scispace - formally typeset
Search or ask a question

Showing papers on "Atmospheric pressure published in 1985"


Book
01 Jan 1985
TL;DR: In this paper, the authors present an overview of the Earth and its atmosphere, including the following: 1. Earth and Its Atmosphere. 2. Earth's Changing Climate. 3. Seasonal and Daily Temperatures. 4. Atmospheric Humidity. 5. Air Pressure and Winds. 6. Stability and Cloud Development. 7. Precipitation.
Abstract: 1. Earth and Its Atmosphere. 2. Energy: Warming the Earth and the Atmosphere. 3. Seasonal and Daily Temperatures. 4. Atmospheric Humidity. 5. Condensation: Dew, Fog, and Clouds. 6. Stability and Cloud Development. 7. Precipitation. 8. Air Pressure and Winds. 9. Wind: Small-Scale and Local Systems. 10. Wind: Global Systems. 11. Air Masses and Fronts. 12. Middle-Latitude Cyclones. 13. Weather Forecasting. 14. Thunderstorms. 15. Tornadoes. 16. Hurricanes. 17. Earth's Changing Climate. 18. Global Climate. 19. Air Pollution. 20. Light, Color, and Atmospheric Optics.

574 citations


Journal ArticleDOI
TL;DR: In this paper, detailed species concentration profiles have been measured using optical and mass spectrometric methods in an atmospheric pressure methane air diffusion flame burning on a Wolfhard-Parker slot burner.

269 citations


Journal ArticleDOI
TL;DR: In this article, the injection of powders into an inductively coupled plasma is modeled and the plasma-particle interaction and its effect on plasma fields is considered, and it is demonstrated that for most applications, such interactions must be considered in any model.

151 citations


Journal ArticleDOI
TL;DR: In this paper, the first continuous-wave operation at temperatures up to 23°C of an Al0.26In0.48P double heterostructure (DH) laser has been achieved for the first time.
Abstract: Continuous‐wave (cw) operation at temperatures up to 23 °C of an Al0.26Ga0.26In0.48P/Ga0.52In0.48P/ Al0.26Ga0.26In0.48P double heterostructure (DH) laser has been achieved for the first time. The threshold current was 160 mA at 20 °C for a device with a 10‐μm‐wide and 250‐μm‐long ion‐implanted stripe geometry. The emission wavelength was 671 nm during cw operation at 10 °C. To reduce thermal resistance to a heat sink, a dually stacked structure made of a thin (∼0.3 μm) p‐AlGaInP layer and a p‐Al0.76Ga0.24As layer was used as a cladding layer. The DH wafer was grown by atmospheric pressure metalorganic chemical vapor deposition.

131 citations


Journal ArticleDOI
TL;DR: In this paper, the catalyzed oxidation of carbon monoxide has been studied over platinum single crystals of (111), (100), and (13, 1, 1) orientation. And the oscillatory behavior of this reaction has been investigated over platinum surfaces.

122 citations



Journal ArticleDOI
TL;DR: In this article, precise equations were derived for measuring oxygen and hydrogen overvoltages by using the particularly suitable Hg/HgO/OH− as well as reversible hydrogen reference electrodes in the temperature range 20-200°C, overall pressure range 1-200 bar, and concentration range 0-18 m KOH or 0-25 m NaOH.

97 citations


Journal ArticleDOI
01 Dec 1985-Icarus
TL;DR: In this article, the horizontal flow of SO 2 gas from day side to night side of Io is calculated, and the surface is assumed to be covered by a frost whose vapor pressure at the subsolar point is orders of magnitude larger than that on the night side.

93 citations


Journal ArticleDOI
TL;DR: In this article, the thermal conductivity of some molten salts was measured at atmospheric pressure, using the coaxial cylinder method, and the experimental thermal diffusivity coefficients are in agreement with calculated values using a simple linear mixing law.
Abstract: The thermal conductivity of some molten salts was measured at atmospheric pressure, using the coaxial cylinder method. The pure compounds NaCO3, KNO3, and NaNO2, the equimolar mixture NaNO3-KNO3, and HITEC, which is a three-component mixture, NaNO3-NaNO2-KNO3 (0.07-0.40-0.53 in weight), were investigated. For mixtures, it was found that the experimental thermal conductivity coefficients are in agreement with calculated values using a simple linear mixing law. The thermal diffusivity was calculated and compared with experimental data.

