Open Access. Powered by Scholars. Published by Universities.®
- Discipline
-
- Engineering (12)
- Condensed Matter Physics (10)
- Materials Science and Engineering (9)
- Atomic, Molecular and Optical Physics (8)
- Applied Mathematics (4)
-
- Chemistry (4)
- Computer Sciences (4)
- Biological and Chemical Physics (3)
- Elementary Particles and Fields and String Theory (3)
- Numerical Analysis and Scientific Computing (3)
- Chemical Engineering (2)
- Computational Chemistry (2)
- Electrical and Computer Engineering (2)
- Engineering Physics (2)
- Engineering Science and Materials (2)
- Materials Chemistry (2)
- Nanoscience and Nanotechnology (2)
- Numerical Analysis and Computation (2)
- Other Applied Mathematics (2)
- Physical Chemistry (2)
- Quantum Physics (2)
- Statistical, Nonlinear, and Soft Matter Physics (2)
- American Studies (1)
- Arts and Humanities (1)
- Astrophysics and Astronomy (1)
- Computational Engineering (1)
- Data Science (1)
- Dynamics and Dynamical Systems (1)
- Institution
-
- Missouri University of Science and Technology (13)
- University of South Florida (4)
- University of Texas at El Paso (4)
- Western University (3)
- Louisiana Tech University (2)
-
- Ministry of Higher and Secondary Specialized Education of the Republic of Uzbekistan (2)
- University of Central Florida (2)
- University of Nebraska at Omaha (2)
- Brigham Young University (1)
- Clemson University (1)
- Louisiana State University (1)
- Michigan Technological University (1)
- Northern Illinois University (1)
- Purdue University (1)
- The University of Akron (1)
- University at Albany, State University of New York (1)
- University of Arkansas, Fayetteville (1)
- University of Tennessee, Knoxville (1)
- Washington University in St. Louis (1)
- West Virginia University (1)
- Publication Year
- Publication
-
- Physics Faculty Research & Creative Works (11)
- Open Access Theses & Dissertations (4)
- USF Tampa Graduate Theses and Dissertations (4)
- Doctoral Dissertations (3)
- Electronic Thesis and Dissertation Repository (3)
-
- Electronic Theses and Dissertations (2)
- All Dissertations (1)
- Arts & Sciences Electronic Theses and Dissertations (1)
- Chemistry Faculty Publications (1)
- Dissertations, Master's Theses and Master's Reports (1)
- Graduate Research Theses & Dissertations (1)
- Graduate Theses, Dissertations, and Problem Reports (1)
- Karakalpak Scientific Journal (1)
- LSU Doctoral Dissertations (1)
- Legacy Theses & Dissertations (2009 - 2024) (1)
- Master's Theses (1)
- Masters Theses (1)
- Mechanical Engineering Undergraduate Honors Theses (1)
- Physics Faculty Publications (1)
- Scientific-technical journal (1)
- The Summer Undergraduate Research Fellowship (SURF) Symposium (1)
- Theses and Dissertations (1)
- Williams Honors College, Honors Research Projects (1)
- Publication Type
Articles 1 - 30 of 44
Full-Text Articles in Physics
Atomic-Level Mechanisms Of Fast Relaxation In Metallic Glasses, Leo W. Zella
Atomic-Level Mechanisms Of Fast Relaxation In Metallic Glasses, Leo W. Zella
Doctoral Dissertations
Glasses are ubiquitous in daily life and have unique properties which are a consequence of the underlying disordered structure. By understanding the fundamental processes that govern these properties, we can modify glasses for desired applications. Key to understanding the structure-dynamics relationship in glasses is the variety of relaxation processes that exist below the glass transition temperature. Though these relaxations are well characterized with macroscopic experimental techniques, the microscopic nature of these relaxations is difficult to elucidate with experimental tools due to the requirements of timescale and spatial resolution. There remain many questions regarding the microscopic nature of relaxation in glass …
The Influence Of Allostery Governing The Changes In Protein Dynamics Upon Substitution, Joseph Hess
The Influence Of Allostery Governing The Changes In Protein Dynamics Upon Substitution, Joseph Hess
All Dissertations
