Physical Sciences and Mathematics Commons^™

Scalability Improvements To Nrlmol For Dft Calculations Of Large Molecules, Carlos Manuel Diaz

Open Access Theses & Dissertations

Advances in high performance computing (HPC) have provided a way to treat large, computationally demanding tasks using thousands of processors. With the development of more powerful HPC architectures, the need to create efficient and scalable code has grown more important. Electronic structure calculations are valuable in understanding experimental observations and are routinely used for new materials predictions. For the electronic structure calculations, the memory and computation time are proportional to the number of atoms. Memory requirements for these calculations scale as N2, where N is the number of atoms. While the recent advances in HPC offer platforms with large numbers …

Density Functional Study Of Reactivity And Regioselectivity Of H2o@C60, Govinda Bahadur Kc

Open Access Theses & Dissertations

The exohedral reactivity of endohedral fullerene has aroused significant interest because of its potential applications in biology, medicine and material science. The encapsulation of a single water molecule without any hydrogen bonding to other compounds, inside the hydrophobic environment of C60 is an intriguing topic to study about. In 2011, Kurotobi and Murata successfully synthesized H2O@C60 fullerene. The presence of a polar water molecule inside the cage is expected to cause changes in the exohedral reactivity of C60. In order to find out the impact of an entrapped single water molecule on the reactivity of C60 fullerene, we use density …

Two-Photon Excitation Based Photochemistry And Neural Imaging, Kevin Andrew Hatch

Open Access Theses & Dissertations

Two-photon microscopy is a fluorescence imaging technique which provides distinct advantages in three-dimensional cellular and molecular imaging. The benefits of this technology may extend beyond imaging capabilities through exploitation of the quantum processes responsible for fluorescent events. This study utilized a two-photon microscope to investigate a synthetic photoreactive collagen peptidomimetic, which may serve as a potential material for tissue engineering using the techniques of two-photon photolysis and two-photon polymerization. The combination of these techniques could potentially be used to produce a scaffold for the vascularization of engineered three-dimensional tissues in vitro to address the current limitations of tissue engineering. Additionally, …

Innovations In Thermoelectric Materials Research: Compound Agglomeration, Testing And Preselection, Hugo Lopez

Open Access Theses & Dissertations

Thermoelectric materials have the capacity to convert a temperature differential into electrical power and vice versa. They will represent the next revolution in alternative energies once their efficiencies are enhanced so they can complement other forms of green energies that depend on sources other than a temperature differential.

Progress in materials science depends on the ability to discover new materials to eventually understand them and to finally improve their properties. The work presented here is aimed at dynamizing the screening of materials of thermoelectric interest. The results of this project will enable: theoretical preselection of thermoelectric compounds based on their …

Educational Use Of Social Media: Exploring Science And Engineering College Students' Perceptions About Utilizing Facebook To Enhance The Learning Of Physics, Angel Salvador Marquez

Open Access Theses & Dissertations

The aim of this qualitative investigation is to explore a group of science and engineering students' perceptions about utilizing Facebook to enhance the learning of physics. Particularly, a survey composed of multiple choice and open-ended questions was employed as to obtain participantsâ?? reactions on a proposed scenario where Facebook is utilized in an Introductory Classical Mechanics course as the medium to manage the following academic activities throughout the semester: examinations, class preparations, study guides, homework assignments, lab preparations, creating group studies, and class participation dynamics. Out of the 120 potential candidates, 106 of them accepted to voluntarily participate in this …

Study On Dioxygen Binding To Heme Using Scan Functional, Zegnet Yimer Muhammed

Open Access Theses & Dissertations

Density functional theory, a quantum mechanical based electronic structure method with GGA-PBE and MGG-SCAN functionals, are used to investigate the structure and energies of singlet, triplet, and quintet spin states of FeP (iron Porphyrin), FePIm (imidazole iron porphyrin), and FePImO2 (dioxygen imidazole iron porphyrin) systems. The binding and release of dioxygen to and from hemoglobin (Hb) are the most crucial reaction takes place in human body to sustain the existence of life. FePImO2 is used to model this phenomenon. When O2 binds to FePIm, the system undergoes a conformational change. i.e. from domed structure of FePIm in which the Fe …

Dft Study On The Structure And Properties Of Vsc2n@C68, Surendra Bhatta

Open Access Theses & Dissertations

A computational study on the structure and electronic properties of the VSc2N@C68 molecule was carried out using the density functional theory. This molecule is based on the recent report on the synThesis of the VSc2N@C80 and V2ScN@C80 fullerenes. The Sc3N@C68 is also a stable endohedral fullerene that has a cage with fuse pentagonal rings. The doping by a V atom changes the structure as well as the spin state of the Sc3N@C68 from S=0 to S=1 state. Since the C68 has 6332 isomers, we have carried out an extensive search for the lowest energy structure of the C68 in several …

Sparse Matrix Diagonalization In The Nrlmol Electronic Structure Code, Md Mahmudulla Hassan

Open Access Theses & Dissertations

Density functional theory (DFT) based simulations are playing a major role in quantum mechanical studies of materials ranging from molecules, nanoparticles to the biological systems as they offer insights that are not directly accessible from experiments and also due to their ability to make sufficiently accurate predictions. The DFT implementation in the NRLMOL electronic structure code employs Gaussian basis sets to express the Kohn-Sham orbitals. A major computationally demanding task in the electronic structure calculations is solution of the generalized eigenvalue problem, that is the determination of nontrivial solutions (λ, c) of Hc = λOc where H and O are …

Equation Of State Of A Dense And Magnetized Neutron System, Md Masud

Open Access Theses & Dissertations

Neutron stars (NSs) are the windows to check the validation of physical laws at extreme conditions, for example, at very high densities and strong magnetic fields and thus to reach the equations of state (EoS) for a better understanding of the structure as well as the composition of the NSs. In our investigations, it is found that the system's (NSs) pressure becomes anisotropic due to the breaking of rotational symmetry in the presence of strong magnetic fields, which even can be significantly sufficient to lead into the deformation of NSs or to destroy itself.

Complex Gleason Measures And The Nemytsky Operator, Miguel Angel Valles

Open Access Theses & Dissertations

This Thesis is devoted to generalize previous results on Gleason measures

to complex Gleason measures, and to develop a functional calculus

for complex measures in relation to the Nemytsky operator. Furthermore

we present the interpretation of our results in the field of quantum

mechanics, some concrete examples and further extensions of several

theorems.

Studying Grazing Behavior Of Cafeteria Roenbergensis With Two-Photon Microscopy, Faisal Abedin Abedin

Open Access Theses & Dissertations

Major innovations in recent years have largely revolutionized the fluorescence imaging. Two-photon fluorescence microscopy is one of them. Two photon fluorescence microscopy has evolved as an alternative to conventional single-photon confocal microscopy and has been shown to provide several advantages. These include three-dimensionally resolved fluorescence imaging of living cells deep within thick, strongly scattering samples, and reduced phototoxicity, enabling long term imaging of photosensitive biological specimens. The inherent three-dimensional resolution of TPE microscopy has been exploited in a number of studies wherein spatial discrimination of fluorescence signals at the micrometer and submicrometer scale within thick biological specimens proved critical. In …