86 citations


Patent
14 Jun 1985
TL;DR: In this paper, the display is adjusted to a desired value by noting the display indication with the reference side of the transducer at atmospheric pressure, substituting a known offset pressure for atmospheric pressure on the reference-side, to produce a new display indication, and adjusting the display to produce that amount of displacement (between the display indications in steps 1 and 2) which corresponds to the known offsetpressure multiplied by the desired calibration value.
Abstract: Sensitivity or span calibration is adjusted to a desired value by (1) noting the display indication with the reference side of the transducer at atmospheric pressure, (2) substituting a known offset pressure for atmospheric pressure on the reference side, to produce a new display indication, and (3) adjusting the display to produce that amount of displacement (between the display indications in steps 1 and 2) which corresponds to the known offset pressure multiplied by the desired calibration value. With the sensitivity or span calibration adjusted to a desired value, the zero point of the display is adjusted by (1) independently measuring the mean of the actual pressure, (2) noting the mean value of the display indication, and (3) adjusting the zero point to eliminate discrepancy between the mean value of the display and the mean of the actual pressure. The apparatus has a port for a substitute reference pressure, and an external pressure gauge for measuring the mean pressure through an auxiliary lumen of the catheter.

79 citations


Journal ArticleDOI
TL;DR: In this article, a laser-induced fluorescence study of the CH radical in atmospheric pressure flames of methane, oxygen, and nitrogen was conducted using rotationally resolved fluorescence scans, where rotational transfer occurred at a rate, dependent on rotational level, 2-5 times that of quenching.
Abstract: Laser-induced fluorescence studies have been made of the CH radical in atmospheric pressure flames of methane, oxygen, and nitrogen. Individual rotational levels within the υ′ = 0 and 1 vibrational levels of the A2Δ and B2Σ− states are excited by a dye laser operating in the 380–440-nm region. Studies were made of collisional energy transfer pathways within and between the states, using rotationally resolved fluorescence scans. Rotational transfer occurred at a rate, dependent on rotational level, 2–5 times that of quenching. Vibrational transfer was slow but transfer between A(υ′ = 1) and B(υ′ = 0) took place at rates ~0.2 that of quenching.

Patent
11 Sep 1985
TL;DR: In this paper, a monodisperse aerosol generator forms a stable jet of liquid at a velocity allowing columnar breakup into droplets of uniform size and spacing, which is then dispersed by entrainment in a high velocity gaseous stream.
Abstract: A monodisperse aerosol generator forms a stable jet of liquid at a velocity allowing columnar breakup into droplets of uniform size and spacing To prevent degradation of the monodisperse aerosol, it is dispersed by entrainment in a high velocity gaseous stream To provide an interface for direct injection into a mass spectrometer or to interface a liquid chromatograph with a mass spectrometer, the generator is followed by a desolvation chamber operating at about atmospheric pressure and a multistage pressure reducer which evacuates solvent vapor and gaseous medium to form a high momentum, solvent-depleted solute aerosol beam which is input into the mass spectrometer

Journal ArticleDOI
TL;DR: In this paper, it was shown that surface flashover is a local, relatively high-pressure phenomenon and that flashover values range well within an order of magnitude (∼18-80kV/cm).
Abstract: Desorbed gases from insulator surfaces may be much more important in flashover initiation than properties of the dielectric surface. Ambient neutral densities, immediately above the insulator surface, in the initial stages of flashover have been calculated to lie in the range from 2×1017/cm3 to 2×1021/cm3 with a mean of about 1×1019/cm3, whether flashover occurred on surfaces in air at atmospheric pressure or in vacuum as low as 10−6 Torr. The evidence presented indicates that, for dc and microsecond pulse voltages, surface flashover is a local, relatively high‐pressure phenomenon. Comparison of field strengths of surface flashover for various insulating materials perpendicular to the electrodes, operating pressures, and voltage waveforms appears to indicate that flashover values range well within an order of magnitude (∼18–80kV/cm). A filamentary nature of the flashover discharge is shown and is consistent with gas breakdown phenomena. Ionization wave front velocities are examined and these compare favorably with those obtained from gaseous breakdown studies.

Journal ArticleDOI
TL;DR: In this paper, an experiment with water flowing in a round tube at atmospheric pressure was performed to study critical heat flux (CHF) at low mass velocities, flow stagnation and flow reversal conditions.


