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Sample records for ages metallicities detailed

  1. Sometimes age is just a detail

    CERN Multimedia

    Anaïs Schaeffer

    2012-01-01

    Shree Bose, the young woman who won the 2011 Google Science Fair competition, visited CERN at the end of June. She had the chance to be here for the Higgs update seminar and, as she told the Bulletin, was "completely blown away”.   Shree Bose, in the LHC tunnel. In 2011, Google launched its first global science competition for teenagers aged 13 to 18: the Google Science Fair. Several thousand young students from 91 countries took part in the contest by submitting a personal and original scientific work. Shree Bose won first prize in the 17-18 age category and the Google Science Fair “Grand prize”. Her work? She discovered a way to improve ovarian cancer treatment – no less – by overcoming patients’ resistance to chemotherapy drugs. Along with two other winners of the competition, Shree went to the White House to meet US President Obama, and presented her work at TED Women in Los Angeles. She was also nam...

  2. Detailed study of flat bands appearing in metallic photonic crystals

    Energy Technology Data Exchange (ETDEWEB)

    Vala, Ali Soltani [Department of Solid State Physics, Faculty of Physics, University of Tabriz, PO Box 51665-163, Tabriz (Iran, Islamic Republic of); Research Institute for Applied Physics and Astronomy, University of Tabriz, PO Box 51665-163, Tabriz (Iran, Islamic Republic of); Sedghi, Aliasghar; Hosseini, Naser [Department of Solid State Physics, Faculty of Physics, University of Tabriz, PO Box 51665-163, Tabriz (Iran, Islamic Republic of); Kalafi, Manouchehr [Department of Solid State Physics, Faculty of Physics, University of Tabriz, PO Box 51665-163, Tabriz (Iran, Islamic Republic of); Research Institute for Applied Physics and Astronomy, University of Tabriz, PO Box 51665-163, Tabriz (Iran, Islamic Republic of); Excellence Centre for Photonics, University of Tabriz, PO Box 51665-163, Tabriz (Iran, Islamic Republic of)

    2011-09-15

    It has been difficult to compute the band structures of metallic photonic crystals for H-polarization. The existence of surface plasmon modes is the major reason for difficulty due to the localized nature of these modes. In this study, by virtue of the efficiency of the newly developed Dirichlet-to-Neumann map method, we are able to investigate the details of the flat bands in a two dimensional square lattice with metallic cylinders. We have obtained fine band structure for H polarization around the flat band region which has not been reported to the best of our knowledge. Our numerical results show that for the frequency around the surface plasmon, the modes are highly localized at the interface of the cylindrical metallic rods and air background and also by approaching the modes to the surface plasmon frequency the localization length decreases and the number of field's nodes increases considerably. (copyright 2011 WILEY-VCH Verlag GmbH and Co. KGaA, Weinheim) (orig.)

  3. Tile-based Level of Detail for the Parallel Age

    Energy Technology Data Exchange (ETDEWEB)

    Niski, K; Cohen, J D

    2007-08-15

    Today's PCs incorporate multiple CPUs and GPUs and are easily arranged in clusters for high-performance, interactive graphics. We present an approach based on hierarchical, screen-space tiles to parallelizing rendering with level of detail. Adapt tiles, render tiles, and machine tiles are associated with CPUs, GPUs, and PCs, respectively, to efficiently parallelize the workload with good resource utilization. Adaptive tile sizes provide load balancing while our level of detail system allows total and independent management of the load on CPUs and GPUs. We demonstrate our approach on parallel configurations consisting of both single PCs and a cluster of PCs.

  4. Detailed Abundances of Two Very Metal-Poor Stars in Dwarf Galaxies

    CERN Document Server

    Kirby, Evan N

    2012-01-01

    The most metal-poor stars in dwarf spheroidal galaxies (dSphs) can show the nucleosynthetic patterns of one or a few supernovae. These supernovae could have zero metallicity, making metal-poor dSph stars the closest surviving links to Population III stars. Metal-poor dSph stars also help to reveal the formation mechanism of the Milky Way halo. We present the detailed abundances from Keck/HIRES spectroscopy for two very metal-poor stars in two Milky Way dSphs. One star, in the Sculptor dSph, has [Fe I/H] = -2.40. The other star, in the Ursa Minor dSph, has [Fe I/H] = -3.16. Both stars fall in the previously discovered low-metallicity, high-[alpha/Fe] plateau. Most abundance ratios of very metal-poor stars in these two dSphs are largely consistent with very metal-poor halo stars. However, the abundances of Na and some r-process elements lie at the lower end of the envelope defined by inner halo stars of similar metallicity. We propose that the metallicity dependence of supernova yields is the cause. The earlies...

  5. DETAILED ABUNDANCES OF TWO VERY METAL-POOR STARS IN DWARF GALAXIES

    Energy Technology Data Exchange (ETDEWEB)

    Kirby, Evan N.; Cohen, Judith G. [Department of Astronomy, California Institute of Technology, 1200 E. California Blvd., MC 249-17, Pasadena, CA 91125 (United States)

    2012-12-01

    The most metal-poor stars in dwarf spheroidal galaxies (dSphs) can show the nucleosynthetic patterns of one or a few supernovae (SNe). These SNe could have zero metallicity, making metal-poor dSph stars the closest surviving links to Population III stars. Metal-poor dSph stars also help to reveal the formation mechanism of the Milky Way (MW) halo. We present the detailed abundances from Keck/HIRES spectroscopy for two very metal-poor stars in two MW dSphs. One star, in the Sculptor dSph, has [Fe I/H] = -2.40. The other star, in the Ursa Minor dSph, has [Fe I/H] = -3.16. Both stars fall in the previously discovered low-metallicity, high-[{alpha}/Fe] plateau. Most abundance ratios of very metal-poor stars in these two dSphs are largely consistent with very metal-poor halo stars. However, the abundances of Na and some r-process elements lie at the lower end of the envelope defined by inner halo stars of similar metallicity. We propose that the metallicity dependence of SN yields is the cause. The earliest SNe in low-mass dSphs have less gas to pollute than the earliest SNe in massive halo progenitors. As a result, dSph stars at -3 < [Fe/H] < -2 sample SNe with [Fe/H] << -3, whereas halo stars in the same metallicity range sample SNe with [Fe/H] {approx} -3. Consequently, enhancements in [Na/Fe] and [r/Fe] were deferred to higher metallicity in dSphs than in the progenitors of the inner halo.

  6. Aging of Transition Metal Dichalcogenide Monolayers.

    Science.gov (United States)

    Gao, Jian; Li, Baichang; Tan, Jiawei; Chow, Phil; Lu, Toh-Ming; Koratkar, Nikhil

    2016-02-23

    Two-dimensional sheets of transition metal dichalcogenides are an emerging class of atomically thin semiconductors that are considered to be "air-stable", similar to graphene. Here we report that, contrary to current understanding, chemical vapor deposited transition metal dichalcogenide monolayers exhibit poor long-term stability in air. After room-temperature exposure to the environment for several months, monolayers of molybdenum disulfide and tungsten disulfide undergo dramatic aging effects including extensive cracking, changes in morphology, and severe quenching of the direct gap photoluminescence. X-ray photoelectron and Auger electron spectroscopy reveal that this effect is related to gradual oxidation along the grain boundaries and the adsorption of organic contaminants. These results highlight important challenges associated with the utilization of transition metal dichalcogenide monolayers in electronic and optoelectronic devices. We also demonstrate a potential solution to this problem, featuring encapsulation of the monolayer sheet by a 10-20 nm thick optically transparent polymer (parylene C). This strategy is shown to successfully prevent the degradation of the monolayer material under accelerated aging (i.e., high-temperature, oxygen-rich) conditions. PMID:26808328

  7. Th Ages for Metal-Poor Stars

    CERN Document Server

    Johnson, J A; Johnson, Jennifer A.; Bolte, Michael

    2001-01-01

    With a sample of 22 metal-poor stars, we demonstrate that the heavy element abundance pattern (Z > 55) is the same as the r-process contributions to the solar nebula. This bolsters the results of previous studies that there is a universal r-process production pattern. We use the abundance of thorium in five metal-poor stars, along with an estimate of the initial Th abundance based on the abundances of stable r-process elements, to measure their ages. We have four field red giants with errors of 4.2 Gyr in their ages and one M92 giant with an error of 5.6 Gyr, based on considering the sources of observational error only. We obtain an average age of 11.4 Gyr, which depends critically on the assumption of an initial production ratio of Th/Eu of 0.496. If the Universe is 15 Gyr old, then the initial Th/Eu value should be 0.590, in agreement with some theoretical models of the r-process.

  8. Detailed abundance analysis of a metal-poor giant in the Galactic Center

    CERN Document Server

    Ryde, N; Rich, R M; Thorsbro, B; Schultheis, M; Origlia, L; Chatzopoulos, S

    2016-01-01

    We report the first results from our program to examine the metallicity distribution of the Milky Way nuclear star cluster connected to SgrA*, with the goal of inferring the star formation and enrichment history of this system, as well as its connection and relationship with the central 100 pc of the bulge/bar system. We present the first high resolution (R~24,000), detailed abundance analysis of a K=10.2 metal-poor, alpha-enhanced red giant projected at 1.5 pc from the Galactic Center, using NIRSPEC on Keck II. A careful analysis of the dynamics and color of the star locates it at about 26 pc line-of-sight distance in front of the nuclear cluster. It probably belongs to one of the nuclear components (cluster or disk), not to the bar-bulge or classical disk. A detailed spectroscopic synthesis, using a new linelist in the K band, finds [Fe/H]~-1.0 and [alpha/Fe]~+0.4, consistent with stars of similar metallicity in the bulge. As known giants with comparable [Fe/H] and alpha enhancement are old, we conclude tha...

  9. Ecological Risk Assessment of a Metal-Contaminated Area in the Tropics. Tier II: Detailed Assessment.

    Science.gov (United States)

    Niemeyer, Júlia Carina; Moreira-Santos, Matilde; Ribeiro, Rui; Rutgers, Michiel; Nogueira, Marco Antonio; da Silva, Eduardo Mendes; Sousa, José Paulo

    2015-01-01

    This study presents data on the detailed evaluation (tier 2) of a site-specific ecological risk assessment (ssERA) in a former smelter area contaminated with metals (Santo Amaro, Bahia, Brazil). Combining information from three lines of evidence (LoE), chemical (ChemLoE), ecotoxicological (EcotoxLoE) and ecological (EcoLoE), in the Triad approach, integrated risk values were calculated to rank sites and confirm the potential risk disclosed with tier 1. Risk values were calculated for the habitat and for the retention functions in each sampling point. Habitat function included the ChemLoE calculated from total metal concentrations. The EcotoxLoE was based on reproduction tests with terrestrial invertebrates (Folsomia candida, Enchytraeus crypticus, Eisenia andrei), shoot length and plant biomass (Avena sativa, Brassica rapa). For the EcoLoE, ecological parameters (microbial parameters, soil invertebrate community, litter breakdown) were used to derive risk values. Retention function included the ChemLoE, calculated from extractable metal concentrations, and the EcotoxLoE based on eluate tests with aquatic organisms (Daphnia magna reproduction and Pseudokirchneriella subcapitata growth). Results related to the habitat function indicated that the metal residues are sufficient to cause risk to biota, while the low metal levels in extracts and the general lack of toxicity in aquatic tests indicated a high soil retention capacity in most sampling points. Integrated risk of tier 2 showed the same trend of tier 1, suggesting the need to proceed with remediation actions. The high risk levels were related to direct toxicity to organisms and indirect effects, such as failure in the establishment of vegetation and the consequent loss of habitat quality for microorganisms and soil fauna. This study shed some light on the selection of tools for the tier 2 of an ssERA in tropical metal-contaminated sites, focusing on ecological receptors at risk and using available chemical

  10. Ecological Risk Assessment of a Metal-Contaminated Area in the Tropics. Tier II: Detailed Assessment.

    Directory of Open Access Journals (Sweden)

    Júlia Carina Niemeyer

    Full Text Available This study presents data on the detailed evaluation (tier 2 of a site-specific ecological risk assessment (ssERA in a former smelter area contaminated with metals (Santo Amaro, Bahia, Brazil. Combining information from three lines of evidence (LoE, chemical (ChemLoE, ecotoxicological (EcotoxLoE and ecological (EcoLoE, in the Triad approach, integrated risk values were calculated to rank sites and confirm the potential risk disclosed with tier 1. Risk values were calculated for the habitat and for the retention functions in each sampling point. Habitat function included the ChemLoE calculated from total metal concentrations. The EcotoxLoE was based on reproduction tests with terrestrial invertebrates (Folsomia candida, Enchytraeus crypticus, Eisenia andrei, shoot length and plant biomass (Avena sativa, Brassica rapa. For the EcoLoE, ecological parameters (microbial parameters, soil invertebrate community, litter breakdown were used to derive risk values. Retention function included the ChemLoE, calculated from extractable metal concentrations, and the EcotoxLoE based on eluate tests with aquatic organisms (Daphnia magna reproduction and Pseudokirchneriella subcapitata growth. Results related to the habitat function indicated that the metal residues are sufficient to cause risk to biota, while the low metal levels in extracts and the general lack of toxicity in aquatic tests indicated a high soil retention capacity in most sampling points. Integrated risk of tier 2 showed the same trend of tier 1, suggesting the need to proceed with remediation actions. The high risk levels were related to direct toxicity to organisms and indirect effects, such as failure in the establishment of vegetation and the consequent loss of habitat quality for microorganisms and soil fauna. This study shed some light on the selection of tools for the tier 2 of an ssERA in tropical metal-contaminated sites, focusing on ecological receptors at risk and using available

  11. THE EFFECT OF ALUM AND METALS ON PAPER AGING

    Institute of Scientific and Technical Information of China (English)

    Byun~HoYoo~; KyoungHwaChoi; MyoungKuLee; SeJongKim

    2004-01-01

    Books and archives experience aging which isaffected by a variety of factors, such asmicroorganism, humidity, light and components ofpaper [l]. Thus, the studies concerning impacts ofthose factors on paper aging are required. In thispaper, an accelerated paper aging was carried out toinvestigate the effects of acid and metals such asalum, copper ( 11 ) sulfate, copper ( 1] ) chloride, andiron ( IU ) chloride on paper aging. It was found thatboth acid and metals had impacts on paper aging. Inparticular, paper aging was far more accelerated incase that acid and metals were present in paper at thesame time.

  12. A search for stars of very low metal abundance. VI. Detailed abundances of 313 metal-poor stars

    Energy Technology Data Exchange (ETDEWEB)

    Roederer, Ian U.; Preston, George W.; Thompson, Ian B.; Shectman, Stephen A.; Burley, Gregory S.; Kelson, Daniel D. [Carnegie Observatories, 813 Santa Barbara Street, Pasadena, CA 91101 (United States); Sneden, Christopher, E-mail: iur@umich.edu [Department of Astronomy, University of Texas at Austin, 1 University Station, C1400, Austin, TX 78712 (United States)

    2014-06-01

    We present radial velocities, equivalent widths, model atmosphere parameters, and abundances or upper limits for 53 species of 48 elements derived from high resolution optical spectroscopy of 313 metal-poor stars. A majority of these stars were selected from the metal-poor candidates of the HK Survey of Beers, Preston, and Shectman. We derive detailed abundances for 61% of these stars for the first time. Spectra were obtained during a 10 yr observing campaign using the Magellan Inamori Kyocera Echelle spectrograph on the Magellan Telescopes at Las Campanas Observatory, the Robert G. Tull Coudé Spectrograph on the Harlan J. Smith Telescope at McDonald Observatory, and the High Resolution Spectrograph on the Hobby-Eberly Telescope at McDonald Observatory. We perform a standard LTE abundance analysis using MARCS model atmospheres, and we apply line-by-line statistical corrections to minimize systematic abundance differences arising when different sets of lines are available for analysis. We identify several abundance correlations with effective temperature. A comparison with previous abundance analyses reveals significant differences in stellar parameters, which we investigate in detail. Our metallicities are, on average, lower by ≈0.25 dex for red giants and ≈0.04 dex for subgiants. Our sample contains 19 stars with [Fe/H] ≤–3.5, 84 stars with [Fe/H] ≤–3.0, and 210 stars with [Fe/H] ≤–2.5. Detailed abundances are presented here or elsewhere for 91% of the 209 stars with [Fe/H] ≤–2.5 as estimated from medium resolution spectroscopy by Beers, Preston, and Shectman. We will discuss the interpretation of these abundances in subsequent papers.

  13. Ecological Risk Assessment of a Metal-Contaminated Area in the Tropics. Tier II: Detailed Assessment

    OpenAIRE

    Júlia Carina Niemeyer; Matilde Moreira-Santos; Rui Ribeiro; Michiel Rutgers; Marco Antonio Nogueira; Eduardo Mendes da Silva; José Paulo Sousa

    2015-01-01

    This study presents data on the detailed evaluation (tier 2) of a site-specific ecological risk assessment (ssERA) in a former smelter area contaminated with metals (Santo Amaro, Bahia, Brazil). Combining information from three lines of evidence (LoE), chemical (ChemLoE), ecotoxicological (EcotoxLoE) and ecological (EcoLoE), in the Triad approach, integrated risk values were calculated to rank sites and confirm the potential risk disclosed with tier 1. Risk values were calculated for the habi...

  14. Dynamical Observation and Detailed Description of Catalysts under Strong Metal-Support Interaction.

    Science.gov (United States)

    Zhang, Shuyi; Plessow, Philipp N; Willis, Joshua J; Dai, Sheng; Xu, Mingjie; Graham, George W; Cargnello, Matteo; Abild-Pedersen, Frank; Pan, Xiaoqing

    2016-07-13

    Understanding the structures of catalysts under realistic conditions with atomic precision is crucial to design better materials for challenging transformations. Under reducing conditions, certain reducible supports migrate onto supported metallic particles and create strong metal-support states that drastically change the reactivity of the systems. The details of this process are still unclear and preclude its thorough exploitation. Here, we report an atomic description of a palladium/titania (Pd/TiO2) system by combining state-of-the-art in situ transmission electron microscopy and density functional theory (DFT) calculations with structurally defined materials, in which we visualize the formation of the overlayers at the atomic scale under atmospheric pressure and high temperature. We show that an amorphous reduced titania layer is formed at low temperatures, and that crystallization of the layer into either mono- or bilayer structures is dictated by the reaction environment and predicted by theory. Furthermore, it occurs in combination with a dramatic reshaping of the metallic surface facets. PMID:27280326

  15. Detailed abundances in extremely metal poor dwarf stars extracted from SDSS

    CERN Document Server

    Sbordone, Luca; Caffau, Elisabetta; Ludwig, Hans-Gunther

    2012-01-01

    We report on the result of an ongoing campaign to determine chemical abundances in extremely metal poor (EMP) turn-off (TO) stars selected from the Sloan Digital Sky Survey (SDSS) low resolution spectra. This contribution focuses principally on the largest part of the sample (18 stars out of 29), observed with UVES@VLT and analyzed by means of the automatic abundance analysis code MyGIsFOS to derive atmosphere parameters and detailed compositions. The most significant findings include i) the detection of a C-rich, strongly Mg-enhanced star ([Mg/Fe]=1.45); ii) a group of Mn-rich stars ([Mn/Fe]>-0.4); iii) a group of Ni-rich stars ([Ni/Fe]>0.2). Li is measured in twelve stars, while for three upper limits are derived.

  16. Ar-39-Ar-40 Ages of Two Nakhlites, MIL03346 and Y000593: A Detailed Analysis

    Science.gov (United States)

    Park, Jisun; Garrison, Daniel; Bogard, Donald

    2007-01-01

    Radiometric dating of martian nakhlites by several techniques have given similar ages of approx.1.2-1.4 Ga [e.g. 1, 2]. Unlike the case with shergottites, where the presence of martian atmosphere and inherited radiogenic Ar-40 produce apparent Ar-39-Ar-40 ages older than other radiometric ages, Ar-Ar ages of nakhlites are similar to ages derived by other techniques. However, even in some nakhlites the presence of trapped martian Ar produces some uncertainty in the Ar-Ar age. We present here an analysis of such Ar-Ar ages from the MIL03346 and Y000593 nakhlites.

  17. Bronze Age metal artefacts found on Cyprus - metal from Anatolia and the Western Mediterranean

    Directory of Open Access Journals (Sweden)

    Stos-Gale, Zofia A.

    2010-12-01

    Full Text Available Hundreds of Bronze Age metal artefacts excavated on archaeological sites in Cyprus have been analysed for their lead isotope and elemental composition in the Isotrace Laboratory, University of Oxford, in the years 1982-2002. In parallel, but in particular after 1995, hundreds of samples of minerals and slags collected from the mines and smelting sites around the Troodos Mountains were also analysed. Most of the results were published in various articles over the years, but the interpretation of some of the lead isotope data needs a current revision in view of new research conducted in Spain, Sardinia and southern France. It has been known that the lead isotope data for metal artefacts from the Cypriot Bronze Age sites shows that not all of the copper is consistent with origin from the Cypriot ores. In addition, the lead and silver artefacts found there must have been imported, because there are no lead or silver ores on Cyprus. The re-evaluation of the data shows that about 11 % of the analysed metal artefacts are consistent with the origin from the deposits in the Aegean and Turkey, while about 14 % with sources in the Western Mediterranean. This paper discusses in detail the current interpretation of the research into the sources of imported metal found in the Bronze Age context on Cyprus.

    Cientos de objetos de metal de la Edad del Bronce excavados en yacimientos de Chipre han sido analizados para conocer su composición elemental y sus isótopos de plomo en el Isotrace Laboratory de la Universidad de Oxford entre los años 1982 y 2002. Especialmente con posterioridad a 1995 cientos de muestras de minerales y escorias recogidas de minas y sitios de reducción de minerales localizadas en el entorno de las montañas de Troodos también fueron analizadas. La mayoría de los resultados fueron publicados en varios artículos a lo largo del tiempo, pero la interpretación de algunos análisis de isótopos de plomo necesitan de una revisión a

  18. The Gaia-ESO Survey: Detailed Abundances in the Metal-poor Globular Cluster NGC 4372

    CERN Document Server

    Roman, I San; Geisler, D; Villanova, S; Kacharov, N; Koch, A; Carraro, G; Tautvaišiene, G; Vallenari, A; Alfaro, E J; Bensby, T; Flaccomio, E; Francois, P; Korn, A J; Pancino, E; Recio-Blanco, A; Smiljanic, R; Bergemann, M; Costado, M T; Damiani, F; Heiter, U; Hourihane, A; Jofré, P; Lardo, C; de Laverny, P; Masseron, T; Morbidelli, L; Sbordone, L; Sousa, S G; Worley, C C; Zaggia, S

    2015-01-01

    We present the abundance analysis for a sample of 7 red giant branch stars in the metal-poor globular cluster NGC 4372 based on UVES spectra acquired as part of the Gaia-ESO Survey. This is the first extensive study of this cluster from high resolution spectroscopy. We derive abundances of O, Na, Mg, Al, Si, Ca, Sc, Ti, Fe, Cr, Ni, Y, Ba, and La. We find a metallicity of [Fe/H] = -2.19 $\\pm$ 0.03 and find no evidence for a metallicity spread. This metallicity makes NGC 4372 one of the most metal-poor galactic globular clusters. We also find an {\\alpha}-enhancement typical of halo globular clusters at this metallicity. Significant spreads are observed in the abundances of light elements. In particular we find a Na-O anti-correlation. Abundances of O are relatively high compared with other globular clusters. This could indicate that NGC 4372 was formed in an environment with high O for its metallicity. A Mg-Al spread is also present which spans a range of more than 0.5 dex in Al abundances. Na is correlated wit...

  19. Galaxy gas flows inferred from a detailed, spatially resolved metal budget

    CERN Document Server

    Belfiore, F; Bothwell, M

    2015-01-01

    We use the most extensive integral field spectroscopic map of a local galaxy, NGC 628, combined with gas and stellar mass surface density maps, to study the distribution of metals in this galaxy out to 3 effective radii ($\\rm R_e$). At each galactocentric distance, we compute the metal budget and thus constrain the mass of metals lost. We find that in the disc about half of the metals have been lost throughout the lifetime of the galaxy. The fraction of metals lost is higher in the bulge ($\\sim$70%) and decreases towards the outer disc ($\\rm \\sim 3 \\ R_e$). In contrast to studies based on the gas kinematics, which are only sensitive to ongoing outflow events, our metal budget analysis enables us to infer the average outflow rate during the galaxy lifetime. By using simple physically motivated models of chemical evolution we can fit the observed metal budget at most radii with an average outflow loading factor of order unity, thus clearly demonstrating the importance of outflows in the evolution of disc galaxi...

  20. The metallicity spread and the age-metallicity relation of ω Centauri

    International Nuclear Information System (INIS)

    ω Centauri is a peculiar globular cluster formed by a complex stellar population. To investigate it, we studied 172 stars belonging to the five SGBs that we can identify in our photometry, in order to measure their [Fe/H] content as well as estimate their age dispersion and the age-metallicity relation. The first important result is that all of these SGBs have a distribution in metallicity with a spread that exceeds the observational errors and typically displays several peaks that indicate the presence of several subpopulations. We were able to identify at least six of them based on their mean [Fe/H] content. These metallicity-based subpopulations are seen to varying extents in each of the five SGBs. Taking advantage of the age sensitivity of the SGB, we showed that, first of all, at least half of the subpopulations have an age spread of at least 2 Gyr. Then, we obtained an age-metallicity relation that is the most complete to date for this cluster. Interpretation of the age-metallicity relation is not straightforward, but it is possible that the cluster (or what we can call its progenitor) was initially composed of two populations with different metallicities. Because of their age, it is very unlikely that the most metal-rich derives from the most metal-poor by some kind of chemical evolution process, so they can be assumed to be two independent primordial objects, or perhaps two separate parts of a single larger object, that merged in the past to form the present-day cluster.

  1. Detailed first-principles studies on surface energy and work function of hexagonal metals

    Science.gov (United States)

    Ji, De-Peng; Zhu, Quanxi; Wang, Shao-Qing

    2016-09-01

    The surface energies and work functions for ten kinds of Miller-indices surfaces of hexagonal metals, Be, Mg, Tc, Re, Ru, and Os are calculated by means of the density functional theory (DFT) method. The results show that the metals belonging to the same group have a very similar rule in work functions and surface energies. The work functions of (0001), (01 1 - 1)" separators=",, and (10 1 - 0)" separators=", surfaces are generally larger than the work functions of (11 2 - 1)" separators=",, (11 2 - 2)" separators=",, (11 2 - 3)" separators=",, and (31 4 - 0)" separators=", surfaces. In contrast to work functions, there is more regularity in the crystallographic orientation dependence of surface energies. However, for the metals belonging to different groups, there are always some differences in the exact order of orientation dependence. It is also shown that the work functions and surface energies of the main group metals decrease as they go from top to the bottom in the same group of periodic table, while for the transition metals, they do not always obey this rule.

  2. Ages and Metallicities of Hickson Compact Group Galaxies

    CERN Document Server

    Proctor, R N; Hau, G K T; Beasley, M A; De Silva, G M; Contreras, R; Terlevich, A I; Proctor, Robert N.; Forbes, Duncan A.; Hau, George K. T.; Beasley, Michael A.

    2004-01-01

    Hickson Compact Groups (HCGs) constitute an interesting extreme in the range of environments in which galaxies are located, as the space density of galaxies in these small groups are otherwise only found in the centres of much larger clusters. The work presented here uses Lick indices to make a comparison of ages and chemical compositions of galaxies in HCGs with those in other environments (clusters, loose groups and the field). The metallicity and relative abundance of `$\\alpha$-elements' show strong correlations with galaxy age and central velocity dispersion, with similar trends found in all environments. However, we show that the previously reported correlation between $\\alpha$-element abundance ratios and velocity dispersion disappears when a full account is taken of the the abundance ratio pattern in the calibration stars. This correlation is thus found to be an artifact of incomplete calibration to the Lick system. Variations are seen in the ranges and average values of age, metallicity and $\\alpha$-e...

  3. Detailed Chemical Abundances in NGC 5824: Another Metal-Poor Globular Cluster with Internal Heavy Element Abundance Variations

    CERN Document Server

    Roederer, Ian U; Bailey, John I; Spencer, Meghin; Crane, Jeffrey D; Shectman, Stephen A

    2015-01-01

    We present radial velocities, stellar parameters, and detailed abundances of 39 elements derived from high-resolution spectroscopic observations of red giant stars in the luminous, metal-poor globular cluster NGC 5824. We observe 26 stars in NGC 5824 using the Michigan/Magellan Fiber System (M2FS) and two stars using the Magellan Inamori Kyocera Echelle (MIKE) spectrograph. We derive a mean metallicity of [Fe/H]=-1.94+/-0.02 (statistical) +/-0.10 (systematic). The metallicity dispersion of this sample of stars, 0.08 dex, is in agreement with previous work and does not exceed the expected observational errors. Previous work suggested an internal metallicity spread only when fainter samples of stars were considered, so we cannot exclude the possibility of an intrinsic metallicity dispersion in NGC 5824. The M2FS spectra reveal a large internal dispersion in [Mg/Fe], 0.28 dex, which is found in a few other luminous, metal-poor clusters. [Mg/Fe] is correlated with [O/Fe] and anti-correlated with [Na/Fe] and [Al/F...

  4. Detailed study of the TE band structure of two dimensional metallic photonic crystals with square symmetry

    Energy Technology Data Exchange (ETDEWEB)

    Sedghi, Aliasghar [Islamic Azad University, Shabestar (Iran, Islamic Republic of); Valiaghaie, Soma [Islamic Azad University, Sanandaj (Iran, Islamic Republic of); Soufiani, Ahad Rounaghi [Islamic Azad University, Sufian (Iran, Islamic Republic of)

    2014-10-15

    By virtue of the efficiency of the Dirichlet-to-Neumann map method, we have calculated, for H-polarization (TE mode), the band structure of 2D photonic crystals with a square lattice composed of metallic rods embedded in an air background. The rod in the unit cell is chosen to be circular in shape. Here, from a practical point of view, in order to obtain maximum band gaps, we have studied the band structure as a function of the size of the rods. We have also studied the flat bands appearing in the band structures and have shown that for frequencies around the surface plasmon frequency, the modes are highly localized at the interface between the metallic rods and the air background.

  5. Radioactive Ages of Metal-Poor Halo Stars

    Institute of Scientific and Technical Information of China (English)

    Ji Li; Gang Zhao

    2004-01-01

    The abundances of long-lived radioactive elements Th and U observed in metal-poor halo stars can be used as chronometers to determine the age of individual stars, and hence set a lower limit on the age of the Galaxy and hence of the universe.This radioactive dating requires the zero-decay productions of Th and U, which involves complicated r-process nucleosynthesis calculations. Several parametric rprocess models have been used to calculate the initial abundance ratios of Th/Eu and U/Th, but, due to the sharp sensitivity of these models to nuclear physics inputs, the calculations have relatively large uncertainties which lead to large uncertainties in the age determinations. In order to reduce these uncertainties, we present a simple method to estimate the initial productions of Th and U, which only depends on the solar system abundances and the stellar abundances of stable r-process elements.From our calculations of the initial abundance ratios of Th/Eu and U/Th, we reestimate the ages of those very metal-poor halo stars with published abundances of Th and U. Our age estimates are consistent, within the errors, with the other age determinations derived from r-process models, and offer useful constrains for r-process theoretical calculations. The advantages and limitations of our simple method of radioactive dating are discussed.

  6. The age-metallicity dependence for white dwarfs

    CERN Document Server

    Romero, A D; Kepler, S O

    2015-01-01

    We present a theoretical study on the metallicity dependence of the initial$-$to$-$final mass relation and its influence on white dwarf age determinations. We compute a grid of evolutionary sequences from the main sequence to $\\sim 3\\, 000$ K on the white dwarf cooling curve, passing through all intermediate stages. During the thermally-pulsing asymptotic giant branch no third dredge-up episodes are considered and thus the photospheric C/O ratio is below unity for sequences with metallicities larger than $Z=0.0001$. We consider initial metallicities from $Z=0.0001$ to $Z=0.04$, accounting for stellar populations in the galactic disk and halo, with initial masses below $\\sim 3M_{\\odot}$. We found a clear dependence of the shape of the initial$-$to$-$final mass relation with the progenitor metallicity, where metal rich progenitors result in less massive white dwarf remnants, due to an enhancement of the mass loss rates associated to high metallicity values. By comparing our theoretical computations with semi em...

  7. Charting the evolution of the ages and metallicities of massive galaxies since z = 0.7

    Energy Technology Data Exchange (ETDEWEB)

    Gallazzi, Anna; Zibetti, Stefano [INAF-Osservatorio Astrofisico di Arcetri, Largo Enrico Fermi 5, I-50125 Firenze (Italy); Bell, Eric F. [Department of Astronomy, University of Michigan, 500 Church St., Ann Arbor, MI 48109 (United States); Brinchmann, Jarle [Leiden Observatory, Leiden University, 2300RA, Leiden (Netherlands); Kelson, Daniel D., E-mail: gallazzi@arcetri.astro.it [Observatories of the Carnegie Institution of Washington, Pasadena, CA 91101 (United States)

    2014-06-10

    Detailed studies of the stellar populations of intermediate-redshift galaxies can shed light onto the processes responsible for the growth of the massive galaxy population in the last 8 billion years. We here take a step toward this goal by means of deep, multiobject rest-frame optical spectroscopy, performed with the Inamori Magellan Areal Camera and Spectrograph on the Magellan telescope, of a sample of ∼70 galaxies in the Extended Chandra Deep Field South survey with redshift 0.65 ≤ z ≤ 0.75, apparent R > 22.7 mag{sub Vega}, and stellar mass >10{sup 10} M {sub ☉}. We measure velocity dispersion and stellar absorption features for individual sources. We interpret them by means of a large Monte Carlo library of star formation histories, following the Bayesian approach adopted for previous low redshift studies, and derive constraints on the stellar mass, mean stellar age, and stellar metallicity of these galaxies. We characterize for the first time the relations between stellar age and stellar mass and between stellar metallicity and stellar mass at z ∼ 0.7 for the galaxy population as a whole and for quiescent and star-forming galaxies separately. These relations of increasing age and metallicity with galaxy mass for the galaxy population as a whole have a similar shape as the z ∼ 0.1 analog derived for Sloan Digital Sky Survey galaxies but are shifted by –0.28 dex in age and by –0.13 dex in metallicity, at odds with simple passive evolution. Considering z = 0.7 quiescent galaxies alone, we find that no additional star formation and chemical enrichment are required for them to evolve into the present-day quiescent population. However, other observations require the quiescent population to grow from z = 0.7 to the present day. This growth could be supplied by the quenching of a fraction of z = 0.7 M {sub *} > 10{sup 11} M {sub ☉} star-forming galaxies with metallicities already comparable to those of quiescent galaxies, thus leading to the

  8. Charting the evolution of the ages and metallicities of massive galaxies since z = 0.7

    International Nuclear Information System (INIS)

    Detailed studies of the stellar populations of intermediate-redshift galaxies can shed light onto the processes responsible for the growth of the massive galaxy population in the last 8 billion years. We here take a step toward this goal by means of deep, multiobject rest-frame optical spectroscopy, performed with the Inamori Magellan Areal Camera and Spectrograph on the Magellan telescope, of a sample of ∼70 galaxies in the Extended Chandra Deep Field South survey with redshift 0.65 ≤ z ≤ 0.75, apparent R > 22.7 magVega, and stellar mass >1010 M ☉. We measure velocity dispersion and stellar absorption features for individual sources. We interpret them by means of a large Monte Carlo library of star formation histories, following the Bayesian approach adopted for previous low redshift studies, and derive constraints on the stellar mass, mean stellar age, and stellar metallicity of these galaxies. We characterize for the first time the relations between stellar age and stellar mass and between stellar metallicity and stellar mass at z ∼ 0.7 for the galaxy population as a whole and for quiescent and star-forming galaxies separately. These relations of increasing age and metallicity with galaxy mass for the galaxy population as a whole have a similar shape as the z ∼ 0.1 analog derived for Sloan Digital Sky Survey galaxies but are shifted by –0.28 dex in age and by –0.13 dex in metallicity, at odds with simple passive evolution. Considering z = 0.7 quiescent galaxies alone, we find that no additional star formation and chemical enrichment are required for them to evolve into the present-day quiescent population. However, other observations require the quiescent population to grow from z = 0.7 to the present day. This growth could be supplied by the quenching of a fraction of z = 0.7 M * > 1011 M ☉ star-forming galaxies with metallicities already comparable to those of quiescent galaxies, thus leading to the observed increase of the scatter in age

  9. Red Giants in the Small Magellanic Cloud. II. Metallicity Gradient and Age-Metallicity Relation

    CERN Document Server

    Dobbie, P D; Subramaniam, A; Keller, S

    2015-01-01

    We present results from the largest CaII triplet line metallicity study of Small Magellanic Cloud (SMC) field red giant stars to date, involving 3037 objects spread across approximately 37.5 sq. deg., centred on this galaxy. We find a median metallicity of [Fe/H]=-0.99+/-0.01, with clear evidence for an abundance gradient of -0.075+/-0.011 dex / deg. over the inner 5 deg. We interpret the abundance gradient to be the result of an increasing fraction of young stars with decreasing galacto-centric radius, coupled with a uniform global age-metallicity relation. We also demonstrate that the age-metallicity relation for an intermediate age population located 10kpc in front of the NE of the Cloud is indistinguishable from that of the main body of the galaxy, supporting a prior conjecture that this is a stellar analogue of the Magellanic Bridge. The metal poor and metal rich quartiles of our RGB star sample (with complementary optical photometry from the Magellanic Clouds Photometric Survey) are predominantly older ...

  10. Constraining stellar population models - I. Age, metallicity, and abundance pattern compilation for Galactic globular clusters

    CERN Document Server

    Roediger, Joel C; Graves, Genevieve; Schiavon, Ricardo

    2013-01-01

    We present an extenstive literature compilation of age, metallicity, and chemical abundance pattern information for the 41 Galactic globular clusters (GGCs) studied by Schiavon et al. (2005). Our compilation constitutes a notable improvement over previous similar work, particularly in terms of chemical abundances. Its primary purpose is to enable detailed evaluations of and refinements to stellar population synthesis models designed to recover the above information for unresolved stellar systems based on their integrated spectra. However, since the Schiavon sample spans a wide range of the known GGC parameter space, our compilation may also benefit investigations related to a variety of astrophysical endeavours, such as the early formation of the Milky Way, the chemical evolution of GGCs, and stellar evolution and nucleosynthesis. For instance, we confirm with our compiled data that the GGC system has a bimodal metallicity distribution and is uniformly enhanced in the alpha-elements. When paired with the ages...

  11. Maps of heavy metals in the soils of the European Union and proposed priority areas for detailed assessment.

    Science.gov (United States)

    Tóth, Gergely; Hermann, Tamás; Szatmári, Gábor; Pásztor, László

    2016-09-15

    Soil contamination is one of the greatest concerns among the threats to soil resources in Europe and globally. Despite of its importance there was only very course scale (1/5000km(2)) data available on soil heavy metal concentrations prior to the LUCAS topsoil survey, which had a sampling density of 200km(2). Based on the results of the LUCAS sampling and auxiliary information detailed and up-to-date maps of heavy metals (As, Cd, Cr, Cu, Hg, Pb, Zn, Sb, Co and Ni) in the topsoil of the European Union were produced. Using the maps of heavy metal concentration in topsoil we made a spatial prediction of areas where local assessment is suggested to monitor and eventually control the potential threat from heavy metals. Most of the examined elements remain under the corresponding threshold values in the majority of the land of the EU. However, one or more of the elements exceed the applied threshold concentration on 1.2Mkm(2), which is 28.3% of the total surface area of the EU. While natural backgrounds might be the reason for high concentrations on large proportion of the affected soils, historical and recent industrial and mining areas show elevated concentrations (predominantly of As, Cd, Pb and Hg) too, indicating the magnitude of anthropogenic effect on soil quality in Europe. PMID:27261421

  12. Characterizing the Chemistry of the Milky Way Stellar Halo: Detailed Chemical Analysis of a Metal-Poor Stellar Stream

    CERN Document Server

    Roederer, Ian U; Thompson, Ian B; Preston, George W; Shectman, Stephen A

    2010-01-01

    We present the results of a detailed abundance analysis of one of the confirmed building blocks of the Milky Way stellar halo, a kinematically-coherent metal-poor stellar stream. We have obtained high resolution and high S/N spectra of 12 probable stream members using the MIKE spectrograph on the Magellan-Clay Telescope at Las Campanas Observatory and the 2dCoude spectrograph on the Smith Telescope at McDonald Observatory. We have derived abundances or upper limits for 51 species of 46 elements in each of these stars. The stream members show a range of metallicity (-3.4 < [Fe/H] < -1.5) but are otherwise chemically homogeneous, with the same star-to-star dispersion in [X/Fe] as the rest of the halo. This implies that, in principle, a significant fraction of the Milky Way stellar halo could have formed from accreted systems like the stream. The stream stars show minimal evolution in the alpha or Fe-group elements over the range of metallicity. This stream is enriched with material produced by the main an...

  13. Metal and nutrient dynamics on an aged intensive green roof.

    Science.gov (United States)

    Speak, A F; Rothwell, J J; Lindley, S J; Smith, C L

    2014-01-01

    Runoff and rainfall quality was compared between an aged intensive green roof and an adjacent conventional roof surface. Nutrient concentrations in the runoff were generally below Environmental Quality Standard (EQS) values and the green roof exhibited NO3(-) retention. Cu, Pb and Zn concentrations were in excess of EQS values for the protection of surface water. Green roof runoff was also significantly higher in Fe and Pb than on the bare roof and in rainfall. Input-output fluxes revealed the green roof to be a potential source of Pb. High concentrations of Pb within the green roof soil and bare roof dusts provide a potential source of Pb in runoff. The origin of the Pb is likely from historic urban atmospheric deposition. Aged green roofs may therefore act as a source of legacy metal pollution. This needs to be considered when constructing green roofs with the aim of improving pollution remediation.

  14. Metal and nutrient dynamics on an aged intensive green roof.

    Science.gov (United States)

    Speak, A F; Rothwell, J J; Lindley, S J; Smith, C L

    2014-01-01

    Runoff and rainfall quality was compared between an aged intensive green roof and an adjacent conventional roof surface. Nutrient concentrations in the runoff were generally below Environmental Quality Standard (EQS) values and the green roof exhibited NO3(-) retention. Cu, Pb and Zn concentrations were in excess of EQS values for the protection of surface water. Green roof runoff was also significantly higher in Fe and Pb than on the bare roof and in rainfall. Input-output fluxes revealed the green roof to be a potential source of Pb. High concentrations of Pb within the green roof soil and bare roof dusts provide a potential source of Pb in runoff. The origin of the Pb is likely from historic urban atmospheric deposition. Aged green roofs may therefore act as a source of legacy metal pollution. This needs to be considered when constructing green roofs with the aim of improving pollution remediation. PMID:24017999

  15. Helium nano-bubble evolution in aging metal tritides.

    Energy Technology Data Exchange (ETDEWEB)

    Cowgill, Donald F.

    2004-05-01

    A continuum-scale, evolutionary model of helium (He) nano-bubble nucleation, growth and He release for aging bulk metal tritides is presented which accounts for major features of the experimental database. Bubble nucleation, modeled as self-trapping of interstitially diffusing He atoms, is found to occur during the first few days following tritium introduction into the metal and is sensitive to the He diffusivity and pairing energy. An effective helium diffusivity of 0.3 x 10{sup -16} cm{sup 2}/s at 300 K is required to generate the average bubble density of 5x 1017 bubbles/cm3 observed by transmission electron microscopy (TEM). Early bubble growth by dislocation loop punching with a l/radius bubble pressure dependence produces good agreement with He atomic volumes and bubble pressures determined from swelling data, nuclear magnetic resonance (NMR) measurements, and hydride pressure-composition-temperature (PCT) shifts. The model predicts that later in life neighboring bubble interactions may first lower the loop punching pressure through cooperative stress effects, then raise the pressure by partial blocking of loops. It also accounts for the shape of the bubble spacing distribution obtained from NMR data. This distribution is found to remain fixed with age, justifying the separation of nucleation and growth phases, providing a sensitive test of the growth formulation, and indicating that further significant bubble nucleation does not occur throughout life. Helium generated within the escape depth of surfaces and surface-connected porosity produces the low-level early helium release. Accelerated or rapid release is modeled as inter-bubble fracture using an average ligament stress criterion. Good agreement is found between the predicted onset of fracture and the observed He-metal ratio (HeM) for rapid He release from bulk palladium tritide. An examination of how inter-bubble fracture varies over the bubble spacing distribution shows that the critical Hem will be

  16. Nanoscale Structure, Dynamics, and Aging Behavior of Metallic Glass Thin Films

    Science.gov (United States)

    Burgess, J. A. J.; Holt, C. M. B.; Luber, E. J.; Fortin, D. C.; Popowich, G.; Zahiri, B.; Concepcion, P.; Mitlin, D.; Freeman, M. R.

    2016-08-01

    Scanning tunnelling microscopy observations resolve the structure and dynamics of metallic glass Cu100‑xHfx films and demonstrate scanning tunnelling microscopy control of aging at a metallic glass surface. Surface clusters exhibit heterogeneous hopping dynamics. Low Hf concentration films feature an aged surface of larger, slower clusters. Argon ion-sputtering destroys the aged configuration, yielding a surface in constant fluctuation. Scanning tunnelling microscopy can locally restore the relaxed state, allowing for nanoscale lithographic definition of aged sections.

  17. Nanoscale Structure, Dynamics, and Aging Behavior of Metallic Glass Thin Films

    Science.gov (United States)

    Burgess, J. A. J.; Holt, C. M. B.; Luber, E. J.; Fortin, D. C.; Popowich, G.; Zahiri, B.; Concepcion, P.; Mitlin, D.; Freeman, M. R.

    2016-01-01

    Scanning tunnelling microscopy observations resolve the structure and dynamics of metallic glass Cu100−xHfx films and demonstrate scanning tunnelling microscopy control of aging at a metallic glass surface. Surface clusters exhibit heterogeneous hopping dynamics. Low Hf concentration films feature an aged surface of larger, slower clusters. Argon ion-sputtering destroys the aged configuration, yielding a surface in constant fluctuation. Scanning tunnelling microscopy can locally restore the relaxed state, allowing for nanoscale lithographic definition of aged sections. PMID:27498698

  18. Nanoscale Structure, Dynamics, and Aging Behavior of Metallic Glass Thin Films.

    Science.gov (United States)

    Burgess, J A J; Holt, C M B; Luber, E J; Fortin, D C; Popowich, G; Zahiri, B; Concepcion, P; Mitlin, D; Freeman, M R

    2016-08-08

    Scanning tunnelling microscopy observations resolve the structure and dynamics of metallic glass Cu100-xHfx films and demonstrate scanning tunnelling microscopy control of aging at a metallic glass surface. Surface clusters exhibit heterogeneous hopping dynamics. Low Hf concentration films feature an aged surface of larger, slower clusters. Argon ion-sputtering destroys the aged configuration, yielding a surface in constant fluctuation. Scanning tunnelling microscopy can locally restore the relaxed state, allowing for nanoscale lithographic definition of aged sections.

  19. CONSTRAINING STELLAR POPULATION MODELS. I. AGE, METALLICITY AND ABUNDANCE PATTERN COMPILATION FOR GALACTIC GLOBULAR CLUSTERS

    International Nuclear Information System (INIS)

    We present an extensive literature compilation of age, metallicity, and chemical abundance pattern information for the 41 Galactic globular clusters (GGCs) studied by Schiavon et al. Our compilation constitutes a notable improvement over previous similar work, particularly in terms of chemical abundances. Its primary purpose is to enable detailed evaluations of and refinements to stellar population synthesis models designed to recover the above information for unresolved stellar systems based on their integrated spectra. However, since the Schiavon sample spans a wide range of the known GGC parameter space, our compilation may also benefit investigations related to a variety of astrophysical endeavors, such as the early formation of the Milky Way, the chemical evolution of GGCs, and stellar evolution and nucleosynthesis. For instance, we confirm with our compiled data that the GGC system has a bimodal metallicity distribution and is uniformly enhanced in the α elements. When paired with the ages of our clusters, we find evidence that supports a scenario whereby the Milky Way obtained its globular clusters through two channels: in situ formation and accretion of satellite galaxies. The distributions of C, N, O, and Na abundances and the dispersions thereof per cluster corroborate the known fact that all GGCs studied so far with respect to multiple stellar populations have been found to harbor them. Finally, using data on individual stars, we verify that stellar atmospheres become progressively polluted by CN(O)-processed material after they leave the main sequence. We also uncover evidence which suggests that the α elements Mg and Ca may originate from more than one nucleosynthetic production site. We estimate that our compilation incorporates all relevant analyses from the literature up to mid-2012. As an aid to investigators in the fields named above, we provide detailed electronic tables of the data upon which our work is based at http

  20. Preliminary result on the analysis of Late Bronze Age metals

    International Nuclear Information System (INIS)

    Complete text of publication follows. The main event of the complex cultural changes during the transition from Middle to Late Bronze Age was the appearance of Tumulus culture in the Danube-Tisza region. In this period people rose mounds (tumuli) above their graves made from stone and soil. According to our present knowledge we believe that the ethnically inhomogeneous Tumulus culture was made homogenous by commerce (especially bronze commerce). Depots were typical of the final period of Middle Bronze Age called Koszider-phase. During the tumulus period the practice of hiding depots came to its end, bronze objects were put into graves. Therefore, it would be important to analyze the relation between the Koszider and Tumulus metallurgy. The main question to be answered is the following: were the trade connections and exchange of goods discontinued during the time of cultural changes? Examination of archaeological finds is carried out usually by typological methods which provide information on the attire fashion and funeral rite of cultures. The inherent capability of analytical techniques makes it possible to draw conclusions on the provenance of metals, thus facilitating to establish the contemporary trade routes. The metal finds from the southern part of the Great Hungarian Plain has not been investigated yet, though it would be important from the point of view of Tumulus culture. The main question is whether there is any noticeable change between the metallurgical craftsmanship of the consecutive eras. Therefore, it is important to determine the composition of the used raw materials, their sources, as well as the applied manufacturing technologies. For the characterization of archaeological bronze finds both conventional X-ray fluorescence (XRF) method and micro proton induced X-ray fluorescence (micro-PIXE) techniques are applied. The first one serves for the determination of the bulk composition of samples while the second one for the characterization of

  1. TOWARD THE GENERAL RED GIANT BRANCH SLOPE-METALLICITY-AGE CALIBRATION. I. METALLICITIES, AGES, AND KINEMATICS FOR EIGHT LARGE MAGELLANIC CLOUD CLUSTERS

    International Nuclear Information System (INIS)

    In this paper, we discuss the properties of color-magnitude diagrams, age, metallicity, and radial velocities of eight massive Large Magellanic Cloud (LMC) clusters using data taken from the FORS2 multiobject spectrograph at the 8.2 m Very Large Telescope/Unit Telescope 1. The strong near-infrared Ca II triplet lines of red giant branch stars obtained from the high signal-to-noise ratio spectra are used to determine the metallicity and radial velocity of cluster members. We report for the first time spectroscopically determined metallicity values for four clusters based on the mean [Fe/H] value of ∼10 cluster members each. We found two concentrations in the distribution of ages of the target clusters. Six have ages between 0.8 Gyr and 2.2 Gyr and the other two, NGC 1754 and NGC 1786, are very old. The metallicity of the six intermediate-age clusters, with a mean age of 1.5 Gyr, is -0.49 with a scatter of only 0.04. This tight distribution suggests that a close encounter between the LMC and Small Magellanic Cloud may have caused not only the restart of cluster formation in the LMC but also the generation of the central bar. The metallicity for the two old clusters is similar to that of the other old, metal-poor LMC clusters. We find that the LMC cluster system exhibits disk-like rotation with no clusters appearing to have halo kinematics and there is no evidence of a metallicity gradient in the LMC, in contrast with the stellar population of the Milky Way and M33, where the metallicity decreases as galactocentric distance increases. The LMC's stellar bar may be the factor responsible for the dilution of any kind of gradient in the LMC.

  2. The Effect of Major Mergers on Age and Metallicity Across the Fundamental Plane

    CERN Document Server

    Porter, L A; Croton, D J; Covington, M D; Graves, G J; Faber, S M; Primack, J R

    2012-01-01

    Recent low-redshift observations have attempted to determine the star formation histories of elliptical galaxies by tracking correlations between the stellar population parameters (age and metallicity) and the structural parameters that enter the fundamental plane (size and velocity dispersion). These studies have found that velocity dispersion, rather than effective radius or dynamical mass, is the main predictor of a galaxy's stellar age and metallicity. In this work, we apply an analytic model that predicts the structural properties of remnants formed in major mergers to progenitor disk galaxies with properties taken from two different semi-analytic models. We predict the effective radius, velocity dispersion, luminosity, age, and metallicity of the merger remnants, enabling us to compare directly to observations of early-type galaxies. While we find a tight correlation between age and velocity dispersion, we find a stronger dependence of age and metallicity on effective radius than observations report. Th...

  3. The LAMOST Spectroscopic Survey of Star Clusters in M31. II. Metallicities, Ages, and Masses

    Science.gov (United States)

    Chen, Bingqiu; Liu, Xiaowei; Xiang, Maosheng; Yuan, Haibo; Huang, Yang; Shi, Jianrong; Fan, Zhou; Huo, Zhiying; Wang, Chun; Ren, Juanjuan; Tian, Zhijia; Zhang, Huawei; Liu, Gaochao; Cao, Zihuang; Zhang, Yong; Hou, Yonghui; Wang, Yuefei

    2016-08-01

    We select from Paper I a sample of 306 massive star clusters observed with the Large Sky Area Multi–Object Fibre Spectroscopic Telescope (LAMOST) in the vicinity fields of M31 and M33, and determine their metallicities, ages, and masses. Metallicities and ages are estimated by fitting the observed integrated spectra with stellar synthesis population (SSP) models with a pixel–to–pixel spectral fitting technique. Ages for most young clusters are also derived by fitting the multi–band photometric measurements with model spectral energy distributions (SEDs). The estimated cluster ages span a wide range, from several million years to the age of the universe. The numbers of clusters younger and older than 1 Gyr are, respectively, 46 and 260. With ages and metallicities determined, cluster masses are then estimated by comparing the multi–band photometric measurements with SSP model SEDs. The derived masses range from ∼ {10}3 to ∼ {10}7 M ⊙, peaking at ∼ {10}4.3 and ∼ {10}5.7 M ⊙ for young (\\lt 1 Gyr) and old (\\gt 1 Gyr) clusters, respectively. Our estimated metallicities, ages, and masses are in good agreement with available literature values. Old clusters richer than [Fe/H] ∼ ‑0.7 dex have a wide range of ages. Those poorer than [Fe/H] ∼ ‑0.7 dex seem to be composed of two groups, as previously found for Galactic globular clusters—one of the oldest ages with all values of metallicity down to ∼ -2 dex and another with metallicity increasing with decreasing age. The old clusters in the inner disk of M 31 (0–30 kpc) show a clear metallicity gradient measured at ‑0.038 ± 0.023 dex kpc‑1.

  4. A new, detailed ice-age oxygen-18 record from the ice-sheet margin in central West Greenland

    Science.gov (United States)

    Reeh, Niels; Oerter, Hans; Letréguilly, Anne; Miller, Heinz; Hubberten, Hans-Wolfgang

    1991-10-01

    A new detailed oxygen-18 record measured on surface-ice samples from a West Greenland ice-margin location reveals the hitherto longest climatic record from the Greenland ice sheet, spanning the last c. 150,000 years. The new record implies that the Greenland deep ice-core records from Dye3 and Camp Century need to be re-interpreted. A comparison with the deuterium record from the Vostok deep ice core, Antarctica indicates that climate behaved differently in the northern and southern hemispheres during the last glacial/interglacial cycle, with major differences occurring in Emiliani isotopic stage 5.

  5. Influence of organism age on metal toxicity to Daphnia magna.

    Science.gov (United States)

    Hoang, Tham C; Klaine, Stephen J

    2007-06-01

    Aquatic organisms living in surface water experience contaminant exposure at different life stages. While some investigators have examined the influence of organism age on the toxicity of pollutants, the general assumption in toxicology has been that young organisms were more sensitive than older organisms. In fact, some standardized toxicity tests call for the use of organisms less than 24 h old. This research characterized the age sensitivity of the water flea Daphnia magna to copper, zinc, selenium, and arsenic. During 21-d toxicity tests, organisms were exposed to a single 12-h pulse of either 70 microg/L Cu, 750 microg/L Zn, 1000 microg/L Se, or 5000 microg/L As at different ages ranging from 3 h to 10 d old. Mortality and reproduction were compiled over 21 d. During the juvenile stage, mortality increased and cumulative reproduction decreased with age, respectively. However, mortality decreased and cumulative reproduction increased with age when organisms became adult. Peak sensitivity occurred in 4-d-old organisms exposed to Cu and Zn, while 2- to 3-d-old organisms were most sensitive to As and Se. Growth of D. magna over 21 d was not affected by the 12-h pulse of Cu, Zn, Se, or As given at any organism age. This indicates the recovery of the organisms after exposure termination. PMID:17571686

  6. An Age Difference of 2 Gyr between a Metal-Rich and a Metal-Poor Globular Cluster

    CERN Document Server

    Hansen, B M S; Anderson, J; Dotter, A; Richer, H B; Rich, R M; Shara, M M; Fahlman, G G; Hurley, J R; King, I R; Reitzel, D; Stetson, P B

    2013-01-01

    Globular clusters trace the formation history of the spheroidal components of both our Galaxy and others, which represent the bulk of star formation over the history of the universe. They also exhibit a range of metallicities, with metal-poor clusters dominating the stellar halo of the Galaxy, and higher metallicity clusters found within the inner Galaxy, associated with the stellar bulge, or the thick disk. Age differences between these clusters can indicate the sequence in which the components of the Galaxy formed, and in particular which clusters were formed outside the Galaxy and later swallowed along with their original host galaxies, and which were formed in situ. Here we present an age determination of the metal-rich globular cluster 47 Tucanae by fitting the properties of the cluster white dwarf population, which implies an absolute age of 9.9 (0.7) Gyr at 95% confidence. This is about 2.0 Gyr younger than inferred for the metal-poor cluster NGC 6397 from the same models, and provides quantitative evi...

  7. Mid-infrared followup of cold brown dwarfs: diversity in age, mass and metallicity

    Energy Technology Data Exchange (ETDEWEB)

    Saumon, Didier [Los Alamos National Laboratory; Leggett, Sandy K [GEMINI OBSERVATORY; Burningham, Ben [HERTFORDSHITE UNIV; Marley, Mark S [NASA AMES; Waren, S J [IMPERIAL COLLEGE LONDON; Jones, H R A [HERTFORDSHIRE U; Pinfield, D J [HERTFORDSHIRE U; Smart, R L [ASTRONOMICAL OBS

    2009-01-01

    We present new Spitzer IRAC [3.6], [4.5], [5.8] and [8.0] photometry of nine very late-type T dwarfs. Combining this with previously published photometry, we investigate trends with type and color that are useful for both the planning and interpretation of infrared surveys designed to discover the coldest T or Y dwarfs. Brown dwarfs with effective temperature (T{sub eff}) below 700 K emit more than half their flux at wavelengths longer than 3 {micro}m, and the ratio of the mid-infrared flux to the near-infrared flux becomes very sensitive to T{sub eff} at these low temperatures. We confirm that the color H (1.6 {micro}m) - [4.5] is a good indicator of T{sub eff} with a relatively weak dependence on metallicity and gravity. Conversely, the colors H - K (2.2 {micro}m) and [4.5] - [5.8] are sensitive to metallicity and gravity. Thus near- and mid-infrared photometry provide useful indicators of the fundamental properties of brown dwarfs, and if temperature and gravity are known, then mass and age can be reliably determined from evolutionary models. There are twelve dwarfs currently known with H - [4.5] > 3.0, and {approx} 500 < T{sub eff} K {approx}< 800, which we examine in detail. The ages of the dwarfs in the sample range from very young (0.1 - 1.0 Gyr) to relatively old (3 - 12 Gyr). The mass range is possibly as low as 5 Jupiter masses to up to 70 Jupiter masses, i.e. near the hydrogen burning limit. The metallicities also span a large range, from [m/H]= -0.3 to [m/H]= +0.2. The small number of T8 - T9 dwarfs found in the UKIRT Infrared Deep Sky Survey to date appear to be predominantly young low-mass dwarfs. Accurate mid-infrared photometry of cold brown dwarfs is essentially impossible from the ground, and extensions to the mid-infrared space missions warm-Spitzer and WISE are desirable in order to obtain the vital mid-infrared data for cold brown dwarfs, and to discover more of these rare objects.

  8. SMC west halo: a slice of the galaxy that is being tidally stripped?. Star clusters trace age and metallicity gradients

    Science.gov (United States)

    Dias, B.; Kerber, L.; Barbuy, B.; Bica, E.; Ortolani, S.

    2016-06-01

    Context. The evolution and structure of the Magellanic Clouds is currently under debate. The classical scenario in which both the Large and Small Magellanic Clouds (LMC, SMC) are orbiting the Milky Way has been challenged by an alternative in which the LMC and SMC are in their first close passage to our Galaxy. The clouds are close enough to us to allow spatially resolved observation of their stars, and detailed studies of stellar populations in the galaxies are expected to be able to constrain the proposed scenarios. In particular, the west halo (WH) of the SMC was recently characterized with radial trends in age and metallicity that indicate tidal disruption. Aims: We intend to increase the sample of star clusters in the west halo of the SMC with homogeneous age, metallicity, and distance derivations to allow a better determination of age and metallicity gradients in this region. Positions are compared with the orbital plane of the SMC from models. Methods: Comparisons of observed and synthetic V(B-V) colour-magnitude diagrams were used to derive age, metallicity, distance, and reddening for star clusters in the SMC west halo. Observations were carried out using the 4.1 m SOAR telescope. Photometric completeness was determined through artificial star tests, and the members were selected by statistical comparison with a control field. Results: We derived an age of 1.23 ± 0.07 Gyr and [Fe/H] = -0.87 ± 0.07 for the reference cluster NGC 152, compatible with literature parameters. Age and metallicity gradients are confirmed in the WH: 2.6 ± 0.6 Gyr/° and -0.19 ± 0.09 dex/°, respectively. The age-metallicity relation for the WH has a low dispersion in metallicity and is compatible with a burst model of chemical enrichment. All WH clusters seem to follow the same stellar distribution predicted by dynamical models, with the exception of AM-3, which should belong to the counter-bridge. Brück 6 is the youngest cluster in our sample. It is only 130 ± 40 Myr old and

  9. A Detailed Study on Issues and Challenges of Management Education in Digital Age with Special Reference to Lucknow District

    Directory of Open Access Journals (Sweden)

    Yasir Arafat ELAHI

    2013-06-01

    Full Text Available Higher education especially management education in India stands at a crossroad. Without change, the traditional university structure of educating and training tomorrow’s business leaders is likely to be surpassed and discarded in the increasingly diverse and technological global economy. The Objective of this is paper is to study the competencies and characteristics of Management Teachers in the changing digital age, to identify the issues and challenges that arise in management education. This paper will help in developing better understanding of issues and challenges related with Management Education and will be helpful for Owners, Administrators and Government. It has been found that the current curriculum in management education does not prepare students to face the challenges in business environment. Managing uncertainty and complexity are not taught in Business Schools. Business Schools merely teach the concepts with case studies and does not focus on the challenges arising out of rapid growing technology and the challenges involved in running an enterprise. Unfortunately, the best talent is going to industry where salaries are lucrative. Those who come to academic area are the ones who could not be absorbed in the industry or joined this profession by chance or chose this career out of passion. The data collected from respondents suggests that Management Students should be provided with latest teaching pedagogy and Management Teachers should be paid good remuneration for their work.

  10. A Detailed Characterization of the Dysfunctional Immunity and Abnormal Myelopoiesis Induced by Severe Shock and Trauma in the Aged

    Science.gov (United States)

    Nacionales, Dina C.; Szpila, Benjamin; Ungaro, Ricardo; Lopez, M. Cecilia; Zhang, Jianyi; Gentile, Lori F.; Cuenca, Angela L.; Vanzant, Erin; Mathias, Brittany; Jyot, Jeevan; Westerveld, Donevan; Bihorac, Azra; Joseph, Anna; Mohr, Alicia; Duckworth, Lizette V.; Moore, Frederick A.; Baker, Henry V.; Leeuwenburgh, Christiaan; Moldawer, Lyle L.; Brakenridge, Scott; Efron, Philip A.

