Molecular airborne

Figure Bl.4.3. (a) A schematic illustration of the THz emission spectrum of a dense molecular cloud core at 30 K and the atmospheric transmission from ground and airborne altitudes (adapted, with pennission, from [17]). (b) The results of 345 GHz molecular line surveys of tlu-ee cores in the W3 molecular cloud the graphics at left depict tire evolutionary state of the dense cores inferred from the molecular line data [21],...

Thiuram Sulfides. These compounds, (8) and (9), are an important class of accelerator. Thiurams are produced by the oxidation of sodium dithiocarbamates. The di- and polysulfides can donate one or more atoms of sulfur from their molecular stmcture for vulcanization. The use of these compounds at relatively high levels with litde or no elemental sulfur provides articles with improved heat resistance. The short-chain (methyl and ethyl) thiurams and dithiocarbamates ate priced 2/kg. Producers have introduced ultra-accelerators based on longer-chain and branched-chain amines that are less volatile and less toxic. This development is also motivated by a desire to rninirnize airborne nitrosamines. 

Because of their hydrophobic nature, siUcones entering the aquatic environment should be significantly absorbed by sediment or migrate to the air—water interface. SiUcones have been measured in the aqueous surface microlayer at two estuarian locations and found to be comparable to levels measured in bulk (505). Volatile surface siloxanes become airborne by evaporation, and higher molecular weight species are dispersed as aerosols. 

Because SPMDs have high sampling rates (Rs s) for vapor phase contaminants, all SPMDs are assembled in an environmentally controlled room equipped with an activated carbon air filtration system for the removal of airborne contaminants. SPMDs of almost any length can be prepared after allowance of space for the molecular welds or heat seals (i.e., 2.5 cm for each end). However, different... 

Sabljic, A., H. Glisten, J. Schonherr, and M. Riederer. 1990. Modeling Plant Uptake of Airborne Organic Chemicals. 1. Plant Cuticle/Water Partitioning and Molecular Connectivity. Environ. Sci. Technol. 24, 1321-1326. 

The application of C (Is) NEXAFS spectroscopy to C speciation in airborne particulate matter is still in its early stages, and the assignment of NEXAFS absorption peaks to particular molecular species is not an easy task. On the other hand, there are also experimental evidences that exposure to radiation can induce reactions and alter the sample, which implies the need to monitor radiation damages by performing more than one scan of a spectrum (Braun, 2005 Braun et al., 2006). Nevertheless, this analytical technique can be used not only to identify and fingerprint structural characteristics of OC but also to simulate the chemical and physical aging of airborne particulate matter (Braun et al., 2006). 

Hydrogen chloride is the first chlorine-bearing interstellar molecule to have been detected. Its lowest rotational transition (J = 1 -> 0) at 625.9 GHz has been observed in the Orion Molecular Cloud (OMC-1) in emission with the Kuiper Airborne Observatory, (Blake, Keene, and Phillips, 1985) since atmospheric opacity at this... 

Worker exposure to alkanes, especially the lower-molecular-mass compounds, is most likely to come from inhalation. In an effort to set reasonable values for the exposure by inhalation of vapors of solvents, hydrocarbons, and other volatile organic liquids, the American Conference of Governmental Industrial Hygienists sets threshold limit values (TLVs) for airborne toxicants.1 2 The time-weighted average exposure (E) is calculated by the formula... 

Sabljic, A., Glisten, H., Schonherr, J., and Riederer, M., Modeling plant uptake of airborne organic chemicals. Plant cuticle/water partitioning and molecular connectivity, Environ. Sci. Tech., 24, 1321-1326, 1990. 

Acridine char nitrogen, retention as function of burnoff, 307/, 308/ Advection fluxes, calculation, 41-43 Aerosol particle size distribution, molecular clusters, 317 Aerosol scavenging pathway, acetic and formic acid formation, 223 Aerosol species, transformation over the western Atlantic, 52 Aerosol sulfate airborne determination, 298 See also Sulfate... 

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