Vinylation of the chloro–ethyl and dichloro zirconium complexes [Zr(CpSi2Cp)ClX] (CpSi2Cp=1,1%,2,2%-(SiMe2)2(h-C5H3)2; X=Et, Cl) with one or two equivalents of Mg(CH CH2)Cl gave the new zirconacyclopentane [Zr(CpSi2Cp){hCH2 (CH2)2 CH2}] and (h-butadiene)zirconium [Zr(CpSi2Cp){h-(butadiene)}] complexes, respectively. Addition of a toluene solution of PhC CPh to the zirconacyclopentane compound a...

Objective: To evaluate fracture strength of veneered translucent zirconium dioxide crowns designed with different porcelain layer thicknesses. Materials and Methods: Sixty crowns, divided into six groups of 10, were used in this study. Groups were divided according to different thicknesses of porcelain veneer on translucent zirconium dioxide cores of equal thickness (0.5 mm). Porcelain thicknes...

A series of salen-type zirconium complexes of the general formula LZrCl2 (L = N,N 0-ethylenebis(salicylideneiminate), 3a; N, N 0-ethylenebis(3,5-di-tert-butylsalicylideneiminate), 3b; N,N 0-ethylenebis(5-methoxysalicylideneiminate), 3c; N,N 0-ethylenebis(5chlorosalicylideneiminate), 3d; N,N 0-ethylenebis(5-nitrosalicylideneiminate), 3e; N,N 0-o-phenylenebis(salicylideneiminate), 4a; N,N 0-o-phe...

nano-encapsulated iron oxide in zirconium oxide-coated mica pigments are thermally stable,innocuous to human health, non-combustible, and they do not conduct electricity. they could beapplied in several industries such as thermoplastics, cosmetics, food packaging, children toys, paints,automobiles coating, security purposes, and banknotes. nowadays, they are highly desirable inceramic decoratio...

The impact of wear factors on composite materials is examined in this article. Stir casting was used to produce AA7075 alloys with varied nano-zirconium boride weight ratios. dry sliding test done utilizing pin-on-disc equipment. L27 orthogonal array built by Taguchi’s experiments for optimization. We calculated the proportion responses that could be attributed input parameters using SNR and AN...

nanocomposite of zro2/zno was prepared under ultrasonic irradiation by sol gel process from directly mixing zirconium and zinc gels, and the mixture was placed under ultrasonic irradiation for 2 hours then aging time the filtrated composite gel was calcinated at 500°c for 3h in furnace. the precursor sol of zirconium was prepared from an aqueous solution of zrcl4 and zinc acetate dihydrated was...

The direct coupling of unactivated carboxylic acids with amines can be performed in toluene 110 °C in the absence of catalyst. The use of simple zirconium catalysts at 5 mol% loading gave amide formation in as little as 4 h.

Titanosilicalite-1 (TS-1) in combination with sulfated zirconia efficiently catalyzes the epoxidation of 1-octene with aqueous hydrogen peroxide. The presence of both octahedral zirconium and sulfate species in the catalysts enhances the epoxidation rates.

In this article we explore sources and magnitude of positive and negative error in soil ingestion estimates for children on a subject-week and trace element basis. Errors varied among trace elements. Yttrium and zirconium displayed predominantly negative error; titanium and vanadium usually displayed positive error. These factors lead to underestimation of soil ingestion estimates by yttrium an...

A series of novel porous zirconium phosphonate-supported 9-amino-9-deoxy-epi-cinchonidines of general formulae Zr(OH)(4-2x)(O(3)PR)(x)·nH(2)O and Zr(HPO(4))(2-x)(O(3)PR)(x)·nH(2)O with the different arm chain lengths (n = 2-6) and mean diameters of approximately 20-40 nm have been prepared as heterogeneous organocatalysts. The different microtextures of zirconium phosphonates were also obtained...