Showing papers by "Pacific Northwest National Laboratory published in 1985"

Pollution monitoring of Puget Sound with honey bees

Abstract: To show that honey bees are effective biological monitors of environmental contaminants over large geographic areas, beekeepers of Puget Sound, Washington, collected pollen and bees for chemical analysis From these data, kriging maps of arsenic, cadmium, and fluoride were generated Results, based on actual concentrations of contaminants in bee tissues, show that the greatest concentrations of contaminants occur close to Commencement Bay and that honey bees are effective as large-scale monitors

Catalytic Steam Gasification of Biomass for Methanol and Methane Production

Abstract: The purpose of the project is to evaluate the technical and economic feasibility of producing specific gas products via the catalytic gasification of biomass. The results of research conducted from October 1980 to November 1982 are presented. The project was comprised of laboratory studies, process development, and economic analyses. The laboratory studies were conducted to develop operating conditions and catalyst systems for generating methane-rich gas, synthesis gases, hydrogen, and carbon monoxide. The process development unit (PDU), previously used for tests at atmospheric pressure, was modified for operation at absolute pressures of up to 10 atm (1000 kPa). A program for use on a microcomputer was written to determine the effect of yield changes at elevated pressures on process economics.

Current densities measured in human models exposed to 60-Hz electric fields

Abstract: This paper gives current densities measured in homogeneous grounded human models exposed to vertical, 60-Hz electric fields. The methods used for these measurements were validated by measuring the current densities induced in a grounded hemisphere and in a grounded prolate hemispheroid; agreement between measurement and theory was good. For an unperturbed field strength of 10 kV/m, current densities measured in the human chest were in the range 125-300 nA/cmS. A strong horizontal current-density enhancement was observed in the axillae, with peak values of about 400 nA/cmS. The vertical current density in the arms, when held downward, was in the opposite direction to that in the chest. Current densities in the abdomen, pelvis, and legs were a strong function of whether the body was grounded through one or both feet. With one foot grounded, the horizontal current density in the lower pelvic region, just above the crotch, was 770 nA/cmS. This value was the largest of those measured in the head, arms, or torso of the human model. Scaling factors derived from these data and similar data for animals will provide a quantitative basis for comparing animal and human exposure to 60-Hz electric fields. In addition, current-density data given in thismore » paper can be directly extrapolated to higher frequencies, at least to 1 MHz. 29 references, 8 figures, 3 tables.« less

Quantum Monte Carlo calculation of the singlet–triplet splitting in methylene

Abstract: The fixed‐node quantum Monte Carlo (QMC) method is used to calculate the total energy of CH2 in the 3B1 and 1A1 states. For both states, the best QMC variationally bounded energies lie more than 15 kcal/mol (0.024 h) below the best previous variational calculations. Subtracting these energies to obtain the singlet–triplet splitting yields Te=9.4±2.2 kcal/mol. Adjusting for zero‐point energies and relativistic effects, we obtain T0=8.9±2.2 kcal/mol. This result is in excellent agreement with the recent direct measurements of McKellar et al. of T0=9.05±0.06 kcal/mol, and of Leopold et al. of ∼9 kcal/mol, as well as with recent threoretical investigations which indicate an energy gap of 9–11 kcal/mol. We summarize the QMC method, discuss a possible scheme for iteratively correcting the procedure, and note that the present results were obtained using only single determinant functions for both states, in contrast to conventional ab initio approaches which must use at least two configurations to properly descri...

Hydrogen exchange between the methyl and hydride ligands of dicyclopentadienylhydridomethyltungsten prior to methane elimination

Abstract: The elimination of methane from Cp/sub 2/W(H)CH/sub 3/ (Cp-cyclopentadiene) was investigated using thermolysis and acetonitrile-toluene mixtures as the matrix. With the use of deuterium labeled intermediates, an intramolecular methane elimination was found in dilute solutions while the process appears to be intermolecular at higher concentrations. Results for /sup 1/H, /sup 2/H, /sup 13/C NMR were used to calculate the final mole fractions of 16 isotopically labeled species occurring in mixtures of Cp/sub 2/W(H)/sup 13/ CH/sub 3/ Cp/sub 2/W(H)CD/sub 3/ mixtures. Analysis of results shows that the tungsten hydride in Cp/sub 2/W(H)CH/sub 3/ is able to exchange with the C-H bonds in the methyl ligand of another molecule of the same material, at a rate which competes well with intramolecular methane except in a very dilute solution. The compounds discussed are among the first hydrides for which intermolecular exchange with an aliphatic ligand has been reported. 16 references.

