Showing papers by "Pacific Northwest National Laboratory published in 1980"
TL;DR: A review of published numerical values of resuspension variables, rates, factors, and weathering half-lives can be found in this article, showing that there is great uncertainty in accurately predicting ressuspension.
217 citations
TL;DR: In vitro biological tests showed the ash from the 18 May 1980 eruption of Mount St. Helens to be nontoxic to alveolar macrophages, which are an important part of the lungs' natural clearance mechanism.
Abstract: Samples of ash from the 18 May 1980 eruption of Mount St. Helens were collected from several locations in eastern Washington and Montana. The ash was subjected to a variety of analyses to determine its chemical, physical, mineralogical, and biological characteristics. Chemically, the ash samples were of dacitic composition. Particle size data showed bimodal distributions and differed considerably with location. However, all samples contained comparable amounts of particles less than 3.5 micrometers in diameter (respirable fraction). Mineralogically, the samples ranged from almost totally glassy to almost totally crystalline. Crystalline samples were dominated by plagioclase feldspar (andesine) and orthopyroxene (hypersthene), with smaller amounts of titanomagnetite and hornblende. All but one of the samples contained from less than 1 percent to 3 percent free crystalline silica (quartz, trydimite, or cristobalite) in both the bulk samples and 1 to 2 percent in the fractions smaller than 3.5 micrometers. The long-lived natural radionuclide content of the ash was comparable to that of crustal material; however, relatively large concentrations of short-lived radon daughters were present and polonium-210 content was inversely correlated with particle size. In vitro biological tests showed the ash to be nontoxic to alveolar macrophages, which are an important part of the lungs' natural clearance mechanism. On the basis of a substantial body of data that has shown a correlation between macrophage cytotoxicity and fibrogenicity of minerals, the ash is not predicted to be highly fibrogenic.
185 citations
170 citations
134 citations
TL;DR: The average flux of 7 Be across the ocean surface was calculated to be 0.027 atoms cm −2 s −1 which is probably not significantly greater than the worldwide average 7 Be flux across land and ocean surfaces of 0.022 atoms cm−2 s−1 calculated by Lal and Peters as discussed by the authors.
125 citations
TL;DR: These data are used to show that the actual electric fields experienced by animals depend strongly on the shape of the body and its orientation relative to the electric field and ground plane.
Abstract: Published and new data for grounded humans, swine, and rats exposed to vertical, 60-Hz electric fields are used to determine field strengths at the surfaces of the bodies and average components of induced-current density along the axes of the bodies At the tops of the bodies, surface electric fields are increased (enhanced) over the unperturbed field strength present before the subjects entered the field by factors of 17,7, and 4 for humans, swine, and rats, respectively For an unperturbed field strength of 10 kV/m, average induced axial current densities in the neck, chest, abdomen, and feet are: 550, 190, 250, and 2000 nA/cm2, respectively, for humans; 40, 13, 20, and 1100 nA/cm2, respectively, for swine; and 28, 16, 2, and 1400 nA/cm2, respectively, for rats These data are used to show that the actual electric fields experienced by animals depend strongly on the shape of the body and its orientation relative to the electric field and ground plane This fact must be taken into account if biological data obtained with laboratory animals are to be used for the assessment of possible hazards to humans exposed to 60-Hz electric fields
102 citations
TL;DR: A complete configuration interaction (CI) ground state surface for the H3+ system has been calculated using 5S and 3(Px,Py,Px) basis functions at each center.
Abstract: A complete configuration interaction (CI) ground state surface for the H3+ system has been calculated using 5S and 3(Px,Py,Px) basis functions at each center A total of 650 nuclear geometries has been considered which makes the new surface appropriate not only for scattering calculations, but also for the evaluation of the vibrational–rotational spectrum of the H3+ molecule Significant deviations are found from the analytic Giese and Gentry potential used in many previous theoretical studies, especially for large and small nonequilibrium H–H separations which are important for vibrational excitation of the H2 molecule Vibrational–rotational excitation cross sections have been calculated in the rotational sudden approximation where the vibrational degree of freedom is treated exactly by solving seven vibrationally coupled radial equations The use of the new surface leads to increased vibrational excitation compared to previous calculations utilizing the same scattering approximation and to excellent ag
90 citations
TL;DR: The results of a series of neurophysiologic tests and measurements indicate that only synaptic transmission is significantly and consistently affected by chronic (30-day) exposure to a 60-Hz, 100-kV/m electric field.
