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The application of electrostatic technology to the protection of optical components in earth-mounted and satellite orbital systems has been investigated. Theory and experiment indicate it is quite practical to prevent dust deposition in an earth environment. A mathematical analysis indicates even better results should be obtained in an orbital vehicle.

Electrostatic techniques can be used to keep dust and aerosols from depositing on optical components. The system makes use of a corona discharge and a safety screen, located out of the optical path, to charge the incoming dust and then push it away from the optical surface. The system is effective for the dust particles normally found in the atmosphere, there are no exposed high voltage components or moving parts, and power consumption is quite limited.

The application of electrostatic techniques has been investigated as a repulsion system to keep dust off mirrors that might be used in high-power laser systems. A demonstration unit for a 30 cm mirror was built and shipped to Kirtland Air Force Base as part of the program. Other efforts investigated the development of technology that might be used to keep dust and contaminants off large mirrors in an orbiting space platform. If there is dust deposition it may be practical to clean the reflecting surfaces with a dry wipe-off system without damaging delicate coatings or metal films. (Author)

We have developed ways to utilize discarded tires for erosion control structures, bank stabilization and slope stabilization and erosion control in the form of engineered structures for each of these applications. This paper also describes and illustrates a channel erosion control structure made entirely from individual tires used to form side walls, wing walls and aprons for the structure. In this case the individual tires were bound together with nylon rope to form a flexible structure. This structure was built in a ephemeral wash (gully) on a local ranch near Tucson, AZ and has been in place for over ten years.

Studies of rock drilling with water-based mud have indicated the existence of a current of electrons from the rock to the drill. If this so-called “normal current” is reduced to zero or is reversed by an applied potential, there is a significant reduction in drill wear. The wear rate is enhanced if oxygen is bubbled through the drilling mud and reduced if nitrogen is used, but in any case the electrical effects can still be observed. Observation of the normal drilling current with an oscilloscope has suggested that, when the drill is “sharp”, the normal current is a time-varying d.c. signal with most of the signal levels at frequencies below 25 Hz. As the drill becomes dull, the number of higher frequency signals and the overall signal amplitude increase. We suggest that this change in signal frequency with wear can be used to monitor the condition of an operational drill.

It is suggested that the exoelectron emission from the catalyst may be used to monitor the rate of oxidation of CO and CH4 over palladium catalysts. Indirect heating of the catalyst and atmospheric pressure have no effect upon this monitoring system. Although the mechanism relating catalysis to exoelectron emission is not clear, it is considered possible that electron emission is triggered by the adsorption-desorption cycle.

A number of workers have linked the pathogenicity of silica with its capacity to damage biological membranes. We have investigated this membrane damaging process using red blood cells as a model membrane system. The following factors in the silica-membrane interaction were studied: concentration of reactants; rate of reaction; temperature dependence of the reaction; the effects of osmolarity, ionic strength, and pH on the reaction; factors terminating the reaction; the effect of the polymeric state of the silica; the effect of sialic acid removal from the membrane; the size-stability characteristics of the membrane defects; and the identity of the membrane component involved in the reaction. Our results suggest that silica hydrogen bonds to protein components of the membrane and subsequently abstracts these proteins from the membrane. These results appear to support the mechanism underlying the pathogenesis of silicosis advanced by A. C. Allison in 1971 with the exception that our experimental findings favor a silica-protein interaction rather than the silica-lipid interaction proposed by Allison.

New applications of electrostatics to the control of dust are investigated. Technology for pushing systems to keep dust off optical systems and move particulates out of airstreams are discussed. Other electrostatic techniques for removal of water droplets and smoke are investigated.

Electric field effect on chemisorption of oxygen on zinc oxide, discussing electron transfer mechanism

Exo-electron emission was observed during catalytic oxidation of CO, H 2 or NH 3 on hot platinum. The exo-electron current level was related to the rate of reaction. Suppressing or enhancing the exo-electron current decreased or increased the rate of reaction.

Thermionic emission measurement for palladium filament exposed to molecular and atomic hydrogen beam - hydrogen chemisorption on palladium

The introduction of sterile collodial carbon into the dermis produces an area of low electrical resistance in the intact skin. The low resistance spot is suitable for long term, dry contact, stimulation or specialized ECG/EEG measurements.

A surface ionization detector for hydrogen has been developed. This device detects hydrogen in the presence of air at one atmosphere. The detector is not sensitive to other atmospheric gases, e.g., O2, N2, and CO2, and operates at H2/air levels as low as 0.1% by volume.

A chemisorption detector for hydrogen has been developed. The device depends upon the change in work function of a palladium filament when it is exposed to hydrogen. The detector is effective over the pressure range of 10−5 to 10−8 Torr. The system has been checked for sensitivity to other gases, i.e., O2 and N2; it responds strongly to O2 and weakly to N2.

The impact of fine particles and organic contamination on device yield is very serious. We have investigated several technologies in this area. They include: 1) Application of thermophoresis for the prevention of surface contamination. 2) The use of electrets for collection of particles that might otherwise settle on surfaces. 3) The use of dry ice snow as a cleaning medium for the removal of particulates and organic contamination.

Etude experimentale. Le procede convient mieux aux tissus qui collectent la poussiere en surface qu'a ceux qui la retiennent en profondeur

The theory of the constant‐current hot‐wire circuit for measurement of very high gas temperatures is developed and it is shown that such a system may be used above the melting point of the wire itself.

Hot metal filaments are often used to evaporate another metal for deposition of thin films. If the metal being evaporated can alloy with the filament, a significant number of high‐energy electrons are emitted during the alloying‐evaporation process.

Liquid nitrogen-cooled shield against oil vapor contamination of proton accelerator in vacuum chamber