Journal ArticleDOI
TL;DR: In this article, the gas phase reactions of polycyclic aromatic hydrocarbons (PAH) adsorbed on combustion generated particles were studied at room temperature and atmospheric pressure in a 5800V Teflon-coated environmental chamber.

Journal ArticleDOI
TL;DR: In this article, the rotational Raman scattering was identified as a potentially significant interference in the fluorescence measurements at low OH concentration levels (down to 5ppm) typical of the rich flames.
Abstract: OH concentration measurements have been performed in rich, atmospheric pressure CH4/O2/N2 flames using laser-saturated fluorescence. Both sooting and non-sooting conditions have been investigated. OH is thought to be an important species in soot chemistry because of its role in the oxidation of soot and soot precursors. In the sooting flame, the centerline axial OH concentration drops sharply 3-4 mm above the burner surface. Visible soot emission begins only after the OH concentration decreases significantly from its peak value in the flame zone. Rotational Raman scattering was identified as a potentially significant interference in the fluorescence measurements at the low OH concentration levels (down to 5 ppm) typical of the rich flames. Laser-saturated fluorescence and optical absorption measurements of OH concentration were also performed in a lean, atmospheric pressure CH4/O2/N2 flame. A combination fluorescence-absorption calibration in the lean flame was used to determine absolute OH numbe...

Journal ArticleDOI
TL;DR: In this article, the lattice vibrations in the molecular crystal SnI4 have been investigated by high-pressure and high-temperature Raman spectroscopy, showing successive phase transitions at about 1.5, 10 and 20 GPa in a pressure-increasing process.
Abstract: For pt.I see ibid., vol.18, p.789 (1985). The lattice vibrations in the molecular crystal SnI4 have been investigated by high-pressure and high-temperature Raman spectroscopy. This material shows successive phase transitions at about 1.5, 10 and 20 GPa in a pressure-increasing process. Above 20 GPa an amorphous state is realised. On decreasing the pressure this amorphous state persists to about 2 GPa. Below this pressure the structure changes to another amorphous state and then a new crystal phase, at very close to atmospheric pressure. In the high-pressure amorphous state a strong A1-symmetric peak arising from the breathing mode of the SnI4 tetrahedral molecules splits into a doublet. This is interpreted in terms of pressure-induced dimerisation. The spectra for the liquid are also measured, for comparison with those for the amorphous state.

Journal ArticleDOI
01 Feb 1985-Fuel
TL;DR: In this article, a high-pressure microdilatometer was used to measure the thermoplastic properties of a Pittsburgh seam hvA coal (PSOC1099).

Patent
26 Aug 1985
TL;DR: In this article, a body of metal is heated to an elevated temperature at a total pressure above the vapor pressure of aluminum but less than atmospheric pressure, and then contacted with a mass of refractory material and cooled, thereby forming a composite.
Abstract: A method for bonding aluminum and aluminum alloys to refractory materials. A body of metal is heated to an elevated temperature at a total pressure above the vapor pressure of aluminum but less than atmospheric pressure. Oxygen partial pressure is maintained sufficiently low to prevent substantial oxidation of the metal. The heated body is contacted with a mass of refractory material and cooled, thereby forming a composite.

Journal ArticleDOI
TL;DR: In this article, the authors measured the actual rates of silane formation from CH3Cl and silicon in a differential batch reactor at atmospheric pressure and 520-620 K, on three clean, nonporous, silicon-containing surfaces.

Journal ArticleDOI
TL;DR: In this paper, the failure process in waisted tensile specimens of pultruded 60% volume fraction carbon fiber-epoxide was investigated at atmospheric and superposed hydrostatic pressures up to 300 MN m−2.
Abstract: The failure process in waisted tensile specimens of pultruded 60% volume fraction carbon fibre-epoxide was investigated at atmospheric and superposed hydrostatic pressures up to 300 MN m−2. The maximum principal stress at fracture decreased from ~ 2.0 GN m−2 at atmospheric pressure to ~ 1.5 GN m−2 by 200 MN m−2 superposed pressure and then remained approximately constant. These latter failures were fairly flat and no damage preceding the catastrophic fracture was detected, which indicates that composite strength is solely controlled by fibre strength. Fracture of fibres at lower pressures appeared to commence also in the range 1.5 to 1.6 GN m−2, but, as it did not result in catastrophic failure, account has to be taken of the resin and the fibre bundles. Debonding was initiated at ~ 1.2 GN m−2 at atmospheric pressure and this stress increased to ~ 1.5 GN m−2 when 150 MN m−2 superposed pressure was applied; the pressure dependence was related to that of the resin tensile strength. This process is described as the first stage, straightening and debond initiation of curved surface bundles, on our model of tensile failure. The second stage, delamination, i.e. the growth of transverse cracks leading to the detachment of these bundles, was impeded by the transverse pressure, being suppressed beyond 150 MN m−2. Only below this pressure was load redistribution between bundles possible, but, as the pressure was increased from atmospheric, it become more difficult, resulting in a decrease in the composite tensile strength and reduced fibre pull-out.

