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Atmospheric transport and deposition of acidic air pollutants

Description: Although general principles which govern atmospheric chemistry of sulfur are understood, a purely theoretical estimation of the magnitude of the processes is not likely to be useful. Furthermore, the data base necessary to make empirical estimates does not yet exist. The sulfur budget of the atmosphere appears to be dominated by man-associated sulfur. The important processes in deposition of man-associated sulfur are wet deposition of sulfate and dry deposition of SO/sub 2/. The relative importance of sulfate and SO/sub 2/ to sulfur deposition (input to watersheds) depends on the air concentrations, and either compound may be the greater contributor depending on conditions. (PSB)
Date: January 1, 1981
Creator: Murphy, C.E. Jr.
Partner: UNT Libraries Government Documents Department

Model for absorption and release of gaseous materials by forest canopies. [Tritium]

Description: A model of the physical processes defining the absorption and release of materials by a forest canopy has been developed. The model deals with the turbulent transport of gaseous materials in the surface boundary layer near the canopy, the turbulent transport in the canopy atmosphere, the transport through the boundary layer near the leaf and soil surface, and the solution of the gaseous materials in intracellular fluids and subsequent diffusion into the leaf cells. The model is used to simulate the uptake of molecular tritium by the forest canopy and the subsequent release of tritiated water. Results of dynamic simulations of tritium uptake and release are compared with data collected at the time of a release of molecular tritium to the atmosphere.
Date: January 1, 1976
Creator: Murphy, C. E. Jr.
Partner: UNT Libraries Government Documents Department

Environmental transport and cycling of tritium in the vicinity of atmospheric releases. [Savannah River Plant]

Description: Routine releases of tritium to the atmosphere from the Savannah River Plant (SRP) have averaged 5.12 x 10/sup 5/ curies per year during the period 1974 to 1977. Patterns of tritium dispersion in the environment surrounding SRP indicate a power law relationship between air concentration and distance from the source. The relationship between the concentration of tritiated water in vegetation and distance is more complex. A model of the tritium dispersion and cycling in the environment explains the dispersion patterns in terms of the ratio of tritiated hydrogen to tritiated water, climate, and vegetation characteristics. The annual variation in the environmental patterns around the SRP is almost completely determined by the fraction of tritiated hydrogen in the release.
Date: January 1, 1978
Creator: Murphy, C.E. Jr. & Pendergast, M.M.
Partner: UNT Libraries Government Documents Department

Tritium transport around nuclear facilities

Description: The transport and cycling of tritium around nuclear facilities is reviewed with special emphasis on studies at the Savannah River Laboratory, Aiken, South Carolina. These studies have shown that the rate of deposition from the atmosphere, the site of deposition, and the subsequent cycling are strongly influenced by the compound with which the tritium is associated. Tritiated hydrogen is largely deposited in the soil, while tritiated water is deposited in the greatest quantity in the vegetation. Tritiated hydrogen is converted in the soil to tritiated water that leaves the soil slowly, through drainage and transpiration. Tritiated water deposited directly to the vegetation leaves the vegetation more rapidly after exposure. Only a small part of the tritium entering the vegetation becomes bound in organic molecules. However, it appears tht the existence of soil organic compounds with tritium concentrations greater than the equilibrium concentration in the associated water can be explained by direct metabolism of tritiated hydrogen in vegetation.
Date: January 1, 1981
Creator: Murphy, C.E. Jr. & Sweet, C.W.
Partner: UNT Libraries Government Documents Department

Effect of vegetation on air quality: the value of forest vegetation as a filter for industrial sources of air pollutants

Description: A general model that can be used to estimate the deposition of gaseous pollutants by forests is made with described. Then the model is used to estimate the deposition of fluoride as hydrogen fluoride (HF) around an aluminum refinery. A comparison of spatial and temporal concentration patterns is made with data collected around the ALUAR plant in Puerto Madryn, Argentina. Finally, the area of forest needed to remove a significant portion of the fluoride from the atmosphere is estimated.
Date: January 1, 1980
Creator: Murphy, C.E. Jr. & Ares, J.O.
Partner: UNT Libraries Government Documents Department

