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Showing 1 to 20 of 20 for “"Fluoride ions"”.
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Available fluoride ion in solution and one minute fluoride release rate of a toothpaste formulation
… to occur, bioavailable calcium, phosphate, and fluoride ions must be present at the surface of the tooth. Toothpaste products supply bioavailable fluoride ions to the oral cavity. Calcium and phosphate ions are supplied primarily through the saliva, but in limited quantity. In this research, …
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Microfluidic modules for pre-concentration of [¹⁸F]fluoride in positron emission tomography (PET) radiotracer synthesis
… such as (i) superior control over reaction conditions leading to high yields and conversion rates, (ii) reduced reagent consumption and radioactive waste production as well as (iii) potential for automation with minimised shielding requirement. That said, most devices presented so far have focused …
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Novel Potentiometric Enzyme Electrode Based on the Fluoride Ion-Selective Sensor.
… peroxide using an immobilized enzyme and a fluoride ion-selective electrode. The reaction between hydrogen peroxide and certain organo-fluoro compounds is catalyzed by the enzyme horseradish peroxidase to release fluoride ions.
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The sol-gel synthesis of anti-stokes luminescent glass materials
… easy to manufacture, have weak anti-Stokes emissions, whereas rare earth doped fluoride materials have considerably improved anti-Stokes luminescence but are less chemically stable and highly reactive. Recent interest in glass ceramics has proposed alternative matrices with the advantages of both …
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Synthesis and characterization of molybdenum and vanadium framework materials
… molybdenophosphate sheets wherein multiple guest ions, ammonium cations and free orthophosphate (PO4)3- or halide (Cl-, Br-), are hosted. Anion exchange investigations were performed, showing the affinity of the Br- analogue to be completely exchange with Cl- anions. Hydrothermal syntheses with a …
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Phosphate, Calcium, and Fluoride Ion Release From Polyurethane Based Microcapsules Formulated in a Resin Based Dental Varnish
… undersaturated with calcium and phosphate ions, resulting in these ions being leached out from the enamel. Remineralization is promoted in an environment with a pH above 5.5 in the salivary fluid, especially when the saliva is supersaturated with calcium and phosphate ions.|This research …
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The effect of microcapsules on dental formulation viscosities
… that release calcium, phosphate, and fluoride ions. The microcapsules approach provides a slow sustained release of ions which is useful in the remineralization process. In order to use these microcapsules in dental materials, the effect of microcapsule incorporation on viscosity needs …
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ΡΥΘΜΙΣΗ ΤΩΝ ΕΠΙΦΑΝΕΙΑΚΩΝ ΦΟΡΤΙΩΝ ΚΑΤΑΛΥΤΙΚΩΝ ΦΟΡΕΩΝ ΜΕ ΤΗ ΧΡΗΣΗ ΤΡΟΠΟΠΟΙΗΤΩΝ
… DOPING OF Γ-AL203 AMOUNTS OF SODIUM, LITHIUM AND FLUORIDE IONS WAS USED FORREGULATING THE ZERO POINT OF CHARGE (ZPC), SURFACE ACIDITY CONSTANTS AND THE CONCENTRATION OF THE CHARGED SURFACE GROUPS, DETERMINED POTENTIOMETRICALLY, OVERA WIDE PH RANGE. THE ADSORPTION OF IONIC SPECIES CONTAINING THE …
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Asymmetric synthesis of novel anthracyclinones
… anthracyclinones by Lewis acid promoted cyclisations of ortho-methallyl anthraquinonyl chiral dioxanes has been investigated. Tin tetrachloride-N,N-dimethylformamide promoted cyclisation of the dioxane (30) proceeded with excellent stereoselectivity to give an 82% yield of the diastereomerically …
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The effect of high pressure on the quadrupole interaction in iron-fluorine compounds
… iron ion is a slightly distorted octahedron of fluoride ions. A detailed analysis was made of the quadrupole pplitting of the Mossbauer spectra for both the ferrous and the ferric salts. The analysis proceeded along two lines: the usual pointcharge approximation and a covalent approximation …
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Quantification of molecular aggregation equilibria using spectroscopic measurements and random mixing modeling
… and magnitude of hydrophobic and ionic interactions remains a subject of theoretical debate, and has yet to be experimentally determined. Here, Raman vibrational spectroscopy is combined with multivariate curve resolution (Raman-MCR) to experimentally quantify both the number of hydrophobic …
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Synthesis and characterisation of lanthanide and other inorganic framework materials
Five new cerium (IV) fluoride and fluoride–arsenate framework structures have been synthesised through hydrothermal techniques using CeF4 as a fluoride source. Cs[CeIV2F8[F.H2O]] (I) consists of layers, formed from linked Ce(F,O)n polyhedra cross-linked by hydrogen bonding that defines channels …
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Analyte sensing with luminescent quantum dots.
… unique optical properties and potential applications. Their narrow size-tunable emission spectra, broad absorption spectra, resistance to photobleaching and long fluorescent lifetimes make them ideal for sensing ions and small molecules. This thesis explores the potential of QDs to function as …
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Fundamental studies on ionomer glasses
Composition-structure-property relationships were studied in glasses of the type used to produce glass lonomer dental cements. These materials are currently being developed as a bone cement in joint replacement surgery. Initially, a simple quaternary (25i02-Al203-CaO-CaF2) glass was produced and …
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Development of zeolite based acid catalysts for the synthesis of methyl tertiary butyl ether
… in relatively low concentration using ammonium fluoride as precursor, and subsequently activated stepwise at high temperatures, showed two maxima for the MTBE yield. The first maximum occurring at the final activation temperature 325C̕, corresponded to the positive effect of chemisorbed HF …
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The Thermal Stability of Anodic Oxide Coatings - Strength and Durability of Adhesively Bonded Ti-6Al-4V Alloy
… This study suggests that the presence of fluoride ions in the anodic oxide coating, prior to bonding, is detrimental to the bond strength of adhesively bonded Ti-alloy when exposed to high temperatures. The wedge test configuration was used to investigate the influence of temperature on …
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Reactions of aluminum with halogen containing oxides
… method to produce high temperature reactions, and some compositions such as aluminum (Al) and iodine pentoxide (I2O5) also have biocidal properties. This study examines the thermal degradation behavior of I2O5 mixed with micron and nanometer scale aluminum (Al) particles. Differential …
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Electroactive Conjugated Polymers as Charge-Transport Materials for Optoelectronic Thin-Film Devices
… also demonstrated that TAB 4 can reversibly bind fluoride ions and that the binding event significantly influences the optical absorption characteristics of the chromophore. It can be assumed, that the above mentioned properties, which have a profound influence on the photophysical behaviour of …
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Fabrication of Macadamia Nutshell Powder-AI/Fe Metal Oxide Modified Diatomaceous Earth Composite Beads for Fluoride and Pathogen Removal Groundwater
Contamination of drinking water due to fluoride and pathogens is a severe health hazard problem. Excess of fluoride (>1.5 mg/L) in drinking water leads to dental and skeletal fluorosis whereas the presence of pathogens in water can lead to adverse health effects, including gastrointestinal illness, …
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Electrochemical and Photoelectrochemical Study of Conduction modes in Nanostructured TiO2 Films
… and the substrate (anode). Positively charged ions (Ar+) are accelerated toward the TiO2 target (a co-target Nb is placed beside the TiO2 cathode for Nb doping) and their impact sputters atoms off the target. These atoms travel across the chamber and a fraction of them land on stainless steel, …