USO DE ENZIMAS FIBROLÍTICAS CON ENSILADO DE CAÑA DE AZUCAR (Saccharum spp.) PARA LA ENGORDA DE TORETES EN PASTOREO

An experiment was carried out with the objective of evaluating the productive response and digestibility of dry matter in bulls grazing on African star grass (Cynodon plectostachyus L.), supplemented with sugar cane ensilage (SCE) (Saccharum spp.) and a fibrolytic enzymatic complex. Forty (40) Bos taurusxBos indicus young beef bulls were used (initial weight 375±29 kg) during a period of 125 days. They were fed individually with restricted access to the ensilage (16 % RP), and organized in a Completely Random Design with four treatments and ten repetitions in the following way: 1) Control (TP), 2) TP+SCE, 3) TP+SC+15g Fibrozyme animal-1 day-1, 4) TP+SCE+30g Fibrozyme animal-1 day-1. The animal load was eight animals ha-1 in the treatments with SCE and 3.3 in the control. The daily weight gain of the young beef bulls improved (P<0.05) with the use of the enzyme: 1) 395.17b, 2) 457.60ab, 3) 703.76a, 4) 621.21ab g day-1, which was associated with a higher consumption: 1) 11.36b, 2)14.68ab, 3) 17.09a, 4) 15.25ab kg animal-1 day-1 and digestibility of the dry matter (P<0.05), compared to the control group: 1) 63.21b, 2) 63.67b, 3) 68.58a, 4) 66.61ab (%). The use of fibrolytic enzymes in sugar cane ensilage increased the digestibility, improved the consumption, weight gain, and food conversion in young beef bulls grazing on African star grass.Se realizó un experimento con el objetivo de evaluar la respuesta productiva y digestibilidad de la materia seca en novillos pastoreando pasto Estrella de África (Cynodon plectostachyus L.), complementados con ensilado de caña de azúcar (ECA) (Saccharum spp.) y un complejo enzimático fibrolítico. Se utilizaron 40 toretes cruzados Bos taurusxBos indicus (peso inicial 375±29 kg) durante un periodo de 125 días. Se alimentaron de forma individual con acceso restringido al ensilado (16% PC), y organizados en un Diseño Completamente al Azar con cuatro tratamientos y diez repeticiones de la siguiente forma: 1) Testigo (TP), 2) TP+ECA, 3) TP+ECA+15g Fibrozyme animal-1 día-1, 4) TP+E+A+30g Fibrozyme animal-1 día-1. La carga animal fue de ocho animales ha-1 en los tratamientos con ECA y de 3.3 en el testigo. Se mejoró la ganancia diaria de peso de los toretes (P<0.05) con el uso de la enzima 1) 395.17b, 2) 457.60ab, 3) 703.76a, 4) 621.21ab g día-1, lo cual se asoció a un mayor consumo: 1) 11.36b, 2)14.68ab, 3) 17.09a, 4) 15.25ab kg animal-1 día-1 y digestibilidad de la materia seca (P<0.05) comparado con el grupo testigo: 1) 63.21b, 2) 63.67b, 3) 68.58a, 4) 66.61ab (%). El uso de enzimas fibrolíticas en ensilado de caña de azúcar incrementó la digestibilidad, mejoró el consumo, la ganancia de peso, y la conversión alimenticia en toretes pastoreando Estrella Africana

Infinite-time concentration in aggregation-diffusion equations with a given potential

Typically, aggregation-diffusion is modeled by parabolic equations that combine linear or nonlinear diffusion with a Fokker-Planck convection term. Under very general suitable assumptions, we prove that radial solutions of the evolution process converge asymptotically in time towards a stationary state representing the balance between the two effects. Our parabolic system is the gradient how of an energy functional, and in fact we show that the stationary states are minimizers of a relaxed energy. Here, we study radial solutions of an aggregation-diffusion model that combines nonlinear fast diffusion with a convection term driven by the gradient of a potential, both in balls and the whole space. We show that, depending on the exponent of fast diffusion and the potential, the steady state is given by the sum of an explicit integrable function, plus a Dirac delta at the origin containing the rest of the mass of the initial datum. Furthermore, it is a global minimizer of the relaxed energy. This splitting phenomenon is an uncommon example of blow-up in inffinite time.Depto. de Análisis Matemático y Matemática AplicadaFac. de Ciencias MatemáticasFALSEUnión Europea. Horizonte 2020Ministerio de Ciencia e Innovación (MICINN)pu

Transesterificación de ésteres grasos con arilaminoalcoholes. Síntesis de mono- y diacilderivados del 3-fenilamino-1,2-propanodiol

