Wind turbine for developing countries

Aquest treball avarca des de reunions amb personal de qualitat d’una fàbrica decremalleres fins a la proposta d’un prototip d’una màquina que solucionés els seusproblemes concrets de producció. Pel camí s’ha fet recerca envers de solucionsprèvies que fossin factibles a realitzar en uns pocs mesos i amb els medis limitatsdels que es desponiaLes solucions, tant de mètodes d’assaig i observació com de disseny són un reflexclar de procés d’enginyeria en l’àmbit industrial espanyol. Els medis escassegen,però amb temps (tampoc gaire) i enginy es troben formes de satisfer lesnecessitats. Al cap i a la fi és el que s’espera de nosaltres com a enginyers.

Plan de seguridad y salud para el suministro y montaje del Parque Eólico Rancho Viejo en el T.M. de Medina-Sidonia (Cádiz)

No hace más de 3 años se podía leer en las revistas especializadas que España había pasado a ocupar el tercer puesto en el ranking mundial por potencia eólica instalada. La industria eólica española a su vez ha pasado a ocupar el tercer puesto en la fabricación e instalación de aerogeneradores, con una cuota de mercado del 13%, siendo así un sector con gran capacidad de exportación. Por otra parte, tras diez años de promulgación de la Ley 31/95, de 8 de noviembre, de Prevención de Riesgos Laborales, y después su desarrollo reglamentario, es un hecho incontestable que, pese a todo, y a los ingentes esfuerzos realizados por los distintos actores implicados en la prevención de riesgos laborales (Estado, Comunidades Autónomas, Agentes Sociales, Entidades especializadas, etcetera), existe un sector como el de la construcción que, constituyendo uno de los ejes del crecimiento económico de nuestro país, está sometido a unos riesgos especiales y continúa registrando una siniestralidad laboral muy notoria por sus cifras y gravedad. La legislación de prevención, los manuales sobre las distintas disciplinas preventivas, los libros especializados, los expertos... han abordado ya, con mayor o menor acierto, muchas de las cuestiones generales y específicas que afectan a la seguridad y salud: la evaluación de riesgos, las medidas higiénicas, los equipos de trabajo y equipos de protección individual, la planificación, la formación, los servicios de prevención , los sistemas de gestión de la prevención, las auditorías ... forman parte de los contenidos que se han ido creando en torno a este tema. No obstante, resulta de gran interés la elaboración de un estudio de Seguridad y Salud, en el que partiendo de un desarrollo técnico concreto, pero sobre todo integral, es decir, que comprenda todas las fases para el suministrp e instalación de aerogeneradores para un parque eólico, vayamos desgranando cada uno de los puntos desarrollados en su construcción. Entre las conclusiones más destacadas de este trabajo, se encuentra la definición de las condiciones relativas a la prevención de accidentes y enfermedades laborales durante la ejecución de los trabajos de suministro e instalación de un parque eólico y la gestión de su prevención, las características de las instalaciones preceptivas para higiene y bienestar de los trabajadores, así como directrices básicas mínimas, que deben reflejarse y desarrollarse en el Plan de Seguridad y Salud que las empresas contratistas deberán presentar para su aprobación por el director de obra, antes del comienzo de los trabajos, de forma que sea posible la disminución de accidentes laborales así como evitar las posibles sanciones administrativas y/o penales.

Discriminating crop, weeds and soil surface with a terrestrial LIDAR sensor

In this study, the evaluation of the accuracy and performance of a light detection and ranging (LIDAR) sensor for vegetation using distance and reflection measurements aiming to detect and discriminate maize plants and weeds from soil surface was done. The study continues a previous work carried out in a maize field in Spain with a LIDAR sensor using exclusively one index, the height profile. The current system uses a combination of the two mentioned indexes. The experiment was carried out in a maize field at growth stage 12–14, at 16 different locations selected to represent the widest possible density of three weeds: Echinochloa crus-galli (L.) P.Beauv., Lamium purpureum L., Galium aparine L.and Veronica persica Poir.. A terrestrial LIDAR sensor was mounted on a tripod pointing to the inter-row area, with its horizontal axis and the field of view pointing vertically downwards to the ground, scanning a vertical plane with the potential presence of vegetation. Immediately after the LIDAR data acquisition (distances and reflection measurements), actual heights of plants were estimated using an appropriate methodology. For that purpose, digital images were taken of each sampled area. Data showed a high correlation between LIDAR measured height and actual plant heights (R2 = 0.75). Binary logistic regression between weed presence/absence and the sensor readings (LIDAR height and reflection values) was used to validate the accuracy of the sensor. This permitted the discrimination of vegetation from the ground with an accuracy of up to 95%. In addition, a Canonical Discrimination Analysis (CDA) was able to discriminate mostly between soil and vegetation and, to a far lesser extent, between crop and weeds. The studied methodology arises as a good system for weed detection, which in combination with other principles, such as vision-based technologies, could improve the efficiency and accuracy of herbicide spraying.

