Abstract: An air separation process using pressure swing adsorption techniques, for providing high purity oxygen. Two sections are employed one comprising beds of molecular sieve carbon and the other comprising beds of zeolite molecular sieve. Air is fed to a first of the sections which provides an oxygen-rich gas stream as feedstock for the next section where further enrichment takes place. The zeolite sieve section serves to effect a separation as between oxygen and nitrogen while the carbon sieve section serves to effect a separation as between oxygen and argon and the processes performed at each section are integrated in such a manner as to minimize power consumption and make use of gas recycled from the second section to the first in addition to the flow of gas from the first section to the second.

Abstract: Supplies for the objective lens scanning coils and stigmator coils of a scanning electron microscope are arranged for digital control by a small computer which receives a digitized input from an imaging electron collector. For a specimen of suitable structure the computer can be programmed for automatic focusing and astigmatism correction or the operator can intervene to apply a manual correction. Astigmatism is detected by comparing the directional derivatives of intensity for corresponding points in two frames with lens settings above and below focus. By taking the difference between the derivatives for each direction of measurement the effect of structural directional features is eliminated; by summing the differences for all directions a value (S) is obtained which represents the magnitude of astigmatism. The required orientation of the stigmator field can be calculated and the excitation current scanned through a range of values to determine the setting for which S is a minimum.

Abstract: The operation of a vacuum-conveying hopper feeder is controlled using pneumatic logic circuitry including a leak sensor relay providing improved control accuracy and with a sensor orifice which becomes occluded by a spring-loaded plunger when the feeder body is filled to a predetermined weight. The leak sensor relay connects through a pneumatic logic NOT element to an aspirator or pump control valve and releases the vacuum allowing the contents of the body to be dumped. Time delay elements can be included between the relay, NOT element, and control valve so as to continue the filling for a predetermined interval following occlusion of the sensor orifice and to continue the dumping for a period following unblocking of the orifice.

Abstract: The invention relates to a system for treating liquid such as aqueous liquor with a gas that is sparingly soluble therein by introducing the gas into a pressurized stream of the liquid at a sufficient rate to dissolve some of the gas in the stream and additionally to form finely dispersed bubbles of undissolved gas which are carried within the stream. The velocity of the stream is sufficiently high to ensure that the bubbles do not combine to form a discrete vapor phase. The stream is introduced into a volume of the liquid under turbulent conditions so that the bubbles of undissolved gas are broken into even finer bubbles which either dissolve or are consumed in the liquid volume.

Abstract: Pure oxygen or a gas containing more oxygen than air is injected under pressure into sewage held in or flowing through a sewer. This injection can be used to prevent the concentration of dissolved oxygen in the sewer falling to a level at which there occurs bacterial reduction to hydrogen sulfide of sulfate present in the sewage. The injection can also be used to oxidize to sulfur any sulfide dissolved in the sewage.The pure oxygen or the gas containing more oxygen than air may be injected into sewage flowing through a sewage pipe forming part of a gravity sewer, into a pump used to transfer the sewage through the sewer, or into a part of the sewer where sewage is collected before being transferred through the sewer.

Abstract: A process for treating aqueous waste material having a biochemical oxygen demand, which process comprises passing the aqueous waste material along an elongate treatment tank or other elongate container for containing a volume of such material, having a transverse support structure or structures extending along the length of the tank or container and supporting aerobic micro-organisms, and dissolving an oxygenating gas in aqueous waste material at a plurality of positions spaced along the tank.

Abstract: A textile cot assembly and sleeve comprising same is provided and such assembly has a rigid cylindrical support and an elastomeric sleeve disposed in a stretched condition concentrically around the support.