The Canadian experimental HT release of June 10, 1987, US measurements

Description: In June 1987, an experiment was performed at the Chalk River Nuclear Laboratories in Ontario, Canada, to study the oxidation of elemental tritium (HT) released to the environment. The experiment involved a 30-minute release of 3.54 TBq (95.7 Ci)of HT to the atmosphere at an elevation of one meter. Scientists from six countries participated in the experiment. The air measurements showed HT concentrations downwind of the release in general agreement with classical atmospheric diffusion (Gaussian) up to the maximum distance measured (400 m). The HTO/HT ratios were shown to slowly increase downwind (approx. 4 x 10/sup /minus/5/ at 50 m to almost 10/sup /minus/3/ at 400 m) as conversion of HT took place. After the release, HTO concentrations in the atmosphere remained elevated. Vegetation samples were also taken since the vegetation and associated soil system have been implicated in the oxidation of HT. Freeze-dried water from vegetation samples was found to be low in HTO immediately after the release suggesting a low direct uptake of HTO in air by vegetation. The tritiated water concentration increased during the first day, peaking during the second day (about 15--30 kBq/L of water at 50 m from the source), and decreasing by the end of the second day. This pattern suggests oxidation in the soil followed by plant uptake through sorption of soil water. This was confirmed by measurements taken by other groups at the experiment site. The HTO in vegetation decreased with distance downwind with the same pattern as the HT measured during the release indicating that the oxidation of HT was linearly related to the HT concentration in the atmosphere during the exposure period. An adequate description of the process can be made through the observed phenomenon of HT deposition into the soil with subsequent rapid oxidation by soil bacteria. 30 refs., ...
Date: September 1, 1988
Creator: Jalbert, R.A. & Murphy, C.E.
Partner: UNT Libraries Government Documents Department

US team measurements during the June 1987 experimental HT release at the Chalk River Nuclear Laboratories, Ontario, Canada

Description: In June 1987, an experiment was performed at the Chalk River Nuclear Laboratories in Ontario, Canada, to study the oxidation of HT in the environment. The experiment involved a 30-minute release of 100 Ci of HT to the atmosphere at an elevation of one meter. The HTOHT ratios were shown to slowly increase downwind (/approximately/4 /times/ 10/sup /minus/5/ at 50 meters to almost 10/sup /minus/3 at 400 meters) as conversion of HT takes place. For several days after the release, HTO concentrations in the atmosphere remained elevated. Freeze-dried water from vegetation samples was found to be very low in HTO immediately after the release suggesting a very low direct uptake of HTO in air by vegetation. The tritiated water concentration increased during the first day, peaking during the second day (about 400 to 600 pCiml of water at 50 meters from the source) and decreasing by the end of the second day. The organically bound tritium continued to accumulate during the period following exposure (about 10 pCigm dry weight at 50 meters after two days). 4 refs., 6 figs., 2 tabs.
Date: January 1, 1988
Creator: Jalbert, R. A. & Murphy, C. E.
Partner: UNT Libraries Government Documents Department

Assessment of potential radiation dose-to-man from an acute tritium release into a forest ecosystem

Description: On May 2, 1974, 479,000 curies of tritium gas escaped from a Savannah River Plant exhaust stack. The tritium first reached the ground in a pine forested area and was partially assimilated into the ecosystem. Samples of vegetation collected and measured for a period of 70 days showed an increase in the levels of tritiated water. Cycling of the tritium retained in the forest ecosystem resulted in a higher concentration of tritiated water vapor in the air at breathing height near the forest floor than that calculated by the usual models used for predicting air concentration. In addition, the model for tritium cycling in the forest predicts a diurnal cycle of tritiated water vapor concentration with higher concentrations at night when air movement under the canopy is slower. The potential dose to the maximum individual because of inhalation and skin absorption of tritium as HTO after the release was calculated three ways: by using the body water model from the International Commission on Radiological Protection (ICRP) Publication 2 and assimilation during the passage of the puff; by using the body water model from the ICRP Publication 2 and assimilation during an extended exposure period to tritium determined by the experimental measurements; and by using a three-compartment dosimetry model with retention half times of 9, 30, and 450 days with the extended exposure period. The potential doses were 0.14, 0.80, and 0.89 mrem, respectively. These potential doses show the necessity of considering the interaction of radioactive material with the ecosystem for dose calculation.
Date: January 1, 1977
Creator: Watts, J. R. & Murphy, C. E. Jr.
Partner: UNT Libraries Government Documents Department

Lampsilis teres, Specimen #317

Description: One preserved mussel specimen including both the left and right valves. The specimen exhibits an elliptical shape; moderately thick shell; white internal coloring; tan external coloring; no external sculpturing. Collected in the San Jacinto basin. The specimen measures between 100 - 120 mm in length and was assessed to be recently dead when collected.
Date: October 5, 1975
Creator: Boone, Constance; Murphy, C.; Murphy, C. & Boone, Constance
Partner: Elm Fork Natural Heritage Museum

Toxolasma parvum, Specimen #1115

Description: One preserved mussel specimen including the left valve only. The specimen exhibits an elliptical shape; thick shell; single looped beak sculpturing; white internal coloring; tan external coloring; no external sculpturing. Collected in the Trinity basin. The specimen measures between 0 - 60 mm in length and was assessed to be very-long dead when collected.
Date: October 18, 1974
Creator: Britton, Joseph & Murphy, C.
Partner: Elm Fork Natural Heritage Museum