Plan de seguridad y salud para el suministro y montaje del Parque Eólico Rancho Viejo en el T.M. de Medina-Sidonia (Cádiz)

No hace más de 3 años se podía leer en las revistas especializadas que España había pasado a ocupar el tercer puesto en el ranking mundial por potencia eólica instalada. La industria eólica española a su vez ha pasado a ocupar el tercer puesto en la fabricación e instalación de aerogeneradores, con una cuota de mercado del 13%, siendo así un sector con gran capacidad de exportación. Por otra parte, tras diez años de promulgación de la Ley 31/95, de 8 de noviembre, de Prevención de Riesgos Laborales, y después su desarrollo reglamentario, es un hecho incontestable que, pese a todo, y a los ingentes esfuerzos realizados por los distintos actores implicados en la prevención de riesgos laborales (Estado, Comunidades Autónomas, Agentes Sociales, Entidades especializadas, etcetera), existe un sector como el de la construcción que, constituyendo uno de los ejes del crecimiento económico de nuestro país, está sometido a unos riesgos especiales y continúa registrando una siniestralidad laboral muy notoria por sus cifras y gravedad. La legislación de prevención, los manuales sobre las distintas disciplinas preventivas, los libros especializados, los expertos... han abordado ya, con mayor o menor acierto, muchas de las cuestiones generales y específicas que afectan a la seguridad y salud: la evaluación de riesgos, las medidas higiénicas, los equipos de trabajo y equipos de protección individual, la planificación, la formación, los servicios de prevención , los sistemas de gestión de la prevención, las auditorías ... forman parte de los contenidos que se han ido creando en torno a este tema. No obstante, resulta de gran interés la elaboración de un estudio de Seguridad y Salud, en el que partiendo de un desarrollo técnico concreto, pero sobre todo integral, es decir, que comprenda todas las fases para el suministrp e instalación de aerogeneradores para un parque eólico, vayamos desgranando cada uno de los puntos desarrollados en su construcción. Entre las conclusiones más destacadas de este trabajo, se encuentra la definición de las condiciones relativas a la prevención de accidentes y enfermedades laborales durante la ejecución de los trabajos de suministro e instalación de un parque eólico y la gestión de su prevención, las características de las instalaciones preceptivas para higiene y bienestar de los trabajadores, así como directrices básicas mínimas, que deben reflejarse y desarrollarse en el Plan de Seguridad y Salud que las empresas contratistas deberán presentar para su aprobación por el director de obra, antes del comienzo de los trabajos, de forma que sea posible la disminución de accidentes laborales así como evitar las posibles sanciones administrativas y/o penales.

Determination of sea surface salinity and wind speed by L-band microwave radiometry from a fixed platform

The European Space Agency Soil Moisture andOcean Salinity (SMOS) mission aims at obtaining global maps ofsoil moisture and sea surface salinity from space for large-scale andclimatic studies. It uses an L-band (1400–1427 MHz) MicrowaveInterferometric Radiometer by Aperture Synthesis to measurebrightness temperature of the earth’s surface at horizontal andvertical polarizations ( h and v). These two parameters will beused together to retrieve the geophysical parameters. The retrievalof salinity is a complex process that requires the knowledge ofother environmental information and an accurate processing ofthe radiometer measurements. Here, we present recent resultsobtained from several studies and field experiments that were partof the SMOS mission, and highlight the issues still to be solved.

Horizontal Grid Size Selection and its Influence on Mesoscale Model Simulations

The use of two-dimensional spectral analysis applied to terrain heights in order to determine characteristic terrain spatial scales and its subsequent use for the objective definition of an adequate grid size required to resolve terrain forcing are presented in this paper. In order to illustrate the influence of grid size, atmospheric flow in a complex terrain area of the Spanish east coast is simulated by the Regional Atmospheric Modeling System (RAMS) mesoscale numerical model using different horizontal grid resolutions. In this area, a grid size of 2 km is required to account for 95% of terrain variance. Comparison among results of the different simulations shows that, although the main wind behavior does not change dramatically, some small-scale features appear when using a resolution of 2 km or finer. Horizontal flow pattern differences are significant both in the nighttime, when terrain forcing is more relevant, and in the daytime, when thermal forcing is dominant. Vertical structures also are investigated, and results show that vertical advection is influenced highly by the horizontal grid size during the daytime period. The turbulent kinetic energy and potential temperature vertical cross sections show substantial differences in the structure of the planetary boundary layer for each model configuration

Information-sharing implications of horizontal mergers

We analyze the effects of uncertainty and private information on horizontal mergers. Firms face uncertain demands or costs and receive private signals. They may decide to merge sharing their private information. If the uncertainty parameters are independent and the signals are perfect, uncertainty generates an informational advantage only to the merging firms, increasing merger incentives and decreasing free-riding effects. Thus, mergers become more profitable and stable. These results generalize to the case of correlated parameters if the correlation is not very severe, and for perfect correlation if the firms receive noisy signals. From the normative point of view, mergers are socially less harmful compared to deterministic markets and may even be welfare enhancing. If the signals are, instead, publicly observed, uncertainty does not necessarily give more incentives to merge, and mergers are not always less socially harmful.

