ALBERT

Description: In this paper we examine the variations of the boreal summer season sea breeze circulation along the Florida panhandle coast from relatively high resolution (10 km) regional climate model integrations. The 23 year climatology (1979–2001) of the multidecadal dynamically downscaled simulations forced by the National Centers for Environmental Prediction–Department of Energy (NCEP-DOE) Reanalysis II at the lateral boundaries verify quite well with the observed climatology. The variations at diurnal and interannual time scales are also well simulated with respect to the observations. We show from composite analyses made from these downscaled simulations that sea breezes in northwestern Florida are associated with changes in the size of the Atlantic Warm Pool (AWP) on interannual time scales. In large AWP years when the North Atlantic Subtropical High becomes weaker and moves further eastward relative to the small AWP years, a large part of the southeast U.S. including Florida comes under the influence of relatively strong anomalous low-level northerly flow and large-scale subsidence consistent with the theory of the Sverdrup balance. This tends to suppress the diurnal convection over the Florida panhandle coast in large AWP years. This study is also an illustration of the benefit of dynamic downscaling in understanding the low-frequency variations of the sea breeze.

Description: [1]  Today it is widely accepted that during its early evolution the Earth experienced a magma ocean that covered most its surface. The separation of metal from silicate was much facilitated in the environment of such a magma ocean. The differentiation mechanism is known as the ‘metal-rain scenario’. Our study will focus on the settling dynamics of these metal droplets. [2]  Because of the low viscosity of molten silicate and a higher rotation period of the Earth at that time the rotation has a potentially strong influence on the dynamics of the magma ocean. We use numerical 3D fluid simulations to analyze the combined effect of strong rotation and convection on the settling of the iron droplets. [3]  We show that the influence of rotation on the settling depends on the latitude. At the poles the influence of rotation is only marginal. At the equator, three different scenarios can be distinguished. First, at low rotation rates, the particles form a dense layer at the bottom. Second, for higher rotation rates the particles stay mostly suspended and layers form in the temperature field. Third, at higher rotation rates the particles form a ribbon-like structure in the middle of the box. [4]  The influence of rotation on the iron droplets may lead to a scenario where part of the iron is kept in the mantle instead of transported to the core. This would have a strong influence on the later states of the differentiation process and the amountof siderophile elements in the mantel.

Description: Ecological Applications, Volume 0, Issue 0, Ahead of Print.

Description: The commonly used, but no longer available, reference materials NIST SRM 976 (Cu) and ‘JMC Lyon’ (Zn) were calibrated against the new reference materials ERM ® -AE633, ERM ® -AE647 (Cu) and IRMM-3702 (Zn), certified for isotope amount ratios. This cross-calibration of new with old reference materials provides a continuous and reliable comparability of already published with future Cu and Zn isotope data. The Cu isotope amount ratio of NIST SRM 976 yielded δ 65/63 Cu values of −0.01 ± 0.05‰ and −0.21 ± 0.05‰ relative to ERM ® -AE633 and ERM ® -AE647, respectively, and a δ 66/64 Zn IRMM-3702 value of −0.29 ± 0.05‰ was determined for ‘JMC Lyon’. Furthermore, we separated Cu and Zn from five geological reference materials (BCR-2, BHVO-2, BIR-1, AGV-1 and G-2) using a two-step ion-exchange chromatographic procedure. Possible isotope fractionation of Cu during chromatographic purification and introduction of resin- and/or matrix-induced interferences were assessed by enriched 65 Cu isotope addition. Instrumental mass bias correction for the isotope ratio determinations by MC-ICP-MS was performed using calibrator-sample bracketing with internal Ni doping for Cu and a double spike approach for Zn. Our results for the five geological reference materials were in very good agreement with literature data, confirming the accuracy and applicability of our analytical protocol. Les matériaux de référence NIST SRM 976 (Cu) et ‘JMC Lyon’ (Zn), utilisés couramment mais qui ne sont plus disponibles, ont étéétalonnés par rapport au nouveau matériaux de référence ERM ® -AE633, ERM ® -AE647 (Cu) et IRMM 3702 (Zn), certifiés pour les rapports isotopiques. Cette inter-calibration de nouvelles matériaux de référence avec des anciens fournit une comparabilité continu et fiable des données istopiques du Cu et du Zn déjà publiées avec les données futures. Les rapports isotopiques du Cu du NIST SRM 976 ont donné des valeurs de δ 65/63 Cu de −0.01 ± 0.05‰ et 0.21 ± 0.05‰ par rapport respectivement à ERM ® -AE633 et ERM ® -AE647, et une valeur de δ 66/64 Zn IRMM3702 de −0.29 ± 0.05‰ a été déterminé pour ‘JMC Lyon’. Par ailleurs, nous avons séparés le Cu et le Zn de cinq matériaux de référence géologiques (BCR-2, BHVO-2, le BIR-1, AGV-1 et G-2) en utilisant une procédure en deux étapes de chromatographie échangeuse d’ions. Le possible fractionnement isotopique du Cu lors de la purification chromatographique et l’introduction de résine et/ou les possible interférences induites par la matrice ont étéévaluées par l’enrichissement en isotope 65 Cu. La correction du biais de masse instrumental pour les déterminations des rapports isotopiques par MC-ICP-MS a été réalisée en utilisant la technique du bracketing avec un dopage interne en Ni pour le Cu et une approche dite du double spike pour le Zn. Nos résultats pour les cinq matériaux géologiques de référence étaient en très bon accord avec les données de la littérature, confirmant l’exactitude et l’applicabilité de notre protocole d’analyse.

