Authors:F. Franco, L. Pérez-Maqueda, and J. Pérez-Rodríguez
Kaolinites from well-known sources (KGa-1 and KGa-2) were used to study the influence of the particle-size reduction on the
dehydroxylation process. Size reduction of particles was obtained by ultrasound treatment to avoid the effect of the progressive
amorphization of the structure, which takes place with the traditional grinding treatment. The particle-size reduction causes
an increase of the mass loss between 140 and 390°C attributed to the loss of the hydroxyl groups exposed on the external surface
of kaolinite; a shift to lower temperatures of the endothermic effect related with the mass loss between 390 and 600°C; and
a shift of the end of dehydroxylation to lower temperatures. The first modification can be explained by an increase of the
number of hydroxyls exposed on the external surface of kaolinite which is proportional to the new surface generated in the
particle reduction process, whereas the shift of the dehydroxylation to lower temperatures is related to the reduction of
the dimensions of the particles which favour the diffusion controlled mechanisms. Comparing between the DTA curves to the
TG curves of the studied samples shows that the observed modifications in the thermal properties induced by the particle-size
reduction are greater for the low-defect kaolinite. The intensity of these modifications depends on the effectiveness of the
The number of the cities with canalized water and sewage treatment stations has increased lately and consequently having in
mind the great concern on environment preservation and the quality of the water used by society. However, these stations are
nowadays causing another kind of problem: a huge quantity of sludge as residue. Due to the implication of the residue on the
environment and, consequently, to human life quality, performing of an accurate investigation about the components of such
sludge, as well as the thermal stability of this residue in the environment become necessary. This paper presents a study
on sludge from water and sewage treatment station, as well as the thermal characterization of residue. Such study was performed
through FTIR, atomic absorption, thermoanalytical (TG/DTG, DTA) techniques, that made it possible to observe that the main
components of the sludge are clay, carbonates and organic substance, presenting a low rate of metals and a unique thermal
behavior since the sludge from the treatment station has a higher thermal stability.
For recent years, the labeling and application of Somatostatin and Its Analogues have been becoming more and more important in the both diagnosis and treatment of a variety of tumors, especially the neuroendocrine tumors. This paper's goals are to deal with the chemical aspects of the radiolabeling of somatostatin and its analogues. It reviews the selected radionuclides and bifunctional chelating agents may be used in the labeling of Somatostatin and its analogues with metal radionuclides. The prospects of application of the Labelled Somatostatin and its analogues are comparatively assessed.
Radiation treatment in the presence of catalysts such as anatase, P25 and bentonite showed efficient removal of TCE (trichloroethylene) and PCE (perchloroethylene) compared with gamma-irradiation alone. Gamma-ray pretreatment of P25 and bentonite enhanced the decomposition of TCE and PCE, respectively. The change in the catalysts by gamma-rays was characterized by their EPR spectra. For anatase and bentonite, the peaks in the spectra increased significantly, and the pattern of the spectra changed in the case of P25. The relationship between the peaks and pollutant decomposition should be further clarified due to the complexity of the spectra.
A system made up by a Zymark robot and a separation automate preteats spent fuel samples and monitors a tri-n-octylphosphine oxide column extraction chromatographic procedure in order to isolate and purify uranium and plutonium present in the samples, prior to the spectrometric measurements. Up to 16 subsamples of spent fuel in dried or solution form are handled simultaneously in a completely unattended mode. The throughput of the robotized analytical procedure has increased by a factor of 3 compared to the earlier manual procedure without loss in the quality of the chemical treatment and of the mass- and -spectrometric measurements.
Authors:J. Irigaray, H. Elmir, D. Pepin, and P. Communal
At French spa, La Bourboule, arsenical mineral waters are applicated by several ways. The process and degree of absorption of water are not well known; so, we tried to study absorption, measuring arsenic concentration in the blood and in some organs. On rabbits, thirty minutes after the animal had drunk mineral water, the increase of arsenic concentration in its blood is about twenty times and it is only about three to nine time in lungs, bronchia and traches. On human subjects, it was observed an increase of five times in the blood, two hours after treatment.
Authors:H. Yoshino, K. Murata, Y. Yamamura, T. Tsuji, H. Nishikawa, K. Kikuchi, and I. Ikemoto
The effect of thermal treatment on the electrical conductivity was studied for a quasi-one-dimensional organic conductor,
(DIMET)2I3 (DIMET=dimethyl(ethylenedithio)tetrathiafulvalene). After heating the samples up to a temperature between 340 and 370 K,
the electric resistivity was measured at low temperature down to 2 K and under pressure up to 1.6 Gpa. (DIMET)2I3 shows irreversible decrease in the electric resistivity between 350 and 356 K on heating. It was found that the heating above
350 K suppresses the spin-density-wave transition at 40 K and another metal-insulator transition appears at 18 K.
Authors:K. Kim, S. Choi, D. Ahn, S. Paek, B. Park, H. Lee, K. Yi, and I. Hwang
This paper describes ongoing research into the multi-physics model development of an electrorefining process for the treatment
of spent nuclear fuel. A forced convection of molten eutectic (LiCl–KCl) electrolyte in an electrorefining cell is considered
to establish an appropriate electro-fluid model within the 3-dimensional framework of a conventional computational fluid dynamic
model. This computational platform includes the electrochemical reaction rate of charge transfer kinetics which is described
by a Butler–Volmer equation, while mass transport is considered using an ionic transport equation. The coupling of the local
overpotential distribution and uranium concentration gradient makes it possible to predict the local current density distribution
at the electrode surfaces.
The ability to map boron and hydrogen distributions in the body is paramount to the success of boron neutron capture therapy
(BNCT). We investigated treatment-time quantitative mapping of these distributions by detecting (i) 0.48 MeV de-excitation
photons from neutron capture by boron-10; (ii) 2.22 MeV photons from neutron capture by hydrogen; and (iii) transmitted neutrons.
Monte Carlo simulations reported no detectable difference when 10B in tumour was varied from 0 to 50 ppm, and when the tumour size was varied from 0.0 to 9.5 cm3.
Authors:E. Kowalska, P. Kowalczyk, J. Radomska, E. Czerwosz, H. Wronka, and M. Bystrzejewski
Carbon nanotubes (CNTs) were synthesized using a chemical vapour deposition
(CVD) method. The properties of CNTs before and after vacuum annealing treatment
were studied using scanning electron microscopy (SEM), scanning tunneling
microscopy/spectroscopy (STM/STS) and thermogravimetric analysis (TG). Field
emission characteristics of the raw and vacuum heated (up to 650C) carbon
nanotube films (CNTFs) were measured in a diode system. Emissive properties
of the CNTFs depend on an annealing process during which structural changes
in the nanotube walls take place. The structural changes, related to saturation
of dangling bonds, influence a rate of oxidation process and also improve
the emissive field properties.