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1.
The composite ion exchangers were tested for their ability to remove UO2
2+ from aqueous solutions. Polyacrylonitrile (PAN) composites having natural zeolite, clinoptilolite, and synthetic zeolite, zeolite X, were used as an adsorbents. The influences of pH, U(VI) concentration, temperature and contact time on the sorption behavior of U(VI) were investigated in order to gain a macroscopic understanding of the sorption mechanism. The optimum adsorption conditions were determined for two composites. The sorption behaviors of uranium on both composites from aqueous systems have been studied by batch technique. Parameters on desorption were also investigated to recover the adsorbed uranium. 相似文献
2.
Tsakalof AK Bairachtari KA Aslani IS Chryssoulakis ID Kolisis FN 《Journal of separation science》2004,27(3):167-173
The materials and especially organic materials used for creation of art objects can be utilized by various microorganisms for their growth and facilitate the microbial colonization of the object. An understanding of the chemical alterations in artefacts caused by the presence of microorganisms can be crucial for correct identification of the materials initially used for the artefact creation--nowadays an important step in restoration and/or art-historical investigation of the art object. The present article describes a model experiment in which we investigated the possible chemical alterations in animal glue films used as substrate for growth of the fungus Aspergillus niger. The sterilized animal glue solution was poured into Petri dishes, inoculated with Aspergillus niger, and subsequently incubated at 15 degrees C for 0, 7, 9, 14, and 28 days. After interruption of incubation, the content of the Petri dish was analyzed for amino acid composition by the GC-MS based method. It was found that the growth of Aspergillus niger on animal glue films did not cause significant changes in the amino acid composition of the film and had no impact on animal glue identification. 相似文献
3.
4.
Sema Erenturk Sabriye Yusan D. Alkim Turkozu Zeyneb Camtakan M. Kirami Olgen Mahmut A. A. Aslani Sule Aytas M. Akif Isik 《Journal of Radioanalytical and Nuclear Chemistry》2014,300(3):919-931
In this study, radioactivity levels of 228 lake water samples, 63 upper and depth sediment samples and 12 fish samples from Lake Van were investigated from 2005 to 2008 and the distribution patterns of the radionuclides were presented. Analysis included gross alpha–beta and total radium isotopes activities and uranium concentrations of the water, and gross alpha and gross beta activities and relevant 238U, 232Th and 40K activity of the sediment and fish samples of the lake. Mean gross alpha, gross beta and radium isotopes activities of lake water were found 0.74 ± 0.46, 0.02 ± 0.01 and 0.06 ± 0.04 Bq/L, respectively. Mean gross alpha and beta activities in upper and depth sediments were found to be 41 ± 6 and 1,514 ± 74 Bq/kg; 77 ± 5 and 394 ± 24 Bq/kg at a 95 % confidence level, respectively. Mean activities of 238U, 232Th and 40K activity concentrations in upper and depth sediments were determined to be 225 ± 22, 70 ± 7 and 486 ± 39 Bq/kg; 174 ± 4, 63 ± 3 and 263 ± 25 Bq/kg, respectively. The mean gross alpha and beta, 238U, 232Th and 40K aktivities in fish samples were established as 47 ± 18, 470 ± 12, 0.57 ± 0.220, 0.022 ± 0.006, 319 ± 11 Bq/kg, respectively. The transfer factor from lake water to fish tissues, annual intake by humans consuming fish, and annual committed effective doses were estimated and evaluated. 相似文献
5.
?. Ayta? S. Akyil M. A. A. Aslani U. Aytekin 《Journal of Radioanalytical and Nuclear Chemistry》1999,240(3):973-976
In this study, the removal of uranium from aqueous solutions by diatomite earth (Kieselguhr) fine particules has been investigated.
Diatomite earth is an important adsorbent material in chromatographic studies. Uranium adsorption capacity of four different
types of diatomite was determined. The adsorption of uranium on the chosen diatomite sample was examined as a function of
uranium concentration, solution pH, contact time and temperature. The adsorption of uranium on diatomite followed a Langmuir-type
isotherm. 相似文献
6.