In this paper the synthesis of acylderivatives of 3-phenylamino- 1,2 propanediol has been studied. These compounds are prepared by transesterification of fatty acids methyl esters with the amino-alcohol and sodium methoxide as catalyst. The reaction was carried out with mechanical stirring under vacuum. The effect of temperature, molar relation of reactives, time and concentration of catalyst on the reaction yield has been investigated. Yield increases with temperature and ester concentration until the optimun reaction temperature is reached. This temperature depend on molar relation ester/aminoalcohol (140 °C for 1/1 and 2/1 values and 120 °C for 4/1 value). The composition of reaction mixture was evaluated from the mono/di relation. This relation decrease when temperature and molar relation increase.En el presente trabajo se ha abordado la síntesis de los acilderivados del 3-fenilamino-1,2-propanodiol por transesterificación de ésteres metílicos de ácidos grasos con 3-fenilamino- 1,2-propanodiol utilizando metóxido sódico como catalizador. La reacción se lleva a cabo bajo presión reducida y agitación mecánica. Se ha estudiado la influencia de la temperatura, relación molar de los reactivos, tiempo y concentración de catalizador sobre el rendimiento de la reacción. El rendimiento aumenta con la temperatura y la concentración de éster hasta alcanzar la temperatura óptima de reacción. Esta temperatura depende de la relación molar y es de 140 °C para las relaciones molares éster: 3-fenilamino-1,2-propanodiol (1:1) y (2:1) y de 120 °C para (4:1). La composición de la mezcla de reacción se evalúa mediante la relación mono-/di-. Esta relación disminuye conforme aumenta la temperatura y la relación molar

Vortex formation for a non-local interaction model with Newtonian repulsion and superlinear mobility

We consider density solutions for gradient flow equations of the form $u_t = \nabla \cdot ( \gamma(u) \nabla \mathrm N(u))$, where $\mathrm N$ is the Newtonian repulsive potential in the whole space $\mathbb R^d$ with the nonlinear convex mobility $\gamma(u)=u^\alpha$, and $\alpha>1$. We show that solutions corresponding to compactly supported initial data remain compactly supported for all times leading to moving free boundaries as in the linear mobility case $\gamma(u)=u$. For linear mobility it was shown that there is a special solution in the form of a disk vortex of constant intensity in space $u=c_1t^{-1}$ supported in a ball that spreads in time like $c_2t^{1/d}$, thus showing a discontinuous leading front or shock. Our present results are in sharp contrast with the case of concave mobilities of the form $\gamma(u)=u^\alpha$, with $0<\alpha<1$ studied in [9]. There, we developed a well-posedness theory of viscosity solutions that are positive everywhere and moreover display a fat tail at infinity. Here, we also develop a well-posedness theory of viscosity solutions that in the radial case leads to a very detail analysis allowing us to show a waiting time phenomena. This is a typical behavior for nonlinear degenerate diffusion equations such as the porous medium equation. We will also construct explicit self-similar solutions exhibiting similar vortex-like behaviour characterizing the long time asymptotics of general radial solutions under certain assumptions. Convergent numerical schemes based on the viscosity solution theory are proposed analysing their rate of convergence. We complement our analytical results with numerical simulations ilustrating the proven results and showcasing some open problems

Dependence of the Star Formation Efficiency on the Parameters of Molecular Cloud Formation Simulations

We investigate the response of the star formation efficiency (SFE) to the main parameters of simulations of molecular cloud formation by the collision of warm diffuse medium (WNM) cylindrical streams, neglecting stellar feedback and magnetic fields. The parameters we vary are the Mach number of the inflow velocity of the streams, Msinf, the rms Mach number of the initial background turbulence in the WNM, and the total mass contained in the colliding gas streams, Minf. Because the SFE is a function of time, we define two estimators for it, the "absolute" SFE, measured at t = 25 Myr into the simulation's evolution (sfeabs), and the "relative" SFE, measured 5 Myr after the onset of star formation in each simulation (sferel). The latter is close to the "star formation rate per free-fall time" for gas at n = 100 cm^-3. We find that both estimators decrease with increasing Minf, although by no more than a factor of 2 as Msinf increases from 1.25 to 3.5. Increasing levels of background turbulence similarly reduce the SFE, because the turbulence disrupts the coherence of the colliding streams, fragmenting the cloud, and producing small-scale clumps scattered through the numerical box, which have low SFEs. Finally, the SFE is very sensitive to the mass of the inflows, with sferel decreasing from ~0.4 to ~0.04 as the the virial parameter in the colliding streams increases from ~0.15 to ~1.5. This trend is in partial agreement with the prediction by Krumholz & McKee (2005), since the latter lies within the same range as the observed efficiencies, but with a significantly shallower slope. We conclude that the observed variability of the SFE is a highly sensitive function of the parameters of the cloud formation process, and may be the cause of significant scatter in observational determinations.Comment: 19 pages, submitted to MNRA