Residence time atomic number

The rate of deposition is measured by the deposition current. From the current, the number of atoms discharged per second and per unit of surface area can be calculated. Multiplying this value with the residence time, the number of atoms arriving during the residence time per unit of surface area is obtained (Eq. (J35))... 

Figure 9. A schematic and ideal model showing how the residence time of the magma in a steady-state reservoir of constant mass M, replenished with an influx O of magma and thoroughly mixed, can be calculated from disequilibrium data, in the simplifying case where crystal fractionation is neglected (Pyle 1992). The mass balance equation describing the evolution through time of the concentration [N2] (number of atoms of the daughter nuclide per unit mass of magma) in the reservoir is ...

Relatiornship of mearn oceanic residence time to atomic number. Residence times from MBARi PTEO http //www.mbari.org/chemsensor/summary.htmi. Residence times do not inciude seasait cyciing. 

Chemically pure reagents were used. Cadmium was added as its sulfate salt in concentrations of about 50 ppm. Lanthanides were added as nitrates. For the experiments with other metal ions so-called "black acid from a Nissan-H process was used. In this acid a large number of metal ions were present. To achieve calcium sulfate precipitation two solutions, one consisting of calcium phosphate in phosphoric acid and the other of a phosphoric acid/sulfuric acid mixture, were fed simultaneously in the 1 liter MSMPR crystallizer. The power input by the turbine stirrer was 1 kW/m. The solid content was about 10%. Each experiment was conducted for at least 8 residence times to obtain a steady state. During the experiments lic iid and solid samples were taken for analysis by ICP (Inductively Coupled Plasma spectrometry, based on atomic emission) and/or INAA (Instrumental Neutron Activation Analysis). The solid samples were washed with saturated gypsum solution (3x) and with acetone (3x), and subsequently dried at 30 C. The details of the continuous crystallization experiments are given in ref. [5]. 

The Henry s law constants for the gas-phase PCBs are generally in the range 20-100Pa m3 mol-1 at 298K and show little variation with the number of chlorine atoms, and the average value is H = 48 Pa m3 mol 1 at 298 K.65 This value of H corresponds to a washout ratio for PCBs of Wg = 50 at 298 K and an atmospheric residence time due to wet deposition of several tens of years (for removal from the well-mixed troposphere at an average temperature of 298 K... 

A possible hierarchy of reservoir sizes (measured in number of molecules or atoms) is given in Figure 15.18. The mean residence time (years) is also given. Figure 15.18 gives a selection for certain elements the list could be amplified or modified. 

We recall here that the definition of turnover rate used in this review is based on the number (or moles) of exposed surface atoms. Thus TOF is an alternative but particularly expressive way of representing the rate (refer to Section III, A). However, it is clear that the reciprocal of the TOF is not the residence time of an active intermediate on the surface. To know this quantity, it would be necessary to know the active sites per surface atom for the particular system. Usually, this quantity is not at present measurable by any general type of experiment. 

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