    2015-01-01

    The elderly are particularly susceptible to trauma, and their outcomes are frequently dismal. Such patients often have complicated clinical courses and ultimately die from infection and sepsis. Recent research has revealed that although elderly subjects have increased baseline inflammation as compared to their younger counterparts, the elderly do not respond to severe infection/injury with an exaggerated inflammatory response. Initial retrospective analysis of clinical data from the Glue Grant trauma database demonstrated that despite a similar frequency, elderly trauma patients have worse outcomes to pneumonia than younger subjects. Subsequent analysis with a murine trauma model also demonstrated that elderly mice had increased mortality after post-trauma Pseudomonas pneumonia. Blood, bone marrow, and bronchoalveolar lavage sample analyses from juvenile and 20–24 month old mice showed that increased mortality to trauma combined with secondary infection in the aged are not due to an exaggerated inflammatory response. Rather, they are due to a failure of bone marrow progenitors, blood neutrophils, and bronchoalveolar lavage cells to initiate and complete an ‘emergency myelopoietic’ response, engendering myeloid cells that fail to clear secondary infection. In addition, the elderly appeared unable to effectively resolve their inflammatory response to severe injury. PMID:26246141

  11. Using colours to determine the stellar ages and metallicities of distant galaxies

    CERN Document Server

    Li, Zhongmu

    2013-01-01

    The determination of stellar populations of galaxies are important for studying the formation and evolution of galaxies, because all galaxies contain many stars and they evolve with galaxies. Spectra data are usually used to determine the stellar populations of nearby galaxies as they have the ability to disentangle the degeneracy between stellar age and metallicity. However, it is difficult to give similar studies to distant (e.g., $z >$ 0.3) galaxies because of the lack of reliable spectra data. This is actually limited by current observational equipments and methods. In fact, the information of the stellar ages and metallicities of distant galaxies are crucial for solving the problem of galaxy formation and evolution. Colours can give us some information of the stellar populations of distant galaxies. In the paper, I introduce our works about using colours to estimate the ages and metallicities of the stellar populations of galaxies. Some potential colours for studying stellar-population parameters (age an...

  12. Younger age at onset of sporadic Parkinson's disease among subjects occupationally exposed to metals and pesticides

    OpenAIRE

    Ratner Marcia H.; Farb David H.; Ozer Josef; Feldman Robert G.; Durso Raymon

    2014-01-01

    An earlier age at onset of Parkinson’s disease (PD) has been reported to be associated with occupational exposures to manganese and hydrocarbon solvents suggesting that exposure to neurotoxic chemicals may hasten the progression of idiopathic PD. In this study the role of occupational exposure to metals and pesticides in the progression of idiopathic PD was assessed by looking at age at disease onset. The effects of heritable genetic risk factors, which may also influence age at onset, was mi...

  13. Characterization of the structural details of residual austenite in the weld metal of a 9Cr1MoNbV welded rotor

    Institute of Scientific and Technical Information of China (English)

    Xia Liu; Hui-jun Ji; Peng Liu; Peng Wang; Feng-gui Lu; Yu-lai Gao

    2014-01-01

    The existence of residual austenite in weld metal plays an important role in determining the properties and dimensional accuracy of welded rotors. An effective corrosive agent and the metallographic etching process were developed to clearly reveal the characteristics of residual austenite in the weld metal of a 9Cr1MoNbV welded rotor. Moreover, the details of the distribution, shape, length, length-to-width ratio, and the content of residual austenite were systematically characterized using the Image-Pro Plus image analysis software. The results revealed that the area fraction of residual austenite was approximately 6.3% in the observed weld seam; the average area, length, and length-to-width ratio of dispersed residual austenite were quantitatively evaluated to be (5.5 ± 0.1)μm2, (5.0 ± 0.1)μm, and (2.2 ± 0.1), re-spectively. The newly developed corrosive agent and etching method offer an appropriate approach to characterize residual austenite in the weld metal of welded rotors in detail.

  14. uvby(-$\\beta$) photometry of high-velocity and metal-poor stars X. Stars of very low metal abundance: observations, reddenings, metallicities, classifications, distances, and relative ages

    CERN Document Server

    Schuster, W J; Michel, R; Nissen, P E; García, G

    2004-01-01

    uvby(--$\\beta$) photometry has been obtained for an additional 411 very metal-poor stars selected from the HK survey, and used to derive basic parameters such as interstellar reddenings, metallicities, photometric classifications, distances, and relative ages... These very metal-poor stars are compared to M92 in the c_0,(b-y)_0 diagram, and evidence is seen for field stars 1-3 Gyrs younger than this globular cluster. The significance of these younger very metal-poor stars is discussed in the context of Galactic evolution, mentioning such possibilities as hierarchical star-formation/mass-infall of very metal-poor material and/or accretion events whereby this material has been acquired from other (dwarf) galaxies with different formation and chemical-enrichment histories

  15. Mass-luminosity relation for FGK main sequence stars: metallicity and age contributions

    CERN Document Server

    Gafeira, Ricardo; Fernandes, João

    2012-01-01

    The stellar mass-luminosity relation (MLR) is one of the most famous empirical "laws", discovered in the beginning of the 20th century. MLR is still used to estimate stellar masses for nearby stars, particularly for those that are not binary systems, hence the mass cannot be derived directly from the observations. It's well known that the MLR has a statistical dispersion which cannot be explained exclusively due to the observational errors in luminosity (or mass). It is an intrinsic dispersion caused by the differences in age and chemical composition from star to star. In this work we discuss the impact of age and metallicity on the MLR. Using the recent data on mass, luminosity, metallicity, and age for 26 FGK stars (all members of binary systems, with observational mass-errors \\leq 3%), including the Sun, we derive the MLR taking into account, separately, mass-luminosity, mass-luminosity-metallicity, and mass-luminosity-metallicity-age. Our results show that the inclusion of age and metallicity in the MLR, ...

  16. Mid-infrared followup of cold brown dwarfs: Diversity in age, mass and metallicity

    Directory of Open Access Journals (Sweden)

    Pinfield D.J.

    2011-07-01

    Full Text Available We use Spitzer IRAC 3.6–8.0 μm photometry of late-type T dwarfs to investigate various trends which can aid the planning and interpretation of infrared (IR surveys for the coldest T or Y dwarfs. Brown dwarfs with effective temperature (Teff50% of their flux at λ>3 μm, and the ratio of the mid-IR to the near-IR flux becomes very sensitive to Teff. The color H − [4.5] is a good indicator of Teff with a weak dependence on metallicity ([m/H] and gravity (g while H −K and [4.5] − [5.8] are sensitive to [m/H] and g. Thus Teff and g can be constrained and mass and age can then be determined from evolutionary models. There are 12 dwarfs known with H − [4.5] > 3.0 and 500 ≲ Teff K ≲ 800, which we examine in detail. The ages of these dwarfs range from very young (0.1–1.0 Gyr to old (3–12 Gyr. The mass range is possibly as low as 5 MJup to 70 MJup, and [m/H] also spans a large range of ~ −0.3 to ~ +0.3. The T8–T9 dwarfs found so far in the UKIRT IR Deep Sky Survey are unexpectedly young and low-mass. Extensions to the warm Spitzer and WISE space missions are needed to obtain mid-IR data for cold brown dwarfs, and to discover more of these rare objects.

  17. Stellar Ages and Metallicities of Central and Satellite Galaxies: Implications for Galaxy Formation and Evolution

    CERN Document Server

    Pasquali, Anna; Fontanot, Fabio; Bosch, Frank C van den; De Lucia, Gabriella; Mo, H J; Yang, Xiaohu

    2009-01-01

    Using a large SDSS galaxy group catalogue, we study how the stellar ages and metallicities of central and satellite galaxies depend on stellar mass and halo mass. We find that satellites are older and metal-richer than centrals of the same stellar mass. In addition, the slopes of the age-stellar mass and metallicity-stellar mass relations are found to become shallower in denser environments. This is due to the fact that the average age and metallicity of low mass satellite galaxies increase with the mass of the halo in which they reside. A comparison with the semi-analytical model of Wang et al. (2008) shows that it succesfully reproduces the fact that satellites are older than centrals of the same stellar mass and that the age difference increases with the halo mass of the satellite. This is a consequence of strangulation, which leaves the stellar populations of satellites to evolve passively, while the prolonged star formation activity of centrals keeps their average ages younger. The resulting age offset i...

  18. HIPPARCOS age-metallicity relation of the solar neighbourhood disc stars

    OpenAIRE

    Ibukiyama, A.; Arimoto, N.

    2002-01-01

    We derive age-metallicity relations (AMRs) and orbital parameters for the 1658 solar neighbourhood stars to which accurate distances are measured by the HIPPARCOS satellite. The sample stars comprise 1382 thin disc stars, 229 thick disc stars, and 47 halo stars according to their orbital parameters. We find a considerable scatter for thin disc AMR along the one-zone Galactic chemical evolution (GCE) model. Orbits and metallicities of thin disc stars show now clear relation each other. The sca...

  19. Mechanisms of Heavy Metal Sequestration in Soils: Plant-Microbe Interactions and Organic Matter Aging

    Energy Technology Data Exchange (ETDEWEB)

    Teresa W.-M. Fan; Richard M. Higashi; David Crowley; Andrew N. Lane: Teresa A. Cassel; Peter G. Green

    2004-12-31

    For stabilization of heavy metals at contaminated sites, the three way interaction among soil organic matter (OM)-microbes-plants, and their effect on heavy metal binding is critically important for long-term sustainability, a factor that is poorly understood at the molecular level. Using a soil aging system, the humification of plant matter such as wheat straw was probed along with the effect on microbial community on soil from the former McClellan Air Force Base.

  20. F stars, metallicity, and the ages of red galaxies at z > 1

    OpenAIRE

    Nolan, Louisa A.; Dunlop, James S; Jimenez, Raul; Heavens, Alan F.

    2001-01-01

    We explore whether the rest-frame near-UV spectral region, observable in high-redshift galaxies via optical spectroscopy, contains sufficient information to allow the degeneracy between age and metallicity to be lifted. We do this by testing the ability of evolutionary synthesis models to reclaim the correct metallicity when fitted to the near-UV spectra of F stars of known (sub-solar and super-solar) metallicity. F stars are of particular interest because the rest-frame near-UV spectra of th...

  1. Age and metallicity gradients in early-type galaxies: A dwarf to giant sequence

    CERN Document Server

    Koleva, Mina; De Rijcke, Sven; Zeilinger, Werner W

    2011-01-01

    We studied the stellar populations of 40 early-type galaxies using medium resolution long-slit spectroscopy along their major axes (and along the minor axis for two of them), from 10^7 Msol to 10^12 Msol (-9.2 > M_B > -22.4 mag). All the studied galaxies lie on the mass-metallicity and age-mass relations. The transition type dwarfs deviate from the latter relation having younger mean age, and the low-mass dwarf spheroidals have older ages, marking a discontinuity in the relation, possibly due to selection effects. In all mass regimes, the mean metallicity gradients are approximately -0.2 and the mean age gradients +0.1 dex per decade of radius. The individual gradients are widely spread: $ -0.1 < \

  2. Modeling the Ages and Metallicities of Early-Type Galaxies in Fundamental Plane Space

    CERN Document Server

    Porter, L A; Primack, J R; Croton, D J; Covington, M D; Graves, G J; Faber, S M

    2014-01-01

    Recent observations have probed the formation histories of nearby elliptical galaxies by tracking correlations between the stellar population parameters, age and metallicity, and the structural parameters that enter the Fundamental Plane, radius and velocity dispersion sigma. These studies have found intriguing correlations between these four parameters. In this work, we make use of a semi-analytic model, based on halo merger trees extracted from the Bolshoi cosmological simulation, that predicts the structural properties of spheroid-dominated galaxies based on an analytic model that has been tested and calibrated against an extensive suite of hydrodynamic+N-body binary merger simulations. We predict the radius, sigma, luminosity, age, and metallicity of spheroid-dominated galaxies, enabling us to compare directly to observations. Our model predicts a strong correlation between age and sigma for early-type galaxies, and no significant correlation between age and radius, in agreement with observations. In addi...

  3. The LAMOST spectroscopic survey of star clusters in M31. II. Metallicities, ages and masses

    CERN Document Server

    Bingqiu, Chen; Maosheng, Xiang; Haibo, Yuan; Yang, Huang; Jianrong, Shi; Zhou, Fan; Zhiying, Huo; Chun, Wang; Juanjuan, Ren; Zhijia, Tian; Huawei, Zhang; Gaochao, Liu; Zihuang, Cao; Yong, Zhang; Yonghui, Hou; Yuefei, Wang

    2016-01-01

    We select from Paper I a sample of 306 massive star clusters observed with the Large Sky Area Multi-Object Fibre Spectroscopic Telescope (LAMOST) in the vicinity fields of M31 and M33 and determine their metallicities, ages and masses. Metallicities and ages are estimated by fitting the observed integrated spectra with stellar synthesis population (SSP) models with a pixel-to-pixel spectral fitting technique. Ages for most young clusters are also derived by fitting the multi-band photometric measurements with model spectral energy distributions (SEDs). The estimated cluster ages span a wide range, from several million years to the age of the universe. The numbers of clusters younger and older than 1 Gyr are respectively 46 and 260. With ages and metallicities determined, cluster masses are then estimated by comparing the multi-band photometric measurements with SSP model SEDs. The derived masses range from $\\sim 10^{3}$ to $\\sim 10^7$ $M_{\\odot}$, peaking at $\\sim 10^{4.3}$ and $\\sim 10^{5.7}$ $M_{\\odot}$ for...

  4. Hair as an indicator of the body burden of metals in relation to age

    International Nuclear Information System (INIS)

    Many factors influencing metal deposition in hair are still unknown. Animal experiments were performed to obtain data on the mechanism of transfer of elements into hair and to estimate whether hair retention is influenced by age, sex and chelating agent treatment. Experiments were performed on albino rats (Wistar strain) of different age and sex. Whole body hair (skin included) and organ retention of various elements was determined at different periods of time after intraperitoneal administration of the radioactive isotopes 115mCd, 203Hg, 54Mn, 59Fe, 65Zn, 141Ce, 137Cs, 203Pb and 85Sr. In some experiments DTPA was used for reducing body retention of 155mCd and 141Ce and DMPS for reducing 203Hg retention. Results show that hair and organ retention of elements in rats varies with age, sex and chelation treatment and such changes are specific for each element and can not be generalized. Age as a factor influencing hair retention of metals is likely to be more important for some elements than for others. In kinetic studies we found that due to differences in element distribution and kinetics, the relationship between hair and organ retention at various time intervals varies both with age and the element concerned. Sex influences not only hair but also metal retention and distribution in other organs. (author). 4 refs

  5. A detailed investigation of surface modification in metallic glasses subjected to 130 MeV sup 2 sup 8 Si ion irradiation

    CERN Document Server

    Narayan, H; Agrawal, H M; Kushwaha, R P S; Sen-Gupta, A; Sharma, S K; Narlikar, Anant V; Kanjilal, D

    2002-01-01

    Surface modification induced in four metallic glasses by 4.64 MeV/u sup 2 sup 8 Si ion irradiation has been investigated in detail using optical microscopy, SEM and STM. Results obtained in two separate runs have been presented here. The effects of ion fluence (phi) and tilt angle (theta) on surface modification have been studied both qualitatively and quantitatively. It has been found that for S sub e values smaller than that for track formation, swift heavy ion irradiation leads to smoothing of the irradiated surfaces. The smoothing is evident from decreasing mean roughness R sub q and reduction in height of the 'hills' and filling up of the 'valleys' in the SEM and STM pictures. The observations have been explained on the basis of the theory of shear flow within the framework of the viscoelastic model.

  6. Gender and age differences in mixed metal exposure and urinary excretion

    International Nuclear Information System (INIS)

    Background: Little is known about the variation in exposure to toxic metals by age and gender and other potential modifying factors. We evaluated age and gender differences by measurements of metal/element concentrations in urine in a rural population in Matlab, Bangladesh, in three age groups: 8–12 (N=238), 14–15 (N=107) and 30–88 (N=710) years of age, living in an area with no point sources of metal exposure but where elevated water arsenic concentrations are prevalent. Results: We found marked differences in urine concentrations of metals and trace elements by gender, age, tobacco use, socioeconomic and nutritional status. Besides a clearly elevated urinary arsenic concentration in all age groups (medians 63–85 μg As/L), and despite the low degree of contamination from industries and traffic, the urine concentrations of toxic metals such as cadmium and lead were clearly elevated, especially in children (median 0.31 μg Cd/L and 2.9 μg Pb/L, respectively). In general, women had higher urinary concentrations of toxic metals, especially Cd (median 0.81 μg/L) compared to men (0.66 μg/L) and U (median 10 ng/L in women, compared to 6.4 ng/L in men), while men had higher urinary concentrations of the basic and essential elements Ca (69 mg/L in men, 30–50 years, compared to 52 mg/L in women), Mg (58 mg/L in men compared to 50 mg/L in women), Zn (182 μg/L in men compared to 117 μg/L in women) and Se (9.9 μg/L in men compared to 8.7 μg/L in women). Manganese was consistently higher in females than in males in all age groups, suggesting a biological difference between females and males in Mn metabolism. Increasing socioeconomic status decreased the toxic metal exposure significantly in children and especially in men. Poor iron status was detected in 17% of children, adolescents and women, but only in 6% of men. Also zinc deficiency was more prevalent in females than in males. Conclusions: Women and children seemed to be more at risk for toxic metal

  7. Gender and age differences in mixed metal exposure and urinary excretion

    Energy Technology Data Exchange (ETDEWEB)

    Berglund, Marika, E-mail: Marika.Berglund@ki.se [Institute of Environmental Medicine, Karolinska Institutet, Stockholm (Sweden); Lindberg, Anna-Lena [Institute of Environmental Medicine, Karolinska Institutet, Stockholm (Sweden); Rahman, Mahfuzar; Yunus, Mohammad [International Centre for Diarrhoeal Disease Research (Bangladesh); Grander, Margaretha [Institute of Environmental Medicine, Karolinska Institutet, Stockholm (Sweden); Loennerdal, Bo [Department of Nutrition, University of California, Davis, CA 95616 (United States); Vahter, Marie [Institute of Environmental Medicine, Karolinska Institutet, Stockholm (Sweden)

    2011-11-15

    Background: Little is known about the variation in exposure to toxic metals by age and gender and other potential modifying factors. We evaluated age and gender differences by measurements of metal/element concentrations in urine in a rural population in Matlab, Bangladesh, in three age groups: 8-12 (N=238), 14-15 (N=107) and 30-88 (N=710) years of age, living in an area with no point sources of metal exposure but where elevated water arsenic concentrations are prevalent. Results: We found marked differences in urine concentrations of metals and trace elements by gender, age, tobacco use, socioeconomic and nutritional status. Besides a clearly elevated urinary arsenic concentration in all age groups (medians 63-85 {mu}g As/L), and despite the low degree of contamination from industries and traffic, the urine concentrations of toxic metals such as cadmium and lead were clearly elevated, especially in children (median 0.31 {mu}g Cd/L and 2.9 {mu}g Pb/L, respectively). In general, women had higher urinary concentrations of toxic metals, especially Cd (median 0.81 {mu}g/L) compared to men (0.66 {mu}g/L) and U (median 10 ng/L in women, compared to 6.4 ng/L in men), while men had higher urinary concentrations of the basic and essential elements Ca (69 mg/L in men, 30-50 years, compared to 52 mg/L in women), Mg (58 mg/L in men compared to 50 mg/L in women), Zn (182 {mu}g/L in men compared to 117 {mu}g/L in women) and Se (9.9 {mu}g/L in men compared to 8.7 {mu}g/L in women). Manganese was consistently higher in females than in males in all age groups, suggesting a biological difference between females and males in Mn metabolism. Increasing socioeconomic status decreased the toxic metal exposure significantly in children and especially in men. Poor iron status was detected in 17% of children, adolescents and women, but only in 6% of men. Also zinc deficiency was more prevalent in females than in males. Conclusions: Women and children seemed to be more at risk for toxic

  8. Chemical composition effect on VVER-1000 RPV weld metal thermal aging

    Science.gov (United States)

    Gurovich, B. A.; Chernobaeva, A. A.; Erak, D. Yu; Kuleshova, E. A.; Zhurko, D. A.; Papina, V. B.; Skundin, M. A.; Maltsev, D. A.

    2015-10-01

    Temperature and fast neutron flux simultaneously affect the material of welded joints of reactor pressure vessels under irradiation. Understanding thermal aging effects on the weld metal allows for an explanation of the mechanisms that govern an increase in the ductile-to-brittle transition temperature of the reactor pressure vessel materials under long term irradiation at operation temperature. This paper reports on new results and reassessment of the VVER-1000 weld metal surveillance specimen database performed at the National Research Center "Kurchatov Institute". The current database of VVER-1000 weld metal thermal aging at 310-320 °C includes 50 transition temperature values with the maximum holding time of 208,896 h. The updated database completed with the information on intergranular fracture shear and phosphorous content in the grain boundaries has allowed us to propose a new mechanism of VVER-1000 weld materials thermal aging at 310-320 °C and develop models of ductile-to-brittle transition temperature shift for VVER-1000 weld metal during a long-term exposure at 310-320 °C.

  9. Direct evaluation of injection efficiency from metals into trap-free small-molecule-based transport layers: probing the details of interface formation

    Science.gov (United States)

    Abkowitz, Martin A.; Ioannidis, Andronique; Facci, John S.

    1999-10-01

    For devices based on the use of electronic polymers there is practical interest in exploring the variations in contact behavior that might result under realistic manufacturing conditions like multilayer device assembly based on solution coating technology. Small molecule doped polymers (MDPs) developed principally as large area coatings for electrophotographic use are now finding wider device applications. These polymers are insulators capable of transporting excess injected charge with a unipolar drift mobility which can be tuned over a wide range by varying the concentration of transport active species. Most significant in the present context, MDPs can be rendered trap free by molecular design. These unique characteristics of MDPs make it possible to analyze the relative injection efficiencies of their interfaces with various contacts simply by a direct comparison of current voltage characteristics with time of flight drift mobility measurements carried out on the same film coatings. Measurements were carried out by measuring dark hole injection into the MDP film TPD/polycarbonate and a polymeric analog, PTPB, from various preformed metal substrates as well as evaporated top contacts. For preformed metal substrates under fully relaxed conditions, it was found that while injection efficiency nominally scaled with the estimated interfacial energy step there was significant variance that in some cases could be clearly associated with the specific details of interfacial chemistry. Time and temperature dependent phenomenon were also delineated and analyzed. Here contact injection efficiencies were observed to increase monotonically, following initial formation, from an emission limited to final steady state which could be ohmic.

  10. Age-Related Uptake of Heavy Metals in Human Spinal Interneurons.

    Science.gov (United States)

    Pamphlett, Roger; Kum Jew, Stephen

    2016-01-01

    Toxic heavy metals have been implicated in the loss of spinal motoneurons in amyotrophic lateral sclerosis/motor neuron disease (ALS/MND). Motoneuron loss in the spinal anterior horn is severe in ALS/MND at the time of death, making this tissue unsuitable for examination. We therefore examined spinal cords of people without muscle weakness to look for any presence of heavy metals that could make these neurons susceptible to damage. Spinal cord samples from 50 individuals aged 1-95 y who had no clinical or histopathological evidence of spinal motoneuron loss were studied. Seven μm formalin-fixed paraffin-embedded sections were stained for heavy metals with silver nitrate autometallography (AMGHM) which detects intracellular mercury, silver or bismuth. Neurons in the spinal cord were classified as interneurons or α-motoneurons based on their site and cell body diameter. Spinal interneurons containing heavy metals were present in 8 of 24 people (33%) aged 61-95 y, but not at younger ages. These AMGHM interneurons were most numerous in the lumbar spinal cord, with moderate numbers in the caudal cervical cord, few in the rostral cervical cord, and almost none in the thoracic cord. All people with AMGHM interneurons had occasional AMGHM staining in α-motoneurons as well. In one man AMGHM staining was present in addition in dorsomedial nucleus and sensory neurons. In conclusion, heavy metals are present in many spinal interneurons, and in a few α-motoneurons, in a large proportion of older people. Damage to inhibitory interneurons from toxic metals in later life could result in excitotoxic injury to motoneurons and may underlie motoneuron injury or loss in conditions such as ALS/MND, multiple sclerosis, sarcopenia and calf fasciculations. PMID:27611334

  11. STAR CLUSTERS IN M31. II. OLD CLUSTER METALLICITIES AND AGES FROM HECTOSPEC DATA

    International Nuclear Information System (INIS)

    We present new high signal-to-noise spectroscopic data on the M31 globular cluster (GC) system, obtained with the Hectospec multifiber spectrograph on the 6.5 m MMT. More than 300 clusters have been observed at a resolution of 5 A and with a median S/N of 75 per A, providing velocities with a median uncertainty of 6 km s-1. The primary focus of this paper is the determination of mean cluster metallicities, ages, and reddenings. Metallicities were estimated using a calibration of Lick indices with [Fe/H] provided by Galactic GCs. These match well the metallicities of 24 M31 clusters determined from Hubble Space Telescope color-magnitude diagrams, the differences having an rms of 0.2 dex. The metallicity distribution is not generally bimodal, in strong distinction with the bimodal Galactic globular distribution. Rather, the M31 distribution shows a broad peak, centered at [Fe/H] = -1, possibly with minor peaks at [Fe/H] = -1.4, -0.7, and -0.2, suggesting that the cluster systems of M31 and the Milky Way had different formation histories. Ages for clusters with [Fe/H] > - 1 were determined using the automatic stellar population analysis program EZAges. We find no evidence for massive clusters in M31 with intermediate ages, those between 2 and 6 Gyr. Moreover, we find that the mean ages of the old GCs are remarkably constant over about a decade in metallicity (-0.95∼< [Fe/H] ∼<0.0).

  12. Species- and age-related variation in metal exposure and accumulation of two passerine bird species

    Energy Technology Data Exchange (ETDEWEB)

    Berglund, A.M.M., E-mail: asa.berglund@emg.umu.se [Section of Ecology, 20014 University of Turku (Finland); Koivula, M.J.; Eeva, T. [Section of Ecology, 20014 University of Turku (Finland)

    2011-10-15

    We measured the concentration of several elements (arsenic [As], calcium [Ca], cadmium [Cd], copper [Cu], nickel [Ni], lead [Pb], selenium [Se] and zinc [Zn]) in adult and nestling pied flycatchers (Ficedula hypoleuca) and great tits (Parus major) at different distances to a Cu-Ni smelter in 2009. Feces of nestlings generally failed to correspond with internal element concentrations but reflected the pollution exposure, indicating an increased stress by removal of excess metals. The uptake of Cu and Ni were regulated, but As, Cd, Pb and Se accumulated in liver tissue. Pied flycatchers had generally higher element concentrations than great tits. The higher accumulation of As and Pb in pied flycatcher livers was explained by a more efficient absorption, whereas the higher Cd concentration was primarily due to different intake of food items. Age-related differences occurred between the two species, though both Cd and Se accumulated with age. - Highlights: > We measured metal concentrations in feces and livers of two passerine species. > We examined species- and age-related differences in polluted environments. > Feces was evaluated as a useful non-destructive measure of increased stress. > Generally pied flycatchers accumulated higher concentrations than great tits. > Cadmium and selenium accumulated with age in both species. - Accumulation of metals in liver of two insectivorous passerines reflects inter-specific differences in diet, absorption rate and physiological requirements.

  13. The Response of Artificial Aging to Sorption Properties of Biochar for Potentially Toxic Heavy Metals

    Directory of Open Access Journals (Sweden)

    Frišták Vladimír

    2014-12-01

    Full Text Available This paper evaluates the effect of simulated conditions of artificial aging on sorption capacity of two types of biochar. These were produced by slow pyrolysis from different feedstock - beech wood chips (BC A and garden green waste residues (BC B. Cadmium served as a model for potentially toxic metals. Twenty freeze-thaw cycles were used to simulate physical aging. The determination of biochar physicochemical properties showed main changes in CEC and SA values of aged sorbents. The maximum sorption capacities of aged BC A sorbent were higher by about 26 % and aged BC B sorbent by about 20% compared to Qmax of non-aged biochar. Qmax of aged BC B peaked at 9.4 mg g-1 whereas BC A sorbed significantly less Cd. FT-IR analyses confirmed the changes in structural composition and content of functional groups on biochar surfaces. The artificial physical aging model was assessed as an efficient tool for investigation of natural weathering conditions.

  14. Zero Age Planetary Orbit of Gas Giant Planets Revisited: Reinforcement of the Link with Stellar Metallicity

    CERN Document Server

    Pinotti, Rafael; de Mello, Gustavo Frederico Porto

    2016-01-01

    In 2005 we suggested a relation between the optimal locus of gas giant planet formation, prior to migration, and the metallicity of the host star, based on the core accretion model and radial profiles of dust surface density and gas temperature. At that time, less than two hundred extrasolar planets were known, limiting the scope of our analysis. Here we take into account the expanded statistics allowed by new discoveries, in order to check the validity of some premises. We compare predictions with the present available data and results for different stellar mass ranges. We find that the Zero Age Planetary Orbit (ZAPO) hypothesis continues to hold after a one order of magnitude increase in discovered planets. In particular, the prediction that metal poor stars harbor planets with an average radius distinctively lower than metal rich ones is still evident in the statistics, and cannot be explained away by chaotic planetary formation mechanisms involving migration and gravitational interaction between planets. ...

  15. Symbolic metal bit and saddlebag fastenings in a Middle Bronze Age donkey burial.

    Directory of Open Access Journals (Sweden)

    Guy Bar-Oz

    Full Text Available Here we report the unprecedented discovery of the skeleton of a ritually interred donkey with a metal horse bit in association with its teeth and saddlebag fastenings on its back. This discovery in the Middle Bronze Age III sacred precinct (1700/1650-1550 BCE at Tel Haror, Israel, presents a unique combination of evidence for the early employment of equid harnessing equipment, both for chariot bridling (horse bit and pack animals (saddlebags. The ritually deposited donkey with its unique accoutrements advances our understanding of the broad social and religious significance of equids in the Levantine Bronze Age, previously known mainly from textual and iconographical sources.

  16. Symbolic Metal Bit and Saddlebag Fastenings in a Middle Bronze Age Donkey Burial

    Science.gov (United States)

    Bar-Oz, Guy; Nahshoni, Pirhiya; Motro, Hadas; Oren, Eliezer D.

    2013-01-01

    Here we report the unprecedented discovery of the skeleton of a ritually interred donkey with a metal horse bit in association with its teeth and saddlebag fastenings on its back. This discovery in the Middle Bronze Age III sacred precinct (1700/1650-1550 BCE) at Tel Haror, Israel, presents a unique combination of evidence for the early employment of equid harnessing equipment, both for chariot bridling (horse bit) and pack animals (saddlebags). The ritually deposited donkey with its unique accoutrements advances our understanding of the broad social and religious significance of equids in the Levantine Bronze Age, previously known mainly from textual and iconographical sources. PMID:23484046

  17. The Impact of Companies’ Age on Safety Culture in the Metal Products Industry

    Directory of Open Access Journals (Sweden)

    Maryam Ooshaksaraie

    2009-01-01

    Full Text Available Problem statement: Safety culture is a complex structure in an organization that includes values and attitudes, most of which are potentially changeable and related to actual accident behavior. In this study, the components of safety culture included organizational commitment, management involvement, employee empowerment, reporting system and rewarding system. Approach: The numbers of occupational injuries in industries have steadily increased during recent years. The major objectives of this study were to evaluate the safety culture and to analyze the difference in safety culture in the metal products industry in Iran (Guilan province with regard to companies’ age. Metal products industry was chosen because of the higher occupational injuries rates amongst the industries in Iran. Results: The companies were chosen based on their age. A total of 714 respondents from 14 companies participated in the survey. The method used in this study was a questionnaires quantitative type based on a Lickert scale and the data collected were analyzed statistically. The one-way ANOVA was used to test for significant difference in safety culture in the metal products industry with regard to companies’ age. The results showed that safety culture was not strong based on the mean for average score of 2.58 which was less than 3 compared to the possible maximum of 5. One-way ANOVA analysis revealed that there was a significant difference among safety culture with respect to companies’ age. New companies had stronger safety culture compared to older one. Conclusion: Based on the findings the hypothesis of this study is accepted. This study also indicated that the safety culture in the metal products industry in target population group was not strong however, can be improved through improvement of its five components.

  18. Effects of aging temperature on microstructural evolution at dissimilar metal weld interfaces

    International Nuclear Information System (INIS)

    From the earlier study which characterized the region of a fusion boundary between a low-alloy steel (LAS) and a Ni-based weld metal of as-welded and aged samples at 450 °C for a 30-y-equivalent time, it was observed in the microstructure that the aging treatment induced the formation and growth of Cr precipitates in the fusion boundary region because of the thermodynamic driving force. Now, this research extends the text matrix and continues the previous study by compiling all the test data, with an additional aging heat treatment conducted at 400 °C for 15- and 30-y-equivalent times (6450 and 12,911 h, respectively). The results for the extended test matrix primarily represent the common features of and disparities in the effects of thermal aging on the aged samples at two different heat-treatment temperatures (400 and 450 °C). Although no difference was expected between the samples, because the heat treatment conditions simulate thermal aging effects during the same service time of 30 y, the sample aged at 450 °C exhibited slightly more severe effects of thermal aging than the sample aged at 400 °C. Nevertheless, the trends for these effects are similar and the simulation of thermal aging effects for a light-water reactor appears to be reliable. However, according to a simulation of the same degree of thermal aging effects, it appears that the activation energy for Cr diffusion should be larger than the numerical value used in this study

  19. Effects of aging temperature on microstructural evolution at dissimilar metal weld interfaces

    Science.gov (United States)

    Choi, Kyoung Joon; Yoo, Seung Chang; Kim, Taeho; Bahn, Chi Bum; Kim, Ji Hyun

    2015-07-01

    From the earlier study which characterized the region of a fusion boundary between a low-alloy steel (LAS) and a Ni-based weld metal of as-welded and aged samples at 450 °C for a 30-y-equivalent time, it was observed in the microstructure that the aging treatment induced the formation and growth of Cr precipitates in the fusion boundary region because of the thermodynamic driving force. Now, this research extends the text matrix and continues the previous study by compiling all the test data, with an additional aging heat treatment conducted at 400 °C for 15- and 30-y-equivalent times (6450 and 12,911 h, respectively). The results for the extended test matrix primarily represent the common features of and disparities in the effects of thermal aging on the aged samples at two different heat-treatment temperatures (400 and 450 °C). Although no difference was expected between the samples, because the heat treatment conditions simulate thermal aging effects during the same service time of 30 y, the sample aged at 450 °C exhibited slightly more severe effects of thermal aging than the sample aged at 400 °C. Nevertheless, the trends for these effects are similar and the simulation of thermal aging effects for a light-water reactor appears to be reliable. However, according to a simulation of the same degree of thermal aging effects, it appears that the activation energy for Cr diffusion should be larger than the numerical value used in this study.

  20. Insights for aging management of light water reactor components: Metal containments

    International Nuclear Information System (INIS)

    This report evaluates the available technical information and field experience related to management of aging damage to light water reactor metal containments. A generic aging management approach is suggested for the effective and comprehensive aging management of metal containments to ensure their safe operation. The major concern is corrosion of the embedded portion of the containment vessel and detection of this damage. The electromagnetic acoustic transducer and half-cell potential measurement are potential techniques to detect corrosion damage in the embedded portion of the containment vessel. Other corrosion-related concerns include inspection of corrosion damage on the inaccessible side of BWR Mark I and Mark II containment vessels and corrosion of the BWR Mark I torus and emergency core cooling system piping that penetrates the torus, and transgranular stress corrosion cracking of the penetration bellows. Fatigue-related concerns include reduction in the fatigue life (a) of a vessel caused by roughness of the corroded vessel surface and (b) of bellows because of any physical damage. Maintenance of surface coatings and sealant at the metal-concrete interface is the best protection against corrosion of the vessel

  1. Radiochronological Age of a Uranium Metal Sample from an Abandoned Facility

    Energy Technology Data Exchange (ETDEWEB)

    Meyers, L A; Williams, R W; Glover, S E; LaMont, S P; Stalcup, A M; Spitz, H B

    2012-03-16

    A piece of scrap uranium metal bar buried in the dirt floor of an old, abandoned metal rolling mill was analyzed using multi-collector inductively coupled plasma mass spectroscopy (MC-ICP-MS). The mill rolled uranium rods in the 1940s and 1950s. Samples of the contaminated dirt in which the bar was buried were also analyzed. The isotopic composition of uranium in the bar and dirt samples were both the same as natural uranium, though a few samples of dirt also contained recycled uranium; likely a result of contamination with other material rolled at the mill. The time elapsed since the uranium metal bar was last purified can be determined by the in-growth of the isotope {sup 230}Th from the decay of {sup 234}U, assuming that only uranium isotopes were present in the bar after purification. The age of the metal bar was determined to be 61 years at the time of this analysis and corresponds to a purification date of July 1950 {+-} 1.5 years.

  2. Fusion boundary precipitation in thermally aged dissimilar metal welds studied by atom probe tomography and nanoindentation

    Science.gov (United States)

    Choi, Kyoung Joon; Kim, Taeho; Yoo, Seung Chang; Kim, Seunghyun; Lee, Jae Hyuk; Kim, Ji Hyun

    2016-04-01

    In this study, microstructural and mechanical characterizations were performed to investigate the effect of long-term thermal aging on the fusion boundary region between low-alloy steel and Nickel-based weld metal in dissimilar metal welds used in operating power plant systems. The effects of thermal aging treatment on the low-alloy steel side near the fusion boundary were an increase in the ratio of Cr constituents and Cr-rich precipitates and the formation and growth of Cr23C6. Cr concentrations were calculated using atom probe tomography. The accuracy of simulations of thermal aging effects of heat treatment was verified, and the activation energy for Cr diffusion in the fusion boundary region was calculated. The mechanical properties of fusion boundary region changed based on the distribution of Cr-rich precipitates, where the material initially hardened with the formation of Cr-rich precipitates and then softened because of the reduction of residual strain or coarsening of Cr-rich precipitates.

  3. Effect of thermal aging on SCC and mechanical properties of stainless steel weld metals

    Energy Technology Data Exchange (ETDEWEB)

    Hixon, J.R. [U.S. Nuclear Regulatory Commission (United States); Kim, J.H.; Ballinger, R.G. [Massachusetts Inst. of Technology (United States)

    2007-07-01

    The thermal aging and consequent embrittlement of materials are ongoing issues in cast stainless steels and duplex stainless steel. Spinodal decomposition is largely responsible for the well known '475{sup o}C embrittlement that results in drastic reductions in ductility and toughness in these materials, and this process is operative in welds in either cast or wrought stainless steels where delta ferrite is present. While the embrittlement can occur after several hundred hours of aging at 475{sup o}C, the process is also operative at lower temperatures, including the 300{sup o}C operating temperature of a boiling water reactor (BWR), where ductility reductions have been observed after several tens of thousands of hours. An experimental program is under way in to understand how the spinodal decomposition may affect material properties changes in BWR pipe weld metals. Testing includes nano and micro-structural analysis as well as fatigue and SCC crack growth. In this study we report on the initial results of this program, including tensile, Charpy impact, fracture toughness and SCC crack growth rates of SS weld metals under simulated BWR conditions. The measurement of tensile, microhardness and Charpy-impact energy show an increase in strength, a decrease in ductility, and a decrease in impact energy after aging for 1000 hours at 430 and 400 {sup o}C. Crack growth rates for material in the as welded and aged for 5000 hours at 400{sup o}C have been measured and are generally within the scatter band for wrought material although the aged material data fall at the high end. Unusual insitu unstable fracture behavior has been experienced at toughness values significantly below (<50%) the room temperature fracture toughness. This behavior, termed 'environmental fracture' requires further investigation. (author)

  4. Regional models of metal production in Western Asia in the Chalcolithic, Early and Middle Bronze Ages

    Directory of Open Access Journals (Sweden)

    Avilova, Liudmila

    2008-06-01

    Full Text Available The objective of this work is the reconstruction and comparative analysis of regional models of metal production in the Chalcolithic, Early and Middle Bronze Ages. The work is based on the statistical analysis of unique computer database on archaeological metal finds from four regions of the Near East: Anatolia, Mesopotamia, the Levant, and Iran. The materials are analysed by four indicators: distribution by the chronological periods, artefacts’ function, proportion of used metals and copper- based alloys. The author presents a series of conclusions concerning the preconditions for the beginnings of metal production in Western Asia and the pioneering role of Iran in its emergence, the important role the piedmont territories played in the development of metal production, the leap-like pattern of production dynamics shown by the periods, and its relation to the spread of a producing economy, long-distance exchange, and the emergence of the early civilizations.

    El objetivo de este trabajo es la reconstrucción y análisis comparativo de modelos regionales de producción metalúrgica del Calcolítico y la Edad del Bronce Inicial y Media. Se basa en el análisis estadístico de una base de datos única sobre hallazgos metálicos de cuatro regiones del Próximo Oriente: Anatolia, Mesopotamia, el Levante e Irán. Los materiales se analizan atendiendo a cuatro variables: períodos cronológicos, función de los artefactos, proporción de los metales usados y las distintas aleaciones del cobre. La autora aporta una serie de conclusiones respecto a las precondiciones para los inicios de la producción metalúrgica en el Oeste Asiático; sobre el papel pionero de Irán en su aparición; la importancia de los piedemontes en su desarrollo; el patrón no continuo que se observa en las dinámicas de producción por periodos; y su relación con la expansión de la economía de producción, el intercambio a larga distancia y la aparición de las

  5. Age-metallicity-velocity relation of stars as seen by RAVE

    Science.gov (United States)

    Wojno, Jennifer; Kordopatis, Georges; Steinmetz, Matthias; Matijevič, Gal; McMillan, Paul J.

    2016-08-01

    Throughout the past decade, significant advances have been made in the size and scope of large-scale spectroscopic surveys, allowing for the opportunity to study in-depth the formation history of the Milky Way. Using the fourth data release of the RAdial Velocity Experiment (RAVE), we study the age-metallicity-velocity space of ~ 100,000 FGK stars in the extended solar neighborhood in order to explore evolutionary processes. Combining these three parameters, we better constrain our understanding of these interconnected, fundamental processes.

  6. A mechanical analysis of metallic tritide aging by helium bubble growth

    Energy Technology Data Exchange (ETDEWEB)

    Montheillet, F. [Ecole Nationale Superieure des Mines (SMS), CNRS UMR 5146 (PECM), 158 cours Fauriel, 42023 Saint-Etienne Cedex 2 (France)], E-mail: montheil@emse.fr; Delaplanche, D.; Fabre, A.; Munier, E.; Thiebaut, S. [Commissariat a l' Energie Atomique de Valduc, 21120 Is-sur-Tille (France)

    2008-10-25

    A simple mechanical model is proposed for the aging of a metallic tritide. The material is assumed to be elastic-power law viscoplastic. Part of the helium atoms generated by tritium decay form spherical bubbles that weaken the elastic moduli of the overall material. By contrast, others can be stored in solid solution in the matrix and are likely to increase the moduli. Two variants of the model are compared, assuming either instantaneous or finite rate diffusion of helium. They predict globally similar evolutions of the gas pressure inside the bubbles, the geometrical parameters (bubble radius, overall swelling), as well as the matrix and overall elastic moduli. The results are in good agreement with atomistic calculations of the pressure evolution. Furthermore, recent experimental measurements of the Young modulus changes during aging are better reproduced when He diffusion rate is finite, thus supporting the second variant of the model.

  7. On the Age-Metallicity-Velocity Relation in the Nearby Disk Using the RAVE Survey

    Science.gov (United States)

    Anguiano, Borja; Freeman, Kenneth C.; Steinmetz, Matthias; de Boer, Elizabeth Wylie

    The age-metallicity-velocity relation (AMVR) in the nearby disk is a fundamental issue in our understanding of the evolution of the Milky Way. However, there are still major differences between various versions of this relation (e.g., Twarog 1980, ApJ, 242, 242,Meusinger et al. 1991, A&A, 245, 57, Edvardsson et al. 1993, A&A, 275, 101, Rocha-Pinto et al. 2000, A &A, 358, 850,Quillen & Garnett 2001, Galaxy Disks and Disk Galaxies, ASP, San Francisco, CA, vol. 230, p. 87, Feltzing et al. 2001, A&A, 377,911, and Holmberg et al. 2007, A&A, 475, 519). Also, we have found considerable differences between different methods forage-dating stellar populations and have shown how different methods introduce bias in the AMVR. We are therefore working in a new derivation of these possible relations in the nearby disk, using a carefully selected sample of subgiants stars from RAVE and Geneva-Copenhagen surveys. RAVE provides accurate kinematics and a first estimate of metallicity, temperature, and gravity. Follow-up observations allow us to obtain accurate fundamental parameters via spectrophotometry and highresolution spectroscopy in order to derive reliable ages and generate an AMVR for stars of the Galactic disk.

  8. ADIMEW: Fracture assessment and testing of an aged dissimilar metal weld pipe assembly

    International Nuclear Information System (INIS)

    ADIMEW (Assessment of Aged Piping Dissimilar Metal Weld Integrity) was a three-year collaborative research programme carried out under the EC 5th Framework Programme. The objective of the study was to advance the understanding of the behaviour and safety assessment of defects in dissimilar metal welds between pipes representative of those found in nuclear power plant. ADIMEW studied and compared different methods for predicting the behaviour of defects located near the fusion boundaries of dissimilar metal welds typically used to join sections of austenitic and ferritic piping operating at high temperature. Assessment of such defects is complicated by issues that include: severe mis-match of yield strength of the constituent parent and weld metals, strong gradients of material properties, the presence of welding residual stresses and mixed mode loading of the defect. The study includes the measurement of material properties and residual stresses, predictive engineering analysis and validation by means of a large-scale test. The particular component studied was a 453mm diameter pipe that joins a section of type A508 Class 3 ferritic pipe to a section of type 316L austenitic pipe by means of a type 308 austenitic weld with type 308/309L buttering laid on the ferritic pipe. A circumferential, surface-breaking defect was cut using electro discharge machining into the 308L/309L weld buttering layer parallel to the fusion line. The test pipe was subjected to four-point bending to promote ductile tearing of the defect. This paper presents the results of TWI contributions to ADIMEW including: fracture toughness testing, residual stress measurements and assessments of the ADIMEW test using elastic-plastic, cracked body, finite element analysis. (orig.)

  9. Younger age at onset of sporadic Parkinson’s disease among subjects occupationally exposed to metals and pesticides

    Directory of Open Access Journals (Sweden)

    Ratner Marcia H.

    2014-09-01

    Full Text Available An earlier age at onset of Parkinson’s disease (PD has been reported to be associated with occupational exposures to manganese and hydrocarbon solvents suggesting that exposure to neurotoxic chemicals may hasten the progression of idiopathic PD. In this study the role of occupational exposure to metals and pesticides in the progression of idiopathic PD was assessed by looking at age at disease onset. The effects of heritable genetic risk factors, which may also influence age at onset, was minimized by including only sporadic cases of PD with no family history of the disease (n=58. Independent samples Student t-test revealed that subjects with occupational exposure to metals and/or pesticides (n=36 were significantly (p=0.013 younger than unexposed controls (n=22. These subjects were then divided into three groups [high (n=18, low (n=18, and unexposed (n=22] to ascertain if duration of exposure further influenced age at onset of PD. One-way ANOVA revealed that subjects in the high exposure group were significantly (p=0.0121 younger (mean age: 50.33 years than unexposed subjects (mean age: 60.45 years. Subjects were also stratified by exposure type (metals vs. pesticides. These results suggest that chronic exposure to metals and pesticides is associated with a younger age at onset of PD among patients with no family history of the disease and that duration of exposure is a factor in the magnitude of this effect.

  10. Effect of long-term thermal aging on the fracture toughness of austenitic stainless steel base and weld metals

    Energy Technology Data Exchange (ETDEWEB)

    Huang, F.F.

    1995-09-27

    Compact tension specimens taken from FFTF primary piping materials (Type 316 stainless steel (SS) and 16-8-2 SS weld metal) and from reactor vessel materials (304 SS and 308 SS weld metal) were heated in laboratory furnaces from 100,000 hours. Fracture toughness testing was performed on these specimens, which are 7.62- and 25.4-mm thick, respectively at the aging temperature (482 and 427 degrees). Results were analyzed with the multiple-specimen method. Thermal aging continues to reduce the fracture toughness of FFTF component materials. Results show that thermal aging has a strong effect on the toughness degradation of weld metals, particularly for 16-8-2 SS weld whose aged/unaged Jc ratio is only 0.31 after 100,000-hour aging. The fracture toughness of the 308 and 16-8-2 SS weld metals fluctuated during 20,000 to 50,000-hour aging but deteriorated as the aging time increased to 100,000 hours; the toughness degradation is significant. Fracture control based on a fracture mechanics approach should be considered

  11. A Minimal Fragmentation Approach to Real Time Aerosol Mass Spectrometry: A New Tool for Detailed Laboratory Studies of Organic Aerosol Aging

    Science.gov (United States)

    Campuzano-Jost, P.; Hanna, S.; Simpson, E.; Robb, D.; Blades, M. W.; Hepburn, J. W.; Bertram, A. K.

    2005-12-01

    have used almost exclusively a single photon energy (10.5 eV) to ionize all molecules. We have constructed a new real time aerosol mass spectrometer, based on the designs of Su et al. (2004) & Sykes et al. (2002), which incorporates a new, high-powered, fully tunable VUV source (115-190 nm, 6.5-11 eV ionization energy). This enables us to ionize quantitatively with little to no fragmentation almost all atmospherically relevant organic compounds. Coupled with an ion trap where the primary ions can be stored for further structural analysis, this instrument promises to be both universal and sensitive enough to allow for detailed studies of SOA formation as well as the aging of mixed aerosols. References: Allan, J.D., J.L. Jimenez, et al. (2003)."Quantitative sampling using an Aerodyne aerosol mass spectrometer: 1.Techniques of data interpretation and error analysis" J.Geophys.Res. 108(D9) Nash, D.G., X.F. Liu, et al. (2005)."Aerosol particle mass spectrometry with low photon energy laser ionization" Inter.J.Mass Spec. 241(2-3):89 Oktem,B., M.P. Tolocka, et al. (2004)."On-line analysis of organic components in fine and ultrafine particles by photoionization aerosol mass spectrometry" Anal.Chem. 76(2):253 Su, Y.X., M.F. Sipin, et al. (2004)."Development and characterization of an aerosol time-of-flight mass spectrometer with increased detection efficiency" Anal.Chem. 76(3):712 Sykes, D.C., E. Woods, et al. (2002)."Thermal vaporization-vacuum ultraviolet laser ionization time-of-flight mass spectrometry of single aerosol particles" Anal.Chem. 74(9):2048

  12. Back to the metal age: battle for metals at the host–pathogen interface during urinary tract infection

    Science.gov (United States)

    Subashchandrabose, Sargurunathan

    2015-01-01

    Urinary tract infection (UTI) represents one of the most common bacterial infections in humans and uropathogenic E. coli (UPEC) is the major causative agent of UTI in people. Research on UPEC and other bacterial pathogens causing UTI has now identified the critical role of metal transport systems in the pathogenesis of UTI. Here we review the major effectors of metal transport in bacteria and host proteins that impair metal acquisition by bacterial pathogens. In particular, we describe the studies that identified iron, zinc and nickel import and copper export as key virulence and fitness determinants during UTI. Various metal transport systems and mechanisms that govern the expression of metal transport systems are also presented here. Specific examples from UPEC and other uropathogens, when available, are presented to depict the battle for metals at the host–pathogen interface during UTI. PMID:25677827

  13. STAR CLUSTERS IN M33: UPDATED UBVRI PHOTOMETRY, AGES, METALLICITIES, AND MASSES

    Energy Technology Data Exchange (ETDEWEB)

    Fan, Zhou [Key Laboratory of Optical Astronomy, National Astronomical Observatories, Chinese Academy of Sciences, 20A Datun Road, Chaoyang District, Beijing 100012 (China); De Grijs, Richard, E-mail: zfan@bao.ac.cn, E-mail: grijs@pku.edu.cn [Kavli Institute for Astronomy and Astrophysics, Peking University, Yi He Yuan Lu 5, Hai Dian District, Beijing 100871 (China)

    2014-04-01

    The photometric characterization of M33 star clusters is far from complete. In this paper, we present homogeneous UBVRI photometry of 708 star clusters and cluster candidates in M33 based on archival images from the Local Group Galaxies Survey, which covers 0.8 deg{sup 2} along the galaxy's major axis. Our photometry includes 387, 563, 616, 580, and 478 objects in the UBVRI bands, respectively, of which 276, 405, 430, 457, and 363 do not have previously published UBVRI photometry. Our photometry is consistent with previous measurements (where available) in all filters. We adopted Sloan Digital Sky Survey ugriz photometry for complementary purposes, as well as Two Micron All Sky Survey near-infrared JHK photometry where available. We fitted the spectral-energy distributions of 671 star clusters and candidates to derive their ages, metallicities, and masses based on the updated PARSEC simple stellar populations synthesis models. The results of our χ{sup 2} minimization routines show that only 205 of the 671 clusters (31%) are older than 2 Gyr, which represents a much smaller fraction of the cluster population than that in M31 (56%), suggesting that M33 is dominated by young star clusters (<1 Gyr). We investigate the mass distributions of the star clusters—both open and globular clusters—in M33, M31, the Milky Way, and the Large Magellanic Cloud. Their mean values are log (M {sub cl}/M {sub ☉}) = 4.25, 5.43, 2.72, and 4.18, respectively. The fraction of open to globular clusters is highest in the Milky Way and lowest in M31. Our comparisons of the cluster ages, masses, and metallicities show that our results are basically in agreement with previous studies (where objects in common are available); differences can be traced back to differences in the models adopted, the fitting methods used, and stochastic sampling effects.

  14. Metallicity and Age of the Stellar Stream Around the Disk Galaxy NGC 5907

    CERN Document Server

    Laine, Seppo; Capak, Peter; Arendt, Richard G; Romanowsky, Aaron J; Martinez-Delgado, David; Ashby, Matthew L N; Davies, James E; Majewski, Stephen R; Brodie, Jean P; GaBany, R Jay; Arnold, Jacob A

    2016-01-01

    Stellar streams have become central to studies of the interaction histories of nearby galaxies. To characterize the most prominent parts of the stellar stream around the well-known nearby (d = 17 Mpc) edge-on disk galaxy NGC 5907, we have obtained and analyzed new, deep gri Subaru/Suprime-Cam and 3.6 micron Spitzer/Infrared Array Camera (IRAC) observations. Combining the near-infrared 3.6 micron data with visible-light images allows us to use a long wavelength baseline to estimate the metallicity and age of the stellar population along a ~60 kpc long segment of the stream. We have fitted the stellar spectral energy distribution (SED) with a single-burst stellar population synthesis model and we use it to distinguish between the proposed satellite accretion and minor/major merger formation models of the stellar stream around this galaxy. We conclude that a massive minor merger (stellar mass ratio of at least 1:8) can best account for the metallicity of -0.3 inferred along the brightest parts of the stream.

  15. Beginning of the metal age in the central Balkans according to the results of the archeometallurgy

    Directory of Open Access Journals (Sweden)

    Jovanović B.

    2009-01-01

    Full Text Available The gradual development of the primary copper metallurgy in Balkans starts with production of small jewelry pieces and ends with the serial production of massive tools and weapons. It is confirmed that this metallurgy depended on the contemporary mining, i.e. the available sources of the raw materials. It is also corroborated by the discovery of two Early Eneolithic copper mines: Rudna Glava in Eastern Serbia and Ai-Bunar in Bulgaria /first half and the middle of the 5th millennium BC/. These mines are also the evidence for the local exploitation of the carbonate copper minerals - malachite and azurite. The technology employed is close to the former flint mining in the Late Neolithic; massive pebbles obtained from the neighboring alluvial deposits were used as mining hammers. Identical technology was employed in the mines dating from the later periods /Rudnik, Central Serbia, Jarmovac, Priboj na Limu/. The Vinča culture of the central Balkan followed all metallurgical phases of introduction of metal and use of the carbonate ores /Gradac I - III phase/. This long process of including the metal in wider use lasted generally from the middle of the 5th millennium BC to the end of the 4th millennium BC, i.e. to the appearance of the Bronze Age.

  16. Age-Dependent Changes in Resting Energy Expenditure (REE: Insights from Detailed Body Composition Analysis in Normal and Overweight Healthy Caucasians

    Directory of Open Access Journals (Sweden)

    Corinna Geisler

    2016-06-01

    Full Text Available Age-related changes in organ and tissue masses may add to changes in the relationship between resting energy expenditure (REE and fat free mass (FFM in normal and overweight healthy Caucasians. Secondary analysis using cross-sectional data of 714 healthy normal and overweight Caucasian subjects (age 18–83 years with comprehensive information on FFM, organ and tissue masses (as assessed by magnetic resonance imaging (MRI, body density (as assessed by Air Displacement Plethysmography (ADP and hydration (as assessed by deuterium dilution (D2O and REE (as assessed by indirect calorimetry. High metabolic rate organs (HMR summarized brain, heart, liver and kidney masses. Ratios of HMR organs and muscle mass (MM in relation to FFM were considered. REE was calculated (REEc using organ and tissue masses times their specific metabolic rates. REE, FFM, specific metabolic rates, the REE-FFM relationship, HOMA, CRP, and thyroid hormone levels change with age. The age-related decrease in FFM explained 59.7% of decreases in REE. Mean residuals of the REE-FFM association were positive in young adults but became negative in older subjects. When compared to young adults, proportions of MM to FFM decreased with age, whereas contributions of liver and heart did not differ between age groups. HOMA, TSH and inflammation (plasma CRP-levels explained 4.2%, 2.0% and 1.4% of the variance in the REE-FFM residuals, but age and plasma T3-levels had no effects. HMR to FFM and MM to FFM ratios together added 11.8% on to the variance of REE-FFM residuals. Differences between REE and REEc increased with age, suggesting age-related changes in specific metabolic rates of organs and tissues. This bias was partly explained by plasmaT3-levels. Age-related changes in REE are explained by (i decreases in fat free mass; (ii a decrease in the contributions of organ and muscle masses to FFM; and (iii decreases in specific organ and tissue metabolic rates. Age-dependent changes in the

  17. Age-Dependent Changes in Resting Energy Expenditure (REE): Insights from Detailed Body Composition Analysis in Normal and Overweight Healthy Caucasians.

    Science.gov (United States)

    Geisler, Corinna; Braun, Wiebke; Pourhassan, Maryam; Schweitzer, Lisa; Glüer, Claus-Christian; Bosy-Westphal, Anja; Müller, Manfred J

    2016-01-01

    Age-related changes in organ and tissue masses may add to changes in the relationship between resting energy expenditure (REE) and fat free mass (FFM) in normal and overweight healthy Caucasians. Secondary analysis using cross-sectional data of 714 healthy normal and overweight Caucasian subjects (age 18-83 years) with comprehensive information on FFM, organ and tissue masses (as assessed by magnetic resonance imaging (MRI)), body density (as assessed by Air Displacement Plethysmography (ADP)) and hydration (as assessed by deuterium dilution (D₂O)) and REE (as assessed by indirect calorimetry). High metabolic rate organs (HMR) summarized brain, heart, liver and kidney masses. Ratios of HMR organs and muscle mass (MM) in relation to FFM were considered. REE was calculated (REEc) using organ and tissue masses times their specific metabolic rates. REE, FFM, specific metabolic rates, the REE-FFM relationship, HOMA, CRP, and thyroid hormone levels change with age. The age-related decrease in FFM explained 59.7% of decreases in REE. Mean residuals of the REE-FFM association were positive in young adults but became negative in older subjects. When compared to young adults, proportions of MM to FFM decreased with age, whereas contributions of liver and heart did not differ between age groups. HOMA, TSH and inflammation (plasma CRP-levels) explained 4.2%, 2.0% and 1.4% of the variance in the REE-FFM residuals, but age and plasma T3-levels had no effects. HMR to FFM and MM to FFM ratios together added 11.8% on to the variance of REE-FFM residuals. Differences between REE and REEc increased with age, suggesting age-related changes in specific metabolic rates of organs and tissues. This bias was partly explained by plasmaT3-levels. Age-related changes in REE are explained by (i) decreases in fat free mass; (ii) a decrease in the contributions of organ and muscle masses to FFM; and (iii) decreases in specific organ and tissue metabolic rates. Age-dependent changes in the REE

  18. Age-Dependent Changes in Resting Energy Expenditure (REE): Insights from Detailed Body Composition Analysis in Normal and Overweight Healthy Caucasians

    OpenAIRE

    Geisler, Corinna; Braun, Wiebke; Pourhassan, Maryam; Schweitzer, Lisa; Glüer, Claus-Christian; Bosy-Westphal, Anja; Müller, Manfred J.

    2016-01-01

    Age-related changes in organ and tissue masses may add to changes in the relationship between resting energy expenditure (REE) and fat free mass (FFM) in normal and overweight healthy Caucasians. Secondary analysis using cross-sectional data of 714 healthy normal and overweight Caucasian subjects (age 18–83 years) with comprehensive information on FFM, organ and tissue masses (as assessed by magnetic resonance imaging (MRI)), body density (as assessed by Air Displacement Plethysmography (ADP)...

  19. 17 CFR 240.17Ad-11 - Reports regarding aged record differences, buy-ins and failure to post certificate detail to...

    Science.gov (United States)

    2010-04-01

    ... Securities Exchange Act of 1934 Supervised Investment Bank Holding Company Rules § 240.17Ad-11 Reports... and subsidiary files. (a) Definitions. (1) Issuer capitalization means the market value of the issuer... differences, buy-ins and failure to post certificate detail to master securityholder and subsidiary files....

  20. Circulating human B and plasma cells. Age-associated changes in counts and detailed characterization of circulating normal CD138(-) and CD138(+) plasma cells

    NARCIS (Netherlands)

    Caraux, Anouk; Klein, Bernard; Paiva, Bruno; Bret, Caroline; Schmitz, Alexander; Fuhler, Gwenny M.; Bos, Nico A.; Johnsen, Hans E.; Orfao, Alberto; Perez-Andres, Martin

    2010-01-01

    Generation of B and plasma cells involves several organs with a necessary cell trafficking between them. A detailed phenotypic characterization of four circulating B-cell subsets (immature-, naive-, memory- B-lymphocytes and plasma cells) of 106 healthy adults was realized by multiparametric flow cy

  1. Assessing dietary exposure to cadmium in a metal recycling community in Vietnam: Age and gender aspects

    Energy Technology Data Exchange (ETDEWEB)

    Minh, Ngo Duc [Vietnamese Academy of Agriculture Sciences, Soils and Fertilizers Research Institute (SFRI), Tu Liem, Hanoi (Viet Nam); Hough, Rupert Lloyd, E-mail: rupert.hough@hutton.ac.uk [The James Hutton Institute, Craigiebuckler, Aberdeen, AB15 8QH (United Kingdom); Thuy, Le Thi [Vietnamese Academy of Agriculture Science, Institute of Agricultural Environment (IAE), Tu Liem, Hanoi (Viet Nam); Nyberg, Ylva [Department of Crop Production Ecology, PO Box 7043, Swedish University of Agricultural Sciences (SLU), SE-750 07 Uppsala (Sweden); Mai, Le Bach [National Institute of Nutrition, 48b Tang Bat Ho, Hoan Kiem, Hanoi (Viet Nam); Vinh, Nguyen Cong [Vietnamese Academy of Agriculture Sciences, Soils and Fertilizers Research Institute (SFRI), Tu Liem, Hanoi (Viet Nam); Khai, Nguyen Manh [Faculty of Environmental Sciences, Ha Noi University of Science (HUS-VNU), 334 Nguyen Trai, Thanh Xuan, Ha Noi (Viet Nam); Oeborn, Ingrid [Department of Crop Production Ecology, PO Box 7043, Swedish University of Agricultural Sciences (SLU), SE-750 07 Uppsala (Sweden)

    2012-02-01

    This study estimates the dietary exposure to cadmium (Cd), and associated potential health risks, for individuals living and working in a metal recycling community (n = 132) in Vietnam in comparison to an agricultural (reference) community (n = 130). Individual-level exposure to Cd was estimated through analysis of staple foodstuffs combined with information from a food frequency questionnaire. Individual-level exposure estimates were compared with published 'safe' doses to derive a Hazard Quotient (HQ) for each member of the study population. Looking at the populations as a whole, there were no significant differences in the diets of the two villages. However, significantly more rice was consumed by working age adults (18-60 years) in the recycling village compared to the reference village (p < 0.001). Rice was the main staple food with individuals consuming 461 {+-} 162 g/d, followed by water spinach (103 {+-} 51 kg/d). Concentrations of Cd in the studied foodstuffs were elevated in the metal recycling village. Values of HQ exceeded unity for 87% of adult participants of the metal recycling community (39% had a HQ > 3), while 20% of adult participants from the reference village had an HQ > 1. We found an elevated health risk from dietary exposure to Cd in the metal recycling village compared to the reference community. WHO standard of 0.4 mg Cd/kg rice may not be protective where people consume large amounts of rice/have relatively low body weight. - Highlights: Black-Right-Pointing-Pointer First individual-level risk assessment of cadmium in recycling villages of Vietnam. Black-Right-Pointing-Pointer Dietary analysis undertaken for a recycling community and an agricultural community. Black-Right-Pointing-Pointer No significant differences were found between the diets of the two populations. Black-Right-Pointing-Pointer 87% of people in the recycling community had elevated health risk. Black-Right-Pointing-Pointer WHO standard (0.4 mg Cd/kg rice) may

  2. Las Lunas (Yuncler, Toledo. A Bronze Age hoard with metallic materials from the southern Iberian Meseta

    Directory of Open Access Journals (Sweden)

    Urbina Martínez, Dionisio

    2010-06-01

    Full Text Available Here we present the results of the preliminary study carried out on a new group of metallic materials of the Final Bronze Age, recovered at the end of 2008 in the archaeological excavations at the settlement of Las Lunas (Yuncler, Toledo, Spain. Its geographical situation far away from the main zones of distribution of this type of finds, the singularity of the materials, and the evidence of Atlantic and Mediterranean relations make these materials a remarkable sample for the study of the Final Bronze Age in the centre of the Iberian Peninsula.

