Environmental impact and risk of a mine and metallurgical waste in Sierra Minera, Cartagena-La Unión (Murcia, Spain)

La actividad minera de la Sierra de Cartagena-La Unión se remonta a tiempos pre-romanos y finaliza en el año 1991. En los últimos 150 años, la minería ha generado trabajo y riqueza. Como resultado de la misma quedan actualmente más de 2.300 estructuras mineras (residuos minero-metalúrgicos, pozos mineros y cortas) que tienen un volumen global de 200 millones de metros cúbicos y contienen metales (Pb, Zn, Cu, Cd,l), las cuales producen un impacto y un riesgo para el medio ambiente El impacto ambiental más acentuado en el área continental se concreta en el efecto sobre el suelo, la flora y la fauna asociada; en segundo lugar el producido a las aguas subterráneas y, en tercero a la contaminación de las riberas de las ramblas que constituyen vías de evacuación de la escorrentía superficial. El impacto sobre el medio marino tiene dos orígenes: el directo y más perjudicial que ha sido producido en el Mar Mediterráneo (Bahías de Portman y Gorguel), y el indirecto ocasionado en la Laguna del Mar Menor El impacto ambiental se concreta en dos zonas: una de impacto directo sobre 100 km² otra de impacto inducido de 145 km². Los depósitos de residuos también representan riesgos ambientales. El riesgo más importante es el de erosión hídrica, pues el agua arranca y transporta partículas ricas en metales y contamina las masas de aguas continentales y marinas. Otro riesgo de importancia es el producido por los hundimientos en zonas afectadas por galerías durante la ocurrencia de movimientos sísmicosUniversidad Politécnica de CartagenaPrograma de doctorado en Ingeniería de la Tierra y del Territori

Técnicas avanzadas de medida de dispersión cromática a frecuencias ópticas

La fibra óptica a pesar de tener buenas propiedades, también presenta limitaciones, una de estas limitaciones es la dispersión. La dispersión es un fenómeno que introduce un retardo diferente a cada una de las componentes espectrales que se transmiten por la fibra óptica. Este proyecto esta basado en el estudio de este fenómeno y la medida del mismo a partir de métodos conocidos y propuestas de mejoras de estos. Se realiza un estudio matemático genérico del esquema básico de medida que tiene en cuenta todos los parámetros que pueden controlarse de forma externa, con el objetivo de identificar nuevos métodos de medida usando el mismo esquema experimental básico. Además, se monta en el laboratorio y se automatiza uno de los procesos básicos para la realización de las medidas, la determinación de la función de transferencia del modulador Mach-Zehnde

Luter system a new approach to CSP energy diversification

Luter system is a new concept of CSP. Luter system is a Dish-Stirling concept but trying to solve some of the typical problems in this CSP systems. This research was done in VICNI ENERGIA. As a result of the previous studies a Patent was fill in. The new CSP Dish-Stirling concept was supported by CDTI (Spanish development agency) in IDI20100067. Part of the development was done by AIDO, R+D institute specialized in Optics and photonics

Consideration of tip speed limitations in preliminary analysis of minimum COE wind turbines

A relation between Cost Of Energy, COE, maximum allowed tip speed, and rated wind speed, is obtained for wind turbines with a given goal rated power. The wind regime is characterised by the corresponding parameters of the probability density function of wind speed. The non-dimensional characteristics of the rotor: number of blades, the blade radial distributions of local solidity, twist angle, and airfoil type, play the role of parameters in the mentioned relation. The COE is estimated using a cost model commonly used by the designers. This cost model requires basic design data such as the rotor radius and the ratio between the hub height and the rotor radius. Certain design options, DO, related to the technology of the power plant, tower and blades are also required as inputs. The function obtained for the COE can be explored to �nd those values of rotor radius that give rise to minimum cost of energy for a given wind regime as the tip speed limitation changes. The analysis reveals that iso-COE lines evolve parallel to iso-radius lines for large values of limit tip speed but that this is not the case for small values of the tip speed limits. It is concluded that, as the tip speed limit decreases, the optimum decision for keeping minimum COE values can be: a) reducing the rotor radius for places with high weibull scale parameter or b) increasing the rotor radius for places with low weibull scale paramete