Journal ArticleDOI
TL;DR: In this paper, a microwave-induced plasma has been sustained with the use of nitrogen as the nebulizer and plasma supporting gas, and a concentric tube torch was constructed so the plasma could be easily ignited and maintained.
Abstract: A microwave-induced plasma has been sustained with the use of nitrogen as the nebulizer and plasma supporting gas A concentric tube torch was constructed so the plasma could be easily ignited and maintained This new plasma emission source has a flame-like appearance and extends 10 cm beyond the cavity, at an applied power of 250 W The nitrogen plasma readily accepts aerosol samples and is compatible with sample introduced from a conventional nebulizer system The radial (side-on) optical viewing configuration was found to have lower background emission than the more commonly employed axial (end-on) configuration Optimum operating conditions were established from the effects of applied power, flow rate, and signal-to-background noise on the intensity of both atom and ion transitions A discussion of the background spectral features and the analytical potential of this new source is presented

Journal ArticleDOI
TL;DR: In this article, the authors made measurements of radial fuel distributions obtained with various types of pressure-swir l atomizers, using a "patternator" which comprises 29 sampling tubes placed 4.5 deg apart on an arc of 10 cm.
Abstract: Measurements are made of the radial fuel distributions obtained with various types of pressure-swir l (simplex) atomizers, using a "patternator" which comprises 29 sampling tubes placed 4.5 deg apart on an arc of 10 cm. The patternator is mounted in a pressure vessel 10 cm below the fuel nozzle with the nozzle axis located at the center of curvature. The volume of fuel collected in each tube is proportional to the fuel flow at the sampling point. The results of tests performed over wide ranges of fuel injection pressure and ambient pressure show that spray angles diminish with increases in ambient gas pressure up to around 0.69 MPa (100 psia), above which they remain sensibly constant. Changes in the fuel injection pressure have differing effects on spray-cone angle depending on the ambient pressure. At normal atmospheric pressure an increase in fuel injection pressure causes the spray angle to first widen and then contract. At ambient pressures above around 2 atm the spray contracts continuously with increase in fuel injection pressure. Measurements of circumferenti al fuel distribution show that some nozzle designs possess a high degree of uniformity, while others exhibit significant deviations from the mean value.

Journal ArticleDOI
TL;DR: In this paper, a wall stabilized argon arc (40-200 A) at atmospheric pressure with diameters of 5 and 8 mm is studied by spectroscopy and interferometry, where the plasma is assumed to be partial local thermal equilibrium and this assumption is verified with the aid of a collisional-radiative model.
Abstract: The parameters and transport properties of a wall stabilized argon arc (40-200 A) at atmospheric pressure with diameters of 5 and 8 mm are studied by spectroscopy and interferometry. The plasma is assumed to be partial local thermal equilibrium and this assumption is verified with the aid of a collisional-radiative model. The departures from Saha-equilibrium of the argon neutral ground state are found to be associated with particle diffusion and the escape of recombination radiation. The measurement of the total excitation rate, from the ground level, including direct ionization, of neutral argon is in reasonable agreement with the literature value

Journal ArticleDOI
TL;DR: In this paper, the rate constants for the reactions of OH radicals with seventeen aromatic hydrocarbons were determined at atmospheric pressure and room temperature from competitive reactions with hexane, using H2O2 as the OH-radical source.
Abstract: The rate constants for the reactions of OH radicals with seventeen aromatic hydrocarbons were determined at atmospheric pressure and room temperature from competitive reactions with hexane, using H2O2 as the OH-radical source. A useful trend was found in the structure-reactivity relationship.