    Se exponen los resultados del primer estudio realizado sobre un nuevo conjunto de materiales metálicos del Bronce Final recuperado a finales de 2008 en las excavaciones arqueológicas del yacimiento de Las Lunas (Yuncler, Toledo, España. La localización geográfica del hallazgo, lejos de las principales zonas de dispersión conocidas para este tipo de conjuntos, la singularidad de los objetos que integra, y las relaciones atlánticas y mediterráneas que evidencian sus materiales, lo convierten en un ejemplo destacado para el estudio de este período en el centro de la Península Ibérica.

  3. Carbon-enhanced metal-poor stars: a window on AGB nucleosynthesis and binary evolution. I. Detailed analysis of 15 binary stars with known orbital periods

    CERN Document Server

    Abate, C; Karakas, A I; Izzard, R G

    2015-01-01

    AGB stars are responsible for producing a variety of elements, including carbon, nitrogen, and the heavy elements produced in the slow neutron-capture process ($s$-elements). There are many uncertainties involved in modelling the evolution and nucleosynthesis of AGB stars, and this is especially the case at low metallicity, where most of the stars with high enough masses to enter the AGB have evolved to become white dwarfs and can no longer be observed. The stellar population in the Galactic halo is of low mass ($\\lesssim 0.85M_{\\odot}$) and only a few observed stars have evolved beyond the first giant branch. However, we have evidence that low-metallicity AGB stars in binary systems have interacted with their low-mass secondary companions in the past. The aim of this work is to investigate AGB nucleosynthesis at low metallicity by studying the surface abundances of chemically peculiar very metal-poor stars of the halo observed in binary systems. To this end we select a sample of 15 carbon- and $s$-element-en...

  4. A Study of Microstructural Changes by Thermal Aging in the Interface between Low Alloy Steel and Ni-base Alloy Filler Metal

    International Nuclear Information System (INIS)

    As-welded condition at FB may not cause serious cracking issues, but thermal aging may change the local microstructure and decrease the cracking resistance and/or the strength. This study mainly focused on a potential microstructural change due to the thermal aging: Cr carbides formation at the low alloy steel side of FB region. This study is focused on the characterization of FB region between Alloy 152 and A533 Gr. B LAS in order to take a kind of proactive approach rather than reactive one. And, such data will be important for assessing aging effects of structural components and evaluating the long-term operation of commercial power plants. Therefore, the current study is aiming at the investigation of the thermal effect on the interface between Alloy 152 filler metal and A533 Gr. B. In order to investigate the effect of the thermal aging on the change of structure and chemistry in that region, the detail instrumental analysis in the fusion boundary region of A533 Gr. B-Alloy 152 DMW joint were performed. The following conclusions can be drawn from the study. Firstly, while the microhardness in the FB region is decreased after the thermally aging heat treatment for 2,750-hrs, that is re-increased after the treatment for 5,500-hrs. It is believed that the changed microhardness could be caused by the microstructural change and the residual stress relief during the thermal aging heat treatment. Next, the distribution of Ni, Fe and Cr became relatively uniform in the dilution zone in the weld metal region of DMW, and the concentration of Fe is lower, but those of other elements are higher in A533 Gr. B near the FB region after aging heat treatment. And, the precipitates are mainly formed in the HAZ of A533Gr.B near the FB, and the increase in size and number density of the precipitates is observed after aging heat treatment. The thermal aging can promote the formation of carbides in the HAZ of A533 Gr. B near the FB region in DMW of A533 Gr. B - Alloy 152. Finally

  5. Relationship between the Concentrations of Heavy Metals and Bioelements in Aging Men with Metabolic Syndrome

    Directory of Open Access Journals (Sweden)

    Iwona Rotter

    2015-04-01

    Full Text Available Heavy metals may exacerbate metabolic syndrome (MS but abnormal serum concentrations of bioelements may also co-exist with MS. The primary aim of the study was to assess the relationship of blood heavy metal and bioelement concentrations and MS, in men aged 50–75 years. Heavy metals—lead (Pb, cadmium (Cd, mercury (Hg, arsenic (As, tungsten (W, Macroelements—magnesium (Mg and calcium (Ca, and microelements—iron (Fe, zinc (Zn copper (Cu, chromium (Cr, molybdenum (Mo, selenium (Se and manganese (Mn, body mass index (BMI, waist to hip ratio (WHR, abdominal circumference (AC and blood pressure (BP, total cholesterol (TCh, high-density lipoprotein (HDL, low-density lipoprotein (LDL, triglyceride (TG, fasting plasma glucose (FPG, insulin, and Homeostasis Model Assessment—Insulin resistance (HOMA-IR. The men with MS showed statistically significant higher Zn and lower Mg concentrations. Those with diabetes had higher Ca concentration and lower Mg concentration. Cr and Mn concentrations were significantly higher in obese men. The participants with hypertension had lower Mg concentration. We found statistically significant positive correlations (W-TCh, W-LDL, Mg-TCh, Mg-LDL, Ca-TCh, Ca-LDL, Ca-insulin, Ca-HOMAR-IR, Zn-TG, Zn-insulin, Zn-HOMA-IR, Cu-BP systolic, Mn-BMI, Mn-AC, Mn-WHR, Mn-insulin, Mn-HOMA-IR, Se-TCh, Se-LDL, Se-TG, Se-insulin, Se-HOMA-IR, Cr-TCh, Cr-HDL, Cr-LDL, Cr-TG and negative correlations (Cd-insulin, Hg-WHR, W-insulin, W-HOMA-IR, Mg-BMI, Mg-AC, Mg-WHR, Mg-BP systolic, Mo-insulin, Mn-HDL. Tungsten may contribute to lipid disorders. Magnesium appears to play the protective role in the occurrence of metabolic disorders. Microelements Mn, Cr and Se may intensify MS.

  6. Assessing dietary exposure to cadmium in a metal recycling community in Vietnam: Age and gender aspects

    International Nuclear Information System (INIS)

    This study estimates the dietary exposure to cadmium (Cd), and associated potential health risks, for individuals living and working in a metal recycling community (n = 132) in Vietnam in comparison to an agricultural (reference) community (n = 130). Individual-level exposure to Cd was estimated through analysis of staple foodstuffs combined with information from a food frequency questionnaire. Individual-level exposure estimates were compared with published ‘safe’ doses to derive a Hazard Quotient (HQ) for each member of the study population. Looking at the populations as a whole, there were no significant differences in the diets of the two villages. However, significantly more rice was consumed by working age adults (18–60 years) in the recycling village compared to the reference village (p 3), while 20% of adult participants from the reference village had an HQ > 1. We found an elevated health risk from dietary exposure to Cd in the metal recycling village compared to the reference community. WHO standard of 0.4 mg Cd/kg rice may not be protective where people consume large amounts of rice/have relatively low body weight. - Highlights: ► First individual-level risk assessment of cadmium in recycling villages of Vietnam. ► Dietary analysis undertaken for a recycling community and an agricultural community. ► No significant differences were found between the diets of the two populations. ► 87% of people in the recycling community had elevated health risk. ► WHO standard (0.4 mg Cd/kg rice) may not be protective for rice-based cultures.

  7. Detailed impedance characterization of a well performing and durable Ni:CGO infiltrated cermet anode for metal-supported solid oxide fuel cells

    DEFF Research Database (Denmark)

    Nielsen, Jimmi; Klemensø, Trine; Blennow Tullmar, Peter

    2012-01-01

    as a transmission line response could account for the intermediate frequency arc. The PET model enabled a detailed insight into the effect of adding minor amounts of Ni into the infiltrated CGO and allowed an estimation of important characteristics such as the electrochemical utilization thickness of the anode...

  8. Early atmospheric metal pollution provides evidence for Chalcolithic/Bronze Age mining and metallurgy in Southwestern Europe.

    Science.gov (United States)

    Martínez Cortizas, Antonio; López-Merino, Lourdes; Bindler, Richard; Mighall, Tim; Kylander, Malin E

    2016-03-01

    Although archaeological research suggests that mining/metallurgy already started in the Chalcolithic (3rd millennium BC), the earliest atmospheric metal pollution in SW Europe has thus far been dated to ~3500-3200 cal.yr. BP in paleo-environmental archives. A low intensity, non-extensive mining/metallurgy and the lack of appropriately located archives may be responsible for this mismatch. We have analysed the older section (>2100 cal.yr. BP) of a peat record from La Molina (Asturias, Spain), a mire located in the proximity (35-100 km) of mines which were exploited in the Chalcolithic/Bronze Age, with the aim of assessing evidence of this early mining/metallurgy. Analyses included the determination of C as a proxy for organic matter content, lithogenic elements (Si, Al, Ti) as markers of mineral matter, and trace metals (Cr, Cu, Zn, Pb) and stable Pb isotopes as tracers of atmospheric metal pollution. From ~8000 to ~4980 cal.yr. BP the Pb composition is similar to that of the underlying sediments (Pb 15 ± 4 μg g(-1); (206)Pb/(207)Pb 1.204 ± 0.002). A sustained period of low (206)Pb/(207)Pb ratios occurred from ~4980 to ~2470 cal.yr. BP, which can be divided into four phases: Chalcolithic (~4980-3700 cal.yr. BP), (206)Pb/(207)Pb ratios decline to 1.175 and Pb/Al ratios increase; Early Bronze Age (~3700-3500 cal.yr. BP), (206)Pb/(207)Pb increase to 1.192 and metal/Al ratios remain stable; Late Bronze Age (~3500-2800 cal.yr. BP), (206)Pb/(207)Pb decline to their lowest values (1.167) while Pb/Al and Zn/Al increase; and Early Iron Age (~2800-2470 cal.yr. BP), (206)Pb/(207)Pb increase to 1.186, most metal/Al ratios decrease but Zn/Al shows a peak. At the beginning of the Late Iron Age, (206)Pb/(207)Pb ratios and metal enrichments show a rapid return to pre-anthropogenic values. These results provide evidence of regional/local atmospheric metal pollution triggered by the earliest phases of mining/metallurgy in the area, and reconcile paleo-environmental and

  9. Early atmospheric metal pollution provides evidence for Chalcolithic/Bronze Age mining and metallurgy in Southwestern Europe.

    Science.gov (United States)

    Martínez Cortizas, Antonio; López-Merino, Lourdes; Bindler, Richard; Mighall, Tim; Kylander, Malin E

    2016-03-01

    Although archaeological research suggests that mining/metallurgy already started in the Chalcolithic (3rd millennium BC), the earliest atmospheric metal pollution in SW Europe has thus far been dated to ~3500-3200 cal.yr. BP in paleo-environmental archives. A low intensity, non-extensive mining/metallurgy and the lack of appropriately located archives may be responsible for this mismatch. We have analysed the older section (>2100 cal.yr. BP) of a peat record from La Molina (Asturias, Spain), a mire located in the proximity (35-100 km) of mines which were exploited in the Chalcolithic/Bronze Age, with the aim of assessing evidence of this early mining/metallurgy. Analyses included the determination of C as a proxy for organic matter content, lithogenic elements (Si, Al, Ti) as markers of mineral matter, and trace metals (Cr, Cu, Zn, Pb) and stable Pb isotopes as tracers of atmospheric metal pollution. From ~8000 to ~4980 cal.yr. BP the Pb composition is similar to that of the underlying sediments (Pb 15 ± 4 μg g(-1); (206)Pb/(207)Pb 1.204 ± 0.002). A sustained period of low (206)Pb/(207)Pb ratios occurred from ~4980 to ~2470 cal.yr. BP, which can be divided into four phases: Chalcolithic (~4980-3700 cal.yr. BP), (206)Pb/(207)Pb ratios decline to 1.175 and Pb/Al ratios increase; Early Bronze Age (~3700-3500 cal.yr. BP), (206)Pb/(207)Pb increase to 1.192 and metal/Al ratios remain stable; Late Bronze Age (~3500-2800 cal.yr. BP), (206)Pb/(207)Pb decline to their lowest values (1.167) while Pb/Al and Zn/Al increase; and Early Iron Age (~2800-2470 cal.yr. BP), (206)Pb/(207)Pb increase to 1.186, most metal/Al ratios decrease but Zn/Al shows a peak. At the beginning of the Late Iron Age, (206)Pb/(207)Pb ratios and metal enrichments show a rapid return to pre-anthropogenic values. These results provide evidence of regional/local atmospheric metal pollution triggered by the earliest phases of mining/metallurgy in the area, and reconcile paleo-environmental and

  10. Main: Clone Detail [KOME

    Lifescience Database Archive (English)

    Full Text Available Clone Detail Mapping Pseudomolecule data detail Detail information Mapping to the TIGR japonica Pseudomolecu...les kome_mapping_pseudomolecule_data_detail.zip kome_mapping_pseudomolecule_data_detail ...

  11. Radial Age and Metal Abundance Gradients in the Stellar Content of M32

    CERN Document Server

    Rose, J A; Caldwell, N; Schiavon, R P; Vazdekis, A; Yamada, Y; Rose, James A.; Arimoto, Nobuo; Caldwell, Nelson; Schiavon, Ricardo P.; Vazdekis, Alexandre; Yamada, Yoshihiko

    2004-01-01

    We present long-slit spectroscopy of the elliptical galaxy M32, obtained with the 8-m Subaru telescope at Mauna Kea, the 1.5-m Tillinghast telescope at the F. L. Whipple Observatory, and the 4-m Mayall telescope at the Kitt Peak National Observatory. The spectra cover the Lick index red spectral region as well as higher order Balmer lines in the blue. Spectra have been taken with the slit off-set from the nucleus to avoid scattered light contamination from the bright nucleus of M32. An analysis of numerous absorption features, particularly involving the H$\\gamma$ and H$\\beta$ Balmer lines, reveals that systematic radial trends are evident in the integrated spectrum of M32. Population synthesis models indicate a radial change in both the age and chemical composition of the light-weighted mean stellar population in M32, from the nucleus out to 33", i.e., approximately 1.0 effective radius, R_e. Specifically, the light-weighted mean stellar population at 1 R_e is older, by \\~3 Gyr, and more metal-poor, by ~-0.25...

  12. The age-metallicity relation in the solar neighbourhood from a pilot sample of white dwarf-main sequence binaries

    Science.gov (United States)

    Rebassa-Mansergas, A.; Anguiano, B.; García-Berro, E.; Freeman, K. C.; Cojocaru, R.; Manser, C. J.; Pala, A. F.; Gänsicke, B. T.; Liu, X.-W.

    2016-08-01

    The age-metallicity relation (AMR) is a fundamental observational constraint for understanding how the Galactic disc formed and evolved chemically in time. However, there is not yet an agreement on the observational properties of the AMR for the solar neighborhood, primarily due to the difficulty in obtaining accurate stellar ages for individual field stars. We have started an observational campaign for providing the much needed observational input by using wide white dwarf-main sequence (WDMS) binaries. White dwarfs are "natural" clocks and can be used to derive accurate ages. Metallicities can be obtained from the main sequence companions. Since the progenitors of white dwarfs and the main sequence stars were born at the same time, WDMS binaries provide a unique opportunity to observationally constrain in a robust way the properties of the AMR. In this work we present the AMR derived from analysing a pilot sample of 23 WDMS binaries and provide clear observational evidence for the lack of correlation between age and metallicity at young and intermediate ages (0-7 Gyrs).

  13. The age-metallicity relation in the solar neighbourhood from a pilot sample of white dwarf-main sequence binaries

    CERN Document Server

    Rebassa-Mansergas, A; García-Berro, E; Freeman, K C; Cojocaru, R; Manser, C J; Pala, A F; Gänsicke, B T; Liu, X -W

    2016-01-01

    The age-metallicity relation (AMR) is a fundamental observational constraint for understanding how the Galactic disc formed and evolved chemically in time. However, there is not yet an agreement on the observational properties of the AMR for the solar neighbourhood, primarily due to the difficulty in obtaining accurate stellar ages for individual field stars. We have started an observational campaign for providing the much needed observational input by using wide white dwarf-main sequence (WDMS) binaries. White dwarfs are natural clocks and can be used to derive accurate ages. Metallicities can be obtained from the main sequence companions. Since the progenitors of white dwarfs and the main sequence stars were born at the same time, WDMS binaries provide a unique opportunity to observationally constrain in a robust way the properties of the AMR. In this work we present the AMR derived from analysing a pilot sample of 23 WDMS binaries and provide clear observational evidence for the lack of correlation between...

  14. THE AGE-METALLICITY RELATIONSHIP OF THE LARGE MAGELLANIC CLOUD FIELD STAR POPULATION FROM WIDE-FIELD WASHINGTON PHOTOMETRY

    International Nuclear Information System (INIS)

    We analyze age and metallicity estimates for an unprecedented database of some 5.5 million stars distributed throughout the Large Magellanic Cloud (LMC) main body, obtained from CCD Washington CT1 photometry, reported on in Piatti et al. We produce a comprehensive field star age-metallicity relationship (AMR) from the earliest epoch until ∼1 Gyr ago. This AMR reveals that the LMC has not evolved chemically as either a closed-box or bursting system, exclusively, but as a combination of both scenarios that have varied in relative strength over the lifetime of the galaxy, although the bursting model falls closer to the data in general. Furthermore, while old and metal-poor field stars have been preferentially formed in the outer disk, younger and more metal-rich stars have mostly been formed in the inner disk, confirming an outside-in formation. We provide evidence for the formation of stars between 5 and 12 Gyr, during the cluster age gap, although chemical enrichment during this period was minimal. We find no significant metallicity gradient in the LMC. We also find that the range in the metallicity of an LMC field has varied during the lifetime of the LMC. In particular, we find only a small range of the metal abundance in the outer disk fields, whereas an average range of Δ[Fe/H] = +0.3 ± 0.1 dex appears in the inner disk fields. Finally, the cluster and field AMRs show a satisfactory match only for the last 3 Gyr, while for the oldest ages (>11 Gyr), the cluster AMR is a remarkable lower envelope to the field AMR. Such a difference may be due to the very rapid early chemical evolution and lack of observed field stars in this regime, whereas the globular clusters are easily studied. This large difference is not easy to explain as coming from stripped ancient Small Magellanic Cloud (SMC) clusters, although the field SMC AMR is on average ∼0.4 dex more metal-poor at all ages than that of the LMC but otherwise very similar.

  15. Evaluation of aging embrittlement of low-carbon austenitic stainless steel weld metal near the BWR operating temperature

    International Nuclear Information System (INIS)

    To evaluate the rate of thermal embrittlement of type 316 low-carbon stainless steel weld metal at BWR operating temperature, aging test at 310degC, 335degC, and 400degC was carried out. Hardness of each ferrite and austenite phase of specimens was measured selectively by microhardness tester. Hardness of ferrite was increased apparently with all three aging temperatures, whereas hardness of austenite was not changed. Changes in the microstructure of ferrite aged at 310degC for 11,000h and 18,000h were analyzed by TEM. It has been revealed that hardening of ferrite with aging at 310degC was result of spinodal decomposition. Arrhenius plots for hardening rate of ferrite at each three aging temperature was plotted, and apparent activation energy was estimated. Using the apparent activation energy, hardening rate at 288degC was discussed. (author)

  16. Trace metal contamination influenced by land use, soil age, and organic matter in montreal tree pit soil.

    Science.gov (United States)

    Kargar, Maryam; Jutras, Pierre; Clark, O Grant; Hendershot, William H; Prasher, Shiv O

    2013-09-01

    The short life span of many street trees in the Montreal downtown area may be due in part to higher than standard concentrations of trace metals in the tree pit soils. The effects of land use, soil organic matter, and time since tree planting in a given tree pit (soil age) were studied with respect to the total concentration of trace metals (Cr, Ni, Cu, Zn, Cd, and Pb) in soil collected from tree pits on commercial and residential streets. Contingency table analysis and multiple linear regression were applied to study how these variables were related to the total concentrations of trace metals in soil. Other variables, such as pH, street width, distance of the tree pit from the curb, and tree pit volume, were also used as input to statistical analysis to increase the analysis' explanatory power. Significantly higher concentrations of Cu, Cd, Zn, and Pb were observed in soils from commercial streets, possibly as a result of heavier traffic as compared with residential streets. Soil organic matter was positively correlated with the concentrations of Cu and Pb, probably due to the ability of organic matter to retain these trace metals. Nickel, Cu, Zn, Cd, and Pb were positively correlated with the soil age presumably because trace metals accumulate in the tree pit soil over time. This knowledge can be helpful in providing soil quality standards aimed at improving the longevity of downtown street trees. PMID:24216430

  17. Market value of asteroidal precious metals in an age of diminishing terrestrial resources

    Science.gov (United States)

    Kargel, Jeffrey S.

    1996-01-01

    In the next century Mankind may have to choose from two options for our supply and usage of some nonrenewable natural resources, such as gold, platinum metals, and fossil fuels: learn to live with diminishing supplies of these materials obtained at ever increasing economic and environmental cost, or reach into difficult places and develop new technologies to give us what we need to sustain economic growth. Either prospect faces formidable technological and economic challenges. Exploitation of asteroids for precious and strategic metals is a possible environmentally friendly remedy for impending shortages of some resources. Certain types of asteroids could completely replace terrestrial sources of platinum metals. Asteroid metal mining may become a 21st-century space industry worth ten to fifty billion dollars annually (1995 dollars). Asteroids could make the United States and other countries self sufficient in many strategic metals, and it could usher new technologies and increase our applications of existing technologies that depend on these metals.

  18. Effect of thermal aging to microstructure of the interface of low alloy Steel and Ni-based alloy filler metal of dissimilar weld metal

    Energy Technology Data Exchange (ETDEWEB)

    Choi, Kyoung Joon; Shin, Sang Hoon; Kim, Jong Jin; Choi, Sang Il; Kim, Ji Hyun [Ulsan National Institute of Science and Technology, Ulsan (Korea, Republic of)

    2012-10-15

    Dissimilar Metal Welds (DMWs) is generally applied to nuclear power plants for manufacturing and machining in structural components such as reactor pressure vessels and pressurizer nozzles. Alloy 152 is used frequently as filler metal in the manufacture of the DMW in light water reactors to join the low alloy steel pressure vessel nozzles and steam generator nozzles to nickel-based wrought alloy or austenitic stainless steel components. However, in recent years cracking phenomena has been observed in the welded joints. Additionally, the number of long-term aged nuclear power plants is increasing. Concerns have been raised to the integrity and reliability in the joint transition zone due to the high susceptibility of the heat affected zone (HAZ) and the fusion boundary (FB) to stress corrosion cracking in combination with thermal aging. Since the material microstructure and chemical composition are key parameters affecting the stress corrosion cracking, improving the understanding of stress corrosion cracking at the FB region requires fundamental understanding of the unique microstructure of the FB region in DMW. Despite the potential degradation and consequent risk in the DMW, there is still a lack of the fundamental understanding of microstructure in the FB region, in particular the region containing unidentified band structures near the FB. As the life of nuclear power plants becomes long cycle, concerns have been raised to the integrity and reliability in the region after getting thermal aging effect. The long term exposure of this kind of material could experience the thermal aging which can form the chromium carbides near the FB by promoting the diffusion of C content at the service temperature. Therefore, the current study is aiming at the investigation of the thermal effect on the interface between Alloy 152 filler metal and A533 Gr. B. The used tools are Vickers hardness tester and Scanning Electron Microscope (SEM)

  19. Status report. KfK contribution to the development of DEMO-relevant test blankets for NET/ITER. Pt. 1: Self-cooled liquid metal breeder blanket. Vol. 2. Detailed version

    International Nuclear Information System (INIS)

    A self-cooled liquid metal breeder blanket for a fusion DEMO-reactor and the status of the development programme is described as a part of the European development programme of DEMO relevant test blankets for NET/ITER. Volume 1 (KfK 4907) contains a summary. Volume 2 (KfK 4908) a more detailed version of the report. Both volumes contain sections on previous studies on self-cooled liquid metal breeder blankets, the reference blanket design for a DEMO-reactor, a typical test blanket design including the ancillary loop system and the building requirements for NET/ITER together with the present status of the associated RandD-programme in the fields of neutronics, magnetohydrodynamics, tritium removal and recovery, liquid metal compatibility and purification, ancillary loop system, safety and reliability. An outlook is given regarding the required RandD-programme for the self-cooled liquid metal breeder blanket prior to tests in NET/ITER and the relevant test programme to be performed in NET/ITER. (orig.)

  20. Cryogenic aging of metals. (Latest citations from the EI Compendex*plus database). Published Search

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    1997-02-01

    The bibliography contains citations concerning the behaviour of metals at low temperatures. Citations discuss the kinetics of precipitates as well as mechanical properties such as ductility and fatigue. Also discussed are practical applications of cryogenically treated metals, particularly in the electronics industry. (Contains 50-250 citations and includes a subject term index and title list.) (Copyright NERAC, Inc. 1995)

  1. Cryogenic aging of metals. (Latest citations from the EI Compendex*plus database). Published Search

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    1996-04-01

    The bibliography contains citations concerning the behaviour of metals at low temperatures. Citations discuss the kinetics of precipitates as well as mechanical properties such as ductility and fatigue. Also discussed are practical applications of cryogenically treated metals, particularly in the electronics industry. (Contains 50-250 citations and includes a subject term index and title list.) (Copyright NERAC, Inc. 1995)

  2. Contribution to the study of rectification at the metal-semiconductor contact: analysis of aging in silicon Schottky diodes

    International Nuclear Information System (INIS)

    The formation of the barrier height and the aging of metal-semiconductor contacts during exposure to air have been studied. The evolution of the electrical characteristics, especially the barrier height, of silicon Schottky diodes results from the diffusion of oxygen through the electrode and its accumulation at the interface. The diffusion coefficient of oxygen has been deduced for each metal used. In a first step the oxygen neutralize a fixed positive charge which remains at the semiconductor surface after etching; then, as silicon is oxidized, a MIS device is formed. Similar results have been obtained in the case of germanium, while no aging appears with cadmium telluride. In this case the barrier height seems to be determined by chemical reactions at the interface

  3. Fundamental stellar parameters and age-metallicity relation of Kepler red giants in comparison with theoretical evolutionary tracks

    CERN Document Server

    Takeda, Y; Sato, B; Liu, Y -J; Chen, Y -Q; Zhao, G

    2016-01-01

    Spectroscopic parameters (effective temperature, metallicity, etc) were determined for a large sample of ~100 red giants in the Kepler field, for which mass, radius, and evolutionary status had already been asteroseismologically established. These two kinds of spectroscopic and seismic information suffice to define the position on the "luminosity versus effective temperature" diagram and to assign an appropriate theoretical evolutionary track to each star. Making use of this advantage, we examined whether the stellar location on this diagram really matches the assigned track, which would make an interesting consistency check between theory and observation. It turned out that satisfactory agreement was confirmed in most cases (~90%, though appreciable discrepancies were seen for some stars such as higher-mass red-clump giants), suggesting that recent stellar evolution calculations are practically reliable. Since the relevant stellar age could also be obtained by this comparison, we derived the age-metallicity ...

  4. Top-metal ageing effects on electro-thermal distributions in an IGBT chip under short circuit conditions

    OpenAIRE

    MOUSSODJI, Jeff; Kociniewski, Thierry; Khatir, Zoubir

    2013-01-01

    A new electro-thermal model of a semiconductor device has been carried-out in order to investigate electrical and thermal mappings of power devices during critical operations. This model allows evaluating the effect of chip metallization ageing on temperature distributions and current sharing between cells within an IGBT chip during short-circuits operations. One of the failure mechanisms in IGBT is due to the switch on of the npnp parasitic thyristor. This phenomenon so called Latch-up and o...

  5. Influence of soil ageing on bioavailability and ecotoxicity of lead carried by process waste metallic ultrafine particles.

    Science.gov (United States)

    Schreck, E; Foucault, Y; Geret, F; Pradere, P; Dumat, C

    2011-11-01

    Ultrafine particulate matters enriched with metals are emitted into the atmosphere by industrial activities and can impact terrestrial and aquatic ecosystems. Thus, this study investigated the environmental effects of process particles from a lead-recycling facility after atmospheric deposition on soils and potential run-off to surface waters. The toxicity of lead-enriched PM for ecosystems was investigated on lettuce and bacteria by (i) germination tests, growth assays, lead transfer to plant tissues determination and (ii) Microtox analysis. The influence of ageing and soil properties on metal transfer and ecotoxicity was studied using three different soils and comparing various aged, spiked or historically long-term polluted soils. Finally, lead availability was assessed by 0.01 M CaCl(2) soil extraction. The results showed that process PM have a toxic effect on lettuce seedling growth and on Vibrio fischeri metabolism. Soil-PM interactions significantly influence PM ecotoxicity and bioavailability; the effect is complex and depends on the duration of ageing. Solubilisation or stabilisation processes with metal speciation changes could be involved. Finally, Microtox and phytotoxicity tests are sensitive and complementary tools for studying process PM ecotoxicity.

  6. A MASSIF Effort To Determine The Mass-Luminosity Relation for Stars of Various Ages, Metallicities, and Evolution States

    Science.gov (United States)

    Henry, Todd J.; Beedict, G. Fritz; Gies, Douglas R.; Golimowski, David A.; Ianna, Philip A.; Mason, Brian; McArthur, Barbara; Nelan, Edmund; Torres, Guillermo

    2004-01-01

    The MASSIF (Masses and Stellar Systems with Interferometry) Team will use SIM to investigate the mass content of the Galaxy - from huge stars to barely glimmering brown dwarfs, and from hot white dwarfs to exotic black holes. We will target various samples of the Galactic population to determine and relate the fundamental characteristics of mass, luminosity, age, composition, and multiplicity - attributes that together yield an extensive understanding of the stars. Our samples will include distant clusters that span a factor of 5000 in age, and commonplace stars and substellar objects that lurk near the Sun. The principal goals of the MASSIF Key Project are to (1) define the mass-luminosity relation for main sequence stars in five fundamental clusters so that effects of age and metallicity can be mapped (Trapezium, TW Hydrae, Pleiades, Hyades, and M67), and (2) determine accurate masses for representative examples of nearly every type of star, stellar descendant or brown dwarf in the Galaxy.

  7. Storage of hydrogen isotopes. Investigation of the aging behaviour of metallic tritides

    International Nuclear Information System (INIS)

    This report aims at giving a synthesis of scientific works performed by the author while indicating the reasons for his choice of research topics, and the perspectives which could be interesting to follow. After an overview of his professional course, the author proposes an analysis of the available literature at the time he started his research works. Then, he comments the results he obtained during his research thesis in the field of short duration aging (more precisely with experimental investigations on the aging behaviour of palladium and palladium alloys which are used in tritium storage). The following periods of his research career dealt with long duration aging, and then with aging modelling

  8. CCD Photometry of the Globular Cluster omega Centauri. II. Stellar Populations and Age-Metallicity Relation

    CERN Document Server

    Rey, S C; Ree, C; Joo, J M; Sohn, Y J; Walker, A

    2004-01-01

    We present wide-field and high-precision BV and Ca & Stromgren by photometry of omega Centauri, which represents one of the most extensive photometric surveys to date for this cluster. The member stars of omega Cen are well discriminated from foreground Galactic field stars in the hk [=(Ca-b)-(b-y)] vs. b-y diagram. The resulting "cleaned" color-magnitude diagram (CMD) has allowed us to obtain an accurate distribution of the red horizontal branch (HB) and the asymptotic giant branch stars. We confirm the presence of several red giant branches (RGBs) with the most metal-rich sequence well separated from other bluer metal-poor ones. Our population models suggest that four populations with different metallicities can reproduce the observed nature of the RGB. The HB distribution is also found to be consistent with the multiple stellar populations of the RGB. From our population models, we propose that the most metal-rich population is about 4 Gyr younger than the dominant metal-poor population, indicating tha...

  9. The Role of Evolutionary Age and Metallicity in the Formation of Classical Be Circumstellar Disks II. Assessing the Evolutionary Nature of Candidate Disk Systems

    CERN Document Server

    Wisniewski, John P; Magalhaes, Antonio M; Bjorkman, Jon E; Meade, Marilyn R; Pereyra, Antonio

    2007-01-01

    (Abridged version) We present the first detailed imaging polarization observations of six SMC and six LMC clusters, known to have large populations of B-type stars which exhibit excess H-alpha emission, to constrain the evolutionary status of these stars and hence better establish links between the onset of disk formation in classical Be stars and cluster age and/or metallicity. The wavelength dependence of our intrinsic polarization data provides a diagnostic of the dominant and any secondary polarigenic agents present, enabling us to discriminate pure gas disk systems, i.e. classical Be stars, from composite gas plus dust disk systems, i.e. Herbig Ae/Be or B[e] stars. Our intrinsic polarization results, along with available near-IR color information, strongly supports the suggestion of Wisniewski et al. that classical Be stars are present in clusters of age 5-8 Myr, and contradict assertions that the Be phenomenon only develops in the second half of a B star's main sequence lifetime, i.e. no earlier than 10...

  10. Universal Aging Mechanism for Static and Sliding Friction of Metallic Nanoparticles

    Science.gov (United States)

    Feldmann, Michael; Dietzel, Dirk; Tekiel, Antoni; Topple, Jessica; Grütter, Peter; Schirmeisen, André

    2016-07-01

    The term "contact aging" refers to the temporal evolution of the interface between a slider and a substrate usually resulting in increasing friction with time. Current phenomenological models for multiasperity contacts anticipate that such aging is not only the driving force behind the transition from static to sliding friction, but at the same time influences the general dynamics of the sliding friction process. To correlate static and sliding friction on the nanoscale, we show experimental evidence of stick-slip friction for nanoparticles sliding on graphite over a wide dynamic range. We can assign defined periods of aging to the stick phases of the particles, which agree with simulations explicitly including contact aging. Additional slide-hold-slide experiments for the same system allow linking the sliding friction results to static friction measurements, where both friction mechanisms can be universally described by a common aging formalism.

  11. Effect of Transport and Aging Processes on Metal Speciation in Iron Oxyhydroxide Aggregates, Tar Creek Superfund Site, Oklahoma

    Science.gov (United States)

    Estes, E. R.; Schaider, L. A.; Shine, J. P.; Brabander, D. J.

    2010-12-01

    Following the cessation of mining activity in the late 20th century, Tar Creek Superfund Site was left highly contaminated by Pb, Zn, and Cd. Tar Creek, which flows through the site and into the Neosho River, has been studied extensively because of its potential to transport metals from the mining site to downstream communities. Previous research identified aggregated iron oxyhydroxide material, which forms when mine seepage mixes with Tar Creek surface water, as a major transport vector of metals. Frequent flooding in Tar Creek deposits aggregates on downstream floodplains, where wetting and drying processes alter the speciation of iron and other metals. This study seeks to better quantify those changes and to determine how transport and aging affects the human and ecological health risk. Sequential extractions of aggregate samples collected from the creek demonstrate that Fe is present in both amorphous (10-35% of Fe extracted) and more crystalline (8-23% of Fe extracted) phases. Substantial portions of heavy metals sorb to amorphous iron oxyhydroxide phases (accounting for 10-30% of Pb and Zn extracted) but are not associated with more crystalline iron oxide phases (representing only 1% or less of the Pb and Zn extracted). Samples have a high organic matter content (18-25% mass loss on ignition), but only Fe was significantly extracted by the oxidizing step targeting organic matter (1-2% of Pb and Zn extracted, but 10-26% of Fe extracted). The majority of metals were extracted by the soluble or residual steps. If metals and organic matter inhibit transformation of amorphous iron oxyhydroxide material to nano and crystalline iron oxides, then a steady-state volume of amorphous iron oxyhydroxide material with a high total sorption capacity may exist within Tar Creek, enhancing the metal flux accommodated by this transport mechanism. Once transported downstream and deposited on floodplains, however, it is hypothesized that repeated changes in soil matrix

  12. Aging of iron (hydr)oxides by heat treatment and effects on heavy metal binding

    DEFF Research Database (Denmark)

    Sørensen, Mette Abildgaard; Starckpoole, M. M.; Frenkel, A. I.;

    2000-01-01

    oxides were transformed to hematite, which had a greater thermodynamic stability but less surface area than the initial products. Heat treatment also caused some volatilization of heavy metals (most notably, Hg). Leaching with water at pH 9 (L/S 10, 24 h) and weak acid extraction showed that heat...

  13. Effect of aging parameters on the micro structure and properties of ZA-27/aluminite metal matrix composites

    Energy Technology Data Exchange (ETDEWEB)

    Sharma, S.C.; Sastry, Shanta; Krishna, M

    2002-11-18

    The effect of heat treatment and aging at various temperatures for different intervals of time on the microstructure of ZA-27 matrix alloy and aluminite particulate reinforced ZA-27 alloy metal matrix composites (MMCs) has been studied using micro hardness, electrical resistivity, X-ray diffraction and differential scanning calorimetry (DSC) data. The composite samples were aged at 32, 80, 180, and 250 deg. C after solutionizing at 320 deg. C for 3 h followed by cold water quenching. The micro hardness values showed an initial increase reaching a peak value which was followed by a reduction in hardness values with increase in aging time. The trend followed by electrical resistivity was very similar to that of hardness. Further, the time to reach peak hardness decreased with increase in the weight percentage of the reinforcement. These results indicated that the aging and precipitation kinetics in the matrix alloy are significantly accelerated due to the presence of particulate reinforcement. Changes in the properties of the composites during aging are explained on the basis of micro structural alterations caused by the heat treatment.

  14. Assessment and management of ageing of major nuclear power plant components important to safety: Metal components of BWR containment systems

    International Nuclear Information System (INIS)

    plant components addressed in the reports. This report addresses the metal components of BWR containment systems. The primary ageing mechanisms that may potentially impact the structural capacity, leaktight integrity, or service life of BWR containments are corrosion of metal components and stress corrosion cracking of bellows. Other potential degradation mechanisms include fatigue and mechanical wear. Areas of concern are where surfaces are inaccessible for inspection (e.g areas adjacent to floors, where the containment vessel is embedded in concrete, and locations adjacent to equipment or other structures)

  15. On the metallicity dependance of the [Y/Mg] - age relation for solar type stars

    CERN Document Server

    Feltzing, S; McMillan, P J; Stonkute, E

    2016-01-01

    Several recent studies of Solar twins in the Solar neighbourhood have shown a tight correlation between various elemental abundances and age, in particular [Y/Mg]. If this relation is real and valid for other types of stars as well as elsewhere in the Galaxy it would provide a very powerful tool to derive ages of stars without the need to resort to determining their masses (evolutionary stage) very precisely. The method would also likely work if the stellar parameters have relatively large errors. The studies presented in the recent literature span a narrow range of [Fe/H]. By studying a larger sample of Solar neighbourhood dwarfs with a much larger range in [Fe/H], we find that the relation between [Y/Mg] and age depends on the [Fe/H] of the stars. Hence, it appears that the [Y/Mg] - age relation is unique to Solar analogues.

  16. Electro-migration of heavy metals in an aged electroplating contaminated soil affected by the coexisting hexavalent chromium.

    Science.gov (United States)

    Zhang, Weihua; Zhuang, Luwen; Tong, Lizhi; Lo, Irene M C; Qiu, Rongliang

    2012-02-01

    Cr(VI) was often reported to oxidize soil organic matter at acidic environments due to its high ORP, probably thus changing cationic metal species bound to soil organic matter, and influencing their electro-migration patterns. However, such an effect on the electro-migration was not confirmed in most previous studies. Therefore, this study applied a fixed voltage direct current field on an aged electroplating contaminated clayed soil, with a special interest in the direct or indirect influence of Cr(VI) on the electro-migration of other coexisting metals. After 353 h electrokinetic process, 81% of Zn, 53% of Ni and 22% of Cu in the original soil were electro-migrated into the electrolyte, and most of the remaining concentrated near the cathode. The Cr(VI) oxidized some soil organic matter along its migration pathway, with a pronounced reaction occurred near the anode at low pHs. The resulting Cr(III) reversed its original movement, and migrated towards the cathode, leading to the occurrence of a second Cr concentration peak in the soil. Metal species analyses showed that the amount of metals bound to soil organic matter significantly decreased, while a substantial increase in the Cr species bound to Fe/Mn (hydro-)oxides was observed, suggesting an enhancement of cationic metal electro-migration by the reduction of Cr(VI) into Cr(III). However, the Cr(VI) may form some stable lead chromate precipitates, and in turn demobilize Pb in the soil, as the results showed a low Pb removal and an increase in its acid-extractable and residual fractions after electrokinetic remediation. PMID:22197017

  17. Fiber Bragg Gratings, IT Techniques and Strain Gauge Validation for Strain Calculation on Aged Metal Specimens

    OpenAIRE

    Ander Montero; Idurre Saez de Ocariz; Ion Lopez; Pablo Venegas; Javier Gomez; Joseba Zubia

    2011-01-01

    This paper studies the feasibility of calculating strains in aged F114 steel specimens with Fiber Bragg Grating (FBG) sensors and infrared thermography (IT) techniques. Two specimens have been conditioned under extreme temperature and relative humidity conditions making comparative tests of stress before and after aging using different adhesives. Moreover, a comparison has been made with IT tecniques and conventional methods for calculating stresses in F114 steel. Implementation of Structural...

  18. Effects of Thermal Aging on Material Properties, Stress Corrosion Cracking, and Fracture Toughness of AISI 316L Weld Metal

    Science.gov (United States)

    Lucas, Timothy; Forsström, Antti; Saukkonen, Tapio; Ballinger, Ronald; Hänninen, Hannu

    2016-08-01

    Thermal aging and consequent embrittlement of materials are ongoing issues in cast stainless steels, as well as duplex, and high-Cr ferritic stainless steels. Spinodal decomposition is largely responsible for the well-known "748 K (475 °C) embrittlement" that results in drastic reductions in ductility and toughness in these materials. This process is also operative in welds of either cast or wrought stainless steels where δ-ferrite is present. While the embrittlement can occur after several hundred hours of aging at 748 K (475 °C), the process is also operative at lower temperatures, at the 561 K (288 °C) operating temperature of a boiling water reactor (BWR), for example, where ductility reductions have been observed after several tens of thousands of hours of exposure. An experimental program was carried out in order to understand how spinodal decomposition may affect changes in material properties in Type 316L BWR piping weld metals. The study included material characterization, nanoindentation hardness, double-loop electrochemical potentiokinetic reactivation (DL-EPR), Charpy-V, tensile, SCC crack growth, and in situ fracture toughness testing as a function of δ-ferrite content, aging time, and temperature. SCC crack growth rates of Type 316L stainless steel weld metal under simulated BWR conditions showed an approximate 2 times increase in crack growth rate over that of the unaged as-welded material. In situ fracture toughness measurements indicate that environmental exposure can result in a reduction of toughness by up to 40 pct over the corresponding at-temperature air-tested values. Material characterization results suggest that spinodal decomposition is responsible for the degradation of material properties measured in air, and that degradation of the in situ properties may be a result of hydrogen absorbed during exposure to the high-temperature water environment.

  19. Effects of Thermal Aging on Material Properties, Stress Corrosion Cracking, and Fracture Toughness of AISI 316L Weld Metal

    Science.gov (United States)

    Lucas, Timothy; Forsström, Antti; Saukkonen, Tapio; Ballinger, Ronald; Hänninen, Hannu

    2016-06-01

    Thermal aging and consequent embrittlement of materials are ongoing issues in cast stainless steels, as well as duplex, and high-Cr ferritic stainless steels. Spinodal decomposition is largely responsible for the well-known "748 K (475 °C) embrittlement" that results in drastic reductions in ductility and toughness in these materials. This process is also operative in welds of either cast or wrought stainless steels where δ-ferrite is present. While the embrittlement can occur after several hundred hours of aging at 748 K (475 °C), the process is also operative at lower temperatures, at the 561 K (288 °C) operating temperature of a boiling water reactor (BWR), for example, where ductility reductions have been observed after several tens of thousands of hours of exposure. An experimental program was carried out in order to understand how spinodal decomposition may affect changes in material properties in Type 316L BWR piping weld metals. The study included material characterization, nanoindentation hardness, double-loop electrochemical potentiokinetic reactivation (DL-EPR), Charpy-V, tensile, SCC crack growth, and in situ fracture toughness testing as a function of δ-ferrite content, aging time, and temperature. SCC crack growth rates of Type 316L stainless steel weld metal under simulated BWR conditions showed an approximate 2 times increase in crack growth rate over that of the unaged as-welded material. In situ fracture toughness measurements indicate that environmental exposure can result in a reduction of toughness by up to 40 pct over the corresponding at-temperature air-tested values. Material characterization results suggest that spinodal decomposition is responsible for the degradation of material properties measured in air, and that degradation of the in situ properties may be a result of hydrogen absorbed during exposure to the high-temperature water environment.

  20. Spectroscopic study of globular clusters in the halo of M31 with the Xinglong 2.16m telescope Ⅱ dynamics, metallicity and age

    Institute of Scientific and Technical Information of China (English)

    Zhou Fan; Ya-Fang Huang; Jin-Zeng Li; Xu Zhou; Jun Ma; Yong-Heng Zhao

    2012-01-01

    In Paper I,we performed spectroscopic observations on 11 confirmed globular clusters(GCs)in M31 with the Xinglong 2.16 m telescope.We mainly focused on the fitting method and the metallicity gradient for the M31 GC sample.Here,we analyze and further discuss the dynamics,metallicity and age,and their distributions,as well as the relationships between these parameters.In our work,eight more confirmed GCs in the halo of M31 were observed,most of which lack previous spectroscopic information.These star clusters are located far from the galactic center at a projected radius of ~ 14 to ~ 117 kpc,which is more spatially extended than that in the previous work.Firstly,we measured the Lick absorption-line indices and the radial velocities.Then the ages and metallicity values of [Fe/H] and [α/Fe] were fitted by comparing the observed spectral feature indices and the Single Stellar Population model of Thomas et al.in the Cassisi and Padova stellar evolutionary tracks,respectively.Our results show that most of the star clusters in our sample are older than 10 Gyr except B290,which is ~ 5.5 Gyr,and most of them are metal-poor with metallicity [Fe/H] < -1,suggesting that these clusters were born at the early stage of the galaxy's formation.We find that the metallicity gradient for the outer halo clusters with Υp > 25 kpc may have an insignificant slope of-0.005 ± 0.005 dex kpc-1 and if the outliers G001 and H1 1 are excluded,the slope does not change significantly,with a value of-0.002 ± 0.003 dex kpc-1.We also find that the metallicity is not a function of age for the GCs with age < 7 Gyr,but for the old GCs with age > 7 Gyr,there seems to be a trend that the older ones have lower metallicity.Additionally,we plot metallicity distributions with the largest sample of M31 GCs so far and show the bimodality is not significant,and the number of metal-poor and metal-rich groups becomes comparable.The spatial distributions show that the metal-rich group is more

  1. Detail and survey radioautographs

    Energy Technology Data Exchange (ETDEWEB)

    Wainwright, Wm.W.

    1949-04-19

    The much used survey or contact type of radioautograph is indispensible for a study of the gross distribution of radioactive materials. A detail radioautograph is equally indispensible. The radioautograph makes possible the determination of plutonium with respect to cells. Outlines of survey and detail techniques are given.

  2. LOCKE Detailed Specification Tables

    CERN Document Server

    Menezo, Lucia G; Gregorio, Jose-Angel

    2012-01-01

    This document shows the detailed specification of LOCKE coherence protocol for each cache controller, using a table-based technique. This representation provides clear, concise visual information yet includes sufficient detail (e.g., transient states) arguably lacking in the traditional, graphical form of state diagrams.

  3. Detailed chronology of mid-altitude fluvial system response to changing climate and societies at the end of the Little Ice Age (Southwestern Alps and Cévennes, France)

    Science.gov (United States)

    Astrade, Laurent; Jacob-Rousseau, Nicolas; Bravard, Jean-Paul; Allignol, Françoise; Simac, L.

    2011-10-01

    Over a historical timescale, landscapes have been strongly affected by fluctuations in climate and by the impact of human societies. This study examines the historical evolution of mid-altitude fluvial systems in the Western Alps and Cévennes (SE Massif Central) in the context of marked climate and anthropogenic change at the end of the Little Ice Age (late 19th century). This work contributes to the reconstruction of river paleodynamics by investigating the nature and chronology of geomorphological changes in upper river basins. In order to produce a detailed reconstruction of hydromorphological changes, we combined two approaches: the study of historical archives and the use of bioindicators (the dating of terraces using dendrochronology and of silt benches using lichenometry in order to reconstruct the evolution of the river channels). The 19th century is a particularly propitious period for the study of surface dynamics because archives have preserved a wealth of qualitative and quantitative data concerning rivers (economic statistics, meteorological and hydrological observations, illustrative documents, descriptions by contemporary observers). It is also a period for which reliable dating methods are available for detrital deposits in rivers. The period provides new information on how the transition between the Little Ice Age and current climate conditions affected the evolution of drainage basins and stream channels by highlighting a succession of phases in the erosive process (e.g., the preparatory role of the drought of 1830-1838 in the erosion crisis of 1855-1870) and refining the chronology of events (very early onset of riverbed incision). The results highlight the effect of climate (small hydroclimatic fluctuations), amplified by strong anthropization, on the rhythm of landscape change and on the relative stabilization of the landscape at the end of the 19th century. In addition, the synchronization of phenomena on the two sides of the Rhone Valley

  4. Comparative evaluation of shear bond strengths of veneering porcelain to base metal alloy and zirconia substructures before and after aging – An in vitro study

    OpenAIRE

    Sreekala, Laju; Narayanan, Mahesh; Eerali, Sunil M.; Eerali, Susil M.; Varghese, Joju; Zainaba Fathima, A. l.

    2015-01-01

    Objective: The aim of this study was to evaluate and compare the shear bond strength of veneering porcelain to base metal alloy and zirconia substructures before and after aging. Scanning electron microscopy (SEM) was used to determine the failure pattern. Materials and Methods: Twenty rectangular blocks (9 mm length × 4 mm height × 4 mm width) of base metal alloy (Bellabond plus, Bego, Germany) and zirconia (Will ceramZ zirconia K block) were fabricated for shear bond strength test. Surface ...

  5. Metals exposure and risk of small-for-gestational age birth in a Canadian birth cohort: The MIREC study

    International Nuclear Information System (INIS)

    Background: Lead, mercury, cadmium and arsenic are some of the most common toxic metals to which Canadians are exposed. The effect of exposure to current low levels of toxic metals on fetal growth restriction is unknown. Objective: The aim of this study was to examine relationships between exposure to lead, mercury, cadmium and arsenic during pregnancy, and risk of small for gestational age (SGA) birth. Methods: Lead, mercury, cadmium and arsenic levels were measured in blood samples from the first and third trimesters in 1835 pregnant women from across Canada. Arsenic species in first trimester urine were also assessed. Relative risks and 95% confidence intervals were estimated using log binomial multivariate regression. Important covariates including maternal age, parity, pre-pregnancy BMI, and smoking, were considered in the analysis. An exploratory analysis was performed to examine potential effect modification of these relationships by single nucleotide polymorphisms (SNPs) in GSTP1 and GSTO1 genes. Results: No association was found between blood lead, cadmium or arsenic and risk for SGA. We observed an increased risk for SGA for the highest compared to the lowest tertile of exposure for mercury (>1.6 µg/L, RR=1.56.; 95% CI=1.04–2.58) and arsenobetaine (>2.25 µg/L, RR=1.65; 95% CI=1.10–2.47) after adjustment for the effects of parity and smoking. A statistically significant interaction was observed in the relationship between dimethylarsinic acid (DMA) levels in urinary arsenic and SGA between strata of GSTO1 A104A (p for interaction=0.02). A marginally significant interaction was observed in the relationship between blood lead and SGA between strata of GSTP1 A114V (p for interaction=0.06). Conclusions: These results suggest a small increase in risk for SGA in infants born to women exposed to mercury and arsenic. Given the conflicting evidence in the literature this warrants further investigation in other pregnant populations. - Highlights: • Metals

  6. Metals exposure and risk of small-for-gestational age birth in a Canadian birth cohort: The MIREC study

    Energy Technology Data Exchange (ETDEWEB)

    Thomas, Shari [Department of Public Health Sciences, Queen’s University, Kingston, Ontario (Canada); Arbuckle, Tye E., E-mail: Tye.Arbuckle@hc-sc.gc.ca [Population Studies Division, Healthy Environments and Consumer Safety Branch, Health Canada, Ottawa (Canada); Fisher, Mandy [Population Studies Division, Healthy Environments and Consumer Safety Branch, Health Canada, Ottawa (Canada); Fraser, William D. [Sainte Justine University Hospital Research Center, University of Montreal, Montreal (Canada); Ettinger, Adrienne [Center for Perinatal, Pediatric & Environmental Epidemiology, Yale School of Public Health, New Haven, CT (United States); King, Will [Department of Public Health Sciences, Queen’s University, Kingston, Ontario (Canada)

    2015-07-15

    Background: Lead, mercury, cadmium and arsenic are some of the most common toxic metals to which Canadians are exposed. The effect of exposure to current low levels of toxic metals on fetal growth restriction is unknown. Objective: The aim of this study was to examine relationships between exposure to lead, mercury, cadmium and arsenic during pregnancy, and risk of small for gestational age (SGA) birth. Methods: Lead, mercury, cadmium and arsenic levels were measured in blood samples from the first and third trimesters in 1835 pregnant women from across Canada. Arsenic species in first trimester urine were also assessed. Relative risks and 95% confidence intervals were estimated using log binomial multivariate regression. Important covariates including maternal age, parity, pre-pregnancy BMI, and smoking, were considered in the analysis. An exploratory analysis was performed to examine potential effect modification of these relationships by single nucleotide polymorphisms (SNPs) in GSTP1 and GSTO1 genes. Results: No association was found between blood lead, cadmium or arsenic and risk for SGA. We observed an increased risk for SGA for the highest compared to the lowest tertile of exposure for mercury (>1.6 µg/L, RR=1.56.; 95% CI=1.04–2.58) and arsenobetaine (>2.25 µg/L, RR=1.65; 95% CI=1.10–2.47) after adjustment for the effects of parity and smoking. A statistically significant interaction was observed in the relationship between dimethylarsinic acid (DMA) levels in urinary arsenic and SGA between strata of GSTO1 A104A (p for interaction=0.02). A marginally significant interaction was observed in the relationship between blood lead and SGA between strata of GSTP1 A114V (p for interaction=0.06). Conclusions: These results suggest a small increase in risk for SGA in infants born to women exposed to mercury and arsenic. Given the conflicting evidence in the literature this warrants further investigation in other pregnant populations. - Highlights: • Metals

  7. Detailed balance and entanglement

    International Nuclear Information System (INIS)

    We study a connection between quantum detailed balance, which is a concept of importance in statistical mechanics, and entanglement. We also explore how this connection fits into thermofield dynamics. (paper)

  8. Detailed Soils 24K

    Data.gov (United States)

    Kansas Data Access and Support Center — This data set is a digital soil survey and is the most detailed level of soil geographic data developed by the National Cooperative Soil Survey. The information was...

  9. Heavy metal composition in stormwater and retention in ponds dependent on pond age, design and catchment type

    DEFF Research Database (Denmark)

    Egemose, Sara; Sønderup, Melanie J.; Grudinina, Anna;

    2015-01-01

    Heavy metals have toxic effects on flora and fauna in the aquatic environments and are of great concern in stormwater. Heavy metal runoff was studied in 37 stormwater ponds in Denmark with varying heavy metal load, catchment type and pond design. The studied metals were Cu, Cr, Cd, Pb, Ni and Zn...

  10. Impact of Age on Long-Term Outcome After Primary Angioplasty With Bare-Metal or Drug-Eluting Stent (From the DESERT Cooperation)

    DEFF Research Database (Denmark)

    De Luca, Giuseppe; Dirksen, Maurits T; Spaulding, Christian;

    2013-01-01

    stent thrombosis, which may be more pronounced in elderly patients. Therefore, the aim of this study was to evaluate the impact of age on outcome in patients with STEMI who underwent primary angioplasty with bare-metal stents (BMS) or DES. Our population comprised 6,298 patients who underwent primary...... angioplasty and stent implantation included in the Drug-Eluting Stent in Primary Angioplasty (DESERT) Cooperation database. Age was significantly associated with female gender (p...

  11. Degradation of impact fracture during accelerated aging of weld metal on microalloyed steel; Degradacion de la tenacidad al impacto durante el envejecimiento acelerado de soldadura en acero microaleado

    Energy Technology Data Exchange (ETDEWEB)

    Vargas-Arista, B.; Hallen, J. M.; Albiter, A.; Angeles-Chavez, C.

    2008-07-01

    The effect of accelerated aging on the toughness and fracture of the longitudinal weld metal on an API5L-X52 line pipe steel was evaluated by Charpy V-notch impact test, fracture analysis and transmission electron microscopy. Aging was performed at 250 degree centigrade for 100 to 1000 h. The impact results indicated a significant reduction in the fracture energy and impact toughness as a function of aging time, which were achieved by the scanning electron microscope fractography that showed a decrease in the vol fraction of microvoids by Charpy ductile failure with the aging time, which favored the brittle fracture by transgranular cleavage. The minimum vol fraction of microvoids was reached at 500 h due to the peak aged. The microstructural analysis indicated the precipitation of transgranular iron nano carbides in the aged specimens, which was related to the deterioration of toughness and change in the ductile to brittle behavior. (Author) 15 refs.

  12. Three Latin Phonological Details

    DEFF Research Database (Denmark)

    Olsen, Birgit Anette

    2006-01-01

    The present paper deals with three minor details of Latin phonology: 1) the development of the initial sequence *u¿l¿-, where it is suggested that an apparent vacillation between ul- and vol-/vul- represents sandhi variants going back to the proto-language, 2) the adjectives ama¯rus ‘bitter' and ......' and ava¯rus ‘greedy' and 3) the internal cluster -mpl- of the nouns exemplum and templum....

  13. The age-mass-metallicity-activity relation for solar-type stars: comparisons with asteroseismology and the NGC 188 open cluster

    Science.gov (United States)

    Lorenzo-Oliveira, D.; Porto de Mello, G. F.; Schiavon, R. P.

    2016-10-01

    Context. The Mount Wilson Ca ii index log(R'_HK) is the accepted standard metric of calibration for the chromospheric activity versus age relation for FGK stars. Recent results claim its inability to discern activity levels, and thus ages, for stars older than ~2 Gyr, which would severely hamper its application to date disk stars older than the Sun. Aims: We present a new activity-age calibration of the Mt. Wilson index that explicitly takes mass and [Fe/H] biases into account; these biases are implicit in samples of stars selected to have precise ages, which have so far not been appreciated. Methods: We show that these selection biases tend to blur the activity-age relation for large age ranges. We calibrate the Mt. Wilson index for a sample of field FGK stars with precise ages, covering a wide range of mass and [Fe/H] , augmented with data from the Pleiades, Hyades, M 67 clusters, and the Ursa Major moving group. Results: We further test the calibration with extensive new Gemini/GMOS log ()R'HK) data of the old, solar [Fe/H] clusters, M 67 and NGC 188. The observed NGC 188 activity level is clearly lower than M 67. We correctly recover the isochronal age of both clusters and establish the viability of deriving usable chromospheric ages for solar-type stars up to at least ~6 Gyr, where average errors are ~0.14 dex provided that we explicitly account for the mass and [Fe/H] dimensions. We test our calibration against asteroseismological ages, finding excellent correlation (ρ = + 0.89). We show that our calibration improves the chromospheric age determination for a wide range of ages, masses, and metallicities in comparison to previous age-activity relations.

  14. Heavy metal exposure, in combination with physical activity and aging, is related with oxidative stress in Japanese women from a rural agricultural community.

    Science.gov (United States)

    Cui, Xiaoyi; Ohtsu, Mayumi; Mise, Nathan; Ikegami, Akihiko; Mizuno, Atsuko; Sakamoto, Takako; Ogawa, Masanori; Machida, Munehito; Kayama, Fujio

    2016-01-01

    This study aimed to evaluate the relationships between oxidative stress and heavy metal exposure (lead [Pb] and cadmium [Cd]), as well as co-factors such as physical activity and age, in Japanese women. This study was conducted with female subjects from a rural agricultural community in Japan. Subjects were asked to complete lifestyle-related questionnaires and undergo a group health examination. Physical activity, alcohol consumption, body mass index, and other demographic information were collected. Blood and urine samples were collected to measure urinary 8-hydroxydeoxyguanosine (8-OHdG) levels and blood and urinary Cd and Pb concentrations. Urine samples were analyzed using high performance liquid chromatography and flameless atomic absorption spectrometry; blood samples were analyzed using inductively coupled plasma-mass spectrometry. Age, physical activity, and blood and urinary Cd and Pb concentrations were included in structural equation modeling analysis. Two latent factors for heavy metal exposure and physical activity were produced to predict the total influence of the variables. The final model was good: CMIN/DF = 0.775, CFI = 1.000, GFI = 0.975, AGFI = 0.954, RMSEA = 0.000. 8-OHdG levels were positively associated with heavy metal exposure, physical activity, and age (standard β of path analysis: 0.33, 0.38, and 0.20, respectively). Therefore, oxidative stress is associated with both, environmental and lifestyle factors, in combination with aging. PMID:27386333

  15. Heavy metal exposure, in combination with physical activity and aging, is related with oxidative stress in Japanese women from a rural agricultural community.

    Science.gov (United States)

    Cui, Xiaoyi; Ohtsu, Mayumi; Mise, Nathan; Ikegami, Akihiko; Mizuno, Atsuko; Sakamoto, Takako; Ogawa, Masanori; Machida, Munehito; Kayama, Fujio

    2016-01-01

    This study aimed to evaluate the relationships between oxidative stress and heavy metal exposure (lead [Pb] and cadmium [Cd]), as well as co-factors such as physical activity and age, in Japanese women. This study was conducted with female subjects from a rural agricultural community in Japan. Subjects were asked to complete lifestyle-related questionnaires and undergo a group health examination. Physical activity, alcohol consumption, body mass index, and other demographic information were collected. Blood and urine samples were collected to measure urinary 8-hydroxydeoxyguanosine (8-OHdG) levels and blood and urinary Cd and Pb concentrations. Urine samples were analyzed using high performance liquid chromatography and flameless atomic absorption spectrometry; blood samples were analyzed using inductively coupled plasma-mass spectrometry. Age, physical activity, and blood and urinary Cd and Pb concentrations were included in structural equation modeling analysis. Two latent factors for heavy metal exposure and physical activity were produced to predict the total influence of the variables. The final model was good: CMIN/DF = 0.775, CFI = 1.000, GFI = 0.975, AGFI = 0.954, RMSEA = 0.000. 8-OHdG levels were positively associated with heavy metal exposure, physical activity, and age (standard β of path analysis: 0.33, 0.38, and 0.20, respectively). Therefore, oxidative stress is associated with both, environmental and lifestyle factors, in combination with aging.

  16. Detailed Debunking of Denial

    Science.gov (United States)

    Enting, I. G.; Abraham, J. P.

