Abstract: An elasticator and a preparation method thereof and a casing expansion loss prevention elastic spacer fluid for cementing are provided. The preparation method of the elasticator includes the following steps of: (1) taking polycaprolactone and an inorganic porous material for fully mixing under a heating condition to obtain a mixture; and (2) mixing the mixture with a high-elastic modulus rubber powder to obtain an elasticator.

Abstract: One embodiment relates to an LLC resonant power converter system. The system includes a transformer comprising a primary inductor and a secondary inductor and a switch control stage configured to generate a plurality of switching signals having a duty-cycle. The system also includes an input stage comprising the primary inductor and a plurality of switches that are controlled in response to the respective plurality of switching signals to generate a primary resonant current and an output stage comprising the secondary inductor and being configured to conduct an output current through a load based on a secondary resonant current to generate an output voltage. The system further includes a controller configured to limit a magnitude of the output current to a predetermined magnitude in response to variations of the load.

Abstract: This present invention relates to a measuring device for measuring consistency of cement slurry for a consistometer. The measuring device comprises a high-pressure vessel, a slurry cup and a magnetic driver, wherein the slurry cup is rotatably mounted inside the high-pressure vessel by the magnetic driver, stir blades are hanged in the slurry cup, and the magnetic driver is driven by a driving motor which is located outside the high-pressure vessel and is further provided with a tension sensor. The invention cancels the conventional mode for measuring consistency by a potentiometer, uses the tension sensor to measure the torque transferred from the driving motor to the magnetic driver, i.e. the cutting torque created by the stir blades on cement slurries within the slurry cup, thereby measuring the consistency of cement slurry.

Abstract: One embodiment relates to an LLC resonant power converter system. The system includes a transformer comprising a primary inductor and a secondary inductor and a switch control stage configured to generate a plurality of switching signals having a duty-cycle. The system also includes an input stage comprising the primary inductor and a plurality of switches that are controlled in response to the respective plurality of switching signals to generate a primary resonant current and an output stage comprising the secondary inductor and being configured to conduct an output current through a load based on a secondary resonant current to generate an output voltage. The system further includes a controller configured to limit a magnitude of the output current to a predetermined magnitude in response to variations of the load.

Abstract: Open and short systems and methods for testing integrated circuits are disclosed. An example implementation includes engaging an integrated circuit testing module with an integrated circuit testing apparatus, the integrated circuit testing module for receiving an integrated circuit, a first set of contact points, and a second set of contact points; engaging a first probe onto at least one of the contact points of the first set of contact points, controllably engaging at least one of a second probe onto at least one contact pair of the integrated circuit testing module, and providing an electrical stimulus to the integrated circuit testing module.

Abstract: This present invention relates to a measuring device for measuring consistency of cement slurry for a consistometer. The measuring device comprises a high-pressure vessel, a slurry cup and a magnetic driver, wherein the slurry cup is rotatably mounted inside the high-pressure vessel by the magnetic driver, stir blades are hanged in the slurry cup, and the magnetic driver is driven by a driving motor which is located outside the high-pressure vessel and is further provided with a tension sensor. The invention cancels the conventional mode for measuring consistency by a potentiometer, uses the tension sensor to measure the torque transferred from the driving motor to the magnetic driver, i.e. the cutting torque created by the stir blades on cement slurries within the slurry cup, thereby measuring the consistency of cement slurry.

Abstract: An embodiment of the invention provides a method of reducing surge current in an LLC converter. The LLC converter comprises a switching circuit having a first switch and a second switch, a resonant circuit, and a rectification circuit. During start up of the LLC converter, first and second signals having a fixed period and a variable duty cycle are applied to the first and second switches respectively. When a predetermined voltage on a load configured to be coupled to the rectification circuit is reached, the first and second signals are changed to signals having a variable period and a fixed duty cycle.

Abstract: Systems and methods of resonant DC/DC conversion disclosed herein improve the basic resonant converter designs by proactively setting and coordinating the gate drive timings between the primary side and secondary side. By proactively setting and coordinating gate drives timings between the primary side and secondary side, both efficiency and transient performance optimizations may be achieved with or without diode emulation mode, depending on whether the switching frequency is below resonance or above resonance, and the nature of the load characteristics. If the switching frequency of the converter is determined to be at or below the resonance frequency, the output transistors may be configured to be fully active at or above a predetermined output load current. The turn-on timing of the output transistors is dependant on the load for a given output voltage, and is almost independent of input voltage. Turn-on timing may be significantly different at light load to no load.

Abstract: Open and short systems and methods for testing integrated circuits are disclosed. An example implementation includes engaging an integrated circuit testing module with an integrated circuit testing apparatus, the integrated circuit testing module for receiving an integrated circuit, a first set of contact points, and a second set of contact points; engaging a first probe onto at least one of the contact points of the first set of contact points, controllably engaging at least one of a second probe onto at least one contact pair of the integrated circuit testing module, and providing an electrical stimulus to the integrated circuit testing module.

Abstract: An embodiment of the invention provides a method of reducing surge current in an LLC converter. The LLC converter comprises a switching circuit having a first switch and a second switch, a resonant circuit, and a rectification circuit. During start up of the LLC converter, first and second signals having a fixed period and a variable duty cycle are applied to the first and second switches respectively. When a predetermined voltage on a load configured to be coupled to the rectification circuit is reached, the first and second signals are changed to signals having a variable period and a fixed duty cycle.

Abstract: Methods and systems are provided for controlling the output power to DC electric heater elements to reduce the input current ripple and to fine-tune the output power to meet the fine-tuning percentage requirement. In one embodiment, a method is performed for controlling output power to heater elements in an electric heater system. The process includes receiving a power request by the heater system, providing output power controls for each heater element, and determining a particular output power control based on output power controls provided for each heater element and the power requested. Further, the heater system selectively controls the output power to one or more of the heater elements to meet the power request.

Abstract: Methods and systems are provided for controlling the output power to DC electric heater elements to reduce the input current ripple and to fine-tune the output power to meet the fine-tuning percentage requirement. In one embodiment, a method is performed for controlling output power to heater elements in an electric heater system. The process includes receiving a power request by the heater system, providing output power controls for each heater element, and determining a particular output power control based on output power controls provided for each heater element and the power requested. Further, the heater system selectively controls the output power to one or more of the heater elements to meet the power request.