RESUMEN
The adsorption and later bioavailability of 137Cs from the system humic acid (HA)/humic acid like compounds (HALC) and montmorillonite was investigated. The setup of the experiments should approach as much as possible natural conditions when 137Cs is introduced into soil with HALC from decomposed biomass. The significant differences were found in the trials containing various HA/HALC and also pure montmorillonite. The 137Cs was more available when it reached soil in association with HALC originated from compost than when it was adsorbed on stable humic acids. Moreover, the long term interaction of 137Cs with HALC led to decrease of 137Cs adsorbed on montmorillonite and increase of its bioavailable fraction. UV-Vis spectrometry and infrared spectroscopy showed the clear difference between HA, fresh HALC and old HALC which could partially explain the different results.
Asunto(s)
Bentonita/química , Biomasa , Radioisótopos de Cesio/química , Compostaje/métodos , Disponibilidad Biológica , Radioisótopos de Cesio/análisisRESUMEN
We report the final results of the Phase II SIMPLE measurements, comprising two run stages of 15 superheated droplet detectors each, with the second stage including an improved neutron shielding. The analyses include a refined signal analysis, and revised nucleation efficiency based on a reanalysis of previously reported monochromatic neutron irradiations. The combined results yield a contour minimum of σp=5.7×10(-3) pb at 35 GeV/c2 in the spin-dependent sector of weakly interacting massive particle (WIMP) proton interactions, the most restrictive to date for MW}≤60 GeV/c2 from a direct search experiment and overlapping, for the first time, with results previously obtained only indirectly. In the spin-independent sector, a minimum of 4.7×10(-6) pb at 35 GeV/c2 is achieved, with the exclusion contour challenging a significant part of the light mass WIMP region of current interest.
RESUMEN
The fission spectral interference of ruthenium on the instrumental neutron activation analysis of barium in samples containing uranium is extensively discussed. In particular the dependence of the correction factor on the phi epi/phi th ratio is studied. An excellent agreement between experimental and calculated values is achieved. A procedure is suggested for the resolution of multiple interferences in the general case where uranium, barium and/or ruthenium are present in samples to be analysed.