Aerial Environments

Chemical processes that occur in the soil and aerial environment determine the extent and rate of all plant metabolic processes. The crop growth factors—water, light, essential nutrient elements (Table 1), temperature, and space—are utilized most efficiently when the chemical, physical, and microbiological interactions among the crops, soil, and air are optimal. 

Fig. 1. Comparisons between the predicted values of daily growth and those measured nondestructively by means of gas exchange of whole plants exposed to different aerial environments.

Apart from UV radiation, there exist other phenomena in an aerial environment that require adaptation of plant life one concerns the relatively low humidity, and another the feeding pressure of herbivores. As in all chemical phenomena at the water/land interface, cinnamates are involved. Resistance to desiccation is provided by the water-impervious coating with waxes containing cutin in the aerial parts and suberin in the underground parts and at wound surfaces. Both... 

Mechanical strength is a property generally associated with secondary walls these walls contain substantial deposits of cellulose microfibrils and lignin, a highly cross-linked phenolic polymer that is synthesized and covalently linked into the wall at the cessation of cell expansion. Secondary walls allow plants to exploit the aerial environment and account for the ability of eucalyptus and redwood trees to reach heights of more than 100 m. 

The extreme climatic and physical environments in which propellers operate test the limits of aerodynamics, mechanical engineering, and structural theory. Depending upon the size of the power source, aerial propellers can he made from wood, metal, or composite materials and feature from two to six long... 

Methyl parathion has been released to the environment mainly as a result of its use as an insecticide on crops. It is applied to agricultural crops by aerial or ground spraying equipment. Methyl parathion has been detected in surface waters and sediments, rainwater, aquatic organisms, and food. There are no known natural sources of the compound. Methyl parathion has been identified in at least 16 of the 1,585 hazardous waste sites on the NPL (HazDat 2001). 

Draper WM, Street JC. 1981. Drift from a commercial, aerial application of methyl and ethyl parathion An estimation of potential human exposure. Bull Environ Contam Toxicol 26 530-536. 

Nuclear power plants in the United States are supposed to be designed well enough to prevent accidents as serious as the one at Chernobyl. Nevertheless, the Three Mile Island plant in Pennsylvania, an aerial view of which is shown in Figure 22-14Z). experienced a partial meltdown in 1979. This accident was caused by a malfunctioning coolant system. A small amount of radioactivity was released into the environment, but because there was no explosion, the extent of contamination was minimal. 

Draper, W.M., R.D. Gibson, and J.C. Street. 1981. Drift from and transport subsequent to a commercial aerial application of carbofuran an estimation of potential human exposure. Bull. Environ. Contam. Toxicol. 26 537-543. 

Forsythe, D.J. and N.D. Westcott. 1994. Carbofuran residues in grasshoppers and vegetation from aerially sprayed prairie pastures potential effects on wildlife. Environ. Toxicol. Chem. 13 299-306. 

Cunningham, P.A. and L.E. Myers. 1986. Dynamics of diflubenzuron (dimilin) concentrations in water and sediment of a supratidal saltmarsh site following repetitive aerial applications for mosquito control. Environ. Pollut. 41A 63-88. 

Sundaram, K.M.S., S.B. Holmes, D.P. Kreutzweiser, A. Sundaram, and P.D. Kingsbury. 1991. Environmental persistence and impact of diflubenzuron in a forest aquatic environment following aerial application. Arch. Environ. Contam. Toxicol. 20 313-324. 

Summerlin, J.W., A.C.F. Hung, and S.B. Vinson. 1977. Residues in nontarget ants, species simplification and recovery of populations following aerial applications of mirex. Environ, Entomol. 6 193-197. 

Wiemeyer, S.N., T.G. Lamont, C.M. Bunck, C.R. Sindelar, FJ. Gramlich, J.D. Fraser, and M.A. Byrd. 1984. Organochlorine pesticide, polychlorobiphenyl, and mercury residues in bald eagle eggs — 1966-79 — and their relationships to shell thinning and reproduction. Arch. Environ. Contam. Toxicol. 13 529-549. Wolfe, J.L. and B.R. Norment. 1973. Accumulation of mirex residues in selected organisms after an aerial treatment, Mississippi, 1971-1972. Pestic. Monitor. Jour. 7 112-114. 

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