Marine energy exploitation in the mediterranean region: steps forward and challenges

This works aims to describe current perspectives for marine energy exploitation in the Mediterranean basin, highlighting challenges and opportunities as well as the factors that still limit its market deployment. Technologies for the conversion of Marine Energy (ME) into electricity are now ready for full-scale deployment in farms of devices, making the final step from demonstration to operability and commercial exploitation. Although marine energy is more abundant along the Atlantic and Nordic European coasts, significant resources are also available in the Mediterranean Sea, opening up new perspectives for sustainable energy production in sensitive coastal areas and for the economic development of Southern Europe. The implementation of ME converters in the Mediterranean is in fact liable to induce significant technological advancements leading to product innovation, due to the local low energy levels which impose more restrictive constraints on device efficiency and environmental compatibility. In addition, the milder climate allows the testing of concepts and prototypes in the natural environment at more affordable costs, lowering capital risks for new and innovative small and medium enterprises. Research institutions and industrial players in Mediterranean countries have already taken up the challenge, despite the numerous limiting factors that still need to be removed. In particular, the ME sector adds up to the many different traditional maritime activities and to the new ocean-related industries that are developing, potentially exacerbating the competition for the use of marine space in the Mediterranean region and threatening its environmental status. The ME sector needs therefore to design suitable instruments to involve all the relevant stakeholders in a participative public debate as to how to best manage the maritime space. As the prospective sea use patterns are rapidly changing, an adequate international legal and policy framework needs to be designed for the coherent management of sea space, and Marine Spatial Planning needs to be finally implemented by EU Member States also in the Mediterranean area. To this end, the creation of transnational clusters of stakeholders is expected be an effective catalyzer, especially as they can foster the exchange of knowledge and best practices both across European countries and between the North and the South shore of the Mediterranean basin

Long term evolution of heat budget in the Mediterranean Sea from Med-CORDEX forced and coupled simulations

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Acoustic impact of a wave energy converter in Mediterranean shallow waters

In this study, underwater noise from a full-scale wave energy converter system (ISWEC), installed on the coast of Pantelleria Island (central Mediterranean Sea), was characterized. The noise was measured using an autonomous acoustic recorder anchored to the sea bottom 40 m from the ISWEC hull. Acoustic monitoring continued for 15 months, starting 7 months before (PRE), 2 months during (INST) and 6 months after the ISWEC installation (POST). The levels of noise, assessed with power spectrum density and octave and third-octave band sound pressure levels (BSPLs), were higher during the POST period than during the PRE period at lower frequencies up to 4 kHz and increased with wave height. During the ISWEC activation for energy production (POST_ON) in the wave height range 1–2.9 m, the BSPLs increased much more at lower frequencies up to 4 kHz (the median BSPLs at 63 Hz for the PRE, POST, and POST_ON conditions were 73, 106, and 126 dB re 1μPa, respectively). Considering the biophonies that make up the soundscape of the area, we examined the possible masking of fish choruses due to ISWEC noise and highlighted that at a distance of 1000 m, the 800 Hz peak frequency was 10 dB above the ISWEC signal. Within this distance from ISWEC, a possible masking effect is supposed

