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Full-Text Articles in Physics

Comparative Experimental And Theoretical Study Of Dopamine And Serotonin Interaction, Jose A. Guerrero Jan 2020

Comparative Experimental And Theoretical Study Of Dopamine And Serotonin Interaction, Jose A. Guerrero

Open Access Theses & Dissertations

To accurately identify and measure the concentrations of dopamine (DA) and serotonin (5-HT) in mixtures of these neurotransmitters without labeling, a comprehensive, comparative computational and Raman experimental analysis is provided. While the distinction between these two analytes may be accomplished for concentrations in the millimolar range of these mixtures, their accurate quantification remains unattainable. As shown for the first time in this study, potential creation of a new composite resulting from their interactions with each other could be a reason for this lack of quantification.

Although this new hydrogen-bonded complex greatly complicates future analyte differentiation and quantification at concentrations typical ...


Independent And Simultaneous Control Of Electromagnetic Wave Properties In Self-Collimating Photonic Crystals Using Spatial Variance, Jesus Javier Gutierrez Jan 2020

Independent And Simultaneous Control Of Electromagnetic Wave Properties In Self-Collimating Photonic Crystals Using Spatial Variance, Jesus Javier Gutierrez

Open Access Theses & Dissertations

Photonic crystals are engineered periodic structures that provide great control over electromagnetic waves. One of these mechanisms is self-collimation, in which the electromagnetic wave travels through the photonic crystal along an axis of the lattice without diffracting or spreading. This mechanism of self-collimation is a dispersion phenomenon, which is dependent on the unit cell's physical and geometrical characteristics. An algorithm for generating spatially variant lattices (SVL) was developed that can change geometrical properties in photonic crystals as a function of position, like unit cell orientation, fill fraction, symmetry, and others in a manner that is smooth, continuous, and virtually ...


Density Functional Calculations On Single Molecular (1d) And Van Der Waals Bi -Layered (2d) Magnets., Md Shamsul Alam Jan 2020

Density Functional Calculations On Single Molecular (1d) And Van Der Waals Bi -Layered (2d) Magnets., Md Shamsul Alam

Open Access Theses & Dissertations

Low-dimensional magnetic materials show novel properties that is not seen in bulk magnets. The weak interactions such as spin-orbit interactions, electron correlation, van der Waals interaction in case magnetic bi-layers, play an important role in determining the properties of the system. Using density functional theory, we computationally investigated two categories of magnetic material- 1: Single Molecular Magnets (SMM) 2: Van der Waals layered Cr-Halide magnets. We used different classes of density functionals to examine the spin ordering and magnetic anisotropy barriers in several single molecule magnets - Mn12, Co4, Ni4, V15. We find that the magnetic anisotropy barrier significantly depends on ...


Some Fermi-Lowdin Orbital Self-Interaction Correction Studies On Atomic Systems, Christopher Alexis Ibarra Jan 2020

Some Fermi-Lowdin Orbital Self-Interaction Correction Studies On Atomic Systems, Christopher Alexis Ibarra

Open Access Theses & Dissertations

Density Function Theory (DFT) is a popular quantum chemistry calculation method with many appeals but also deficiencies. Many modification and additions to the method have been made over the years, such as self-interaction corrections and new density functional approximations. We review here the theoretical background needed for a basic understanding of quantum chemistry calculations. In addition, we present the quantum chemistry calculation method used in this paper called Fermi-Lowdin Self-Interaction Correction (FLOSIC), including the base code it was implemented on, the Naval Research Laboratory Molecular Orbital Library (NRLMOL) Code, and the resulting modified code simply called FLOSIC. Furthermore, we explore ...


Mathematical Modeling Of Microemulsification Processes, Numerical Simulations And Applications To Drug Delivery, Ogochukwu Nneka Ifeacho Jan 2020

Mathematical Modeling Of Microemulsification Processes, Numerical Simulations And Applications To Drug Delivery, Ogochukwu Nneka Ifeacho

Open Access Theses & Dissertations

Microemulsion systems are a great pharmaceutical tool for the delivery of formulations containing multiple hydrophilic and hydrophobic ingredients of varying physicochemical properties. These systems are gaining popularity because of its long shelf life, improved drug solubilisation capacity, easy preparation and improvement of bioavailability. Despite the advantages associated with the use of microemulsion systems in pharmaceutical industries, the major challenge impeding their use has been and continues to be the lack of understanding of these systems.

Microemulsions can be mathematically modeled by an initial boundary value problem involving a sixth order nonlinear time dependent equation. In this Thesis, we present a ...


Development And Assesment Of Local Scaled Self-Interaction Corrected Density Functional Method With Simple Scaling Factor, Selim Romero Jan 2020

Development And Assesment Of Local Scaled Self-Interaction Corrected Density Functional Method With Simple Scaling Factor, Selim Romero

Open Access Theses & Dissertations

The Hohenberg-Kohn-Sham (HKS) density functional theory (DFT) is widely used to compute electronic structures of atoms, molecules, and solids. It is an exact theory in which ground state electron density plays the role of basic variable, same as the wavefunction does in quantum mechanics. The total ground state energy is a functional of electron density. The practical application of HKS DFT require approximation to the exchange-correlation energy functional. Many density functional approximations (DFAs) with various degree of sophistication and complexities have been developed. Depending on the complexity, these functionals include electron density, density gradients, density Laplacian, kinetic energy densities, Hartree-Fock ...