Abstract: Wave soldering method and apparatus for fluxing a substrate in a low oxygen containing atmosphere, preheating the fluxed substrate at least partially in a non-low oxygen containing atmosphere, and soldering the preheated substrate in a low oxygen containing atmosphere.

Abstract: This arterial blood monitoring system takes advantage of the basic statistical property that arterial blood contains a plurality of dominant absorbers, whose measured light absorption spectra appear as a constant over a short interval of time. By measuring the transmitted light as it varies with arterial pulsation at selected wavelengths of light, over a common light path, the relative amount of these dominant absorbers in the arterial blood can noninvasively be determined. To ensure the common light path, a sandwich construction light detector is used.

Abstract: A method of soldering for surface mounting of a printed circuit board, which comprises performing reflow soldering with a rosin-based cream solder in a special atmospheric gas comprising an inert gas such as N.sub.2, Ar or He and containing about 10,000 ppm or less of oxygen and 0.5-3.0% of moisture is disclosed.

Abstract: In a process integration, particularly with a blast furnace, low grade fuel gas produced by the furnace is compressed and moisturized. The moisturized fuel is burnt using a major part of a compressed air stream to support its combustion. The resulting combustion gases are then expanded with the generation of power. The minor part of the air is separated into oxygen and nitrogen. Oxygen is used in the blast furnace.

Abstract: A feed gas stream containing at least 60% by volume of hydrogen sulphide is burnt in a first combustion region to form water vapor and sulphur dioxide. Oxygen is employed to support combustion is the region. Thermal reaction then takes place in a thermal reaction region between hydrogen sulphide and sulphur dioxide to form sulphur vapor and water vapor. The resulting gas mixture is then cooled and sulphur vapor is extracted in a condenser. The gas mixture then passes into a second combustion region in which a further portion of the hydrogen sulphide is burnt in the presence of oxygen to form further sulphur dioxide and to adjust the mole ratio of hydrogen sulphide to sulphur dioxide to about 2:1. Further reaction between hydrogen sulphide and sulphur dioxide may be conducted in a further thermal reaction region and in catalytic reactors with further sulphur extraction in further condensers.

Abstract: Cyanide present in aqueous streams, such as effluents from electroplating and gold mining operations is reduced or eliminated by contacting the cyanide-containing stream with oxygen and carbon dioxide in the presence of ferrous ions, nickelous ions or cobaltous ions. The oxygen may be provided by air or oxygen and the contacting is carried out until the pH of the aqueous stream is reduced to a value in the range of about 6 to 8 and preferably 6.5 to 7.5.

Abstract: A method of separating air in which a compressed air stream is divided into first and second subsidiary streams. The first subsidiary air stream is cooled by heat exchange to a temperature suitable for its separation by rectification and introduced into the higher pressure stage of a double rectification column. The second subsidiary air stream is further compressed and then at least part of it is cooled by heat exchange to a first intermediate temperature below ambient temperature but above those temperatures at which the double rectification column operates. The thus cooled second subsidiary air stream is expanded in a first expansion turbine and is withdrawn therefrom at a second intermediate temperature below the first intermediate temperature but above those temperatures at which the double rectification column operates. After withdrawal, the second subsidiary air stream is introduced into a second expansion turbine where it is further expanded.

Abstract: This invention relates to the extraction of metal values from metal bearing ores. More specifically, according to the invention, in a process for extracting metal values from metal bearing ores, there is provided a method of enhancing metal value recovery from the ore. The method comprises introducing, upstream of a metal recovery section 26, a gaseous or liquid agent capable of promoting recovery of the metal values from the ore, into the gland service water from at least one of the pumps 30. The introduction of the gaseous or liquid agent is by means of an arrangement 35. The agent may be oxygen.

Abstract: Apparatus and method for metering the flow rate of a fluid through a conduit in which a low inertia transducer is placed between the inlet and outlet, the transducer having a substantially cylindrical housing and a rotatable element concentric to the housing which together define an arcuate pathway for the flow of the fluid. A pressure sensor generates a pressure error signal corresponding to a change in pressure between the inlet and outlet and translates the same into a detectable signal which is used to change the speed of the rotatable element to reduce the differential pressure between the inlet and outlet.

Abstract: A process for the preparation of highly purified optical isomers of desflurane, i.e. 2-(difluoromethoxy)-1,1,1,2-tetrafluoroethane, is described wherein the highly purified opposite optical isomer of iso-flurane is reacted with bromine trifluoride in the cold, preferably in the presence of a solvent. A preferred solvent is bromine. The highly purified positive isomer of desflurane is advantageous over the negative isomer or the racemate.

Abstract: A combination of a protective tube and guidewire straightener used to locate a guidewire into a patient for introducing a catheter into a patient's bloodvessel. The guidewire straightener has a flexible end that flexes inwardly to lock the guidewire in a fixed position within the protective tube. The protective tube has an opening so that the guidewire straightener can be rotated by the user to align the flexible end with the opening to allow the flexible end to be released outwardly to unlock the guidewire so that it can move within the protective tube. A further opening in the shape of an elongated slot is formed in the protective tube and which allows the user to move the guidewire to advance or retract the guidewire from the protective tube. The positioning of the components are such that a user, by the manipulation of only one hand, can unlock the guidewire from it's fixed position and advance it into the patient, leaving the user's other hand free to carry out other operations.

