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Articles 1 - 19 of 19
Full-Text Articles in Physical Sciences and Mathematics
Comparison Of Various Mean Field Formulations For Retrieving Refractive Indices Of Aerosol Particles Containing Inclusions, Kristin S. Dooley, Jessica Deyoung
Comparison Of Various Mean Field Formulations For Retrieving Refractive Indices Of Aerosol Particles Containing Inclusions, Kristin S. Dooley, Jessica Deyoung
Journal of the Arkansas Academy of Science
Application of effective medium approximation (EMA) methods to two-component systems are presented. Systems studied are composed of water, sulfate, soot, and dust as these are commonly encountered atmospheric aerosol components. Atmospheric models often employ EMAs to include internally mixed aerosols without the computational burden of exact theory. In the current work, several types of mixing rules (Maxwell-Garnet, Bruggeman, and coherent potential approximation) have been applied to various two-component internally mixed particles at 550 nm using volume fractions of the minor component below 0.1. As expected, results show that the formulations tested produce very similar effective refractive indices indicating that electric …
Characterizing Nanoparticle Size By Dynamic Light Scattering, M. Zaman, S. Ang, S. Singh
Characterizing Nanoparticle Size By Dynamic Light Scattering, M. Zaman, S. Ang, S. Singh
Journal of the Arkansas Academy of Science
The Dynamic Light Scattering (DLS) Technique was used to determine the size, shape and diffusion coefficient of rod-like nanoparticles. The intensity auto-correlation functions of light scattered by particles in a solution were measured and analyzed to obtain the relaxation rates for decay of intensity correlations. These decay rates are related to the diffusion coefficients pertaining to the motion of the particle. In the case of nanorods, there are two types of motion - translational and rotational. By disentangling the relaxation rates, corresponding to these two types of motion, the shape and size of nanoparticles were characterized. These experiments, though limited …
Solid State Dye Sensitive Solar Cells Based On Zno Nanowire As The N-Type Semiconductor, S. Abdulalmohsin
Solid State Dye Sensitive Solar Cells Based On Zno Nanowire As The N-Type Semiconductor, S. Abdulalmohsin
Journal of the Arkansas Academy of Science
We fabricated solid state dye-sensitized solar cells with ZnO nanorods as the n-type material and polypyrrole as the p-type material. The ZnO nanorods were grown on indium-tin oxide (ITO) glass by electrochemical methods for one hour. Scanning electron micrographs of the ZnO nanowire (NW) indicated a length of about 1 micrometer and a diameter of approximately 100-200 nm for the nanorods. Polypyrrole deposited on ITO/ZnO NW/dye and the fabricated device of ITO glass/ZnO nanorods/dye/polypyrrole/Ag showed a power conversion efficiency of 1.29%.
Effects Of Annealing On The Electronic Transitions Of Zns Thin Films, S. S. Chiad, W. A. Jabbar, N. F. Habubi
Effects Of Annealing On The Electronic Transitions Of Zns Thin Films, S. S. Chiad, W. A. Jabbar, N. F. Habubi
Journal of the Arkansas Academy of Science
Thin films of zinc sulphide were prepared using a flash evaporation technique. The obtained thin films were subjected to heat treatment to investigate the effect of annealing on the transmittance spectrum and the electronic transitions. It has been found that annealing affected the transmission spectrum and caused an increase in the direct optical band gap. The optical parameters, oscillator energy E0 and dispersion energy Ed were determined using the Wemple DiDomenico single oscillator model. The optical energy gap obtained from the Wemple and DiDomenico model was in good agreement with the optical energy gap proposed by the Tauc theory.
