Abstract: A kernel for enforcing a hierarchical invocation structure prevents upcalls by executing kernel operations during each invocation of code unit of application by another code unit. Kernel operations determine the priority of the invoking unit of code based on the hierarchy of the invocation structure. Only invocations by either lower priority units, or the unit itself are allowed. Once invoked, the kernel operates to establish a priority for the invoked task. The kernel provides various event mechanisms to provide for priority based preemption concurrently with the enforced invocation structure, thus allowing the handling of asynchronous events in a multitasking environment. The event mechanisms allow a unit of code to signal the occurrence of a condition, which may be captured by other code units. The kernel determines the proper code unit for responding to the condition, and employs scope rules to further define the handling operation.

Abstract: A vascular assist device which maintains a static graduated pressure as the minimum pressure at all times during use. At least two inflatable chambers which wrap around selected portions of a limb apply elevated pressure to selected portions of a limb to disgorge blood therefrom. The inflatable chambers also apply static pressure which is graduated from distal to proximal along selected portions of a limb, such as from the ankle to the hip. A separate inflatable foot chamber can be included and is not necessarily utilized in conjunction with the compression phases for the ankle, calf, or thigh inflatable chambers. A desired pressure level is generated and maintained in a pressure accumulator, and a pressure regulator and regulator valve control the pressure in the inflatable chambers. The inflatable chambers between the ankle and hip are inflated to a predetermined and uniform dynamic pressure which is maintained in the inflatable chambers for a predetermined amount of time.

Abstract: An improved extruded track lighting system having a support rail with a pair of cylindrical conductors exposed on an insulating extrusion. Various light fixtures having clamp brackets may be easily snapped on and off the support rails. Each of the clamp brackets includes a pair of parallel flat legs having gripping portions to conform with exposed cylindrical conductors on either side of the support rail. Alternatively, the clamp brackets may include outwardly extending tangs which can be forced between a pair of conductors on the interior of the extrusion. The brackets are simply swiveled with respect to the rail to couple or remove. No independent fastening means are needed to tighten the clamp brackets to the support rails. In one embodiment a light fixture includes a single swivel axis, while in another embodiment a light fixture includes a universal joint providing two orthogonal swivel axes between the lamp and the support rail.

Abstract: A method of producing an extruded plastics foam of enhanced physical strength includes intimately mixing a blowing agent incorporation CO.sub.2, the major portion of which is a natural gas, in a plastics resin melt to form a homogenous resin mix, and extruding the resin mix through an exit die into a region of lower pressure. At the point of extrusion out of the exit die, the temperature of the resin mix is adjusted so that it is below the critical temperature.

Abstract: A composite board which includes a core and inner and outer surface layers, said core and surface layers each including cellulose material and a cured resin binding said cellulose material together, wherein the resin in the core of the composite is an acid setting resin and the core includes a low steam volatile weak acid in an amount of between 2 to 8% by weight to the dry weight of the cellulose material in the core.

Abstract: Sheeting in the form of fibre board comprising cellulose fibres and a thermosetting resin in an amount sufficient to bond the cellulose fibres together when compressed the sheeting having a density of 1100 kg/m.sup.3 or greater. The method of manufacturing the sheeting comprises the steps of combining the cellulose fibres and thermosetting resin together and forming a mat or web, and thereafter heating and compressing the mat or web to a density of at least 1100 kg/m.sup.3.

Abstract: A silicon carbide ceramic body having a high degree of lubricity as a result of large graphite inclusions in the body. The graphite inclusions have an average size of at least about 100 micrometers. The graphite-loaded silicon carbide component is preferably formed by spray drying graphite particles independent of the silicon carbide, blending the graphite agglomerates and silicon carbide to form a raw batch, forming the raw batch into a green body, and sintering the green body to produce a graphite-loaded silicon carbide ceramic body having good density and good strength.

Abstract: A plastics container includes a neck and an outlet opening, a container body and a base; the base comprising a plurality of circumferentially spaced legs, each leg terminating in a foot portion on which the container is adapted to stand wherein each leg is provided with at least one longitudinally inwardly extending crease. Preferably each leg is provided with a single crease which extends downwardly and inwardly at least to the extent necessary so to substantially divide the foot portion of each leg into two separate support portions on which the container is adapted to stand.

Abstract: A silicon carbide ceramic body having a high degree of lubricity as a result of large graphite inclusions in the body. The graphite inclusions have an average size of at least about 100 micrometers. The graphite-loaded silicon carbide component is preferably formed by spray drying graphite particles independent of the silicon carbide, blending the graphite agglomerates and silicon carbide to form a raw batch, forming the raw batch into a green body, and sintering the green body to produce a graphite-loaded silicon carbide ceramic body having good density and good strength.

Abstract: Reinforced concrete building products are manufactured using a two-part mould (2, 3), the two parts being hinged together about an axis (4) which is adjacent an edge of each part-mould (2, 3). Glass-reinforced concrete is applied to each part-mould (2, 3), then allowed to partly dry before the part-moulds (2, 3) are folded together to produce a finished product.

Abstract: An apparatus and a method are provided for vascular examination of a limb by inflation of a flexible-walled pneumatic chamber mounted to the limb and calibration of the pressure within the chamber in units of volume. Calibration is accomplished by inflating the chamber to a preselected reference pressure, altering the volume of the chamber, and measuring the calibration pressure at the altered volume. The calibration pressure is stored for use off-line in scaling subsequent pressure fluctuations as changes in limb volume.

Abstract: A fluid pump is disclosed herein having a frame defining an internal pumping chamber in combination with a flexible diaphragm. A top ring retains the diaphragm in position on the frame and includes a central area carrying an actuation mechanism for cyclically maintaining the fluid pumping operation in the pumping chamber. Inlet and outlet valves are disposed in the frame and interconnected with the pumping chamber to complete the pump. The actuation mechanism includes a motor-driven eccentric cam coupled to the central diaphragm area with top surface attachment only.

Abstract: A tamper indicating closure member for containers is disclosed having a cap member with a top wall and a peripheral skirt integral therewith. Also included is a separable band portion interconnected to the skirt by a frangible bridge element. The band portion is capable of coacting with an axially inclined ramp surface defined by a circumferential bead on the neck, thereby substantially preventing transverse movement of the closure band portion relative to the container neck.

Abstract: A two part closure for an open necked container is provided in which a cover member which may be of metal extends over the opening and a holding member which may be of plastic extends over the container neck.