The focus of this research is to investigate the effects of allostery on the function/activity of an enzyme, human immunodeficiency virus type 1 (HIV-1) protease, using well-defined statistical analyses of the dynamic changes of the protein and variants with unique single point substitutions 1. The experimental data1 evaluated here only characterized HIV-1 protease with one of its potential target substrates. Probing the dynamic interactions of the residues of an enzyme and its variants can offer insight of the developmental importance for allosteric signaling and their connection to a protein’s function. The realignment of the secondary structure elements can …
Mechanical Behavior Of Metallic Core-Shell Nanoparticles Under Compressive Loading, Phillip Tomich
Mechanical Behavior Of Metallic Core-Shell Nanoparticles Under Compressive Loading, Phillip Tomich
Graduate Research Theses & Dissertations
Core/shell metallic nanoparticles have been shown to be a promising material type for additive manufacturing in the aerospace and automotive fields. Within additive manufacturing they will be used to accurately make an array of nanoparticles within the grains of metal matrix composites. This in turn will help to strengthen the material while remaining ductility and light weight. In this study, copper/aluminum core/shell nanoparticles are compressed under [100], [110], [111], and [112] directions to showcase their anisotropic material properties. Models of their individual counterparts were also investigated. There are no previous works showing the deformation mechanisms of copper/aluminum core/shell nanoparticles. Molecular …
Investigation Of Defect Production And Displacement Energies In Wurtzite Aluminum Nitride, Sean Anderson
Investigation Of Defect Production And Displacement Energies In Wurtzite Aluminum Nitride, Sean Anderson
Masters Theses
"Aluminum Nitride is an active element of sensors that monitor the performance and well-being of the nuclear reactors due to its piezoelectric properties. Yet, the variations of its properties under irradiation are largely unexplored. We report the results of the molecular dynamics simulations of the structural changes in AlN under irradiation via the knock-on atom technique. By creating and evolving the irradiation cascades due to energetic particle interaction with the atom of the crystalline lattice we determine the rate of the defect production as a function of the deposited energy. Further, we determine a displacement energy, a key characteristic that …
Generation Of Phase Transitions Boundaries Via Convolutional Neural Networks, Christopher Alexis Ibarra
Generation Of Phase Transitions Boundaries Via Convolutional Neural Networks, Christopher Alexis Ibarra
Open Access Theses & Dissertations
Accurate mapping of phase transitions boundaries is crucial in accurately modeling the equation of state of materials. The phase transitions can be structural (solid-solid) driven by temperature or pressure or a phase change like melting which defines the solid-liquid melt line. There exist many computational methods for evaluating the phase diagram at a particular point in temperature (T) and pressure (P). Most of these methods involve evaluation of a single (P,T) point at a time. The present work partially automates the search for phase boundaries lines utilizing a machine learning method based on convolutional neural networks and an efficient search …
A Molecular Dynamics Study Of Polymer Chains In Shear Flows And Nanocomposites, Venkat Bala
A Molecular Dynamics Study Of Polymer Chains In Shear Flows And Nanocomposites, Venkat Bala
Electronic Thesis and Dissertation Repository
In this work we study single chain polymers in shear flows and nanocomposite polymer melts extensively through the use of large scale molecular dynamics simulations through LAMMPS. In the single polymer chain shear flow study, we use the Lattice Boltzmann method to simulate fluid dynamics and also include thermal noise as per the \emph{fluctuation-dissipation} theorem in the system. When simulating the nanocomposite polymer melts, we simply use a Langevin thermostat to mimic a heat bath. In the single polymer in shear flow study we investigated the margination of a single chain towards solid surfaces and how strongly the shear flow …
Theoretical Investigation On Optical Properties Of 2d Materials And Mechanical Properties Of Polymer Composites At Molecular Level, Geeta Sachdeva
Theoretical Investigation On Optical Properties Of 2d Materials And Mechanical Properties Of Polymer Composites At Molecular Level, Geeta Sachdeva