    2012-12-01

    The disinformation campaign against climate science has been compared to a guerilla war whose tactics undermine the traditional checks and balances of science. One comprehensive approach has to been produce archives of generic responses such as the websites of RealClimate and SkepticalScience. We review our experiences with an alternative approach of detailed responses to a small number of high profile cases. Our particular examples were Professor Ian Plimer and Christopher Monckton, the Third Viscount Monckton of Brenchley, each of whom has been taken seriously by political leaders in our respective countries. We relate our experiences to comparable examples such as John Mashey's analysis of the Wegman report and the formal complaints about Lomborg's "Skeptical Environmentalist" and Durkin's "Great Global Warming Swindle". Our two approaches used contrasting approaches: an on-line video of a lecture vs an evolving compendium of misrepresentations. Additionally our approaches differed in the emphasis. The analysis of Monckton concentrated on the misrepresentation of the science, while the analysis of Plimer concentrated on departures from accepted scientific practice: fabrication of data, misrepresentation of cited sources and unattributed use of the work of others. Benefits of an evolving compendium were the ability to incorporate contributions from members of the public who had identified additional errors and the scope for addressing new aspects as they came to public attention. `Detailed debunking' gives non-specialists a reference point for distinguishing non-science when engaging in public debate.

  17. THULE: A detailed description

    International Nuclear Information System (INIS)

    This report describes the THULE scheme of lattice physics calculation which has been developed in FORTRAN for the IBM 7090. This scheme predicts the neutron flux over energy and space, for many groups and regions, together with reactivity and reaction rate edits for both a single lattice cell and a reactor core. This report describes in detail the input requirements for the THULE programme which forms the main part of the scheme. Brief descriptions of the 7090 programmes TED 6 and NOAH are included as appendices. TED 6 will produce the THULE edits from a WDSN output tape and NOAH is a version of the METHUSELAH programme which contains many of the THULE edits and will also produce input cards for THULE. (author)

  18. The age of the Galactic disk - Inflow, chemical evolution, astration, and radioactivity

    Science.gov (United States)

    Clayton, Donald D.

    1989-01-01

    Theoretical models of Galactic evolution and observational data on the age of the Galaxy are compared, with a focus on recent results. Topics addressed include the infall of material and its effects on the age-metallicity relation, the distribution of metallicity, the present gas fraction and metallicity, and the age spectrum of interstellar nuclei; the chemical evolution of the solar neighborhood; the key results of nuclear cosmochronology; and astration effects on Galactic age. It is found that both nuclear cosmochronology and detailed stellar and Galactic evolution models tend to support an age of 12-16 Gyr.

  19. Crowdsourcing detailed flood data

    Science.gov (United States)

    Walliman, Nicholas; Ogden, Ray; Amouzad*, Shahrzhad

    2015-04-01

    Over the last decade the average annual loss across the European Union due to flooding has been 4.5bn Euros, but increasingly intense rainfall, as well as population growth, urbanisation and the rising costs of asset replacements, may see this rise to 23bn Euros a year by 2050. Equally disturbing are the profound social costs to individuals, families and communities which in addition to loss of lives include: loss of livelihoods, decreased purchasing and production power, relocation and migration, adverse psychosocial effects, and hindrance of economic growth and development. Flood prediction, management and defence strategies rely on the availability of accurate information and flood modelling. Whilst automated data gathering (by measurement and satellite) of the extent of flooding is already advanced it is least reliable in urban and physically complex geographies where often the need for precise estimation is most acute. Crowdsourced data of actual flood events is a potentially critical component of this allowing improved accuracy in situations and identifying the effects of local landscape and topography where the height of a simple kerb, or discontinuity in a boundary wall can have profound importance. Mobile 'App' based data acquisition using crowdsourcing in critical areas can combine camera records with GPS positional data and time, as well as descriptive data relating to the event. This will automatically produce a dataset, managed in ArcView GIS, with the potential for follow up calls to get more information through structured scripts for each strand. Through this local residents can provide highly detailed information that can be reflected in sophisticated flood protection models and be core to framing urban resilience strategies and optimising the effectiveness of investment. This paper will describe this pioneering approach that will develop flood event data in support of systems that will advance existing approaches such as developed in the in the UK

  20. Comparative study of ageing, heat treatment and accelerated carbonation for stabilization of municipal solid waste incineration bottom ash in view of reducing regulated heavy metal/metalloid leaching

    OpenAIRE

    Santos, Rafael; Mertens, Gilles; Salman, Muhammad; Cizer, Özlem; Gerven, Tom Van

    2013-01-01

    This study compared the performance of four different approaches for stabilization of regulated heavy metal and metalloid leaching from municipal solid waste incineration bottom ash (MSWI-BA): (i) short term (three months) heap ageing, (ii) heat treatment, (iii) accelerated moist carbonation, and (iv) accelerated pressurized slurry carbonation. Two distinct types of MSWI-BA were tested in this study: one originating from a moving-grate furnace incineration operation treating exclusively house...

  1. Thermoelectric properties of metallic antiperovskites AXD3 (A=Ge, Sn, Pb, Al, Zn, Ga; X=N, C; D=Ca, Fe, Co)

    Science.gov (United States)

    Bilal, Muhammad; Ahmad, Iftikhar; Asadabadi, Saeid Jalali; Ahmad, Rashid; Maqbool, Muhammad

    2015-05-01

    In this paper we communicate the thermoelectric properties of carbon and nitrogen based metallic antiperovskites ANCa3 (A=Ge, Sn, Pb), BCFe3 (B=Al, Zn, Ga) and SnCD3 (D=Co and Fe) using the ab-initio calculations to explore efficient metallic thermoelectric materials. The consistency of the calculated results of SnCCo3 and SnCFe3 with the experimental results confirms the reliability of our theoretical calculations for the other investigated metallic antiperovskites. The results indicate that the thermopower of these materials can be enhanced by changing the chemical potential. The dimensionless figure of merit for the three nitrides approaches 0.96 at room temperature, which proves the usefulness of these materials in thermoelectric generators. Furthermore, the thermal conductivity is minimum at room temperature for chemical potential values between -0.25 μ(eV) and 0.25 μ(eV), and provides the maximum values of dimensionless figure of merit in this range. The striking feature of these studies is identifying a metallic compound, SnNCa3, with the highest value of Seebeck coefficient at room temperature out of all metals. The results anticipate that these materials could be efficient in thermoelectric generators; however, this needs experimental verification.[Figure not available: see fulltext.

  2. CERN in detail

    CERN Multimedia

    Laëtitia Pedroso

    2010-01-01

    Before, you had to go on the TPG website to find a tram-route, use Google Maps to see an aerial photo of CERN, and look for CERN buildings on map.web.cern.ch. Now, that's ancient history, with a new Geographical Information System (GIS) Portal set up by the Design Office and Patrimony Service (GS/SEM/DOP).  It's a one-stop-shop for all this information and much more.   A screenshot of the GIS Portal. Over the past few days, you might have noticed the new interface called MAPSearch that pops up when you make a building search using the Building and Roads field on the CERN homepage. This is a simplified version of the new GIS web Portal, a project on which the GS Department's Design Office and Patrimony Service has been working since January 2010. "In today's informatics age, we need to respond ever more quickly to increasing numbers of specific user requests," explains Project Leader Youri Robert. This is more than just a new release of an old tool, it's a completely n...

  3. An Estimate of the Age Distribution of Terrestrial Planets in the Universe: Quantifying Metallicity as a Selection Effect

    OpenAIRE

    Lineweaver, Charles H.

    2000-01-01

    Planets like the Earth cannot form unless elements heavier than helium are available. These heavy elements, or `metals', were not produced in the big bang. They result from fusion inside stars and have been gradually building up over the lifetime of the Universe. Recent observations indicate that the presence of giant extrasolar planets at small distances from their host stars, is strongly correlated with high metallicity of the host stars. The presence of these close-orbiting giants is incom...

  4. The effect of progenitor age and metallicity on luminosity and 56Ni yield in Type Ia supernovae

    CERN Document Server

    Howell, D A; Brown, E F; Conley, A; Le Borgne, D; Hsiao, E Y; Astier, Pierre; Balam, D; Balland, C; Basa, S; Carlberg, R G; Fouchez, D; Guy, J; Hardin, D; Hook, I M; Pain, R; Perrett, K; Pritchet, C J; Regnault, N; Baumont, S; Du, J Le; Lidman, C; Perlmutter, S; Suzuki, N; Walker, E S; Wheeler, J C

    2008-01-01

    Timmes, Brown & Truran found that metallicity variations could theoretically account for a 25% variation in the mass of 56Ni synthesized in Type Ia supernovae (SNe Ia), and thus account for a large fraction of the scatter in observed SN Ia luminosities. Higher-metallicity progenitors are more neutron-rich, producing more stable burning products relative to radioactive 56Ni. We develop a new method for estimating bolometric luminosity and 56Ni yield in SNe Ia and use it to test the theory with data from the Supernova Legacy Survey. We find that the average 56Ni yield does drop in SNe Ia from high metallicity environments, but the theory can only account for 7%--10% of the dispersion in SN Ia 56Ni mass, and thus luminosity. This is because the effect is dominant at metallicities significantly above solar, whereas we find that SN hosts have predominantly subsolar or only moderately above-solar metallicities. We also show that allowing for changes in O/Fe with the metallicity [Fe/H] does not have a major effe...

  5. The Role of Evolutionary Age and Metallicity in the Formation of Classical BE Circumstellar Disks II. Assessing the True Nature of Candidate Disk Systems

    Science.gov (United States)

    Wisniewski, J. P.; Bjorkman, K. S.; Magalhaes, A. M.; Bjorkman, J. E.; Meade, M. R.; Pereyra, Antonio

    2007-01-01

    Photometric 2-color diagram (2-CD) surveys of young cluster populations have been used to identify populations of B-type stars exhibiting excess Ha emission. The prevalence of these excess emitters, assumed to be "Be stars". has led to the establishment of links between the onset of disk formation in classical Be stars and cluster age and/or metallicity. We have obtained imaging polarization observations of six SMC and six LMC clusters whose candidate Be populations had been previously identified via 2-CDs. The interstellar polarization (ISP) associated with these data has been identified to facilitate an examination of the circumstellar environments of these candidate Be stars via their intrinsic polarization signatures, hence determine the true nature of these objects. We determined that the ISP associated with the SMC cluster NGC 330 was characterized by a modified Serkowski law with a lambda(sub max) of approx. 4500Angstroms, indicating the presence of smaller than average dust grains. The morphology of the ISP associated with the LMC cluster NGC 2100 suggests that its interstellar environment is characterized by a complex magnetic field. Our intrinsic polarization results confirm the suggestion of Wisniewski et al. that a substantial number of bona-fide classical Be stars are present in clusters of age 5-8 Myr. Hence, our data contradict recent assertions that the Be phenomenon develops in the second half of a B star's main sequence lifetime, i.e. no earlier than 10 Myr. These data imply that a significant number of B-type stars must emerge onto the zero-age-main-sequence rotating at near-critical rotation rates, although we can not rule out the possibility that these data instead reveal the presence of a sub-group of the Be phenomenon characterized by sub-critically rotating objects. Comparing the polarimetric properties of our dataset to a similar survey of Galactic classical Be stars, we find that the prevalence of polarimetric Balmer jump signatures

  6. Fractionation and leachability of heavy metals from aged and recent Zn metallurgical leach residues from the Três Marias zinc plant (Minas Gerais, Brazil).

    Science.gov (United States)

    Sethurajan, Manivannan; Huguenot, David; Lens, Piet N L; Horn, Heinrich A; Figueiredo, Luiz H A; van Hullebusch, Eric D

    2016-04-01

    Various mineral processing operations to produce pure metals from mineral ores generate sludges, residues, and other unwanted by-products/wastes. As a general practice, these wastes are either stored in a reservoir or disposed in the surrounding of mining/smelting areas, which might cause adverse environmental impacts. Therefore, it is important to understand the various characteristics like heavy metal leaching features and potential toxicity of these metallurgical wastes. In this study, zinc plant leach residues (ZLRs) were collected from a currently operating Zn metallurgical industry located in Minas Gerais (Brazil) and investigated for their potential toxicity, fractionation, and leachability. Three different ZLR samples (ZLR1, ZLR2, and ZLR3) were collected, based on their age of production and deposition. They mainly consisted of Fe (6-11.5 %), Zn (2.5 to 5.0 %), and Pb (1.5 to 2.5 %) and minor concentrations of Al, Cd, Cu, and Mn, depending on the sample age. Toxicity Characteristic Leaching Procedure (TCLP) results revealed that these wastes are hazardous for the environment. Accelerated Community Bureau of Reference (BCR) sequential extraction clearly showed that potentially toxic heavy metals such as Cd, Cu, Pb, and Zn can be released into the environment in high quantities under mild acidic conditions. The results of the liquid-solid partitioning as a function of pH showed that pH plays an important role in the leachability of metals from these residues. At low pH (pH 2.5), high concentrations of metals can be leached: 67, 25, and 7 % of Zn can be leached from leach residues ZLR1, ZLR2, and ZLR3, respectively. The release of metals decreased with increasing pH. Geochemical modeling of the pH-dependent leaching was also performed to determine which geochemical process controls the leachability/solubility of the heavy metals. This study showed that the studied ZLRs contain significant concentrations of non-residual extractable fractions of Zn and can

  7. Spatial distribution of metals in soils in Baltimore, Maryland: Role of native parent material, proximity to major roads, housing age and screening guidelines

    International Nuclear Information System (INIS)

    We investigated the spatial distribution of heavy metal above-background (anthropic) contents of Cd, Co, Cu, Cr, Fe, Mn, Ni, Pb, Ti, V, and Zn in Baltimore City surface soils and related these levels to potential contaminating sources. Composite soil samples (0-10 cm depth) were digested using a nitric and hydrochloric extraction technique. Slightly more than 10% of plots exceeded United States Environmental Protection Agency screening guidelines for Pb. In a principal component analysis, the first component corresponded to Co, Cr, and Fe, which are constituents of local mafic rocks. The second component corresponded to Cu, Pb, and Zn which were significantly higher within than beyond a 100 m buffer of the major roads within the city; furthermore, Pb and Zn were higher in older residential lots. - Spatial distribution of metals in soils of an older US city (Baltimore) was affected by parent material, proximity to major roads, and housing age

  8. Metals-contaminated benthic invertebrates in the Clark Fork River, Montana: Effects on age-0 brown trout and rainbow trout

    Science.gov (United States)

    Woodward, Daniel F.; Farag, Aïda M.; Bergman, Harold L.; Delonay, Aaron J.; Little, Edward E.; Smiths, Charlie E.; Barrows, Frederic T.

    1995-01-01

    Benthic organisms in the upper Clark Fork River have recently been implicated as a dietary source of metals that may be a chronic problem for young-of-the-year rainbow trout (Oncorhynchus mykiss). In this present study, early life stage brown trout (Salmo trutta) and rainbow trout were exposed for 88 d to simulated Clark Fork River water and a diet of benthic invertebrates collected from the river. These exposures resulted in reduced growth and elevated levels of metals in the whole body of both species. Concentrations of As, Cd, Cu, and Pb increased in whole brown trout; in rainbow trout, As and Cd increased in whole fish, and As also increased in liver. Brown trout on the metals-contaminated diets exhibited constipation, gut impaction, increased cell membrane damage (lipid peroxidation), decreased digestive enzyme production (zymogen), and a sloughing of intestinal mucosal epithelial cells. Rainbow trout fed the contaminated diets exhibited constipation and reduced feeding activity. We believe that the reduced standing crop of trout in the Clark Fork River results partly from chronic effects of metals contamination in benthic invertebrates that are important as food for young-of-the-year fish.

  9. Analysis of the relationship between the blood concentration of several metals, macro- and micronutrients and endocrine disorders associated with male aging.

    Science.gov (United States)

    Rotter, Iwona; Kosik-Bogacka, Danuta I; Dołęgowska, Barbara; Safranow, Krzysztof; Kuczyńska, Magdalena; Laszczyńska, Maria

    2016-06-01

    Beyond 30 years of age, men experience a decline in the production of testosterone, yet only a few develop late-onset hypogonadism. This study was designed to determine the relationship between blood concentrations of metals, macro- and micronutrients and age-related testosterone deficiency and associated hormonal changes in aging men. The research involved 313 men aged 50-75 years. We used ELISA to determine the concentrations of total testosterone (TT), free testosterone (FT), estradiol (E2), dehydroepiandrosterone sulfate (DHEAS) and sex hormone-binding globulin (SHBG). We calculated free androgen index (FAI). With the use of emission spectrometry in inductively coupled argon plasma, we determined the whole-blood concentrations of lead (Pb), cadmium (Cd), mercury (Hg), arsenic (As) and tungsten (W), as well as serum concentrations of magnesium (Mg), iron (Fe), calcium (Ca), copper (Cu), zinc (Zn), selenium (Se), chromium (Cr), manganese (Mn) and molybdenum (Mo). The study showed no relationship between TT and FT and the concentrations of metals. Men with TT deficiency had significantly lower concentrations of Mg and Fe and increased Mn. Men with FT deficiency had higher W and Cr levels and lower Fe. Assessing the correlation between the concentrations of hormones, SHBG and FAI, and the concentration of metals and macro- and microelements in the blood of the men, we found positive correlations between the concentrations of TT-Mg, TT-Fe, TT-Mo, FT-Fe, E2-As, SHBG-Mn, FAI-W, FAI-As, FAI-Zn and FAI-Ca, and negative correlations between the concentrations of TT-Mn, FT-Cd, FT-Cr, E2-Hg, E2-Cr, SHBG-W, SHBG-As, SHBG-Zn, SHBG-Ca, FAI-Pb and FAI-Mn. Positive correlations between As and E2 and between As and FAI may suggest a lack of association between this metal and hypogonadism in people not exposed to excess As levels. Our research indicates a positive relationship between the concentrations of Mg, Fe and Zn and endocrine system in aging men, in contrast to Mn and

  10. The Role of Evolutionary Age and Metallicity in the Formation of Classical Be Circumstellar Disks I. New Candidate Be Stars in the LMC, SMC, and Milky Way

    CERN Document Server

    Wisniewski, J P; Wisniewski, John P.; Bjorkman, Karen S.

    2006-01-01

    We present B, V, R, and H alpha photometry of 8 clusters in the Small Magellanic Cloud, 5 in the Large Magellanic Cloud, and 3 Galactic clusters, and use 2 color diagrams (2-CDs) to identify candidate Be star populations in these clusters. We find evidence that the Be phenomenon is enhanced in low metallicity environments, based on the observed fractional early-type candidate Be star content of clusters of age 10-25 Myr. Numerous candidate Be stars of spectral types B0 to B5 were identified in clusters of age 5-8 Myr, challenging the suggestion of Fabregat & Torrejon (2000) that classical Be stars should only be found in clusters at least 10 Myr old. These results suggest that a significant number of B-type stars must emerge onto the zero-age-main-sequence as rapid rotators. We also detect an enhancement in the fractional content of early-type candidate Be stars in clusters of age 10-25 Myr, suggesting that the Be phenomenon does become more prevalent with evolutionary age. We briefly discuss the mechanis...

  11. Use of human nails as bio-indicators of heavy metals environmental exposure among school age children in Kenya

    Energy Technology Data Exchange (ETDEWEB)

    Hussein Were, Faridah [Department of Chemistry in the School of Pure and Applied Sciences at Kenyatta University, P.O. Box 43844-00100 GPO Nairobi (Kenya); Njue, Wilson [Department of Chemistry in the School of Pure and Applied Sciences at Kenyatta University, P.O. Box 43844-00100 GPO Nairobi (Kenya)], E-mail: wilsonnjue@yahoo.com; Murungi, Jane; Wanjau, Ruth [Department of Chemistry in the School of Pure and Applied Sciences at Kenyatta University, P.O. Box 43844-00100 GPO Nairobi (Kenya)

    2008-04-15

    Metal pollution and its health effects present a challenge currently facing the developing countries. Metal poisoning is usually difficult and expensive to assess or screen in these countries due to limited resources, which means that policies, guidelines, regulations and institutional managements are limited. Hair and nail as biopsy materials were suggested as more attractive biomarkers in assessing heavy metals environmental exposure. This paper deals with quantitative determination of lead (Pb), cadmium (Cd), calcium (Ca), zinc (Zn), and iron (Fe) in fingernails of children (n = 200) in urban and rural areas using atomic absorption spectrometry. Factors that were suspected to influence the accumulation of Pb and Cd in children were obtained through a questionnaire. The mean levels of heavy metals in children in urban areas were found to be higher (27.5 {+-} 1.8 {mu}g/g Pb and 0.73 {+-} 0.08 {mu}g/g Cd) than in rural areas (19.7 {+-} 0.9 {mu}g/g Pb and 0.44 {+-} 0.06 {mu}g/g Cd). The difference was significant (P < 0.05; DF = 168, t-test). Other factors that were found to have significant influence were socio-economic background, health conditions, dietary habits and environmental risk exposure. The results also showed that the school location has more influence on the heavy metals level than the area of residence. The children in a school near the highway were found to have a mean of 34.4 {+-} 3.5 {mu}g/g Pb as compared to those who lived near the highway (31.6 {+-} 2.8 {mu}g/g Pb), however the difference was not significant (P > 0.05), suggesting a common source of contaminants in the areas. The correlation results also indicated that a high level of Pb in the nail influenced negatively Zn and Fe but not Ca levels (R = - 0.256 Zn; - 0.188 Fe) while high levels of Cd had a negative relationship with Fe only (R = - 0.241). The association of toxic metals in the nails of children with environmental exposure, and nutritional status implies that policies and actions

  12. The Carina project. VII. Toward the breaking of the age-metallicity degeneracy of red giant branch stars using the C {sub U,} {sub B,} {sub I} index

    Energy Technology Data Exchange (ETDEWEB)

    Monelli, M.; Milone, A. P.; Gallart, C.; Aparicio, A. [Instituto de Astrofísica de Canarias, Calle Via Lactea s/n, E-38205 La Laguna, Tenerife (Spain); Fabrizio, M.; Cassisi, S.; Buonanno, R. [Istituto Nazionale di Astrofisica-Osservatorio Astronomico Collurania, Via M. Maggini, I-64100 Teramo (Italy); Bono, G. [Dipartimento di Fisica, Universitá di Roma Tor Vergata, Via della Ricerca Scientifica 1, I-00133 Rome (Italy); Stetson, P. B. [Dominion Astrophysical Observatory, NRC-Herzberg, 5071 West Saanich Road, Victoria, BC, V9E 2E7 (Canada); Walker, A. R. [Cerro Tololo Inter-American Observatory, National Optical Astronomy Observatory, Casilla 603, La Serena (Chile); Nonino, M. [Istituto Nazionale di Astrofisica-Osservatorio Astronomico di Trieste, Via G. B. Tiepolo 11, I-40131 Trieste (Italy); Dall' Ora, M. [INAF—Osservatorio Astronomico di Capodimonte, Salita Moiariello 16, I-80131 Napoli (Italy); Ferraro, I.; Iannicola, G.; Pulone, L. [Istituto Nazionale di Astrofisica-Osservatorio Astronomico di Roma, Via Frascati 33, Monte Porzio Catone, I-00044 Rome (Italy); Thévenin, F., E-mail: monelli@iac.es [Université de Nice Sophia-antipolis, CNRS, Observatoire de la Côte d' Azur, Laboratoire Lagrange, BP 4229, F-06304 Nice (France)

    2014-12-01

    We present an analysis of photometric and spectroscopic data of the Carina dSph galaxy, testing a new approach similar to that used to disentangle multiple populations in Galactic globular clusters (GCs). We show that a proper color combination is able to separate a significant fraction of the red giant branch (RGB) of the two main Carina populations (the old one, ∼12 Gyr, and the intermediate-age one, 4-8 Gyr). In particular, the c {sub U,} {sub B,} {sub I} = (U – B) – (B – I) pseudo-color allows us to follow the RGB of both populations along a relevant portion of the RGB. We find that the oldest stars have a more negative c {sub U,} {sub B,} {sub I} pseudo-color than intermediate-age ones. We correlate the pseudo-color of RGB stars with their chemical properties, finding a significant trend between the iron content and the c {sub U,} {sub B,} {sub I}. Stars belonging to the old population are systematically more metal-poor ([Fe/H] =–2.32 ± 0.08 dex) than the intermediate-age ones ([Fe/H] =–1.82 ± 0.03 dex). This gives solid evidence of the chemical evolution history of this galaxy, and we have a new diagnostic that can allow us to break the age-metallicity degeneracy of H-burning advanced evolutionary phases. We compared the distribution of stars in the c {sub U,} {sub B,} {sub I} plane with theoretical isochrones, finding that no satisfactory agreement can be reached with models developed in a theoretical framework based on standard heavy element distributions. Finally, we discuss possible systematic differences when compared with multiple populations in GCs.

  13. The Carina project. VII. Toward the breaking of the age-metallicity degeneracy of red giant branch stars using the C U, B, I index

    International Nuclear Information System (INIS)

    We present an analysis of photometric and spectroscopic data of the Carina dSph galaxy, testing a new approach similar to that used to disentangle multiple populations in Galactic globular clusters (GCs). We show that a proper color combination is able to separate a significant fraction of the red giant branch (RGB) of the two main Carina populations (the old one, ∼12 Gyr, and the intermediate-age one, 4-8 Gyr). In particular, the c U, B, I = (U – B) – (B – I) pseudo-color allows us to follow the RGB of both populations along a relevant portion of the RGB. We find that the oldest stars have a more negative c U, B, I pseudo-color than intermediate-age ones. We correlate the pseudo-color of RGB stars with their chemical properties, finding a significant trend between the iron content and the c U, B, I. Stars belonging to the old population are systematically more metal-poor ([Fe/H] =–2.32 ± 0.08 dex) than the intermediate-age ones ([Fe/H] =–1.82 ± 0.03 dex). This gives solid evidence of the chemical evolution history of this galaxy, and we have a new diagnostic that can allow us to break the age-metallicity degeneracy of H-burning advanced evolutionary phases. We compared the distribution of stars in the c U, B, I plane with theoretical isochrones, finding that no satisfactory agreement can be reached with models developed in a theoretical framework based on standard heavy element distributions. Finally, we discuss possible systematic differences when compared with multiple populations in GCs.

  14. On Detailing in Contemporary Architecture

    DEFF Research Database (Denmark)

    Kristensen, Claus; Kirkegaard, Poul Henning

    2010-01-01

    Details in architecture have a significant influence on how architecture is experienced. One can touch the materials and analyse the detailing - thus details give valuable information about the architectural scheme as a whole. The absence of perceptual stimulation like details and materiality...... / tactility can blur the meaning of the architecture and turn it into an empty statement. The present paper will outline detailing in contemporary architecture and discuss the issue with respect to architectural quality. Architectural cases considered as sublime piece of architecture will be presented...

  15. VLSI metallization

    CERN Document Server

    Einspruch, Norman G; Gildenblat, Gennady Sh

    1987-01-01

    VLSI Electronics Microstructure Science, Volume 15: VLSI Metallization discusses the various issues and problems related to VLSI metallization. It details the available solutions and presents emerging trends.This volume is comprised of 10 chapters. The two introductory chapters, Chapter 1 and 2 serve as general references for the electrical and metallurgical properties of thin conducting films. Subsequent chapters review the various aspects of VLSI metallization. The order of presentation has been chosen to follow the common processing sequence. In Chapter 3, some relevant metal deposition tec

  16. Old age and super-solar metallicity in a massive z~1.4 early-type galaxy from VLT/X-Shooter spectroscopy

    CERN Document Server

    Lonoce, Ilaria; Maraston, Claudia; Thomas, Daniel; Mancini, Chiara; Cimatti, Andrea; Ciocca, Federica; Citro, Annalisa; Daddi, Emanuele; Alighieri, Sperello di Serego; Gargiulo, Adriana; Maiolino, Roberto; Mannucci, Filippo; Moresco, Michele; Pozzetti, Lucia; Quai, Salvatore; Saracco, Paolo

    2015-01-01

    We present the first estimate of age, stellar metallicity and chemical abundance ratios, for an individual early-type galaxy at high-redshift (z = 1.426) in the COSMOS field. Our analysis is based on observations obtained with the X-Shooter instrument at the VLT, which cover the visual and near infrared spectrum at high (R >5000) spectral resolution. We measure the values of several spectral absorptions tracing chemical species, in particular Magnesium and Iron, besides determining the age-sensitive D4000 break. We compare the measured indices to stellar population models, finding good agreement. We find that our target is an old (t > 3 Gyr), high-metallicity ([Z/H] > 0.5) galaxy which formed its stars at z_{form} > 5 within a short time scale ~0.1 Gyr, as testified by the strong [\\alpha/Fe] ratio ( > 0.4), and has passively evolved in the first > 3-4 Gyr of its life. We have verified that this result is robust against the choice and number of fitted spectral features, and stellar population model. The result...

  17. Ageing behaviour of unary hydroxides in trivalent metal salt solutions: Formation of layered double hydroxide (LDH)-like phases

    Indian Academy of Sciences (India)

    Michael Rajamathi; P Vishnu Kamath

    2000-10-01

    The hydroxides of Mg, Ni, Cu and Zn transform into layered double hydroxide (LDH)-like phases on ageing in solutions of Al or Cr salts. This reaction is similar to acid leaching and proceeds by a dissolution–reprecipitation mechanism offering a simple method of LDH synthesis, with implications for the accepted theories of formation of LDH minerals in the earth’s crust.

  18. On the absolute age of the metal-rich globular M71 (NGC 6838): I. optical photometry

    CERN Document Server

    Di Cecco, Alessandra; Moroni, Pier Giorgio Prada; Tognelli, Emanuele; Allard, France; Stetson, Peter B; Buonanno, Roberto; Ferraro, Ivan; Iannicola, Giacinto; Monelli, Matteo; Nonino, Mario; Pulone, Luigi

    2015-01-01

    We investigated the absolute age of the Galactic globular cluster M71 (NGC 6838) by using optical ground-based images (u',g',r',i',z') collected with the MegaCam camera at the Canada-France-Hawaii-Telescope (CFHT). We performed a robust selection of field and cluster stars by applying a new method based on the 3D (r',u'-g',g'-r') Color-Color-Magnitude-Diagram. The comparison between the Color-Magnitude-Diagram of the candidate cluster stars and a new set of isochrones, at the locus of the Main Sequence Turn Off (MSTO), suggests an absolute age of 12+/-2 Gyr. The absolute age was also estimated using the difference in magnitude between the MSTO and the so-called main sequence knee, a well defined bending occurring in the lower main sequence. This feature was originally detected in the near-infrared (NIR) bands and explained as a consequence of an opacity mechanism (collisionally induced absorption of molecular hydrogen) in the atmosphere of cool low-mass stars (Bono et al. 2010). The same feature was also dete...

  19. The Carina Project VII: Towards the breaking of the age-metallicity degeneracy of red giant branch stars using the c_UBI index

    CERN Document Server

    Monelli, M; Fabrizio, M; Bono, G; Stetson, P B; Walker, A R; Cassisi, S; Gallart, C; Nonino, M; Aparicio, A; Buonanno, R; Dall'Ora, M; Ferraro, I; Iannicola, G; Pulone, L; Thévenin, F

    2014-01-01

    We present an analysis of photometric and spectroscopic data of the Carina dSph galaxy, testing a new approach similar to that used to disentangle multiple populations in Galactic globular clusters (GCs). We show that a proper colour combination is able to separate a significant fraction of the red giant branch (RGB) of the two main Carina populations (the old one, \\sim 12 Gyr, and the intermediate-age one, 4-8 Gyr). In particular, the c_UBI=(U-B)-(B-I) pseudo-colour allows us to follow the RGB of both populations along a relevant portion of the RGB. We find that the oldest stars have more negative c_UBI pseudo-colour than intermediate-age ones. We correlate the pseudo-colour of RGB stars with their chemical properties, finding a significant trend between the iron content and the c_UBI. Stars belonging to the old population are systematically more metal poor ([Fe/H]=-2.32\\pm0.08 dex) than the intermediate-age ones ([Fe/H]=-1.82\\pm0.03 dex). This gives solid evidence on the chemical evolution history of this g...

  20. Computed tomography:the details.

    Energy Technology Data Exchange (ETDEWEB)

    Doerry, Armin Walter

    2007-07-01

    Computed Tomography (CT) is a well established technique, particularly in medical imaging, but also applied in Synthetic Aperture Radar (SAR) imaging. Basic CT imaging via back-projection is treated in many texts, but often with insufficient detail to appreciate subtleties such as the role of non-uniform sampling densities. Herein are given some details often neglected in many texts.

  1. Atomic diffusion in metal poor stars. The influence on the Main Sequence fitting distance scale, subdwarfs ages and the value of Delta Y/ Delta Z

    Science.gov (United States)

    Salaris, M.; Groenewegen, M. A. T.; Weiss, A.

    2000-03-01

    The effect of atomic diffusion on the Main Sequence (MS) of metal-poor low mass stars is investigated. Since diffusion alters the stellar surface chemical abundances with respect to their initial values, one must ensure - by calibrating the initial chemical composition of the theoretical models - that the surface abundances of the models match the observed ones of the stellar population under scrutiny. When properly calibrated, our models with diffusion reproduce well within the errors the Hertzsprung-Russell diagram of Hipparcos subdwarfs with empirically determined T_eff values and high resolution spectroscopical [Fe/H] determinations. Since the observed surface abundances of subdwarfs are different from the initial ones due to the effect of diffusion, while the globular clusters stellar abundances are measured in Red Giants, which have practically recovered their initial abundances after the dredge-up, the isochrones to be employed for studying globular clusters and Halo subdwarfs with the same observational value of [Fe/H] are different and do not coincide. This is at odds with the basic assumption of the MS-fitting technique for distance determinations. However, the use of the rather large sample of Hipparcos lower MS subdwarfs with accurate parallaxes keeps at minimum the effect of these differences, for two reasons. First, it is possible to use subdwarfs with observed [Fe/H] values close to the cluster one; this minimizes the colour corrections (which are derived from the isochrones) needed to reduce all the subdwarfs to a mono-metallicity sequence having the same [Fe/H] than the cluster. Second, one can employ objects sufficiently faint so that the differences between the subdwarfs and cluster MS with the same observed value of [Fe/H] are small (they increase for increasing luminosity). We find therefore that the distances based on standard isochrones are basically unaltered when diffusion is taken properly into account. On the other hand, the absolute ages

  2. AGE AND ORIGIN OF BASE- AND PRECIOUS-METAL VEINS OF THE COEUR D'ALENE MINING DISTRICT, IDAHO

    Energy Technology Data Exchange (ETDEWEB)

    Fleck, R J; Criss, R E; Eaton, G F; Cleland, R W; Wavra, C S; Bond, W D

    2000-11-07

    Ore-bearing quartz-carbonate veins of the Coeur d'Alene mining district yield {sup 87}Sr/{sup 86}Sr ratios of 0.74 to >1.60 for low-Rb/Sr, carbonate gangue minerals, similar to current ranges measured in Middle Proterozoic, high-Rb/Sr rocks of the Belt Supergroup. Stable-isotope and fluid-inclusion studies establish a genetic relationship between vein formation and metamorphic-hydrothermal systems of the region. These extraordinary {sup 87}Sr/{sup 86}Sr ratios require accumulation of radiogenic {sup 87}Sr in a high Rb/Sr system over an extended period prior to incorporation of Sr into the veins by hydrothermal processes. Evaluation of the age and composition of potential sources of highly radiogenic Sr indicates that the ore-bearing veins of the Coeur d'Alene district formed within the last 200 Ma from components scavenged from sedimentary and metasedimentary rocks of the Belt Supergroup, the primary host-rocks of the district. These results are consistent with a Cretaceous or Early Tertiary age for these veins. Pb-Zn deposits that yield Pb isotope, K-Ar, and Ar-Ar results indicative of a Proterozoic age probably formed during deposition or diagenesis of the Belt Supergroup at 1350-1500 Ma, possibly as Sullivan-type syngenetic deposits. K-Ar and Rb-Sr apparent ages and {delta}{sup 18}O values of Belt Supergroup rocks decrease southward from the Coeur d'Alene district toward the Idaho batholith, normal to the trends of metamorphic isograds, fold axes, foliation, and the major reverse faults of the district. Isoclinal folding, thrust faulting, high-temperature metamorphism, granitic plutonism, and regional-scale metamorphic-hydrothermal activity is documented in the region between 140 Ma and 45 Ma, but no similar combination of events is recognized for Late Proterozoic time. Combined with Sr results from the veins, the evidence strongly favors formation of the ore-bearing carbonate veins of the district by fluids related to a complex metamorphic

  3. The TRENDS High-Contrast Imaging Survey. VI. Discovery of a Mass, Age, and Metallicity Benchmark Brown Dwarf

    CERN Document Server

    Crepp, Justin R; Bechter, Eric B; Montet, Benjamin T; Johnson, John Asher; Piskorz, Danielle; Howard, Andrew W; Isaacson, Howard

    2016-01-01

    The mass and age of substellar objects are degenerate parameters leaving the evolutionary state of brown dwarfs ambiguous without additional information. Theoretical models are normally used to help distinguish between old, massive brown dwarfs and young, low mass brown dwarfs but these models have yet to be properly calibrated. We have carried out an infrared high-contrast imaging program with the goal of detecting substellar objects as companions to nearby stars to help break degeneracies in inferred physical properties such as mass, age, and composition. Rather than using imaging observations alone, our targets are pre-selected based on the existence of dynamical accelerations informed from years of stellar radial velocity (RV) measurements. In this paper, we present the discovery of a rare benchmark brown dwarf orbiting the nearby ($d=18.69\\pm0.19$ pc), solar-type (G9V) star HD 4747 ([Fe/H]=$-0.22\\pm0.04$) with a projected separation of only $\\rho=11.3\\pm0.2$ AU ($\\theta \\approx$ 0.6''). Precise Doppler m...

  4. Evolution of long-lived globular cluster stars. II. Sodium abundance variations on the asymptotic giant branch as a function of globular cluster age and metallicity

    CERN Document Server

    Charbonnel, C

    2016-01-01

    Long-lived stars in GCs exhibit chemical peculiarities with respect to their halo counterparts. In particular, Na-enriched stars are identified as belonging to a 2d stellar population born from cluster material contaminated by the H-burning ashes of a 1st stellar population. Their presence and numbers in different locations of the CMDs provide important constraints on the self-enrichment scenarios. In particular, the ratio of Na-poor to Na-rich stars on the AGB has recently been found to vary strongly from cluster to cluster, while it is relatively constant on the RGB. We investigate the impact of both age and metallicity on the theoretical Na spread along the AGB within the framework of the fast rotating massive stars scenario for GC self-enrichment. (tb continued)

  5. Phonetic Detail in American English

    Institute of Scientific and Technical Information of China (English)

    Ray Freeze

    1987-01-01

    @@ In the course of teaching general phonetics and phonological analysis in the psat few years,l have found some phonetic detail which some native speakers as well as non-native speakers were unaware of. This subtle detail will be the focus of this presentation. Som e of this detail many of you will already be aware of because of your experience in learning, teaching, and thinking about English. If anything is new to you, I hope you might enjoy hearing about it even if it turns out not to be useful in your work.

  6. Metal pneumoconiosis

    International Nuclear Information System (INIS)

    The occurrence of two cases of metal pneumoconiosis in a metal works has been used to draw attention to this rare occupational disease. The technology for the manufacture and precessing is described with special reference to dust exposure at the various stages. After an historical review, there is a detailed discussion of the clinical and radiological features of the two cases. Problems concerning the prognosis, differential diagnosis and the laws concerning compensation are discussed. (orig.)

  7. X-ray diffraction analysis and metal physics modeling of static strain aging and thermal dislocation recovery in the mechanically affected zone of surface finished hardened steel

    Energy Technology Data Exchange (ETDEWEB)

    Gegner, Juergen [SKF GmbH, Dept. of Material Physics, Schweinfurt (Germany)

    2009-07-01

    After heat treatment, finish machining of the hardened steel represents the last manufacturing step of machine elements. The practically most important operation of grinding is applied to achieve edge zone compressive residual stresses, best surface quality and dimensional accuracy. Metal removal involves high plastic deformation work. Glide and intersection processes raise the density and produce lower energy substructures of dislocations. The temperature and time behavior of post-machining thermal treatment is analyzed on ground and honed martensitic SAE 52100 rolling bearing steel. Microstructure stabilization is reflected in a large XRD line width decrease on the surface. The kinetics is modeled by rate-controlling carbide dissolution as the carbon source for Cottrell-type segregation at dislocations. This static strain aging is verified by the formation of a slight white etching surface layer. The metal physics model is extended to also consider superimposed thermal dislocation recovery. Both effects are separable. In rolling contact fatigue tests under mixed friction running conditions, air reheating of the samples below the tempering temperature, which avoids hardness loss, leads to a significant lifetime increase. Thermal post-treatment after cold working results in similar changes of the XRD line width in the larger mechanically affected edge zone.

  8. Violence in the Dark Ages

    CERN Document Server

    Thacker, R J

    2002-01-01

    A wide range of observational and theoretical arguments suggest that the universe experienced a period of heating and metal enrichment, most likely from starbursting dwarf galaxies. Using a hydrodynamic simulation we have conducted a uniquely detailed theoretical investigation of this epoch at the end of the cosmological ``dark ages''. Outflows strip baryons from pre-viralized halos with total masses $\\lesssim10{}^{10}$ M${}_\\odot$, reducing their number density and the overall star formation rate, while pushing these quantities toward their observed values. We show that the metallicity of $\\lesssim10{}^{10}$ M${}_\\odot$ objects increases with size, but with a large scatter, reproducing the metallicity-luminosity relation of dwarf galaxies. Galaxies $\\gtrsim10{}^{10}$ M${}_\\odot$ form with a roughly constant initial metallicity of 10% solar, explaining the observed lack of metal-poor disk stars in these objects. Outflows enrich roughly 20% of the simulation volume, yielding a mean metallicity of 0.3% solar, i...

  9. Relationship between perinatal antioxidant vitamin and heavy metal levels and the growth and cognitive development of children at 5 years of age.

    Science.gov (United States)

    Liu, Yongfang; Chen, Qian; Wei, Xiaoping; Chen, Li; Zhang, Xuan; Chen, Ke; Chen, Jie; Li, Tingyu

    2015-01-01

    To evaluate how prenatal exposure to antioxidant vitamins and heavy metals affects subsequent development. Maternal serum and cord serum levels of antioxidant vitamins (A, E, and C) were determined. Full-state, performance, and verbal intelligence quotients (FSIQ, PIQ, and VIQ, respectively) of 97 children were assessed at 5 years of age. The placental transport ratio (PTR: cord level relative to maternal serum level) of vitamin A (VA) was associated positively with FSIQ score (p=0.041), vitamin E (VE)-PTR was associated positively with PIQ (p=0.002) and FSIQ (p=0.025) scores, and cord serum cadmium (Cd) level was correlated negatively with VIQ score (p=0.025) at 5 years of age. High VE-PTR protected against low PIQ (OR=0.025; p=0.021) and FSIQ (ORhigher maternal education (OR=0.038; 95% CI, 0.003-0.458; p=0.010) and economic level (OR=0.047; 95% CI, 0.004-0.579; p=0.017) were protective against a low FSIQ score. VA-PTR predicted physical growth. VA-PTR and VE-PTR predicted intelligence test performance at 5 years old. High Cd in cord blood may negatively affect subsequent intelligence.

  10. Transformative Dynamics in Detailed Planning

    DEFF Research Database (Denmark)

    Quitzau, Maj-Britt; Poulsen, Naja; Gustavsson, Ted;

    that the translation process relies heavily on integration of impositions in the detailed plan, although this has clear limitations, since some sustainable strategies are more difficult to impose than others. It also shows how strategic navigation may represent an alternative translation strategy to promote more...... difficult sustainable strategies that address the project design more directly. In conclusion, the paper argues that strategic navigation represents a stronger mediator of change compared to the detailed plan, but that especially timing issues in the coordination between formal planning and design processes...

  11. Ages and sources of components of Zn-Pb, Cu, precious metal, and platinum group element deposits in the goodsprings district, clark county, Nevada

    Science.gov (United States)

    Vikre, P.; Browne, Q.J.; Fleck, R.; Hofstra, A.; Wooden, J.

    2011-01-01

    The Goodsprings district, Clark County, Nevada, includes zinc-dominant carbonate replacement deposits of probable late Paleozoic age, and lead-dominant carbonate replacement deposits, copper ?? precious metal-platinum group element (PGE) deposits, and gold ?? silver deposits that are spatially associated with Late Triassic porphyritic intrusions. The district encompasses ??500 km2 although the distribution of all deposits has been laterally condensed by late Mesozoic crustal contraction. Zinc, Pb, and Cu production from about 90 deposits was ??160,000 metric tons (t) (Zn > Pb >> Cu), 2.1 million ounces (Moz) Ag, 0.09 Moz Au, and small amounts of PGEs-Co, V, Hg, Sb, Ni, Mo, Mn, Ir, and U-were also recovered. Zinc-dominant carbonate replacement deposits (Zn > Pb; Ag ?? Cu) resemble Mississippi Valley Type (MVT) Zn-Pb deposits in that they occur in karst and fault breccias in Mississippian limestone where the southern margin of the regional late Paleozoic foreland basin adjoins Proterozoic crystalline rocks of the craton. They consist of calcite, dolomite, sphalerite, and galena with variably positive S isotope compositions (??34S values range from 2.5-13%), and highly radiogenic Pb isotope compositions (206Pb/204Pb >19), typical of MVT deposits above crystalline Precambrian basement. These deposits may have formed when southward flow of saline fluids, derived from basinal and older sedimentary rocks, encountered thinner strata and pinch-outs against the craton, forcing fluid mixing and mineral precipitation in karst and fault breccias. Lead-dominant carbonate replacement deposits (Pb > Zn, Ag ?? Cu ?? Au) occur among other deposit types, often near porphyritic intrusions. They generally contain higher concentrations of precious metals than zinc-dominant deposits and relatively abundant iron oxides after pyrite. They share characteristics with copper ?? precious metal- PGE and gold ?? silver deposits including fine-grained quartz replacement of carbonate minerals in

  12. DAGAL: Detailed Anatomy of Galaxies

    CERN Document Server

    Knapen, Johan H

    2016-01-01

    The current IAU Symposium is closely connected to the EU-funded network DAGAL (Detailed Anatomy of Galaxies), with the final annual network meeting of DAGAL being at the core of this international symposium. In this short paper, we give an overview of DAGAL, its training activities, and some of the scientific advances that have been made under its umbrella.

  13. Older adults report moderately more detailed autobiographical memories

    Directory of Open Access Journals (Sweden)

    Robert S Gardner

    2015-05-01

    Full Text Available Autobiographical memory (AM is an essential component of the human mind. Although the amount and types of subjective detail (content that compose AMs constitute important dimensions of recall, age-related changes in memory content are not well characterized. Previously, we introduced the Cue-Recalled Autobiographical Memory test (CRAM; see http://cramtest.info, an instrument that collects subjective reports of AM content, and applied it to college-aged subjects. CRAM elicits AMs using naturalistic word-cues. Subsequently, subjects date each cued AM to a life period and count the number of remembered details from specified categories (features, e.g., temporal detail, spatial detail, persons, objects, and emotions. The current work applies CRAM to a broad range of individuals (18-78 years old to quantify the effects of age on AM content. Subject age showed a moderately positive effect on AM content: older compared with younger adults reported ~16% more details (~25 vs. ~21 in typical AMs. This age-related increase in memory content was similarly observed for remote and recent AMs, although content declined with the age of the event among all subjects. In general, the distribution of details across features was largely consistent among younger and older adults. However, certain types of details, i.e., those related to objects and sequences of events, contributed more to the age effect on content. Altogether, this work identifies a moderate age-related feature-specific alteration in the way life events are subjectively recalled, among an otherwise stable retrieval profile.

  14. Older adults report moderately more detailed autobiographical memories.

    Science.gov (United States)

    Gardner, Robert S; Mainetti, Matteo; Ascoli, Giorgio A

    2015-01-01

    Autobiographical memory (AM) is an essential component of the human mind. Although the([A-z]+) amount and types of subjective detail (content) that compose AMs constitute important dimensions of recall, age-related changes in memory content are not well characterized. Previously, we introduced the Cue-Recalled Autobiographical Memory test (CRAM; see http://cramtest.info), an instrument that collects subjective reports of AM content, and applied it to college-aged subjects. CRAM elicits AMs using naturalistic word-cues. Subsequently, subjects date each cued AM to a life period and count the number of remembered details from specified categories (features), e.g., temporal detail, spatial detail, persons, objects, and emotions. The current work applies CRAM to a broad range of individuals (18-78 years old) to quantify the effects of age on AM content. Subject age showed a moderately positive effect on AM content: older compared with younger adults reported ∼16% more details (∼25 vs. ∼21 in typical AMs). This age-related increase in memory content was similarly observed for remote and recent AMs, although content declined with the age of the event among all subjects. In general, the distribution of details across features was largely consistent among younger and older adults. However, certain types of details, i.e., those related to objects and sequences of events, contributed more to the age effect on content. Altogether, this work identifies a moderate age-related feature-specific alteration in the way life events are subjectively recalled, among an otherwise stable retrieval profile. PMID:26042064

  15. Metals 2000

    Energy Technology Data Exchange (ETDEWEB)

    Allison, S.W.; Rogers, L.C.; Slaughter, G. [Oak Ridge National Lab., TN (United States); Boensch, F.D. [6025 Oak Hill Lane, Centerville, OH (United States); Claus, R.O.; de Vries, M. [Virginia Polytechnic Inst. and State Univ., Blacksburg, VA (United States)

    1993-05-01

    This strategic planning exercise identified and characterized new and emerging advanced metallic technologies in the context of the drastic changes in global politics and decreasing fiscal resources. In consideration of a hierarchy of technology thrusts stated by various Department of Defense (DOD) spokesmen, and the need to find new and creative ways to acquire and organize programs within an evolving Wright Laboratory, five major candidate programs identified are: C-17 Flap, Transport Fuselage, Mach 5 Aircraft, 4.Fighter Structures, and 5. Missile Structures. These results were formed by extensive discussion with selected major contractors and other experts, and a survey of advanced metallic structure materials. Candidate structural applications with detailed metal structure descriptions bracket a wide variety of uses which warrant consideration for the suggested programs. An analysis on implementing smart skins and structures concepts is given from a metal structures perspective.

  16. Aircraft empennage structural detail design

    Science.gov (United States)

    Meholic, Greg; Brown, Rhonda; Hall, Melissa; Harvey, Robert; Singer, Michael; Tella, Gustavo

    1993-01-01

    This project involved the detailed design of the aft fuselage and empennage structure, vertical stabilizer, rudder, horizontal stabilizer, and elevator for the Triton primary flight trainer. The main design goals under consideration were to illustrate the integration of the control systems devices used in the tail surfaces and their necessary structural supports as well as the elevator trim, navigational lighting system, electrical systems, tail-located ground tie, and fuselage/cabin interface structure. Accommodations for maintenance, lubrication, adjustment, and repairability were devised. Weight, fabrication, and (sub)assembly goals were addressed. All designs were in accordance with the FAR Part 23 stipulations for a normal category aircraft.

  17. A Generalized Detailed Balance Relation

    Science.gov (United States)

    Ruelle, David

    2016-08-01

    Given a system M in a thermal bath we obtain a generalized detailed balance relation for the ratio r=π _τ (K→ J)/π _τ (J→ K) of the transition probabilities M:J→ K and M:K→ J in time τ . We assume an active bath, containing solute molecules in metastable states. These molecules may react with M and the transition J→ K occurs through different channels α involving different reactions with the bath. We find that r=sum p^α r^α , where p^α is the probability that channel α occurs, and r^α depends on the amount of heat (more precisely enthalpy) released to the bath in channel α.

  18. A generalized detailed balance relation

    CERN Document Server

    Ruelle, David

    2015-01-01

    Given a system $M$ in a thermal bath we obtain a generalized detailed balance relation for the ratio $r=\\pi_\\tau(K\\to J)/\\pi_\\tau(J\\to K)$ of the transition probabilities $M:J\\to K$ and $M:K\\to J$ in time $\\tau$. We assume an active bath, containing solute molecules in metastable states. These molecules may react with $M$ and the transition $J\\to K$ occurs through different channels $\\alpha$ involving different reactions with the bath. We find that $r=\\sum p^\\alpha r^\\alpha$, where $p^\\alpha$ is the probability that channel $\\alpha$ occurs, and $r^\\alpha$ depends on the amount of heat (more precisely enthalpy) released to the bath in channel $\\alpha$.

  19. The fine details of evolution.

    Science.gov (United States)

    Laskowski, Roman A; Thornton, Janet M; Sternberg, Michael J E

    2009-08-01

    Charles Darwin's theory of evolution was based on studies of biology at the species level. In the time since his death, studies at the molecular level have confirmed his ideas about the kinship of all life on Earth and have provided a wealth of detail about the evolutionary relationships between different species and a deeper understanding of the finer workings of natural selection. We now have a wealth of data, including the genome sequences of a wide range of organisms, an even larger number of protein sequences, a significant knowledge of the three-dimensional structures of proteins, DNA and other biological molecules, and a huge body of information about the operation of these molecules as systems in the molecular machinery of all living things. This issue of Biochemical Society Transactions contains papers from oral presentations given at a Biochemical Society Focused Meeting to commemorate the 200th Anniversary of Charles Darwin's birth, held on 26-27 January 2009 at the Wellcome Trust Conference Centre, Cambridge. The talks reported on some of the insights into evolution which have been obtained from the study of protein sequences, structures and systems. PMID:19614583

  20. Comparison between analytical and test results for transformer base details

    International Nuclear Information System (INIS)

    A caveat concerning weak-way bending of sheet metal transformer base details is included in the Generic Implementation Procedure (GIP) for resolution of Unresolved Safety Issue (USI) A-46. The weak-way bending caveat originated from a concern by the Senior Seismic Review and Advisory Panel (SSRAP). Transformer base details have, however, performed satisfactorily during past strong motion earthquakes. A transformer with thin sheet metal base supports without bracing for lateral forces was recently evaluated for seismic adequacy. Simple analyses indicated very high stresses and field conditions (lack of washers) raised the potential for sheet metal pull-through at the anchor bolts. Shake table testing was therefore performed to confirm that transformer base details have much higher seismic capacity than indicated by linear-elastic analysis. This paper will compare the analytically predicted performance of thin sheet metal transformer supports to the actual performance observed in past strong motion earthquakes; laboratory shake table test data is also presented as confirmation of the experience data

  1. Relationship between weight, age and hatching success and the concentration of heavy metals in nestling blue macaw (Anodorhynchus hyacinthinus Latham, 1790 in the Pantanal,Mato Grosso do Sul

    Directory of Open Access Journals (Sweden)

    Marina Drago Marchesi

    2015-06-01

    Full Text Available Abstract: The concentration of heavy metals (Cr, Fe, Al, As, Cd, Cu, Pb, Mo, Ni, Se and Zn was evaluated in the blood of nestling blue macaws (Anodorhynchus hyacinthinus captured in the Pantanal, Mato Grosso do Sul (n=26 in 2012; this was based on the hypothesis that these birds exhibit levels of these heavy metals in their organism and that these interfere in hatching success, weight and age of the chicks. Blood samples were digested with nitric acid and hydrochloric acid and the quantification of metals was performed by ICP-OES (Optical Emission Spectroscopy and Inductively Coupled Plasma. Blood samples of nestlings showed concentrations of Cr (0.10μg/g Fe (3.06μg/g Al (3.46μg/g, Cd (0.25μg/g Cu (0.74μg/g, Mo (0.33μg/g, Ni (0.61μg/g, Se (0.98μg/g, and Zn (2.08μg/g. The levels of heavy metals found were not associated with weight, age and hatching success of the chicks.

  2. Storage of hydrogen isotopes. Investigation of the aging behaviour of metallic tritides; Stockage des isotopes de l'hydrogene etude du vieillissement des tritiures metalliques

    Energy Technology Data Exchange (ETDEWEB)

    Thiebaut, St.

    2010-06-15

    This report aims at giving a synthesis of scientific works performed by the author while indicating the reasons for his choice of research topics, and the perspectives which could be interesting to follow. After an overview of his professional course, the author proposes an analysis of the available literature at the time he started his research works. Then, he comments the results he obtained during his research thesis in the field of short duration aging (more precisely with experimental investigations on the aging behaviour of palladium and palladium alloys which are used in tritium storage). The following periods of his research career dealt with long duration aging, and then with aging modelling

  3. Ageing of metal / ultra thin oxides / semiconductor structures under current injection by Fowler-Nordheim effect and X rays irradiation; Vieillissement des structures metal / oxyde ultra-mince / semiconducteur sous injection de courants par effet fowler-nordheim et irradiation par rayons X

    Energy Technology Data Exchange (ETDEWEB)

    Kassmi, K.; Maimouni, R. [Laboratoire d`electronique appliquee L.E.A.A., (Morocco); Sarrabayrouse, G. [Centre National de la Recherche Scientifique (CNRS), 31 - Toulouse (France). Lab. d`Automatique et d`Analyse des Systemes

    1995-12-31

    In this paper, we are investigating the aging effect by injection of currents (by Fowler-Nordheim FN effect) and irradiation (by X-rays) on metal / ultra thin oxide / semiconductor structures with oxide layers of thickness lying between 40 and 120 angstrom. We are particularly presenting the influence of oxide layer thickness, the dose of irradiation on the degradation of both oxide and oxide-semiconductor interface. (author). 15 refs.

  4. Gestational age

    Science.gov (United States)

    Fetal age - gestational age; Gestation; Neonatal gestational age; Newborn gestational age ... Gestational age can be determined before or after birth. Before birth, your health care provider will use ...

  5. Monte Carlo methods beyond detailed balance

    NARCIS (Netherlands)

    Schram, Raoul D.; Barkema, Gerard T.

    2015-01-01

    Monte Carlo algorithms are nearly always based on the concept of detailed balance and ergodicity. In this paper we focus on algorithms that do not satisfy detailed balance. We introduce a general method for designing non-detailed balance algorithms, starting from a conventional algorithm satisfying

  6. The Age-Mass-Metallicity-Activity relation of solar-type stars: Comparisons with asteroseismology and the NGC 188 open cluster

    CERN Document Server

    Lorenzo-Oliveira, Diego; Schiavon, Ricardo P

    2016-01-01

    The Mount Wilson Ca II index log$(R'_{\\rm HK})$ is the accepted standard metric of calibration for the chromospheric activity versus age relation of FGK stars. Recent results claim its inability to discern activity levels, and thus ages, for stars older than $\\sim$2 Gyr, which would severely hamper its application to date disk stars older than the Sun. We present a new activity-age calibration of the Mt. Wilson index explicitly taking into account mass and $[$Fe/H$]$ biases, implicit in samples of stars selected to have precise ages, that have so far gone unappreciated. We show that these selection biases tend to blur the activity-age relation for large age ranges. We calibrate the Mt. Wilson index for a sample of field FGK stars with precise ages, covering a wide range of mass and $[$Fe/H$]$, augmented with data from the Pleiades, Hyades, M67 clusters, and the Ursa Major moving group. We further test the calibration with extensive new Gemini/GMOS log$(R'_{\\rm HK})$ data of the old, solar $[$Fe/H$]$ clusters ...

  7. Technology of Strengthening Steel Details by Surfacing Composite Coatings

    Science.gov (United States)

    Burov, V. G.; Bataev, A. A.; Rakhimyanov, Kh M.; Mul, D. O.

    2016-04-01

    The article considers the problem of forming wear resistant meal ceramic coatings on steel surfaces using the results of our own investigations and the analysis of achievements made in the country and abroad. Increasing the wear resistance of surface layers of steel details is achieved by surfacing composite coatings with carbides or borides of metals as disperse particles in the strengthening phase. The use of surfacing on wearing machine details and mechanisms has a history of more than 100 years. But still engineering investigations in this field are being conducted up to now. The use of heating sources which provide a high density of power allows ensuring temperature and time conditions of surfacing under which composites with peculiar service and functional properties are formed. High concentration of energy in the zone of melt, which is created from powder mixtures and the hardened surface layer, allows producing the transition zone between the main material and surfaced coating. Surfacing by the electron beam directed from vacuum to the atmosphere is of considerable technological advantages. They give the possibility of strengthening surface layers of large-sized details by surfacing powder mixtures without their preliminary compacting. A modified layer of the main metal with ceramic particles distributed in it is created as a result of heating surfaced powders and the detail surface layer by the electron beam. Technology of surfacing allows using powders of refractory metals and graphite in the composition of powder mixtures. They interact with one another and form the particles of the hardening phase of the composition coating. The chemical composition of the main and surfaced materials is considered to be the main factor which determines the character of metallurgical processes in local zones of melt as well as the structure and properties of surfaced composition.

  8. Physical aging in Zr46.75Ti8.25Cu7.5Ni10Be27.5 typical bulk metallic glass manifested as enthalpy relaxation

    Institute of Scientific and Technical Information of China (English)

    WEN Ping; ZHAO ZuoFeng; WANG WeiHua

    2008-01-01

    Enthalpy recovery is not only an important characteristic of physical aging of glass, but also a good tool to investigate the physical aging. Using differential scanning calorimeter (DSC), the enthalpy recovery of Zr46.75Ti8.25Cu7.5Ni10Be27.5 bulk metallic glass (BMG) was studied. The typical characteristics of enthalpy recovery of glass including the sub-Tg peak and 'overshot' were found in BMG. The evolution of the sub-Tg peak and 'overshot' were described by the free volume theory and Hodge's model, respectively. It was found that the former failed to describe the enthalpy recovery in the BeG, while the latter could give a qualitative explanation. In com-bination with the dynamics in the BMG, the origin of the enthalpy recovery in the BMG was discussed. The results show that BMGs are an ideal material to investi-gate the physical aging. The further understanding of physical aging of BMGs is useful to clarify the nature of glass and improve the application and device of new types of BMGs.

  9. Physical aging in Zr46.75Ti8.25Cu7.5Ni10Be27.5 typical bulk metallic glass manifested as enthalpy relaxation

    Institute of Scientific and Technical Information of China (English)

    2008-01-01

    Enthalpy recovery is not only an important characteristic of physical aging of glass,but also a good tool to investigate the physical aging. Using differential scanning calorimeter (DSC),the enthalpy recovery of Zr46.75Ti8.25Cu7.5Ni10Be27.5 bulk metallic glass (BMG) was studied. The typical characteristics of enthalpy recovery of glass including the sub-Tg peak and ‘overshot’ were found in BMG. The evolution of the sub-Tg peak and ‘overshot’ were described by the free volume theory and Hodge’s model,respectively. It was found that the former failed to describe the enthalpy recovery in the BMG,while the latter could give a qualitative explanation. In com-bination with the dynamics in the BMG,the origin of the enthalpy recovery in the BMG was discussed. The results show that BMGs are an ideal material to investi-gate the physical aging. The further understanding of physical aging of BMGs is useful to clarify the nature of glass and improve the application and device of new types of BMGs.

  10. Detailed Properties of Populous Clusters in the Large Magellanic Cloud

    Science.gov (United States)

    Grocholski, Aaron J.; Sarajedini, A.; Cole, A. A.; Geisler, D.; Olsen, K. A.; Tiede, G. P.; Smith, V. V.; Mancone, C. L.

    2006-12-01

    We present results from a program aimed at better understanding the ages, velocities, metallicities and distances of populous clusters in the LMC. In an effort to update previous [Fe/H] determinations, we have used the FORS2 instrument on the VLT to obtain near infrared spectra for more than 200 stars in 28 LMC clusters. The absorption lines of the Ca II Triplet were then used to calculate velocities and abundances for a sample of clusters spanning a large range of ages ( 1-13 Gyr) and metallicities (-0.3 ≥ [Fe/H] ≥ -2.0). To calculate cluster ages, we have compiled deep optical photometry for 15 LMC clusters using a combination of published photometry, VLT/FORS2 images and archival HST/WFPC2 images. These data, in conjunction with our derived metallicities, have allowed us to determine accurate cluster ages via main sequence fitting with theoretical isochrones. Finally, we have used the K-band luminosity of core helium burning red clump (RC) stars to determine distances for 17 LMC clusters. Using ISPI on the CTIO 4m, we obtained near infrared (JK) photometry down to K 18.5, which allowed us to measure the apparent K-band RC magnitude of each cluster. In addition, age and abundance can be used to predict the absolute K-band RC magnitude of a given cluster; thus, we have combined the apparent and absolute magnitudes with cluster reddenings and calculated the distance to each individual cluster. These distances are used to probe the structure of the LMC as traced by its cluster population. This work is supported by NSF CAREER grant AST-0094048 to Ata Sarajedini.

