Chemical mobility

RADIOACTIVE DISEQUILIBRIA IN WEATHERING PROFILES DATING AND TRACING OF CHEMICAL MOBILITY... 

Characterization and time scale of chemical mobility in weathering profiles... 

Dequincey O, Chabaux F, Clauer N, Sigmarsson O, Liewig N, Leprun J-C (2002) Chemical mobillizations in laterites Evidence from trace elements and 2 U- " U- °Th disequilibria. Geochim Cosmochim Acta 66 1197-1210... 

Our own epoch is that of qualitative explanation in which considerations of analogy are particularly fertile. The most perfect instrument is the study of chemical mobilities " (Job s special interest). Their epoch, they thought, was a historical period in need of a general theory to coordinate the principles worked out in the last several years.57... 

The low level of EOF in coated capillaries permits separations to be carried out with very short effective capillary lengths. Earlier work using chemical mobilization was performed using capillaries as short as 11 cm with internal... 

After the proteins are focused in the capillary, the isoforms are mobilized past the detector for UV detection. The mobilization step utilizes either hydrodynamic pressure or chemical means. Chemical mobilization can be performed using either ionic or zwitterionic compounds. The general consensus is that hydrodynamic mobilization results in reduced resolution. Bio-Rad (Hercules, CA) zwitterion cathodic mobilizer with chemical mobilization provides superior resolution (Figure 21). 

McCall, P.J., Swann, R.L., Laskowski, D.A., Vrona, S.A., Unger, S.M.,andDishburger, H.J. Prediction of chemical mobility in soil from sorption coefficients, in Aquatic Toxicology and Hazard Assessment, Fourth Conference, ASTMSTP 737, Branson, D.R. and K.L. Dickson, Eds. (Philadelphia, PA American Society for Testing and Materials, 1981), pp. 49-58. 

Hook JE (1983) Movement of phosphates and nitrogen in soils following apphcation of municipal wastewater. In Nielson DW, Elrik DE, Tanji KK (eds) Chemical mobility and reactivity in soil system. Soil Sci Soc Am Spec Publ 11 241-255... 

Ancient fluid flows chemical mobility and alteration... 

Onsite extraction Chemical mobilization Chelators or surfactants used to mobilize metals, needs associated recovery technique... 

In situ extraction Chemical mobilization Same as above... 

To confirm the hypothesis of ax-eq-ax complexing and to obtain better values of the stability constants, a chemically mobile system was sought in which the equilibrium position can be altered by complex formation. Such a system was found in the anomeric equilibrium of D-allose. 

The rate at which a particular reaction occurs is important because it could provide real-time prediction capabilities. In addition, it could identify a particular reaction in a given process as the rate-controlling reaction of the process. For example, chemical mobility in soils, during rain events, is controlled by the rate at which a particular species desorbs or solubilizes, Similarly, the rate at which a particular soil chemical biodegrades is controlled by the rate at which the soil chemical becomes available substrate. 

Based on Equation 10.3, chemical mobility differs from water mobility by a factor of 1 + (pb/x)Xd. This factor is also known as the retardation factor. The larger the retardation factor, the smaller is the velocity of the chemical species in relationship to the velocity of water. Note, however, that the retardation factor contains a reactivity factor (Kd) and two soil physical parameters, bulk density (pb) and porosity (t). The two parameters affect retardation by producing a wide range of total porosity in soils as well as various pore sizes. Pore size regulates the nature of solute flow. For example, in very small pores, solute movement is controlled by diffusion, while in large pores, solute flow is controlled by mass flow. 

Gammons C. H. and Williams-Jones A. E. (1997) Chemical mobility of gold in the porphyry-epithermal environment. Econ. Geol. Bull. Soc. Econ. Geol. 92(1), 45-59. 

The texture and morphology of the synthesized objects were studied by the set of the instrumental methods XRD, FT-IR, SEM, TEM, BET, N2 adsorption-desorption. Model reaction of thiophene hydrodesulfurization (HDS) was used to investigate the chemical mobility of Ni-containing particles obtained by different ways. 

MacDowell-Boyer, L. M. (1992) Chemical Mobilization of Micron-Sized Particles in Saturated Porous Media Under Steady Flow Conditions, Environ. Sci. Technol. 26, 586-593. 

DeQuincey, O., Chabaux, F., Clauer, N., Sigmarsson, O., Liewig, N. Leprun, J-C. (2002) Chemical mobilizations in laterites evidence from trace elements and 238U-234U-230Th disequilibria. Geochimica et Cosmochimica Acta 66, 1197— 1210. 

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