Abstract: A hose includes a generally cylindrical tubular structure with at least one layer of steel ligaments near the outer surface, the steel ligaments being enclosed within a tubular layer including polymeric material; the flexible hose also incorporates a multiplicity of sensing coils embedded within the tubular layer, each such sensing coil being a flat coil lying in a plane substantially parallel to the adjacent layer of steel ligaments, so that an axis of the coil orthogonal to the plane of the flat coil extends in a radial direction relative to the hose. Each such sensing coil may form part of an electronic module that also incorporates a signal processing circuit and an RE power-receiving and data-transmission circuit. When that portion of the hose is subjected to an alternating magnetic field, signals from the sensing coils can be analysed to deduce information about the stress in the steel ligaments.

Abstract: A hose includes a generally cylindrical tubular structure with at least one layer of steel ligaments near the outer surface, the steel ligaments being enclosed within a tubular layer including polymeric material; the flexible hose also incorporates a multiplicity of sensing coils embedded within the tubular layer, each such sensing coil being a flat coil lying in a plane substantially parallel to the adjacent layer of steel ligaments, so that an axis of the coil orthogonal to the plane of the flat coil extends in a radial direction relative to the hose. Each such sensing coil may form part of an electronic module that also incorporates a signal processing circuit and an RE power-receiving and data-transmission circuit. When that portion of the hose is subjected to an alternating magnetic field, signals from the sensing coils can be analysed to deduce information about the stress in the steel ligaments.

Abstract: The present invention relates to a cell-free, multi-layered medical device having bespoke, multifunctional bioactivity for the purpose of regeneration of skeletal tissues. The medical device may actively promote homing of stem cells into the medical device and promote their differentiation into the required cell type and promote de-novo tissue formation. The invention includes methods of making the medical device, uses of the medical device in promoting regeneration of the articular cartilage of a joint surface and in promoting healing and regeneration of skeletal tissues, for example, meniscal cartilage, tendon and ligament tissues and also healing of bone tissue indications such as fractures.

Abstract: The present invention relates to a cell-free, multi-layered medical device having bespoke, multifunctional bioactivity for the purpose of regeneration of skeletal tissues. The medical device may actively promote homing of stem cells into the medical device and promote their differentiation into the required cell type and promote de-novo tissue formation. The invention includes methods of making the medical device, uses of the medical device in promoting regeneration of the articular cartilage of a joint surface and in promoting healing and regeneration of skeletal tissues, for example, meniscal cartilage, tendon and ligament tissues and also healing of bone tissue indications such as fractures.

Abstract: An apparatus for measuring material properties of an object of ferromagnetic material, the apparatus including a probe, the probe including an electromagnet core defining two spaced-apart poles for inducing a magnetic field in the object, and a drive coil wound around the electromagnet core, and means to supply an alternating electric current to the drive coil to generate an alternating magnetic field in the electromagnet core and consequently in the object, wherein the probe also includes two sensing coils arranged in the vicinity of each of the poles, for sensing the magnetic flux density that links the core and the object, such sensing coils are significantly more sensitive to changes in material properties than are sensing coils overwound onto the drive coil.

Abstract: A system for monitoring a subsea well is presented. The system includes the subsea well, where the subsea well includes a production tube, an annulus A co-axial to the production tube and positioned exterior to the production tube, an annulus B co-axial to the annulus A and positioned exterior to the annulus A, and a casing wall disposed between the annulus A and annulus B. Furthermore, the system includes a first sensor disposed on or about the production tube, the annulus A, the casing wall, or combinations thereof and configured to measure a first parameter. The system also includes a controller coupled to the subsea well and configured to analyze the first parameter measured by the first sensor and detect an anomaly in one or more components of the subsea well. Methods and non-transitory computer readable medium configured to perform the method for monitoring a subsea well are also presented.

Abstract: An apparatus for measuring material properties of an object of ferromagnetic material, the apparatus including a probe, the probe including an electromagnet core defining two spaced-apart poles for inducing a magnetic field in the object, and a drive coil wound around the electromagnet core, and means to supply an alternating electric current to the drive coil to generate an alternating magnetic field in the electromagnet core and consequently in the object, wherein the probe also includes two sensing coils arranged in the vicinity of each of the poles, for sensing the magnetic flux density that links the core and the object, such sensing coils are significantly more sensitive to changes in material properties than are sensing coils overwound onto the drive coil.

