etchants were aqueous solutions of 5wt% sodium fluoride (NaF), ammonium tluoride (NH4F), sodium hydrogen fluoride (NaFHF), and ammonium hydrogcn fluoride (NH{FHF). Cast specimcns of commercially pure titanium were air-abraded with alumina, etched for 30 seconcls, and then primed with a phosphate primer. An acrylic rod was bollded to the spccimen with a tri-n-butylborane-initiated self-curing lu...

the aim of the present study was to prepare nano-sized calcium fluoride (caf2). calcium fluoride nanoparticles were synthesized by cacl2.6h2o and ammonium fluoride. nanoparticles were synthesized by co-precipitation method. the synthesized nanocrystals were characterized by x-ray diffraction (xrd), fourier transform infrared spectroscopy (ftir), scanning electron microscopy (sem). the crystalli...

An efficient reagent-controlled methodology for generating highly substituted diverse scaffolds from a common substrate has been developed; thus, treatment of a common precursor with different desilylating reagents, such as ammonium fluoride, caesium fluoride and PPTS, triggers different domino reaction sequences, yielding highly substituted pyridines, phenols and benzopyrans, respectively; the...

The synthesis of (U,Th)O(2) solid solutions at a relatively low temperature of 1100 °C using a new technique is described. First, separate actinide oxides were reacted with ammonium hydrogen fluoride to form ammonium actinide fluorides at room temperature. Subsequently, this fluoride was converted to an actinide oxide solid solution using a two-phase reaction process, which involved heating of ...

The aim of the present study was to prepare nano-sized calcium fluoride (CaF2). Calcium fluoride nanoparticles were synthesized by CaCl2.6H2O and ammonium fluoride. Nanoparticles were synthesized by co-precipitation method. The synthesized nanocrystals were characterized by X-ray diffraction (XRD), Fourier transform infrared spectroscopy (FTIR), scanning electro...

We have synthesized the fluorine-I 8 labeled derivative of N-fert-butyl-aphenylnitrone (PBN), a free radical spin trapping agent widely used with electron spin resonance (ESR). N-tert-Butyl-a-(4-[18F]fluorophenyl)nitrone ([18F]FPBN) could be prepared with low radiochemical yield (3% decay corrected) by the direct aromatic nucleophilic substitution of N-tertbutyl-a-(4-nitrophenyl)nitrone with [1...

The potential for biological nitrification of an industrial waste containing 4,000 mg of ammonia N (NH(4)-N) and 10,000 mg of fluoride per liter was investigated. Ammonium sulfate and sodium fluoride were tested in various combinations of 100 to 2,000 mg of NH(4)-N per liter and 0 to 5,000 mg of F per liter in suspended-growth stirred-tank reactors containing enriched cultures of nitrifying bac...

The title compounds, tetra-butyl-ammonium chloride-1,1'-(1,2-phenyl-ene)bis-(3-m-tolyl-urea) (1/1), C16H36N+·Cl-·C22H22N4O2 or [(n-Bu4N+·Cl-)(C22H22N4O2)] (I) and tetra-butyl-ammonium bromide-1,1'-(1,2-phenyl-ene)bis-(3-m-tolyl-urea) (1/1), C16H36N+·Br-·C22H22N4O2 or [(n-Bu4N+·Br-)(C22H22N4O2)] (II), both comprise a tetra-butyl-ammonium cation, a halide anion and an ortho-phenyl-ene bis-urea mo...

Addition of an excess of t-butyl isocyanide to solid Mo2 (0, CCF3 )4 or MO?_ (0, CMe)4 gives (t-BuNC), Mo(Oz CCF3 )* or (t-BuNC), Mo(Oz CMe), , respectively. The quadruple bond in K4 MO* Cl8 or Cl4 MO, (n-Bus P)4 also can be cleaved by an excess of t-butyl isocyanide to yield (t-BuNC), MoCl, _ The anionic ligands can be exchanged with ammonium hexafluorophosphate in presence of excess t-BuNC to...

The inhibition of acetylcholinesterase and other hydrolytic enzymes by methanesulfonyl fluoride, other sulfonyl fluorides, and anhydrides of methanesulfonic acid has been studied by several workers (2-5). Certain alkyl ammonium ions greatly increase the rate of irreversible inhibition of acetylcholinesterase by methanesulfonyl fluoride (6). The inhibition arises from the formation of a specific...