Abstract:
To determine properties of multiple oil and gas wells, oscillations at different test frequencies are applied to the flow rate and/or pressure of multiple wells. Measurements of flow rate and/or pressure and temperature in flows downstream of a production header of the multiple wells are then obtained. Such measurements from the flows of the multiple wells are subjected to a frequency analysis of the pressure, flow rate and/or temperature measurements to determine pressure, flow rate and/or temperature variations induced by the applied oscillations. Properties of the different wells of the multiple wells based on the results of the frequency analysis are thus determined.
Abstract:
An apparatus and method are described for effectively priming a non-electrically conductive filter for removal of solid inclusions from liquid metal. In one embodiment, the ceramic filter media is surrounded by a low frequency induction coil (1-60 Hz) with its axis aligned in the direction of the net metal flow. The coil is positioned to enhance the heating of any metal frozen onto, or in the pores of, the filter element. In one embodiment, the coil is positioned in order to generate Lorentz forces, which act to cause heated metal to impinge on the upper surface of the filter element, enhancing the priming action. Once a filter equipped with such a coil has been primed, it can be kept hot or reheated, and subsequently reused during several batch tapping sequences.
Abstract:
Disclosed herein is a method of generating a generator matrix for defining how to systematically code source data, the method comprising: determining source nodes for comprising a plurality of sub-stripes of source data, wherein the number of source nodes is K and the number of sub-stripes of source data comprised by each source node is S; determining redundant nodes for comprising a plurality of sub-stripes of coded data, wherein the number of redundant nodes is R and the number of sub-stripes of coded data comprised by each redundant node is S; determining values of a first generator matrix according to a systematic coding technique such that K of the rows of the generator matrix to define how to generate all of the K source nodes as comprising source data and R of the rows of the first generator matrix define how to generate all of the R redundant nodes as comprising combinations of two or more of the source nodes; generating a second generator matrix, with a first dimension (K×S) and a second dimension ((K+R)×S), in dependence on the determined first generator matrix, wherein each value of the second generator matrix defines how to generate the data comprised by a respective sub-stripe of a node defined by the first generator matrix such that the values of the second generator matrix define how to generate all of the sub-stripes of all of the nodes defined by the first generator matrix; and changing one or more of the values of the second generator matrix so that a sub-stripe of at least one of the redundant nodes is defined, by the systematic coding technique, as being dependent on a combination of two or more sub-stripes of data in the source nodes and is further defined as being dependent on one or more further sub-stripes of data, in a respective one or more source nodes, that the sub-stripe of the redundant node was not defined as being dependent on by the systematic coding technique. Advantageously, when the second generator matrix is used to generate erasure coded data in a data storage system, the amount of data that needs to be obtained to reconstruct a lost data node is less than if Reed-Solomon or other known coding techniques had been used.
Abstract:
An apparatus and method are described for effectively priming a non-electrically conductive filter for removal of solid inclusions from liquid metal. In one embodiment, the ceramic filter media is surrounded by a low frequency induction coil (1-60 Hz) with its axis aligned in the direction of the net metal flow. The coil is positioned to enhance the heating of any metal frozen onto, or in the pores of the filter element. In one embodiment, the coil is positioned in order to generate Lorentz forces, which act to cause heated metal to impinge on the upper surface of the filter element, enhancing the priming action. Once a filter equipped with such a coil has been primed, it can be kept hot or reheated, and subsequently reused during several batch tapping sequences.
Abstract:
A composition of matter comprising a plurality of nanowires on a substrate, said nanowires having been grown epitaxially on said substrate in the presence of a metal catalyst such that a catalyst deposit is located at the top of at least some of said nanowires, wherein said nanowires comprise at least one group III-V compound or at least one group II-VI compound or comprises at least one non carbon group IV element; and wherein a graphitic layer is in contact with at least some of the catalyst deposits on top of said nanowires.
Abstract:
A method of well testing to determine properties of oil and gas wells 8 comprises: applying oscillations to the flow rate and/or pressure at multiple wells 8 wherein the oscillations applied at different wells of the multiple wells are at different test frequencies; receiving measurements of flow rate in flows downstream of a production header that combines the flows from the multiple wells 8, and/or receiving measurements of pressure and/or temperature from individual wells 8; carrying out a frequency analysis of the pressure, flow rate and/or temperature measurements to determine pressure, flow rate and/or temperature variations induced by the applied oscillations; and determining properties of the different wells 8 of the multiple wells 8 based on the results of the frequency analysis at the test frequencies for the wells 8.
Abstract:
A membrane suitable for separating a gas from a gas mixture comprising a non cross-linked PVAm having a molecular weight of at least Mw 100,000 carried on a support wherein after casting onto the support, said PVAm has been heated to a temperature in the range 50 to 150° C., e.g. 80 to 120° C.