Abstract: A whole blood sample is placed in a tube such as a capillary tube, with a plastic float. The float is axially elongated and has a specific gravity which causes it to float in the packed red blood cells when the sample is centrifuged in the tube. The hemoglobin concentration of the packed red blood cells is measured by measuring the depth that the float sinks into the red cell layer, and then the hemoglobin concentration of the blood is calculated. The hemoglobin can be measured in this manner because virtually the only red cell component which contributes density to the red cells is the hemoglobin. The hemoglobin concentration of the whole blood is calculated by multiplying the mean corpuscular hemoglobin concentration of the packed red blood cells by the packed cell volume % (hematocrit) of the whole blood. All of the necessary calculations may be performed by a preprogrammed microprocessor.

Abstract: An escalator handrail is driven by a pair of angularly offset rollers. The angular offset of the rollers causes a wedging effect at the roller nip whereby the driving force imparted by the rollers to the handrail is increased.

Abstract: A safety brake for stopping an escalator in the event of a malfunction or the like, includes a locking pawl to prevent disengagement of the brake until the latter is intentionally released. Over the locking pawl reach a reinforcement of the brake. The brake is released by energizing a solenoid which displaces the locking pawl to an inoperative position. Once the locking pawl is disabled, the brake shoes are released from engagement with the escalator drive shaft brake disk. Locking and release of the brake shoes are initiated by springs and solenoid.

Abstract: Improved electrical insulating tapes are disclosed having a poly(ethylene terephthalate) film component. The film has one amorphous surface and an opposite crystalline surface. In a preferred embodiment, a composite insulating material is provided having the film component with a fiber glass yarn strand layer adhered thereto. The fiber glass yarn strands are substantially continuous and uninterrupted, and are substantially parallel to the axis of elongation of the tape, and to each other.

Abstract: A system and method for regulating the total oxygen content entering the cathode side of a fuel cell stack at less than full power depends on measurement of: oxygen partial pressure in the cathode exhaust stream; total flow entering the cathode; and current produced by the stack. During partial power operation of the stack, it is desirable to limit the cathode potential, or voltage, by recycling cathode exhaust and mixing it with incoming fresh air fed into the cathodes. This system ensures that the total oxygen flow to the cathodes remains constant at any given current by reducing the amount of fresh air flowing to the cathodes as the recycled cathode exhaust flow is increased.

Abstract: The fuel cell stack is made from two basic finished component subassemblies which are stacked repetitively atop each other in alternating fashion. One of the components is an electrode subassembly, and the other is a separator plate-flow field subassembly. The subassemblies are formed from several different material layers which are sintered and shrunk to operating size and density prior to the stack being assembled. The finished subassemblies are layered atop each other to form the stack and then heated to an elevated subsintering temperature and subjected to a light compressive load so that abutting surfaces of the adjacent subassemlies are creep flattened into intimate adherent contact with each other thereby forming a monolithic stack assembly.

Abstract: Excess or waste water produced by the operation of a fuel cell power plant is discharged directly into the ambient environment by a discharge system which ensures that only the cleanest water in the system can be discharged. The discharge system is controlled by the amount of water in the power plant water storage tank. The storage tank receives contaminated water from the power plant, and also receives clean water from demineralizing beds. When the quantity of water in the storage tank exceeds a predetermined amount, the clean incoming water from the demineralizing beds is diverted into a drain passage where it is drained from the power plant. The drainage of clean water stops when the amount of water in the storage tank drops below the predetermined amount.

Abstract: The device directs a stream of air onto the top surface of a supply of water contained in a tank. The air is directed onto the water by a diffuser so as to create a turbulence on the surface of the water. The diffuser comprises a plenum which hovers over the water surface as a result of the air flow therethrough. The plenum is formed with a buoyant skirt which allows the plenum to float in the water when there is no air flowing through the plenum. The air leaving the water tank is thus moisturized. The device can be used to remove fibrous contaminants such as asbestos from the air, or can be used as an air humidifier, or the like.

Abstract: Heat is more efficiently transferred to the catalyst tubes in a fuel cell power plant reformer by mounting sleeves about the individual catalyst tubes. The sleeves define helical hot gas flow paths on the outside of the catalyst tubes. Adjacent flow paths are separated from each other by arcuate ribs between the tubes and sleeves that provide line contact with the outer surface of the tubes for improved heat transfer. The ribs may be formed with circular rods attached to the tubes or sleeves, or by helical grooves with semi-circular configurations formed in the sleeves. Approximately fifty percent greater heat transfer can be achieved using the line contact ribs to form the hot gas flow paths. The sleeves, tubes and ribs are all made of metal.

Abstract: A whole blood sample is placed in a tube such as a capillary tube, with a plastic float. The float is axially elongated and has a specific gravity which causes it to float in the packed red blood cells when the sample is centrifuged in the tube. The hemoglobin concentration of the packed red blood cells is measured by measuring the depth that the float sinks into the red cell layer, and then the hemoglobin concentration of the blood is calculated. The hemoglobin can be measured in this manner because virtually the only red cell component which contributes density to the red cells is the hemoglobin. The hemoglobin concentration of the whole blood is calculated by multiplying the mean corpuscular hemoglobin concentration of the packed red blood cells by the packed cell volume % (hematocrit) of the whole blood. All of the necessary calculations may be performed by a preprogramed microprocessor.

