Geological origin

Spherulites have been observed in organic and inorganic systems of synthetic, biological, and geological origin, including moon rocks, and are therefore not unique to polymers. 

The problem with triads, as well as the other important numerical hypothesis due to Prout, is easy to discern in retrospect. It is simply that atomic weight, which both concepts draw upon, is not the most fundamental quantity that can be used to systematize the elements. The atomic weight of any element depends on the particular geological origin of the sample examined. In addition, the atomic weight of any particular element is an average of several isotopes of the particular element. 

Minerals and rocks of similar composition but of different geographic or geologic origin generally include different relative amounts of thorium and uranium impurities after generally long periods of time they also include, therefore, different relative amounts of the isotopes of lead. The... 

There is no evidence to suggest that coarse aggregate shape or geological origin affect the amount of air entrainment obtained. The only exception is where crushed rock aggregates contain an appreciable quantity of dust which could influence the fine aggregate gradings considered below. 

Mullite is almost twice as abundant in low-Ca fly ash when compared to high-Ca fly ash, mainly due to differences in the Al content of the clay minerals associated with the coal (McCarthy et al. 1990). Using atomic absorption spectroscopy (AAS) and scanning electron microscopy /electron microprobe analyses (SEM/ EMPA) Stevenson Huber (1987) found a correlation between the elemental composition of ash particles and the clay mineral species in the raw coal. They concluded that the geologic origin of the coal had a significant impact on the microchemical composition of the ash. 

The biohazard in soils attributable to heavy metals, and to metalloids such as arsenic, has often been assessed by determination of their total soil contents and national guidelines based on such total contents are currently in use (see for example, Appendices 3-6 in Alloway, 1995). Total soil contents, however, reflect the geological origins of soils as well as the anthropogenic inputs such as pollutants from industrial processes and are poor indicators of mobility or bioavailability. A more relevant assessment of the contents of elemental contamination can be made by measuring the pseudototal element contents of a soil by the... 

The speciation of Hg in all kinds of environmental matrices (air, water, sediment, and seafood/fish) has been studied for several years now and it is still a hot topic in ongoing studies. Different environmental compartments show different ratios between the abundance of species for example, for natural waters the abundance of Me-Hg and Hg2+ depends on the geological origin and the pretreatment (filtered or not filtered). From less than 1 percent [13] to around 5 percent [14, 15], especially for unfiltered seawater, Hg as Me-Hg has been reported. While phytoplankton contains around 15 percent, in zooplankton around 20 percent of total Hg is present in the form of Me-Hg [15, 16]. In foods they can occur as different species, normally in trace amounts. The level of Hg in the environment is generally low, but there are some species with a greater tendency to accumulate. The accumulation of Hg species is higher in fish than in any other aquatic organisms. The contribution of Me-Hg increases in herbivorous fish to approximately 70 percent [17], while in predatory fish a maximum of nearly 100 percent... 

In this chapter, the relationship of geological origins and interfacial properties of bentonite clay will be reviewed first. Then we will discuss the migration of water-soluble substances in rocks and soil, and the effect of sorption on the migration. A linear model will be derived by which the quantity of ion sorbed on rocks can be estimated when the mineral composition and sorption parameters of the mineral components are known. Surface acid-base properties of soils will be discussed, and the sorption of an anion (cyanide ion) will be shown on different soils and sediments. 

RELATIONSHIP BETWEEN INTERFACIAL PROPERTIES AND GEOLOGICAL ORIGIN OF BENTONITE CLAY... 

Bentonite rocks have many uses in the chemical and oil industries and also in agriculture and environmental protection. The usefulness of bentonite for each of these applications is based on its interfacial properties. These properties are determined by geological origin, chemical and mineral composition (especially montmorillonite content), and particle size distribution, and they include the specific surface area (internal and external), cation-exchange capacity (CEC), acid-base properties of the edge sites, viscosity, swelling, water permeability, adsorption of different substances, and migration rate of soluble substances in bentonite clay. 

As a consequence of this, the properties and possible application of bentonites are determined by both the montmorillonite content and geological origin. The origin appears in the particle size and external surface properties. 

The application of the linear model will be shown for cesium-137 and strontium-85 ions. Cs-137 and the different strontium isotopes, especially Sr-90, are important components of nuclear wastes. As seen previously in Table 3.2, the cesium ion has a different sorption property on bentonite samples from the Sajobabony deposit, depending on geological origin and composition. Similarly, different bentonite rocks from the Carpathian Basin (Table 3.4) show different sorption properties, including kinetics and equilibrium (Figure 3.4, Table 3.5 Nagy et al. 2003b Konya et al. 2005). 

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