Mineralogical system

The dominant processes controlling the movements of P through terrestrial ecosystems are schematically presented in Fig. 14-4. In a general way, the overall movement of P on the continents may be envisioned as the constant erosion of P from continental rocks and transport in both dissolved and particulate form by rivers to the ocean, stopping occasionally along this pathway to interact with biological and mineralogical systems. 

For this scheme, m, n, and p have been defined for minerals as being even numbers. Notice also that the formula for bismuthite and aikinite have been doubled in keeping with the reported model where only (l) = Cu and (ll) = Pb are known [78]. Also defined are the terms A (A=m/4) and B (B=n/2). It has been observed that for most mineralogical systems, when A-i-B is even, the corresponding space group was the non-centrosymmetric, Pmc2i, and when A-vB is... 

Thus, these data represent a mineralogical system of four main variables, changing with geological time (=depth) (Figure 2). The four main mineralogical phases are ... 

The mineralogical system described above is one clue to the understanding of the paleogeographical set-up during the late Cretaceous in Israel, as well as a main factor for any assessment of oil shale s quality. 

Ostwald s step rule holds that a thermodynamically unstable mineral reacts over time to form a sequence of progressively more stable minerals (e.g., Morse and Casey, 1988 Steefel and Van Cappellen, 1990 Nordeng and Sibley, 1994). The step rule is observed to operate, especially at low temperature, in a number of mineralogic systems, including the carbonates, silica polymorphs, iron and manganese oxides, iron sulfides, phosphates, clay minerals, and zeolites. 

Processes involving degradation of organic matter typically exhibit non-linear and delayed developments. Different from mineralogical systems, these effects cannot sufficiently be described, modelled and predicted. This is even worse, as important decisions on waste technologies would need information about the long-term behaviour of critical pollutants. 

Chenevix obtained chlorine dioxide by the action of sulphuric acid on potassium chlorate, but he did not determine its composition. He analysed corundum and examined the chemical nature of the humours of the eye. Nicolas found phosphate of lime in them, but this was not found by Chenevix or by Berzelius. Chenevix analysed native cuprous oxide ( red octahedral copper ore ) from Cornwall, finding its composition more correctly than Proust (see p. 646), and several other minerals, and examined the magnetism of nickel and cobalt. He criticised the mineralogical systems of Werner and Haiiiy. ... 

An important application in that respect is distinguishing cis and trans configurations of an octahedral 64(011)2 (or (0H)402) Fe " coordination, which quite often occurs in mineralogical systems (Fig. 3.3). Simple point-charge calculations show that the quadrupole splitting should follow the relation Atrans = Ads-... 

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