. While this atmosphere is not physical and used only for numerical reasons, it can still influence the results of the simulations. For example, studies of merger dynamics, merger remnant, disk mass, ejecta mass, and kinetic energy of ejecta, are hampered by the presence of the artificial zero velocity lowdensity material. To avoid this problem, we have developed a new method to evolve the neutron star systems, without the need for an artificial atmosphere. We describe this method, which we call vacuum method, we present tests with it, and compare it to the conventional atmosphere method. For these tests, we first consider the evolution of stable, oscillating, and collapsing single neutron stars. We also study simulations of the inspiral and merger of binaries using both methods. We find better mass conservation in lowdensity regions and near refinement boundaries, as well as better ejecta material conservation for the new method. However, the gravitational wave predictions produced by our simulations are almost identical for both methods, since they are mainly due to the bulk motion of the stars which is not strongly affected by the presence or absence of an artificial atmosphere.
Show less  Date Issued
 2019
 PURL
 http://purl.flvc.org/fau/fd/FA00013403
 Subject Headings
 Neutron stars, Double stars, Simulations, Gravitational waves, Vacuum
 Format
 Document (PDF)
 Title
 Narcissism, perceptions of peer relationships, and targetspecific aggression in middle childhood.
 Creator
 Anderson, Chelsie., Charles E. Schmidt College of Science, Department of Psychology
 Abstract/Description

This study examined how narcissism affects preadolescent children's choices of peer targets for aggression. Based on the idea that narcissists have a grandiose sense of self that requires nourishment, we hypothesized that narcissistic children are especially likely to attack peers who threaten, or fail to nourish, their grandiose self. We assessed narcissism and the degree to which each child's aggression toward peers depended on (a) the child's perceived liking by each peer, (b) the child's...
Show moreThis study examined how narcissism affects preadolescent children's choices of peer targets for aggression. Based on the idea that narcissists have a grandiose sense of self that requires nourishment, we hypothesized that narcissistic children are especially likely to attack peers who threaten, or fail to nourish, their grandiose self. We assessed narcissism and the degree to which each child's aggression toward peers depended on (a) the child's perceived liking by each peer, (b) the child's liking of each peer, (c) each peer's actual liking of the child, and (d) the child's perceived similarity to each peer. Participants were 197 children in the fourth through eighth grades at a university school. Narcissism predicted the four types of targetspecific aggression in disparate ways for boys and girls. Narcissistic boys were especially likely to direct aggression toward male peers whom (a) they perceived as disliking them, (b) they disliked, and (c) they perceived as dissimilar to themselves. Narcissistic girls were especially likely to attack female peers whom they perceived as similar to themselves. Narcissism may enhance different motives for boys and girls in samesex peer relatinships. We propose that narcissism enhances investment in status and rivalry amoung girls while enhancing the motive to attack dissimilar peers among boys.
Show less  Date Issued
 2012
 PURL
 http://purl.flvc.org/FAU/3356886
 Subject Headings
 Identity (Psychology) in children, Adjustment (Psychology), Sex differences (Psychology), Affect (Psychology), Aggressiveness, Narcissism, Philosophy, Interpersonal relations in children, Social interaction in children, Selfesteem in children
 Format
 Document (PDF)
 Title
 Geochemical conditions and groundwatersurface interactions within a municipal well field in MiamiDade County, Florida.
 Creator
 Antolino, Dominick J., Charles E. Schmidt College of Science, Department of Geosciences
 Abstract/Description

This thesis presents a preliminary study on geochemical conditions within the Snapper Creek well field in MiamiDade County, Florida. The study investigates the background groundwater chemistry within the Biscayne aquifer in order to provide information on the geochemical processes and waterrock interactions within the study site. In conjunction with hydraulic gradient information, major ion chemistry and deuterium and oxygen18 data were used as environmental tracers to help describe the...
Show moreThis thesis presents a preliminary study on geochemical conditions within the Snapper Creek well field in MiamiDade County, Florida. The study investigates the background groundwater chemistry within the Biscayne aquifer in order to provide information on the geochemical processes and waterrock interactions within the study site. In conjunction with hydraulic gradient information, major ion chemistry and deuterium and oxygen18 data were used as environmental tracers to help describe the groundwatersurface water interactions between the well field and the Snapper Creek canal. Hydrologic data show there is potential for natural groundwater recharge from the canal within the shallow flow zone of the Biscayne aquifer and chemical data show evidence of canalgroundwater mixing within this zone. The limitations for the v environmental tracers employed within the study are addressed, as well as recommendations for further research involving natural geochemical tracers and groundwatersurface water interactions near municipal well fields. This study was part of a larger effort being conducted by the U.S. Geological Survey in order to assess municipal well field pumping effects on the Snapper Creek (C2) canal.
Show less  Date Issued
 2011
 PURL
 http://purl.flvc.org/FAU/3329830
 Subject Headings
 Groundwater flow, Simulations, Groundwater flow, Hydrogeology, Aquifiers
 Format
 Document (PDF)
 Title
 Firstprinciples study of metastable phases and structural anomalies of Fe, Al, Zn, and Cd under pressure.
 Creator
 Apostol, Florin., Florida Atlantic University, Charles E. Schmidt College of Science, Department of Physics
 Abstract/Description

