Middle clouds

All of the clouds are low density, because the visibility inside the densest region of the clouds is a few kilometers. The average and maximum optical depths (t) in visible light of all cloud layers are 29 and 40, respectively, versus average and maximum t values of 6 and 350 for terrestrial clouds. Average mass densities for Venus clouds are 0.01-0.02 g m versus an average mass density of 0.1-0.5 g m for fog clouds on Earth. Venus cloud layers are typically divided into the subcloud haze (32-48 km), the lower cloud (48-51 km), middle cloud (51-57 km), upper cloud (57-70 km), and upper haze (70-90 km). 

Cloud types often are classified based on altitude. High clouds have their bases above 7 km (23,000 ft) and include the wispy mare s tail clouds known as cirrus the cirrocumulus, known as mackerel sky and the layers of cirro-stratus. Middle clouds have altitudes between 2 and 7 km (6500 to 23,000 ft), and are either the rounded altocumulus or the layered altostratus. Low clouds have bases from near Earth s surface to about 2 km (6500 ft), and include stratocumulus, stratus, and nimbostratus. Nimbostratus clouds usually bring rain or snow. Clouds with vertical development extend from about 2 to 7 km or more, and include cumulonimbus (thunderhead clouds) and cumulus. 

Venus s atmosphere is predominantly a combination of clouds and haze that extends from an altitude of about 18 miles (30 km) above the planet s surface to an altitude of more than 50 miles (80 km). Its structure appears to consist of three parts. Closest to the surface is a haze of roughly constant density, extending from the bottom of the cloud to an altitude of about 18 miles (30 km). Next is the most obvious layer, a fairly dense, sharply defined cloud at an altitude of about 30 miles (50 km). This cloud consists primarily of droplets of sulfuric acid. Finally, a haze that gradually becomes thinner with altitude is located above the middle cloud to an altitude of about 50 miles (80 km). The density of the Venusian cloud structure at various altitudes is shown in the graph on page 102. 

Figure 15.31 shows a zonally averaged climatology based on six cloud types high clouds (Ci, Cs), middle clouds (As, Ac), low clouds (St, Sc), cumulus, cumulonimbus, and nimbostratus. The altitude, thickness, and cloud cover are shown with a 10° resolution. Note that the cirrus base heights vary with latitude but their thickness is fixed at 1.7 km due to limitations of the observations. 

Figure 5.3 shows a moment of flame propagation in an unconfined propane cloud. On the left side, a flame is propagating through a premixed portion of the cloud its flame is characteristically weakly luminous. In the middle of the photograph, fuel-rich portions of the cloud are burning with characteristically higher flames in a more-or-less cylindrical, somewhat tilted, flame shape. 

It may also be represented as a hexagon with a circle in the middle. The circle is a symbol of the n cloud encircling the benzene ring. The delocalized electrons associated with the benzene ring impart very special properties to aromatic hydrocarbons. They have chemical properties of single-bond compounds such as paraffin hydrocarbons and doublebond compounds such as olefins, as well as many properties of their own. 

FIGURE 2.1 A side view of the structure of the prototype G-protein-coupled, 7TM receptor rhodopsin. The x-ray structure of bovine rhodopsin is shown with horizontal gray lines, indicating the limits of the cellular lipid membrane. The retinal ligand is shown in a space-filling model as the cloud in the middle of the structure. The seven transmembrane (7TM) helices are shown in solid ribbon form. Note that TM-III is rather tilted (see TM-III at the extracellular and intracellular end of the helix) and that kinks are present in several of the other helices, such as TM-V (to the left), TM-VI (in front of the retinal), and TM-VII. In all of these cases, these kinks are due to the presence of a well-conserved proline residue, which creates a weak point in the helical structure. These kinks are believed to be of functional importance in the activation mechanism for 7TM receptors in general. Also note the amphipathic helix-VIII which is located parallel to the membrane at the membrane interface. 

