A liquid chromatographic (LC) system and a method of exchanging a liquid in an LC system are disclosed. The LC system includes an LC pump with at least one pump head having a primary and a secondary pump head, each with a syringe-like cylinder body having an inner wall surface and a plunger translatable through the cylinder body leaving an interspace between the inner wall surface and the plunger when the plunger is translated through the cylinder body, an upstream inlet valve configured to allow liquid into the cylinder body and a downstream outlet valve configured to allow liquid out of the cylinder body. The LC system further includes at least one liquid-exchange pump connected either to the upstream inlet valve of the primary pump head or to the downstream outlet valve of the secondary pump head.

There is provided a technique that includes: a main controller configured to execute a process recipe including a plurality of steps to perform a predetermined process on a substrate so as to acquire device data when executing the process recipe; and a storage part configured to store the acquired device data, wherein the main controller is configured to: acquire the device data in a predetermined specific step among the steps constituting the process recipe; calculate a value of the acquired device data in the specific step; compare the calculated value with a value of the device data in the specific step calculated at a time of previous execution of the process recipe; and generate an alarm when the calculated value shows a predefined tendency.

An inflatable object with a sag to enclose pressurized air to a predetermined threshold pressure and to obtain a shape, a decorative dress to cover at least a portion of the sag and having characteristics of an object having the shape when covering the sag outer surface, couplings on the sag outer surface to which the decorative dress is attached, a frame to support at least a portion of the sag, an air pump coupled to the sag by a unidirectional inlet valve, and to provide the insufflated air to the sag, an optional sensor coupled to the sag and configured to detect sag air pressure; and a controller, coupled between the sensor and the pump. The controller operates the pump to automatically maintain a threshold pressure of air within the sag. The sensor and the controller are disposed on the sag surface.

A home-based, low-cost, self-contained, fast-fill natural gas refueling station for providing compress natural gas (CNG) fuel for motor vehicles. The station compresses utility supplied natural gas and stores the CNG in a CNG storage facility located inside the station. In preferred embodiments the refueling station is located adjacent to a driveway at a home. The compressor preferably is a multi-stage gas compressor having at least three stages of compression. Applicant estimates that savings based today prices for CNG as compared to gasoline, a typical family with only one car could pay for the station in three years. If the family has several cars the station could pay for itself much earlier.

A multistage compressor including: at least a first compressor main body and a second compressor main body configured to suck compressed gas discharged from the first compressor main body to discharge the compressed gas with higher pressure; a first driving source configured to drive the first compressor main body; a second driving source configured to drive the second compressor main body; an intermediate pipe configured to connect a discharge side of the first compressor main body and a suction side of the second compressor main body; a low-pressure side discharge piping system branched from the intermediate pipe; an on-off valve disposed in the low-pressure side discharge piping system and configured to switch permission and prohibition of a flow of compressed gas discharged from the first compressor main body; and a control unit configured to control driving of the first driving source and the second driving source.

An engine (12) drives a variable capacity-type hydraulic pump (16), discharged hydraulic oil is selectively supplied to a cooling fan (19) and a hoist cylinder (11) in accordance with switching of a selection valve (17), thereby controlling the same on the basis of each target value. A pump discharge pressure (Pp) of the hydraulic oil discharged from the hydraulic pump (16) and a motor supply pressure (Pm) of the hydraulic oil supplied to a hydraulic motor (18) via the selection valve (17) are detected by sensors (27, 28) and are compared with pressure determination values stored in advance as a pump discharge pressure (Pp) and an actuator supply pressure (Pm) generated when the target value is achieved. Presence/absence of abnormality in the hydraulic actuator control device (15) is determined on the basis of a result of the comparison, and when abnormality is determined to have occurred, control is performed to minimize the capacity of the hydraulic pump (16).

A compressor, which includes a cylinder block and a piston assembly arranged inside the cylinder block; the piston assembly comprises a first piston, a second piston arranged inside the first piston, and a movable assembly connected to the first piston, and the movable assembly is configured to drive the first piston and the second piston to reciprocate; the cylinder block is provided with a first compression chamber that defines a space for the first piston to move up and down; the cylinder block is provided with a gas storage chamber for storing the gas after the first compression, and the gas storage chamber is connected to the first compression chamber; and the cylinder block is also provided with a second compression chamber that defines a space for the second piston to move up and down, and the second compression chamber is connected to the gas storage chamber.

An air system and method includes an air compressor, a temperature sensors, a valve, and a controller. The air compressor is configured to receive filtered air. The temperature sensor is positioned at or near an outlet of the air compressor and configured to sense a temperature at or near the outlet of the air compressor. The valve is operatively connected to an outlet of the air compressor and external to the air compressor. The controller is configured to monitor the sensed temperature at the outlet of the air compressor and control the valve to permit air to flow from the outlet of the air compressor through the valve to unload the air compressor if the sensed temperature exceeds a threshold temperature.

A motor drive and method to control a motor in a fluid system. The method may comprise determining a pressure; determining a proportional error as a limited difference between the pressure and a pressure setpoint; determining an integral step as a limited proportional error; determining an integral error as a limited sum of the integral step and a preceding unbound integral error; determining an error as the product of the integral error, the proportional error, and a gain factor; and generating a control signal to cause the inverter to output a motor voltage to drive the motor and maintain the pressure about the pressure setpoint.

The purpose of the present invention is to provide an air compressing apparatus capable of establishing a sufficient air-filling rate while reducing noise at the initiation of operations. To solve this problem, in the present invention, the air compressing apparatus comprises a compressor body that compresses air, a motor that drives the compressor body, an inverter that controls the rotation speed of the motor, a control circuit connected to the inverter, and a pressure sensor that detects the pressure of air compressed in the compressor body, wherein the control circuit controls operation of the compressor body by operating at a low speed activation mode that operates the compressor body at a low speed rotational frequency lower than a maximum rotational speed when the air compressing apparatus is activated, and on the basis of a pressure value detected by the pressure sensor and elapsed time from activation, switching from the low speed activation mode to a normal operating mode that operates at variable frequencies including a maximum rotational frequency.