Abstract: Unique systems, methods, techniques and apparatuses of solid state circuit breaker protection are disclosed. One exemplary embodiment is a solid state circuit breaker comprising a primary switching device including a first terminal and a second terminal and a voltage clamping circuit coupled in parallel with the primary switching device. The voltage clamping circuit includes a metal-oxide varistor (MOV) coupled in series between the first terminal and an auxiliary semiconductor device, the auxiliary semiconductor device being arranged so as to selectively couple the MOV with the second terminal, and a bypass circuit coupled between the first terminal and the auxiliary semiconductor device.

Abstract: A skin layer of a superconducting tape has a woven mesh structure and is disposed on a surface of a superconducting tape. The skin layer of a superconducting tape solves the problem where a vapor layer generated when a superconductor is in a normal resistive state greatly reduces the efficiency of a heat exchange between the superconductor and liquid nitrogen. Further provided are the superconducting tape and a superconducting coil.

Abstract: The invention discloses a biological desulfurizer for removing organic sulfur in fracturing flowback fluid and application thereof. The biological desulfurizer includes a compound with a triazine structure formed by modifying chitosan with aldehydes and inorganic salts. The triazine structure has a good removal effect on hydrogen sulfide and organic sulfur such as mercaptan and sulfide. The biological desulfurizer of the invention has a sulfur capacity of up to 250 g/kg and a desulfurization efficiency of over 95% in 15 min. It can effectively remove the stink of sulfur-containing working water, improve the working environment of the well site, and reduce the impact of sulfur compounds on the atmospheric environment during the development of oil and gas fields.

Abstract: A clear personal cleansing composition having an anionic surfactant, a cationic deposition polymer, an aqueous carrier and a level of inorganic salt of from about 0 to about 1 wt %. The composition is substantially free of sulfates and has a % T of greater than about 80%. The composition can further comprise amphoteric surfactants. The composition remains phase stable and minimizes coacervate formulation until after dilution with water.

Abstract: Disclosed herein is a hybrid resonant capacitor circuit including a first capacitor configured to discharge resonant current to interrupt a load current to a switch in parallel with the hybrid resonant capacitor circuit, a second capacitor coupled in parallel with the first capacitor, wherein the second capacitor is configured to transfer energy stored in the second capacitor to the first capacitor after discharge of the resonant current from the first capacitor, and a current limiter coupled in series with the second capacitor. A static transfer switch including a thyristor switch and the hybrid resonant capacitor circuit is also disclosed herein, as is a method for facilitating multiple consecutive voltage source transfers between a first voltage source and a second voltage source powering a load, using the hybrid resonant capacitor circuit.

Abstract: In one aspect, a solid-state switching apparatus is provided that includes a pair of anti-parallel thyristors, a quasi-resonant turn-off circuit, a sensor, and a control circuit. The turn-off circuit is coupled in parallel with the pair of anti-parallel thyristors and includes a first selectively conductive path and a second selectively conductive path. The sensor is configured to sense a thyristor current conducted by at least one of the pair of anti-parallel thyristors. The control circuit is configured to receive the sensed thyristor current from the sensor and determine a magnitude of the sensed thyristor current and a polarity of the sensed thyristor current. The control circuit is further configured to activate, in response to determining that the magnitude is greater than a threshold value, one of the first selectively conductive path and the second selectively conductive path based on the polarity to commutate and interrupt the thyristor current.

Abstract: A dissolvable solid fibrous shampoo article having a plurality of fibrous elements. The fibrous elements contain one or more polymeric structurants; one or more cationic polymers, a surfactant system, and two or more salts that include an inorganic salt and an organic salt. The plurality of fibrous elements are intertangled or otherwise associated with one another to form the fibrous article. The present invention provides a dissolvable solid fibrous shampoo articles having an adequate strength during manufacturing while not slowing down the dissolution of the structure during usage.

Abstract: A dissolvable fibrous solid shampoo article containing fibrous elements. The fibrous elements can contain a polymeric structurant, a surfactant, and optionally a cationic polymer. The fibrous article is substantially free of lamellar structures and can have a hand dissolution of less than 15 strokes.

Abstract: In one aspect, a solid-state switching apparatus is provided that includes a pair of anti-parallel thyristors, a quasi-resonant turn-off circuit, a sensor, and a control circuit. The turn-off circuit is coupled in parallel with the pair of anti-parallel thyristors and includes a first selectively conductive path and a second selectively conductive path. The sensor is configured to sense a thyristor current conducted by at least one of the pair of anti-parallel thyristors. The control circuit is configured to receive the sensed thyristor current from the sensor and determine a magnitude of the sensed thyristor current and a polarity of the sensed thyristor current. The control circuit is further configured to activate, in response to determining that the magnitude is greater than a threshold value, one of the first selectively conductive path and the second selectively conductive path based on the polarity to commutate and interrupt the thyristor current.

Abstract: A method of operating a static transfer switch is provided. The method includes monitoring a voltage waveform for each phase of first and second power sources, and calculating flux for each phase of the power sources. The method also includes determining (i) a first flux difference between the respective flux of the first phases of the first and second power sources, (ii) a second flux difference between the respective flux of the second phases of the first and second power sources, and (iii) a third flux difference between the respective flux of the third phases of the first and second power sources. The method further includes turning off a third solid-state switch to disconnect the third phase of the first power source from a load, in response to the controller determining that the third flux difference is greater the first and second flux differences.

