Abstract: An index monitoring system for selectively removing an index, where the index is used in a computerized database search. An example method implemented by the system includes displaying a list of indexes on the display device; providing an indication of an index usage criterion associated with each of two or more of the indexes, where the index usage criterion is derived at least in part from prior execution of a particular database query statement; displaying on the display device an indication of the particular database query statement; and optionally accepting a signal from a user-input device to remove an index.

Abstract: An index monitoring system for selectively removing an index, where the index is used in a computerized database search. An example method implemented by the system includes displaying a list of indexes on the display device; providing an indication of an index usage criterion associated with each of two or more of the indexes, where the index usage criterion is derived at least in part from prior execution of a particular database query statement; displaying on the display device an indication of the particular database query statement; and optionally accepting a signal from a user-input device to remove an index.

Abstract: An adaptive overload system for controlling the amount of traffic processed by a network access controller is described for a network access controller arranged to control a plurality of network access points. Each network access point provides traffic with access to the communications network and the system comprises determining at the network access controller if an overload condition exists, and if so, generating at least one global constraint to restrict the rate at which a network access point admits said traffic to the communications network. The controller then multicasts at least one global traffic constraint to one or more of said plurality of network access points. Each network access point receiving the global constraint then processes the global traffic constraint to determine a plurality of local constraint conditions.

Abstract: Liquid chromatography apparatus includes a solvent mixer which comprises a tapering or conical enclosed chamber (21) having an inlet (22) adjacent its larger end and an outlet tube (23) which extends through the base of the chamber (21) and has its open end adjacent to the apex (25) of the chamber. The mixing action takes place as the shape of the chamber (21) and position of the inlet (22) causes the liquid to shear in layers as it rotates up the chamber wall from the larger to the smaller end. The shear causes a good mixing action without requiring any movable devices within the chamber to stir the liquid.

Abstract: Liquid chromatograph apparatus includes a solvent proportioning valve arrangement which comprises a block (21) having four inlet passages and a number of outlet passages communicating with a common outlet passage (28) and an outlet port (29) to which a tube may be attached for connection to the inlet of a pump. Each inlet passage (30) is connected to a solvent source by a tube (43) which passes into a chamber (32) mounted on the block (21). The chamber (32) is air-tight and contains a quantity of gas or air to absorb shock waves in the liquid when the diaphragm (26) blocks the inlet (30) and outlet (27) passages.

Abstract: Liquid chromatograph apparatus includes a solvent mixer which comprises a tapering or conical enclosed chamber (21) having an inlet (22) adjacent its larger end and an outlet tube (23) which extends thrugh the base of the chamber (21) and has its open end adjacent to the apex (25) of the chamber. The mixing action takes place as the shape of the chamber (21) and position of the inlet (22) causes the liquid to shear in layers as it rotates up the chamber wall from the larger to the smaller end. The shear causes a good mixing action without requiring any movable devices within the chamber to stir the liquid.