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Sample records for azufre elemental sobre

  1. Los Azufres silicic center (Mexico): inference of caldera structural elements from gravity, aeromagnetic, and geoelectric data

    NASA Astrophysics Data System (ADS)

    Campos-Enriquez, J. O.; Gardun˜o-Monroy, V. H.

    1995-08-01

    Los Azufres geothermal field is located within a silicic volcanic complex in central Mexico. The complex is one of the major silicic centers in the Trans-Mexican Volcanic Belt (TMVB). Pradal and Robin (1985) first suggested the existence of the Los Azufres caldera, and Ferrari et al. (1991) recognized the existence of a collapse structure. According to Pradal and Robin this is a caldera of resurgent type. This geophysical study aims to contribute to the knowledge of the structure of the Los Azufres area. Gravity, aeromagnetic, magnetotelluric (MT) and d.c. vertical electric-resistivity soundings were analyzed. Results show that Los Azufres is a very structurally complex setting with relatively thin crust caused by the extensional tectonics characterizing this central sector of the TMVB. Faults belonging to the E-W to NE-SW (extensional neotectonics) and NW-SE (Basin and Range province) systems are observed to affect the geologic units of Los Azufres. According to our study, the Los Azufres geothermal field is located in a structural high located in the middle of a sub-circular depression delimited to the north-northeast by the Santa Ines Range, and to the southwest by the Mil Cumbres formation. The larger depression consists of two narrow, deep depressions that correspond to La Venta and to the Valley of Juarez. They are separated by the above mentioned structural high. These sub-depressions are believed to be the sites of a maximum caldera collapse, and the structural high is interpreted to be at least in part the caldera's resurgent dome. Geoelectric structure of the caldera derived from d.c. resistivity indicates that the brines of the Los Azufres geothermal system ascend along faults, both bounding and internally disrupting the structural high/resurgent dome. A reasonable correlation is observed between gravity and aeromagnetic data.

  2. Naturally occurring heavy radioactive elements in the geothermal microcosm of the Los Azufres (Mexico) volcanic complex.

    PubMed

    Abuhani, W A; Dasgupta-Schubert, N; Villaseñor, L M; García Avila, D; Suárez, L; Johnston, C; Borjas, S E; Alexander, S A; Landsberger, S; Suárez, M C

    2015-01-01

    The Los Azufres geothermal complex of central Mexico is characterized by fumaroles and boiling hot-springs. The fumaroles form habitats for extremophilic mosses and ferns. Physico-chemical measurements of two relatively pristine fumarolic microcosms point to their resemblance with the paleo-environment of earth during the Ordovician and Devonian periods. These geothermal habitats were analysed for the distribution of elemental mass fractions in the rhizospheric soil (RS), the native volcanic substrate (VS) and the sediments (S), using the new high-sensitivity technique of polarized x-ray energy dispersive fluorescence spectrometry (PEDXRF) as well as instrumental neutron activation analysis (INAA) for selected elements. This work presents the results for the naturally occurring heavy radioactive elements (NOHRE) Bi, Th and U but principally the latter two. For the RS, the density was found to be the least and the total organic matter content the most. Bi was found to be negligibly present in all substrate types. The average Th and U mass fractions in the RS were higher than in the VS and about equal to their average mass fractions in the S. The VS mass fraction of Th was higher, and of U lower, than the mass fractions in the earth's crust. In fact for the fumaroles of one site, the average RS mass fractions of these elements were higher than the averaged values for S (without considering the statistical dispersion). The immobilization of the NOHRE in the RS is brought about by the bio-geochemical processes specific to these extremophiles. Its effectiveness is such that despite the small masses of these plants, it compares with, or may sometimes exceed, the immobilization of the NOHRE in the S by the abiotic and aggressive chemical action of the hot-springs. These results indicate that the fumarolic plants are able to transform the volcanic substrate to soil and to affect the NOHRE mass fractions even though these elements are not plant nutrients. Mirrored back to

  3. Thermal extraction analysis of five Los Azufres production wells

    SciTech Connect

    Kruger, Paul; Quijano, Luis

    1995-01-26

    Thermal energy extraction from five wells supplying 5-MWe wellhead generators in three zones of the Los Azufres geothermal field has been examined from production and chemical data compiled over 14-years of operation. The data, as annual means, are useful in observing small-scale changes in reservoir performance with continuous production. The chemical components are chloride for quality control and the geothermometer elements for reservoir temperatures. The flowrate and fluid enthalpy data are used to calculate the thermal extraction rates. Integration of these data provides an estimate of the total energy extracted from the zone surrounding the well. The combined production and chemical geothermometer data are used to model the produced fluid as coming from just-penetrating wells for which the annual produced mass originates from a series of concentric hemispheric shells moving out into the reservoir. Estimates are made of the drawdown distance into the reservoir and the far-field conditions.

  4. Pilot fruit drier for Los Azufres geothermal field, Michoacan, Mexico

    SciTech Connect

    Lund, J.W.

    1993-02-01

    Comision Federal de Electricidad (CFE) has a Division in charge of the exploration of a geothermal reservoir located in Los Azufres, State of Michoacan. At present, CFE is only using the steam of the wells and rejecting the hot water that comes off associated with the steam. Based on a trip to the Los Azufres geothermal field in December of 1992, a design for a pilot geothermal fruit drier was undertaken for CFE. The details of the geothermal field and the local fruit production are detailed.

  5. Pilot fruit drier for Los Azufres geothermal field, Michoacan, Mexico

    SciTech Connect

    Lund, J.W.

    1993-02-01

    Comision Federal de Electricidad (CFE) has a Division in charge of the exploration of a geothermal reservoir located in Los Azufres, State of Michoacan. At present, CFE is only using the steam of the wells and rejecting the hot water that comes off associated with the steam. Based on a trip to the Los Azufres geothermal field in December of 1992, a design for a pilot geothermal fruit drier was undertaken for CFE. The details of the geothermal field and the local fruit production are detailed.

  6. Los Azufres geothermal field: Observed response after 12-year exploitation

    SciTech Connect

    Maldonado, G.J.

    1995-12-31

    Exploitation of the Los Azufres Geothermal field was initiated in August 1982, with the electric power generation of five 5-MW wellhead units. Since then another 70 MW have been installed. A large amount of information has been compiled, including geologic, geochemical, production, and reservoir characteristics. The data were evaluated to detect the extent of observable changes in the main reservoir parameters over the twelve-year production period. Pressure and temperature measurements in Los Azufres wells show that geothermal fluid distribution is strongly influenced by the presence of permeable structures. Wellhead production and chemical analysis of the separated brine show that we are dealing with a highly heterogeneous reservoir, were the drawdown and enthalpy changes depend on the position of the well being studied.

  7. Wood and fruit drying in Los Azufres geothermal field, Mexico

    SciTech Connect

    Casimiro, E.; Pastrana, E.

    1996-12-31

    The main object of Comision Federal de Electricidad (CFE`s) Geothermal Field at Los Azufres, is to generate geothermal electricity; however with the new politics in Mexico CFE has built a pilot project in order to profit from the geothermal residual energy and to attract national or foreign investors and convince them that direct-use of geothermal energy is an attractive feasible and economical possibility. The object of this paper is to present the CFE experiences in wood and fruit drying using geothermal energy.

  8. Natural Vertical Flow in the Los Azufres, Mexico, Geothermal Reservoir

    SciTech Connect

    Iglesias, E.R.; Arellano, V.M.; Ortiz-Ramirez, J.

    1986-01-21

    This work focuses on estimating the mass (M) and energy (E) flow rates, the permeability k, and the relative permeability functions R{sub L} and R{sub V} associated with the natural vertical flow in the reservoir. To estimate M and E we used the standard 1-D vertical equations for two-phase flow, complemented with boundary conditions at the boiling and dew interfaces. These boundary conditions were derived in an earlier stage of this study that established an approximate 1-D vertical model of the reservoir. The estimated values of M and E were then used together with the previously established liquid saturation vertical profile of the reservoir, and the differential equation expressing the pressure gradient, to fit, by trial and error, the observed natural pressure profile. The accuracy of the fit depends on the assumed value for the vertical permeability and on the chosen forms for the relative permeability functions. They estimated M {approx} 6.9 x 10{sup -8} kg m{sup -2} s{sup -1} and E {approx} 0.2 W m{sup -2}. These results lie well within the ample ranges of mass and energy flowrates per unit area found in geothermal fields worldwide. The estimated values of M and E support the previous inference that there is an extensive caprock in the reservoir. The best fit to the natural pressure gradient implies a vertical permeability of about 0.08 mD, residual water- and steam-saturations of about 0.04 and 0.00 respectively, and ''fracture relative permeabilities'' (i.e., R{sub L} + R{sub V} = 1). This work addresses a major obstacle for a successful analysis of the Los Azufres geothermal reservoir, which is characterized by an extensive two-phase region: the former unavailability of reasonably reliable relative permeability functions. Furthermore, the present characterization of the vertical natural flow provides important constraints for both lumped- and distributed-parameter models of the reservoir. Finally, this work gives information on reservoir properties that

  9. Origin of rainwater acidity near the Los Azufres geothermal field, Mexico

    USGS Publications Warehouse

    Verma, M.P.; Quijano, J.L.; Johnson, Chad; Gerardo, J.Y.; Arellano, V.

    2000-01-01

    The chemical and isotopic compositions of rainwater were monitored at Los Azufres geothermal field (88 MWe) and its surroundings during May - September 1995, which is the rainy season. Samples were collected from eight sites: three within the field, three in its surroundings and two sufficiently far from the field such that they have no geothermal input. The concentrations of Cl-, SO42- and NO3- were measured in about 350 samples and found to be generally <5 ppm. Chloride concentrations remained constant with time, but sulfate and nitrate concentrations decreased, which suggests a nearby industrial source for the sulfate and nitrate. A mixing model for Cl-, SO42- and ??34S also suggests an industrial source for the rainwater sulfur. The determination of pH was found to be necessary, but is not sufficient to characterize rainwater acidity. The Gran titration method was used to determine alkalinity with respect to equivalence point of H2CO3(*). Values of alkalinity were found to range from 10-4 to 10-6 eq/L, and were negative only for some samples from Vivero and Guadalajara. Thus, SO42- and NO3- are in general not in acidic form (i.e. balanced by Na+, Ca2+, etc. rather than H+). Sulfate ??34S values were about -1.5??? in Los Azufres and its surroundings, and in Morelia, but differed from the value of -0.2??? for Guadalajara. The ??34S values for H2S from the Los Azufres geothermal wells are in the range -3.4 to 0.0???. The ??34S ranges for the natural and anthropogenic sources for environmental sulfur overlap, making it difficult to differentiate between the contribution of different sources. However, a similarity of values of ??34S at Los Azufres and Morelia (85 km distant) suggest a regional source of sulfate that is not associated with geothermal emissions from Los Azufres. (C) 2000 Published by Elsevier Science Ltd on behalf of CNR.The chemical compositions of rainwater were analyzed at Los Azufres geothermal field in Spain from May-September 1995. The

  10. Initial Measurements of Petrophysical Properties on Rocks from the Los Azufres, Mexico, Geothermal Field

    SciTech Connect

    Contreras, E.; Iglesias, E.; Razo, E.

    1986-01-21

    Petrophysical properties of geothermal reservoir rocks are valuable information for many activities, including reservoir characterization, modeling, field test analysis and planning of exploitation techniques. Petrophysical data of rocks from geothermal reservoirs located in volcanic areas is in general very scarce. In particular, no petrophysical data of rocks from the Los Azufres geothermal field area has ever been published. This work presents the results of initial petrophysical studies on outcrop rocks and drill core samples from the Los Azufres geothermal field. These studies are the first part of an ongoing experimental program intended to establish a data-base about physical properties of the Los Azufres rocks, in support of the many reservoir engineering activities which require of such information. The experimental work carried out consisted of laboratory measurements of density, porosity, permeability, compressibility, thermal conductivity, thermal expansion, electrical resistivity and sonic wave velocities. Some of the experiments were aimed at investigation of the effects of temperature, pressure, saturation and other parameters on the physical properties of rocks.

  11. INITIAL CHEMICAL AND RESERVOIR CONDITIONS AT LOS AZUFRES WELLHEAD POWER PLANT STARTUP

    SciTech Connect

    Kruger, P.; Semprini, L.; Verma, S.; Barragan, R.; Molinar, R.; Aragon, A.; Ortiz, J.; Miranda, C.

    1985-01-22

    One of the major concerns of electric utilities in installing geothermal power plants is not only the longevity of the steam supply, but also the potential for changes in thermodynamic properties of the resource that might reduce the conversion efficiency of the design plant equipment. Production was initiated at Los Azufres geothermal field with wellhead generators not only to obtain electric energy at a relatively early date, but also to acquire needed information about the resource so that plans for large central power plants could be finalized. Commercial electric energy production started at Los Azufres during the summer of 1982 with five 5-MWe wellhead turbine-generator units. The wells associated with these units had undergone extensive testing and have since been essentially in constant production. The Los Azufres geothermal reservoir is a complex structural and thermodynamic system, intersected by at least 4 major parallel faults and producing geothermal fluids from almost all water to all steam. The five wellhead generators are associated with wells of about 30%, 60%, and 100% steam fraction. A study to compile existing data on the chemical and reservoir conditions during the first two years of operation has been completed. Data have been compiled on mean values of wellhead and separator pressures, steam and liquid flowrates, steam fraction, enthalpy, and pertinent chemical components. The compilation serves both as a database of conditions during the start-up period and as an initial point to observe changes with continued and increased production. Current plans are to add additional wellhead generators in about two years followed by central power plants when the data have been sufficiently evaluated for optimum plant design. During the next two years, the data acquired at the five 5-MWe wellhead generator units can be compared to this database to observe any significant changes in reservoir behavior at constant production.

  12. Direct use of the geothermal energy at Los Azufres geothermal field, Mexico

    SciTech Connect

    Sanchez-Velasco, E.; Casimiro-Espinoza, E.

    1995-12-31

    The main object of Comision Federal de Electricidad (CFE`s) Geothermal Field at Los Azufres, is to generate geothermal electricity; however with the new politics in Mexico, CFE has designed a pilot project in order to profit from the geothermal residual energy and to attract national or foreign investors and convince them that direct use of geothermal energy is an attractive feasible and economical project. The object of this paper is to present the CFE experiences in different pilot projects applied to direct uses of geothermal energy.

  13. One Year Experience with Portable Back-Pressure Turbines in Los Azufres

    SciTech Connect

    Hiriart, Gerardo L.

    1983-12-15

    This paper contains the experience gained after one year operating five 5 MW portable, back-pressure, geothermal power plants at Los Azufres. A brief description of the field and te equipment is given. Cost figures of the whole installation and a list of what they believe are the advantages and disadvantages is also presented. The main conclusion is that the use of this type of turbogenerators is quite attractive in new undeveloped fields and also in countries with financial problems where initial capital cost investments must be kept as low as possible at the expenses of long term steam consumption.

  14. Pressure Buildup Testing of Well 18 in Los Azufres Field, Mexico

    SciTech Connect

    Upton, Pedro Sanchez; Gudmundsson, Jon-Steinar

    1987-01-20

    Well 18 is a production well in the southern zone of Los Azufres geothermal field in México (see Figure 1). The well is located on the eastern flank of the drilled area, and produces a steam/water mixture from a depth of 1200-1250 m. A 19 hour pressure buildup test that was carried out in March 1986, is the subject of this paper. It is part of work reported by Sánchez-U. (1986) at the Geothermal Training Programme in Iceland. The permeability-thickness product of well 18 in Los Azufres field was determined 5.4 dm from a Horner plot. The well was found to be intersected by a fracture, as evident from the slope on a log-log plot at early time, and a skin value of -5.3. The overall pressure buildup of the well was found to be typical for double-porosity reservoir behavior, having a storativity ratio of 0.1. An outer boundary behavior was observed in the pressure buildup data. 1 tab., 6 figs., 14 refs.

  15. The use of air as a natural tracer infractured hydrothermal systems, Los Azufres, Mexico, case study

    SciTech Connect

    Mario Cesar Sudrez Arriaga; Hector Gutierrez Puente, Josefina Moreno Ochoa

    1991-01-01

    Injection of atmospheric air mixed with cold water has been occurring since 1982 at the Los Azufres geothermal field. Several chemical and thermodynamical evidences show that air injection into this fractured hydrothermal system could be considered as a long term natural tracer test. Nitrogen and Argon separated from the air mixture migrate, under the action of the induced injection-extraction gradient, from reinjection sectors to production zones following preferential paths closely related to high permeability conduits. A coarse numerical estimation of the average permeability tensor existing at Tejamaniles, the southern sector, explains the unsuccessful recovery of the artificial tracer tests performed in past years: the anisotropic nature of the fractured volcanic rock would demand considerably quantities of tracer in order to be detected at the producing wells, especially when fluid extraction was low. At the same time concentrations of calcium, cesium, chloride, potassium, rubidium and sodium, are increasing in the liquid produced by the oldest wells of this field's sector.

  16. Hydrothermal characteristics of the well A-29 at the Los Azufres geothermal field, Mexico

    SciTech Connect

    Viggiano-Guerra, J.C.; Gutierrez-Negrin, L.C.A.

    1995-12-31

    Three distinct hydrothermal zones can be identified in the well A-29, located at the northeastern border of the Los Azufres, Mexico, geothermal field. They are the zeolite, epidote and amphibole-gamet zones. High temperatures (over 300{degrees}C) were measured, but the well did not produce mass flow. This can be explained by a self-sealing process as a result of three trends recognized in the evolution of geothermal fluids: boiling, boiling and gas losses, and dilution. A certain cooling of at least 25{degrees}C seems to be happening in the well, especially in the epidote zone and in the upper portions of the amphibole-gamet zone.

  17. Predicting thermal conductivity of rocks from the Los Azufres geothermal field, Mexico, from easily measurable properties

    SciTech Connect

    Garcia, Alfonso; Contreras, Enrique; Dominquez, Bernardo A.

    1988-01-01

    A correlation is developed to predict thermal conductivity of drill cores from the Los Azufres geothermal field. Only andesites are included as they are predominant. Thermal conductivity of geothermal rocks is in general scarce and its determination is not simple. Almost all published correlations were developed for sedimentary rocks. Typically, for igneous rocks, chemical or mineral analyses are used for estimating conductivity by using some type of additive rule. This requires specialized analytical techniques and the procedure may not be sufficiently accurate if, for instance, a chemical analysis is to be changed into a mineral analysis. Thus a simple and accurate estimation method would be useful for engineering purposes. The present correlation predicts thermal conductivity from a knowledge of bulk density and total porosity, properties which provide basic rock characterization and are easy to measure. They may be determined from drill cores or cuttings, and the procedures represent a real advantage given the cost and low availability of cores. The multivariate correlation proposed is a quadratic polynomial and represents a useful tool to estimate thermal conductivity of igneous rocks since data on this property is very limited. For porosities between 0% and 25%, thermal conductivity is estimated with a maximum deviation of 22% and a residual mean square deviation of 4.62E-3 n terms of the log{sub 10}(k{rho}{sub b}) variable. The data were determined as part of a project which includes physical, thermal and mechanical properties of drill cores from Los Azufres. For the correlation, sixteen determinations of thermal conductivity, bulk density and total porosity are included. The conductivity data represent the first determinations ever made on these rocks.

  18. Correlation of eruptive products, Volcán Azufral, Colombia: Implications for rapid emplacement of domes and pyroclastic flow units

    NASA Astrophysics Data System (ADS)

    Williams, Matthew; Bursik, M. I.; Cortes, G. P.; Garcia, A. M.

    2017-07-01

    The eruptive history and morphology of Azufral Volcano, Colombia, is explored and analyzed to provide a more complete picture of past eruptions, as well as to infer what eruption styles may occur in the future. Through the use of principal component analysis on Fe-Ti oxides, domes can be correlated to the pyroclastic deposits, enabling the identification of a full eruptive sequence. The findings suggest that eruptive activity at Azufral Volcano is largely explosive, experiencing long periods of quiescence, punctuated by short periods of pyroclastic activity and volcanic debris avalanches. Geomorphology of the dome complex is reinterpreted to better understand the sequence of dome growth. This reinterpretation, along with geochemical analysis and comparison via PCA, allows for reclassification of a major deposit, originally thought to be a juvenile block-and-ash flow, as a volcanic debris avalanche.

  19. Vapliq hydrothermal systems, and the vertical permeability of Los Azufres, Mexico, geothermal reservoir

    SciTech Connect

    Iglesias, Eduardo R.; Arellano, Victor M.

    1988-01-01

    We identify a new category of natural hydrothermal systems intermediate between liquid- and vapor-dominated. This category is characterized by a “vapliq” vertical pressure profile, which is nearly vaporstatic in the shallower portion of the system, and nearly boiling-point-for-depth at depth. The prototype of these systems is the geothermal field of Los Azufres, Mexico. To explore the thermohydrological conditions conducent to this type of system, we propose a 1-D vertical scenario based on generally accepted conceptual models of liquid- and vapor-dominated geothermal reservoirs. We use the corresponding mass and thermal energy transport equations to establish that a necessary condition for the existence of 2-phase hydrothermal systems is that the absolute value of the vertical thermal flux must exceed Q{sub min}, a parameter that depends only on the values of the pressure and of the thermal conductivity at the boiling point of the system. The values of Q{sub min} are typically 1-4 times the average terrestrial flux. We also find that geothermal systems in which convective heat transport is accomplished by the well-known heat-pipe mechanism can exist only if the corresponding heat flux exceeds Q{sub min} and the permeability at the boiling point of the system is smaller than k{sub Bmax}, a parameter that depends only on the values of the pressure and of the thermal conductivity at the boiling point. Typical values of k{sub Bmax} are 1-3 {times} 10{sup -18} m{sup 2}, suggesting a reason for the fact that all vapor-dominated systems are associated with very-low matrix permeability formations. Applying these insights, and the mass and heat transport equations to Los Azufres, we conclude that a contrast of 1-3 orders of magnitude exists between the vertical permeability at the boiling point and that corresponding to the vapor-dominated portion of the system. We propose that similar permeability contrasts may be responsible for the characteristic composite pressure

  20. Response of the Los Azufres Geothermal Field to Four Years of 25 MW Wellhead Generation

    SciTech Connect

    Kruger, P.; Ortiz, J.; Miranda, G.; Gallardo, M.

    1987-01-20

    Production and chemical data have been compiled and analyzed on a six-month averaged basis for the first four years of electric energy generation with five 5-MW wellhead generators at the Los Azufres geothermal field. The data were evaluated with respect to the extent of observable thermal drawdown of the reservoir from 25 MW of generation in relation to the estimated capacity of the field of several hundred megawatts of power. The analysis updates the previous one compiled after the first two years of continuous production, at which time the results indicated that differences in reservoir temperature estimated from geochemical thermometers and wellhead production data were not statistically significant based on the number of data and the standard deviations. Analysis of the data after four years of operation were made for the larger number of data and smaller standard deviations. The results review the adequacy of the sampling frequency and the reliability of the measurements from statistical t-Test of the means of the first and second two-year periods. 3 figs., 5 tabs., 20 refs.

  1. Chemical and Isotopic Evidence of Steam Upflow and Partial Condensation in Los Azufres Reservoir

    SciTech Connect

    Nieva, D.; Verma, M.; Santoyo, E.; Barragan, R.M.; Portugal, E.; Ortiz, J.; Quijano, J.L.

    1987-01-20

    Data of chemical and isotopic composition of fluids from Los Azufres wells, collected over a two year period, provide evidence of a process of upward flow and partial condensation of steam in the reservoir, which explains part of the previously reported heterogeneity in isotopic composition of the liquid phase (Nieva et al, 1983). For the southern part of the field, a direct correlation is found between chloride and oxygen-18 concentrations, and an inverse correlation between these parameters and deuterium and carbon dioxide concentrations in the liquid phase of the reservoir. Chloride ion concentrations increase gradually from ca 660 ppm in the production zones of shallow wells to ca 1900 ppm in the case of deep wells. This observation agrees with predictions based on the well-known model for vapor dominated systems of White et al (1971). For the northern part of the field the same correlations are observed, except for the deuterium concentration which in this case correlates directly with oxygen-18. It is concluded that the same process of steam upflow occurs in the northern section but that some other process — perhaps a mixture with other hydrothermal fluid — is also occurring. 3 tabs., 16 refs., 8 figs.

  2. Petrophysical Properties of Twenty Drill Cores from the Los Azufres, Mexico, Geothermal Field

    SciTech Connect

    Iglesias, E.R.; Contreras L., E.; Garcia G., A.; Dominquez A., Bernardo

    1987-01-20

    For this study we selected 20 drill cores covering a wide range of depths (400-3000 m), from 15 wells, that provide a reasonable coverage of the field. Only andesite, the largely predominant rock type in the field, was included in this sample. We measured bulk density, grain (solids) density, effective porosity and (matrix) permeability on a considerable number of specimens taken from the cores; and inferred the corresponding total porosity and fraction of interconnected total porosity. We characterized the statistical distributions of the measured and inferred variables. The distributions of bulk density and grain density resulted approximately normal; the distributions of effective porosity, total porosity and fraction of total porosity turned out to be bimodal; the permeability distribution resulted highly skewed towards very small (1 mdarcy) values, though values as high as 400 mdarcies were measured. We also characterized the internal inhomogeneity of the cores by means of the ratio (standard deviation/mean) corresponding to the bulk density in each core (in average there are 9 specimens per core). The cores were found to present clearly discernible inhomogeneity; this quantitative characterization will help design new experimental work and interpret currently available and forthcoming results. We also found statistically significant linear correlations between total density and density of solids, effective porosity and total density, total porosity and total density, fraction of interconnected total porosity and the inverse of the effective porosity, total porosity and effective porosity; bulk density and total porosity also correlate with elevation. These results provide the first sizable and statistically detailed database available on petrophysical properties of the Los Azufres andesites. 1 tab., 16 figs., 4 refs.

  3. Microbial diversity in Los Azufres geothermal field (Michoacán, Mexico) and isolation of representative sulfate and sulfur reducers.

    PubMed

    Brito, Elcia M S; Villegas-Negrete, Norberto; Sotelo-González, Irene A; Caretta, César A; Goñi-Urriza, Marisol; Gassie, Claire; Hakil, Florence; Colin, Yannick; Duran, Robert; Gutiérrez-Corona, Felix; Piñón-Castillo, Hilda A; Cuevas-Rodríguez, Germán; Malm, Olaf; Torres, João P M; Fahy, Anne; Reyna-López, Georgina E; Guyoneaud, Rémy

    2014-03-01

    Los Azufres spa consists of a hydrothermal spring system in the Mexican Volcanic Axis. Five samples (two microbial mats, two mud pools and one cenote water), characterized by high acidity (pH between 1 and 3) and temperatures varying from 27 to 87 °C, were investigated for their microbial diversity by Terminal-Restriction Fragment Length Polymorphism (T-RFLP) and 16S rRNA gene library analyses. These data are the first to describe microbial diversity from Los Azufres geothermal belt. The data obtained from both approaches suggested a low bacterial diversity in all five samples. Despite their proximity, the sampling points differed by their physico-chemical conditions (mainly temperature and matrix type) and thus exhibited different dominant bacterial populations: anoxygenic phototrophs related to the genus Rhodobacter in the biomats, colorless sulfur oxidizers Acidithiobacillus sp. in the warm mud and water samples, and Lyzobacter sp.-related populations in the hot mud sample (87 °C). Molecular data also allowed the detection of sulfate and sulfur reducers related to Thermodesulfobium and Desulfurella genera. Several strains affiliated to both genera were enriched or isolated from the mesophilic mud sample. A feature common to all samples was the dominance of bacteria involved in sulfur and iron biogeochemical cycles (Rhodobacter, Acidithiobacillus, Thiomonas, Desulfurella and Thermodesulfobium genera).

  4. Eruptive History of the Rhyolitic Guangoche Volcano, Los Azufres Volcanic Field, Central Mexico

    NASA Astrophysics Data System (ADS)

    Rangel Granados, E.; Arce, J. L.; Macias, J. L.; Layer, P. W.

    2014-12-01

    Guangoche is a rhyolitic and polygenetic volcano with a maximum elevation of 2,760 meters above sea level. It is situated to the southwest of the Los Azufres Volcanic Field (LAVF), in the central sector of the Trans-Mexican Volcanic Belt. Guangoche volcano is the youngest volcano described within the LAVF. It shows a horseshoe shaped crater open to the south, with a central lava dome. Its eruptive history during late Pleistocene has been intense with six explosive eruptions that consists of: 1) A southwards sector collapse of the volcano that generated a debris avalanche deposit with megablocks of heterogenous composition; 2) A plinian-type eruption that generated a pumice fall deposit and pyroclastic density currents by column collapse at 30.6 ka; 3) A plinian-type eruption "White Pumice Sequence" (29 ka) that developed a 22-km-high eruptive column, with a MDR of 7.0 x 107 kg/s (vol. = 0.53 km3); 4) A dome-destruction event, "Agua Blanca Pyroclastic Sequence" at 26.7 ka, that deposited a block-and-ash flow deposit; 5) A subplinian-plinian type eruption "Ochre Pyroclastic Sequence" (<26 ka) with an important initial phreatomagmatic phase, that generated pyroclastic density currents and pumice fallouts. The subplinian-plinian event generated a 16-km-high eruptive column, with a MDR of 1.9 x 107 kg/s, and magma volume of 0.38 km3; 6) The eruptive history ended with a subplinian eruption (<<26 ka), that generated a multilayered fall deposit, that developed a 11-km-high eruptive column, with a MDR of 2.9 x 106 kg/s and a magma volume of 0.26 km3. Volcanic activity at Guangoche volcano has been intense and future activity should not be discarded. Unfortunately, the last two events have not been dated yet. Guangoche rhyolitic magma is characterized by low-Ba contents suggesting crystal mush extraction for their genesis.

  5. Heterogeneity of the Liquid Phase, and Vapor Separation in Los Azufres (Mexico) Geothermal Reservoir

    SciTech Connect

    Nieva, D.; Quijano, L.; Garfias, A.; Barragan, R.M.; Laredo, F.

    1983-12-15

    Data of chemical and isotopic composition of fluids from Los Azufres geothermal wells is interpreted in order to characterize the composition of the liquid phase, and to define the relation between this phase and fluids from steam-producing wells. Chemical and specific enthalpy data show that most wells considered are fed a mixture of steam and liquid. Thus, flashing occurs in the formation. This poses a problem on the interpretation of isotopic data, because the composition of the feeding mixture need not be representative of the composition of the liquid phase in the reservoir. Two extreme alternatives for the interpretation of isotopic data are considered. In the first alternative the composition of the total discharge is considered to be the same as that of the liquid in the reservoir. In the second alternative the feeding fluid is considered to be a mixture of the liquid phase in the reservoir and the calculated fraction of steam. In addition, this steam is assumed to separate from a much larger mass of that liquid phase at the downhole temperature. The contribution of steam is then subtracted from the total discharge to yield the composition of the liquid phase. Using data for silica concentration in total discharge and separated water, the chloride concentration in the reservoir liquid is calculated. This result is used to calculate the fraction of steam in the feeding mixture of each well. The isotopic data is then corrected as proposed for the second alternative, to yield the composition of the liquid phase. Comparison of the corrected and uncorrected isotopic values shows that the correction has an important effect only when the steam mass fraction in the feeding mixture is large (> 20%). The correction tends to reduce the dispersion of data points in a {delta} D vs {delta}{sup 18}O diagram. Points representing composition of liquid phase show an approximately linear distribution, suggesting a process of mixing of two fluids. Available data appears to

  6. Permeability enhancement due to cold water injection: A Case Study at the Los Azufres Geothermal Field, Mexico

    SciTech Connect

    Benson, S.M.; Daggett, J.; Ortiz, J.; Iglesias, E.; Comision Federal de Electricidad, Morelia; Instituto de Investigaciones Electricas, Cuernavaca )

    1989-04-01

    Pressure transient buildup and falloff data from 3 wells at the Los Azufres geothermal field have been evaluated to determine the extent to which cold water infection increases the permeability of the near-bore reservoir formation. Simultaneous analysis of the buildup and falloff data provides estimates of the permeability-thickness of the reservoir, the skin factor of the well, and the degree of permeability enhancement in the region behind the thermal front. Estimates of permeability enhancement range from a factor of 4 to 9, for a temperature change of about 150{degree}C. The permeability enhancement is attributed to thermally induced contraction and stress-cracking of the formation. 9 refs., 18 figs.

  7. Evolution of the geothermal fluids at Los Azufres, Mexico, as traced by noble gas isotopes, δ18O, δD, δ13C and 87Sr/86Sr

    NASA Astrophysics Data System (ADS)

    Pinti, D. L.; Castro, M. C.; Shouakar-Stash, O.; Tremblay, A.; Garduño, V. H.; Hall, C. M.; Hélie, J.-F.; Ghaleb, B.

    2013-01-01

    Isotopes of noble gases, CO2, H2O and Sr were measured in 10 geothermal wells and 8 hot springs, fumaroles and mud volcanoes at Los Azufres, the second most important geothermal field in Mexico. The aim of this study is to provide additional information on fluid circulation in the field and surrounding areas (Araró hot springs), as well as on physical processes such as boiling, steam separation and invasion of re-injected brines following over 25 years of geothermal fluid exploitation. Mantle helium dominates in fluids from the northern production zone of Marítaro, with measured 3He/4He ratios up to 7 Ra (where Ra is the atmospheric ratio of 1.386 × 10- 6). 3He/4He ratios are positively correlated with 87Sr/86Sr ratios and with δD and δ18O. These relationships suggest that Los Azufres fluids represent a mixing between primary magmatic 3He-rich fluids and groundwater currently discharging at Araró hot springs and enriched in radiogenic 4He acquired from Miocene andesites. Unusually high He ratios together with radiogenic Sr isotopic ratios suggest that thermal waters acquired mantle He from deep-seated parent magmas and radiogenic Sr possibly during their uprising through the metamorphic basement. 40Ar/36Ar ratios of 366 to 429 measured in two wells indicate either mantle-derived argon or a radiogenic 40Ar in situ component, suggesting the local presence of an older crustal fluid component in the northern part of the field. Ne, Kr and Xe are entirely of atmospheric origin, but processes of boiling, steam separation and re-injection of used brines have led to fractionation of their elemental abundances. Comparison with previous studies suggests that the boiling zone in the northern production zone is currently extending further north (Marítaro hot springs). In the southwestern productive zone, re-injected brines might account for more than 90% of the exploited fluids.

  8. Mineralogical-chemical composition and environmental risk potential of pond sediments at the geothermal field of Los Azufres, Mexico

    NASA Astrophysics Data System (ADS)

    Birkle, P.; Merkel, B.

    2002-01-01

    Since 1982, estimated amounts of 9,400 t, 15,000 kg, 720 kg and 105 kg of Si, Fe, As and Cs respectively have accumulated at the bottom of 18 evaporation ponds as part of the geothermal production cycle at Los Azufres. This accumulation is caused by precipitation of brine solutes during the evaporation of 10% of the total pond water volume before its re-injection into the reservoir. Extraction experiments with pond precipitates and geochemical simulations with the PHREEQC program indicate the high solubility of most precipitates under natural environmental conditions. The comparisons with the primary brine composition indicate that less than 1% of most dissolved brine solutes, except for Co, Cu, Mn, Pb, Ag, Fe and Si, are accumulated at the pond bottom. Arsenic has maximum values of 160 mg/kg in the pond sediments, and Mo, Hg and Tl also exceed international environmental standards for contaminated soils. Elevated concentrations and the mobility potential of several metals and non-metals require the application of remediation techniques for the final disposal of the sediments in the future.

  9. Application of the Gauss theorem to the study of silicic calderas: The calderas of La Primavera, Los Azufres, and Los Humeros (Mexico)

    NASA Astrophysics Data System (ADS)

    Campos-Enríquez, J. O.; Domínguez-Méndez, F.; Lozada-Zumaeta, M.; Morales-Rodríguez, H. F.; Andaverde-Arredondo, J. A.

    2005-10-01

    We explored applications (including limitations) of Gauss's theorem to the study of silicic calderas. First it enables us to determine the mass deficiency from calderas. Mass deficiency itself has also other potential applications. It enables to make qualitative comparisons between calderas. We can use the mass deficiency to test, in a quick way and as a preliminary step to a formal gravity inversion, for the feasibility of caldera types of simple geometry (i.e., piston subsidence and funnel models). This application can be done in a straightforward way, once the mass deficiency has been determined. For this purpose the mass deficiency is converted to the volume of material missing at the caldera. Subsequently, for example, this volume and the respective caldera diameter enable us to estimate the height of the cylinder fitting the piston subsidence model. If the obtained parameters are congruent with the known geology and geophysical information then the model may be considered further in the inversion of the gravity data for the detailed structure. Other simple models (i.e., the funnel model) can also be analyzed in this way. In particular, when working with a piston subsidence caldera type, the Gauss theorem enables us to estimate the caldera collapse (very difficult to obtain based on geologic information alone). These possible uses of Gauss's theorem are illustrated with the calderas of La Primavera, Los Azufres, and Los Humeros caldera (Mexico). The obtained mass deficiency from these calderas follow the linear mass deficiency-diameter trend observed for other calderas. In particular, because of their diameters and mass deficiencies, La Primavera and Krakatau calderas can be considered equiparable. This comparison is of the most importance considering that La Primavera is located in the neighbourhood of a metropolis (Guadalajara City). Since geophysical studies have already established a piston subsidence model for these calderas, we assessed Gauss's theorem

  10. Two scales of inflation at Lastarria-Cordon del Azufre volcanic complex, central Andes, revealed from ASAR-ENVISAT interferometric data

    NASA Astrophysics Data System (ADS)

    Froger, J.-L.; Remy, D.; Bonvalot, S.; Legrand, D.

    2007-03-01

    ASAR-ENVISAT Interferometric Synthetic Aperture Radar (InSAR) data collected over the Lastarria-Cordon del Azufre complex (Chile-Argentina) between March 2003 and May 2005 show the persistence of the large wavelength ground inflation revealed by Pritchard and Simons in 2002 from the analysis of ERS InSAR data [Nature 418 (2002) 167-170]. After reducing the tropospheric contribution in the interferograms using a combination of data network adjustment and analysis of MODIS images, we produced an accurate interferometric time series showing a 2 yr long temporal evolution of the ground displacements patterns. Two distinct inflating signals are detected. The main signal covers an elliptical area with a 45 km NNE-SSW major axis and a 37 km minor axis. It is correlated with a regional topographic dome. We estimated its maximum inflation rate to ˜ 2.5 cm yr - 1 . We inverted the InSAR data for a range of source geometries (spherical, prolate ellipsoids, penny-shaped cracks). The inferred source parameters for 2003-2005 period are consistent with an over-pressured reservoir at shallow to intermediate crustal depths (7-15 km), with an average volumetric rate of inflation of about 14 × 10 6 m 3 yr - 1 . In addition to this main signal a new feature highlighted by the ASAR data is short wavelength inflation (6 km wide) at the location of Lastarria volcano on the northern margin of the large wavelength signal. We explain this short wavelength signal by a spherical over-pressured source lying 1000 m below the summit of Lastarria volcano. We estimate the average volumetric rate of inflation during the observation period to be ˜ 35 × 10 3 m 3 yr - 1 . It is remarkable that both volumetric variations for the large and small inflations exhibit the same evolution during the 2003-2005 period, suggesting that both processes could be related. On the basis of the inversion results and of arguments provided by field evidences and a morpho-structural analysis of the Digital Elevation

  11. Application of ASAR-ENVISAT Data for Monitoring Andean Volcanic Activity : Results From Lastarria-Azufre Volcanic Complex (Chile-Argentina)

    NASA Astrophysics Data System (ADS)

    Froger, J.; Remy, D.; Bonvalot, S.; Franco Guerra, M.

    2005-12-01

    Since the pioneer study on Mount Etna by Massonnet et al., in 1995, several works have illustrated the promising potentiality of Synthetic Aperture Radar Interferometry (INSAR) for the monitoring of volcanoes. In the case of wide, remote or hazardous volcanic areas, in particular, INSAR represents a safer and more economic way to acquire measurements than from ground based geodetic networks. Here we present the preliminary results of an interferometric survey made with ASAR-ENVISAT data on a selection of South American volcanoes where deformation signals had been previously evidenced or are expected. An interesting result is the detection of a present-day active ground deformation on the Azufre-Lastarria area (Chile-Argentina) indicating that process, identified during 1998-2000 by Pritchard and Simmons (2004) from ERS data, is still active. The phase signal visible on ASAR interferograms (03/2003-06/2005) is roughly elliptical with a 45 km NNE-SSW major axis. Its amplitude increases as a function of time and is compatible with ground uplift in the line of sight of the satellite. The ASAR time series (up to 840 days, 7 ASAR images) indicates variable deformation rate that might confirm the hypothesis of a non uniform deformation process. We investigated the origin and the significance of the deformation using various source modelling strategies (analytical and numerical). The observed deformation can be explained by the infilling of an elliptical magmatic reservoir lying between 7 and 10 km depth. The deformation could represent the first stage of a new caldera forming as it is correlated with a large, although subtle, topographic depression surrounded by a crown of monogenetic centers. A short wavelength inflation has also been detected on Lastaria volcano. It could result from the on-going infilling of a small subsurface magmatic reservoir, eventually supplied by the deeper one. All these observations point out the need of a closer monitoring of this area in

  12. Elemental ZOO

    NASA Astrophysics Data System (ADS)

    Helser, Terry L.

    2003-04-01

    This puzzle uses the symbols of 39 elements to spell the names of 25 animals found in zoos. Underlined spaces and the names of the elements serve as clues. To solve the puzzle, students must find the symbols that correspond to the elemental names and rearrange them into the animals' names.

  13. Elemental metabolomics.

    PubMed

    Zhang, Ping; Georgiou, Constantinos A; Brusic, Vladimir

    2017-01-10

    Elemental metabolomics is quantification and characterization of total concentration of chemical elements in biological samples and monitoring of their changes. Recent advances in inductively coupled plasma mass spectrometry have enabled simultaneous measurement of concentrations of > 70 elements in biological samples. In living organisms, elements interact and compete with each other for absorption and molecular interactions. They also interact with proteins and nucleotide sequences. These interactions modulate enzymatic activities and are critical for many molecular and cellular functions. Testing for concentration of > 40 elements in blood, other bodily fluids and tissues is now in routine use in advanced medical laboratories. In this article, we define the basic concepts of elemental metabolomics, summarize standards and workflows, and propose minimum information for reporting the results of an elemental metabolomics experiment. Major statistical and informatics tools for elemental metabolomics are reviewed, and examples of applications are discussed. Elemental metabolomics is emerging as an important new technology with applications in medical diagnostics, nutrition, agriculture, food science, environmental science and multiplicity of other areas. © The Author 2017. Published by Oxford University Press. All rights reserved. For Permissions, please email: journals.permissions@oup.com.

  14. Elemental health

    SciTech Connect

    Tonneson, L.C.

    1997-01-01

    Trace elements used in nutritional supplements and vitamins are discussed in the article. Relevant studies are briefly cited regarding the health effects of selenium, chromium, germanium, silicon, zinc, magnesium, silver, manganese, ruthenium, lithium, and vanadium. The toxicity and food sources are listed for some of the elements. A brief summary is also provided of the nutritional supplements market.

  15. Superheavy Elements

    ERIC Educational Resources Information Center

    Tsang, Chin Fu

    1975-01-01

    Discusses the possibility of creating elements with an atomic number of around 114. Describes the underlying physics responsible for the limited extent of the periodic table and enumerates problems that must be overcome in creating a superheavy nucleus. (GS)

  16. Elemental Education.

    ERIC Educational Resources Information Center

    Daniel, Esther Gnanamalar Sarojini; Saat, Rohaida Mohd.

    2001-01-01

    Introduces a learning module integrating three disciplines--physics, chemistry, and biology--and based on four elements: carbon, oxygen, hydrogen, and silicon. Includes atomic model and silicon-based life activities. (YDS)

  17. Elemental Education.

    ERIC Educational Resources Information Center

    Daniel, Esther Gnanamalar Sarojini; Saat, Rohaida Mohd.

    2001-01-01

    Introduces a learning module integrating three disciplines--physics, chemistry, and biology--and based on four elements: carbon, oxygen, hydrogen, and silicon. Includes atomic model and silicon-based life activities. (YDS)

  18. Superheavy Elements

    ERIC Educational Resources Information Center

    Tsang, Chin Fu

    1975-01-01

    Discusses the possibility of creating elements with an atomic number of around 114. Describes the underlying physics responsible for the limited extent of the periodic table and enumerates problems that must be overcome in creating a superheavy nucleus. (GS)

  19. Element 117

    SciTech Connect

    2010-04-08

    An international team of scientists from Russia and the United States, including two Department of Energy national laboratories and two universities, has discovered the newest superheavy element, element 117. The team included scientists from the Joint Institute of Nuclear Research (Dubna, Russia), the Research Institute for Advanced Reactors (Dimitrovgrad), Lawrence Livermore National Laboratory, Oak Ridge National Laboratory, Vanderbilt University, and the University of Nevada, Las Vegas.

  20. Element 117

    ScienceCinema

    None

    2016-09-30

    An international team of scientists from Russia and the United States, including two Department of Energy national laboratories and two universities, has discovered the newest superheavy element, element 117. The team included scientists from the Joint Institute of Nuclear Research (Dubna, Russia), the Research Institute for Advanced Reactors (Dimitrovgrad), Lawrence Livermore National Laboratory, Oak Ridge National Laboratory, Vanderbilt University, and the University of Nevada, Las Vegas.

  1. FUEL ELEMENT

    DOEpatents

    Bean, R.W.

    1963-11-19

    A ceramic fuel element for a nuclear reactor that has improved structural stability as well as improved cooling and fission product retention characteristics is presented. The fuel element includes a plurality of stacked hollow ceramic moderator blocks arranged along a tubular raetallic shroud that encloses a series of axially apertured moderator cylinders spaced inwardly of the shroud. A plurality of ceramic nuclear fuel rods are arranged in the annular space between the shroud and cylinders of moderator and appropriate support means and means for directing gas coolant through the annular space are also provided. (AEC)

  2. Mercury, elemental

    Integrated Risk Information System (IRIS)

    Mercury , elemental ; CASRN 7439 - 97 - 6 Human health assessment information on a chemical substance is included in the IRIS database only after a comprehensive review of toxicity data , as outlined in the IRIS assessment development process . Sections I ( Health Hazard Assessments for Noncarcinoge

  3. Element Research.

    ERIC Educational Resources Information Center

    Herald, Christine

    2001-01-01

    Describes a research assignment for 8th grade students on the elements of the periodic table. Students use web-based resources and a chemistry handbook to gather information, construct concept maps, and present the findings to the full class using the mode of their choice: a humorous story, a slideshow or gameboard, a brochure, a song, or skit.…

  4. Element Research.

    ERIC Educational Resources Information Center

    Herald, Christine

    2001-01-01

    Describes a research assignment for 8th grade students on the elements of the periodic table. Students use web-based resources and a chemistry handbook to gather information, construct concept maps, and present the findings to the full class using the mode of their choice: a humorous story, a slideshow or gameboard, a brochure, a song, or skit.…

  5. Superheavy Elements

    NASA Astrophysics Data System (ADS)

    Hofmann, S.

