ALBERT

All Library Books, journals and Electronic Records Telegrafenberg

X
feed icon rss

Your email was sent successfully. Check your inbox.

An error occurred while sending the email. Please try again.

Proceed reservation?

Export
Filter
Collection
Keywords
Publisher
Years
  • 1
    facet.materialart.
    Unknown
    High-pressure polymorphism of PbF_{2} to 75 GPa (2016)
    American Physical Society (APS)
    Details
    Publication Date: 2016-07-07
    Description: Author(s): Camelia V. Stan, Rajkrishna Dutta, Claire E. White, Vitali Prakapenka, and Thomas S. Duffy Lead fluoride, Pb F 2 , was investigated experimentally in the laser-heated diamond anvil cell by x-ray diffraction to pressures of 75 GPa at room temperature and to 64.5 GPa and 2430 K, as well as through first-principles density functional theory calculations up to 70 GPa. During room temperature com… [Phys. Rev. B 94, 024104] Published Wed Jul 06, 2016
    Keywords: Structure, structural phase transitions, mechanical properties, defects
    Print ISSN: 1098-0121
    Electronic ISSN: 1095-3795
    Topics: Physics
    Published by American Physical Society (APS)
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    PAPER CURRENT
  • 2
    facet.materialart.
    Unknown
    Strength and texture of Pt compressed to 63 GPa (2015)
    American Institute of Physics (AIP)
    Details
    Publication Date: 2015-02-11
    Description: Angle- and energy-dispersive X-ray diffraction experiments in a radial geometry were performed in the diamond anvil cell on polycrystalline platinum samples at pressures up to 63 GPa. Observed yield strength and texture depend on grain size. For samples with 70–300-nm particle size, the yield strength is 5–6 GPa at ∼60 GPa. Coarse-grained (∼2- μ m particles) Pt has a much lower yield strength of 1–1.5 GPa at ∼60 GPa. Face-centered cubic metals Pt and Au have lower strength to shear modulus ratio than body-centered cubic or hexagonal close-packed metals. While a 300-nm particle sample exhibits the 〈110〉 texture expected of face-centered-cubic metals under compression, smaller and larger particles show a weak mixed 〈110〉 and 〈100〉 texture under compression. Differences in texture development may also occur due to deviations from uniaxial stress under compression in the diamond anvil cell.
    Print ISSN: 0021-8979
    Electronic ISSN: 1089-7550
    Topics: Physics
    Published by American Institute of Physics (AIP)
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    PAPER CURRENT
  • 3
    facet.materialart.
    Unknown
    Orai/CRACM1 and K Ca 3.1 ion channels interact in the human lung mast cell plasma membrane (2015)
    BioMed Central
    Details
    Publication Date: 2015-07-17
    Description: Background: Orai/CRACM1 ion channels provide the major Ca 2+ influx pathway for FcεRI-dependent human lung mast cell (HLMC) mediator release. The Ca 2+ -activated K + channel K Ca 3.1 modulates Ca 2+ influx and the secretory response through hyperpolarisation of the plasma membrane. We hypothesised that there is a close functional and spatiotemporal interaction between these Ca 2+ - and K + -selective channels. Results: Activation of FcεRI-dependent HLMC K Ca 3.1 currents was dependent on the presence of extracellular Ca 2+ , and attenuated in the presence of the selective Orai blocker GSK-7975A. Currents elicited by the K Ca 3.1 opener 1-EBIO were also attenuated by GSK-7975A. The Orai1 E106Q dominant-negative mutant ablated 1-EBIO and FcεRI-dependent K Ca 3.1 currents in HLMCs. Orai1 but not Orai2 was shown to co-immunoprecipitate with K Ca 3.1 when overexpressed in HEK293 cells, and Orai1 and K Ca 3.1 were seen to co-localise in the HEK293 plasma membrane using confocal microscopy. Conclusion: K Ca 3.1 activation in HLMCs is highly dependent on Ca 2+ influx through Orai1 channels, mediated via a close spatiotemporal interaction between the two channels.
    Electronic ISSN: 1478-811X
    Topics: Biology , Medicine
    Published by BioMed Central
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    PAPER CURRENT
  • 4
    facet.materialart.
    Unknown
    X-ray diffraction of molybdenum under shock compression to 450 GPa (2015)
    American Physical Society (APS)
    Details
    Publication Date: 2015-11-21
    Description: Author(s): Jue Wang, Federica Coppari, Raymond F. Smith, Jon H. Eggert, Amy E. Lazicki, Dayne E. Fratanduono, J. Ryan Rygg, Thomas R. Boehly, Gilbert W. Collins, and Thomas S. Duffy Molybdenum (Mo) is a body-centered-cubic (bcc) transition metal that has widespread technological applications. Although the bcc transition elements are used as test cases for understanding the behavior of metals under extreme conditions, the melting curves and phase transitions of these elements ha… [Phys. Rev. B 92, 174114] Published Fri Nov 20, 2015
