جستجوی مقالات مرتبط با کلیدواژه "dysprosium" در نشریات گروه "فیزیک"

In this study, the extraction of dysprosium was investigated using a supported liquid membrane (SLM) system. The experiments were performed using bis (2, 4, and 4-trimethylpentyl) phosphinic acid (Cyanex272) as the carrier. The effect of various parameters such as stirrer speed, feed phase pH, extractant concentration, initial metal concentration and membrane pore size on dysprosium transfer was studied. The highest membrane permeability was obtained with Cyanex272 at concentration of0.6 M and initial pH of the feed phase equal to 5 and stripping phase concentration of 1 M. Under optimal conditions, the membrane permeability of 2.15×10-5 m s-1 was obtained. Examination of SLM stability showed that the membrane used was stable for 6 periods (3 days) and permeability did not change significantly

In this study, the thermoluminescece (TL) behavior of potassium chloride dosimeter doped with dysprosium impurity (KCl:Dy)  was studied. Evaluation of the morphology, shape and size of prepared crystal were done by X-ray diffraction (XRD) and scanning electron microscopy (SEM) analysis. Potassium chloride was prepared by co-precipitation with different percentages of dysprosium impurities and the best TL response was determined for gamma rays in 0.5 mol% of impurity. The optimum annealing regime was obtained at 700  for 30 minutes. Using a general order kinetic based on computer simulator, the glow curve and corresponding kinetics parameters were calculated. The TL glow curve of synthesized dosimeter shows two peaks at 393 and 415 K. Also, other dosimetric properties such as fading and TL dose response were studied

In this research, the synthesis of strontium aluminate nanoparticles (SrAl2O4) by using of combustion method assisted by microwave and doping them with dysprosium (SrAl2O4:Dy) have been investigated. Characterization of nanoparticles was performed by XRD, FT-IR, EDS, FESEM, UV-Vis and PL. In the synthesis stage, the data of XRDs confirmed the formation of the monoclinic phase of strontium aluminate with space group P1211, in the sample with the fuel to nitrate ratio of 3 to 1, pH value of 5.5, and microwave irradiation time of 5 minutes, calcination time of an hour and calcination temperature of 600 °C. By using the X-ray powder diffraction data and Scherrer's formula, the average size of nanocrystallites was obtained about 26 nm. In the substitution stage, in order to optimize the luminescence of SrAl2O4 nanoparticles, different percentages of doping were investigated. Among the synthesized nanoparticles, the sample of Sr0.9Al2O4: Dy0.1 nanoparticles with the average nanoparticles size 34±3 nm; most frequent distribution of nanoparticles between 30 and 35 nm; optical gap energy equal to 4.21 ± 0.01 eV and with the highest emission intensity in photoluminescence spectrum, was chosen as an optimal sample in terms of the structural and optical properties.

BaSO4: Dy nanocrystalline is prepared by the co-precipitation method. The shape and morphology of the prepared nanocrystalline is observed using a Energy- dispersive X-ray spectroscopy (EDX) and XRD pattern. The prepared pellets are exposed to the gamma radiation emitted by a 60Co source at room temperature. Then the themoluminescence (TL) properties of BaSO4: Dy nanocrystalline pellets are studied. Results show that thermoluminescence response is increased by increasing the 60Co dose rate so that the BaSO4:Dy has a linear response in a range of 0.1-1 kGy.