Abstract: A system for monitoring a subsea well is presented. The system includes the subsea well, where the subsea well includes a production tube, an annulus A co-axial to the production tube and positioned exterior to the production tube, an annulus B co-axial to the annulus A and positioned exterior to the annulus A, and a casing wall disposed between the annulus A and annulus B. Furthermore, the system includes a first sensor disposed on or about the production tube, the annulus A, the casing wall, or combinations thereof and configured to measure a first parameter. The system also includes a controller coupled to the subsea well and configured to analyze the first parameter measured by the first sensor and detect an anomaly in one or more components of the subsea well. Methods and non-transitory computer readable medium configured to perform the method for monitoring a subsea well are also presented.

Abstract: A method of measuring biaxial stress in an object of a ferromagnetic material in which material in a region (10) in the vicinity of a surface of the object is subjected to a conditioning method by application of a conditioning magnetic field that is at least initially at a high field strength. Values of biaxial stress within the said region are measured with an electromagnetic measuring probe (14) in at least two different orientations, the electromagnetic measuring probe (14) using an alternating measuring magnetic field that is at a field strength well below saturation. The conditioning may subject the region (10) to a low frequency alternating magnetic field (38, 58) initially at a high field strength, and gradually reducing the strength to zero over a decay time period at least equal to the time for many cycles of the low frequency magnetic field. Conditioning the material enables the stress to then be measured more accurately, and enables ambiguities in biaxial stress to be resolved.

Abstract: A flexible elongate structure, such as a flexible riser (10) for connecting oil and gas wells to floating production platforms, comprising at least one layer (20) of steel wires near the surface which extend at least partly along the length of the structure, can be monitored by inducing a magnetic field in the steel wires using an electromagnetic coil, and monitoring the magnetic flux density near the surface of the structure so as to detect if any wires have broken. Measurements are made at two different frequencies, the lower frequency giving an output dependent both on stresses and on the number of adjacent wires in the layer (20), and the higher frequency giving an output primarily dependent on the number of these wires. By comparing these two measurements a corrected output parameter (P) may be obtained that is indicative only of stress. A break in a wire can be expected to change the stress in that and adjacent wires.

Abstract: A method of measuring biaxial stress in an object of a ferromagnetic material in which material in a region (10) in the vicinity of a surface of the object is subjected to a conditioning method by application of a conditioning magnetic field that is at least initially at a high field strength. Values of biaxial stress within the said region are measured with an electromagnetic measuring probe (14) in at least two different orientations, the electromagnetic measuring probe (14) using an alternating measuring magnetic field that is at a field strength well below saturation. The conditioning may subject the region (10) to a low frequency alternating magnetic field (38, 58) initially at a high field strength, and gradually reducing the strength to zero over a decay time period at least equal to the time for many cycles of the low frequency magnetic field. Conditioning the material enables the stress to then be measured more accurately, and enables ambiguities in biaxial stress to be resolved.

Abstract: A flexible elongate structure, such as a flexible riser (10) for connecting oil and gas wells to floating production platforms, comprising at least one layer (20) of steel wires near the surface which extend at least partly along the length of the structure, can be monitored by inducing a magnetic field in the steel wires using an electromagnetic coil, and monitoring the magnetic flux density near the surface of the structure so as to detect if any wires have broken. Measurements are made at two different frequencies, the lower frequency giving an output dependent both on stresses and on the number of adjacent wires in the layer (20), and the higher frequency giving an output primarily dependent on the number of these wires. By comparing these two measurements a corrected output parameter (P) may be obtained that is indicative only of stress. A break in a wire can be expected to change the stress in that and adjacent wires.

Abstract: A flexible elongate structure, such as a flexible riser (10), comprising at least one layer (20) of steel wires near the surface which extend at least partly along the length of the structure, can be monitored by inducing a small, alternating magnetic field in the steel wires using an electromagnetic coil, and monitoring the magnetic flux density near the surface of the structure so as to asses the stress and hence detect if any wires have broken. By using an array of stress-measuring electromagnetic probes (24) around the structure some spatial resolution can be provided as to the location of any break in the wires.