Toxolasma parvum, Specimen #1116

Description: One preserved mussel specimen including the left valve only. The specimen exhibits an elliptical shape; thick shell; single looped beak sculpturing; white internal coloring; tan external coloring; no external sculpturing. Collected in the Trinity basin. The specimen measures between 0 - 60 mm in length and was assessed to be long dead when collected.
Date: October 18, 1974
Creator: Britton, Joseph & Murphy, C.
Partner: Elm Fork Natural Heritage Museum

Toxolasma parvum, Specimen #1117

Description: One preserved mussel specimen including the right valve only. The specimen exhibits an elliptical shape; thick shell; single looped beak sculpturing; white internal coloring; tan external coloring; no external sculpturing. Collected in the Trinity basin. The specimen measures between 0 - 60 mm in length and was assessed to be long dead when collected.
Date: October 18, 1974
Creator: Britton, Joseph & Murphy, C.
Partner: Elm Fork Natural Heritage Museum

Leptodea fragilis, Specimen #466

Description: One preserved mussel specimen including the right valve only. The specimen exhibits an oval shape; thin shell; double looped beak sculpturing; white internal coloring; tan external coloring; no external sculpturing. Collected in the Red River basin. The specimen measures between 60 - 100 mm in length and was assessed to be very-long dead when collected.
Date: April 25, 1975
Creator: Britton, Joseph & Murphy, C.
Partner: Elm Fork Natural Heritage Museum

Leptodea fragilis, Specimen #467

Description: One preserved mussel specimen including both the left and right valves. The specimen exhibits an oval shape; thin shell; double looped beak sculpturing; white internal coloring; off-white external coloring; no external sculpturing. Collected in the Red River basin. The specimen measures between 0 - 60 mm in length and was assessed to be very-long dead when collected.
Date: April 25, 1975
Creator: Britton, Joseph & Murphy, C.
Partner: Elm Fork Natural Heritage Museum

Leptodea fragilis, Specimen #468

Description: One preserved mussel specimen including the right valve only. The specimen exhibits an oval shape; thin shell; double looped beak sculpturing; white internal coloring; tan external coloring; no external sculpturing. Collected in the Red River basin. The specimen measures between 0 - 60 mm in length and was assessed to be long dead when collected.
Date: April 25, 1975
Creator: Britton, Joseph & Murphy, C.
Partner: Elm Fork Natural Heritage Museum

Toxolasma parvum, Specimen #1118

Description: One preserved mussel specimen including both the left and right valves. The specimen exhibits an elliptical shape; thick shell; single looped beak sculpturing; bluish-white internal coloring; tan external coloring; no external sculpturing. Collected in the Red River basin. The specimen measures between 0 - 60 mm in length and was assessed to be relatively-recently dead when collected.
Date: April 25, 1975
Creator: Britton, Joseph & Murphy, C.
Partner: Elm Fork Natural Heritage Museum

Pyganodon grandis, Specimen #764

Description: One preserved mussel specimen including both the left and right valves. The specimen exhibits a round shape; thin shell; double looped beak sculpturing; white internal coloring; brown external coloring; no external sculpturing. Collected in the Trinity basin. The specimen measures between 60 - 100 mm in length and was assessed to be relatively-recently dead when collected.
Date: October 18, 1974
Creator: Britton, Joseph & Murphy, C.
Partner: Elm Fork Natural Heritage Museum

Pyganodon grandis, Specimen #765

Description: One preserved mussel specimen including the right valve only. The specimen exhibits a round shape; thin shell; double looped beak sculpturing; white internal coloring; tan external coloring; no external sculpturing. Collected in the Trinity basin. The specimen measures between 100 - 120 mm in length and was assessed to be relatively-recently dead when collected.
Date: October 18, 1974
Creator: Britton, Joseph & Murphy, C.
Partner: Elm Fork Natural Heritage Museum

The Uptake of Hydrogen Fluoride by a Forest

Description: A mathematical model of hydrogen fluoride (HF) deposition and accumulation of fluoride in a Eucalyptus rostrata forest has been developed. The model is based on tree physiology and meteorological principles. The data base for the model was derived from a literature survey of the physiological characteristics of E. rostrata and similar eucalyptus species and from current knowledge of meteorological processes in plant canopies.
Date: December 18, 1980
Creator: Murphy, C.E. Jr.
Partner: UNT Libraries Government Documents Department

Tritium Deposition in Pine Trees and Soil from Atmospheric Releases of Molecular Tritium

Description: Much of the tritium found in soil and leaf litter near a chemical separations facility is incorporated into soil organic matter in a stable non-exchangeable form. Formation of this ''bound'' tritium seems to result from the uptake of molecular tritium (HT) by living pine needles. Soil and litter microbes convert HT to HTO more rapidly, but no measurable organic tritium is formed. This report discusses this study.
Date: February 16, 1982
Creator: Murphy, C.E. Jr.
Partner: UNT Libraries Government Documents Department