Search Results
You are looking at 1 - 5 of 5 items for
- Author or Editor: P. Dimotakis x
- Refine by Access: All Content x
Abstract
Radiochromium doped potassium chromate exhibits partly an oscillatory exchange between trivalent and hexavalent states of the51Cr during isothermal treatment. Thermodynamically dissipative structures created by51Cr/III/ interstitials give rise to rythmic increase and decrease of the transferred yield to the parent lattice. A temperature effect has been noticed on the oscillations by increasing mainly the frequency while a dose effect increases the frequency for the same temperature and decreases the amplitudes. The last is due probably to the elimination of available51Cr/III/ interstitials after radiation annealing. The Volterra-Lotka model is used to explain the oscillatory exchange of51Cr.
Abstract
The monotonic kinetics of isothermal yield of51Cr(VI) in51Cr(III)-doped potassium chromate reveals a common mechanistic scheme with that of neutron irradiated K2CrO4, including two first order processes during the examined first hour. One of them is fast and the other very slow, but both seem to be controlled by two thermal coefficients.
Abstract
Doping of crystalline /CoEDTA/2 Ba and /Co(en)3/(NO3)3 by60Co2+ creates a thermodynamically dissipative structure which gives rise to an oscillatory exchange of the radiocobalt with the inactive Co/III/ of the complex ions. The same compounds in which energetic60Co atoms have been produced by neutron irradiation show kinetically the same oscillatory parameters. The Volterra-Lotka model is applied for the oscillations.
Abstract
The oscillatory phenomenon during isothermal annealing of neutron irradiated crystalline cobaltic complexes is shown to extend for heating times up to 120 h without significant damping of amplitude and frequency of the oscillations. A mechanistic approach based on the Volterra-Lotka model is attempted involving defects and dissipative structure according to non-equilibrium thermodynamics.
Abstract
In continuation, of an early study of trace metal /TM/ccontent of Greek lignites and power plant ashes, taken to assess mobilization of TM in Greece by the operation of power plants, new data are presented. Both power plant sites in Greece, i. e. /a/ Northern /Ptolemais, Kardia/, and /b/ Southern /Megalopolis/ have been examined for trace metal content in ashes and in locally used lignites. Instrumental neutron activation analysis /INAA/ was used to determine the content of about 30 minor and major elements. The uranium content of southern Greek lignites was found again to be exceptionally high. The new data are correlated with those of our previous investigation.