Abstract: Material properties such as stress in a ferromagnetic material may be measured using an electromagnetic probe. While generating an alternating magnetic field in the object, and sensing the resulting magnetic field with a sensor, the signals from the magnetic sensor may be resolved into in-phase and quadrature components. The signals are affected by both geometrical parameters such as lift-off and by material properties, but these influences may be separated by mapping the in-phase and quadrature components directly into material property and lift-off components, and hence a material property and/or the lift-off may be determined. The mapping may be represented in the impedance plane as two sets of contours representing signal variation with lift-off (A) (for different values of stress) and signal variation with stress (B) (for different values of lift-off), the contours of both sets (A, B) being curved. The stress contours (B) intersect any one liftoff contour (A) at a constant angle.

Abstract: In a railway line, thermally-induced stresses are a factor for both rail breaks and rail buckling. These stresses are in the longitudinal direction. A nondestructive measuring technique enables the residual stress in a rail to be determined, and hence the thermally-induced stress. An electromagnetic probe is used to measure the stresses in the rail web in the vertical direction, and in the direction parallel to the longitudinal axis. The residual stress in the longitudinal direction can be deduced from the measured stress in the vertical direction; hence the thermally-induced stress can be determined.

Abstract: The onset of rolling contact fatigue in an object may be detected by measuring the residual stresses in the surface of the object, and monitoring changes in their magnitude or their direction. The values of residual stresses in the surface are those averaged over a depth that may be in the range say 0.1 mm to 8.0 mm, for example about 2.5 mm. For ferromagnetic objects such as rails, the method may utilize an electromagnetic probe. Prior to rolling contact fatigue the surface stresses are compressive, and the onset of rolling contact fatigue may be characterized by a marked decrease of the stress in the generally transverse direction.

Abstract: Stress in the wall of a pipe (12) is measured using a pig (10) carrying at least one linear array of probes, so that the probes (30) in the array pass in succession over a location on the pipe wall. Each probe (30) comprises an electromagnetic core (32) with two spaced apart electromagnetic poles (34), and a magnetic sensor (36) arranged to sense the reluctance of that part of the magnetic circuit between the poles (34), and an alternating magnetic field is generated in the electromagnet means and consequently in the pipe wall. Successive probes (30) in the array are oriented differently so that the corresponding orientations of the magnetic field in the pipe wall are different. Preferably the probes (30) also include sensors (38) between the two poles (34) to sense magnetic flux perpendicular to the direction of the free space magnetic field between the poles. The signal from the sensor (36) and (38) enable the stress to be determined. Such an array may be used with any long object of ferromagnetic material.

Abstract: The variation in properties of a ferromagnetic material with depth below the surface is assessed in a nondestructive fashion using a probe that incorporates an electromagnet. An alternating magnetic field is generated in the electromagnet and so in the object, and a magnetic sensor is arranged to sense a magnetic field due to the electromagnet. Signals from the magnetic sensor are analysed into an in-phase component and a quadrature component, and these are mapped directly into material property and lift-off components; this analysis enables accurate measurements of material property (such as stress) to be distinguished from changes in lift-off. The measurements are repeated for at least five different frequencies of the alternating magnetic field; and the measurements at different frequencies are deconvolved assuming a functional form for the variation of material property with depth, the function having no more than five unknown constants. The stress at depths for example in the range 0.5 mm to 5.

Abstract: Stress in the wall of a pipe (12) is measured using a pig (10) carrying at least one linear array of probes, so that the probes (30) in the array pass in succession over a location on the pipe wall. Each probe (30) comprises an electromagnetic core (32) with two spaced apart electromagnetic poles (34), and a magnetic sensor (36) arranged to sense the reluctance of that part of the magnetic circuit between the poles (34), and an alternating magnetic field is generated in the electromagnet means and consequently in the pipe wall. Successive probes (30) in the array are oriented differently so that the corresponding orientations of the magnetic field in the pipe wall are different. Preferably the probes (30) also include sensors (38) between the two poles (34) to sense magnetic flux perpendicular to the direction of the free space magnetic field between the poles. The signal from the sensor (36) and (38) enable the stress to be determined. Such an array may be used with any long object of ferromagnetic material.

Abstract: The onset of rolling contact fatigue in an object may be detected by measuring the residual stresses in the surface of the object, and monitoring changes in their magnitude or their direction. The values of residual stresses in the surface are those averaged over a depth that may be in the range say 0.1 mm to 8.0 mm, for example about 2.5 mm. For ferromagnetic objects such as rails, the method may utilise an electromagnetic probe. Prior to rolling contact fatigue the surface stresses are compressive, and the onset of rolling contact fatigue may be characterised by a marked decrease of the stress in the generally transverse direction.