Deterioration storage

Batteries stored at -20°C are expected to retain approximately 80% to 90% of their initial capacity after 10 years. Since low temperatures retard deterioration, storage at low temperatures is an advantageous method for preserving battery capacity. A storage temperature of 0°C is very effective. 

Spike recoveries for samples are used to detect systematic errors due to the sample matrix or the stability of the sample after its collection. Ideally, samples should be spiked in the field at a concentration between 1 and 10 times the expected concentration of the analyte or 5 to 50 times the method s detection limit, whichever is larger. If the recovery for a field spike is unacceptable, then a sample is spiked in the laboratory and analyzed immediately. If the recovery for the laboratory spike is acceptable, then the poor recovery for the field spike may be due to the sample s deterioration during storage. When the recovery for the laboratory spike also is unacceptable, the most probable cause is a matrix-dependent relationship between the analytical signal and the concentration of the analyte. In this case the samples should be analyzed by the method of standard additions. Typical limits for acceptable spike recoveries for the analysis of waters and wastewaters are shown in Table 15.1. ... 

Biodeterioration. For objects made out of organic materials, mold and insect attack are a principal cause of damage. Microbiological organisms can also be responsible for serious deterioration of outdoor stone. Museums, especially storage areas, are quite conducive to providing the conditions in which infestations can occur. Objects are stored in close proximity, and left untouched for prolonged periods, often with Htde if any ak movement. 

Equipment for storing and handling methanol may be made of carbon or stainless steel. Methanol is aggressive toward copper, zinc, magnesium, tin, lead, and alurninum, which should therefore be avoided. Gasket materials must also be chosen carefiiUy, because some elastomers swell and deteriorate when exposed to methanol. Similarly, the use of plastics for storage is not recommended. 

Plasticizer esters are relatively iaert, thermally stable Hquids with high flash points and low volatihty. Consequently they can be stored safely ia mild steel storage tanks or dmms for extended periods of time. Exposure to high temperatures for extended periods, as encountered ia dmms ia hot climates, is not recommended since it may lead to a deterioration in product quaUty with respect to color, odor, and electrical resistance. 

Storage time by itself is not expected to affect the maintenance of stetiHty. However, longer storage times may increase the incidence of potentially harmful conditions. Frequent handling, wetness, and possible deterioration of the packaging material are typical examples of conditions that may compromise stetiHty and limit the shelf life of a package. The package contents may have a specific shelf life as weU. 

Coal storage results in some deterioration of the fuel owing to air oxidation. Moreover, if inadequate care is taken, spontaneous heating and combustion may result. As the rank of coal decreases, it oxidizes more easily and must be piled more carefully. Anthracite does not usually present a problem. 

During storage, natural pigments often deteriorate with time because of exposure to light, heat, air, and moisture or because of interaction of the components of the food with each other or with the packaging material. The color of maraschino cherries, for example, fares so poorly with storage that they are routinely bleached then artificially colored. 

Siace dimer acids, monomer acids, and trimer acids are unsaturated, they are susceptible to oxidative and thermal attack, and under certain conditions they are slightly corrosive to metals. Special precautions are necessary, therefore, to prevent product color development and equipment deterioration. Type 304 stainless steel is recommended for storage tanks for dimer acids. Eor heating coils and for agitators 316 stainless steel is preferred (heating coils with about 4s m (50 ft ) of heat transfer surface ia the form of a 5.1 cm schedule-10 U-bend scroU are recommended for a 37. 9-m (10,000-gal) tank. Dimer acid storage tanks should have an iaert gas blanket. 

S. Lundgren and E. Jobson, Deterioration of Three-Way Automotive Catalysts, Part II—Oyygen Storage Capacity at Exhaust Conditions, SAE 930944, Society of Automotive Engineers, Warrendale, Pa., 1993. 

The inventoiy system needed is FIFO, which is desirable when inventories are subject to obsolescence or deterioration or when they consist of raw materials that fluc tuate widely in value. The capital investment for a typical aisle-rack storage system having a 5000-paUet capacity (I deep) is 6.5 per stored pallet (this does not include hft-truck investment). 

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