Dissertations, Master's Theses and Master's Reports
The field of two-dimensional (2D) layered materials provides a new platform for studying diverse physical phenomena that are scientifically interesting and relevant for technological applications. Theoretical predictions from atomically resolved computational simulations of 2D materials play a pivotal role in designing and advancing these developments. The focus of this thesis is 2D materials especially graphene and BN studied using density functional theory (DFT) and molecular dynamics (MD) simulations. In the first half of the thesis, the electronic structure and optical properties are discussed for graphene, antimonene, and borophene. It is found that the absorbance in (atomically flat) multilayer antimonene (group …
Study Of The Geometric Structure Of Low-Atomic Copper Clusters Using Computer Simulation, Nodirbek Ikromjonovich Ibrokhimov
Study Of The Geometric Structure Of Low-Atomic Copper Clusters Using Computer Simulation, Nodirbek Ikromjonovich Ibrokhimov
Scientific-technical journal
In this work, we investigated the geometric structure of small neutral copper clusters with low energy using the MD (Molecular Dynamics) method. When calculating the processes of interatomic interaction, we used a potential EAM (Embedded-atom method). A computer model of Cun (n = 2-13) clusters has been created. The geometric shapes of the Cu2, Cu3, Cu4, Cu5, Cu6, Cu7, Cu8, Cu9, Cu10, Cu11, Cu12, and Cu13 clusters have been studied and the structural parameters (Cu-Cu bond …
Computational Study Of Grain Structure Evolution In Cdte/Cds Via Molecular Dynamics, Sharmin Abdullah
Computational Study Of Grain Structure Evolution In Cdte/Cds Via Molecular Dynamics, Sharmin Abdullah
Open Access Theses & Dissertations
Grain structure analysis plays an important role in the identification of grain boundary characteristics, which can affect the efficiency of Cadmium Telluride/Cadmium Sulfide (CdTe/CdS) solar cells since they can act as recombination centers for carriers. Computer simulations such as molecular dynamics (MD) can be a very convenient and cost- effective method of investigating the growth evolution and grain structure of materials. The recently reported and experimentally validated MD simulated growth of polycrystalline CdTe/CdS films shows that these materials mostly consist of zinc blende (ZB) and wurtzite (WZ) structures, along with highly disordered atoms. However, little information about the semiconductor compound …
Multi-Scale Computational Modeling Of Metal/Ceramic Interfaces, Abu Shama Mohammad Miraz
Multi-Scale Computational Modeling Of Metal/Ceramic Interfaces, Abu Shama Mohammad Miraz
Master's Theses
Multi-scale atomistic calculations were carried out to understand the interfacial features that dictate the mechanical integrity of the metal/ceramic nanolaminates. As such, first principles density functional theory (DFT) calculations were performed to understand the electronic and atomistic factors governing adhesion and resistance to shear for simple metal/ceramic interfaces, whereas molecular dynamics (MD) simulations were performed to observe the impact of interfacial structures, such as misfit dislocation network geometries and orientation relationships, on interfacial mechanical properties.
For the DFT investigation, we choose metals with different crystal structures, namely - Cu (fcc), Cr (bcc) and Ti (hcp) along with a variety of …
Multi-Scale Computational Modeling Of Metal/Ceramic Interfaces, Abu Shama Mohammad Miraz
Multi-Scale Computational Modeling Of Metal/Ceramic Interfaces, Abu Shama Mohammad Miraz
Doctoral Dissertations
Multi-scale atomistic calculations were carried out to understand the interfacial features that dictate the mechanical integrity of the metal/ceramic nanolaminates. As such, first principles density functional theory (DFT) calculations were performed to understand the electronic and atomistic factors governing adhesion and resistance to shear for simple metal/ceramic interfaces, whereas molecular dynamics (MD) simulations were performed to observe the impact of interfacial structures, such as misfit dislocation network geometries and orientation relationships, on interfacial mechanical properties.
