Computation-free presentation of the fundamental group of generic (p,q)(p,q)-torus curves

In this note, we present a new method for computing fundamental groups of curve complements using a variation of the Zariski-Van Kampen method on general ruled surfaces. As an application we give an alternative (computation-free) proof for the fundamental group of generic $(p,q)$-torus curves.Comment: 7 pages, 3 figure

Cartier and Weil Divisors on Varieties with Quotient Singularities

The main goal of this paper is to show that the notions of Weil and Cartier $\mathbb{Q}$-divisors coincide for $V$-manifolds and give a procedure to express a rational Weil divisor as a rational Cartier divisor. The theory is illustrated on weighted projective spaces and weighted blow-ups.Comment: 16 page

Uniformly ergodic probability measures

Let $G$ be a locally compact group and $\mu$ be a probability measure on $G$. We consider the convolution operator $\lambda_1(\mu)\colon L_1(G)\to L_1(G)$ given by $\lambda_1(\mu)f=\mu \ast f$ and its restriction $\lambda_1^0(\mu)$ to the augmentation ideal $L_1^0(G)$. Say that $\mu$ is uniformly ergodic if the Ces\`aro means of the operator $\lambda_1^0(\mu)$ converge uniformly to 0, that is, if $\lambda_1^0(\mu)$ is a uniformly mean ergodic operator with limit 0 and that $\mu$ is uniformly completely mixing if the powers of the operator $\lambda_1^0(\mu)$ converge uniformly to 0. We completely characterize the uniform mean ergodicity of the operator $\lambda_1(\mu)$ and the uniform convergence of its powers and see that there is no difference between $\lambda_1(\mu)$ and $\lambda_1^0(\mu)$ in this regard. We prove in particular that $\mu$ is uniformly ergodic if and only if $G$ is compact, $\mu$ is adapted (its support is not contained in a proper closed subgroup of $G$) and 1 is an isolated point of the spectrum of $\mu$. The last of these three conditions is actually equivalent to $\mu$ being spread-out (some convolution power of $\mu$ is not singular). The measure $\mu$ is uniformly completely mixing if and only if $G$ is compact, $\mu$ is spread-out and the only unimodular value of the spectrum of $\mu$ is 1.Comment: Updated version. References to previous related results are improved. 21 page

Oxygen transfer rate during the production of alginate by Azotobacter vinelandii under oxygen-limited and non oxygen-limited conditions

<p>Abstract</p> <p>Background</p> <p>The oxygen transfer rate (OTR) and dissolved oxygen tension (DOT) play an important role in determining alginate production and its composition; however, no systematic study has been reported about the independent influence of the OTR and DOT. In this paper, we report a study about alginate production and the evolution of the molecular mass of the polymer produced by a wild-type <it>A. vinelandii </it>strain ATCC 9046, in terms of the maximum oxygen transfer rate (OTR_max) in cultures where the dissolved oxygen tension (DOT) was kept constant.</p> <p>Results</p> <p>The results revealed that in the two dissolved oxygen conditions evaluated, strictly controlled by gas blending at 0.5 and 5% DOT, an increase in the agitation rate (from 300 to 700 rpm) caused a significant increase in the OTR_max(from 17 to 100 mmol L^-1h^-1for DOT of 5% and from 6 to 70 mmol L^-1h^-1for DOT of 0.5%). This increase in the OTR_maximproved alginate production, as well as the specific alginate production rate (SAPR), reaching a maximal alginate concentration of 3.1 g L^-1and a SAPR of 0.031 g _algg _biom^-1h^-1in the cultures at OTR_maxof 100 mmol L^-1h^-1. In contrast, the mean molecular mass (MMM) of the alginate isolated from cultures developed under non-oxygen limited conditions increased by decreasing the OTR_max, reaching a maximal of 550 kDa at an OTR_maxof 17 mmol L^-1h^-1. However, in the cultures developed under oxygen limitation (0.5% DOT), the MMM of the polymer was practically the same (around 200 kDa) at 300 and 700 rpm, and this remained constant throughout the cultivation.</p> <p>Conclusions</p> <p>Overall, our results showed that under oxygen-limited and non oxygen-limited conditions, alginate production and its molecular mass are linked to the OTR_max, independently of the DOT of the culture.</p

Propuesta para readaptación deportiva durante el proceso de rehabilitación de jugadores del Club Universidad Nacional

El proceso de rehabilitación deportiva permite identificar y gestionar a los diferentes especialistas con el jugador lesionado. El presente trabajo expone una propuesta de intervención para la readaptación deportiva que permita identificar etapas y procedimientos de acuerdo con las características de los jugadores lesionados de los diferentes equipos profesionales y equipos de formación del Club Universidad Nacional A.C. Se propuso una intervención tomando como referencia una metodología que permita la individualización de la rehabilitación deportiva. La aplicación de la propuesta dio como resultado identificar posibles áreas de oportunidad para mejorar los procedimientos que ya se realizan, así como coordinar una intervención adecuada y oportuna de los diferentes especialistas dentro del servicio médico del club

Estudio comparativo de vinos elaborados con barricas y productos alternativos tras un posterior envejecimiento en botella

En el presente trabajo fin de grado se ha realizado un estudio comparativo de un vino tinto embotellado que fue envejecido en diferentes sistemas: en barricas y con productos alternativos (astillas y duelas) de roble francés y de roble americano, siendo un total de 6 tipos de vinos procedentes de 6 sistemas de envejecimiento diferentes. El vino tras mantenerse en botella durante nueve años ha sido estudiado desde distintos ámbitos mediante la realización de análisis químico y análisis sensorial. Se analizaron 5 botellas de cada tipo de vino, un total de 30 botellas, con el fin de analizar la vida útil de los vinos procedentes de los distintos sistemas y la influencia del sistema de envejecimiento y tipo de madera empleadaGrado en Enologí

Resultado de tratamientos locales en Sinovitis crónica Hemofílica

Se estudian sesenta y cinco rodillas hemofílicas en igual numero de pacientes afectados por los primeros estadios de afectación articular, en forma de sinovitis crónica. Dichas articulaciones fueron tratadas con procedimientos locales destructores de la sinovial, la indicación para estos procedimientos fue el fracaso de las medidas terapéuticas sistémicas (sustitución del factor deficitario) tras 6 meses de tratamiento. Los procedimientos destructores fueron históricamente empleados: primero la sinovectomia quirúrgica (18 casos), después la sinoviortesis con isótopos radiactivos (38 casos) y finalmente la sinovectomia artroscópica (9 casos). Los resultados de este trabajo indican la utilidad de la sinovect. Artroscópica para el tratamiento de la sinovitis hemofílica de rodilla; la sinoviortesis es un procedimiento de calidad intermedia; frente a la sinovectomia quirúrgica que proporciona unos resultados poco satisfactorios, debido especialmente a la notable pérdida de movilidad que se origina tras su realización

Modelling deformation-induced martensite transformation in high-carbon steels

The transformation behaviour of retained austenite in steels is known to differ according to chemical composition and other microstructural attributes. Earlier research indicated that austenite in high-carbon steels transforms into martensite only when the applied stress exceeds a critical value, contrary to low-carbon steels where transformation occurs in the early stages of deformation. Although transformation models have been proposed, most are optimised for low-carbon steels. Here, we propose physics-based models applied to high-carbon steels to overcome previous limitations. The models have fewer free parameters (4) compared to previous approaches (6), exhibiting improvements in the numerical and physical interpretation of the austenite transformation process. We envision the use of these models as tools for alloy design, also highlighting their scientific and technological value