Abstract: A method for performing uptower maintenance of a wind turbine in order to replace the main bearing on the turbine shaft is disclosed. Embodiments of this method to perform maintenance may include installing a rotor lock to resist rotation of the main shaft during maintenance, providing a lifting device in order to elevate the main shaft, removing the main bearing from its main bearing housing, and installing a replacement split main bearing. A crane may also be installed uptower to assist in the maintenance.

Abstract: A fiber optic apparatus is provided including a support bracket configured to be mounted to an equipment rack, the bracket having a movable projection extending therefrom and a chassis configured to support fiber optic communication equipment, the chassis including a plurality of detents or apertures configured to receive the movable projection, wherein the engagement of the movable projection into one of the detents or apertures defines the projection of the chassis from the rack.

Abstract: An untethered apparatus for measuring properties along a subterranean well includes a housing, and one or more sensors configured to measure data along the subterranean well. The data includes one or more physical, chemical, geological or structural properties in the subterranean well. The untethered apparatus further includes a processor configured to control the one or more sensors measuring the data and to store the measured data, and a transmitter configured to transmit the measured data to a receiver arranged external to the subterranean well. Further, the untethered apparatus includes a controller configured to control the buoyancy or the drag of the untethered apparatus to control a position of the untethered apparatus in the subterranean well. The processor includes instructions defining measurement parameters for the one or more sensors of the untethered apparatus within the subterranean well.

Abstract: Embodiments provide systems and methods for utilizing acoustic sensors to detect defects via online or in situ monitoring of additive manufacturing (AM) processes. Sensors may capture acoustic waves associated with AM manufacturing operations. The acoustic emissions in combination with other sensing data, such as cameras or thermometers, may be used to characterize the state of the AM process, such as to detect a defect has occurred or confirm a defect has not occurred. When defects are detected, the AM process may be stopped to prevent further processing of a defective part. When defects are predicted as likely to occur, operational parameters of the AM device or process may be adjusted to mitigate the occurrence of a defect. The techniques disclosed herein enable detection of defects that occur underneath the surface of the part being manufactured, as well as correct issues with the AM device or process before a defect occurs.

Abstract: A method and a system for interrogating an optical fiber includes a probe signal that has a first frequency comb at a first repetition rate (?f) injected into the optical fiber. A backscattering signal that includes the probe signal convolved with an impulse response of the optical fiber in reflection which is sensitive to at least one parameter being measured from the optical fiber is gathered. The backscattering signal is beaten with a local oscillator signal to generate a beating signal, the local oscillator signal including a second frequency comb at a second repetition rate that is offset from the first repetition rate (?f+?f) and being mutually coherent with the first frequency comb. The resulting beating signal is analysed to thereby determine the at least one parameter being measured from the optical fiber.

Abstract: A photocathode emitter can include a transparent substrate, a photocathode layer, and a plasmonic structure array disposed between the transparent substrate and the photocathode layer. The plasmonic structure can serve as a spot-confining structure and an electrical underlayer for biasing the photocathode. The plasmonic structure can confine the incident light at subwavelength sizes.

Abstract: Embodiments provide systems and methods for utilizing acoustic sensors to detect defects via online or in situ monitoring of additive manufacturing (AM) processes. Sensors may capture acoustic waves associated with AM manufacturing operations. The acoustic emissions in combination with other sensing data, such as cameras or thermometers, may be used to characterize the state of the AM process, such as to detect a defect has occurred or confirm a defect has not occurred. When defects are detected, the AM process may be stopped to prevent further processing of a defective part. When defects are predicted as likely to occur, operational parameters of the AM device or process may be adjusted to mitigate the occurrence of a defect. The techniques disclosed herein enable detection of defects that occur underneath the surface of the part being manufactured, as well as correct issues with the AM device or process before a defect occurs.

Abstract: A computer-implemented method, computer program product and computer system (100) for identifying weeds in a crop field using a dual task convolutional neural network (120) having a topology with an intermediate module (121) to execute a classification task being associated with a first loss function (LF1), and with a semantic segmentation module (122) to execute a segmentation task with a second different loss function (LF2). The intermediate module and the segmentation module are being trained together, taking into account the first and second loss functions (LF1, LF2).

Abstract: Embodiments of tuning fork-based sensors are disclosed. The sensors may include a measurement sensor that includes a diaphragm disposed on a proximal end and a plurality of forks extending from the diaphragm toward the distal end of the sensor. The diaphragm may have a domed geometry defining a curved surface. The plurality of forks may extending from the curved surface of the diaphragm toward the distal end and each of the plurality of forks may include a stub portion connected to the diaphragm, a stem portion, and a paddle portion. Some sensors, such as measurement sensors, may include a stem portion formed from a corrosive material. A reference sensor may be provided to compensate for changes in frequency measurements due to temperature, viscosity, or other environmental factors present in the environment where the sensors are deployed.

Abstract: An apparatus for determining properties of an uncharacterized downhole fluid. The apparatus comprises an oscillation driver circuit comprising an amplifier having an output and an input, a feedback loop between the output and input of an amplifier or a logic gate, an electromechanical resonator disposed within the feedback loop such that a the resonator is driven by the oscillation driver circuit, wherein a resonant frequency of the resonator defines an oscillation frequency of the oscillator circuit, and a switch device for causing the oscillator circuit to stop driving the resonator, which thereby enables observation of a decay rate of the oscillation of the electromechanical resonator within the uncharacterized fluid. The electromechanical resonator is enclosed in a conductive layer to protect the resonator against capacitive effects of the downhole fluid.