For the DFT investigation, we choose metals with different crystal structures, namely - Cu (fcc), Cr (bcc) and Ti (hcp) along with a variety of …
Mechanical Behavior Of Cyclo-18 On Nickel And Copper Substrates, Reagan Michael Kraft
Mechanical Behavior Of Cyclo-18 On Nickel And Copper Substrates, Reagan Michael Kraft
Mechanical Engineering Undergraduate Honors Theses
Carbyne, an -hybridized allotrope of carbon, has been the subject of many studies recently due to its incredible mechanical properties and small size. More recently, another -hybridized allotrope known as cyclo-18, has gained interest. In this study, computational molecular dynamics will be used to determine the mechanical properties of cyclo-18. Peeling and shearing tests of the molecule will be conducted on nickel and copper, which are respectively active and less-active transition metals. Additionally, a carbyne chain of equal length will undergo the same tests on the copper substrate to compare the mechanical properties of the two. The results conclude that …
Copper Clusters: Study Of Geometric Structure Using Computer Simulation, Nodirbek Ikromjonovich Ibrokhimov
Copper Clusters: Study Of Geometric Structure Using Computer Simulation, Nodirbek Ikromjonovich Ibrokhimov
Karakalpak Scientific Journal
In this work, we investigated the geometric structure of small neutral copper clusters with low energy using the MD (Molecular Dynamics) method. When calculating the processes of interatomic interaction, we used a potential EAM (Embedded-atom method). A computer model of Cun (n = 2-13) clusters has been created. The geometric shapes of the Cu2, Cu3, Cu4, Cu5, Cu6, Cu7, Cu8, Cu9, Cu10, Cu11, Cu12, and Cu13 clusters have been studied and the structural parameters (Cu-Cu bond …
Adsorption And Reconfiguration Of Amphiphiles At Silica-Water Interfaces: Role Of Electrostatic Interactions, Van Der Waals Forces And Hydrogen Bonds, Yao Wu
LSU Doctoral Dissertations
The ability to explore and predict metastable structures of hybrid self-assemblies is of central importance for the next generation of advanced materials with novel properties. As compared to their thermodynamically stable forms, the kinetically stabilized materials show improved functionality potentially over their stable counterparts. The self-assembly processes usually originate from weak intermolecular interactions, involving a dynamic competition between attractive and repulsive interactions. These weak forces, including van der Waals (vdW), electrostatic interaction and the hydrogen bonding (H-bonding), can be tuned by external stimuli, e.g., confinement, temperature and ionization, and consequently driving hybrid materials into different configurations. It is challenging to …
A Molecular Dynamics Study Of Temperature Dependent Wetting In Alkane-Water Systems, Pauf Neupane
A Molecular Dynamics Study Of Temperature Dependent Wetting In Alkane-Water Systems, Pauf Neupane
Doctoral Dissertations
“The wetting behavior of aqueous organic systems is of great importance in several environmental and industrial processes such as the formation and growth of atmospheric aerosols, crude oil recovery from an oil field, onsite cleaning of natural gas, and clean-up of oil spills. In this work, we employed molecular dynamics (MD) simulations to explore the temperature dependent wetting behavior of octane and nonane on water in planar interfaces as well as in nanodroplets using PYS alkane and SPC/E and TIP4P/2005 water models.
For planar interfaces, we found unusual wetting behavior of octane and nonane on SPC/E water, but generally not …
Phase Diagram Of Nuclear Matter, Adrian Gaytan Terrazas
Phase Diagram Of Nuclear Matter, Adrian Gaytan Terrazas
Open Access Theses & Dissertations
Nowadays it is well known that nuclear matter has a liquid and a gas phase, as well as a coexistence of phases region. Symmetric nuclear matter (same number of protons and neutrons) exhibit phase transitions from the gas phase to a liquid-gas mixture. A useful tool to represent such phases and transitions is through diagrams that show the necessary conditions of density and temperature to be in either of the phases.
Now the question is, what if we extend the traditional phase diagram for symmetric matter to the asymmetric
cases (different number of protons and neutrons)?
