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Full-Text Articles in Physics

Dft-Based Study Of Electric Field Effect On The Polarizability Of Three Ringed Nematic Liquid Crystal Molecules, Pranav Upadhyay, Mirtunjai Mishra, Ankur Trivedi, Jitendra Kumar, Asheesh Kumar, Devesh Kumar Dec 2020

Dft-Based Study Of Electric Field Effect On The Polarizability Of Three Ringed Nematic Liquid Crystal Molecules, Pranav Upadhyay, Mirtunjai Mishra, Ankur Trivedi, Jitendra Kumar, Asheesh Kumar, Devesh Kumar

Makara Journal of Science

Owing to its successful application to complex molecular systems, computational density functional theory (DFT) has been used to study the effect of an electric field on the molecular polarizability and HOMO–LUMO gap of 1-phenyl-4-{2-[(1s,4r)-4-pentylcyclohexyl]ethyl}benzene (1) and its fluoro-, chloro-, and cyano- derivatives, namely, 1-fluoro-4-(4-{2-[(1s,4r)-4-pentylcyclohexyl]ethyl}phenyl)benzene (2), 1-chloro-4-(4-{2-[(1s,4r)-4-pentylcyclohexyl]ethyl}phenyl)benzene (3), and 4-(4-{2-[(1s,4r)-4-pentylcyclohexyl]ethyl}phenyl)benzonitrile (4). These molecules belong to the family of nematic liquid crystals with three rings: two benzene and one cyclohexane. Furthermore, two DFT approaches, namely, B3LYP and M062X, have been used to examine the results obtained. This study reveals a remarkable feature: the polarizability of these molecules follows nearly a step function …


Studying The Linear Complex Pt Symmetric Potential, Roland Lombard Nov 2020

Studying The Linear Complex Pt Symmetric Potential, Roland Lombard

Journal of the Arab American University مجلة الجامعة العربية الامريكية للبحوث

We investigate the spectrum of the linear complex PT symmetric potential V(x) = λ|x| + icx. Semi analytical solutions are given by using properties of the Airy functions. The numerical integration of the differential equation system is discussed. We show that the number of eigenstates with a real eigenvalue is limited, depending on the ratio c/λ and on the quantum number n, reflecting a spontaneous breaking of the PT symmetry. For the ground state ( n = 0), we conjecture the eigenvalue to be real whatever the value of c.


Self-Aggregation Of C60 Particles In A Volume Of Evaporating Droplets On A Flat Surface, Urol Makhmanov, Abdulmutallib Kokhkharov, Sagdilla Bakhramov, Donats Erts Sep 2020

Self-Aggregation Of C60 Particles In A Volume Of Evaporating Droplets On A Flat Surface, Urol Makhmanov, Abdulmutallib Kokhkharov, Sagdilla Bakhramov, Donats Erts

Bulletin of National University of Uzbekistan: Mathematics and Natural Sciences

The experimental results on the self-aggregation of fullerene C60 particles in a microvolume of drying droplets of a colloidal solution of fullerene on a solid substrate are presented. Using methods of scanning electron microscopy and atomic force microscopy, it was shown that in the volume of an evaporating droplet of a solution of fullerene C60 in xylene, deposited on the surface of a flat silicon substrate at room temperature, nanostructured and porous mC60 aggregates of quasispherical and elongated spherical shapes with geometrical sizes in average diameter up to D≈4000 nm are synthesized. It is established that an …


Intermolecular Dynamics Of Condensed State: Study Of Temperature Effect On Anisotropy Relaxation By Vibration Spectroscopy, Bakhodir Eshchanov, Shavkat Otajonov, Jurat Gayipov, Dilafruz Xudoyberdiyeva, Sarvarbek Qurbanbayev Sep 2020

Intermolecular Dynamics Of Condensed State: Study Of Temperature Effect On Anisotropy Relaxation By Vibration Spectroscopy, Bakhodir Eshchanov, Shavkat Otajonov, Jurat Gayipov, Dilafruz Xudoyberdiyeva, Sarvarbek Qurbanbayev

Bulletin of National University of Uzbekistan: Mathematics and Natural Sciences

As a result of the experimental study of the spectra of anisotropic scattering of light, a character of orientation movement of molecules in aromatic hydrocarbons has been analyzed. The obtained results have been interpreted from the viewpoint of a model of inhibited rotation and the contributions of the rotational and vibrational degrees of freedom to a molecule spectrum have been estimated. With increasing temperature of liquids under study and approaching a critical state, the rotational degrees of freedom "freeze", and the vibrational degrees have become more significant.


Quantum Interference In Monocyclic Molecules: A Novel And Straightforward Phase Wave Model, Zainelabideen Yousif Mijbil Jun 2020

Quantum Interference In Monocyclic Molecules: A Novel And Straightforward Phase Wave Model, Zainelabideen Yousif Mijbil

Karbala International Journal of Modern Science

We have proposed by far the simplest model, so-called phase wave model (PWM), to predict quantum interference states in monocyclic molecules. Meanwhile, transmission coefficient calculations were also performed using Green’s function method incorporated with Hückel (Tight Binding) approximation. An impressive agreement has been obtained between the results of the phase wave model and the ones from transmission coefficient calculations for the chosen model systems, namely benzene, cycloheptatriene, cyclooctatetraene, and [10]annulene. PWM represents the phase of wave functions of the incoming electrons by a wave and associates a single wavelength of the phase with five atoms/sites. Hence, the electrical conductance would …


Guidelines For Studying The Dynamics Of Nanostructural Phenomena In Liquids By Dynamic Light Scattering., Shavkat Esirgapovich Qarshiboyev, Lionard Sabirov, Leonid Chaikov, Marina Kirichenko Jan 2020

Guidelines For Studying The Dynamics Of Nanostructural Phenomena In Liquids By Dynamic Light Scattering., Shavkat Esirgapovich Qarshiboyev, Lionard Sabirov, Leonid Chaikov, Marina Kirichenko

Scientific Journal of Samarkand University

The paper describes the principles of correlation spectroscopy of scattered light and a method for determining the size of particles suspended in a liquid using such spectroscopy - the method of dynamic light scattering (DLS). Some features of the application of the DLS method are considered.


Structuring Light For Investigating Optical Vortices, Andrew Voitiv, Mark Siemens Jan 2020

Structuring Light For Investigating Optical Vortices, Andrew Voitiv, Mark Siemens

DU Undergraduate Research Journal Archive

Vortices are well known in our world: tornadoes, hurricanes, and quickly stirred iced tea all demonstrate the vortex phenomenon. In addition to these classical fluids, vortices exist in laser light. While classical fluid vortex dynamics is one of the oldest studied physics problems, the study of optical vortices is only a few decades old. Paralleling the community’s curiosity of quantized vortices in quantum fluids, such as super fluid helium and Bose-Einstein condensate, there is immense interest in the study of optical vortices. In this article, we cover the basic theory of structuring light to generate optical vortices and then discuss …