    The nuclear shell model predicts that the next doubly magic shell closure beyond 208Pb is at a proton number Z=114, 120, or 126 and at a neutron number N=172 or 184. The outstanding aim of experimental investigations is the exploration of this region of spherical `SuperHeavy Elements' (SHEs). Experimental methods have been developed which allowed for the identification of new elements at production rates of one atom per month. Using cold fusion reactions which are based on lead and bismuth targets, relatively neutron-deficient isotopes of the elements from 107 to 113 were synthesized at GSI in Darmstadt, Germany, and/or at RIKEN in Wako, Japan. In hot fusion reactions of 48Ca projectiles with actinide targets more neutron-rich isotopes of the elements from 112 to 116 and even 118 were produced at the Flerov Laboratory of Nuclear Reactions (FLNR) at the Joint Institute for Nuclear Research (JINR) in Dubna, Russia. Recently, part of these data which represent the first identification of nuclei located on the predicted island of SHEs were confirmed in two independent experiments. The decay data reveal that for the heaviest elements, the dominant decay mode is α emission rather than fission. Decay properties as well as reaction cross-sections are compared with results of theoretical studies. Finally, plans are presented for the further development of the experimental set-up and the application of new techniques. At a higher sensitivity, the detailed exploration of the region of spherical SHEs will be in the center of interest of future experimental work. New data will certainly challenge theoretical studies on the mechanism of the synthesis, on the nuclear decay properties, and on the chemical behavior of these heaviest atoms at the limit of stability.

  6. FUEL ELEMENT

    DOEpatents

    Fortescue, P.; Zumwalt, L.R.

    1961-11-28

    A fuel element was developed for a gas cooled nuclear reactor. The element is constructed in the form of a compacted fuel slug including carbides of fissionable material in some cases with a breeder material carbide and a moderator which slug is disposed in a canning jacket of relatively impermeable moderator material. Such canned fuel slugs are disposed in an elongated shell of moderator having greater gas permeability than the canning material wherefore application of reduced pressure to the space therebetween causes gas diffusing through the exterior shell to sweep fission products from the system. Integral fission product traps and/or exterior traps as well as a fission product monitoring system may be employed therewith. (AEC)

  7. FUEL ELEMENT

    DOEpatents

    Howard, R.C.; Bokros, J.C.

    1962-03-01

    A fueled matrlx eontnwinlng uncomblned carbon is deslgned for use in graphlte-moderated gas-cooled reactors designed for operatlon at temperatures (about 1500 deg F) at which conventional metallic cladding would ordlnarily undergo undesired carburization or physical degeneratlon. - The invention comprlses, broadly a fuel body containlng uncombined earbon, clad with a nickel alloy contalning over about 28 percent by' weight copper in the preferred embodlment. Thls element ls supporirted in the passageways in close tolerance with the walls of unclad graphite moderator materlal. (AEC)

  8. Rolling-Element Bearings

    NASA Technical Reports Server (NTRS)

    Hamrock, B. J.; Anderson, W. J.

    1983-01-01

    Rolling element bearings are a precision, yet simple, machine element of great utility. A brief history of rolling element bearings is reviewed and the type of rolling element bearings, their geometry and kinematics, as well as the materials they are made from and the manufacturing processes they involve are described. Unloaded and unlubricated rolling element bearings, loaded but unlubricated rolling element bearings and loaded and lubricated rolling element bearings are considered. The recognition and understanding of elastohydrodynamic lubrication covered, represents one of the major development in rolling element bearings.

  9. Discrete Element Modeling

    SciTech Connect

    Morris, J; Johnson, S

    2007-12-03

    The Distinct Element Method (also frequently referred to as the Discrete Element Method) (DEM) is a Lagrangian numerical technique where the computational domain consists of discrete solid elements which interact via compliant contacts. This can be contrasted with Finite Element Methods where the computational domain is assumed to represent a continuum (although many modern implementations of the FEM can accommodate some Distinct Element capabilities). Often the terms Discrete Element Method and Distinct Element Method are used interchangeably in the literature, although Cundall and Hart (1992) suggested that Discrete Element Methods should be a more inclusive term covering Distinct Element Methods, Displacement Discontinuity Analysis and Modal Methods. In this work, DEM specifically refers to the Distinct Element Method, where the discrete elements interact via compliant contacts, in contrast with Displacement Discontinuity Analysis where the contacts are rigid and all compliance is taken up by the adjacent intact material.

  10. Elements of Film.

    ERIC Educational Resources Information Center

    Bobker, Lee R.

    A film is the successful combination of two distinct groups of elements: (1) the technical elements by which the film is made (camera, lighting, sound and editing) and (2) the esthetic elements that transform the craft into an art. This book attempts to combine the study of these elements by providing technical information about the process of…

  11. Organic Elemental Analysis.

    ERIC Educational Resources Information Center

    Ma, T. S.; Wang, C. Y.

    1984-01-01

    Presents a literature review on methods used to analyze organic elements. Topic areas include methods for: (1) analyzing carbon, hydrogen, and nitrogen; (2) analyzing oxygen, sulfur, and halogens; (3) analyzing other elements; (4) simultaneously determining several elements; and (5) determing trace elements. (JN)

  12. Organic Elemental Analysis.

    ERIC Educational Resources Information Center

    Ma, T. S.; Wang, C. Y.

    1984-01-01

    Presents a literature review on methods used to analyze organic elements. Topic areas include methods for: (1) analyzing carbon, hydrogen, and nitrogen; (2) analyzing oxygen, sulfur, and halogens; (3) analyzing other elements; (4) simultaneously determining several elements; and (5) determing trace elements. (JN)

  13. FUEL ELEMENT SUPPORT

    DOEpatents

    Wyman, W.L.

    1961-06-27

    The described cylindrical fuel element has longitudinally spaced sets of short longitudinal ribs circumferentially spaced from one another. The ribs support the fuel element in a coolant tube so that there is an annular space for coolant flow between the fuel element and the interior of the coolant tube. If the fuel element grows as a result of reactor operation, the circumferential distribution of the ribs maintains the uniformity of the annular space between the coolant tube and the fuel element, and the collapsibility of the ribs prevents the fuel element from becoming jammed in the coolant tube.

  14. Element-ary Development.

    ERIC Educational Resources Information Center

    Schamp, Homer W., Jr.

    1989-01-01

    Describes the historic development of the periodic table from the four-element theory to the Lavoisier's table. Presents a table listing the old and new names of chemicals and the Lavoisier's table of elements. Lists two references. (YP)

  15. Trace Elements and Health

    ERIC Educational Resources Information Center

    Pettyjohn, Wayne A.

    1972-01-01

    Summarizes the effects of arsenic, lead, zinc, mercury, and cadmium on human health, indicates the sources of the elements in water, and considers the possibility of students in high schools analyzing water for trace amounts of the elements. (AL)

  16. Trace Elements and Health

    ERIC Educational Resources Information Center

    Pettyjohn, Wayne A.

    1972-01-01

    Summarizes the effects of arsenic, lead, zinc, mercury, and cadmium on human health, indicates the sources of the elements in water, and considers the possibility of students in high schools analyzing water for trace amounts of the elements. (AL)

  17. Element-ary Development.

    ERIC Educational Resources Information Center

    Schamp, Homer W., Jr.

    1989-01-01

    Describes the historic development of the periodic table from the four-element theory to the Lavoisier's table. Presents a table listing the old and new names of chemicals and the Lavoisier's table of elements. Lists two references. (YP)

  18. Orthotropic hole element

    NASA Technical Reports Server (NTRS)

    Markham, J. W.; Smith, C. V.

    1983-01-01

    A finite element was developed to adequately represent the state of stress in the region around a circular hole in orthotropic material experiencing reasonably general loading. This has been achieved through a complementary virtual work formulation of the stiffness and stress matrices for a square element with a center circular hole. The element has been incorporated into COSMIC/NASTRAN as a dummy element. Sample problems have been solved and these results are presented.

  19. NEUTRONIC REACTOR CONTROL ELEMENT

    DOEpatents

    Beaver, R.J.; Leitten, C.F. Jr.

    1962-04-17

    A boron-10 containing reactor control element wherein the boron-10 is dispersed in a matrix material is describeri. The concentration of boron-10 in the matrix varies transversely across the element from a minimum at the surface to a maximum at the center of the element, prior to exposure to neutrons. (AEC)

  20. Organic Elemental Analysis.

    ERIC Educational Resources Information Center

    Ma, T. S.; Gutterson, Milton

    1980-01-01

    Reviews general developments in computerization and data processing of organic elemental analyses; carbon, hydrogen, and nitrogen analyzers; procedures for determining oxygen, sulfur, and halogens, as well as other nometallic elements and organometallics. Selected papers on trace analysis of nonmetals and determination of metallic elements are…

  1. Elemental Chemical Puzzlers

    ERIC Educational Resources Information Center

    Thomas, Nicholas C.

    2009-01-01

    This paper provides nine short chemically based puzzles or problems extensible for use with students from middle school to college. Some of these will strengthen students' recognition of individual elements and element names. Others require students to focus on the salient properties of given chemical elements.

  2. Organic Elemental Analysis.

    ERIC Educational Resources Information Center

    Ma, T. S.; Gutterson, Milton

    1980-01-01

    Reviews general developments in computerization and data processing of organic elemental analyses; carbon, hydrogen, and nitrogen analyzers; procedures for determining oxygen, sulfur, and halogens, as well as other nometallic elements and organometallics. Selected papers on trace analysis of nonmetals and determination of metallic elements are…

  3. Geochemical model update of the Los Azufres, Mexico, geothermal reservoir

    SciTech Connect

    Hinojosa, E.T.

    1997-12-31

    Chemical and isotopic analyses of fluids produced by wells the Los Azuftes, Michoacan, geothermal field, have been studied to establish a geochemical model of the field. Water produced by the wells has a sodium-chloride composition characteristic of geothermal brine. This to be in equilibrium with the host rock at temperatures which vary from 280{degrees}C to 340{degrees}C. Based on steam data, the wells are producing from a liquid dominanted zone. The isotopic composition of the wells presents a shift with respect to meteoric line of {delta}{sup 18}O typical to fluids of geothermal origin which have equilibrated with rock at high temperatures.

  4. The synthetic elements

    SciTech Connect

    Hoffman, D.C.

    1990-05-01

    Prior to 1940, the heaviest element known was uranium, discovered in 1789. Since that time the elements 93 through 109 have been synthesized and identified and the elements 43, 61, 85, and 87 which were missing form the periodic tables of the 1930's have been discovered. The techniques and problems involved in these discoveries and the placement of the transuranium elements in the periodic table will be discussed. The production and positive identification of elements heavier than Md (Z=101), which have very short half-lives and can only be produced an atom-at-a-time, are very difficult and there have been controversies concerning their discovery. Some of the new methods which have been developed and used in these studies will be described. The prospects for production of still heavier elements will be considered.

  5. Cohesive Elements for Shells

    NASA Technical Reports Server (NTRS)

    Davila, Carlos G.; Camanho, Pedro P.; Turon, Albert

    2007-01-01

    A cohesive element for shell analysis is presented. The element can be used to simulate the initiation and growth of delaminations between stacked, non-coincident layers of shell elements. The procedure to construct the element accounts for the thickness offset by applying the kinematic relations of shell deformation to transform the stiffness and internal force of a zero-thickness cohesive element such that interfacial continuity between the layers is enforced. The procedure is demonstrated by simulating the response and failure of the Mixed Mode Bending test and a skin-stiffener debond specimen. In addition, it is shown that stacks of shell elements can be used to create effective models to predict the inplane and delamination failure modes of thick components. The results indicate that simple shell models can retain many of the necessary predictive attributes of much more complex 3D models while providing the computational efficiency that is necessary for design.

  6. Chemistry of superheavy elements.

    PubMed

    Schädel, Matthias

    2006-01-09

    The number of chemical elements has increased considerably in the last few decades. Most excitingly, these heaviest, man-made elements at the far-end of the Periodic Table are located in the area of the long-awaited superheavy elements. While physical techniques currently play a leading role in these discoveries, the chemistry of superheavy elements is now beginning to be developed. Advanced and very sensitive techniques allow the chemical properties of these elusive elements to be probed. Often, less than ten short-lived atoms, chemically separated one-atom-at-a-time, provide crucial information on basic chemical properties. These results place the architecture of the far-end of the Periodic Table on the test bench and probe the increasingly strong relativistic effects that influence the chemical properties there. This review is focused mainly on the experimental work on superheavy element chemistry. It contains a short contribution on relativistic theory, and some important historical and nuclear aspects.

  7. Multifacet holographic optical elements

    NASA Technical Reports Server (NTRS)

    Case, S. K.; Haugen, P. R.

    1981-01-01

    New types of holographic optical elements, combining the flexibility of computer generated holograms with the large space bandwidth product and high diffraction efficiency of interferometrically recorded volume phase holograms, are demonstrated. The optical elements are recorded by subdividing a volume hologram film surface into numerous small areas (facets), each of which is individually exposed under computer control. Each facet is used to produce a portion of the desired final wavefront. Three different optical elements are demonstrated.

  8. NEUTRONIC REACTOR CONTROL ELEMENT

    DOEpatents

    Newson, H.W.

    1960-09-13

    A novel composite neutronic reactor control element is offered. The element comprises a multiplicity of sections arranged in end-to-end relationship, each of the sections having a markedly different neutron-reactive characteristic. For example, a three-section control element could contain absorber, moderator, and fuel sections. By moving such an element longitudinally through a reactor core, reactivity is decreased by the absorber, increased slightly by the moderator, or increased substantially by the fuel. Thus, control over a wide reactivity range is provided.

  9. FUEL ELEMENT INTERLOCKING ARRANGEMENT

    DOEpatents

    Fortescue, P.; Nicoll, D.

    1963-01-01

    This patent relates to a system for mutually interlocking a multiplicity of elongated, parallel, coextensive, upright reactor fuel elements so as to render a laterally selfsupporting bundle, while admitting of concurrent, selective, vertical withdrawal of a sizeable number of elements without any of the remaining elements toppling, Each element is provided with a generally rectangular end cap. When a rank of caps is aligned in square contact, each free edge centrally defines an outwardly profecting dovetail, and extremitally cooperates with its adjacent cap by defining a juxtaposed half of a dovetail- receptive mortise. Successive ranks are staggered to afford mating of their dovetails and mortises. (AEC)

  10. The Elements of Empathy.

    ERIC Educational Resources Information Center

    Iannotti, Ronald J.

    When assessing the influence of empathy on prosocial motivation, analyzing empathy alone would lead to a misunderstanding. We must also assess other elements of the situation, such as the altruist's coping skills and situational constraints. In a similar manner empathy itself should be conceptualized as a process with many elements. One way to…

  11. Automatic finite element generators

    NASA Technical Reports Server (NTRS)

    Wang, P. S.

    1984-01-01

    The design and implementation of a software system for generating finite elements and related computations are described. Exact symbolic computational techniques are employed to derive strain-displacement matrices and element stiffness matrices. Methods for dealing with the excessive growth of symbolic expressions are discussed. Automatic FORTRAN code generation is described with emphasis on improving the efficiency of the resultant code.

  12. Movies and Literary Elements.

    ERIC Educational Resources Information Center

    Keller, Rodney D.

    Showing ten-minute movie clips can be an effective way to motivate students to read literature and to teach elements of fiction, namely plot, character, setting, symbol, irony, and theme. A clip from "And Then There Were None" may be used to teach various elements of plot, including conflict and the four types of conflict (man vs. man,…

  13. The Elements Drawing.

    ERIC Educational Resources Information Center

    Dkeidek, Iyad M.

    2003-01-01

    Presents an educational game designed for first- or second-year high school students who have already studied themes related to the periodic table elements, such as their symbols, electronic configurations, properties, and uses. The game is designed to help students learn the symbols of the elements and their properties or uses in a fun, engaging…

  14. The Elements Drawing.

    ERIC Educational Resources Information Center

    Dkeidek, Iyad M.

    2003-01-01

    Presents an educational game designed for first- or second-year high school students who have already studied themes related to the periodic table elements, such as their symbols, electronic configurations, properties, and uses. The game is designed to help students learn the symbols of the elements and their properties or uses in a fun, engaging…

  15. NEUTRONIC REACTOR FUEL ELEMENT

    DOEpatents

    Kesselring, K.A.; Seybolt, A.U.

    1958-12-01

    A reactor fuel element of the capillary tube type is described. The element consists of a thin walled tube, sealed at both ends, and having an interior coatlng of a fissionable material, such as uranium enriched in U-235. The tube wall is gas tight and is constructed of titanium, zirconium, or molybdenum.

  16. Movies and Literary Elements.

    ERIC Educational Resources Information Center

    Keller, Rodney D.

    Showing ten-minute movie clips can be an effective way to motivate students to read literature and to teach elements of fiction, namely plot, character, setting, symbol, irony, and theme. A clip from "And Then There Were None" may be used to teach various elements of plot, including conflict and the four types of conflict (man vs. man,…

  17. Elemental Food for Thought

    ERIC Educational Resources Information Center

    Cady, Susan

    2005-01-01

    One of the first tasks students learn in chemistry is to pronounce and spell the names of elements and learn their corresponding chemical symbols. Repetitive oral recitation is commonly used to learn this information, but games and puzzles can make this task creative, variable, and fun. Elemental Food for Thought is a puzzlelike activity that…

  18. Proceedings of transuranium elements

    SciTech Connect

    Not Available

    1992-01-01

    The identification of the first synthetic elements was established by chemical evidence. Conclusive proof of the synthesis of the first artificial element, technetium, was published in 1937 by Perrier and Segre. An essential aspect of their achievement was the prediction of the chemical properties of element 43, which had been missing from the periodic table and which was expected to have properties similar to those of manganese and rhenium. The discovery of other artificial elements, astatine and francium, was facilitated in 1939-1940 by the prediction of their chemical properties. A little more than 50 years ago, in the spring of 1940, Edwin McMillan and Philip Abelson synthesized element 93, neptunium, and confirmed its uniqueness by chemical means. On August 30, 1940, Glenn Seaborg, Arthur Wahl, and the late Joseph Kennedy began their neutron irradiations of uranium nitrate hexahydrate. A few months later they synthesized element 94, later named plutonium, by observing the alpha particles emitted from uranium oxide targets that had been bombarded with deuterons. Shortly thereafter they proved that is was the second transuranium element by establishing its unique oxidation-reduction behavior. The symposium honored the scientists and engineers whose vision and dedication led to the discovery of the transuranium elements and to the understanding of the influence of 5f electrons on their electronic structure and bonding. This volume represents a record of papers presented at the symposium.

  19. Elemental Food for Thought

    ERIC Educational Resources Information Center

    Cady, Susan

    2005-01-01

    One of the first tasks students learn in chemistry is to pronounce and spell the names of elements and learn their corresponding chemical symbols. Repetitive oral recitation is commonly used to learn this information, but games and puzzles can make this task creative, variable, and fun. Elemental Food for Thought is a puzzlelike activity that…

  20. MOLDED SEALING ELEMENT

    DOEpatents

    Bradford, B.W.; Skinner, W.J.

    1959-03-24

    Molded sealing elements suitable for use under conditions involving exposure to uranium hexafluoride vapor are described. Such sealing elements are made by subjecting graphitic carbons to a preliminary treatment with uranium hexafluoride vapor, and then incorporating polytetrafluorethylene in them. The resulting composition has good wear resistant and frictional properties and is resistant to disintegration by uranium hexafluoride over long periods of exposure.

  1. NUCLEAR REACTOR FUEL ELEMENT

    DOEpatents

    Wheelock, C.W.; Baumeister, E.B.

    1961-09-01

    A reactor fuel element utilizing fissionable fuel materials in plate form is described. This fuel element consists of bundles of fuel-bearing plates. The bundles are stacked inside of a tube which forms the shell of the fuel element. The plates each have longitudinal fins running parallel to the direction of coolant flow, and interspersed among and parallel to the fins are ribs which position the plates relative to each other and to the fuel element shell. The plate bundles are held together by thin bands or wires. The ex tended surface increases the heat transfer capabilities of a fuel element by a factor of 3 or more over those of a simple flat plate.

  2. The heaviest elements

    SciTech Connect

    Hoffman, D.C. Lawrence Berkeley Lab., CA )

    1994-05-02

    How long does an atom need to exist before it's possible to do any meaningful chemistry on it Is it possible to learn anything at all about the reactions of an element for which no more than a few dozen atoms have ever existed simultaneously These are some of the questions colleagues in a few laboratories worldwide attempt to answer as they investigate the chemistry of the heaviest elements--elements produced one atom at a time in accelerators by bombarding radioactive targets with high-intensity beams of heavy ions. All of these elements spontaneously decay; the most stable of them have half-lives of only a few minutes, some that are less stable exist for only milliseconds. So far, no chemical studies have been performed on elements whose longest lived isotopes last only milliseconds because the difficulties of doing chemistry on this time scale under highly radioactive conditions are enormous. Over the past 10 years, however, nuclear chemists have developed new techniques or adapted existing ones to begin to probe the chemical properties of those very heavy elements that have half-lives in the range of seconds to minutes. Although the classic experiments are now nearly 40 years old, they are worth describing, as they were the first of their kind and illustrate many of the techniques that are still used and essential in studying these very short-lived, radioactive elements.

  3. Neutronic fuel element fabrication

    DOEpatents

    Korton, George

    2004-02-24

    This disclosure describes a method for metallurgically bonding a complete leak-tight enclosure to a matrix-type fuel element penetrated longitudinally by a multiplicity of coolant channels. Coolant tubes containing solid filler pins are disposed in the coolant channels. A leak-tight metal enclosure is then formed about the entire assembly of fuel matrix, coolant tubes and pins. The completely enclosed and sealed assembly is exposed to a high temperature and pressure gas environment to effect a metallurgical bond between all contacting surfaces therein. The ends of the assembly are then machined away to expose the pin ends which are chemically leached from the coolant tubes to leave the coolant tubes with internal coolant passageways. The invention described herein was made in the course of, or under, a contract with the U.S. Atomic Energy Commission. It relates generally to fuel elements for neutronic reactors and more particularly to a method for providing a leak-tight metal enclosure for a high-performance matrix-type fuel element penetrated longitudinally by a multiplicity of coolant tubes. The planned utilization of nuclear energy in high-performance, compact-propulsion and mobile power-generation systems has necessitated the development of fuel elements capable of operating at high power densities. High power densities in turn require fuel elements having high thermal conductivities and good fuel retention capabilities at high temperatures. A metal clad fuel element containing a ceramic phase of fuel intimately mixed with and bonded to a continuous refractory metal matrix has been found to satisfy the above requirements. Metal coolant tubes penetrate the matrix to afford internal cooling to the fuel element while providing positive fuel retention and containment of fission products generated within the fuel matrix. Metal header plates are bonded to the coolant tubes at each end of the fuel element and a metal cladding or can completes the fuel-matrix enclosure

  4. Elements in biological AMS

    SciTech Connect

    Vogel, J.S.; McAninch, J.; Freeman, S.

    1996-08-01

    AMS (Accelerator Mass Spectrometry) provides high detection sensitivity for isotopes whose half-lives are between 10 years and 100 million years. {sup 14}C is the most developed of such isotopes and is used in tracing natural and anthropogenic organic compounds in the Earth`s biosphere. Thirty-three elements in the main periodic table and 17 lanthanides or actinides have long lived isotopes, providing potential tracers for research in elemental biochemistry. Overlap of biologically interesting heavy elements and possible AMS tracers is discussed.

  5. NEUTRONIC REACTOR FUEL ELEMENT

    DOEpatents

    Shackleford, M.H.

    1958-12-16

    A fuel element possessing good stability and heat conducting properties is described. The fuel element comprises an outer tube formed of material selected from the group consisting of stainhess steel, V, Ti. Mo. or Zr, a fuel tube concentrically fitting within the outer tube and containing an oxide of an isotope selected from the group consisting of U/sup 235/, U/sup 233/, and Pu/sup 239/, and a hollow, porous core concentrically fitting within the fuel tube and formed of an oxide of an element selected from the group consisting of Mg, Be, and Zr.

  6. Experiments on Superheavy Elements

    NASA Astrophysics Data System (ADS)

    Hofmann, Sigurd

    An overview of present experimental investigation of superheavy elements is given. Using cold fusion reactions which are based on lead and bismuth targets, relatively neutron deficient isotopes of the elements from 107 to 113 were synthesized at GSI in Darmstadt, Germany, and/or at RIKEN in Wako, Japan. In hot fusion reactions of 48Ca projectiles with actinide targets more neutron rich isotopes of the elements from 112 to 116 and even 118 were produced at FLNR in Dubna, Russia. Recently, part of these data which represent the first identification of nuclei located on the predicted island of SHEs were confirmed in two independent experiments. The data are compared with theoretical descriptions.

  7. NUCLEAR REACTOR FUEL ELEMENT

    DOEpatents

    Anderson, W.F.; Tellefson, D.R.; Shimazaki, T.T.

    1962-04-10

    A plate type fuel element which is particularly useful for organic cooled reactors is described. Generally, the fuel element comprises a plurality of fissionable fuel bearing plates held in spaced relationship by a frame in which the plates are slidably mounted in grooves. Clearance is provided in the grooves to allow the plates to expand laterally. The plates may be rigidly interconnected but are floatingly supported at their ends within the frame to allow for longi-tudinal expansion. Thus, this fuel element is able to withstand large temperature differentials without great structural stresses. (AEC)

  8. Elements of discovery.

    PubMed

    Toledo-Pereyra, Luis H

    2008-01-01

    I understand discovery as the essence of thinking man, or to paraphrase the notable French philosopher René Descartes, "I think, therefore I discover." In this study, I introduce discovery as the foundation of modern science. Discovery consists of six stages or elements, including: concept, belief, ability, support, proof, and protection. Each element is discussed within the context of the whole discovery enterprise. Fundamental tenets for understanding discovery are given throughout the paper, and a few examples illustrate the significance of some of the most important elements. I invite clinicians, researchers, and/or clinical researchers to integrate themselves into the active process of discovery. Remember--I think, therefore I discover.

  9. Injector element characterization methodology

    NASA Technical Reports Server (NTRS)

    Cox, George B., Jr.

    1988-01-01

    Characterization of liquid rocket engine injector elements is an important part of the development process for rocket engine combustion devices. Modern nonintrusive instrumentation for flow velocity and spray droplet size measurement, and automated, computer-controlled test facilities allow rapid, low-cost evaluation of injector element performance and behavior. Application of these methods in rocket engine development, paralleling their use in gas turbine engine development, will reduce rocket engine development cost and risk. The Alternate Turbopump (ATP) Hot Gas Systems (HGS) preburner injector elements were characterized using such methods, and the methodology and some of the results obtained will be shown.

  10. Discovery of element 112

    SciTech Connect

    Hofmann, S.

    1996-12-31

    The new elements 110, 111, and 112 were synthesized and unambiguously identified in experiments at SHIP. Due to strong shell effects the dominant decay mode is not fission, but emission of alpha particles. Theoretical investigations predict that maximum shell effects should exist in nuclei near proton number 114 and neutron number 184. Measurements give hope that isotopes of element 114 close to the island of spherical Superheavy Elements could be produced by fusion reactions using {sup 118}Pb as target. systematic studies of the reaction cross-sections indicate that transfer of nucleons is the important process to initiate the fusion.

  11. Multi-Element Airfoil System

    NASA Technical Reports Server (NTRS)

    Turner, Travis L. (Inventor); Khorrami, Mehdi R. (Inventor); Lockard, David P. (Inventor); McKenney, Martin J. (Inventor); Atherley, Raymond D. (Inventor); Kidd, Reggie T. (Inventor)

    2014-01-01

    A multi-element airfoil system includes an airfoil element having a leading edge region and a skin element coupled to the airfoil element. A slat deployment system is coupled to the slat and the skin element, and is capable of deploying and retracting the slat and the skin element. The skin element substantially fills the lateral gap formed between the slat and the airfoil element when the slat is deployed. The system further includes an uncoupling device and a sensor to remove the skin element from the gap based on a critical angle-of-attack of the airfoil element. The system can alternatively comprise a trailing edge flap, where a skin element substantially fills the lateral gap between the flap and the trailing edge region of the airfoil element. In each case, the skin element fills a gap between the airfoil element and the deployed flap or slat to reduce airframe noise.

  12. Rock in Its Elements

    ERIC Educational Resources Information Center

    MacCluskey, Thomas

    1969-01-01

    A discussion of the following musical elements of rock: rhythm, melody, harmony, and form. A impromptu analysis made at a session of the Youth Music Symposium, July 25, 1969. Remarks transcribed from tape. (Author/AP)

  13. Space Radiation Program Element

    NASA Technical Reports Server (NTRS)

    Krenek, Sam

    2008-01-01

    This poster presentation shows the various elements of the Space Radiation Program. It reviews the program requirements: develop and validate standards, quantify space radiation human health risks, mitigate risks through countermeasures and technologies, and treat and monitor unmitigated risks.

  14. Transposable elements in cancer.

    PubMed

    Burns, Kathleen H

    2017-07-01

    Transposable elements give rise to interspersed repeats, sequences that comprise most of our genomes. These mobile DNAs have been historically underappreciated - both because they have been presumed to be unimportant, and because their high copy number and variability pose unique technical challenges. Neither impediment now seems steadfast. Interest in the human mobilome has never been greater, and methods enabling its study are maturing at a fast pace. This Review describes the activity of transposable elements in human cancers, particularly long interspersed element-1 (LINE-1). LINE-1 sequences are self-propagating, protein-coding retrotransposons, and their activity results in somatically acquired insertions in cancer genomes. Altered expression of transposable elements and animation of genomic LINE-1 sequences appear to be hallmarks of cancer, and can be responsible for driving mutations in tumorigenesis.

  15. New functionalities in abundant element oxides: ubiquitous element strategy.

    PubMed

    Hosono, Hideo; Hayashi, Katsuro; Kamiya, Toshio; Atou, Toshiyuki; Susaki, Tomofumi

    2011-06-01

    While most ceramics are composed of ubiquitous elements (the ten most abundant elements within the Earth's crust), many advanced materials are based on rare elements. A 'rare-element crisis' is approaching owing to the imbalance between the limited supply of rare elements and the increasing demand. Therefore, we propose a 'ubiquitous element strategy' for materials research, which aims to apply abundant elements in a variety of innovative applications. Creation of innovative oxide materials and devices based on conventional ceramics is one specific challenge. This review describes the concept of ubiquitous element strategy and gives some highlights of our recent research on the synthesis of electronic, thermionic and structural materials using ubiquitous elements.

  16. JACKETED FUEL ELEMENT

    DOEpatents

    Wigner, E.P.; Szilard, L.; Creutz, E.C.

    1959-02-01

    These fuel elements are comprised of a homogeneous metallic uranium body completely enclosed and sealed in an aluminum cover. The uranium body and aluminum cover are bonded together by a layer of zinc located between them. The bonding layer serves to improve transfer of heat, provides an additional protection against corrosion of the uranium by the coolant, and also localizes any possible corrosion by preventing travel of corrosive material along the surface of the fuel element.

  17. COMPOSITE FUEL ELEMENT

    DOEpatents

    Hurford, W.J.; Gordon, R.B.; Johnson, W.A.

    1962-12-25

    A sandwich-type fuel element for a reactor is described. This fuel element has the shape of an elongated flat plate and includes a filler plate having a plurality of compartments therein in which the fuel material is located. The filler plate is clad on both sides with a thin cladding material which is secured to the filler plate only to completely enclose the fuel material in each compartment. (AEC)

  18. Trace elements in dialysis.

    PubMed

    Filler, Guido; Felder, Sarah

    2014-08-01

    In end-stage chronic kidney disease (CKD), pediatric nephrologists must consider the homeostasis of the multiple water-soluble ions that are influenced by renal replacement therapy (RRT). While certain ions such as potassium and calcium are closely monitored, little is known about the handling of trace elements in pediatric dialysis. RRT may lead to accumulation of toxic trace elements, either due to insufficient elimination or due to contamination, or to excessive removal of essential trace elements. However, trace elements are not routinely monitored in dialysis patients and no mechanism for these deficits or toxicities has been established. This review summarizes the handling of trace elements, with particular attention to pediatric data. The best data describe lead and indicate that there is a higher prevalence of elevated lead (Pb, atomic number 82) levels in children on RRT when compared to adults. Lead is particularly toxic in neurodevelopment and lead levels should therefore be monitored. Monitoring of zinc (Zn, atomic number 30) and selenium (Se, atomic number 34) may be indicated in the monitoring of all pediatric dialysis patients to reduce morbidity from deficiency. Prospective studies evaluating the impact of abnormal trace elements and the possible therapeutic value of intervention are required.

  19. Elemental sulfur coarsening kinetics.

    PubMed

    Garcia, Angel A; Druschel, Gregory K

    Elemental sulfur exists is a variety of forms in natural systems, from dissolved forms (noted as S8(diss) or in water as S8(aq)) to bulk elemental sulfur (most stable as α-S8). Elemental sulfur can form via several biotic and abiotic processes, many beginning with small sulfur oxide or polysulfidic sulfur molecules that coarsen into S8 rings that then coalesce into larger forms: [Formula: see text] Formation of elemental sulfur can be possible via two primary techniques to create an emulsion of liquid sulfur in water called sulfur sols that approximate some mechanisms of possible elemental sulfur formation in natural systems. These techniques produce hydrophobic (S8(Weimarn)) and hydrophilic (S8(polysulfide)) sols that exist as nanoparticle and colloidal suspensions. These sols begin as small sulfur oxide or polysulfidic sulfur molecules, or dissolved S8(aq) forms, but quickly become nanoparticulate and coarsen into micron sized particles via a combination of classical nucleation, aggregation processes, and/or Ostwald ripening. We conducted a series of experiments to study the rate of elemental sulfur particle coarsening using dynamic light scattering (DLS) analysis under different physical and chemical conditions. Rates of nucleation and initial coarsening occur over seconds to minutes at rates too fast to measure by DLS, with subsequent coarsening of S8(nano) and S8(sol) being strongly temperature dependent, with rates up to 20 times faster at 75°C compared to 20°C. The addition of surfactants (utilizing ionic and nonionic surfactants as model compounds) results in a significant reduction of coarsening rates, in addition to known effects of these molecules on elemental sulfur solubility. DLS and cryo-SEM results suggest coarsening is largely a product of ripening processes rather than particle aggregation, especially at higher temperatures. Fitting of the coarsening rate data to established models for Ostwald ripening additionally support this as a primary

  20. Employment Administration: Elements and Effects.

    ERIC Educational Resources Information Center

    Webb, Mel

    1983-01-01

    The basic elements of personnel administration are defined and examined and the interaction between the elements are described. The elements include job analysis, job classification, recruitment, selection, induction into the organization, evaluation of job performance, and termination. (MLW)

  1. Nuclear fuel element

    DOEpatents

    Zocher, Roy W.

    1991-01-01

    A nuclear fuel element and a method of manufacturing the element. The fuel element is comprised of a metal primary container and a fuel pellet which is located inside it and which is often fragmented. The primary container is subjected to elevated pressure and temperature to deform the container such that the container conforms to the fuel pellet, that is, such that the container is in substantial contact with the surface of the pellet. This conformance eliminates clearances which permit rubbing together of fuel pellet fragments and rubbing of fuel pellet fragments against the container, thus reducing the amount of dust inside the fuel container and the amount of dust which may escape in the event of container breach. Also, as a result of the inventive method, fuel pellet fragments tend to adhere to one another to form a coherent non-fragmented mass; this reduces the tendency of a fragment to pierce the container in the event of impact.

  2. Elemental sulfur recovery process

    DOEpatents

    Flytzani-Stephanopoulos, Maria; Hu, Zhicheng

    1993-01-01

    An improved catalytic reduction process for the direct recovery of elemental sulfur from various SO.sub.2 -containing industrial gas streams. The catalytic process provides combined high activity and selectivity for the reduction of SO.sub.2 to elemental sulfur product with carbon monoxide or other reducing gases. The reaction of sulfur dioxide and reducing gas takes place over certain catalyst formulations based on cerium oxide. The process is a single-stage, catalytic sulfur recovery process in conjunction with regenerators, such as those used in dry, regenerative flue gas desulfurization or other processes, involving direct reduction of the SO.sub.2 in the regenerator off gas stream to elemental sulfur in the presence of a catalyst.

  3. Elemental sulfur recovery process

    DOEpatents

    Flytzani-Stephanopoulos, M.; Zhicheng Hu.

    1993-09-07

    An improved catalytic reduction process for the direct recovery of elemental sulfur from various SO[sub 2]-containing industrial gas streams. The catalytic process provides combined high activity and selectivity for the reduction of SO[sub 2] to elemental sulfur product with carbon monoxide or other reducing gases. The reaction of sulfur dioxide and reducing gas takes place over certain catalyst formulations based on cerium oxide. The process is a single-stage, catalytic sulfur recovery process in conjunction with regenerators, such as those used in dry, regenerative flue gas desulfurization or other processes, involving direct reduction of the SO[sub 2] in the regenerator off gas stream to elemental sulfur in the presence of a catalyst. 4 figures.

  4. Transposable elements in Drosophila

    PubMed Central

    McCullers, Tabitha J.; Steiniger, Mindy

    2017-01-01

    ABSTRACT Transposable elements (TEs) are mobile genetic elements that can mobilize within host genomes. As TEs comprise more than 40% of the human genome and are linked to numerous diseases, understanding their mechanisms of mobilization and regulation is important. Drosophila melanogaster is an ideal model organism for the study of eukaryotic TEs as its genome contains a diverse array of active TEs. TEs universally impact host genome size via transposition and deletion events, but may also adopt unique functional roles in host organisms. There are 2 main classes of TEs: DNA transposons and retrotransposons. These classes are further divided into subgroups of TEs with unique structural and functional characteristics, demonstrating the significant variability among these elements. Despite this variability, D. melanogaster and other eukaryotic organisms utilize conserved mechanisms to regulate TEs. This review focuses on the transposition mechanisms and regulatory pathways of TEs, and their functional roles in D. melanogaster. PMID:28580197

  5. Probabilistic boundary element method

    NASA Technical Reports Server (NTRS)

    Cruse, T. A.; Raveendra, S. T.

    1989-01-01

    The purpose of the Probabilistic Structural Analysis Method (PSAM) project is to develop structural analysis capabilities for the design analysis of advanced space propulsion system hardware. The boundary element method (BEM) is used as the basis of the Probabilistic Advanced Analysis Methods (PADAM) which is discussed. The probabilistic BEM code (PBEM) is used to obtain the structural response and sensitivity results to a set of random variables. As such, PBEM performs analogous to other structural analysis codes such as finite elements in the PSAM system. For linear problems, unlike the finite element method (FEM), the BEM governing equations are written at the boundary of the body only, thus, the method eliminates the need to model the volume of the body. However, for general body force problems, a direct condensation of the governing equations to the boundary of the body is not possible and therefore volume modeling is generally required.

  6. Elemental composition of Ceres

    NASA Astrophysics Data System (ADS)

    Prettyman, T. H.; Yamashita, N.; Toplis, M. J.; McSween, H. Y., Jr.; Schorghofer, N.; Marchi, S.; Feldman, W. C.; Castillo, J. C.; Forni, O.; Lawrence, D. J.; Ammannito, E.; Ehlmann, B. L.; Sizemore, H. G.; Joy, S. P.; Polanskey, C. A.; Rayman, M.; Raymond, C. A.; Russell, C. T.

    2016-12-01

    The elemental composition of Ceres' regolith to depths of several decimeters within broad spatial regions is determined from global, low-altitude mapping data acquired by Dawn's Gamma Ray and Neutron Detector (GRaND). GRaND is sensitive to specific elements such as H, C, O, Si, K, Fe and compositional parameters, including the neutron macroscopic absorption cross section and average atomic mass of the regolith. We use elemental data acquired by GRaND to constrain regolith physical and chemical properties, and geochemical processes underlying Ceres' formation and evolution. Forward modeling and spatial deconvolution of mapped neutron counting data enable comparisons with high-resolution data sets, including absorption bands associated with OH and ammonium observed by Dawn's Visible and InfraRed mapping spectrometer (VIR), and geophysical models of the distribution of near-surface water ice. The GRaND data show that Ceres regolith is hydrogen rich, with an elemental composition similar to aqueously altered carbonaceous chondrites and consistent with the observation of widespread hydrated minerals by VIR. Decreased neutron counts at high latitude indicate that water ice is present beneath the surface in broad surface regions within depths sensed by GRaND as anticipated by ice stability models. If aqueous alteration of accreted materials was pervasive within Ceres' interior, processes such as large-scale convection may have separated brine-rich liquids from solid residues resulting in chemical fractionation. If so, then the elemental composition of the regolith should be different from Ceres' bulk. We test this hypothesis by comparing the elemental composition of Ceres' regolith to carbonaceous chondrites that underwent isochemical alteration on smaller parent bodies. The analysis considers potential contamination of the regolith by exogenic materials following Ceres' formation.

  7. Intelligent Elements for ISHM

    NASA Technical Reports Server (NTRS)

    Schmalzel, John L.; Morris, Jon; Turowski, Mark; Figueroa, Fernando; Oostdyk, Rebecca

    2008-01-01

    There are a number of architecture models for implementing Integrated Systems Health Management (ISHM) capabilities. For example, approaches based on the OSA-CBM and OSA-EAI models, or specific architectures developed in response to local needs. NASA s John C. Stennis Space Center (SSC) has developed one such version of an extensible architecture in support of rocket engine testing that integrates a palette of functions in order to achieve an ISHM capability. Among the functional capabilities that are supported by the framework are: prognostic models, anomaly detection, a data base of supporting health information, root cause analysis, intelligent elements, and integrated awareness. This paper focuses on the role that intelligent elements can play in ISHM architectures. We define an intelligent element as a smart element with sufficient computing capacity to support anomaly detection or other algorithms in support of ISHM functions. A smart element has the capabilities of supporting networked implementations of IEEE 1451.x smart sensor and actuator protocols. The ISHM group at SSC has been actively developing intelligent elements in conjunction with several partners at other Centers, universities, and companies as part of our ISHM approach for better supporting rocket engine testing. We have developed several implementations. Among the key features for these intelligent sensors is support for IEEE 1451.1 and incorporation of a suite of algorithms for determination of sensor health. Regardless of the potential advantages that can be achieved using intelligent sensors, existing large-scale systems are still based on conventional sensors and data acquisition systems. In order to bring the benefits of intelligent sensors to these environments, we have also developed virtual implementations of intelligent sensors.

  8. Technetium, the missing element.

    PubMed

    de Jonge, F A; Pauwels, E K

    1996-03-01

    The history of the discovery of technetium is reviewed within the framework of the discovery and production of artificial radioactivity in the twentieth century. Important elements of this history are the accidental production of this element in a cyclotron in Berkeley, California, USA, a machine devised by Ernest Orlando Lawrence, and its subsequent discovery in 1937 by Carlo Perrier and Emilio Segrè in scrap metal parts sent by Lawrence to Palermo, Italy by mail. A detailed account is given of the steps taken; the history of the later discovery of the technetium-99m isotope in 1938 is likewise examined. Sources of natural and artificial technetium are briefly discussed.

  9. FUEL ELEMENT CONSTRUCTION

    DOEpatents

    Simnad, M.T.

    1961-08-15

    A method of preventing diffusible and volatile fission products from diffusing through a fuel element container and contaminating reactor coolant is described. More specifically, relatively volatile and diffusible fission products either are adsorbed by or react with magnesium fluoride or difluoride to form stable, less volatile, less diffusible forms. The magnesium fluoride or difluoride is disposed anywhere inwardly from the outer surface of the fuel element container in order to be contacted by the fission products before they reach and contaminate the reactor coolant. (AEC)

  10. CONSTRUCTION OF NUCLEAR FUEL ELEMENTS

    DOEpatents

    Weems, S.J.

    1963-09-24

    >A rib arrangement and an end construction for nuclearfuel elements laid end to end in a coolant tube are described. The rib arrangement is such that each fuel element, when separated from other fuel elements, fits loosely in the coolant tube and so can easily be inserted or withdrawn from the tube. The end construction of the fuel elements is such that the fuel elements when assembled end to end are keyed against relative rotation, and the ribs of each fuel element cooperate with the ribs of the adjacent fuel elements to give the assembled fuel elements a tight fit with the coolant tube. (AEC)

  11. CEDS Addresses: Rubric Elements

    ERIC Educational Resources Information Center

    US Department of Education, 2015

    2015-01-01

    Common Education Data Standards (CEDS) Version 4 introduced a common data vocabulary for defining rubrics in a data system. The CEDS elements support digital representations of both holistic and analytic rubrics. This document shares examples of holistic and analytic project rubrics, available CEDS Connections, and a logical model showing the…

  12. Elemental Chem Lab

    ERIC Educational Resources Information Center

    Franco Mariscal, Antonio Joaquin

    2008-01-01

    This educative material uses the symbols of 45 elements to spell the names of 32 types of laboratory equipment usually found in chemical labs. This teaching material has been divided into three puzzles according to the type of the laboratory equipment: (i) glassware as reaction vessels or containers; (ii) glassware for measuring, addition or…

  13. Plant transposable elements

    SciTech Connect

    Nelson, O. )

    1988-01-01

    This document presents 27 publications from a symposium on the transposable portions of various plant genomes. Topics include gene regulation, genetic analysis, recombinant technology, mutator functions, gene tagging, extrachromosomal elements, and gene activation in common laboratory plants like tobacco, maize, and alfalfa. Individual papers were processed separately for the data base. (TEM)

  14. Plants' essential chemical elements

    Treesearch

    Kevin T. Smith

    2007-01-01

    Every garden center and hardware store sells fertilizer guaranteed to "feed" plants. In a strict sense, we can't feed plants. Food contains an energy source. Green plants capture solar energy and make their own food through photosynthesis! Photosynthesis and other metabolic processes require chemical elements in appropriate doses for plants to survive...

  15. The Transuranium Elements.

    ERIC Educational Resources Information Center

    Seaborg, Glenn T.

    1985-01-01

    Discusses the unusual chemistry of the transuranium elements as well as their impact on the periodic table. Also considers the practical applications of transuranium isotopes, such as their use in nuclear fuel for the large-scale generation of electricity. (JN)

  16. NEUTRONIC REACTOR FUEL ELEMENT

    DOEpatents

    Gurinsky, D.H.; Powell, R.W.; Fox, M.

    1959-11-24

    A nuclear fuel element comprising a plurality of nuclear fuel bearing strips is presented. The strips are folded along their longitudinal axes to an angle of about 60 deg and are secured at each end by ferrule to form an elongated assembly suitable for occupying a cylindrical coolant channel.

  17. Photovoltaic radiation detector element

    DOEpatents

    Agouridis, Dimitrios C.

    1983-01-01

    A radiation detector element is formed of a body of semiconductor material, a coating on the body which forms a photovoltaic junction therewith, and a current collector consisting of narrow metallic strips, the aforesaid coating having an opening therein the edge of which closely approaches but is spaced from the current collector strips.

  18. Senescence responsive transcriptional element

    DOEpatents

    Campisi, Judith; Testori, Alessandro

    1999-01-01

    Recombinant polynucleotides have expression control sequences that have a senescence responsive element and a minimal promoter, and which are operatively linked to a heterologous nucleotide sequence. The molecules are useful for achieving high levels of expression of genes in senescent cells. Methods of inhibiting expression of genes in senescent cells also are provided.

  19. TABLE OF RADIOACTIVE ELEMENTS.

    SciTech Connect

    HOLDEN,N.E.

    2001-06-29

    For those chemical elements which have no stable nuclides with a terrestrial isotopic composition, the data on radioactive half-lives and relative atomic masses for the nuclides of interest and importance have been evaluated and the recommended values and uncertainties are listed.