Journal ArticleDOI
21 Feb 1985-Nature
TL;DR: In this article, microscopic and kinetic observations of the oxidation on Pt wire surfaces below 600 K and at atmospheric pressure were presented, suggesting that the catalyst functions through formation of oxy-and/or carboxyl-Pt complexes in a two-dimensional chemisorbed layer, envisaged as a monolayer possessing fluid properties and enhanced reactivity.
Abstract: The catalytic properties of Pt, which have been studied in a variety of forms of the metal (single crystals, wires or dispersed on a support), may be influenced by the method of preparing the metal surface. Pt surfaces undergo retexturing1 during catalytic reactions at high temperatures (>1,000 K) and a relatively facile sintering process has also been described2. Engel and Ertl3 have reviewed the heterogeneous oxidation of carbon monoxide on Pt (CO + 1/2 O2 → CO2), emphasizing studies concerned with the behaviour of the reaction at very low pressures and on clean surfaces (for example, on single crystal faces). Under these conditions the kinetic behaviour is determined by the ratio of the partial pressures of the reactants and is relatively insensitive to the total pressure. Here, we describe microscopic and kinetic observations of the oxidation on Pt wire surfaces below 600 K and at atmospheric pressure. The surface reactions are apparently more complicated here than at low pressure; extrapolations from the low to the high pressure regimes may not be applicable because of changes in the rate-controlling parameters. We present evidence of the mobility of Pt atoms (often considered immobile) on the surface and suggest that the catalyst functions through formation of oxy- and/or carboxyl-Pt complexes in a two-dimensional chemisorbed layer, envisaged as a monolayer possessing fluid properties and enhanced reactivity, containing both adsorbed reactant gases and mobile catalyst atoms.

Journal ArticleDOI
01 Jan 1985
TL;DR: In this article, a simplified model to study the mechanism controlling the growth of vapor bubbles in superheated pure and multicomponent liquids is formulated, which is used to analyze the effect of ambient pressure and of the presence of solid particles or gas pockets on the nature and character of the liquid-phase disruption which may occur during the vaporization and burnng of emulsified and multi-component fuel droplets.
Abstract: A simplified model to study the mechanism controlling the growth of vapor bubbles in superheated pure and multicomponent liquids is formulated. The model is used to analyze the effect of ambient pressure and of the presence of solid particles or gas pockets on the nature and character of the liquid-phase disruption which may occur during the vaporization and burnng of emulsified and multicomponent fuel droplets. The analysis is in good qualitative agreement with existing atmospheric pressure experimental results. The “micro-explosive” buring of water-in-fuel emulsion droplets is caused by the very fast growth of superheated water-vapor bubbles. It is shown that the growth rate of these bubbles is primarily governed by the pressure difference between the superheated vapor and the liquid and by the inertia imparted to the liquid by the motion of the bubble surface (“Inertia controlled growth”). For the multicomponent fuel cases the model shows that the disruption of the droplets results from a much slower vapor-bubble growth which is governed by heat diffusion from the liquid to the bubble rather than by inertial and pressure effects (“Diffusion controlled growth”). Furthermore, it is predicted that any emulsion or multicomponent fuel droplet for which liquid-phase disruption is observed at atmospheric pressure will also exhibit disruption at higher pressures. However, as the ambient-pressure is increased the bubble growth rate will decrease in both solution and emulsion cases, resulting in a less effective and slower disruption. Finally, it is shown that through a reduction in the super-heat limit temperature, the presence of solid particles or dissolved gases in the liquid may also result in a less effective and slower disruption.

Journal ArticleDOI
TL;DR: In this paper, a new type of analyzer for detecting low-energy electrons emitted from solid surfaces in an arbitrary gas atmosphere was constructed, equipped with two grids for the external quenching of the counter discharge and for the suppression of a positive-ion bombardment.
Abstract: A new type of analyzer for detecting low-energy electrons emitted from solid surfaces in an arbitrary gas atmosphere was constructed. It was equipped with two grids for the external quenching of the counter discharge and for the suppression of a positive-ion bombardment. The work functions of metals and semi-conductors, the oxide film thickness on Si, and exoelectrons from CaF2 were successfully measured for the first time in air at atmospheric pressure by use of the open counter for low-energy electron detection.

Journal ArticleDOI
01 May 1985-Polymer
TL;DR: In this paper, the radiation-induced hexagonal phase diagrams of irradiated polyethylenes have been studied as a function of pressure to 5 kbar, and used as a basis for comparing the radiation induced hexagonal phases with the hexagonal and pseudo-hexagonal rotator phases of n-paraffins and with disordered hexagonal (anabaric) structure formed by linear polyethylene at high pressure.