Cat. A1

Mucilage and cellulosic derivatives as clarifiers for the improvement of the non-centrifugal sugar production process

Non-centrifugal cane sugar (NCS) is the second most important Colombian agribusiness in social importance. However, the sugar cane industry is facing some challenges caused by the controversial nutritional and safety attributes of NCS. Some Colombian …

Riemann problems and delta-shock solutions for a Keyfitz-Kranzer system with a forcing term

In this work, we study Riemann problems and delta-shock solutions for a nonsymmetric Keyfitz-Kranzer system with a Coulomb-like friction term or linear damping. We show the existence of an intricate delta-shock wave solution and its generalized …

Radicals and Köthe's conjecture for skew PBW extensions

The aim of this paper is to investigate different radicals (Wedderburn radical, lower nil radical, Levitzky radical, upper nil radical, the set of all nilpotent elements, the sum of all nil left ideals) of the noncommutative rings known as skew …

A review on the productive potential of the Muscovy Duck

Muscovy ducks (*Cairina moschata*) are one of the most exploited species in the duck-farming industry due to their large size, meat quality, and considerable economic value for small farmers and large factories. This study reviews the available …

On the Szegő transformation for some spectral perturbations of matrix measures

Given a normalized measure mu supported on [-1,1], a measure sigma supported on the unit circle can be defined by using the so-called Szego transformation. This also establishes a well known relation between the corresponding Stieltjes and …

A geometric realization of socle-projective categories for posets of type A

This paper establishes a link between the theory of cluster algebras and the theory of representations of partially ordered sets. We introduce a class of posets by requiring avoidance of certain types of peak-subposets and show that these posets can …

CMV block matrices for symmetric matrix measures on the unit circle

In this contribution, we study the relationship between the CMV block matrices associated with two symmetric positive definite matrix measures supported on the unit circle. We also consider certain transformations of an orthogonality matrix measure …

Lagrangian structure for two dimensional non-barotropic compressible fluids

We study the Lagrangian structure for weak solutions of two dimensional Navier–Stokes equations for a non-barotropic compressible fluid, i.e. we show the uniqueness of particle trajectories for two dimensional compressible fluids including the energy …

Complemented subspaces of homogeneous polynomials

Let 𝐾(𝑛𝐸;𝐹) (resp. 𝑤(𝑛𝐸;𝐹)) denote the subspace of all 𝑃∈(𝑛𝐸;𝐹) which are compact (resp. weakly continuous on bounded sets). We show that if 𝐾(𝑛𝐸;𝐹) contains an isomorphic copy of 𝑐0, then 𝐾(𝑛𝐸;𝐹) is not complemented in (𝑛𝐸;𝐹). Likewise we show …

Lower Bounds for Possible Singular Solutions for the Navier–Stokes and Euler Equations Revisited

In this paper we give optimal lower bounds for the blow-up rate of the 𝐻˙𝑠(𝕋3)-norm, 1/252