Mineral measurement

In order to study the potential reducing capacity of some of the common accessory iron containing minerals measurements were performed with pyrite, magnetite, hornblende, biotite and chlorite in deaerated groundwater for Tc and U. Moreover, the effect of addition of a reducing agent (Fe2+) was investigated. 

Carbon Mineralization Measured by Gas Chromatography Carbon dioxide accumulation may also be conveniently measured by gas chromatography. In this case the incubation vessels are sealed with a Suba-Seal, and volumes of air are removed via a syringe at intervals. Again, the incubation vessels should be opened at intervals to permit aeration. 

Considerable interest centres on the Mantle constituting, as it does, more than half of the Earth by volume and by weight. Attention has been focussed on several problems, including the chemical composition, mineralogy, phase transitions and element partitioning in the Mantle, and the geophysical properties of seismicity, heat transfer by radiation, electrical conductivity and magnetism in the Earth. Many of these properties of the Earth s interior are influenced by the electronic structures of transition metal ions in Mantle minerals at elevated temperatures and pressures. Such effects are amenable to interpretation by crystal field theory based on optical spectral data for minerals measured at elevated temperatures and pressures. 

In Figure 1, we present the Mossbauer spectrum of Na,K(Fe) chabazlte mineral measured at room temperature. The spectrum is composed of a symmetric doublet. The solid line in Figure 1 is a least squares fit to the data assuming a single quadrupole interaction. The quadrupole splitting of 0.49 0.02 mm/s and an isomer shift of 0.35 0.02 mm/s with respect to Fe metal obtained from this fit is typical for a high spin ferric (3d ) ion (20). 

Lohman, T. G., Slaughter, M. H., Boileau, R. A., Bunt, J. Lussier, L. U984) Bone mineral measurements and their relation to body density in children, youth and adults. Human Biol. 56, 667-679. 

Light (or near-ir and uv radiation) that is incident on opaque minerals is partly absorbed and partly reflected by them. There are two kinds of reflection processes that occurring when light is reflected from a flat polished surface of the mineral (specular reflectance) and that occurring when the light is reflected from the mineral after it has been finely powdered (diffuse reflectance). The latter arises from radiation that has penetrated the crystals (as in an electronic absorption spectrum) and reappeared at the surface after multiple scatterings in this case there will also be a specular component to the reflectance from light that is reflected from the surfaces of the particles. The specular reflectance of a flat polished surface of an opaque mineral measured at normal incidence can be related to the n and k terms of the complex refractive index (N) in which ... 

Figure 5. Molecular weight variation measured under commercial composting conditions and average percent mineralization measured with the CMR(—),...

Keppler H. and Rauch M. (2000) Water solubility in nominally anhydrous minerals measured by FTIR and H MAS NMR the effect of sample preparation. Phys. Chem. Mineral. 21, 371-376. 

TsurltanI I, Honda R, Ishizaki M, Yamada Y, Nishijo M, Nakagawa H. Bone mineral measurement In Inhabitants In a cadmium polluted area by ultrasound bone densitometer. Jpn J Hyg (in Japanese) 1994 49 125. 

R.B. Mazess, Ed., Third International Conference on Bone Mineral Measurement, Am. J. Roentgenol. Radium Ther. Nucl. Med., 126, 1266 (1976). 

Jaseous argon is easily lost from minerals. Measurements based on the 40k/402 method may therefore not be as rehable as desired. 

TABLE 7.10 Laboratory weathering (dissolution) rates of calcite, corundum, and some silicate minerals measured at pH = 4... 

In spite of these inherent shortcomings, the measurement of urinary hydroxyproline offers a useful index of bone matrix metabolism to add to the spate of techniques of bone mineral measurement used to study the endocrinology and metabolism of bone (B8). 

Of the other minerals measured only magnesium, phosphorus and iron show significant positive correlations with TSS while calcium exhibited a strong negative correlation (-0.88)( data not shown). 

In vitro studies to investigate the formation of DNA adducts, using either primary cells or immortal cell lines in culture, allow the investigation of the interactions of compounds like PhlP with other dietary components, such as phytochemicals, vitamins, and minerals. Measurements of DNA adduct formation in cells treated in culture can be compared with... 

A Novel Phantom for Accurate Performance Assessment of Bone Mineral Measurement Techniques DEXA and QCT... 

Healthcare and professional organizations expressed their concern about the lack of standardization, assessment of accuracy and precision, variation of sensitivity and error by variation of bone density in bone mineral measurement techniques like DEXA and QCT, whereas there are generally recognized as important and unresolved issues[2,3]. 

Christopher E. Cann (1988) Quantitative CT for Determination of bone mineral density-A review. RSNA Radiology 166 509-522 Willi A. Kalender, Dieter Felsenberg, Harry K. Genant, Manfred Fischer, Jan Dequeker, Jonathan Reeve. (1995) The European Spine Phantom — a tool for standardization and quality control in spinal bone mineral measurements by DXA and QCT. European Journal of Radiology Vol. 20 83-92... 

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