  20. Heating element support clip

    DOEpatents

    Sawyer, W.C.

    1995-08-15

    An apparatus for supporting a heating element in a channel formed in a heater base is disclosed. A preferred embodiment includes a substantially U-shaped tantalum member. The U-shape is characterized by two substantially parallel portions of tantalum that each have an end connected to opposite ends of a base portion of tantalum. The parallel portions are each substantially perpendicular to the base portion and spaced apart a distance not larger than a width of the channel and not smaller than a width of a graphite heating element. The parallel portions each have a hole therein, and the centers of the holes define an axis that is substantially parallel to the base portion. An aluminum oxide ceramic retaining pin extends through the holes in the parallel portions and into a hole in a wall of the channel to retain the U-shaped member in the channel and to support the graphite heating element. The graphite heating element is confined by the parallel portions of tantalum, the base portion of tantalum, and the retaining pin. A tantalum tube surrounds the retaining pin between the parallel portions of tantalum. 6 figs.

  1. NUCLEAR REACTOR ELEMENT

    DOEpatents

    Sanz, M.C.; Scully, C.N.

    1961-06-27

    The patented fuel element is a hexagonal graphite body having an axial channel therethrough. The graphite is impregnated with uranium which is concentrated near the axial channel. Layers of tantalum nitride and tantalum carbide are disposed on the surface of the body confronting the channel.

  2. NEUTRONIC REACTOR FUEL ELEMENT

    DOEpatents

    Stacy, J.T.

    1958-12-01

    A reactor fuel element having a core of molybdenum-uranium alloy jacketed in stainless steel is described. A barrier layer of tungsten, tantalum, molybdenum, columbium, or silver is interposed between the core and jacket to prevent formation of a low melting eutectic between uranium and the varlous alloy constituents of the stainless steel.

  3. Heating element support clip

    DOEpatents

    Sawyer, William C.

    1995-01-01

    An apparatus for supporting a heating element in a channel formed in a heater base is disclosed. A preferred embodiment includes a substantially U-shaped tantalum member. The U-shape is characterized by two substantially parallel portions of tantalum that each have an end connected to opposite ends of a base portion of tantalum. The parallel portions are each substantially perpendicular to the base portion and spaced apart a distance not larger than a width of the channel and not smaller than a width of a graphite heating element. The parallel portions each have a hole therein, and the centers of the holes define an axis that is substantially parallel to the base portion. An aluminum oxide ceramic retaining pin extends through the holes in the parallel portions and into a hole in a wall of the channel to retain the U-shaped member in the channel and to support the graphite heating element. The graphite heating element is confined by the parallel portions of tantalum, the base portion of tantalum, and the retaining pin. A tantalum tube surrounds the retaining pin between the parallel portions of tantalum.

  4. JACKETED REACTOR FUEL ELEMENT

    DOEpatents

    Smith, K.F.; Van Thyne, R.J.

    1958-12-01

    A fuel element is described for fast reactors comprised of a core of uranium metal containing material and a jacket around the core, the jacket consisting of from 2.5 to 15 percent of titanium, from 1 to 5 percent of niobium, and from 80 to 96.5 percent of vanadium.

  5. Abundances of light elements.

    PubMed Central

    Pagel, B E

    1993-01-01

    Recent developments in the study of abundances of light elements and their relevance to cosmological nucleosynthesis are briefly reviewed. The simplest model, based on standard cosmology and particle physics and assuming homogeneous baryon density at the relevant times, continues to stand up well. PMID:11607388

  6. TABLE OF RADIOACTIVE ELEMENTS.

    SciTech Connect

    HOLDEN,N.E.

    2001-06-29

    For those chemical elements which have no stable nuclides with a terrestrial isotopic composition, the data on radioactive half-lives and relative atomic masses for the nuclides of interest and importance have been evaluated and the recommended values and uncertainties are listed.

  7. Elemental Chem Lab

    ERIC Educational Resources Information Center

    Franco Mariscal, Antonio Joaquin

    2008-01-01

    This educative material uses the symbols of 45 elements to spell the names of 32 types of laboratory equipment usually found in chemical labs. This teaching material has been divided into three puzzles according to the type of the laboratory equipment: (i) glassware as reaction vessels or containers; (ii) glassware for measuring, addition or…

  8. The Transuranium Elements.

    ERIC Educational Resources Information Center

    Seaborg, Glenn T.

    1985-01-01

    Discusses the unusual chemistry of the transuranium elements as well as their impact on the periodic table. Also considers the practical applications of transuranium isotopes, such as their use in nuclear fuel for the large-scale generation of electricity. (JN)

  9. Picture-Element Comparator

    NASA Technical Reports Server (NTRS)

    Gennery, D. B.

    1986-01-01

    Proposed circuit, called "neighborhood comparison operator," compares data from neighboring picture elements (pixels) to find peaks, ridges, and valleys in picture data. Circuit also able to expand or shrink pixel regions. Circuit concept developed for image-processing computers. Circuit handles data stream of 12-bit pixels rather than conventional 8 or 16 bits. Consist entirely of standard logic chips.

  10. Capturing the Essential Elements

    ERIC Educational Resources Information Center

    Racine, David

    2004-01-01

    When a program with demonstrated effectiveness is expanded, knowing how it works and why it works the way it does is an indispensable first step in preserving its quality. This report draws on P/PV's experience with different programs to show how to define a model's essential elements to increase the chances of successful replication. It contains…

  11. Element-topology-independent preconditioners for parallel finite element computations

    NASA Technical Reports Server (NTRS)

    Park, K. C.; Alexander, Scott

    1992-01-01

    A family of preconditioners for the solution of finite element equations are presented, which are element-topology independent and thus can be applicable to element order-free parallel computations. A key feature of the present preconditioners is the repeated use of element connectivity matrices and their left and right inverses. The properties and performance of the present preconditioners are demonstrated via beam and two-dimensional finite element matrices for implicit time integration computations.

  12. Element-topology-independent preconditioners for parallel finite element computations

    NASA Technical Reports Server (NTRS)

    Park, K. C.; Alexander, Scott

    1992-01-01

    A family of preconditioners for the solution of finite element equations are presented, which are element-topology independent and thus can be applicable to element order-free parallel computations. A key feature of the present preconditioners is the repeated use of element connectivity matrices and their left and right inverses. The properties and performance of the present preconditioners are demonstrated via beam and two-dimensional finite element matrices for implicit time integration computations.

  13. Polynomial Beam Element Analysis Module

    SciTech Connect

    Ning, S. Andrew

    2013-05-01

    pBEAM (Polynomial Beam Element Analysis Module) is a finite element code for beam-like structures. The methodology uses Euler? Bernoulli beam elements with 12 degrees of freedom (3 translation and 3 rotational at each end of the element).

  14. Production of transuranium elements

    SciTech Connect

    Wham, R.M.; Chattin, F.R.; Knauer, J.B.

    1993-12-31

    The Radiochemical Engineering Development Center (REDC) has the programmatic responsibility for the Department of Energy`s Transuranium Element Program. Principle elements from the program are einsteinium, berkelium, and fermium. Targets containing curium oxide mixed with aluminum powder are fabricated by the REDC and irradiated in the Oak Ridge National Laboratory (ORNL) High Flux Isotope Reactor. Following an irradiation period of 6-12 months, targets are returned to the REDC for chemical processing. Processing operations consists of aluminum dejacketing in a caustic-nitrate solution, filtration, acid dissolution, solvent extraction, anion exchange, and finally a cation exchange to recover the actinides. The processing operations take place in heavily shielded hot cell facilities and all operations are carried out remotely. The chemistry for the separations has been well established over the 26-yr. operating life of the facility.

  15. Oxygen, a paradoxical element?

    PubMed

    Greabu, Maria; Battino, M; Mohora, Maria; Olinescu, R; Totan, Alexandra; Didilescu, Andreea

    2008-01-01

    Oxygen is an essential element for life on earth. No life may exist without oxygen. But in the last forty years, conclusive evidence demonstrated the double-edge sword of this element. In certain conditions, oxygen may produce reactive species, even free radicals. More, the production of reactive oxygen species (ROS) takes place everywhere: in air, nature or inside human bodies. The paradox of oxygen atom is entirely due to its peculiar electronic structure. But life began on earth, only when nature found efficient weapons against ROS, these antioxidants, which all creatures are extensibly endowed with. The consequences of oxygen activation in human bodies are only partly known, in spite of extensive scientific research on theoretical, experimental and clinical domains.

  16. The individual element test revisited

    NASA Technical Reports Server (NTRS)

    Militello, Carmelo; Felippa, Carlos A.

    1991-01-01

    The subject of the patch test for finite elements retains several unsettled aspects. In particular, the issue of one-element versus multielement tests needs clarification. Following a brief historical review, we present the individual element test (IET) of Bergan and Hanssen in an expanded context that encompasses several important classes of new elements. The relationship of the IET to the multielement forms A, B, and C of the patch test and to the single element test are clarified.

  17. OXIDATION OF TRANSURANIC ELEMENTS

    DOEpatents

    Moore, R.L.

    1959-02-17

    A method is reported for oxidizing neptunium or plutonium in the presence of cerous values without also oxidizing the cerous values. The method consists in treating an aqueous 1N nitric acid solution, containing such cerous values together with the trivalent transuranic elements, with a quantity of hydrogen peroxide stoichiometrically sufficient to oxidize the transuranic values to the hexavalent state, and digesting the solution at room temperature.

  18. Nuclear fuel element

    DOEpatents

    Meadowcroft, Ronald Ross; Bain, Alastair Stewart

    1977-01-01

    A nuclear fuel element wherein a tubular cladding of zirconium or a zirconium alloy has a fission gas plenum chamber which is held against collapse by the loops of a spacer in the form of a tube which has been deformed inwardly at three equally spaced, circumferential positions to provide three loops. A heat resistant disc of, say, graphite separates nuclear fuel pellets within the cladding from the plenum chamber. The spacer is of zirconium or a zirconium alloy.

  19. Elements of String Cosmology

    NASA Astrophysics Data System (ADS)

    Gasperini, Maurizio

    2011-03-01

    Preface; Acknowledgements; Notation, units and conventions; 1. A short review of standard and inflationary cosmology; 2. The basic string cosmology equations; 3. Conformal invariance and string effective action; 4. Duality symmetries and cosmological solutions; 5. Inflationary kinematics; 6. The string phase; 7. The cosmic background of relic gravitational waves; 8. Scalar perturbations and the anisotropy of the CMB radiation; 9. Dilaton phenomenology; 10. Elements of brane cosmology; Index.

  20. New functionalities in abundant element oxides: ubiquitous element strategy

    PubMed Central

    Hosono, Hideo; Hayashi, Katsuro; Kamiya, Toshio; Atou, Toshiyuki; Susaki, Tomofumi

    2011-01-01

    While most ceramics are composed of ubiquitous elements (the ten most abundant elements within the Earth's crust), many advanced materials are based on rare elements. A ‘rare-element crisis’ is approaching owing to the imbalance between the limited supply of rare elements and the increasing demand. Therefore, we propose a ‘ubiquitous element strategy’ for materials research, which aims to apply abundant elements in a variety of innovative applications. Creation of innovative oxide materials and devices based on conventional ceramics is one specific challenge. This review describes the concept of ubiquitous element strategy and gives some highlights of our recent research on the synthesis of electronic, thermionic and structural materials using ubiquitous elements. PMID:27877391

  1. Assessment of trace element status.

    PubMed

    Delves, H T

    1985-08-01

    Biochemical and clinical investigations involving trace elements are made for the diagnosis of inherited or acquired deficiencies of essential trace elements and their treatment, to monitor the efficacy of the therapeutic administration of non-essential trace elements in order to achieve maximum clinical response with minimum toxicity, and for the early detection of excessive ingestion of non-essential toxic trace elements. The wide range of tests used to assess trace element status in these three areas of clinical importance is discussed with examples of essential and of toxic trace elements since therapeutic use of trace elements is discussed elsewhere in this issue. Particular attention is given to zinc, copper, selenium, lead and cadmium because the various tests used to assess the status of these elements encompass the principles of all currently available tests. Although trace element analysis of body fluids and tissues is the most useful and most commonly used method of assessment of trace element status, this is of limited value and no single test may be considered as ideal for any element. The provision of more detailed information from elemental analysis of cellular and subcellular fractions and of protein fractions from plasma leads inexorably to measurements of element-dependent enzymes, metalloproteins and of low molecular weight element-binding ligands. Even at this level of discrimination the choice of body tissue or tissue fluid for investigation is determined by the trace element and its principal metabolic targets.

  2. The transuranium elements: From neptunium and plutonium to element 112

    SciTech Connect

    Hoffman, D.C. |

    1996-07-26

    Beginning in the 1930`s, both chemists and physicists became interested in synthesizing new artificial elements. The first transuranium element, Np, was synthesized in 1940. Over the past six decades, 20 transuranium elements have been produced. A review of the synthesis is given. The procedure of naming the heavy elements is also discussed. It appears feasible to produce elements 113 and 114. With the Berkeley Gas-filled Separator, it should be possible to reach the superheavy elements in the region of the spherical Z=114 shell, but with fewer neutrons than the N=184 spherical shell. 57 refs, 6 figs.

  3. Method of securing filter elements

    SciTech Connect

    Brown, Erik P.; Haslam, Jeffery L.; Mitchell, Mark A.

    2016-10-04

    A filter securing system including a filter unit body housing; at least one tubular filter element positioned in the filter unit body housing, the tubular filter element having a closed top and an open bottom; a dimple in either the filter unit body housing or the top of the tubular filter element; and a socket in either the filter unit body housing or the top of the tubular filter element that receives the dimple in either the filter unit body housing or the top of the tubular filter element to secure the tubular filter element to the filter unit body housing.

  4. Nuclear reactor fuel element

    DOEpatents

    Johnson, Carl E.; Crouthamel, Carl E.

    1980-01-01

    A nuclear reactor fuel element is described which has an outer cladding, a central core of fissionable or mixed fissionable and fertile fuel material and a layer of oxygen gettering material on the inner surface of the cladding. The gettering material reacts with oxygen released by the fissionable material during irradiation of the core thereby preventing the oxygen from reacting with and corroding the cladding. Also described is an improved method for coating the inner surface of the cladding with a layer of gettering material.

  5. [Healthcare marketing elements].

    PubMed

    Ameri, Cinzia; Fiorini, Fulvio

    2014-01-01

    Marketing puts its foundation on a few key concepts: need-demand, product-service, satisfaction, exchange, market, or business structure manufacturing / supply. The combination of these elements allows you to build an effective marketing strategy. Crucial in this respect is to remember the Porter matrix, which shows that for a correct analysis of the relevant market is necessary to refer to the "five forces at play", ie: customers, competitors, new entrants and substitutes threat. Another key lever for proper marketing oriented approach is the continuous and constant monitoring of the application, anticipating their dissatisfactions.

  6. Origin of the Elements

    NASA Astrophysics Data System (ADS)

    Truran, J. W., Jr.; Heger, A.

    2003-12-01

    Nucleosynthesis is the study of the nuclear processes responsible for the formation of the elements which constitute the baryonic matter of the Universe. The elements of which the Universe is composed indeed have a quite complicated nucleosynthesis history, which extends from the first three minutes of the Big Bang through to the present. Contemporary nucleosynthesis theory associates the production of certain elements/isotopes or groups of elements with a number of specific astrophysical settings, the most significant of which are: (i) the cosmological Big Bang, (ii) stars, and (iii) supernovae.Cosmological nucleosynthesis studies predict that the conditions characterizing the Big Bang are consistent with the synthesis only of the lightest elements: 1H, 2H, 3He, 4He, and 7Li (Burles et al., 2001; Cyburt et al., 2002). These contributions define the primordial compositions both of galaxies and of the first stars formed therein. Within galaxies, stars and supernovae play the dominant role both in synthesizing the elements from carbon to uranium and in returning heavy-element-enriched matter to the interstellar gas from which new stars are formed. The mass fraction of our solar system (formed ˜4.6 Gyr ago) in the form of heavy elements is ˜1.8%, and stars formed today in our galaxy can be a factor 2 or 3 more enriched (Edvardsson et al., 1993). It is the processes of nucleosynthesis operating in stars and supernovae that we will review in this chapter. We will confine our attention to three broad categories of stellar and supernova site with which specific nucleosynthesis products are understood to be identified: (i) intermediate mass stars, (ii) massive stars and associated type II supernovae, and (iii) type Ia supernovae. The first two of these sites are the straightforward consequence of the evolution of single stars, while type Ia supernovae are understood to result from binary stellar evolution.Stellar nucleosynthesis resulting from the evolution of single

  7. FUEL ELEMENT CONSTRUCTION

    DOEpatents

    Zumwalt, L.R.

    1961-08-01

    Fuel elements having a solid core of fissionable material encased in a cladding material are described. A conversion material is provided within the cladding to react with the fission products to form stable, relatively non- volatile compounds thereby minimizing the migration of the fission products into the coolant. The conversion material is preferably a metallic fluoride, such as lead difluoride, and may be in the form of a coating on the fuel core or interior of the cladding, or dispersed within the fuel core. (AEC)

  8. Semiclassical integrable matrix elements

    SciTech Connect

    Morehead, J.J.

    1996-03-01

    A semiclassical expression for matrix elements of an arbitrary operator with respect to the eigenstates of an integrable Hamiltonian is derived. This is essentially the Heisenberg correspondence principle, and it is shown via the Weyl correspondence that the approximation is valid through the lowest two orders in {h_bar}. The result is used to prove that an asymptotic form of the Clebsch-Gordan coefficients for two large and one small angular momenta is valid through two orders. {copyright} {ital 1996 The American Physical Society.}

  9. FUEL ELEMENT FABRICATION METHOD

    DOEpatents

    Hix, J.N.; Cooley, G.E.; Cunningham, J.E.

    1960-05-31

    A method is given for assembling and fabricating a fuel element comprising a plurality of spaced parallel fuel plates of a bowed configuration supported by and between a pair of transperse aluminum side plates. In this method, a brasing alloy is preplated on one surface of the aluminum side plates in the form of a cladding or layer-of uniform thickness. Grooves are then cut into the side plates through the alloy layer and into the base aluminum which results in the utilization of thinner aluminum side plates since a portion of the necessary groove depth is supplied by the brazing alloy.

  10. Abundances of the elements.

    NASA Technical Reports Server (NTRS)

    Urey, H. C.

    1972-01-01

    An elemental abundance table along the lines used by Suess and Urey (1956) is presented. Since this early work, other studies have been made, and improvement in the abundance tables has been made as more reliable data have become available. Some changes in the original tables have been made, but the original abundances and their variations with mass numbers remain remarkably similar. The solar abundance of iron for many years appeared to be very much less relative to silicon than would be indicated by the data from the meteorites.

  11. Ring-laser gyroscope system using dispersive element(s)

    NASA Technical Reports Server (NTRS)

    Smith, David D. (Inventor)

    2010-01-01

    A ring-laser gyroscope system includes a ring-laser gyroscope (RLG) and at least one dispersive element optically coupled to the RLG's ring-shaped optical path. Each dispersive element has a resonant frequency that is approximately equal to the RLG's lasing frequency. A group index of refraction defined collectively by the dispersive element(s) has (i) a real portion that is greater than zero and less than one, and (ii) an imaginary portion that is less than zero.

  12. Element-by-element Solution Procedures for Nonlinear Structural Analysis

    NASA Technical Reports Server (NTRS)

    Hughes, T. J. R.; Winget, J. M.; Levit, I.

    1984-01-01

    Element-by-element approximate factorization procedures are proposed for solving the large finite element equation systems which arise in nonlinear structural mechanics. Architectural and data base advantages of the present algorithms over traditional direct elimination schemes are noted. Results of calculations suggest considerable potential for the methods described.

  13. The CEBAF Element Database

    SciTech Connect

    Theodore Larrieu, Christopher Slominski, Michele Joyce

    2011-03-01

    With the inauguration of the CEBAF Element Database (CED) in Fall 2010, Jefferson Lab computer scientists have taken a step toward the eventual goal of a model-driven accelerator. Once fully populated, the database will be the primary repository of information used for everything from generating lattice decks to booting control computers to building controls screens. A requirement influencing the CED design is that it provide access to not only present, but also future and past configurations of the accelerator. To accomplish this, an introspective database schema was designed that allows new elements, types, and properties to be defined on-the-fly with no changes to table structure. Used in conjunction with Oracle Workspace Manager, it allows users to query data from any time in the database history with the same tools used to query the present configuration. Users can also check-out workspaces to use as staging areas for upcoming machine configurations. All Access to the CED is through a well-documented Application Programming Interface (API) that is translated automatically from original C++ source code into native libraries for scripting languages such as perl, php, and TCL making access to the CED easy and ubiquitous.

  14. Heavy-element nucleosynthesis

    SciTech Connect

    Mathews, G.J.

    1990-10-30

    New measurements and theoretical studies of nuclear properties, together with new astronomical data on the growth of heavy-element abundances during the early history of the Galaxy, now provide a clearer picture of where in nature the elements heavier than iron are produced by rapid (r-process) and show (s-process) neutron capture reactions. The nuclear data suggest that the r-process involves a high-neutron-density beta-flow equilibrium environment and that the s-process may have occurred at a temperature and neutron density consistent with a {sup 13}C({alpha},n){sup 16}0 neutron source. The astronomical data, when compared with simple galactic chemical evolution modes, suggests that the r-process is associated with type II supernovae and that the neutron source must be manufactured by the star. Low-mass type II supernovae are proposed as the most important contributors to the r-process. A {sup 13}C neutron source in intermediate-mass stars is proposed for the s-process. 64 refs., 7 figs.

  15. Cohesive Zone Model User Element

    SciTech Connect

    Tippetts, Trevor

    2007-04-17

    Cohesive Zone Model User Element (CZM UEL) is an implementation of a Cohesive Zone Model as an element for use in finite element simulations. CZM UEL computes a nodal force vector and stiffness matrix from a vector of nodal displacements. It is designed for structural analysts using finite element software to predict crack initiation, crack propagation, and the effect of a crack on the rest of a structure.

  16. Multi-element microelectropolishing method

    DOEpatents

    Lee, P.J.

    1994-10-11

    A method is provided for microelectropolishing a transmission electron microscopy nonhomogeneous multi-element compound foil. The foil is electrolyzed at different polishing rates for different elements by rapidly cycling between different current densities. During a first portion of each cycle at a first voltage a first element electrolyzes at a higher current density than a second element such that the material of the first element leaves the anode foil at a faster rate than the second element and creates a solid surface film, and such that the solid surface film is removed at a faster rate than the first element leaves the anode foil. During a second portion of each cycle at a second voltage the second element electrolyzes at a higher current density than the first element, and the material of the second element leaves the anode foil at a faster rate than the first element and creates a solid surface film, and the solid surface film is removed at a slower rate than the second element leaves the foil. The solid surface film is built up during the second portion of the cycle, and removed during the first portion of the cycle. 10 figs.

  17. Multi-element microelectropolishing method

    DOEpatents

    Lee, Peter J.

    1994-01-01

    A method is provided for microelectropolishing a transmission electron microscopy nonhomogeneous multi-element compound foil. The foil is electrolyzed at different polishing rates for different elements by rapidly cycling between different current densities. During a first portion of each cycle at a first voltage a first element electrolyzes at a higher current density than a second element such that the material of the first element leaves the anode foil at a faster rate than the second element and creates a solid surface film, and such that the solid surface film is removed at a faster rate than the first element leaves the anode foil. During a second portion of each cycle at a second voltage the second element electrolyzes at a higher current density than the first element, and the material of the second element leaves the anode foil at a faster rate than the first element and creates a solid surface film, and the solid surface film is removed at a slower rate than the second element leaves the foil. The solid surface film is built up during the second portion of the cycle, and removed during the first portion of the cycle.

  18. REACTOR FUEL ELEMENTS TESTING CONTAINER

    DOEpatents

    Whitham, G.K.; Smith, R.R.

    1963-01-15

    This patent shows a method for detecting leaks in jacketed fuel elements. The element is placed in a sealed tank within a nuclear reactor, and, while the reactor operates, the element is sparged with gas. The gas is then led outside the reactor and monitored for radioactive Xe or Kr. (AEC)

  19. Conversion of Osculating Orbital Elements to Mean Orbital Elements

    NASA Technical Reports Server (NTRS)

    Der, Gim J.; Danchick, Roy

    1996-01-01

    Orbit determination and ephemeris generation or prediction over relatively long elapsed times can be accomplished with mean elements. The most simple and efficient method for orbit determination, which is also known as epoch point conversion, performs the conversion of osculating elements to mean elements by iterative procedures. Previous epoch point conversion methods are restricted to shorter elapsed times with linear convergence. The new method presented in this paper calculates an analytic initial guess of the unknown mean elements from a first order theory of secular perturbations and computes a transition matrix with accurate numerical partials. It thereby eliminates the problem of an inaccurate initial guess and an identity transition matrix employed by previous methods. With a good initial guess of the unknown mean elements and an accurate transition matrix, converging osculating elements to mean elements can be accomplished over long elapsed times with quadratic convergence.

  20. Nuclear fuel element

    DOEpatents

    Armijo, Joseph S.; Coffin, Jr., Louis F.

    1980-04-29

    A nuclear fuel element for use in the core of a nuclear reactor is disclosed and has an improved composite cladding comprised of a moderate purity metal barrier of zirconium metallurgically bonded on the inside surface of a zirconium alloy tube. The metal barrier forms a shield between the alloy tube and a core of nuclear fuel material enclosed in the composite cladding. There is a gap between the cladding and the core. The metal barrier forms about 1 to about 30 percent of the thickness of the composite cladding and has low neutron absorption characteristics. The metal barrier serves as a preferential reaction site for gaseous impurities and fission products and protects the alloy tube from contact and reaction with such impurities and fission products. Methods of manufacturing the composite cladding are also disclosed.

  1. Nuclear fuel element

    DOEpatents

    Armijo, Joseph S.; Coffin, Jr., Louis F.

    1983-01-01

    A nuclear fuel element for use in the core of a nuclear reactor is disclosed and has a composite cladding having a substrate and a metal barrier metallurgically bonded on the inside surface of the substrate so that the metal barrier forms a shield between the substrate and the nuclear fuel material held within the cladding. The metal barrier forms about 1 to about 30 percent of the thickness of the cladding and is comprised of a low neutron absorption metal of substantially pure zirconium. The metal barrier serves as a preferential reaction site for gaseous impurities and fission products and protects the substrate from contact and reaction with such impurities and fission products. The substrate of the composite cladding is selected from conventional cladding materials and preferably is a zirconium alloy. Methods of manufacturing the composite cladding are also disclosed.

  2. Photoconductive circuit element reflectometer

    DOEpatents

    Rauscher, C.

    1987-12-07

    A photoconductive reflectometer for characterizing semiconductor devices at millimeter wavelength frequencies where a first photoconductive circuit element (PCE) is biased by a direct current voltage source and produces short electrical pulses when excited into conductance by short first laser light pulses. The electrical pulses are electronically conditioned to improve the frequency related amplitude characteristics of the pulses which thereafter propagate along a transmission line to a device under test. Second PCEs are connected along the transmission line to sample the signals on the transmission line when excited into conductance by short second laser light pulses, spaced apart in time a determinable period from the first laser light pulses. Electronic filters connected to each of the second PCEs act as low-pass filters and remove parasitic interference from the sampled signals and output the sampled signals in the form of slowed-motion images of the signals on the transmission line. 4 figs.

  3. Photoconductive circuit element reflectometer

    DOEpatents

    Rauscher, Christen

    1990-01-01

    A photoconductive reflectometer for characterizing semiconductor devices at millimeter wavelength frequencies where a first photoconductive circuit element (PCE) is biased by a direct current voltage source and produces short electrical pulses when excited into conductance by short first laser light pulses. The electrical pulses are electronically conditioned to improve the frequency related amplitude characteristics of the pulses which thereafter propagate along a transmission line to a device under test. Second PCEs are connected along the transmission line to sample the signals on the transmission line when excited into conductance by short second laser light pulses, spaced apart in time a variable period from the first laser light pulses. Electronic filters connected to each of the second PCEs act as low-pass filters and remove parasitic interference from the sampled signals and output the sampled signals in the form of slowed-motion images of the signals on the transmission line.

  4. Lithium peroxide primary element

    SciTech Connect

    Winsel, A.

    1982-05-04

    In a galvanic primary element of the system Li/H/sub 2/O/sub 2/, the aqueous cathode depolarizer H/sub 2/O/sub 2/ is fixated as a polyurethane gel. It can thereby be controlled and caused to react with the anode metal in accordance with the current drain requirements. This is accomplished using a ram to press the gel toward a conductor which covers the lithium anode, which may take the form of a metal grid and/or a gas diffusion electrode. The oxygen which forms in the working layer through catalytic decomposition of hydrogen peroxide creates a gas bubble when the current is interrupted or the ram is stopped, thereby interrupting the further supply of hydrogen peroxide to the catalyst.

  5. RECONDITIONING FUEL ELEMENTS

    DOEpatents

    Brandt, H.L.

    1962-02-20

    A process is given for decanning fuel elements that consist of a uranium core, an intermediate section either of bronze, silicon, Al-Si, and uranium silicide layers or of lead, Al-Si, and uranium silicide layers around said core, and an aluminum can bonded to said intermediate section. The aluminum can is dissolved in a solution of sodium hydroxide (9 to 20 wt%) and sodium nitrate (35 to 12 wt %), and the layers of the intermediate section are dissolved in a boiling sodium hydroxide solution of a minimum concentration of 50 wt%. (AEC) A method of selectively reducing plutonium oxides and the rare earth oxides but not uranium oxides is described which comprises placing the oxides in a molten solvent of zinc or cadmium and then adding metallic uranium as a reducing agent. (AEC)

  6. Cosmological element production.

    PubMed

    Wagoner, R V

    1967-03-17

    Two recent observations appear to have provided critical information about the past history of the universe. The thermal character of the microwave background radiation suggests that the universe has expanded from a state of high temperature and density, and places constraints on such a big-bang cosmology. The observations of very weak helium lines in the spectra of certain stars in the halo of our galaxy are possibly due to a low primeval abundance of this element. However, the simplest model of a big-bang cosmology leads to much higher helium abundances, such as are observed in the solar system and in many stars. The production of helium can be reduced either by altering the early expansion rate or by introducing degenerate electron neutrinos. Observations of interstellar and intergalactic deuterium and He(4), and possibly even He(3) and Li(7), are needed to test the various models.

  7. The Moon: Biogenic elements

    NASA Technical Reports Server (NTRS)

    Gibson, Everett K., Jr.; Chang, Sherwood

    1992-01-01

    The specific objectives of the organic chemical exploration of the Moon involve the search for molecules of possible biological or prebiological origin. Detailed knowledge of the amount, distribution, and exact structure of organic compounds present on the Moon is extremely important to our understanding of the origin and history of the Moon and to its relationship to the history of the Earth and solar system. Specifically, such knowledge is essential for determining whether life on the Moon exists, ever did exist, or could develop. In the absence of life or organic matter, it is still essential to determine the abundance, distribution, and origin of the biogenic elements (e.g., H, C, O, N, S, P) in order to understand how the planetary environment may have influenced the course of chemical evolution. The history and scope of this effort is presented.

  8. The fantastic four.. elements

    NASA Astrophysics Data System (ADS)

    Marsili, Antonella; D'Addezio, Giuliana; Rubbia, Giuliana; Ramieri, Caterina; Todaro, Riccardo; Scipilliti, Francesca; Tosto, Eleonora

    2015-04-01

    With a "Sunday between territory and music to 'National Institute of Geophysics and Volcanology," October 12, 2014 the headquarters of INGV Roma kicked off the activities of the second edition of the Week of Planet Earth. The laboratory of scientific outreach and museum activities together with volunteers of the National Civil Service have organized the whole day dedicated to the dissemination of earth sciences, involving adults and children. Especially for primary school children a laboratory was made involving three amusing activities all aimed at inspiring respect for the Earth: a theatrical representation called "The Fantastic 4... elements", a behavioral game and a nursery rhyme reading. The theater as a means of communication of science is an innovative and creative way to introduce children to important scientific concepts. The use of this methodology and simple language favoring the emotional involvement of the child facilitating learning. The main character is a child, chosen to facilitate the identification of the spectators with the protagonist, that through a fantastic journey discovers the importance of the four elements of our planet: earth, fire, air and water. As a second step, volunteers involved children in reading a nursery rhyme "the ABC to become a Friend of the Earth" inviting them to protect and respect the environment and its resources. Finally, the behavioral game gave indications about behaviors to adopt to safeguard the planet. Volunteers introduced a billboard divided into two colors, green to indicate the right behaviors and red for the wrong ones. Each child, after reading a card with indication on the behavior to adopt, had to decide if they were correct or not with respect to the environment safeguard. After listening to the children's answer, the volunteer gave the correct explanation about the appropriate behavior to adopt. At the end of the activities, each child received a certificate as "a friend of Planet Earth".

  9. Chemical characterization of element 112.

    PubMed

    Eichler, R; Aksenov, N V; Belozerov, A V; Bozhikov, G A; Chepigin, V I; Dmitriev, S N; Dressler, R; Gäggeler, H W; Gorshkov, V A; Haenssler, F; Itkis, M G; Laube, A; Lebedev, V Ya; Malyshev, O N; Oganessian, Yu Ts; Petrushkin, O V; Piguet, D; Rasmussen, P; Shishkin, S V; Shutov, A V; Svirikhin, A I; Tereshatov, E E; Vostokin, G K; Wegrzecki, M; Yeremin, A V

    2007-05-03

    The heaviest elements to have been chemically characterized are seaborgium (element 106), bohrium (element 107) and hassium (element 108). All three behave according to their respective positions in groups 6, 7 and 8 of the periodic table, which arranges elements according to their outermost electrons and hence their chemical properties. However, the chemical characterization results are not trivial: relativistic effects on the electronic structure of the heaviest elements can strongly influence chemical properties. The next heavy element targeted for chemical characterization is element 112; its closed-shell electronic structure with a filled outer s orbital suggests that it may be particularly susceptible to strong deviations from the chemical property trends expected within group 12. Indeed, first experiments concluded that element 112 does not behave like its lighter homologue mercury. However, the production and identification methods used cast doubt on the validity of this result. Here we report a more reliable chemical characterization of element 112, involving the production of two atoms of (283)112 through the alpha decay of the short-lived (287)114 (which itself forms in the nuclear fusion reaction of 48Ca with 242Pu) and the adsorption of the two atoms on a gold surface. By directly comparing the adsorption characteristics of (283)112 to that of mercury and the noble gas radon, we find that element 112 is very volatile and, unlike radon, reveals a metallic interaction with the gold surface. These adsorption characteristics establish element 112 as a typical element of group 12, and its successful production unambiguously establishes the approach to the island of stability of superheavy elements through 48Ca-induced nuclear fusion reactions with actinides.

  10. Elements and elasmobranchs: hypotheses, assumptions and limitations of elemental analysis.

    PubMed

    McMillan, M N; Izzo, C; Wade, B; Gillanders, B M

    2017-02-01

    Quantifying the elemental composition of elasmobranch calcified cartilage (hard parts) has the potential to answer a range of ecological and biological questions, at both the individual and population level. Few studies, however, have employed elemental analyses of elasmobranch hard parts. This paper provides an overview of the range of applications of elemental analysis in elasmobranchs, discussing the assumptions and potential limitations in cartilaginous fishes. It also reviews the available information on biotic and abiotic factors influencing patterns of elemental incorporation into hard parts of elasmobranchs and provides some comparative elemental assays and mapping in an attempt to fill knowledge gaps. Directions for future experimental research are highlighted to better understand fundamental elemental dynamics in elasmobranch hard parts. © 2016 The Fisheries Society of the British Isles.

  11. Slave finite elements: The temporal element approach to nonlinear analysis

    NASA Technical Reports Server (NTRS)

    Gellin, S.

    1984-01-01

    A formulation method for finite elements in space and time incorporating nonlinear geometric and material behavior is presented. The method uses interpolation polynomials for approximating the behavior of various quantities over the element domain, and only explicit integration over space and time. While applications are general, the plate and shell elements that are currently being programmed are appropriate to model turbine blades, vanes, and combustor liners.

  12. Chemistry of the superheavy elements.

    PubMed

    Schädel, Matthias

    2015-03-13

    The quest for superheavy elements (SHEs) is driven by the desire to find and explore one of the extreme limits of existence of matter. These elements exist solely due to their nuclear shell stabilization. All 15 presently 'known' SHEs (11 are officially 'discovered' and named) up to element 118 are short-lived and are man-made atom-at-a-time in heavy ion induced nuclear reactions. They are identical to the transactinide elements located in the seventh period of the periodic table beginning with rutherfordium (element 104), dubnium (element 105) and seaborgium (element 106) in groups 4, 5 and 6, respectively. Their chemical properties are often surprising and unexpected from simple extrapolations. After hassium (element 108), chemistry has now reached copernicium (element 112) and flerovium (element 114). For the later ones, the focus is on questions of their metallic or possibly noble gas-like character originating from interplay of most pronounced relativistic effects and electron-shell effects. SHEs provide unique opportunities to get insights into the influence of strong relativistic effects on the atomic electrons and to probe 'relativistically' influenced chemical properties and the architecture of the periodic table at its farthest reach. In addition, they establish a test bench to challenge the validity and predictive power of modern fully relativistic quantum chemical models. © 2015 The Author(s) Published by the Royal Society. All rights reserved.

  13. COMPARTMENTED REACTOR FUEL ELEMENT

    DOEpatents

    Cain, F.M. Jr.

    1962-09-11

    A method of making a nuclear reactor fuel element of the elongated red type is given wherein the fissionable fuel material is enclosed within a tubular metal cladding. The method comprises coating the metal cladding tube on its inside wall with a brazing alloy, inserting groups of cylindrical pellets of fissionable fuel material into the tube with spacing members between adjacent groups of pellets, sealing the ends of the tubes to leave a void space therewithin, heating the tube and its contents to an elevated temperature to melt the brazing alloy and to expand the pellets to their maximum dimensions under predetermined operating conditions thereby automatically positioning the spacing members along the tube, and finally cooling the tube to room temperature whereby the spacing disks become permanently fixed at their edges in the brazing alloy and define a hermetically sealed compartment for each fl group of fuel pellets. Upon cooling, the pellets contract thus leaving a space to accommodate thermal expansion of the pellets when in use in a reactor. The spacing members also provide lateral support for the tubular cladding to prevent collapse thereof when subjected to a reactor environment. (AEC)

  14. Lubrication of Machine Elements

    NASA Technical Reports Server (NTRS)

    Hamrock, B. J.

    1984-01-01

    The understanding of hydrodynamic lubrication began with the classical experiments of Tower and Petrov. Reynolds used a reduced form of the Navier-Stokes equations and the continuity equation to generate a second order differential equation for the pressure in the narrow, converging gap of a bearing contact. Such a pressure enables a load to be transmitted between the surfaces with very low friction since the surfaces are completely separated by a film of fluid. In such a situation it is the physical properties of the lubricant, notably the dynamic viscosity, that dictate the behavior of the contact. The understanding of boundary lubrication is normally attributed to Hardy and Doubleday. In boundary lubrication it is the physical and chemical properties of thin films of molecular proportions and the surfaces to which they are attached that determine contact behavior. The lubricant viscosity is not an influential parameter. Research is devoted to a better understanding and more precise definition of other lubrication regimes between these extremes. One such regime, elastohydrodynamic lubrication, occurs in nonconformal contacts, where the pressures are high and the bearing surfaces deform elastically. In this situation the viscosity of the lubricant may raise considerably, and this further assists the formation of an effective fluid film. The science of these three lubrication regimes (hydrodynamic, elastohydrodynamic, and boundary) are described and the manner in which this science is used in the design of machine elements is examined.

  15. Resistive hydrogen sensing element

    DOEpatents

    Lauf, Robert J.

    2000-01-01

    Systems and methods are described for providing a hydrogen sensing element with a more robust exposed metallization by application of a discontinuous or porous overlay to hold the metallization firmly on the substrate. An apparatus includes: a substantially inert, electrically-insulating substrate; a first Pd containing metallization deposited upon the substrate and completely covered by a substantially hydrogen-impermeable layer so as to form a reference resistor on the substrate; a second Pd containing metallization deposited upon the substrate and at least a partially accessible to a gas to be tested, so as to form a hydrogen-sensing resistor; a protective structure disposed upon at least a portion of the second Pd containing metallization and at least a portion of the substrate to improve the attachment of the second Pd containing metallization to the substrate while allowing the gas to contact said the second Pd containing metallization; and a resistance bridge circuit coupled to both the first and second Pd containing metallizations. The circuit determines the difference in electrical resistance between the first and second Pd containing metallizations. The hydrogen concentration in the gas may be determined. The systems and methods provide advantages because adhesion is improved without adversely effecting measurement speed or sensitivity.

  16. Elements of gas contracts

    SciTech Connect

    O`Neal, J.

    1995-12-01

    The gas marketing scene has taken on a new look from the days of the {open_quotes}Long Term{close_quotes} or {open_quotes}Life of Lease{close_quotes} Contracts. In the past natural gas was of ten sold direct from the wellhead or a producer-owned facility to a pipeline company at a flat rate price and the only parties involved were producer or seller and buyer. Today, the parties involved in the marketing process might include a gathering entity to gather gas at a central point and provide gathering, compression and/or dehydration services; multiple pipeline companies for transportation; sales representatives or marketing brokers to negotiate a sale of the available gas on a monthly basis; and purchasers or end users. New terms have also been introduced in the process such as: {open_quotes}LDC{close_quotes} (local distribution company), {open_quotes}FERC Order 636{close_quotes}, {open_quotes}Price Delivered-to-Pipeline{close_quotes} and the various {open_quotes}levels of Service{close_quotes} under Gas Sales and Purchase Agreements. Four common levels of service are: {open_quotes}Firm{close_quotes}, {open_quotes}Baseload{close_quotes}, {open_quotes}Swing{close_quotes} and {open_quotes}Baseload/Operational{close_quotes}. It is evident that current marketing plans often require a separate contract for each service or commitment. Contract contents vary greatly, but most contain the following elements.

  17. RF tuning element

    NASA Technical Reports Server (NTRS)

    McGrath, William R. (Inventor); Lubecke, Victor M. (Inventor)

    1992-01-01

    A device for tuning a circuit includes a substrate, a transmission line on the substrate that includes first and second conductors coupled to a circuit to be tuned, and a movable short-circuit for varying the impedance the transmission line presents to the circuit to be tuned. The movable short-circuit includes a dielectric layer disposed atop the transmission line and a distributed shorting element in the form of a conductive member that is configured to be slid along at least a portion of the transmission line atop the dielectric layer. The conductive member is configured to span the first and second conductors of the transmission line and to define at least a first opening that spans the two conductors so that the conductive member includes first and second sections separated by the first opening. The first and second sections of the conductive member combine with the first and second conductors of the transmission line to form first and second low impedance sections of transmission line, and the opening combines with the first and second conductors of the transmission line and the dielectric layer to form a first high impedance section of transmission line intermediate the first and second low impedance sections. Each of the first low impedance section and the first high impedance section have a length along the transmission line of approximately one-quarter wavelength, thus providing a periodic variation of transmission line impedance. That enhances reflection of rf power.

  18. EAF optimal managing elements

    NASA Astrophysics Data System (ADS)

    Ioana, A.; Constantin, N.; Dragna, E. C.

    2017-01-01

    Electric Arc Furnaces (EAF) is an important and complex aggregate. We present elements of EAF operating efficiency. The reliability of the EAF is mainly determined by electric circuit reliability and especially of the transformator of the furnace. This due to the fact that, in an electric steel plant, the objective „24 tapping/day” involves. Due to the complexity of the process, the EAF operation needs a computer usage and, in his componence, it must have two independent calculation units (UC1) and (UC2). Based on these two input sets (Σi1) and ((Σi2), the calculation unit (UC1) builds the general operation procedure based on mathematical methods. For that purpose, there are used the results of the 5 mathematical methods: the mathematical model to write-off the function objective (M.F.O.); the mathematical model of calculating the charge (M.C.C.); the mathematical model of conducting the effective melt (M.C.M.); the mathematical model of reheating the charge (M.R.C.); the mathematical model of blasting the reactive dusts (M.B.R.D.).

  19. Vesta's Elemental Composition

    NASA Technical Reports Server (NTRS)

    Prettyman, T. H.; Beck, A. W.; Feldman, W. C.; Lawrence, D. J.; McCoy, T. J.; McSween, H. Y.; Mittlefehldt, D. W.; Peplowski, P. N.; Raymond, C. A.; Reedy, R. C.; Russell, C. T.; Titus, T. N.; Toplis, M. J.; Yamashita, N.

    2014-01-01

    Many lines of evidence (e.g. common geochemistry, chronology, O-isotope trends, and the presence of different HED rock types in polymict breccias) indicate that the howardite, eucrite, and diogenite (HED) meteorites originated from a single parent body. Meteorite studies show that this protoplanet underwent igneous differentiation to form a metallic core, an ultramafic mantle, and a basaltic crust. A spectroscopic match between the HEDs and 4 Vesta along with a plausible mechanism for their transfer to Earth, perhaps as chips off V-type asteroids ejected from Vesta's southern impact basin, supports the consensus view that many of these achondritic meteorites are samples of Vesta's crust and upper mantle. The HED-Vesta connection was put to the test by the NASA Dawn mission, which spent a year in close proximity to Vesta. Measurements by Dawn's three instruments, redundant Framing Cameras (FC), a Visible-InfraRed (VIR) spectrometer, and a Gamma Ray and Neutron Detector (GRaND), along with radio science have strengthened the link. Gravity measurements by Dawn are consistent with a differentiated, silicate body, with a dense Fe-rich core. The range of pyroxene compositions determined by VIR overlaps that of the howardites. Elemental abundances determined by nuclear spectroscopy are also consistent with HED-compositions. Observations by GRaND provided a new view of Vesta inaccessible by telescopic observations. Here, we summarize the results of Dawn's geochemical investigation of Vesta and their implications.

  20. FUEL ELEMENT FOR NEUTRONIC REACTORS

    DOEpatents

    Evans, T.C.; Beasley, E.G.

    1961-01-17

    A fuel element for neutronic reactors, particularly the gas-cooled type of reactor, is described. The element comprises a fuel-bearing plate rolled to form a cylinder having a spiral passageway passing from its periphery to its center. In operation a coolant is admitted to the passageway at the periphery of the element, is passed through the spiral passageway, and emerges into a central channel defined by the inner turn of the rolled plate. The advantage of the element is that the fully heated coolant (i.e., coolant emerging into the central channel) is separated and thus insulated from the periphery of the element, which may be in contact with a low-temperature moderator, by the intermediate turns of the spiral fuel element.

  1. NUCLEAR REACTOR FUEL ELEMENT ASSEMBLY

    DOEpatents

    Stengel, F.G.

    1963-12-24

    A method of fabricating nuclear reactor fuel element assemblies having a plurality of longitudinally extending flat fuel elements in spaced parallel relation to each other to form channels is presented. One side of a flat side plate is held contiguous to the ends of the elements and a welding means is passed along the other side of the platertransverse to the direction of the longitudinal extension of the elements. The setting and speed of travel of the welding means is set to cause penetration of the side plate with welds at bridge the gap in each channel between adjacent fuel elements with a weld-through bubble of predetermined size. The fabrication of a high strength, dependable fuel element is provided, and the reduction of distortion and high production costs are facilitated by this method. (AEC)

  2. Elemental Mercury Spills

    PubMed Central

    Baughman, Thomas A.

