Abstract The objective of the study was to identify the influence of heat treatment in obtaining condensable tannins compounds from Pinus spp bark residues for adhesive production. The heat treatments were: (a) bark without heat treatment (control); (b) bark exposed at 60 °C for 50 h dry; (c) bark exposed at 120 °C for 10 h in steam; (d) bark attached to the trunk exposed at 120 °C for 10 h in steam. For the chemical characterization of the material, the crust was ground and classified, the tannic compounds were extracted under reflux with distilled water for 2 h, and in addition, sodium carbonate and sodium sulphite salts were added, both at 5% in relation to dry mass. The properties of commercial tannin from Acacia mearnsii (acacia negra) were evaluated as the control. The tannin extraction process was carried out in an autoclave, and then used for the evaluation of properties such as viscosity, pH, gel formation time, solids content and density. It was determined that both the bark exposed at 120 °C for 10 h in steam and the bark adhered to the trunk (subjected to steam at 120 °C for 10 hours) for both salts, have higher tannin yields. Tannic extracts obtained from sodium carbonate have an alkaline structure, high viscosity, and shorter gel formation time. However, extracts obtained from sodium sulphite provide an acidic character and solids content close to those found in aqueous tannic extracts obtained from black acacia.

Resumen Se identificó la influencia del tratamiento térmico en la obtención de compuestos tánicos condensables a partir de residuos de corteza de Pinus spp para la producción de adhesivo. Los tratamientos térmicos fueron: (a) corteza sin tratamiento térmico (testigo); (b) corteza expuesta a 60 °C durante 50 h en seco; (c) corteza expuesta a 120 °C durante 10 h en vapor; (d) corteza adherida al tronco expuesta a 120 °C durante 10 h en vapor. Para su caracterización química, la corteza fue molida y clasificada. Se extrajeron los compuestos tánicos mediante reflujo con agua destilada durante 2 h; se adicionaron sales de carbonato de sodio y sulfito de sodio, ambos a 5% en relación con la masa seca. Para el testigo fueron evaluadas las propiedades del tanino comercial de Acacia mearnsii (acacia negra). El proceso de extracción de taninos fue realizado en autoclave y se evaluaron las siguientes propiedades: viscosidad, pH, tiempo de formación de gel, contenido de sólidos y densidad. Tanto la corteza expuesta a 120 °C durante 10 horas en vapor como la adherida al tronco sometida a 120 °C a vapor durante 10 h, para ambas sales, exhibieron los mayores rendimientos de taninos. Los extractos tánicos obtenidos a partir de carbonato de sodio presentaron una estructura alcalina, alta viscosidad y menor tiempo de formación de gel. Sin embargo, los extractos obtenidos a partir de sulfito de sodio proporcionaron un carácter ácido y contenido de sólidos próximos a los encontrados en los extractos tánicos acuosos obtenido de la acacia negra.

ABSTRACT. The objective of this work was to determine the adequate nitrogen (N) dose via fertigation associated with the maximum economic production of maize for silage, in two agricultural crops (summer and winter), in the municipality of Canindé de São Francisco-SE, Brazil. The experimental design was in randomized blocks, with four replicates. The treatments consisted of four doses of N (0, 80, 160, and 240 kg ha-1) using urea. The cultivar planted was the hybrid Bt Feroz. The evaluated characteristics were as follows: shoot fresh and dry mass productivity, gross and net incomes, the rate of return and net profit margin. There was an interaction between N doses and agricultural crops for all variables. Higher agroeconomic efficiency in the production of maize for silage was obtained from the winter harvest. In the summer crop, the rate of return (1.82) and the net profit margin (45.52%) were highest when the plants were fertigated with 56.04 and 58.92 kg ha-1 of N, respectively. In winter, the yields of fresh mass, gross and net incomes increased linearly with increasing doses of N, with a profit proportional to the invested capital since nitrogen fertigation did not influence the rate of return (2.24) and the net profit margin (55.22%).

ABSTRACT: Exploration seismology provides the main source of information about the Earth’s subsurface, which in many cases can be presented as a simple model of horizontal or near-horizontal layers. After the seismic acquisition step, conventional seismic processing of reflection data provides an image of the subsurface by using information about the reflections of these layers. The traveltime from a source to different receivers is adjusted using a hyperbolic function. This expression is used in the case involving an isotropic medium, which is a simplification of nature, whereas geologically complex media are generally anisotropic. A subsurface model that more closely resembles reality is the vertical transverse isotropy, which defines two parameters that are required to correct the traveltimes: the NMO velocity and the anellipticity parameter. In this paper, we reviewed the literature and methodology for velocity analysis of seismic data acquired from anisotropic media. A model with horizontal layers and anisotropic behavior was developed and evaluated. The anisotropic velocity was compared to the isotropic velocity, and the results were analyzed. Finally, the methodology was applied to real seismic data, i.e. an experimental landline from Tenerife Field, Colombia. The results show the importance of the anellipticity parameter in models with anisotropic layers.

The U-Mo alloys are investigated with the goal to become nuclear material to fabricate high-density fuel elements for high performance research reactors. The enrichment level (20% 235U) suggests that the U-Mo alloys should be between 6 to 10 wt. (%), which can reach up to 9 gU.cm-3 in fuel density. Nevertheless, the U-Mo alloys are very reactive with Al. Interdiffusion reaction products are formed since nuclear fission promotes chemical interaction layer during operation, leading to potential structural failure. Present studies were made with treated hot rolled diffusion couples of U-10Mo inserted in Al (AA1050). The U-10Mo/AA1050 pairs were treated in two temperatures (150 ºC and 550 ºC) with three soaking times (5, 40 and 80 hours). From microstructure analyses, rapid diffusion of Al happened inside U-10Mo in the first heating at 540 ºC during 15 minutes, reaching 8 at% Al in a range of 170 μm towards U-10Mo. Longer time at 550 ºC treatment maintain this level of Al-content up to 1000 μm inside U-10Mo. In this study, the results suggested the formation of a barrier made by residual elements, which promoted little interdiffusion phenomena between U-10Mo and alloy AA1050. Silicon co-diffusion with Al, along the interdiffusion line, is thought to be an important indication for this interdiffusion blockage.