Disclosed is a sheath delivery system that uses a continuous flow of sheath fluid into a pressurized internal reservoir that substantially matches the outflow of sheath fluid through the nozzle of a flow cytometer. A substantially constant level of the sheath fluid is maintained. If the sheath fluid level falls below a desired level, or goes above a desired level, a dampened control system is used to reach the desired level. In addition, air pressure in the pressurized internal container is controlled so that an external sheath container can be removed and refilled with additional sheath fluid without stopping the sheath delivery system 100. Differences in pressure are detected by a droplet camera, which measures the droplet breakoff point to determine the pressure of the sheath fluid in the nozzle.

A liquid chromatography monitoring system comprises a computer or electronic controller comprising computer-readable instructions operable to: (a) draw a fluid into a syringe pump; (b) configure a valve so as to fluidically couple the pump to either a fluidic pathway through a fluidic system or to a plug that prevents fluid flow; (c) cause the syringe pump to progressively compress the fluid therein or expel the fluid to the fluidic pathway, while measuring a pressure of the fluid; (d) determine a profile of the variation of the measured pressure; (e) compare the determined profile to an expected profile that depends upon the fluid; and (f) provide a notification of a sub-optimal operating condition or malfunction if the determined profile varies from the expected profile by greater than a predetermined tolerance.

A hydronic distribution system includes self-regulating valves networked together and operable to share valve temperature and valve position information with a microprocessor or other type of controller. The microprocessor runs one or more algorithms that process the temperatures and positions of the valves and then computes a desired speed for one or more variable speed pumps within the system. Controlling the pumps to operate at the desired speed and still maintain the correct amount of process fluid flow needed by the system reduces the overall energy use of the hydronic distribution system, saves on the operational lives of the pumps, and increases system efficiency.

A pump cassette comprising an assembly of a middle plate interposed between a top plate and a bottom plate is disclosed. The assembly forms the cassette and defines a plurality of fluid flowpaths, at least one diaphragm pump, at least one diaphragm valve, and at least one mixing pod. In some embodiments, the cassette includes one or more sensing features for permitting the sensing of various properties of a subject media. In certain such embodiments, the bottom plate comprises one or more sensor ports configured to hold one or more sensor probes that extend through one or more sensor element apertures in the middle plate.

A particle focusing system includes an inlet; an inertial focusing microchannel disposed in a substrate and connected to the inlet; and a pressure/flow source configured to drive a particle-containing fluid through the inertial focusing microchannel, where the inertial focusing microchannel includes a side wall having an irregular surface. The side wall includes a first irregularity protruding from a baseline surface away from a longitudinal axis of the inertial focusing microchannel. Alternatively or additionally, the first irregularity and the baseline surface form an angle more than or equal to 135 degrees. The inertial focusing microchannel may have a substantially rectangular cross-section having a height and a width, and a ratio of height to width is approximately 5:4 to 4:1. The system may also include a downstream expanding region having a side wall, where the side wall has a stepped surface.

A pump cassette is disclosed. The pump cassette includes a housing having at least one fluid inlet line and at least one fluid outlet line. The cassette also includes at least one reciprocating pressure displacement membrane pump within the housing. The pressure pump pumps a fluid from the fluid inlet line to the fluid outlet line. A hollow spike is also included on the housing as well as at least one metering pump. The metering pump is fluidly connected to the hollow spike on the housing and to a metering pump fluid line. The metering pump fluid line is fluidly connected to the fluid outlet line.

A transfer pump has a pump base with a pump chamber and an output port in the top surface of the pump base. A riser tube extends from the outlet and terminates at a launder having a first end juxtaposed the riser tube, an open top, and a bottom having a launder opening. This structure enables the movement of molten metal out of a vessel with relatively little turbulence.

Methods for managing a hazardous fluid within a pipeline and within a storage facility, and in particular for managing a potential or actual leak of the hazardous fluid. Such methods include the detection of such an event by one or more sensors, and the containment and the mitigation of the event.

Automated control mechanisms and methods for controlling fluid flow in a hemodialysis apparatus are described. The methods can involve a controller receiving information from a pressure sensor in a control chamber of a reciprocating diaphragm-based blood pump and causing the application of a time-varying pressure waveform on a diaphragm of the blood pump during a fill-stroke of the blood pump. The controller can be configured and programmed to monitor a pressure variation in the control chamber measured by the pressure sensor and to compare the measured pressure variation to a pre-determined value. Based on such comparison, the controller can initiate a procedure to pause or stop a dialysate pump of the hemodialysis apparatus if the magnitude of the measured pressure variation deviates from the pre-determined value.

Nanomechanical, nanoelectromechanical, and other molecular-scale pump assemblies are described. In certain embodiments, the pump assembly includes a cavity. The cavity includes a plurality of nanofilaments, a surface proximate at least one of the nanofilaments, a fluid flow path, and an opening. Molecules of a fluid that flows from the opening through the cavity along the fluid flow path collide with the surface or one or more of the nanofilaments such that the molecules are accelerated along the fluid flow path. A molecular-scale pump assembly includes a plate defining a plurality of openings, and a plurality of cantilevered molecular-scale beams positioned over each opening. In certain embodiments, molecules of a fluid are accelerated through the opening by asymmetric oscillation and in other embodiments charges are guided along a conductive channel by asymmetric collisions.