Scielo RSS <![CDATA[Journal of applied research and technology]]> vol. 17 num. 3 lang. pt <![CDATA[SciELO Logo]]> <![CDATA[Density distribution effect on the analysis of the <sup>6</sup>Li+ <sup>58</sup>Ni reaction]]> Abstract The effect of density variation on the optical-model (OM) analysis of 6Li + 58Ni is investigated by using bare potentials extracted from different density distributions of the weakly-bound 6Li nucleus. For each of the bare potentials, the real and imaginary parts of the direct-reaction and fusion polarization potentials are deduced from respective χ2 fittings to the elastic scattering and fusion data. The results obtained show that variations in the density distribution of the weakly-bound projectile can change the strengths of the dynamic direct-reaction polarization potential, however, it cannot make a noticeable difference on the OM predictions of fusion cross sections. <![CDATA[A new methodology to optimize operation cycles in a BWR using heuristic techniques]]> Abstract A new system to optimize fuel assembly design, fuel reload design and control rod patterns design is shown. Fuel assembly optimization is made in two steps. In the first one, a recurrent neural network for the fuel lattice design of the bottom of the fuel assembly is used. In the second one, the top of the fuel assembly is built adding gadolinia to bottom fuel lattice. Fuel reload is optimized by another recurrent neural network whereas the control rod patterns are optimized by an ant colony method. This new system starts building a fresh fuel batch. Later, a seed fuel reload is optimized according to a Haling calculation. Afterwards an iterative process is started: firstly, control rod patterns through the cycle are optimized, once that a new fuel reload with previously optimized control rod patterns is found. If thermal limits cannot be satisfied in this iterative process after several iterations, a new seed fuel reload is designed. If cold shutdown margin cannot be fulfilled, then gadolonia concentration is increased into the fuel assembly. Finally, if energy requirements cannot be fulfilled, then the uranium enrichment of the fuel lattice of the bottom fuel assembly is increased. Results of this new system are successful: thermal limits and cold shutdown margin are fulfilled, and energy requirements are reached. <![CDATA[Devolatilization of a particle coal in a plasma reactor]]> Abstract In this paper, a warm plasma reactor is used to increase the discharge by the addition of 3 different nitrogen-coal carbon mixtures. An experimental study was carried out to determine the temperatures profile in a jet plasma along the chamber, according to nitrogen/coal ratio and power consumption. The coal particle was also characterized in function of its size. An important effect when the volatile components released from the coal is manifested and passing through the plasma jet, this produce the plasma jet increase. This effect has a great importance to performance improvement in plasma reactor profitable for greenhouse gas (GHG) treatment. As a consequence, the high temperature surrounding the plasma jet, augments the degradation capacity. The experimental analysis, the kinetic parameters of the combustion of nitrogen-coal mixture was taking in consideration, as well as the appearance of a considerable amount of new radicals. In addition, increasing the plasma jet has a significant impact on the overall reactor performance of coal particles that release volatile component. This allows prompt increase and much enhanced plasma jet stability. The aim of this study was to evaluate and develop a model in order to know the temperature behavior in a plasma jet. Different sizes of coal particles at specific rate of 5 slm (standard liter per minute) of a nitrogen-coal mixture have been simulated in this model. The advantages of this technique is to simulate other sizes of particle and obtaining the best condition and operating parameters of plasma reactor. <![CDATA[Methylene blue degradation assessment by advanced oxidation methods]]> Abstract Experimental investigation about methylene blue degradation in aqueous solution applying several Advanced Oxidation Processes such as O3, O3/H2O2, O3/UV and O3/UV/H2O2 was accomplished. Methylene blue treatment consisted in evaluating the degradation of an initial concentration of 22 ppm in 500 ml of aqueous solution. The contaminant degradation efficiencies were analyzed considering parameters such as: treatment time, three different pH values for the solution and O3 and H2O2 as oxidizing reagents. The discoloration of the samples was examined throughout the experimental each 10 minutes. Using O3/UV/H2O2 (10 ppm) with an initial 7 pH and a treatment time of 60 minutes the highest degradation efficiency of 98% was achieved. <![CDATA[<em>In vitro</em> assessment of murine melanoma cells sensitivity to non-thermal atmospheric plasma]]> Abstract Melanoma is a dangerous skin cancer incidence of which has been increasing over the past years, so is important the search for new treatments. The purpose of the present work is to evaluate the relative sensitivity of a melanoma cell line to helium-generated non-thermal plasma. For that, three cell types were used (murine melanoma B16 cells, mouse embryo fibroblasts, and peripherical blood lymphocytes) and both cytotoxicity and genotoxicity were evaluated. The lethality produced by no-thermal plasma was higher in melanoma mouse cells compared with lymphocytes and fibroblasts. Accordingly, B16 cells showed higher levels of DNA fragmentation by this agent. Overall, the results suggest that non-thermal plasma has the potential to become a good alternative for treating skin cancer. <![CDATA[Nickel (II) sorption from aqueous media by <em>Agave salmiana</em> as biosorbent]]> Abstract In this work, the removal of nickel from aqueous solutions by Agave salmiana was investigated. For this purpose the removal of this heavy metal (Ni2+) was carried out in a batch system as a function of contact time, pH, and the initial concentration of the metallic specie in solution. The sorption data were fitted to pseudo-first order and pseudo-second order kinetic models to found the parameters which describe the processes. It was found that the maximum sorption of the Agave for Ni2+ was at pH 10 and pseudo-second order kinetic model well described the biosorption behavior of this heavy metal by the non-living biomass. Furthermore, the maximum sorption capacity obtained from the isotherm was 10 mgNi/gAgave. <![CDATA[Escherichia coli bacteria inactivation employing ozone and ultraviolet radiation using a reactor with continuously flowing water]]> Abstract The study on the inactivation of Escherichia coli (E. coli) bacteria in water flowing continuously in a treatment system based on two different reactors is presented. The bacteria inactivation is achieved in a water volume of 500 mL inoculated with an E. coli concentration of 1.45×103 bacteria/mL using combined treatment with ozone and ultraviolet (UV) radiation. Inoculated water firstly is introduced to cylindrical reactor supplied with ozone at a concentration of 1000-1100 ppm and, subsequently, transferred to a rectangular geometry reactor subjected to UV radiation with an energy per volume of 1.44 J/mL. Inactivation efficiency of E. coli bacteria in the water of 99.32% was attained in a total treatment time of 180 seconds. <![CDATA[CoMoW/Al<sub>2</sub>O<sub>3</sub>-MgO-Li<sub>2</sub>O Catalytic formulations for DBT hydrodesulphurization]]> Abstract Low acidity catalytic formulations were prepared incorporating MgO and Li2O to the conventional CoMoW/Al2O3 catalysts. The CoMoW active phases were impregnated using an ammoniacal solution containing the metallic complexes as citrates. A high dispersion of the Co, Mo and W species in octahedral coordination, inhibiting the agglomeration towards phases like MoO3, WO3 and Co3O4, was attained. The obtained formulations preserve the catalytic activity in the hydrodesulphurization (HDS) reaction of dibenzothiophene (DBT), enhancing the selectivity towards the direct desulphurization route. The prepared formulations show a lower hydrogenation function due to its low acidity.