Tropical conditions

The strippable films deposited from solvents in the cold are much thinner (= 0.05-0.25 mm) than those from the hot-dip materials, and their protective properties are not nearly so good. A possible difficulty which must be watched for is the development of brittleness on ageing and consequent difficulty of stripping. Latex films containing inhibitors such as sodium benzoate have been found to deteriorate under tropical conditions, but may have a use in more temperate climates. 

This chapter examines climatic and tectonic controls on erosion in the tropics and the implications of these observations regarding the composition of erosion products in general. The role of glaciations in continental denudation will then be examined and contrasted with tropical conditions. Finally, we will briefly examine human effects. 

Kathpal TS, Singh A, Dhankhar JS, et al. 1997. Pate of endosulfan in cotton soil under sub-tropical conditions in Northern India. Pestic Sci 50 21-27. 

Rao DMR. 1981. Improved cleanup technique for estimation of endosulfan residues from fish tissues under tropical conditions. J Assoc Off Anal Chem 64 340-342. 

Singh NC, TP Dasgupta, EV Roberts, A Mansingh (1991) Dynamics of pesticides in tropical conditions. 1. Kinetic studies of volatilization, hydrolysis, and photolysis of dieldrin and a- and b-endosulfan. J Agric Food Chem 39 575-579. 

The ZOE cement is easy to mix and a greater amount of powder can be incorporated into this cement (5 1 by mass) than any other, where even 4 1 by mass is unusual. Because the ZOE cement is sensitive to moisture it can be formulated to have a long working time under normal room conditions (23 °C, relative humidity 50 %) and a rapid set once placed in the warm and moist conditions of the mouth. This is a considerable clinical advantage, making it convenient to use. The cement can be used in a war pack for use on the battlefield. Nevertheless, sensitiveness to humidity can give rise to problems in use under tropical conditions. 

Storage stability Stable enough for use as a bomb filling even under tropical conditions. However, the agent darkens and deposits a crystalline solid in storage. 

Crude G-series agents are relatively stable at low to moderate temperatures. Stability increases with purity and distilled materials can be stored even under tropical conditions. The presence of moisture facilitates decomposition of agents during storage. Stabilizers... 

Military-specific agents are stable even under tropical conditions and can be stored in glass, aluminum, or steel. Stabilizers are not required. Some potentially dual use agents are sensitive to heat and light and may require stabilizers for long-term storage. 

The principal soil inhabiting pests of corn are the larvae of Diahrotica and white grubs. While more research needs to be done on the dosage requirements and residual effects of the chemicals used to control these important pests under tropical conditions, results to date indicate that the soil insecticides commonly used in the United States, such as chlordan, aldrin, and dieldrin, are promising. 

Among the many factors that affect cotton production are insects and diseases. Probably no other cultivated crop is so attractive to such a wide variety of insects, and in tropical conditions they multiply rapidly and spread. Therefore, the economical production of cotton in these areas, as elsewhere, often depends on whether or not the insects are controlled. 

Kaolinite A clay mineral produced by intense weathering under tropical conditions. As a result, it is depleted in all cations except for silicon and aluminum. 

Evidently rates of decomposition are greater than expected for simple anaerobic decomposition. Figure 3.10 shows comparable rates of organic matter decomposition in soils that were kept continuously flooded or well-drained under otherwise similar, tropical conditions for 3-4years (Neue and Scharpenseel, 1987). Clearly,... 

Figure 3.10 Decomposition of " C-labelled rice straw in (a) well-drained upland soils and (b) continuously submerged lowland soils under tropical conditions (adapted from Neue and Scharpenseel, 1987). Reprinted with permission from Elsevier...

Ammonia volatilization from fertilizers is a function of the type of fertilizer, soil conditions, meteorological conditions-temperature, wind speed, precipita-tion-and fertilizer management. Table 8.6 shows the global use of nitrogenous fertilizers and the corresponding NH3 emissions based on empirical emission factors for different fertilizer types in temperate and tropical conditions (Bouwman... 

THE USE OF A FACTORIAL DESIGN TO EVALUATE THE PHYSICAL STABILITY OF TABLETS AFTER STORAGE UNDER TROPICAL CONDITIONS... 

In section 8.3 a study is described in which the SIR of crushing strength and the SIR of disintegration time are used to evaluate batches of tablets prepared for several combinations of filler-binders and disintegrants, with respect to their physical stability after storage under tropical conditions. 

P. York, A preliminary study of the physical stability of tablets prepared from powders stored under tropical conditions. Pharm., 31 (1976) 383. 

---