This study uses classical …
The Structural Information Filtered Features Potential For Machine Learning Calculations Of Energies And Forces Of Atomic Systems., Jorge Arturo Hernandez Zeledon
The Structural Information Filtered Features Potential For Machine Learning Calculations Of Energies And Forces Of Atomic Systems., Jorge Arturo Hernandez Zeledon
Graduate Theses, Dissertations, and Problem Reports
In the last ten years, machine learning potentials have been successfully applied to the study of crystals, and molecules. However, more complex materials like clusters, macro-molecules, and glasses are out reach of current methods. The input of any machine learning system is a tensor of features (the most universal type are rank 1 tensors or vectors of features), the quality of any machine learning system is directly related to how well the feature space describes the original physical system. So far, the feature engineering process for machine learning potentials can not describe complex material. The current methods are highly inefficient …
Understanding The Nature Of Nanoscale Wetting Through All-Atom Simulations, Oliver Evans
Understanding The Nature Of Nanoscale Wetting Through All-Atom Simulations, Oliver Evans
Williams Honors College, Honors Research Projects
The spreading behavior of spherical and cylindrical water droplets between 30Å and 100Å in radius on a sapphire surface is investigated using all-atom molecular dynamics simulations for durations on the order of tens of nanoseconds. A monolayer film develops rapidly and wets the surface, while the bulk of the droplet spreads on top of the monolayer, maintaining the shape of a spherical cap. Unlike previous simulations in the literature, the bulk radius is found to increase to a maximum value and receed as the monolayer continues to expand. Simple time and droplet size dependence is observed for monolayer radius and …
Dynamics Of Discs In A Nematic Liquid Crystal, Alena Antipova
Dynamics Of Discs In A Nematic Liquid Crystal, Alena Antipova
Electronic Thesis and Dissertation Repository
In this thesis, a new way of simulating a two-way coupling between a liquid crystal and an immersed object is proposed. It can be used for objects of various geometries and can be expanded to be used for an object of any geometry. Additionally, a simple yet effective model was suggested for calculations of transmitted light through a nematic liquid crystal sample. This model allowed us to clarify the behavior of a ferromagnetic disc in a nematic liquid crystal observed in experiments and incorrectly interpreted at that time.
Our simulations have demonstrated the following: in the absence of external forces …
A Molecular Dynamics Study Of The Structure-Dynamics Relationships Of Supercooled Liquids And Glasses, Ryan Joseph Soklaski
A Molecular Dynamics Study Of The Structure-Dynamics Relationships Of Supercooled Liquids And Glasses, Ryan Joseph Soklaski
Arts & Sciences Electronic Theses and Dissertations
Central to the field of condensed matter physics is a decades old outstanding problem in the study of glasses – namely explaining the extreme slowing of dynamics in a liquid as it is supercooled towards the so-called glass transition. Efforts to universally describe the stretched relaxation processes and heterogeneous dynamics that characteristically develop in supercooled liquids remain divided in both their approaches and successes. Towards this end, a consensus on the role that atomic and molecular structures play in the liquid is even more tenuous. However, mounting material science research efforts have culminated to reveal that the vast diversity of …
Molecular Dynamics Study On Defect Reduction Strategies Towards The Fabrication Of High Performance Cd1-Xznxte/Cds Solar Cells, Jose Juan Chavez
Molecular Dynamics Study On Defect Reduction Strategies Towards The Fabrication Of High Performance Cd1-Xznxte/Cds Solar Cells, Jose Juan Chavez
Open Access Theses & Dissertations
