Search results for "Calcium"
showing 10 items of 1740 documents
CCDC 2122007: Experimental Crystal Structure Determination
2022
Related Article: Cristina Negro, Cristina Bilanin, Xiaoni Qu, Judit Oliver-Meseguer, Jesús Ferrando-Soria, Antonio Leyva-Pérez, Donatella Armentano, Emilio Pardo|2022|Chem.Commun.|58|5578|doi:10.1039/D2CC01137A
CCDC 1451174: Experimental Crystal Structure Determination
2017
Related Article: Thais Grancha, Jesús Ferrando-Soria, Joan Cano, Pedro Amoros , Beatriz Seoane, Jorge Gascon, Montse Bazaga-García, Enrique R. Losilla, Aurelio Cabeza, Donatella Armentano, Emilio Pardo|2016|Chem.Mater.|28|4608|doi:10.1021/acs.chemmater.6b01286
Solid-state compatibility of Ca:LaNbO4 with perovskite cathodes: Evidences from X-ray microspectroscopy
2022
The solid-state compatibility between calcium-doped lanthanum niobate and three perovskite cathode materials was investigated using two X-ray microbeam techniques, micro X-ray fluorescence and micro X-ray absorption spectroscopy. The cathode powders (lanthanum strontium ferrite, either cobalt or copper-doped, and lanthanum strontium cobaltite) in contact with the dense electrolyte pellet were annealed at 1150 degrees C for 12-144 h to simulate the effect of thermal stresses due to fabrication and long-term operation. As a result, several interdiffusion phenomena were then observed on the bilayer cross-sections: in particular, the chemical state and coordination environment of calcium, iron,…
Uptake of actinides by calcium silicate hydrate (C-S-H) phases
2018
Abstract The sorption of actinides (Th, U – Am) was studied in dependence of the solid-to-liquid (S/L) ratio (0.5–20.0 g/L) and the calcium-to-silicon (C:S) ratio. The C:S ratio was varied between 1.80 and 0.70 to simulate the changing composition of the C-S-H phases during cement degradation from high to low C:S ratios. The decrease of the calcium content in the C-S-H phases by time is accompanied by a decrease in pH in the corresponding suspensions from 12.6 to 10.2. X-ray photoelectron spectroscopy (XPS) of the C-S-H phases showed an increasing depletion of Ca on the surface with increasing C:S ratio in comparison to the composition of the solid phase as a whole. The sorption experiments…
In vitro-Untersuchungen über den Einfluß von Digitoxin auf die Aufnahme von Calcium in Lipoidextrakte aus dem Herzmuskel / In-Vitro Studies of the Ef…
1969
In fruheren Versuchen an isolierten subcellularen Strukturen des Hundeherzens war eine Freisetzung von gebundenem Ca durch Herzglykoside beschrieben worden [3–5]. Da das cellular gebundene Ca vorwiegend in einer Bindung an die Lipoidkomponente der Membranstrukturen vorzuliegen scheint [1], wurde gepruft, ob Digitalis die Ca-Bindung an Lipoide zu beeinflussen vermag. Aus Meerschweinchenherzen wurden Mito-chondrien und Mikrosomen isoliert, die Lipoide extrahiert [2] und anschliesend nach der Methode von Nayler[6] die Aufnahme von Ca in diese Extrakte bei Aquilibrierung mit 45Ca-haltiger Tyrodelosung (1, 8 mM [Ca]) bestimmt. Bei Anwesenheit von Digitoxin wurde in einem Konzentrationsbereich vo…
ChemInform Abstract: Synthesis, Configuration, and Calcium Modulatory Properties of Enantiomerically Pure 5-Oxo-1,4,5,6,7,8-hexahydroquinoline-3-carb…
1992
Dialysability of Calcium, Iron, and Zinc in Beans, Chick Peas, and Lentils
2002
Influence of HCl pretreatment and organo-mineral complexes on laser diffraction measurement of loess–paleosol-sequences
2016
Abstract The influence of different sample pretreatment methods on grain size distributions in particle size analysis has been subject to controversial discussions. Standard sample preparation typically comprises the disaggregation of aggregated and agglomerated particles into single primary particles, i.e., the organic binding material is oxidized by hydrogen peroxide (H2O2) and the contained carbonates are dissolved by hydrochloric acid (HCl). The aim of this study is to evaluate the effects of HCl treatment on grain size analyses of Late Pleistocene and Holocene loess–paleosol-sequences investigated by a Beckman Coulter LS 13320 laser particle analyzer. For this purpose, samples from two…
Intrinsic viscosities of polyelectrolytes: specific salt effects and viscometric master curves.
2013
Dilute solutions of the sodium salt of polystyrene sulfonic acid (PSS-Na) were measured viscometrically as a function of composition in aqueous solvents of different salinity, where the extra salt was either NaCl or CaCl2. Such experiments yield {η}, the generalized intrinsic viscosities (hydrodynamic specific volume) of the polyelectrolyte for arbitrary polymer concentrations, c. In the limit of infinite dilution {η} becomes identical to the intrinsic viscosity [η]. For NaCl {η} decreases monotonously with rising c, whereas maxima are passed in the case of CaCl2. Condensing c and the concentration of extra salt in the mixed solvent into a single variable enables the establishment of predic…
Designed peptides for biomineral polymorph recognition: a case study for calcium carbonate
2020
With their unique ability for substrate recognition and their sequence-specific self-assembly properties, peptides play an important role in controlling the mineralization of inorganic materials in natural systems and in controlling the assembly of soft materials into complex structures required for biological functions. Here we report the use of an engineered heptapeptide that can differentiate between the crystalline anhydrous polymorphs of calcium carbonate. This peptide contains the positively charged amino acid arginine as well as proline rather than the prototypical negatively charged aspartate or glutamate units. Its affinity to vaterite compared to aragonite was demonstrated by fluo…