    2006-01-01

    Sources of elemental mercury (Hg0) include old natural gas regulators, manometers, sphygmomanometers, thermometers, and thermostats. Causes of Hg0 spills include improper storage, container breakage, children playing with Hg0, the breakage of devices containing Hg0, and ritualistic use of Hg0. Inhalation is the primary exposure route for Hg0. Mercury released into the environment can enter lakes and streams, where bacteria convert it into methylmercury, which bioaccumulates in fish. Chronic exposure to Hg0 vapors can damage the kidneys and neurologic system. Short-term exposure to high levels of Hg0 vapors may cause lung damage, nausea, vomiting, diarrhea, increases in blood pressure or heart rate, skin rashes, and eye irritation, among other effects. Minimizing Hg0 dispersal is important after an Hg0 spill. Tracking by shoes or apparel or vacuuming can spread Hg0, increasing airborne concentrations and cleanup costs. The Illinois Department of Public Health’s response to an Hg0 spill depends on the size of the spill. Airborne concentrations after large spills are mapped with a mercury vapor analyzer (MVA). The cleanup begins with the spill site and any hot spots that were identified with the MVA. Hard surfaces can usually be cleaned, but contaminated porous items must be discarded. Leaving marginally contaminated items outdoors for a month or more during warm weather may dissipate the Hg0. After a cleanup, clearance sampling is conducted to determine if further cleanup is needed. The best way to prevent Hg0 spills is reduce its use. PMID:16451846

  3. Archaeal Extrachromosomal Genetic Elements

    PubMed Central

    Wang, Haina; Peng, Nan; Shah, Shiraz A.

    2015-01-01

    SUMMARY Research on archaeal extrachromosomal genetic elements (ECEs) has progressed rapidly in the past decade. To date, over 60 archaeal viruses and 60 plasmids have been isolated. These archaeal viruses exhibit an exceptional diversity in morphology, with a wide array of shapes, such as spindles, rods, filaments, spheres, head-tails, bottles, and droplets, and some of these new viruses have been classified into one order, 10 families, and 16 genera. Investigation of model archaeal viruses has yielded important insights into mechanisms underlining various steps in the viral life cycle, including infection, DNA replication and transcription, and virion egression. Many of these mechanisms are unprecedented for any known bacterial or eukaryal viruses. Studies of plasmids isolated from different archaeal hosts have also revealed a striking diversity in gene content and innovation in replication strategies. Highly divergent replication proteins are identified in both viral and plasmid genomes. Genomic studies of archaeal ECEs have revealed a modular sequence structure in which modules of DNA sequence are exchangeable within, as well as among, plasmid families and probably also between viruses and plasmids. In particular, it has been suggested that ECE-host interactions have shaped the coevolution of ECEs and their archaeal hosts. Furthermore, archaeal hosts have developed defense systems, including the innate restriction-modification (R-M) system and the adaptive CRISPR (clustered regularly interspaced short palindromic repeats) system, to restrict invasive plasmids and viruses. Together, these interactions permit a delicate balance between ECEs and their hosts, which is vitally important for maintaining an innovative gene reservoir carried by ECEs. In conclusion, while research on archaeal ECEs has just started to unravel the molecular biology of these genetic entities and their interactions with archaeal hosts, it is expected to accelerate in the next decade. PMID

  4. Elements of metabolic evolution.

    PubMed

    Huber, Claudia; Kraus, Florian; Hanzlik, Marianne; Eisenreich, Wolfgang; Wächtershäuser, Günter

    2012-02-13

    Research into the origin of evolution is polarized between a genetics-first approach, with its focus on polymer replication, and a metabolism-first approach that takes aim at chemical reaction cycles. Taking the latter approach, we explored reductive carbon fixation in a volcanic hydrothermal setting, driven by the chemical potential of quenched volcanic fluids for converting volcanic C1 compounds into organic products by transition-metal catalysts. These catalysts are assumed to evolve by accepting ever-new organic products as ligands for enhancing their catalytic power, which in turn enhances the rates of synthetic pathways that give rise to ever-new organic products, with the overall effect of a self-expanding metabolism. We established HCN, CO, and CH(3)SH as carbon nutrients, CO and H(2) as reductants, and iron-group transition metals as catalysts. In one case, we employed the "cyano-system" [Ni(OH)(CN)] with [Ni(CN)(4)](2-) as the dominant nickel-cyano species. This reaction mainly produced α-amino acids and α-hydroxy acids as well as various intermediates and derivatives. An organo-metal-catalyzed mechanism is suggested that mainly builds carbon skeletons by repeated cyano insertions, with minor CO insertions in the presence of CO. The formation of elemental nickel (Ni(0)) points to an active reduced-nickel species. In another case, we employed the mercapto-carbonyl system [Co(2)(CO)(8)]/Ca(OH)(2)/CO for the double-carbonylation of mercaptans. In a "hybrid system", we combined benzyl mercaptan with the cyano system, in which [Ni(OH)(CN)] was the most productive for the double-carbon-fixation reaction. Finally, we demonstrated that the addition of products of the cyano system (Gly, Ala) to the hybrid system increased productivity. These results demonstrate the chemical possibility of metabolic evolution through rate-promotion of one synthetic reaction by the products of another.

  5. Analytic elements of smooth shapes

    NASA Astrophysics Data System (ADS)

    Strack, Otto D. L.; Nevison, Patrick R.

    2015-10-01

    We present a method for producing analytic elements of a smooth shape, obtained using conformal mapping. Applications are presented for a case of impermeable analytic elements as well as for head-specified ones. The mathematical operations necessary to use the elements in practical problems can be carried out before modeling of flow problems begins. A catalog of shapes, along with pre-determined coefficients could be established on the basis of the approach presented here, making applications in the field straight forward.

  6. FUEL ELEMENT FOR NUCLEAR REACTORS

    DOEpatents

    Bassett, C.H.

    1961-05-16

    A fuel element particularly adapted for use in nuclear reactors of high power density is offered. It has fissionable fuel pellet segments mounted in a tubular housing and defining a central passage in the fuel element. A burnable poison element extends through the central passage, which is designed to contain more poison material at the median portion than at the end portions thereby providing a more uniform hurnup and longer reactivity life.

  7. FUEL ELEMENTS FOR NUCLEAR REACTORS

    DOEpatents

    Blainey, A.; Lloyd, H.

    1961-07-11

    A method of sheathing a tubular fuel element for a nuclear reactor is described. A low melting metal core member is centered in a die, a layer of a powdered sheathing substance is placed on the bottom of the die, the tubular fuel element is inserted in the die, the space between the tubular fuel element and the die walls and core member is filled with the same powdered sheathing substance, a layer of the same substance is placed over the fissile material, and the charge within the die is subjected to pressure in the direction of the axis of the fuel element at the sintering temperature of the protective substance.

  8. Single element magnetic suspension actuator

    NASA Technical Reports Server (NTRS)

    Groom, Nelson J. (Inventor)

    1991-01-01

    The invention, a single element magnetic suspension actuator with bidirectional force capability along a single axis, includes an electromagnet and a nonmagnetic suspended element. A permanent magnet mounted on the suspended element interacts with a magnetic field established by the electromagnet to produce bidirectional forces in response to a variable force command voltage V (sub FC) applied to the electromagnet. A sensor measures the position of the suspended element on the single axis which is a function of force command voltage V (sub FC).

  9. 15. VIEW OF DUMMY FUEL ELEMENT ON FUEL ELEMENT HOLDER. ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    15. VIEW OF DUMMY FUEL ELEMENT ON FUEL ELEMENT HOLDER. SHOWS AIR FORCE MAN AT EDGE OF TANK. INEL PHOTO NUMBER 65-6176, TAKEN NOVEMBER 10, 1965. - Idaho National Engineering Laboratory, Advanced Reentry Vehicle Fusing System, Scoville, Butte County, ID

  10. Element-by-element factorization algorithms for heat conduction

    NASA Technical Reports Server (NTRS)

    Hughes, T. J. R.; Winget, J. M.; Park, K. C.

    1983-01-01

    Element-by-element solution strategies are developed for transient heat conduction problems. Results of numerical tests indicate the effectiveness of the procedures proposed. The small database requirements and attractive architectural features of the algorithms suggest considerable potential for solving large scale problems.

  11. Trace Elements in River Waters

    NASA Astrophysics Data System (ADS)

    Gaillardet, J.; Viers, J.; Dupré, B.

    2003-12-01

    Trace elements are characterized by concentrations lower than 1 mg L-1 in natural waters. This means that trace elements are not considered when "total dissolved solids" are calculated in rivers, lakes, or groundwaters, because their combined mass is not significant compared to the sum of Na+, K+, Ca2+, Mg2+, H4SiO4, HCO3-, CO32-, SO42-, Cl-, and NO3-. Therefore, most of the elements, except about ten of them, occur at trace levels in natural waters. Being trace elements in natural waters does not necessarily qualify them as trace elements in rocks. For example, aluminum, iron, and titanium are major elements in rocks, but they occur as trace elements in waters, due to their low mobility at the Earth's surface. Conversely, trace elements in rocks such as chlorine and carbon are major elements in waters.The geochemistry of trace elements in river waters, like that of groundwater and seawater, is receiving increasing attention. This growing interest is clearly triggered by the technical advances made in the determination of concentrations at lower levels in water. In particular, the development of inductively coupled plasma mass spectrometry (ICP-MS) has considerably improved our knowledge of trace-element levels in waters since the early 1990s. ICP-MS provides the capability of determining trace elements having isotopes of interest for geochemical dating or tracing, even where their dissolved concentrations are extremely low.The determination of trace elements in natural waters is motivated by a number of issues. Although rare, trace elements in natural systems can play a major role in hydrosystems. This is particularly evident for toxic elements such as aluminum, whose concentrations are related to the abundance of fish in rivers. Many trace elements have been exploited from natural accumulation sites and used over thousands of years by human activities. Trace elements are therefore highly sensitive indexes of human impact from local to global scale. Pollution

  12. Elemental analysis of scorpion venoms.

    PubMed

    Al-Asmari, AbdulRahman K; Kunnathodi, Faisal; Al Saadon, Khalid; Idris, Mohammed M

    2016-01-01

    Scorpion venom is a rich source of biomolecules, which can perturb physiological activity of the host on envenomation and may also have a therapeutic potential. Scorpion venoms produced by the columnar cells of venom gland are complex mixture of mucopolysaccharides, neurotoxic peptides and other components. This study was aimed at cataloguing the elemental composition of venoms obtained from medically important scorpions found in the Arabian peninsula. The global elemental composition of the crude venom obtained from Androctonus bicolor, Androctonus crassicauda and Leiurus quinquestriatus scorpions were estimated using ICP-MS analyzer. The study catalogued several chemical elements present in the scorpion venom using ICP-MS total quant analysis and quantitation of nine elements exclusively using appropriate standards. Fifteen chemical elements including sodium, potassium and calcium were found abundantly in the scorpion venom at PPM concentrations. Thirty six chemical elements of different mass ranges were detected in the venom at PPB level. Quantitative analysis of the venoms revealed copper to be the most abundant element in Androctonus sp. venom but at lower level in Leiurus quinquestriatus venom; whereas zinc and manganese was found at higher levels in Leiurus sp. venom but at lower level in Androctonus sp. venom. These data and the concentrations of other different elements present in the various venoms are likely to increase our understanding of the mechanisms of venom activity and their pharmacological potentials.

  13. The Search for Heavy Elements

    ScienceCinema

    None

    2016-07-12

    The 1994 documentary "The Search for Heavy Elements" chronicles the expansion of the periodic table through the creation at Berkeley Lab of elements heavier than uranium. The documentary features a mix of rarely-seen archival footage, historical photos, and interviews with scientists who made history, such as Glenn Seaborg and Albert Ghiorso.

  14. Elemental analysis of scorpion venoms

    PubMed Central

    Al-Asmari, AbdulRahman K; Kunnathodi, Faisal; Al Saadon, Khalid; Idris, Mohammed M

    2016-01-01

    Scorpion venom is a rich source of biomolecules, which can perturb physiological activity of the host on envenomation and may also have a therapeutic potential. Scorpion venoms produced by the columnar cells of venom gland are complex mixture of mucopolysaccharides, neurotoxic peptides and other components. This study was aimed at cataloguing the elemental composition of venoms obtained from medically important scorpions found in the Arabian peninsula. The global elemental composition of the crude venom obtained from Androctonus bicolor, Androctonus crassicauda and Leiurus quinquestriatus scorpions were estimated using ICP-MS analyzer. The study catalogued several chemical elements present in the scorpion venom using ICP-MS total quant analysis and quantitation of nine elements exclusively using appropriate standards. Fifteen chemical elements including sodium, potassium and calcium were found abundantly in the scorpion venom at PPM concentrations. Thirty six chemical elements of different mass ranges were detected in the venom at PPB level. Quantitative analysis of the venoms revealed copper to be the most abundant element in Androctonus sp. venom but at lower level in Leiurus quinquestriatus venom; whereas zinc and manganese was found at higher levels in Leiurus sp. venom but at lower level in Androctonus sp. venom. These data and the concentrations of other different elements present in the various venoms are likely to increase our understanding of the mechanisms of venom activity and their pharmacological potentials. PMID:27826410

  15. The way to superheavy elements

    NASA Astrophysics Data System (ADS)

    Ishkhanov, B. S.; Tretyakova, T. Yu.

    2017-05-01

    This review is devoted to the studies of heavy and superheavy elements and the methods of their synthesis and identification. Special attention is paid to the latest discoveries in the area of superheavy elements with Z = 107-112 in cold fusion reactions and Z = 113-118 in reactions between 48Ca and actinides.

  16. Finite element shell instability analysis

    NASA Technical Reports Server (NTRS)

    1975-01-01

    Formulation procedures and the associated computer program for finite element thin shell instability analysis are discussed. Data cover: (1) formulation of basic element relationships, (2) construction of solution algorithms on both the conceptual and algorithmic levels, and (3) conduction of numerical analyses to verify the accuracy and efficiency of the theory and related programs therein are described.

  17. Lubrication of rolling element bearings

    NASA Technical Reports Server (NTRS)

    Parker, R. J.

    1980-01-01

    This paper is a broad survey of the lubrication of rolling-element bearings. Emphasis is on the critical design aspects related to speed, temperature, and ambient pressure environment. Types of lubrication including grease, jets, mist, wick, and through-the-race are discussed. The paper covers the historical development, present state of technology, and the future problems of rolling-element bearing lubrication.

  18. The Search for Heavy Elements

    SciTech Connect

    2008-04-17

    The 1994 documentary "The Search for Heavy Elements" chronicles the expansion of the periodic table through the creation at Berkeley Lab of elements heavier than uranium. The documentary features a mix of rarely-seen archival footage, historical photos, and interviews with scientists who made history, such as Glenn Seaborg and Albert Ghiorso.

  19. Chemical experiments with superheavy elements.

    PubMed

    Türler, Andreas

    2010-01-01

    Unnoticed by many chemists, the Periodic Table of the Elements has been extended significantly in the last couple of years and the 7th period has very recently been completed with eka-Rn (element 118) currently being the heaviest element whose synthesis has been reported. These 'superheavy' elements (also called transactinides with atomic number > or = 104 (Rf)) have been artificially synthesized in fusion reactions at accelerators in minute quantities of a few single atoms. In addition, all isotopes of the transactinide elements are radioactive and decay with rather short half-lives. Nevertheless, it has been possible in some cases to investigate experimentally chemical properties of transactinide elements and even synthesize simple compounds. The experimental investigation of superheavy elements is especially intriguing, since theoretical calculations predict significant deviations from periodic trends due to the influence of strong relativistic effects. In this contribution first experiments with hassium (Hs, atomic number 108), copernicium (Cn, atomic number 112) and element 114 (eka-Pb) are reviewed.

  20. Radioactive elements in stellar atmospheres

    SciTech Connect

    Gopka, Vira; Yushchenko, Alexander; Goriely, Stephane; Shavrina, Angelina; Kang, Young Woon

    2006-07-12

    The identification of lines of radioactive elements (Tc, Pm and elements with 83

  1. Sobre el estado evolutivo de β Pictoris

    NASA Astrophysics Data System (ADS)

    Brunini, A.; Benvenuto, O. G.

    Desde el descubrimiento de fuertes excesos infrarrojos en β Pictoris, esta estrella ha sido muy estudiada y es considerada candidata a poseer un sistema planetario propio. β Pic está rodeada de un disco asimétrico de polvo que se observa de canto y que esta vacío a distancias <= 40 AU. Esto se considera una fuerte evidencia en favor de la presencia de (al menos) un planeta gigante. Recientemente se han observado líneas de material circunestelar que se han interpretado como consecuencia de la caída de objetos cometarios sobre esta estrella. Recientemente se ha utilizado la existencia del disco de polvo para atribuir una edad corta (pre - secuencia principal) a βPic. Sin embargo, la evaporación de estos cometas provee suficiente polvo como para explicar la presencia del disco observado sin necesidad de edades cortas. En este trabajo mostramos que la comparación entre la tasa de impactos cometarios estimada en el Sistema Solar para diferentes etapas de su evolución y los datos observados en β Pic indica edades avanzadas para β Pic. Esta estimación debe tomarse con cautela ya que depende de la estructura de los sistemas planetarios. Además mostramos que, desde el punto de vista de la evolución estelar y con las incertezas presentes en la luminosidad y la temperatura efectiva, existe un continuo de edades posible para β Pic. Sin embargo, empleando los datos provenientes de los flujos cometarios encontramos que una edad prolongada es consistente con ambos tratamientos.

  2. Trace elements in coal ash

    USGS Publications Warehouse

    Deonarine, Amrika; Kolker, Allan; Doughten, Michael W.

    2015-01-01

    In this fact sheet, the form, distribution, and behavior of trace elements of environmental interest in samples of coal fly ash were investigated in response to concerns about element mobility in the event of an ash spill. The study includes laboratory-based leaching experiments to examine the behavior of trace elements, such as arsenic (As) and chromium (Cr), in response to key environmental factors including redox conditions (degree of oxygenation), which are known to vary with depth within coal ash impoundments and in natural ecosystems. The experiments show that As dissolves from samples of coal fly ash into simulated freshwater under both oxic (highly oxygenated) and anoxic (poorly oxygenated) conditions, whereas dissolved Cr concentrations are very redox dependent. This U.S. Geological Survey research helps define the distribution of elements such as As in coal ash and shows that element mobility can vary considerably under different conditions expected in the environment.

  3. Second order tensor finite element

    NASA Technical Reports Server (NTRS)

    Oden, J. Tinsley; Fly, J.; Berry, C.; Tworzydlo, W.; Vadaketh, S.; Bass, J.

    1990-01-01

    The results of a research and software development effort are presented for the finite element modeling of the static and dynamic behavior of anisotropic materials, with emphasis on single crystal alloys. Various versions of two dimensional and three dimensional hybrid finite elements were implemented and compared with displacement-based elements. Both static and dynamic cases are considered. The hybrid elements developed in the project were incorporated into the SPAR finite element code. In an extension of the first phase of the project, optimization of experimental tests for anisotropic materials was addressed. In particular, the problem of calculating material properties from tensile tests and of calculating stresses from strain measurements were considered. For both cases, numerical procedures and software for the optimization of strain gauge and material axes orientation were developed.

  4. Trace elements and bone health.

    PubMed

    Zofková, Ivana; Nemcikova, Petra; Matucha, Petr

    2013-08-01

    The importance of nutrition factors such as calcium, vitamin D and vitamin K for the integrity of the skeleton is well known. Moreover, bone health is positively influenced by certain elements (e.g., zinc, copper, fluorine, manganese, magnesium, iron and boron). Deficiency of these elements slows down the increase of bone mass in childhood and/or in adolescence and accelerates bone loss after menopause or in old age. Deterioration of bone quality increases the risk of fractures. Monitoring of homeostasis of the trace elements together with the measurement of bone density and biochemical markers of bone metabolism should be used to identify and treat patients at risk of non-traumatic fractures. Factors determining the effectivity of supplementation include dose, duration of treatment, serum concentrations, as well as interactions among individual elements. Here, we review the effect of the most important trace elements on the skeleton and evaluate their clinical importance.

  5. Atmophilic elements in lunar soils

    NASA Technical Reports Server (NTRS)

    Chou, C.-L.; Baedecker, P. A.; Wasson, J. T.

    1973-01-01

    Ten volatile elements are more abundant in soil 14163 than in 14259 by factors of 1.4 or greater, too high to be explained by the 15% higher KREEP content of 14163. The enrichments suggest that these elements are easily volatilized by energetic events generated by solar particles or micrometeorites and as a result move from site to site through the lunar atmosphere. The elements Zn, C, and Cd are correlated with excess Ar-40 in Apollo 15 soils. Since concentrations also increase in the direction of the Apennine Front, the correlation chiefly indicates that the Front regolith is enriched in these elements relative to the Apollo 15 regolith away from the Front. The absence of known lunar rock types showing Zn and Cd concentrations as high as those in the Apollo 15 Front regolith or the Apollo 14 or 16 highlands regoliths and the relatively uniform concentrations of both elements in these soils despite differences in major element composition suggest that large amounts of these elements were released as volatiles during early lunar magmatic activity.

  6. Elemental Impurities in Pharmaceutical Excipients.

    PubMed

    Li, Gang; Schoneker, Dave; Ulman, Katherine L; Sturm, Jason J; Thackery, Lisa M; Kauffman, John F

    2015-12-01

    Control of elemental impurities in pharmaceutical materials is currently undergoing a transition from control based on concentrations in components of drug products to control based on permitted daily exposures in drug products. Within the pharmaceutical community, there is uncertainty regarding the impact of these changes on manufactures of drug products. This uncertainty is fueled in part by a lack of publically available information on elemental impurity levels in common pharmaceutical excipients. This paper summarizes a recent survey of elemental impurity levels in common pharmaceutical excipients as well as some drug substances. A widely applicable analytical procedure was developed and was shown to be suitable for analysis of elements that are subject to United States Pharmacopoeia Chapter <232> and International Conference on Harmonization's Q3D Guideline on Elemental Impurities. The procedure utilizes microwave-assisted digestion of pharmaceutical materials and inductively coupled plasma mass spectrometry for quantitative analysis of these elements. The procedure was applied to 190 samples from 31 different excipients and 15 samples from eight drug substances provided through the International Pharmaceutical Excipient Council of the Americas. The results of the survey indicate that, for the materials included in the study, relatively low levels of elemental impurities are present. © 2015 The Authors. Journal of Pharmaceutical Sciences published by Wiley Periodicals, Inc. and the American Pharmacists Association.

  7. Terminological aspects of data elements

    SciTech Connect

    Strehlow, R.A. ); Kenworthey, W.H. Jr. ); Schuldt, R.E. )

    1991-01-01

    The creation and display of data comprise a process that involves a sequence of steps requiring both semantic and systems analysis. An essential early step in this process is the choice, definition, and naming of data element concepts and is followed by the specification of other needed data element concept attributes. The attributes and the values of data element concept remain associated with them from their birth as a concept to a generic data element that serves as a template for final application. Terminology is, therefore, centrally important to the entire data creation process. Smooth mapping from natural language to a database is a critical aspect of database, and consequently, it requires terminology standardization from the outset of database work. In this paper the semantic aspects of data elements are analyzed and discussed. Seven kinds of data element concept information are considered and those that require terminological development and standardization are identified. The four terminological components of a data element are the hierarchical type of a concept, functional dependencies, schematas showing conceptual structures, and definition statements. These constitute the conventional role of terminology in database design. 12 refs., 8 figs., 1 tab.

  8. Elements of butterfly wing patterns.

    PubMed

    Nijhout, H F

    2001-10-15

    The color patterns on the wings of butterflies are unique among animal color patterns in that the elements that make up the overall pattern are individuated. Unlike the spots and stripes of vertebrate color patterns, the elements of butterfly wing patterns have identities that can be traced from species to species, and typically across genera and families. Because of this identity it is possible to recognize homologies among pattern elements and to study their evolution and diversification. Individuated pattern elements evolved from non-individuated precursors by compartmentalization of the wing into areas that became developmentally autonomous with respect to color pattern formation. Developmental compartmentalization led to the evolution of serially repeated elements and the emergence of serial homology. In these compartments, serial homologues were able to acquire site-specific developmental regulation and this, in turn, allowed them to diverge morphologically. Compartmentalization of the wing also reduced the developmental correlation among pattern elements. The release from this developmental constraint, we believe, enabled the great evolutionary radiation of butterfly wing patterns. During pattern evolution, the same set of individual pattern elements is arranged in novel ways to produce species-specific patterns, including such adaptations as mimicry and camouflage.

  9. Highly labile elements. [in meteorites

    NASA Technical Reports Server (NTRS)

    Lipschutz, Michael E.; Woolum, Dorothy S.

    1988-01-01

    Certain elements of high lability are very responsive to thermal processes, being either highly volatile during primary nebular condensation or highly mobile by postaccretionary metamorphic or shock heating. Data for highly labile elements indicate that different thermal processes were important in the genesis of each of the chondritic groups and a discussion of each is given. Contents of highly labile elements in a given group of contemporary falls differ from those of the same group that fell in Antarctica more than 0.1 Myr ago. This difference is due either to a time-dependent change in meteorite sources or, less likely, orbital variation of the meteorite flux to Earth.

  10. Highly labile elements. [in meteorites

    NASA Technical Reports Server (NTRS)

    Lipschutz, Michael E.; Woolum, Dorothy S.

    1988-01-01

    Certain elements of high lability are very responsive to thermal processes, being either highly volatile during primary nebular condensation or highly mobile by postaccretionary metamorphic or shock heating. Data for highly labile elements indicate that different thermal processes were important in the genesis of each of the chondritic groups and a discussion of each is given. Contents of highly labile elements in a given group of contemporary falls differ from those of the same group that fell in Antarctica more than 0.1 Myr ago. This difference is due either to a time-dependent change in meteorite sources or, less likely, orbital variation of the meteorite flux to Earth.

  11. Finite element computational fluid mechanics

    NASA Technical Reports Server (NTRS)

    Baker, A. J.

    1983-01-01

    Finite element analysis as applied to the broad spectrum of computational fluid mechanics is analyzed. The finite element solution methodology is derived, developed, and applied directly to the differential equation systems governing classes of problems in fluid mechanics. The heat conduction equation is used to reveal the essence and elegance of finite element theory, including higher order accuracy and convergence. The algorithm is extended to the pervasive nonlinearity of the Navier-Stokes equations. A specific fluid mechanics problem class is analyzed with an even mix of theory and applications, including turbulence closure and the solution of turbulent flows.

  12. Generalized two-port elements

    NASA Astrophysics Data System (ADS)

    Tenreiro Machado, J.; Galhano, Alexandra M.

    2017-01-01

    The development of models constitutes a fundamental step in the study of natural and artificial systems. Present day science aims to address broader and more complex areas of application requiring, therefore, new concepts and models. This paper explores the concept of generalized two-port network by embedding the ideas of fractional calculus, memristor, transformer and gyrator. Each element represents separately one possible direction for generalizing the classical elements, but the cross-fertilization of the distinct topics has been overlooked. In this line of thought, the proposal of a novel element is a logical conjecture for obeying the symmetries that have been discovered in nature.

  13. Finite element computational fluid mechanics

    NASA Technical Reports Server (NTRS)

    Baker, A. J.

    1983-01-01

    Finite element analysis as applied to the broad spectrum of computational fluid mechanics is analyzed. The finite element solution methodology is derived, developed, and applied directly to the differential equation systems governing classes of problems in fluid mechanics. The heat conduction equation is used to reveal the essence and elegance of finite element theory, including higher order accuracy and convergence. The algorithm is extended to the pervasive nonlinearity of the Navier-Stokes equations. A specific fluid mechanics problem class is analyzed with an even mix of theory and applications, including turbulence closure and the solution of turbulent flows.

  14. A controllable nanomechanical memory element

    NASA Astrophysics Data System (ADS)

    Badzey, Robert L.; Zolfagharkhani, Guiti; Gaidarzhy, Alexei; Mohanty, Pritiraj

    2004-10-01

    We report the realization of a completely controllable high-speed nanomechanical memory element fabricated from single-crystal silicon wafers. This element consists of a doubly clamped suspended nanomechanical beam structure, which can be made to switch controllably between two stable and distinct states at a single frequency in the megahertz range. Because of their submicron size and high normal-mode frequencies, these nanomechanical memory elements offer the potential to rival the current state-of-the-art electronic data storage and processing.

  15. Method for detecting an element

    DOEpatents

    Blackwood, Larry G.; Reber, Edward L.; Rohde, Kenneth W.

    2007-02-06

    A method for detecting an element is disclosed and which includes the steps of providing a gamma-ray spectrum which depicts, at least in part, a test region having boundaries, and which has a small amount of the element to be detected; providing a calculation which detects the small amount of the element to be detected; and providing a moving window and performing the calculation within the moving window, and over a range of possible window boundaries within the test region to determine the location of the optimal test region within the gamma-ray spectrum.

  16. FUEL ELEMENTS FOR NEUTRONIC REACTORS

    DOEpatents

    Foote, F.G.; Jette, E.R.

    1963-05-01

    A fuel element for a nuclear reactor is described that consists of a jacket containing a unitary core of fissionable material and a filling of a metal of the group consisting of sodium and sodium-potassium alloys. (AEC)

  17. On numerically accurate finite element

    NASA Technical Reports Server (NTRS)

    Nagtegaal, J. C.; Parks, D. M.; Rice, J. R.

    1974-01-01

    A general criterion for testing a mesh with topologically similar repeat units is given, and the analysis shows that only a few conventional element types and arrangements are, or can be made suitable for computations in the fully plastic range. Further, a new variational principle, which can easily and simply be incorporated into an existing finite element program, is presented. This allows accurate computations to be made even for element designs that would not normally be suitable. Numerical results are given for three plane strain problems, namely pure bending of a beam, a thick-walled tube under pressure, and a deep double edge cracked tensile specimen. The effects of various element designs and of the new variational procedure are illustrated. Elastic-plastic computation at finite strain are discussed.

  18. A Rainbow of Martian Elements

    NASA Technical Reports Server (NTRS)

    2004-01-01

    This graph or spectrum taken by the alpha particle X-ray spectrometer onboard the Mars Exploration Rover Spirit shows the variety of elements present in the soil at the rover's landing site. In agreement with past missions to Mars, iron and silicon make up the majority of the martian soil. Sulfur and chlorine were also observed as expected. Trace elements detected for the first time include zinc and nickel. These latter observations demonstrate the power of the alpha particle X-ray spectrometer to pick up the signatures of elements too faint to be seen before. The alpha particle X-ray spectrometer uses alpha particles and X-rays to measure the presence and abundance of all major rock-forming elements except hydrogen.

  19. Environmental research on actinide elements

    SciTech Connect

    Pinder, J.E. III; Alberts, J.J.; McLeod, K.W.; Schreckhise, R.G.

    1987-08-01

    The papers synthesize the results of research sponsored by DOE's Office of Health and Environmental Research on the behavior of transuranic and actinide elements in the environment. Separate abstracts have been prepared for the 21 individual papers. (ACR)

  20. Alu elements and hominid phylogenetics

    PubMed Central

    Salem, Abdel-Halim; Ray, David A.; Xing, Jinchuan; Callinan, Pauline A.; Myers, Jeremy S.; Hedges, Dale J.; Garber, Randall K.; Witherspoon, David J.; Jorde, Lynn B.; Batzer, Mark A.

    2003-01-01

    Alu elements have inserted in primate genomes throughout the evolution of the order. One particular Alu lineage (Ye) began amplifying relatively early in hominid evolution and continued propagating at a low level as many of its members are found in a variety of hominid genomes. This study represents the first conclusive application of short interspersed elements, which are considered nearly homoplasy-free, to elucidate the phylogeny of hominids. Phylogenetic analysis of Alu Ye5 elements and elements from several other subfamilies reveals high levels of support for monophyly of Hominidae, tribe Hominini and subtribe Hominina. Here we present the strongest evidence reported to date for a sister relationship between humans and chimpanzees while clearly distinguishing the chimpanzee and human lineages. PMID:14561894

  1. Essential Elements of Geologic Reports.

    ERIC Educational Resources Information Center

    Webb, Elmer James

    1988-01-01

    Described is a report outline for geologic reports. Essential elements include title; abstract; introduction; stratigraphy; petrography; geochemistry; petrology; geophysics; structural geology; geologic history; modeling; economics; conclusions; and recommendations. (Author/CW)

  2. Essential Elements of Geologic Reports.

    ERIC Educational Resources Information Center

    Webb, Elmer James

    1988-01-01

    Described is a report outline for geologic reports. Essential elements include title; abstract; introduction; stratigraphy; petrography; geochemistry; petrology; geophysics; structural geology; geologic history; modeling; economics; conclusions; and recommendations. (Author/CW)

  3. How Certain Trace Elements Behave.

    ERIC Educational Resources Information Center

    Zingaro, Ralph A.

    1979-01-01

    Fluorine, selenium, tin, and arsenic are among the trace elements occurring in the environment which are considered. Emphasis is given to developing a qualitative survey of the extent and kinds of metal transformations and their resultant effects. (CS)

  4. Elemental ABAREX -- a user's manual.

    SciTech Connect

    Smith, A.B.

    1999-05-26

    ELEMENTAL ABAREX is an extended version of the spherical optical-statistical model code ABAREX, designed for the interpretation of neutron interactions with elemental targets consisting of up to ten isotopes. The contributions from each of the isotopes of the element are explicitly dealt with, and combined for comparison with the elemental observables. Calculations and statistical fitting of experimental data are considered. The code is written in FORTRAN-77 and arranged for use on the IBM-compatible personal computer (PC), but it should operate effectively on a number of other systems, particularly VAX/VMS and IBM work stations. Effort is taken to make the code user friendly. With this document a reasonably skilled individual should become fluent with the use of the code in a brief period of time.

  5. FUEL ELEMENT FOR NUCLEAR REACTORS

    DOEpatents

    Dickson, J.J.

    1963-09-24

    A method is described whereby fuel tubes or pins are cut, loaded with fuel pellets and a heat transfer medium, sealed at each end with slotted fittings, and assembled into a rectangular tube bundle to form a fuel element. The tubes comprising the fuel element are laterally connected between their ends by clips and tabs to form a linear group of spaced parallel tubes, which receive their vertical support by resting on a grid. The advantages of this method are that it permits elimination of structural material (e.g., fuel-element cans) within the reactor core, and removal of at least one fuel pin from an element and replacement thereof so that a burnable poison may be utilized during the core lifetime. (AEC)

  6. How Certain Trace Elements Behave.

    ERIC Educational Resources Information Center

    Zingaro, Ralph A.

    1979-01-01

    Fluorine, selenium, tin, and arsenic are among the trace elements occurring in the environment which are considered. Emphasis is given to developing a qualitative survey of the extent and kinds of metal transformations and their resultant effects. (CS)

  7. Alu elements and hominid phylogenetics.

    PubMed

    Salem, Abdel-Halim; Ray, David A; Xing, Jinchuan; Callinan, Pauline A; Myers, Jeremy S; Hedges, Dale J; Garber, Randall K; Witherspoon, David J; Jorde, Lynn B; Batzer, Mark A

    2003-10-28

    Alu elements have inserted in primate genomes throughout the evolution of the order. One particular Alu lineage (Ye) began amplifying relatively early in hominid evolution and continued propagating at a low level as many of its members are found in a variety of hominid genomes. This study represents the first conclusive application of short interspersed elements, which are considered nearly homoplasy-free, to elucidate the phylogeny of hominids. Phylogenetic analysis of Alu Ye5 elements and elements from several other subfamilies reveals high levels of support for monophyly of Hominidae, tribe Hominini and subtribe Hominina. Here we present the strongest evidence reported to date for a sister relationship between humans and chimpanzees while clearly distinguishing the chimpanzee and human lineages.

  8. Sensing device with whisker elements

    NASA Technical Reports Server (NTRS)

    Hartmann, Mitra J. (Inventor); Solomon, Joseph H. (Inventor)

    2010-01-01

    A sensing device includes an elongated whisker element having a flexible cantilever region and a base region where a change in moment or curvature is generated by bending of the cantilever region when it contacts an object. One or more sensor elements cooperatively associated with the whisker element provide one or more output signals that is/are representative of two orthogonal components of change in moment or curvature at the whisker base region to permit determination of object distance, fluid velocity profile, or object contour (shape) with accounting for lateral slip of the whisker element and frictional characteristics of the object. Multiple sensing devices can be arranged in arrays in a manner to sense object contour without or with adjustment for lateral slip.

  9. Sensing Device with Whisker Elements

    NASA Technical Reports Server (NTRS)

    Hartmann, Mitra J. (Inventor); Solomon, Joseph H. (Inventor)

    2013-01-01

    A sensing device includes an elongated whisker element having a flexible cantilever region and a base region where a change in moment or curvature is generated by bending of the cantilever region when it contacts an object. One or more sensor elements cooperatively associated with the whisker element provide one or more output signals that is/are representative of two orthogonal components of change in moment or curvature at the whisker base region to permit determination of object distance, fluid velocity profile, or object contour (shape) with accounting for lateral slip of the whisker element and frictional characteristics of the object. Multiple sensing devices can be arranged in arrays in a manner to sense object contour without or with adjustment for lateral slip.

  10. Methane Propulsion Elements for Mars

    NASA Technical Reports Server (NTRS)

    Percy, Tom; Polsgrove, Tara; Thomas, Dan

    2017-01-01

    Human exploration beyond LEO relies on a suite of propulsive elements to: (1) Launch elements into space, (2) Transport crew and cargo to and from various destinations, (3) Provide access to the surface of Mars, (4) Launch crew from the surface of Mars. Oxygen/Methane propulsion systems meet the unique requirements of Mars surface access. A common Oxygen/Methane propulsion system is being considered to reduce development costs and support a wide range of primary & alternative applications.

  11. Toward automatic finite element analysis

    NASA Technical Reports Server (NTRS)

    Kela, Ajay; Perucchio, Renato; Voelcker, Herbert

    1987-01-01

    Two problems must be solved if the finite element method is to become a reliable and affordable blackbox engineering tool. Finite element meshes must be generated automatically from computer aided design databases and mesh analysis must be made self-adaptive. The experimental system described solves both problems in 2-D through spatial and analytical substructuring techniques that are now being extended into 3-D.

  12. Evaluation of Hologram Optical Elements

    DTIC Science & Technology

    1975-06-01

    SUMMARY This report is the third in a series th?c cover the investigation of the properties and applications of holo- graphic optics. This type of...Design gy 6.2. Fabrication 97 7. Single Hologram Element Properties 101 7.1. Selection of Study Parameters 101 7.2. Case 1: Q...the Important Cases to be Analyzed in the Single Hologram Element Properties Study. . .106 14 mammiammtii . •MMaWaaaiuuia ttttmrngUdttt^Mi

  13. Elements of EAF automation processes

    NASA Astrophysics Data System (ADS)

    Ioana, A.; Constantin, N.; Dragna, E. C.

    2017-01-01

    Our article presents elements of Electric Arc Furnace (EAF) automation. So, we present and analyze detailed two automation schemes: the scheme of electrical EAF automation system; the scheme of thermic EAF automation system. The application results of these scheme of automation consists in: the sensitive reduction of specific consummation of electrical energy of Electric Arc Furnace, increasing the productivity of Electric Arc Furnace, increase the quality of the developed steel, increasing the durability of the building elements of Electric Arc Furnace.

  14. ANSYS duplicate finite-element checker routine

    NASA Technical Reports Server (NTRS)

    Ortega, R.

    1995-01-01

    An ANSYS finite-element code routine to check for duplicated elements within the volume of a three-dimensional (3D) finite-element mesh was developed. The routine developed is used for checking floating elements within a mesh, identically duplicated elements, and intersecting elements with a common face. A space shuttle main engine alternate turbopump development high pressure oxidizer turbopump finite-element model check using the developed subroutine is discussed. Finally, recommendations are provided for duplicate element checking of 3D finite-element models.

  15. Transient finite element method using edge elements for moving conductor

    SciTech Connect

    Tani, Koji; Nishio, Takayuki; Yamada, Takashi ); Kawase, Yoshihiro . Dept. of Information Science)

    1999-05-01

    For the next generation of high speed railway systems and automobiles new braking systems are currently under development. These braking systems take into account the eddy currents, which are produced by the movement of the conductor in the magnetic field. For their optimum design, it is necessary to know the distribution of eddy currents in the moving conductor. The finite element method (FEM) is often used to simulate them. Here, transient finite element method using edge elements for moving conductor is presented. Here the magnetic vector potential is interpolated at the upwind position and the time derivative term is discretized by the backward difference method. As a result, the system matrix becomes symmetric and the ICCG method is applicable to solve the matrix. This method is used to solve an eddy current rail brake system. The results demonstrate that this approach is suitable to solve transient problems involving movement.

  16. Eukaryotic transposable elements as mutagenic agents

    SciTech Connect

    Lambert, M.E. . Banbury Center); McDonald, J.F. ); Weinstein, I.B. )

    1988-01-01

    This book contains the proceedings on eukaryotic transposable elements as mutagenic agents. Topics covered include: overview of prokaryotic transposable elements, mutational effects of transposable element insertions, inducers/regulators of transposable element expression and transposition, genomic stress and environmental effects, and inducers/regulators of retroviral element expression.

  17. New Perspectives on the Essential Trace Elements.

    ERIC Educational Resources Information Center

    Frieden, Earl

    1985-01-01

    Provides a comprehensive overview of the 19 essential trace elements, examining: the concept of essentiality; evolution of these elements; possible future essential elements; the lanthanides and actinides; how essential trace elements work; the metalloenzymes; the nonmetals; iodine and the thyroid hormones; and antagonism among these elements. (JN)

  18. New Perspectives on the Essential Trace Elements.

    ERIC Educational Resources Information Center

    Frieden, Earl

    1985-01-01

    Provides a comprehensive overview of the 19 essential trace elements, examining: the concept of essentiality; evolution of these elements; possible future essential elements; the lanthanides and actinides; how essential trace elements work; the metalloenzymes; the nonmetals; iodine and the thyroid hormones; and antagonism among these elements. (JN)

  19. Relativistic Dipole Matrix Element Zeros

    NASA Astrophysics Data System (ADS)

    Lajohn, L. A.; Pratt, R. H.

    2002-05-01

    There is a special class of relativistic high energy dipole matrix element zeros (RZ), whose positions with respect to photon energy ω , only depend on the bound state l quantum number according to ω^0=mc^2/(l_b+1) (independent of primary quantum number n, nuclear charge Z, central potential V and dipole retardation). These RZ only occur in (n,l_b,j_b)arrow (ɛ , l_b+1,j_b) transitions such as ns_1/2arrow ɛ p_1/2; np_3/2arrow ɛ d_3/2: nd_5/2arrow ɛ f_5/2 etc. The nonrelativistic limit of these matrix elements can be established explicitly in the Coulomb case. Within the general matrix element formalism (such as that in [1]); when |κ | is substituted for γ in analytic expressions for matrix elements, the zeros remain, but ω^0 now becomes dependent on n and Z. When the reduction to nonrelativistic form is completed by application of the low energy approximation ω mc^2 mc^2, the zeros disappear. This nonzero behavior was noted in nonrelativistic dipole Coulomb matrix elements by Fano and Cooper [2] and later proven by Oh and Pratt[3]. (J. H. Scofield, Phys. Rev. A 40), 3054 (1989 (U. Fano and J. W. Cooper, Rev. Mod. Phys. 40), 441 (1968). (D. Oh and R. H. Pratt, Phys. Rev. A 34), 2486 (1986); 37, 1524 (1988); 45, 1583 (1992).

  20. Brain trace elements and aging

    NASA Astrophysics Data System (ADS)

    Hebbrecht, Geert; Maenhaut, Willy; Reuck, Jacques De

    1999-04-01

    Degenerative mechanisms involved in the aging process of the brain are to a certain extent counteracted by repair mechanisms. In both degenerative and recovery processes, trace elements are involved. The present study focused on the role of two minor (i.e., K and Ca) and six trace elements (i.e., Mn, Fe, Cu, Zn, Se and Rb) in the aging process. The elements were determined by PIXE in cerebral cortex and white matter, basal ganglia, brainstem and cerebellar cortex of 18 postmortem human brains, from persons without a history of neurologic or psychiatric disease who deceased between the age of 7 and 79. This age range allowed us to study the relationship between elemental concentrations and age. The most prominent findings were a concentration decrease for K and Rb and a concentration increase for the elements Ca, Fe, Zn and Se. The study supports recent findings that Ca and Fe are involved in brain degenerative processes initiated by oxygen free radicals, whereas Zn and Se are involved in immunological reactions counteracting the aging process.

  1. Elemental Compositions of Yellowknife Bay Rocks

    NASA Image and Video Library

    2013-03-18

    This graphic presents results from APXS onboard NASA rover Curiosity, with the comparisons simplified across diverse elements by dividing the amount of each element measured in the rocks by the amount of the same element in a local soil.

  2. Finite elements of nonlinear continua.

    NASA Technical Reports Server (NTRS)

    Oden, J. T.

    1972-01-01

    The finite element method is extended to a broad class of practical nonlinear problems, treating both theory and applications from a general and unifying point of view. The thermomechanical principles of continuous media and the properties of the finite element method are outlined, and are brought together to produce discrete physical models of nonlinear continua. The mathematical properties of the models are analyzed, and the numerical solution of the equations governing the discrete models is examined. The application of the models to nonlinear problems in finite elasticity, viscoelasticity, heat conduction, and thermoviscoelasticity is discussed. Other specific topics include the topological properties of finite element models, applications to linear and nonlinear boundary value problems, convergence, continuum thermodynamics, finite elasticity, solutions to nonlinear partial differential equations, and discrete models of the nonlinear thermomechanical behavior of dissipative media.

  3. An Overview of Climatic Elements

    NASA Technical Reports Server (NTRS)

    Crutcher, H. L.; Johnson, D. L.

    2007-01-01

    This Technical Publication (TP) addresses some climatic elements with emphasis on atmospheric composition, including gas radiative characteristics. Solar radiation is discussed with considerable information on the mathematical and statistical formulae. On a worldwide basis, temperature and precipitation for the globe are discussed along with interaction in drought. Also included is the simultaneous interaction with winds, humidity, and solar radiation. Volcanology gets minimum treatment. The oceans and seas are treated in chart form along with the interrelationship of oceanic currents and El Nino and La Nina, and ENSO phenomena. Upper air circulations are discussed. Various cloud formations up to 85-95 km altitude are described. Information on tornadoes and hurricanes is also included. One section is devoted to the climate physical-chemical elements. A short discussion is given on the importance for the quality of data and/or information in descriptions of the climate. This TP presents only an overview or survey of these and other various climatic elements.

  4. Finite elements of nonlinear continua.

    NASA Technical Reports Server (NTRS)

    Oden, J. T.

    1972-01-01

    The finite element method is extended to a broad class of practical nonlinear problems, treating both theory and applications from a general and unifying point of view. The thermomechanical principles of continuous media and the properties of the finite element method are outlined, and are brought together to produce discrete physical models of nonlinear continua. The mathematical properties of the models are analyzed, and the numerical solution of the equations governing the discrete models is examined. The application of the models to nonlinear problems in finite elasticity, viscoelasticity, heat conduction, and thermoviscoelasticity is discussed. Other specific topics include the topological properties of finite element models, applications to linear and nonlinear boundary value problems, convergence, continuum thermodynamics, finite elasticity, solutions to nonlinear partial differential equations, and discrete models of the nonlinear thermomechanical behavior of dissipative media.

