Abstract: A memory controller component of a memory system stores memory access requests within a transaction queue until serviced so that, over time, the transaction queue alternates between occupied and empty states. The memory controller transitions the memory system to a low power mode in response to detecting the transaction queue is has remained in the empty state for a predetermined time. In the transition to the low power mode, the memory controller disables oscillation of one or more timing signals required to time data signaling operations within synchronous communication circuits of one or more attached memory devices and also disables one or more power consuming circuits within the synchronous communication circuits of the one or more memory devices.

Abstract: An electroporator for high-throughput electroporation is constructed with a well plate in which each well has internal electrodes that extend beyond the opening of the well to form contact areas, either as horizontal platforms extending laterally from the well rims or as extended heights of thin electrode plates. The electroporator also includes a lid that contains circuitry and electrical contacts that mate with the exposed contact areas in the well plate. The interchangeability of lids allows the wells to be shocked according to different protocols.

Abstract: A file for storing and displaying cards is disclosed. The card file consists of a base, a cover, and a tray, the cover being pivotally attached to the base and the tray being slidably disposed with respect to the cover and pivotally coupled to the base. The tray is attached to the base in such a way that when the cover is opened, the tray pivots downwardly, thereby presenting the cards at an angle. The weight of the address cards keeps the device in either the open or closed orientation chosen by the user. The card file in accordance with the present invention can be suitably adapted to display a picture or time keeping instrument in the face of the cover, so that when the cards are concealed, the card file serves as an office accessory.

Abstract: A geosynthetic clay liner with a low permeability or controlled permeability intermediate sheet is provided. The liner includes two outer sheets with two layers of bentonite and an intermediate sheet disposed therebetween. The intermediate sheet may be rippled or deformed to enhance the structural stability of the liner. The intermediate sheet may be chosen from a material with low or ultra-low permeability characteristics or may be chosen from a material with controlled or directional permeability characteristics.

Abstract: A cutter assembly for a rotary drag-type drill bit includes a preform cutting element comprising a front facing table of polycrystalline diamond bonded to a tungsten carbide substrate, the cutting element being mounted on a tungsten carbide carrier which is received in a socket in the body of the drill bit. The carrier comprises a sector-shaped portion of a disc, and the cutting element is bonded to one of the straight edge surfaces of the carrier, adjacent the apex of the sector shape. The side surfaces of the carrier taper inwardly, as viewed in cross-section, as they extend towards the curved edge surface of the carrier.

Abstract: A rotary drill bit comprises a bit body, a shank for connection to a drill string, a plurality of cutters mounted on the bit body, and a gauge structure which extends around the bit body and, in use, engages the surrounding formation forming the sides of the borehole being drilled. At least a section of the gauge structure is rotatably mounted on the bit body so that, in use, the gauge section may remain substantially non-rotating in engagement with the formation while the bit body rotates relative to it. The external surface of the non-rotating gauge section may be formed with longitudinal grooves to permit the flow of drilling fluid past the gauge section to the annulus. Alternatively the outer surface of the gauge section may be generally cylindrical, in which case internal passages are provided through the gauge section, and/or the bit body, for the flow of drilling fluid past the gauge section to the annulus.

Abstract: A rotary drill bit for drilling holes in subsurface formations comprises a bit body having a shank for connection to a drill string, a number of circumferentially spaced blades on the bit body each extending outwardly away from the central axis of rotation of the bit, a number of cutters mounted side-by-side along each blade, and a passage in the bit body for supplying drilling fluid to the surface of the bit for cleaning and cooling the cutters. The blades comprise alternating primary and secondary blades. The cutters on the primary blades are primary cutters which are located at different radial distances from the bit axis so as to define a cutting profile which, in use, covers substantially the whole of the bottom of the bore hole being drilled. At least the majority of the cutters on the secondary blades are secondary cutters each of which is located at substantially the same radial distance from the bit axis as an associated primary cutter on the preceding primary blade.

Abstract: A rotary drill bit comprises a bit body having a shank for connection to a drill string, a plurality of cutters mounted on the bit body, each cutter having a cutting face, and means for supplying drilling fluid to the surface of the bit body to cool and clean the cutters. At least some of the cutters are lateral cutters located to act sideways on the formation being drilled, and the cutting faces of such lateral cutters are orientated to exhibit negative side rake and negative top rake with respect to the surface of the formation. The negative side rake angle is greater than 20.degree. and may be as much as 90.degree., and the negative top rake angle is also more than 20.degree.. A single cutter may include two cutting faces at different negative side rake angles, e.g.

Abstract: A preform cutting element, for use on a rotary drill bit, includes a facing table of polycrystalline diamond bonded to a tungsten carbide substrate, a cutting edge being formed by part of the peripheral surface of the facing table. The rear surface of the facing table is integrally formed with a plurality of spaced elongate ribs which project into the substrate, at least the majority of the ribs being located in the vicinity of the cutting edge. The ribs may intersect the cutting edge and extend only part way across the facing table from the cutting edge. The ribs may vary in width and/or depth.

Abstract: A preform element, such as a cutting element for a drag-type drill bit, includes a facing table of superhard material having a front face, a peripheral surface, and a rear surface bonded to a substrate which is less hard than the superhard material. The rear surface of the facing table is integrally formed with a plurality of ribs which project into the substrate and extend in directions outwardly away from an inner area of the facing table towards the peripheral surface thereof.

Abstract: A geosynthetic clay liner with a low permeability or controlled permeability intermediate sheet is provided. The liner includes two outer sheets with two layers of bentonite and an intermediate sheet disposed therebetween. The intermediate sheet may be rippled or deformed to enhance the structural stability of the liner. The intermediate sheet may be chosen from a material with low or ultra-low permeability characteristics or may be chosen from a material with controlled or directional permeability characteristics.

Abstract: A utility cart (10) includes a base support member (11) which is supported on wheels (17). Side walls (12, 13) are removably positioned on the base support member (11) by inserting downwardly extending projections (25) into slots (24) formed in the base support member (11). Front and rear end walls (14, 15) have slots (28) therein to engage flanges (30) formed on the side walls (12, 13) to interlock the end walls (14, 15) to the side walls (12, 13). The bottoms of the end walls (14, 15) are also provided with downwardly extending projections (25) which are received in additional slots (24) formed in the base support member (11).