Description: Element ratios and water stable isotopes reveal the presence of only two independent deep brines in the Kinnarot Basin, Israel: the evaporite dissolution brine of Zemah-1 and the inferred Ha’on mother brine (HMB) with low and high Br/Cl ratios, respectively. HMB is considered to be a representative of the Late Pliocene evaporated Sedom Sea. The freshwater-diluted evaporation brine emerges as Ha’on brine on the eastern shore of Lake Tiberias and is also identified in the pore water of lake sediments. HMB is converted into Tiberias mother brine (TMB) by dolomitization of limestones and alteration of abundant volcanic rocks occurring along the western side of the lake. The Ha’on and Tiberias brines, both characterized by high δD and δ 18 O values, are similar in Na/Cl and Br/Cl ratios but are dissimilar in Br/K ratios because these brines were subjected to different degrees of interactions with rocks and sediments. Excepting the brine from KIN 8, all brines from the Tabigha area including the nearby off-shore Barbutim brine are related to the TMB. The brine KIN 8 and all brines from the Fuliya and Hammat Gader areas are related to the HMB. The brine encountered in wildcat borehole Zemah-1 is generated by halite-anhydrite/gypsum dissolution and is independent from the HMB system.

Description: Na 5 [FeO 3 ][OH] has been obtained from a redox reaction between iron metal and CdO in the presence of Na 2 O and NaOH at 450 °C (5 d) as red crystals. The structure has been determined from single crystal data ( Pnma , Z = 8, a = 990.94(7) pm, b = 1016.41(7) pm, c = 1185.35(8) pm, wR 2 = 0.050) and evaluated by MAPLE calculations. In addition, we present experimental single-crystal IR and Raman spectroscopic data to discuss aspects of the isolated [FeO 3 ] 4– complexes and non-coordinating hydroxide in comparison with the respective cobalt compounds. Additional ab-initio lattice dynamic calculations are included for comparison.

Description: Natural glycosaminoglycans (GAGs) and chemically modified GAG derivatives are known to support osteogenic differentiation of mesenchymal stromal cells (MSC). This effect has mainly been described to be mediated by increasing the effectiveness of bone anabolic growth factors such as bone morphogenetic proteins (BMPs) due to the binding and presentation of the growth factor or by modulating its signal transduction pathway. In the present study, the influence of chondroitin sulfate (CS) and two chemically over-sulfated CS derivatives on osteogenic differentiation of human mesenchymal stromal cells (hMSC) and on BMP-2 and transforming growth factor β1 (TGF-β1) signalling was investigated. Over-sulfated CS derivatives induced an increase of tissue non-specific alkaline phosphatase (TNAP) activity and calcium deposition, whereas collagen synthesis was slightly decreased. The BMP-2-induced Smad1/5 activation was inhibited in the presence of over-sulfated CS derivatives leading to a loss of BMP-2-induced TNAP activity and calcium deposition. In contrast, the TGF-β1-induced activation of Smad2/3 and collagen synthesis were not affected by the over-sulfated CS derivatives. BMP-2 and TGF-β1 did not activate the extracellular signal-regulated kinase 1/2 or mitogen-activated protein kinase p38 in hMSC. These data suggest that over-sulfated CS derivatives themselves are able to induce osteogenic differentiation, probably independent of BMP-2 and TGF-β1 signalling, and offer therefore an interesting approach for the improvement of bone healing. J. Cell. Physiol. © 2012 Wiley Periodicals, Inc.

Description: A central concern of future research activities in the field of carbon capture and storage is the reduction of energy demand for solvent regeneration. This also includes, besides the development of more efficient CO 2 absorbents, the exploration of alternative desorption methods. The stripping process is generally regarded as the state-of-the-art in amine scrubbing, although significant amounts of heat are required for steam generation in the stripper. Against this background, a new desorption technique on the basis of pressureless amine scrubbing is under development, in which an ultrasonic field is used to accelerate the CO 2 desorption. With the new ultrasound method, applied for a patent, desorption of CO 2 can be performed at temperatures below 80 °C. This special feature of the ultrasonic-assisted CO 2 degassing can be applied advantageously together with weakly binding CO 2 absorbents which are in use in connection with a high CO 2 partial pressure in the raw gas. Based on pressureless amine scrubbing, a new ultrasound technique is developed for CO 2 capture, in which an ultrasonic field accelerates CO 2 desorption. The conditions in terms of reactor geometry, solvent variation, desorption temperature, and ultrasound frequency and power are optimized. With this novel technology, applied for a patent, CO 2 desorption can be performed at temperatures below 80 °C.

Description: Two anomalously warm inflow pulses into the Atlantic Water Layer of the Arctic Ocean have occurred since the late 1980s. As a consequence temperatures of the Arctic basins at 200–800 m depth have increased considerably in comparison to earlier decades. The warm inflow pulses also had a low density. Owing to the decadal time scale of the circulation in the Atlantic Water Layer large pools of anomalously light water have thereby formed in the Arctic Ocean. These will slowly drain back south into the Nordic Seas. We submit that they will be able to influence the overflows into the Atlantic across the Greenland-Scotland ridges. The Atlantic meridional overturning is fed by these overflows. Our model experiments indicate that the low-density anomalies from the Arctic Ocean may be able to reduce the Denmark Strait overflow 15–25 years after the entrance of the original signal through Fram Strait into the Arctic Ocean. The actual size of the reduction depends on the exact path and speed of the anomalies inside the Arctic proper and on local processes in the Arctic Ocean and the Nordic Sea.