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The solar components

Noble gas abundances in lunar soils and chondrites, (a) Elemental abundance patterns for trapped solar wind in lunar soils, normalized to solar system abundances, (b) Elemental abundance patterns for planetary trapped noble gases, normalized to solar system abundances. This diagram is intended to illustrate patterns only vertical positions are arbitrary. Modified from Ozima and Podosek (2002). [Pg.373]


In general, the test object caimot be heated above its operating temperature in space. As free molecular conditions are obtained around the object, it outgases and, if solar-spectmm photons impinge on the object, increases the release of gas. Because the object is in a vessel and the area of the hole lea ding to the gas pump is small compared with the projected interior area of the vessel, molecules originating from the test object can return to the test object provided that they do not interact in some manner with the vessel walls and the other components of the molecular environment. The object inside the vessel estabhshes an entirely different system than the clean, dry, and empty vacuum vessel. The new system no longer has the capabiUty to reach the clean, dry, and empty base pressure within a reasonable time. [Pg.368]

Stratospheric ozone is in a dynamic equilibrium with a balance between the chemical processes of formation and destruchon. The primary components in this balance are ultraviolet (UV) solar radiation, oxygen molecules (O2), and oxygen atoms (O) and may be represented by the following reactions ... [Pg.159]

The principal components of atmospheric chemical processes are hydrocarbons, oxides of nitrogen, oxides of sulfur, oxygenated hydrocarbons, ozone, and free radical intermediates. Solar radiation plays a crucial role in the generation of free radicals, whereas water vapor and temperature can influence particular chemical pathways. Table 12-4 lists a few of the components of each of these classes. Although more extensive tabulations may be found in "Atmospheric Chemical Compounds" (8), those listed in... [Pg.169]

FIGURE 11.31 Radiaiion fluxes at the buildirtg facade the solar radiation components (direct or beam, diffuse, and reflected radiation from the ground or other buildings) and the components of the radiation back from the building facade (reflected solar and thermal infrared radiation from the building envelope). [Pg.1063]

The solar radiation absorbed on external building surfaces increases the wall surface temperature, thus leading to a change in the heat conducted through the component. In low-wind conditions, free convective flows drift up the warm external wall surface. This changes the convective heat transfer and leads to increased temperatures of supply air for natural ventilation. [Pg.1065]

In addition to biogeochemical cycles (discussed in Section 6.5), the hydrosphere is a major component of many physical cycles, with climate among the most prominent. Water affects the solar radiation budget through albedo (primarily clouds and ice/snow), the terrestrial radiation budget as a strong absorber of terrestrial emissions, and global temperature distribution as the primary transporter of heat in the ocean and atmosphere. [Pg.124]

O Exposure to ultraviolet radiation from the sun is recognized as one of the primary triggers for skin carcinogenesis. Based on their wavelengths, UV radiation is divided into three components UVA (320 00 nm), UVB (280-320 nm), and UVC (200-280 nm).15 UVB accounts for only 5% of the solar radiation that reaches the earth, but it is the primary carcinogenic component in the UV spectrum.15 The following sequence of events describes the process in which UV radiation causes skin cancer (1) UV radiation reaches the earth, and on the skin, it reaches the cells in the epidermal layer (i.e., squamous cells, basal cells, and melanocytes),16 (2) the UV radiation (specifically... [Pg.1427]

The Planetary Energy Balance [3] of Incoming Solar (340 W/m2) minus Reflected (101 W/m2) minus Radiated (238 W/m2) = 1 W/m2. This excess energy warms the oceans and melts glaciers and ice sheets. The GHG component is 2 W/m2. The amount of heat required to melt enough ice to raise sea level 1 m is about 12 Watt-years (averaged over the planet)—energy that could be accumulated in 12 years if the planet is out of balance by 1 W/m2 per year. [Pg.53]

The same group, in a previous work, reported on the realization of a hybrid anode electrode [197]. An appreciable improvement in methanol oxidation activity was observed at the anode in direct methanol fuel cells containing Pt-Ru and Ti02 particles. Such an improvement was ascribed to a synergic effect of the two components (photocatalyst and metal catalyst). A similar behavior was also reported for a Pt-Ti02-based electrode [198]. Another recent study involved the electrolysis of aqueous solutions of alcohols performed on a Ti02 nanotube-based anode under solar irradiation [199]. [Pg.114]

Fig. 1. The color-magnitude diagram of NGC 188 from [2] with the location of the detached eclipsing binary V12 [3] overplotted. From radial-velocity measurements we find (assuming an inclination of 90 degrees since we do not yet have photometry of the eclipses) that the masses of the two components are 1.06 and 1.08 solar masses. We estimate that we will be able to reach a precision of 1% in the mass estimate. We are in the process of acquiring eclipse photometry such that the radii and orbital inclination can be determined. Since both components are very close to the cluster turnoff their masses and radii can be directly used to give a very accurate age estimate for the cluster by comparing to isochrones in the (mass, radius) plane and requiring that they both lie on the same isochrone. Fig. 1. The color-magnitude diagram of NGC 188 from [2] with the location of the detached eclipsing binary V12 [3] overplotted. From radial-velocity measurements we find (assuming an inclination of 90 degrees since we do not yet have photometry of the eclipses) that the masses of the two components are 1.06 and 1.08 solar masses. We estimate that we will be able to reach a precision of 1% in the mass estimate. We are in the process of acquiring eclipse photometry such that the radii and orbital inclination can be determined. Since both components are very close to the cluster turnoff their masses and radii can be directly used to give a very accurate age estimate for the cluster by comparing to isochrones in the (mass, radius) plane and requiring that they both lie on the same isochrone.
Apart from inversions, there is another way to determine whether or not there is mixing in the Sun. Any spherically symmetric, localized sharp feature or discontinuity in the Sun s internal structure leaves a definite signature on the solar p-mode frequencies. Gough (1990) showed that changes of this type contribute a characteristic oscillatory component to the frequencies z/ / of those modes which penetrate below the localized perturbation. The amplitude of the oscillations increases with increasing severity of the discontinuity, and the wavelength of the oscillation is essentially the acoustic depth of the sharp-feature. Solar modes... [Pg.285]

The volatile-trapping mechanism has a further problem associated with the temperature. Very volatile molecules such as N2, CO and CH4 are not easily trapped in laboratory ice simulation experiments unless the ice temperature is 75 K, which is somewhat lower than the estimated Saturnian subnebula temperature. This has led to the suggestion that the primary source of nitrogen within the Titan surface ices was NH3, which became rapidly photolysed to produce H2 and N2 upon release from the ice. The surface gravity is insufficient to trap the H2 formed and this would be lost to space. However, the origin of methane on Titan is an interesting question. Methane is a minor component of comets, with a CH4/CO ratio of clCT1 compared with the present atmospheric ratio of > 102. The D/H ratio is also intermediate between that of comets and the solar nebula, so there must be an alternative source of methane that maintains the carbon isotope ratio and the D/H isotope ratio and explains the abundance on Titan. [Pg.292]


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