  5. Finite elements: Theory and application

    NASA Technical Reports Server (NTRS)

    Dwoyer, D. L. (Editor); Hussaini, M. Y. (Editor); Voigt, R. G. (Editor)

    1988-01-01

    Recent advances in FEM techniques and applications are discussed in reviews and reports presented at the ICASE/LaRC workshop held in Hampton, VA in July 1986. Topics addressed include FEM approaches for partial differential equations, mixed FEMs, singular FEMs, FEMs for hyperbolic systems, iterative methods for elliptic finite-element equations on general meshes, mathematical aspects of FEMS for incompressible viscous flows, and gradient weighted moving finite elements in two dimensions. Consideration is given to adaptive flux-corrected FEM transport techniques for CFD, mixed and singular finite elements and the field BEM, p and h-p versions of the FEM, transient analysis methods in computational dynamics, and FEMs for integrated flow/thermal/structural analysis.

  6. Elemental composition of leukocyte subfractions

    NASA Astrophysics Data System (ADS)

    Admans, L. L.; Spyrou, N. M.

    2003-01-01

    The aim of this preliminary investigation was to determine the elemental concentration of various subfractions of leukocytes in a normal subject. Little work has been published on the elemental composition of these subfractions. First, a reliable technique for separation of these subfractions had to be established so that it could be applied to the determination of elemental concentrations in leukocyte subfractions from patients undergoing heart bypass surgery. Instrumental neutron activation analysis (INAA) utilising short irradiation and counting was the technique employed. Various washing media were examined during the separation of the leukocyte subfractions, for contamination of these small samples of peripheral blood mononuclear cells (PBMC) and polymorphonuclearcytes (PMN). Early results showed Mg and Se were present in these subfractions. Possibilities for further work are also discussed.

  7. Trace elements in Jamaican tobacco.

    PubMed

    Grant, C N; Lalor, G C; Vutchkov, M K

    2004-03-01

    The concentrations of 28 elements, in hand-made cigars, "rope" tobacco and freshly picked tobacco leaves from the parish of Manchester in central Jamaica, were compared with locally packaged and imported cigarettes and cigars. Except for chromium and vanadium, which are lower in the imported products, the elemental concentrations of all the brands sold in Jamaica are rather similar. The means for aluminium, cadmium, caesium, cerium, chromium, iron, thorium, uranium, vanadium and zinc for the Manchester material exceed the maximum values of the other tobaccos. The significant concentrations of heavy metals, and especially cadmium, which is about 50 times that of commercial cigarettes, reflect the known high concentrations in the soils in the region. This tobacco is not filtered and the smoke contains 50% of the cadmium. This, and the concentrations of radioactive elements, may indicate an additional health risk compared with commercial cigarettes. A study of three samples of marijuana indicates a similar level of risk from heavy metals.

  8. [Oncological data elements in histopathology].

    PubMed

    Haroske, G; Kramm, T; Mörz, M; Oberholzer, M

    2010-09-01

    In order to cope with increasing demands to supply information to a variety of documentation systems outside pathology, pathologists need to set standards both for the content and the use of the information they generate. Oncological datasets based on a set vocabulary are urgently required for use both in pathology and in further processing. Data elements were defined according to German pathology report guidelines for colorectal cancers in line with ISO 11179 requirements for the relations between data element concepts and value domains, as well as for further formal conditions, which can be exported in XML together with metadata information. Tests on 100 conventionally written diagnoses showed their principal usability and an increasing degree of guideline conformity in diagnoses commensurate with training time. This set of oncological data elements is a valuable checklist tool for pathologists, enabling formatted information export for further use and saving documentation effort.

  9. Finite elements: Theory and application

    NASA Technical Reports Server (NTRS)

    Dwoyer, D. L. (Editor); Hussaini, M. Y. (Editor); Voigt, R. G. (Editor)

    1988-01-01

    Recent advances in FEM techniques and applications are discussed in reviews and reports presented at the ICASE/LaRC workshop held in Hampton, VA in July 1986. Topics addressed include FEM approaches for partial differential equations, mixed FEMs, singular FEMs, FEMs for hyperbolic systems, iterative methods for elliptic finite-element equations on general meshes, mathematical aspects of FEMS for incompressible viscous flows, and gradient weighted moving finite elements in two dimensions. Consideration is given to adaptive flux-corrected FEM transport techniques for CFD, mixed and singular finite elements and the field BEM, p and h-p versions of the FEM, transient analysis methods in computational dynamics, and FEMs for integrated flow/thermal/structural analysis.

  10. Element flux in cleaved limestones

    SciTech Connect

    McNaught, M.A.; Erslev, E.A. . Dept. of Earth Resources)

    1992-01-01

    Spaced cleavage in limestone is commonly assumed to result from dissolution of carbonate minerals and passive concentration of other minerals in cleavage zones. More complicated processes are suggested by new element data acquired with the CSU XRF-macroprobe. Overlapping spot analyses were made along bed parallel traverses across cleavage zones in samples from the Twin Creek Formation (TCF) of southeast Idaho and the Poxono Island Formation (PIF) of eastern Pennsylvania. If calcite is the sole mobile phase, Ca should decrease as the other immobile elements increase proportionately. Though Ca is the only major element which consistently decreases in cleavage zones, changes in the relative proportions of the other elements indicate varying degrees of mobility. Al and Ti both increase in cleavage zones and maintain a constant ratio, suggesting immobile behavior. Because Al is more abundant than Ti, mobilities of other elements are determined relative to Al. Mg/Al and Fe/Al ratios are constant for PIF samples but show no systematic relationships in TCF samples, which have lower phyllosilicate contents. Si/Al ratios are relatively constant for most samples but in some PIF samples Si/Al ratios decrease in cleavage zones. This may be the result of dissolution of quartz or Si loss during phyllosilicate reactions. K/Al ratios are constant for limestones with average K/Al atomic ratios of 1/3 whereas samples lower K/Al ratios show increasing K/Al in cleavage zones. This suggests that the growth of new phyllosilicates in the K-poor cleavage zones causes preferential scavenging of potassium. In rocks with K/Al ratios of illite or muscovite, K appears to accumulate with Al by residual concentration. Thus, Al and Ti may be the only viable major element markers for calculating volume flux.

  11. Parallel, Implicit, Finite Element Solver

    NASA Astrophysics Data System (ADS)

    Lowrie, Weston; Shumlak, Uri; Meier, Eric; Marklin, George

    2007-11-01

    A parallel, implicit, finite element solver is described for solutions to the ideal MHD equations and the Pseudo-1D Euler equations. The solver uses the conservative flux source form of the equations. This helps simplify the discretization of the finite element method by keeping the specification of the physics separate. An implicit time advance is used to allow sufficiently large time steps. The Portable Extensible Toolkit for Scientific Computation (PETSc) is implemented for parallel matrix solvers and parallel data structures. Results for several test cases are described as well as accuracy of the method.

  12. Cosmic origins of the elements

    SciTech Connect

    Bennett, G.

    1988-08-01

    The story of nucleosynthesis - the origin of the elements - ties the vastly great to the submicroscopically small and links the earliest moments of the universe to today. It units astronomy with physics, chemistry, and even geology in a colorful tapestry that weaves together you, the stars, and the Big Bang itself. The elements were created during two epochs of the universe. The first epoch closed out the Big Bang and divides the end of that explosion from the beginning of the universe we know. The second epoch began when the first stars were born and continues down to today.

  13. Status of transuranium element production

    SciTech Connect

    King, L.J.

    1985-01-01

    The Transuranium Processing Plant at Oak Ridge National Laboratory has been the production, storage, and distribution center for the heavy-element research program of the US Department of Energy since 1966. During the past four years, annual production rates of transcurium elements have been relatively stable, averaging 34 mg of /sup 249/Bk, 369 mg of /sup 252/Cf, 1.4 mg of /sup 253/Es, and 0.7 pg of /sup 257/Fm. The extensive provisions for changing and modifying equipment have allowed continual updating of the plant to include new concepts in chemical processes and equipment design. 21 refs., 4 figs., 2 tabs.

  14. Gas and humidity sensing element

    SciTech Connect

    Komine, Y.; Sawada, T.

    1984-06-26

    A gas and humidity sensing element in a single integral structure made of a base plate of apatite ceramics, on which a particular metal oxide such as tin oxide, zinc oxide, or composite oxide of titanium and niobium is provided. The sensing element has a function of sensing gas and humidity with outstanding sensitivity to bad smell gas and alcoholic gas, in which the humidity is sensed and measured by variations in electrical resistance of the apatite ceramic base plate and the bad smell gas such as hydrogen sulfide, methyl mercaptan, etc. is sensed and measured by variations in electrical resistance of the metal oxide.

  15. Transposable elements and circular DNAs

    PubMed Central

    2016-01-01

    ABSTRACT Circular DNAs are extra-chromosomal fragments that become circularized by genomic recombination events. We have recently shown that yeast LTR elements generate circular DNAs through recombination events between their flanking long terminal repeats (LTRs). Similarly, circular DNAs can be generated by recombination between LTRs residing at different genomic loci, in which case the circular DNA will contain the intervening sequence. In yeast, this can result in gene copy number variations when circles contain genes and origins of replication. Here, I speculate on the potential and implications of circular DNAs generated through recombination between human transposable elements. PMID:28090380

  16. Spent graphite fuel element processing

    SciTech Connect

    Holder, N.D.; Olsen, C.W.

    1981-07-01

    The Department of Energy currently sponsors two programs to demonstrate the processing of spent graphite fuel elements. General Atomic in San Diego operates a cold pilot plant to demonstrate the processing of both US and German high-temperature reactor fuel. Exxon Nuclear Idaho Company is demonstrating the processing of spent graphite fuel elements from Rover reactors operated for the Nuclear Rocket Propulsion Program. This work is done at Idaho National Engineering Laboratory, where a hot facility is being constructed to complete processing of the Rover fuel. This paper focuses on the graphite combustion process common to both programs.

  17. Moderately volatile elements. [in meteorites

    NASA Technical Reports Server (NTRS)

    Palme, H.; Larimer, J. W.; Lipschutz, M. E.

    1988-01-01

    That the fractionation of moderately volatile and highly volatile elements was a major process in the early solar system is reflected in the variable concentrations of Rb and associated variations in initial Sr-isotopic ratios in chondritic meteorites. Greater knowledge of processes leading to volatile depletion would place stronger constraints on the formation conditions of solid material in the solar system. It will especially become possible to ascertain whether evaporation or incomplete condensation was the major process in establishing the elemental abundance patterns observed in primitive meteorites and planets.

  18. Phytoremediation of Soil Trace Elements

    USDA-ARS?s Scientific Manuscript database

    This chapter summarizes research progress in development of phytoremediation technologies. Some soils have become contaminated by trace elements enough to kill plants, inhibit soil organisms, and/or threaten wildlife, humans or the environment. Traditional remediation by dig and haul methods are v...

  19. Compact Fuel Element Environment Test

    NASA Technical Reports Server (NTRS)

    Bradley, D. E.; Mireles, O. R.; Hickman, R. R.; Broadway, J. W.

    2012-01-01

    Deep space missions with large payloads require high specific impulse (I(sub sp)) and relatively high thrust to achieve mission goals in reasonable time frames. Conventional, storable propellants produce average I(sub sp). Nuclear thermal rockets (NTRs) capable of high I(sub sp) thrust have been proposed. NTR employs heat produced by fission reaction to heat and therefore accelerate hydrogen, which is then forced through a rocket nozzle providing thrust. Fuel element temperatures are very high (up to 3,000 K) and hydrogen is highly reactive with most materials at high temperatures. Data covering the effects of high-temperature hydrogen exposure on fuel elements are limited. The primary concern is the mechanical failure of fuel elements that employ high melting point metals, ceramics, or a combination (cermet) as a structural matrix into which the nuclear fuel is distributed. It is not necessary to include fissile material in test samples intended to explore high-temperature hydrogen exposure of the structural support matrices. A small-scale test bed designed to heat fuel element samples via noncontact radio frequency heating and expose samples to hydrogen for typical mission durations has been developed to assist in optimal material and manufacturing process selection without employing fissile material. This Technical Memorandum details the test bed design and results of testing conducted to date.

  20. High performance rolling element bearing

    NASA Technical Reports Server (NTRS)

    Bursey, Jr., Roger W. (Inventor); Olinger, Jr., John B. (Inventor); Owen, Samuel S. (Inventor); Poole, William E. (Inventor); Haluck, David A. (Inventor)

    1993-01-01

    A high performance rolling element bearing (5) which is particularly suitable for use in a cryogenically cooled environment, comprises a composite cage (45) formed from glass fibers disposed in a solid lubricant matrix of a fluorocarbon polymer. The cage includes inserts (50) formed from a mixture of a soft metal and a solid lubricant such as a fluorocarbon polymer.

  1. Extrachromosomal genetic elements in Micrococcus.

    PubMed

    Dib, Julián Rafael; Liebl, Wolfgang; Wagenknecht, Martin; Farías, María Eugenia; Meinhardt, Friedhelm

    2013-01-01

    Micrococci are Gram-positive G + C-rich, nonmotile, nonspore-forming actinomycetous bacteria. Micrococcus comprises ten members, with Micrococcus luteus being the type species. Representatives of the genus play important roles in the biodegradation of xenobiotics, bioremediation processes, production of biotechnologically important enzymes or bioactive compounds, as test strains in biological assays for lysozyme and antibiotics, and as infective agents in immunocompromised humans. The first description of plasmids dates back approximately 28 years, when several extrachromosomal elements ranging in size from 1.5 to 30.2 kb were found in Micrococcus luteus. Up to the present, a number of circular plasmids conferring antibiotic resistance, the ability to degrade aromatic compounds, and osmotolerance are known, as well as cryptic elements with unidentified functions. Here, we review the Micrococcus extrachromosomal traits reported thus far including phages and the only quite recently described large linear extrachromosomal genetic elements, termed linear plasmids, which range in size from 75 kb (pJD12) to 110 kb (pLMA1) and which confer putative advantageous capabilities, such as antibiotic or heavy metal resistances (inferred from sequence analyses and curing experiments). The role of the extrachromosomal elements for the frequently proven ecological and biotechnological versatility of the genus will be addressed as well as their potential for the development and use as genetic tools.

  2. FUEL ELEMENT FOR NUCLEAR REACTOR

    DOEpatents

    Carney, K.G. Jr.

    1959-07-14

    A nuclear fuel element comprising a large number og wafers of fissionable material and a protective jacket having compartments holding these wafers is described. The compartments of the jacket aid the removal of heat from the wafers, keep the wafers or fragments thereof from migrating in the jacket, and permit the escape of gaseous fission products.

  3. Dryout of BWR fuel elements

    SciTech Connect

    Reisch, Frigyes

    2006-07-01

    To increase the power output of the presently operating power reactors is a worldwide trend. One limiting factor from the safety and commercial point of views is the maximum allowable thermal load of the fuel. The findings of the presented loop experiments are that the margin to the burnout of the fuel elements can be defined by a single parameter the void. (authors)

  4. Element material experiment by EFFU

    NASA Technical Reports Server (NTRS)

    Hashimoto, Yoshihiro; Ichikawa, Masaaki; Takei, Mitsuru; Torii, Yoshihiro; Ota, Kazuo

    1995-01-01

    National Space Development Agency of JAPAN (NASDA) is planning to perform Element Material Exposure Experiment using Exposed Facility Flyer Unit (EFFU). Several materials which will be used on JEM (Japanese Experiment Module for the space station) will be exposed. Space environment monitoring is also planned in this experiment. Several ground based tests are now being performed and getting useful data.

  5. Infrared trace element detection system

    DOEpatents

    Bien, Fritz; Bernstein, Lawrence S.; Matthew, Michael W.

    1988-01-01

    An infrared trace element detection system including an optical cell into which the sample fluid to be examined is introduced and removed. Also introduced into the optical cell is a sample beam of infrared radiation in a first wavelength band which is significantly absorbed by the trace element and a second wavelength band which is not significantly absorbed by the trace element for passage through the optical cell through the sample fluid. The output intensities of the sample beam of radiation are selectively detected in the first and second wavelength bands. The intensities of a reference beam of the radiation are similarly detected in the first and second wavelength bands. The sensed output intensity of the sample beam in one of the first and second wavelength bands is normalized with respect to the other and similarly, the intensity of the reference beam of radiation in one of the first and second wavelength bands is normalized with respect to the other. The normalized sample beam intensity and normalized reference beam intensity are then compared to provide a signal from which the amount of trace element in the sample fluid can be determined.

  6. Infrared trace element detection system

    DOEpatents

    Bien, F.; Bernstein, L.S.; Matthew, M.W.

    1988-11-15

    An infrared trace element detection system includes an optical cell into which the sample fluid to be examined is introduced and removed. Also introduced into the optical cell is a sample beam of infrared radiation in a first wavelength band which is significantly absorbed by the trace element and a second wavelength band which is not significantly absorbed by the trace element for passage through the optical cell through the sample fluid. The output intensities of the sample beam of radiation are selectively detected in the first and second wavelength bands. The intensities of a reference beam of the radiation are similarly detected in the first and second wavelength bands. The sensed output intensity of the sample beam in one of the first and second wavelength bands is normalized with respect to the other and similarly, the intensity of the reference beam of radiation in one of the first and second wavelength bands is normalized with respect to the other. The normalized sample beam intensity and normalized reference beam intensity are then compared to provide a signal from which the amount of trace element in the sample fluid can be determined. 11 figs.

  7. Superheavy Elements - Achievements and Challenges

    SciTech Connect

    Ackermann, Dieter

    2009-03-04

    The search for superheavy elements (SHE) has yielded exciting results for both the 'cold fusion' approach with reactions employing Pb and Bi targets and the ''hot fusion'' reactions with {sup 48}Ca beams on actinide targets. The most recent activities at GSI were the successful production of a more neutron rich isotope of element 112 in the reaction {sup 48}Ca+{sup 238}U confirming earlier result from FLNR, and the attempt to synthesize an isotope with Z 120 in the reaction {sup 64}Ni+{sup 238}U. Apart from the synthesis of new elements, advanced nuclear structure studies for heavy and super heavy elements promise a detailed insight in the properties of nuclear matter under the extreme conditions of high Z and A. The means are evaporation residue(ER)-{alpha}-{alpha} and -{alpha}-{gamma} coincidence techniques applied after separation of the reaction products from the beam. Recent examples of interesting physics to be discovered in this region of the chart of nuclides are the investigation of K-isomers observed for {sup 252,254}No and indicated for {sup 270}Ds. Fast chemistry and precision mass measurements deliver in addition valuable information on the fundamental properties of the SHE.

  8. Trace elements: implications for nursing.

    PubMed

    Hayter, J

    1980-01-01

    Although most were unknown a few years ago, present evidence indicates that at least 25 trace elements have some pertinence to health. Unlike vitamins, they cannot be synthesized. Some trace elements are now considered important only because of their harmful effects but traces of them may be essential. Zinc is especially important during puberty, pregnancy and menopause and is related to protein metabolism. Both fluoride and cadmium accumulate in the body year after year. Cadmium is positively correlated with several chronic diseases, especially hypertension. It is obtained from smoking and drinking soft water. Silicon, generally associated with silicosis, may be necessary for healthy bone and connective tissue. Chromium, believed to be the glucose tolerance factor, is obtained from brewer's yeast, spices, and whole wheat products. Copper deficiency may be implicated in a wide range of cardiovascular and blood related disorders. Either marginal deficiencies or slight excesses of most trace elements are harmful. Nurses should instruct patients to avoid highly refined foods, fad diets, or synthetic and fabricated foods. A well balanced and varied diet is the best safeguard against trace element excesses or deficiencies.

  9. Quadrilateral finite element mesh coarsening

    SciTech Connect

    Staten, Matthew L; Dewey, Mark W; Benzley, Steven E

    2012-10-16

    Techniques for coarsening a quadrilateral mesh are described. These techniques include identifying a coarsening region within the quadrilateral mesh to be coarsened. Quadrilateral elements along a path through the coarsening region are removed. Node pairs along opposite sides of the path are identified. The node pairs along the path are then merged to collapse the path.

  10. FOIL ELEMENT FOR NUCLEAR REACTOR

    DOEpatents

    Noland, R.A.; Walker, D.E.; Spinrad, B.I.

    1963-07-16

    A method of making a foil-type fuel element is described. A foil of fuel metal is perforated in; regular design and sheets of cladding metal are placed on both sides. The cladding metal sheets are then spot-welded to each other through the perforations, and the edges sealed. (AEC)

  11. Electrical Resistivity of Alkali Elements.

    DTIC Science & Technology

    1976-01-01

    rubidium, cesium, and francium ) and contains recommended reference values (or provisional or typical values). The compiled data include all the...and information on the electrical resistivity of alkali elements (lithium, sodium, potassium, rubidium, cesium, and francium ) and contains...107Ic. Magnetic Flux Density Dependence o.. .. ... .... 112 4.6. Francium ..........................115j a. Temperature Dependence

  12. Boundary elements for structural analysis

    NASA Technical Reports Server (NTRS)

    1989-01-01

    The intent here is to discuss the status of the boundary element method (BEM) for structural analysis, both in terms of the present and anticipated capabilities of the method and in terms of the incorporation of the method in the design/analysis process, particularly for gas turbine engine components.

  13. Sunspots, Starspots, and Elemental Abundances

    NASA Astrophysics Data System (ADS)

    Doschek, G. A.; Warren, H. P.

    2017-07-01

    Element abundances in the solar photosphere, chromosphere, transition region, and corona are key parameters for investigating sources of the solar wind and for estimating radiative losses in the quiet corona and in dynamical events such as solar flares. Abundances in the solar corona and photosphere differ from each other depending on the first ionization potential (FIP) of the element. Normally, abundances with FIP values less than about 10 eV are about 3-4 times more abundant in the corona than in the photosphere. However, recently, an inverse FIP effect was found in small regions near sunspots where elements with FIP less than 10 eV are less abundant relative to high FIP elements (≥slant 10 eV) than they are in the photosphere. This is similar to fully convective stars with large starspots. The inverse FIP effect is predicted to occur in the vicinity of sunspots/starspots. Up to now, the solar anomalous abundances have only been found in very spatially small areas. In this paper, we show that in the vicinity of sunspots there can be substantially larger areas with abundances that are between coronal and photospheric abundances and sometimes just photospheric abundances. In some cases, the FIP effect tends to shut down near sunspots. We examine several active regions with relatively large sunspots that were observed with the Extreme-ultraviolet Imaging Spectrometer on the Hinode spacecraft in cycle 24.

  14. Parameters of the Heaviest Element

    NASA Astrophysics Data System (ADS)

    Khazan, Albert

    2008-10-01

    The theory of equilateral hyperbola, which looks for the heaviest element of the Periodical Table of Elements, manifests the fact that, according to the boundary conditions, the arc along the ordinate axis is limited by the line Y=1, while the arc can be continued up to any value of X along the abscissa axis. Calculation shows: to draw the hyperbolae in the same scale the value X=600 is necessary and sufficient. The top of each hyperbola, found through Lagrange's theorem, should be located in the real axis. Beryllium: the ratio Y=K/X gives the coordinates X=60.9097, Y=0.14796. On the other hand, the formal properties of equilateral hyperbolae give Xo=Yo=3.00203 (these are the sq. root of the atomic mass of the element, 9.0122). This shows that there is the reciprocal law for coming from one reference in the case to another: X/Xo=Yo/Y=20.2895. We call this number the scaling coefficient. As seen the tangent of the angle of the real axis is Y/X=0.00242917, while this line intersects the line Y=1 in the point where K=X=411.663243. Assuming this X into our equation we deduced, we arrive at the number 155. These two values are attributed to the heaviest element of the Table (Progr. Phys., 2007, 1, 38; 2, 83; 2, 104; 2008, 3, 56).

  15. New elements produced at GSI

    SciTech Connect

    Hofmann, Sigurd

    1998-12-21

    In two series of experiments at SHIP, six new elements (Z=107-112) were synthesized via fusion reactions using lead or bismuth targets and 1n-deexcitation channels. The isotopes were unambiguously identified by means of {alpha}-{alpha} correlations. Not fission, but alpha decay is the dominant decay mode. Cross-sections decrease by two orders of magnitude from bohrium (Z=107) to element 112, for which a cross-section of 1 pb was measured. Based on our results, it is likely that the production of isotopes of element 114 close to the island of spherical SuperHeavy Elements (SHE) could be achieved by fusion reactions using {sup 208}Pb targets. Systematic studies of the reaction cross-sections indicate that the transfer of nucleons is an important process for the initiation of fusion. The data allow for the fixing of a narrow energy window for the production of SHE using 1n-emission channels. The likelihood of broadening the energy window by investigation of radiative capture reactions, use of neutron deficient projectile isotopes and use of actinide targets is discussed.

  16. Structural Truss Elements and Forces

    ERIC Educational Resources Information Center

    Troyer, Steve; Griffis, Kurt; Shackelford, Ray

    2005-01-01

    In the field of construction, most structures are supported by several groups of truss systems working together synergistically. A "truss" is a group of centered and balanced elements combined to carry a common load (Warner, 2003). Trusses provide strength against loads and forces within a structure. Though a complex field of study, structural…

  17. Documentary Elements in Early Films.

    ERIC Educational Resources Information Center

    Sanderson, Richard A.

    Focusing on documentary elements, this study examines the film content and film techniques of 681 motion pictures produced in the United States prior to 1904. Analysis of films by type, subject matter, and trends in subject matter shows that one-third of the early films are documentary in type and three-fourths of the films use subject matter of a…

  18. Single element laser beam shaper

    DOEpatents

    Zhang, Shukui [Yorktown, VA; Shinn, Michelle D [Newport News, VA

    2005-09-13

    A single lens laser beam shaper for converting laser beams from any spatial profile to a flat-top or uniform spatial profile. The laser beam shaper includes a lens having two aspheric surfaces. The beam shaper significantly simplifies the overall structure in comparison with conventional 2-element systems and therefore provides great ease in alignment and reduction of cost.

  19. Lumped Element Kinetic Inductance Detectors

    NASA Astrophysics Data System (ADS)

    Doyle, S.; Mauskopf, P.; Naylon, J.; Porch, A.; Duncombe, C.

    2008-04-01

    Kinetic Inductance Detectors (KIDs) provide a promising solution to the problem of producing large format arrays of ultra sensitive detectors for astronomy. Traditionally KIDs have been constructed from superconducting quarter-wave resonant elements capacitively coupled to a co-planar feed line [1]. Photon detection is achieved by measuring the change in quasi-particle density caused by the splitting of Cooper pairs in the superconducting resonant element. This change in quasi-particle density alters the kinetic inductance, and hence the resonant frequency of the resonant element. This arrangement requires the quasi-particles generated by photon absorption to be concentrated at positions of high current density in the resonator. This is usually achieved through antenna coupling or quasi-particle trapping. For these detectors to work at wavelengths shorter than around 500 μm where antenna coupling can introduce a significant loss of efficiency, then a direct absorption method needs to be considered. One solution to this problem is the Lumped Element KID (LEKID), which shows no current variation along its length and can be arranged into a photon absorbing area coupled to free space and therefore requiring no antennas or quasi-particle trapping. This paper outlines the relevant microwave theory of a LEKID, along with theoretical and measured performance for these devices.

  20. Transposable elements for insect transformation

    USDA-ARS?s Scientific Manuscript database

    The germ-line of more than 35 species from five orders of insects have been genetically transformed, using vectors derived from Class II transposable elements. Initially the P and hobo vector systems developed for D. melanogaster were not applicable to other species, but four transposons found in ot...

  1. Fast acting multiple element valve

    DOEpatents

    Yang, Jefferson Y. S.; Wada, James M.

    1991-01-01

    A plurality of slide valve elements having plural axial-spaced annular parts and an internal slide are inserted into a bulkhead in a fluid conduit from a downstream side of the bulkhead, locked in place by a bayonet coupling and set screw, and project through the bulkhead into the upstream conduit. Pneumatic lines connecting the slide valve element actuator to pilot valves are brought out the throat of the valve element to the downstream side. Pilot valves are radially spaced around the exterior of the valve to permit the pneumatic lines to be made identical, thereby to minimize adverse timing tolerances in operation due to pressure variations. Ring manifolds surround the valve adjacent respective pilot valve arrangements to further reduce adverse timing tolerances due to pressure variations, the manifolds being directly connected to the respective pilot valves. Position sensors are provided the valve element slides to signal the precise time at which a slide reaches or passes through a particular point in its stroke to initiate a calibrated timing function.

  2. Elemental Compositions of Extrasolar Planetesimals

    NASA Astrophysics Data System (ADS)

    Xu, Siyi; Jura, M.

    2014-01-01

    The composition of extrasolar rocky planets is essential for understanding the formation and evolution of these alien worlds. Studying externally-polluted white dwarfs provides the only method to directly measure the elemental compositions of extrasolar planetesimals, the building blocks of planets. The standard model is that some planetesimals can survive to the white dwarf phase, get perturbed, enter into the tidal radius of the white dwarf and get accreted, polluting its pure hydrogen or helium atmosphere. We have been performing high-resolution spectroscopic observations on a number of polluted white dwarfs to measure the bulk compositions of the accreted objects. To have a full picture of the abundance pattern, we gathered data from both Keck/HIRES and HST/COS. I will present the analysis for one of the most interesting objects -- G29-38. It is the first white dwarf identified with an infrared excess from debris of pulverized planetesimals and among the very first identified polluted hydrogen atmosphere white dwarfs. Our analysis indicates that the accreted extrasolar planetesimal is enhanced in refractory elements and depleted in volatile elements. A detailed comparison with solar system objects show that the observed composition can be best interpreted as a blend of chondritic object with some refractory-rich material, a result from post-nebular processing. When all polluted white dwarfs are viewed as an ensemble, we find that the elemental compositions of accreted extrasolar planetesimals resemble to those of solar system objects to zeroth order. (i) The big four elements, O, Fe, Mg and Si are also dominant. Objects with exotic compositions, e.g. diamond planets and refractory-dominated planets, are yet to be found. (ii) Volatiles, such as carbon and water, are only trace constituents. In terms of bulk composition, solar system objects are essentially normal.

  3. Trace elements and rat pouchitis.

    PubMed

    Drzymała-Czyż, Sławomira; Banasiewicz, Tomasz; Walas, Stanisław; Kościński, Tomasz; Wenska-Chyży, Ewa; Drews, Michał; Walkowiak, Jarosław

    2012-01-01

    The procedure of restorative proctocolectomy is associated with a complete removal of the colon and slight reduction of ileum length, which together can lead to systemic shortages of trace elements. Inflammatory changes in the pouch mucosa may also have some impact. However, there is no data on trace elements in pouchitis. Therefore, in the present study we aimed to assess the effect of acute pouchitis on the status of selected trace elements in rats. Restorative proctocolectomy with the construction of intestinal J-pouch was performed in twenty-four Wistar rats. Three weeks after the surgery, pouchitis was induced. Eight untreated rats created the control group. Liver concentrations of selected micronutrients (Zn, Cu, Co, Mn, Se) were measured in both groups six weeks later, using inductively coupled plasma mass spectrometry. Liver concentrations of trace elements did not differ between the study and the control groups. However, copper, cobalt and selenium concentrations [μg/g] were statistically lower (p<0.02, p<0.05 and p<0.04, respectively) in rats with severe pouchitis (n=9) as compared with rats with mild pouchitis (n=7) [median (range): Cu--7.05 (3.02-14.57) vs 10.47 (5.16-14.97); Co--0.55 (0.37-0.96) vs 0.61 (0.52-0.86); Se--1.17 (0.69-1.54) vs 1.18 (0.29-1.91)]. In conclusion, it seems that acute pouchitis can lead to a significant deficiency of trace elements.

  4. Trace elements of fibrous diamonds

    NASA Astrophysics Data System (ADS)

    Weiss, Y.; Griffin, W. L.; Navon, O.

    2009-04-01

    Twenty-seven fibrous diamonds from Kankan, Udachnaya, Diavik, DeBeers Pool and Koingnaas were analyzed for their trace element contents using the cellulose calibration LA-ICP-MS method; their major and volatile content were previously determined by EPMA and FTIR. This set of diamonds carries high-Mg carbonatitic, saline and low-Mg carbonatitic to silicic high-density fluid (HDFs) which represent the four end-members found in microinclusion-bearing diamonds. The trapped HDFs in all diamonds are highly enriched in incompatible elements typically reaching levels of a few thousand times the primitive mantle values. The majority of diamonds show similar patterns from Pr towards the more compatible elements, with moderate to high negative anomalies of Sr, Zr, Hf, Ti and Y. These anomalies are found in kimberlitic melts as well as in other metasomatic fluids in the lithospheric mantle. In the low-Mg carbonatitic to silicic HDFs and in the saline ones, two patterns are distinguished in the most incompatible elements (Cs-Ce). The first (designated "Table") has significantly higher Ba, U, Th and LREE compared to Nb, Ta and, in most cases, K, Rb and Cs. The second pattern ("Bench") is flatter with no significant anomalies in this range. The high-Mg carbonatitic HDFs do not show such defined patterns. Still, high-Mg carbonatitic HDFs from Kankan show higher depletion of the alkalis, and to a lesser extent Nb and Ta, compared with Udachnaya high-Mg HDFs. The present database is still limited, but "Table" patterns were found in the coat of a Kankan diamond that carries eclogitic inclusions in its core and in a Diavik diamond with peridotitic micro-mineral inclusions in its coat. Thus, the two patterns are probably not related to the peridotitic or eclogitic rocks that host the diamonds. "Table" and "Bench" patterns of the incompatible elements are found in HDFs of diverse major-element compositions (carbonatitic, silicic and saline). This suggests that the two patterns reflect

  5. 49 CFR 563.7 - Data elements.

    Code of Federal Regulations, 2014 CFR

    2014-10-01

    ... 49 Transportation 6 2014-10-01 2014-10-01 false Data elements. 563.7 Section 563.7 Transportation..., DEPARTMENT OF TRANSPORTATION EVENT DATA RECORDERS § 563.7 Data elements. (a) Data elements required for all vehicles. Each vehicle equipped with an EDR must record all of the data elements listed in Table I, during...

  6. 49 CFR 563.7 - Data elements.

    Code of Federal Regulations, 2013 CFR

    2013-10-01

    ... 49 Transportation 6 2013-10-01 2013-10-01 false Data elements. 563.7 Section 563.7 Transportation..., DEPARTMENT OF TRANSPORTATION EVENT DATA RECORDERS § 563.7 Data elements. (a) Data elements required for all vehicles. Each vehicle equipped with an EDR must record all of the data elements listed in Table I, during...

  7. 49 CFR 563.7 - Data elements.

    Code of Federal Regulations, 2012 CFR

    2012-10-01

    ... 49 Transportation 6 2012-10-01 2012-10-01 false Data elements. 563.7 Section 563.7 Transportation..., DEPARTMENT OF TRANSPORTATION EVENT DATA RECORDERS § 563.7 Data elements. (a) Data elements required for all vehicles. Each vehicle equipped with an EDR must record all of the data elements listed in Table I, during...

  8. The Transuranium Elements - Present Status: Nobel Lecture

    DOE R&D Accomplishments Database

    Seaborg, G. T.

    1951-12-12

    The discovery of the transuranium elements and the work done on them up to the present time are reviewed. The properties of these elements, their relationship to other elements, their place in the periodic table, and the possibility of production and identification of other transuranium elements are discussed briefly.

  9. 47 CFR 13.203 - Examination elements.

    Code of Federal Regulations, 2013 CFR

    2013-10-01

    ... 47 Telecommunication 1 2013-10-01 2013-10-01 false Examination elements. 13.203 Section 13.203... Examination elements. (a) A written examination (written Element) must prove that the examinee possesses the... commercial radio operator license. For each Element, the Commission shall establish through public notices...

  10. 47 CFR 13.203 - Examination elements.

    Code of Federal Regulations, 2014 CFR

    2014-10-01

    ... 47 Telecommunication 1 2014-10-01 2014-10-01 false Examination elements. 13.203 Section 13.203... Examination elements. (a) A written examination (written Element) must prove that the examinee possesses the... commercial radio operator license. For each Element, the Commission shall establish through public notices...

  11. 47 CFR 13.203 - Examination elements.

    Code of Federal Regulations, 2012 CFR

    2012-10-01

    ... 47 Telecommunication 1 2012-10-01 2012-10-01 false Examination elements. 13.203 Section 13.203... Examination elements. (a) A written examination (written Element) must prove that the examinee possesses the... commercial radio operator license. For each Element, the Commission shall establish through public notices...

  12. Optical Element, Device, Method, and Applications

    DTIC Science & Technology

    2011-04-14

    optical element is a phase-only element; and h) repeating steps ( c -f). 28. The method of claim 26, further comprising: c1) in step (c), setting...jl(l;, 11) to 0, wherein the optical element is an amplitude-only element; and h) repeating steps ( c -f). * * * * *

  13. Low cost, lightweight fuel cell elements

    NASA Technical Reports Server (NTRS)

    Kindler, Andrew (Inventor)

    2001-01-01

    New fuel cell elements for use in liquid feed fuel cells are provided. The elements including biplates and endplates are low in cost, light in weight, and allow high efficiency operation. Electrically conductive elements are also a part of the fuel cell elements.

  14. Actinomycete integrative and conjugative elements

    PubMed Central

    te Poele, Evelien M.; Bolhuis, Henk

    2008-01-01

    This paper reviews current knowledge on actinomycete integrative and conjugative elements (AICEs). The best characterised AICEs, pSAM2 of Streptomyces ambofaciens (10.9 kb), SLP1 (17.3 kb) of Streptomyces coelicolor and pMEA300 of Amycolatopsis methanolica (13.3 kb), are present as integrative elements in specific tRNA genes, and are capable of conjugative transfer. These AICEs have a highly conserved structural organisation, with functional modules for excision/integration, replication, conjugative transfer, and regulation. Recently, it has been shown that pMEA300 and the related elements pMEA100 of Amycolatopsis mediterranei and pSE211 of Saccharopolyspora erythraea form a novel group of AICEs, the pMEA-elements, based on the unique characteristics of their replication initiator protein RepAM. Evaluation of a large collection of Amycolatopsis isolates has allowed identification of multiple pMEA-like elements. Our data show that, as AICEs, they mainly coevolved with their natural host in an integrated form, rather than being dispersed via horizontal gene transfer. The pMEA-like elements could be separated into two distinct populations from different geographical origins. One group was most closely related to pMEA300 and was found in isolates from Australia and Asia and pMEA100-related sequences were present in European isolates. Genome sequence data have enormously contributed to the recent insight that AICEs are present in many actinomycete genera. The sequence data also provide more insight into their evolutionary relationships, revealing their modular composition and their likely combined descent from bacterial plasmids and bacteriophages. Evidence is accumulating that AICEs act as modulators of host genome diversity and are also involved in the acquisition of secondary metabolite clusters and foreign DNA via horizontal gene transfer. Although still speculative, these AICEs may play a role in the spread of antibiotic resistance factors into pathogenic bacteria

  15. FUEL ELEMENT FOR NUCLEAR REACTORS

    DOEpatents

    Bassett, C.H.

    1961-11-21

    A fuel element is designed which is particularly adapted for reactors of high power density used to generate steam for the production of electricity. The fuel element consists of inner and outer concentric tubes forming an annular chamber within which is contained fissionable fuel pellet segments, wedge members interposed between the fuel segments, and a spring which, acting with wedge members, urges said fuel pellets radially into contact against the inner surface of the outer tube. The wedge members may be a fertile material convertible into fissionable fuel material by absorbing neutrons emitted from the fissionable fuel pellet segments. The costly grinding of cylindrical fuel pellets to close tolerances for snug engagement is reduced because the need to finish the exact size is eliminated. (AEC)

  16. The Origin of the Elements

    ScienceCinema

    Murphy, Edward

    2016-07-12

    The world around us is made of atoms. Did you ever wonder where these atoms came from? How was the gold in our jewelry, the carbon in our bodies, and the iron in our cars made? In this lecture, we will trace the origin of a gold atom from the Big Bang to the present day, and beyond. You will learn how the elements were forged in the nuclear furnaces inside stars, and how, when they die, these massive stars spread the elements into space. You will learn about the origin of the building blocks of matter in the Big Bang, and we will speculate on the future of the atoms around us today.

  17. The Origin of the Elements

    SciTech Connect

    Murphy, Edward

    2012-11-20

    The world around us is made of atoms. Did you ever wonder where these atoms came from? How was the gold in our jewelry, the carbon in our bodies, and the iron in our cars made? In this lecture, we will trace the origin of a gold atom from the Big Bang to the present day, and beyond. You will learn how the elements were forged in the nuclear furnaces inside stars, and how, when they die, these massive stars spread the elements into space. You will learn about the origin of the building blocks of matter in the Big Bang, and we will speculate on the future of the atoms around us today.

  18. Surface energies of elemental crystals

    NASA Astrophysics Data System (ADS)

    Tran, Richard; Xu, Zihan; Radhakrishnan, Balachandran; Winston, Donald; Sun, Wenhao; Persson, Kristin A.; Ong, Shyue Ping

    2016-09-01

    The surface energy is a fundamental property of the different facets of a crystal that is crucial to the understanding of various phenomena like surface segregation, roughening, catalytic activity, and the crystal’s equilibrium shape. Such surface phenomena are especially important at the nanoscale, where the large surface area to volume ratios lead to properties that are significantly different from the bulk. In this work, we present the largest database of calculated surface energies for elemental crystals to date. This database contains the surface energies of more than 100 polymorphs of about 70 elements, up to a maximum Miller index of two and three for non-cubic and cubic crystals, respectively. Well-known reconstruction schemes are also accounted for. The database is systematically improvable and has been rigorously validated against previous experimental and computational data where available. We will describe the methodology used in constructing the database, and how it can be accessed for further studies and design of materials.

  19. Heavy Elements and Cool Stars

    NASA Technical Reports Server (NTRS)

    Wahlgren, Glenn M.; Carpenter, Kenneth G.; Norris, Ryan P.

    2008-01-01

    We report on progress in the analysis of high-resolution near-IR spectra of alpha Orionis (M2 Iab) and other cool, luminous stars. Using synthetic spectrum techniques, we search for atomic absorption lines in the stellar spectra and evaluate the available line parameter data for use in our abundance analyses. Our study concentrates on the post iron-group elements copper through zirconium as a means of investigating the slow neutron-capture process of nucleosynthesis in massive stars and the mechanisms that transport recently processed material up into the photospheric region. We discuss problems with the atomic data and model atmospheres that need to be addressed before theoretically derived elemental abundances from pre-supernova nucleosynthesis calculations can be tested by comparison with abundances determined from observations of cool, massive stars.

  20. Self supporting heat transfer element

    DOEpatents

    Story, Grosvenor Cook; Baldonado, Ray Orico

    2002-01-01

    The present invention provides an improved internal heat exchange element arranged so as to traverse the inside diameter of a container vessel such that it makes good mechanical contact with the interior wall of that vessel. The mechanical element is fabricated from a material having a coefficient of thermal conductivity above about 0.8 W cm.sup.-1.degree. K.sup.-1 and is designed to function as a simple spring member when that member has been cooled to reduce its diameter to just below that of a cylindrical container or vessel into which it is placed and then allowed to warm to room temperature. A particularly important application of this invention is directed to a providing a simple compartmented storage container for accommodating a hydrogen absorbing alloy.

  1. Surface energies of elemental crystals.

    PubMed

    Tran, Richard; Xu, Zihan; Radhakrishnan, Balachandran; Winston, Donald; Sun, Wenhao; Persson, Kristin A; Ong, Shyue Ping

    2016-09-13

    The surface energy is a fundamental property of the different facets of a crystal that is crucial to the understanding of various phenomena like surface segregation, roughening, catalytic activity, and the crystal's equilibrium shape. Such surface phenomena are especially important at the nanoscale, where the large surface area to volume ratios lead to properties that are significantly different from the bulk. In this work, we present the largest database of calculated surface energies for elemental crystals to date. This database contains the surface energies of more than 100 polymorphs of about 70 elements, up to a maximum Miller index of two and three for non-cubic and cubic crystals, respectively. Well-known reconstruction schemes are also accounted for. The database is systematically improvable and has been rigorously validated against previous experimental and computational data where available. We will describe the methodology used in constructing the database, and how it can be accessed for further studies and design of materials.

  2. Element of an inductive coupler

    DOEpatents

    Hall, David R.; Fox, Joe

    2006-08-15

    An element for an inductive coupler in a downhole component comprises magnetically conductive material, which is disposed in a recess in annular housing. The magnetically conductive material forms a generally circular trough. The circular trough comprises an outer generally U-shaped surface, an inner generally U-shaped surface, and two generally planar surfaces joining the inner and outer surfaces. The element further comprises pressure relief grooves in at least one of the surfaces of the circular trough. The pressure relief grooves may be scored lines. Preferably the pressure relief grooves are parallel to the magnetic field generated by the magnetically conductive material. The magnetically conductive material is selected from the group consisting of soft iron, ferrite, a nickel iron alloy, a silicon iron alloy, a cobalt iron alloy, and a mu-metal. Preferably, the annular housing is a metal ring.

  3. NEST: Noble Element Simulation Technique

    NASA Astrophysics Data System (ADS)

    Szydagis, M.; Barry, N.; Kazkaz, K.; Mock, J.; Stolp, D.; Sweany, M.; Tripathi, M.; Uvarov, S.; Walsh, N.; Woods, M.

    2013-07-01

    NEST (Noble Element Simulation Technique) offers comprehensive, accurate, and precise simulation of the excitation, ionization, and corresponding scintillation and electroluminescence processes in liquid noble elements, useful for direct dark matter detectors, double beta decay searches, PET scans, and general radiation detection technology. Written in C++, NEST is an add-on module for the Geant4 simulation package that incorporates more detailed physics than is currently available into the simulation of scintillation. NEST is of particular use for low-energy nuclear recoils. All available liquid xenon data on nuclear recoils and electron recoils to date have been taken into consideration in arriving at the current models. NEST also handles the magnitude of the light and charge yields of nuclear recoils, including their electric field dependence, thereby shedding light on the possibility of detection or exclusion of a low-mass dark matter WIMP by liquid xenon detectors.

  4. Composite oxygen ion transport element

    DOEpatents

    Chen, Jack C.; Besecker, Charles J.; Chen, Hancun; Robinson, Earil T.

    2007-06-12

    A composite oxygen ion transport element that has a layered structure formed by a dense layer to transport oxygen ions and electrons and a porous support layer to provide mechanical support. The dense layer can be formed of a mixture of a mixed conductor, an ionic conductor, and a metal. The porous support layer can be fabricated from an oxide dispersion strengthened metal, a metal-reinforced intermetallic alloy, a boron-doped Mo.sub.5Si.sub.3-based intermetallic alloy or combinations thereof. The support layer can be provided with a network of non-interconnected pores and each of said pores communicates between opposite surfaces of said support layer. Such a support layer can be advantageously employed to reduce diffusion resistance in any type of element, including those using a different material makeup than that outlined above.

  5. Representation Elements of Spatial Thinking

    NASA Astrophysics Data System (ADS)

    Fiantika, F. R.

    2017-04-01

    This paper aims to add a reference in revealing spatial thinking. There several definitions of spatial thinking but it is not easy to defining it. We can start to discuss the concept, its basic a forming representation. Initially, the five sense catch the natural phenomenon and forward it to memory for processing. Abstraction plays a role in processing information into a concept. There are two types of representation, namely internal representation and external representation. The internal representation is also known as mental representation; this representation is in the human mind. The external representation may include images, auditory and kinesthetic which can be used to describe, explain and communicate the structure, operation, the function of the object as well as relationships. There are two main elements, representations properties and object relationships. These elements play a role in forming a representation.

