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Full-Text Articles in Physical Sciences and Mathematics
Physical Characteristics And Classification Of The Large Amplitude Variable Star V1719 Cygni, Ashley Lieber, Logan Siems, Julia Kennefick, Michael Fitzgerald
Physical Characteristics And Classification Of The Large Amplitude Variable Star V1719 Cygni, Ashley Lieber, Logan Siems, Julia Kennefick, Michael Fitzgerald
Inquiry: The University of Arkansas Undergraduate Research Journal
Pulsating stars are used as standard candles which are helpful in determining distances to stellar objects along with the relationship between their period and apparent luminosity. The focus of this study was the variable star, V1719 Cygni, which is often classified as a Delta (δ) Scuti star, but there exists debate that it should be classified as a RR Lyrae star due to its abnormal light curve and similar characteristics between the two variable star categories. Observational data was taken in 2019 using the Las Cumbres Observatory international telescope network. The resulting data were calibrated using comparison stars in the …
Computational Study Of A Novel Dinuclear Metal Complex, Dragos Seghete
Computational Study Of A Novel Dinuclear Metal Complex, Dragos Seghete
Inquiry: The University of Arkansas Undergraduate Research Journal
The first compound containing an M-H-M was recently reported by Vicic et al. With recent availability of large computational resources, molecular modeling has become a reliable tool for confirming experimental results. The novel dinuclear Ni complex [( dippm)2Ni2Br2]( 0 -H) was investigated in this work from a theoretical perspective. Full geometry optimization was carried on the dinuclear Ni complex at the DFT/B3LYP with the 6-31G* basis set. The result verifies the linear Ni-H-Ni bond. Two different starting structures that converged to the same geometry confirm that a global minimum was reached. The computed structure differs from the experimentally determined one …
Analysis Of Phytoestrogens By High Performance Liquid Chromatography, Anne A. Grippo, Yan Xie, Benjamin L. Rougeau, William V. Wyatt
Analysis Of Phytoestrogens By High Performance Liquid Chromatography, Anne A. Grippo, Yan Xie, Benjamin L. Rougeau, William V. Wyatt
Journal of the Arkansas Academy of Science
Phytoestrogens are biochemicals synthesized in plants which mimic steroidal estrogen activity in mammals. Analysis of these compounds in the legumes which produce them and in body fluids is important to the study of their physiological effects. High pressure liquid chromatography (HPLC) has been found to be an efficient and sensitive method of identification and quantitation of isoflavonoids, one class of phytoestrogen. Here we report the separation of three isoflavonoids, biochanin A, genistein and daidzein using an HPLC system with a Cg reverse phase column and a linear gradient mobile phase containing acetonitrile and acetic acid/water (10/90, v/v) over 60 minutes. …
Thermal Decomposition Studies Of Selected Transition Metal Polysulfide Complexes. Ii. Effect Of Atmosphere On Decomposition, Benjamin Rougeau, Mark Draganjac
Thermal Decomposition Studies Of Selected Transition Metal Polysulfide Complexes. Ii. Effect Of Atmosphere On Decomposition, Benjamin Rougeau, Mark Draganjac
Journal of the Arkansas Academy of Science
Initial studies involved the thermal decomposition profile of five polysulfide complexes in air up to 550 °C. Since our first report to the Academy in 1990, we have obtained the capability to run samples up to 1500°C under various gases. Thermal Gravimetric Analysis (TGA) and Differential Thermal Analysis (DTA)of a series of transition metal polysulfide complexes are presented. Compounds analyzed included Cp2TiS5 ,MoS9 2",MoOS8 2", Zn(S x ) 2", Cd(S x ) 2-, Fe2S122 - and NiS82.
Effective, Reliable, Inexpensive Cryofixation Device, Lawrence A. Mink, Roger A. Buchanan
Effective, Reliable, Inexpensive Cryofixation Device, Lawrence A. Mink, Roger A. Buchanan
Journal of the Arkansas Academy of Science
No abstract provided.
Rotational Symmetries Of Nuclear States: Spin Determinations In Advanced Laboratory, Wilfred J. Braithwaite
Rotational Symmetries Of Nuclear States: Spin Determinations In Advanced Laboratory, Wilfred J. Braithwaite
Journal of the Arkansas Academy of Science
An advanced laboratory experiment is described which shows the connection between the rotational symmetries of nuclear states and the assignments of spins to discrete nuclear states. Standard angular correlation methods were used to study the two sequential gamma ray transitions in each ⁶⁰Ni nucleus, populated by unobserved beta decays from a weak radioactive ⁶⁰Co source. The chosen electronics and detectors were inexpensive and easy to operate. This experiment was extended to introduce students to real-world data acquisition, using finite-geometry detectors, which resulted in enormously larger coincident data rates.