An ultralow background germanium gamma-ray spectrometer

Abstract: An ultralow background 135 cm 3 intrinsic Ge detector has been developed providing a new benchmark in low background gamma-ray spectroscopy. The radioactive background from construction materials has been reduced by more than two orders of magnitude over conventional low background gamma-ray spectrometers. The sources of background in standard commercial cryostats have been identified and eliminated. Data taken with this prototype after elimination of most cosmic ray induced background are presented. The first application of the prototype as well as a large, second generation, multicrystal (∼ 1440 cm 3 ) germanium detector will be an ultrasensitive search for neutrinoless and two-neutrino double beta decay of 76 Ge.

Comparisons of the yields and properties of the oil products from direct thermochemical biomass liquefaction processes

Abstract: Several different direct thermochemical biomass conversion processes are compared based on the results of an experimental program using standard wood and peat feedstocks. The program was part of the International Energy Agency, Biomass Liquefaction Test Facility project. The operating conditions of the processes compared differed greatly. General correlations of the properties of the oils produced from these processes are made based on the severity of the operating conditions. Important parameters in considering process severity are temperature, pressure, time at reaction conditions and added reactants or catalysts. On a compare plusieurs procedes directs differents de transformation thermochimique de la biomasse, en se basant sur les resultats d'un programme experimental ou I'ou employait des alimentations de bois et de tourbe. Le programme faisait partie du projet d'installation d'essais de liquefaction de la biomasse de I'Agence internationale d'Energie. Les conditions operatoires des procedes compares etaient tres differentes. Les proprietes des huiles produites par ces divers procedes ont ete correlees avec la severite des conditions operatoires. Celle-ci a pour parametres importants, la temperature, la pression, le temps dc sejour dans les conditions de la reaction et les reactifs ou les catalyseurs ajoutes.

Cross sections for ionization of gases by 10-2000-keV He+ ions and for electron capture and loss by 5-350-keV He+ ions.

Abstract: Cross sections for production of positive and negative charge for 10--2000-keV ${\mathrm{He}}^{+}$ ions on He, Ne, Ar, Kr, ${\mathrm{H}}_{2}$, ${\mathrm{N}}_{2}$, CO, ${\mathrm{O}}_{2}$, ${\mathrm{CH}}_{4}$, and ${\mathrm{CO}}_{2}$ were measured by the transverse-field method Electron-capture and -loss cross sections for 5--350-keV ${\mathrm{He}}^{+}$ ions on the same targets were measured by the method of beam deflection of various charge states after passing through a known length of target gas Secondary-emission detectors were used to detect neutral, singly charged, and doubly charged beam components The equation ${\ensuremath{\sigma}}_{+}$-${\ensuremath{\sigma}}_{\mathrm{\ensuremath{-}}}$=${\ensuremath{\sigma}}_{10}$-${\ensuremath{\sigma}}_{12}$ relating the four measured cross sections was utilized to make a least-squares adjustment of the data

Radiation effects in actinide host phases

Abstract: Three crystalline ceramic materials, which occur as host phases for the long-lived actinides in many nuclear waste formulations, were doped with Cm-244, and the effects of self-radiation damage from alpha decay on microstructure and physical properties were investigated. The irradiation-induced micro- structure consists of individual amorphous tracks from both the alpha-recoil particles and the spontaneous fission fragments. The overlap of the tracks at higher doses leads to a completely amorphous state at a cumulative dose of 1.3–2.3 × 1025 alpha decays/m3. This radiation-induced amorphization process results in a stored energy of ∼ 128 J/g, 5–10% swelling, factor of 10–50 increase in leachability, and an increase in fracture toughness.

Kriging for estimating spatial pattern of contaminants: Potential and problems.