We present a general method for the linear least-squares solutionof overdetermined and underdetermined systems. The method isparticularly efficient when the coefficient matrix is quasi-square,that is when the number of rows and number of columns is almostthe same. The numerical methods for linear least-squares problemsand minimum-norm solutions do not generally take account ofthis special characteristic. The proposed method is based onLU factorization of the original quasi-square matrix A, assumingthat A has full rank. In the overdetermined case, the LU factorsare used to compute a basis for the null space of AT. The right-handside vector b is then projected onto this subspace and the least-squaressolution is obtained from the solution of this reduced problem.In the case of underdetermined systems, the desired solutionis again obtained through the solution of a reduced system.The use of this method may lead to important savings in computationaltime for both dense and sparse matrices. It is also shown inthe paper that, even in cases where the matrices are quite small,sparse solvers perform better than dense solvers. Some practicalexamples that illustrate the use of the method are included. 相似文献
7.
S. Akyil M. A. A. Aslani G. Gurboga S. Aytas M. Eral 《Journal of Radioanalytical and Nuclear Chemistry》2002,254(1):9-14
Both Indian mustard and sunflower were grown in a hydroponic solution treated with different concentration activities of 134Cs or with different amounts of copper or with both in order to investigate the interaction between copper and radiocesium. It was found that 134Cs activity concentration applied in the nutrient solution exerted more influence on the uptake and translocation of copper by Indian mustard than by sunflower. Indian mustard grown in hydroponic solution containing certain levels of copper and being treated with higher 134Cs activity concentration showed higher uptake of copper than sunflower. However, in the case of root copper concentrations, sunflower showed significantly higher copper immobilization by roots than Indian mustard. It was also found that the presence of copper in the hydroponic solution did modify radiocesium uptake by both species. The application of 1 mg/l in the growth medium could greatly increase the uptake of 134Cs by both species. With 3 mg/l concentration of copper amended to the solution, the accumulation of 134Cs by both species was decreased compared to the 1 mg/l copper treatment. These lines of evidence show that there is stronger interaction between copper and radiocesium in Indian mustard than in sunflower during the root uptake through nutrient solution. 相似文献
8.
Alireza Aslani Mohammadreza Arefi Khalil Beyki-Shuraki Aziz Babapoor 《Journal of Saudi Chemical Society》2013,17(4):403-407
Lead iodide, bromide and chloride nanoparticles (NP-PbX2, X = I, Br and Cl) with various morphologies were successfully prepared through a simple hydrothermal method without any additives or stabilizers. By treating the PbX2 in EtOH/CH2Cl2 solution at 170 °C for 12 h, the corresponding PbX2 nanoparticles were synthesized. The average sizes of PbX2 nanoparticles were between 30 and 80 nm. The structure, morphology, surface and size of PbX2 nanoparticles were determined by X-ray diffraction powder, Scanning Electron Microscopy, solid state Photo Luminescent, BET surface area and solid state UV. 相似文献
9.
A. R. Jalilian M. Sheikhha M. Mirzaei G. R. Aslani A. Shafiee 《Journal of Radioanalytical and Nuclear Chemistry》2004,260(2):373-377
5-[2-(2-Chlorophenoxy)phenyl]-1,3,4-oxadiazole-2-yl-4-fluorobenzoate 6a, the non-classic benzodiazepine ligand, has been shown to elicit a significant anticonvulsant activity against pentylenetetrazole-induced
convulsion. In order to perform biological studies, we decided to prepare the [18F]-labeled compound. This compound was prepared in no-carrier-added (n.c.a) form from 5-[2-(2-chlorophenoxy)phenyl]-1,3,4-oxadiazole-2-yl-4-N,N,N-trimethylanilinium
triflate 5 in one step at 125 °C in Kryptofix 2.2.2/[18F] and DMSO as the solvent followed by column chromatography. The synthesis took 20 minutes with an overall radiochemical
yield of 70-75% (EOS) and a specific activity about 74 GBq/mmole and chemical-radiochemical purity more than 95%.
This revised version was published online in July 2006 with corrections to the Cover Date. 相似文献
10.
Alireza Aslani Mohammad Reza ArefiAziz Babapoor Asghar AmiriKhalil Beyki-Shuraki 《Applied Surface Science》2011,257(11):4885-4889
ZnO-MgO and ZnO-NiO mixed oxides nanoparticles were produced from a solution containing Zinc acetate, Mg and Ni nitrate by Solvothermal method. The calcination process of the ZnO-MgO and ZnO-NiO composites nanoparticles brought forth polycrystalline two-phase ZnO-MgO and ZnO-NiO nanoparticles of 40-80 nm in diameters. ZnO, MgO and NiO were crystallized into würtzite and rock salt structures, respectively. The optical properties of ZnO-MgO and ZnO-NiO nanoparticles were obtained by solid state UV and solid state florescent. The XRD, SEM and Raman spectroscopies of these nanoparticles were analyzed. 相似文献