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Al2O3 /TiN double and Al2O3/Cr/TiN triple coatings were produced on stainless steel substrates using plasma-detonation techniques. Investigation of the microstructure and characteristics of the coatings after the preparation was performed by X-ray diffraction (XRD), transmission electron microscopy (TEM) and Auger electron spectroscopy (AES). The corrosion resistance of the coatings was studied in several electrolytic solutions (0.5 M H2SO4, 1 M HCl, 0.75 M NaCl) using electrochemical techniques (open circuit potential, cyclovoltammetry and potentiodynamic polarization). The obtained results showed, in most of the cases, an improvement of the corrosion resistance, except in NaCl solutions. The effect of the controlled thickness of TiN and Cr layers as well as the additional treatment with a high-current electron beam was also investigated. Nuclear reaction analysis (NRA), Rutherford backscattering spectroscopy (RBS) and scanning electron microscopy (SEM) were applied for the characterization of the samples before and after the corrosion experiments. 相似文献
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Kapashi Eleftheria Kapnisti Maria Dafnomili Argyro Noli Fotini 《Journal of Radioanalytical and Nuclear Chemistry》2019,321(1):217-226
Journal of Radioanalytical and Nuclear Chemistry - The use of three biosorbents based on AloeVera wastes for the removal of thorium and barium from aqueous solutions (Cinit:... 相似文献
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Tsamos Panagiotis Stoulos Stylianos Noli Fotini 《Journal of Radioanalytical and Nuclear Chemistry》2022,331(9):3703-3711
Journal of Radioanalytical and Nuclear Chemistry - Oil and oil products belong to the naturally occurring radioactive materials-ΝΟRΜs. In the present study, the radiological status... 相似文献
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A common problem in applied mathematics is that of finding a function in a Hilbert space with prescribed best approximations from a finite number of closed vector subspaces. In the present paper we study the question of the existence of solutions to such problems. A finite family of subspaces is said to satisfy the Inverse Best Approximation Property (IBAP) if there exists a point that admits any selection of points from these subspaces as best approximations. We provide various characterizations of the IBAP in terms of the geometry of the subspaces. Connections between the IBAP and the linear convergence rate of the periodic projection algorithm for solving the underlying affine feasibility problem are also established. The results are applied to investigate problems in harmonic analysis, integral equations, signal theory, and wavelet frames. 相似文献
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Charizani Andromachi Noli Fotini 《Journal of Radioanalytical and Nuclear Chemistry》2022,331(2):807-815
Journal of Radioanalytical and Nuclear Chemistry - Biosorption of barium onto pomegranate peel was studied by gamma-spectrometry regarding different parameters. Adjustment of the isotherms to... 相似文献
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S. Sarri P. Misaelides F. Noli L. Papadopoulou D. Zamboulis 《Journal of Radioanalytical and Nuclear Chemistry》2013,298(1):399-403
The iodide removal from aqueous solutions (initial I?-concentration: 300–5,000 mg/L) by a low and a high molecular weight polyethylenimine-epichlorohydrin resin was investigated both in absence and presence of background electrolytes (NaCl and Na2SO4, ionic strength due to background electrolyte 0.1 M) using a batch technique, 131I as radioactive tracer and high-resolution γ-ray spectrometry. The experiments in absence of background electrolyte were performed using solutions of initial pH 3 and 7, whereas those in presence using solutions of initial pH 3. The results, which demonstrated the high iodide-removal efficiency of both resins, were modeled using the Langmuir and Freundlich isotherm equations. The experimental data were better reproduced using the Langmuir equation. Using this equation maximum sorption capacity values (Q max) of 638.8 and 603.3 mg/g were obtained for the high molecular weight resin from solutions of initial pH 3 and 7 respectively, whereas the corresponding values for the low molecular weight one were slightly lower (552.4 and 507.5 mg/g respectively). The iodide uptake by the resins strongly depended on the presence of competing anions and especially of sulfates. The examination of sections of the I-loaded resins grains by scanning electron microscopy/energy dispersive spectroscopy (SEM/EDS) revealed that iodine was evenly distributed throughout the bulk of the resins and not only bound to their surface. 相似文献
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M. Kapnisti A. G. Hatzidimitriou F. Noli E. Pavlidou 《Journal of Radioanalytical and Nuclear Chemistry》2014,302(1):679-688
The uptake of cesium from aqueous solutions (pH 5) using titanium phosphates was investigated in the absence and presence of background electrolyte (0.1 M NaNO3) using a batch technique. The determination of cesium was performed by gamma spectroscopy using 137Cs as tracer. The obtained sorption isotherms could be satisfactorily reproduced by a Langmuir sorption equation. The maximum uptake capacity values (q max) calculated fitting the experimental data by this equation were 167 and 118 mg/g for solutions of initial pH 5 in the absence and presence of background electrolyte. Kinetics data obtained at 293, 308 and 323 K could satisfactorily reproduced by the pseudo-second order equation. It was demonstrated that the new synthesized materials can remove considerable amounts of cesium from aqueous solutions and ion exchange is considered to be the principal mechanism for cesium removal. Toxicity characteristic leaching procedure and desorption tests provided data about the application of the sorbents in environmental remediation. 相似文献
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