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Capacitor uses all-tantalum seals and straight, ungelled, 30-percent sulphuric acid electrolyte to reduce leakage from order of milliamperes to low-microampere region. Design offers better reliability in severe environments encountered in military and industrial electronics systems.
The strength of the bond between metals and SiO2 was studied by measuring the static coefficient of friction of metals contacting alpha-quartz in ultrahigh vacuum. It was found that copper with either chemisorbed oxygen, nitrogen, or sulphur exhibited higher contact strength on stoichiometric SiO2 than did clean copper. Since the surface density of states induced by these species on copper is similar, it appears that the strength of the interfacial bond can be related to the density of states on the metal surface.
As the world supply of petroleum crude oil is being depleted, the supply of high-quality crude oil is also dwindling. This dwindling supply is beginning to manifest itself in the form of crude oils containing higher percentages of aromatic compounds, sulphur, nitrogen, and trace constituents. The result of this trend is described and the change in important crude oil characteristics, as related to aircraft fuels, is discussed. As available petroleum is further depleted, the use of synthetic crude oils (those derived from coal and oil shale) may be required. The principal properties of these syncrudes and the fuels that can be derived from them are described. In addition to the changes in the supply of crude oil, increasing competition for middle-distillate fuels may require that specifications be broadened in future fuels. The impact that the resultant potential changes in fuel properties may have on combustion and thermal stability characteristics is illustrated and discussed in terms of ignition, soot formation, carbon deposition flame radiation, and emissions.
The strength of the bond between metals and SiO2 is studied by measuring the static coefficient of friction of metals contacting alpha-quartz in ultrahigh vacuum. It was found that copper with either chemisorbed oxygen, nitrogen or sulphur exhibited higher contact strength on stoichiometric SiO2 than did clean copper. Since the surface density of states induced by these species on copper is similar, it appears that the strength of the interfacial bond can be related to the density of states on the metal surface.
Three day old mice were continuously exposed to sulphur dioxide concentrations at 0ppm, 0.05ppm, 0.15ppm and 1ppm for eight weeks. At the end of the experiment, blood samples were collected and centrifuged for electrophoresis studies of the serum in 5 percent acrylamide gel. The length of bands of different serum proteins from the SO2 exposed mice was at a variance as compared with the length of bands from the control exposed mice and alpha-1 band seems to be missing from the serum of SO2 exposed mice.
A model is presented in which a plasma boundary layer of Jupiter is formed from plasma of internal origin. It is proposed that, unlike the Earth's boundary layer, which is thought to consist principally of solar wind plasma, Jupiter's boundary layer consists principally of sulphur and oxygen from the Io plasma torus, plus a small component of hydrogen from Jupiter's ionosphere. Fresh plasma is supplied to the boundary layer once each planetary rotation period by a convection pattern that rotates with Jupiter.
A study of cosmic ray intensity variations using data registered by Detector C on Pioneer 10 and the Sulphur Mountain neutron monitor is presented. The spacecraft data were corrected for temperature, Radioisotope Thermoelectric Generator background, and contamination by energetic solar particle events. A consistent long-term solar cycle variation intensity is observed, but additional contribution is observed in the neighborhood of 5.1 AU which is attributed to energetic electrons of Jovian origin. The spectral variation in long-term changes of the cosmic ray intensity is studied by comparing the low-energy and high-energy data, and an average value of their ratio during 1972-1977 was found to agree with the value for the 1965-1972 interval.
A methodology is presented for predicting coal prices in regional markets for the target time frames 1985 and 2000 that could subsequently be used to guide the development of an advanced coal extraction system. The model constructed is a supply and demand model that focuses on underground mining since the advanced technology is expected to be developed for these reserves by the target years. Coal reserve data and the cost of operating a mine are used to obtain the minimum acceptable selling price that would induce the producer to bring the mine into production. Based on this information, market supply curves can be generated. Demand by region is calculated based on an EEA methodology that emphasizes demand by electric utilities and demand by industry. The demand and supply curves are then used to obtain the price targets. The results show a growth in the size of the markets for compliance and low sulphur coal regions. A significant rise in the real price of coal is not expected even by the year 2000. The model predicts heavy reliance on mines with thick seams, larger block size and deep overburden.
A new type of apparatus for high-pressure experiments at low temperature (1.5 K) is presented. It uses a flat diamond anvil with a spherical indentor. It utilizes a load ring placed under the sample, so that the load (and hence pressure) can be measured in situ at low temperature. The apparatus was successfully used to investigate the high-conductivity state of sulphur. It can be used to investigate other thin film samples.
The structure and mechanisms of the sputter-induced coronae surrounding the Galilean satellites of Jupiter are considered. Calculations are presented of the particle flux distributions expected in sputtering by collisional cascade and thermal spike mechanisms, and the coronae produced by the two mechanisms are examined. Consideration is then given to the coronal structures generated by sputtering of the surface of Io by corotating sulphur and oxygen plasma, and the sputtering of ice on the surfaces of the outer Galilean satellites as represented by Europa.
