Abstract: A new depressant for use in enhanced separation of polymetallic sulphides is described. The depressant agent is used in conjunction with conventional collector agents and forthing agents in the flotation separation of copper, nickel, lead, zinc sulphides by depressing iron sulphides such as pyrrhotite, pyrite and marcasite in the tailing. The depressant consists of a cross-linked starch chemically combined with a polyacrylate and sugar free lignin sulphonate.

Abstract: A piping arrangement for two or three Claus catalytic converters and condenser sets used for recovering sulphur from gas streams containing hydrogen sulphide. One of the converters is operated at a sub-dewpoint temperature while the other(s) is(are) operated at a higher temperature for regenerating the catalyst. The piping arrangement includes two four-way switching valves that allow an influent gas stream to be switched between the two converters without leaving stagnant gas in the piping.

Abstract: A scum skimming device is disclosed for use in a waste treatment system having a circular sedimentation tank. Such tanks typically have a central waste liquid inlet pipe having inlet ports and an outlet weir around the periphery to maintain the waste liquid level in the tank at a predetermined desired level. The scum skimming device consists of at least one scum skimming blade which is biased into a position partly above and partly below the liquid surface and which sweeps the surface of the tank, the blade being supported from a bottom sludge rake by articulated support posts. The device also consists of a generally helical blade extending to the tank periphery and being positioned with a portion of the helical blade below the waste liquid level when the tank is in use, and a drive means for rotating the generally helical blade.

Abstract: A heat exchanger having two or more tube bundles extending parallel to the shell with a central longitudinal space between the tube bundles. The tube bundles have a longitudinal axis is symmetry in such space. The tubes in each bundle are laid out in concentric arcs. The arcs of each bundle have a common center of curvature which is displaced from the axis of symmetry and also from the center of curvature of each other tube bundle. The corners between the tube bundles may contain fill-in tubes. This allows compact tube packing while preserving relatively uniform fluid velocities.

Abstract: A variable volume terminal unit for an air handling system includes a duct having an air by-pass outlet in its top wall, and a deflector blade that can be moved between a "straight through" position in which the by-pass outlet is closed, and a position in which at least some of the air flowing through the duct is deflected through the by-pass outlet. The deflector blade is of an angled shape selected so that, in the deflecting position, the blade presents a substantially symmetrical surface to the incoming air, while in the straight-through position, the blade closes the by-pass outlet.

Abstract: During the oxidation or photooxidation of contaminants in wastewater, a gaseous oxidizing agent is introduced into a wastewater steam. The mixed stream is passed through a liquid ring compressor prior to its entry into an ultraviolet light reactor. In an alternate embodiment, the oxidizing agent and the wastewater are each introduced into the liquid ring compressor.

Abstract: A method of treating a liquid effluent or groundwater containing organic contaminants is provided. The liquid effluent or groundwater containing the organic contaminants is contacted with hydrogen peroxide and transition metal ions. The hydrogen peroxide and transition metal ions are present in effective amounts based on the concentration of the organic contaminants in the liquid effluent or groundwater. The liquid effluent or groundwater is then irradiated with UV light having a poly- chromatic output between about 200 to 400 nm to decompose the organic contaminants. The ratio of hydrogen peroxide to transition metal ions is selected so as to favor the absorption of UV light by the hydrogen peroxide in the irradiation step.

Abstract: The present invention provides a method of compacting a sheet article, for example an article of underwear, to produce a stable, substantially rigid, compacted article. This reduces space required for storage and distribution and facilitates packaging of the article. Compaction is effected by placing the article, or a plurality of articles, in a mould cavity, and subjecting them to elevated pressure for a certain time. The pressure and time are selected to compact the article sufficiently to form the stable, rigid body, but simultaneously not being so great as to either damage the article or compact it so much that water or other liquid is required to recover the article from its compacted state to its original state.

Abstract: An explosive composition comprising an explosive mixture of ammonium nitrate and fuel oil. The fuel oil is selected to provide an oil separation sufficiently low so that the explosive is detonatable. The fuel oil is also selected such that the viscosity of the explosive is sufficiently low so that the explosive may be loadable into a borehole. The explosive is substantially free of tackifying agents.

Abstract: This invention relates to a femoral insert for a hip joint prothesis for use in a femur that has been cut across the femoral neck to form a cut surface. The insert includes a stem having a proximal end attachable to a generally spherical head member, a distal end and a bend located therebetween. A collar is provided for transferring axial loads from the stem to the femur at the cut surface. A sleeve is secured within the femur, the sleeve having a central orifice for receiving the stem. The sleeve permits the stem to move axially but restricts the stem from any rotational or toggling movement. The sleeve is secured into the femur below the cut surface.

Abstract: Material transfer apparatus comprises a vacuum source for drawing material entrained in a first fluid stream through an inlet conduit into a separation chamber, a valve for transferring material collected in the chamber to an inlet of a first section of an outlet conduit and a pressure source for pushing material entrained in a second fluid stream from the valve and through the outlet conduit. The outlet conduit carries the material entrained in the second fluid stream from the air lock to an elevated material outlet, the conduit comprising the first section and further second and third sections. The substantially rigid first section leads from the air lock to a flexible, curved second section, and a substantially rigid third section leads from the second section to the elevated material outlet. The first and third sections are connected by a hinge member including a locking device for fixing the angle between the first and third sections and permitting the height of the material outlet to be varied.

Abstract: Apparatus is described for the pyrolysis of coal comprising a pyrolysis tower through which crushed coal and hot gas are counter-currently passed. The tower enables a controlled temperature profile to be maintained in the tower, and contains inner appurtenances which define cascading passageways to promote heat exchange and mixing of the coal with the hot gas. The coal volatiles are carried out of the top of the tower by the gas. The pyrolysis tower may be conjoined with a gasifier so as to most directly utilize the char residuals remaining after pyrolysis of the coal while they are still hot to more efficiently produce a hot synthesis gas, to be used to perform thermal pyrolysis in the tower.

Abstract: Lavage apparatus comprises lavage fluid supply apparatus, a first catheter having a distal end for positioning in the uterus of an animal and a proximal end for communication with the lavage fluid supply, a pair of bilateral catheters connected to the proximal end of the first catheter for extending into respective horns of the uterus, and catheter locating means for locating the catheters in the uterus. The first catheter defines respective supply and drain lumens. The bilateral catheters each define respective lumens for fluid communication between the supply lumen and the interior of the respective uterine horn. The lavage fluid supply apparatus may include a pump for supplying lavage fluid under pressure. The supply may also include a lavage fluid storage tank for containing a volume of fluid, and a heater to maintain the temperature of the stored fluid within a predetermined range.

Abstract: A display stand has a base having a front and a rear, and a back support extending up from the rear of the base. Stops are provided at the front of the base. Means are provided for bracing the base and the back, in conjunction with an object, to form a stable triangulated structure. The bracing comprises a frictional finish on the stand for gripping an object and a horizontal support surface, with resilient stiffening elements between the base and the back and between the stops and the base.

Abstract: The clipping circuit has a voltage reference and a transconductance connected to a voltage input. The input is connected through the transconductance to an output resistor. The voltage output is taken between the output resistor and the transconductance. The voltage reference has a third current source feeding a diode connected transistor and a resistor. A second current source feeds into the resistor after the transistor. The base of the diode connected transistor is connected to the voltage input. The transconductance has a second transistor whose base is connected to the voltage input, collector sinks current from a fourth current source and emitter feeds current to a resistor. A first current source feeds current to a third transistor and to a current mirror. The base of the third transistor is connected between the fourth current source and the collector of the second transistor.