Abstract: The present invention is directed to a fiber optic sensor for analyzing pH which comprises (a) a fluorescence-based fiber optic sensor; and (b) a fluorescent dye-polymeric matrix in contact with the sensor, wherein the fluorescent dye is seminaphthorhodaflor-1-isothiocyanate, the polymer is a hydrogel selected from the group consisting of polyhydroxyethylmethacrylate, polyvinylpyrrolidone, cellulose, dextrans, and polysaccharides, and the dye is chemically bonded to the polymer.

Abstract: An improved process is provided for the production of a partial oxidation product by the vapor phase reaction of a hydrocarbon with substantially pure oxygen in the presence of a suitable catalyst. In the improved process, the partial oxidation product is removed, carbon dioxide and excess carbon monoxide, present in the reactor effluent as by-products, are also removed and the remaining gaseous effluent, comprised mainly of carbon monoxide and unreacted hydrocarbon, is recycled to the reactor. The concentration of carbon monoxide throughout the system is maintained sufficiently high to prevent the formation of a flammable mixture in the reactor or associated equipment.

Abstract: Oxygen is separated from air by pressure swing adsorption in plant 2. The oxygen is passed through an ozone generator 4. The resulting ozonated oxygen is passed upwardly through a contactor 6 countercurrently to the flow of a side stream of water to be treated with ozone. The side stream containing dissolved ozone flows from the contactor 6 to a mixer 8 in which it is mixed with a main stream of water. The effluent gas from the contactor 6 contains air displaced from the water and undissolved oxygen. It is divided into two parts. One part flows to the pressure swing adsorption plant 2 and is separated therein with the air. The other part is dried by temperature swing adsorption in drier 20 and the resulting dried gas is ozonated in the ozone generator 4 with the oxygen from the plant 2.

Abstract: A liquid cryogen is supplied, preferably by means of a reservoir, to a dispensing tube so that the liquid cryogen tends to flow from the dispensing tube. A heating coil wrapped around the dispensing tube heats the dispensing tube so that the liquid cryogen undergoes nucleate boiling within the dispensing tube to form a vapor block, and thereby at least impede the liquid cryogen from flowing from the dispensing tube. Flow is reestablished within the dispensing tube by terminating the heating of the dispensing tube, e.g. by turning off electrical power supplied to the heating coil. The heating of the dispensing tube can be sufficient to stop the flow of liquid cryogen. Additionally, the dispensing tube can be cyclically heated by a timing circuit connected to the heating coil. Such cyclical heating is used to throttle the flow of the liquid cryogen from the dispensing tube.

Abstract: The present invention provides a capacitance pressure transducer of increased thermal and mechanical stability and thus performance over prior art designs. A cell formed by a cell housing containing a plane parallel capacitor plate and an inlet tube is connected to an outer protective cover solely by the inlet tube. The cell housing is contained within an air tight environmental enclosure (also supported solely by the inlet tube) of sufficient rigidity as to isolate the cell housing from changes in atmospheric pressure. The plane parallel capacitor plate is formed by a circular diaphragm peripherally connected to the tension ring and an electrode disk located within the tension ring.

Abstract: A method and apparatus in which a container is provided with a refrigeration facility. A holder for holding carbon dioxide snow is placed within the interior of the container so that the carbon dioxide snow is in gaseous communication with the interior of the container. The holder or a continuous wall region of the holder, constituting about 15% of the total wall area of the holder, is fabricated of a flexible material that is at least substantially impermeable to the carbon dioxide snow and permeable to gaseous carbon dioxide. Additionally, a combination container and holder is disclosed along with a combination holder and support structure. The support structure is attachable to the container to support the holder so that the carbon dioxide snow is in gaseous communication with the interior of the container.

Abstract: A liquid-vapour contact column includes an array of vertically spaced horizontal liquid-vapour contact trays having generally circumferential sides and arrangement of downcomers to conduct liquid from each tray in the array to the tray below. Each tray has gas passages to enable gas to pass into contact with the liquid. A weir is disposed on the floor of at least one downcomer. Each side of the weir is spaced from the corresponding side of the downcomer. This arrangement counteracts a tendency for liquid flowing along the floor of the downcomer to become detached from the sides of the downcomer, such detachment leading to maldistribution of liquid on the tray and hence to less efficient operation of the column.

Abstract: A flow control valve is disclosed wherein a deformable elastomeric element is positioned at least partially within the flow path of a fluid passing between an inlet and an outlet. By deforming the elastomeric element, the cross-section of the flow path of the fluid is changed, thereby controlling the flow of fluid through the flow control valve. The elastomeric element may be of various standard configurations and is easy and inexpensive to replace in the event of excessive wear.

Abstract: A pressure swing adsorption plant for the separation of gas mixtures includes at least one pressure vessel containing an adsorbent bed that is able preferentially to adsorb at least one component of the gas mixture. The pressure vessel has an inlet at its top for the feed gas mixture, an outlet at its bottom for non-adsorbed gas and at least one heat conductive member containing a liquid medium arranged within the bed such that, in operation, heat is able to be conducted by convection through the liquid from a region of maximum temperature at or near the bottom of the bed to a region of minimum temperature at or near the top of the bed.