  6. A collection of edge-based elements

    NASA Technical Reports Server (NTRS)

    Kempel, Leo C.; Volakis, John L.

    1992-01-01

    Edge-based elements have proved useful in solving electromagnetic problems since they are nondivergent. Previous authors have presented several two and three dimensional elements. Herein, we present four types of elements which are suitable for modeling several types of three dimensional geometries. Distorted brick and triangular prism elements are given in cartesian coordinates as well as the specialized cylindrical shell and pie-shaped prism elements which are suitable for problems best described in polar cylindrical coordinates.

  7. Elements of Bayesian experimental design

    SciTech Connect

    Sivia, D.S.

    1997-09-01

    We consider some elements of the Bayesian approach that are important for optimal experimental design. While the underlying principles used are very general, and are explained in detail in a recent tutorial text, they are applied here to the specific case of characterising the inferential value of different resolution peakshapes. This particular issue was considered earlier by Silver, Sivia and Pynn (1989, 1990a, 1990b), and the following presentation confirms and extends the conclusions of their analysis.

  8. Ares I Upper Stage Element

    NASA Technical Reports Server (NTRS)

    Chojnacki, Kent

    2009-01-01

    This slide presentation reviews the elements that make up the Ares I launch vehicle, with particular attention devoted to the upper stage of the vehicle. The upper stage elememnts, a lunar mission profile, and the upper stage objectives are reviewed. The work that Marshall Space Flight Center is doing is highlighted: work on the full scale welding process, the vertical milling machining, and the thermal protection system.

  9. Sunspots, Starspots, and Elemental Abundances

    NASA Astrophysics Data System (ADS)

    Doschek, George A.; Warren, Harry P.

    2017-08-01

    The composition of plasma in solar and stellar atmospheres is not fixed, but varies from feature to feature. These variations are organized by the First Ionization Potential (FIP) of the element. Solar measurements often indicate that low FIP elements (< 10eV, such as Fe, Si, Mg) are enriched by factors of 3-4 in the corona relative to high FIP elements (>10 eV, such as C, N, O, Ar, He) compared to abundances in the photosphere. Stellar observations have also shown similar enrichments. An inverse FIP effect, where the low FIP elements are depleted, has been observed in stellar coronae of stars believed to have large starspots in their photospheres. The abundances are important for determining radiative loss rates in models, tracing the origin of the slow solar wind, and for understanding wave propagation in the chromosphere and corona. Recently, inverse FIP effects have been discovered in the Sun (Doschek, Warren, & Feldman 2015, ApJ, 808, L7) from spectra obtained by the Extreme-ultraviolet Imaging Spectrometer (EIS) on the Hinode spacecraft. The inverse FIP regions seem always to be near sunspots and cover only a very small area (characteristic length = a few arcseconds). However, in pursuing the search for inverse FIP regions, we have found that in some sunspot groups the coronal abundance at a temperature of 3-4 MK can be near photospheric over much larger areas of the sun near the sunspots (e.g., 6,000 arcsec2). Also, sometimes the abundances at 3-4 MK are in between coronal and photospheric values. This can occur in small areas of an active region. It is predicted (Laming 2015, Sol. Phys., 12, 2) that the FIP effect should be highly variable in the corona. Several examples of coronal abundance variations are presented. Our work indicates that a comprehensive re-investigation of solar abundances is highly desirable. This work is supported by a NASA Hinode grant.

  10. Neutrino induced light element synthesis

    SciTech Connect

    Hartmann, D.H.; Mathews, G.; Weaver, T.A. ); Haxton, W.C. . Dept. of Physics); Woosley, S.E. California Univ., Santa Cruz, CA . Board of Studies in Astronomy and Astrophysics)

    1990-01-01

    As the core of a massive star collapses to form a neutron star, the flux of neutrinos in the overlying shells of heavy elements becomes so great that, despite the small cross section, substantial nuclear transmutation is induced. Neutrinos, especially the higher energy {mu}- and {tau}-neutrinos, excite heavy elements and even helium to particle unbound levels. The evaporation of a single neutron or proton, and the back reaction of these nucleons on other species present, significantly alters the outcome of traditional nucleosynthesis calculations leading to a new process: {nu}-nucleosynthesis. The process was first studied by Domogatsky et al. and Woosley. Recent work by Epstein, Colgate, and Haxton and Woosley and Haxton suggested that a large number of elements could owe their existence in nature to {nu}-induced reactions in supernovae. A parametrized study of this process including shock wave propagation was carried out by Woosley et al. for selected zones of a 20 M{sub {circle dot}} star. Here we give preliminary results for a 25 M{sub {circle dot}} star, including all {nu}-reactions in all stellar zones.

  11. Peridynamic Multiscale Finite Element Methods

    SciTech Connect

    Costa, Timothy; Bond, Stephen D.; Littlewood, David John; Moore, Stan Gerald

    2015-12-01

    The problem of computing quantum-accurate design-scale solutions to mechanics problems is rich with applications and serves as the background to modern multiscale science research. The prob- lem can be broken into component problems comprised of communicating across adjacent scales, which when strung together create a pipeline for information to travel from quantum scales to design scales. Traditionally, this involves connections between a) quantum electronic structure calculations and molecular dynamics and between b) molecular dynamics and local partial differ- ential equation models at the design scale. The second step, b), is particularly challenging since the appropriate scales of molecular dynamic and local partial differential equation models do not overlap. The peridynamic model for continuum mechanics provides an advantage in this endeavor, as the basic equations of peridynamics are valid at a wide range of scales limiting from the classical partial differential equation models valid at the design scale to the scale of molecular dynamics. In this work we focus on the development of multiscale finite element methods for the peridynamic model, in an effort to create a mathematically consistent channel for microscale information to travel from the upper limits of the molecular dynamics scale to the design scale. In particular, we first develop a Nonlocal Multiscale Finite Element Method which solves the peridynamic model at multiple scales to include microscale information at the coarse-scale. We then consider a method that solves a fine-scale peridynamic model to build element-support basis functions for a coarse- scale local partial differential equation model, called the Mixed Locality Multiscale Finite Element Method. Given decades of research and development into finite element codes for the local partial differential equation models of continuum mechanics there is a strong desire to couple local and nonlocal models to leverage the speed and state of the

  12. Finite Element Analysis of Elasto-plastic Plate Bending Problems using Transition Rectangular Plate Elements

    NASA Astrophysics Data System (ADS)

    Kanber, Bahattin; Bozkurt, O. Yavuz

    2006-08-01

    In this work, the finite element analysis of the elasto-plastic plate bending problems is carried out using transition rectangular plate elements. The shape functions of the transition plate elements are derived based on a practical rule. The transition plate elements are all quadrilateral and can be used to obtain efficient finite element models using minimum number of elements. The mesh convergence rates of the models including the transition elements are compared with the regular element models. To verify the developed elements, simple tests are demonstrated and various elasto-plastic problems are solved. Their results are compared with ANSYS results.

  13. Method of monitoring stored nuclear fuel elements

    SciTech Connect

    Borloo, E.; Buergers, W.; Crutzen, S.; Vinche, C.

    1983-05-24

    To monitor a nuclear fuel element or fuel elements located in a store, e.g. a pond in a swimming pool reactor, the store is illuminated ultrasonically using one or more transducers transmitting ultrasonic signals in one or more predetermined directions to obtain an output which, because it depends on the number and relative location of the fuel elements in the store, and the structure of the store itself is distinctive to the fuel elements or elements stored therein. From this distinctive output is derived an identity unique to the stored fuel element or elements and a reference signal indicative of the whole structure when intact, the reference signal and identity being recorded. Subsequent ultrasonic testing of the store and its contents under identical operating conditions produces a signal which is compared to the recorded reference signal and if different therefrom reveals the occurrence of tampering with the store and/or the fuel element or elements.

  14. Calculation of binary phase diagrams between the actinide elements, rare earth elements, and transition metal elements

    SciTech Connect

    Selle, J E

    1992-06-26

    Attempts were made to apply the Kaufman method of calculating binary phase diagrams to the calculation of binary phase diagrams between the rare earths, actinides, and the refractory transition metals. Difficulties were encountered in applying the method to the rare earths and actinides, and modifications were necessary to provide accurate representation of known diagrams. To calculate the interaction parameters for rare earth-rare earth diagrams, it was necessary to use the atomic volumes for each of the phases: liquid, body-centered cubic, hexagonal close-packed, and face-centered cubic. Determination of the atomic volumes of each of these phases for each element is discussed in detail. In some cases, empirical means were necessary. Results are presented on the calculation of rare earth-rare earth, rare earth-actinide, and actinide-actinide diagrams. For rare earth-refractory transition metal diagrams and actinide-refractory transition metal diagrams, empirical means were required to develop values for the enthalpy of vaporization for rare earth elements and values for the constant (C) required when intermediate phases are present. Results of using the values determined for each element are presented.

  15. 7 CFR 29.6081 - Elements of quality and degrees of each element.

    Code of Federal Regulations, 2014 CFR

    2014-01-01

    ... 7 Agriculture 2 2014-01-01 2014-01-01 false Elements of quality and degrees of each element. 29... STANDARD CONTAINER REGULATIONS TOBACCO INSPECTION Standards Elements of Quality § 29.6081 Elements of quality and degrees of each element. These standardized words or terms are used to describe tobacco...

  16. 7 CFR 29.1101 - Elements of quality and degrees of each element.

    Code of Federal Regulations, 2012 CFR

    2012-01-01

    ... 7 Agriculture 2 2012-01-01 2012-01-01 false Elements of quality and degrees of each element. 29... STANDARD CONTAINER REGULATIONS TOBACCO INSPECTION Standards Elements of Quality § 29.1101 Elements of quality and degrees of each element. These standardized words or terms are used to describe tobacco...

  17. 7 CFR 29.3586 - Elements of quality and degrees of each element.

    Code of Federal Regulations, 2014 CFR

    2014-01-01

    ... 7 Agriculture 2 2014-01-01 2014-01-01 false Elements of quality and degrees of each element. 29... STANDARD CONTAINER REGULATIONS TOBACCO INSPECTION Standards Elements of Quality § 29.3586 Elements of quality and degrees of each element. These standardized words or terms are used to describe tobacco...

  18. 7 CFR 29.2351 - Elements of quality and degrees of each element.

    Code of Federal Regulations, 2014 CFR

    2014-01-01

    ... 7 Agriculture 2 2014-01-01 2014-01-01 false Elements of quality and degrees of each element. 29... STANDARD CONTAINER REGULATIONS TOBACCO INSPECTION Standards Elements of Quality § 29.2351 Elements of quality and degrees of each element. Tobacco attributes or characteristics which constitute quality are...

  19. 7 CFR 29.3101 - Elements of quality and degrees of each element.

    Code of Federal Regulations, 2011 CFR

    2011-01-01

    ... 7 Agriculture 2 2011-01-01 2011-01-01 false Elements of quality and degrees of each element. 29... STANDARD CONTAINER REGULATIONS TOBACCO INSPECTION Standards Elements of Quality § 29.3101 Elements of quality and degrees of each element. These standardized words or terms are used to describe tobacco...

  20. 7 CFR 29.3101 - Elements of quality and degrees of each element.

    Code of Federal Regulations, 2014 CFR

    2014-01-01

    ... 7 Agriculture 2 2014-01-01 2014-01-01 false Elements of quality and degrees of each element. 29... STANDARD CONTAINER REGULATIONS TOBACCO INSPECTION Standards Elements of Quality § 29.3101 Elements of quality and degrees of each element. These standardized words or terms are used to describe tobacco...

  1. 7 CFR 29.6081 - Elements of quality and degrees of each element.

    Code of Federal Regulations, 2013 CFR

    2013-01-01

    ... 7 Agriculture 2 2013-01-01 2013-01-01 false Elements of quality and degrees of each element. 29... STANDARD CONTAINER REGULATIONS TOBACCO INSPECTION Standards Elements of Quality § 29.6081 Elements of quality and degrees of each element. These standardized words or terms are used to describe tobacco...

  2. 7 CFR 29.1101 - Elements of quality and degrees of each element.

    Code of Federal Regulations, 2011 CFR

    2011-01-01

    ... 7 Agriculture 2 2011-01-01 2011-01-01 false Elements of quality and degrees of each element. 29... STANDARD CONTAINER REGULATIONS TOBACCO INSPECTION Standards Elements of Quality § 29.1101 Elements of quality and degrees of each element. These standardized words or terms are used to describe tobacco...

  3. 7 CFR 29.6081 - Elements of quality and degrees of each element.

    Code of Federal Regulations, 2012 CFR

    2012-01-01

    ... 7 Agriculture 2 2012-01-01 2012-01-01 false Elements of quality and degrees of each element. 29... STANDARD CONTAINER REGULATIONS TOBACCO INSPECTION Standards Elements of Quality § 29.6081 Elements of quality and degrees of each element. These standardized words or terms are used to describe tobacco...

  4. 7 CFR 29.2601 - Elements of quality and degrees of each element.

    Code of Federal Regulations, 2012 CFR

    2012-01-01

    ... 7 Agriculture 2 2012-01-01 2012-01-01 false Elements of quality and degrees of each element. 29... STANDARD CONTAINER REGULATIONS TOBACCO INSPECTION Standards Elements of Quality § 29.2601 Elements of quality and degrees of each element. Tobacco attributes or characteristics which constitute quality are...

  5. 7 CFR 29.2601 - Elements of quality and degrees of each element.

    Code of Federal Regulations, 2013 CFR

    2013-01-01

    ... 7 Agriculture 2 2013-01-01 2013-01-01 false Elements of quality and degrees of each element. 29... STANDARD CONTAINER REGULATIONS TOBACCO INSPECTION Standards Elements of Quality § 29.2601 Elements of quality and degrees of each element. Tobacco attributes or characteristics which constitute quality are...

  6. 7 CFR 29.1101 - Elements of quality and degrees of each element.

    Code of Federal Regulations, 2013 CFR

    2013-01-01

    ... 7 Agriculture 2 2013-01-01 2013-01-01 false Elements of quality and degrees of each element. 29... STANDARD CONTAINER REGULATIONS TOBACCO INSPECTION Standards Elements of Quality § 29.1101 Elements of quality and degrees of each element. These standardized words or terms are used to describe tobacco...

  7. 7 CFR 29.3101 - Elements of quality and degrees of each element.

    Code of Federal Regulations, 2012 CFR

    2012-01-01

    ... 7 Agriculture 2 2012-01-01 2012-01-01 false Elements of quality and degrees of each element. 29... STANDARD CONTAINER REGULATIONS TOBACCO INSPECTION Standards Elements of Quality § 29.3101 Elements of quality and degrees of each element. These standardized words or terms are used to describe tobacco...

  8. 7 CFR 29.3101 - Elements of quality and degrees of each element.

    Code of Federal Regulations, 2013 CFR

    2013-01-01

    ... 7 Agriculture 2 2013-01-01 2013-01-01 false Elements of quality and degrees of each element. 29... STANDARD CONTAINER REGULATIONS TOBACCO INSPECTION Standards Elements of Quality § 29.3101 Elements of quality and degrees of each element. These standardized words or terms are used to describe tobacco...

  9. 7 CFR 29.3586 - Elements of quality and degrees of each element.

    Code of Federal Regulations, 2013 CFR

    2013-01-01

    ... 7 Agriculture 2 2013-01-01 2013-01-01 false Elements of quality and degrees of each element. 29... STANDARD CONTAINER REGULATIONS TOBACCO INSPECTION Standards Elements of Quality § 29.3586 Elements of quality and degrees of each element. These standardized words or terms are used to describe tobacco...

  10. 7 CFR 29.2351 - Elements of quality and degrees of each element.

    Code of Federal Regulations, 2012 CFR

    2012-01-01

    ... 7 Agriculture 2 2012-01-01 2012-01-01 false Elements of quality and degrees of each element. 29... STANDARD CONTAINER REGULATIONS TOBACCO INSPECTION Standards Elements of Quality § 29.2351 Elements of quality and degrees of each element. Tobacco attributes or characteristics which constitute quality are...

  11. 7 CFR 29.6081 - Elements of quality and degrees of each element.

    Code of Federal Regulations, 2011 CFR

    2011-01-01

    ... 7 Agriculture 2 2011-01-01 2011-01-01 false Elements of quality and degrees of each element. 29... STANDARD CONTAINER REGULATIONS TOBACCO INSPECTION Standards Elements of Quality § 29.6081 Elements of quality and degrees of each element. These standardized words or terms are used to describe tobacco...

  12. 7 CFR 29.3586 - Elements of quality and degrees of each element.

    Code of Federal Regulations, 2012 CFR

    2012-01-01

    ... 7 Agriculture 2 2012-01-01 2012-01-01 false Elements of quality and degrees of each element. 29... STANDARD CONTAINER REGULATIONS TOBACCO INSPECTION Standards Elements of Quality § 29.3586 Elements of quality and degrees of each element. These standardized words or terms are used to describe tobacco...

  13. 7 CFR 29.1101 - Elements of quality and degrees of each element.

    Code of Federal Regulations, 2014 CFR

    2014-01-01

    ... 7 Agriculture 2 2014-01-01 2014-01-01 false Elements of quality and degrees of each element. 29... STANDARD CONTAINER REGULATIONS TOBACCO INSPECTION Standards Elements of Quality § 29.1101 Elements of quality and degrees of each element. These standardized words or terms are used to describe tobacco...

  14. 7 CFR 29.2601 - Elements of quality and degrees of each element.

    Code of Federal Regulations, 2014 CFR

    2014-01-01

    ... 7 Agriculture 2 2014-01-01 2014-01-01 false Elements of quality and degrees of each element. 29... STANDARD CONTAINER REGULATIONS TOBACCO INSPECTION Standards Elements of Quality § 29.2601 Elements of quality and degrees of each element. Tobacco attributes or characteristics which constitute quality are...

  15. 7 CFR 29.2351 - Elements of quality and degrees of each element.

    Code of Federal Regulations, 2013 CFR

    2013-01-01

    ... 7 Agriculture 2 2013-01-01 2013-01-01 false Elements of quality and degrees of each element. 29... STANDARD CONTAINER REGULATIONS TOBACCO INSPECTION Standards Elements of Quality § 29.2351 Elements of quality and degrees of each element. Tobacco attributes or characteristics which constitute quality are...

  16. 7 CFR 29.2601 - Elements of quality and degrees of each element.

    Code of Federal Regulations, 2010 CFR

    2010-01-01

    ... 7 Agriculture 2 2010-01-01 2010-01-01 false Elements of quality and degrees of each element. 29... STANDARD CONTAINER REGULATIONS TOBACCO INSPECTION Standards Elements of Quality § 29.2601 Elements of quality and degrees of each element. Tobacco attributes or characteristics which constitute quality...

  17. 7 CFR 29.3586 - Elements of quality and degrees of each element.

    Code of Federal Regulations, 2011 CFR

    2011-01-01

    ... 7 Agriculture 2 2011-01-01 2011-01-01 false Elements of quality and degrees of each element. 29... STANDARD CONTAINER REGULATIONS TOBACCO INSPECTION Standards Elements of Quality § 29.3586 Elements of quality and degrees of each element. These standardized words or terms are used to describe...

  18. 7 CFR 29.2351 - Elements of quality and degrees of each element.

    Code of Federal Regulations, 2010 CFR

    2010-01-01

    ... 7 Agriculture 2 2010-01-01 2010-01-01 false Elements of quality and degrees of each element. 29... STANDARD CONTAINER REGULATIONS TOBACCO INSPECTION Standards Elements of Quality § 29.2351 Elements of quality and degrees of each element. Tobacco attributes or characteristics which constitute quality...

  19. 7 CFR 29.2351 - Elements of quality and degrees of each element.

    Code of Federal Regulations, 2011 CFR

    2011-01-01

    ... 7 Agriculture 2 2011-01-01 2011-01-01 false Elements of quality and degrees of each element. 29... STANDARD CONTAINER REGULATIONS TOBACCO INSPECTION Standards Elements of Quality § 29.2351 Elements of quality and degrees of each element. Tobacco attributes or characteristics which constitute quality...

  20. 7 CFR 29.2601 - Elements of quality and degrees of each element.

    Code of Federal Regulations, 2011 CFR

    2011-01-01

    ... 7 Agriculture 2 2011-01-01 2011-01-01 false Elements of quality and degrees of each element. 29... STANDARD CONTAINER REGULATIONS TOBACCO INSPECTION Standards Elements of Quality § 29.2601 Elements of quality and degrees of each element. Tobacco attributes or characteristics which constitute quality...

  1. Implicit Space-Time Conservation Element and Solution Element Schemes

    NASA Technical Reports Server (NTRS)

    Chang, Sin-Chung; Himansu, Ananda; Wang, Xiao-Yen

    1999-01-01

    Artificial numerical dissipation is in important issue in large Reynolds number computations. In such computations, the artificial dissipation inherent in traditional numerical schemes can overwhelm the physical dissipation and yield inaccurate results on meshes of practical size. In the present work, the space-time conservation element and solution element method is used to construct new and accurate implicit numerical schemes such that artificial numerical dissipation will not overwhelm physical dissipation. Specifically, these schemes have the property that numerical dissipation vanishes when the physical viscosity goes to zero. These new schemes therefore accurately model the physical dissipation even when it is extremely small. The new schemes presented are two highly accurate implicit solvers for a convection-diffusion equation. The two schemes become identical in the pure convection case, and in the pure diffusion case. The implicit schemes are applicable over the whole Reynolds number range, from purely diffusive equations to convection-dominated equations with very small viscosity. The stability and consistency of the schemes are analysed, and some numerical results are presented. It is shown that, in the inviscid case, the new schemes become explicit and their amplification factors are identical to those of the Leapfrog scheme. On the other hand, in the pure diffusion case, their principal amplification factor becomes the amplification factor of the Crank-Nicolson scheme.

  2. Monitoring arrangement for vented nuclear fuel elements

    DOEpatents

    Campana, Robert J.

    1981-01-01

    In a nuclear fuel reactor core, fuel elements are arranged in a closely packed hexagonal configuration, each fuel element having diametrically opposed vents permitting 180.degree. rotation of the fuel elements to counteract bowing. A grid plate engages the fuel elements and forms passages for communicating sets of three, four or six individual vents with respective monitor lines in order to communicate vented radioactive gases from the fuel elements to suitable monitor means in a manner readily permitting detection of leakage in individual fuel elements.

  3. Trace Elements and Chemotherapy Sensitivity.

    PubMed

    Liu, Zhihui; Yang, Weiping; Long, Gang; Wei, Changyuan

    2016-10-01

    Trace elements might be associated with the development of hepatocellular carcinoma (HCC) and the efficacy of chemotherapy against HCC. Therefore, this study aimed to explore the association between trace elements and efficacy of chemotherapy in patients with HCC. Cancer, cancer-adjacent, and cancer-free tissues were collected intraoperatively from 55 patients with HCC between January 2001 and April 2004 at the Affiliated Tumor Hospital of Guangxi Medical University in Guangxi (China), a high HCC incidence area in the world. Trace element levels were analyzed by atomic absorption spectrophotometry. In vitro sensitivity of cancer cells to five chemotherapeutic drugs (5-fluorouracil, doxorubicin, cisplatin, carboplatin, and mitomycin) was tested using the 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide (MTT) assay in cancer cells from 32 patients. Zinc, copper, manganese, and selenium levels had the same gradient distribution in different liver tissues: cancer < cancer-adjacent < cancer-free tissues. Copper levels of cancer tissues were negatively correlated with body weight (r = -0.278, P = 0.027), while manganese and selenium levels were negatively correlated with age (r = -0.297, P = 0.015; r = -0.285, P = 0.018, respectively). Simple correlation analyses revealed that the carboplatin sensitivity was negatively correlated with selenium levels of cancer tissues, while doxorubicin sensitivity was negatively correlated with manganese levels (r = -0.497, P = 0.004). Partial correlation analyses showed that doxorubicin sensitivity only was negatively correlated with manganese levels (r = -0.450, P = 0.014). These results suggest that the selenium and manganese content in primary HCC tissues could influence the response of the HCC cells to carboplatin and doxorubicin. These preliminary results provide a basis for future studies.

  4. Stratified volume diffractive optical elements

    NASA Astrophysics Data System (ADS)

    Chambers, Diana Marie

    2000-11-01

    Gratings with high diffraction efficiency into a single order find use in applications ranging from optical interconnects to beam steering. Such gratings have been realized with volume holographic, blazed, and diffractive optical techniques. However, each of these methods has limitations that restrict the range of applications in which they can be used. In this work an alternate, novel approach and method for creating high efficiency gratings has been developed. These new gratings are named stratified volume diffractive optical elements (SVDOE's). In this approach diffractive optic techniques are used to create an optical structure that emulates volume grating behavior. An SVDOE consists of binary gratings interleaved with homogeneous layers in a multi-layer, stratified grating structure. The ridges of the binary gratings form fringe planes analogous to those of a volume hologram. The modulation and diffraction of an incident beam, which occur concurrently in a volume grating, are achieved sequentially by the grating layers and the homogeneous layers, respectively. The layers in this type of structure must be fabricated individually, which introduces the capability to laterally shift the binary grating layers relative to one another to create a grating with slanted fringe planes. This allows an element to be designed with high diffraction efficiency into the first order for any arbitrary angle of incidence. A systematic design process has been developed for SVDOE's. Optimum modulation depth of the SVDOE is determined analytically and the number of grating layers along with the thickness of homogeneous layers is determined by numerical simulation. A rigorous electromagnetic simulation of the diffraction properties of multi-layer grating structures, based on the Rigorous Coupled-Wave Analysis (RCWA) algorithm, was developed and applied to SVDOE performance prediction. Fabrication of an SVDOE structure presents unique challenges. Microfabrication combined with

  5. Elements of critical incident debriefing.

    PubMed

    Curtis, J M

    1995-08-01

    The present paper lists a number of specific therapeutic steps involved in critical incident debriefing. These therapeutic suggestions, while by no means exhaustive, include (a) identification, (b) labeling, (c) articulation, (d) expression, (e) externalization, (f) ventilation, (g) validation, and (h) acceptance. More careful attention to these specific elements--regardless of debriefers' training and backgrounds--might improve therapeutic consistency for trauma victims afflicted with stress-related symptoms. Further applications of these therapeutic steps were also suggested for other types of behavioral problems.

  6. Microgyroscope with integrated vibratory element

    NASA Technical Reports Server (NTRS)

    Tang, Tony K. (Inventor); Rodger, Damien C. (Inventor); Gutierrez, Roman C. (Inventor)

    2002-01-01

    A microgyroscope having a suspended vertical post uses the Coriolis force to detect the rotation rate. The microgyroscope consists of a single vertical post which is the rotation rate sensing element. The vertical post is formed from the same silicon wafers as the rest of the microgyroscope. A first portion of the vertical post and the clover-leaf structure are made from a first silicon wafer. A second portion of the vertical post and the baseplate are made from a second silicon wafer. The two portions are then bonded together to from the clover-leaf gyroscope with an integrated post structure.

  7. METHOD OF MAKING FUEL ELEMENTS

    DOEpatents

    Bean, C.H.; Macherey, R.E.

    1959-12-01

    A method is described for fabricating fuel elements, particularly for enclosing a plate of metal with a second metal by inserting the plate into an aperture of a frame of a second plate, placing a sheet of the second metal on each of opposite faces of the assembled plate and frame, purging with an inert gas the air from the space within the frame and the sheets while sealing the seams between the frame and the sheets, exhausting the space, purging the space with air, re-exhausting the spaces, sealing the second aperture, and applying heat and pressure to bond the sheets, the plate, and the frame to one another.

  8. Elemental composition of Malawian rice.

    PubMed

    Joy, Edward J M; Louise Ander, E; Broadley, Martin R; Young, Scott D; Chilimba, Allan D C; Hamilton, Elliott M; Watts, Michael J

    2017-08-01

    Widespread potential dietary deficiencies of calcium (Ca), iron (Fe), iodine (I), selenium (Se) and zinc (Zn) have been identified in Malawi. Several deficiencies are likely to be compounded by high phytic acid (PA) consumption. Rice (Oryza sativa) is commonly consumed in some Malawian populations, and its mineral micronutrient content is important for food security. The considerable irrigation requirements and flooded conditions of paddy soils can also introduce or mobilise potentially toxic elements including arsenic (As), cadmium (Cd) and lead (Pb). The aim of this study was to determine the mineral composition of rice sampled from farmers' fields and markets in Malawi. Rice was sampled from 18 extension planning areas across Malawi with 21 white (i.e. polished) and 33 brown samples collected. Elemental composition was determined by inductively coupled plasma-mass spectrometry (ICP-MS). Arsenic speciation was performed using high-performance liquid chromatography (HPLC)-ICP-MS. Concentration of PA was determined using a PA-total phosphorus assay. Median total concentrations (mg kg(-1), dry weight) of elements important for human nutrition in brown and white rice, respectively, were: Ca = 66.5 and 37.8; Cu = 3.65 and 2.49; Fe = 22.1 and 7.2; I = 0.006 and <0.005; Mg = 1130 and 265; Mn = 18.2 and 9.6; Se = 0.025 and 0.028; and Zn = 17.0 and 14.4. In brown and white rice samples, respectively, median PA concentrations were 5438 and 1906 mg kg(-1), and median PA:Zn molar ratios were 29 and 13. Concentrations of potentially toxic elements (mg kg(-1), dry weight) in brown and white rice samples, respectively, were: As = 0.030 and 0.006; Cd  ≤ 0.002 and 0.006; Pb = 0.008 and 0.008. Approximately 95 % of As was found to be inorganic As, where this could be quantified. Malawian rice, like the more widely consumed staple grain maize, contains inadequate Ca, I, Se or Zn to meet dietary requirements. Biofortification strategies could

  9. Highly siderophile elements in chondrites

    USGS Publications Warehouse

    Horan, M.F.; Walker, R.J.; Morgan, J.W.; Grossman, J.N.; Rubin, A.E.

    2003-01-01

    The abundances of the highly siderophile elements (HSE), Re, Os, Ir, Ru, Pt and Pd, were determined by isotope dilution mass spectrometry for bulk samples of 13 carbonaceous chondrites, 13 ordinary chondrites and 9 enstatite chondrites. These data are coupled with corresponding 187Re-187Os isotopic data reported by Walker et al. [Geochim. Cosmochim. Acta, 2002] in order to constrain the nature and timing of chemical fractionation relating to these elements in the early solar system. The suite of chondrites examined displays considerable variations in absolute abundances of the HSE, and in the ratios of certain HSE. Absolute abundances of the HSE vary by nearly a factor of 80 among the chondrite groups, although most vary within a factor of only 2. Variations in concentration largely reflect heterogeneities in the sample aliquants. Different aliquants of the same chondrite may contain variable proportions of metal and/or refractory inclusions that are HSE-rich, and sulfides that are HSE-poor. The relatively low concentrations of the HSE in CI1 chondrites likely reflect dilution by the presence of volatile components. Carbonaceous chondrites have Re/Os ratios that are, on average, approximately 8% lower than ratios for ordinary and enstatite chondrites. This is also reflected in 187Os/188Os ratios that are approximately 3% lower for carbonaceous chondrites than for ordinary and enstatite chondrites. Given the similarly refractory natures of Re and Os, this fractionation may have occurred within a narrow range of high temperatures, during condensation of these elements from the solar nebula. Superimposed on this major fractionation are more modest movements of Re or Os that occurred within the last 0-2 Ga, as indicated by minor open-system behavior of the Re-Os isotope systematics of some chondrites. The relative abundances of other HSE can also be used to discriminate among the major classes of chondrites. For example, in comparison to the enstatite chondrites

  10. Essential Grid Workflow Monitoring Elements

    SciTech Connect

    Gunter, Daniel K.; Jackson, Keith R.; Konerding, David E.; Lee,Jason R.; Tierney, Brian L.

    2005-07-01

    Troubleshooting Grid workflows is difficult. A typicalworkflow involves a large number of components networks, middleware,hosts, etc. that can fail. Even when monitoring data from all thesecomponents is accessible, it is hard to tell whether failures andanomalies in these components are related toa given workflow. For theGrid to be truly usable, much of this uncertainty must be elim- inated.We propose two new Grid monitoring elements, Grid workflow identifiersand consistent component lifecycle events, that will make Gridtroubleshooting easier, and thus make Grids more usable, by simplifyingthe correlation of Grid monitoring data with a particular Gridworkflow.

  11. Finite element simulation of microindentation

    NASA Astrophysics Data System (ADS)

    Zhuk, D. I.; Isaenkova, M. G.; Perlovich, Yu. A.; Krymskaya, O. A.

    2017-05-01

    Finite element models are created to describe the testing of a material by a Berkovich indenter. The results of calculations by these models are compared to experimental data on indentation of the same material (grade 10 steel). The experimental and calculated data agree well with each other. The developed models for an indenter and the material to be tested are used to find the laws of behavior of a material during indentation. The state of stress in the material under an indenter is studied by various methods. The indentation results are plotted versus the mechanical properties of a material.

  12. FUEL ELEMENT FOR NUCLEAR REACTORS

    DOEpatents

    Bassett, C.H.

    1961-05-01

    A nuclear reactor fuel element comprising high density ceramic fissionable material enclosed in a tubular cladding of corrosion-resistant material is described. The fissionable material is in the form of segments of a tube which have cooperating tapered interfaces which produce outward radial displacement when the segments are urged axially together. A resilient means is provided within the tubular housing to constantly urge the fuel segments axially. This design maintains the fuel material in tight contacting engagement against the inner surface of the outer cladding tube to eliminate any gap therebetween which may be caused by differential thermal expansion between the fuel material and the material of the tube.

  13. Generic element processor (application to nonlinear analysis)

    NASA Technical Reports Server (NTRS)

    Stanley, Gary

    1989-01-01

    The focus here is on one aspect of the Computational Structural Mechanics (CSM) Testbed: finite element technology. The approach involves a Generic Element Processor: a command-driven, database-oriented software shell that facilitates introduction of new elements into the testbed. This shell features an element-independent corotational capability that upgrades linear elements to geometrically nonlinear analysis, and corrects the rigid-body errors that plague many contemporary plate and shell elements. Specific elements that have been implemented in the Testbed via this mechanism include the Assumed Natural-Coordinate Strain (ANS) shell elements, developed with Professor K. C. Park (University of Colorado, Boulder), a new class of curved hybrid shell elements, developed by Dr. David Kang of LPARL (formerly a student of Professor T. Pian), other shell and solid hybrid elements developed by NASA personnel, and recently a repackaged version of the workhorse shell element used in the traditional STAGS nonlinear shell analysis code. The presentation covers: (1) user and developer interfaces to the generic element processor, (2) an explanation of the built-in corotational option, (3) a description of some of the shell-elements currently implemented, and (4) application to sample nonlinear shell postbuckling problems.

  14. Type I Repressors of P Element Mobility

    PubMed Central

    Gloor, G. B.; Preston, C. R.; Johnson-Schlitz, D. M.; Nassif, N. A.; Phillis, R. W.; Benz, W. K.; Robertson, H. M.; Engels, W. R.

    1993-01-01

    We describe here a family of P elements that we refer to as type I repressors. These elements are identified by their repressor functions and their lack of any deletion within the first two-thirds of the canonical P sequence. Elements belonging to this repressor class were isolated from P strains and were made in vitro. We found that type I repressor elements could strongly repress both a cytotype-dependent allele and P element mobility in somatic and germline tissues. These effects wer very dependent on genomic position. Moreover, we observed that an element's ability to repress in one assay positively correlated with its ability to repress in either of the other two assays. The type I family of repressor elements includes both autonomous P elements and those lacking exon 3 of the P element. Fine structure deletion mapping showed that the minimal 3' boundary of a functional type I element lies between nucleotide position 1950 and 1956. None of 12 elements examined with more extreme deletions extending into exon 2 made repressor. We conclude that the type I repressors form a structurally distinct group that does not include more extensively deleted repressor elements such as the KP element described previously. PMID:8224830

  15. New alternating direction procedures in finite element analysis based upon EBE approximate factorizations. [element-by-element

    NASA Technical Reports Server (NTRS)

    Hughes, T. J. R.; Winget, J.; Levit, I.; Tezduyar, T. E.

    1983-01-01

    Element-by-element approximate factorization procedures are proposed for solving the large finite element equation systems which arise in computational mechanics. A variety of techniques are compared on problems of structural mechanics, heat conduction and fluid mechanics. The results obtained suggest considerable potential for the methods described.

  16. Characterization of electrodeposited elemental boron

    SciTech Connect

    Jain, Ashish; Anthonysamy, S. Ananthasivan, K.; Ranganathan, R.; Mittal, Vinit; Narasimhan, S.V.; Vasudeva Rao, P.R.

    2008-07-15

    Elemental boron was produced through electrowinning from potassium fluoroborate dissolved in a mixture of molten potassium fluoride and potassium chloride. The characteristics of the electrodeposited boron (raw boron) as well as the water and acid-leached product (processed boron) were studied. The chemical purity, specific surface area, size distribution of particles and X-ray crystallite size of the boron powders were investigated. The morphology of the deposits was examined using scanning electron microscopy (SEM). The chemical state of the matrix, as well as the impurity phases present in them, was established using X-ray photoelectron spectroscopy (XPS). In order to interpret and understand the results obtained, a thermodynamic analysis was carried out. The gas-phase corrosion in the head space as well as the chemistry behind the leaching process were interpreted using this analysis. The ease of oxidation of these powders in air was investigated using differential thermal analysis (DTA) coupled with thermogravimetry (TG). From the results obtained in this study it was established that elemental boron powder with a purity of 95-99% could be produced using a high temperature molten salt electrowinning process. The major impurities were found to be oxygen, carbon, iron and nickel.

  17. Elemental Abundances in NGC 3516

    NASA Technical Reports Server (NTRS)

    Turner, T. J.; Kraemer, S. B.; Mushotzky, R. F.; George, I. M.; Gabel, J. R.

    2003-01-01

    We present Reflection Grating Spectrometer data from an XMM-Newton observation of the Seyfert 1 galaxy NGC 3516, taken while the continuum source was in an extremely low flux state. This observation offers a rare opportunity for a detailed study of emission from a Seyfert 1 galaxy as these are usually dominated by high nuclear continuum levels and heavy absorption. The spectrum shows numerous narrow emission lines (FWHM approximately less than 1300 kilometers per second) in the 0.3 - 2 keV range, including the H-like lines of C, N, and O and the He-like lines of N, O and Ne. The emission-line ratios and the narrow width of the radiative recombination continuum of CVI indicate that the gas is photoionized and of fairly low temperature (kT approximately less than 0.01 keV). The availability of emission lines from different elements for two iso-electronic sequences allows us to constrain the element abundances. These data show that the N lines are far stronger than would be expected from gas of solar abundances. Based on our photoionization models we find that nitrogen is overabundant in the central regions of the galaxy, compared to carbon, oxygen and neon by at least a factor of 2.5. We suggest that this is the result of secondary production of nitrogen in intermediate mass stars, and indicative of the history of star formation in NGC 3516.

  18. Mars Surface Tunnel Element Concept

    NASA Technical Reports Server (NTRS)

    Rucker, Michelle A.; Mary, Natalie; Howe, A. Scott; Jeffries, Sharon

    2016-01-01

    How Mars surface crews get into their ascent vehicle has profound implications for Mars surface architecture. To meet planetary protection protocols, the architecture has get Intravehicular Activity (IVA)-suited crew into a Mars Ascent Vehicle (MAV) without having to step outside into the Mars environment. Pushing EVA suit don/doff and EVA operations to an element that remains on the surface also helps to minimize MAV cabin volume, which in turn can reduce MAV cabin mass. Because the MAV will require at least seven kilograms of propellant to ascend each kilogram of cabin mass, minimal MAV mass is desired. For architectures involving more than one surface element-such as an ascent vehicle and a pressurized rover or surface habitat-a retractable tunnel is an attractive solution. Beyond addressing the immediate MAV access issue, a reusable tunnel may be useful for other surface applications once its primary mission is complete. A National Aeronautics and Space Administration (NASA) team is studying the optimal balance between surface tunnel functionality, mass, and stowed volume as part of the Evolvable Mars Campaign (EMC). The "Minimum Functional Tunnel" is a conceptual design that performs a single function. Having established this baseline configuration, the next step is to trade design options, evaluate other applications, and explore alternative solutions.

  19. Disease management contracting: key elements.

    PubMed

    Knutson, D J

    1996-01-01

    Although the data at the outset of a contractual agreement can often be incomplete or inaccurate, and the analytical tools necessary to interpret these data are still being developed, partners about to enter a disease management (DM) arrangement can nonetheless take steps to ensure that the relationship will be sound and successful. Pharmaceutical firms (and other service providers) wishing to enter into DM relationships with managed-care organizations must consider several important factors of the contracting process to protect their financial interests and benefit from the partnership, particularly in the first 1 to 2 years of the arrangement. This paper provides recommendations for both general strategies and financial elements of DM contracting, and defines several contractual elements that can help to secure a harmonious and profitable partnership. These suggestions address concerns for various types of partnerships, including risk-sharing and fee-for-service plans. Early and careful consideration of the legal aspects of the DM business can protect companies from incurring significant, unanticipated losses.

  20. Surface energies of elemental crystals

    PubMed Central

    Tran, Richard; Xu, Zihan; Radhakrishnan, Balachandran; Winston, Donald; Sun, Wenhao; Persson, Kristin A.; Ong, Shyue Ping

    2016-01-01

    The surface energy is a fundamental property of the different facets of a crystal that is crucial to the understanding of various phenomena like surface segregation, roughening, catalytic activity, and the crystal’s equilibrium shape. Such surface phenomena are especially important at the nanoscale, where the large surface area to volume ratios lead to properties that are significantly different from the bulk. In this work, we present the largest database of calculated surface energies for elemental crystals to date. This database contains the surface energies of more than 100 polymorphs of about 70 elements, up to a maximum Miller index of two and three for non-cubic and cubic crystals, respectively. Well-known reconstruction schemes are also accounted for. The database is systematically improvable and has been rigorously validated against previous experimental and computational data where available. We will describe the methodology used in constructing the database, and how it can be accessed for further studies and design of materials. PMID:27622853

  1. Scarcity of rare earth elements.

    PubMed

    de Boer, M A; Lammertsma, K

    2013-11-01

    Rare earth elements (REEs) are important for green and a large variety of high-tech technologies and are, therefore, in high demand. As a result, supply with REEs is likely to be disrupted (the degree of depends on the REE) in the near future. The 17 REEs are divided into heavy and light REEs. Other critical elements besides REEs, identified by the European Commission, are also becoming less easily available. Although there is no deficiency in the earth's crust of rare earth oxides, the economic accessibility is limited. The increased demand for REEs, the decreasing export from China, and geopolitical concerns on availability contributed to the (re)opening of mines in Australia and the USA and other mines are slow to follow. As a result, short supply of particularly terbium, dysprosium, praseodymium, and neodymium is expected to be problematic for at least the short term, also because they cannot be substituted. Recycling REEs from electronic waste would be a solution, but so far there are hardly any established REE recycling methods. Decreasing the dependency on REEs, for example, by identifying possible replacements or increasing their efficient use, represents another possibility.

  2. Fuel elements of thermionic converters

    SciTech Connect

    Hunter, R.L.; Gontar, A.S.; Nelidov, M.V.; Nikolaev, Yu.V.; Schulepov, L.N.

    1997-01-01

    Work on thermionic nuclear power systems has been performed in Russia within the framework of the TOPAZ reactor program since the early 1960s. In the TOPAZ in-core thermionic convertor reactor design, the fuel element`s cladding is also the thermionic convertor`s emitter. Deformation of the emitter can lead to short-circuiting and is the primary cause of premature TRC failure. Such deformation can be the result of fuel swelling, thermocycling, or increased unilateral pressure on the emitter due to the release of gaseous fission products. Much of the work on TRCs has concentrated on preventing or mitigating emitter deformation by improving the following materials and structures: nuclear fuel; emitter materials; electrical insulators; moderator and reflector materials; and gas-exhaust device. In addition, considerable effort has been directed toward the development of experimental techniques that accurately mimic operational conditions and toward the creation of analytical and numerical models that allow operational conditions and behavior to be predicted without the expense and time demands of in-pile tests. New and modified materials and structures for the cores of thermionic NPSs and new fabrication processes for the materials have ensured the possibility of creating thermionic NPSs for a wide range of powers, from tens to several hundreds of kilowatts, with life spans of 5 to 10 years.

  3. Minor elements in Keweenawan lavas, Michigan

    USGS Publications Warehouse

    Cornwall, H.R.; Rose, H.J.

    1957-01-01

    The distribution of minor elements in three basaltic flows of the Keweenawan series, of Michigan, is related to differentiation in the flows. Thus, nickel is most abundant in the early differentiates; nickel, chromium, and barium are generally deficient in the pegmatites, which formed late; whereas copper, vanadium, yttrium, and other minor elements are concentrated in the pegmatites. The minor-element content of individual minerals in the Greenstone flow varies markedly from one mineral to another and seems to depend primarily on the presence or absence in the minerals of major elements for which the minor elements can substitute. Minor elements have substituted most readily for those major elements with similar ionic radii. Valence and electronegativity also seem to influence the ease of substitution. The distribution of other minor elements in copper-bearing lodes of the Michigan copper district shows no apparent relation to copper mineralization. ?? 1957.

  4. Removable preheater elements improve oxide induction furnace

    NASA Technical Reports Server (NTRS)

    Leipold, M. H.

    1964-01-01

    Heat and corrosion resistant preheater elements are used in oxide induction furnaces to raise the temperature to the level for conducting electricity. These preheater elements are then removed and the induction coil energized.

  5. Queuing register uses fluid logic elements

    NASA Technical Reports Server (NTRS)

    1966-01-01

    Queuing register /a multistage bit-shifting device/ uses a series of pure fluid elements to perform the required logic operations. The register has several stages of three-state pure fluid elements combined with two-input NOR gates.

  6. Infinite Possibilities for the Finite Element.

    ERIC Educational Resources Information Center

    Finlayson, Bruce A.

    1981-01-01

    Describes the uses of finite element methods in solving problems of heat transfer, fluid flow, etc. Suggests that engineers should know the general concepts and be able to apply the principles of finite element methods. (Author/WB)

  7. Measuring Venus' Bulk Elemental Composition with BECA

    NASA Astrophysics Data System (ADS)

    Parsons, A. M.; Grau, J.; Lawrence, D. J.; Miles, J.; Peplowski, P. N.; Perkins, L.; Schweitzer, J. S.; Starr, R. D.

    2016-10-01

    The Bulk Elemental Composition Analyzer (BECA) instrument uses high energy neutrons and gamma rays to measure the bulk elemental composition of Venus beneath a landed probe. We will present the results of a BECA prototype tested at NASA/GSFC.

  8. Trace elements in ocean ridge basalts

    NASA Technical Reports Server (NTRS)

    Kay, R. W.; Hubbard, N. J.

    1978-01-01

    A study is made of the trace elements found in ocean ridge basalts. General assumptions regarding melting behavior, trace element fractionation, and alteration effects are presented. Data on the trace elements are grouped according to refractory lithophile elements, refractory siderophile elements, and volatile metals. Variations in ocean ridge basalt chemistry are noted both for regional and temporal characteristics. Ocean ridge basalts are compared to other terrestrial basalts, such as those having La/Yb ratios greater than those of chondrites, and those having La/Yb ratios less than those of chondrites. It is found that (1) as compared to solar or chondrite ratios, ocean ridge basalts have low ratios of large, highly-charged elements to smaller less highly-charged elements, (2) ocean ridge basalts exhibit low ratios of volatile to nonvolatile elements, and (3) the transition metals Cr through Zn in ocean ridge basalts are not fractionated more than a factor of 2 or 3 from the chondritic abundance ratios.