Cadmium Telluride is a material widely used in terrestrial thin film photovoltaic applications due to its nearly ideal band gap (~1.5 eV) and high absorption coefficient. Due to its low manufacturing cost, this technology has the potential to become a significant energy resource if higher energy conversion efficiencies are achieved. However, the module efficiencies (~14%) are still far from the theoretical maximum (~30%) for this material in a single junction configuration. The reason behind this low performance is attributed to the high number of defects that are present within the device materials. The physics behind the formation mechanisms of these …
Building Predictive Chemistry Models, Christopher Browne, Nicolas Onofrio, Alejandro Strachan
Building Predictive Chemistry Models, Christopher Browne, Nicolas Onofrio, Alejandro Strachan
The Summer Undergraduate Research Fellowship (SURF) Symposium
Density Functional Theory (DFT) simulations allow for sophisticated modeling of chemical interactions, but the extreme computational cost makes it inviable for large scale applications. Molecular dynamics models, specifically ReaxFF, can model much larger simulations with greater speed, but with lesser accuracy. The accuracy of ReaxFF can be improved by comparing predictions of both methods and tuning ReaxFF’s parameters. Molecular capabilities of ReaxFF were gauged by simulating copper complexes in water over a 200 ps range, and comparing energy predictions against ReaxFF. To gauge solid state capabilities, volumetric strain was applied to simulated copper bulk and the strain response functions used …
Phonon Thermal Transport Through Tilt Grain Boundaries In Strontium Titanate, Zexi Zheng, Xiang Chen, Bowen Deng, Aleksandr V. Chernatynskiy, Shengfeng Yang, Jinjun Xiong, Youping Chen
Phonon Thermal Transport Through Tilt Grain Boundaries In Strontium Titanate, Zexi Zheng, Xiang Chen, Bowen Deng, Aleksandr V. Chernatynskiy, Shengfeng Yang, Jinjun Xiong, Youping Chen
Physics Faculty Research & Creative Works
In this work, we perform nonequilibrium molecular dynamics simulations to study phonon scattering at two tilt grain boundaries (GBs) in SrTiO3. Mode-wise energy transmission coefficients are obtained based on phonon wave-packet dynamics simulations. The Kapitza conductance is then quantified using a lattice dynamics approach. The obtained results of the Kapitza conductance of both GBs compare well with those obtained by the direct method, except for the temperature dependence. Contrary to common belief, the results of this work show that the optical modes in SrTiO3 contribute significantly to phonon thermal transport, accounting for over 50% of the Kapitza …
Kapitza Resistance Of Si/Sio₂ Interface, Bowen Deng, Aleksandr V. Chernatynskiy, Marat Khafizov, David H. Hurley, Simon R. Phillpot
Kapitza Resistance Of Si/Sio₂ Interface, Bowen Deng, Aleksandr V. Chernatynskiy, Marat Khafizov, David H. Hurley, Simon R. Phillpot
Physics Faculty Research & Creative Works
A phonon wave packet dynamics method is used to characterize the Kapitza resistance of a Si/SiO2 interface in a Si/SiO2/Si heterostructure. By varying the thickness of SiO2 layer sandwiched between two Si layers, we determine the Kapitza resistance for the Si/SiO 2 interface from both wave packet dynamics and a direct, non-equilibrium molecular dynamics approach. The good agreement between the two methods indicates that they have each captured the anharmonic phonon scatterings at the interface. Moreover, detailed analysis provides insights as to how individual phonon mode scatters at the interface and their contribution to the Kapitza …
Hybrid Lattice Boltzmann - Molecular Dynamics Simulations With Both Simple And Complex Fluids, Frances E. Mackay
Hybrid Lattice Boltzmann - Molecular Dynamics Simulations With Both Simple And Complex Fluids, Frances E. Mackay
Electronic Thesis and Dissertation Repository
The behaviour and properties of colloidal suspensions strongly depend on the interactions arising between the immersed colloidal particles and the solvent. However, modelling such interactions is not at all straightforward; the larger time and length scales experienced by the colloidal particles compared to the solvent molecules makes all-atom molecular dynamics (MD) simulations of such systems completely impractical. Therefore a coarse-grained representation of the fluid is required, along with a method to couple this fluid to the colloidal particles.
