Atmospheric applications

Electric Power Research Institute, "Survey of Plume Models for Atmospheric Application," Report No. EPRI EA-2243. System Application, Inc., Palo Alto, CA, 1982. 

CNTs have been prepared recently by electrolysis and by electron irradiation of tube precursors. For example. Hsu e/ al. [30,31] have described the condensed-phase preparation of MWCNTs by an electrolytic method using a graphite rod (cathode) and carbon crucible (anode) (Fig. 6) in conjunction with molten LiCl as the electrolyte, maintained at 600°C under an Ar atmosphere. Application of a dc current (3-20 A, <20 V) for 2 min yielded MWCNTs (2-10 nm in diameter, >0.5 pm in length) consisting of 5-20 concentric layers with an interlayer... 

The low concentrations of ozone normally present in the atmosphere are sufficient to cause severe oxidation and cracking in polyolefins (2-13) and many other polymers such as polystyrene (6,11,12,14.15). poly(vinyl chloride) ( y, J 2,J 6) and rubbers (11,12,17-20). Where the ozone concentration is increased by air pollution, higher altitudes or the present of electrical machinery, the rate of degradation considerably increases.The prevention of such degradation represents a matter of considerable economic interest since it can greatly improve service life of polymers and plastics. An additional application of this research is to apprise the suitability of polymers for upper atmosphere application (Space Shutle flights) where a plentitude of ozone and atomic oxygen prevails. 

Up to this point we have assumed a fluid occupying an infinite domain. For atmospheric applications a boundary at z = 0, the earth, is present. 

Duval, M.M., (1980) "Source Resolution Studies of Ambient Polycyclic Aromatic Hydrocarbons in the Los Angeles Atmosphere Application of a Chemical Species Balance Method with First Order Chemical Decay", Thesis, Master of Science in Engineering, UCLA. 

Table 4.6 summarizes the wavelength and temperature dependence for O( D) production recommended by Talukdar et al. (1998). Beyond 329 nm, the quantum yield from the spin-forbidden process appears to be 0.05-0.06 (Silvente et al., 1997 Talukdar et al., 1998). The absorption cross sections of 03 become sufficiently small beyond 360 nm that O( D) production beyond this wavelength is not expected to be significant for atmospheric applications. 

FTIR Fourier transform infrared spectroscopy has been used for many years to measure atmospheric gases. Because FTIR has become such a common analytical method, we do not describe the technique itself here but rather refer the reader to several excellent books and articles on the subject (e.g., see Griffiths and de Haseth, 1986 Wayne, 1987). For reviews of some atmospheric applications, see Tuazon etal. (1978,1980), Marshall et al. (1994), and Hanst and Hanst (1994). 

Two types of mass analyzers have been used extensively in atmospheric applications quadrupole mass filters and time-of-flight (TOF) instruments. The use of ion traps is also being increasingly explored for this application. For the fundamental principles of mass... 

The detectors used in mass spectrometers for atmospheric applications are essentially the same as for other MS applications and are commonly electron multipliers, either channeltrons or multichannel plate... 

Hartmann. Infrared collision-induced absorption by N2 near 4.3 pm for atmospheric applications measurements and empirical modeling. Appl. Opt., 35 5911, 1996. 

Small loads are commonly processed in a box furnace. The product is placed on the furnace hearth through a door. Box furnaces may be single-ended or double-ended. A single-ended box furnace is usually used in an air atmosphere application where the product can be removed hot from the furnace for cooling. A double-ended box furnace is usually used in a controlled atmosphere application. In this case a water cooler is attached to one end. The product can be placed on the hearth (in the heat chamber) through the front door, then after the product reaches temperature, it is manually transferred into the water cooler for cooling before it is manually removed out the exit door on the other end of the water cooler. 

A particular, and unusual, atmospheric application of such data involves the formation of noctilucent clouds (NLC s) in the vicinity of the mesopause (at 82 km, in the summer hemisphere, where temperatures can fall as low as 130 K, and ice can exist even at the miniscule ambient water vapor concentrations found there). The presence of laige water-aggregated hydronium ions led to the suggestion [e.g., 63-65] that these provide condensation sites for ice particles. Detailed simulation studies bore out the likely relationship between positive ion nucleation and the behavior of some NLC s [66], notwithstanding a strong possibility that meteoritic dust and smoke also had a dominant role [67], ITie contribution to NLC formation of hydronium-ion/electron... 

Since atmospheric aerosols comprise particles with a wide range of sizes, it is often convenient to use mathematical models to describe the atmospheric aerosol distribution (Seinfeld and Pandis, 1998). A series of mathematical models have been proposed, of which the lognormal distribution has been the most used in atmospheric applications (Seinfeld and Pandis, 1998 Horvath, 2000). Useful discussions of the various aerosol size distribution models are provided by Seinfeld and Pandis (1998) and Jaenicke (1998). In general, atmospheric aerosols size distributions are shown graphically in terms of the volume (or mass) distributions, surface area distributions, or number distributions as a function of particle size (Jaenicke, 1998). 

Clegg, S.L. and Brimblecombe, R (1990) Solubility of volatile electrolytes in multi-component solutions with atmospheric applications. In Chemical Modelling in Aqueous Systems II (eds Melchior, D.C. and Bassett, R.L.). American Chemical Society, Washington, DC. 

Some Properties of Femtosecond Laser Filamentation Relevant to Atmospheric Applications Part I. The Robustness of Filamentation... 

In summary, from the direct observation of the vertical propagation of femtosecond-terawatt laser pulses in the atmosphere, it is demonstrated that not only the filaments, but also the whole beam, have a non-linear behaviour [18]. The overall beam is partially recollimated near to the non-linear focus. Also, filamentation can occur at 2 km altitude, which is essential for remote atmospheric applications of filamentation. 

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