  11. Tritium in metals

    International Nuclear Information System (INIS)

    In this Chapter a review is given of some of the important features of metal tritides as opposed to hydrides and deuterides. After an introduction to the topics of tritium and tritium in metals information will be presented on a variety of metal-tritium systems. Of main interest here are the differences from the classic hydrogen behavior; the so called isotope effect. A second important topic is that of aging effects produced by the accumulation of 3He in the samples. (orig.)

  12. Nabokov's Details: Making Sense of Irrational Standards

    OpenAIRE

    Horgan, Pelagia

    2012-01-01

    Vladimir Nabokov's passion for detail is well-known, central to our very idea of the "Nabokovian." Yet Nabokov's most important claims for detail pose a challenge for the reader who would take them seriously. Startlingly extreme and deliberately counterintuitive -- Nabokov called them his "irrational standards" -- these claims push the very limits of reason and belief. Nabokov's critics have tended to treat his more extravagant claims for detail -- including his assertion that the "capacity t...

  13. Displaying of Details in Subvoxel Accuracy

    Institute of Scientific and Technical Information of China (English)

    蔡文立; 陈天洲; 等

    1996-01-01

    Under the volume segmentation in voxel space,a lot of details,some fine and thin objects,are ignored.In order to accurately display these details,this paper has developed a methodology for volume segmentation in subvoxel space.In the subvoxel space,most of the “bridges”between adjacent layers are broken down.Based on the subvoxel space,an automatic segmentation algorithm reserving details is discussed.After segmentation,volume data in subvoxel space are reduced to original voxel space.Thus,the details with width of only one or several voxels are extracted and displayed.

  14. Evaluating sol-gel ceramic thin films for metal implant applications: III. In vitro aging of sol-gel-derived zirconia films on Ti-6Al-4V.

    Science.gov (United States)

    Kirk, P B; Filiaggi, M J; Sodhi, R N; Pilliar, R M

    1999-01-01

    Sol-gel-derived zirconia films were deposited onto polished Ti-6Al-4V substrates by dip-coating from an alkoxide precursor solution. No change in morphology of the zirconia film was observed after aging at 37 degrees C for 4-12 weeks in pH 4.0 buffer solution or Hanks' balanced salt solution (HBSS), although a precipitate predominantly composed of calcium phosphate was formed on those films aged in HBSS. X-ray diffraction identified the phase of the zirconia film as either cubic or tetragonal, and revealed no degradation to the monoclinic phase after aging. By a substrate straining test, the fracture strain of the coating was revealed to be 1.5%, above the yield strain of the titanium alloy substrate. At this strain level, through-thickness cracks formed in the coating where slip bands emerged from the substrate. Qualitatively, the adhesion of the film was sufficient to prevent gross delamination of the film at high strain levels, although small regions of delamination were caused by compressive buckling of the film. This behavior indicates generally good adhesion. No change in this behavior was observed after aging.

  15. Isotope age of the rare metal pegmatite formation in the Kolmozero-Voron'ya greenstone belt (Kola region of the Fennoscandian shield): U-Pb (TIMS) microlite and tourmaline dating

    Science.gov (United States)

    Kudryashov, Nikolay; Lyalina, Ludmila; Mokrushin, Artem; Zozulya, Dmitry; Groshev, Nikolay; Steshenko, Ekaterina; Kunakkuzin, Evgeniy

    2016-04-01

    The Kolmozero-Voron'ya greenstone belt is located in the central suture zone, which separates the Murmansk block from the Central-Kola and the Keivy blocks. The belt is represented by volcano-sedimentary rocks of Archaean age of 2.9-2.5 Ga. Rare metal pegmatites (Li, Cs with accessory Nb, Ta, and Be) occur among amphibolite and gabbroid intrusions in the northwestern and southeastern parts of the belt. According to the Rb-Sr data, the age of pegmatites was considered to be 2.7 Ga. Until recently there was no generally accepted point of view on the origin of pegmatites. Now we have isotopic data for a range of rock complexes that could pretend to be parental granites for the rare metal pegmatites. These are granodiorites with the zircon age of 2733±Ma, and microcline and tourmaline granites, which Pb-Pb isochronal age on tourmaline from the tourmaline granite located near the deposit is estimated to be 2520±70 Ma. The pegmatite field of the Vasin Myl'k deposit with the lepidolite--albite--microcline--spodumene--pollucite association is located among amphibolites in the northwestern part of the belt. The deposit is represented by subparallel low-angle zoned veins up to 220 m long and 5 m thick dipping in the southeastern direction at an angle of 10° too 30°. The minerals of the columbite--tonalite group from Vasin Myl'k deposit include microlite, simpsonite, and torolite, and are the oldest among different minerals represented by several generations in pegmatites under consideration. Zircons from the pegmatites are mostly represented by crystals with the structure affected by the action of fluids that put certain restrictions on its use as a geochronometer of the crystallization process. Microlite from the pegmatite taken from the dump of a prospecting drill hole was used for U--Pb (TIMS). The mineral is represented by 0.5--1.0 mm long euhedral octahedral crystals. It is brown in color, and transparent. The microlite crystals were preliminarily cleaned from

  16. Detailed Analysis of Motor Unit Activity

    DEFF Research Database (Denmark)

    Nikolic, Mile; Sørensen, John Aasted; Dahl, Kristian;

    1997-01-01

    System for decomposition of EMG signals intotheir constituent motor unit potentials and their firing patterns.The aim of the system is detailed analysis ofmotor unit variability.......System for decomposition of EMG signals intotheir constituent motor unit potentials and their firing patterns.The aim of the system is detailed analysis ofmotor unit variability....

  17. Understanding brains: details, intuition, and big data.

    Directory of Open Access Journals (Sweden)

    Eve Marder

    2015-05-01

    Full Text Available Understanding how the brain works requires a delicate balance between the appreciation of the importance of a multitude of biological details and the ability to see beyond those details to general principles. As technological innovations vastly increase the amount of data we collect, the importance of intuition into how to analyze and treat these data may, paradoxically, become more important.

  18. Provenance of early bronze age metal artefacts in western Switzerland using elemental and lead isotopic compositions and their possible relation with copper minerals of the nearby Valais

    OpenAIRE

    Cattin, Florence; Guénette-Beck, Barbara; Curdy, Philippe; Meisser, Nicolas; Ansermet, Stefan; Hofmann, Beda; Kündig, Rainer; Hubert, Vera; Wörle, Marie; Hametner, Kathrin; Günther, Detlef; Wichser, Adrian; Ulrich, Andrea; Villa, Igor M.; Besse, Marie

    2011-01-01

    Ten Early Bronze Age (BzA1, 2200-2000 BC) copper artefacts from the central Valais region from Switzerland were studied for their elemental composition and lead isotope ratios. In order to answer the archaeological question of a local copper supply, a database for copper minerals across the Valais (Switzerland) has been established. This database contains 69 data on lead isotope ratios as well as additional information on the minerals and geochemical associations for copper minerals from 38 l...

  19. Aging Skin

    Science.gov (United States)

    ... email address Submit Home > Healthy Aging > Wellness Healthy Aging Aging skin More information on aging skin When it ... treated early. Return to top More information on Aging skin Read more from womenshealth.gov Varicose Veins ...

  20. Atomic diffusion in metal poor stars The influence on the Main Sequence fitting distance scale, subdwarfs ages and the value of Delta Y/DeltaZ

    CERN Document Server

    Salaris, M; Weiss, A

    2000-01-01

    The effect of atomic diffusion on the Main Sequence (MS) of metal-poor low mass stars is investigated. Since diffusion alters the stellar surface chemical abundances with respect to their initial values, one must ensure - by calibrating the initial chemical composition of the theoretical models - that the surface abundances of the models match the observed ones of the stellar population under scrutiny. Since the observed surface abundances of subdwarfs are different from the initial ones due to the effect of diffusion, while the globular clusters stellar abundances are measured in Red Giants, which have practically recovered their initial abundances after the dredge-up, the isochrones to be employed for studying globular clusters and Halo subdwarfs with the same observational value of [Fe/H] are different and do not coincide. We find, however,that the current MS-fitting distances derived from HIPPARCOS subdwarfs using colour corrections from standard isochrones are basically unaltered when diffusion is taken ...

  1. Post Entitlement Management Information - Detail Database

    Data.gov (United States)

    Social Security Administration — Contains data that supports the detailed and aggregate receipt, pending and clearance data, as well as other strategic and tactical MI for many Title II and Title...

  2. Fine phonetic detail and intonational meaning

    OpenAIRE

    Post, B.M.B.; Imperio, M. d'; Gussenhoven, C.

    2007-01-01

    International audience The development of theories about form-function relations in intonation should be informed by a better understanding of the dependencies that hold among different phonetic parameters. Fine phonetic detail encodes both linguistically structured meaning and paralinguistic meaning.

  3. Template Assembly for Detailed Urban Reconstruction

    KAUST Repository

    Nan, Liangliang

    2015-05-04

    We propose a new framework to reconstruct building details by automatically assembling 3D templates on coarse textured building models. In a preprocessing step, we generate an initial coarse model to approximate a point cloud computed using Structure from Motion and Multi View Stereo, and we model a set of 3D templates of facade details. Next, we optimize the initial coarse model to enforce consistency between geometry and appearance (texture images). Then, building details are reconstructed by assembling templates on the textured faces of the coarse model. The 3D templates are automatically chosen and located by our optimization-based template assembly algorithm that balances image matching and structural regularity. In the results, we demonstrate how our framework can enrich the details of coarse models using various data sets.

  4. Eros details enhanced by computer processing

    Science.gov (United States)

    2000-01-01

    The NEAR camera's ability to show details of Eros's surface is limited by the spacecraft's distance from the asteroid. That is, the closer the spacecraft is to the surface, the more that details are visible. However mission scientists regularly use computer processing to squeeze an extra measure of information from returned data. In a technique known as 'superresolution', many images of the same scene acquired at very, very slightly different camera pointing are carefully overlain and processed to bright out details even smaller than would normally be visible. In this rendition constructed out of 20 image frames acquired Feb. 12, 2000, the images have first been enhanced ('high-pass filtered') to accentuate small-scale details. Superresolution was then used to bring out features below the normal ability of the camera to resolve.Built and managed by The Johns Hopkins University Applied Physics Laboratory, Laurel, Maryland, NEAR was the first spacecraft launched in NASA's Discovery Program of low-cost, small-scale planetary missions. See the NEAR web page at http://near.jhuapl.edu for more details.

  5. Structural detailing of openings in sandwich panels

    NARCIS (Netherlands)

    Tomà, T.; Courage, W.

    1996-01-01

    European Recommendations exist which provide calculation rules to determine the strength and stiffness of sandwich panels composed of two metal faces with a foam in between. In case of openings in such panels (e.g. for windows) an influence will appear with regard to the stiffness and loadbearing ca

  6. Contribution to a Theory of Detailed Design

    DEFF Research Database (Denmark)

    Mortensen, Niels Henrik

    1999-01-01

    It has been recognised, that literature actually do not propose a theory of detailed design. In this paper a theory contribution is proposed, linking part design to organ design and allowing a type of functional reasoning. The proposed theory satisfies our need for explaining the nature of a part...... structure, for support of synthesis of part structure, i.e. detailed design, and our need for digital modelling of part structures.The aim of this paper is to contribute to a design theory valid for detailed design. The proposal is based upon the theory's ability to explain the nature of machine parts...... and assemblies, to support the synthesis of parts and to allow the modelling, especially digital modelling of a part structure. The contribution is based upon Theory of Technical Systems, Hubka, and the Domain Theory, Andreasen. This paper is based on a paper presented at ICED 99, Mortensen, but focus...

  7. Fatigue-Prone Details in Steel Bridges

    Directory of Open Access Journals (Sweden)

    Mohsen Heshmati

    2012-11-01

    Full Text Available This paper reviews the results of a comprehensive investigation including more than 100 fatigue damage cases, reported for steel and composite bridges. The damage cases are categorized according to types of detail. The mechanisms behind fatigue damage in each category are identified and studied. It was found that more than 90% of all reported damage cases are of deformation-induced type and generated by some kind of unintentional or otherwise overlooked interaction between different load-carrying members or systems in the bridge. Poor detailing, with unstiffened gaps and abrupt changes in stiffness at the connections between different members were also found to contribute to fatigue cracking in many details.

  8. Local address and emergency contact details

    CERN Multimedia

    2013-01-01

    The HR Department would like to remind members of the personnel that they are responsible for ensuring that their personal data concerning local address and preferred emergency contact details remains valid and up-to-date.   Both are easily accessible via the links below: Local address: https://edh.cern.ch/Document/Personnel/LocalAddressChange   Emergency contacts: https://edh.cern.ch/Document/Personnel/EC   Please take a few minutes to check your details and modify if necessary. Thank you in advance. HR Department Head Office

  9. Detail in architecture: Between arts & crafts

    Science.gov (United States)

    Dulencin, Juraj

    2016-06-01

    Architectural detail represents an important part of architecture. Not only can it be used as an identifier of a specific building but at the same time enhances the experience of the realized project. Within it lie the signs of a great architect and clues to understanding his or her way of thinking. It is therefore the central topic of a seminar offered to architecture students at the Brno University of Technology. During the course of the semester-long class the students acquaint themselves with atypical architectural details of domestic and international architects by learning to read them, understand them and subsequently draw them by creating architectural blueprints. In other words, by general analysis of a detail the students learn theoretical thinking of its architect who, depending on the nature of the design, had to incorporate a variety of techniques and crafts. Students apply this analytical part to their own architectural detail design. The methodology of the seminar consists of experiential learning by project management and is complemented by a series of lectures discussing a diversity of details as well as materials and technologies required to implement it. The architectural detail design is also part of students' bachelors thesis, therefore, the realistic nature of their blueprints can be verified in the production process of its physical counterpart. Based on their own documentation the students choose the most suitable manufacturing process whether it is supplied by a specific technology or a craftsman. Students actively participate in the production and correct their design proposals in real scale with the actual material. A student, as a future architect, stands somewhere between a client and an artisan, materializes his or her idea and adjusts the manufacturing process so that the final detail fulfills aesthetic consistency and is in harmony with its initial concept. One of the very important aspects of the design is its economic cost, an

  10. 不同棚龄土壤重金属含量变化及污染评价%Content Changes and Pollution Evaluation of Heavy-metals in Different Cultivation Ages of Greenhouse Soils

    Institute of Scientific and Technical Information of China (English)

    方勇

    2012-01-01

    The status quo of heavy-metals accumulation in the different cultivation ages of greenhouse soils from Jinhua suburb was studied. The results showed that when applying manures from big scale farm to the greenhouse soil, the contents of heavy-metals (Cr, Pb and Cu) in greenhouse soil increased with increasing cultivation age (0-8 years), and there were significant positive correlation between them; particularly, when Cu content in the soil increased at an average annual rate of 7.565mg/kg, the Cu content in 24.14% of the greenhouse soil exceeded standard, but the change of Cd content had no apparent regularity; 75% of the greenhouse soil with five years cultivation age reached the second level of warning limit, and 100% of the greenhouse' soil with eight years cultivation age exceeded the warning limit level. Therefore, under the present cultivation management conditions, the greenhouse cultivation will lead the accumulation of heavy metals, and critical period of the greenhouse soil for clean use was about five years. It suggested that during cultivation process in the greenhouse, using organic fertilizers, such as composting manures, as much as possible; meanwhile, adopting some measures timely, such as irrigation treatment, applying lime nitrogen and phytoremediation, to ensure the ecological safety of the greenhouse soil.%为揭示设施大棚中土壤重金属的变化趋势,采用单因子污染指数和综合污染指数法研究了浙江金华市郊不同棚龄的设施大棚土壤中污染重金属的积累现状.结果表明,设施大棚中施用规模化养殖畜禽粪,使土壤重金属(Cr、Pb、Cu)含量随棚龄(0~8 a)增加而递增,且两者之间呈显著的正相关关系,特别是土壤Cu含量平均以7.565 mg/(kg·a)的速度增加,导致有24.14%的设施土壤Cu含量超标;而Cd含量变化没有明显的规律性.并且,5a棚龄设施土壤有75%达污染警戒限水平(2级),而棚龄8a设施土壤100%都达到或

  11. Surface Detail Capturing for Realistic Facial Animation

    Institute of Scientific and Technical Information of China (English)

    Pei-Hsuan Tu; I-Chen Lin; Jeng-Sheng Yeh; Rung-Huei Liang; Ming Ouhyoung

    2004-01-01

    In this paper, a facial animation system is proposed for capturing both geometrical information and illumination changes of surface details, called expression details, from video clips simultaneously, and the captured data can be widely applied to different 2D face images and 3D face models. While tracking the geometric data,we record the expression details by ratio images. For 2D facial animation synthesis, these ratio images are used to generate dynamic textures. Because a ratio image is obtained via dividing colors of an expressive face by those of a neutral face, pixels with ratio value smaller than one are where a wrinkle or crease appears. Therefore, the gradients of the ratio value at each pixel in ratio images are regarded as changes of a face surface, and original normals on the surface can be adjusted according to these gradients. Based on this idea, we can convert the ratio images into a sequence of normal maps and then apply them to animated 3D model rendering. With the expression detail mapping, the resulted facial animations are more life-like and more expressive.

  12. New details emerge from the Einstein files

    CERN Multimedia

    Overbye, D

    2002-01-01

    For many years the FBI spied on Einstein. New details of this surveilance are emerging in "The Einstein File: J. Edgar Hoover's Secret War Against the World's Most Famous Scientist," by Fred Jerome, who sued the government with the help of the Public Citizen Litigation Group to obtain a less censored version of the file (1 page).

  13. Big Heads, Small Details and Autism

    Science.gov (United States)

    White, Sarah; O'Reilly, Helen; Frith, Uta

    2009-01-01

    Autism is thought to be associated with a bias towards detail-focussed processing. While the cognitive basis remains controversial, one strong hypothesis is that there are high processing costs associated with changing from local into global processing. A possible neural mechanism underlying this processing style is abnormal neural connectivity;…

  14. Dwarf galaxies around the Milky Way: linking ages, kinematics and chemistry

    Science.gov (United States)

    Hill, Vanessa

    2015-08-01

    I will review recent observations of stellar populations in dwarf galaxies around the Milky Way, with special emphasis on the picture emerging for the evolution of these systems when combining kinematics, metallicities, detailed abundances and ages for large samples of stars. Very recently, the conditions in these systems at the earliest epochs have been the subject of dedicated investigations, in the form of observing extremely-metal poor stars in dwarf galaxies, and I will review with special care this area, including the apparent carbon paucity in some dwarf galaxies (eg. Sculptor). Finally, I will highlight the expected return from the Gaia space astrometric mission for our understanding of nearby dwarf galaxies.

  15. Protein oxidation and ageing

    DEFF Research Database (Denmark)

    Linton, S; Davies, Michael Jonathan; Dean, R T

    2001-01-01

    of redox-active metal ions that could catalyse oxidant formation. As a result of this decrease in antioxidant defences, and increased rate of ROS formation, it is possible that the impact of ROS increases with age. ROS are known to oxidise biological macromolecules, with proteins an important target....... If the argument that the impact of ROS increases with age is true, then proteins would be expected to accumulate oxidised materials with age, and the rate of such accumulation should increase with time, reflecting impaired inefficiency of homeostasis. Here we review the evidence for the accumulation of oxidised......, or modified, extra- and intra-cellular proteins in vivo....

  16. Perceived age as a biomarker of ageing: a clinical methodology

    DEFF Research Database (Denmark)

    Gunn, David A; Murray, Peter G; Tomlin, Cyrena C;

    2008-01-01

    of facial ageing is detailed. The methodology utilises facial photographs of subjects to present images to large numbers of age assessors who are primarily nationals of the country of study origin. In five observational studies in five different countries involving 874 female subjects it was found...... measure when large numbers of adult age assessors are used and can be utilised globally in studies to investigate facial ageing....

  17. Detailed sectional anatomy of the spine

    International Nuclear Information System (INIS)

    Morphologic studies on the human spine constitute a special challenge because of the spine's complex topographic anatomy and the intimate relationship between the supporting skeleton and the contiguous soft tissues (muscles, discs, joint capsules) as well as the neurovascular contents of the spinal canal and intervertebral foramina. The improving resolution and multiplanar image reformatting capabilities of modern CT scanners call for accurate anatomic reference material. Such anatomic images should be available without distortion, in natural colors, and in considerable detail. The images should present the anatomy in the correct axial, sagittal, and coronal planes and should also be sufficiently closely spaced so as to follow the thin cuts of modern CT scanners. This chapter details one of several recent attempts to correlate gross anatomy with the images depicted by high-resolution CT. The methods of specimen preparation, sectioning, and photographing have been documented elsewhere

  18. Thirty Meter Telescope Detailed Science Case: 2015

    CERN Document Server

    Skidmore, Warren; Fukugawa, Misato; Goswami, Aruna; Hao, Lei; Jewitt, David; Laughlin, Greg; Steidel, Charles; Hickson, Paul; Simard, Luc; Schöck, Matthias; Treu, Tommaso; Cohen, Judith; Anupama, G C; Dickinson, Mark; Harrison, Fiona; Kodama, Tadayuki; Lu, Jessica R; Macintosh, Bruce; Malkan, Matt; Mao, Shude; Narita, Norio; Sekiguchi, Tomohiko; Subramaniam, Annapurni; Tanaka, Masaomi; Tian, Feng; A'Hearn, Michael; Akiyama, Masayuki; Ali, Babar; Aoki, Wako; Bagchi, Manjari; Barth, Aaron; Bhalerao, Varun; Bradac, Marusa; Bullock, James; Burgasser, Adam J; Chapman, Scott; Chary, Ranga-Ram; Chiba, Masashi; Cooray, Asantha; Crossfield, Ian; Currie, Thayne; Das, Mousumi; Dewangan, G C; de Grijs, Richard; Do, Tuan; Dong, Subo; Evslin, Jarah; Fang, Taotao; Fang, Xuan; Fassnacht, Christopher; Fletcher, Leigh; Gaidos, Eric; Gal, Roy; Ghez, Andrea; Giavalisco, Mauro; Grady, Carol A; Greathouse, Thomas; Gogoi, Rupjyoti; Guhathakurta, Puragra; Ho, Luis; Hasan, Priya; Herczeg, Gregory J; Honda, Mitsuhiko; Imanishi, Masa; Inanmi, Hanae; Iye, Masanori; Kamath, U S; Kane, Stephen; Kashikawa, Nobunari; Kasliwal, Mansi; Kirby, Vishal KasliwalEvan; Konopacky, Quinn M; Lepine, Sebastien; Li, Di; Li, Jianyang; Liu, Junjun; Liu, Michael C; Lopez-Rodriguez, Enrigue; Lotz, Jennifer; Lubin, Philip; Macri, Lucas; Maeda, Keiichi; Marchis, Franck; Marois, Christian; Marscher, Alan; Martin, Crystal; Matsuo, Taro; Max, Claire; McConnachie, Alan; McGough, Stacy; Melis, Carl; Meyer, Leo; Mumma, Michael; Muto, Takayuki; Nagao, Tohru; Najita, Joan R; Navarro, Julio; Pierce, Michael; Prochaska, Jason X; Oguri, Masamune; Ojha, Devendra K; Okamoto, Yoshiko K; Orton, Glenn; Otarola, Angel; Ouchi, Masami; Packham, Chris; Padgett, Deborah L; Pandey, Shashi Bhushan; Pilachowsky, Catherine; Pontoppidan, Klaus M; Primack, Joel; Puthiyaveettil, Shalima; Ramirez-Ruiz, Enrico; Reddy, Naveen; Rich, Michael; Richter, Matthew J; Schombert, James; Sen, Anjan Ananda; Shi, Jianrong; Sheth, Kartik; Srianand, R; Tan, Jonathan C; Tanaka, Masayuki; Tanner, Angelle; Tominaga, Nozomu; Tytler, David; U, Vivian; Wang, Lingzhi; Wang, Xiaofeng; Wang, Yiping; Wilson, Gillian; Wright, Shelley; Wu, Chao; Wu, Xufeng; Xu, Renxin; Yamada, Toru; Yang, Bin; Zhao, Gongbo; Zhao, Hongsheng

    2015-01-01

    The TMT Detailed Science Case describes the transformational science that the Thirty Meter Telescope will enable. Planned to begin science operations in 2024, TMT will open up opportunities for revolutionary discoveries in essentially every field of astronomy, astrophysics and cosmology, seeing much fainter objects much more clearly than existing telescopes. Per this capability, TMT's science agenda fills all of space and time, from nearby comets and asteroids, to exoplanets, to the most distant galaxies, and all the way back to the very first sources of light in the Universe. More than 150 astronomers from within the TMT partnership and beyond offered input in compiling the new 2015 Detailed Science Case. The contributing astronomers represent the entire TMT partnership, including the California Institute of Technology (Caltech), the Indian Institute of Astrophysics (IIA), the National Astronomical Observatories of the Chinese Academy of Sciences (NAOC), the National Astronomical Observatory of Japan (NAOJ),...

  19. Detailed Electrochemical Characterisation of Large SOFC Stacks

    DEFF Research Database (Denmark)

    Mosbæk, Rasmus Rode; Hjelm, Johan; Barfod, R.;

    2012-01-01

    application of advanced methods for detailed electrochemical characterisation during operation. An operating stack is subject to steep compositional gradients in the gaseous reactant streams, and significant temperature gradients across each cell and across the stack, which makes it a complex system...... Fuel Cell A/S was characterised in detail using electrochemical impedance spectroscopy. An investigation of the optimal geometrical placement of the current probes and voltage probes was carried out in order to minimise measurement errors caused by stray impedances. Unwanted stray impedances...... are particularly problematic at high frequencies. Stray impedances may be caused by mutual inductance and stray capacitance in the geometrical set-up and do not describe the fuel cell. Three different stack geometries were investigated by electrochemical impedance spectroscopy. Impedance measurements were carried...

  20. Langevin dynamics neglecting detailed balance condition.

    Science.gov (United States)

    Ohzeki, Masayuki; Ichiki, Akihisa

    2015-07-01

    An improved method for driving a system into a desired distribution, for example, the Gibbs-Boltzmann distribution, is proposed, which makes use of an artificial relaxation process. The standard techniques for achieving the Gibbs-Boltzmann distribution involve numerical simulations under the detailed balance condition. In contrast, in the present study we formulate the Langevin dynamics, for which the corresponding Fokker-Planck operator includes an asymmetric component violating the detailed balance condition. This leads to shifts in the eigenvalues and results in the acceleration of the relaxation toward the steady state. The numerical implementation demonstrates faster convergence and shorter correlation time, and the technique of biased event sampling, Nemoto-Sasa theory, further highlights the efficacy of our method. PMID:26274123

  1. Fatigue-Prone Details in Steel Bridges

    OpenAIRE

    Mohsen Heshmati; Mohammad Al-Emrani; Reza Haghani

    2012-01-01

    This paper reviews the results of a comprehensive investigation including more than 100 fatigue damage cases, reported for steel and composite bridges. The damage cases are categorized according to types of detail. The mechanisms behind fatigue damage in each category are identified and studied. It was found that more than 90% of all reported damage cases are of deformation-induced type and generated by some kind of unintentional or otherwise overlooked interaction between different load-carr...

  2. Detailed Jet Dynamics in a Collapsing Bubble

    Science.gov (United States)

    Supponen, Outi; Obreschkow, Danail; Kobel, Philippe; Farhat, Mohamed

    2015-12-01

    We present detailed visualizations of the micro-jet forming inside an aspherically collapsing cavitation bubble near a free surface. The high-quality visualizations of large and strongly deformed bubbles disclose so far unseen features of the dynamics inside the bubble, such as a mushroom-like flattened jet-tip, crown formation and micro-droplets. We also find that jetting near a free surface reduces the collapse time relative to the Rayleigh time.

  3. Thirty Meter Telescope Detailed Science Case: 2015

    OpenAIRE

    Skidmore, Warren; Dell'Antonio, Ian; Fukugawa, Misato; Goswami, Aruna; Hao, Lei; Jewitt, David; Laughlin, Greg; Steidel, Charles; Hickson, Paul; Simard, Luc; Schöck, Matthias; Treu, Tommaso; Cohen, Judith; Anupama, G. C; Dickinson, Mark

    2015-01-01

    The TMT Detailed Science Case describes the transformational science that the Thirty Meter Telescope will enable. Planned to begin science operations in 2024, TMT will open up opportunities for revolutionary discoveries in essentially every field of astronomy, astrophysics and cosmology, seeing much fainter objects much more clearly than existing telescopes. Per this capability, TMT's science agenda fills all of space and time, from nearby comets and asteroids, to exoplanets, to the most dist...

  4. The OPERA neutrino velocity measurement: Analysis details

    International Nuclear Information System (INIS)

    The OPERA neutrino experiment at the underground Gran Sasso Laboratory has measured the velocity of neutrinos from the CERN CNGS beam over a baseline of about 730 km. An early arrival time of CNGS muon neutrinos with respect to the one computed assuming the speed of light in vacuum was measured. Details on the statistical analysis of the nominal beam data sample and the short-bunch analysis as well as additional cross checks and an outlook of upcoming measurements are discussed.

  5. Detailed spectral analysis of decellularized skin implants

    Science.gov (United States)

    Timchenko, E. V.; Timchenko, P. E.; Volova, L. T.; Dolgushkin, D. A.; Shalkovsky, P. Y.; Pershutkina, S. V.

    2016-08-01

    The resutls of detailed analysis of donor skin implants using Raman spectroscopy method are presented. Fourier-deconvolution method was used to separate overlapping spectrum lines and to improve its informativeness. Based on the processed spectra were introduced coefficients that represent changes in relative concentration of implant components, which determines the quality of implants. It was established that Raman spectroscopy method can be used in assessment of skin implants.

  6. Virus templated metallic nanoparticles

    Science.gov (United States)

    Aljabali, Alaa A. A.; Barclay, J. Elaine; Lomonossoff, George P.; Evans, David J.

    2010-12-01

    Plant viruses are considered as nanobuilding blocks that can be used as synthons or templates for novel materials. Cowpea mosaic virus (CPMV) particles have been shown to template the fabrication of metallic nanoparticles by an electroless deposition metallization process. Palladium ions were electrostatically bound to the virus capsid and, when reduced, acted as nucleation sites for the subsequent metal deposition from solution. The method, although simple, produced highly monodisperse metallic nanoparticles with a diameter of ca. templated particles were prepared with cobalt, nickel, iron, platinum, cobalt-platinum and nickel-iron.Plant viruses are considered as nanobuilding blocks that can be used as synthons or templates for novel materials. Cowpea mosaic virus (CPMV) particles have been shown to template the fabrication of metallic nanoparticles by an electroless deposition metallization process. Palladium ions were electrostatically bound to the virus capsid and, when reduced, acted as nucleation sites for the subsequent metal deposition from solution. The method, although simple, produced highly monodisperse metallic nanoparticles with a diameter of ca. templated particles were prepared with cobalt, nickel, iron, platinum, cobalt-platinum and nickel-iron. Electronic supplementary information (ESI) available: Additional experimental detail, agarose gel electrophoresis results, energy dispersive X-ray spectra, ζ-potential measurements, dynamic light scattering data, nanoparticle tracking analysis and an atomic force microscopy image of Ni-CPMV. See DOI: 10.1039/c0nr00525h

  7. Structural concepts and details for seismic design

    Energy Technology Data Exchange (ETDEWEB)

    1991-09-01

    This manual discusses building and building component behavior during earthquakes, and provides suggested details for seismic resistance which have shown by experience to provide adequate performance during earthquakes. Special design and construction practices are also described which, although they might be common in some high-seismic regions, may not be common in low and moderate seismic-hazard regions of the United States. Special attention is given to describing the level of detailing appropriate for each seismic region. The UBC seismic criteria for all seismic zones is carefully examined, and many examples of connection details are given. The general scope of discussion is limited to materials and construction types common to Department of Energy (DOE) sites. Although the manual is primarily written for professional engineers engaged in performing seismic-resistant design for DOE facilities, the first two chapters, plus the introductory sections of succeeding chapters, contain descriptions which are also directed toward project engineers who authorize, review, or supervise the design and construction of DOE facilities. 88 refs., 188 figs.

  8. Detail analysis of fusion neutronics benchmark experiment on beryllium

    Energy Technology Data Exchange (ETDEWEB)

    Konno, Chikara, E-mail: konno.chikara@jaea.go.j [Fusion Research and Development Directorate, Japan Atomic Energy Agency, Tokai-mura, Naka-gun, Ibaraki-ken 319-1195 (Japan); Ochiai, Kentaro; Takakura, Kosuke; Ohnishi, Seiki; Kondo, Keitaro [Fusion Research and Development Directorate, Japan Atomic Energy Agency, Tokai-mura, Naka-gun, Ibaraki-ken 319-1195 (Japan); Wada, Masayuki [Japan Computer System, Mito-shi, Ibaraki-ken 310-0805 (Japan); Sato, Satoshi [Fusion Research and Development Directorate, Japan Atomic Energy Agency, Tokai-mura, Naka-gun, Ibaraki-ken 319-1195 (Japan)

    2010-12-15

    Our previous analysis of the integral experiments (in situ and TOF experiments) on beryllium with DT neutrons at JAEA/FNS pointed out two problems by using MCNP4C and the latest nuclear data libraries; one was a strange larger neutron peak around 12 MeV appearing in the TOF experiment analysis with JEFF-3.1 and the other was an overestimation on law energy neutrons in the in situ experiment analyses with all the nuclear data libraries. We investigated reasons for these problems in detail. It was found out that the official ACE file MCJEFF3.1 of JEFF-3.1 had an inconsistency with the original JEFF-3.1, which caused the strange larger neutron peak around 12 MeV in the TOF experiment analysis. We also found out that the calculated thermal neutron peak was probably too large in the in situ experiment. On trial we examined influence of the thermal neutron scattering law data of beryllium metal in ENDF/B-VI. The result pointed out that the coherent elastic scattering cross-section data in the thermal neutron scattering law data of beryllium metal were probably too large.

  9. Rural Aging

    Science.gov (United States)

    ... Rural Health > Topics & States > Topics View more Rural Aging The nation's population is aging, and with that change comes increased healthcare needs. ... Disease Control and Prevention report, The State of Aging and Health in America 2013 , the population 65 ...

  10. Constraints on the Distance Moduli, Helium and Metal Abundances, and Ages of Globular Clusters from their RR Lyrae and Non-variable Horizontal-branch Stars. I. M3, M15, and M92

    Science.gov (United States)

    VandenBerg, Don A.; Denissenkov, P. A.; Catelan, Márcio

    2016-08-01

    Up-to-date isochrones, zero-age horizontal-branch (ZAHB) loci, and evolutionary tracks for core He-burning stars are applied to the color–magnitude diagrams of M3, M15, and M92, focusing in particular on their RR Lyrae populations. Periods for the ab- and c-type variables are calculated using the latest theoretical calibrations of {log} {P}{ab} and {log} {P}c as a function of luminosity, mass, effective temperature ({T}{{eff}}), and metallicity. Our models are generally able to reproduce the measured periods to well within the uncertainties implied by the stellar properties on which pulsation periods depend, as well as the mean periods and cluster-to-cluster differences in and , on the assumption of well-supported values of E(B-V), {(m-M)}V, and [Fe/H]. While many of RR Lyrae in M3 lie close to the same ZAHB that fits the faintest horizontal-branch (HB) stars at bluer or redder colors, the M92 variables are all significantly evolved stars from ZAHB locations on the blue side of the instability strip. M15 appears to contain a similar population of HB stars as M92, along with additional helium-enhanced populations not present in the latter which comprise most of its RR Lyrae stars. The large number of variables in M15 and the similarity of the observed values of and in M15 and M92 can be explained by HB models that allow for variations in Y. Similar ages (∼12.5 Gyr) are found for all three clusters, making them significantly younger than the field halo subgiant HD 140283. Our analysis suggests a preference for stellar models that take diffusive processes into account.

  11. Metals and Neuronal Metal Binding Proteins Implicated in Alzheimer’s Disease

    Directory of Open Access Journals (Sweden)

    Joana S. Cristóvão

    2016-01-01

    Full Text Available Alzheimer’s disease (AD is the most prevalent age-related dementia affecting millions of people worldwide. Its main pathological hallmark feature is the formation of insoluble protein deposits of amyloid-β and hyperphosphorylated tau protein into extracellular plaques and intracellular neurofibrillary tangles, respectively. Many of the mechanistic details of this process remain unknown, but a well-established consequence of protein aggregation is synapse dysfunction and neuronal loss in the AD brain. Different pathways including mitochondrial dysfunction, oxidative stress, inflammation, and metal metabolism have been suggested to be implicated in this process. In particular, a body of evidence suggests that neuronal metal ions such as copper, zinc, and iron play important roles in brain function in health and disease states and altered homeostasis and distribution as a common feature across different neurodegenerative diseases and aging. In this focused review, we overview neuronal proteins that are involved in AD and whose metal binding properties may underlie important biochemical and regulatory processes occurring in the brain during the AD pathophysiological process.

  12. Detailed modeling of mountain wave PSCs

    Directory of Open Access Journals (Sweden)

    S. Fueglistaler

    2003-01-01

    Full Text Available Polar stratospheric clouds (PSCs play a key role in polar ozone depletion. In the Arctic, PSCs can occur on the mesoscale due to orographically induced gravity waves. Here we present a detailed study of a mountain wave PSC event on 25-27 January 2000 over Scandinavia. The mountain wave PSCs were intensively observed by in-situ and remote-sensing techniques during the second phase of the SOLVE/THESEO-2000 Arctic campaign. We use these excellent data of PSC observations on 3 successive days to analyze the PSCs and to perform a detailed comparison with modeled clouds. We simulated the 3-dimensional PSC structure on all 3 days with a mesoscale numerical weather prediction (NWP model and a microphysical box model (using best available nucleation rates for ice and nitric acid trihydrate particles. We show that the combined mesoscale/microphysical model is capable of reproducing the PSC measurements within the uncertainty of data interpretation with respect to spatial dimensions, temporal development and microphysical properties, without manipulating temperatures or using other tuning parameters. In contrast, microphysical modeling based upon coarser scale global NWP data, e.g. current ECMWF analysis data, cannot reproduce observations, in particular the occurrence of ice and nitric acid trihydrate clouds. Combined mesoscale/microphysical modeling may be used for detailed a posteriori PSC analysis and for future Arctic campaign flight and mission planning. The fact that remote sensing alone cannot further constrain model results due to uncertainities in the interpretation of measurements, underlines the need for synchronous in-situ PSC observations in campaigns.

  13. Detailed measurement on a HESCO diffuser

    DEFF Research Database (Denmark)

    Jensen, Rasmus Lund; Holm, Dorte; Nielsen, Peter V.

    2007-01-01

    This paper focuses on measuring the inlet velocity from a HESCO diffuser used in the IEA Annex 20 work as a function of the volume flow it provides. The aim of the present work is to establish a relation between the inlet velocity, the effective area and the airflow. This is important because...... the inlet velocity is a very important boundary condition both in CFD calculation and general flow measurements. If only the volume flow and the geometrical area are used, a relatively large error in the inlet velocity may result. From the detailed measurements it was possible to establish an expression...

  14. A detailed phylogeny for the Methanomicrobiales

    Science.gov (United States)

    Rouviere, P.; Mandelco, L.; Winker, S.; Woese, C. R.

    1992-01-01

    The small subunit rRNA sequence of twenty archaea, members of the Methanomicrobiales, permits a detailed phylogenetic tree to be inferred for the group. The tree confirms earlier studies, based on far fewer sequences, in showing the group to be divided into two major clusters, temporarily designated the "methanosarcina" group and the "methanogenium" group. The tree also defines phylogenetic relationships within these two groups, which in some cases do not agree with the phylogenetic relationships implied by current taxonomic names--a problem most acute for the genus Methanogenium and its relatives. The present phylogenetic characterization provides the basis for a consistent taxonomic restructuring of this major methanogenic taxon.

  15. Advances in metal forming expert system for metal forming

    CERN Document Server

    Hingole, Rahulkumar Shivajirao

    2015-01-01

    This comprehensive book offers a clear account of the theory and applications of advanced metal forming. It provides a detailed discussion of specific forming processes, such as deep drawing, rolling, bending extrusion and stamping. The author highlights recent developments of metal forming technologies and explains sound, new and powerful expert system techniques for solving advanced engineering problems in metal forming. In addition, the basics of expert systems, their importance and applications to metal forming processes, computer-aided analysis of metalworking processes, formability analysis, mathematical modeling and case studies of individual processes are presented.

  16. Fatigue damage accumulation of details in cars according to criterion of specific energy of total strain

    Directory of Open Access Journals (Sweden)

    L.I. Vakulenko

    2013-08-01

    Full Text Available Purpose. Modern ideas about the accumulation of fatigue damages in the details of railway vehicles are based on models that estimate the durability of metal systems and depend on the number of cycles and the magnitude of deformations or stresses. These models allow one to assess with a sufficient degree of adequacy the weakening of metal systems in polycyclic fatigue and at the presence of the elastic strain only in the details of rolling stock. However, the possibility of plastic deformation appearing during operation of rail transport structures is not taken into account. The aim of this work is a construction of a mathematical model that allows estimating the durability of metal systems with regard to the appearing of the plastic component in the process of deformation of parts of railway vehicles. Methodology. With the use of modern methods of solid mechanics the influence of the parameters of plastic deformation on the durability of highly loaded structural elements was analyzed. Findings. The effect of elastic and plastic deformation on the energy dissipation under cyclic loading was studied. Originality. It was shown analytically that the softening parameters of metal systems are related to the total energy of deformation, which characterizes features of the degradation processes in the metal structures under external loads. Practical value. Ratios were proposed, they allow estimating residual life of details in a sequential multilevel cyclic loading.

  17. Constraints on the Distance Moduli, Helium and Metal Abundances, and Ages of Globular Clusters from their RR Lyrae and Non-Variable Horizontal-Branch Stars. I. M3, M15, and M92

    CERN Document Server

    VandenBerg, Don A; Catelan, Marcio

    2016-01-01

    Up-to-date isochrones, zero-age horizontal branch (ZAHB) loci, and evolutionary tracks for core He-burning stars are applied to the color-magnitude diagrams (CMDs) of M3, M15, and M92, focusing in particular on their RR Lyrae populations. Periods for ab- and c-type variables are calculated using the latest theoretical calibrations of log P_ab and log P_c as a function of luminosity, mass, effective temperature, and metallicity. Our models are generally able to reproduce the measured periods to well within the uncertainties implied by the stellar properties on which pulsation periods depend, as well as the mean periods and cluster-to-cluster differences in and , on the assumption of well-supported values of E(B-V), (m-M)_V, and [Fe/H]. While many of the RR Lyrae in M3 lie close to the same ZAHB that fits the faintest HB stars at bluer or redder colors, the M92 variables are all significantly evolved stars from ZAHB locations on the blue side of the instability strip. M15 appears to contain a similar populatio...

  18. Detailed radon emanation mapping in Northern Latium

    International Nuclear Information System (INIS)

    Detailed radon surveys over 5,000 km2 of Northern Latium, covering the northern part of the volcanic province of Central Italy, commenced in the mid eighties as part of a geothermal exploration programme; the surveys have subsequently been continued and amplified with environmental protection in mind. The area is now covered by ground emission maps, radon levels in water supplies, emissions from the different lithologies and concentrations in houses. The high uraniferous content of the volcanics, the porous nature of the ubiquitous pyroclastics, and active geothermal systems in the area combine to convey to ground level high concentrations of radon. The emissions show strong lateral variations which are geologically and tectonically controlled, such that only detailed surveys reveal the extent and locations of anomalous radon emanations. Unfortunately, long ago towns often developed in strategic locations. For Northern Latium this means on volcanic highs formed by faulted tuff blocks, two geological features associated with particularly high radon emissions. As a result, in contrast to the low average indoor radon concentrations for the greater part of Italy, in some of these town the average values exceed 450 Bq/m3. (author). 1 fig

  19. Thirty Meter Telescope Detailed Science Case: 2015

    Science.gov (United States)

    Skidmore, Warren; TMT International Science Development Teams; Science Advisory Committee, TMT

    2015-12-01

    The TMT Detailed Science Case describes the transformational science that the Thirty Meter Telescope will enable. Planned to begin science operations in 2024, TMT will open up opportunities for revolutionary discoveries in essentially every field of astronomy, astrophysics and cosmology, seeing much fainter objects much more clearly than existing telescopes. Per this capability, TMT's science agenda fills all of space and time, from nearby comets and asteroids, to exoplanets, to the most distant galaxies, and all the way back to the very first sources of light in the universe. More than 150 astronomers from within the TMT partnership and beyond offered input in compiling the new 2015 Detailed Science Case. The contributing astronomers represent the entire TMT partnership, including the California Institute of Technology (Caltech), the Indian Institute of Astrophysics (IIA), the National Astronomical Observatories of the Chinese Academy of Sciences (NAOC), the National Astronomical Observatory of Japan (NAOJ), the University of California, the Association of Canadian Universities for Research in Astronomy (ACURA) and US associate partner, the Association of Universities for Research in Astronomy (AURA). Cover image: artist's rendition of the TMT International Observatory on Mauna Kea opening in the late evening before beginning operations.

  20. Detalhes da utilização do íon hidróxido, HO-, no tratamento de efluentes contaminados com metal pesado zinco - doi: 10.4025/actascitechnol.v33i3.8379 Details of hydroxide ion utilization in the treatment of contaminated effluents with zinc - doi: 10.4025/actascitechnol.v33i3.8379

    Directory of Open Access Journals (Sweden)

    Luzia Otilia Bortotti Favero

    2011-07-01

    Full Text Available O estudo abordou o tratamento do efluente gerado num Espectrômetro de Absorção Atômica - EAA, no tocante ao metal pesado zinco, utilizando a propriedade do cátion formar o precipitado Zn(OH2(ppt. O assunto foi tratado teórica e praticamente. Teoricamente foram levantados parâmetros termodinâmicos e analisada matematicamente a solubilidade do Zn(OH 2(ppt com a variação do pH. Experimentalmente foi analisado o comportamento da solução aquosa do Zn(OH 2(ppt e da solução in natura do efluente descartado com o pH. As medidas da concentração de zinco nas diversas situações foram realizadas pelo método da EAA, com limite de detecção (LD de 0,030 mg L-1. Os resultados nas diferentes situações de solução e pH do meio, para a solubilidade mínima do Zn(OH (ppt, SMínima, em mg L-1, foram: valor teórico = 2,3; valor experimental para solução de Zn(OH (ppt = 0,92; valor para solução in natura = 0,092, respectivamente. Estes valores estão de conformidade com BRASIL-Resolução Conama n. 397/2008.This work analyzed the treatment of effluent produced by an Atomic Absorption Spectrometer (AAS containing the heavy metal zinc, utilizing the capacity of Zn2+ to react with hydroxide ion (HO-, forming Zn(OH 2(ppt. The content was treated theoretically and experimentally. Theoretically, the thermodynamic parameters were assessed and the solubility of Zn(OH 2(ppt with pH variation was analyzed mathematically. Experimentally, the study analyzed the behavior of the Zn(OH 2(ppt aqueous solution and in natura solution of discarded effluent with the medium pH. The values of zinc concentration in the different situations were measured using AAS, flame modality, with detection limit (DL 0.030 mg L-1. The results in the different situations of solution and medium pH for the minimum solubility of Zn(OH 2(ppt, in mg L-1, were: theoretical value = 2.3; experimental value for the Zn(OH 2(ppt solution = 0.92; in natural effluent = 0.092, respectively

  1. COOEE bitumen: chemical aging

    CERN Document Server

    Lemarchand, Claire A; Dyre, Jeppe C; Hansen, Jesper S

    2013-01-01

    We study chemical aging in "COOEE bitumen" using molecular dynamic simulations. The model bitumen is composed of four realistic molecule types: saturated hydrocarbon, resinous oil, resin, and asphaltene. The aging reaction is modelled by the chemical reaction: "2 resins $\\rightarrow$ 1 asphaltene". Molecular dynamic simulations of four bitumen compositions, obtained by a repeated application of the aging reaction, are performed. The stress autocorrelation function, the fluid structure, the rotational dynamics of the plane aromatic molecules, and the diffusivity of each molecule, are determined for the four different compositions. The aging reaction causes a significant dynamics slowdown, which is correlated to the aggregation of asphaltene molecules in larger and dynamically slower nanoaggregates. Finally, a detailed description of the role of each molecule types in the aggregation and aging processes is given.

  2. Arterial Ageing

    OpenAIRE

    Lee, Seung-Jun; Park, Sung-Ha

    2013-01-01

    Arterial ageing is characterized by age associated degeneration and sclerosis of the media layer of the large arteries. However, besides ageing, clinical conditions, which enhance oxidative stress and inflammation act to accelerate the degree of arterial ageing. In this review, we summarized the pathophysiology and contributing factors that accelerate arterial ageing. Among them, we focused on hypertension, the renin-angiotensin-aldosterone system and vascular inflammation which are modifiabl...

  3. A meaningful expansion around detailed balance

    CERN Document Server

    Colangeli, Matteo; Wynants, Bram

    2011-01-01

    We consider Markovian dynamics modeling open mesoscopic systems which are driven away from detailed balance by a nonconservative force. A systematic expansion is obtained of the stationary distribution around an equilibrium reference, in orders of the nonequilibrium forcing. The first order around equilibrium has been known since the work of McLennan (1959), and involves the transient irreversible entropy flux. The expansion generalizes the McLennan formula to higher orders, complementing the entropy flux with the dynamical activity. The latter is more kinetic than thermodynamic and is a possible realization of Landauer's insight (1975) that, for nonequilibrium, the relative occupation of states also depends on the noise along possible escape routes. In that way nonlinear response around equilibrium can be meaningfully discussed in terms of two main quantities only, the entropy flux and the dynamical activity. The expansion makes mathematical sense as shown in the simplest cases from exponential ergodicity.

  4. Detailed Design of Intelligent Object Framework

    Directory of Open Access Journals (Sweden)

    Sasa Savicand Hao Shi

    2013-12-01

    Full Text Available The design and implementation of Intelligent Object Framework(IOF aims to unite the communication and device management through a platform independent ma nagement protocol in conjunction with a management application. The Core Framework is devel oped using Microsoft Visual Studio, Microsoft’s .NET Framework and Microsoft’s Windows Mobile SDK. Secondary Intelligent Object is developed using Tibbo Integrated Development Environment (TIDE and T-BASIC programming language that is loaded on an EM1026 Embedded Device Platform running Tibbo Op erating System (TiOS. The backend database is based on Microsoft’s SQL Server.In this paper, prot ocols associated with Smart Living are first reviewed.The system architecture and intelligent ob ject management studio are presented. Then device application design and database design are detailed . Finally conclusions are drawn and future work is addressed.

  5. Optomechanical details in injection-molded assemblies

    Science.gov (United States)

    Hebert, Raymond T.

    1995-12-01

    With the advent of low-cost electro-optic components such as LEDs, laser diodes and CCD imaging devices, the cost and performance demands now fall upon the optical subsystems in order to achieve realistic marketing targets for many emerging commercial and consumer products. One of the many benefits of injection-molded plastic optics is the diversity of features that are available to the design team. Once designed and incorporated into the tooling, many features are virtually free in high-volume production. These features can include mechanical details as well as optical functions. Registration features can be included for precisely positioning optical elements to one another or to other assemblies such as printed circuit boards or housings. Snaps, compression features, spring-loading elements, standoffs, self-tapping screws or ultrasonically weldable features can greatly facilitate ease of assembly.

  6. Radioactive contamination mapping system detailed design report

    International Nuclear Information System (INIS)

    The Hanford Site's 100 Area production reactors released radioactively and chemically contaminated liquids into the soil column. The primary source of the contaminated liquids was reactor coolant and various waste waters released from planned liquid discharges, as well as pipelines, pipe junctions, and retention basins leaking into the disposal sites. Site remediation involves excavating the contaminated soils using conventional earthmoving techniques and equipment, treating as appropriate, transporting the soils, and disposing the soils at ERDF. To support remediation excavation, disposal, and documentation requirements, an automated radiological monitoring system was deemed necessary. The RCMS (Radioactive Contamination Mapping System) was designed to fulfill this need. This Detailed Design Report provides design information for the RCMS in accordance with Bechtel Hanford, Inc. Engineering Design Project Instructions

  7. Detailed Chromospheric Activity Nature of KIC 9641031

    CERN Document Server

    Yoldaş, Ezgi

    2016-01-01

    This study depends on KIC 9641031 eclipsing binary system with a chromospherically active component. There are three type variations, such as geometrical variations due to eclipses, sinusoidal variations due to the rotational modulations and also flares, in the light curves obtained with the data taken from the Kepler Mission Database. Taking into account results obtained from KIC 9641031's observations in the Kepler Mission Database, we present and discuss the details of chromospheric activity. The sinusoidal light variations due to rotational modulation and the flare events were modelled separately. 92 different data subsets separated using the analytic models described in the literature were modelled separately to obtain the cool spot configuration. It is seen that just one component of the system is chromospherically active star. On this component, there are two active regions separated by about 180 deg longitudinally between the latitudes of +50 deg and +100 deg, whose locations and forms are rapidly cha...

  8. New metals

    International Nuclear Information System (INIS)

    The aim of this report is to estimate the exposure to various metals and metal compounds and discuss the available information of the possible toxic effects of these metals and compounds. In the first section, some metals are defined as those with either a large or a fast increasing exposure to living organisms. The available information on toxicity is discussed in the second section. In the third section interesting metals are defined as compounds having a large exposure and an apparent insufficient knowledge of their possible toxic effects. Comments on each of these metals are also to be found in the third section. (G.B.)

  9. Optoelectronic pH Meter: Further Details

    Science.gov (United States)

    Jeevarajan, Antony S.; Anderson, Mejody M.; Macatangay, Ariel V.

    2009-01-01

    A collection of documents provides further detailed information about an optoelectronic instrument that measures the pH of an aqueous cell-culture medium to within 0.1 unit in the range from 6.5 to 7.5. The instrument at an earlier stage of development was reported in Optoelectronic Instrument Monitors pH in a Culture Medium (MSC-23107), NASA Tech Briefs, Vol. 28, No. 9 (September 2004), page 4a. To recapitulate: The instrument includes a quartz cuvette through which the medium flows as it is circulated through a bioreactor. The medium contains some phenol red, which is an organic pH-indicator dye. The cuvette sits between a light source and a photodetector. [The light source in the earlier version comprised red (625 nm) and green (558 nm) light-emitting diodes (LEDs); the light source in the present version comprises a single green- (560 nm)-or-red (623 nm) LED.] The red and green are repeatedly flashed in alternation. The responses of the photodiode to the green and red are processed electronically to obtain the ratio between the amounts of green and red light transmitted through the medium. The optical absorbance of the phenol red in the green light varies as a known function of pH. Hence, the pH of the medium can be calculated from the aforesaid ratio.

  10. Some articulatory details of emotional speech

    Science.gov (United States)

    Lee, Sungbok; Yildirim, Serdar; Bulut, Murtaza; Kazemzadeh, Abe; Narayanan, Shrikanth

    2005-09-01

    Differences in speech articulation among four emotion types, neutral, anger, sadness, and happiness are investigated by analyzing tongue tip, jaw, and lip movement data collected from one male and one female speaker of American English. The data were collected using an electromagnetic articulography (EMA) system while subjects produce simulated emotional speech. Pitch, root-mean-square (rms) energy and the first three formants were estimated for vowel segments. For both speakers, angry speech exhibited the largest rms energy and largest articulatory activity in terms of displacement range and movement speed. Happy speech is characterized by largest pitch variability. It has higher rms energy than neutral speech but articulatory activity is rather comparable to, or less than, neutral speech. That is, happy speech is more prominent in voicing activity than in articulation. Sad speech exhibits longest sentence duration and lower rms energy. However, its articulatory activity is no less than neutral speech. Interestingly, for the male speaker, articulation for vowels in sad speech is consistently more peripheral (i.e., more forwarded displacements) when compared to other emotions. However, this does not hold for female subject. These and other results will be discussed in detail with associated acoustics and perceived emotional qualities. [Work supported by NIH.

  11. Detailed Chemical Kinetic Modeling of Cyclohexane Oxidation

    Energy Technology Data Exchange (ETDEWEB)

    Silke, E J; Pitz, W J; Westbrook, C K; Ribaucour, M

    2006-11-10

    A detailed chemical kinetic mechanism has been developed and used to study the oxidation of cyclohexane at both low and high temperatures. Reaction rate constant rules are developed for the low temperature combustion of cyclohexane. These rules can be used for in chemical kinetic mechanisms for other cycloalkanes. Since cyclohexane produces only one type of cyclohexyl radical, much of the low temperature chemistry of cyclohexane is described in terms of one potential energy diagram showing the reaction of cyclohexyl radical + O{sub 2} through five, six and seven membered ring transition states. The direct elimination of cyclohexene and HO{sub 2} from RO{sub 2} is included in the treatment using a modified rate constant of Cavallotti et al. Published and unpublished data from the Lille rapid compression machine, as well as jet-stirred reactor data are used to validate the mechanism. The effect of heat loss is included in the simulations, an improvement on previous studies on cyclohexane. Calculations indicated that the production of 1,2-epoxycyclohexane observed in the experiments can not be simulated based on the current understanding of low temperature chemistry. Possible 'alternative' H-atom isomerizations leading to different products from the parent O{sub 2}QOOH radical were included in the low temperature chemical kinetic mechanism and were found to play a significant role.

  12. Detailed Aerosol Characterization using Polarimetric Measurements

    Science.gov (United States)

    Hasekamp, Otto; di Noia, Antonio; Stap, Arjen; Rietjens, Jeroen; Smit, Martijn; van Harten, Gerard; Snik, Frans

    2016-04-01

    Anthropogenic aerosols are believed to cause the second most important anthropogenic forcing of climate change after greenhouse gases. In contrast to the climate effect of greenhouse gases, which is understood relatively well, the negative forcing (cooling effect) caused by aerosols represents the largest reported uncertainty in the most recent assessment of the International Panel on Climate Change (IPCC). To reduce the large uncertainty on the aerosol effects on cloud formation and climate, accurate satellite measurements of aerosol optical properties (optical thickness, single scattering albedo, phase function) and microphysical properties (size distribution, refractive index, shape) are essential. There is growing consensus in the aerosol remote sensing community that multi-angle measurements of intensity and polarization are essential to unambiguously determine all relevant aerosol properties. This presentations adresses the different aspects of polarimetric remote sensing of atmospheric aerosols, including retrieval algorithm development, validation, and data needs for climate and air quality applications. During past years, at SRON-Netherlands Instite for Space Research retrieval algorithms have been developed that make full use of the capabilities of polarimetric measurements. We will show results of detailed aerosol properties from ground-based- (groundSPEX), airborne- (NASA Research Scanning Polarimeter), and satellite (POLDER) measurements. Also we will discuss observational needs for future instrumentation in order to improve our understanding of the role of aerosols in climate change and air quality.

  13. Basic and detail engineering development of PTAMB

    International Nuclear Information System (INIS)

    The purpose of the future Treatment and Conditioning of Medium and Low Activity Solid and Liquid Waste Plant (PTAMB) of the National Atomic Energy Commission (CNEA) will be to put up medium and low activity solid and liquid waste and to verify the quality of the conditioned waste generated in Ezeiza Atomic Center (CAE), Constituyentes Atomic Center (CAC) and other national producers outside CNEA. The PTAMB is a Class I Radioactive Installation (according to Basic Standard AR 10.1.1, Rev. 3 RNA, paragraphs 17 and 22) also called Relevant Installation. The aim of this document is to list the steps that carried out the Projects Department of the National Program of Radioactive Waste Management (PNGRR) to arrive to the realization of the detailed engineering of the plant. The project is in Public Tender stage and the beginning of the construction would be March 2010. Once built, the Plant will process the radioactive waste contained in the conceptual engineering, offering more precise control of these and their compatibility with the new final disposal systems to build. (author)

  14. Level of detail technique for plant models

    Institute of Scientific and Technical Information of China (English)

    Xiaopeng ZHANG; Qingqiong DENG; Marc JAEGER

    2006-01-01

    Realistic modelling and interactive rendering of forestry and landscape is a challenge in computer graphics and virtual reality. Recent new developments in plant growth modelling and simulation lead to plant models faithful to botanical structure and development, not only representing the complex architecture of a real plant but also its functioning in interaction with its environment. Complex geometry and material of a large group of plants is a big burden even for high performances computers, and they often overwhelm the numerical calculation power and graphic rendering power. Thus, in order to accelerate the rendering speed of a group of plants, software techniques are often developed. In this paper, we focus on plant organs, i.e. leaves, flowers, fruits and inter-nodes. Our approach is a simplification process of all sparse organs at the same time, i. e. , Level of Detail (LOD) , and multi-resolution models for plants. We do explain here the principle and construction of plant simplification. They are used to construct LOD and multi-resolution models of sparse organs and branches of big trees. These approaches take benefit from basic knowledge of plant architecture, clustering tree organs according to biological structures. We illustrate the potential of our approach on several big virtual plants for geometrical compression or LOD model definition. Finally we prove the efficiency of the proposed LOD models for realistic rendering with a virtual scene composed by 184 mature trees.

  15. Happy Aging

    Institute of Scientific and Technical Information of China (English)

    梁秉中

    2009-01-01

    Aging is a normal physiological process in human life.The decline in the ability to repair and regenerate predisposes the aging person to develop disabling problems in the cardiovascular and skeletal systems.Full awareness of aging problems and advocations on the means to prevent their occurrence are mounting.European and US groups rely on scientific,target-oriented means to treat aging manifestations. Oriental medicine aims at prevention,using nutrition and exercise to maintain internal harmony.

  16. Population Aging

    OpenAIRE

    Weil, David N.

    2006-01-01

    Population aging is primarily the result of past declines in fertility, which produced a decades long period in which the ratio of dependents to working age adults was reduced. Rising old-age dependency in many countries represents the inevitable passing of this %u201Cdemographic dividend.%u201D Societies use three methods to transfer resources to people in dependent age groups: government, family, and personal saving. In developed countries, families are predominant in supporting children, w...

  17. Silicone metalization

    Science.gov (United States)

    Maghribi, Mariam N.; Krulevitch, Peter; Hamilton, Julie

    2006-12-05

    A system for providing metal features on silicone comprising providing a silicone layer on a matrix and providing a metal layer on the silicone layer. An electronic apparatus can be produced by the system. The electronic apparatus comprises a silicone body and metal features on the silicone body that provide an electronic device.

  18. Ageing Polulations

    DEFF Research Database (Denmark)

    Christiansen, Terkel; Lauridsen, Jørgen Trankjær; Bech, Mickael

    2013-01-01

    An ageing society is characterised by an increasing median age of the population. The purpose of this chapter is to document the existing knowledge about the association between population ageing and health care expenditure, and to supplement this overview by a summary of our original research. S...

  19. Creative Aging.

    Science.gov (United States)

    Ager, Charlene Lee; And Others

    1981-01-01

    Explores some divergent attitudes toward aging, negative as well as positive. Presents a neurophysiological framework to support the belief that aging is an active and creative process. Explores physical, psychological, and sociological aspects, and identifies three factors in the creative aging process. (Author/JAC)

  20. Skin Aging

    Science.gov (United States)

    Your skin changes as you age. You might notice wrinkles, age spots and dryness. Your skin also becomes thinner and loses fat, making it ... heal, too. Sunlight is a major cause of skin aging. You can protect yourself by staying out ...

  1. Detailed Globes Enhance Education and Recreation

    Science.gov (United States)

    2007-01-01

    Orbis World Globes creates inflatable globes-Earthballs-in many sizes that depict Earth as it is seen from space, complete with atmospheric cloud cover. Orbis designs and produces the most visually authentic replicas of Earth ever created, and NASA took notice of Orbis globes and employed a 16-inch diameter EarthBall for an educational film it made aboard the STS-45 shuttle mission. Orbis later collaborated with NASA to create two 16-foot diameter world globes for display at the 2002 Olympic Winter Games in Salt Lake City, using more detailed satellite imagery. The satellite image now printed on all Orbis globes displays 1-kilometer resolution and is 21,600 by 43,200 pixels in size, and Orbis globes are otherwise meteorologically accurate, though the cloud cover has been slightly reduced in order for most of the landforms to be visible. Orbis also developed the exclusive NightGlow Cities feature, enabling EarthBalls to display the world's cities as they appear as the Earth revolves from daylight into night. Orbis inflatable globes are available in sizes from 1 to 100 feet in diameter, with the most common being the standard 16-inch and 1-meter diameter EarthBalls. Applications include educational uses from preschools to universities, games, and for a variety of display purposes at conferences, trade shows, festivals, concerts, and parades. A 16-foot diameter Orbis globe was exhibited at the United Nations' World Urban Forum, in Vancouver, Canada; the Space 2006 conference, in San Jose, California; and the X-Prize Cup Personal Spaceflight Exposition in Las Cruces, New Mexico.

