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1.
N. Megouda M. S. Hamlat H. Kadi H. Saibi A. Gherbi 《Journal of Radioanalytical and Nuclear Chemistry》2007,272(1):75-79
Batch sorption experiments have been carried out to remove natural uranium (NORM) from water obtained together with crude
oil and natural gas, using Algerian bentonites. The effect of some important factors such as S/L ratio, pH, initial concentration, particle size was evaluated and a kinetic study performed. The value of the distribution
coefficient (K
d) at equilibrium for natural uranium varied from 30 to 600 cm3·g−1 and 50 to 1100 cm3·g−1 (∼10% margin error) using natural bentonite and drilling bentonite, respectively. The isotherms showed that the data are
consistent with both Freundlich and Langmuir models. 相似文献
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The objective was to examine how a bicontinuous cubic phase influences the diffusion and electrochemical activity of dissolved molecules. The cubic phase is a structure with three-dimensional continuous channels of water separated by an apolar membrane. A redox active molecule can dissolve in three different environments. A hydrophobic molecule will prefer the interior of the membrane, a hydrophilic molecule will prefer the water channels, and an amphiphilic molecule will be situated with its headgroup at the surface of the membrane and its tail in the interior. The electrochemical activity was measured with cyclic voltammetry and the transport behavior with chronocoulometry. All the molecules were redox active in the cubic phase; that is, all the molecules could reach the surface of the electrode and react. The cubic phase made the kinetics of the charge transfer slower, showing a quasi-reversible behavior. The reason may be that a layer of the membrane adheres to the hydrophobic electrode surface. The diffusion experiment showed that the diffusion was slower than in solution. The molecules that were restricted to diffuse within the membrane gave particularly low mass transport rates. 相似文献
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Masoud Behzad Karel Samec Sang-In Bak Yacine Kadi Claudio Tenreiro Seung-Woo Hong Jong-Seo Chai 《Journal of Radioanalytical and Nuclear Chemistry》2014,299(2):1001-1006
A worldwide challenge in the near future will be to find a way of producing radioisotopes in sufficient quantity without relying on research reactors. The motivation for this innovative work on targets lies in the accelerator-based production of radioisotopes using a neutron converter target as in the transmutation by adiabatic resonance crossing concept. Thermal analysis of a multi-channel helium cooled device is performed with the computational fluid dynamics code CFX. Different boundary conditions are taken into account in the simulation process and many important parameters such as maximum allowable solid target temperature as well as uniform inlet velocity and outlet pressure changes in the channels are investigated. The results confirm that the cooling configuration works well; hence such a solid target could be operated safely and may be considered for a prototype target. 相似文献
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In this study, total phenolic and flavonoid contents, acute toxicity and the antinociceptive activity of Artemisia campestris and Artemisia herba-alba, individually and in combination, were investigated using multiple forms of pain in animals. Our results have been shown that plants are relatively safe without clinical signs of toxicity in animals. Thus, extracts were presented high levels in phenolic and flavonoid contents. Artemisia decoctions with 100, 200, 400 mg/kg b-w studied dose, clearly attenuate chemical and thermal noxious stimuli in writhing, formalin and hot-plate tests, and significantly reduced paw oedema in formalin test. Additionally, binary combination forms exhibited a great improvement in intensity and amplitude of antinociceptive activity in comparison with both plants used individually by a relative interference with opioid system. Our findings suggested the central and peripheral analgesic properties and confirmed the folkloric medicinal use of these plants in pain symptom treatment. 相似文献
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Photosensitive supramolecular peptide hydrogels with the gelators forming by the integration of photosensitive moieties and peptides have been briefly summarized the hydrogelation capabilities, the expressing manner serving as smart materials, and practical applications. 相似文献
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Telomere length is an important measure of cell and tissue regenerative capacities. The mean telomere length is classically used as global indicator of a tissue telomere length. In skeletal muscle, which is made of postmitotic myonuclei and satellite cells (muscle stem cells), minimum telomere length is also used to assess the telomere length of satellite cells and newly incorporated myonuclei. At present, the estimation of the method reproducibility during the assessment of mean and minimum telomere length using Southern blot analysis has never been documented. The aim of this report is to describe a signal modelization for improved precision of assessment of minimum and mean telomere lengths and to document the method reproducibility. Telomeres are assessed using a Southern technique where the gel is directly hybridized with the specific probe without the membrane-transferring step in order to prevent telomeric low signal loss. We found that the improved signal analysis for determination of telomere length is associated with coefficients of variation ranging from 1.37 to 4.29% for the mean telomeric restriction fragment (TRF) length and from 2.04 to 4.95% for the minimum TRF length. Improved method reproducibility would allow saving time and biological material as duplicate and triplicate measurement of the same sample is no longer required. 相似文献
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M. Senouci H. Hibbo B. Hammoudi M. Kadi B. Imine 《Thermophysics and Aeromechanics》2016,23(2):165-171
The aim of this study is to investigate numerically the effects of four vortices on the dynamic, scalar, and turbulent fields of the hydrogen jet. These vortices, which appear in the vicinities of the nozzle, are created by the vortex generators (VGs), and they are assembled with periodicity or symmetry in order, respectively, to give four vortices of the same or opposite direction. A second-order Reynolds stress model is used to investigate asymmetric turbulent jet. The results indicate that the presence of the vortex near the emission jet section noticeably enhances mixing to ensure a good combustion. 相似文献
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An ISO GUM measurement uncertainty estimation procedure was developed for a liquid-chromatographic drug quality control method-assay of simvastatin in drug formulation. In quantification of uncertainty components several practical approaches for including difficult-to-estimate uncertainty sources (such as uncertainty due to peak integration, uncertainty due to nonlinearity of the calibration curve, etc.) have been presented. Detailed analysis of contributions of the various uncertainty sources was carried out. The results were calculated based on different definitions of the measurand and it was demonstrated that unequivocal definition of the measurand is essential in order to get rigorous uncertainty estimate. Two different calibration methods - single-point (1P) and five-point (5P) - were used and the obtained uncertainties and uncertainty budgets were compared. Results calculated using 1P and 5P calibrations agree very well. The uncertainty estimate for 1P is only slightly larger than with 5P calibration. 相似文献