Abstract: Several reports have suggested that the nervous system can be affected by exposure to electric fields and that these effects may have detrimental health consequences for the exposed organism. The purpose of this study was to investigate the effects of chronic (30-day) exposure of rats to a 60Hz, 100-kV/m electric field on synaptic transmission and peripheral-nerve function. One hundred forty-four rats, housed in individual polycarbonate cages were exposed to uniform, vertical, 60-Hz electric fields in a system free of corona discharge and ozone formation and in which the animals did not receive spark discharges or other shocks during exposure. Following 30 days of exposure to the electric field, superior cervical sympathetic ganglia, vagus and sciatic nerves were removed from rats anesthetized with urethan, placed in a temperature-controlled chamber, and superfused with a modified mammalian Ringer's solution equilibrated with 95% O2 and 5% CO2. Several measures and tests were used to characterize synaptic transmission and peripheral-nerve function. These included amplitude, area, and configuration of the postsynaptic or whole-nerve compound-action potential; conduction velocity; accommodation; refractory period; strength-duration curves; conditioning-test (C-T) response, frequency response; post-tetanic response; and high-frequency-induced fatigue. The results of a series of neurophysiologic tests and measurements indicate that only synaptic transmission is significantly and consistently affected by chronic (30-day) exposure to a 60-Hz, 100-kV/m electric field. Specifically, and increase in synaptic excitability was detected in replicated measurements of the C-T response ratio. In addition, there are trends in other data that can be interpreted to suggest a generalized increase in neuronal excitability in exposed animals.
73 citations
TL;DR: In this paper, the role of grain boundaries in the oxidation of stainless steel was examined and compared by Auger electron spectroscopy to learn more about the role the grain boundaries played in the material's oxidation.
Abstract: The oxides formed on large-grained (∼40 °m) and small-grained (∼4 μm) 304 stainless steel oxidized in air at 800 °C have been examined and compared by Auger electron spectroscopy to learn more about the role of grain boundaries in the oxidation of the materials. For vacuum preannealed specimens, relatively thick iron oxides formed over the grains and thin, chromium-rich oxides formed over grain boudaries of large-grained material. The oxide formed over the entire surface of the small-grained material was a thin chromium-rich layer similar to that formed over grain boundaries of the large-grained samples. The oxidation of both small- and large-grained samples was consistent with selective formation of Cr2O3 at grain boundaries followed by a lateral diffusion of Cr and spreading of Cr2O3. A protective Cr2O3 layer formed readily on small-grained material but not on large-grained material. In contrast to the differences in oxide morphology for small- and large-grained preannealed specimens, oxide morphologies were similar for small- and large-grained material when the outer surface layer was removed by polishing after annealing and before oxidation tests. Surface differences, not adequately defined by Auger and SEM studies, caused marked changes in oxide morphologies for large-grained material. The difference in oxidation behavior before and after polishing was attributed to enhanced oxidation at grain boundaries during the vacuum preannealing treatment and to differences in defect concentrations in the surface region.
63 citations
TL;DR: Gas-chromatographic mass spectral analyses were performed on mutagenically active components from the basic, basic tar and neutral tar subfractions of a coal-derived liquid heavy distillate, showing that the concentrations of primary aromatic amines followed essentially the same distribution as the mutagenic activity.
Abstract: Gas-chromatographic mass spectral (GCMS) analyses were performed on mutagenically active components from the basic, basic tar and neutral tar subfractions of a coal-derived liquid heavy distillate. The latter material is a component fraction of an experimental oil produced in a solvent refined coal process (SRC II) pilot plant. Mutagenicity was determined with the Ames/Salmonella assay system. Thin-layer chromatography (TLC) was used to separate mutagenically active components of the basic, basic tar and neutral tar fractions from some of the other compounds contained in these complex materials. For the 3 fractions tested, mutagenic activity was localized in approx. the same TLC regions, with relative mobilities (R f ) ranging from 0.1 to 0.3. GCMS analysis of the TLC regions showed that the concentrations of primary aromatic amines, as obtained by measuring peak areas for the (M + 1) + ion as formed in the chemical ionization mode, followed essentially the same distribution as the mutagenic activity. Primary aromatic amines identified in the active regions included aminonaphthalenes, aminoanthracenes, aminophenanthrenes, aminopyrenes and aminochrysenes. With the exception of small amounts of aminonaphthalene, primary aromatic amines were not found in TLC regions that lacked mutagenic activity.
63 citations
TL;DR: The elemental solubilities of three coal fly ash samples and two coastal marine-aerosol samples in seawater are different as mentioned in this paper, and the coal fly-ash samples were collected from the electrostatic precipitators on coal-fired power plants.
TL;DR: The experimental data support the hypothesis that the observed behavioral effects are the result of direct interaction of the electric field with the animal, and not of secondary factors such as electric shocks, corona discharge, audible noise, ozone, or vibration of the experimental apparatus.