Abstract: The cell stack can be operated as a fuel cell stack or as an electrolysis cell stack. The stack consists of a series of alternate fuel cell subassemblies with intervening electrolysis cell subassemblies, and interspersed cooling plates. The water produced and consumed in the two modes of operation migrates between adjacent cell subassemblies. The component plates are annular with a central hydrogen plenum and integral internal oxygen manifolds. No fluid pumps are needed to operate the stack in either mode.

Abstract: A guide for supporting a moving handrail or an escalator or moving walk is formed from a sheet of rolled spring steel or the like. The guide fits onto the top edge of a glass balustrade on the escalator or walk. The guide is secured to the glass balustrade solely by means of a spring clamping action which results from stressing the guide when it is forced down over the glass. The guide is formed with opposed planar clamping surfaces which flank the glass balustrade and are biased inwardly thereagainst by outer radiused edges of the guide which are stressed when the guide is pressed onto the glass. The radiused edges, when stressed, act as hairpin or torsion springs to force the clamp surfaces toward the glass. A gasket of paper or plastic is mounted directly on the glass for engagement by the clamping surfaces to provide increased protection for the glass.

Abstract: The sub machine gun fires single shots in semi automatic fashion, and also fires fully automatically, with the firing mode being manually selectable. The firing mode selection also includes a safe setting, and there is a grip safety which renders the gun inoperative unless the pistol grip is squeezed. The safeties are configured and balanced so that the gun will not fire if dropped. There is one manually operable latch that allows complete take down of the action. When the receiver cover is lifted with the bolt cocked, the bolt will not accidentally move forward to fire the gun. The slide actuator holds the receiver cover in its open position. The barrel is latched in place by a latch pin that cannot unintentionally be removed from the gun and misplaced. The barrel latch pin can be partially withdrawn to allow removal of the barrel from the receiver.

Abstract: A centrifuge tube is used to hold a mixture of several constituents, and also contains a generally cylindrical float. The float settles, after centrifugation, into the zone occupied by the constituent whose volume is to be measured. The constituent layer will settle, after centrifugation, into the annular space between the tube bore and the outside of the float, and will be expanded axially due to the restricted volume of the annular space. The degree of expansion is dependent upon the respective sizes of the float O.D. and the tube bore ID, both of which must be closely controlled for accurate results. A known volume of a control material is placed in the tube to settle into the annular space during centrifugation in an area thereof outside of the constituent layer zone. The length of the band of the control material is measured after centrifugation and is compared to a known length which will result if the annular space is of the proper target volume.

Abstract: In order to achieve good stack water chemistry and minimize corrosion in a fuel cell stack water cooling loop, the oxygen concentration in the water must remain within a relatively narrow range. Stacks using steam separators produce water in the separators which is relatively devoid of oxygen. Makeup water is used to replace the steam lost from the separator, which makeup water is relatively rich in oxygen. The flow rates of the makeup water and steam separator water are controlled to produce a proper oxygen concentration in the recirculated coolant water. Some of the makeup water will be added directly into the steam separator so that it will be stripped of oxygen and the rest will be added subsequent to the steam separator.

Abstract: Fuel Cell stack coolant water is processed by moving the two-phase water/steam coolant exhaust through a steam separator wherein the water phase is separated from the steam phase. The water phase is then moved through a heat exchanger where its temperature is lowered to a subcooled level which is below the coolant operating temperature in the stack. A flow control valve is associated with the coolant heat exchanger to regulate water flow through and/or around the heat exchanger depending on the temperature of the water which leaves the steam separator. By subcooling the coolant before it reenters the stack, a lessening of electrolyte loss through evaporation is achieved. By eliminating steam condensation as a form of system heat rejection, system engineering is simplified and construction costs are lowered.

Abstract: A fuel cell or fuel cell stack of the type utilizing a solid polymer electrolyte membrane is cooled by evaporation of water in the hydrogen reactant chamber of the cells. A porous graphite plate or water permeated membrane is disposed in the hydrogen reactant chamber adjacent to the electrolyte membrane. If a graphite plate is used, it is preferably grooved on the surface facing the electrolyte. The resultant lands preferably contact the supported catalyst layer on the membrane to cool the latter. Water is forced into the pores of the plate or membrane from the edge thereof, and the water vapor is carried out of the cells in the hydrogen reactant exhaust stream. A separate cooling system is thus avoided.

Abstract: The fuel cell power plant has a closed water circulation system whose only source of fresh water is the electrochemical reaction in the power section. The water becomes contaminated with ammonia and carbon dioxide in the fuel contact cooler and the ammonia and carbon dioxide are stripped out of the water by steam produced by operating the plant. The ammonia and carbon dioxide-laden steam is vented from the plant. The amount of water lost from the plant as steam is less than the amount of available water produced in the electrochemical reaction.

Abstract: A non-combustible, inorganic heat insulation which can be sprayed onto a surface being insulated is particularly useful for forming the cold face insulation layer in a catalytic reformer housing. The insulation is formed from an inorganic cement having glass and/or ceramic microspheres mixed therein.

Abstract: A safety device for use in the comb part of an escalator landing is operable to detect objects which pass into the comb from the escalator treads. The device includes a photodetector which is positioned beneath the comb and which detects a light beam projected across the comb where the treads pass through the comb. When a foreign object passes under the comb and blocks the light beam, this potential hazard is sensed by the detector. If the light beam remains blocked for a predetermined time period, the detector energizes and amplifier which in turn causes a relay to stop operation of the escalator motor.