Seeing Conditions

The study of atmospheric seeing has become a relatively advanced science, and the telescope builder is well advised to consult the experts in choosing a site or designing an enclosure. Having chosen a site, one may be guided by the tmism that seeing seldom improves by disturbing Mother Nature. 

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Titanium dioxide is extensively used for both house paint and artist s paint, because it is permanent and has good covering power. Titanium oxide pigment accounts for the largest use of the element. Titanium paint is an excellent reflector of infrared, and is extensively used in solar observatories where heat causes poor seeing conditions. 

The four ESO s 8 m Very Large Teleseopes, built on NTT s experienee, routinely deliver data limited by the sole atmospherie turbulence, even under best seeing conditions, and within unprecedented reliability. 

Under 1 arcsec seeing, the LGS FWHM was 1.4 arcsec. Images taken with the Keck primary mirror defocused (Fig. 24) demonstrated the level of distortion expected for an off-axis projection system. Low-level scattering was also minimal, consistent with expectations and seeing conditions. 

To avoid gas-liquid mass transfer Hmitation, which would have a negative influence on productivity, in correctly operated bioreactors there are turbulent flow conditions with more or less pronounced turbulence, for which the Reynolds stress formula (Eq. (2)) can be used. Whereas, as a rule there is fully developed turbulent flow in technical apparatuses (see condition (6) and explanations in Sect. 8), this is frequently not the case in laboratory fermenters. Equations (3) and (4) are then only valid to a limited extent. 

The value of the product v x ro becomes critical as, on one hand (see condition (42)), it must be low, but on the other it must be high enough to satisfy <5, diffusion layer is depicted with a discontinuous line) just fulfils both conditions, except in the rear downstream flow if v < 10-6 m2 s. ... 

The consequences of interstellar dust may be seen with the unaided eye. Under good seeing conditions dark patches can be observed in the Milky Way. These dark areas, we now know, do not result from the irregular distribution of stars in our galaxy but rather from the very effective obscuration of starlight by irregular clouds of small particles, the interstellar dust. 

This results when 5-amino-2-hydroxyphenylarsinie acid is treated with cyanogen bromide (see conditions given for p-carbamidophenylarsinic acid, p. 209). It forms needle-shaped crystals, soluble in hot water or alkalis, insoluble in mineral acids. 

Meteor activity is often described in terms of the number of meteors observed per hour. The observed hourly rate of meteors will be dependent upon the prevalent seeing conditions, and factors such as the presence of a full moon, local light pollution, and... 

Figure 20.4 Pulsed polarography. NPP and DPP techniques. The diagram shows at which instants the measurements are made (see the arrows a and h). Examples of measurements. The measurement of ascorbic acid (vitamin C) in a fruit juice (see conditions) corresponds to an oxidation on the working electrode.

Fig. 4. Hydrodynamic voltammogram of 7.0 x 10 M phenol. See conditions for Fig. 3. (From Wehmeyer et al., 1983, with permission.)...

Variables optimized by experimental design Dichloromethane-ethanol solvent mixture was found to be the most efficient solvent SEE conditions 0.3 g urban air particulate matter, 0.5 g river sediment modifier added, different modifiers (methanol, CH2CI2, toluene, hexane, acetonitrile, aniline, diethylamine, acetic acid and its mixture) and concentrations (1 to 10%), 400 atm, 80°C, 1 ml/min, 5 min static,... 

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