Screening agents

The chromophores are yellow and act as uv screening agents. The reactions occur at surfaces and uv penetration is avoided. Mechanical properties are thereby protected (47). 

For many processes, one or more predominant factors effectively minimize the number of possibilities for plant location. Raw material and transportation costs may be such that a plant must be located near a source. Thus, only the sites near to sources of raw material need be studied and these may be few in number. Similarly, labor requirements may be hear y enough to eliminate cities below a certain size. These and other factors serve as effective screening agents that save both time and money. 

See Free-radical scavengers, Peroxide decomposers, Quenchers, Ultraviolet absorbers, Ultraviolet screening agents. 

Quantum yields and lifetimes of emission (fluorescence) as well as other principal rates of deactivation have been measured on 2-hydroxy benzophenone and 2-hydroxyphenyl benzotriazole derivatives. Polymerizable UV screening agents have been prepared and copolymerized with acrylics in order to obtain transparent films containing nonfugitive UV screening agents. Preliminary results of studies of photodegradation on these copolymers are also reported here. 

The function of MAAs as intracellular screening agents has been inferred in numerous red algae from a decrease in concentration with increasing depth (Hoyer et al. 2001,2003). Supra- and eulittoral red algal species typically experience... 

Based on higher TOP, yield factor and screening efficiency values, it can be safely concluded that WP and RP are better screening agents than HC and other screening agents. 

Apart from interest in its synthesis and properties, some of the work on indolizines has been concerned with the search for drugs, for dyestuffs and for light-screening agents used in photographic emulsions. 

The literature confirms that the fragrance mix remains the best screening agent for contact allergy to perfumes because it can detect some 70 to 80% of all perfume allergies.10,11 However,... 

The convenient UV absorption region of 2,5-diaryl-1,3,4-oxadiazoles enables them to be used as light-screening agents and optical bright-eners.8-9-12 13 174... 

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