Synthesis And Characterization Of Ruthenium Complexes Containing Chlorophenanthroline And Bipyridine, Anwar A. Bhuiyan, S. Kudo, J. Bartlett
Synthesis And Characterization Of Ruthenium Complexes Containing Chlorophenanthroline And Bipyridine, Anwar A. Bhuiyan, S. Kudo, J. Bartlett
Journal of the Arkansas Academy of Science
The divalent ruthenium polypyridine complexes hold promise as efficient photocatalysts for solar energy conversion schemes. This paper deals with the synthesis and spectroscopic investigation of ruthenium polypyridine complexes, which may be useful as photosensitizers. The homoleptic ruthenium(II) complex Ru(Cl-phen)3(PF6)2 (where Cl-phen = 5- chloro-1,10-phenanthroline), and heteroleptic ruthenium(II) complexes Ru(Cl-phen)2(bpy)(PF6)2, and Ru(Cl-phen)(bpy)2(PF6)2 (where bpy = 2,2′-bipyridine) have been prepared by following the standard synthetic procedure. Silica and alumina column chromatographies were used to purify the compounds. Mass spectroscopy, nuclear magnetic resonance (nmr) spectroscopy, and elemental analysis were used to confirm the identity and the integrity of the complexes. Absorption and emission …
Optical Characterization Of Silver Doped Poly (Vinyl Alcohol) Films, W. A. Jabbar, N. F. Habubi, S. S. Chiad
Optical Characterization Of Silver Doped Poly (Vinyl Alcohol) Films, W. A. Jabbar, N. F. Habubi, S. S. Chiad
Journal of the Arkansas Academy of Science
Silver-doped PVA films were prepared by casting method in order to study the effect of silver on the optical properties of poly(vinyl alcohol) using UV/VIS spectroscopy. It was found that these thin films have an indirect optical band gap (2.4-1.3) eV as the doping percentage increase. Extinction coefficient and refractive index increase as the doping percentage increase, while in general the optical dispersion parameters show an opposite behavior with doping
Synthesis And Characterization Of Homoleptic And Heteroleptic Ruthenium Polypyridine Complexes, Anwar A. Bhuiyan, S. Kudo, C. Wade, R. F. Davis
Synthesis And Characterization Of Homoleptic And Heteroleptic Ruthenium Polypyridine Complexes, Anwar A. Bhuiyan, S. Kudo, C. Wade, R. F. Davis
Journal of the Arkansas Academy of Science
The homoleptic ruthenium(II) complex Ru(C13H10N2)3(PF6)2, and heteroleptic ruthenium(II) complexes Ru(C13H10N2)2(C10H8N2)(PF6)2, and Ru(C13H10N2)(C10H8N2)2(PF6)2 have been prepared by following the standard synthetic procedure. These complexes were then purified by repeated column chromatography. The identity and the integrity of the complexes were confirmed by elemental analysis and mass spectroscopy. The calculated and the experimental values for the elemental analysis were in good agreement. The calculated and the experimental molar masses obtained were also identical. Ultravioletvisible absorption and emission spectroscopic methods were used to investigate the properties of these complexes. The absorption spectra of all complexes consist of a series of absorption bands in …
Resonance Raman Spectroscopy For The Investigation Of Heteroleptic Ruthenium Polypyridine Complexes, Anwar A. Bhiuyan
Resonance Raman Spectroscopy For The Investigation Of Heteroleptic Ruthenium Polypyridine Complexes, Anwar A. Bhiuyan
Journal of the Arkansas Academy of Science
No abstract provided.
Quantifying Soil Chemical Properties Using Near Infrared Reflectance Spectroscopy, Robert L. Ficklin, Shane M. Foley, Robert E. Kissell Jr.
Quantifying Soil Chemical Properties Using Near Infrared Reflectance Spectroscopy, Robert L. Ficklin, Shane M. Foley, Robert E. Kissell Jr.
Journal of the Arkansas Academy of Science
Methodologies for determining soil chemical properties have evolved dramatically during the past century. Early geochemical analyses were conducted exclusively through the use of wet chemistry techniques that were relatively reliable but painstaking and subject to errors at various stages of analysis. Near infrared reflectance spectroscopy (NIRS) has emerged as a new approach for rapidly analyzing a variety of materials including soils. In this study soil samples were taken from eight study areas across the Ozark Highlands of Arkansas, and NIRS calibration models were developed to determine the accuracy of using NIRS to analyze soils compared with standard soil chemical analysis …
Measurement And Modeling Of Light Transmission Through Turbid Media, Alois (Al) J. Adams, Michael Fahrenwald, Long Do
Measurement And Modeling Of Light Transmission Through Turbid Media, Alois (Al) J. Adams, Michael Fahrenwald, Long Do
Journal of the Arkansas Academy of Science
No abstract provided.
Synthesis Of A Ruthenium-Tetra(Tht)Dichloride Compound And The Molecular Structure Of The Partially Oxidized Compound Rucl2(Tht)2.2(Tht-O)1.8, L. A. Thornton, Mark Draganjac, Andres Meza, A. W. Cordes
Synthesis Of A Ruthenium-Tetra(Tht)Dichloride Compound And The Molecular Structure Of The Partially Oxidized Compound Rucl2(Tht)2.2(Tht-O)1.8, L. A. Thornton, Mark Draganjac, Andres Meza, A. W. Cordes
Journal of the Arkansas Academy of Science
No abstract provided.
Non-Commercial Software For The Analysis And Interpretation Of High Resolution Molecular Spectra, A. R. Ford, Scott W. Reeve
Non-Commercial Software For The Analysis And Interpretation Of High Resolution Molecular Spectra, A. R. Ford, Scott W. Reeve
Journal of the Arkansas Academy of Science
No abstract provided.