  2. Cumulative theoretical uncertainties in lithium depletion boundary age

    CERN Document Server

    Tognelli, Emanuele; Degl'Innocenti, Scilla

    2015-01-01

    We performed a detailed analysis of the main theoretical uncertainties affecting the age at the lithium depletion boundary (LDB). To do that we computed almost 12000 pre-main sequence models with mass in the range [0.06, 0.4] M_sun by varying input physics (nuclear reaction cross-sections, plasma electron screening, outer boundary conditions, equation of state, and radiative opacity), initial chemical elements abundances (total metallicity, helium and deuterium abundances, and heavy elements mixture), and convection efficiency (mixing length parameter, alpha_ML). As a first step, we studied the effect of varying these quantities individually within their extreme values. Then, we analysed the impact of simultaneously perturbing the main input/parameters without an a priori assumption of independence. Such an approach allowed us to build for the first time the cumulative error stripe, which defines the edges of the maximum uncertainty region in the theoretical LDB age. We found that the cumulative error stripe ...

  3. A detailed framework to incorporate dust in hydrodynamical simulations

    CERN Document Server

    Grassi, T; Haugboelle, T; Schleicher, D R G

    2016-01-01

    Dust plays a key role in the evolution of the ISM and its correct modelling in numerical simulations is therefore fundamental. We present a new and self-consistent model that treats grain thermal coupling with the gas, radiation balance, and surface chemistry for molecular hydrogen. This method can be applied to any dust distribution with an arbitrary number of grain types without affecting the overall computational cost. In this paper we describe in detail the physics and the algorithm behind our approach, and in order to test the methodology, we present some examples of astrophysical interest, namely (i) a one-zone collapse with complete gas chemistry and thermochemical processes, (ii) a 3D model of a low-metallicity collapse of a minihalo starting from cosmological initial conditions, and (iii) a turbulent molecular cloud with H-C-O chemistry (277 reactions), together with self-consistent cooling and heating solved on the fly. Although these examples employ the publicly available code KROME, our approach c...

  4. Detailed glycan structural characterization by electronic excitation dissociation.

    Science.gov (United States)

    Yu, Xiang; Jiang, Yan; Chen, Yajie; Huang, Yiqun; Costello, Catherine E; Lin, Cheng

    2013-11-01

    The structural complexity and diversity of glycans parallel their multilateral functions in living systems. To better understand the vital roles glycans play in biological processes, it is imperative to develop analytical tools that can provide detailed glycan structural information. This was conventionally achieved by multistage tandem mass spectrometry (MS(n)) analysis using collision-induced dissociation (CID) as the fragmentation method. However, the MS(n) approach lacks the sensitivity and throughput needed to analyze complex glycan mixtures from biological sources, often available in limited quantities. We define herein the critical parameters for a recently developed fragmentation technique, electronic excitation dissociation (EED), which can yield rich structurally informative fragment ions during liquid chromatographic (LC)-MS/MS analysis of glycans. We further demonstrate that permethylation, reducing end labeling and judicious selection of the metal charge carrier, can greatly facilitate spectral interpretation. With its high sensitivity, throughput, and compatibility with online chromatographic separation techniques, EED appears to hold great promise for large-scale glycomics studies. PMID:24080071

  5. Recall of Details Never Experienced: Effects of Age, Repetition, and Semantic Cues

    Science.gov (United States)

    Holliday, Robyn E.; Reyna, Valerie F.; Brainerd, Charles J.

    2008-01-01

    To test theoretical predictions about the role of meaning connections in false memory, the effects of semantic cues and list repetition on children's false memories were evaluated across early childhood to mid-adolescence using the Deese-Roediger-McDermott (DRM) paradigm. True recall and false recall increased from 7 to 13 years. Study list…

  6. Signatures of aging

    Energy Technology Data Exchange (ETDEWEB)

    Cornwall, J.; Dyson, F.; Garwin, R.; Hammer, D.; Happer, W.; Lewis, N.; Schwitters, R.; Sullivan, J.; Williams, E.

    1998-01-06

    The Department of Energy and its three weapons laboratories (LANL, LLNL, and SNL) have developed a Stockpile Stewardship and Management Program (SSMP) in response to their designated mission of maintaining an effective, i.e. reliable and safe, nuclear deterrent without underground nuclear tests (UGTs). The need to ensure the effectiveness of an aging stockpile presents new challenges of major importance. In this study we review what is known about the aging of critical constituents, particularly the high explosives, polymers, and metals in the enduring stockpile. We discuss data that are required to provide a fuller understanding of aging, and how to obtain that data as a basis for anticipating and addressing potential stockpile problems. Our particular concern is problems that may arise in the short term, i.e. within the next 5 to 10 years, and their implied requirements for preventive maintenance and remanufacture.

  7. Skin aging:

    OpenAIRE

    Puizina-Ivić, Neira

    2008-01-01

    There are two main processes that induce skin aging: intrinsic and extrinsic. A stochastic process that implies random cell damage as a result of mutations during metabolic processes due to the production of free radicals is also implicated. Extrinsic aging is caused by environmental factors such as sun exposure, air pollution, smoking, alcohol abuse, and poor nutrition. Intrinsicaging reflects the genetic background and depends on time. Various expressions of intrinsic aging include smooth, ...

  8. Speciation in Metal Toxicity and Metal-Based Therapeutics

    Directory of Open Access Journals (Sweden)

    Douglas M. Templeton

    2015-04-01

    Full Text Available Metallic elements, ions and compounds produce varying degrees of toxicity in organisms with which they come into contact. Metal speciation is critical to understanding these adverse effects; the adjectives “heavy” and “toxic” are not helpful in describing the biological properties of individual elements, but detailed chemical structures are. As a broad generalization, the metallic form of an element is inert, and the ionic salts are the species that show more significant bioavailability. Yet the salts and other chelates of a metal ion can give rise to quite different toxicities, as exemplified by a range of carcinogenic potential for various nickel species. Another important distinction comes when a metallic element is organified, increasing its lipophilicity and hence its ability to penetrate the blood brain barrier, as is seen, for example, with organic mercury and tin species. Some metallic elements, such as gold and platinum, are themselves useful therapeutic agents in some forms, while other species of the same element can be toxic, thus focusing attention on species interconversions in evaluating metal-based drugs. The therapeutic use of metal-chelating agents introduces new species of the target metal in vivo, and this can affect not only its desired detoxification, but also introduce a potential for further mechanisms of toxicity. Examples of therapeutic iron chelator species are discussed in this context, as well as the more recent aspects of development of chelation therapy for uranium exposure.

  9. AR-aging as a new approach for enhanced results

    Science.gov (United States)

    Hays, C.; Stemmler, R. P.

    1998-12-01

    MAR-aging steels have earned a niche in the metal market arena, especially where aerospace and outerspace applications are concerned. MAR-aging steels owe their high strength, excellent fracture toughness, and good ductility to a precipitation-hardening (aging) mechanism that has been debated by scientists for several years. Because of today’s trend toward more demanding design requirements and a continuing need to better understand the MAR-aging family of materials, six different alloys (C-200, C-250, C-300, C-350, T-250, and T-300) were selected for study using a singular processing treatment: a hot-wall zone-gradient furnace. These alloys were evaluated for the effects of a specific thermal gradient (°C/cm) from 1231 °C (2250 °F) at the hot-wall limit to about 260 °C (500 °F) at the opposite end, the cold wall. All six alloys were evaluated in terms of their microstructure, microhardness, composition, and associated properties as a result of this specific thermal processing method. In this paper, detailed observations on the C-350 alloy are presented, and the results are interpreted in terms of a new heat treatment cycle called AR-aging.

  10. Fatigue Damage Estimation in Existing Railway Steel Bridges by Detailed Loading History Analysis

    OpenAIRE

    Alessio Pipinato; Carlo Pellegrino; Claudio Modena

    2012-01-01

    Fatigue life estimation of metal historical bridges is a key issue for managing cost-effective decisions regarding rehabilitation or replacement of existing infrastructure. Because of increasing service loads and speeds, this type of assessment method is becoming relevant. Hence there is a need to estimate how long these structures could remain in service. In this paper a method to estimate fatigue damage in existing steel railway bridges by detailed loading history analysis is presented. The...

  11. Detailed atmospheric abundance analysis of the optical counterpart of the IR source IRAS 16559-2957

    CERN Document Server

    Molina, R E

    2013-01-01

    We have undertaken a detailed abundance analysis of the optical counterpart of the IR source IRAS16559-2957 with the aim of confirming its possible post-AGB nature. The star shows solar metallicity and our investigation of a large number of elements including CNO and 12C/13C suggests that this object has experienced the first dredge-up and it is likely still at RGB stage.

  12. A detailed study of metallic glass formation in copper-hafnium-titanium alloys

    Institute of Scientific and Technical Information of China (English)

    Ignacio A. Figueroa; Sandro Baez-Pimiento; John D. Plummer; Omar Novelo-Peralta; Hywell A. Davies; Iain Todd

    2012-01-01

    Recently we have reported a number of bulk glass forming compositions in the CuHf-Ti system,with the critical thickness for complete glass formation,dc1 ranging from 2 mm to 4 mm.In order to improve the glass forming ability (GFA) getting even larger dc1 the prevailing approach is to use complex multicomponent systems.This strategy has been investigated by us for the Cu-Hf-Ti bulk glass forming alloy Cu55Hf25Ti20 using >1 at.pct additions of B,Y,Nb,Ta,Al,Mn,Si or V but with no significant improvement in the GFA.Clearly,it is necessary,in order to utilise the full potential of the base ternary system,to identify the best glass-forming compositions as a basis for extending the search into multi-dimensional compositional space.Thus,CuxHfyTiz alloys,where x=(40-70) at.pct,y=(5-30) at.pct,and z=(10-36) at.pct,were prepared by melt spinning and copper mould suction-casting.The composition dependence of the GFA for the Cu-Hf-Ti alloys,as measured by dc for rod and ribbon samples,is reported over the composition range given above.

  13. BEHAVIOUR OF METALS IN MUNICIPAL SLUDGE INCINERATORS

    Science.gov (United States)

    The emission of toxic metals from sewage sludge incinerators can present a risk to human health and the environment. ignificant base of data on the behaviour of metals in sludge incinerators has been compiled. hese data were examined in detail to identify the mechanisms responsib...

  14. Healthy Ageing

    OpenAIRE

    Schans, Cees van der

    2015-01-01

    Presentatie gehouden bij de bijeenkomst voor het Regionaal Genootschap Fysiotherapie Het Noorden op 10 februari te Marum, over het belang van fysieke activiteit voor healthy ageing en de rol van de fysiotherapeut hierin

  15. Liquid metals fire control engineering handbook

    International Nuclear Information System (INIS)

    This handbook reviews the basic requirements of the use of liquid metals with emphasis on sodium which has the greatest current usage. It delineates the concepts necessary to design facilities both radioactive and nonradioactive for use with liquid metals. It further reviews the state-of-the-art in fire extinguishers and leak detection equipment and comments on their application and sensitivity. It also provides details on some engineering features of value to the designer of liquid metal facilities

  16. Determination of the details of technical standard concerning the transport of nuclear fuel materials outside the works or the enterprise

    International Nuclear Information System (INIS)

    The determination is defined under the regulations concerning the transport of nuclear fuel materials outside the works or the enterprise. The least dangerous nuclear fuel materials designated by the Director General of Science and Technology Agency include, besides such materials listed and corresponding to the particular terms, natural or depleted uranium, natural thorium and their compounds whose surface is covered by corrosion resistance metal. The permissible density of surface stipulated by the Director is 1/100,000 micro-curie per centi-meter2 for radioactive substances not emitting alpha rays and 1/10,000 micro-curie per centi-meter2 for radioactive substances emitting alpha rays. General test conditions of A, BM and BU type of loads are in detail provided for. The nuclear fuel materials defined by the Director not as fission materials are uranium 233 and 235, plutonium 238 or 241, whose quantity or combined quantity of such substances do not exceed 15 grams and natural or depleted uranium. The permissible accumulative dose specified for employees is the figure (unit rem) calculated by the formula D=5 (N-18), when D means the permissible accumulative dose and N number of the age. The permissible exposure dose shall be 3 rem for 3 months for employees and 1.5 rem for a year for persons other than employees. (Okada, K.)

  17. Cosmic metal production and the mean metallicity of the Universe

    CERN Document Server

    Calura, F

    2004-01-01

    By means of detailed chemo-photometric models for elliptical, spiral and irregular galaxies, we evaluate the cosmic history of the production of chemical elements as well as the metal mass density of the present-day universe. We then calculate the mean metal abundances for galaxies of different morphological types, along with the average metallicity of galactic matter in the universe (stars, gas and intergalactic medium). For the average metallicity of galaxies in the local universe, we find Z_gal= 0.0175, i.e. close to the solar value. We find the main metal production in spheroids (ellipticals and bulges) to occur at very early times, implying an early peak in the metal production and a subsequent decrease. On the other hand, the metal production in spirals and irregulars is always increasing with time. We perform a self-consistent census of the baryons and metals in the local universe finding that, while the vast majority of the baryons lies outside galaxies in the inter-galactic medium (IGM), 52 % of the ...

  18. 46 CFR 70.25-1 - Electrical engineering details.

    Science.gov (United States)

    2010-10-01

    ... 46 Shipping 3 2010-10-01 2010-10-01 false Electrical engineering details. 70.25-1 Section 70.25-1 Shipping COAST GUARD, DEPARTMENT OF HOMELAND SECURITY (CONTINUED) PASSENGER VESSELS GENERAL PROVISIONS General Electrical Engineering Requirements § 70.25-1 Electrical engineering details. All electrical engineering details and installations shall...

  19. 46 CFR 188.25-1 - Electrical engineering details.

    Science.gov (United States)

    2010-10-01

    ... 46 Shipping 7 2010-10-01 2010-10-01 false Electrical engineering details. 188.25-1 Section 188.25-1 Shipping COAST GUARD, DEPARTMENT OF HOMELAND SECURITY (CONTINUED) OCEANOGRAPHIC RESEARCH VESSELS GENERAL PROVISIONS General Electrical Engineering Requirements § 188.25-1 Electrical engineering details. (a) The electrical engineering details...

  20. 46 CFR 90.25-1 - Electrical engineering details.

    Science.gov (United States)

    2010-10-01

    ... 46 Shipping 4 2010-10-01 2010-10-01 false Electrical engineering details. 90.25-1 Section 90.25-1 Shipping COAST GUARD, DEPARTMENT OF HOMELAND SECURITY (CONTINUED) CARGO AND MISCELLANEOUS VESSELS GENERAL PROVISIONS General Electrical Engineering Requirements § 90.25-1 Electrical engineering details. (a) All electrical engineering details...

  1. Sensor for metal detection

    KAUST Repository

    Kodzius, Rimantas

    2014-06-26

    NOVELTY - The sensor has a microfluidic flow channel that is provided with an inlet port, an outlet port, and a detection chamber. The detection chamber is provided with a group of sensing electrodes (4) having a working electrode (8), a counter electrode (9), and a reference electrode (10). A flow sensor is configured to measure flow in the channel. A temperature sensor (6) is configured to measure temperature in the channel (3). An electrical connection is configured to connect the sensor to a sensing device. USE - Sensor for detecting metal such as toxic metal in sample such as clinical sample such as stool, saliva, sputum, bronchial lavage, urine, vaginal swab, nasal swab, biopsy, tissue, tears, breath, blood, serum, plasma, cerebrospinal fluid, peritoneal fluid, pleural fluid, pericardial fluid, joint fluid, and amniotic fluid, water sample, food sample, air sample, and soil sample (all claimed). ADVANTAGE - The sensor for use with the portable analytical instrument is configured for detection of metalsin samples. The sensor can provide the excellent solution for on-site metal detection, including heavy metal detection. The sensors can provide significant advantages in higher throughput, lower cost, at the same time being less labor intensive and less dependent on individual skills. The disposable design of the sensor, the enhanced reliability and repeatability of measurements can be obtained. The sensors can be widely applied in various industries. DETAILED DESCRIPTION - INDEPENDENT CLAIMS are included for the following: (1) a system for detecting metal in sample; and (2) a method for using sensor for detecting metal in sample. DESCRIPTION OF DRAWING(S) - The drawing shows a schematic view of the sensor prototype. Channel (3) Sensing electrodes (4) Temperature sensor (6) Working electrode (8) Counter electrode (9) Reference electrode (10)

  2. Ageing management in Sweden

    International Nuclear Information System (INIS)

    Since the adoption of the 1997 act of parliament concerning the abolishment of nuclear power in Sweden plant lives are no longer limited until 2010 as they were following the referendum in 1980. The Swedish Nuclear Power Inspectorate (SKI) has therefore in its most recent general regulations from 2004 introduced requirements for nuclear power plants to develop ageing management programmes which should have been in place by the end of 2005. Since SKI:s role is not to provide detailed regulations but to ensure that the licensees take the full responsibility for the safety of their plants the detailed contents of the programmes have not been stipulated by SKI. An ageing management programme should coordinate the plant efforts in other programmes such as maintenance, monitoring, inspection, environmental qualification, chemistry, periodic testing and surveillance programmes that should already exist. In this way an integrated and long term approach to these issues can be ensured and become a natural part in the overall management of the plant. To this end it is important that the ageing management programme, as all other central programmes and processes, is documented in the quality assurance system, overall management system and is included in the underlying safety analysis report of the plant. Once the ageing management programmes have been established SKI is planning to assess them specifically through a combination of inspection and document reviews during 2008 and 2009. Thereafter it is anticipated that the major regulatory effort will be concentrated to the assessment of the periodic safety reviews to determine the effectiveness of the programmes and whether further specific regulatory action is required. SKI will also continue its active involvement in national and international research efforts to improve the understanding of ageing and degradation mechanisms. (author)

  3. Demographic Consequences of Defeating Aging

    OpenAIRE

    Gavrilov, Leonid A.; Gavrilova, Natalia S.

    2010-01-01

    A common objection against starting a large-scale biomedical war on aging is the fear of catastrophic population consequences (overpopulation). This fear is only exacerbated by the fact that no detailed demographic projections for radical life extension scenario have been conducted so far. This study explores different demographic scenarios and population projections, in order to clarify what could be the demographic consequences of a successful biomedical war on aging. A general conclusion o...

  4. An Examination of the Association between Interviewer Question Type and Story-Grammar Detail in Child Witness Interviews about Abuse

    Science.gov (United States)

    Feltis, Brooke B.; Powell, Martine B.; Snow, Pamela C.; Hughes-Scholes, Carolyn H.

    2010-01-01

    Objective: This study compared the effects of open-ended versus specific questions, and various types of open-ended questions, in eliciting story-grammar detail in child abuse interviews. Methods: The sample included 34 police interviews with child witnesses aged 5-15 years ("M" age = 9 years, 9 months). The interviewers' questions and their…

  5. Hormesis in aging.

    Science.gov (United States)

    Rattan, Suresh I S

    2008-01-01

    Hormesis in aging is represented by mild stress-induced stimulation of protective mechanisms in cells and organisms resulting in biologically beneficial effects. Single or multiple exposure to low doses of otherwise harmful agents, such as irradiation, food limitation, heat stress, hypergravity, reactive oxygen species and other free radicals have a variety of anti-aging and longevity-extending hormetic effects. Detailed molecular mechanisms that bring about the hormetic effects are being increasingly understood, and comprise a cascade of stress response and other pathways of maintenance and repair. Although the extent of immediate hormetic effects after exposure to a particular stress may only be moderate, the chain of events following initial hormesis leads to biologically amplified effects that are much larger, synergistic and pleiotropic. A consequence of hormetic amplification is an increase in the homeodynamic space of a living system in terms of increased defence capacity and reduced load of damaged macromolecules. Hormetic strengthening of the homeodynamic space provides wider margins for metabolic fluctuation, stress tolerance, adaptation and survival. Hormesis thus counter-balances the progressive shrinkage of the homeodynamic space, which is the ultimate cause of aging, diseases and death. Healthy aging may be achieved by hormesis through mild and periodic, but not severe or chronic, physical and mental challenges, and by the use of nutritional hormesis incorporating mild stress-inducing molecules called hormetins. The established scientific foundations of hormesis are ready to pave the way for new and effective approaches in aging research and intervention.

  6. Atmospheric pollutants in alpine peat bogs record a detailed chronology of industrial and agricultural development on the Australian continent

    International Nuclear Information System (INIS)

    Two peat bogs from remote alpine sites in Australia were found to contain detailed and coherent histories of atmospheric metal pollution for Pb, Zn, Cu, Mo, Ag, As, Cd, Sb, Zn, In, Cr, Ni, Tl and V. Dramatic increases in metal deposition in the post-1850 AD portion of the cores coincide with the onset of mining in Australia. Using both Pb isotopes and metals, pollutants were ascribed to the main atmospheric pollution emitting sources in Australia, namely mining and smelting, coal combustion and agriculture. Results imply mining and metal production are the major source of atmospheric metal pollution, although coal combustion may account for up to 30% of metal pollutants. A novel finding of this study is the increase in the otherwise near-constant Y/Ho ratio after 1900 AD. We link this change to widespread and increased application of marine phosphate fertiliser in Australia's main agricultural area (the Murray Darling Basin). - Detailed records of atmospheric metal pollution accumulation in Australia are presented and are shown to trace the industrial and agricultural development of the continent.

  7. Metallic spintronic devices

    CERN Document Server

    Wang, Xiaobin

    2014-01-01

    Metallic Spintronic Devices provides a balanced view of the present state of the art of metallic spintronic devices, addressing both mainstream and emerging applications from magnetic tunneling junction sensors and spin torque oscillators to spin torque memory and logic. Featuring contributions from well-known and respected industrial and academic experts, this cutting-edge work not only presents the latest research and developments but also: Describes spintronic applications in current and future magnetic recording devicesDiscusses spin-transfer torque magnetoresistive random-access memory (STT-MRAM) device architectures and modelingExplores prospects of STT-MRAM scaling, such as detailed multilevel cell structure analysisInvestigates spintronic device write and read optimization in light of spintronic memristive effectsConsiders spintronic research directions based on yttrium iron garnet thin films, including spin pumping, magnetic proximity, spin hall, and spin Seebeck effectsProposes unique solutions for ...

  8. Age Rules

    Science.gov (United States)

    Taylor, G. J.

    2015-10-01

    The ages of rocks from the lunar highlands vary widely, even for a single rock sample. This makes it difficult to quantitatively test ideas for early lunar differentiation and formation of the crust. Lars Borg and Amy Gaffney (Lawrence Livermore National Laboratory), and Charles Shearer (University of New Mexico) have devised a set of guidelines to apply to geochronological data that leads to a relative ranking of the reliability of the age determined for a sample. Applying their guidelines to existing data for lunar highland rocks shows an upper limit on rock ages between 4340 and 4370 million years. This is essentially the same as the so-called model ages of the formation of KREEP (a chemical component enriched in potassium, rare earth elements, and phosphorous) and of the formation of the deep source regions that melted to produce mare basalts. The numerous ages close to 4370 million years suggests a complicated and protracted cooling of the primordial lunar magma ocean or a widespread vigorous period of magmatic activity in the Moon.

  9. Successful ageing

    DEFF Research Database (Denmark)

    Bülow, Morten Hillgaard; Söderqvist, Thomas

    2014-01-01

    prevention strategies; and the importance of individual, societal and scientific conceptualisations and understandings of ageing. By presenting an account of the recent historical uses, interpretations and critiques of the concept, the article unfolds the practical and normative complexities of ‘ successful......Since the late 1980s, the concept of ‘ successful ageing’ has set the frame for discourse about contemporary ageing research. Through an analysis of the reception to John W. Rowe and Robert L. Kahn's launch of the concept of ‘ successful ageing’ in 1987, this article maps out the important themes...

  10. Age management

    OpenAIRE

    Kratochvilová, Markéta

    2014-01-01

    The Bachelor‘s thesis focuses on Age Management and its areas of influence. This term is most often discussed in connection with a problem which is currently common for all European Union countries – the ageing of society. In the near future, the structure of society is very likely to be altered drastically as a consequence of this phenomenon and due to the severity of the effects, it is necessary to begin addressing this problem. The first part of the thesis concerns itself with processing d...

  11. Plasma metallization

    CERN Document Server

    Crowther, J M

    1997-01-01

    Many methods are currently used for the production of thin metal films. However, all of these have drawbacks associated with them, for example the need for UHV conditions, high temperatures, exotic metal precursors, or the inability to coat complex shaped objects. Reduction of supported metal salts by non-isothermal plasma treatment does not suffer from these drawbacks. In order to produce and analyse metal films before they become contaminated, a plasma chamber which could be attached directly to a UHV chamber with XPS capability was designed and built. This allowed plasma treatment of supported metal salts and surface analysis by XPS to be performed without exposure of the metal film to the atmosphere. Non-equilibrium plasma treatment of Nylon 66 supported gold(lll) chloride using hydrogen as the feed gas resulted in a 95% pure gold film, the remaining 5% of the film being carbon. If argon or helium were used as the feed gases during plasma treatment the resultant gold films were 100% pure. Some degree of s...

  12. Ca II triplet spectroscopy of RGB stars in NGC 6822: kinematics and metallicities

    Science.gov (United States)

    Swan, J.; Cole, A. A.; Tolstoy, E.; Irwin, M. J.

    2016-03-01

    We present a detailed analysis of the chemistry and kinematics of red giants in the dwarf irregular galaxy NGC 6822. Spectroscopy at ≈8500 Å was acquired for 72 red giant stars across two fields using FORS2 at the VLT. Line-of-sight extinction was individually estimated for each target star to accommodate the variable reddening across NGC 6822. The mean radial velocity was found to be = -52.8 ± 2.2 km s-1 with dispersion σv = 24.1 km s-1, in agreement with other studies. Ca II triplet equivalent widths were converted into [Fe/H] metallicities using a V magnitude proxy for surface gravity. The average metallicity was = -0.84 ± 0.04 with dispersion σ = 0.31 dex and interquartile range 0.48. Our assignment of individual reddening values makes our analysis more sensitive to spatial variations in metallicity than previous studies. We divide our sample into metal-rich and metal-poor stars; the former were found to cluster towards small radii with the metal-poor stars more evenly distributed across the galaxy. The velocity dispersion of the metal-poor stars was found to be higher than that of the metal-rich stars (σ _{v_MP}=27.4 km s-1; σ _{v_MR}=21.1 km s-1); combined with the age-metallicity relation this indicates that the older populations have either been dynamically heated during their lifetimes or were born in a less disc-like distribution than the younger stars.. The low ratio vrot/σv suggests that within the inner 10 arcmin, NGC 6822's stars are dynamically decoupled from the H I gas, and possibly distributed in a thick disc or spheroid structure.

  13. Influence of pigment and opacifier on dimensional stability and detail reproduction of maxillofacial silicone elastomer.

    Science.gov (United States)

    Haddad, Marcela Filié; Goiato, Marcelo Coelho; Dos Santos, Daniela Micheline; Pesqueira, Aldiéris Alves; Moreno, Amália; Pellizzer, Eduardo Piza

    2011-09-01

    We evaluated the influence of chemical disinfection and accelerated aging on the dimensional stability and detail reproduction of a silicone elastomer containing an opacifier and/or a pigment. A total of 120 samples were fabricated from Silastic MDX 4-4210 silicone and divided into groups (n = 10) according to pigment and/or opacifier (ceramic powder and/or barium sulfate) and disinfectant solution (neutral soap, Efferdent, or 4% chlorhexidine). The specimens were disinfected 3 times per week during 60 days and then subjected to accelerated aging for 1008 hours. Dimensional stability and detail reproduction tests were performed after specimens' fabrication (baseline) and chemical disinfection and periodically during accelerated aging (252, 504, and 1008 hours). The results were analyzed using 3-way repeated-measures analysis of variance and the Tukey Honestly Significant Difference test (a = 0.05). All groups exhibited dimensional changes over time. The disinfectant, pigment, and time (P < 0.0001) affected the dimensional stability of silicone. Statistically significant dimensional differences were not observed between the tested groups. Accelerated aging influenced the dimensional stability of the samples. All groups scored 2 in the detail reproduction tests, which represents the full reproduction of 3 test grooves with accurate angles. Incorporation of opacifier and/or pigment alters the dimensional stability of silicones used in facial prosthetics but seems to have no influence on detail reproduction. Accelerated aging is responsible for most of the dimensional changes in Silastic MDX4 4210, but all dimensional changes measured in this study remained within the limits of stability necessary for this application. PMID:21959398

  14. Aging Secret

    Science.gov (United States)

    Journal of College Science Teaching, 2005

    2005-01-01

    The canny world of advertising has caught on to the free radical theory of aging, marketing a whole array of antioxidants for preventing anything from wrinkles to dry hair to reducing the risk of heart disease--promising to help slow the hands of time. Working with genetically engineered mice--to produce a natural antioxidant enzyme called…

  15. Age Spots

    Science.gov (United States)

    ... for treating age spots include: Improved appearance. Enhanced self-esteem. Promotion of better skin health. What you need ... 480px View Render 320px View Connect with ASDS: Facebook LinkedIn YouTube Twitter Quick Links About ASDS Advocacy ...

  16. Aging perspectives

    NARCIS (Netherlands)

    Cosco, T.D.; Brehme, D.; Grigoruta, N.; Kaufmann, L.K.; Lemsalu, L.; Meex, R.C.R.; Schuurmans, A.T.; Sener, N.

    2014-01-01

    Despite the proliferation of successful ageing (SA) research, the literature is dominated by researcher-driven Anglophone conceptualisations. To date, lay perspectives of SA have not been examined in Europe or Turkey. The current study aims to conduct a mixed-methods examination of conceptualisation

  17. Successful ageing

    DEFF Research Database (Denmark)

    Kusumastuti, Sasmita; Derks, Marloes G M; Tellier, Siri;

    2016-01-01

    . METHODS: We performed a novel, hypothesis-free and quantitative analysis of citation networks exploring the literature on successful ageing that exists in the Web of Science Core Collection Database using the CitNetExplorer software. Outcomes were visualized using timeline-based citation patterns...

  18. Constipation in old age.

    LENUS (Irish Health Repository)

    Gallagher, Paul

    2009-01-01

    The prevalence of constipation increases with age. However, constipation is not a physiological consequence of normal ageing. Indeed, the aetiology of constipation in older people is often multifactorial with co-morbid diseases, impaired mobility, reduced dietary fibre intake and prescription medications contributing significantly to constipation in many instances. A detailed clinical history and physical examination including digital rectal examination is usually sufficient to uncover the causes of constipation in older people; more specialized tests of anorectal physiology and colonic transit are rarely required. The scientific evidence base from which to develop specific treatment recommendations for constipation in older people is, for the most part, slim. Constipation can be complicated by faecal impaction and incontinence, particularly in frail older people with reduced mobility and cognitive impairment; preventative strategies are important in those at risk.

  19. Endocrine Disease in Aged Horses.

    Science.gov (United States)

    Durham, Andy E

    2016-08-01

    Aging horses may be at particular risk of endocrine disease. Two major equine endocrinopathies, pituitary pars intermedia dysfunction and equine metabolic syndrome, are commonly encountered in an aging population and may present with several recognizable signs, including laminitis. Investigation, treatment, and management of these diseases are discussed. Additionally, aging may be associated with development of rarer endocrinopathic problems, often associated with neoplasia, including diabetes mellitus and other confounders of glucose homeostasis, as well as thyroid, parathyroid, and adrenal diseases. Brief details of the recognition and management of these conditions are presented. PMID:27449391

  20. Metallic Hydrogen

    Science.gov (United States)

    Silvera, Isaac; Zaghoo, Mohamed; Salamat, Ashkan

    2015-03-01

    Hydrogen is the simplest and most abundant element in the Universe. At high pressure it is predicted to transform to a metal with remarkable properties: room temperature superconductivity, a metastable metal at ambient conditions, and a revolutionary rocket propellant. Both theory and experiment have been challenged for almost 80 years to determine its condensed matter phase diagram, in particular the insulator-metal transition. Hydrogen is predicted to dissociate to a liquid atomic metal at multi-megabar pressures and T =0 K, or at megabar pressures and very high temperatures. Thus, its predicted phase diagram has a broad field of liquid metallic hydrogen at high pressure, with temperatures ranging from thousands of degrees to zero Kelvin. In a bench top experiment using static compression in a diamond anvil cell and pulsed laser heating, we have conducted measurements on dense hydrogen in the region of 1.1-1.7 Mbar and up to 2200 K. We observe a first-order phase transition in the liquid phase, as well as sharp changes in optical transmission and reflectivity when this phase is entered. The optical signature is that of a metal. The mapping of the phase line of this transition is in excellent agreement with recent theoretical predictions for the long-sought plasma phase transition to metallic hydrogen. Research supported by the NSF, Grant DMR-1308641, the DOE Stockpile Stewardship Academic Alliance Program, Grant DE-FG52-10NA29656, and NASA Earth and Space Science Fellowship Program, Award NNX14AP17H.

  1. Research on the Hotel Image Based on the Detail Service

    Science.gov (United States)

    Li, Ban; Shenghua, Zheng; He, Yi

    Detail service management, initially developed as marketing programs to enhance customer loyalty, has now become an important part of customer relation strategy. This paper analyzes the critical factors of detail service and its influence on the hotel image. We establish the theoretical model of influencing factors on hotel image and propose corresponding hypotheses. We use applying statistical method to test and verify the above-mentioned hypotheses. This paper provides a foundation for further study of detail service design and planning issues.

  2. Half metallic ferromagnets.

    Science.gov (United States)

    Dowben, Peter

    2007-08-01

    as surface and interface reconstructions. Thus spin injection, i.e. the spin polarization of the current through the interface, may be effectively reduced to very low values, although the non-equilibrium spin polarization of the electron density can have very high values in select devices. Underlying these issues is the need to consider the definition of polarization: not all polarizations are equal. Polarization depends on the measurement. We do not always measure a polarization that follows the usual definition of spin polarization, and in many cases, it is not exactly clear what polarization has been measured. For example, there are corrections for the Fermi velocity ν(↓,↑) and spin relaxation τ(↓,↑): [Formula: see text] where n = 1 applies to the ballistic regime and n = 2 applies to the diffuse regime [3]. Neglecting interfaces and other complications, the diffuse regime (n = 2) should be the spin polarization of the bulk conductivity while ballistic regime (n = 1) is the polarization of the tunnel current and, in principle, Andreev reflection. As a result, suitable spin dependent Fermi velocity corrections might overcome an otherwise lackluster polarization for some device structures. Even measurements of polarization that are Fermi velocity independent (n = 0) may still depend on the wave vector and details of the interface band structure: as in the case of spin polarized photoemission and inverse photoemission. This special issue cannot possibly give due justice to all the various aspects of the physics of half metallic systems. By including both advocates and critics of half metallic ferromagnetism, the special issue should provide at least a taste of the controversies and challenges that exist in the study of half metallic ferromagnets. It may be that 'nature abhors half-metallicity' [2], and that relatively minor structural and thermal perturbations have a disproportionally strong effect on the density of states at the Fermi level, but in spite

  3. PREFACE: Half Metallic Ferromagnets

    Science.gov (United States)

    Dowben, Peter

    2007-08-01

    surface and interface reconstructions. Thus spin injection, i.e. the spin polarization of the current through the interface, may be effectively reduced to very low values, although the non-equilibrium spin polarization of the electron density can have very high values in select devices. Underlying these issues is the need to consider the definition of polarization: not all polarizations are equal. Polarization depends on the measurement. We do not always measure a polarization that follows the usual definition of spin polarization, and in many cases, it is not exactly clear what polarization has been measured. For example, there are corrections for the Fermi velocity ν↓,↑ and spin relaxation τ↓,↑: equation 1 where n = 1 applies to the ballistic regime and n = 2 applies to the diffuse regime [3]. Neglecting interfaces and other complications, the diffuse regime (n = 2) should be the spin polarization of the bulk conductivity while ballistic regime (n = 1) is the polarization of the tunnel current and, in principle, Andreev reflection. As a result, suitable spin dependent Fermi velocity corrections might overcome an otherwise lackluster polarization for some device structures. Even measurements of polarization that are Fermi velocity independent (n = 0) may still depend on the wave vector and details of the interface band structure: as in the case of spin polarized photoemission and inverse photoemission. This special issue cannot possibly give due justice to all the various aspects of the physics of half metallic systems. By including both advocates and critics of half metallic ferromagnetism, the special issue should provide at least a taste of the controversies and challenges that exist in the study of half metallic ferromagnets. It may be that 'nature abhors half-metallicity' [2], and that relatively minor structural and thermal perturbations have a disproportionally strong effect on the density of states at the Fermi level, but in spite of much study half

  4. Introduction to metal-nanoparticle plasmonics

    CERN Document Server

    Pelton, Matthew

    2013-01-01

    Based on a popular article in Laser and Photonics Reviews, this book provides an explanation and overview of the techniques used to model, make, and measure metal nanoparticles, detailing results obtained and what they mean. It covers the properties of coupled metal nanoparticles, the nonlinear optical response of metal nanoparticles, and the phenomena that arise when light-emitting materials are coupled to metal nanoparticles. It also provides an overview of key potential applications and offers explanations of computational and experimental techniques giving readers a solid grounding

  5. Combustion instability detection using the wavelet detail of pressure fluctuations

    Institute of Scientific and Technical Information of China (English)

    Junjie JI; Yonghao LUO

    2008-01-01

    A combustion instability detection method that uses the wavelet detail of combustion pressure fluctuations is put forward. To confirm this method, combustion pressure fluctuations in a stoker boiler are recorded at stable and unstable combustion with a pressure transducer. Daubechies one-order wavelet is chosen to obtain the wavelet details for comparison. It shows that the wavelet approximation indicates the general pressure change in the furnace, and the wavelet detail magnitude is consistent with the intensity of turbulence and combustion noise. The magnitude of the wavelet detail is nearly constant when the combustion is stable, however, it will fluctuate much when the combustion is unstable.

  6. Golden Age

    Institute of Scientific and Technical Information of China (English)

    2013-01-01

      Sometimes, a moment can announce the end of an age. The gold market is like that. Within two transaction days, the gold slumped by 13%and saw a 25%tumble from the high point in August 2011. According to the classic investment theory, a 20%-above decline means the shift from“a bull”to“a bear”market.   The super bear market of gold has lasted a dozen years. But the bull-to-bear shift was completed within only 20 minutes. Wall Street’s analysts and ordinary Chinese people had different understandings to the golden age.   Expecting a bear market, Wall Street continuously dumped gold, resulting in a diving of gold price. Seeing the benefits, leisure Chinese madams made a gold rush, causing a slight bounce of gold price. On April 23, renowned investment bank Goldman Sachs suspended the short sale. So,“Chinese aunts”beating back Wall Street’s analysts became the hottest topic online for the time being.   What are the decisive factors for the crash of gold price? Will the gold market complete a real bull-to-bear shift? Will the golden age of gold be farther or nearer?

  7. Durability of metals from archaeological objects, metal meteorites, and native metals

    Energy Technology Data Exchange (ETDEWEB)

    Johnson, A.B. Jr.; Francis, B.

    1980-01-01

    Metal durability is an important consideration in the multi-barrier nuclear waste storage concept. This study summarizes the ancient metals, the environments, and factors which appear to have contributed to metal longevity. Archaeological and radiochemical dating suggest that human use of metals began in the period 6000 to 7000 BC. Gold is clearly the most durable, but many objects fashioned from silver, copper, bronze, iron, lead, and tin have survived for several thousand years. Dry environments, such as tombs, appear to be optimum for metal preservation, but some metals have survived in shipwrecks for over a thousand years. The metal meteorites are Fe-base alloys with 5 to 60 wt% Ni and minor amounts of Co, I, and S. Some meteoritic masses with ages estimated to be 5,000 to 20,000 years have weathered very little, while other masses from the same meteorites are in advanced stages of weathering. Native metals are natural metallic ores. Approximately five million tonnes were mined from native copper deposits in Michigan. Copper masses from the Michigan deposits were transported by the Pleistocene glaciers. Areas on the copper surfaces which appear to represent glacial abrasion show minimal corrosion. Dry cooling tower technology has demonstrated that in pollution-free moist environments, metals fare better at temperatures above than below the dewpoint. Thus, in moderate temperature regimes, elevated temperatures may be useful rather than detrimental for exposures of metal to air. In liquid environments, relatively complex radiolysis reactions can occur, particularly where multiple species are present. A dry environment largely obviates radiolysis effects.

  8. Durability of metals from archaeological objects, metal meteorites, and native metals

    International Nuclear Information System (INIS)

    Metal durability is an important consideration in the multi-barrier nuclear waste storage concept. This study summarizes the ancient metals, the environments, and factors which appear to have contributed to metal longevity. Archaeological and radiochemical dating suggest that human use of metals began in the period 6000 to 7000 BC. Gold is clearly the most durable, but many objects fashioned from silver, copper, bronze, iron, lead, and tin have survived for several thousand years. Dry environments, such as tombs, appear to be optimum for metal preservation, but some metals have survived in shipwrecks for over a thousand years. The metal meteorites are Fe-base alloys with 5 to 60 wt% Ni and minor amounts of Co, I, and S. Some meteoritic masses with ages estimated to be 5,000 to 20,000 years have weathered very little, while other masses from the same meteorites are in advanced stages of weathering. Native metals are natural metallic ores. Approximately five million tonnes were mined from native copper deposits in Michigan. Copper masses from the Michigan deposits were transported by the Pleistocene glaciers. Areas on the copper surfaces which appear to represent glacial abrasion show minimal corrosion. Dry cooling tower technology has demonstrated that in pollution-free moist environments, metals fare better at temperatures above than below the dewpoint. Thus, in moderate temperature regimes, elevated temperatures may be useful rather than detrimental for exposures of metal to air. In liquid environments, relatively complex radiolysis reactions can occur, particularly where multiple species are present. A dry environment largely obviates radiolysis effects

  9. 46 CFR 56.75-30 - Pipe joining details.

    Science.gov (United States)

    2010-10-01

    ... 46 Shipping 2 2010-10-01 2010-10-01 false Pipe joining details. 56.75-30 Section 56.75-30 Shipping COAST GUARD, DEPARTMENT OF HOMELAND SECURITY (CONTINUED) MARINE ENGINEERING PIPING SYSTEMS AND APPURTENANCES Brazing § 56.75-30 Pipe joining details. (a) Silver brazing. (1) Circumferential pipe joints...

  10. 46 CFR 56.75-25 - Detail requirements.

    Science.gov (United States)

    2010-10-01

    ... 46 Shipping 2 2010-10-01 2010-10-01 false Detail requirements. 56.75-25 Section 56.75-25 Shipping COAST GUARD, DEPARTMENT OF HOMELAND SECURITY (CONTINUED) MARINE ENGINEERING PIPING SYSTEMS AND APPURTENANCES Brazing § 56.75-25 Detail requirements. (a) Pipe may be fabricated by brazing when the...

  11. ZBLAN supercontinuum generation - detailed comparison between measurement and simulation

    DEFF Research Database (Denmark)

    Agger, Christian; Petersen, Christian; Dupont, Sune;

    2011-01-01

    We present a detailed comparison between modeling and experiments on supercontinuum generation in a ZBLAN fiber. Good agreement is obtained when pumping both in the normal and anomalous dispersion regimes.......We present a detailed comparison between modeling and experiments on supercontinuum generation in a ZBLAN fiber. Good agreement is obtained when pumping both in the normal and anomalous dispersion regimes....

  12. Commentary: The Perils of Seduction: Distracting Details or Incomprehensible Abstractions?

    Science.gov (United States)

    Goetz, Ernest T.; Sadoski, Mark

    1995-01-01

    Reviews studies that have explicitly investigated the "seductive detail" effect (in which a reader's attention is diverted toward the interesting but unimportant seductive details and away from the uninteresting but important main ideas). Concludes that these studies do not provide convincing evidence for the existence of the effect. Argues that…

  13. 44 CFR 5.27 - Deletion of identifying details.

    Science.gov (United States)

    2010-10-01

    ... 44 Emergency Management and Assistance 1 2010-10-01 2010-10-01 false Deletion of identifying details. 5.27 Section 5.27 Emergency Management and Assistance FEDERAL EMERGENCY MANAGEMENT AGENCY..., FEMA may delete identifying details when making available or publishing an opinion, statement of...

  14. Space Telecommunications Radio System (STRS) Architecture, Tutorial Part 2 - Detailed

    Science.gov (United States)

    Handler, Louis

    2014-01-01

    The STRS architecture detail presentation presents each requirement in the STRS Architecture Standard with some examples and supporting information. The purpose is to give a platform provider, application provider, or application integrator a better, more detailed understanding of the STRS Architecture Standard and its use.

  15. Detailed analysis of a quench bomb for the study of aluminum agglomeration in solid propellants

    Science.gov (United States)

    Gallier, S.; Kratz, J.-G.; Quaglia, N.; Fouin, G.

    2016-07-01

    A standard quench bomb (QB) - widely used to characterize condensed phase from metalized solid propellant combustion - is studied in detail. Experimental and numerical investigations proved that collected particles are mostly unburned aluminum (Al) agglomerates despite large quenching distances. Particles are actually found to quench early as propellant surface is swept by inert pressurant. Further improvements of the QB are proposed which allow measuring both Al agglomerates and alumina residue with the same setup. Finally, the results obtained on a typical aluminized ammonium perchlorate (AP) / hydroxyl-terminated polybutadiene (HTPB) propellant are briefly discussed.

  16. Metal Dusting-Mechanisms and Preventions

    Institute of Scientific and Technical Information of China (English)

    J.Q.ZHANG; D.J.YOUNG

    2009-01-01

    Metal dusting attacks iron, low and high alloy steels and nickel-or cobalt-base alloys by disintegrating bulk metals and alloys into metal particles in a coke deposit. It occurs in strongly carburising gas atmospheres (carbon activity aC>1) at elevated temperatures (400℃~1000℃). This phenomenon has been studied for decades, but the detailed mechanism is still not well understood. Current methods of protection against metal dusting are either directed to the process conditions-temperature and gas composition-or to the development of a dense adherent oxide layer on the surface of the alloy by selective oxidation. However, metal dusting still occurs by carbon dissolving in the base metal via defects in the oxide scale. The research work at UNSW is aimed at determining the detailed mechanism of metal dusting of both ferritic and austenitic alloys, in particular the microprocesses of graphite deposition, nanoparticle formation and underlying metal destruction. This work was carried out using surface observation, cross-section analysis by focused ion beam and electron microscopic examination of coke deposits at different stages of the reaction. It was found that surface orientation affected carbon deposition and metal dusting at the initial stage of the reaction. Metal dusting occurred only when graphite grew into the metal interior where the volume expansion is responsible for metal disintegration and dusting. It was also found that the metal dusting process could be significantly changed by alterations in alloy chemistry. Germanium was found to affect the iron dusting process by destabilising FeC but increasing the rate of carbon deposition and dusting, which questions the role of cementite in ferritic alloy dusting. Whilst adding copper to iron did not change the carburisation kinetics, cementite formation and coke morphology, copper alloying reduced nickel and nickel-base alloy dusting rates significantly. Application of these fundamental results to the dusting

  17. EFFECTS OF METAL IONS ON THE CONFORMATIONAL CHANGES OF DNA

    Institute of Scientific and Technical Information of China (English)

    G. Q. Liu; Y.Y. Meng; S.H. Liu; Y.H. Hu

    2005-01-01

    DNA takes on multi-different conformations such as A-, B-, C-, D- and Z-form. These conformations can transit to one another when DNA deposited in some metal ions solutions or when changing the concentrations of the same metal ions. Here, several major conformational transitions of DNA induced by metal ions under different environment were introduced and the mechanism of the interaction of metal ions with DNA was discuss in detail.

  18. Minor heavy metal: A review on occupational and environmental intoxication

    OpenAIRE

    Wiwanitkit Viroj

    2008-01-01

    Heavy metal is widely used in industries and presents as a problematic environmental pollution. Some heavy metals, especially lead and mercury, are well described for their occupational and environmental intoxication whereas the other minor heavy metals are less concerned. In this article, the author will present the details of occupational and environmental minor heavy metal intoxication. This review focuses mainly on aluminum, tin, copper, manganese, chromium, cadmium and nickel.

  19. Detailed chemical abundances of extragalactic globular clusters using high resolution, integrated light spectra

    Science.gov (United States)

    Colucci, Janet E.

    Globular clusters (GCs) are luminous, observationally accessible objects that are good tracers of the total star formation and evolutionary history of galaxies. We present the first detailed chemical abundances for GCs in M31 using a new abundance analysis technique designed for high resolution, integrated light (IL) spectra of GCs. This technique has recently been developed using a training set of old GCS in the Milky Way (MW), and makes possible detailed chemical evolution studies of distant galaxies, where high resolution abundance analysis of individual stars are not obtainable. For the 5 M31 GCs presented here, we measure abundances of 14 elements: Mg, Al, Si, Ca, Sc, Ti, V, Cr, Mn, Fe, Co, Ni, Y, and Ba. We find the M31 GCs have ages (>10 Gyr) and chemical properties similar to MW GCs, including an enhancement in the alpha-elements Ca, Ti and Si of [alpha/Fe]˜ +0.4. In this thesis, we also further develop this IL abundance analysis method to include GCs of ages 10 Myr--12 Gyrs using GCs in the Large Magellanic Cloud (LMC), which contains the necessary sample of clusters over this wide age range. This work demonstrates for the first time that this IL abundance analysis method can be used on clusters of all ages, and that ages can be constrained to within 1--2 Gyr for clusters with ages of ˜2 Gyr and within a few 100 Myr for clusters with ages chemical abundances of 22 elements are reported for six LMC clusters.

  20. Broken detailed balance at mesoscopic scales in active biological systems.

    Science.gov (United States)

    Battle, Christopher; Broedersz, Chase P; Fakhri, Nikta; Geyer, Veikko F; Howard, Jonathon; Schmidt, Christoph F; MacKintosh, Fred C

    2016-04-29

    Systems in thermodynamic equilibrium are not only characterized by time-independent macroscopic properties, but also satisfy the principle of detailed balance in the transitions between microscopic configurations. Living systems function out of equilibrium and are characterized by directed fluxes through chemical states, which violate detailed balance at the molecular scale. Here we introduce a method to probe for broken detailed balance and demonstrate how such nonequilibrium dynamics are manifest at the mesosopic scale. The periodic beating of an isolated flagellum from Chlamydomonas reinhardtii exhibits probability flux in the phase space of shapes. With a model, we show how the breaking of detailed balance can also be quantified in stationary, nonequilibrium stochastic systems in the absence of periodic motion. We further demonstrate such broken detailed balance in the nonperiodic fluctuations of primary cilia of epithelial cells. Our analysis provides a general tool to identify nonequilibrium dynamics in cells and tissues. PMID:27126047

  1. Aging Perspectives

    Directory of Open Access Journals (Sweden)

    Theodore D Cosco

    2014-05-01

    Full Text Available Despite the proliferation of successful ageing (SA research, the literature is dominated by researcher-driven Anglophone conceptualisations. To date, lay perspectives of SA have not been examined in Europe or Turkey. The current study aims to conduct a mixed-methods examination of conceptualisations of SA in seven underrepresented countries. Using snowball sampling via social media sites, an online survey consisting of established closed-ended and open-ended items – translated into seven languages – was administered. Grounded theory methods and descriptive statistics were used to analyse qualitative and quantitative data, respectively.

  2. Ice ages

    International Nuclear Information System (INIS)

    The Earth's climate undergoes great changes in cycles of 104 to 105 years. Deep sea sediments contain proof of these changes. The critical parameter is the O18/O16 isotope ratio. The astronomical theory is discussed of ice ages based on the changes in the shape of the Earth's orbit around the sun. Forecasts for the future are given - in the coming years the climate is expected to get warmer owing to increased CO2 levels in the atmosphere, and then a long cooler period is expected to follow. (M.D.)

  3. Modeling the Metallicity Distribution of Globular Clusters

    CERN Document Server

    Muratov, Alexander L

    2010-01-01

    Observed metallicities of globular clusters reflect physical conditions in the interstellar medium of their high-redshift host galaxies. Globular cluster systems in most large galaxies display bimodal color and metallicity distributions, which are often interpreted as indicating two distinct modes of cluster formation. The metal-rich and metal-poor clusters have systematically different locations and kinematics in their host galaxies. However, the red and blue clusters have similar internal properties, such as the masses, sizes, and ages. It is therefore interesting to explore whether both metal-rich and metal-poor clusters could form by a common mechanism and still be consistent with the bimodal distribution. We present such a model, which prescribes the formation of globular clusters semi-analytically using galaxy assembly history from cosmological simulations coupled with observed scaling relations for the amount and metallicity of cold gas available for star formation. We assume that massive star clusters...

  4. Toxicity of heavy metals and metal-containing nanoparticles on plants.

    Science.gov (United States)

    Mustafa, Ghazala; Komatsu, Setsuko

    2016-08-01

    Plants are under the continual threat of changing climatic conditions that are associated with various types of abiotic stresses. In particular, heavy metal contamination is a major environmental concern that restricts plant growth. Plants absorb heavy metals along with essential elements from the soil and have evolved different strategies to cope with the accumulation of heavy metals. The use of proteomic techniques is an effective approach to investigate and identify the biological mechanisms and pathways affected by heavy metals and metal-containing nanoparticles. The present review focuses on recent advances and summarizes the results from proteomic studies aimed at understanding the response mechanisms of plants under heavy metal and metal-containing nanoparticle stress. Transport of heavy metal ions is regulated through the cell wall and plasma membrane and then sequestered in the vacuole. In addition, the role of different metal chelators involved in the detoxification and sequestration of heavy metals is critically reviewed, and changes in protein profiles of plants exposed to metal-containing nanoparticles are discussed in detail. Finally, strategies for gaining new insights into plant tolerance mechanisms to heavy metal and metal-containing nanoparticle stress are presented. This article is part of a Special Issue entitled: Plant Proteomics - a bridge between fundamental processes and crop production, edited by Dr. Hans-Peter Mock. PMID:26940747

  5. Toxicity of heavy metals and metal-containing nanoparticles on plants.

    Science.gov (United States)

    Mustafa, Ghazala; Komatsu, Setsuko

    2016-08-01

    Plants are under the continual threat of changing climatic conditions that are associated with various types of abiotic stresses. In particular, heavy metal contamination is a major environmental concern that restricts plant growth. Plants absorb heavy metals along with essential elements from the soil and have evolved different strategies to cope with the accumulation of heavy metals. The use of proteomic techniques is an effective approach to investigate and identify the biological mechanisms and pathways affected by heavy metals and metal-containing nanoparticles. The present review focuses on recent advances and summarizes the results from proteomic studies aimed at understanding the response mechanisms of plants under heavy metal and metal-containing nanoparticle stress. Transport of heavy metal ions is regulated through the cell wall and plasma membrane and then sequestered in the vacuole. In addition, the role of different metal chelators involved in the detoxification and sequestration of heavy metals is critically reviewed, and changes in protein profiles of plants exposed to metal-containing nanoparticles are discussed in detail. Finally, strategies for gaining new insights into plant tolerance mechanisms to heavy metal and metal-containing nanoparticle stress are presented. This article is part of a Special Issue entitled: Plant Proteomics--a bridge between fundamental processes and crop production, edited by Dr. Hans-Peter Mock.

  6. Aging Blepharoplasty

    Directory of Open Access Journals (Sweden)

    Inchang Cho

    2013-09-01

    Full Text Available In performing upper blepharoplasty in the elderly, looking younger and keeping the eyelidsharmonious with the rest of the face have to be achieved at the same time. The most importantgoal in upper blepharoplasty for aging is correcting the drooping upper eyelid skin, and inthis process, the surgeon may or may not create a double eyelid fold. The pros and cons haveto be fully discussed with the patient, but the author personally prefers creating a doublefold unless the patient refuses, because it is efficient in correcting and preventing furtherdrooping of the skin. In most patients, the brow is elevated to compensate for the droopingeyelid, and when the drooping is corrected, brow ptosis may ensue. The surgeon has to preparefor these consequences before performing the procedure, and estimate the exact amountof skin to be excised. In the elderly, the skin and the orbicularis oculi muscle is thin, with adecreased amount of subcutaneous fat and retro-orbicularis oculi fat, and in most cases,excision of the skin alone is enough to correct the deformity. Removing large portions ofsoft tissue may also prolong the recovery period. Unlike younger patients, the lower skinflap should not be stretched too much in the elderly, as it may create an aggressive lookingappearance. A few wrinkles in the lower flap should remain untouched to create a naturallook. In this article, the author’s own methods of performing an aging blepharoplasty aredescribed specifically, with a step-by-step guide and surgical tips.

  7. Investigating the Interaction of Graphic Organizers and Seductive Details: Can a Graphic Organizer Mitigate the Seductive-Details Effect?

    Science.gov (United States)

    Rowland-Bryant, Emily; Skinner, Christopher H.; Skinner, Amy L.; Saudargas, Richard; Robinson, Daniel H.; Kirk, Emily R.

    2009-01-01

    The interaction between seductive details (SD) and a graphic organizer (GO) was investigated. Undergraduate students (n = 207) read a target-material passage about Freud's psychosexual stages. Depending on condition, the participants also read a biographical paragraph (SD-only), viewed a graphic organizer that linked the seductive details to the…

  8. Recovering and Preventing Loss of Detailed Memory: Differential Rates of Forgetting for Detail Types in Episodic Memory

    Science.gov (United States)

    Sekeres, Melanie J.; Bonasia, Kyra; St-Laurent, Marie; Pishdadian, Sara; Winocur, Gordon; Grady, Cheryl; Moscovitch, Morris

    2016-01-01

    Episodic memories undergo qualitative changes with time, but little is known about how different aspects of memory are affected. Different types of information in a memory, such as perceptual detail, and central themes, may be lost at different rates. In patients with medial temporal lobe damage, memory for perceptual details is severely impaired,…

  9. Characteristics and impact of drug detailing for gabapentin.

    Directory of Open Access Journals (Sweden)

    Michael A Steinman

    2007-04-01

    Full Text Available BACKGROUND: Sales visits by pharmaceutical representatives ("drug detailing" are common, but little is known about the content of these visits or about the impact of visit characteristics on prescribing behavior. In this study, we evaluated the content and impact of detail visits for gabapentin by analyzing market research forms completed by physicians after receiving a detail visit for this drug. METHODS AND FINDINGS: Market research forms that describe detail visits for gabapentin became available through litigation that alleged that gabapentin was promoted for "off-label" uses. Forms were available for 97 physicians reporting on 116 detail visits between 1995 and 1999. Three-quarters of recorded visits (91/116 occurred in 1996. Two-thirds of visits (72/107 were 5 minutes or less in duration, 65% (73/113 were rated of high informational value, and 39% (42/107 were accompanied by the delivery or promise of samples. During the period of this study, gabapentin was approved by the US Food and Drug Administration only for the adjunctive treatment of partial seizures, but in 38% of visits (44/115 the "main message" of the visit involved at least one off-label use. After receiving the detail visit, 46% (50/108 of physicians reported the intention to increase their prescribing or recommending of gabapentin in the future. In multivariable analysis, intent to increase future use or recommendation of gabapentin was associated with receiving the detail in a small group (versus one-on-one setting and with low or absent baseline use of the drug, but not with other factors such as visit duration, discussion of "on-label" versus "off-label" content, and the perceived informational value of the presentation. CONCLUSIONS: Detail visits for gabapentin were of high perceived informational value and often involved messages about unapproved uses. Despite their short duration, detail visits were frequently followed by physician intentions to increase their future

  10. Detailed black hole state counting in loop quantum gravity

    Science.gov (United States)

    Agullo, Ivan; Barbero G., J. Fernando; Borja, Enrique F.; Diaz-Polo, Jacobo; Villaseñor, Eduardo J. S.

    2010-10-01

    We give a complete and detailed description of the computation of black hole entropy in loop quantum gravity by employing the most recently introduced number-theoretic and combinatorial methods. The use of these techniques allows us to perform a detailed analysis of the precise structure of the entropy spectrum for small black holes, showing some relevant features that were not discernible in previous computations. The ability to manipulate and understand the spectrum up to the level of detail that we describe in the paper is a crucial step toward obtaining the behavior of entropy in the asymptotic (large horizon area) regime.

  11. Detailed black hole state counting in loop quantum gravity

    CERN Document Server

    Agullo, Ivan; Borja, Enrique F; Diaz-Polo, Jacobo; Villaseñor, Eduardo J S; 10.1103/PhysRevD.82.084029

    2011-01-01

    We give a complete and detailed description of the computation of black hole entropy in loop quantum gravity by employing the most recently introduced number-theoretic and combinatorial methods. The use of these techniques allows us to perform a detailed analysis of the precise structure of the entropy spectrum for small black holes, showing some relevant features that were not discernible in previous computations. The ability to manipulate and understand the spectrum up to the level of detail that we describe in the paper is a crucial step towards obtaining the behavior of entropy in the asymptotic (large horizon area) regime.

  12. Reliability assessment of welded steel details in bridges using inspection

    DEFF Research Database (Denmark)

    Toft, Henrik Stensgaard; Sørensen, John Dalsgaard; Yalamas, T.;

    2014-01-01

    membrane stresses are estimated using a generic bridge structure and traffic measurements. The optimal reliability level for a welded detail in a bridge subjected to fatigue are estimated by cost benefit-analysis taking into account the risk of human lives through the Life Quality Index. Since the optimal......This paper presents a bilinear two-dimensional probabilistic fracture mechanics model for fatigue crack growth in welded steel details. The model takes besides membrane stresses also the influence of misalignments and bending stresses in the welded detail into account. The distribution of the...

  13. Nanocomposites Based on Metal and Metal Sulfide Clusters Embedded in Polystyrene

    Directory of Open Access Journals (Sweden)

    Gianfranco Carotenuto

    2011-08-01

    Full Text Available Transition-metal alkane-thiolates (i.e., organic salts with formula Me(SRx, where R is a linear aliphatic hydrocarbon group, –CnH2n+1 undergo a thermolysis reaction at moderately low temperatures (close to 200 °C, which produces metal atoms or metal sulfide species and an organic by-product, disulfide (RSSR or thioether (RSR molecules, respectively. Alkane-thiolates are non-polar chemical compounds that dissolve in most techno-polymers and the resulting solid solutions can be annealed to generate polymer-embedded metal or metal sulfide clusters. Here, the preparation of silver and gold clusters embedded into amorphous polystyrene by thermolysis of a dodecyl-thiolate precursor is described in detail. However, this chemical approach is quite universal and a large variety of polymer-embedded metals or metal sulfides could be similarly prepared.

  14. Analysis of Common Fatigue Details in Steel Truss Structures

    Institute of Scientific and Technical Information of China (English)

    张玉玲; 潘际炎; 潘际銮

    2004-01-01

    Generally, the number of fatigue cycles, the range of the repeated stresses, and the type of the structural details are the key factors affecting fatigue in large-scale welded structures. Seven types of structure details were tested using a 2000-kN hydraulic-pressure-servo fatigue machine to imitate fatigue behavior in modern steel-truss-structures fabricated using thicker welded steel plates and integral joint technology. The details included longitudinal edge welds, welded attachment affecting detail, integral joint, and weld repairs on plate edges. The fatigue damage locations show that the stress (normal or shear), the shape, and the location of the weld start and end points are three major factors reducing the fatigue strength. The test results can be used for similar large structures.

  15. Transport van perkplanten kan in details nog beter

    NARCIS (Netherlands)

    Harkema, H.; Westra, E.H.

    2012-01-01

    De perkgoedsector pakt veel zaken die de kwaliteit betreffen goed aan. Er zijn alleen nog wat details die beter kunnen. Te denken valt aan licht geven tijdens tranport en lage luchtvochtigheid voorkomen.

  16. CDC WONDER: Detailed Mortality - Underlying Cause of Death

    Data.gov (United States)

    U.S. Department of Health & Human Services — The Detailed Mortality - Underlying Cause of Death data on CDC WONDER are county-level national mortality and population data spanning the years 1999-2009. Data are...

  17. All the Exquisite Details of a Coffee Mug.

    Science.gov (United States)

    Larsen, Dave M., Jr.