Abstract: An apparatus for measuring a viscosity of a fluid is disclosed. The apparatus includes a Parylene coated quartz tuning fork for immersion in the fluid and an electronic circuit to excite a vibration of the Parylene coated quartz tuning fork and measure one or more vibrational parameters of the Parylene coated quartz tuning fork. A computer processor is configured to determine a non-Newtonian viscosity from the vibration of the Parylene coated quartz tuning fork based, at least in part, on a Stokes flow hydrodynamic model. The computer processor is coupled to a memory for storing a calibration curve to determine a Newtonian viscosity of the fluid from the non-Newtonian viscosity of the fluid.

Abstract: Fiber optic equipment that supports independently translatable fiber optic modules and/or fiber optic equipment trays containing one or more fiber optic modules is disclosed. In some embodiments, one or more fiber optic modules are disposed in a plurality of independently translatable fiber optic equipment trays which are received in a tray guide system. In this manner, each fiber optic equipment tray is independently translatable within the guide system. One or more fiber optic modules may also be disposed in one or more module guides disposed in the fiber optic equipment trays to allow each fiber optic module to translate independently of other fiber optic modules in the same fiber optic equipment tray. In other embodiments, a plurality of fiber optic modules are disposed in a module guide system disposed in the fiber optic equipment that translate independently of other fiber optic modules disposed within the module guide system.

Abstract: A photocathode emitter includes a transparent substrate, a photocathode layer, and a plasmonic structure array disposed between the transparent substrate and the photocathode layer. The plasmonic structure array is configured to operate at a wavelength from 193 nm to 430 nm. The plasmonic structure array can be made of aluminum. An electron beam can be generated from a light beam directed at the plasmonic structure array of the photocathode emitter.

Abstract: A method and a system for interrogating an optical fiber includes a probe signal that has a first frequency comb at a first repetition rate (?f) injected into the optical fiber. A backscattering signal that includes the probe signal convolved with an impulse response of the optical fiber in reflection which is sensitive to at least one parameter being measured from the optical fiber is gathered. The backscattering signal is beaten with a local oscillator signal to generate a beating signal, the local oscillator signal including a second frequency comb at a second repetition rate that is offset from the first repetition rate (?f+?f) and being mutually coherent with the first frequency comb. The resulting beating signal is analysed to thereby determine the at least one parameter being measured from the optical fiber.

Abstract: Embodiments provide systems and methods for utilizing acoustic sensors to detect defects via online or in situ monitoring of additive manufacturing (AM) processes. Sensors may capture acoustic waves associated with AM manufacturing operations. The acoustic emissions in combination with other sensing data, such as cameras or thermometers, may be used to characterize the state of the AM process, such as to detect a defect has occurred or confirm a defect has not occurred. When defects are detected, the AM process may be stopped to prevent further processing of a defective part. When defects are predicted as likely to occur, operational parameters of the AM device or process may be adjusted to mitigate the occurrence of a defect. The techniques disclosed herein enable detection of defects that occur underneath the surface of the part being manufactured, as well as correct issues with the AM device or process before a defect occurs.

Abstract: The present invention discloses compositions and methods for repair and reconstruction of defects and injuries to soft tissues. Some aspects of the disclosure provide methods for corneal reconstruction by applying an engineered bioadhesive, glycidyl methacrylate-substituted gelatin and a visible light activated photoinitiator in presence of visible light to the corneal defect.

Abstract: The present invention relates, but without limitation, to a system and method for detecting the formation of ice on a surface of a body (1) on which an air stream impinges. Said system comprises: a first and a second temperature detectors (2, 5) with different thermal inertia; and an electro-optic module (10) connected to both detectors (2, 5). Thus, by calculating the different responses of the detectors (2, 5) it is possible to detect the ice formation on a body (1), and more advantageously, the almost instantaneously freezing of supercooled water on a body (1). The present invention can be applied to aircrafts, wind turbines or to electrical power transmission lines.

Abstract: A method and device are described for making in situ measurements of the density and viscosity of downhole fluids at subterranean wells. An oscillator circuit is deployed in the well comprising an amplifier, a feedback loop, and an electromechanical resonator. The electromechanical resonator is a component in the feedback loop of the oscillator circuit, and has a resonance mode that determines the frequency of the oscillator circuit. The electromechanical resonator is also in contact with the fluid such that the density and viscosity of the fluid influence the resonant frequency and damping of the resonator. The frequency of the oscillator is measured by a microcontroller. In one embodiment, the oscillator circuit periodically stops driving the electromechanical resonator such that the oscillation decays and the rate of decay is also measured by the microcontroller. The density and viscosity of the fluid are determined from the frequency and rate of decay of the oscillation.

Abstract: Techniques for determining rheological properties of a fluid include actuating a resonator disposed in a volume that contains a fluid sample to operate the resonator in the fluid sample at a predetermined actuation scheme; measuring at least one characteristic of the resonator based on the operation of the resonator in the fluid sample; comparing the at least one measured characteristic to a rheological model that associates characteristics of the fluid sample to one or more rheological properties; and based on the comparison, determining one or more rheological properties of the fluid sample.

Abstract: The present invention provides a device or medical device comprising a graphene coating. Particularly, the graphene coating features substantially high transmittance, biointegrity and biocompatibility.