A particulate metering system includes an air flow origin and a plurality of particulate accelerators. A single particulate source is in communication with the particulate accelerators. Each of a plurality of operated conveyances can be in operable communication with the single particulate source and one of the particulate accelerators. The system includes a confluence of the air flow and the particulate within the mixing area of each of the particulate accelerators. Each of a plurality of discharges can be associated with the particulate accelerators. The operated conveyances can operate at different rates. The system can include one or more gearboxes adapted to be inverted and controlled by a second drive system. The system and controls provide variable application rates of particulate across rows in a field.

A method is provided for determining the frequency of a multi-rate well testing operation in a gas-lifted hydrocarbon well. A well performance characteristic of the well is monitored using single-rate well tests. The monitored well performance characteristic is compared to a current well model performance characteristic. If the monitored well performance characteristic differs from the current well model performance characteristic by less than a predetermined amount, an amount of gas is injected into the well based on the current well model performance characteristic. If the monitored well performance characteristic differs from the current well model performance characteristic by more than a predetermined amount, a multi-rate well test is initiated the results of the multi-rate well test are fitted to a revised well model performance characteristic, and an amount of gas is injected into the well based on the revised well model performance characteristic.

A method is provided for determining the frequency of a multi-rate well testing operation in a gas-lifted hydrocarbon well. A well performance characteristic of the well is monitored using single-rate well tests. The monitored well performance characteristic is compared to a current well model performance characteristic. If the monitored well performance characteristic differs from the current well model performance characteristic by less than a predetermined amount, an amount of gas is injected into the well based on the current well model performance characteristic. If the monitored well performance characteristic differs from the current well model performance characteristic by more than a predetermined amount, a multi-rate well test is initiated the results of the multi-rate well test are fitted to a revised well model performance characteristic, and an amount of gas is injected into the well based on the revised well model performance characteristic.

A valve assembly may include: a valve body with a fluid path extending between the inlet port and the outlet port; a valve member with a closed position blocking the fluid path and an open position; a sensor the fluid flow; an actuator coupled to the valve member; and a controller for the actuator with a set point value and a default flow rate indicative of nominal flow through the fluid path. The controller may: read the sensor; calculate a flow rate; compare the flow rate to a threshold value indicative of substantially zero flow rate; and if the measure of flow rate is below the threshold value, calculate a position of the valve member directly from the set point value and the default flow rate, produce a control signal from the calculated position, and communicate the control signal to the actuator.

A valve assembly may include: a valve body with a fluid path extending between the inlet port and the outlet port; a valve member with a closed position blocking the fluid path and an open position; a sensor the fluid flow; an actuator coupled to the valve member; and a controller for the actuator with a set point value and a default flow rate indicative of nominal flow through the fluid path. The controller may: read the sensor; calculate a flow rate; compare the flow rate to a threshold value indicative of substantially zero flow rate; and if the measure of flow rate is below the threshold value, calculate a position of the valve member directly from the set point value and the default flow rate, produce a control signal from the calculated position, and communicate the control signal to the actuator.

An interactive fish tank system includes a nozzle array provided in a water tank, wherein a plurality of bubble nozzles from which bubbles are emitted are arranged in the nozzle array; a computing device configured to receive user action information inputted from at least one user action input device, generate bubble conversion information by which characteristics of the user action information are expressed as bubbles generated from at least one of the plurality of bubble nozzles, and generate a control signal for supplying air to emit bubbles corresponding to the bubble conversion information; and an air injection device connected to the plurality of bubble nozzles through hoses, wherein the air injection device supplies air to at least one of the plurality of bubble nozzles based on the control signal.

An interactive fish tank system includes a nozzle array provided in a water tank, wherein a plurality of bubble nozzles from which bubbles are emitted are arranged in the nozzle array; a computing device configured to receive user action information inputted from at least one user action input device, generate bubble conversion information by which characteristics of the user action information are expressed as bubbles generated from at least one of the plurality of bubble nozzles, and generate a control signal for supplying air to emit bubbles corresponding to the bubble conversion information; and an air injection device connected to the plurality of bubble nozzles through hoses, wherein the air injection device supplies air to at least one of the plurality of bubble nozzles based on the control signal.

An aircraft pneumatic system including a pneumatic actuator arranged to operate at a pressure value at least equal to a pressure threshold, a line fluidly connected between a pneumatic source and the pneumatic actuator, and a venturi disposed upstream of the line and downstream of the pneumatic source. The venturi is configured to receive a source flow from the source at a mass flow rate, the mass flow rate being between a lower, nominal flow rate value and a higher, graded flow rate value. The venturi is sized such that when the mass flow rate is at the nominal flow rate value, a line pressure inside the line corresponds to a source pressure upstream of the venturi, and when the mass flow rate to the venturi is at the graded flow rate value, the line pressure is less than the source pressure.

An electric fuel flow control device for use with oil and gas equipment, such as fueling systems for frac pumps. The electric fuel flow control device includes a battery, control circuitry, an enclosure that encloses the control circuity, and includes an electric fluid sensor, a valve, a beacon light, a status light, a button, an adapter cap enabling connection to a fuel tank, and a mandrel. The electric fuel flow control device may be used as a primary fuel flow control device or a backup fuel flow control device.

An electric fuel flow control device for use with oil and gas equipment, such as fueling systems for frac pumps. The electric fuel flow control device includes a battery, control circuitry, an enclosure that encloses the control circuity, and includes an electric fluid sensor, a valve, a beacon light, a status light, a button, an adapter cap enabling connection to a fuel tank, and a mandrel. The electric fuel flow control device may be used as a primary fuel flow control device or a backup fuel flow control device.