Sensitivity to drying

Norris, W. P. et al., Aust. J. Chem., 1983, 36, 306 A powerful high explosive, of comparable sensitivity to dry picric acid. 

While Giardia is sensitive to freezing of soil, Cryptosporidium is more resistant. Mahdy et al. (2008) reported Giardia cysts in soil were inactivated after 7 days at -4 °C, but Cryptosporidium could survive for >12 weeks. However, persistence of both protozoa was reduced to 8 weeks at 4 °C and 4 weeks at 25 °C (Mahdy et al., 2008). Cryptosporidium have been shown to be particularly sensitive to drying. Various studies have shown less than 5% viability following 4 h of air drying at room temperature (Anderson, 1986 Nasser et al., 2007 Robertson et al, 1992). 

Herpesviruses range in size from 120 to 300 nm and have DNA genomes and outer lipid membranes (envelopes). As enveloped viruses, herpesviruses are sensitive to drying and adverse conditions. Herpesviruses are spread by inoculation of susceptible mucous membranes or direct cell-to-cell contact. Over 100 herpesviruses have been identified, but only 5 cause human eye infections with any frequency herpes simplex virus-1 (HSV-1), herpes simplex virus-2 (HSV-2), varicella zoster virus (VZV), cytomegalovirus (CMV), and Epstein-Barr virus. Herpesviruses can cause blepharitis, conjunctivitis, epithelial and stromal keratitis, uveitis, retinitis, and ARN. HSV-1 is the most frequent cause of primary and recurrent eye disease. The host immime system influences the rates of reactivation. Immimocompromised patients tend to have more frequent reactivations and more severe disease manifestations. The strain of virus also affects the... 

Another important criterion of sensitivity to drying is the permeability coefficient in relationship (76) or the moisture permeability coefficient according to Lykov. This is defined for the stage of constant drying rate as ... 

Amorphous silica has also been mentioned as a starting metal oxide material for the preparation of particulate mesoporous membranes. These membranes were prepared from commercial sols, Ludox (DuPont) or Cecasol (Sobret), and coated on a macroporous a-alumina support [35]. In contrast to crystalline membrane materials such as alumina, titania or zirconia, the evolution of pore size with temperature of amorphous silica membranes was revealed to be more sensitive to drying conditions than to firing temperature (Table 7.1). When heat-treated for several hours at 800°C the silica top layer transformed from an amorphous state to cristobalite. 

Mushroom mycelium is extremely sensitive to dry air. Although a fully colonized substrate is primarily protected from dehydration by its container (the tray, jar or plastic bag), the cropping surface remains exposed. Should the exposed surface dry out, the mycelium dies and forms a hardened mat of cells. By covering the surface with a moist casing layer, the mycelium is protected from the damaging effects of drying. Moisture loss from the substrate is also reduced. 

Although virus survival on many types of inanimate surfaces and objects is frequently much longer [4], viruses, which are particularly sensitive to drying, may survive better on the skin than when dried onto surfaces, depending on the ambient relative humidity. 

Unstable water-soluble vitamins, such as ascorbic acid, are sensitive to drying. The loss of ascorbic acid is dependent on the presence and type of heavy metals, such as copper and iron, light, water activity level in the product, dissolved oxygen, and the temperature of drying. The losses of ascorbic acid during drying have been between 10% and 50%. 

Most detergents are substances which are sensitive to drying, so the drying time of the ethanol extract should be limited to 2 hours at 83 °C. 

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