Properly Stacked Materials

Load the sample on an appropriate RP column (internal diameter of the column chosen according to the starting biological material available, 300 A for granulometry, internal diameter from 3.8 to 7 mm, a Ci8 or C8 column is recommended for step 1). It is recommended to equilibrate the column with 2% acetonitrile in acidified water (0.05 % TFA) to remove the hydrophilic molecules and to properly stack the interesting material. 

Storage Segregated storage Uncongested storage of combustibles gangways/adequate breaks Material stacked in the open should be away from windows Flammable liquids in properly designed storerooms bulk quantities in fixed, bunded, adequately spaced tanks... 

It has been recognized for some time that fluids in motion, such as the atmosphere or the ocean, disperse added materials. This properly has been exploited by engineers in a variety of ways, such as the use of smoke stacks for boiler furnaces and ocean ontfalls for the release of treated wastewaters. It is now known that dilution is seldom the solution to an enviromnental problem the dispersed pollutants may accumulate to undesirable levels in certain niches in an ecosystem, be transformed by biological and photochemical processes to other pollntants, or have nnanticipated health or ecological effects even at highly dilute concentrations. It is therefore necessary to rmderstand the transport and transformation of chemicals in the natural environment and through the trophic chain ctrlminating in man. 

Much unnecessary exposure to harmful materials arises from the accumulation of dust, other solids, and liquids around a workstation, as well as open containers of solvents and other chemicals stacked in open storage areas. Enforcement of cleanliness and tidiness can do much to reduce this unnecessary exposure. A regular cleanup schedule should be instituted along with immediate cleanup of spills, covering of open containers, and general tidy practices. Toxic wastes should not be allowed to accumulate. Arrangements should be made for their proper disposal. 

Polymeric proton exchange membrane needs to be maintained properly humidified to guarantee a satisfactory ion conductivity during stack operation (see Sect. 3.2). In fact it exists a strong relationship between proton conductivity and water content of Nafion material used as membrane in PEMFC [24, 25]. Unfortunately the water produced at cathode side and the air moisture could be not sufficient to maintain properly wet the membranes in all working conditions, because of complex phenomena involving water within MEA [26] (Fig. 4.7). 

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