Abstract Although studies have shown positive effects of gonadotropin releasing hormone (GnRH) or prostaglandin F2α (PGF2α) at the moment of fixed-time artificial insemination (FTAI) in the conception rate (CR) of cattle, its effects on treatments based on progesterone (P4) and estradiol benzoate (EB) is still not conclusive. The objective of this study was (1) to evaluate the effect of a PGF2α analogue at FTAI in the CR of crossbred beef cows submitted to a 11d FTAI protocol based on P4 and EB; and (2) to describe the CR between PGF2α-treated and control cows in different body condition scores (BCS) and parity categories. Crossbred (½ Nellore and ½ Angus) beef cows were submitted to a synchronization protocol and randomly assigned into 2 groups: Control (n = 163), at FTAI cows received 2 mL of saline solution as a placebo, and PGF2α (n = 163), at FTAI cows were treated with PGF2α analogue (10 mg of dinoprost tromethamine). Pregnancy diagnosis was performed 33d post-FTAI. Binary logistic regression model was used to analyze the effect of PGF2α treatment on CR. There was no difference in CR between PGF2α and control groups (P > 0.05; odds ratio (OR) = 0.92; confidence interval (CI) = 0.59-1.4). A greater CR was found in heifers (P = 0.0006, OR = 2.65, CI = 1.61 - 4.38) and multiparous (P = 0.0006, OR = 2.12, CI = 1.04 - 4.3) when compared to primiparous cows. Cows with low BCS (4; 9-point scale) showed lower CR when compared with moderate BCS (5-6; 9-point scale) (P < 0.05; OR = 0.10; CI = 0.06 - 0.18). There was no numerical difference on CR between PGF2α-treated and control cows in different BCS and parity categories. The results suggested that the CR in this study was not influenced by 10 mg PGF2α analogue at FTAI.

RESUMEN La turba es un material orgánico que se ha utilizado ampliamente como adsorbente eficiente y de bajo costo. Dado que muchos estudios tienden a centrarse en las turbas templadas, hay una falta de conocimiento sobre el mecanismo de adsorción de las turbas tropicales. Este trabajo investiga el uso de dos turbas brasileñas (Cravinhos - C y Luis Antonio - LA) de la cuenca del río Mogi-Guacu para la adsorción de plomo (Pb), zinc (Zn) y cadmio (Cd), con el fin de contribuir al uso de materiales locales y de fácil acceso para remediar sitios contaminados. Las turbas adsorbieron un alto porcentaje de cationes, especialmente cationes Pb (100,0-46,3%), mostrando la turba comercial C una mayor adsorción que la turba LA. La orden de eliminación fue Pb2+ > Cd2+ ≥ Zn2+ para C y Pb2+ > Zn2+ > Cd2+ para LA. Los datos de equilibrio por lotes para turbas y para todos los metales se ajustaron mejor a la isoterma de Langmuir, con capacidades de adsorción (qm) para Pb, Zn y Cd de 37,3134, 29,0674 y 21,2890 mmol kg-1 en turba C y 21,7391, 14,2550 y 3,6460. mmol kg-1 en LA, respectivamente, valores comparables a los de otras turbas y biosorbentes. Las turbas estudiadas se consideran materiales adsorbentes eficientes, alternativos y de bajo costo para estos metales. La proximidad de las turberas a áreas con alto potencial de contaminación requiere el uso de materiales locales para reducir los costos de remediación.

ABSTRACT Peat is an organic material that has been widely used as an efficient and low-cost adsorbent. As many studies tend to focus on temperate peats, there is a lack of knowledge about the adsorption mechanism of tropical peats. This paper investigates the use of two Brazilian peats (Cravinhos - C and Luis Antônio - LA) from the Mogi-Guaçu river basin for the adsorption of lead (Pb), zinc (Zn), and cadmium (Cd), in order to contribute to the use of local and easy access materials to remediate contaminated sites. The peats adsorbed a high percentage of cations, especially Pb cations (100.0-46.3%), with commercial peat C showing higher adsorption than peat LA. The removal order was Pb2+ > Cd2+ ≥ Zn2+ for C and Pb2+ > Zn2+ > Cd2+ for LA. The batch data for both peats and for all metals were better fit by the Langmuir isotherm, with adsorption capacities (q m ) for Pb, Zn, and Cd of 37.3134, 29.0674 and 21.2890 mmol kg-1 in peat C and 21.7391, 14.2550 and 3.6460 mmol kg-1 in LA, respectively, values comparable to those of other peats and biosorbents. The studied peats are considered efficient, alternative and low-cost adsorptive materials for these metals. The proximity of peatlands to areas with high potential for contamination necessitates the use of local materials to reduce remediation costs.