Contaminação ambiental e biodiversidade do fitoplâncton no Lago Cajititlán

Lake Cajititlán faces severe environmental health problems. A phytoplankton biodiversity study was undertaken to calculate biological contamination indicators and to determine the relative abundance of phytoplankton genera in its ecosystem. In the environment, algae produce both benefits such as oxygen and the conversion of light energy into chemicals, something which is reflected in the accumulation of biomass through photosynthesis collateral damage, such as the production of toxins: by Cyanophyta algae. Five monitoring points were established, and samples were collected monthly, in 2014. Phytoplankton identification and morphological classification were performed by microscopy. This paper is the first of its kind to describe the predominant communities in the lake chlorophytes, followed by cyanophytes and the evolutionary correlation of the genera using phylogenetic trees.The study gave rise to expectations in different research fields since species with environmental health and human health applications (Scenedesmus spp. and Chlorella spp.), species which are sources of biomolecules with a high nutritional value as proteins and vitamins, such as Monoraphidium spp., a species with application in the synthesis of biofuels (Botryococcus spp.), and species with a therapeutic application as producers of antioxidants and immune modulators or as producers of toxins, such as Pseudanabaena spp., were identified. A strong correlation between the presence of the cyanophyte species found (Microcystis spp. and Anabaena spp.) and the death of fish during the summer was observed.El Lago Cajititlán, enfrenta severos problemas de salud ambiental; por ello se emprendió un estudio de biodiversidad del fitoplancton, con la finalidad de detectar indicadores biológicos de contaminación y determinar la abundancia relativa de los géneros en dicho ecosistema. Las algas en el medio ambiente producen beneficios: como el oxígeno y la conversión de energía luminosa en química, reflejada en la acumulación de biomasa por medio de la fotosíntesis, o bien, daños colaterales como la producción de toxinas por algas cianófitas. Se establecieron 5 puntos de monitoreo y se recolectaron muestras con frecuencia mensual durante 2014. La identificación y clasificación morfológica se realizó por microscopía óptica. Este documento es el primero en describir las comunidades predominantes en el lago: clorófitas, seguido por cianófitas y la correlación evolutiva de los géneros, mediante el empleo de árboles filogenéticos.El estudio proporcionó expectativas en el área de investigación ya que se identificaron especies con aplicación en salud ambiental y salud humana, Scenedesmus spp. y Chlorella spp. Especies que son fuente de biomoléculas de alto valor nutricional como proteínas y vitaminas, como Monoraphidium spp. De aplicación en la síntesis de biocombustibles, Botryococcus spp. Con aplicación terapéutica como productoras de antioxidantes, inmunomoduladores o productoras de toxinas, como Pseudanabaena spp. Se ha observado una fuerte relación entre las especies de cianófitas encontradas Microcystis spp.; Anabaena spp. y la muerte de peces durante el verano.O Lago Cajititlán enfrenta graves problemas de saúde ambiental. Por esta razão, realizou-se um estudo sobre a biodiversidade do fitoplancton com o objetivo de detectar indicadores biológicos de contaminação e determinar a abundância relativa dos géneros no referido ecossistema. As algas produzem benefícios para o ambiente como o oxigénio e a conversão de energia luminosa em química, referida na acumulação de biomassa a través da fotossíntese, ou são causadoras de danos colaterais como a produção de toxinas por algas cianofíceas. Estabeleceram-se 5 pontos de monitorização e recolheram-se a mostras com uma frequência mensal durante o ano de 2014. A identificação e a classificação morfológica foi realizada por microscopia ótica. Este artigo é o primeiro a descrever as comunidades predominantes no lago: clorofíceas, seguidas por cianofíceas e a correlação evolutiva dos géneros, mediante a aplicação de árvores filogenéticas.O estudo gero u expetativas na área da investigação uma vez que se identifcaram espécies com aplicação em saúde ambiental e em saúde humana, Scenedesmus spp. e Chlorella spp. Espécies que são fonte de biomoléculas de alto valor nutricional nomeadamente proteínas e vitaminas como a Monoraphidiums pp. De aplicaçãon a síntese de biocombustíveis, Botryococcus spp. Com aplicação terapêutica como produtoras de antioxidantes, imuno modeladores ou produtoras de toxinas, como a Pseudanabaena spp. Observou-se uma forte relação entre as espécies cianofíceas encontradas, Microcystis spp. e Anabaena spp., e a morte de peixes durante o verão

Hydraulic criticality of the exchange flow through the Strait of Gibraltar

Author Posting. © American Meteorological Society, 2009. This article is posted here by permission of American Meteorological Society for personal use, not for redistribution. The definitive version was published in Journal of Physical Oceanography 39 (2009): 2779-2799, doi:10.1175/2009JPO4075.1.The hydraulic state of the exchange circulation through the Strait of Gibraltar is defined using a recently developed critical condition that accounts for cross-channel variations in layer thickness and velocity, applied to the output of a high-resolution three-dimensional numerical model simulating the tidal exchange. The numerical model uses a coastal-following curvilinear orthogonal grid, which includes, in addition to the Strait of Gibraltar, the Gulf of Cadiz and the Alboran Sea. The model is forced at the open boundaries through the specification of the surface tidal elevation that is characterized by the two principal semidiurnal and two diurnal harmonics: M2, S2, O1, and K1. The simulation covers an entire tropical month. The hydraulic analysis is carried out approximating the continuous vertical stratification first as a two-layer system and then as a three-layer system. In the latter, the transition zone, generated by entrainment and mixing between the Atlantic and Mediterranean flows, is considered as an active layer in the hydraulic model. As result of these vertical approximations, two different hydraulic states have been found; however, the simulated behavior of the flow only supports the hydraulic state predicted by the three-layer case. Thus, analyzing the results obtained by means of the three-layer hydraulic model, the authors have found that the flow in the strait reaches maximal exchange about 76% of the tropical monthlong period