  9. Fuel elements of research reactors in China

    SciTech Connect

    Yongmao, Z.; Dianshan, C.; Guofang, Q.

    1988-01-01

    This paper describes the current status of design, fabrication of fuel elements for research reactors in China, emphasis is placed on the technology of fuel elements for the High Flux Engineering Test Reactor (HFETR).

  10. SUPG Finite Element Simulations of Compressible Flows

    NASA Technical Reports Server (NTRS)

    Kirk, Brnjamin, S.

    2006-01-01

    The Streamline-Upwind Petrov-Galerkin (SUPG) finite element simulations of compressible flows is presented. The topics include: 1) Introduction; 2) SUPG Galerkin Finite Element Methods; 3) Applications; and 4) Bibliography.

  11. Wave dispersion properties of compound finite elements

    NASA Astrophysics Data System (ADS)

    Melvin, Thomas; Thuburn, John

    2017-06-01

    Mixed finite elements use different approximation spaces for different dependent variables. Certain classes of mixed finite elements, called compatible finite elements, have been shown to exhibit a number of desirable properties for a numerical weather prediction model. In two-dimensions the lowest order element of the Raviart-Thomas based mixed element is the finite element equivalent of the widely used C-grid staggering, which is known to possess good wave dispersion properties, at least for quadrilateral grids. It has recently been proposed that building compound elements from a number of triangular Raviart-Thomas sub-elements, such that both the primal and (implied) dual grid are constructed from the same sub-elements, would allow greater flexibility in the use of different advection schemes along with the ability to build arbitrary polygonal elements. Although the wave dispersion properties of the triangular sub-elements are well understood, those of the compound elements are unknown. It would be useful to know how they compare with the non-compound elements and what properties of the triangular sub-grid elements are inherited? Here a numerical dispersion analysis is presented for the linear shallow water equations in two dimensions discretised using the lowest order compound Raviart-Thomas finite elements on regular quadrilateral and hexagonal grids. It is found that, in comparison with the well known C-grid scheme, the compound elements exhibit a more isotropic dispersion relation, with a small over estimation of the frequency for short waves compared with the relatively large underestimation for the C-grid. On a quadrilateral grid the compound elements are found to differ from the non-compound Raviart-Thomas quadrilateral elements even for uniform elements, exhibiting the influence of the underlying sub-elements. This is shown to lead to small improvements in the accuracy of the dispersion relation: the compound quadrilateral element is slightly better for

  12. Finite element analysis of flexible, rotating blades

    NASA Technical Reports Server (NTRS)

    Mcgee, Oliver G.

    1987-01-01

    A reference guide that can be used when using the finite element method to approximate the static and dynamic behavior of flexible, rotating blades is given. Important parameters such as twist, sweep, camber, co-planar shell elements, centrifugal loads, and inertia properties are studied. Comparisons are made between NASTRAN elements through published benchmark tests. The main purpose is to summarize blade modeling strategies and to document capabilities and limitations (for flexible, rotating blades) of various NASTRAN elements.

  13. Finite Element Anlaysis of Laminated Composite Plates

    DTIC Science & Technology

    1988-09-01

    4.2, results depicting maximum displacement obtained using 2 x 2 integration points, 3 x 3 integration points and ’ heterosis ’ [Ref. 4] elements are...thick and thin plates. This element gives better predictions for thick plates than heterosis ele- ment, however, for thin plates, heterosis element...results showing the normalized maximum displacements are shown in Figure 4.8. The heterosis element results in about ten percent error while the

  14. Superheavy Element Research at Tasca at GSI

    NASA Astrophysics Data System (ADS)

    Düllmann, Christoph E.

    2014-09-01

    Experiments on the synthesis of the heaviest elements are in the center of the current research program on superheavy elements at GSI Darmstadt. At the gas-filled recoil separator TASCA, search experiments for the new elements 119 and 120 have been performed in the reactions 50Ti + 249Bk and 50Ti + 249Cf, respectively, and the production of element 117 in the reaction 48Ca + 249Bk was studied. The experiments were performed successfully and the data are currently under analysis.

  15. Stacked switchable element and diode combination

    DOEpatents

    Branz, Howard M.; Wang, Qi

    2006-06-27

    A device (10) comprises a semiconductor diode (12) and a switchable element (14) positioned in stacked adjacent relationship so that the semiconductor diode (12) and the switchable element (14) are electrically connected in series with one another. The switchable element (14) is switchable from a low-conductance state to a high-conductance state in response to the application of a forming voltage to the switchable element (14).

  16. Stacked Switchable Element and Diode Combination

    DOEpatents

    Branz, H. M.; Wang, Q.

    2006-06-27

    A device (10) comprises a semiconductor diode (12) and a switchable element (14) positioned in stacked adjacent relationship so that the semiconductor diode (12) and the switchable element (14) are electrically connected in series with one another. The switchable element (14) is switchable from a low-conductance state to a high-conductance state in response to the application of a forming voltage to the switchable element (14).

  17. Elements of Regolith Simulant's Cost Structure

    NASA Technical Reports Server (NTRS)

    Rickman, Douglas L.

    2009-01-01

    The cost of lunar regolith simulants is much higher than many users anticipate. After all, it is nothing more than broken rock. This class will discuss the elements which make up the cost structure for simulants. It will also consider which elements can be avoided under certain circumstances and which elements might be altered by the application of additional research and development.

  18. Assignment Of Finite Elements To Parallel Processors

    NASA Technical Reports Server (NTRS)

    Salama, Moktar A.; Flower, Jon W.; Otto, Steve W.

    1990-01-01

    Elements assigned approximately optimally to subdomains. Mapping algorithm based on simulated-annealing concept used to minimize approximate time required to perform finite-element computation on hypercube computer or other network of parallel data processors. Mapping algorithm needed when shape of domain complicated or otherwise not obvious what allocation of elements to subdomains minimizes cost of computation.

  19. 21 CFR 184.1375 - Iron, elemental.

    Code of Federal Regulations, 2013 CFR

    2013-04-01

    ... 21 Food and Drugs 3 2013-04-01 2013-04-01 false Iron, elemental. 184.1375 Section 184.1375 Food... Specific Substances Affirmed as GRAS § 184.1375 Iron, elemental. (a) Iron, elemental (CAS Reg. No. 7439-89-6) is metallic iron obtained by any of the following processes: reduced iron, electrolytic iron, and...

  20. 21 CFR 184.1375 - Iron, elemental.

    Code of Federal Regulations, 2012 CFR

    2012-04-01

    ... 21 Food and Drugs 3 2012-04-01 2012-04-01 false Iron, elemental. 184.1375 Section 184.1375 Food... Specific Substances Affirmed as GRAS § 184.1375 Iron, elemental. (a) Iron, elemental (CAS Reg. No. 7439-89-6) is metallic iron obtained by any of the following processes: reduced iron, electrolytic iron, and...

  1. 21 CFR 184.1375 - Iron, elemental.

    Code of Federal Regulations, 2011 CFR

    2011-04-01

    ... 21 Food and Drugs 3 2011-04-01 2011-04-01 false Iron, elemental. 184.1375 Section 184.1375 Food... Specific Substances Affirmed as GRAS § 184.1375 Iron, elemental. (a) Iron, elemental (CAS Reg. No. 7439-89-6) is metallic iron obtained by any of the following processes: reduced iron, electrolytic iron, and...

  2. 21 CFR 184.1375 - Iron, elemental.

    Code of Federal Regulations, 2010 CFR

    2010-04-01

    ... 21 Food and Drugs 3 2010-04-01 2009-04-01 true Iron, elemental. 184.1375 Section 184.1375 Food and... Substances Affirmed as GRAS § 184.1375 Iron, elemental. (a) Iron, elemental (CAS Reg. No. 7439-89-6) is metallic iron obtained by any of the following processes: reduced iron, electrolytic iron, and carbonyl...

  3. 21 CFR 184.1375 - Iron, elemental.

    Code of Federal Regulations, 2014 CFR

    2014-04-01

    ... 21 Food and Drugs 3 2014-04-01 2014-04-01 false Iron, elemental. 184.1375 Section 184.1375 Food... GRAS § 184.1375 Iron, elemental. (a) Iron, elemental (CAS Reg. No. 7439-89-6) is metallic iron obtained by any of the following processes: reduced iron, electrolytic iron, and carbonyl iron. (1) Reduced...

  4. Tool Releases Optical Elements From Spring Brackets

    NASA Technical Reports Server (NTRS)

    Gum, J. S.

    1984-01-01

    Threaded hooks retract bracket arms holding element. Tool uses three hooks with threaded shanks mounted in ring-shaped holder to pull on tabs to release optical element. One person can easily insert or remove optical element (such as prism or lens) from spring holder or bracket with minimal risk of damage.

  5. 49 CFR 236.576 - Roadway element.

    Code of Federal Regulations, 2012 CFR

    2012-10-01

    ... 49 Transportation 4 2012-10-01 2012-10-01 false Roadway element. 236.576 Section 236.576..., Train Control and Cab Signal Systems Inspection and Tests; Roadway § 236.576 Roadway element. Roadway elements, except track circuits, including those for test purposes, shall be gaged monthly for height and...

  6. 49 CFR 236.576 - Roadway element.

    Code of Federal Regulations, 2011 CFR

    2011-10-01

    ... 49 Transportation 4 2011-10-01 2011-10-01 false Roadway element. 236.576 Section 236.576..., Train Control and Cab Signal Systems Inspection and Tests; Roadway § 236.576 Roadway element. Roadway elements, except track circuits, including those for test purposes, shall be gaged monthly for height and...

  7. 49 CFR 236.576 - Roadway element.

    Code of Federal Regulations, 2013 CFR

    2013-10-01

    ... 49 Transportation 4 2013-10-01 2013-10-01 false Roadway element. 236.576 Section 236.576..., Train Control and Cab Signal Systems Inspection and Tests; Roadway § 236.576 Roadway element. Roadway elements, except track circuits, including those for test purposes, shall be gaged monthly for height and...

  8. 49 CFR 236.576 - Roadway element.

    Code of Federal Regulations, 2014 CFR

    2014-10-01

    ... 49 Transportation 4 2014-10-01 2014-10-01 false Roadway element. 236.576 Section 236.576..., Train Control and Cab Signal Systems Inspection and Tests; Roadway § 236.576 Roadway element. Roadway elements, except track circuits, including those for test purposes, shall be gaged monthly for height and...

  9. Elements of Effective E-Learning Design

    ERIC Educational Resources Information Center

    Brown, Andrew R.; Voltz, Bradley D.

    2005-01-01

    Preparing and developing e-learning materials is a costly and time consuming enterprise. This paper highlights the elements of effective design that we consider assist in the development of high quality materials in a cost efficient way. We introduce six elements of design and discuss each in some detail. These elements focus on paying attention…

  10. Element Cycles: An Environmental Chemistry Board Game

    ERIC Educational Resources Information Center

    Pippins, Tracy; Anderson, Cody M.; Poindexter, Eric F.; Sultemeier, S. Whitney; Schultz, Linda D.

    2011-01-01

    "Element Cycles" is an activity designed to reinforce correlation of essential elements and their different forms in the ecosystem. Students are assigned essential elements to research as homework, then share results, and construct game boards with four ecosphere sections: geosphere (earth), hydrosphere (water), atmosphere (air), and biosphere…

  11. Assignment Of Finite Elements To Parallel Processors

    NASA Technical Reports Server (NTRS)

    Salama, Moktar A.; Flower, Jon W.; Otto, Steve W.

    1990-01-01

    Elements assigned approximately optimally to subdomains. Mapping algorithm based on simulated-annealing concept used to minimize approximate time required to perform finite-element computation on hypercube computer or other network of parallel data processors. Mapping algorithm needed when shape of domain complicated or otherwise not obvious what allocation of elements to subdomains minimizes cost of computation.

  12. 14 CFR 25 - Traffic and Capacity Elements

    Code of Federal Regulations, 2012 CFR

    2012-01-01

    ... 14 Aeronautics and Space 4 2012-01-01 2012-01-01 false Traffic and Capacity Elements Section 25... Traffic Reporting Requirements Section 25 Traffic and Capacity Elements General Instructions. (a) All prescribed reporting for traffic and capacity elements shall conform with the data compilation standards...

  13. Finite element model and identification procedure

    NASA Technical Reports Server (NTRS)

    How, Jonathan P.; Blackwood, Gary; Anderson, Eric; Balmes, Etienne

    1992-01-01

    Viewgraphs on finite element model and identification procedure are presented. Topics covered include: interferometer finite element model; testbed mode shapes; finite element model update; identification procedure; shaker locations; data analysis; modal frequency and damping comparison; computational procedure; fit comparison; residue analysis; typical residues; identification/FEM residual comparison; and pathlength control using isolation mounts.

  14. 40 CFR 721.10068 - Elemental mercury.

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... 40 Protection of Environment 30 2010-07-01 2010-07-01 false Elemental mercury. 721.10068 Section... Substances § 721.10068 Elemental mercury. (a) Definitions. The definitions in § 721.3 apply to this section... elemental mercury (CAS. No. 7439-97-6) is subject to reporting under this section for the significant...

  15. Element Cycles: An Environmental Chemistry Board Game

    ERIC Educational Resources Information Center

    Pippins, Tracy; Anderson, Cody M.; Poindexter, Eric F.; Sultemeier, S. Whitney; Schultz, Linda D.

    2011-01-01

    "Element Cycles" is an activity designed to reinforce correlation of essential elements and their different forms in the ecosystem. Students are assigned essential elements to research as homework, then share results, and construct game boards with four ecosphere sections: geosphere (earth), hydrosphere (water), atmosphere (air), and biosphere…

  16. Downhole Elemental Analysis with LIBS

    NASA Technical Reports Server (NTRS)

    Moreschini, Paolo; Zacny, Kris; Rickman, Doug

    2011-01-01

    In this paper we discuss a novel instrument, currently under development at Honeybee Robotics with SBIR funding from NASA. The device is designed to characterize elemental composition as a function of depth in non-terrestrial geological formations. The instrument consists of a miniaturized laser-induced breakdown spectrometer (LIBS) analyzer integrated in a 2" diameter drill string. While the drill provides subsurface access, the LIBS analyzer provides information on the elemental composition of the borehole wall. This instrument has a variety of space applications ranging from exploration of the Moon for which it was originally designed, to Mars, as well as a variety of terrestrial applications. Subsurface analysis is usually performed by sample acquisition through a drill or excavator, followed by sample preparation and subsequent sample presentation to an instrument or suite of instruments. An alternative approach consisting in bringing a miniaturized version of the instrument to the sample has many advantages over the traditional methodology, as it allows faster response, reduced probability of cross-contamination and a simplification in the sampling mechanisms. LIBS functions by focusing a high energy laser on a material inducing a plasma consisting of a small fraction of the material under analysis. Optical emission from the plasma, analyzed by a spectrometer, can be used to determine elemental composition. A triangulation sensor located in the sensor head determines the distance of the sensor from the borehole wall. An actuator modifies the position of the sensor accordingly, in order to compensate for changes due to the profile of the borehole walls. This is necessary because LIBS measurements are negatively affected by changes in the relative position of the focus of the laser with respect to the position of the sample (commonly referred to as the "lens to sample distance"). Profiling the borehole is done by adjusting the position of the sensor with a

  17. Downhole elemental analysis with LIBS

    NASA Astrophysics Data System (ADS)

    Moreschini, P.; Zacny, K.; Rickman, D.

    2011-12-01

    In this paper we discuss a novel instrument, currently under development at Honeybee Robotics with SBIR funding from NASA. The device is designed to characterize elemental composition as a function of depth in non-terrestrial geological formations. The instrument consists of a miniaturized LIBS analyzer integrated in a 2" diameter drill string. While the drill provides subsurface access, the LIBS analyzer provides information on the elemental composition of the borehole wall. This instrument has a variety of space applications ranging from exploration of the Moon for which it was originally designed, to Mars, as well as a variety of terrestrial applications. Subsurface analysis is usually performed by sample acquisition through a drill or excavator, followed by sample preparation and subsequent sample presentation to an instrument or suite of instruments. An alternative approach consisting in bringing a miniaturized version of the instrument to the sample has many advantages over the traditional methodology, as it allows faster response, reduced probability of cross-contamination and a simplification in the sampling mechanisms. LIBS functions by focusing a high energy laser on a material inducing a plasma consisting of a small fraction of the material under analysis. Optical emission from the plasma, analyzed by a spectrometer, can be used to determine elemental composition. A triangulation sensor located in the sensor head determines the distance of the sensor from the borehole wall. An actuator modifies the position of the sensor accordingly, in order to compensate for changes due to the profile of the borehole walls. This is necessary because LIBS measurements are negatively affected by changes in the relative position of the focus of the laser with respect to the position of the sample (commonly referred to as the "lens to sample distance"). Profiling the borehole is done by adjusting the position of the sensor with a vertical stage; a second actuator at the

  18. Thermionic fuel element technology status

    NASA Technical Reports Server (NTRS)

    Holland, J. W.; Horner, M. W.; Yang, L.

    1985-01-01

    The results of research, conducted between the mid-1960s and 1973, on the multiconverter thermionic fuel elements (TFEs) that comprise the reactor core of an SP-100 thermionic reactor system are presented. Fueled-emitter technology, insulator technology and cell and TFE assembly technology of the prototypical TFEs which were tested in-pile and out-of-pile during these years are described. The proto-TFEs have demonstrated reproducible performance within 5 percent and no premature failures within the 1.5 yr of operation (with projected 3-yr lifetimes). The two primary life-limiting factors had been identified as thermionic emitter dimensional increase due to interactions with the fuel and electrical insulator structural damage from fast neutrons. Multiple options for extending TFE lifetimes to 7 yr or longer are available and will be investigated in the 1984-1985 SP-100 program for resolution of critical technology issues. Design diagrams and test graphs are included.

  19. Moving elements for transport processes

    SciTech Connect

    Mueller, A.; Sepehrnoori, K.; Thrasher, R.

    1987-08-01

    The authors consider a class of convection-dominated flows fundamental to reservoir simulation and their approximate solutions by use of finite-element techniques and moving meshes. Both the solution field and the coordinate functions enter as primary unknowns in the resulting problem statement. Hence the mesh evolves with the solution, and the method is particularly well-suited to those problems where tracking of sharp solution fronts is important. Examples of particular interest related to petroleum reservoir simulation are the model convection/diffusion, Burgers, and Buckley-Leverett equations, which are considered in the numerical studies. They consider effective solution techniques and system integration, as well as questions related to the use of constraints for limiting the permissible distortion of the mesh.

  20. Nutrient metal elements in plants.

    PubMed

    DalCorso, Giovanni; Manara, Anna; Piasentin, Silvia; Furini, Antonella

    2014-10-01

    Plants need many different metal elements for growth, development and reproduction, which must be mobilized from the soil matrix and absorbed by the roots as metal ions. Once taken up by the roots, metal ions are allocated to different parts of the plant by the vascular tissues. Metals are naturally present in the soil, but human activities, ranging from mining and agriculture to sewage processing and heavy industry, have increased the amount of metal pollution in the environment. Plants are challenged by environmental metal ion concentrations that fluctuate from low to high toxic levels, and have therefore evolved mechanisms to cope with such phenomena. In this review, we focus on recent data that provide insight into the molecular mechanisms of metal absorption and transport by plants, also considering the effect of metal deficiency and toxicity. We also highlight the positive effects of some non-essential metals on plant fitness.

  1. Common Data Elements in Radiology.

    PubMed

    Rubin, Daniel L; Kahn, Charles E

    2017-06-01

    Diagnostic radiologists generally produce unstructured information in the form of images and narrative text reports. Although designed for human consumption, radiologic reports contain a wealth of information that could be valuable for clinical care, research, and quality improvement if that information could be extracted by automated systems. Unfortunately, the lack of structure in radiologic reports limits the ability of information systems to share information easily with other systems. A common data element (CDE)-a unit of information used in a shared, predefined fashion-can improve the ability to exchange information seamlessly among information systems. In this article, a model and a repository of radiologic CDEs is described, and three important applications are highlighted. CDEs can help advance radiologic practice, research, and performance improvement, and thus, it is crucial that CDEs be adopted widely in radiologic information systems. (©) RSNA, 2016.

  2. Spectroscopy of the Heaviest Elements

    NASA Astrophysics Data System (ADS)

    Clark, Roderick

    2009-10-01

    The specific ``magic'' proton and neutron numbers, representing major spherical shell gaps, beyond 208Pb are a matter of considerable debate. It is well established that nuclei near Z=100, N=152 (252Fm) have well-deformed prolate shapes. By performing prompt and delayed gamma-ray spectroscopy on deformed transfermium nuclei we can learn about the single-particle structure, shell gaps, pairing correlations, and excitation modes in the heaviest nuclei. After a brief overview of state-of-the-art measurements, I will describe recent results from experiments at the 88-Inch Cyclotron of the Lawrence Berkeley National Laboratory which use the Berkeley Gas-filled Separator (BGS). I will then discuss the prospects of a new generation of spectroscopy measurements on the heaviest elements when the BGS is used in conjunction with the GRETINA gamma--ray tracking array.

  3. Elements of the cognitive universe

    NASA Astrophysics Data System (ADS)

    Topsøe, Flemming

    2017-06-01

    "The least biased inference, taking available information into account, is the one with maximum entropy". So we are taught by Jaynes. The many followers from a broad spectrum of the natural and social sciences point to the wisdom of this principle, the maximum entropy principle, MaxEnt. But "entropy" need not be tied only to classical entropy and thus to probabilistic thinking. In fact, the arguments found in Jaynes' writings and elsewhere can, as we shall attempt to demonstrate, profitably be revisited, elaborated and transformed to apply in a much more general abstract setting. The approach is based on game theoretical thinking. Philosophical considerations dealing with notions of cognition - basically truth and belief - lie behind. Quantitative elements are introduced via a concept of description effort. An interpretation of Tsallis Entropy is indicated.

  4. Boundary elements and surface plasmons

    SciTech Connect

    Goloskie, R.; Thio, T.; Ram-Mohan, L.R.

    1996-09-01

    We present an elementary introduction to the boundary element method (BEM). We use the BEM to calculate the electromagnetic field enhancements in the vicinity of metallic wires of arbitrary cross-section. The local electric field shows resonant peaks, as a function of the frequency of incident radiation, at the natural frequencies of the electronic plasma in the wires. We consider the effect of the shape of the cross-section of the wire on the resonant frequency, the proximity effect due to neighboring wires, and the influence of a substrate. The calculations are performed using enhanced continuity conditions at the boundaries. We discuss the advantages of such an approach. The field enhancements are predicted for a number of geometries. {copyright} {ital 1996 American Institute of Physics.}

  5. Mars Surface Tunnel Element Concept

    NASA Technical Reports Server (NTRS)

    Rucker, Michelle A.

    2016-01-01

    How crews get into or out of their ascent vehicle has profound implications for Mars surface architecture. Extravehicular Activity (EVA) hatches and Airlocks have the benefit of relatively low mass and high Technology Readiness Level (TRL), but waste consumables with a volume depressurization for every ingress/egress. Perhaps the biggest drawback to EVA hatches or Airlocks is that they make it difficult to keep Martian dust from being tracked back into the ascent vehicle, in violation of planetary protection protocols. Suit ports offer the promise of dust mitigation by keeping dusty suits outside the cabin, but require significant cabin real estate, are relatively high mass, and current operational concepts still require an EVA hatch to get the suits outside for the first EVA, and back inside after the final EVA. This is primarily because current designs don't provide enough structural support to protect the suits from ascent/descent loads or potential thruster plume impingement. For architectures involving more than one surface element-such as an ascent vehicle and a rover or surface habitat-a retractable tunnel is an attractive option. By pushing spacesuit don/doff and EVA operations to an element that remains on the surface, ascended vehicle mass and dust can be minimized. What's more, retractable tunnels provide operational flexibility by allowing surface assets to be re-configured or built up over time. Retractable tunnel functional requirements and design concepts being developed as part of the National Aeronautics and Space Administration's (NASA) Evolvable Mars Campaign (EMC) work will add a new ingress/egress option to the surface architecture trade space.

  6. Remediation using trace element humate surfactant

    DOEpatents

    Riddle, Catherine Lynn; Taylor, Steven Cheney; Bruhn, Debra Fox

    2016-08-30

    A method of remediation at a remediation site having one or more undesirable conditions in which one or more soil characteristics, preferably soil pH and/or elemental concentrations, are measured at a remediation site. A trace element humate surfactant composition is prepared comprising a humate solution, element solution and at least one surfactant. The prepared trace element humate surfactant composition is then dispensed onto the remediation site whereby the trace element humate surfactant composition will reduce the amount of undesirable compounds by promoting growth of native species activity. By promoting native species activity, remediation occurs quickly and environmental impact is minimal.

  7. Sobre os sistemas de referência celeste

    NASA Astrophysics Data System (ADS)

    Poppe, P. C. R.; Martin, V. A. F.

    2003-02-01

    Apresentamos neste trabalho, algumas discussões sobre os sistemas de referência utilizados em Astronomia. Claramente, não é possível esgotar todo este assunto num único texto, mas esperamos, contudo, que o presente material possa ser apreciado nos cursos de Introdução à Astronomia, que estão cada vez mais presentes nas atuais propostas curriculares das graduações de Física. As discussões pertinentes às "Bases de Referência Celeste", serão apresentadas em um outro trabalho.

  8. Chemical characterization of bohrium (element 107)

    PubMed

    Eichler; Bruchle; Dressler; Dullmann; Eichler; Gaggeler; Gregorich; Hoffman; Hubener; Jost; Kirbach; Laue; Lavanchy; Nitsche; Patin; Piguet; Schadel; Shaughnessy; Strellis; Taut; Tobler; Tsyganov; Turler; Vahle; Wilk; Yakushev

    2000-09-07

    The arrangement of the chemical elements in the periodic table highlights resemblances in chemical properties, which reflect the elements' electronic structure. For the heaviest elements, however, deviations in the periodicity of chemical properties are expected: electrons in orbitals with a high probability density near the nucleus are accelerated by the large nuclear charges to relativistic velocities, which increase their binding energies and cause orbital contraction. This leads to more efficient screening of the nuclear charge and corresponding destabilization of the outer d and f orbitals: it is these changes that can give rise to unexpected chemical properties. The synthesis of increasingly heavy elements, now including that of elements 114, 116 and 118, allows the investigation of this effect, provided sufficiently long-lived isotopes for chemical characterization are available. In the case of elements 104 and 105, for example, relativistic effects interrupt characteristic trends in the chemical properties of the elements constituting the corresponding columns of the periodic table, whereas element 106 behaves in accordance with the expected periodicity. Here we report the chemical separation and characterization of six atoms of element 107 (bohrium, Bh), in the form of its oxychloride. We find that this compound is less volatile than the oxychlorides of the lighter elements of group VII, thus confirming relativistic calculations that predict the behaviour of bohrium, like that of element 106, to coincide with that expected on the basis of its position in the periodic table.

  9. Triangular spectral elements for incompressible fluid flow

    NASA Technical Reports Server (NTRS)

    Mavriplis, C.; Vanrosendale, John

    1993-01-01

    We discuss the use of triangular elements in the spectral element method for direct simulation of incompressible flow. Triangles provide much greater geometric flexibility than quadrilateral elements and are better conditioned and more accurate when small angles arise. We employ a family of tensor product algorithms for triangles, allowing triangular elements to be handled with comparable arithmetic complexity to quadrilateral elements. The triangular discretizations are applied and validated on the Poisson equation. These discretizations are then applied to the incompressible Navier-Stokes equations and a laminar channel flow solution is given. These new triangular spectral elements can be combined with standard quadrilateral elements, yielding a general and flexible high order method for complex geometries in two dimensions.

  10. Transition elements based on transfinite interpolation

    NASA Technical Reports Server (NTRS)

    Odabas, Onur R.; Sarigul-Klijn, Nesrin

    1993-01-01

    In this study the transfinite interpolation methodology, a 'blending-function' method in particular, is utilized for the formulation of transition elements. The method offers a formal way of meeting continuity requirements in a transition element. Element shape functions are derived by blending the continuity requirements of individual boundary segments. The blending directions are naturally orthogonal in rectangular domains therefore interpolation of the boundaries over rectangular 2D and 3D elements can be performed with minimal effort. In triangular domains, however, the choice of blending directions and interpolants is not straightforward. For that reason, two interpolation techniques are proposed for blending of the boundaries of triangular domains. A series of transition elements of various classes compatible with elements of different orders and dimensions is developed and the full potential of the transfinite interpolation, as it applies to element formulation, is explored.

  11. Rare earth elements: end use and recyclability

    USGS Publications Warehouse

    Goonan, Thomas G.

    2011-01-01

    Rare earth elements are used in mature markets (such as catalysts, glassmaking, lighting, and metallurgy), which account for 59 percent of the total worldwide consumption of rare earth elements, and in newer, high-growth markets (such as battery alloys, ceramics, and permanent magnets), which account for 41 percent of the total worldwide consumption of rare earth elements. In mature market segments, lanthanum and cerium constitute about 80 percent of rare earth elements used, and in new market segments, dysprosium, neodymium, and praseodymium account for about 85 percent of rare earth elements used. Regardless of the end use, rare earth elements are not recycled in large quantities, but could be if recycling became mandated or very high prices of rare earth elements made recycling feasible.

  12. Data transmission element for downhole drilling components

    DOEpatents

    Hall, David R.; Hall, Jr., H. Tracy; Pixton, David S.; Dahlgren, Scott; Fox, Joe; Sneddon, Cameron; Briscoe, Michael

    2006-01-31

    A robust data transmission element for transmitting information between downhole components, such as sections of drill pipe, in the presence of hostile environmental conditions, such as heat, dirt, rocks, mud, fluids, lubricants, and the like. The data transmission element components include a generally U-shaped annular housing, a generally U-shaped magnetically conductive, electrically insulating element such as ferrite, and an insulated conductor. Features on the magnetically conducting, electrically insulating element and the annular housing create a pocket when assembled. The data transmission element is filled with a polymer to retain the components within the annular housing by filling the pocket with the polymer. The polymer can bond with the annular housing and the insulated conductor but preferably not the magnetically conductive, electrically insulating element. A data transmission element is mounted within a recess proximate a mating surface of a downhole drilling component, such as a section of drill pipe.

  13. Transpositionally active episomal hAT elements

    PubMed Central

    2009-01-01

    Background hAT elements and V(D)J recombination may have evolved from a common ancestral transposable element system. Extrachromosomal, circular forms of transposable elements (referred to here as episomal forms) have been reported yet their biological significance remains unknown. V(D)J signal joints, which resemble episomal transposable elements, have been considered non-recombinogenic products of V(D)J recombination and a safe way to dispose of excised chromosomal sequences. V(D)J signal joints can, however, participate in recombination reactions and the purpose of this study was to determine if hobo and Hermes episomal elements are also recombinogenic. Results Up to 50% of hobo/Hermes episomes contained two intact, inverted-terminal repeats and 86% of these contained from 1-1000 bp of intercalary DNA. Episomal hobo/Hermes elements were recovered from Musca domestica (a natural host of Hermes), Drosophila melanogaster (a natural host of hobo) and transgenic Drosophila melanogaster and Aedes aegypti (with autonomous Hermes elements). Episomal Hermes elements were recovered from unfertilized eggs of M. domestica and D. melanogaster demonstrating their potential for extrachromosomal, maternal transmission. Reintegration of episomal Hermes elements was observed in vitro and in vivo and the presence of Hermes episomes resulted in lower rates of canonical Hermes transposition in vivo. Conclusion Episomal hobo/Hermes elements are common products of element excision and can be maternally transmitted. Episomal forms of Hermes are capable of integration and also of influencing the transposition of canonical elements suggesting biological roles for these extrachromosomal elements in element transmission and regulation. PMID:20003420

  14. Transuranium elements: Past, present, and future

    SciTech Connect

    Seaborg, G.T.

    1995-06-01

    In this illustrative Account the authors shall concentrate on four of these elements, chosen for their current interest or pivotal role. The story of plutonium is one of the most dramatic in the history of science, and today, plutonium is at the focus of an extraordinary dilemma. Mendelevium (element 101) has played a pivotal role in blazing the trail for the discovery of the heaviest elements on the basis of {open_quotes}one atom at a time{close_quotes} production. Seaborgium (element 106) was recently named in my honor by the discoverers and may be the last element, at least for some time, for which it will be possible to determine many chemical properties. And element 110 represents recent evidence, after a lapse of 10 years, for the discovery of a chemical element. Recent (1994) recommendations of the IUPAC Commission on the Nomenclature of Inorganic Chemistry for the renaming of elements 104-108 have met with widespread rejection. The author is using the names proposed by the acknowledged discoverers (elements 106-109) or, in the case of the disputed elements 104 and 105, the most logical names. 21 refs., 5 figs.

  15. Recycling of Rare Earth Elements

    NASA Astrophysics Data System (ADS)

    Lorenz, Tom; Bertau, Martin

    2017-01-01

    Any development of an effective process for rare earth (RE) recycling has become more and more challenging, especially in recent years. Since 2011, when commodity prices of REs had met their all-time maximum, prices have dropped rapidly by more than 90 %. An economic process able to offset these fluctuations has to take unconventional methods into account beside well-known strategies like acid/basic leaching or solvent extraction. The solid-state chlorination provides such an unconventional method for mobilizing RE elements from waste streams. Instead of hydrochloric acid this kind of chlorination decomposes NH4Cl thermally to release up to 400 °C hot HCl gas. After cooling the resulting solid metal chlorides may be easily dissolved in pH-adjusted water. Without producing strongly acidic wastes and with NH4Cl as cheap source for hydrogen chloride, solid-state chlorination provides various advantages in terms of costs and disposal. In the course of the SepSELSA project this method was examined, adjusted and optimized for RE recycling from fluorescent lamp scraps as well as Fe14Nd2B magnets. Thereby many surprising influences and trends required various analytic methods to examine the reasons and special mechanisms behind them.

  16. Finite element coiled cochlea model

    NASA Astrophysics Data System (ADS)

    Isailovic, Velibor; Nikolic, Milica; Milosevic, Zarko; Saveljic, Igor; Nikolic, Dalibor; Radovic, Milos; Filipović, Nenad

    2015-12-01

    Cochlea is important part of the hearing system, and thanks to special structure converts external sound waves into neural impulses which go to the brain. Shape of the cochlea is like snail, so geometry of the cochlea model is complex. The simplified cochlea coiled model was developed using finite element method inside SIFEM FP7 project. Software application is created on the way that user can prescribe set of the parameters for spiral cochlea, as well as material properties and boundary conditions to the model. Several mathematical models were tested. The acoustic wave equation for describing fluid in the cochlea chambers - scala vestibuli and scala timpani, and Newtonian dynamics for describing vibrations of the basilar membrane are used. The mechanical behavior of the coiled cochlea was analyzed and the third chamber, scala media, was not modeled because it does not have a significant impact on the mechanical vibrations of the basilar membrane. The obtained results are in good agreement with experimental measurements. Future work is needed for more realistic geometry model. Coiled model of the cochlea was created and results are compared with initial simplified coiled model of the cochlea.

  17. Mars Surface Tunnel Element Concept

    NASA Technical Reports Server (NTRS)

    Rucker, Michelle A.; Jefferies, Sharon; Howe, A. Scott; Howard, Robert; Mary, Natalie; Watson, Judith; Lewis, Ruthan

    2016-01-01

    When the first human visitors on Mars prepare to return to Earth, they will have to comply with stringent planetary protection requirements. Apollo Program experience warns that opening an EVA hatch directly to the surface will bring dust into the ascent vehicle. To prevent inadvertent return of potential Martian contaminants to Earth, careful consideration must be given to the way in which crew ingress their Mars Ascent Vehicle (MAV). For architectures involving more than one surface element-such as an ascent vehicle and a pressurized rover or surface habitat-a retractable tunnel that eliminates extravehicular activity (EVA) ingress is an attractive solution. Beyond addressing the immediate MAV access issue, a reusable tunnel may be useful for other surface applications, such as rover to habitat transfer, once its primary mission is complete. A National Aeronautics and Space Administration (NASA) team is studying the optimal balance between surface tunnel functionality, mass, and stowed volume as part of the Evolvable Mars Campaign (EMC). The study team began by identifying the minimum set of functional requirements needed for the tunnel to perform its primary mission, as this would presumably be the simplest design, with the lowest mass and volume. This Minimum Functional Tunnel then becomes a baseline against which various tunnel design concepts and potential alternatives can be traded, and aids in assessing the mass penalty of increased functionality. Preliminary analysis indicates that the mass of a single-mission tunnel is about 237 kg, not including mass growth allowance.

  18. Superheavy element chemistry at GARIS

    NASA Astrophysics Data System (ADS)

    Haba, Hiromitsu

    2016-12-01

    A gas-jet transport system has been installed to the RIKEN GAs-filled Recoil Ion Separator, GARIS to start up SuperHeavy Element (SHE) chemistry. This system is a promising approach for exploring new frontiers in SHE chemistry: background radioactivities from unwanted by-products are suppressed, a high gas-jet transport yield is achieved, and new chemical reactions can be investigated. Useful radioisotopes of 261Rfa,b, 262Db, and 265Sga,b for chemical studies were produced in the reactions of 248Cm(18O,5n)261Rfa,b, 248Cm(19F,5n)262Db, and 248Cm(22Ne,5n)265Sga,b, respectively. They were successfully extracted to a chemistry laboratory by the gas-jet method. Production and decay properties of 261Rfa,b, 262Db, and 265Sga,b were investigated in detail with the rotating wheel apparatus for α- and spontaneous fission spectrometry. Present status and perspectives of the SHE chemistry at GARIS are also briefly presented.

  19. Transfer reactions with heavy elements

    SciTech Connect

    Hoffman, D.C.

    1986-04-01

    Transfer reactions for several transuranium elements are studied. (/sup 248/Cm, /sup 249/Bk, /sup 249/CF, /sup 254/Es), /sup 16,18/O, /sup 20,22/Ne, and /sup 40,48/Ca projectiles are used. The production of neutron-rich heavy actinides is enhanced by the use of neutron-rich projectiles /sup 18/O and /sup 22/Ne. The maxima of the isotopic distributions occur at only 2 to 3 mass numbers larger for /sup 48/Ca than for /sup 40/Ca reactions with /sup 248/Cm. The cross sections decrease rapidly with the number of nucleons transferred. The use of neutron-rich targets favors the production of neutron-rich isotopes. ''Cold'' heavy targets are produced. Comparisons with simple calculations of the product excitation energies assuming binary transfers indicate that the maxima of the isotopic distributions occur at the lightest product isotope for which the energy exceeds the reaction barrier. The cross sections for transfer of the same nucleon clusters appear to be comparable for a wide variety of systems. 23 refs., 4 figs., 4 tabs.

  20. A simple nonlinear element model

    NASA Astrophysics Data System (ADS)

    Mikhailov, S. G.; Rudenko, O. V.

    2017-05-01

    We study experimentally the behavior of a nonlinear element, a light plate pressed to the opening in the cavity of an acoustic resonator. Measurements of field oscillations inside and outside the cavity have shown that for large amplitudes, they become essentially anharmonic. The time dependences of displacement of the plate with increasing amplitude of the exciting voltage demonstrates a gradual change in the shape of vibrations from harmonic to half-period oscillation. A constant component appears in the cavity: rarefaction or outflow of the medium through the orifice. We construct a theory for nonlinear oscillations of a plate taking into account its different elastic reactions to compression and rarefaction with allowance for monopole radiation by the small-wave-size plate or radiation of a plane wave by the plate. We calculate the amplitudes of the harmonics and solve the problem of low-frequency stationary noise acting on the plate. We obtain expressions for the correlation function and mean power at the output given a normal random process at the input.

  1. Dynamic heater for display elements

    NASA Astrophysics Data System (ADS)

    Dehmlow, Brian P.; Bishop, Gary D.; Steffensmeier, Martin J.; Sampica, James D.; Skarohlid, Mark C.

    1997-07-01

    Liquid crystal display (LCD) deliver optimal performance when the entire display surface is isothermal and at a controllable temperature. This condition creates uniform electro-optical properties within the liquid crystal layer. This paper describes a dynamic, multicontact heater system that actively compensates for uneven heat loads, thereby creating the desired isothermal condition. The heater system includes a uniform resistive sheet, with multiple electrical contacts around the perimeter. A switch network connects each heater contact to a power supply, ground potential, or a high impedance. A microprocessor monitors the display temperature, and detects non-uniformity, and selectively applies heat to cold areas of the display. The dynamic heater system employs a variety of heating patterns to create the desired isothermal condition.Heating patterns vary in duration, power applied, and location on the display face. The microprocessor control loop can also detect and isolate faulty drive elements, and compensate for non- uniformity in the heater itself. The heater prevents stress- induced delaminations, mechanical distortions, and stress- induced birefringence in optical components. Test results indicate that a dynamic heater can be beneficial in the thermal design of LCD products.

  2. Functions over RDF Language Elements

    NASA Astrophysics Data System (ADS)

    Schandl, Bernhard

    RDF data are usually accessed using one of two methods: either, graphs are rendered in forms perceivable by human users (e.g., in tabular or in graphical form), which are difficult to handle for large data sets. Alternatively, query languages like SPARQL provide means to express information needs in structured form; hence they are targeted towards developers and experts. Inspired by the concept of spreadsheet tools, where users can perform relatively complex calculations by splitting formulas and values across multiple cells, we have investigated mechanisms that allow us to access RDF graphs in a more intuitive and manageable, yet formally grounded manner. In this paper, we make three contributions towards this direction. First, we present RDFunctions, an algebra that consists of mappings between sets of RDF language elements (URIs, blank nodes, and literals) under consideration of the triples contained in a background graph. Second, we define a syntax for expressing RDFunctions, which can be edited, parsed and evaluated. Third, we discuss Tripcel, an implementation of RDFunctions using a spreadsheet metaphor. Using this tool, users can easily edit and execute function expressions and perform analysis tasks on the data stored in an RDF graph.

  3. Interstitial Functionalization in elemental Si

    NASA Astrophysics Data System (ADS)

    Kiefer, Boris; Fohtung, Edwin

    Societies in the 21st century will face many challenges. Materials science and materials design will be essential to address and master some if not all of these challenges. Semiconductors are among the most important technological material classes. Properties such as electrical transport are strongly affected by defects and a central goal continues to be the reduction of defect densities as much as possible in these compounds. Here we present results of interstitial Fe doping in elemental Si using first-principles DFT calculations. The preliminary results show that Fe will only occupy octahedral interstitial sites. The analysis of the electronic structure shows that the compounds are ferromagnetic and that a bandgap opens as interstitial Fe concentrations decrease, with a possible intermittent semi-metallic phase. The formation energy for interstitial Fe is unfavorable, as expected, by ~1.5 eV but becomes favorable as the chemical potential of Fe increases. Therefore, we expect that biasing the system with an external electrical field will lead to the formation of these materials. Thus, our results show that interstitial defects can be beneficial for the design of functionalities that differ significantly from those of the host material.

  4. Itinerant magnetism without magnetic elements

    NASA Astrophysics Data System (ADS)

    Morosan, Emilia

    The origin of magnetism in metals has been traditionally discussed in two diametrically opposite limits: itinerant and local moments. Surprisingly, there are very few known examples of materials that are close to the itinerant limit, and their properties are not universally understood. In the case of the two such examples discovered several decades ago, both itinerant ferromagnets (IFMs) ZrZn2 and Sc3In, the understanding of their magnetic ground states draws on the existence of 3d electrons subject to strong spin fluctuations. In this talk I will contrast the physical properties of these two IFMs without magnetic elements with those of the recently discovered first itinerant antiferromagnetic (IAFM) metal with no magnetic constituents, TiAu. The IFMs have surprisingly different properties, with ZrZn2 showing signatures of mean field, Fermi liquid behavior, while the Sc3In compound is characterized by non-mean field magnetization exponents, and displays non fermi liquid behavior in both the FM and the paramagnetic states. The IAFM TiAu orders below a Neel temperature TN ~ K, about an order of magnitude smaller than in the IAFM Cr, rendering the spin fluctuations in TiAu more important at low temperatures. Like in the two IFMs, doping induces a quantum phase transition in TiAu, and the quantum critical behavior in all three systems is discussed and compared. This work is supported by NSF DMR-1506704.

  5. Visualization of higher order finite elements.

    SciTech Connect

    Thompson, David C.; Pebay, Philippe Pierre; Crawford, Richard H.; Khardekar, Rahul Vinay

    2004-04-01

    Finite element meshes are used to approximate the solution to some differential equation when no exact solution exists. A finite element mesh consists of many small (but finite, not infinitesimal or differential) regions of space that partition the problem domain, {Omega}. Each region, or element, or cell has an associated polynomial map, {Phi}, that converts the coordinates of any point, x = ( x y z ), in the element into another value, f(x), that is an approximate solution to the differential equation, as in Figure 1(a). This representation works quite well for axis-aligned regions of space, but when there are curved boundaries on the problem domain, {Omega}, it becomes algorithmically much more difficult to define {Phi} in terms of x. Rather, we define an archetypal element in a new coordinate space, r = ( r s t ), which has a simple, axis-aligned boundary (see Figure 1(b)) and place two maps onto our archetypal element:

  6. Automated Fuel Element Closure Welding System

    SciTech Connect

    Wahlquist, D.R.

    1993-03-01

    The Automated Fuel Element Closure Welding System is a robotic device that will load and weld top end plugs onto nuclear fuel elements in a highly radioactive and inert gas environment. The system was developed at Argonne National Laboratory-West as part of the Fuel Cycle Demonstration. The welding system performs four main functions, it (1) injects a small amount of a xenon/krypton gas mixture into specific fuel elements, and (2) loads tiny end plugs into the tops of fuel element jackets, and (3) welds the end plugs to the element jackets, and (4) performs a dimensional inspection of the pre- and post-welded fuel elements. The system components are modular to facilitate remote replacement of failed parts. The entire system can be operated remotely in manual, semi-automatic, or fully automatic modes using a computer control system. The welding system is currently undergoing software testing and functional checkout.

  7. Automated Fuel Element Closure Welding System

    SciTech Connect

    Wahlquist, D.R.

    1993-01-01

    The Automated Fuel Element Closure Welding System is a robotic device that will load and weld top end plugs onto nuclear fuel elements in a highly radioactive and inert gas environment. The system was developed at Argonne National Laboratory-West as part of the Fuel Cycle Demonstration. The welding system performs four main functions, it (1) injects a small amount of a xenon/krypton gas mixture into specific fuel elements, and (2) loads tiny end plugs into the tops of fuel element jackets, and (3) welds the end plugs to the element jackets, and (4) performs a dimensional inspection of the pre- and post-welded fuel elements. The system components are modular to facilitate remote replacement of failed parts. The entire system can be operated remotely in manual, semi-automatic, or fully automatic modes using a computer control system. The welding system is currently undergoing software testing and functional checkout.

  8. Isotopic Compositions of the Elements, 2001

    NASA Astrophysics Data System (ADS)

    Böhlke, J. K.; de Laeter, J. R.; De Bièvre, P.; Hidaka, H.; Peiser, H. S.; Rosman, K. J. R.; Taylor, P. D. P.

