Abstract The effect of synthesis parameters on the microstructural behavior and morphology during the yttrium oxide (Y2O3) formation is reported. Y2O3 crystals were produced by a modified sol-gel route assisted by polyvinyl alcohol solution varying the calcination temperature and solution pH. The crystalline phase formation was investigated using X-ray powder diffraction combined with the Rietveld refinement method. The microstructural properties were analyzed by using the Williamson-Hall formalism. The calcination temperature followed the thermal events observed in the differential thermal analysis combined with the thermogravimetric analysis of the precursor xerogel. It was seen that the combination of PVA and pH variation can be used to minimize the calcination time and temperature. The morphological analysis showed samples with different sizes and appearances depending on pH and calcination temperature. Therefore, it was shown that the parameters in the synthesis process can be used to tailor the properties of Y2O3, such as crystallite size, degree of structural ordering, and morphology, and consequently, improve the desired application. YO Y O (Y2O3 reported Y2O solgel sol gel Xray X ray method WilliamsonHall Williamson Hall formalism xerogel Therefore size ordering consequently application (Y2O

Resumo A seleção pode impactar a forma de crescimento, mudando o desempenho e os valores assintóticos. No entanto, existem poucas informações sobre o crescimento das famílias em programas de criação de peixes. O objetivo deste estudo foi examinar o desempenho e as curvas de crescimento de famílias de tilápia-do-Nilo AquaAmérica. Foram avaliadas 20 famílias AquaAmérica cultivadas em tanques-rede (13,5 m3) por 181 dias. O modelo de regressão não linear de Gompertz foi ajustado aos dados pelo método dos mínimos quadrados ponderados, tomando o inverso da variância do peso nas diferentes famílias e nas diferentes idades como variável de ponderação. O modelo foi ajustado para descrever o crescimento em peso e características morfométricas. Duas famílias apresentaram pesos maiores (P <0,05) em 133 dias (família AA10: 743,2 g; família AA16: 741,2 g) e 181 dias (família AA10: 1422,1 g; família AA16: 1393,4 g) de experimento em relação a outras famílias. Em ambos os períodos experimentais, os machos apresentaram maior peso, com maior contraste entre os sexos ocorrendo aos 181 dias. A análise das três famílias mais contrastantes (AA1, AA9 e AA14) mostrou que o valor assintótico para o peso foi maior (P <0,05) na família AA9 (3926,3 g) do que na família AA14 (3251,6 g), mas a taxa de crescimento específica e a idade no ponto de inflexão não diferiu significativamente entre as famílias. Em conclusão, duas das 20 famílias eram muito superiores; machos exibiram um maior crescimento, principalmente no período de 181 dias; e a curva de crescimento diferiu entre as famílias, principalmente quanto ao peso assintótico.

Abstract Selection can affect growth, changing performance and asymptotic values. However, there is little information about the growth of families in fish breeding programs. The aim of this study was to evaluate the performance and growth of families of Nile tilapia AquaAmérica. Twenty AquaAmérica families cultivated in a net cage (13.5 m3) for 181 days were evaluated. The nonlinear Gompertz regression model was fitted to the data by the weighted least squares method, taking the inverse of the variance of weight in different families and at different ages as the weighting variable. The model was adjusted to describe the growth in weight and morphometric characteristics. Two families showed highest (P<0.05) weights at both 133 days (family AA10: 743.2 g; family AA16: 741.2 g) and 181 days (family AA10: 1,422.1 g; family AA16: 1,393.4 g) of the experiment. In both experimental periods, the males showed a heavier weight, with the greatest contrast between the sexes occurring at 181 days. The analysis of the three most contrasting families (AA1, AA9 and AA14) showed that the asymptotic value for weight was higher (P<0.05) in family AA9 (3,926.3 g) than in family AA14 (3,251.6 g), but specific growth rate and age at the inflection point did not differ significantly between families. In conclusion, two of the 20 families were superior; males exhibited a greater growth, mainly in the period of 181 days; and the growth curve differed between the families, especially for asymptotic weight.

ABSTRACT A semi-batch bubble reactor has been developed to produce fatty acid ethyl ester (biodiesel) by acid-catalyzed esterification of oleic acid with superheated ethanol vapor. In this paper, the effects of reaction temperature (110, 130 and 150°C), ethanol volumetric flow rate (1.35, 2.50 and 3.65 mL/min) and vapor bubble size on the reactor performance were evaluated. The results demonstrated that temperature and volumetric flow rate have significant effects on the chemical reaction, gas phase solubility and mass transfer limitations. In addition, the free fatty acid conversion velocity was increased by approximately 56% when a microporous stainless-steel tube was employed to generate and distribute the vapor bubbles inside the reactor, which allowed the process to reach 95% conversion in approximately 40 minutes for the operating temperature of 150°C and volumetric flow rate of 2.5 mL/min.

AbstractNH4NO3 simultaneously provides a readily assimilable nitrogen source (ammonia) and a reserve of nitrogen (nitrate), allowing for an increase in Arthrospira platensis biomass production while reducing the cost of the cultivation medium. In this study, a 22plus star central composite experimental design combined with response surface methodology was employed to analyze the influence of light intensity (I) and the total amount of added NH4NO3 (Mt) on a bench-scale tubular photobioreactor for fed-batch cultures. The maximum cell concentration (Xm), cell productivity (PX) and biomass yield on nitrogen (YX/N) were evaluated, as were the protein and lipid contents. Under optimized conditions (I = 148 μmol·photons·m-2·s-1 and Mt = 9.7 mM NH4NO3), Xm = 4710 ±34.4 mg·L-1, PX = 478.9 ±3.8 mg·L-1·d-1 and YX/N = 15.87 ±0.13 mg·mg-1 were obtained. The best conditions for protein content in the biomass (63.2%) were not the same as those that maximized cell growth (I = 180 μmol·photons·m-2·s-1 and Mt = 22.5 mM NH4NO3). Based on these results, it is possible to conclude that ammonium nitrate is an interesting alternate nitrogen source for the cultivation of A. platensisin a fed-batch process and could be used for other photosynthetic microorganisms.

In this paper we present a study of feasibility by using Cassino Parallel Manipulator (CaPaMan) as an earthquake simulator. We propose a suitable formulation to simulate the frequency, amplitude and acceleration magnitude of seismic motion by means of the movable platform motion by giving a suitable input motion. In this paper we have reported numerical simulations that simulate the three principal earthquake types for a seismic motion: one at the epicenter (having a vertical motion), another far from the epicenter (with the motion on a horizontal plane), and a combined general motion (with a vertical and horizontal motion).