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Scour compromises the operation of offshore facilities. This article describes the results of an investigation aimed at the analysis of different methods used in the scour protection systems design at offshore wind farms. The study is focused on transitional waters, where monopile foundations present medium or large diameters. Using the experience of offshore wind farms currently installed, a new design formula is proposed. All of this with the aim of improving a preliminary design of scour protection systems considering maritime parameters.

En este trabajo se analiza la existencia de una cultura sistémica en las redes virtuales de fabricación global (RVFG). Para convalidar tal modelo, basado en un modelo conceptual de cultura sistémica, se aplica la metodología del caso a un ejemplo de la industria aeronáutica que ha constituido una de las relaciones con más éxito dentro de las RVFGs, la colaboración entre GE y SNECMA para la fabricación del motor CFM 56. Estas organizaciones están formadas por empresas muy dinámicas que fabrican todo tipo de productos o servicios y establecen entre sí relaciones de tipo horizontal y vertical, pudiendo incluso ser competidores: no es necesario mantener internamente grandes recursos fabriles, sino gestionar y compartir eficientemente los recursos de la red. El estudio de la cultura organizacional a nivel de red incluye aspectos como la similitud de las prácticas culturales entre sus actores, la integración social, la transferencia de conocimiento tácito o la importancia de la confianza en la red. La presencia, bajo una perspectiva sistémica, de unos valores y prácticas culturales homogéneas en las que se puedan identificar los actores de la red, permitiría fortalecer la pertenencia al grupo o establecer una red social que subyaga a la propia RVFG y que facilite e incremente las interacciones entre sus miembros. La factibilidad de este planteamiento facilitaría la formación de nuevas RVFGs al poder establecer un modelo prescriptivo cultural a nivel de red. Palabras clave: Redes virtuales de fabricación global, GE, SNECMA, cultura interempresarial, industria aeronáutica.

The installation of offshore scour protection systems in offshore wind farms allows avoid the effect of scour phenomenon around these structures. Up to date, numerous research projects have been carried out to justify the necessity of the scour protection systems and also to optimize their design. Protection systems based on riprap is frequently used due to its low cost and easy availability compared to other solutions such as geotextile bags or prefabricated concrete blocks. The sizing of these structures can be performed according to a series of recommendations that can optimize the costs associated with them, but there have been only few studies with real data up to now which have allowed identify the need for such protections. This investigation aims to assess the functionality of the scour protections adopted through the available data about their characteristics and the scour depth developed around the foundations. In this sense, this paper presents the results of a study that analyzes the functionality of scour protections in different European offshore wind farms.

Greenhouse gas emission reduction is the pillar of the Kyoto Protocol and one of the main goals of the European Union (UE) energy policy. National reduction targets for EU member states and an overall target for the EU-15 (8%) were set by the Kyoto Protocol. This reduction target is based on emissions in the reference year (1990) and must be reached by 2012. EU energy policy does not set any national targets, only an overall reduction target of 20% by 2020. This paper transfers global greenhouse gas emission reduction targets in both these documents to the transport sector and specifically to CO2 emissions. It proposes a nonlinear distribution method with objective, dynamic targets for reducing CO2 emissions in the transport sector, according to the context and characteristics of each geographical area. First, we analyse CO2 emissions from transport in the reference year (1990) and their evolution from 1990 to 2007. We then propose a nonlinear methodology for distributing dynamic CO2 emission reduction targets. We have applied the proposed distribution function for 2012 and 2020 at two territorial levels (EU member states and Spanish autonomous regions). The weighted distribution is based on per capita CO2 emissions and CO2 emissions per gross domestic product. Finally, we show the weighted targets found for each EU member state and each Spanish autonomous region, compare them with the real achievements to date, and forecast the situation for the years the Kyoto and EU goals are to be met. The results underline the need for ?weighted? decentralised decisions to be made at different territorial levels with a view to achieving a common goal, so relative convergence of all the geographical areas is reached over time. Copyright © 2011 John Wiley & Sons, Ltd.