    2005-03-01

    The Commission on Atomic Weights and Isotopic Abundances of the International Union of Pure and Applied Chemistry completed its last review of the isotopic compositions of the elements as determined by isotope-ratio mass spectrometry in 2001. That review involved a critical evaluation of the published literature, element by element, and forms the basis of the table of the isotopic compositions of the elements (TICE) presented here. For each element, TICE includes evaluated data from the "best measurement" of the isotope abundances in a single sample, along with a set of representative isotope abundances and uncertainties that accommodate known variations in normal terrestrial materials. The representative isotope abundances and uncertainties generally are consistent with the standard atomic weight of the element Ar(E) and its uncertainty U[Ar(E)] recommended by CAWIA in 2001.

  9. Chemistry of the actinide elements. Second edition

    SciTech Connect

    Katz, J.J.; Seaborg, G.T.; Morss, L.R.

    1987-01-01

    This is an exhaustive, updated discourse on the chemistry of Actinides, Volume 1 contains a systematic coverage of the elements Ac, Th, Pa, U, Np, and Pu, which constitutes Part 1 of the work. The characterization of each element is discussed in terms of its nuclear properties, occurrence, preparation, atomic and metallic properties, chemistry of specific compounds, and solution chemistry. The first part of Volume 2 follows the same format as Volume 1 but is confined to the elements Am, Cm, Bk, Cf, and Es, plus a more condensed coverage of the Transeinsteinium elements (Fm, Md, No, Lw, and 104-109). Part 2 of this volume is devoted to a discussion of the actinide elements in general, with a specific focus on electronic spectra, thermodynamic and magnetic properties, the metallic state, structural chemistry, solution kinetics, organometallic chemistry for /sigma/- and /pi/-bonded compounds, and some concluding remarks on the superheavy elements.

  10. Waveguide finite elements for curved structures

    NASA Astrophysics Data System (ADS)

    Finnveden, Svante; Fraggstedt, Martin

    2008-05-01

    A waveguide finite element formulation for the analysis of curved structures is introduced. The formulation is valid for structures that along one axis have constant properties. It is based on a modified Hamilton's principle valid for general linear viscoelastic motion, which is derived here. Using this principle, material properties such as losses may be distributed in the system and may vary with frequency. Element formulations for isoparametric solid elements and deep shell elements are presented for curved waveguides as well as for straight waveguides. In earlier works, the curved elements have successfully been used to model a passenger car tyre. Here a simple validation example and convergence study is presented, which considers a finite length circular cylinder and all four elements presented are used, in turn, to model this structure. Calculated results compare favourably to those in the literature.

  11. Evolutionary inheritance of elemental stoichiometry in phytoplankton

    PubMed Central

    Quigg, Antonietta; Irwin, Andrew J.; Finkel, Zoe V.

    2011-01-01

    The elemental composition of phytoplankton is a fusion of the evolutionary history of the host and plastid, resulting in differences in genetic constraints and selection pressures associated with environmental conditions. The evolutionary inheritance hypothesis predicts similarities in elemental composition within related taxonomic lineages of phytoplankton. To test this hypothesis, we measured the elemental composition (C, N, P, S, K, Mg, Ca, Sr, Fe, Mn, Zn, Cu, Co, Cd and Mo) of 14 phytoplankton species and combined these with published data from 15 more species from both marine and freshwater environments grown under nutrient-replete conditions. The largest differences in the elemental profiles of the species distinguish between the prokaryotic Cyanophyta and primary endosymbiotic events that resulted in the green and red plastid lineages. Smaller differences in trace element stoichiometry within the red and green plastid lineages are consistent with changes in trace elemental stoichiometry owing to the processes associated with secondary endosymbioses and inheritance by descent with modification. PMID:20826483

  12. Evolutionary inheritance of elemental stoichiometry in phytoplankton.

    PubMed

    Quigg, Antonietta; Irwin, Andrew J; Finkel, Zoe V

    2011-02-22

    The elemental composition of phytoplankton is a fusion of the evolutionary history of the host and plastid, resulting in differences in genetic constraints and selection pressures associated with environmental conditions. The evolutionary inheritance hypothesis predicts similarities in elemental composition within related taxonomic lineages of phytoplankton. To test this hypothesis, we measured the elemental composition (C, N, P, S, K, Mg, Ca, Sr, Fe, Mn, Zn, Cu, Co, Cd and Mo) of 14 phytoplankton species and combined these with published data from 15 more species from both marine and freshwater environments grown under nutrient-replete conditions. The largest differences in the elemental profiles of the species distinguish between the prokaryotic Cyanophyta and primary endosymbiotic events that resulted in the green and red plastid lineages. Smaller differences in trace element stoichiometry within the red and green plastid lineages are consistent with changes in trace elemental stoichiometry owing to the processes associated with secondary endosymbioses and inheritance by descent with modification.

  13. Thermally conductive porous element-based recuperators

    NASA Technical Reports Server (NTRS)

    Du, Jian Hua (Inventor); Chow, Louis C (Inventor); Lin, Yeong-Ren (Inventor); Wu, Wei (Inventor); Kapat, Jayanta (Inventor); Notardonato, William U. (Inventor)

    2012-01-01

    A heat exchanger includes at least one hot fluid flow channel comprising a first plurality of open cell porous elements having first gaps there between for flowing a hot fluid in a flow direction and at least one cold fluid flow channel comprising a second plurality of open cell porous elements having second gaps therebetween for flowing a cold fluid in a countercurrent flow direction relative to the flow direction. The thermal conductivity of the porous elements is at least 10 W/mK. A separation member is interposed between the hot and cold flow channels for isolating flow paths associated these flow channels. The first and second plurality of porous elements at least partially overlap one another to form a plurality of heat transfer pairs which transfer heat from respective ones of the first porous elements to respective ones of the second porous elements through the separation member.

  14. Asteroid family identifications and proper elements

    NASA Technical Reports Server (NTRS)

    Williams, J. G.

    1989-01-01

    This paper lists proper elements and family memberships for the first 2065 numbered asteroids plus 20 higher numbered objects. All proper elements were calculated using the Williams (1969) theory. The information contained in the 13 columns of the table is discussed in detail. It is noted that the proper elements and family assignments for the first 1796 numbered objects are mostly identical to those reported previously by Williams (1979). However, proper elements were recalculated for 68 objects in the earlier list, and entries were made for asteroids omitted from that list. Family identifications have changed for several objects as a result of the improvement of the osculating elements and a recalculation of the proper elements of asteroids which formerly had poor orbits.

  15. Devices based on controlled magnetic elements

    NASA Astrophysics Data System (ADS)

    Gluzman, P. L.; Milovzorov, V. P.; Iudin, V. V.

    The book is concerned with the theory and optimal design of multifunctional magnetic elements with a controlled transfer ratio and devices based on them. In particular, attention is given to the classification of devices based on controlled magnetic elements and the functional properties of their base structures; devices based on magnetic elements with feedback and external signal control; analysis of single-component controlled magnetic elements with a constant magnetic conductor cross section; and parametric synthesis of optimal functional transducers. The discussion also covers the synthesis of frequency multipliers based on magnetic synthesizers of multiextremal functions; stability and accuracy of controlled magnetic elements and devices based on them; and some applications of devices based on controlled magnetic elements.

  16. Isotopic compositions of the elements, 2001

    USGS Publications Warehouse

    Böhlke, J.K.; De Laeter, J. R.; De Bievre, P.; Hidaka, H.; Peiser, H.S.; Rosman, K.J.R.; Taylor, P.D.P.

    2005-01-01

    The Commission on Atomic Weights and Isotopic Abundances of the International Union of Pure and Applied Chemistry completed its last review of the isotopic compositions of the elements as determined by isotope-ratio mass spectrometry in 2001. That review involved a critical evaluation of the published literature, element by element, and forms the basis of the table of the isotopic compositions of the elements (TICE) presented here. For each element, TICE includes evaluated data from the "best measurement" of the isotope abundances in a single sample, along with a set of representative isotope abundances and uncertainties that accommodate known variations in normal terrestrial materials. The representative isotope abundances and uncertainties generally are consistent with the standard atomic weight of the element A r(E) and its uncertainty U[Ar(E)] recommended by CAWIA in 2001. ?? 2005 American Institute of Physics.

  17. Trace elements in marine ostracodes

    NASA Astrophysics Data System (ADS)

    Dwyer, Gary S.; Cronin, Thomas M.; Baker, Paul A.

    Extending the work of Cadot, Kaesler, De Deckker, Chivas, and Corrège, we have measured the elemental chemistry of shells of marine ostracodes to evaluate the usefulness of ostracode shell chemistry as a paleoenvironmental proxy. Our work has focused primarily on Mg/Ca, Sr/Ca, and Na/Ca ratios of two common genera: deep-sea genus Krithe and shallow marine/estuarine genus Loxoconcha. We evaluated in vivo effects including genus, species, gender, ontogeny, shell size, intra-shell heterogeneity (Mg), water temperature, and salinity, and postmortem diagenetic effects including partial dissolution, recrystallization, and shell surface contamination. Analysis of modern (core-top), fossil, and laboratory-raised specimens across a wide range of temperature and salinity conditions confirms earlier work indicating that Krithe and Loxoconcha Mg/Ca ratios are dominantly controlled by water temperature. Sr/Ca and Na/Ca ratios co-vary with temperature in core-top Krithe, but not in cultured Loxoconcha suggesting that the Krithe Sr/Ca and Na/Ca correlation with temperature may be related to another variable that broadly co-varies with temperature. Phylogenetic and ontogenetic effects are also indicated, including different Mg-thermodependence and intra-shell Mg distribution between Krithe and Loxoconcha. Inter-specific effects are suggested for two species of Krithe. Magnesium uptake in eldest juvenile shells seems to be identical to that of adult shells, thus greatly increasing the amount of shell material available for paleoenvironmental studies. No salinity effects were observed. Shell Na/Ca ratios showed a dramatic decrease with increasing dissolution (natural and artificial) in waters that are undersaturated with respect to calcite, whereas Mg/Ca ratios displayed a minor decrease and Sr/Ca ratios showed no change. Of the ratios studied, Mg/Ca offers the most promise for Quaternary marine studies as a paleothermometer. Further calibration studies are needed to better

  18. Exact finite elements for conduction and convection

    NASA Technical Reports Server (NTRS)

    Thornton, E. A.; Dechaumphai, P.; Tamma, K. K.

    1981-01-01

    An appproach for developing exact one dimensional conduction-convection finite elements is presented. Exact interpolation functions are derived based on solutions to the governing differential equations by employing a nodeless parameter. Exact interpolation functions are presented for combined heat transfer in several solids of different shapes, and for combined heat transfer in a flow passage. Numerical results demonstrate that exact one dimensional elements offer advantages over elements based on approximate interpolation functions. Previously announced in STAR as N81-31507

  19. Domain decomposition methods for mortar finite elements

    SciTech Connect

    Widlund, O.

    1996-12-31

    In the last few years, domain decomposition methods, previously developed and tested for standard finite element methods and elliptic problems, have been extended and modified to work for mortar and other nonconforming finite element methods. A survey will be given of work carried out jointly with Yves Achdou, Mario Casarin, Maksymilian Dryja and Yvon Maday. Results on the p- and h-p-version finite elements will also be discussed.

  20. Rack for storing spent nuclear fuel elements

    DOEpatents

    Rubinstein, Herbert J.; Clark, Philip M.; Gilcrest, James D.

    1978-06-20

    A rack for storing spent nuclear fuel elements in which a plurality of aligned rows of upright enclosures of generally square cross-sectional areas contain vertically disposed fuel elements. The enclosures are fixed at the lower ends thereof to a base. Pockets are formed between confronting walls of adjacent enclosures for receiving high absorption neutron absorbers, such as Boral, cadmium, borated stainless steel and the like for the closer spacing of spent fuel elements.

  1. Exact finite elements for conduction and convection

    NASA Technical Reports Server (NTRS)

    Thornton, E. A.; Dechaumphai, P.; Tamma, K. K.

    1981-01-01

    An appproach for developing exact one dimensional conduction-convection finite elements is presented. Exact interpolation functions are derived based on solutions to the governing differential equations by employing a nodeless parameter. Exact interpolation functions are presented for combined heat transfer in several solids of different shapes, and for combined heat transfer in a flow passage. Numerical results demonstrate that exact one dimensional elements offer advantages over elements based on approximate interpolation functions. Previously announced in STAR as N81-31507

  2. The elements of life and medicines.

    PubMed

    Chellan, Prinessa; Sadler, Peter J

    2015-03-13

    Which elements are essential for human life? Here we make an element-by-element journey through the periodic table and attempt to assess whether elements are essential or not, and if they are, whether there is a relevant code for them in the human genome. There are many difficulties such as the human biochemistry of several so-called essential elements is not well understood, and it is not clear how we should classify elements that are involved in the destruction of invading microorganisms, or elements which are essential for microorganisms with which we live in symbiosis. In general, genes do not code for the elements themselves, but for specific chemical species, i.e. for the element, its oxidation state, type and number of coordinated ligands, and the coordination geometry. Today, the biological periodic table is in a position somewhat similar to Mendeleev's chemical periodic table of 1869: there are gaps and we need to do more research to fill them. The periodic table also offers potential for novel therapeutic and diagnostic agents, based on not only essential elements, but also non-essential elements, and on radionuclides. Although the potential for inorganic chemistry in medicine was realized more than 2000 years ago, this area of research is still in its infancy. Future advances in the design of inorganic drugs require more knowledge of their mechanism of action, including target sites and metabolism. Temporal speciation of elements in their biological environments at the atomic level is a major challenge, for which new methods are urgently needed.

  3. Directivity and spacing for the antenna elements

    NASA Technical Reports Server (NTRS)

    Koshy, V. K.

    1983-01-01

    The optimum design choice for the MST radar antenna was considered. The following factors are required: directivity and gain; beam width and its symmetry; sidelobe levels, near and wide angle; impedance matching; feeder network losses; polarization diversity; steerability; cost effectiveness; and maintainability. The directivity and related beam forming aspects of various antenna elements and directivity aspects when such elements are formed into an array are discussed. Array performance for important variables, in particular, the spacing of the elements is considered.

  4. Drinfeld twisting elements on Hom-bialgebras

    NASA Astrophysics Data System (ADS)

    Makhlouf, A.; Torrecillas, B.

    2014-09-01

    The purpose of this paper is to introduce the concept of a twisting element based on a Hom- bialgebra and to use it to provide twists or deformations of Hom-associative algebras. Moreover we review the module theory in Hom-setting and show that a twisting element based on a bialgebra gives rise to a twisting element based on a Hom-bialgebra.

  5. Two-Element Transducer for Ultrasound

    NASA Technical Reports Server (NTRS)

    Lecroissette, D. H.; Heyser, R. C.

    1986-01-01

    Separation of transmitting and receiving units improves probing of deep tissue. Ultrasonic transducer has dual elements to increase depth at which sonic images are made of biological tissue. Transducer uses separate transmitting and receiving elements, and frequency response of receiving element independently designed to accommodate attenuation of higher frequencies by tissue. New transducer intended for pulse-echo ultrasonic systems in which reflected sound pulses reveal features in tissue.

  6. The elements of life and medicines

    PubMed Central

    Chellan, Prinessa; Sadler, Peter J

    2015-01-01

    Which elements are essential for human life? Here we make an element-by-element journey through the periodic table and attempt to assess whether elements are essential or not, and if they are, whether there is a relevant code for them in the human genome. There are many difficulties such as the human biochemistry of several so-called essential elements is not well understood, and it is not clear how we should classify elements that are involved in the destruction of invading microorganisms, or elements which are essential for microorganisms with which we live in symbiosis. In general, genes do not code for the elements themselves, but for specific chemical species, i.e. for the element, its oxidation state, type and number of coordinated ligands, and the coordination geometry. Today, the biological periodic table is in a position somewhat similar to Mendeleev's chemical periodic table of 1869: there are gaps and we need to do more research to fill them. The periodic table also offers potential for novel therapeutic and diagnostic agents, based on not only essential elements, but also non-essential elements, and on radionuclides. Although the potential for inorganic chemistry in medicine was realized more than 2000 years ago, this area of research is still in its infancy. Future advances in the design of inorganic drugs require more knowledge of their mechanism of action, including target sites and metabolism. Temporal speciation of elements in their biological environments at the atomic level is a major challenge, for which new methods are urgently needed. PMID:25666066

  7. Benchmarking the QUAD4/TRIA3 element

    NASA Technical Reports Server (NTRS)

    Pitrof, Stephen M.; Venkayya, Vipperla B.

    1993-01-01

    The QUAD4 and TRIA3 elements are the primary plate/shell elements in NASTRAN. These elements enable the user to analyze thin plate/shell structures for membrane, bending and shear phenomena. They are also very new elements in the NASTRAN library. These elements are extremely versatile and constitute a substantially enhanced analysis capability in NASTRAN. However, with the versatility comes the burden of understanding a myriad of modeling implications and their effect on accuracy and analysis quality. The validity of many aspects of these elements were established through a series of benchmark problem results and comparison with those available in the literature and obtained from other programs like MSC/NASTRAN and CSAR/NASTRAN. Never-the-less such a comparison is never complete because of the new and creative use of these elements in complex modeling situations. One of the important features of QUAD4 and TRIA3 elements is the offset capability which allows the midsurface of the plate to be noncoincident with the surface of the grid points. None of the previous elements, with the exception of bar (beam), has this capability. The offset capability played a crucial role in the design of QUAD4 and TRIA3 elements. It allowed modeling layered composites, laminated plates and sandwich plates with the metal and composite face sheets. Even though the basic implementation of the offset capability is found to be sound in the previous applications, there is some uncertainty in relatively simple applications. The main purpose of this paper is to test the integrity of the offset capability and provide guidelines for its effective use. For the purpose of simplicity, references in this paper to the QUAD4 element will also include the TRIA3 element.

  8. Exact finite elements for conduction and convection

    NASA Technical Reports Server (NTRS)

    Thornton, E. A.; Dechaumphai, P.; Tamma, K. K.

    1981-01-01

    An approach for developing exact one dimensional conduction-convection finite elements is presented. Exact interpolation functions are derived based on solutions to the governing differential equations by employing a nodeless parameter. Exact interpolation functions are presented for combined heat transfer in several solids of different shapes, and for combined heat transfer in a flow passage. Numerical results demonstrate that exact one dimensional elements offer advantages over elements based on approximate interpolation functions.

  9. LOG PERIODIC DIPOLE ARRAY WITH PARASITIC ELEMENTS

    DTIC Science & Technology

    The design and measured characteristics of dipole and monopole versions of a log periodic array with parasitic elements are discussed. In a dipole...for the elements to obtain log periodic performance of the anntenna. This design with parasitic elements lends itself to a monopole version of the...antenna which has a simplified feeding configuration. The result is a log periodic antenna design that can be used from high frequencies through microwave frequencies.

  10. Quadratic finite elements and incompressible viscous flows.

    SciTech Connect

    Dohrmann, Clark R.; Gartling, David K.

    2005-01-01

    Pressure stabilization methods are applied to higher-order velocity finite elements for application to viscous incompressible flows. Both a standard pressure stabilizing Petrov-Galerkin (PSPG) method and a new polynomial pressure projection stabilization (PPPS) method have been implemented and tested for various quadratic elements in two dimensions. A preconditioner based on relaxing the incompressibility constraint is also tested for the iterative solution of saddle point problems arising from mixed Galerkin finite element approximations to the Navier-Stokes equations. The preconditioner is demonstrated for BB stable elements with discontinuous pressure approximations in two and three dimensions.

  11. The New Element Berkelium (Atomic Number 97)

    DOE R&D Accomplishments Database

    Seaborg, G. T.; Thompson, S. G.; Ghiorso, A.

    1950-04-26

    An isotope of the element with atomic number 97 has been discovered as a product of the helium-ion bombardment of americium. The name berkelium, symbol Bk, is proposed for element 97. The chemical separation of element 97 from the target material and other reaction products was made by combinations of precipitation and ion exchange adsorption methods making use of its anticipated (III) and (IV) oxidation states and its position as a member of the actinide transition series. The distinctive chemical properties made use of in its separation and the equally distinctive decay properties of the particular isotope constitute the principal evidence for the new element.

  12. Books and monographs on finite element technology

    NASA Technical Reports Server (NTRS)

    Noor, A. K.

    1985-01-01

    The present paper proviees a listing of all of the English books and some of the foreign books on finite element technology, taking into account also a list of the conference proceedings devoted solely to finite elements. The references are divided into categories. Attention is given to fundamentals, mathematical foundations, structural and solid mechanics applications, fluid mechanics applications, other applied science and engineering applications, computer implementation and software systems, computational and modeling aspects, special topics, boundary element methods, proceedings of symmposia and conferences on finite element technology, bibliographies, handbooks, and historical accounts.

  13. Separation of transuranium elements from irradiated targets

    SciTech Connect

    Wham, R.M.; Benker, D.E.; Felker, L.K.; Chattin, F.R.

    1993-12-31

    Aluminum targets containing curium/americium oxide are irradiated to produce the transcurium actinides einsteinium, fermium, berkelium, and californium. Recovery of recycle curium/americium and the transcurium elements involves several chemical processing steps to selectively recover those elements and remove fission products. Chemical processing steps developed at the Radiochemical Engineering Development Center (REDC) include aluminum dejacketing, solvent extraction to remove bulk impurities, solvent extraction to remove plutonium, anion exchange to partition curium and transcurium elements from the rare earths, and a second anion exchange cycle to separate americium/curium from the transcurium elements.

  14. The Essential Elements of Cooperative Learning.

    ERIC Educational Resources Information Center

    Watson, Scott B.

    1992-01-01

    Discusses four elements of cooperative learning in science classrooms: cooperative task structures; cooperative incentive structures; individual accountability; and heterogeneous grouping. Presents and describes seven cooperative learning methods. (MDH)

  15. Investigation of uses of holographic optical elements

    NASA Technical Reports Server (NTRS)

    Zech, R. G.; Latta, J. N.

    1973-01-01

    The data represent a thorough study of the aberrations and imaging properties of holographic optical elements. Principle studies include (1) the indepth experimental investigation of single holographic optical elements, (2) the verification of the accuracy of the theoretical computer-based description of hologram behavior, (3) the computer-generation of interferograms that are characteristic of a prescribed aberrated imaging condition, (4) the experimental verification of wavelength optimization, (5) the experimental determination of the space bandwidth product of single holographic optical elements as a function of bending and field angle, and (6) the first experimental study of the aberration properties of holographic optical elements constructed in very thick (750 microns) recording media.

  16. Low exchange element for nuclear reactor

    DOEpatents

    Brogli, Rudolf H.; Shamasunder, Bangalore I.; Seth, Shivaji S.

    1985-01-01

    A flow exchange element is presented which lowers temperature gradients in fuel elements and reduces maximum local temperature within high temperature gas-cooled reactors. The flow exchange element is inserted within a column of fuel elements where it serves to redirect coolant flow. Coolant which has been flowing in a hotter region of the column is redirected to a cooler region, and coolant which has been flowing in the cooler region of the column is redirected to the hotter region. The safety, efficiency, and longevity of the high temperature gas-cooled reactor is thereby enhanced.

  17. Bi-stable optical element actuator device

    DOEpatents

    Holdener, Fred R.; Boyd, Robert D.

    2002-01-01

    The present invention is a bistable optical element actuator device utilizing a powered means to move an actuation arm, to which an optical element is attached, between two stable positions. A non-powered means holds the actuation arm in either of the two stable positions. The optical element may be a electromagnetic (EM) radiation or particle source, an instrument, or EM radiation or particle transmissive reflective or absorptive elements. A bearing is used to transfer motion and smoothly transition the actuation arm between the two stable positions.

  18. NIOSH Method 9102: Elements on Wipes

    EPA Pesticide Factsheets

    Method 9102 describes procedures for analysis of elements, including arsenic, vanadium, osmium, thallium and titanium, on wipe samples using inductively coupled plasma (ICP) – atomic emission spectrometry (AES).

  19. Finite element modelling of buried structures

    NASA Technical Reports Server (NTRS)

    Playdon, D. K.; Simmonds, S. H.

    1984-01-01

    In many structures the final stress states are dependent on the sequence of construction or the stress states at various stages of construction are of interest. Such problems can be analyzed using finite element programs that have the capability of adding (birthing) elements to simulate the progress of construction. However, the usual procedure of assembling elements may lead to numerical instabilities or stress states that are unrealistic. Both problems are demonstrated in the analysis of a structure using the program ADINA. A technique which combines application of a preload with element birthing to overcome these problems is described and illustrated.

  20. Books and monographs on finite element technology

    NASA Technical Reports Server (NTRS)

    Noor, A. K.

    1985-01-01

    The present paper proviees a listing of all of the English books and some of the foreign books on finite element technology, taking into account also a list of the conference proceedings devoted solely to finite elements. The references are divided into categories. Attention is given to fundamentals, mathematical foundations, structural and solid mechanics applications, fluid mechanics applications, other applied science and engineering applications, computer implementation and software systems, computational and modeling aspects, special topics, boundary element methods, proceedings of symmposia and conferences on finite element technology, bibliographies, handbooks, and historical accounts.

  1. Two position optical element actuator device

    DOEpatents

    Holdener, Fred R.; Boyd, Robert D.

    2002-01-01

    The present invention is a two position optical element actuator device utilizing a powered means to hold an actuation arm, to which an optical element is attached, in a first position. A non-powered means drives the actuation arm to a second position, when the powered means ceases to receive power. The optical element may be a electromagnetic (EM) radiation or particle source, an instrument, or EM radiation or particle transmissive, reflective or absorptive elements. A bearing is used to transfer motion and smoothly transition the actuation arm from the first to second position.

  2. Low impedance printed circuit radiating element

    NASA Technical Reports Server (NTRS)

    Rahm, James K. (Inventor); Frankievich, Robert H. (Inventor); Martinko, John D. (Inventor)

    1993-01-01

    A printed circuit radiating element comprises a geometrically symmetric planar area of a conducting material separated from a ground plane by a dielectric medium. The driving point of the radiating element is at the base of a notch in one side thereof so that the driving impedance is reduced from that obtained when the element is driven at its edge. Symmetrically disposed on opposite sides of an axis of symmetry of the element along which the driving point lies are two notches which restore the electrical symmetry of the radiating element thereby to suppress higher order modes. The suppression of these higher order modes results in a radiation pattern with minimal cross-polarized energy in the principal planes and high port-to-port isolation which could not be achieved with an asymmetrical element. Two driving points may be employed with the radiating element to produce a dual linearly polarized antenna and a reactive combiner or hybrid may be employed to obtain circularly-polarized radiations. The shape of the radiating element may be square, rectangular or circular, for example, in accordance with the desired characteristics. A plurality of radiating elements may be interconnected via appropriate transmission paths to form an antenna array.

  3. Classification and nomenclature of retrotransposable elements.

    PubMed

    Capy, P

    2005-01-01

    The classification and nomenclature of retrotransposable elements is reviewed. A comparison is made between the initial classification summarized in Capy et al. (1997b), and the more recent proposal based on the classification of the viruses (Hull, 2001). Several problems, mainly relating to the position of elements belonging to the DIRS-like or Bel-like groups, are discussed. The first classification is now out of date, and must be revisited to take account of the discovery of new elements, however the second cannot be extended to the DNA elements. There is therefore, clear evidence of the need to adopt a general and a common classification.

  4. Magnetic network elements in solar cycle 23

    NASA Astrophysics Data System (ADS)

    Jin, Chunlan; Wang, Jingxiu

    2013-07-01

    In this report, we present our recent effort to understand the cyclic behavior of network magnetic elements based on the unique database from full-disk observations provided by Michelson Doppler Imager on board the Solar and Heliospheric Observatory in the interval including the entire cycle 23. The following results are unclosed. (1) The quiet regions dominate the solar magnetic flux for about 8 years in solar cycle 23, and from the solar minimum to maximum they contribute (0.94-1.44)×1023Mx flux to the solar photosphere. In the entire cycle 23, the magnetic flux of the quiet regions is 1.12 times that of active regions. The occupation ratio of quiet region flux equally characterizes the course of a solar cycle. (2) With the increasing magnetic flux per element, the variations of numbers and total flux of the network elements show three-fold scenario: no-correlation, anti-correlation, and correlation with sunspots, respectively. The anti-correlated elements covering the range of (3-32)×1018Mx occupy 77% of total element number and 37% of quiet Sun flux. (3) The time-latitude distribution of anti-correlated magnetic elements is out of phase with that of sunspots, while the correlated elements display the similar butterfly diagram of sunspots but with wider latitude distribution. These results imply that the correlated elements are the debris of decayed sunspots, and the source of anti-correlated elements is modulated by sunspot magnetic field.

  5. Resistance heating elements with specific heating profiles

    NASA Technical Reports Server (NTRS)

    Hirschberg, M. H.

    1976-01-01

    Bundled, interrupted, resistance heating elements provide specific heating profiles. Design allows for easily tailored lengths and locations of "hot sections" and larger surface areas for heat radiation.

  6. Spectral analysis method for detecting an element

    DOEpatents

    Blackwood, Larry G [Idaho Falls, ID; Edwards, Andrew J [Idaho Falls, ID; Jewell, James K [Idaho Falls, ID; Reber, Edward L [Idaho Falls, ID; Seabury, Edward H [Idaho Falls, ID

    2008-02-12

    A method for detecting an element is described and which includes the steps of providing a gamma-ray spectrum which has a region of interest which corresponds with a small amount of an element to be detected; providing nonparametric assumptions about a shape of the gamma-ray spectrum in the region of interest, and which would indicate the presence of the element to be detected; and applying a statistical test to the shape of the gamma-ray spectrum based upon the nonparametric assumptions to detect the small amount of the element to be detected.

  7. Trace Elements in Ovaries: Measurement and Physiology.

    PubMed

    Ceko, Melanie J; O'Leary, Sean; Harris, Hugh H; Hummitzsch, Katja; Rodgers, Raymond J

    2016-04-01

    Traditionally, research in the field of trace element biology and human and animal health has largely depended on epidemiological methods to demonstrate involvement in biological processes. These studies were typically followed by trace element supplementation trials or attempts at identification of the biochemical pathways involved. With the discovery of biological molecules that contain the trace elements, such as matrix metalloproteinases containing zinc (Zn), cytochrome P450 enzymes containing iron (Fe), and selenoproteins containing selenium (Se), much of the current research focuses on these molecules, and, hence, only indirectly on trace elements themselves. This review focuses largely on two synchrotron-based x-ray techniques: X-ray absorption spectroscopy and x-ray fluorescence imaging that can be used to identify the in situ speciation and distribution of trace elements in tissues, using our recent studies of bovine ovaries, where the distribution of Fe, Se, Zn, and bromine were determined. It also discusses the value of other techniques, such as inductively coupled plasma mass spectrometry, used to garner information about the concentrations and elemental state of the trace elements. These applications to measure trace elemental distributions in bovine ovaries at high resolutions provide new insights into possible roles for trace elements in the ovary.

  8. Method of lightening radiation darkened optical elements

    DOEpatents

    Reich, Frederich R.; Schwankoff, Albert R.

    1980-01-01

    A method of lightening a radiation-darkened optical element in wich visible optical energy or electromagnetic radiation having a wavelength in the range of from about 2000 to about 20,000 angstroms is directed into the radiation-darkened optical element; the method may be used to lighten radiation-darkened optical element in-situ during the use of the optical element to transmit data by electronically separating the optical energy from the optical output by frequency filtering, data cooling, or interlacing the optic energy between data intervals.

  9. Avisos de salud sobre el PFOA y PFOS en el agua potable

    EPA Pesticide Factsheets

    La EPA estableció avisos de salud sobre el ácido perfluorooctanoico (PFOA) y el sulfonato de perfluorooctano (PFOS) para proporcionar información a los operadores de sistemas de agua potable y funcionarios estatales, tribales y locales sobre los riesgos de

  10. Adaptive implicit-explicit and parallel element-by-element iteration schemes

    NASA Technical Reports Server (NTRS)

    Tezduyar, T. E.; Liou, J.; Nguyen, T.; Poole, S.

    1989-01-01

    Adaptive implicit-explicit (AIE) and grouped element-by-element (GEBE) iteration schemes are presented for the finite element solution of large-scale problems in computational mechanics and physics. The AIE approach is based on the dynamic arrangement of the elements into differently treated groups. The GEBE procedure, which is a way of rewriting the EBE formulation to make its parallel processing potential and implementation more clear, is based on the static arrangement of the elements into groups with no inter-element coupling within each group. Various numerical tests performed demonstrate the savings in the CPU time and memory.

  11. Adaptive implicit-explicit and parallel element-by-element iteration schemes

    NASA Astrophysics Data System (ADS)

    Tezduyar, T. E.; Liou, J.; Nguyen, T.; Poole, S.

    Adaptive implicit-explicit (AIE) and grouped element-by-element (GEBE) iteration schemes are presented for the finite element solution of large-scale problems in computational mechanics and physics. The AIE approach is based on the dynamic arrangement of the elements into differently treated groups. The GEBE procedure, which is a way of rewriting the EBE formulation to make its parallel processing potential and implementation more clear, is based on the static arrangement of the elements into groups with no inter-element coupling within each group. Various numerical tests performed demonstrate the savings in the CPU time and memory.

  12. Adaptive implicit-explicit and parallel element-by-element iteration schemes

    NASA Technical Reports Server (NTRS)

    Tezduyar, T. E.; Liou, J.; Nguyen, T.; Poole, S.

    1989-01-01

    Adaptive implicit-explicit (AIE) and grouped element-by-element (GEBE) iteration schemes are presented for the finite element solution of large-scale problems in computational mechanics and physics. The AIE approach is based on the dynamic arrangement of the elements into differently treated groups. The GEBE procedure, which is a way of rewriting the EBE formulation to make its parallel processing potential and implementation more clear, is based on the static arrangement of the elements into groups with no inter-element coupling within each group. Various numerical tests performed demonstrate the savings in the CPU time and memory.

  13. Lubrication of rolling-element bearings

    NASA Technical Reports Server (NTRS)

    Parker, R. J.

    1980-01-01

    The lubrication of rolling element bearings is surveyed. Emphasis is on the critical design aspects related to speed, temperature, and ambient pressure environment. Types of lubrication including grease, jets, mist, wick, and through the race are discussed. The historical development, present state of technology, and the future problems of rolling element bearing lubrication are discussed.

  14. Trace Element Analysis of Biological Samples.

    ERIC Educational Resources Information Center

    Veillon, Claude

    1986-01-01

    Reviews background of atomic absorption spectrometry techniques. Discusses problems encountered and precautions to be taken in determining trace elements in the parts-per-billion concentration range and below. Concentrates on determining chromium in biological samples by graphite furnace atomic absorption. Considers other elements, matrices, and…

  15. DISSOLUTION OF ZIRCONIUM-CONTAINING FUEL ELEMENTS

    DOEpatents

    Horn, F.L.

    1961-12-12

    Uranium is recovered from spent uranium fuel elements containing or clad with zirconium. These fuel elements are placed in an anhydrous solution of hydrogen fluoride and nitrogen dioxide. Within this system uranium forms a soluble complex and zirconium forms an insoluble complex. The uranium can then be separated, treated, and removed from solution as uranium hexafluoride. (AEC)

  16. 19 CFR 149.3 - Data elements.

    Code of Federal Regulations, 2010 CFR

    2010-04-01

    ... 19 Customs Duties 2 2010-04-01 2010-04-01 false Data elements. 149.3 Section 149.3 Customs Duties U.S. CUSTOMS AND BORDER PROTECTION, DEPARTMENT OF HOMELAND SECURITY; DEPARTMENT OF THE TREASURY (CONTINUED) IMPORTER SECURITY FILING § 149.3 Data elements. (a) Shipments intended to be entered into the...

  17. 19 CFR 149.3 - Data elements.

    Code of Federal Regulations, 2011 CFR

    2011-04-01

    ... 19 Customs Duties 2 2011-04-01 2011-04-01 false Data elements. 149.3 Section 149.3 Customs Duties U.S. CUSTOMS AND BORDER PROTECTION, DEPARTMENT OF HOMELAND SECURITY; DEPARTMENT OF THE TREASURY (CONTINUED) IMPORTER SECURITY FILING § 149.3 Data elements. (a) Shipments intended to be entered into the...

  18. 19 CFR 149.3 - Data elements.

    Code of Federal Regulations, 2013 CFR

    2013-04-01

    ... 19 Customs Duties 2 2013-04-01 2013-04-01 false Data elements. 149.3 Section 149.3 Customs Duties U.S. CUSTOMS AND BORDER PROTECTION, DEPARTMENT OF HOMELAND SECURITY; DEPARTMENT OF THE TREASURY (CONTINUED) IMPORTER SECURITY FILING § 149.3 Data elements. (a) Shipments intended to be entered into the...

  19. 19 CFR 149.3 - Data elements.

    Code of Federal Regulations, 2014 CFR

    2014-04-01

    ... 19 Customs Duties 2 2014-04-01 2014-04-01 false Data elements. 149.3 Section 149.3 Customs Duties U.S. CUSTOMS AND BORDER PROTECTION, DEPARTMENT OF HOMELAND SECURITY; DEPARTMENT OF THE TREASURY (CONTINUED) IMPORTER SECURITY FILING § 149.3 Data elements. (a) Shipments intended to be entered into the...

  20. 19 CFR 149.3 - Data elements.

    Code of Federal Regulations, 2012 CFR

    2012-04-01

    ... 19 Customs Duties 2 2012-04-01 2012-04-01 false Data elements. 149.3 Section 149.3 Customs Duties U.S. CUSTOMS AND BORDER PROTECTION, DEPARTMENT OF HOMELAND SECURITY; DEPARTMENT OF THE TREASURY (CONTINUED) IMPORTER SECURITY FILING § 149.3 Data elements. (a) Shipments intended to be entered into the...

  1. Heavy Metals and Related Trace Elements.

    ERIC Educational Resources Information Center

    Leland, Harry V.; And Others

    1978-01-01

    Presents a literature review of heavy metals and related trace elements in the environment, covering publications of 1976-77. This review includes: (1) trace treatment in natural water and in sediments; and (2) bioaccumulation and toxicity of trace elements. A list of 466 references is presented. (HM)

  2. NUCLEAR REACTOR FUEL-BREEDER FUEL ELEMENT

    DOEpatents

    Currier, E.L. Jr.; Nicklas, J.H.

    1962-08-14

    A fuel-breeder fuel element was developed for a nuclear reactor wherein discrete particles of fissionable material are dispersed in a matrix of fertile breeder material. The fuel element combines the advantages of a dispersion type and a breeder-type. (AEC)

  3. The New Element Curium (Atomic Number 96)

    DOE R&D Accomplishments Database

    Seaborg, G. T.; James, R. A.; Ghiorso, A.

    1948-01-01

    Two isotopes of the element with atomic number 96 have been produced by the helium-ion bombardment of plutonium. The name curium, symbol Cm, is proposed for element 96. The chemical experiments indicate that the most stable oxidation state of curium is the III state.

  4. Data Element Definitions for Secondary Services.

    ERIC Educational Resources Information Center

    Council of Europe, Strasbourg (France). Documentation Center for Education in Europe.

    The results of the efforts of the National Federation of Science Abstracting and Indexing Services (NFSAIS) Bibliographic Citation Committee (BCC) Working Group on Data Element Definition are reported. The report contains a recommended uniform approach to the handling of bibliographic data elements. The approach is an amalgam of current practices…

  5. Microstrip antenna arrays with parasitic elements

    NASA Technical Reports Server (NTRS)

    Lee, Kai-Fong

    1996-01-01

    This research was concerned with using parasitic elements to improve the bandwidth, gain and axial ratio characteristics of microstrip antennas and arrays. Significant improvements in these characteristics were obtained using stacked and coplanar parasitic elements. Details of the results are described in a total of 16 journal and 17 conference papers. These are listed in Section four of this report.

  6. Octupole correlations in the heavy elements

    SciTech Connect

    Chasman, R.R.

    1986-01-01

    The effects of octupole correlations on the nuclear structure of the heavy elements are discussed. The cluster model description of the heavy elements is analyzed. The relevance of 2/sup 6/-pole deformation and fast El transitions to an octupole model is considered. 30 refs., 21 figs., 1 tab.

  7. The Elements Go to the Movies

    ERIC Educational Resources Information Center

    Taarea, Dina; Thomas, Nicholas C.

    2010-01-01

    The names of many common elements have found their way into the titles of feature films: gold, silver, iron, copper, and lead, for example, appear in hundreds of movie titles. Surprisingly, perhaps, more than two dozen other elements, including iodine, cadmium, zinc, calcium, argon, chlorine, and others, have also been used in film titles. In this…

  8. Biological trace element measurements using synchrotron radiation

    SciTech Connect

    Giauque, R.D.; Jaklevic, J.M.; Thompson, A.C.

    1985-07-01

    The feasibility of performing x-ray fluorescence trace element determinations at concentrations substantially below the ppM level for biological materials is demonstrated. Conditions for achieving optimum sensitivity were ascertained. Results achieved for five standard reference materials were, in most cases, in excellent agreement with listed values. Minimum detectable limits of 20 ppM were measured for most elements.

  9. The Superheavy Elements and Anti-Gravity

    SciTech Connect

    Anastasovski, Petar K.

    2004-02-04

    The essence of any propulsion concept is to overcome gravity. Anti-gravity is a natural means to achieve this. Thus, the technology to pursue anti-gravity, by using superheavy elements, may provide a new propulsion paradigm. The theory of superluminal relativity provides a hypothesis for existence of elements with atomic number up to Z = 145, some of which may possess anti-gravity properties. Analysis results show that curved space-time exists demonstrating both gravitic and anti-gravitic properties not only around nuclei but inside the nuclei as well. Two groups of elements (Z < 64 and 63 < Z <145) exist that demonstrate these capabilities. The nuclei of the first group of elements have the masses with only the property of gravity. The nuclei of the elements of the second group have the masses with both properties: gravity and anti-gravity in two different ranges of curved space-time around the nuclei.. The hypothetical element with Z = 145 is the unique among all elements whose nucleus has only anti-gravity property. It is proposed that this element be named Hawking, in honour of Stephen W. Hawking.

  10. The Superheavy Elements and Anti-Gravity

    NASA Astrophysics Data System (ADS)

    Anastasovski, Petar K.

    2004-02-01

    The essence of any propulsion concept is to overcome gravity. Anti-gravity is a natural means to achieve this. Thus, the technology to pursue anti-gravity, by using superheavy elements, may provide a new propulsion paradigm. The theory of superluminal relativity provides a hypothesis for existence of elements with atomic number up to Z = 145, some of which may possess anti-gravity properties. Analysis results show that curved space-time exists demonstrating both gravitic and anti-gravitic properties not only around nuclei but inside the nuclei as well. Two groups of elements (Z < 64 and 63 < Z <145) exist that demonstrate these capabilities. The nuclei of the first group of elements have the masses with only the property of gravity. The nuclei of the elements of the second group have the masses with both properties: gravity and anti-gravity in two different ranges of curved space-time around the nuclei.. The hypothetical element with Z = 145 is the unique among all elements whose nucleus has only anti-gravity property. It is proposed that this element be named Hawking, in honour of Stephen W. Hawking.

  11. 36 CFR 230.35 - FLEP elements.

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    ... 36 Parks, Forests, and Public Property 2 2013-07-01 2013-07-01 false FLEP elements. 230.35 Section 230.35 Parks, Forests, and Public Property FOREST SERVICE, DEPARTMENT OF AGRICULTURE STATE AND PRIVATE FORESTRY ASSISTANCE Forest Land Enhancement Program § 230.35 FLEP elements. (a) States may use FLEP funds...

  12. 36 CFR 230.35 - FLEP elements.

    Code of Federal Regulations, 2014 CFR

    2014-07-01

    ... 36 Parks, Forests, and Public Property 2 2014-07-01 2014-07-01 false FLEP elements. 230.35 Section 230.35 Parks, Forests, and Public Property FOREST SERVICE, DEPARTMENT OF AGRICULTURE STATE AND PRIVATE FORESTRY ASSISTANCE Forest Land Enhancement Program § 230.35 FLEP elements. (a) States may use FLEP funds...

  13. 36 CFR 230.35 - FLEP elements.

    Code of Federal Regulations, 2012 CFR

    2012-07-01

    ... 36 Parks, Forests, and Public Property 2 2012-07-01 2012-07-01 false FLEP elements. 230.35 Section 230.35 Parks, Forests, and Public Property FOREST SERVICE, DEPARTMENT OF AGRICULTURE STATE AND PRIVATE FORESTRY ASSISTANCE Forest Land Enhancement Program § 230.35 FLEP elements. (a) States may use FLEP funds...

  14. 36 CFR 230.35 - FLEP elements.

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ... 36 Parks, Forests, and Public Property 2 2011-07-01 2011-07-01 false FLEP elements. 230.35 Section 230.35 Parks, Forests, and Public Property FOREST SERVICE, DEPARTMENT OF AGRICULTURE STATE AND PRIVATE FORESTRY ASSISTANCE Forest Land Enhancement Program § 230.35 FLEP elements. (a) States may use FLEP funds...

  15. 36 CFR 230.35 - FLEP elements.

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... 36 Parks, Forests, and Public Property 2 2010-07-01 2010-07-01 false FLEP elements. 230.35 Section 230.35 Parks, Forests, and Public Property FOREST SERVICE, DEPARTMENT OF AGRICULTURE STATE AND PRIVATE FORESTRY ASSISTANCE Forest Land Enhancement Program § 230.35 FLEP elements. (a) States may use FLEP funds...

  16. Sputter metalization of Wolter type optical elements

    NASA Technical Reports Server (NTRS)

    Ledger, A. M.

    1977-01-01

    An analytical task showed that the coating thickness distribution for both internal and external optical elements coated using either electron beam or sputter sources can be made uniform and will not affect the surface figure of coated elements. Also, sputtered samples of nickel, molybdenum, iridium and ruthenium deposited onto both hot and cold substrates showed excellent adhesion.

  17. 40 CFR 721.10068 - Elemental mercury.

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ... in anti-lock brake systems (ABS) in new motor vehicles. (iv) Manufacture or processing of elemental mercury for use in switches in ABS as new aftermarket replacement parts for motor vehicles that were... active ride control systems in new motor vehicles. (vi) Manufacture or processing of elemental mercury...

  18. 14 CFR 271.6 - Profit element.

    Code of Federal Regulations, 2014 CFR

    2014-01-01

    ... 14 Aeronautics and Space 4 2014-01-01 2014-01-01 false Profit element. 271.6 Section 271.6 Aeronautics and Space OFFICE OF THE SECRETARY, DEPARTMENT OF TRANSPORTATION (AVIATION PROCEEDINGS) ECONOMIC... element. The reasonable return for a carrier for providing essential air service at an eligible place...

  19. 49 CFR 236.744 - Element, roadway.

    Code of Federal Regulations, 2014 CFR

    2014-10-01

    ... 49 Transportation 4 2014-10-01 2014-10-01 false Element, roadway. 236.744 Section 236.744 Transportation Other Regulations Relating to Transportation (Continued) FEDERAL RAILROAD ADMINISTRATION... Element, roadway. That portion of the roadway apparatus of automatic train stop, train control, or cab...

  20. 49 CFR 236.744 - Element, roadway.

    Code of Federal Regulations, 2012 CFR

    2012-10-01

    ... 49 Transportation 4 2012-10-01 2012-10-01 false Element, roadway. 236.744 Section 236.744 Transportation Other Regulations Relating to Transportation (Continued) FEDERAL RAILROAD ADMINISTRATION... Element, roadway. That portion of the roadway apparatus of automatic train stop, train control, or cab...