Impacto del congelamiento del precio de los combustibles en una empresa propietaria de gasolineras

FinanzasSe abarcará en breve un análisis de la evolución histórica de los precios de los combustibles, de las políticas adoptadas por los gobiernos en relación a los precios, un análisis de los subsidios aplicados, y el entorno económico en que se manejan las estaciones de servicios. Con la elaboración de este trabajo se demuestra la pérdida de competitividad que tienen las gasolineras del país producto del congelamiento del precio de los combustibles, ya que los gastos producto de la inflación y políticas gubernamentales aumentan cada año, también se analiza el impacto que tiene el aumento de las ventas producto del incremento del parque automotor lo que ha permitido mantener el negocio en marchaAn analiysis of the historical evolution of fuel prices, policies adopted by governments in relation to prices, an analysis of subsidies applied, and the economic environment in which the service stations are handled will be covered shortly. With the development of this work, the loss of competitiveness that have gas stations in the country product of freezing fuel prices, as the expenses resulting from inflation and government policies increase each year shows, the impact also analyzes the increased product sales increased fleet which has kept the business going

Debt pressure and interactive use of control systems: effects on cost of debt

We study if debt pressure drives the use of interactive management accounting and control systems (MACS) and its consequences. We build on Simons (1990) and argue that financing pressures can threaten strategic investment. To alleviate debt pressures and reduce information asymmetries with lenders, managers are predicted to increase the interactive use of MACS. However, because individual MACS have different features, not all interactive use of individual MACS equally serves to assuage debt pressures. We predict that firms facing high debt pressure interactively use traditional MACS and that when individual MACS use befits the level of debt pressure, firms benefit by experiencing future decreases in their cost of debt. Our findings confirm these predictions. We contribute to the literature by showing that pressures from external stakeholders influence interactive use. We also suggest a new relevant firm outcome affected by MACS use: the future cost of debt. Finally, in additional analyses, we show that concerns over innovation may lead managers to choose apparently non-optimal MACS for interactive use, consistent with managers often juggling conflicting pressures.We acknowledge financial assistance from the Spanish Ministry of Education and Science (ECO2013-48328, ECO2016-77579), CAM (H2015/HUM-3353), FEDER (UNC315-EE-3636), the Catedra UAM- Auditores Madrid and 6th ed. AECA Research Grants (2015-2016)

Optical transitions and excitonic recombination in InAs/InP self-assembled quantum wires

InAs self-assembled quantum wire structures have been grown on InP substrates and studied by means of photoluminescence and polarized-light absorption measurements. According to our calculations, the observed optical transitions in each sample are consistent with wires of different heights, namely from 6 to 13 monolayers. The nonradiative mechanism limiting the emission intensity at room temperature is related to thermal escape of carriers out of the wires.This work has been supported under project No. TIC99-1035-C02 of the Spanish CICYT.Peer reviewe

Public oversight systems for statutory auditors in the European Union

We provide a comparative overview of the process of implementation, harmonization and stabilization of public oversight systems for statutory auditors across the European Union (EU) after Directive 2006/43/EC. We build on institutional change theory to identify potential determinants as to why some countries still lag in this harmonization process. Oversight systems are a key institutional factor to guarantee the quality of financial information, essential to maintain investors’ confidence and deep and stable capital markets. Thus, the harmonization of these systems has long been an objective of the EU. Our analyses serve to identify, analyse and compare how EU countries have incorporated European-wide requirements into their national legal systems. Particularly, we study: (1) basic characteristics of the system and bodies for public oversight, (2) organizational structure, (3) financing (4) transparency, (5) supervisory, and (6) disciplinary mechanisms. We show that significant diversity still exists across systems and that both the incentives for institutional change and the distance between pre-existing systems and the Directive are important explanatory factors of the achieved level of harmonization.We acknowledge financial contribution from the Spanish Ministry of Science and Innovation (ECO2010-19314 and ECO2013-48328), the ICAC (Instituto de Contabilidad y Auditoría de Cuentas) and ASEPUC, through the XVIII Fernandez Pirla Research Funding