Abstract: In repeated short-term tests, and one longer test, behavior of rats was evaluted in a long, narrow shuttlebox. One side of the box was exposed to an electric field at various strengths, while a visually identical opposite side was shielded from exposure. In short-term tests, rats generally remained shielded from electric fields of 90 kV/m and greater during the first session, and maintained this response in subsequent sessions. In the longer test, this same preference response was demonstrated at field strengths of 75 kV/m and greater; however, at 25 and 50 kV/m, rats exhibited a statistically significant preference for the exposed region of the shuttlebox, but only during the light portion of a 12-h light; 12-h dark cycle. The experimental data support the hypothesis that the observed behavioral effects are the result of direct interaction of the electric field with the animal, and not the result of secondary factors such as electric shock, corona discharge, audible noise, ozone, or vibration of the experimental apparatus.
TL;DR: In this paper, the potential energy curves of the ground states of C2(X 1 εg+) and C2−(X 2 ε) have been calculated using SCF, MCSCF, and CI methods.
Abstract: Potential energy curves of the ground states of C2(X 1Σg+) and C2−(X 2Σg+) have been calculated using SCF, MCSCF, and CI methods. Close agreement with experimental dissociation energies, bond lengths, and spectroscopic constants is obtained by a CI calculation including all single and double excitations from the restricted Hartree–Fock configuration, with corrections for the quadrupole excitations estimated by a formula due to Davidson. The restricted Hartree–Fock method overestimates the electron affinity of C2, giving a value 4.33±0.02 eV to be compared with the experimental value of 3.54±0.05 eV. The effect of higher excitations on calculated electron affinity has been investigated, and some general conclusions regarding the computation of molecular electron affinity have been drawn.
TL;DR: The mechanism of radiation effects and their industrial applications for the following classes of polymers: thermoplastics, thermosets, elastomers, films and fibers, and adhesives/coatings/potting compounds are discussed in this paper.
TL;DR: In this paper, UO 2 pellets were fabricated from UO 3 gel microspheres by a combined gel-sphere/pellet fabrication process, and desirable sphere properties were established; calcining cycles, pressing conditions, and sintering cycles were determined.
TL;DR: Optical coatings of high band gap oxides were prepared by reactive sputtering to evaluate their potential for use in fusion lasers operating at wavelengths ranging from the UV to the near IR as discussed by the authors.
TL;DR: In this paper, a fracture mode transition from transgranular ductile rupture to brittle intergranular failure was observed as a function of the grain boundary sulfur concentration and the applied cathodic potential.
TL;DR: The thermal resistance of juvenile coho salmon (Oncorhynchus kisutch) and rainbow trout (Salmo gairdneri) sublethally exposed to nickel was subsequently examined by the critical thermal maximum (CTM) method as discussed by the authors.
TL;DR: The data suggest that inhaled CdO is highly soluble in the lung but that cadmium is slowly excreted from the body, resulting in a long-term dose commitment to several tissues.
TL;DR: The sensitivity of the solar weighted optical properties of selected materials to different terrestrial solar spectral irradiance distributions and computational techniques has been investigated in this article, where spectral transmittance, reflectance, and absorptance of typical materials employed in solar thermal conversion systems were used for the calculations.
Abstract: The sensitivity of the solar weighted optical properties of selected materials to different terrestrial solar spectral irradiance distributions and computational techniques has been investigated. The spectral transmittance, reflectance, and absorptance of typical materials employed in solar thermal conversion systems were used for the calculations. The values obtained for several different solar irradiance distributions and calculational methods show only small differences. A single terrestrial solar irradiance distribution is recommended for use as a standard.
TL;DR: In this paper, air-equilibrated suspensions of 238 Pu and 239 Pu compounds in dilute salt solutions produced HNO 3 at a rate which increased with the H + concentration.
TL;DR: The volatilization of fly ash has been examined by a number of techniques including TGA-DTA, Knudsen cell mass spectrometry, and X-ray fluorescence analysis of sized fly ash, low-temperature ash and parent coal as mentioned in this paper.
01 Jan 1980
TL;DR: The effect of grain boundary chemistry on the tensile ductility and fracture mode of nickel at cathodic potentials was investigated in this article, where a threshold sulfur content was identified above which the fracture mode changed from transgranular ductile rupture to intergranular fracture.
TL;DR: In this article, the authors analyzed the relationship implicit in monthly averages of airborne SO2 and SO2−4 concentrations and total sulfur removed by precipitation scavenging and used these data in evaluating a regional-scale model for sulfur oxide transport, transformation and removal.
TL;DR: The nature of glass-water interactions is complicated at best as discussed by the authors, and understanding these interactions and developing a predictive model is more difficult for complex waste containment glasses than for simple waste containers.
Abstract: The nature of glass-water interactions is complicated at best Understanding these interactions and developing a predictive model is more difficult for complex waste containment glasses than for re
TL;DR: In this paper, the uncertainty and bias in estimates of long-term average wind speeds inherent in continuous and intermittent measurement strategies are examined by simulating the application of the strategies to 40 data sets.