Abstract: This invention relates to luminescent materials, frequently known as "Phosphors" and suitable for use in cathode ray tubes where a high brightness display is required, for example, in the cockpit of an aircraft.In particular the luminescent material of the invention comprises a luminescent material comprising an aluminium garnet host material optionally including at least one of the elements scandium and gallium and activated by trivalent terbium and having a composition according to the formula RE.sub.3 Al.sub.(5-(y+z)) Sc.sub.y Ga.sub.z O.sub.12 :Tb, in which RE is one or more of the elements yttrium, gadolinium, lutetium and bismuth and y and z typically have values in the ranges 0.ltoreq.y.ltoreq.2 and 0.ltoreq.z.ltoreq.5.

Abstract: This invention relates to refining yttrium. Known methods of refining yttrium involve the use of expensive crucibles made from tantalum or tungsten which are only available in relatively small sizes. According to the present invention there is provided a process for the production of yttrium metal and alloys thereof in which calcium (metal) and yttrium fluoride are reacted together by use of a submerged electric arc in a molten slag.

Abstract: This invention relates to a method and apparatus for detecting changes in the composition of a stream of gas. In particular the method comprises the step of disposing a thermometer in the gas stream, in contact with or downstream of a catalyst so as to detect changes in the temperature of the catalyst or of the gas shortly after it leaves the catalyst, such changes being a function of the amount of gas which reacts under the influence of the catalyst.

Abstract: An alloy suitable for use in the fabrication of jewelry containing at least 95% by weight platinum and 1.5 to 3.5% by weight gallium, the balance being at least one of indium, gold, palladium, silver, copper, cobalt, nickel, ruthenium, iridium and rhodium. A Ga/Au/Pt alloy is preferred for ornamental application, and a Ga/In/Pt possibly including gold, silver or palladium is preferred for use in the manufacture of springs and clasps. Alloys are described which comply with hallmarking requirements but yet casting may be effected more easily than with pure platinum.

Abstract: This invention describes an article which may be used at high temperatures under non-oxidizing or reducing conditions. The article comprises a core made from a refractory compound, a sheath of a platinum group metal or of an alloy based on at least obe metal of the platinum group enclosing the core and a barrier layer of magnesia intermediate the core and the sheath.

Abstract: This invention relates to the catalytic hydrogenation of edible oils of animal and vegetable origin. Catalytic hydrogenation according to the invention improves the keeping qualities of such edible oils without impairing their nutritional value or edibility. This is achieved by selectively hydrogenating the triply unsaturated forms of the fatty acids contained in the oil to doubly unsaturated forms using a supported catalyst. The catalyst used contains one or more of the metals Fe, Co, Ni and the platinum group metals and the support may be of extended surface or particulate form, for example, C, stainless steel, ceramics and Fe--Cr--Al--Y alloys.

Abstract: This invention relates to catalysts, especially for the catalytic oxidation of hydrocarbons and carbon monoxide and for the catalytic reduction of oxides of nitrogen in the presence, respectively, of suitable oxidizing and reducing means.In more detail, the catalyst of the invention is capable of removing oxygen from a gas containing an excess of oxygen and restoring such removed oxygen to a gas having an oxygen deficiency, and the catalyst comprises at least one of the platinum group metals platinum, rhodium, ruthenium, palladium, indium and osmium and one or more base metals at least one of which has two or more oxidation states.

Abstract: This specification describes a complex of osmium tetroxide and a compound having a heterocyclic ring containing one or two tertiary nitrogen atoms. The compound may be an aromatic tertiary amine and the tertiary nitrogen atom may be the sole heterocyclic atom in the heterocyclic ring. The complexes described are suitable for fixing and staining cells and may be used in the preparation of biological specimens for examination by electron microscopy.

Abstract: This invention relates to a process for the purification of air and other gaseous media. The invention is particularly directed towards a process for the decomposition of one or more of the oxides of nitrogen present in a gas stream containing gaseous compositions such as carbon monoxide and hydrocarbon. In more detail the process of the invention includes the step of contacting said air or other gaseous media with a catalyst comprising a bronze selected from the group consisting of:(a) compositions having the general formula A.sub.x BO.sub.y where A is selected from the group consisting of the alkali metals, the alkaline earth metals, the rare earths, Ba, PB, Tl, Ni, Cu, NH.sub.4, Ag and H; B is selected from the group consisting of Ti, V, Nb, Mo, Ta, W, Pt and Re, with x normally in the range 0 <2< and y normally lies between 2 and 3; and, (b) compositions having the general formula C.sub.x D.sub.3 O.sub.

Abstract: This invention relates to titanium alloys consisting, apart from impurities, of 60 to 94 weight % titanium and 6 to 40 weight % of at least one additional metal selected from the group consisting of iridium, rhodium, ruthenium, platinum and palladium. Alloys according to this invention possess corrosion rates lower than those of titanium metal alone and they are eminently suitable for carrying electric current.

