Abstract: This application relates to apparatus and methods for providing recommended items to advertise. In some examples, a computing device determines a plurality of first values for a corresponding plurality of first items based on the user's engagement with each of the first items. The computing device may then determine a subset of the plurality of first items based on the first values. The computing device may receive a search request and determine a plurality of second values for a plurality of second items based on the search request. The computing device may determine a plurality of third values for the subset of items based on the plurality of second values for the plurality of second items and the user's engagement with each of the subset of items. The computing device may determine the recommended items based on the plurality of second values and the plurality of third values.

Abstract: A linear motor compressor including a compressor housing and a cylinder housing having a plurality of opposing compression chambers. A piston freely reciprocates within the cylinder housing using a linear electric motor. A piston position feedback control system provides adaptive current output as a function of position feedback and/or velocity feedback from the piston and/or the electric motor, to directly power and control the electric motor, wherein the piston reciprocates without assistance from a mechanical spring or other equivalent centering force.

Abstract: This application relates to apparatus and methods for automatically providing item reviews. In some examples, a website provides a widget on a website allowing a customer to request an item review for an item. In response to the customer requesting the item review, a computing device determine whether suitable reviews for the item are available. If suitable reviews are available, the reviews are provided to the customer requesting the item review. If suitable reviews are not available, the computing device determines a set of customers to request item reviews for the item from, and provides item review requests to the determined set of customers. The computing device receives responses to the item review requests received from the set of customers, and provides an item review based on the received item review requests. In some examples, the website provides the item review to the customer requesting the item review.

Abstract: This application relates to apparatus and methods for automatically providing item reviews. In some examples, a website provides a widget on a website allowing a customer to request an item review for an item. In response to the customer requesting the item review, a computing device determine whether suitable reviews for the item are available. If suitable reviews are available, the reviews are provided to the customer requesting the item review. If suitable reviews are not available, the computing device determines a set of customers to request item reviews for the item from, and provides item review requests to the determined set of customers. The computing device receives responses to the item review requests received from the set of customers, and provides an item review based on the received item review requests. In some examples, the website provides the item review to the customer requesting the item review.

Abstract: A linear motor compressor including a compressor housing and a cylinder housing having a plurality of opposing compression chambers. A piston freely reciprocates within the cylinder housing using a linear electric motor.

Abstract: Described herein are methods and system that use electromagnetic heating to heat wellbores and the fluids therein. The heating is achieved by placing one or more permanent magnets in the wellbore and moving a metallic component and/or the one or more permanent magnets relative to each other. This generates eddy currents in the metallic component, which heat the metallic component. This heat is transferred to the fluids in the wellbore from the metallic component by convection.

Abstract: Described herein are methods and system that use electromagnetic heating to heat wellbores and the fluids therein. The heating is achieved by placing one or more permanent magnets in the wellbore and moving a metallic component and/or the one or more permanent magnets relative to each other. This generates eddy currents in the metallic component, which heat the metallic component. This heat is transferred to the fluids in the wellbore from the metallic component by convection. In some embodiments, permanent magnets are installed in the tubing to induce eddy current heating in a well by converting the linear motion of a sucker rod to rotary motion of a conducting tube using a lead or ball screw. The heater may directly integrate with existing pump jack equipment with little or no additional infrastructure required.

Abstract: A linear motor compressor including a compressor housing and a cylinder housing having a plurality of opposing compression chambers. A piston freely reciprocates within the cylinder housing using a linear electric motor. A piston position feedback control system provides adaptive current output as a function of position feedback and/or velocity feedback from the piston and/or the electric motor, to directly power and control the electric motor, wherein the piston reciprocates without assistance from a mechanical spring or other equivalent centering force.

Abstract: Described herein are methods and system that use electromagnetic heating to heat wellbores and the fluids therein. The heating is achieved by placing one or more permanent magnets in the wellbore and moving a metallic component and/or the one or more permanent magnets relative to each other. This generates eddy currents in the metallic component, which heat the metallic component. This heat is transferred to the fluids in the wellbore from the metallic component by convection. In some embodiments, permanent magnets are installed in the tubing to induce eddy current heating in a well by converting the linear motion of a sucker rod to rotary motion of a conducting tube using a lead or ball screw. The heater may directly integrate with existing pump jack equipment with little or no additional infrastructure required.

Abstract: Described herein are methods and system for welding, for example, girders. The method may include activating a homopolar generator. The method may include applying a force to two metal girders at a desired coupling joint. The method may include generating an electrical pulse using the homopolar generator and conducting the electrical pulse to the desired coupling joint to increase a temperature of the girders. The method may include forming a weld at the desired coupling joint attaching the two metal girders at the desired coupling joint. In some embodiments, the homopolar generator may include a radial bearing rotor including a rotatable shaft and a bearing assembly. The bearing assembly may include nonmagnetic bearings. The homopolar generator may include a field coil. The homopolar generator may include a brush actuation mechanism which when activated engages a plurality of brush devices to the radial bearing rotor.

Abstract: A linear motor compressor including a compressor housing and a cylinder housing having a plurality of opposing compression chambers. A piston freely reciprocates within the cylinder housing using a linear electric motor.

Abstract: Aspects described herein relate to an electromagnetic seismic vibrator (EMSV) architecture that provide wide frequency range operation, ground force application with high fidelity, and low environmental impact. The EMSV architecture can include a base member that can support a force coil and mitigate electrical heating due, at least in part, to spurious currents. The EMSV architecture can include means for restricting movement of a reaction member included in the EMSV architecture relative to the base member. Such means can permit mitigation of damage of the EMSV architecture in scenarios in which control of the EMSV architecture may fail.

Abstract: Aspects described herein relate to an electromagnetic seismic vibrator (EMSV) architecture that provide wide frequency range operation, ground force application with high fidelity, and low environmental impact. The EMSV architecture can include a base member that can support a force coil and mitigate electrical heating due, at least in part, to spurious currents. The EMSV architecture can include means for restricting movement of a reaction member included in the EMSV architecture relative to the base member. Such means can permit mitigation of damage of the EMSV architecture in scenarios in which control of the EMSV architecture may fail.

Abstract: An augmented electromagnetic accelerator apparatus which imparts an initial elocity to a projectile by use of enhanced inductance gradients and allows for the use of cylindrical projectiles by the use of a round bore, using a parallel gun rail geometry The enhanced inductance gradients are achieved by the use of an extra turn around the gun rails and enclosing the rail and the said augmented turn in laminated iron. The augmented accelerator has crossovers at the two ends (breech and muzzle end) which have minimum influences over the electromagnetics in the bore of the accelerator.