    Keywords: Structure, structural phase transitions, mechanical properties, defects
    Print ISSN: 1098-0121
    Electronic ISSN: 1095-3795
    Topics: Physics
    Published by American Physical Society (APS)
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    PAPER CURRENT
  • 5
    facet.materialart.
    Unknown
    Intercomparison of pressure standards (Au, Pt, Mo, MgO, NaCl and Ne) to 2.5 Mbar (2012)
    Wiley
    Details
    Publication Date: 2012-08-30
    Description: We have performed a series of co-compression experiments on Au, Pt, Mo, MgO and NaCl to extend internally consistent pressure calibration and characterize shear strength of pressure media to 2.5 Mbar. Measured unit cell volumes of calibrants show differences between existing pressure scales of ∼10% above 2 Mbar. A new comprehensive pressure scale is proposed in good agreement with recent reduced shock isotherms for Au, Mo and Pt and with internal agreement to 3% at Mbar pressures. Deviatoric stresses were analyzed for each material based on diffraction line broadening and line shifts due to anisotropic strain. The measured strength of Ne at 2.5 Mbar is 8 GPa. Diffraction line width analysis suggests that deviatoric stress conditions at 2.5 Mbar are similar for He and Ne media.
    Print ISSN: 0148-0227
    Topics: Geosciences , Physics
    Published by Wiley on behalf of American Geophysical Union (AGU).
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    PAPER CURRENT
  • 6
    facet.materialart.
    Unknown
    Equation of state of a high-pressure phase of Gd_{3} Ga_{5} O_{12} (2011)
    American Physical Society (APS)
    Details
    Publication Date: 2011-02-25
    Description: Author(s): Z. Mao, S. M. Dorfman, S. R. Shieh, J. F. Lin, V. B. Prakapenka, Y. Meng, and T. S. Duffy Gd_{3} Ga_{5} O_{12} (GGG), which crystallizes in the garnet structure at ambient conditions, was observed to transform to a high-pressure phase at 88 GPa after laser heating at 1500 K. This new phase is stable at least up to 180 GPa, and can be preserved on decompression to 50 GPa. This phase is cu... [Phys. Rev. B 83, 054114] Published Thu Feb 24, 2011
    Keywords: Structure, structural phase transitions, mechanical properties, defects
    Print ISSN: 1098-0121
    Electronic ISSN: 1095-3795
    Topics: Physics
    Published by American Physical Society (APS)
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    PAPER CURRENT
  • 7
    facet.materialart.
    Unknown
    Polyhedral units and network connectivity in GeO2 glass at high pressure: An X-ray total scattering investigation (2014)
    American Institute of Physics (AIP)
    Details
    Publication Date: 2014-08-27
    Description: We report a pressure-induced dense tetrahedral intermediate state via Ge–O–Ge rotation formed at 3–5 GPa and the polyhedral relations in GeO 2 glass up to 17.5 GPa using in situ X-ray total scattering and X-ray absorption (XAFS) techniques. It was found that the nearest-neighbor Ge-Ge correlations show a decrease reaching a minimum between 4 and 6 GPa, and exhibit negative compression behavior at 7–17.5 GPa. The Ge–Ge distance determined by XAFS shows a substantial reduction, i.e., normal compression behavior, at 7–17.5 GPa. The comparison with the theoretical g ( r ) function for rutile-type GeO 2 (16.1 GPa) indicates that the negative compression of intermediate range order reflects the direct formation of GeO 6 octahedral units. Results of coordination number analysis show that GeO 2 glass undergoes a transition from tetrahedral GeO 4 , to GeO 5 units (possibly triangular bipyramidal), and finally to octahedral GeO 6 units. The present investigation provides the structural details of the polyhedral units and their relationships in GeO 2 glass at high pressure.
    Print ISSN: 0003-6951
    Electronic ISSN: 1077-3118
    Topics: Physics
    Published by American Institute of Physics (AIP)
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    PAPER CURRENT
  • 8
    facet.materialart.
    Unknown
    Correction to “Intercomparison of pressure standards (Au, Pt, Mo, MgO, NaCl and Ne) to 2.5 Mbar” (2012)
    Wiley
    Details
    Publication Date: 2012-11-14
    Print ISSN: 0148-0227
    Topics: Geosciences , Physics
    Published by Wiley on behalf of American Geophysical Union (AGU).
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    PAPER CURRENT
  • 9
    facet.materialart.
    Unknown
    Settling Velocity and Grain Shape of Maerl Biogenic Gravel (2014)
    Society for Sedimentary Geology (SEPM)
    Details
    Publication Date: 2014-08-28
