Tantala

Mercaptals, CH2CH(SR)2, are formed in a like manner by the addition of mercaptans. The formation of acetals by noncatalytic vapor-phase reactions of acetaldehyde and various alcohols at 35°C has been reported (67). Butadiene [106-99-0] can be made by the reaction of acetaldehyde and ethyl alcohol at temperatures above 300°C over a tantala—siUca catalyst (68). Aldol and crotonaldehyde are beheved to be intermediates. Butyl acetate [123-86-4] has been prepared by the catalytic reaction of acetaldehyde with 1-butanol [71-36-3] at 300°C (69). 

L.A. Kamenskaya, V.I. Konstantinov, A.M. Matveev, Tesisy dokl. sovesch. po khimii, analisu i tekhnologii niobiya i tantala, Kiev, 1968, p. 22. 

MOCVD reactions are used increasingly, such as the pyrolysis of tantalum ethylate, Ta(OC2H5)5, in oxygen and nitrogen at 340-450°C and at a pressure of <1 Torr. This is followed by an annealing cycle at 600-900°C.P l Tantala is also deposited by the pyrolysis of the tantalum dichlorodiethoxy acetylacetonate at 300-500°C.P ]... 

Sept. 30, 1802 Ekeberg discovers the earth tantala. Birth of A.-J. Balard, the discoverer of bromine, at Montpellier. 

Florence TM, Batley GE. Trace Metal Species in Sea Water-I. Removal of Trace Meals from Seawater by a Chelating resin. Tantala 1976 23 179. 

Ryan DH, Weber JH. Comparison of Chelating Agents Immobilized on Glass with Chelex-100 for Removal and Preconcentrahon of Trace Copper. Tantala 1985 32 859-863. 

In this example (Rgure 41.10), multilayered thin anodic tantala films, comprising 0-rich layers of controlled thicknesses and locations, have been characterized by RF GD-TOFMS [24],... 

FIGURE 41.10 Multilayered anodic tantala films with O isotopes as tracers. Reproduced from Reference [24],... 

Molchan, I.S., Thompson, G.E., Skeldon, R, Trigoulet, N., Tempez, A., Chapon, P. (2010) Analysis of thin impurity-doped layers in anodic alumina and anodic tantala films by glow discharge time-of-flight mass spectrometry. Trans. Inst. Met. Finish, 88(3). 

Tantala, M.W., Nordenson, G.J.P., Deodatis, G., et al. 2008. Earthquake loss estimation for the New York City Metropolitan Region. Soil Dynamics and Earthquake Engineering 28 812-835. 

Tantalum pentoxide (tantalite, tantala) Ta205 [1314-61-0] 441.893 Trigonal (rhombohedral) columbite type 8200 10 2 1882 301.5 ... 

Dielectric used in film supercapacitors. Tantalum oxide is a high-refractive index, low-absorption material usable for making optical coatings from the near-UV (350 nm) to the IR (8 p.m). Insoluble in most chemicals except HF, HF—HNO3 mixtures, oleum, fused alkaU metal hydroxides (e.g. NaOH and KOH) and molten pyrosulfates. Tantalum pentoxide (tantalite, tantala)... 

Furthermore, the presence of mixed Ti-O-Ta bonds eould not be evidenced by XPS analysis, which is also in agreement with XRD data, evideneing the formation of two separate anatase and orthorhombic tantala phases. 

A multinuclear solid-state NMR approach is applied to four templated mesoporous oxides (silica, titania, niobia and tantala) to include and MAS NMR and double resonance Nb, REAPDOR. MAS NMR provides the clearest indication of the local wall structure. 

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