Abstract: This paper discusses and illustrates the use of kriging techniques for estimating the spatial pattern of contaminants in environmental media, particularly soil. The assumptions underlying kriging are reviewed as are some advantages and disadvantages of the method. Lognormal kriging (kriging applied to logarithmic-transformed data) is illustrated using a set of radionuclide soil concentrations at a nuclear testing area on the Nevada Test Site. This example shows how lognormal kriging can be used to estimate average concentrations at points or for blocks of land, concentration contours over space, confidence bands about these contours, and radionuclide inventory in soil. The validity of kriging estimates depends on the accurate estimation and modeling of the spatial correlation structure of the phenomenon. Accuracy is especially important when lognormal kriging is used and estimates of means and their standard deviations are required in the original, untransformed scale. This paper illustrates the bias that can result when a changing correlation structure over space is ignored.

Assessment of intergravel conditions influencing egg and alevin survival during salmonid redd dewatering

Abstract: Extensive water use may alter stream flows so that areas used by salmonids for spawning are dewatered, thus exposing intergravel developmental phases to suddenly changed physical and chemical conditions. Environmental alteration may result in considerable mortality, particularly of the more vulnerable post-hatch phases. Five documented case histories of redd dewatering are reviewed. The primary conditions in the gravel that influence survival during dewatering are residual flow, moisture retention, temperature, gravel composition, dissolved oxygen, alevin behavior, and species characteristics. These factors are discussed and their complex relationships are evaluated. Considerable variation in intergravel conditions can be expected during dewatering at different locations. Onsite studies are needed to obtain data for assessment of potential impacts in other dewatering situations, and for development of effective mitigation procedures.

Evidence for retrovirus in miniature swine with radiation-induced leukemia or metaplasia.

Abstract: Biochemical and morphological evidence indicates that a type-C retrovirus is present in the blood of swine (both leukemic and nonleukemic) exposed to strontium-90 radiation. Nonexposed swine that were leukemic also had virus present. The virus was shown to contain an RNase-sensitive DNA polymerase activity with cation, detergent and template requirements similar to those of known viral reverse transcriptases. The buoyant density of the virus was 1.14 to 1.16 g/ml, which can be converted, by treatment with ether, to a virion core having a density of 1.20 to 1.23 g/ml. Linear regression analysis indicated a correlation between virus-associated DNA polymerase activity and the number of blast cells in the peripheral blood.

Tolerance of Eggs, Embryos, and Alevins of Chinook Salmon to Temperature Changes and Reduced Humidity in Dewatered Redds

Abstract: Changes in temperature and relative humidity can occur in gravel during dewatering of salmonid redds. Four intergravel development phases of chinook salmon Oncorhynchus tshawytscha were exposed to increased or decreased temperatures, and one phase was subjected to reduced relative humidity to define tolerance limits. Abrupt increases in temperature from 10°C to above 22°C for 1–8 h reduced survival of cleavage eggs. Embryos survived 8-h exposures to 25°C and 2-h exposures to 26.5°C. Eleutheroembryo and pre-emergent alevins tolerated 4-h exposures to 23.5°C and 1-h exposures to 25.0°C. Decreases in temperatures from 10.0°C to near freezing (about 0.0°C) did not reduce survival of eggs, embryos, or alevins. Reduced relative humidity adversely affected survival of embryos. Ninety-eight percent of dewatered embryos exposed to 100% relative humidity for up to 24 hours survived. Embryo survival at 90% relative humidity was 0%, 55%, and 100% for exposure periods of 24, 8, and 4 h, respectively. Control ...

Modification of the neubauer technique to assess toxicity of hazardous chemicals in soils

Abstract: The Neubauer technique was modified to provide a sensitive and economical phytoassay for soils and surface waters obtained from a chemical waste site. Use of individual plastic enclosures allowed safe handling and disposal over the course of our experiments. Laboratory tests showed that water from a holding basin was toxic to wheat plants at dilutions of less than 1% and that our modified Neubauer technique produced results compatible with both pot culture and the standard Neubauer test. Further testing of several inorganic constituents of the basin water pointed to an organic toxicant, even though the original water contained high levels of sodium, copper and other elements. The results of testing 26 samples from an abandoned waste pond were negative insofar as toxicity to wheat and lettuce seeds, whereas samples from an abandoned ditch allowed us to determine areal toxicity as well as toxicity as a function of depth and suggested that more than one species should be tested. 10 references, 2 figures, 5 tables.

