GRAS species

Heterogeneous uptake on surfaces has also been documented for various free radicals (DeMore et al., 1994). Table 3 shows values of the gas/surface reaction probabilities (y) of the species assumed to undergo loss to aerosol surface in the model. Only the species where a reaction probability has been measured at a reasonable boundary layer temperature (i.e. >273 K) and on a suitable surface for the marine boundary layer (NaCl(s) or liquid water) have been included. Unless stated otherwise, values for uptake onto NaCl(s), the most likely aerosol surface in the MBL (Gras and Ayers, 1983), have been used. Where reaction probabilities are unavailable mass accommodation coefficients (a) have been used instead. The experimental values of the reaction probability are expected to be smaller than or equal to the mass accommodation coefficients because a is just the probability that a molecule is taken up on the particle surface, while y takes into account the uptake, the gas phase diffusion and the reaction with other species in the particle (Ravishankara, 1997). 

Possible transport mechanisms in a fluid system through the membrane pores are multiple. They vary to a great extent with the membrane pore size and, to a less extent, with chemical interaction between the transported species and the membrane material. Under the driving force of a pressure gra nt, permeants (whether in the form of solvents, solutes or gases) can transport across a membrane by one or more of the mechanisms to be discussed below. The degree by which they affect permeability and permselectivity depends on the operating conditions, membrane characteristics and membrane-permeating species interactions in the application environment. 

Edible fats and/or oils, or mixtures of these, whose origin is vegetable or rendered animal carcass fats or any form of oil from a marine species that has been affirmed as GRAS or listed as a food additive for this use, any or all of which may have been subjected to an accepted process of physico-chemical modification. They may contain small amounts of other lipids such as phosphatides, or unsaponifiable constituents and of free fatty acids naturally present in the fat or oil. 

Most enzymes of industrial importance developed in the past have been derived from species that are GRAS (Generally Regarded as Safe). These include bacterial species for Bacillus and Lactobacillus, and Pseudomonas and fungi from the Ascomycota andZygomycota classes [21]. 

CAM/GRA] Campostrini, 1., Gramaccioli, C. M., Demartin, F., Orlandiite, Pb3Cl4(Se03).H20, a new mineral species, and an associated lead-copper selenite chloride from the Baccu Locci mine, Sardinia, Italy, Can. Mineral., 37, (1999), 1493-1498. Cited on pages 636, 637. 

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