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Articles 1 - 10 of 10
Full-Text Articles in Physical Sciences and Mathematics
Speed Range For Breakdown Waves, Mostafa Hemmati, Eric L. George, Frances Terry
Speed Range For Breakdown Waves, Mostafa Hemmati, Eric L. George, Frances Terry
Journal of the Arkansas Academy of Science
Considering the electrons as the main element in breakdown wave propagation and using a one-dimensional, steady-state, three-fluid, hydrodynamical model, previous investigations have resulted in the completion of a set of equations for conservation of mass, momentum, and energy. We will use the terms proforce and antiforce waves, depending on whether the applied electric field force on electrons is with or against the direction of wave propagation. In the case of antiforce waves, the electron gas temperature and therefore the electron fluid pressure is assumed to be large enough to sustain the wave propagation down the discharge tube. For strong discontinuity …
Locating Napls In Ground Water Using Partitioning Fluorescent Dyes, A. Ghanem, J. Smith, M. Elzey, T. S. Soerens, M. A. Miah, G. Thoma
Locating Napls In Ground Water Using Partitioning Fluorescent Dyes, A. Ghanem, J. Smith, M. Elzey, T. S. Soerens, M. A. Miah, G. Thoma
Journal of the Arkansas Academy of Science
A major challenge in ground water remediation is locating nonaqueous phase liquids (NAPLs). Partitioning tracers can be used to identify NAPL sources between injection and extraction wells. NAPLs are only slightly soluble in water, pose a long-term source of groundwater contamination, and can be difficult to remove. The complexity of recovery processes requires the development of new technologies that guarantee cost effective methods for locating and quantifying NAPLs. Traditional methods like soil coring have been inefficient since they underestimate the quantity of NAPLs and are expensive. Partitioning tracer tests are some of the most recent methods developed for locating these …
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. …
Comparison Of Environmental Assessments Of Two Proposed Harbor Expansions On The Mississippi River, Richard S. Grippo, Bobby Bennett, Randel T. Cox
Comparison Of Environmental Assessments Of Two Proposed Harbor Expansions On The Mississippi River, Richard S. Grippo, Bobby Bennett, Randel T. Cox
Journal of the Arkansas Academy of Science
The National Environmental Policy Act of 1969 requires federally funded projects to be evaluated for environmental impact to determine if a complete environmental impact statement must be prepared. Such an environmental assessment must also be included in any feasibility study for harbor enlargement and bank stabilization measures under the Water Resources Development Act. Population increases, coupled with economic growth from increased agricultural and industrial productivity, have resulted in increased Mississippi River barge transportation needs for Arkansas and Missouri. We report here two such environmental assessments of planned harbor expansions of the New Madrid County and Pemiscot County ports in the …
Changes In Soil Chemistry Beneath Exposed Poultry House Pads And Manure Storage Areas, Stanley L. Chapman, William R. Teague
Changes In Soil Chemistry Beneath Exposed Poultry House Pads And Manure Storage Areas, Stanley L. Chapman, William R. Teague
Journal of the Arkansas Academy of Science
Concerns about nitrates in private drinking water supplies in the older poultry growing areas of Arkansas prompted soil and water testing in the early 1990's. Exposed poultry house pads were recognized as a potential source of nitrates in the groundwater. Soils beneath nine different poultry house pads in five counties were sampled in 10-30 cm increments to bedrock or to a maximum sampling depth of 90 cm. The nine sites had been exposed to natural weathering conditions ranging from never to for more than 20 years. Routine soil tests were conducted by the University of Arkansas Soil Testing Lab at …
Microlevel Climate Change Due To Changes In Surface Features In The Ganges Delta, M. M. Adel
Microlevel Climate Change Due To Changes In Surface Features In The Ganges Delta, M. M. Adel
Journal of the Arkansas Academy of Science
The Ganges had been the world's 8th largest river in terms of the volume of water discharge of 490 km3/yr to the ocean 4 prior to 1975. Since that time, over a period of two decades, India has reduced the Ganges discharge through Bangladesh to 40% from its original annual average discharge of 1,932+7-223 m3 /s by diverting water for irrigation in her upper states. The , resulting consequences have been disastrous due to the depletion of the surface water resources. One of the devastating consequences has been the generation of extreme climate. The summertime maximum temperature has risen to …
Effects Of Predation On Two Species Of Stream-Dwelling Crayfish (Orconectes Marchandi And Cambarus Hubbsi) In Pool And Riffle Microhabitats, Heidi Dukat, Daniel D. Magoulick
Effects Of Predation On Two Species Of Stream-Dwelling Crayfish (Orconectes Marchandi And Cambarus Hubbsi) In Pool And Riffle Microhabitats, Heidi Dukat, Daniel D. Magoulick
Journal of the Arkansas Academy of Science
Community structure may be governed by many abiotic and biotic factors. Of the biotic factors, predation is often considered to be critical in structuring freshwater stream communities. In the Warm Fork of the Spring River, the crayfish Cambarus hubbsi is found mainly in riffles, whereas the crayfish Orconectes marchandi is found in high numbers in pools. We hypothesized that predation, mainly by fish, is a factor causing this segregation. Higher predation rates for C. hubbsi than 0. marchandi in the pools and higher predation rates for 0. marchandi than C. hubbsi in the riffles were expected. A transplant tethering experiment …
Synthesis And Molecular Structure Of [Cpru(Pph3)(Pms)2]Otf1.3/4 C2>H4C12, Paul M. Nave, Mark Draganjac, A. W. Cordes, Tosha M. Barclay
Synthesis And Molecular Structure Of [Cpru(Pph3)(Pms)2]Otf1.3/4 C2>H4C12, Paul M. Nave, Mark Draganjac, A. W. Cordes, Tosha M. Barclay
Journal of the Arkansas Academy of Science
No abstract provided.
Morphometry And Limnology Of Ferguson Lake, Saline County, Arkansas, John D. Rickett, E. P. (Perk) Floyd
Morphometry And Limnology Of Ferguson Lake, Saline County, Arkansas, John D. Rickett, E. P. (Perk) Floyd
Journal of the Arkansas Academy of Science
To more fully understand Ferguson Lake as an ecosystem and eventually relate its water quality and production potential to fisheries management, several limnological variables were sampled monthly from April 1997 through March 1999. Vertical profiles of temperature and dissolved oxygen were recorded, and water samples from 0.5 m. depth were tested for turbidity, pH, total alkalinity, total hardness, ortho-phosphate, nitrate-nitrogen, sulfate, iron and specific conductance. Evaporation rate experiments, spillway discharge and rainfall records were used to estimate lake hydrology. Depth transects on the lake and USGS topographic maps were used to measure and calculate morphometric and watershed features. The lake …
Statistical Analysis Of Climatic Variables In The Arkansas-Red River Basin, Felix Tendeku
Statistical Analysis Of Climatic Variables In The Arkansas-Red River Basin, Felix Tendeku
Journal of the Arkansas Academy of Science
Surface meteorological data for the Arkansas-Red River basin are analyzed in order to provide statistical data for modeling and simulation of climatic trends within the basin. The variables studied are the ambient temperature, temperature range and precipitation. Daily and monthly mean values, spatial and seasonal variations, and frequency distributions are determined.