Abstract: This invention relates to the extraction of metals. More particularly, the invention is concerned with the extraction of one or more precious metals from material containing such metals. By "precious metals", both here and throughout the remainder of this specification, meant gold, silver and the platinum group metals, platinum, palladium, rhodium, ruthenium, iridium and osmium. In particular the invention relates to a process for the extraction of precious metal from a material containing a precious metal selected from the group consisting of gold, silver, platinum, rhodium, ruthenium, iridium and osmium and including heating a mixture comprising the said material, copper sulphide or at least one precursor thereof and a flux.

Abstract: This invention relates to metal powders which will withstand high temperatures and which can be used for decorative and catalytic purposes. In more detail, a metal powder in accordance with the invention comprises particles made from a heat resistant substrate individually coated or encapsulated with a layer of platinum, palladium, rhodium, ruthenium, iridium, osmium, gold or silver or an alloy containing at least one of the said metals.

Abstract: This invention relates to catalysts suitable for the purification of exhaust gases. In particular a catalyst according to the invention comprises a compound selected from the group represented by the general formula A.sub.x M.sub.y O.sub.z in which A is one or more metals selected from the group consisting of Li, Na, K, Mg, Ca, Sr, Ba, Al, Sc, Y, the lanthanides, Ti, Zr, V, Cr, Mn, Fe, Co, Ni, Cu, Zn; M is a metal selected from the group consisting of Ir, Rh, Pt, Pd, and Ru; y has an integral or fractional value within the range from 0.1 to 3.0, z is an integer with a value from 2 to 7 and x has a value such that the compound is electrically neutral.

Abstract: This invention relates to the recovery of precious metals. More particularly, the invention relates to a process for the recovery of a catalytic metal from a carbonaceous residue or support comprising subjecting an aqueous slurry of material containing catalytic metal to be recovered to a temperature of not less than 200.degree. C and a pressure not less than 75 atmospheres in an atmosphere comprising a quantity of oxygen at least sufficient to oxidize substantially all the carbon present, the oxidation being carried out in the presence of a liquid aqueous phase. The process also relates to the recovery of silver from photographic film.

Abstract: A luminescent material comprising a rare earth fluoride host activated with manganese. The material also may include another element such as titanium or zirconium. The material may be used as a coating on the face plate of a cathode ray tube.

Abstract: This invention relates to accelerometers for detecting or measuring accelerations. An accelerometer in accordance with the invention includes a member which is caused to vibrate when the accelerometer is subjected to an acceleration above a threshold value. The member is capable of vibrating in more than one plane and, in vibrating, causes a change to occur in a physical parameter of the accelerometer which is other than a dimensional change due to distortion.

Abstract: This invention relates generally to a process for the production of butyraldehyde by the catalytic hydroformylation of:A. gaseous propylene;B. hydrogen;C. carbon monoxide, the hydrogen and carbon monoxide being present in a molar ratio within the range 1:15 and 2:1; andD. a catalytically effective quantity of a hydrido carbonyl complex of rhodium which includes two phosphorus-containing stabilizing donor ligands selected from the group consisting of triphenyl phosphine and triphenylphosphite.

Abstract: This specification describes a complex of osmium tetroxide and a compound having a heterocyclic ring containing one or two tertiary nitrogen atoms. The compound may be an aromatic tertiary amine and the tertiary nitrogen atom may be the sole heterocyclic atom in the heterocyclic ring. The complexes described are suitable for fixing and staining cells and may be used in the preparation of biological specimens for examination by electron microscopy.

Abstract: This invention relates to catalyst for use in the control of atmospheric pollution and, in particular to the purification of exhaust gases from internal combustion engines. Specific catalysts of the present invention comprise:(a) ruthenium or an alloy thereof and a metal oxide capable of forming a stable mixed oxide (or "ruthenite") with ruthenium dioxide;(b) a compound formed by ruthenium dioxide and a metal oxide capable of forming a stable mixed oxide (or "ruthenite") with ruthenium dioxide; and(c) a mixed oxide containing ruthenium, the oxide being selected from the group consisting of oxides of the pyrochlore type A.sub.2 B.sub.2 O.sub.7, the perovskite type ABO.sub.3, the ilmenite type B.sub.2 O.sub.3 and the spinel type AB.sub.2 O.sub.4.Particularly good results have been obtained where the platinum/ruthenium ratio is within the range 25 - 95 wt.% platinum and 5 - 75 wt.% ruthenium.

Abstract: This invention relates to catalysts which may be used in the purification of air and other gaseous media. More particularly, the invention relates to catalysts which may be used in the decomposition of one or more of the oxides of nitrogen comprising a mixed oxide of iron and cobalt selected from the group consisting of(a) Co.sub.x.sup.II FE.sub.1-x.sup.II Fe.sub.2.sup.III O.sub.4where x normally has values of o.ltoreq.x.ltoreq.1 and(b) Co.sup.II Co.sub.(x-1).sup.III Fe.sub.(3-x).sup.III O.sub.4where x normally has values 1.ltoreq.x.ltoreq.3.