RESUMEN Los suelos lateríticos se han utilizado ampliamente en la construcción de revestimientos de basureros para residuos sólidos. Por otro lado, hay poca práctica en el uso de cambisols (menos arcillosos) para esta finalidad. El uso de suelo local para la construcción de revestimientos para impermeabilizar y retener contaminantes representa una alternativa para controlar este tipo de contaminación. Por lo tanto, el objetivo de este estudio fue determinar las propiedades físicas y químicas de un suelo tropical fuertemente degradado recolectado en la ciudad de Eldorado (Valle de Ribeira), y evaluar la capacidad de este suelo para adsorber plomo (Pb). La contaminación del suelo y el agua por Pb es un problema mundial, y, en el Valle de Ribeira, la contaminación por Pb es común en áreas específicas, debido principalmente a la eliminación inadecuada de los desechos mineros. La eficiencia de la adsorción de Pb por el cambisol fue indirectamente proporcional a las concentraciones de Pb en la solución. Cuando la concentración inicial de 20 mg/L, el porcentaje de adsorción de Pb fue del 92,5% y cuando la concentración inicial fue de 100 mg/L, la tasa de adsorción fue del 81,7%. Además de la retención de Pb, este suelo presentó las siguientes características que son favorables para el uso de suelos en la construcción de revestimientos: es un suelo franco limoso (arcilla de alta plasticidad, CH), con límite de líquido (LL) del 57%, índice de plasticidad (PI) del 33%, medio oxidante y El predominio de las cargas negativas en la superficie de las partículas coloidales. Por lo tanto, se concluye que el suelo residual tropical (cambisol) presenta características que le permiten ser utilizado como revestimiento en la eliminación de residuos que contienen Pb.

ABSTRACT Lateritic soils have been widely used in the construction of landfill base liners for solid waste disposal. On the other hand, there is little practice in the use of cambisols (less clayey) for this finality. The use of local soil for the construction of liners in order to waterproof and retain contaminants represents an alternative to control this type of contamination. Thus, the objective of this study was to determine the physical and chemical properties of a cambisol collected in the city of Eldorado (Ribeira Valley) and to evaluate the ability of this soil to adsorb lead (Pb). The contamination of soil and water by Pb is a worldwide problem, and in the Ribeira Valley the contamination by Pb is common in specific areas mainly due to inadequate mining waste disposal. The efficiency of Pb adsorption by the cambisol was indirectly proportional to the concentrations of Pb in solution. When the initial concentration of 20 mg/L was used, the adsorption percentage of Pb was 92.5% and when the initial concentration was 100 mg/L, the adsorption rate was 81.7%. In addition to the retention of Pb, this soil presented the following characteristics which are favorable for using soils in the construction of liners: a silt loam (a high plasticity clay, CH), with liquid limit (LL) of 57%, plasticity index (PI) of 33%, oxidizing medium and the predominance of negative charges on the surface of the colloidal particles. Thus, it is concluded that this tropical soil (cambisol) exhibits characteristics that allow it to be used as a liner in the disposal of residues containing Pb.

In this study carnauba straw powder was submitted to chemical treatments using alkali (NaOH) or hexane, in order to increase its hydrophilicity and to investigate its potential use for the development of a biodegradable composite. Biocomposites were prepared in solution, using carnauba straw powder and chitosan as matrix, with powder contents of 10 and 50 wt %. Both, straw powder and biocomposites, were characterized by chemical composition analysis, FTIR, TGA, DSC and SEM. According to the results, the chemical treatment using NaOH was efficient in removing the soluble components of the powder and cleaning its surface. DSC analyses demonstrated that the addition of high powder loadings does not reduce the thermal stability of the composite. The elastic modulus of the biocomposites obtained with 10 wt % of untreated carnauba powder remained unaltered, decreasing for a filler content of 50 wt %. The effect of NaOH chemical treatment was more evident for the composite with 50 wt % of powder.

O catalisador nanoestruturado SiO2/ZrO2 foi preparado pelo método sol-gel e apresentou uma área superficial de 131,50 ± 14 m² g-1. As imagens de microscopia eletrônica de varredura mostraram que o catalisador apresentou partículas muito homogêneas de 250 nm de diâmetro. Este material foi aplicado na transesterificação do óleo de soja para a produção de biodiesel. A conversão do óleo em biodiesel teve um rendimento de 96,2 ± 1,4 % em 3 h de reação de transesterificação catalisada pelo material SiO2/ZrO2 (SiZr). O catalisador foi recuperado e reutilizado por seis vezes, mantendo uma eficiência catalítica de 84,1%.

Nanosized SiO2/ZrO2 catalyst with high surface area (131.50 ± 14 m² g-1) was prepared by the sol-gel method. The material presented highly homogeneous particles with an average diameter of 250 nm according to SEM images. It was applied in the transesterification of soybean oil for biodiesel production. The biodiesel conversion reached a yield of 96.2 ± 1.4 % after 3 h of transesterification reaction catalised by SiO2/ZrO2 (SiZr). The catalyst was recovered and reused six times, maintaining a catalytic efficiency of about 84.1 %.