Capital de trabajo, gestión de tesorería y valuación de empresas

In the professional practice, the concept of operational working capital is confused with the accounting definition of working capital, with consequent errors both in the treasury of companies, and in the valuation of companies. In this paper we discuss the important distinction between operational working capital (a characteristic of a business) and the accounting concept of working capital (a financial decision). Also, we challenge the popular view that suggests that firms should finance with long term debt the recurrent portion of their operative working capital, discussing both the implicit costs and risks of such a strategy. Finally, taking the accounting definition of working capital for the operational working capital can lead also to important mistakes in valuation of companies. One of such too frequent mistake is to subtract only the long term debt from the present value of free cash flows to obtain an estimate of the economic value of equity, with a consequent overestimation of its value.En la practica profesional tiende a confundirse el concepto de capital de trabajo operacional, o necesidad operativa de fondos, con la definición contable de capital de trabajo; esta confusión lleva a errores importantes tanto en las áreas de tesorerfa de las firmas como en la valuación de empresas. En este articulo discutimos la importante diferencia entre estos conceptos, y argumentamos que el primero de ellos refleja características de la operación de un negocio, mientras que el segundo representa una decisión de financiamiento. Además, cuestionamos la visión popular que sugiere que las firmas financien su necesidad operativa de fondos con capital de trabajo, discutiendo los costos y riesgos implícitos de dicha decisión. Finalmente, mostramos que la confusión de conceptos mencionada puede Uevar a errores importantes en la valuación de empresas, como la practica demasiado difundida de restar solo la deuda de largo plazo al valor presente de los flujos de caja libres para obtener el valor económico del patrimonio; ello con la eonsiguiente sobre estimación de su valor

HESS J1632-478: an energetic relic

HESS J1632-478 is an extended and still unidentified TeV source in the galactic plane. In order to identify the source of the very high energy emission and to constrain its spectral energy distribution, we used a deep observation of the field obtained with XMM-Newton together with data from Molonglo, Spitzer and Fermi to detect counterparts at other wavelengths. The flux density emitted by HESS J1632-478 peaks at very high energies and is more than 20 times weaker at all other wavelengths probed. The source spectrum features two large prominent bumps with the synchrotron emission peaking in the ultraviolet and the external inverse Compton emission peaking in the TeV. HESS J1632-478 is an energetic pulsar wind nebula with an age of the order of 10^4 years. Its bolometric (mostly GeV-TeV) luminosity reaches 10% of the current pulsar spin down power. The synchrotron nebula has a size of 1 pc and contains an unresolved point-like X-ray source, probably the pulsar with its wind termination shock.Comment: A&A accepted, 9 pages, 5 figures, 4 table

Determinación de tensiones de contacto mediante el M.E.C. en problemas multicuerpo con simetría axial

Se presenta en este trabajo la formulación e implementación de elementos de contorno, del problema de contacto multicuerpo entre materiales elásticos ortótropos en situaciones de pequeños desplazamientos y deformaciones con simetría axial. Se incluye asimismo una breve descripción del programa de ordenador que [513] [514] incluye elementos isoparamétricos lineales y cuadráticos, impone de forma explícita las condiciones de contacto entre n sólidss, permite la consideración de diferentes coeficientes de rozamiento en distintas ecuaciones a resolver en cada uno de los pasos del proceso incremental de carga mediante la utilización de la técnica de subestructuración y condensación de las superficies de interés en procssos de punzonamiento y ajustes con apriete.Peer Reviewe

Observations of the Extended Distribution of Ionized Hydrogen in the Plane of M31

We have used the Wisconsin H-Alpha Mapper (WHAM) to observe the spatially extended distribution of ionized hydrogen in M31 beyond the stellar disk. We obtained five sets of observations, centered near the photometric major axis of M31, that extend from the center of the galaxy to just off the edge of the southwestern HI disk. Beyond the bright stellar disk, but within the HI disk, weak H-alpha is detected with an intensity I(H-alpha) = 0.05 (+0.01 / -0.02) Rayleighs. Since M31 is inclined 77 degrees with respect to the line of sight, this implies that the ambient intergalactic ionizing flux onto each side of M31 is Phi_0 <= 1.6 x 10^4 photons cm^-2 s^-1. Just beyond the outer boundary of the HI disk we find no significant detection of H-alpha and place an upper limit I(H-alpha) <= 0.019 Rayleighs.Comment: To appear in ApJ Letters; 12 pages, 4 figure

Ratio of energies radiated in the universe through accretive processes and nucleosynthesis

We present here a new determination of the ratio of energies radiated by active galactic nuclei and by stars and discuss the reasons for the apparently conflicting results found in previous studies. We conclude that the energy radiated by accretion processes onto super massive black holes is about 1 to 5% of the energy radiated by stars. We also estimate that the total mass accreted on average by a super massive black hole at the centre of a typical 10^11 Msol galaxy is of about 7 10^7 Msol.Comment: 6 pages, 2 figures, accepted by Astronomy & Astrophysic

Simulation of Professional Perfomance, Didactic Tool in Teaching Sport Sciences

La implantación del Espacio Europeo de Educación Superior y su vinculación con la actividad laboral, ha permitido la aplicación de una metodología basada en la simulación del desempeño profesional, que ofrece la posibilidad no sólo de adquirir conocimientos, sino también aplicarlos, analizarlos y tomar decisiones practicando. El alumnado mediante una metodología constituida en cinco etapas secuenciales, diseñadas para la inmersión en situaciones cercanas a la realidad profesional, ha construido sus propios aprendizajes, ha diseñado nuevos planteamientos didácticos y finalmente ha realizado una puesta en común. Los resultados muestran la implicación del alumnado y la adquisición de aprendizajes mediante la conexión entre las aplicaciones prácticas y la posible futura realidad profesional. La simulación ha permitido adquirir competencias en la elaboración y análisis de propuestas aplicadas y el desarrollo de competencias transversales relacionadas con toma de decisiones, trabajo autónomo y en equipo, aspectos determinantes en el éxito profesional de los futuros egresadosThe implantation of the European Higher Education Area and its linkage with the future job of the student has permitted the application of a methodology based on the simulation of professional skills, which offers the possibility not only to acquire knowledge but also to apply, analyze and take decisions practicing. Students, through a methodology consisting of five sequential phases in situations close to the professional reality, have built their own learning, have designed new teaching approaches and finally shared their results. The results show the implication of students on the learning process by connecting practical applications and possible future professional reality. The simulation has allowed students to acquire skills in the design and analysis of applied proposals and the development of generic skills related to decision making, autonomous and team work, determining factors in the career success of future graduate