Synthesis And Characterization Of A Ruthenium-Thioxane Complex, Amanda Wroble, Scotty Sproles, Mark Draganjac, Paul M. Nave
Synthesis And Characterization Of A Ruthenium-Thioxane Complex, Amanda Wroble, Scotty Sproles, Mark Draganjac, Paul M. Nave
Journal of the Arkansas Academy of Science
No abstract provided.
Speed Cut-Off Point For Antiforce Waves, Mostafa Hemmati, Mathues Shane Doss, Eric L. George
Speed Cut-Off Point For Antiforce Waves, Mostafa Hemmati, Mathues Shane Doss, Eric L. George
Journal of the Arkansas Academy of Science
A one-dimensional, three-component, fluid model has been employed to investigate the existence of a speed cut-off point for antiforce breakdown waves. The term antiforce wave is used to identify breakdown waves for which the electric field force on electrons is in the opposite direction of wave propagation. The electron fluid-dynamical equations for antiforce waves are different from those of proforce waves. This presentation will address the difference in the set of equations for proforce and antiforce waves and the method of integration of the set of equations through the dynamical transition region for antiforce waves. Also, for antiforce waves, the …
Separating K+/- From Pi+/- Using In-Flight Decays To Mu+/- + Nu, Wilfred J. Braithwaite, Edwin S. Braithwaite
Separating K+/- From Pi+/- Using In-Flight Decays To Mu+/- + Nu, Wilfred J. Braithwaite, Edwin S. Braithwaite
Journal of the Arkansas Academy of Science
A method is presented for completely distinguishing between charged kaons and charged pions by using their charged muon (plus neutrino) decays (with neutrinos undetected) for meson laboratory momenta up to 1000 MeV/c. When either a charged kaon or a charged pion decays into a muon and a neutrino, momentum-energy (four-momentum) conservation will be used to provide unique "kinematic trajectories" for distinguishing kaon decays from pion decays when the change in three-momentum of the muon from that of either parent kaon or pion is measured (or simulated). Ina magnetic field, observation of a tracked particle showing a "kink" and/or a change …
Coplanarity Test For Selecting A Pair Of Charged-Particle Tracks Resulting From A Single Neutral-Particle Decay, Edwin S. Braithwaite, Wilfred J. Braithwaite
Coplanarity Test For Selecting A Pair Of Charged-Particle Tracks Resulting From A Single Neutral-Particle Decay, Edwin S. Braithwaite, Wilfred J. Braithwaite
Journal of the Arkansas Academy of Science
It is hard to determine directly the position of a neutral subatomic particle, but when such a particle decays into a pair of charged particles, it is easy to determine the positions of the charged decay particles and thereby infer the position of the parent particle at the time of its decay. A minimum of two coordinate points for each of the two decay particles is needed to reconstruct the position of the parent vertex. The mathematics of the reconstruction process is inherently interesting, and it can be used to demonstrate to students the utility of some of the most …
Measuring Strangeness Production From Relativisitic Collisions Between Pairs Of Nuclei Using A Vertex Time Projection Chamber, Christine A. Byrd, Wilfred J. Braithwaite
Measuring Strangeness Production From Relativisitic Collisions Between Pairs Of Nuclei Using A Vertex Time Projection Chamber, Christine A. Byrd, Wilfred J. Braithwaite
Journal of the Arkansas Academy of Science
At collider energies of 200A-GeV, tracking of charged particle pairs originating from neutrals is dominated by singlystrange KJ.' decays. Counting the number ofsecondary vertex pairs is a method of measuring the strangeness production. The VTX is a four-layer micro-strip gas time projection chamber being designed for use with the STAR instrument in an experiment using the Relativistic Heavy Ion Collider under construction at Brookhaven National Laboratory. Simulated pixel data generated from CERN's Monte Carlo detector-modeling program Geant were put into tables using the TAS sorting structures available from the STAR Collaboration. The response of VTX was mapped for charged pion …
Critical Energy Of Torus Knots, Fred Hickling, Wesley Davis, Heather Woolverton
Critical Energy Of Torus Knots, Fred Hickling, Wesley Davis, Heather Woolverton
Journal of the Arkansas Academy of Science
The energy of a smoothly parameterized knot y(t) is defined as rr\ i i lp7 \\dn dsdt Jo Jo \||7M-7(0f (D(t(s),T(t))) 2 j\\ds \\dt where D(y (s), y(t)) is the arc length between the two points y (s) and y(t) on the curve. Simple calculus based arguments are used to locate critical values of the energy functional for torus knots. Explicitly the curves given parametrically by °(«*)W = (V2°iSri).JSSBe V2 C s7nS are CriticalP ° intS ° fthe energy functional whenever a and b are relatively prime.
Note Concerning Cloud Chamber Experiments With Positrons, H. M. Schwartz
Note Concerning Cloud Chamber Experiments With Positrons, H. M. Schwartz
Journal of the Arkansas Academy of Science
No abstract provided.