Interim results of thermal and structural modeling of volcanism on Io were presented. The final results of the modeling are summarized. The basic analysis is an evaluation of the magma trigger mechanism for initiating and maintaining eruptions. Secondary aspects include models of the mechanical mode of magma emplacement, interactions with a sulphur-rich upper crust, and more speculative implications for Io's volcanism.
Mathematical aspects of thermal diffusivity measurements are reviewed and applied to develop an experimental setup at JPL. Certain approximations commonly appearing in the literature are examined in some detail and rejected based upon sensitive slope variations having significant impact on the results. The final mathematical formulation used was one developed by Parker et al. (1961), which evaluated the diffusivity in a way that could be simply evaluated by examining an oscilloscope trace. A computer algorithm was written to examine solution sensitivity to the number of terms taken in the infinite series. The mathematical technique is being used at JPL to evaluate diffusivities of graphite, Boron Carbon and Lanthanum Sulphur compounds in the temperature range of 300 K to 1200 K.
Ground-based measurements strongly support the hypothesis that pollutant materials of anthropogenic origin are being transported over long distances in the midtroposphere and are a significant source of acid rain, acid snow, trace metal deposition, ozone and visibility-reducing aerosols in remote oceanic and polar regions of the Norhern Hemisphere. Atmospheric sulphur budget calculations and studies of acid rain on Bermuda indicate that a large fraction of pollutant materials emitted into the atmosphere in eastern North America are advected eastwards over the North Atlantic Ocean. The first direct airborne measurements of the vertical distribution of tropospheric aerosols over the western North Atlantic is reported here. A newly developed airborne differential adsorption lidar system was used to obtain continuous, remotely sensed aerosol distributions along its flight path. The data document two episodes of long-distance transport of pollutant materials from North America over the North Atlantic Ocean.
Mercury and sulphur dioxide analyses were conducted from 1971 to 1980 on air samples collected immediately downwind of Halemaumau, the Kilauea main vent, in Hawaii. On the basis of these measurements, an Hg/SO2 ratio of 0.00051 has been derived which, when applied to the recently determined SO2 mass output of Halemaumau, yields a calculated Hg flux of 2.6 x 10 to the 8th g annually. This rate is consistent with Varekamp and Busek's (1981) evidence suggesting that volcanogenic Hg significantly contributes to the atmospheric total.
The Anadarko Basin of western Oklahoma is a WNW-ESE elongated trough filled with of Paleozoic sediments. Most models call for tectonic activity to end in Pennsylvanian times. NASA Shuttle Imaging Radar revealed a distinctive and very straight lineament set extending virtually the entire length of the Anadarko Basin. The lineaments cut across the relatively flat-lying Permian units exposed at the surface. The character of these lineaments is seen most obviously as a tonal variation. Major streams, including the Washita and Little Washita rivers, appear to be controlled by the location of the lineaments. Subsurface data indicate the lineaments may be the updip expression of a buried major fault system, the Mountain View fault. Two principal conclusions arise from this analysis: (1) the complex Mountain View Fault system appears to extend southeast to join the Reagan, Sulphur, and/or Mill Creek faults of the Arbuckle Mountains, and (2) this fault system has been reactivated in Permian or younger times.
By ratioing multiple Auger intensities and plotting a two-dimensional occupational scatter diagram while digitally scanning across an area, the number and elemental association of surface phases can be determined. This can prove a useful tool in scanning Auger microscopic analysis of complex materials. The technique is illustrated by results from an anomalous region on the reaction zone of a SiC/Ti-6Al-4V metal matrix composite material. The anomalous region is shown to be a single phase associated with sulphur and phosphorus impurities. Imaging of a selected phase from the ratioed scatter diagram is possible and may be a useful technique for presenting multiple scanning Auger images.
The soft (10-100 A) X-ray spectrum of an M-class solar flare was observed with a high-resolution (0.02 A) rocket-borne spectrograph on 1982 July 13. The spectrum samples an area of 600/sq arcsec on the sun, centered on or near the brightest X-ray feature of the flare. Several hundred emission lines characteristic of temperatures from about 0.5 to 7 x 10 to the 6th K have been photographically recorded. All but three of the stronger lines have been identified. It is argued that previous identification of the line at 17.62 A as iron Ly-alpha is incorrect. Spectral lines from nickel, iron, chromium, calcium, sulphur, silicon, aluminium, magnesium, neon, oxygen, nitrogen, and carbon are tabulated and discussed with extensive reference to earlier work. Absolute line intensities are given and the calibration of the telescope-spectrograph is discussed.
Radial profiles of the ion density and flux-tube content in the Io torus have peak values inside Io's orbit, even though Io is the effective source of these ions. Formation of an inward peak constrains either the velocity distributions or source regions of sputtered neutrals. A further constraint is that the ionization of neutrals on trapped trajectories that return to Io's surface must be limited. A dominant sulphur source is most easily reconciled with these constraints.