Classical horizontal inequity and reranking: an integrated approach

The last 20 years have seen a significant evolution in the literature on horizontal inequity (HI) and have generated two major and "rival" methodological strands, namely, classical HI and reranking. We propose in this paper a class of ethically flexible tools that integrate these two strands. This is achieved using a measure of inequality that merges the well-known Gini coefficient and Atkinson indices, and that allows a decomposition of the total redistributive effect of taxes and transfers in a vertical equity effect and a loss of redistribution due to either classical HI or reranking. An inequality-change approach and a money-metric cost-of-inequality approach are developed. The latter approach makes aggregate classical HI decomposable across groups. As in recent work, equals are identified through a nonparametric estimation of the joint density of gross and net incomes. An illustration using Canadian data from 1981 to 1994 shows a substantial, and increasing, robust erosion of redistribution attributable both to classical HI and to reranking, but does not reveal which of reranking or classical HI is more important since this requires a judgement that is fundamentally normative in nature.

Plataforma cerámica para la accesibilidad horizontal

Desenvolupament d'innovacions en elements vinculats amb l'accessibilitat física, en concret de sistemes de paviments. Es tracta de sistemes de paviments que permetin el desplaçament segur i accessible en el patrimoni arquitectònic, on és habitual que les irregularitats del sòl impedeixin la mobilitat de persones amb discapacitat.

Interpretation of wind components as compositional variables

The classical statistical study of the wind speed in the atmospheric surface layer is madegenerally from the analysis of the three habitual components that perform the wind data,that is, the component W-E, the component S-N and the vertical component,considering these components independent.When the goal of the study of these data is the Aeolian energy, so is when wind isstudied from an energetic point of view and the squares of wind components can beconsidered as compositional variables. To do so, each component has to be divided bythe module of the corresponding vector.In this work the theoretical analysis of the components of the wind as compositionaldata is presented and also the conclusions that can be obtained from the point of view ofthe practical applications as well as those that can be derived from the application ofthis technique in different conditions of weather

Implementation of a robust coded structured light technique for dynamic 3D measurements

This paper presents the implementation details of a coded structured light system for rapid shape acquisition of unknown surfaces. Such techniques are based on the projection of patterns onto a measuring surface and grabbing images of every projection with a camera. Analyzing the pattern deformations that appear in the images, 3D information of the surface can be calculated. The implemented technique projects a unique pattern so that it can be used to measure moving surfaces. The structure of the pattern is a grid where the color of the slits are selected using a De Bruijn sequence. Moreover, since both axis of the pattern are coded, the cross points of the grid have two codewords (which permits to reconstruct them very precisely), while pixels belonging to horizontal and vertical slits have also a codeword. Different sets of colors are used for horizontal and vertical slits, so the resulting pattern is invariant to rotation. Therefore, the alignment constraint between camera and projector considered by a lot of authors is not necessary

Is there a wage penalty for horizontal and vertical mismatch?

This paper studies how the horizontal and vertical mismatches in the labor market affect wage. We do so by taking into account that by choosing a job, wage and mismatches are simultaneously determined. The Seemingly Unrelated Equations model also allows us to control for any omitted variable that could cause biased estimators. We use REFLEX data for Spain. Results reveal that in most cases being horizontally matched has a wage premium and being over-educated does not affect wage. Results suggest that the modeling strategy successfully accounts for some omitted variable that affects simultaneously the probability of being horizontally matched and the wage. This could explain the existence of a wage penalty for over-educated workers when the omitted variable issue is not dealt with.

Horizontal innovation in the theory of growth and development

We analyze recent contributions to growth theory based on the model of expanding variety of Romer (1990). In the first part, we present different versions of the benchmark linear model with imperfect competition. These include the labequipment model, labor-for-intermediates and directed technical change . We review applications of the expanding variety framework to the analysis of international technology diffusion, trade, cross-country productivity differences, financial development and fluctuations. In many such applications, a key role is played by complementarities in the process of innovation.

Allocating ideas: Horizontal competition in tournaments

We develop a stylized model of horizontal and vertical competition intournaments with two competing firms. The sponsor cares about the qualityof the design but also about the design location. A priori not even thesponsor knows his preferred design location, which is only discoveredonce he has seen the actual proposals. We show that the more efficientfirm is more likely to be conservative when choosing the design location.Also, to get some differentiation in design locations, the cost differencebetween contestants can neither be too small nor too big. Therefore, ifthe sponsor mainly cares about the design location, participation in thetournaments by the two lowest cost contestants cannot be optimal for thesponsor.

Search for very high energy gamma-ray emission from pulsar-pulsar wind nebula systems with the MAGIC telescope

The MAGIC collaboration has searched for high-energy gamma-ray emission of some of the most promising pulsar candidates above an energy threshold of 50 GeV, an energy not reachable up to now by other ground-based instruments. Neither pulsed nor steady gamma-ray emission has been observed at energies of 100 GeV from the classical radio pulsars PSR J0205+6449 and PSR J2229+6114 (and their nebulae 3C58 and Boomerang, respectively) and the millisecond pulsar PSR J0218+4232. Here, we present the flux upper limits for these sources and discuss their implications in the context of current model predictions.