MECANISMOS FISIOLÓGICOS E FISIOPATOLÓGICOS DETERMINANTES DA ATIVIDADE VASOMOTORA SIMPÁTICA

The sympathetic vasomotor activity is one of determinants of blood pressure (BP). Understanding the mechanisms involved in the control of the cardiovascular system is important in physiological and pathophysiological condition. The principal sympathetic premotor brain nuclei are confined in the paraventricular nucleus of hypothalamus (PVN) and in the rostralventrolateral medulla (RVLM). In different patophysiological condition, there is an increase in the sympathetic vasomotor tone, in part due to an increase in the activity of the PVN and RVLM neurons. In this brief review, we discussed the major mechanisms of sympathetic activation in different experimental models: 1) renovascular hypertension, 2) renoprival hypertension, 3) cardiac failure, 4) hypertension induced by nitric oxide blockade, 5) obesity and 6) gender differences. The actions of different mediators in the PVN and in the RVLM acting in long term, can change the level of sympathetic nerve activity and blood pressure and therefore, contributing for the progression of cardiovascular disease.A atividade vasomotora simpática é um dos determinantes da pressão arterial (PA). Estabelecer quais são os mecanismos geradores dessa atividade é importante para o entendimento de como o sistema cardiovascular opera, tanto em situações fisiológicas como fisiopatológicas. Os principais grupos pré-motores do simpático estão confinados no núcleo paraventricular do hipotálamo (PVN) e região rostoventrolateral bulbar (RVLM). Em diversas situações fisiopatológicas há aumento na atividade vasomotora simpática, em parte conseqüente a maior atividade dos neurônios do PVN e RVLM. Nesta breve revisão, foram discutidos os principais mecanismos de ativação simpática em diferentes modelos experimentais: 1) hipertensão renovascular, 2) hipertensão por baixa massa renal, 3) insuficiência cardíaca, 4) hipertensão por bloqueio do óxido nítrico, 5) obesidade e 6) dimorfismo sexual. As ações de diferentes mediadores sobre o PVN e RVLM podem em longo prazo determinar novos patamares de atividade simpática, modificando os níveis tensionais e dessa forma, contribuir para a progressão da doença cardiovascular

An eddy-permitting model of the Mediterranean Sea with a two-way grid refinement at Gibraltar.

International audienceAn eddy-permitting model of View the MathML source resolution is implemented covering the whole Mediterranean Sea. Within this grid a View the MathML source resolution model of the Strait of Gibraltar is embedded. The two grids belong to different models that are coupled through an external parallel driver. The robustness of the adopted grid refinement procedure is tested on a multi-decadal integration simulating the present climate. The good agreement found between the model circulation and most of the available observations confirms both the robustness and effectiveness of the two-way grid refinement technique. The effects produced on the Mediterranean circulation by the grid refinement are investigated through the comparison of two simulations differing only in the presence of the grid refinement. Even though the main characteristics of the thermohaline circulation appear similar in the two simulations, some quantitative and qualitative differences are observed: the main differences found in the Strait of Gibraltar propagate into the whole basin, have an impact on the water column stratification, and consequently on the convection events

The 20. century drought fluctuations in Euro-Mediterranean area. Observations and coupled GCM simulations

Consiglio Nazionale delle Ricerche - Biblioteca Centrale - P.le Aldo Moro, 7 , Rome / CNR - Consiglio Nazionale delle RichercheSIGLEITItal

Use of wave forecast for the regulation of ISWEC

The ISWEC (Inertial Sea Wave Energy Converter) is a gyroscopic based WEC developed at the Politecnico di Torino. The system is composed of a sealed hull carrying a gyroscopic system connected to the PTO. The rocking motion of the hull is converted into an internal precession driving the PTO. In this work the “Wave to wire model” model of ISWEC is used together with the wave forecast information to optimize the algorithms of the ISWEC gyro control unit. The availability of the wave forecast is discussed in relation to the dynamics of acceleration of the gyroscope and the effect on the ISWEC productivity. The work is carried out referring to the parameters of the 100 kW full scale ISWEC demonstrator currently under deployment at the Island of Pantelleria and going to be operational by July 2015