324 research outputs found
Deep time foraminifera Mg/Ca paleothermometry: nonlinear correction for secular change in seawater Mg/Ca
No full text[1] The Mg/Ca ratio of foraminifera tests is increasingly being utilized as a paleotemperature proxy. Deep time (pre-Pleistocene) Mg/Ca paleothermometry is complicated by the fact that the Mg/Ca ratio of seawater (Mg/Casw) has undergone considerable secular variation over the Cenozoic. Previous studies have corrected for this by assuming an invariant Mg distribution coefficient (DMg) with Mg/Casw. More recent laboratory culturing has shown that this is not the case, demonstrating that a power relationship best describes the variation in test Mg/Ca (Mg/Catest) with Mg/Casw. Therefore, previous corrections are likely to have led to inaccurate temperature reconstructions. Here, we show how the systematics of such a correction should be applied and demonstrate why this provides good evidence that the Mg/Ca ratio of Paleogene seawater was lower than previously implied by foraminiferal constraints, in agreement with the majority of the proxy Mg/Casw evidence. We also demonstrate how it is indirectly possible to constrain the value of H, the power component of a Mg/Catest–Mg/Casw calibration, potentially enabling the appropriate correction of results derived from species where this relationship has not been calibrated. However, this technique should not be treated as a substitute for culturing. The previous erroneous assumptions regarding both (1) the relationship between Mg/Catest and Mg/Caswand (2) the Mg/Ca ratio of seawater at a given time in the past may counteract each other to differing extents. As a result, previous absolute pre-Pleistocene paleotemperature estimates derived from Mg/Ca ratios in foraminifera should be treated with caution, although relative temperature changes over short (<1 Ma timescales) are likely to be reliable
High Resolution Transmission Electron Microscopy to Study Very Thin Crystalline Layers Buried at an Amorphous-crystalline Interface
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Listrognathus mactator (Thunberg, 1824) (Hymenoptera: Ichneumonidae) A new recorded parasitoid of Cimbex quadrimaculatus (O. F. Mller, 1766) (Hymenoptera: Cimbicidae) in Turkey
No full textListrognathus mactator (Thunberg, 1824) (Hymenoptera: Ichneumonidae) was determined as a larva-pupa parasitoid of the almond pest, Cimbex quadrimaculatus (O. F. Mller, 1766) (Hymenoptera: Cimbicidae). The parasitoid is also recorded from Turkey for the first time
Transmission Electron Microscopy Studies of the Microstructure of Si Layers Grown on GaAs(001) under an Excess As or Al Flux
No full textThe SAVE approach to component-based development of vehicular systems
No full textThe component-based strategy aims at managing complexity, shortening time-to-market, and reducing maintenance requirements by
building systems with existing components. The full potential of this strategy has not yet been demonstrated for embedded software,
mainly because of specific requirements in the domain, e.g., those related to timing, dependability, and resource consumption.
We present SaveCCT – a component technology intended for vehicular systems, show the applicability of SaveCCT in the engineering
process, and demonstrate its suitability for vehicular systems in an industrial case-study. Our experiments indicate that SaveCCT provides
appropriate expressiveness, resource efficiency, analysis and verification support for component-based development of vehicular
software
High-pressure optical spectroscopy and X-ray diffraction studies on synthetic cobalt aluminum silicate garnet
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Photoionization of cold and ultracold Rubidium atoms
No full textPhotoionization of a cold atomic sample offers intriguing possibilities to observe collective effects at extremely low temperatures. Ionization of a rubidium condensate and of cold rubidium atoms in a magneto-optical/magnetic trap through 1-photon and 2-photon absorption processes has been performed. Losses of the remaining trapped cold cloud or the remaining condensate sample have been examined as a function of the ionizing laser parameters
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