In the first part of this thesis, we propose a new method for coupling both point and composite MD particles to an …
Non-Equilibrium Melting And Sublimation Of Graphene Simulated With Two Interatomic Potentials, Brad Steele
Non-Equilibrium Melting And Sublimation Of Graphene Simulated With Two Interatomic Potentials, Brad Steele
USF Tampa Graduate Theses and Dissertations
The mechanisms of the sublimation of graphene at zero pressure and the condensation of carbon vapor is investigated by molecular dynamics (MD) simulations. The interatomic interactions are described by the Reactive Empirical Bond Order potential (REBO). It is found that graphene sublimates at a temperature of 5,200 K. At the onset of sublimation, defects that contain several pentagons and heptagons are formed, that are shown to evolve from double vacancies and stone wales defects. These defects consisting of pentagons and heptagons act as nucleation sites for the gaseous phase. The influence of the interatomic interactions on the sublimation process are …
Properties Of Ferroelectric Perovskite Structures Under Non-Equilibrium Conditions, Qingteng Zhang
Properties Of Ferroelectric Perovskite Structures Under Non-Equilibrium Conditions, Qingteng Zhang
USF Tampa Graduate Theses and Dissertations
Ferroelectric materials have received lots of attention thanks to their intriguing properties such as the piezoelectric and pyroelectric effects, as well as the large dielectric constants and the spontaneous polarization which can potentially be used for information storage. In particular, perovskite crystal has a very simple unit cell structure yet a very rich phase transition diagram, which makes it one of the most intensively studied ferroelectric materials. In this dissertation, we use effective Hamiltonian, a first-principles-based computational technique to study the finite-temperature properties of ferroelectric perovskites. We studied temperature-graded
(BaxSr1-x )TiO3 (BST) bulk alloys as well as the dynamics of …
Experimental And Theoretical Analysis Of Strain Engineered Aluminium Nitride On Silicon For High Quality Aluminium(X)Indium(Y)Gallium(1-X-Y)Nitride Epitaxy, Mihir Hemant Tungare
Experimental And Theoretical Analysis Of Strain Engineered Aluminium Nitride On Silicon For High Quality Aluminium(X)Indium(Y)Gallium(1-X-Y)Nitride Epitaxy, Mihir Hemant Tungare
Legacy Theses & Dissertations (2009 - 2024)
III-Nitrides on Si are of great technological importance due to the availability of large area, epi ready Si substrates and the ability to heterointegrate with mature silicon micro and nanoelectronics. The major roadblock with realizing this is the large difference in thermal expansion coefficients and lattice constants between the two material systems. A novel technique developed in our research lab shows the potential of simultaneous and substantial reduction in dislocation and crack density in GaN on Si (111). Research undertaken in the current doctoral dissertation, validates the superior GaN quality on Si obtained using our technique and determines the factors …
Development Of Interatomic Potentials For Large Scale Molecular Dynamics Simulations Of Carbon Materials Under Extreme Conditions, Romain Perriot
Development Of Interatomic Potentials For Large Scale Molecular Dynamics Simulations Of Carbon Materials Under Extreme Conditions, Romain Perriot
USF Tampa Graduate Theses and Dissertations
The goal of this PhD research project is to devise a robust interatomic potential for large scale molecular dynamics simulations of carbon materials under extreme conditions. This screened-environment dependent reactive empirical bond order potential (SED-REBO) is specifically designed to describe carbon materials under extreme compressive or tensile stresses. Based on the original REBO potential by Brenner and co workers, SED-REBO includes reparametrized pairwise interaction terms and a new screening term, which serves the role of a variable cutoff. The SED-REBO potential overcomes the deficiencies found with the most commonly used interatomic potentials for carbon: the appearance of artificial forces due …
Atomistic Studies Of Shock-Wave And Detonation Phenomena In Energetic Materials, Mikalai Budzevich
Atomistic Studies Of Shock-Wave And Detonation Phenomena In Energetic Materials, Mikalai Budzevich
USF Tampa Graduate Theses and Dissertations
The major goal of this PhD project is to investigate the fundamental properties of energetic materials, including their atomic and electronic structures, as well as mechanical properties, and relate these to the fundamental mechanisms of shock wave and detonation propagation using state-of-the-art simulation methods. The first part of this PhD project was aimed at the investigation of static properties of energetic materials (EMs) with specific focus on 1,3,5-triamino-2,4,6-trinitrobenzene (TATB). The major goal was to calculate the isotropic and anisotropic equations of state for TATB within a range of compressions not accessible to experiment, and to make predictions of anisotropic sensitivity …