Under atmospheric conditions flame travel in an unconfined gas cloud precedes as definite flame front at a determinable velocity. For example, where the ignition point is located in the middle of a volume of a gas, the flame front tends to generally proceed as an expanding sphere from the point of origin. Flame... 

The worst chemical disaster in history occurred on December 3, 1984, in Bhopal, India, a city of some 1.6 million people in the state of Madhya Pradesh. On that date in the middle of the night, a tank at the Union Carbide India Ltd. plant leaked between 25 and 40 tons of methyl isocyanate, a volatile colorless liquid, into the atmosphere of Bhopal. This highly toxic gas settled onto the city and its inhabitants in a silent, if odorous, cloud. The results were horrific some 3800 people died and another 2700 experienced total or partial permanent disability. By some estimates, more than 10% of the population of Bhopal—170,000 people—suffered some adverse effect from the methyl isocyanate leak. 

While such data are not included in this report, our work has also shown that in FCC operations the acidic matrix is able to better crack and isomerize more n-paraffins, thus reducing the n-paraffin content in middle distillate and thereby the characteristic high cloud point associated with it, while also raising octane number by removing or isomerizing n-paraffins in the gasoline fraction. 

Plate 7.1. Natural history of Utetheisa omatrix (left panel). Adult male (top) larva feeding on seedpod of Crotalaria mucronata (middle) adult male courting a female (bottom). The yellow genitalic coremata are partially inflated and thrust toward the female. Natural history of Cosmosoma myrodora (right panel). Adult male resting on leaf of the larval host plant Mikania scandens (top) larva (middle) male courting female (bottom). The flocculent has been released and forms a cloud around the pair. 

Figure 24.7 Two extreme input scenarios for chemical being spilled into a river, (a) Constant input rate J (mass per unit time) during time At leading to a rectangular concentration profile, Cin = J IQ. The dashed line shows how dispersion acts on the edges and leaves the concentration in the middle of the cloud unchanged. (b) Gaussian input scenario. The time integral between t = -2G and t = 2c0 comprises 95% of the total input 3H (see Box 18.2). Dispersion causes the variance to increase according to Eq. 24-60. The maximum concentration is given by Eq. 24-62.

The observation of CST with practical precision is usually very simple. The two liquids are placed in a test tube and are stirred with a thermometer while heating or cooling until the liquids just mix (while heating) or just cloud (on cooling). Determinations of the cloud point are usually more precise than determinations of the temperature of disappearance of two phases. There is very little risk of subcooling a liquid mixture below the CST, and having it remain homogeneous. When the upper layer becomes small before it disappears, more of the major component of the upper layer is added, and the observation is repeated until the interface disappears near the middle of the system. This is necessary in order to... 

In recent years, the middle distillates have been in growing demand as fuel oils and Diesel fuel. As mentioned under the discussion on Diesel-fuel additives, it has been possible to meet this demand only by the inclusion of distillates from catalytic cracking operations. These have higher volumetric heat contents and lower pour and cloud points, but their use has caused problems of stability and compatibility in storage, necessitating use of anti-screen-clogging agents (14, 41, 4 )-... 

FIGURE 3.14 A TT-bond is formed when electrons in two 2p-orbitals pair and overlap side by side. The middle diagram shows the density of the resulting electron cloud, and the bottom diagram shows the corresponding boundary surface. Even though the bond has a complicated shape, with two lobes, it is occupied by one pair of electrons and counts as one bond. 

At all times bodies exhale a subtle vapor, which is manifested more clearly in summer. The warm air sublimates the waters into vapors, and attracts them to itself. When, after a rain, the rays of the sun beam upon the earth, one sees it smoke and exhale itself in vapor. These vapors hover in the air in the form of fogs, when they do not rise far above the surface of the earth but when they mount to the middle region, one sees them float, here and there, in the form of clouds. Then they are resolved into rain, snow, hail, etc., and fall to return to their origin. The workman feels this to his great... 

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