Non-resistant

Where a large collection of data exists then it may be effectively condensed in the form of diagrams. A popular method is the use of iso-corrosion rates plotted on co-ordinates of temperature and concentration for one material and one chemical. Because of the large amount of data on the common acids there are many examples of this type of diagram, e.g. the work of Berg who has chosen metals and alloys that are readily available. He has excluded many metals and alloys on the grounds that they are either Non-resistant or can be substituted by cheaper materials. ... 

Most of the desert pavement stones are covered with a brown-black and shiny crust. When the stones are composed of limestone, the dark crust contrasts strongly with the much lighter inside color exposed on fracture surfaces. The crust forms on various stones, both sedimentary and igneous and is also known under the name of desert varnish , or desert patina . The varnish is less common on non-resistant rocks such as a soft limestone. These, apparently, disintegrate before the crust has time to develop. 

Less than 1 pphm (parts per hundred million) of ozone in the atmosphere can severely attack non-resistant rubbers. However, there is far less, if any, problem with plastics and tests are rarely made. If required, the methods standardised for rubbers in ISO 1431 [24] could be used, which involve exposure in a special cabinet with controlled levels of ozone. 

Vulcanisation of rubber Natural rubber becomes soft at high temperature (>335 K) and brittle at low temperatures (<283 K) and shows high water absorption capacity, it Is soluble in non-polar solvents and Is non-resistant to attack by oxidising agents. To improve upon these physical properties, a process of vulcanisation is carried out. This process consists of heating a mixture of raw rubber with sulphur and an appropriate additive at a temperature range between 373 K to 415 K. On vulcanisation, sulphur forms cross links at the reactive sites of double bonds and thus the rubber gets stiffened. 

Gay M, Montana AM, Moreno V, Prieto M-J, Perez JM, Alonso C (2006) Studies of interaction of trichloro r 2-cis-N, N-dimethyl-l-[6-(N , N -dimethyl-ammoniummethyl)-cyclohex-3-ene-l-yl]-methylammonium platinum(II) chloride with DNA effects on secondary and tertiary structures of DNA. Cytotoxic assays on human ovarian cancer cell lines, resistant and non-resistant to cisplatin. Bioorg Med Chem 14 1565-1572... 

A. A. Meharg, J. Hartley-Whitaker, Arsenic uptake and metabolism in arsenic resistant and non-resistant plant species, New Phytol., 154 (2002), 29-43. 

Redfem, R., Gill, J.E. (1980). Laboratory evaluation of bromadiolone as a rodenticide for use against warfarin-resistant and non-resistant rats and mice. J. Hyg. (Land.) 84(2) 263-8. 

TABLE I The comparative growth of resistant and non-resistant H35 cells treated with MTX-BSA. 

In contrast when the cell extracts from the [ H]MTX(poly-D-lysine) experiment were applied to the Sephadex 6-75 column only the undegraded complex with Blue Dextran 200 was observed. When the experiment was repeated with the non-resistant H35 cells, similar results were obtained. 

Although we have just emphasized the thrust in pesticide research towards the development of environmentally non-resistant species, natural pyrethrin is so labile, especially in sunlight, that cattle barns, for example, would need to be sprayed by pyrethrin several times a day forfly control. The modern derivatives ofpyrethrin retain high selectivity towards insects and low mammalian toxicity but they are resistant during a few days. Some examples of other pesticides were considered in Chapter 11. 

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