Search results for " PHOSPHATE"
showing 10 items of 293 documents
Characterization of Zirconium Phosphate/Polycation Thin Films Grown by Sequential Adsorption Reactions
1997
Monolayer and multilayer thin films consisting of anionic α-zirconium phosphate (α-ZrP) sheets and polycations (poly(allylamine hydrochloride) (PAH), cytochrome c) were characterized by transmission electron microscopy (TEM), ellipsometry, UV−visible absorbance spectroscopy, reflectance FT-IR, XPS, and X-ray diffraction. Titration and powder X-ray diffraction experiments confirm that exfoliation of α-ZrP begins to occur when enough tetra(n-butylammonium) hydroxide (TBA+OH-) has been added to exceed single-layer packing of TBA+ ions (x ≈ 0.50) in the intercalation compound Zr(HPO4)2-x(TBA+PO4-)x·nH2O. The identical contrast of many sheets in TEM micrographs suggests that the suspension is un…
A study of thin surface layers by multilayer Mössbauer spectroscopy /MMS/
1990
A stacking Mossbauer technique, MMS has been applied for studying thin surface layers. The surface layers formed on the57Fe film in aqueous solutions of corrosion inhibitors, such as zinc phosphate and barium metaborate, and in distilled water was studied by this method. It has been found that the corrosion is much slower in the presence of zinc phosphate and barium metaborate. XPS analysis suggests the formation of a mixed iron zinc phosphate on the surface of the57Fe film after corrosion in a zinc phosphate solution.
Mesoporous iron phosphate/phosphonate hybrid materials
2014
Abstract Relatively high surface area pure mesoporous iron-phosphorus oxide-based derivatives have been synthesized through an S + I − surfactant-assisted cooperative mechanism by means of a one-pot preparative procedure from aqueous solution and starting from iron atrane complexes and phosphoric and phosphonic acids. A soft chemical extraction procedure allows opening the pore system of the parent as-prepared materials by exchanging the surfactant without mesostructure collapse. The nature of the pore wall can be modulated from iron phosphate up to hybrids involving approximately 30% of organophosphorus entities (phosphonates or diphosphonates). X-ray powder diffraction, transmission elect…
Improved composite materials for rechargeable lithium metal polymer batteries
1999
Abstract The performance of several polymer electrolytes for lithium metal batteries for electric vehicle applications are reported. The best performing electrolyte is the composite PEO 20 LiCF 3 SO 3 –γLiAlO 2 , which was prepared by a solvent-free procedure. It showed coulombic efficiency values of the lithium deposition–stripping process of 94%–96%. Electrochemical tests of lithium polymer battery (LPB) prototypes based on a 3 V LiMn 2 O 4 composite cathode material laminated together with the PEO 20 LiCF 3 SO 3 –γLiAlO 2 electrolyte gave promising results for electric vehicle applications. Even under non-optimized battery design, the prototypes delivered, at the C/3 rate and at 94°C, 40…
Atomic Layer Deposition of Spinel Lithium Manganese Oxide by Film-Body-Controlled Lithium Incorporation for Thin-Film Lithium-Ion Batteries
2013
Lithium manganese oxide spinels are promising candidate materials for thin-film lithium-ion batteries owing to their high voltage, high specific capacity for storage of electrochemical energy, and minimal structural changes during battery operation. Atomic layer deposition (ALD) offers many benefits for preparing all-solid-state thin-film batteries, including excellent conformity and thickness control of the films. Yet, the number of available lithium-containing electrode materials obtained by ALD is limited. In this article, we demonstrate the ALD of lithium manganese oxide, LixMn2O4, from Mn(thd)3, Li(thd), and ozone. Films were polycrystalline in their as-deposited state and contained le…
Towards the development of a fossil bone geochemical standard: An inter-laboratory study
2007
Ten international laboratories participated in an inter-laboratory comparison of a fossil bone composite with the objective of producing a matrix and structure-matched reference material for studies of the bio-mineralization of ancient fossil bone. We report the major and trace element compositions of the fossil bone composite, using in-situ method as well as various wet chemical digestion techniques. For major element concentrations, the intra-laboratory analytical precision (%RSDr) ranges from 7 to 18%, with higher percentages for Ti and K. The %RSDr are smaller than the inter-laboratory analytical precision (%RSDR; 100% was found for the high field strength elements (Hf, Th, Zr, Nb). The…
Possible impacts of volcanic ash emissions of Mount Etna on the primary productivity in the oligotrophic Mediterranean Sea: Results from nutrient-rel…
2013
Atmospheric deposition of volcanic ash has recently been recognized as an important nutrient source into the surface ocean. Mount Etna (Italy), one of the world's most active volcanoes, is located in the oligotrophic Mediterranean Sea (MedSea). Despite the active volcanism on Mount Etna, the biogeochemical impacts of volcanic ash fallouts on the marine primary productivity (MPP) remain largely unknown. Here we present the results of seawater nutrient release experiments with volcanic ash samples from Mount Etna that have been collected during different eruptive episodes between 2001 and 2007. Our results show that volcanic ash from Mount Etna releases significant amounts of fixed-N (35-855 …
Efficacy and safety of canagliflozin over 52 weeks in patients with type 2 diabetes on background metformin and pioglitazone.
2014
Aim The efficacy and safety of canagliflozin, a sodium glucose co-transporter 2 inhibitor, was evaluated in patients with type 2 diabetes mellitus (T2DM) inadequately controlled with metformin and pioglitazone. Methods In this randomized, double-blind, phase 3 study, patients (N = 342) received canagliflozin 100 or 300 mg during a 26-week, placebo-controlled, core period and a 26-week, active-controlled extension in which placebo-treated patients were switched to sitagliptin 100 mg. Efficacy comparisons for canagliflozin versus placebo at week 26 are reported, with no comparisons versus sitagliptin at week 52 (sitagliptin used to maintain double-blind and control for safety). Safety data ar…
Native, Intact Glucagon-Like Peptide 1 Is a Natural Suppressor of Thrombus Growth Under Physiological Flow Conditions
2020
Objective: In patients with diabetes mellitus, increased platelet reactivity predicts cardiac events. Limited evidence suggests that DPP-4 (dipeptidyl peptidase 4) influences platelets via GLP-1 (glucagon-like peptide 1)-dependent effects. Because DPP-4 inhibitors are frequently used in diabetes mellitus to improve the GLP-1-regulated glucose metabolism, we characterized the role of DPP-4 inhibition and of native intact versus DPP-4-cleaved GLP-1 on flow-dependent thrombus formation in mouse and human blood. Approach and Results: An ex vivo whole blood microfluidics model was applied to approach in vivo thrombosis and study collagen-dependent platelet adhesion, activation, and thrombus for…
Modulation of platelet activation and initial cytokine release by alloplastic bone substitute materials.
2010
Objectives: Platelet-derived cytokines play a crucial role in tissue regeneration. In regenerative dental medicine, bone substitute materials (BSM) are widely used. However, initial interactions of BSM and platelets are still unknown. The aim of this study was to evaluate the potential of platelet activation and subsequent initial cytokine release by different commercial alloplastic BSM. Material and methods: Eight commercial BSM of different origins and chemical compositions (tricalcium phosphate, hydroxyapatite, bioactive glass: SiO2 and mixtures) were incubated with a platelet concentrate (platelet-rich plasma, PRP) of three healthy volunteers at room temperature for 15 min. Platelet cou…