Stable and metastable phases of Fe and Al and structural anomalies of Zn and Cd have been studied by epitaxial Bain path (EBP) and minimum path (MNP) firstprinciples procedures, based on finding equilibrium structures from minimizing the Gibbs free energy G with respect to structure at a given hydrostatic pressure p and temperature T . The main accomplishments are as follows. (1) This dissertation illustrates the effectiveness of the MNP procedure for finding stable and metastable phases of...
Show moreStable and metastable phases of Fe and Al and structural anomalies of Zn and Cd have been studied by epitaxial Bain path (EBP) and minimum path (MNP) firstprinciples procedures, based on finding equilibrium structures from minimizing the Gibbs free energy G with respect to structure at a given hydrostatic pressure p and temperature T . The main accomplishments are as follows. (1) This dissertation illustrates the effectiveness of the MNP procedure for finding stable and metastable phases of an element by studying four Bravais phases of Fe including bodycentered tetragonal (bct), bodycentered cubic (bcc), facecentered cubic (fcc) and rhombohedral (rh) phases. The determination of absolute stability using MNP is new; MNP finds all the elastic constants cjj of a given state and the eigenvalues of the elastic constants matrix, which determine the absolute stability of the state., (2) We have extended our search for stable and metastable phases from zero temperature to finite temperature, which requires the calculations of the Debye temperature Od from cjj in the case of no symmetry. The Debye theory is modified by introducing a parameter B2 that gives the fraction of the full Debye zeropoint energy possessed by the actual dispersive mode frequencies. The value of the lattice parameter of fcc Al at low temperatures,a(T) , is shown to be accurately determined by the modified Debye theory of lattice vibrations and firstprinciples total energy band calculations with the MNP procedure. (3) The existence of structural anomalies in hcp Zn and Cd has been shown from firstprinciples totalenergy calculations using WIEN2k with the EBP procedure., Evaluation of the pressure dependence of various elastic quantities which are much more sensitive to the anomaly shows that the anomalies in hcp Zn and hcp Cd exist over a considerable range of pressure; several abrupt changes in the electron distribution are thereby indicated in that pressure range. (4) Calculations on the zonecenter transverse optical phonon frequencies Vto(p) of hcp Zn, which found oscillatory behavior of Vto(p) in the pressure range of the anomalies, support the conclusions made in (3) on the structural anomalies. Based on this dissertation research four papers have been published in refereed journals.
Show less  Date Issued
 2008
 PURL
 http://purl.flvc.org/FAU/186334
 Subject Headings
 Epitaxy, Mathematical physics, Metals, Electric properties, Phase transformation (Statistical physics)
 Format
 Document (PDF)
 Title
 THE CRITICAL ROLE OF INTERACTIONS BETWEEN ECOLOGICAL FOUNDATION SPECIES IN STRUCTURING A MANGROVE COMMUNITY.
 Creator
 AquinoThomas, Jessene, Brooks, W. Randy, Proffitt, C. Edward, Florida Atlantic University, Department of Biological Sciences, Charles E. Schmidt College of Science
 Abstract/Description

The main objective of this research was to analyze how well my proposed Foundation Species Interaction model explained the benthic communities found on red mangrove (Rhizophora mangle) prop roots. This research investigated the connections between the primary foundation species (mangroves), the dominant secondary foundations species (oysters, sponges, and barnacles), and the resulting biodiversity in order to understand the temporal and spatial variability of the ecosystems at different...
Show moreThe main objective of this research was to analyze how well my proposed Foundation Species Interaction model explained the benthic communities found on red mangrove (Rhizophora mangle) prop roots. This research investigated the connections between the primary foundation species (mangroves), the dominant secondary foundations species (oysters, sponges, and barnacles), and the resulting biodiversity in order to understand the temporal and spatial variability of the ecosystems at different community levels. Chapter 1 was dedicated to explaining my change in ecological theory, the Foundation Species Interaction model. The interactions included in the model between the foundations species that were examined were the mutualistic (+, +), commensal (+, 0), and parasitic (+, ) interactions. Chapter 2 focused on exploration of the mangrove ecosystem in Southeast Florida and establishing where the secondary foundation species and prop root epibionts where found along the latitudinal gradient. The survey investigated the connections between mangroves, the dominant secondary foundations species (e.g. oysters, sponges, and barnacles), and the resulting biodiversity to understand the temporal and spatial variability of the ecosystems at different community levels. Chapter 3 was dedicated to testing the Foundation Species Interaction model’s ability to predict the biodiversity along the latitudinal gradient of the survey. The difference in mangrove prop root communities were largely explained by where the communities laid along the latitudinal gradient and by secondary foundation species presence. The shift from one foundation species to another had sizable effects on biodiversity. Chapter 4 combined the Foundation Species Interaction model with the established predation hypothesis and tested their abilities to explain biodiversity along the latitudinal gradient. This allowed for shifts in community structure to be examined for topdown and bottomup influences. Predation effects changed along the latitudinal gradient, as the predation effects changed so did the effects of each of the individual foundation species.
Show less  Date Issued
 2020
 PURL
 http://purl.flvc.org/fau/fd/FA00013561
 Subject Headings
 Mangrove ecologyFlorida, Rhizophora mangle, Red mangroveEcology, Biodiversity & ecology
 Format
 Document (PDF)