Abstract:
Dihydrocarbyl oxalates are produced by reacting under substantially anhydrous conditions a dihydrocarbyl peroxide with carbon monoxide in the presence of a catalyst comprising a platinum group metal in compound or elemental form and a copper compound, optionally in the presence as promoter of a heterocyclic aromatic nitrogen compound.
Abstract:
Dihydrocarbyl carbonates are produced by reacting in the liquid phase under substantially anhydrous conditions a dihydrocarbyl peroxide, a primary or secondary alcohol and carbon monoxide in the presence as catalyst of copper in elemental or compound form, optionally in the presence as promoter of a heterocyclic aromatic nitrogen compound. The products are useful as additives to internal combustion engine fuels.
Abstract:
A cobalt catalyst for use in the Fischer Tropsch reaction of synthesis gas to form hydrocarbons is activated or regenerated by treatment of a cobalt containing catalyst with a gas containing carbon monoxide, said gas containing less than 30 % v hydrogen. The catalyst obtained has increased activity and greater selectivity towards producing C5+ hydrocarbons.
Abstract:
A method for detecting diamonds in locations which are not easily accessible comprises irradiating material suspected of containing diamonds by means adapted for access to the location, collecting the resultant scattered Raman radiation by means adapted for access to the location and filtering and sensing the radiation to produce a signal whenever radiation characteristic of diamonds is sensed whereby the absence or the presence of diamonds in the location is indicated.
Abstract:
A method of assessing the colour type of diamonds by irradiating the diamonds with laser radiation of different wavelengths and generating a numerical value characteristic of the colour type of the diamond based on the measured intensities of the resultant scattered Raman radiation for two or more different incident radiation wavelengths. The colour type of the diamond may be determined by comparing derived relative intensities of each diamond with those of reference diamonds having been determined by standard subjective assessment. The method may also be used to sort diamonds according to their colour type.
Abstract:
Improved processor element (PE) synchronisation is provided for an SIMD or MISD computer having a controller (4) linked to a plurality of PEs (2) by a global bus. The controller has a code/data-ready means to signal to the PEs that data or an instruction is available on the bus. The PEs each have a processor-ready means (23) to signal to the controller that they are ready to read the data or instruction, and a read-enable means actuated by a code/data-ready signal from the controller to allow the PE to read the data or instruction. A processor-ready signal is initiated when there is no code/data-ready signal from the controller. A code/data-ready signal is only indicated when all the PEs give a ready signal and is only terminated when no PE gives a ready signal.
Abstract:
Synthesis gas (carbon monoxide and hydrogen) is produced by the sequence of primary and secondary reforming comprising; (a) feeding hydrocarbon-containing gas (8) and steam (8) to a primary reforming zone (1) containing a primary steam reforming catalyst (5) under reforming conditions wherein the hydrocarbon gas (8) is partially reformed to produce a primary reformer effluent (9), (b) feeding the primary reformer effluent (9) and oxygen-containing gas (14) to a secondary reforming zone (2) containing secondary reforming catalyst (17) and reforming conditions wherein a secondary reformer effluent is produced (18), (c) passing the secondary reformer effluent to the primary reforming zone (1) as indirect heating medium, and (d) removing the secondary reforming effluent (18) from the primary reforming zone (1) and recovering the raw synthesis gas, wherein the primary reforming zone (1) comprises at least one double-pipe heat exchanger-reactor, the primary steam reforming catalyst (5) being positioned either in the central core (16) of the double-pipe heat exchanger or in the annulus (6) thereof and in that the secondary reformer effluent is passed through whichever of the central core (16) or annulus (6) does not contain the primary steam reforming catalyst (5) countercurrently to the hydrocarbon-containing gas and steam.
Abstract:
A computer has a computation processor and an instruction memory a where instructions relating to computation are stored, and also a control flow processor and a control flow memory where instructions relating to the control flow of the program are stored. The computation instructions processed by the computation processor are determined in accordance with control flow instructions processed in the control flow processor. The invention is particularly applicable to SIMD computers.
Abstract:
Process for the selective recovery of copper from an aqueous metal containing solution in which (a) the solution at a pH of 7 or less is contacted with a chelate exchange resin to selectively remove a substantial proportion or all of the copper from the solution onto the resin. The chelate exchange resin is in the form of an amine substituted cyclic compound on a glycidyl methacrylate substrate. The selectively removed copper is subsequently separated from the resin by elution.
Abstract:
Active carbon is made by treating a carbonaceous feed with a mixture of KOH and NaOH in a molar ratio of NaOH:KOH 80:20 to 20:80, and heating to at least 500oC in an inert atmosphere.