Radionuclide Concentrations in the Arkansas River Upstream and Downstream from the Nuclear I Power Generating Facility

This report summarizes results obtained from a program designed to measure very low levels of some commonly produced radionuc1ides in the Dardenelle Lake area of the Arkansas River near the Arkansas Nuclear I Power Station operated by Arkansas Power and Light Company. The main thrust of this program was to determine the increase in the concentration of the radionuclides as a result of reactor operation as a function of their distance from the source. It was hoped to extend this study to include the effects of these emissions on the uptake of radionuclides into biological systems and their deposition in sediments

Empirical Model for the Variarion in Concentration of Metal Ions During a Precipitation Event

The concentration of a pollutant in an air mass and the concentration of that pollutant in a series of rain water samples from a single event within that air mass, fluctuate during the course of the event. This the result of scavenging, diffusion, and advection processes. A simple mathematical model, containing only a scavenging term has had limited success in describing changes of concentration in rain water. To date, no attempt has been made to include diffusion or advection terms in the model. In this study, a two factor model was developed after determining that (1) the exponential scavenging term is dependent upon the amount of precipitation that has fallen rather than time elapsed and (2) that the magnitude of the diffusion/advection term is inversely proportional to the precipitation rate. Coefficients for the variables in the two terms [Psiav and (bCf), respectively] were determined by the best fit of concentration curve derived from the model equation to experimental points. Time series from 24 rain events samples collected during 1987-88 and during the spring of 1998 were analyzed. The values of Psiav were remarkably constant during both periods, but the two groups of Psiav were different. The values of (bCf) correlated moderately well with the concentrations of ions in the samples

Radionuclides in Dardanelle Lake in the Area of the Nuclear I Facility: 1979-1981

The variations of the concentrations of 90Sr and 137Cs at four stations in Dardanelle Reservoir were analyzed as functions of two parameters: concentration of ionic species and the activity released, Ar, from the two 900 Mw reactors which use the reservoir as a source of cooling water. Multiple regression analyses were performed on the radionuclide concentrations using the two parameters as predictors. The analyses indicated that 90Sr is in a state of equilibrium between the solution and the suspended sediment. The position of the equilibrium was found to be quite sensitive to changes in the concentration of alkaline earth cations, M(II). Thus, the concentration of M(II) has a substantial effect on the removal of 90Sr from the water column. The 137CS concentration varied as Ar, indicating that solution-sediment equilibrium has not been attained since the time necessary for newly released 137Cs to come to equilibrium is greater than the mean residence time of water in Dardanelle Reservoir. The occurrence of 144Ce-144Pr in the Reservoir seems to be a consequence of refueling or maintenance of the reactors; the 141Ce as well as 144Ce, it appears, were originally airborne and find their way to the reservoir through runoff

Radionuclide Concentrations in the Arkansas River Upstream and Downstream from the Nuclear Power Generating Facility

This report summarizes results obtained from a program designed to measure very low levels of some commonly produced radionuc1ides in the Dardenelle Lake area of the Arkansas River near the Arkansas Nuclear I Power Station operated by Arkansas Power and Light Company. The main thrust of this program was to determine the increase in the concentration of the radionuclides as a result of reactor operation as a function of their distance from the source. It was hoped to extend this study to include the effects of these emissions on the uptake of radionuclides into biological systems and their deposition in sediments

Reproduction, Age And Growth, And Movements Of The Gulf Butterfish Peprilus-Burti

Collections were made for gulf butterfish Peprilus burti along a cross-shelf transect at depths of 5-100 m in the Gulf of Mexico off Texas from October 1977 to July 1980. Butterfish mature at 100-160 mm fork length as they approach age I. Spawning occurs primarily from September through May, but length frequencies indicate it concentrates, or is most successful, in distinct Winter (late January-mid-May) and Fall (early September-late October) periods that coincide with downcoast, alongshore currents (toward Mexico). Gonad data and persistence of small fish indicate spawning in winter, but at a low level. Spawning probably occurs offshore and upcoast toward the northcentral Gulf. Surface currents of the cyclonic shelf gyre probably transport eggs/larvae inshore and downcoast to recruit to the bottom in water 5-27 m deep, used as nurseries by butterfish when they are 2-5 months old. Butterfish disperse offshore as they mature and congregate in 36-100 m depths when they are 9-12 months old. They average 130-146 mm in fork length at age I in the northwestern Gulf, but 120-124 mm at age I and about 170 mm at age II in the northcentral Gulf. Estimates for the von Bertalanffy growth parameters L-infinity, K, and t0 were 164 mm, 1.99/year, and -0.20 years, respectively, for pooled northwestern Gulf Winter cohorts and 141 mm, 2.69/year, and -0.06 years, respectively, for pooled Fall cohorts. Somatic growth ceases as spawning approaches in the northwestern Gulf, but fish from the northcentral Gulf show large annual size increments. Butterfish reach about 200 mm in fork length, the largest ones occurring in the northcentral Gulf. Apparent maximum ages are 1-1.5 years in the northwestern Gulf, and 2-2.5 years in the northcentral Gulf. Differences in population attributes suggest complete mortality at age I in the northwestern Gulf or some unknown combination of an offshore and permanent contranatant spawning or postspawning emigration of adults to the northcentral Gulf. The genus Peprilus shows zoogeographic differences in population dynamics near Cape Hatteras, North Carolina

Chemical Composition of Particles of d \u3c 0.20 mu in the Lower Stratospheric Aerosol, Spring 1993

The majority of the mass of stratospheric aerosol collected during the spring of 1993 consisted principally of particles of d \u3e0.20 mu containing a mixture of H2SO4 and (NaK)2SO4. However, the composition of the more numerous particles with d\u3c 0.2 mu was very different. X-ray emission spectra (EDS) of individual particles indicated that there were three different chemical populations of small particles. The most numerous population was almost all C with only traces of S and Na. The second population contained metal sulfates and chlorides, possibly accreted to a C-containing matrix. The third population consisted of S- and Cl- containing species and trace amounts of Na and K ions. The number of equivalents of metal ion was much less than that of S and Cl species, indicating that most of the S and Cl was not ionic, but was covalently bonded, perhaps to a C matrix

Horses grown on limited grain rations

Cover title.Includes bibliographical references

Automated migration analysis based on cell texture: method & reliability

BACKGROUND: In this paper, we present and validate a way to measure automatically the extent of cell migration based on automated examination of a series of digital photographs. It was designed specifically to identify the impact of Second Hand Smoke (SHS) on endothelial cell migration but has broader applications. The analysis has two stages: (1) preprocessing of image texture, and (2) migration analysis. RESULTS: The output is a graphic overlay that indicates the front lines of cell migration superimposed on each original image, with automated reporting of the distance traversed vs. time. Expert preference compares to manual placement of leading edge shows complete equivalence of automated vs. manual leading edge definition for cell migration measurement. CONCLUSION: Our method is indistinguishable from careful manual determinations of cell front lines, with the advantages of full automation, objectivity, and speed