Iran, elements

Great Salt Lake, Utah, is the largest terminal lake in the United States. From its brine, salt, elemental magnesium, magnesium chloride, sodium sulfate, and potassium sulfate ate produced. Other well-known terminal lakes ate Qinghai Lake in China, Tu2 Golu in Turkey, the Caspian Sea and Atal skoje in the states of the former Soviet Union, and Urmia in Iran. There ate thousands of small terminal lakes spread across most countries of the world. Most of these lakes contain sodium chloride, but many contain ions of magnesium, calcium, potassium, boron, lithium, sulfates, carbonates, and nitrates. 

Retinoic acid (RA) describes a group of vitamin A acid (synonym Vitamin A1 acid) derivatives such as all-irans-retinoic acid (tretinoin), 9-cis-retinoic acid and 13-cis retinoic acid (isotretinoin). Retinoic acids act through binding to retinoic acid and retinoid X response elements. 

In the Mediterranean Sea and Middle East area, for example, there are obsidian outflows only in Italy, in some islands in the Aegean Sea, and in Turkey. Artifacts made of obsidian, however, are widely distributed over much of this vast area. Chemical analysis of many of these artifacts has shown that most of the obsidian used to make them originated in one or another of the outflows mentioned, but also in far-distant places such as Armenia and Iran. Plotting on a graph the concentration of selected elements in samples from obsidian sources against that in samples from sites where it was used, enables the identification of the source of the samples (see Fig. 22). Moreover, this type of analysis also makes it possible to trace the routes through which obsidian (and most probably other goods) were traded in antiquity (Renfrew and Dixon 1976). 

In silt clay soils (0-30 cm) of Isfahan, Central Iran, the amount of EDTA-extractable Zn, Cu, Pb, Ni, Cd, Co and Cr were 3.2, 1.8, 2.6, 0.6, 0.16, 0.6 and 0.8 mg/kg, respectively (Khoshgoftarmanesh and Kalbasi, 2002). Concentrations of these trace elements increased in subsoils (30-60 cm) and increased with applications of municipal waste leachate. In the surface soils of agricultural, industrial and urban regions of Isfahan, central Iran, the average DTPA-Cd was 0.09 mg/kg, and about 80% of the soil samples had less than 0.1 mg/kg DTPA-extractable Cd (Amini et al., 2005). DTPA-Cd was strongly correlated with EC in the soils. 

Now consider cis-dinitrogen difluoride (Fig. 3.6). It possesses no axis perpendicular to the plane of the molecule that allows rotation (other than the trivial 360° one) and qualifies as a symmetry element. However, it is possible to draw an axis that lies in the plane of the molecule equidistant between the two nitrogen atoms and also equidistant between the two fluorine atoms. This is also a two-fold axis Rotational axes are denoted by the symbol C , representing the n-fold axis. Thus cis- and irans-dinitrogen difluoride each have a C2 axis. 

However, explanations for growth limitation based on repulsion of metal ions may be somewhat oversimplified. Elements other than vanadium, niobium, tantalum, molybdenum, and tungsten do not form isopoly anions. Other ions which have appropriate radii (e.g., Al, 67 pm Ca, 76 pm l ". 67 pm) for discrete isopoly anion formation instead form chains, sheets, or three-dimensional frameworks. Why does polymerization stop for isopoly anions An oxygen atom in a terminal position in an isopoly anion is strongly ir bonded to a transition metal such as Mo(V or W (VIj. These terminal oxygen atoms are never found Irans to one another because they avoid... 

The complex decomposes slowly when exposed to the atmosphere, but rapidly in chloroform and ethanol solutions. An indication of the configuration of the complexes of this type, the elemental analyses of which are shown in the table below, stems from their solubility characteristics in benzene. Thus the orange-yellow irans-[PdCl2(tdp)2] is quite soluble, whereas the colorless cfs-[PdCl2 P(OCH3)3)2] and remaining pale yellow cis... 

Rochat, J., Salehi, E. et Sarrot-Reynauld, J., 1979. Geochimie des eaux thermominerales. Repartition et origine des halogenures et des elements traces dans les eaux thermales d Azerbaidjan oriental (Iran). C.R. 104eme Congr. Natl. Soc. Sav., Bordeaux, Fasc. Ill, pp. 123—134. 

NAA is commonly used in studies of obsidian. The sources of obsidian in Southwest Asia, the Mediterranean, North America, Mexico, and elsewhere have been examined using NAA. Most of the obsidian in Southwest Asia comes from sources either in the mountains of Turkey or in northern Iran, both outside the Fertile Crescent. The graph below shows the results of the NAA measurement of the elements iron (Fe) and scandium (Sc) in obsidian in Southwest Asia (Fig. 8.10). Samples were also taken from the original sources. There are clear differences among most of the sources. 

Azin F, Raie RM, Mahmoudi MM. 1998. Correlation between the levels of certain carcinogenic and anticarcinogenic trace elements and esophageal cancer in Northern Iran. Ecotoxicol Environ Saf 39 179-184. 

Imported Inorganic Chemical Elements, Oxides and Halogen Salts in Iran, 2002... 

Iran mix, Arab mix, and Dubai short residues (550°C+) obtained from Madras Refineries Ltd., Madras were used as the feed stocks. Their Physico-chemical characteristics, compositional analysis, elemental compositions and average molecular formulae as determined by standard ASTM/BIS/IP methods are given in Table 1. 

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