    Description: A bstract :  The importance of a grain-size-dependent shape metric, convexity, for determining the unusual settling velocity characteristics of maërl, a variety of unattached coralline algae, has been quantified by modeling of settling-tube data. A modification of the general settling-velocity equation of Ferguson and Church (2004) , involving a dependence of the drag coefficient-related constant, C 2 , on grain size, produces a satisfactory fit to the experimental observations. For a given grain size and at Reynolds numbers greater than ~ 220, maërl grains experience greater drag than is predicted for natural quartz grains by Ferguson and Church (2004) because of this grain-size-dependent roughness. Subsequent detailed measurements of maërl grain shape using microscopic image analysis confirm a strong positive linear relationship between grain roughness, quantified by the reciprocal of convexity, and grain size. This departure from the ideal settling characteristics of siliciclastic gravel is hypothesized to explain the observed propensity of maërl, under suitable hydrodynamic conditions, to form beach deposits with a low percentage of sand. Maërl samples from three different sedimentary environments (open marine, intertidal, and beach) exhibit different linear relationships between roughness and grain size, probably resulting from different degrees of abrasion due to a combination of different wave climates and transport histories. This spatial variability in grain texture suggests that a general equation for maërl settling velocity is not possible. However, for maërl, and other branched sediment types, it may only be necessary to measure the convexity of the middle and largest size fractions to estimate the linear variation of C 2 with grain size, resulting in an accurate estimate of the settling-velocity curve. In the broader context of physical sedimentology, our results indicate that, over a range of bottom current conditions between 200 and 250 mm s –1 , where the settling curve of maërl is flat and grain-size invariant relative to siliciclastic sediment, a larger part of the maërl grain-size distribution can remain in suspension compared to the siliciclastic sediment. This contrast in physical properties may be an effective process for the spatial separation of coarse siliciclastic and biogenic sediment.
    Print ISSN: 1527-1404
    Topics: Geosciences
    Published by Society for Sedimentary Geology (SEPM)
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    PAPER CURRENT
  • 10
    facet.materialart.
    Unknown
    Stability and structure of MgSiO3 perovskite to 2300-kilometer depth in Earth's mantle (2001)
    American Association for the Advancement of Science (AAAS)
    Details
    Publication Date: 2001-09-29
    Description: Unexplained features have been observed seismically near the middle (approximately 1700-kilometer depth) and bottom of the Earth's lower mantle, and these could have important implications for the dynamics and evolution of the planet. (Mg,Fe)SiO3 perovskite is expected to be the dominant mineral in the deep mantle, but experimental results are discrepant regarding its stability and structure. Here we report in situ x-ray diffraction observations of (Mg,Fe)SiO3 perovskite at conditions (50 to 106 gigapascals, 1600 to 2400 kelvin) close to a mantle geotherm from three different starting materials, (Mg0.9Fe0.1)SiO enstatite, MgSiO3 glass, and an MgO+SiO2 mixture. Our results confirm the stability of (Mg,Fe)SiO3 perovskite to at least 2300-kilometer depth in the mantle. However, diffraction patterns above 83 gigapascals and 1700 kelvin (1900-kilometer depth) cannot presently rule out a possible transformation from Pbnm perovskite to one of three other possible perovskite structures with space group P2(1)/m, Pmmn, or P4(2)/nmc.〈br /〉〈span class="detail_caption"〉Notes: 〈/span〉Shim, S H -- Duffy, T S -- Shen, G -- New York, N.Y. -- Science. 2001 Sep 28;293(5539):2437-40.〈br /〉〈span class="detail_caption"〉Author address: 〈/span〉Department of Geosciences, Princeton University, Princeton, NJ 08544, USA., CARS, University of Chicago, Chicago, IL 60637, USA. sangshim@uclink.berkeley.edu〈br /〉〈span class="detail_caption"〉Record origin:〈/span〉 〈a href="http://www.ncbi.nlm.nih.gov/pubmed/11577232" target="_blank"〉PubMed〈/a〉
    Print ISSN: 0036-8075
    Electronic ISSN: 1095-9203
    Topics: Biology , Chemistry and Pharmacology , Computer Science , Medicine , Natural Sciences in General , Physics
    Published by American Association for the Advancement of Science (AAAS)
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    PAPER CURRENT
Close ⊗
This website uses cookies and the analysis tool Matomo. More information can be found here...