En este trabajo se analizan los factores más relevantes de la cultura organizacional que aparecen en las redes virtuales de fabricación global (RVFG). Estas organizaciones están formadas por empresas muy dinámicas, que fabrican todo tipo de productos o servicios, y que establecen entre sí relaciones de tipo horizontal y vertical, pudiendo incluso ser competidores: no es necesario mantener internamente grandes recursos fabriles, sino gestionar y compartir eficientemente los recursos de la red. El estudio de la cultura organizacional a nivel de red incluye aspectos como la similitud de las prácticas culturales entre sus actores, la integración social, la transferencia de conocimiento tácito o la importancia de la confianza en la red. Son, en definitiva, los aspectos blandos o “soft factors” de las RVFGs y constituyen uno de los aspectos fundamentales en el funcionamiento eficiente de las mismas. Mediante el modelo teórico propuesto se analizarán todos los factores culturales relevantes en las colaboraciones interempresariales, así como la posible existencia de una cultura organizacional a nivel de red. La presencia, bajo una perspectiva sistémica, de unos valores y prácticas culturales homogéneas en las que se puedan identificar los actores de la red, permitiría fortalecer la pertenencia al grupo o establecer una red social que subyaga a la propia RVFG y que facilite e incremente las interacciones entre sus miembros. La factibilidad de este planteamiento facilitaría la formación de nuevas RVFGs al poder establecer, ex ante, un modelo prescriptivo cultural a nivel de red.

Babassu and camelina oils have been transesterified with methanol by the classical homogeneous basic catalysis method with good yields. The babassu fatty acid methyl ester (FAME) has been subjected to fractional distillation at vacuum, and the low boiling point fraction has been blended with two types of fossil kerosene, a straight-run atmospheric distillation cut (hydrotreated) and a commercial Jet-A1. The camelina FAME has been blended with the fossil kerosene without previous distillation. The blends of babassu biokerosene and Jet-A1 have met some of the specifications selected for study of the ASTM D1655 standard: smoke point, density, flash point, cloud point, kinematic viscosity, oxidative stability and lower heating value. On the other hand, the blends of babassu biokerosene and atmospheric distillation cut only have met the density parameter and the oxidative stability. The blends of camelina FAME and atmospheric distillation cut have met the following specifications: density, kinematic viscosity at −20 °C, and lower heating value. With these preliminary results, it can be concluded that it would be feasible to blend babassu and camelina biokerosenes prepared in this way with commercial Jet-A1 up to 10 vol % of the former, if these blends prove to accomplish all the ASTM D1655-09 standards.

This paper shows how the methodologies used in current practice might lead to an underestimation of energy consumption by different passenger transport modes, and also offers recommendations for improvements to these methodologies. The first recommendation is related to energy consumption rates. The studies reviewed use traditional energy consumption rates based on transportation demand, such as kilowatts-hour per vehicle-kilometre or kilowatts-hour per passenger-kilometre, and include other rates based on transportation supply which might prove useful. Second, energy consumption rates are dependent on factors, and the introduction of homogeneous units which are independent of these factors therefore offers a significant improvement when comparing transport modes. Third, the use of a vehicle energy consumption equation will improve the quality of the assessments. Fourth, we propose that the coefficients which define the energy consumption equation should be broken down to determine market niches and sources for improvements in energy consumption in the vehicle categories.

The electronic structure of modified chalcopyrite CuInS(2) has been analyzed from first principles within the density functional theory. The host chalcopyrite has been modified by introducing atomic impurities M at substitutional sites in the lattice host with M = C, Si, Ge, Sn, Ti, V, Cr, Fe, Co, Ni, Rh, and Ir. Both substitutions M for In and M for Cu have been analyzed. The gap and ionization energies are obtained as a function of the M-S displacements. It is interesting for both spintronic and optoelectronic applications because it can provide significant information with respect to the pressure effect and the nonradiative recombination.