    1999-01-01

    Describes a three-part exercise used in a first semester freshman composition class, intended to show students the world of details in even the most ordinary, everyday objects by having students write about a plastic coffee mug. (SR)

  18. Detailed computation of hot-plasma atomic spectra

    OpenAIRE

    Pain, Jean-Christophe; Gilleron, Franck; Blenski, Thomas

    2015-01-01

    We present recent evolutions of the detailed opacity code SCO-RCG which combines statistical modelings of levels and lines with fine-structure calculations. The code now includes the Partially-Resolved-Transition-Array model, which allows one to replace a complex transition array by a small-scale detailed calculation preserving energy and variance of the genuine transition array and yielding improved high-order moments. An approximate method for studying the impact of strong magnetic field on...

  19. A New Video Coding Method Based on Improving Detail Regions

    Institute of Scientific and Technical Information of China (English)

    2002-01-01

    The Moving Pictures Expert Group (MPEG) and H.263 standard coding method is widely used in video compression. However, the visual quality of detail regions such as eyes and mouth is not content in people at the decoder, as far as the conference telephone or videophone is concerned. A new coding method based on improving detail regions is presented in this paper. Experimental results show that this method can improve the visual quality at the decoder.

  20. Real-Time Crowdsourcing of Detailed Soccer Data

    OpenAIRE

    Perin, Charles; Vuillemot, Romain; Fekete, Jean-Daniel

    2013-01-01

    International audience This article explores how spectators of a live soccer game can collect detailed data while watching the game. Our motivation arouse from the lack of free detailed sport data, contrasting with the large amount of simple statistics collected for every popular games and available on the web. Assuming many spectators carry a smart phone during a game, we implemented a series of input interfaces for collecting data in real time. In a user study, we asked participants to u...

  1. Hidden scale invariance of metals

    DEFF Research Database (Denmark)

    Hummel, Felix; Kresse, Georg; Dyre, Jeppe C.;

    2015-01-01

    of metals making the condensed part of the thermodynamic phase diagram effectively one dimensional with respect to structure and dynamics. DFT computed density scaling exponents, related to the Grüneisen parameter, are in good agreement with experimental values for the 16 elements where reliable data were......Density functional theory (DFT) calculations of 58 liquid elements at their triple point show that most metals exhibit near proportionality between the thermal fluctuations of the virial and the potential energy in the isochoric ensemble. This demonstrates a general “hidden” scale invariance...... available. Hidden scale invariance is demonstrated in detail for magnesium by showing invariance of structure and dynamics. Computed melting curves of period three metals follow curves with invariance (isomorphs). The experimental structure factor of magnesium is predicted by assuming scale invariant...

  2. Detail Enhancement for Infrared Images Based on Propagated Image Filter

    Directory of Open Access Journals (Sweden)

    Yishu Peng

    2016-01-01

    Full Text Available For displaying high-dynamic-range images acquired by thermal camera systems, 14-bit raw infrared data should map into 8-bit gray values. This paper presents a new method for detail enhancement of infrared images to display the image with a relatively satisfied contrast and brightness, rich detail information, and no artifacts caused by the image processing. We first adopt a propagated image filter to smooth the input image and separate the image into the base layer and the detail layer. Then, we refine the base layer by using modified histogram projection for compressing. Meanwhile, the adaptive weights derived from the layer decomposition processing are used as the strict gain control for the detail layer. The final display result is obtained by recombining the two modified layers. Experimental results on both cooled and uncooled infrared data verify that the proposed method outperforms the method based on log-power histogram modification and bilateral filter-based detail enhancement in both detail enhancement and visual effect.

  3. Heavy metal removal and recovery using microorganisms

    International Nuclear Information System (INIS)

    Microorganisms -- bacteria, fungi, and microalgae -- can accumulate relatively large amounts of toxic heavy metals and radionuclides from the environment. These organisms often exhibit specificity for particular metals. The metal content of microbial biomass can be a substantial fraction of total dry weight with concentration factors (metal in dry biomass to metal in solution) exceeding one million in some cases. Both living and inert (dead) microbial biomass can be used to reduce heavy metal concentrations in contaminated waters to very low levels -- parts per billion and even lower. In many respects (e.g. specificity, residual metal concentrations, accumulation factors, and economics) microbial bioremoval processes can be superior to conventional processes, such as ion exchange and caustic (lime or hydroxide) precipitation for heavy metals removal from waste and contaminated waters. Thus, bioremoval could be developed to contribute to the clean-up of wastes at the Savannah River Site (SRS) and other DOE facilities. However, the potential advantages of bioremoval processes must still be developed into practical operating systems. A detailed review of the literature suggests that appropriate bioremoval processes could be developed for the SRS. There is great variability from one biomass source to another in bioremoval capabilities. Bioremoval is affected by pH, other ions, temperature, and many other factors. The biological (living vs. dead) and physical (immobilized vs. dispersed) characteristics of the biomass also greatly affect metal binding. Even subtle differences in the microbial biomass, such as the conditions under which it was cultivated, can have major effects on heavy metal binding

  4. Heavy metal removal and recovery using microorganisms

    Energy Technology Data Exchange (ETDEWEB)

    Wilde, E.W. (Westinghouse Savannah River Co., Aiken, SC (United States)); Benemann, J.R. (Benemann (J.R.), Pinole, CA (United States))

    1991-02-01

    Microorganisms -- bacteria, fungi, and microalgae -- can accumulate relatively large amounts of toxic heavy metals and radionuclides from the environment. These organisms often exhibit specificity for particular metals. The metal content of microbial biomass can be a substantial fraction of total dry weight with concentration factors (metal in dry biomass to metal in solution) exceeding one million in some cases. Both living and inert (dead) microbial biomass can be used to reduce heavy metal concentrations in contaminated waters to very low levels -- parts per billion and even lower. In many respects (e.g. specificity, residual metal concentrations, accumulation factors, and economics) microbial bioremoval processes can be superior to conventional processes, such as ion exchange and caustic (lime or hydroxide) precipitation for heavy metals removal from waste and contaminated waters. Thus, bioremoval could be developed to contribute to the clean-up of wastes at the Savannah River Site (SRS) and other DOE facilities. However, the potential advantages of bioremoval processes must still be developed into practical operating systems. A detailed review of the literature suggests that appropriate bioremoval processes could be developed for the SRS. There is great variability from one biomass source to another in bioremoval capabilities. Bioremoval is affected by pH, other ions, temperature, and many other factors. The biological (living vs. dead) and physical (immobilized vs. dispersed) characteristics of the biomass also greatly affect metal binding. Even subtle differences in the microbial biomass, such as the conditions under which it was cultivated, can have major effects on heavy metal binding.

  5. Heavy metal speciation in the composting process.

    Science.gov (United States)

    Greenway, Gillian M; Song, Qi Jun

    2002-04-01

    Composting is one of the more efficient and environment friendly methods of solid waste disposal and has many advantages when compared with landfill disposal on which the UK and Ireland are currently heavily dependent. Composting is a very complicated process involving intensive microbial activity and the detailed mechanisms of the process have yet to be fully understood. Metal speciation information can provide an insight into the metal-microbial interaction and would help in the evaluation of the quality of compost. This would facilitate the exploitation of composts in remediation of heavy metal contaminated land. In this work a systematic approach to metal speciation in compost has been taken by applying the three-step method for operationally defined metal speciation of soils and sediments, developed by the European Commission's Standards, Measurement and Testing Programme to monitor the change in metal speciation with time (up to 106 days) for four different waste composting processes. The results have shown that in general metals become less available for the first extraction step as the composting process proceeds. This implies that composting tends to redistribute the metals from more labile forms to more fixed forms which may explain why the application of composts could be useful for with heavy metal contaminated land. There are exceptions to this trend and in some cases, certain metals appear to behave differently depending on the source of the compost. PMID:11993774

  6. Detailed Abundances of Stars with Small Planets Discovered by Kepler I: The First Sample

    CERN Document Server

    Schuler, Simon C; Santrich, Orlando J Katime; Cunha, Katia; Smith, Verne V; King, Jeremy R; Teske, Johanna K; Ghezzi, Luan; Howell, Steve B; Isaacson, Howard

    2015-01-01

    We present newly derived stellar parameters and the detailed abundances of 19 elements of seven stars with small planets discovered by NASA's Kepler Mission. Each star save one has at least one planet with a radius <= 1.6 R_Earth, suggesting a primarily rocky composition. The stellar parameters and abundances are derived from high signal-to-noise ratio, high-resolution echelle spectroscopy obtained with the 10-m Keck I telescope and HIRES spectrometer using standard spectroscopic techniques. The metallicities of the seven stars range from -0.32 dex to +0.13 dex, with an average metallicity that is subsolar, supporting previous suggestions that, unlike Jupiter-type giant planets, small planets do not form preferentially around metal-rich stars. The abundances of elements other than iron are in line with a population of Galactic disk stars, and despite our modest sample size, we find hints that the compositions of stars with small planets are similar to stars without known planets and with Neptune-size plane...

  7. Prospects of metal research

    International Nuclear Information System (INIS)

    Topical questions about modern metal research are considered covering fundamentals and applications. Many, hitherto undeveloped distinguished properties of metals, such as resistance against particle and quantum radiations, neutrons, very high and very low temperatures , stresses, and chemical agents; memory effects; superconductivity etc. are pointed out. The following topics are treated: subject and methodology of the science of metals, significance of metals; discovery of new properties of metallic materials; theory of metallic alloys; extreme conditions; intermetallic compounds, polymorphic metals; rare metals (rare earth metals, rhenium, noble metals); questions of strength and technology of metals and alloys; temperature zones of brittle fracture in metals and alloys; alloys with particular electrophysical properties; superconductive metalic materials; 'biological' science of metals; and conclusions. The booklet will be useful for students at technical schools and universities as well as for engineers and scientists engaged in metal research

  8. Detailed study of SNR G306.3-0.9 using XMM-Newton and Chandra observations

    Science.gov (United States)

    Combi, J. A.; García, F.; Suárez, A. E.; Luque-Escamilla, P. L.; Paron, S.; Miceli, M.

    2016-08-01

    Aims: We aim to study the spatial distribution of the physical and chemical properties of the X-ray emitting plasma of the supernova remnant (SNR) G306.3-0.9 in detail to obtain constraints on its ionization stage, the progenitor supernova explosion, and the age of the remnant. Methods: We used combined data from XMM-Newton and Chandra observatories to study the X-ray morphology of G306.3-0.9 in detail. A spatially resolved spectral analysis was used to obtain physical and geometrical parameters of different regions of the remnant. Spitzer infrared observations, available in the archive, were also used to constrain the progenitor supernova and study the environment in which the remnant evolved. Results: The X-ray morphology of the remnant displays a non-uniform structure of semi-circular appearance, with a bright southwest region and very weak or almost negligible X-ray emission in its northern part. These results indicate that the remnant is propagating in a non-uniform environment as the shock fronts are encountering a high-density medium, where enhanced infrared emission is detected. The X-ray spectral analysis of the selected regions shows distinct emission-line features of several metal elements, confirming the thermal origin of the emission. The X-ray spectra are well represented by a combination of two absorbed thermal plasma models: one in equilibrium ionization (VAPEC) with a mean temperature of ~0.19 keV, and another out of equilibrium ionization (VNEI) at a higher temperature of ~1.1 or 1.6-1.9 keV. For regions located in the northeast, central, and southwest part of the SNR, we found elevated abundances of Si, S, Ar, Ca, and Fe, typical of ejecta material. The outer regions located northwest and south show values of the abundances above solar but lower than to those found in the central regions. This suggests that the composition of the emitting outer parts of the SNR is a combination of ejecta and shocked material of the interstellar medium. The

  9. Students' Visualization of Metallic Bonding and the Malleability of Metals

    Science.gov (United States)

    Cheng, Maurice M. W.; Gilbert, John K.

    2014-01-01

    This study investigated the mental representations of metallic bonding and the malleability of metals held by three male students aged 14-15 (Year 10) who were attending a Hong Kong school. One student was selected by their chemistry teacher as representing each of the highest, the medium, and the lowest level of attainment in chemistry in a…

  10. Design Evolution Study - Aging Options

    International Nuclear Information System (INIS)

    The purpose of this study is to identify options and issues for aging commercial spent nuclear fuel received for disposal at the Yucca Mountain Mined Geologic Repository. Some early shipments of commercial spent nuclear fuel to the repository may be received with high-heat-output (younger) fuel assemblies that will need to be managed to meet thermal goals for emplacement. The capability to age as much as 40,000 metric tons of heavy metal of commercial spent nuclear he1 would provide more flexibility in the design to manage this younger fuel and to decouple waste receipt and waste emplacement. The following potential aging location options are evaluated: (1) Surface aging at four locations near the North Portal; (2) Subsurface aging in the permanent emplacement drifts; and (3) Subsurface aging in a new subsurface area. The following aging container options are evaluated: (1) Complete Waste Package; (2) Stainless Steel inner liner of the waste package; (3) Dual Purpose Canisters; (4) Multi-Purpose Canisters; and (5) New disposable canister for uncanistered commercial spent nuclear fuel. Each option is compared to a ''Base Case,'' which is the expected normal waste packaging process without aging. A Value Engineering approach is used to score each option against nine technical criteria and rank the options. Open issues with each of the options and suggested future actions are also presented. Costs for aging containers and aging locations are evaluated separately. Capital costs are developed for direct costs and distributable field costs. To the extent practical, unit costs are presented. Indirect costs, operating costs, and total system life cycle costs will be evaluated outside of this study. Three recommendations for aging commercial spent nuclear fuel--subsurface, surface, and combined surface and subsurface are presented for further review in the overall design re-evaluation effort. Options that were evaluated but not recommended are: subsurface aging in a new

  11. METALS DEPOSITS

    Institute of Scientific and Technical Information of China (English)

    2011-01-01

    <正>20111705 An Junbo(Team 603,Bureau of Nonferrous Metals Geological Exploration of Jilin Province,Hunchun 133300,China);Xu Renjie Geological Features and Ore Genesis of Baishilazi Scheelite Deposit in Yanbian Area(Jilin Geology,ISSN1001-2427,CN22-1099/P,29(3),2010,p.39-43,2 illus.,2 tables,7 refs.)Key words:tungsten ores,Jilin ProvinceThe Baishilazi scheelite deposit is located in contacting zone between the marble of the Late Palaeozoic Qinglongcun Group and the Hercynian biotite granite.The vein and lenticular major ore body is obviously controlled by NE-extending faults and con

  12. Heavy Metal.

    Science.gov (United States)

    Black, Susan

    2001-01-01

    The Centers for Disease Control and Prevention (CDC) estimate that more than 1 million children ages 5 and under are afflicted with unsafe amounts of lead. Schools can be a source of lead poisoning. Other sources include playgrounds near freeways, playground equipment, contaminated soil, and technology rooms with lead-bearing supplies. Sidebars…

  13. THE BIRTH OF A GALAXY: PRIMORDIAL METAL ENRICHMENT AND STELLAR POPULATIONS

    International Nuclear Information System (INIS)

    By definition, Population III stars are metal-free, and their protostellar collapse is driven by molecular hydrogen cooling in the gas phase, leading to large characteristic masses. Population II stars with lower characteristic masses form when the star-forming gas reaches a critical metallicity of 10–6-10–3.5 Z☉. We present an adaptive mesh refinement radiation hydrodynamics simulation that follows the transition from Population III to Population II star formation. The maximum spatial resolution of 1 comoving parsec allows for individual molecular clouds to be well resolved and their stellar associations to be studied in detail. We model stellar radiative feedback with adaptive ray tracing. A top-heavy initial mass function for the Population III stars is considered, resulting in a plausible distribution of pair-instability supernovae and associated metal enrichment. We find that the gas fraction recovers from 5% to nearly the cosmic fraction in halos with merger histories rich in halos above 107 M☉. A single pair-instability supernova is sufficient to enrich the host halo to a metallicity floor of 10–3 Z☉ and to transition to Population II star formation. This provides a natural explanation for the observed floor on damped Lyα systems metallicities reported in the literature, which is of this order. We find that stellar metallicities do not necessarily trace stellar ages, as mergers of halos with established stellar populations can create superpositions of t–Z evolutionary tracks. A bimodal metallicity distribution is created after a starburst occurs when the halo can cool efficiently through atomic line cooling.

  14. Detailed study of the column-based priority logic readout of Topmetal-II- CMOS pixel direct charge sensor

    CERN Document Server

    An, Mangmang; Gao, Chaosong; Han, Mikyung; Huang, Guangming; Ji, Rong; Li, Xiaoting; Mei, Yuan; Pei, Hua; Sun, Quan; Sun, Xiangming; Wang, Kai; Xiao, Le; Yang, Ping; Zhang, Wei; Zhou, Wei

    2016-01-01

    We present the detailed study of the digital readout of Topmetal-II- CMOS pixel direct charge sensor. Topmetal-II- is an integrated sensor with an array of 72X72 pixels each capable of directly collecting external charge through exposed metal electrodes in the topmost metal layer. In addition to the time-shared multiplexing readout of the analog output from Charge Sensitive Amplifiers in each pixel, hits are also generated through comparators with individually DAC settable thresholds in each pixel. The hits are read out via a column-based priority logic structure, retaining both hit location and time information. The in-array column-based priority logic is fully combinational hence there is no clock distributed in the pixel array. Sequential logic and clock are placed on the peripheral of the array. We studied the detailed working behavior and performance of this readout, and demonstrated its potential in imaging applications.

  15. Population aging and legal retirement age

    OpenAIRE

    Lacomba, Juan Antonio; Lagos, Francisco Miguel

    2005-01-01

    This paper analyzes the effects of population aging on the preferred legal retirement age. What is revealed is the crucial role that the indirect ???macro??? effects resulting from a change in the legal retirement age play in the optimal decision. Two Social Security systems are studied. Under a defined contribution scheme aging lowers the preferred legal retirement age. However, under a defined pension scheme the retirement age is delayed. This result shows the relevance of correctly c...

  16. Testing for detailed balance in a financial market

    Science.gov (United States)

    Fiebig, H. R.; Musgrove, D. P.

    2015-06-01

    We test a historical price-time series in a financial market (the NASDAQ 100 index) for a statistical property known as detailed balance. The presence of detailed balance would imply that the market can be modeled by a stochastic process based on a Markov chain, thus leading to equilibrium. In economic terms, a positive outcome of the test would support the efficient market hypothesis, a cornerstone of neo-classical economic theory. In contrast to the usage in prevalent economic theory the term equilibrium here is tied to the returns, rather than the price-time series. The test is based on an action functional S constructed from the elements of the detailed balance condition and the historical data set, and then analyzing S by means of simulated annealing. Checks are performed to verify the validity of the analysis method. We discuss the outcome of this analysis.

  17. Analysis of local influences in structural details of the bridges

    Directory of Open Access Journals (Sweden)

    Adam RUDZIK

    2015-03-01

    Full Text Available The article analyses the problems of local influences in structural details of bridges as the critical locations, whose damages or excessive force may directly affect the safety of users. These analyses are shown on selected examples. Presented is the example of local changes in the forms of proper vibrations in the node of the truss bridge that can be used in expert issues concerning the causes of damages. The second example are the changes in stresses in the stay cable anchorage element including the nonlinear material models. Models of this type can be successfully used by engineers as they allow for analysis of selected structural details without the need for detailed mapping of the entire structure, but only a selected section.

  18. Study on Hierarchical Structure of Detailed Control Planning

    Institute of Scientific and Technical Information of China (English)

    2010-01-01

    Using case studies,this paper analyzes the characteristics of detailed control planning and its hierarchical controls,the form and composition of plan content,and methodological innovations.It then suggests improvements to the planning structure that are oriented at adaptability,fairness,centrality,and scientific principles with regard to the content,methods,and results of the planning.Regarding the hierarchical control system,the paper suggests that the detailed control plan should be composed of "block planning" and "plot planning".It is believed that through a combination of block and plot planning,the problem of joining long-term and short-term planning will be solved and it will be possible to address the need for adjustment and revision of detailed control plan.

  19. Age aspects of habitability

    Science.gov (United States)

    Safonova, M.; Murthy, J.; Shchekinov, Yu. A.

    2016-04-01

    A `habitable zone' of a star is defined as a range of orbits within which a rocky planet can support liquid water on its surface. The most intriguing question driving the search for habitable planets is whether they host life. But is the age of the planet important for its habitability? If we define habitability as the ability of a planet to beget life, then probably it is not. After all, life on Earth has developed within only ~800 Myr after its formation - the carbon isotope change detected in the oldest rocks indicates the existence of already active life at least 3.8 Gyr ago. If, however, we define habitability as our ability to detect life on the surface of exoplanets, then age becomes a crucial parameter. Only after life had evolved sufficiently complex to change its environment on a planetary scale, can we detect it remotely through its imprint on the atmosphere - the so-called biosignatures, out of which the photosynthetic oxygen is the most prominent indicator of developed (complex) life as we know it. Thus, photosynthesis is a powerful biogenic engine that is known to have changed our planet's global atmospheric properties. The importance of planetary age for the detectability of life as we know it follows from the fact that this primary process, photosynthesis, is endothermic with an activation energy higher than temperatures in habitable zones, and is sensitive to the particular thermal conditions of the planet. Therefore, the onset of photosynthesis on planets in habitable zones may take much longer time than the planetary age. The knowledge of the age of a planet is necessary for developing a strategy to search for exoplanets carrying complex (developed) life - many confirmed potentially habitable planets are too young (orbiting Population I stars) and may not have had enough time to develop and/or sustain detectable life. In the last decade, many planets orbiting old (9-13 Gyr) metal-poor Population II stars have been discovered. Such planets had had

  20. Metal fluorides

    International Nuclear Information System (INIS)

    Systems formed by fluorides of alkali, alkali earth, rare earth elements, yttrium, zirconium, hafnium, bismuth, antimony are investigated with the aim of preparing new fluoride materials and studying their thermodynamic and other physical and chemical properties. The respective phase diagrams are plotted. On the basis of the research fluoroberyllate glasses with rare earth additions of improved qualities (moisture resistance, crystallization resistance, resistance against radiation up to 100 Mrad) are prepared. The rho-T-x phase diagrams of the systems studied show that many compounds are sublimated congruently at certain temperatures and incongruently - above them. The existence of congruently sublimated compounds and azeotropically sublimated compositions provides for the preparation of uniform optical films. In connection with the search for new materials-luminophores and matrices of optical quantum generators - the fluoride systems of alkali metals and lanthanides are studied; the formation of binary fluorides of M3LnF6, M2LnF5, MLnF4, MLn2F7, MLn3F10 compositions is established. To search for new solid electrolytes, the solid-phase interaction of Sb-and Bi trifluorides with their oxides and alakali metal fluorides is studied. The electric conductivity of the compounds obtained is studied

  1. Modeling tracers of young stellar population age in star-forming galaxies

    International Nuclear Information System (INIS)

    The young stellar population of a star-forming galaxy is the primary engine driving its radiative properties. As a result, the age of a galaxy's youngest generation of stars is critical for a detailed understanding of its star formation history, stellar content, and evolutionary state. Here we present predicted equivalent widths for the Hβ, Hα, and Brγ recombination lines as a function of stellar population age. The equivalent widths are produced by the latest generations of stellar evolutionary tracks and the Starburst99 stellar population synthesis code, and are the first to fully account for the combined effects of both nebular emission and continuum absorption produced by the synthetic stellar population. Our grid of model stellar populations spans six metallicities (0.001 < Z < 0.04), two treatments of star formation history (a 106 M ☉ instantaneous burst and a continuous star formation rate of 1 M ☉ yr–1), and two different treatments of initial rotation rate (v rot = 0.0v crit and 0.4v crit). We also investigate the effects of varying the initial mass function. Given constraints on galaxy metallicity, our predicted equivalent widths can be applied to observations of star-forming galaxies to approximate the age of their young stellar populations.

  2. Probabilistic Model for Fatigue Crack Growth in Welded Bridge Details

    DEFF Research Database (Denmark)

    Toft, Henrik Stensgaard; Sørensen, John Dalsgaard; Yalamas, Thierry;

    2013-01-01

    In the present paper a probabilistic model for fatigue crack growth in welded steel details in road bridges is presented. The probabilistic model takes the influence of bending stresses in the joints into account. The bending stresses can either be introduced by e.g. misalignment or redistribution...... of stresses in the structure. The fatigue stress ranges are estimated from traffic measurements and a generic bridge model. Based on the probabilistic models for the resistance and load the reliability is estimated for a typical welded steel detail. The results show that large misalignments in the...

  3. SEPAC flight software detailed design specifications, volume 1

    Science.gov (United States)

    1982-01-01

    The detailed design specifications (as built) for the SEPAC Flight Software are defined. The design includes a description of the total software system and of each individual module within the system. The design specifications describe the decomposition of the software system into its major components. The system structure is expressed in the following forms: the control-flow hierarchy of the system, the data-flow structure of the system, the task hierarchy, the memory structure, and the software to hardware configuration mapping. The component design description includes details on the following elements: register conventions, module (subroutines) invocaton, module functions, interrupt servicing, data definitions, and database structure.

  4. Hidden scale invariance of metals

    Science.gov (United States)

    Hummel, Felix; Kresse, Georg; Dyre, Jeppe C.; Pedersen, Ulf R.

    2015-11-01

    Density functional theory (DFT) calculations of 58 liquid elements at their triple point show that most metals exhibit near proportionality between the thermal fluctuations of the virial and the potential energy in the isochoric ensemble. This demonstrates a general "hidden" scale invariance of metals making the condensed part of the thermodynamic phase diagram effectively one dimensional with respect to structure and dynamics. DFT computed density scaling exponents, related to the Grüneisen parameter, are in good agreement with experimental values for the 16 elements where reliable data were available. Hidden scale invariance is demonstrated in detail for magnesium by showing invariance of structure and dynamics. Computed melting curves of period three metals follow curves with invariance (isomorphs). The experimental structure factor of magnesium is predicted by assuming scale invariant inverse power-law (IPL) pair interactions. However, crystal packings of several transition metals (V, Cr, Mn, Fe, Nb, Mo, Ta, W, and Hg), most post-transition metals (Ga, In, Sn, and Tl), and the metalloids Si and Ge cannot be explained by the IPL assumption. The virial-energy correlation coefficients of iron and phosphorous are shown to increase at elevated pressures. Finally, we discuss how scale invariance explains the Grüneisen equation of state and a number of well-known empirical melting and freezing rules.

  5. Demonstration of Thermite and Related Reactions To Form Metals.

    Science.gov (United States)

    Foskett, R. R.

    1994-01-01

    Provides descriptions of a range of resources and methods that can be used to produce metals such as titanium, vanadium, chromium, manganese, iron, and molybdenum. Details on equipment and safety precautions are also outlined. (DDR)

  6. Metal filled porous carbon

    Science.gov (United States)

    Gross, Adam F.; Vajo, John J.; Cumberland, Robert W.; Liu, Ping; Salguero, Tina T.

    2011-03-22

    A porous carbon scaffold with a surface and pores, the porous carbon scaffold containing a primary metal and a secondary metal, where the primary metal is a metal that does not wet the surface of the pores of the carbon scaffold but wets the surface of the secondary metal, and the secondary metal is interspersed between the surface of the pores of the carbon scaffold and the primary metal.

  7. Nanoporous metals for advanced energy technologies

    CERN Document Server

    Ding, Yi

    2016-01-01

    This book covers the state-of-the-art research in nanoporous metals for potential applications in advanced energy fields, including proton exchange membrane fuel cells, Li batteries (Li ion, Li-S, and Li-O2), and supercapacitors. The related structural design and performance of nanoporous metals as well as possible mechanisms and challenges are fully addressed. The formation mechanisms of nanoporous metals during dealloying, the microstructures of nanoporous metals and characterization methods, as well as miscrostructural regulation of nanoporous metals through alloy design of precursors and surface diffusion control are also covered in detail. This is an ideal book for researchers, engineers, graduate students, and government/industry officers who are in charge of R&D investments and strategy related to energy technologies.

  8. Age Discrimination Against Older Workers in the European Union

    OpenAIRE

    Elizabeth Drury

    1994-01-01

    This paper aims to define the concept of age discrimination, to illustrate examples of age discriminatory practices across the European Union, and to describe some positive public policy measures to combat age discrimination.It draws on the results of the first European-wide study of age discrimination against older workers.1 National experts from 11 Member States of the EU examined various forms of age discrimination in their own country. More detailed information is needed, particularly on ...

  9. Evolution of white dwarf stars with high-metallicity progenitors: the role of 22Ne diffusion

    CERN Document Server

    Althaus, Leandro G; Renedo, Isabel; Isern, Jordi; Córsico, Alejandro H; Rohrmann, Rene D

    2010-01-01

    Motivated by the strong discrepancy between the main sequence turn-off age and the white dwarf cooling age in the metal-rich open cluster NGC 6791, we compute a grid of white dwarf evolutionary sequences that incorporates for the first time the energy released by the processes of 22Ne sedimentation and of carbon/oxygen phase separation upon crystallization. The grid covers the mass range from 0.52 to 1.0 Msun, and it is appropriate for the study of white dwarfs in metal-rich clusters. The evolutionary calculations are based on a detailed and self-consistent treatment of the energy released from these two processes, as well as on the employment of realistic carbon/oxygen profiles, of relevance for an accurate evaluation of the energy released by carbon/oxygen phase separation. We find that 22Ne sedimentation strongly delays the cooling rate of white dwarfs stemming from progenitors with high metallicities at moderate luminosities, whilst carbon/oxygen phase separation adds considerable delays at low luminositi...

  10. Age dependent values of dietary intake for assessing human exposures to environmental pollutants

    International Nuclear Information System (INIS)

    Detailed information concerning human food consumption patterns necessary for relating pollutant body burdens to environmental contamination levels was compiled to be used in lieu of site-specific data for calculating health impacts arising from the ingestion of food containing various levels of such pollutants as radionuclides, toxic heavy metals, insecticides and many others. This paper examines available data on human food consumption rates and estimates dietary intake rates by individuals of various ages. Ingestion parameters include intake rates of water and other beverages, milk, vegetables, fruits, meat, poultry, grain and fish. Information was analyzed from documented surveys of individuals within households and from interviews and personal communications. Although average intake rates are often the only data reported in the literature, ranges as well as averages are included in this paper whenever possible. Various results are tabulated including per capita food consumption in 1955 and 1965 and changes in per capita consumption as well as changes by urbanization. Details of milk consumption are presented by selected sex-age groups. Solid food intake is given by age group. Market basket quantities of foods consumed daily are also tabulated. (author)

  11. Pharmaceutical crystallography: is there a devil in the details?

    DEFF Research Database (Denmark)

    Bond, A. D.

    2012-01-01

    Modern instruments for small-molecule crystallography continue to become more sophisticated and more automated. This technical progress provides a basis for frontier research in chemical and pharmaceutical crystallography, but it also encourages analytical crystallographers to become more...... are presented for pharmaceutical compounds, and the potential importance of the "details" in pharmaceutical crystallography is discussed....

  12. Details from the Dashboard: Charter School Race/Ethnicity Demographics

    Science.gov (United States)

    National Alliance for Public Charter Schools, 2012

    2012-01-01

    This "Details from the Dashboard" report examines race/ethnicity breakouts for public charter schools and traditional public schools at the state and the school district level. The data in this report indicate that in the large majority of states, the race/ethnicity student demographics of charter schools are almost identical to those of the…

  13. Detailed behavioral modeling of bang-bang phase detectors

    DEFF Research Database (Denmark)

    Jiang, Chenhui; Andreani, Pietro; Keil, U. D.

    2006-01-01

    In this paper, the metastability of current-mode logic (CML) latches and flip-flops is studied in detail. Based on the results of this analysis, a behavioral model of bang-bang phase detectors (BBPDs) is proposed, which is able to reliably capture the critical deadzone effect. The impact of jitter...

  14. Energetic Mapping of Ni Catalysts by Detailed Kinetic Modeling

    DEFF Research Database (Denmark)

    Bjørgum, Erlend; Chen, De; Bakken, Mari G.;

    2005-01-01

    precursor seems to result in more steplike sites, kinks, and defects for carbon monoxide dissociation. A detailed kinetic modeling of the TPO results based on elementary reaction steps has been conducted to give an energetic map of supported Ni catalysts. Experimental results from the ideal Ni surface fit...

  15. Can quantum coherent solar cells break detailed balance?

    Energy Technology Data Exchange (ETDEWEB)

    Kirk, Alexander P. [School of Electrical, Computer and Energy Engineering, Arizona State University, Tempe, Arizona 85287 (United States)

    2015-07-21

    Carefully engineered coherent quantum states have been proposed as a design attribute that is hypothesized to enable solar photovoltaic cells to break the detailed balance (or radiative) limit of power conversion efficiency by possibly causing radiative recombination to be suppressed. However, in full compliance with the principles of statistical mechanics and the laws of thermodynamics, specially prepared coherent quantum states do not allow a solar photovoltaic cell—a quantum threshold energy conversion device—to exceed the detailed balance limit of power conversion efficiency. At the condition given by steady-state open circuit operation with zero nonradiative recombination, the photon absorption rate (or carrier photogeneration rate) must balance the photon emission rate (or carrier radiative recombination rate) thus ensuring that detailed balance prevails. Quantum state transitions, entropy-generating hot carrier relaxation, and photon absorption and emission rate balancing are employed holistically and self-consistently along with calculations of current density, voltage, and power conversion efficiency to explain why detailed balance may not be violated in solar photovoltaic cells.

  16. Complex and detailed balancing of chemical reaction networks revisited

    NARCIS (Netherlands)

    van der Schaft, Abraham; Rao, Shodhan; Jayawardhana, Bayu

    2015-01-01

    The characterization of the notions of complex and detailed balancing for mass action kinetics chemical reaction networks is revisited from the perspective of algebraic graph theory, in particular Kirchhoff’s Matrix Tree theorem for directed weighted graphs. This yields an elucidation of previously

  17. A Detailed Survey on Various Tracking Methods Using RFID

    OpenAIRE

    S. Arivarasi; S. Krishna Anand

    2013-01-01

    RFID, a wide range of technology is replaced instead of barcode. When multiple RFID readers find a single RFID tag at same time, duplicates occur. The main objective is to eliminate duplicates in RFID data. Designing an exact duplicate elimination method is very difficult. This paper presented a detailed analysis of tracking, monitoring, managing and filtering mechanisms for RFID data.

  18. Details from the Dashboard: Charter Schools by Geographic Region

    Science.gov (United States)

    National Alliance for Public Charter Schools, 2012

    2012-01-01

    While a majority of charter schools nationwide operate in urban and suburban areas, charter schools exist in all corners of the nation, and are expanding into all types of communities. This "Details from the Dashboard" report presents statistics on the number of charter schools and students enrolled in charter schools by the four geographic…

  19. Can quantum coherent solar cells break detailed balance?

    International Nuclear Information System (INIS)

    Carefully engineered coherent quantum states have been proposed as a design attribute that is hypothesized to enable solar photovoltaic cells to break the detailed balance (or radiative) limit of power conversion efficiency by possibly causing radiative recombination to be suppressed. However, in full compliance with the principles of statistical mechanics and the laws of thermodynamics, specially prepared coherent quantum states do not allow a solar photovoltaic cell—a quantum threshold energy conversion device—to exceed the detailed balance limit of power conversion efficiency. At the condition given by steady-state open circuit operation with zero nonradiative recombination, the photon absorption rate (or carrier photogeneration rate) must balance the photon emission rate (or carrier radiative recombination rate) thus ensuring that detailed balance prevails. Quantum state transitions, entropy-generating hot carrier relaxation, and photon absorption and emission rate balancing are employed holistically and self-consistently along with calculations of current density, voltage, and power conversion efficiency to explain why detailed balance may not be violated in solar photovoltaic cells

  20. Detailed bathymetric surveys in the central Indian Basin

    Digital Repository Service at National Institute of Oceanography (India)

    Kodagali, V.N.; KameshRaju, K.A.; Ramprasad, T.; George, P.; Jaisankar, S.

    Over 420,000 line kilometers of echo-sounding data was collected in the Central Indian Basin. This data was digitized, merged with navigation data and a detailed bathymetric map of the Basin was prepared. The Basin can be broadly classified...

  1. Detailed analysis of harmonic effects in the static Kramer drive

    Energy Technology Data Exchange (ETDEWEB)

    Zahawi, B.A. [Manchester School of Engineering, University of Manchester (United Kingdom); Refoufi, L. [Faculty of Engineering, Universite de Boumerdes (Algeria)

    2000-08-01

    A comprehensive examination of harmonic effect in slipenergy recovery drives employing a diode bridge rectifier in the rotor recovery circuit is presented. Torque and stator current pulsations at several speeds of operation are investigated in detail. Experimental verification of computed quantities shows excellent agreement. (orig.)

  2. 20 CFR 422.604 - Request for detailed information.

    Science.gov (United States)

    2010-04-01

    ... Section 422.604 Employees' Benefits SOCIAL SECURITY ADMINISTRATION ORGANIZATION AND PROCEDURES Administrative Review Process Under the Coal Industry Retiree Health Benefit Act of 1992 § 422.604 Request for... whom you have premium responsibility, you may request detailed information as to the work histories...

  3. Pipeline and energy facility siting: getting at the relevant details

    Energy Technology Data Exchange (ETDEWEB)

    Desautels, Denise L.; Mayberry, Alan K.

    2007-10-15

    Due process requirements may be time-consuming and expensive, but they result in an agency being provided the information it needs to make a decision even as the affected participants are given an adequate voice. Here's some advice on how to insure that the crucial details come to the forefront. (author)

  4. Video-based facial animation with detailed appearance texture

    Institute of Scientific and Technical Information of China (English)

    2006-01-01

    Facial shape transformation described by facial animation parameters (FAPs) involves the dynamic movement or deformation of eyes, brows, mouth, and lips, while detailed facial appearance concerns the facial textures such as creases, wrinkles, etc.Video-based facial animation exhibits not only facial shape transformation but also detailed appearance updates. In this paper, a novel algorithm for effectively extracting FAPs from video is proposed. Our system adopts the ICA-enforced direct appearance model (DAM) to track faces from video sequences; and then, FAPs are extracted from every frame of the video based on an extended model of Wincandidate 3.1. Facial appearance details are transformed from each frame by mapping an expression ratio image to the original image. We adopt wavelet to synthesize expressive details by combining the low-frequency signals of the original face and high-frequency signals of the expressive face from each frame of the video. Experimental results show that our proposed algorithm is suitable for reproducing realistic, expressive facial animations.

  5. Details of the battle to control Campeche Bay spill

    Energy Technology Data Exchange (ETDEWEB)

    1979-11-01

    Details of the battle to control Campeche Bay spill from Petroleos Mexicanos' well at Ixtoc 1 are given, including the poor performance of ''Operation Sombrero'' and air and surface monitoring of spill transport, particularly by the US Coast Guard.

  6. The optical transmission characteristics in metallic photonic crystals

    International Nuclear Information System (INIS)

    We theoretically studied electromagnetic wave propagation in a one-dimensional metal/dielectric photonic crystal (1D MDPC) consisting of alternating metallic and dielectric materials by using the transfer matrix method in visible and infrared regions. We have investigated the photonic band gap by using four kinds of metals: silver, lithium, gold and copper. We discuss the details of the calculated results in terms of the thickness of the metallic layer and different kinds of metals, and the plasma frequency. Our results have a potential for applications in optical devices because it is easy and cheap to manufacture.

  7. Aging and Aged in Organized Crime.

    Science.gov (United States)

    Amir, Menachem

    1989-01-01

    Examines problems of the aged in organized crime, basing discussion on organized crime bosses over age 60 operating in Italy, the United States, and Israel. Looks at problems stemming from normative system in organized crime, role of the aged, intergenerational problems, fears of the aged, excuses and justifications, standards of life, and…

  8. The Sounds of Metal

    DEFF Research Database (Denmark)

    Grund, Cynthia M.

    2015-01-01

    Two, I propose that this framework allows for at least a theoretical distinction between the way in which extreme metal – e.g. black metal, doom metal, funeral doom metal, death metal – relates to its sound as music and the way in which much other music may be conceived of as being constituted...

  9. Oral Health and Aging

    Science.gov (United States)

    ... please turn JavaScript on. Feature: Oral Health and Aging Oral Health and Aging Summer 2016 Table of Contents Jerrold H. Epstein, ... they may need. Read More "Oral Health and Aging" Articles Oral Health and Aging / 4 Myths About ...

  10. Skin Care and Aging

    Science.gov (United States)

    ... page please turn Javascript on. Skin Care and Aging How Aging Affects Skin Your skin changes with age. It ... if they bother you. See additional resources on aging skin, including information on treatment options, specific conditions, ...

  11. Preliminary findings of China's detailed fertility survey (the first phase).

    Science.gov (United States)

    1986-10-01

    This article summarizes findings of a fertility sampling survey conducted in April 1985 in the Hebei and Shaanxi provinces and Shanghai, China. Altogether, 13,307 married women of reproductive age were interviewed. The results of the nuptiality section, which surveyed 19,956 women aged 15-49 show that 1) a high marriage rate, a low divorce rate, and a stable marriage relationship exist; 2) during the past 30 years, the number of early marriages has declined remarkably and the median age at marriage has risen; 3) in the past 30 years, the peak age at 1st marriage has risen rapidly for women in Shanghai and Hebei while it has risen relatively slowly for women in Shaanxi; 4) in the past 10 years, the mean age at 1st marriage has increased more than 1 year for Shanghai women, has fluctuated for Shaanxi women, and has decreased for Hebei women; and 5) the total 1st marriage rates were high in the early 1980s, but declined slightly in 1984. Factors which influence nuptiality include 1) education on late marriage, and 2) elimination of arranged marriage. The results of the fertility and infant mortality section show that 1) the number of children ever born has been decreasing year by year, 2) a low proportion of primarily infertile women exists, 3) the parity progressive ratio declined rapidly in Shanghai, but more slowly in Hebei and Shaanxi; 4) infant mortality has declined considerably in the last 25 years, because of improvements in medical and health services; 5) age at 1st birth is increasing; and 6) the magnitude of the rise in median age at 1st birth is smaller than the median age at 1st marriage. During the last 10 years, 1) fertility has declined in both Shaanxi and Hebei; 2) the mean age at childbirth has decreased somewhat; 3) the 1-child policy has won wide response; and 4) among infants born 1980-1983, the mortality rate is 19.3 per 1000 in Shanghai and over 34 per 1000 in both Hebei and Shaanxi. The results of the contraception section show that 1

  12. Age determination of 15 old to intermediate-age small Magellanic cloud star clusters

    Energy Technology Data Exchange (ETDEWEB)

    Parisi, M. C.; Clariá, J. J.; Piatti, A. E. [Observatorio Astronómico, Universidad Nacional de Córdoba, Laprida 854, Córdoba, CP 5000 (Argentina); Geisler, D.; Leiton, R. [Departamento de Astronomía, Universidad de Concepción, Casilla 160-C, Concepción (Chile); Carraro, G. [European Southern Observatory, Casilla 19001, Santiago de Chile (Chile); Costa, E. [Universidad de Chile, Casilla 36-D, Santiago de Chile (Chile); Grocholski, A. J. [Department of Physics and Astronomy, Louisiana State University, 202 Nicholson Hall, Tower Drive, Baton Rouge, LA 70803-4001 (United States); Sarajedini, A., E-mail: celeste@oac.uncor.edu, E-mail: claria@oac.uncor.edu, E-mail: andres@oac.uncor.edu, E-mail: dgeisler@astro-udec.cl, E-mail: roger.leiton@astro-udec.cl, E-mail: gcarraro@eso.org, E-mail: costa@das.uchile.cl, E-mail: grocholski@phys.lsu.edu, E-mail: ata@astro.ufl.edu [Department of Astronomy, University of Florida, P.O. Box 112055, Gainesville, FL 32611 (United States)

    2014-04-01

    We present color-magnitude diagrams in the V and I bands for 15 star clusters in the Small Magellanic Cloud (SMC) based on data taken with the Very Large Telescope (VLT, Chile). We selected these clusters from our previous work, wherein we derived cluster radial velocities and metallicities from calcium II infrared triplet (CaT) spectra also taken with the VLT. We discovered that the ages of six of our clusters have been appreciably underestimated by previous studies, which used comparatively small telescopes, graphically illustrating the need for large apertures to obtain reliable ages of old and intermediate-age SMC star clusters. In particular, three of these clusters, L4, L6, and L110, turn out to be among the oldest SMC clusters known, with ages of 7.9 ± 1.1, 8.7 ± 1.2, and 7.6 ± 1.0 Gyr, respectively, helping to fill a possible 'SMC cluster age gap'. Using the current ages and metallicities from Parisi et al., we analyze the age distribution, age gradient, and age-metallicity relation (AMR) of a sample of SMC clusters measured homogeneously. There is a suggestion of bimodality in the age distribution but it does not show a constant slope for the first 4 Gyr, and we find no evidence for an age gradient. Due to the improved ages of our cluster sample, we find that our AMR is now better represented in the intermediate/old period than we had derived in Parisi et al., where we simply took ages available in the literature. Additionally, clusters younger than ∼4 Gyr now show better agreement with the bursting model of Pagel and Tautvaišienė, but we confirm that this model is not a good representation of the AMR during the intermediate/old period. A more complicated model is needed to explain the SMC chemical evolution in that period.

  13. Mechanical Properties, Purifying Techniques and Processing Methods of Metal Yttrium

    Institute of Scientific and Technical Information of China (English)

    2006-01-01

    The mechanical properties of metal yttrium such as strength, plasticity, hardness and elasticity were introduced. The purifying techniques of yttrium were discussed in detail. The processing methods for metal yttrium including extruding, forging, rolling, wiredrawing and welding were also introduced. Finally, the potential use of yttrium and its alloys were prospected.

  14. An Investigation of Placement and Type of Seductive Details: The Primacy Effect of Seductive Details on Text Recall

    Science.gov (United States)

    Rowland, Emily; Skinner, Christopher H.; Davis-Richards, Kai; Saudargas, Richard; Robinson, Daniel H.

    2008-01-01

    Seductive details are interesting, but sometimes irrelevant to the target material present in texts and lectures. In the current study, 388 undergraduate students read six paragraphs describing Sigmund Freud's psychosexual stages (i.e., target material). Participants in four groups also read one of two biographical paragraphs. The biographical…

  15. Half metallic ferromagnets.

    Science.gov (United States)

    Dowben, Peter

    2007-08-01

    as surface and interface reconstructions. Thus spin injection, i.e. the spin polarization of the current through the interface, may be effectively reduced to very low values, although the non-equilibrium spin polarization of the electron density can have very high values in select devices. Underlying these issues is the need to consider the definition of polarization: not all polarizations are equal. Polarization depends on the measurement. We do not always measure a polarization that follows the usual definition of spin polarization, and in many cases, it is not exactly clear what polarization has been measured. For example, there are corrections for the Fermi velocity ν(↓,↑) and spin relaxation τ(↓,↑): [Formula: see text] where n = 1 applies to the ballistic regime and n = 2 applies to the diffuse regime [3]. Neglecting interfaces and other complications, the diffuse regime (n = 2) should be the spin polarization of the bulk conductivity while ballistic regime (n = 1) is the polarization of the tunnel current and, in principle, Andreev reflection. As a result, suitable spin dependent Fermi velocity corrections might overcome an otherwise lackluster polarization for some device structures. Even measurements of polarization that are Fermi velocity independent (n = 0) may still depend on the wave vector and details of the interface band structure: as in the case of spin polarized photoemission and inverse photoemission. This special issue cannot possibly give due justice to all the various aspects of the physics of half metallic systems. By including both advocates and critics of half metallic ferromagnetism, the special issue should provide at least a taste of the controversies and challenges that exist in the study of half metallic ferromagnets. It may be that 'nature abhors half-metallicity' [2], and that relatively minor structural and thermal perturbations have a disproportionally strong effect on the density of states at the Fermi level, but in spite

  16. FEM study of extrusion complexity and dead metal zone

    OpenAIRE

    S.Z. Qamar

    2009-01-01

    Purpose: Quality of the extruded product and efficiency of the manufacturing process can be seriously affected by inconsistent metal flow through the extrusion die. Metal flow problems can also significantly reduce die life. Various researchers have investigated the effect of profile complexity on extrusion pressure, product quality, die life, etc. However, the relationship between shape complexity and metal flow through the extrusion die has not been studied in detail. Cold extrusion experim...

  17. Biocorrosion: towards understanding interactions between biofilms and metals.

    Science.gov (United States)

    Beech, Iwona B; Sunner, Jan

    2004-06-01

    The term microbially influenced corrosion, or biocorrosion, refers to the accelerated deterioration of metals owing to the presence of biofilms on their surfaces. The detailed mechanisms of biocorrosion are still poorly understood. Recent investigations into biocorrosion have focused on the influence of biomineralization processes taking place on metallic surfaces and the impact of extracellular enzymes, active within the biofilm matrix, on electrochemical reactions at the biofilm-metal interface.

  18. On the metallicity of open clusters. III. Homogenised sample

    CERN Document Server

    Netopil, M; Heiter, U; Soubiran, C

    2016-01-01

    Open clusters are known as excellent tools for various topics in Galactic research. For example, they allow accurately tracing the chemical structure of the Galactic disc. However, the metallicity is known only for a rather low percentage of the open cluster population, and these values are based on a variety of methods and data. Therefore, a large and homogeneous sample is highly desirable. In the third part of our series we compile a large sample of homogenised open cluster metallicities using a wide variety of different sources. These data and a sample of Cepheids are used to investigate the radial metallicity gradient, age effects, and to test current models. We used photometric and spectroscopic data to derive cluster metallicities. The different sources were checked and tested for possible offsets and correlations. In total, metallicities for 172 open cluster were derived. We used the spectroscopic data of 100 objects for a study of the radial metallicity distribution and the age-metallicity relation. W...

  19. Validation of detailed thermal hydraulic models used for LMR safety and for improvement of technical specifications

    Energy Technology Data Exchange (ETDEWEB)

    Dunn, F.E.

    1995-12-31

    Detailed steady-state and transient coolant temperatures and flow rates from an operating reactor have been used to validate the multiple pin model in the SASSYS-1 liquid metal reactor systems analysis code. This multiple pin capability can be used for explicit calculations of axial and lateral temperature distributions within individual subassemblies. Thermocouples at a number of axial locations and in a number of different coolant sub-channels m the XXO9 instrumented subassembly in the EBR-II reactor provided temperature data from the Shutdown Heat Removal Test (SHRT) series. Flow meter data for XXO9 and for the overall system are also available from these tests. Results of consistent SASSYS-1 multiple pin analyses for both the SHRT-45 loss-of-flow-without-scram-test and the S14RT-17 protected loss-of-flow test agree well with the experimental data, providing validation of the SASSYS-1 code over a wide range of conditions.

  20. Detailed kinetic modeling of the thermal degradation of lignins

    International Nuclear Information System (INIS)

    The aim of this kinetic work is to provide a better understanding of the pyrolysis of lignin and biomasses not only in terms of devolatilazation rate but also of the volatile species released. The complexity of both lignin structure and its degradation mechanism meant that a lumping approach suitable for handling the huge amount of initial, intermediate and final products had to be used. Despite these simplifications, the proposed semi-detailed kinetic scheme involves about 100 molecular and radical species in 500 elementary and lumped reactions. It has already been proved that this lignin devolatilization model correctly predicts the degradation rates and the detail of the released products. This work constitutes an initial yet significant step towards deriving a complete kinetic scheme of biomass devolatilization.

  1. A time dependent anatomically detailed model of cardiac conduction

    Science.gov (United States)

    Saxberg, B. E.; Grumbach, M. P.; Cohen, R. J.

    1985-01-01

    In order to understand the determinants of transitions in cardiac electrical activity from normal patterns to dysrhythmias such as ventricular fibrillation, we are constructing an anatomically and physiologically detailed finite element simulation of myocardial electrical propagation. A healthy human heart embedded in paraffin was sectioned to provide a detailed anatomical substrate for model calculations. The simulation of propagation includes anisotropy in conduction velocity due to fiber orientation as well as gradients in conduction velocities, absolute and relative refractory periods, action potential duration and electrotonic influence of nearest neighbors. The model also includes changes in the behaviour of myocardial tissue as a function of the past local activity. With this model, we can examine the significance of fiber orientation and time dependence of local propagation parameters on dysrhythmogenesis.

  2. Samnett: the EMPS model with power flow constraints: implementation details

    Energy Technology Data Exchange (ETDEWEB)

    Helseth, Arild; Warland, Geir; Mo, Birger; Fosso, Olav B.

    2011-12-15

    This report describes the development and implementation of Samnett. Samnett is a new prototype for solving the coupled market and transmission network problem. The prototype is based on the EMPS model (Samkjoeringsmodellen). Results from the market model are distributed to a detailed transmission network model, where a DC power flow detects if there are overloads on monitored lines or interconnections. In case of overloads, power flow constraints are generated and added to the market problem. This report is an updated version of TR A6891 {sup I}mplementing Network Constraints in the EMPS model{sup .} It further elaborates on theoretical and implementation details in Samnett, but does not contain the case studies and file descriptions presented in TR A6891.(auth)

  3. DETAILED MODELLING OF CHARGING BEHAVIOUR OF SMART SOLAR TANKS

    DEFF Research Database (Denmark)

    Fan, Jianhua; Andersen, Elsa; Furbo, Simon;

    The charging behaviour of smart solar tanks for solar combisystems for one-family houses is investigated with detailed Computational Fluid Dynamics (CFD) modelling and Particle Image Velocimetry (PIV) measurements. The smart solar tank can be charged with a variable auxiliary volume fitted...... to the expected future energy demand. Therefore the heat loss from the tank is decreased and the thermal performance of the solar heating system is increased compared to a traditional system with a fixed auxiliary volume. The solar tank can be charged either by an electric heating element situated in the tank...... or by an electric heating element in a side-arm mounted on the side of the tank. Detailed CFD models of the smart tanks are built with different mesh densities in the tank and in the side-arm. The thermal conditions of the tank during charging are calculated with the CFD models. The fluid flow and temperature...

  4. DETAILED MODELLING OF CHARGING BEHAVIOUR OF SMART SOLAR TANKS

    DEFF Research Database (Denmark)

    Fan, Jianhua; Andersen, Elsa; Furbo, Simon;

    2010-01-01

    The charging behaviour of smart solar tanks for solar combisystems for one-family houses is investigated with detailed Computational Fluid Dynamics (CFD) modelling and Particle Image Velocimetry (PIV) measurements. The smart solar tank can be charged with a variable auxiliary volume fitted...... to the expected future energy demand. Therefore the heat loss from the tank is decreased and the thermal performance of the solar heating system is increased compared to a traditional system with a fixed auxiliary volume. The solar tank can be charged either by an electric heating element situated in the tank...... or by an electric heating element in a side-arm mounted on the side of the tank. Detailed CFD models of the smart tanks are built with different mesh densities in the tank and in the side-arm. The thermal conditions of the tank during charging are calculated with the CFD models. The fluid flow and temperature...

  5. Exploring Architectural Details Through a Wearable Egocentric Vision Device.

    Science.gov (United States)

    Alletto, Stefano; Abati, Davide; Serra, Giuseppe; Cucchiara, Rita

    2016-01-01

    Augmented user experiences in the cultural heritage domain are in increasing demand by the new digital native tourists of 21st century. In this paper, we propose a novel solution that aims at assisting the visitor during an outdoor tour of a cultural site using the unique first person perspective of wearable cameras. In particular, the approach exploits computer vision techniques to retrieve the details by proposing a robust descriptor based on the covariance of local features. Using a lightweight wearable board, the solution can localize the user with respect to the 3D point cloud of the historical landmark and provide him with information about the details at which he is currently looking. Experimental results validate the method both in terms of accuracy and computational effort. Furthermore, user evaluation based on real-world experiments shows that the proposal is deemed effective in enriching a cultural experience. PMID:26901197

  6. Exploring Architectural Details Through a Wearable Egocentric Vision Device

    Directory of Open Access Journals (Sweden)

    Stefano Alletto

    2016-02-01

    Full Text Available Augmented user experiences in the cultural heritage domain are in increasing demand by the new digital native tourists of 21st century. In this paper, we propose a novel solution that aims at assisting the visitor during an outdoor tour of a cultural site using the unique first person perspective of wearable cameras. In particular, the approach exploits computer vision techniques to retrieve the details by proposing a robust descriptor based on the covariance of local features. Using a lightweight wearable board, the solution can localize the user with respect to the 3D point cloud of the historical landmark and provide him with information about the details at which he is currently looking. Experimental results validate the method both in terms of accuracy and computational effort. Furthermore, user evaluation based on real-world experiments shows that the proposal is deemed effective in enriching a cultural experience.

  7. Neutrino diffusive transport in hot quark matter: a detailed analysis

    CERN Document Server

    Colvero, Gustavo C

    2014-01-01

    We perform an extensive analysis of neutrino diffusion in quark matter within the MIT bag model at arbitrary temperature and degeneracy. We examine in detail the contribution of each of the relevant weak interaction processes to the total neutrino opacity and evaluate the effect of the strange quark mass, the bag constant, and the QCD perturbative corrections to the MIT bag model. We also investigate the anisotropic contribution to the neutrino distribution function in scatterings, the mean energy transfer and the mean scattering angle. The density and temperature dependence of the diffusion coefficients $D_n$ that govern the cooling and deleptonization of a compact star is shown in detail. Finally, our numerical results for the neutrino mean free paths are compared against known analytic approximations. We conclude that neutrino scattering constitutes a significant portion of the total neutrino opacity in leptonized quark matter and neutrino-quark scattering is, in general, very similar to neutrino-electron ...

  8. Detailed assessment of homology detection using different substitution matrices

    Institute of Scientific and Technical Information of China (English)

    LI Jing; WANG Wei

    2006-01-01

    Homology detection plays a key role in bioinformatics, whereas substitution matrix is one of the most important components in homology detection. Thus, besides the improvement of alignment algorithms, another effective way to enhance the accuracy of homology detection is to use proper substitution matrices or even construct new matrices.A study on the features of various matrices and on the comparison of the performances between different matrices in homology detection enable us to choose the most proper or optimal matrix for some specific applications. In this paper, by taking BLOSUM matrices as an example, some detailed features of matrices in homology detection are studied by calculating the distributions of numbers of recognized proteins over different sequence identities and sequence lengths. Our results clearly showed that different matrices have different preferences and abilities to the recognition of remote homologous proteins. Furthermore, detailed features of the various matrices can be used to improve the accuracy of homology detection.

  9. Metal-phosphate binders

    Science.gov (United States)

    Howe, Beth Ann [Lewistown, IL; Chaps-Cabrera, Jesus Guadalupe [Coahuila, MX

    2009-05-12

    A metal-phosphate binder is provided. The binder may include an aqueous phosphoric acid solution, a metal-cation donor including a metal other than aluminum, an aluminum-cation donor, and a non-carbohydrate electron donor.

  10. Detailed thermal-hydraulic computation into a containment building

    Energy Technology Data Exchange (ETDEWEB)

    Caruso. A.; Flour, I.; Simonin, O. [EDF/LNH, Chatou (France); Cherbonnel, C [EDF/SEPTEN, Villeurbanne (France)

    1995-09-01

    This paper deals with numerical predictions of the influence of water sprays upon stratifications into a containment building using a two-dimensional two-phase flow code. Basic equations and closure assumptions are briefly presented. A test case in a situation involving spray evaporation is first detailed to illustrate the validation step. Then results are presented for a compressible recirculating flow into a containment building with condensation phenomena.

  11. Influence of Cannabis on Fatal Traffic Crash: A Detailed Analysis

    OpenAIRE

    VAN ELSLANDE, Pierre; FOURNIER, Jean-Yves; Jaffard, Magali

    2012-01-01

    The influence of cannabis on traffic crashes is a growing concern. Experimental studies provide ample evidences of cannabis influence on psychomotor and cognitive performances. Epidemiological works describe the excess crash risk that this substance causes. And yet, this psychotropic drug influence in causing crashes is still at the centre of many discussions. The present analysis consists in exploiting crash data in detail to obtain a more precise understanding of the failures that drivers a...

  12. DETAILED MODELLING OF CHARGING BEHAVIOUR OF SMART SOLAR TANKS

    OpenAIRE

    Fan, Jianhua; Andersen, Elsa; Furbo, Simon; Perers, Bengt

    2010-01-01

    The charging behaviour of smart solar tanks for solar combisystems for one-family houses is investigated with detailed Computational Fluid Dynamics (CFD) modelling and Particle Image Velocimetry (PIV) measurements. The smart solar tank can be charged with a variable auxiliary volume fitted to the expected future energy demand. Therefore the heat loss from the tank is decreased and the thermal performance of the solar heating system is increased compared to a traditional system with a fixed au...

  13. NUCLEAR ESPIONAGE: Report Details Spying on Touring Scientists.

    Science.gov (United States)

    Malakoff, D

    2000-06-30

    A congressional report released this week details dozens of sometimes clumsy attempts by foreign agents to obtain nuclear secrets from U.S. nuclear scientists traveling abroad, ranging from offering scientists prostitutes to prying off the backs of their laptop computers. The report highlights the need to better prepare traveling researchers to safeguard secrets and resist such temptations, say the two lawmakers who requested the report and officials at the Department of Energy, which employs the scientists. PMID:17769833

  14. "Academic detailing" improving prescribing practices in North Vancouver, conference told

    OpenAIRE

    Silversides, A.

    1997-01-01

    Physician prescribing practices were the focus of a recent 1-day conference in Toronto. A BC hospital pharmacist outlined a successful initiative that provides physicians with impartial prescribing advice, saying it has resulted in considerable savings and improved prescribing practices in North Vancouver. Drugs of Choice author Dr. Joel Lexchin says such initiatives, called academic detailing, along with peer feedback, are cost-effective ways to improve prescribing habits.

  15. Strategic Pricing and Detailing Behavior in International Markets

    OpenAIRE

    Pradeep K. Chintagunta; Ramarao Desiraju

    2005-01-01

    We study three determinants of the levels of price and detailing effort across geographic markets: the within-market response to each variable, the nature of interfirm strategic interactions both within that market and across markets. We empirically examine the interactions of Prozac, Zoloft, and Paxil across the United States, the United Kingdom, Germany, France, and Italy. Our results indicate that all three factors driving marketing mix interactions are at play in this product category. Th...

  16. Fabrication and ageing of cast austenitic steels

    International Nuclear Information System (INIS)

    An investigation has been undertaken to determine the magnitude of any reduction in properties which may occur in cast duplex stainless steels and weldments during long term exposure to reactor operating conditions. Test panels were fabricated in CF3 stainless steel by a manual metal arc (MMA) process using 19.9.L (Type 308L) consumables. The mechanical properties and intergranular corrosion resistance of parent material and weldments were measured following accelerated ageing at 3750 and 4000C for up to 10,000 hours. Both the impact energy and J/sub R/ fracture toughness properties of the cast austenitic/ferritic stainless steel were reduced following aging at 4000C for 10,000 hours, whereas austenitic stainless steel MMA weld metals exhibited a reduction in J/sub R/ fracture toughness but no change in impact energy. Even in the unaged state, MMA weld metals were shown to have a much lower resistance to stable crack growth than the parent cast steel, and, following aging, there is a further reduction in the ductile tearing resistance of such weld metals. Therefore, in any assessment of the structural integrity of the reactor coolant pump bowl for a pressurized water reactor (PWR), the weld metal fracture properties during service are likely to be of considerable importance

  17. Large-scale violation of detailed balance in biological systems

    Science.gov (United States)

    Broedersz, Chase; Battle, Christopher; Fakhri, Nikta; Mackintosh, Fred; Schmidt, Christopher

    2015-03-01

    Living systems are out of equilibrium. A fundamental manifestation of non-equilibrium dynamics in biological systems is the violation of detailed balance: at the microscopic level, enzymatic processes such as kinetic proofreading or molecular motor activity clearly violate detailed balance. We study how such non-equilibrium dynamics emerge at macroscopic scales in cellular assemblies. We measure the steady-state dynamics of two systems, beating flagella of Chlamydomonas reinhardtii and mechanosensitive primary cilia protruding from epithelial kidney cells. The flagellum exhibits clear non-equilibrium driving, whereas fluctuations in the primary cilium are difficult to differentiate from Brownian motion. We parameterize the shapes of the flagellum and primary cilium using a low-dimensional representation of their configuration phase space, and use the measured dynamics to infer the steady-state probability distributions and probability currents. For both the flagellum and the primary cilium we find significant, coherent circulating probability currents, demonstrating that these systems violate detailed balance at the mesoscopic scale.

