摘要:
Disclosed are systems and methods that include a sampling device, a chromatographic column, and a transfer line through which a fluid containing analytes to be measured are communicated from the sampling device to the column. The pressure at which the fluid containing the analytes is applied at the inlet of the transfer line is adjusted as the temperature of the column increases in accordance with certain relationships in order to maintain a substantially constant flow rate or velocity for the fluid exiting the column. In this way, the system compensates for changes in the viscosity of the fluid flowing through the column that result from changes in the column temperature.
摘要:
A system for controlling the flow rate into a chromatographic column is disclosed generally comprising communicating a fluid to the column through a transfer line, measuring the inlet pressure, determining the outlet pressure, and adjusting the applied pressure until the inlet and outlet pressures produce a desired flow rate for the transfer line outlet. In certain embodiments, the applied pressure is adjusted by controlling a proportional valve. In some embodiments, the outlet pressure is determined by measuring the pressure drop across the transfer line and calculating the outlet pressure from the measured inlet pressure and the pressure drop.
摘要:
Disclosed are systems and methods that include a sampling device, a chromatographic column, and a transfer line through which a fluid containing analytes to be measured are communicated from the sampling device to the column. The pressure at which the fluid containing the analytes is applied at the inlet of the transfer line is adjusted as the temperature of the column increases in accordance with certain relationships in order to maintain a substantially constant flow rate or velocity for the fluid exiting the column. In this way, the system compensates for changes in the viscosity of the fluid flowing through the column that result from changes in the column temperature.
摘要:
A compact tracking coupler includes a plurality of ridged waveguides arranged circumferentially around a circular waveguide wherein long sides of the ridged waveguides extend circumferentially and short sides of the ridged waveguides extend radially relative to the circular waveguide. The compact tracking coupler can be especially useful in a multi-band antenna feed.
摘要:
Wireless terminals, systems, and methods use interlaced diplexers. A first diplexer can provide a first pair of bands separated by a first separation band, and a second diplexer can provide a second pair of bands separated by a second separation band. The first separation band and the second separation band can overlap. Transceivers (comprising transmitters and receivers) can be coupled to the diplexers to provide frequency-division duplex communications using one or both of the pairs of bands.