Search results for "WATER"
showing 10 items of 9348 documents
A New Cross-Flow Type Turbine for Ultra-Low Head in Streams and Channels
2023
In the last few decades, hydropower production has been moving toward a new paradigm of low and diffused power density production of energy with small and mini-hydro plants, which usually do not require significant water storage. In the case of nominal power lower than 20 kW and ultra-low head H (H < 5 m), Archimedes screw or Kaplan type turbines are usually chosen due to their efficiency, which is higher than 0.85. A new cross-flow type turbine called Ultra-low Power Recovery System (UL-PRS) is proposed and its geometry and design criteria are validated in a wide range of operating conditions through 2D numerical analysis computed using the ANSYS Fluent solver. The new proposed solution…
The Ischia Island hydrothermal system: an integrated multidisciplinary (geochemical, geophysical and geological) study
2011
Ischia Island is the emergent portion of a large volcanic complex on the Gulf of Naples (Southern Italy). Ischia volcano has undertaken a complex evolution since 150 ka b.p., with prolonged cycles of effusive and explosive eruptions alternated with quiescence periods (the most recent of which started after the 1302 A.D. Arso eruption). Currently, hot springs (with discharge temperature up to 90 C), fumarolic gas emissions with CO2 up to 97%, and diffuse soil degassing testify a persistent activity state of the Ischia volcano. Ischia Island is a very good example of an active volcano hosting a large hydrothermal system and, in particular, its south-western sector has long been known to be th…
CoS2/TiO2 Nanocomposites for Hydrogen Production under UV Irradiation
2019
Transition metal chalcogenides have intensively focused on photocatalytic hydrogen production for a decade due to their stronger edge and the quantum confinement effect. This work mainly focuses on synthesis and hydrogen production efficiencies of cobalt disulfide (CoS2)-embedded TiO2 nanocomposites. Materials are synthesized by using a hydrothermal approach and the hydrogen production efficiencies of pristine CoS2, TiO2 nanoparticles and CoS2/TiO2 nanocomposites are compared under UV irradiation. A higher amount of hydrogen production (2.55 mmol g&minus
Palermo Costa Sud: futuri prossimi a coordinata 0,0,0
2015
La Costa Sud di Palermo è un territorio che contiene in sé forti elementi di resilienza identitaria, ma che a causa della sua attuale fragilità si presenta come un mosaico scomposto di parti – spesso indistinte – che producono l’effetto opposto di resistenza alla trasformazione. Il contributo propone le questioni di riferimento per la rigenerazione della costa sud, a partire dalle sperimentazioni condotte nel workshop PMO Re-verse (settembre 2014) evento della ricerca PRIN Re-cycle Italy. Nuovi cicli di vita per architetture infrastrutture della città e del paesaggio
The classification of submerged vegetation using hyperspectral MIVIS data
2009
The aim of this research is to use hyperspectral MIVIS data to map the Posidonia oceanica prairies in a coastal lagoon (Stagnone di Marsala). It is approximately 12 km long and 2 km wide and is linked to the open sea by two shallow openings. This environment is characterised by prairies of phanerogams, the most common of which is Posidonia oceanica, an ideal habitat for numerous species of fish, molluscs and crustaceans. A knowledge of the distribution of submerged vegetation is useful to monitor the health of the lagoon. In order to classify the MIVIS imagery, the attenuation effects of the water column have been removed from the signal using Lyzenga’s technique. A comparison between class…
The seaweeds &lt;i&gt;Fucus vesiculosus&lt;/i&gt; and &lt;i&gt;Ascophyllum nodosum&lt;/i&gt; are significant contribu…
2013
Abstract. Based on the results of a pilot study in 2007, which found high mixing ratios of molecular iodine (I2) above the intertidal macroalgae (seaweed) beds at Mweenish Bay (Ireland), we extended the study to nine different locations in the vicinity of Mace Head Atmospheric Research Station on the west coast of Ireland during a field campaign in 2009. The mean values of I2 mixing ratio found above the macroalgae beds at nine different locations ranged from 104 to 393 ppt, implying a high source strength of I2. Such mixing ratios are sufficient to result in photochemically driven coastal new-particle formation events. Mixing ratios above the Ascophyllum nodosum and Fucus vesiculosus beds …
Density Decline in a Mediterranean Seahorse Population: Natural Fluctuations or New Emerging Threats?
2021
Illegal wildlife trade is considered one of the most serious threats to biodiversity worldwide, along with habitat loss/degradation and overfishing of wild stocks. Seahorses are considered at high risk as these fish represent an important component of traditional Chinese medicine but are also sold as curios and ornamental fish. On a worldwide level, illegal trade is controlled by numerous laws and regulations, but it seems to continue by assuming more dynamic routes. In the Mediterranean Sea, Hippocampus guttulatus formed one of the largest populations at Mar Piccolo di Taranto in South-Eastern Italy. During the routine monitoring of this population in 2016, a dramatic density decrease was …
Molecular mechanics models for the image charge, a comment on “including image charge effects in the molecular dynamics simulations of molecules on m…
2017
We re-investigate the image charge model of Iori and Corni (Iori and Corni, J. Comput. Chem. 2008, 29, 1656). We find that a simple symmetrization of their model allows to obtain quantitatively correct results for the electrostatic interaction of a water molecule with a metallic surface. This symmetrization reduces the magnitude of the electrostatic interaction to less than 10% of the total interaction energy. © 2017 Wiley Periodicals, Inc.
Ojituksen ja ennallistamisen aiheuttamat muutokset kasvilajistossa ja –yhteisöissä
2013
Verkostonäkökulma ennallistamiskohteiden valinnassa
2013
Verkostonäkökulma korostuu vahvasti luonnonsuojelun suunnittelussa Suomessa ja maailmalla. Suojelualueita ei voi nähdä yksittäisinä eristyneinä alueina, vaan luonnonsuojelualueiden verkosto ja koko ympäröivä maisema ylläpitävät yhdessä tietyn alueen eliölajistoa. Parhaiden alueiden kytkeytyvyyden varmistamista ja verkostojen ylläpitämistä on myös ehdotettu ratkaisuksi biodiversiteetin säilyttämiselle, kun ilmastonmuutos pakottaa lajeja siirtymään uusille asuinalueille. Verkostonäkökulma kannattaa huomioida myös ennallistamiskohteiden valinnassa – mikä ei kuitenkaan ole yksiselitteistä ja helppoa. nonPeerReviewed