Abstract: A gate driver circuit is provided that includes a turn-on path, a turn-off path, and a fast discharge path. The turn-on path is couplable between a gate of a solid-state switch and a voltage turn-on signal (VGON) from a gate driver, where the turn-on path defines a turn-on time for the solid-state switch. The turn-off path is couplable between the gate and a voltage turn-off signal (VGOFF) from the gate driver, where the turn-off path defines a turn-off time for the solid-state switch. The fast discharge path is selectively couplable in parallel with the turn-off path during a portion of a gate-to-source voltage (VGS) transition for the solid-state switch, where the turn-off path in parallel with the fast discharge path defines a turn-off delay for the solid-state switch and each of the turn-on time, the turn-off time, and the turn-off delay are independently configurable.

Abstract: A method of operating a static transfer switch is provided. The method includes monitoring a voltage waveform for each phase of first and second power sources, and calculating flux for each phase of the power sources. The method also includes determining (i) a first flux difference between the respective flux of the first phases of the first and second power sources, (ii) a second flux difference between the respective flux of the second phases of the first and second power sources, and (iii) a third flux difference between the respective flux of the third phases of the first and second power sources. The method further includes turning off a third solid-state switch to disconnect the third phase of the first power source from a load, in response to the controller determining that the third flux difference is greater the first and second flux differences.

Abstract: A power semiconductor circuit is provided for clamping the voltage across the circuit when a power semiconductor switch is opened (i.e., turned off). The circuit may include a first surge arrester and a first semiconductor switch coupled in parallel with the power semiconductor switch. The first semiconductor switch is coupled in series with the first surge arrester. A second surge arrester may be coupled to the gate of the first semiconductor switch to control current flow through the first semiconductor switch and the first surge arrester.

Abstract: Disclosed herein is a hybrid resonant capacitor circuit including a first capacitor configured to discharge resonant current to interrupt a load current to a switch in parallel with the hybrid resonant capacitor circuit, a second capacitor coupled in parallel with the first capacitor, wherein the second capacitor is configured to transfer energy stored in the second capacitor to the first capacitor after discharge of the resonant current from the first capacitor, and a current limiter coupled in series with the second capacitor. A static transfer switch including a thyristor switch and the hybrid resonant capacitor circuit is also disclosed herein, as is a method for facilitating multiple consecutive voltage source transfers between a first voltage source and a second voltage source powering a load, using the hybrid resonant capacitor circuit.

Abstract: Personal cleansing compositions having an anionic surfactant, cationic deposition polymer, a level of inorganic salt of from about 0 to about 1 wt %, and an aqueous carrier. The composition is substantially free of sulfate containing surfactants. The composition can further comprise amphoteric surfactants. The composition remains phase stable, and minimizes coacervate formulation until after dilution with water.

Abstract: A clear personal cleansing composition having an anionic surfactant, a cationic deposition polymer, an aqueous carrier and a level of inorganic salt of from about 0 to about 1 wt %. The composition is substantially free of sulfates and has a % T of greater than about 80%. The composition can further comprise amphoteric surfactants. The composition remains phase stable and minimizes coacervate formulation until after dilution with water.

Abstract: A clear personal cleansing composition having an anionic surfactant, a cationic deposition polymer, an aqueous carrier and a level of inorganic salt of from about 0 to about 1 wt %. The composition is substantially free of sulfates and has a % T of greater than about 80%. The composition can further comprise amphoteric surfactants. The composition remains phase stable and minimizes coacervate formulation until after dilution with water.

Abstract: An overcurrent fault detector using a High Electron Mobility Transistor (HEMT) operated by a gate driver is disclosed. The overcurrent fault detector includes a band-pass filter and a control circuit. The band-pass filter is configured to receive gate-to-source voltage (VGS) signals of the HEMT and filter the VGS signals to generate a band-limited version of the VGS signals. The control circuit is configured to measure a value of the band-limited version of the VGS signals, determine if the value is greater than a threshold value, and generate a fault signal that disables the gate driver and terminates an overcurrent fault condition in response to determining that the value is greater than the threshold value.

Abstract: In one aspect, a quasi-resonant turn-off circuit is provided. The quasi-resonant turn-off circuit is couplable in parallel with a pair of anti-parallel thyristors. The quasi-resonant turn-off circuit includes a resonant capacitor and an energy recovery circuit. The resonant capacitor is configured to supply a charge to the pair of anti-parallel thyristors to decrease a turn-off time of the pair of anti-parallel thyristors. The energy recovery circuit is configured to recharge the resonant capacitor using remnant energy left in parasitic inductances coupled to the quasi-resonant turn-off circuit after the pair of anti-parallel thyristors is off.

Abstract: A multi-port solid-state circuit breaker system includes a first electrical power bus, a second electrical power bus, and a plurality of breaker legs conductively coupled with the first electrical power bus and the second electrical power bus in parallel with one another. Each of the plurality of breaker legs includes a first power semiconductor device coupled in series with a second power semiconductor device and an input/output port intermediate the first power semiconductor device and the second power semiconductor device. At least one of the first semiconductor device and the second semiconductor device includes an actively controlled switching device. A surge suppressor is conductively coupled in parallel with the plurality of breaker legs.