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Publicatii proprii
Defects induced by gamma irradiation in historical pigments
The paper presents our results concerning a complex investigation by reflectance spectroscopy (RS) and Electron Paramagnetic Resonance (EPR) of the defects induced by gamma irradiation in 22 different historical pigments. Gamma irradiation is used to destroy microflora and insects which are involved in biodeterioration processes of art works such as paintings. At the same time, it can induce defects i.e. color centers which are likely to modify the
Read moreStandardization of 48V
48 V decays by positron emission and electron capture processes with a half life of 15.97 d. It was standardized by a special classic variant of the coincidence method. An usual 4π proportional counter- NaI(Tl) scintillator system was used. A complication arose due to a significant 46 Sc impurity. The low energy capture radiations were not registered and the 46 Sc radiations were included in a new simplified decay scheme. The gamma contribution
Read moreModifications of Viscoelastic Properties of Polysaccharides by Gamma Irradiation
The aim of this work was to establish the effect of gamma irradiation on the viscoelastic properties of the sodium alginate. Aqueous suspensions of sodium alginate at different concentrations (0.25 – 4%) were irradiated using a 60Co gamma-ray source (10, 25 and 50 kGy). The monitored rheological parameters showed the non-Newtonian behavior of the samples is kept by gamma irradiation. The decrease tendency of the apparent viscosity by irradiation
Read moreArchives decontamination by gamma irradiation
The treatment of archives with gamma irradiation is an efficient and environmental friendly alternative for biological decontamination of large volume of archives. It Substitutes the use of chemicals for conservation and contributes to safer workplaces. This work is targeting documents from recent archives where the value of information is not obsolete and may become an important historical and cultural testimony. For it successful treatment, an
Read moreEffects of gamma irradiation on the colour of pigments
The aim of this paper is to investigate the influence of gamma irradiation process on the colour of painted wood panels. Insects and micro-organisms are frequently identified enemies of cultural objects from museums and archives. Based on its biocide effect, gamma radiation Could be used for decontamination and conservation purposes. Important advantages can be mentioned in its favour: no toxic or radioactive residues remained in the treated item;
Read moreStandardization of 68(Ge+Ga)
The radionuclide Ga-68 is mainly a positron emitter (89.2%), with a half-life of 67.7 min. It is used in nuclear medicine, being chemically extracted from the mixture (68)(Ge + Ga); its precursor, Ge-68, disintegrates 100% by electron capture, with a half-life of 270.8 d (Table of radionuclides, comments and Evaluation). A 4pibeta-gamma coincidence method was used for standardization, with a 4pi proportional beta-detector and a NaI(Tl) gamma detector.
Read moreFinite element analysis of heat transfer in transformers from high voltage stations
This present paper presents the modeling and simulation of the thermal transfer in the transformers from the high electric voltage stations using finite element method. As the transformers are of high power and are inversed in oil, a particular interest represents the maintenance of physical and chemical parameters of oil as long a time during operation. For this, one presents the coupled analysis electromagnetic field and thermal field. The procedure
Read moreFinite element analysis of heat transfer in transformers from high voltage stations
This present paper presents the modeling and simulation of the thermal transfer in the transformers from the high electric voltage stations using finite element method. As the transformers are of high power and are inversed in oil, a particular interest represents the maintenance of physical and chemical parameters of oil as long a time during operation. For this, one presents the coupled analysis electromagnetic field and thermal field. The procedure
Read moreFinite element analysis of heat transfer in transformers from high voltage stations
This present paper presents the modeling and simulation of the thermal transfer in the transformers from the high electric voltage stations using finite element method. As the transformers are of high power and are inversed in oil, a particular interest represents the maintenance of physical and chemical parameters of oil as long a time during operation. For this, one presents the coupled analysis electromagnetic field and thermal field. The procedure
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