  18. Detailed chemical kinetic oxidation mechanism for a biodiesel surrogate

    Energy Technology Data Exchange (ETDEWEB)

    Herbinet, O; Pitz, W J; Westbrook, C K

    2007-09-20

    A detailed chemical kinetic mechanism has been developed and used to study the oxidation of methyl decanoate, a surrogate for biodiesel fuels. This model has been built by following the rules established by Curran et al. for the oxidation of n-heptane and it includes all the reactions known to be pertinent to both low and high temperatures. Computed results have been compared with methyl decanoate experiments in an engine and oxidation of rapeseed oil methyl esters in a jet stirred reactor. An important feature of this mechanism is its ability to reproduce the early formation of carbon dioxide that is unique to biofuels and due to the presence of the ester group in the reactant. The model also predicts ignition delay times and OH profiles very close to observed values in shock tube experiments fueled by n-decane. These model capabilities indicate that large n-alkanes can be good surrogates for large methyl esters and biodiesel fuels to predict overall reactivity, but some kinetic details, including early CO{sub 2} production from biodiesel fuels, can be predicted only by a detailed kinetic mechanism for a true methyl ester fuel. The present methyl decanoate mechanism provides a realistic kinetic tool for simulation of biodiesel fuels.

  19. Detailed chemical kinetic oxidation mechanism for a biodiesel surrogate

    Energy Technology Data Exchange (ETDEWEB)

    Herbinet, O; Pitz, W J; Westbrook, C K

    2007-09-17

    A detailed chemical kinetic mechanism has been developed and used to study the oxidation of methyl decanoate, a surrogate for biodiesel fuels. This model has been built by following the rules established by Curran et al. for the oxidation of n-heptane and it includes all the reactions known to be pertinent to both low and high temperatures. Computed results have been compared with methyl decanoate experiments in an engine and oxidation of rapeseed oil methyl esters in a jet stirred reactor. An important feature of this mechanism is its ability to reproduce the early formation of carbon dioxide that is unique to biofuels and due to the presence of the ester group in the reactant. The model also predicts ignition delay times and OH profiles very close to observed values in shock tube experiments fueled by n-decane. These model capabilities indicate that large n-alkanes can be good surrogates for large methyl esters and biodiesel fuels to predict overall reactivity, but some kinetic details, including early CO2 production from biodiesel fuels, can be predicted only by a detailed kinetic mechanism for a true methyl ester fuel. The present methyl decanoate mechanism provides a realistic kinetic tool for simulation of biodiesel fuels.

  20. Detail enhancement of blurred infrared images based on frequency extrapolation

    Science.gov (United States)

    Xu, Fuyuan; Zeng, Deguo; Zhang, Jun; Zheng, Ziyang; Wei, Fei; Wang, Tiedan

    2016-05-01

    A novel algorithm for enhancing the details of the blurred infrared images based on frequency extrapolation has been raised in this paper. Unlike other researchers' work, this algorithm mainly focuses on how to predict the higher frequency information based on the Laplacian pyramid separation of the blurred image. This algorithm uses the first level of the high frequency component of the pyramid of the blurred image to reverse-generate a higher, non-existing frequency component, and adds back to the histogram equalized input blurred image. A simple nonlinear operator is used to analyze the extracted first level high frequency component of the pyramid. Two critical parameters are participated in the calculation known as the clipping parameter C and the scaling parameter S. The detailed analysis of how these two parameters work during the procedure is figure demonstrated in this paper. The blurred image will become clear, and the detail will be enhanced due to the added higher frequency information. This algorithm has the advantages of computational simplicity and great performance, and it can definitely be deployed in the real-time industrial applications. We have done lots of experiments and gave illustrations of the algorithm's performance in this paper to convince its effectiveness.

  1. Applications of GPR in Structural Detailing of the Medway Tunnel

    Science.gov (United States)

    Alani, Amir M.; Faramarzi, Assad

    2013-04-01

    This investigation focuses on applications of GPR on structural detailing of a major tunnel under the River Medway in north Kent, UK. Construction of the tunnel was completed in 1996 and it carries a substantial volume of traffic between two major areas of Medway. The construction of the tunnel is an "immersed tube" tunnel type that connects a number of segments at immersion joint points. This investigation reports on utilisation of two separate GPR antenna systems at different frequencies in establishing structural details of the tunnel roof at immersion joints. The processed data compiled as a result of this investigation provided much needed information to tunnel engineers for forthcoming maintenance planning purposes. It also provided ample information in confirming rather doubted construction plans originally produced. The reported results are conclusive in terms of construction materials used (information was not originally available and needed confirmation) as well as establishing the required information on the formation of the tunnel roof joints. The presentation is complemented by providing detailed information of a complex process of adopting the GPR systems used in this endeavour.

  2. Update on terrestrial ages of Antarctic meteorites

    Energy Technology Data Exchange (ETDEWEB)

    Welten, K C; Nishiizumi, K; Caffee, M W

    2000-01-14

    Terrestrial ages of Antarctic meteorites are one of the few parameters that will help us to understand the meteorite concentration mechanism on blue-ice fields. Traditionally, terrestrial ages were determined on the basis of {sup 36}Cl in the metal phase, which has an uncertainty of about 70 ky. For young meteorites (< 40 ky), the terrestrial age is usually and most accurately determined using {sup 14}C in the stone phase. In recent years two methods have been developed which are independent of shielding effects, the {sup 10}Be-{sup 36}Cl/{sup 10}Be method and the {sup 41}Ca/{sup 36}Cl method. These methods have reduced the typical uncertainties in terrestrial ages by a factor of 2, to about 30 ky. The {sup 10}Be-{sup 36}Cl/{sup 10}Be method is quite dependent on the exposure age, which is unknown for most Antarctic meteorites. The authors therefore also attempt to use the relation between {sup 26}Al and {sup 36}Cl/{sup 26}Al to derive a terrestrial age less dependent on the exposure age. The authors have measured the concentrations of cosmogenic {sup 10}Be, {sup 26}Al and {sup 36}Cl in the metal phase of {approximately} 70 Antarctic meteorites, from more than 10 different ice-fields, including many new ones. They then discuss the trends in terrestrial ages of meteorites from different ice-fields.

  3. Facial Beautification Method Based on Age Evolution

    Institute of Scientific and Technical Information of China (English)

    CHEN Yan; DING Shou-hong; HU Gan-le; MA Li-zhuang

    2013-01-01

    This paper proposes a new facial beautification method using facial rejuvenation based on the age evolution. Traditional facial beautification methods only focus on the color of skin and deformation and do the transformation based on an experimental standard of beauty. Our method achieves the beauty effect by making facial image looks younger, which is different from traditional methods and is more reasonable than them. Firstly, we decompose the image into different layers and get a detail layer. Secondly, we get an age-related parameter:the standard deviation of the Gaussian distribution that the detail layer follows, and the support vector machine (SVM) regression is used to fit a function about the age and the standard deviation. Thirdly, we use this function to estimate the age of input image and generate a new detail layer with a new standard deviation which is calculated by decreasing the age. Lastly, we combine the original layers and the new detail layer to get a new face image. Experimental results show that this algo-rithm can make facial image become more beautiful by facial rejuvenation. The proposed method opens up a new way about facial beautification, and there are great potentials for applications.

  4. Atomistic details of the molecular recognition of DNA-RNA hybrid duplex by ribonuclease H enzyme

    Indian Academy of Sciences (India)

    Gorle Suresh; U Deva Priyakumar

    2015-10-01

    Bacillus halodurans (ℎ) ribonuclease H (RNase H) belongs to the nucleotidyl-transferase (NT) superfamily and is a prototypical member of a large family of enzymes that use two-metal ion (Mg2+ or Mn2+) catalysis to cleave nucleic acids. Long timescale molecular dynamics simulations have been performed on the ℎRNase H-DNA-RNA hybrid complex and the respective monomers to understand the recognition mechanism, conformational preorganization, active site dynamics and energetics involved in the complex formation. Several structural and energetic analyses were performed and significant structural changes are observed in enzyme and hybrid duplex during complex formation. Hybrid molecule binding to RNase H enzyme leads to conformational changes in the DNA strand. The ability of the DNA strand in the hybrid duplex to sample conformations corresponding to typical A- and B-type nucleic acids and the characteristic minor groove width-seem to be crucial for efficient binding. Sugar moieties in certain positions interacting with the protein structure undergo notable conformational transitions. The water coordination and arrangement around the metal ions in active site region are quite stable, suggesting their important role in enzymatic catalysis. Details of key interactions found at the interface of enzyme-nucleic acid complex that are responsible for its stability are discussed.

  5. HE0107-5240, A Chemically Ancient Star.I. A Detailed Abundance Analysis

    CERN Document Server

    Christlieb, N; Korn, A J; Barklem, P S; Beers, T C; Bessell, M S; Karlsson, T; Mizuno-Wiedner, M

    2004-01-01

    We report a detailed abundance analysis for HE0107-5240, a halo giant with [Fe/H]_NLTE=-5.3. This star was discovered in the course of follow-up medium-resolution spectroscopy of extremely metal-poor candidates selected from the digitized Hamburg/ESO objective-prism survey. On the basis of high-resolution VLT/UVES spectra, we derive abundances for 8 elements (C, N, Na, Mg, Ca, Ti, Fe, and Ni), and upper limits for another 12 elements. A plane-parallel LTE model atmosphere has been specifically tailored for the chemical composition of {\\he}. Scenarios for the origin of the abundance pattern observed in the star are discussed. We argue that HE0107-5240 is most likely not a post-AGB star, and that the extremely low abundances of the iron-peak, and other elements, are not due to selective dust depletion. The abundance pattern of HE0107-5240 can be explained by pre-enrichment from a zero-metallicity type-II supernova of 20-25M_Sun, plus either self-enrichment with C and N, or production of these elements in the AG...

  6. Development of steady-state model for MSPT and detailed analyses of receiver

    Science.gov (United States)

    Yuasa, Minoru; Sonoda, Masanori; Hino, Koichi

    2016-05-01

    Molten salt parabolic trough system (MSPT) uses molten salt as heat transfer fluid (HTF) instead of synthetic oil. The demonstration plant of MSPT was constructed by Chiyoda Corporation and Archimede Solar Energy in Italy in 2013. Chiyoda Corporation developed a steady-state model for predicting the theoretical behavior of the demonstration plant. The model was designed to calculate the concentrated solar power and heat loss using ray tracing of incident solar light and finite element modeling of thermal energy transferred into the medium. This report describes the verification of the model using test data on the demonstration plant, detailed analyses on the relation between flow rate and temperature difference on the metal tube of receiver and the effect of defocus angle on concentrated power rate, for solar collector assembly (SCA) development. The model is accurate to an extent of 2.0% as systematic error and 4.2% as random error. The relationships between flow rate and temperature difference on metal tube and the effect of defocus angle on concentrated power rate are shown.

  7. Age Prejudice of 'Act Your Age.'

    Science.gov (United States)

    Ponzo, Zander

    1978-01-01

    Many life-style decisions are often adversely influenced by prejudicial attitudes, norms, and laws about age. The relationship between ways of thinking about developmental tasks and age prejudice is discussed. (Author)

  8. A semi-empirical effective medium theory for metals and alloys

    DEFF Research Database (Denmark)

    Jacobsen, Karsten wedel; Stoltze, Per; Nørskov, Jens kehlet

    1996-01-01

    A detailed derivation of the simplest form of the effective medium theory for bonding in metallic systems is presented, and parameters for the fee metals Ni, Pd, Pt, Cu, Ag and Au are given. The derivation of parameters is discussed in detail to show how new parameterizations can be made. The met......A detailed derivation of the simplest form of the effective medium theory for bonding in metallic systems is presented, and parameters for the fee metals Ni, Pd, Pt, Cu, Ag and Au are given. The derivation of parameters is discussed in detail to show how new parameterizations can be made....... The method and the parameterization is tested for a number of surface and bulk problems. In particular we present calculations of the energetics of metal atoms deposited on metal surfaces. The calculated energies include heats of adsorption, energies of overlayers, both pseudomorphic and relaxed, as well...

  9. Accuracy of Implant Position Transfer and Surface Detail Reproduction with Different Impression Materials and Techniques

    Science.gov (United States)

    Alikhasi, Marzieh; Siadat, Hakimeh; Kharazifard, Mohammad Javad

    2015-01-01

    Objectives: The purpose of this study was to compare the accuracy of implant position transfer and surface detail reproduction using two impression techniques and materials. Materials and Methods: A metal model with two implants and three grooves of 0.25, 0.50 and 0.75 mm in depth on the flat superior surface of a die was fabricated. Ten regular-body polyether (PE) and 10 regular-body polyvinyl siloxane (PVS) impressions with square and conical transfer copings using open tray and closed tray techniques were made for each group. Impressions were poured with type IV stone, and linear and angular displacements of the replica heads were evaluated using a coordinate measuring machine (CMM). Also, accurate reproduction of the grooves was evaluated by a video measuring machine (VMM). These measurements were compared with the measurements calculated on the reference model that served as control, and the data were analyzed with two-way ANOVA and t-test at P= 0.05. Results: There was less linear displacement for PVS and less angular displacement for PE in closed-tray technique, and less linear displacement for PE in open tray technique (P0.05). Conclusion: The open tray technique was more accurate using PE, and also both closed tray and open tray techniques had acceptable results with the use of PVS. The choice of impression material and technique made no significant difference in surface detail reproduction. PMID:27252761

  10. Gaia FGK benchmark stars: Metallicity

    Science.gov (United States)

    Jofré, P.; Heiter, U.; Soubiran, C.; Blanco-Cuaresma, S.; Worley, C. C.; Pancino, E.; Cantat-Gaudin, T.; Magrini, L.; Bergemann, M.; González Hernández, J. I.; Hill, V.; Lardo, C.; de Laverny, P.; Lind, K.; Masseron, T.; Montes, D.; Mucciarelli, A.; Nordlander, T.; Recio Blanco, A.; Sobeck, J.; Sordo, R.; Sousa, S. G.; Tabernero, H.; Vallenari, A.; Van Eck, S.

    2014-04-01

    Context. To calibrate automatic pipelines that determine atmospheric parameters of stars, one needs a sample of stars, or "benchmark stars", with well-defined parameters to be used as a reference. Aims: We provide detailed documentation of the iron abundance determination of the 34 FGK-type benchmark stars that are selected to be the pillars for calibration of the one billion Gaia stars. They cover a wide range of temperatures, surface gravities, and metallicities. Methods: Up to seven different methods were used to analyze an observed spectral library of high resolutions and high signal-to-noise ratios. The metallicity was determined by assuming a value of effective temperature and surface gravity obtained from fundamental relations; that is, these parameters were known a priori and independently from the spectra. Results: We present a set of metallicity values obtained in a homogeneous way for our sample of benchmark stars. In addition to this value, we provide detailed documentation of the associated uncertainties. Finally, we report a value of the metallicity of the cool giant ψ Phe for the first time. Based on NARVAL and HARPS data obtained within the Gaia DPAC (Data Processing and Analysis Consortium) and coordinated by the GBOG (Ground-Based Observations for Gaia) working group and on data retrieved from the ESO-ADP database.Tables 6-76 are only available at the CDS via anonymous ftp to http://cdsarc.u-strasbg.fr (ftp://130.79.128.5) or via http://cdsarc.u-strasbg.fr/viz-bin/qcat?J/A+A/564/A133

  11. Avoiding Aging? Social Psychology's Treatment of Age

    Science.gov (United States)

    Barrett, Anne E.; Redmond, Rebecca; von Rohr, Carmen

    2012-01-01

    Population aging, in conjunction with social and cultural transformations of the life course, has profound implications for social systems--from large-scale structures to micro-level processes. However, much of sociology remains fairly quiet on issues of age and aging, including the subfield of social psychology that could illuminate the impact of…

  12. Old age psychiatry in the modern age.

    Science.gov (United States)

    Warner, James P

    2015-11-01

    Old age psychiatry services globally are under threat. The discipline enjoyed its heyday in the two decades bridging the millennium. More recently there has been a move to integrate old age services with those of working age adults, to create 'ageless' services. Evidence is beginning to accumulate that this is a bad idea.

  13. Structural aging program status report

    Energy Technology Data Exchange (ETDEWEB)

    Naus, D.J.; Oland, C.B. [Oak Ridge National Lab., TN (United States); Ellingwood, B. [Johns Hopkins Univ., Baltimore, MD (United States)] [and others

    1995-04-01

    Research is being conducted at the Oak Ridge National Laboratory (ORNL) under U.S. Nuclear Regulatory Commission (USNRC) sponsorship to address aging management of safety-related concrete structures. Documentation is being prepared to provide the USNRC with potential structural safety issues and acceptance criteria for use in continued service evaluations of nuclear power plants. Program accomplishments have included development of the Structural Materials Information Center containing data and information of the time variation of 144 material properties under the influence of pertinent environmental stressors of aging factors, performance assessments of reinforced concrete structures in several United Kingdom nuclear power facilities, evaluation of European and North American repair practices for concrete, an evaluation of factors affecting the corrosion of metals embedded in concrete, and application of the time-dependent reliability methodology to reinforced concrete flexure and shear structural elements to investigate the role of in-service inspection and repair on their probability of failure.

  14. Structural aging program status report

    International Nuclear Information System (INIS)

    Research is being conducted at the Oak Ridge National Laboratory under Nuclear Regulatory Commission (USNRC) sponsorship to address aging management of safety-related concrete structures. Documentation is being prepared to provide the USNRC with potential structural safety issues and acceptance criteria for use in continued service evaluations of nuclear power plants. Program accomplishments have included development of the Structural Materials Information Center containing data and information on the time variation of 144 material properties under the influence of pertinent environmental stressors or aging factors, performance assessments of reinforced concrete structures in several United Kingdom nuclear power facilities, evaluation of European and North American repair practices for concrete, an evaluation of factors affecting the corrosion of metals embedded in concrete, and application of the time-dependent reliability methodology to reinforced concrete flexure and shear structural elements to investigate the role of in-service inspection and repair on their probability of failure

  15. The Effects of Seductive Details in an Inflatable Planetarium

    Science.gov (United States)

    Gillette, Sean

    Astronomy is becoming a forgotten science, which is evident by its relatively low enrollment figures compared to biology, chemistry, and physics. A portable inflatable planetarium brings relevance back to astronomy and offers support to students and educators by simulating realistic astronomical environments. This study sought to determine if learning is improved in an inflatable planetarium by adhering to the design principles of the cognitive theory of multimedia learning (CTML), specifically the coherence principle, in an authentic classroom. Two groups of 5th grade students of similar ability were purposefully assigned using a 1-teacher-to-many-students format with mean lesson lengths of 34 minutes. The experimental group was differentiated with seductive details, defined as interesting but irrelevant facts that can distract learning. The control group ( n = 28), with seductive details excluded, outperformed the experimental group (n = 28), validating the coherence principle and producing a Cohen's effect size of medium practical significance (d = 0.4). These findings suggest that CTML, when applied to planetarium instruction, does increase student learning and that seductive details do have a negative effect on learning. An adult training project was created to instruct educators on the benefits of CTML in astronomy education. This study leads to positive social change by highlighting astronomy education while providing educators with design principles of CTML in authentic settings to maximize learning, aid in the creation of digital media (astronomical simulations/instructional lessons for planetariums) and provide valuable training for owners of inflatable planetariums with the eventual goal of increasing student enrollment of astronomy courses at the local level.

  16. Liquid metal plasma valve development

    Energy Technology Data Exchange (ETDEWEB)

    None

    1978-06-01

    A program for the development of liquid-metal plasma valves (LMPVs) is discussed in detail. The program consisted of two tasks. The first was the development and testing of valves in the laboratory and the fabrication, instrumentation, testing and in-service operation of two valves at the Bonneville Power Adminstration (BPA) facilities of the Pacific Intertie HVDC Power Tansmission System at Celilo, Oregon. The second task was the design, development, fabrication, installation, and operation of a voltage and current monitoring station and the transient event recording system to go with it. Information is present on the design and development of converter valves; LMPV principles; and the testing of prototype valves. (LCL)

  17. Thin films of metal oxides on metal single crystals: Structure and growth by scanning tunneling microscopy

    International Nuclear Information System (INIS)

    Detailed studies of the growth and structure of thin films of metal oxides grown on metal single crystal surfaces using Scanning Tunneling Microscopy (STM) are presented. The oxide overlayer systems studied are iron oxide and titanium oxide on the Pt(III) surface. The complexity of the metal oxides and large lattice mismatches often lead to surface structures with large unit cells. These are particularly suited to a local real space technique such as scanning tunneling microscopy. In particular, the symmetry that is directly observed with the STM elucidates the relationship of the oxide overlayers to the substrate as well as distinguishing, the structures of different oxides

  18. Detailed Abundances of Stars with Small Planets Discovered by Kepler. I. The First Sample

    Science.gov (United States)

    Schuler, Simon C.; Vaz, Zachary A.; Katime Santrich, Orlando J.; Cunha, Katia; Smith, Verne V.; King, Jeremy R.; Teske, Johanna K.; Ghezzi, Luan; Howell, Steve B.; Isaacson, Howard

    2015-12-01

    We present newly derived stellar parameters and the detailed abundances of 19 elements of seven stars with small planets discovered by NASA's Kepler Mission. Each star, save one, has at least one planet with a radius ≤1.6 R⊕, suggesting a primarily rocky composition. The stellar parameters and abundances are derived from high signal-to-noise ratio, high-resolution echelle spectroscopy obtained with the 10 m Keck I telescope and High Resolution Echelle Spectrometer using standard spectroscopic techniques. The metallicities of the seven stars range from -0.32 to +0.13 dex, with an average metallicity that is subsolar, supporting previous suggestions that, unlike Jupiter-type giant planets, small planets do not form preferentially around metal-rich stars. The abundances of elements other than iron are in line with a population of Galactic disk stars, and despite our modest sample size, we find hints that the compositions of stars with small planets are similar to stars without known planets and with Neptune-size planets, but not to those of stars with giant planets. This suggests that the formation of small planets does not require exceptional host-star compositions and that small planets may be ubiquitous in the Galaxy. We compare our derived abundances (which have typical uncertainties of ≲0.04 dex) to the condensation temperature of the elements; a correlation between the two has been suggested as a possible signature of rocky planet formation. None of the stars demonstrate the putative rocky planet signature, despite at least three of the stars having rocky planets estimated to contain enough refractory material to produce the signature, if real. More detailed abundance analyses of stars known to host small planets are needed to verify our results and place ever more stringent constraints on planet formation models. Some of the data presented herein were obtained at the W.M. Keck Observatory, which is operated as a scientific partnership among the California

  19. Po Superconducting Magnet:detail of the windings

    CERN Multimedia

    1982-01-01

    The Po superconducting dipole was built as a prototype beam transport magnet for the SPS extracted proton beam Po. Its main features were: coil aperture 72 mm, length 5 m, room-temperature yoke, NbTi cable conductor impregnated with solder, nominal field 4.2 T at 4.7 K (87% of critical field). It reached its nominal field without any quench. The photo shows a detail of the inner layer winding before superposing the outer layer to form the complete coil of a pole. Worth noticing is the interleaved glass-epoxy sheet (white) with grooved channels for the flow of cooling helium. See also 8307552X.

  20. Soviet Illegal Whaling: The Devil and the Details

    OpenAIRE

    Ivashchenko, Yulia V.; Clapham, Phillip J.; Brownell, Jr. , Robert L.

    2011-01-01

    In 1948, the U.S.S.R. began a global campaign of illegal whaling that lasted for three decades and, together with the poorly managed “legal” whaling of other nations, seriously depleted whale populations. Although the general story of this whaling has been told and the catch record largely corrected for the Southern Hemisphere, major gaps remain in the North Pacific. Furthermore, little attention has been paid to the details of this system or its economic context. Using interviews with for...

  1. GRB 050822: Detailed analysis of an XRF observed by Swift

    OpenAIRE

    Godet, O; Page, K. L.; Osborne, J.; B. Zhang; Burrows, D.N.; O'Brien, P. T.; Hill, J. E.; Racusin, J.; Beardmore, A. P.; Goad, M. R.; Falcone, A; Morris, D. C.; Ziaeepour, H.

    2007-01-01

    We report on the temporal and spectral characteristics of the early X-ray emission from the GRB 050822 as observed by Swift. This burst is likely to be an XRF showing major X-ray flares in its XRT light-curve. The quality of the data allows a detailed spectral analysis of the early afterglow in the X-ray band. During the X-ray flares, a positive correlation between the count rate and the spectral hardness (i.e. the higher the count rate, the harder the spectrum) is clearly seen for the X-ray ...

  2. Aircraft wing structural detail design (wing, aileron, flaps, and subsystems)

    Science.gov (United States)

    Downs, Robert; Zable, Mike; Hughes, James; Heiser, Terry; Adrian, Kenneth

    1993-01-01

    The goal of this project was to design, in detail, the wing, flaps, and ailerons for a primary flight trainer. Integrated in this design are provisions for the fuel system, the electrical system, and the fuselage/cabin carry-through interface structure. This conceptual design displays the general arrangement of all major components in the wing structure, taking into consideration the requirements set forth by the appropriate sections of Federal Aviation Regulation Part 23 (FAR23) as well as those established in the statement of work.

  3. Number plates – confidentiality and your personal details

    CERN Multimedia

    Since the 15th May 2008, Geneva’s ‘Service des automobiles et de la navigation’ has offered the possibility of finding out the name and address of owners of vehicles registered in the Canton of Geneva simply by sending a SMS of the car’s number plate to 939.However, owners of number plates registered in Geneva can block the divulgence of their personal details by filling out the following form, available at:http://www.ge.ch/san/doc/sms-confidentialite.pdf

  4. Detail study of SiC MOSFET switching characteristics

    DEFF Research Database (Denmark)

    Li, Helong; Munk-Nielsen, Stig

    2014-01-01

    This paper makes detail study of the latest SiC MOSFETs switching characteristics in relation to gate driver maximum current, gate resistance, common source inductance and parasitic switching loop inductance. The switching performance of SiC MOSFETs in terms of turn on and turn off voltage...... and current are presented. Switching losses analysis is made according to the experiment results. The switching characteristics study and switching losses analysis could give some guidelines of gate driver IC and gate resistance selection, switching losses estimation and circuit design of SiC MOSFETs....

  5. Detailed Atmosphere Model Fits to Disk-Dominated ULX Spectra

    OpenAIRE

    Hui, Y; Krolik, Julian H.

    2008-01-01

    We have chosen 6 Ultra-Luminous X-ray sources from the {\\it XMM-Newton} archive whose spectra have high signal-to-noise and can be fitted solely with a disk model without requiring any power-law component. To estimate systematic errors in the inferred parameters, we fit every spectrum to two different disk models, one based on local blackbody emission (KERRBB) and one based on detailed atmosphere modelling (BHSPEC). Both incorporate full general relativistic treatment of the disk surface brig...

  6. Accuracy of Implant Position Transfer and Surface Detail Reproduction with Different Impression Materials and Techniques

    Directory of Open Access Journals (Sweden)

    Marzieh Alikhasi

    2016-03-01

    Full Text Available Objectives: The purpose of this study was to compare the accuracy of implant position transfer and surface detail reproduction using two impression techniques and materials.Materials and Methods: A metal model with two implants and three grooves of 0.25, 0.50 and 0.75 mm in depth on the flat superior surface of a die was fabricated. Ten regular-body polyether (PE and 10 regular-body polyvinyl siloxane (PVS impressions with square and conical transfer copings using open tray and closed tray techniques were made for each group. Impressions were poured with type IV stone, and linear and angular displacements of the replica heads were evaluated using a coordinate measuring machine (CMM. Also, accurate reproduction of the grooves was evaluated by a video measuring machine (VMM. These measurements were compared with the measurements calculated on the reference model that served as control, and the data were analyzed with two-way ANOVA and t-test at P= 0.05.Results: There was less linear displacement for PVS and less angular displacement for PE in closed-tray technique, and less linear displacement for PE in open tray technique (P<0.001. Also, the open tray technique showed less angular displacement with the use of PVS impression material. Detail reproduction accuracy was the same in all the groups (P>0.05(.Conclusion: The open tray technique was more accurate using PE, and also both closed tray and open tray techniques had acceptable results with the use of PVS. The choice of impression material and technique made no significant difference in surface detail reproduction.Keywords: Dental Implants; Dental Impression Materials, Dental Impression Technique

  7. Structural Design and Sizing of a Metallic Cryotank Concept

    Science.gov (United States)

    Sleight, David W.; Martin, Robert A.; Johnson, Theodore F.

    2013-01-01

    This paper presents the structural design and sizing details of a 33-foot (10 m) metallic cryotank concept used as the reference design to compare with the composite cryotank concepts developed by industry as part of NASA s Composite Cryotank Technology Development (CCTD) Project. The structural design methodology and analysis results for the metallic cryotank concept are reported in the paper. The paper describes the details of the metallic cryotank sizing assumptions for the baseline and reference tank designs. In particular, the paper discusses the details of the cryotank weld land design and analyses performed to obtain a reduced weight metallic cryotank design using current materials and manufacturing techniques. The paper also discusses advanced manufacturing techniques to spin-form the cryotank domes and compares the potential mass savings to current friction stir-welded technology.

  8. The β relaxation in metallic glasses: an overview

    Directory of Open Access Journals (Sweden)

    Hai-Bin Yu

    2013-05-01

    Full Text Available Metallic glasses, combining metallic bonding and disordered atomic structures, are at the cutting edge of metallic materials research. Recent advances in this field have revealed that many key questions in glassy physics are inherently connected to one important relaxation mode: the so-called secondary (β relaxation. Here, in metallic glasses, we review the features of β relaxations and their relations to other processes and properties. Special emphasis is put on their current roles and future promise in understanding the glass transition phenomenon, mechanical properties and mechanisms of plastic deformation, diffusion, physical aging, as well as the stability and crystallization of metallic glasses.

  9. Multiple metal resistant transferable phenotypes in bacteria as indicators of soil contamination with heavy metals

    Energy Technology Data Exchange (ETDEWEB)

    Ryan, R.P.; Ryan, D.J.; Dowling, D.N. [Dept. of Science and Health, Inst. of Tech. Carlow, Carlow (Ireland)

    2005-07-01

    Environmental contamination by heavy metals affects microbial communities. The number of single and multiple heavy metal resistant bacteria may be an indicator of the level of contamination. This paper details the isolation and characterisation of metal resistant microorganisms isolated from rhizosphere/soil samples obtained from an abandoned zinc, lead and copper mine and a local unaffected site. This data was compared to the level of heavy metal in the soils to establish the effect of metals on the microbial community and to determine the relationship between pollutant levels and resistant strains. This paper outlines the diversity of transferable resistance determinants between both sites and details the levels of heavy metal resistant bacteria and those expressing transferable multiple heavy metal tolerance. Methods. The sample sites were located in Co. Galway, Ireland. The first sample site (site A) was a former lead, zinc and copper mine, which was closed in 1961 due to exhaustion of ore. The second site (site B) was located two and a half kilometres from the mining site and was not affected by the mining operations. Composite soil samples were characterised for general soil matrix composition, organic content, pH and general chemical parameters. The soil was also enumerated for the total viable heterotrophic counts and tested on Pseudomonas selective agar (PSA) for total Pseudomonas counts and Sucrose Asparagine (SA), which is semi-selective for fluorescent Pseudomonas. (orig.)

  10. The Influence of Metallic Bodies on a Coil Radiating an Alternating Magnetic Field

    Directory of Open Access Journals (Sweden)

    Alladi Prabhakar

    1956-01-01

    Full Text Available The response of a metallic sphere placed in an alternating magnetic field has been studied in details and the conclusions derived therefrom have been verified experimentally. Similar investigations on cylinders and disc are also reported. the recent trend for developing non-metallic mines, in which the metallic components are very few, makes it imperative that a more detailed study with very small cylinder should be carried out.

  11. Metallic glass coating on metals plate by adjusted explosive welding technique

    International Nuclear Information System (INIS)

    Using an adjusted explosive welding technique, an aluminum plate has been coated by a Fe-based metallic glass foil in this work. Scanning electronic micrographs reveal a defect-free metallurgical bonding between the Fe-based metallic glass foil and the aluminum plate. Experimental evidence indicates that the Fe-based metallic glass foil almost retains its amorphous state and mechanical properties after the explosive welding process. Additionally, the detailed explosive welding process has been simulated by a self-developed hydro-code and the bonding mechanism has been investigated by numerical analysis. The successful welding between the Fe-based metallic glass foil and the aluminum plate provides a new way to obtain amorphous coating on general metal substrates.

  12. Heavy metals in a light white dwarf: Abundances of the metal-rich, extremely low-mass GALEX J1717+6757

    CERN Document Server

    Hermes, J J; Koester, D; Bours, M C P; Townsley, D M; Farihi, J; Marsh, T R; Littlefair, Stuart; Dhillon, V S; Gianninas, A; Breedt, E; Raddi, R

    2014-01-01

    Using the Hubble Space Telescope, we detail the first abundance analysis enabled by far-ultraviolet spectroscopy of a low-mass (~0.19 Msun) white dwarf (WD), GALEX J1717+6757, which is in a 5.9-hr binary with a fainter, more-massive companion. We see absorption from nine metals, including roughly solar abundances of Ca, Fe, Ti, and P. We detect a significantly sub-solar abundance of C, and put upper limits on N and O that are also markedly sub-solar. Updated diffusion calculations indicate that all metals should settle out of the atmosphere of this 14,900 K, log(g) = 5.67 WD in the absence of radiative forces in less than 20 yr, orders of magnitude faster than the cooling age of hundreds of Myr. We demonstrate that ongoing accretion of rocky material that is often the cause of atmospheric metals in isolated, more massive WDs is unlikely to explain the observed abundances in GALEX J1717+6757. Using new radiative levitation calculations, we determine that radiative forces can counteract diffusion and support ma...

  13. Post first dredge-up [C/N] ratio as age indicator. Theoretical calibration

    CERN Document Server

    Salaris, Maurizio; Piersimoni, Anna M; Cassisi, Santi

    2015-01-01

    We performed a detailed analysis of the use of [C/N] measured in red giant branch stars between the completion of the first dredge up and the red giant branch bump ([C/N]_{FDU}) as age indicator. [C/N]_{FDU} cannot give accurate ages for individual stars, but may provide a general chronology for the formation of composite populations and add constraints to analyses of red giants from surface gravity-effective temperature diagrams. We provide a theoretical calibration of [C/N]_{FDU} in terms of total metallicity [M/H] and age, for ages greater than 1 Gyr, which we tested against variations in the initial heavy element distribution (scaled-solar vs alpha-enhanced), efficiency of overshooting from MS convective cores and from the convective envelopes, variations in the initial He abundance and in the mixing length parameter. Our calibration is compared with a small sample of available measurements of [C/N]_{FDU} in star clusters and halo field stars, which at least qualitatively confirm the overall trend of the ...

  14. Effects of Heavy Metals on Activated Sludge Microorganism

    Institute of Scientific and Technical Information of China (English)

    XIE Bing; XI Dan-li; CHEN Ji-hua

    2002-01-01

    The efforts of heavy metals on activated sludge microorganisms are reviewed. Although some heavy metals play an important role in the life of microorganism, heavy metals concentrations above toxic levels inhibit biological processes. Copper, zinc, nickel,cadmium and chromium were mostly studied because of their toxicity and widely used, regardless of single or combination. The microorganism response to these heavy metals varied with species and concentrations of metals,factors such as pH, sludge age, MLSS etc. also affect toxicity on the microorganism. The acclimation could extend the microorganism tolerance of heavy metals. The effects of heavy metals on sludge microorganisms could be described with different models, such as Sigmoidal and Monod equation. The kinetic constants are the useful indexes to estimate the heavy metals inhibition on activated sludge system. Methods to measure the toxicity and effects on microorganism community were also reviewed.

  15. Manufacturing details by Neutron Radiography of Archaeological Pottery

    Energy Technology Data Exchange (ETDEWEB)

    Bernedo, Alfredo Victor Bellido; Latini, Rose Mary [Universidade Federal Fluminense (UFF), Niteroi, RJ (Brazil); Souza, Maria Ines Silvani; Vinagre Filho, Ubirajara Maribondo [Instituto de Engenharia Nuclear (IEN/CNEN-RJ), Rio de Janeiro, RJ (Brazil)

    2011-07-01

    Full text: The aim of the present work was to investigate manufacturing details of archaeological pot-sherds ceramics by Neutron Radiography. Pottery is perhaps the most important artefact found in excavation. Its archaeological importance relies on the fact that it can reveal cultural traditions and commercial influences in ancient communities. These pottery was recently discovered in archaeological earth circular structures sites in Acre state Brazil and the characteristics of clay used in their manufacture have been studied by modern scientific techniques such as Instrumental Neutron Activation Analysis (INAA), Thermoluminescence Dating and Moessbauer Spectroscopy. Different fragments of pottery were submitted to a neutron flux of the order of 10{sup 5}n.cm{sup -2}2:s{sup -1} for 3 minutes in the research reactor Argonauta at the Instituto de Engenharia Nuclear/CNEN. Digital processing techniques using imaging plate were applied to the image of the selected sample. The Neutrongraphy shows two different manufacturing details: palette and rollers. The fragment made by the technique of palette show a homogeneous mass and the neutrongraphy of ceramic fragments made by the technique of the rollers, pottery funeral, can be seen horizontal traces of the junction of rollers, overlapping, forming layers supported on each other. This technique allows you to create more stable structures. Thus, both the technique of the pallet as the roller can be characterized by Neutron Radiography. (author)

  16. Effects of Geometric Details on Slat Noise Generation and Propagation

    Science.gov (United States)

    Khorrami, Mehdi R.; Lockard, David P.

    2009-01-01

    The relevance of geometric details to the generation and propagation of noise from leading-edge slats is considered. Typically, such details are omitted in computational simulations and model-scale experiments thereby creating ambiguities in comparisons with acoustic results from flight tests. The current study uses two-dimensional, computational simulations in conjunction with a Ffowcs Williams-Hawkings (FW-H) solver to investigate the effects of previously neglected slat "bulb" and "blade" seals on the local flow field and the associated acoustic radiation. The computations show that the presence of the "blade" seal at the cusp in the simulated geometry significantly changes the slat cove flow dynamics, reduces the amplitudes of the radiated sound, and to a lesser extent, alters the directivity beneath the airfoil. Furthermore, the computations suggest that a modest extension of the baseline "blade" seal further enhances the suppression of slat noise. As a side issue, the utility and equivalence of FW-H methodology for calculating far-field noise as opposed to a more direct approach is examined and demonstrated.

  17. Detailed computation of hot-plasma atomic spectra

    CERN Document Server

    Pain, Jean-Christophe; Blenski, Thomas

    2015-01-01

    We present recent evolutions of the detailed opacity code SCO-RCG which combines statistical modelings of levels and lines with fine-structure calculations. The code now includes the Partially-Resolved-Transition-Array model, which allows one to replace a complex transition array by a small-scale detailed calculation preserving energy and variance of the genuine transition array and yielding improved high-order moments. An approximate method for studying the impact of strong magnetic field on opacity and emissivity was also recently implemented. The Zeeman line profile is modeled by fourth-order Gram-Charlier expansion series, which is a Gaussian multiplied by a linear combination of Hermite polynomials. Electron collisional line broadening is often modeled by a Lorentzian function and one has to calculate the convolution of a Lorentzian with Gram-Charlier distribution for a huge number of spectral lines. Since the numerical cost of the direct convolution would be prohibitive, we propose, in order to obtain t...

  18. The detailed nature of active central cluster galaxies

    CERN Document Server

    Loubser, S I

    2013-01-01

    We present detailed integral field unit (IFU) observations of the central few kiloparsecs of the ionised nebulae surrounding four active central cluster galaxies (CCGs) in cooling flow clusters (Abell 0496, 0780, 1644 and 2052). Our sample consists of CCGs with H{\\alpha} filaments, and have existing data from the X-ray regime available. Here, we present the detailed optical emission-line (and simultaneous absorption line) data over a broad wavelength range to probe the dominant ionisation processes, excitation sources, morphology and kinematics of the hot gas (as well as the morphology and kinematics of the stars). This, combined with the other multiwavelength data, will form a complete view of the different phases (hot and cold gas and stars) and how they interact in the processes of star formation and feedback detected in central galaxies in cooling flow clusters, as well as the influence of the host cluster. We derive the optical dust extinction maps of the four nebulae. We also derive a range of different...

  19. Detailed kinetic modeling study of n-pentanol oxidation

    KAUST Repository

    Heufer, Karl Alexander

    2012-10-18

    To help overcome the world\\'s dependence upon fossil fuels, suitable biofuels are promising alternatives that can be used in the transportation sector. Recent research on internal combustion engines shows that short alcoholic fuels (e.g., ethanol or n-butanol) have reduced pollutant emissions and increased knock resistance compared to fossil fuels. Although higher molecular weight alcohols (e.g., n-pentanol and n-hexanol) exhibit higher reactivity that lowers their knock resistance, they are suitable for diesel engines or advanced engine concepts, such as homogeneous charge compression ignition (HCCI), where higher reactivity at lower temperatures is necessary for engine operation. The present study presents a detailed kinetic model for n-pentanol based on modeling rules previously presented for n-butanol. This approach was initially validated using quantum chemistry calculations to verify the most stable n-pentanol conformation and to obtain C-H and C-C bond dissociation energies. The proposed model has been validated against ignition delay time data, speciation data from a jet-stirred reactor, and laminar flame velocity measurements. Overall, the model shows good agreement with the experiments and permits a detailed discussion of the differences between alcohols and alkanes. © 2012 American Chemical Society.

  20. Manufacturing details by Neutron Radiography of Archaeological Pottery

    International Nuclear Information System (INIS)

    Full text: The aim of the present work was to investigate manufacturing details of archaeological pot-sherds ceramics by Neutron Radiography. Pottery is perhaps the most important artefact found in excavation. Its archaeological importance relies on the fact that it can reveal cultural traditions and commercial influences in ancient communities. These pottery was recently discovered in archaeological earth circular structures sites in Acre state Brazil and the characteristics of clay used in their manufacture have been studied by modern scientific techniques such as Instrumental Neutron Activation Analysis (INAA), Thermoluminescence Dating and Moessbauer Spectroscopy. Different fragments of pottery were submitted to a neutron flux of the order of 105n.cm-22:s-1 for 3 minutes in the research reactor Argonauta at the Instituto de Engenharia Nuclear/CNEN. Digital processing techniques using imaging plate were applied to the image of the selected sample. The Neutrongraphy shows two different manufacturing details: palette and rollers. The fragment made by the technique of palette show a homogeneous mass and the neutrongraphy of ceramic fragments made by the technique of the rollers, pottery funeral, can be seen horizontal traces of the junction of rollers, overlapping, forming layers supported on each other. This technique allows you to create more stable structures. Thus, both the technique of the pallet as the roller can be characterized by Neutron Radiography. (author)

  1. Mortality in vegetarians and nonvegetarians: detailed findings from a collaborative analysis of 5 prospective studies.

    Science.gov (United States)

    Key, T J; Fraser, G E; Thorogood, M; Appleby, P N; Beral, V; Reeves, G; Burr, M L; Chang-Claude, J; Frentzel-Beyme, R; Kuzma, J W; Mann, J; McPherson, K

    1999-09-01

    We combined data from 5 prospective studies to compare the death rates from common diseases of vegetarians with those of nonvegetarians with similar lifestyles. A summary of these results was reported previously; we report here more details of the findings. Data for 76172 men and women were available. Vegetarians were those who did not eat any meat or fish (n = 27808). Death rate ratios at ages 16-89 y were calculated by Poisson regression and all results were adjusted for age, sex, and smoking status. A random-effects model was used to calculate pooled estimates of effect for all studies combined. There were 8330 deaths after a mean of 10.6 y of follow-up. Mortality from ischemic heart disease was 24% lower in vegetarians than in nonvegetarians (death rate ratio: 0.76; 95% CI: 0.62, 0.94; Pvegetarians was greater at younger ages and was restricted to those who had followed their current diet for >5 y. Further categorization of diets showed that, in comparison with regular meat eaters, mortality from ischemic heart disease was 20% lower in occasional meat eaters, 34% lower in people who ate fish but not meat, 34% lower in lactoovovegetarians, and 26% lower in vegans. There were no significant differences between vegetarians and nonvegetarians in mortality from cerebrovascular disease, stomach cancer, colorectal cancer, lung cancer, breast cancer, prostate cancer, or all other causes combined. PMID:10479225

  2. Investigating Detailed Abundance Patterns in the Hyades Cluster

    Science.gov (United States)

    Williams, Drake; Schuler, Simon C.

    2016-01-01

    We have derived the paramters and abundances of up to 17 elements for seven stars within the Hyades open star cluster, through an analysis of high-resolution, high signal-to-noise ratio spectra obtained via the Harlan J. Smith 2.7 m telescope and the 2dcoude cross-dispersed echelle spectrometer at the McDonald Observatory. Four of the stars are solar-type dwarves while three giants were also analyzed to better calculate an overall metallicity of the entire cluster. In addition, we investigated whether there are differences in various stellar abundance trends across the open cluster. Here we present the results of our abundance analysis and stellar parameter derivations of the seven stars and discuss the implications of stellar abundance patterns across star clusters. We acknowledge support provided by grant NNX12AD19G to S.C.S. from the National Aeronautics and Space Administration as part of the Kepler Participating Scientist Program.

  3. Metals and metal derivatives in medicine.

    Science.gov (United States)

    Colotti, Gianni; Ilari, Andrea; Boffi, Alberto; Morea, Veronica

    2013-02-01

    Several chemical elements are required by living organisms in addition to the four elements carbon, hydrogen, nitrogen and oxygen usually present in common organic molecules. Many metals (e.g. sodium, potassium, magnesium, calcium, iron, zinc, copper, manganese, chromium, molybdenum and selenium) are known to be required for normal biological functions in humans. Disorders of metal homeostasis and of metal bioavailability, or toxicity caused by metal excess, are responsible for a large number of human diseases. Metals are also extensively used in medicine as therapeutic and/or diagnostic agents. In the past 5000 years, metals such as arsenic, gold and iron have been used to treat a variety of human diseases. Nowadays, an ever-increasing number of metal-based drugs is available. These contain a broad spectrum of metals, many of which are not among those essential for humans, able to target proteins and/or DNA. This mini-review describes metal-containing compounds targeting DNA or proteins currently in use, or designed to be used, as therapeutics against cancer, arthritis, parasitic and other diseases, with a special focus on the available information, often provided by X-ray studies, about their mechanism of action at a molecular level. In addition, an overview of metal complexes used for diagnosing diseases is presented.

  4. Colloidal chemical synthesis and formation kinetics of uniformly sized nanocrystals of metals, oxides, and chalcogenides.

    Science.gov (United States)

    Kwon, Soon Gu; Hyeon, Taeghwan

    2008-12-01

    Nanocrystals exhibit interesting electrical, optical, magnetic, and chemical properties not achieved by their bulk counterparts. Consequently, to fully exploit the potential of nanocrystals, the synthesis of nanocrystals must focus on producing materials with uniform size and shape. Top-down physical processes can produce large quantities of nanocrystals, but controlling the size is difficult with these methods. On the other hand, colloidal chemical synthetic methods can produce uniform nanocrystals with a controlled particle size. In this Account, we present our synthesis of uniform nanocrystals of various shapes and materials, and we discuss the kinetics of nanocrystal formation. We employed four different synthetic approaches including thermal decomposition, nonhydrolytic sol-gel reactions, thermal reduction, and use of reactive chalcogen reagents. We synthesized uniform oxide nanocrystals via heat-up methods. This method involved slowly heat-up reaction mixtures composed of metal precursors, surfactants, and solvents from room temperature to high temperature. We then held reaction mixtures at an aging temperature for a few minutes to a few hours. Kinetics studies revealed a three-step mechanism for the synthesis of nanocrystals through the heat-up method with size distribution control. First, as metal precursors thermally decompose, monomers accumulate. At the aging temperature, burst nucleation occurs rapidly; at the end of this second phase, nucleation stops, but continued diffusion-controlled growth leads to size focusing to produce uniform nanocrystals. We used nonhydrolytic sol-gel reactions to synthesize various transition metal oxide nanocrystals. We employed ester elimination reactions for the synthesis of ZnO and TiO(2) nanocrystals. Uniform Pd nanoparticles were synthesized via a thermal reduction reaction induced by heating up a mixture of Pd(acac)(2), tri-n-octylphosphine, and oleylamine to the aging temperature. Similarly, we synthesized

  5. Healthy Aging -- Sexual Health

    Science.gov (United States)

    ... address Submit Home > Healthy Aging > Sexual health Healthy Aging This information in Spanish ( en español ) Sexual health ... to discuss with your doctor. Sexual Health and Aging: Keep the Passion Alive (Copyright © Mayo Foundation) - This ...

  6. National Council on Aging

    Science.gov (United States)

    ... Centers Center for Benefits Access Center for Healthy Aging Donate Skip to Content a A Menu Economic ... Seniors Home Equity Older Workers Money Management Healthy Aging Falls Prevention Chronic Disease Management Flu + You Aging ...

  7. Exercise and age

    Science.gov (United States)

    Age and exercise ... It is never too late to start exercising. Exercise has benefits at any age. Don't worry ... as you age. The right kind of regular exercise can also reduce your risk of heart disease, ...

  8. The fracture toughness of Type 316 steel and weld metal

    International Nuclear Information System (INIS)

    This paper describes the results of fracture toughness tests on Type 316 steel and Manual Metal Arc (MMA) weld metal over a range of temperatures from 20 deg. C to 550 deg. C, and includes the effects on toughness of specimen size, post weld heat treatment and thermal ageing. The conclusions reached are that Type 316 steel possesses a superior toughness to the weld metal in the as-welded or stress relieved conditions but the toughness of the steel is degraded to a level similar to that of the weld metal following thermal ageing at temperatures over 600 deg. C. Relatively short term thermal ageing in the temperature range 370 deg. C to 450 deg. C does not appear to affect the toughness of either Type 316 steel or weld metal. (author)

  9. Detailed free span assessment for Mexilhao flow lines

    Energy Technology Data Exchange (ETDEWEB)

    Pereira, Antonio; Franco, Luciano; Eigbe, Uwa; BomfimSilva, Carlos [INTECSEA, Houston, TX (United States); Escudero, Carlos [PETROBRAS S.A., Rio de Janeiro, RJ (Brazil)

    2009-07-01

    The subsea gas production system of Mexilhao Field SPS-35, Santos Basin, offshore Brazil, is composed basically of two rigid 12.75 inches production flow lines approximately 21 km long installed in a fairly rough seabed. During the basic design, the free span assessment was performed considering the maximum allowable free span length determined by the response model proposed by DNV-RP-F105. This approach resulted in a large number of predicted free span requiring corrections, leading to a higher capital cost for the project. In this sense, a detailed free span VIV fatigue assessment was proposed, considering multi-spans and multi-mode effects and also the post lay survey data. The assessment followed the DNV-RP-F105 recommendations for multi-spans and multi-mode effects, using Finite Element Analysis to determine the natural frequencies, mode shapes and corresponding stresses associated with the mode shapes. The assessment was performed in three stages, the first during the detailed design as part of the bottom roughness analysis using the expected residual pipelay tension. The second stage was performed after pipelay, considering the post-lay survey data, where the actual requirements for span correction were determined. Actual pipelay tension was used and seabed soil stiffness adjusted in the model to match the as-laid pipeline profile obtained from the survey data. The first and second stage assessments are seamlessly automated to speed up the evaluation process and allow for quick response in the field, which was important to keep the construction vessel time minimized. The third stage was performed once the corrections of the spans were made and the purpose was to confirm that the new pipeline configuration along the supported spans had sufficient fatigue life for the temporary and operational phases. For the assessment of all three stages, the probability of occurrence and directionality of the near bottom current was considered to improve prediction of the

  10. Transcriptomic profiling of cartilage ageing

    Directory of Open Access Journals (Sweden)

    Mandy Jayne Peffers

    2014-12-01

    Full Text Available The musculoskeletal system is severely affected by the ageing process, with many tissues undergoing changes that lead to loss of function and frailty. Articular cartilage is susceptible to age related diseases, such as osteoarthritis. Applying RNA-Seq to young and old equine cartilage, we identified an over-representation of genes with reduced expression relating to extracellular matrix, degradative proteases, matrix synthetic enzymes, cytokines and growth factors in cartilage from older donors. Here we describe the contents and quality controls in detail for the gene expression and related results published by Peffers and colleagues in Arthritis Research and Therapy 2013 associated with the data uploaded to ArrayExpress (E-MTAB-1386.

  11. Transcriptomic profiling of cartilage ageing.

    Science.gov (United States)

    Peffers, Mandy Jayne; Liu, Xuan; Clegg, Peter David

    2014-12-01

    The musculoskeletal system is severely affected by the ageing process, with many tissues undergoing changes that lead to loss of function and frailty. Articular cartilage is susceptible to age related diseases, such as osteoarthritis. Applying RNA-Seq to young and old equine cartilage, we identified an over-representation of genes with reduced expression relating to extracellular matrix, degradative proteases, matrix synthetic enzymes, cytokines and growth factors in cartilage from older donors. Here we describe the contents and quality controls in detail for the gene expression and related results published by Peffers and colleagues in Arthritis Research and Therapy 2013 associated with the data uploaded to ArrayExpress (E-MTAB-1386). PMID:26484061

  12. Similar incidence of periprosthetic fluid collections after ceramic-on-polyethylene total hip arthroplasties and metal-on-metal resurfacing arthroplasties: results of a screening metal artefact reduction sequence-MRI study

    NARCIS (Netherlands)

    Bisseling, P.; Wit, B.W. de; Hol, A.M.; Gorp, M.J. van; Kampen, A. van; Susante, J.L. van

    2015-01-01

    Patients from a randomised trial on resurfacing hip arthroplasty (RHA) (n = 36, 19 males; median age 57 years, 24 to 65) comparing a conventional 28 mm metal-on-metal total hip arthroplasty (MoM THA) (n = 28, 17 males; median age 59 years, 37 to 65) and a matched control group of asymptomatic patien

  13. TESTING THE ASTEROSEISMIC MASS SCALE USING METAL-POOR STARS CHARACTERIZED WITH APOGEE AND KEPLER

    Energy Technology Data Exchange (ETDEWEB)

    Epstein, Courtney R.; Johnson, Jennifer A.; Tayar, Jamie; Pinsonneault, Marc [Department of Astronomy, Ohio State University, 140 W. 18th Avenue, Columbus, OH 43210 (United States); Elsworth, Yvonne P.; Chaplin, William J. [School of Physics and Astronomy, University of Birmingham, Edgbaston Park Road, West Midlands, Birmingham B15 2TT (United Kingdom); Shetrone, Matthew [McDonald Observatory, The University of Texas at Austin, 1 University Station, C1400, Austin, TX 78712-0259 (United States); Mosser, Benoît [LESIA, CNRS, Université Pierre et Marie Curie, Université Denis Diderot, Observatoire de Paris, F-92195 Meudon Cedex (France); Hekker, Saskia [Max-Planck-Institut für Sonnensystemforschung, Justus-von-Liebig-Weg 3, D-37077 Göttingen (Germany); Harding, Paul [Department of Astronomy, Case Western Reserve University, Cleveland, OH 44106-7215 (United States); Silva Aguirre, Víctor [Stellar Astrophysics Centre, Department of Physics and Astronomy, Aarhus University, Ny Munkegade 120, DK-8000 Aarhus C (Denmark); Basu, Sarbani [Department of Astronomy, Yale University, P.O. Box 208101, New Haven, CT 06520-8101 (United States); Beers, Timothy C. [National Optical Astronomy Observatory, Tucson, AZ 85719, USA and JINA: Joint Institute for Nuclear Astrophysics (United States); Bizyaev, Dmitry [Apache Point Observatory, Sunspot, NM 88349 (United States); Bedding, Timothy R. [Sydney Institute for Astronomy (SIfA), School of Physics, University of Sydney, NSW 2006 (Australia); Frinchaboy, Peter M. [Department of Physics and Astronomy, Texas Christian University, TCU Box 298840, Fort Worth, TX 76129 (United States); García, Rafael A. [Laboratoire AIM, CEA/DSM-CNRS, Universit Paris 7 Diderot, IRFU/SAp, Centre de Saclay, F-91191, Gif-sur-Yvette (France); Pérez, Ana E. García; Hearty, Fred R., E-mail: epstein@astronomy.ohio-state.edu [Department of Astronomy, University of Virginia, Charlottesville, VA 22904 (United States); and others

    2014-04-20

    Fundamental stellar properties, such as mass, radius, and age, can be inferred using asteroseismology. Cool stars with convective envelopes have turbulent motions that can stochastically drive and damp pulsations. The properties of the oscillation frequency power spectrum can be tied to mass and radius through solar-scaled asteroseismic relations. Stellar properties derived using these scaling relations need verification over a range of metallicities. Because the age and mass of halo stars are well-constrained by astrophysical priors, they provide an independent, empirical check on asteroseismic mass estimates in the low-metallicity regime. We identify nine metal-poor red giants (including six stars that are kinematically associated with the halo) from a sample observed by both the Kepler space telescope and the Sloan Digital Sky Survey-III APOGEE spectroscopic survey. We compare masses inferred using asteroseismology to those expected for halo and thick-disk stars. Although our sample is small, standard scaling relations, combined with asteroseismic parameters from the APOKASC Catalog, produce masses that are systematically higher (<ΔM > =0.17 ± 0.05 M {sub ☉}) than astrophysical expectations. The magnitude of the mass discrepancy is reduced by known theoretical corrections to the measured large frequency separation scaling relationship. Using alternative methods for measuring asteroseismic parameters induces systematic shifts at the 0.04 M {sub ☉} level. We also compare published asteroseismic analyses with scaling relationship masses to examine the impact of using the frequency of maximum power as a constraint. Upcoming APOKASC observations will provide a larger sample of ∼100 metal-poor stars, important for detailed asteroseismic characterization of Galactic stellar populations.

  14. Broken Detailed Balance of Filament Dynamics in Active Networks

    Science.gov (United States)

    Gladrow, J.; Fakhri, N.; MacKintosh, F. C.; Schmidt, C. F.; Broedersz, C. P.

    2016-06-01

    Myosin motor proteins drive vigorous steady-state fluctuations in the actin cytoskeleton of cells. Endogenous embedded semiflexible filaments such as microtubules, or added filaments such as single-walled carbon nanotubes are used as novel tools to noninvasively track equilibrium and nonequilibrium fluctuations in such biopolymer networks. Here, we analytically calculate shape fluctuations of semiflexible probe filaments in a viscoelastic environment, driven out of equilibrium by motor activity. Transverse bending fluctuations of the probe filaments can be decomposed into dynamic normal modes. We find that these modes no longer evolve independently under nonequilibrium driving. This effective mode coupling results in nonzero circulatory currents in a conformational phase space, reflecting a violation of detailed balance. We present predictions for the characteristic frequencies associated with these currents and investigate how the temporal signatures of motor activity determine mode correlations, which we find to be consistent with recent experiments on microtubules embedded in cytoskeletal networks.

  15. Broken detailed balance in active fluctuations of semiflexible filaments

    Science.gov (United States)

    Gladrow, Jannes; Fakhri, Nikta; Mackintosh, Fred C.; Schmidt, Christoph F.; Broedersz, Chase P.

    2015-03-01

    Non-equilibrium microscopic force generation in cells often results in stochastic steady-state fluctuations. In the cell cytoskeleton, for example, cytoplasmic myosins can drive vigorous conformational fluctuations of actin filaments and microtubules. We here present an analytical and numerical analysis of randomly driven shape fluctuations of semiflexible filaments in a viscoelastic environment. To detect and quantify non-equilibrium dynamics, we focus on the breaking of detailed balance in a conformational phase space subtended by eigenmodes of the beam equation. Molecular dynamics simulations reveal a non-zero circulatory flux in phase space induced by motor activity. Furthermore, we derived an analytical expression of nonequilibrium mode correlations that allows us to predict temporal effects of active molecular motors.

  16. A Detailed Strategy for Managing Corporation Cyber War Security

    Directory of Open Access Journals (Sweden)

    Walid Al-Ahmad

    2015-05-01

    Full Text Available Modern corporations depend heavily on information and communication technologies and are becoming increasingly interconnected locally and internationally. This interconnectedness and dependency on information technology make corporations vulnerable to cyber attacks. Corporate managers therefore need to understand the growing cyber war threats and implement appropriate strategies to mitigate the risks. This research work is an attempt to develop a generic and detailed strategy to assist corporations in managing the cyber war security. The implementation of such a strategy will definitely lead to a more secure business environment and as a result will attract foreign investments to the Arab countries in the Middle East. Such a strategy can be considered as a first step toward protecting corporations from cyber war threats in an effective manner.

  17. A detailed study of patent system for protection of inventions

    Directory of Open Access Journals (Sweden)

    Tulasi G

    2008-01-01

    Full Text Available Creations of brain are called intellect. Since these creations have good commercial value, are called as property. Inventions are intellectual property and can be protected by patents provided the invention is novel, non-obvious, useful and enabled. To have fare trade among member countries, World Trade Organisation proposed TRIPS agreement. India had taken necessary initiation by signing the World Trade Organisation agreement and transformed to global needs. The aim of this article is to enlighten pharmaceutical professionals especially in the field of research and development about planning inventions by thorough review of prior-art, which saves time and money. A thorough understanding is made possible by providing details of origin; present governing bodies, their role along with the Act that is safeguarding the patent system.

  18. Detail analysis of fusion neutronics benchmark experiment for iron

    Energy Technology Data Exchange (ETDEWEB)

    Konno, Chikara [Fusion Research and Development Directorate, Japan Atomic Energy Agency, Tokai-mura, Naka-gun, Ibaraki-ken 319-1195 (Japan)], E-mail: konno.chikara@jaea.go.jp; Ochiai, Kentaro [Fusion Research and Development Directorate, Japan Atomic Energy Agency, Tokai-mura, Naka-gun, Ibaraki-ken 319-1195 (Japan); Wada, Masayuki [Japan Computer System, Mito 310-0805 (Japan); Takakura, Kosuke; Sato, Satoshi [Fusion Research and Development Directorate, Japan Atomic Energy Agency, Tokai-mura, Naka-gun, Ibaraki-ken 319-1195 (Japan)

    2009-06-15

    In order to specify the best nuclear data on iron, the fusion neutronics benchmark experiment on iron at Japan Atomic Energy Agency (JAEA)/Fusion Neutronics Source (FNS) was analyzed in detail with MCNP-4C and the latest nuclear data libraries, JENDL-3.3, FENDL-2.1, JEFF-3.1 and ENDF/B-VII.0. As a result, totally the calculation result with ENDF/B-VII.0 agreed with the measurement best, except that it underestimated the measured neutron flux above 10 MeV with the depth. It was noted that the calculation result with JENDL-3.3 overestimated the measured neutrons below a few keV. Through the DORT calculations based on the iron data in ENDF/B-VII.0, it was found out that the first inelastic scattering cross-section data of {sup 57}Fe in JENDL-3.3 caused the overestimation.

  19. Detailed ultraviolet asymptotics for AdS scalar field perturbations

    CERN Document Server

    Evnin, Oleg

    2016-01-01

    We present a range of methods suitable for accurate evaluation of the leading asymptotics for integrals of products of Jacobi polynomials in limits when the degrees of some or all polynomials inside the integral become large. The structures in question have recently emerged in the context of effective descriptions of small amplitude perturbations in anti-de Sitter (AdS) spacetime. The limit of high degree polynomials corresponds in this situation to effective interactions involving extreme short-wavelength modes, whose dynamics is crucial for the turbulent instabilities that determine the ultimate fate of small AdS perturbations. We explicitly apply the relevant asymptotic techniques to the case of a self-interacting probe scalar field in AdS and extract a detailed form of the leading large degree behavior, including closed form analytic expressions for the numerical coefficients appearing in the asymptotics.

  20. A detailed and verified wind resource atlas for Denmark

    Energy Technology Data Exchange (ETDEWEB)

    Mortensen, N.G.; Landberg, L.; Rathmann, O.; Nielsen, M.N. [Risoe National Lab., Roskilde (Denmark); Nielsen, P. [Energy and Environmental Data, Aalberg (Denmark)

    1999-03-01

    A detailed and reliable wind resource atlas covering the entire land area of Denmark has been established. Key words of the methodology are wind atlas analysis, interpolation of wind atlas data sets, automated generation of digital terrain descriptions and modelling of local wind climates. The atlas contains wind speed and direction distributions, as well as mean energy densities of the wind, for 12 sectors and four heights above ground level: 25, 45, 70 and 100 m. The spatial resolution is 200 meters in the horizontal. The atlas has been verified by comparison with actual wind turbine power productions from over 1200 turbines. More than 80% of these turbines were predicted to within 10%. The atlas will become available on CD-ROM and on the Internet. (au)