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Articles 1 - 9 of 9
Full-Text Articles in Physical Sciences and Mathematics
Pleistocene Mammals From The South Sulphur River, Hunt County, Texas, Leo Carson Davis, Kenneth M. Ball
Pleistocene Mammals From The South Sulphur River, Hunt County, Texas, Leo Carson Davis, Kenneth M. Ball
Journal of the Arkansas Academy of Science
Preliminary collecting and excavating along the South Sulphur River has produced a diverse list of fossil mammals. The pampathere, Holmesina septentrionalis, and the large armadillo, Dasypus bellus, with their southern affinities from the extinct megafauna, were found in association with Microtus pennsylvanicus, which has a northern distribution at present. This combination of species argues for climatic conditions and biotic communities during the Pleistocene that have no modern counterparts.
Preparation Of A Series Of Substituted N-Phenyl-5-Bromo-6-Chloro- And 5-Bromo-6-Chloronicotinates Of Potential Agricultural Interest, Frank L. Setliff, Maximillia M. Muguluma, Jody Z. Caldwell
Preparation Of A Series Of Substituted N-Phenyl-5-Bromo-6-Chloro- And 5-Bromo-6-Chloronicotinates Of Potential Agricultural Interest, Frank L. Setliff, Maximillia M. Muguluma, Jody Z. Caldwell
Journal of the Arkansas Academy of Science
Substituted phenyl esters of 5-bromo-2-chloronicotinic acid and 5 bromo 6-chloronicotinic acid were prepared. The acids were first converted to their respective acid chlorides using thionyl chloride, and the acid chlorides were immediately transformed to the esters by treatment with the appropriately substituted phenol in sodium hydroxide solution. Aunique chloride displacement of bromide was observed on attempting to convert 5,6-dibromonicotinic acid to its acid chloride
Using Viruses To Examine Soil Treatment Of Septic Tank Effluent, Mark A. Gross, Jenna Hestir, Duane C. Wolf, E. Moye Rutledge
Using Viruses To Examine Soil Treatment Of Septic Tank Effluent, Mark A. Gross, Jenna Hestir, Duane C. Wolf, E. Moye Rutledge
Journal of the Arkansas Academy of Science
Viral contamination of drinking water supplies due to inadequate renovation of septic tank effluent (STE) is a public health concern. The purpose of this paper is to illustrate the use of a bacteriophage to evaluate virus movement in a soil treatment system. Viruses - MS2 bacteriophage - were injected into a wastewater treatment system with soil absorption trenches and drainage tiles, and the drain tile effluent was collected and assayed for the phage. The virus suspension was assayed and a measured amount of STE and virus suspension was pumped into the system allowing for calculation of the influent virus titer. …
Microwave Pasteurization Of Potting Mixes, Rudolph J. Eichenberger
Microwave Pasteurization Of Potting Mixes, Rudolph J. Eichenberger
Journal of the Arkansas Academy of Science
A study was conducted to determine if potting soils could be pasteurized with a typical 1200 watt microwave oven. Microwave radiation times varied from 0 to 6.0 minutes. Preliminary results indicated that "damping-off" diseases could be prevented in tomato seedlings with the use of potting soils pasteurized by microwaves.
Double Tuned Cosine Coil For Nmr Imaging/Microscopy, Roger M. Hawk, Rao P. Gullapalli, Dikoma P. Shungu
Double Tuned Cosine Coil For Nmr Imaging/Microscopy, Roger M. Hawk, Rao P. Gullapalli, Dikoma P. Shungu
Journal of the Arkansas Academy of Science
The fabrication of a cosine coil having unevenly distributed struts is detailed. Placing the struts in such a manner enables a standing wave at the desired frequency and, hence, only one resonance frequency is obtained. This study details the fabrication of a cosine coil tuned to the LJ-7 frequency (77.76 MHz) and then double-tuned to the H-1 frequency (200.1 MHz) when operated at 4.7 Tesla. Double-tuning is attained by placing an LC trap in series with a capacitor used to single-tune the coil. Also, a method is suggested by which a cosine coil can be broadbanded in the lower frequency …
Groundwater Hydrology Of A Population Of Lindera Melissifolia In Arkansas, J. Dainette Priest, Robert D. Wright
Groundwater Hydrology Of A Population Of Lindera Melissifolia In Arkansas, J. Dainette Priest, Robert D. Wright
Journal of the Arkansas Academy of Science
Groundwater hydrology was monitored from October through August in and around a bottomland forest pond containing Lindera melissifolia, pondberry. The study site exhibited a series of low ancient dunes and depressions, with seasonal ponds in the depressions. Ponds showed no surface inlets or outlets. Shallow wells were made and soil cores removed along a transect from the top of one dune across the pond to a lower dune. Piezometers were installed in the wells and groundwater levels monitored. Soil core samples were analyzed to determine particle size distribution at soil profile positions selected during field analysis. It was shown that …
Preparation Of A Series Of N-Phenylamides Of 5-Bromo-6-Chloronicontinic Acid And 5-Bromo-2-Chloronicontinic Acid, Frank L. Setliff, Jody Z. Caldwell
Preparation Of A Series Of N-Phenylamides Of 5-Bromo-6-Chloronicontinic Acid And 5-Bromo-2-Chloronicontinic Acid, Frank L. Setliff, Jody Z. Caldwell
Journal of the Arkansas Academy of Science
A series of N-phenylamides of 5-bromo 6-chloronicotinic acid and 5-bromo-2-chloronicotinic acid were synthesized by treatment of their freshly prepared acid chlorides with the appropriately ring substituted anilines. Thirty new compounds were prepared, and their structures were ascertained by elemental analyses and spectroscopic techniques. Spectroscopic trends in the infrared spectra of the two series were examined in an attempt to correlate structural and electronic effects to hydrogen bonding tendencies.
K-Shell Ionization Measurements For Light Incident Icons, Rahul Mehta, George Bissinger
K-Shell Ionization Measurements For Light Incident Icons, Rahul Mehta, George Bissinger
Journal of the Arkansas Academy of Science
The ionization of the K-shell in targets of copper, silver, dysprosium and gold was investigated with incident ion beams of proton and helium ions in the range 0.5 MeV/u to 3 MeV/u. The x-rays were detected by a HpGe detector. K-shell x-ray production cross section were determined by normalization of the x-ray yield to the incident beam flux, the Rutherford-scattered ions and the nuclear-Coulomb excited gamma ray yield. The multiple normalization procedures minimize the errors in these cross section measurements. The data are compared with the predictions of the ECPSSR theory for K-shell ionization. The atomic number dependence of these …
Lightning: A Complex Natural Phenomenon That Defies Simple Analysis, Mostafa Hemmati
Lightning: A Complex Natural Phenomenon That Defies Simple Analysis, Mostafa Hemmati
Journal of the Arkansas Academy of Science
No abstract provided.