Comparative chemical and biological analysis of coal tar-based therapeutic agents to other coal-derived materials.

Abstract: In this study, methodologies developed for the analysis of synthetic fuel products were applied to the coal tar fractions isolated from coal tar-based pharmaceutical products. A pharmaceutical stock solution of 20% coal tar in alcohol, a 50% coal tar bath emulsion and a 4.3% coal tar shampoo were studied. The toxicology and chemical composition of the coal tar fractions isolated from these materials were compared with an industrial coal tar and with a direct-liquefaction coal liquid product. The coal tars and coal liquid product were fractionated into chemical classes by alumina column chromatography and individual components were identified and quantitated by high-resolution gas chromatography. The microbial mutagenicity of these materials was measured against S. typhimurium, TA 98. In addition, the industrial coal tar, coal-liquid product, and coal tar isolate from the 20% coal tar in alcohol solution were tested for initiating activity in an initiation/promotion mouse skin painting assay for carcinogenicity. The chemical compositions of the coal tar-based therapeutic agents, the industrial coal tar and direct-liquefaction coal liquid were similar. With the exception of the 50% bath emulsion, the microbial mutagenicity and tumor-initiating activity in mouse skin for those materials tested were also similar.

Avian Pox in a Red-tailed Hawk (Buteo jamaicensis)

Abstract: Avian pox has been reported in at least 60 species of birds belonging to 20 different families. However, poxvirus infection in birds of prey is apparently uncommon. On 18 May 1981, an adult male red-tailed hawk was found on the US Department of Energy's Arid Land Ecology Reserve in Benton County, Washington. The bird was incapable of flight and was extremely thin. Nodular proliferations were noted on both feet and cutaneous scab-like lesions around the beak and eyes. The bird was killed in the field and submitted promptly to the diagnostic laboratory for necropsy. This report of pox infection in a free-living adult red-tailed hawk represents one of the few such cases reported in the US. The potential for spread of the virus to other hawks may occur particularly during the nesting season when an infected adult could conceivably pass the virus to a mate and nestlings by direct contact or fomites. Little is known of the natural of avian pox infection in birds of prey. In other birds it is generally considered mild and self-limiting; however, eye lesions resulting in impaired vision may lead to starvation.

Numerical calculation and measurement of 60-Hz current densities induced in an upright grounded cylinder.

Abstract: Power-frequency electric fields are strongly perturbed in the vicinity of human beings and experimental animals. As a consequence, the extrapolation of biological data from laboratory animals to human-exposure situations cannot use the unperturbed exposure field strength as a common exposure parameter. Rather, comparisons between species must be based on the actual electric fields at the outer surfaces of and inside the bodies of the subjects. Experimental data have been published on surface and internal fields for a few exposure situations, but it is not feasible to characterize experimentally more than a small fraction of the diverse types of exposures which occur in the laboratory and in the field. A predictive numerical model is needed, one whose predictions have been verified in situations where experimental data are available, and one whose results can be used with confidence in new exposure situations. This paper describes a numerical technique which can be used to develop such a model, and it carries out this development for a test case, that of a homogeneous right-circular cylinder resting upright on-end on a ground plane and exposed to a vertical, uniform, 60-Hz electric field. The accuracy of the model is tested by comparing short-circuit currents and induced current densities predicted by it to measured values: Agreement is good.

Effects of α‐Radiolysis on Leaching of a Nuclear Waste Glass

Abstract: The effects of α-radiolysis on leaching were studied in compositionally identical Pu-doped waste glass samples which were prepared at different α-activities (dose rates) by varying the 239Pu/238Pu isotopic ratio in the Pu dopant The results of 14-, 28-, and 56-d static leach tests at 40°C, in both deionized water and brine solution, indicate that α-radiolysis at the samplelsolution interface increased Pu and Si release by a factor of ≅3