Search results for " Wind"
showing 10 items of 403 documents
I nomi dei venti in Sicilia tra toponomastica, geomorfologia e “mondo magico”. Possibili itinerari di ricerca
2014
Il sistema anemonomastico siciliano appare leggibile su due livelli: da un lato i nomi dialettali dei venti ripropongono in larga misura quelli presenti nell’italiano tramontana, maestrale, greco, scirocco, libeccio, dall’altro si rileva un numero impressionante di anemonimi rifatti su un toponimo e, più spesso, sull’etnico corrispondente, se il paese che dà il nome al vento è situato lungo la direzione da cui esso spira. Ciò è particolarmente evidente per i nomi dei venti “freddi”. Per essi, mediante una ricerca su una piccola porzione del territorio siciliano le Madonie , è stato possibile raccogliere almeno due anemonimi di origine toponimica in ciascuno dei centri indagati. Mediante lo …
Using simulation to analize wind power penetration: the case of North and Northeast Region
2017
Brazil is rich in renewable sources that can be used for energy generation. The renewable source of energy generation predominantly in Brazil is hydropower. However, the availability of hydropower depends on the useful volume reserves, which is subject to rainfall. Consequently, wind power is a renewable source that is being integrated into the electricity-interconnected system in Brazil. The growth of wind power generation depends on the financial resources and the delays in transmission projects. Despite the Brazilian incentives policy in wind power, the insufficient of transmission infrastructure affects to electricity price in electricity market. This paper addresses the effects of the …
Using simulation to Analyze wind power penetration: The case of North and Northeast Brazil
2016
Brazil is rich in renewable sources that can be used for energy generation. The renewable source of energy generation predominantly in Brazil is hydropower. However, the availability of hydropower depends on the useful volume reserves, which is subject to rainfall. Consequently, wind power is a renewable source that is being integrated into the electricity-interconnected system in Brazil. The growth of wind power generation depends on the financial resources and the delays in transmission projects. Despite the Brazilian incentives policy in wind power, the insufficient of transmission infrastructure affects to electricity price in electricity market. This paper addresses the effects of the …
Hydrodynamic Analysis of Floating Docks With Alternative Geometries for Floating Wind Turbine Installation
2021
Abstract Installation of spar floating wind turbine offshore is a challenging task. Usually, the spar platform is upended first, and mating of the tower assembly with the spar platform is assisted by a crane vessel. Due to motions of the spar platforms and of the crane vessel, such an operation often takes place in shielded areas with relatively small wave heights and wind speed. The floating dock concept has been recently proposed to expand the weather window for installing spar floating wind turbines. The idea is to use a cylindrical dock to shield the spar platform from wave excitations. However, because of the trapped internal fluid, the cylindrical geometry is subjected to piston mode …
Parameter tuning for nacelle-based passive structural control of a spar-type floating wind turbine
2013
This paper deals with the modeling and parameter tuning of a spar-type floating wind turbine with a tuned mass damper (TMD) installed in nacelle. Firstly, a mathematical model for the system surge-heave-pitch motion is established based on first principles. Secondly, different parameter tuning methods are adopted to find the optimal TMD parameters for load reduction. Thirdly, nonlinear wind turbine simulations with different designs are conducted under different wind and wave conditions. The results show that TMD with small spring and damping coefficients will help to produce much load reduction in above rated condition. However, it may deteriorate system performance when the turbine is wor…
Smart grid for offshore wind farms: Towards an information model based on the IEC 61400-25 standard
2012
Nowadays, wind energy is one of the most recognized renewable energy sources. Onshore wind farms have been built in many countries, such as Denmark, Norway, UK, Italy, Brazil and the US. To utilize the more stable wind resources, wind farms have moved off the shore, first to shallow waters near shore and now extending to deeper waters and far off the shore. Deep-water offshore solutions will give access to large areas with high wind, and less sensitivity to noise, visual impacts and size. However, the cost of developing and operating an offshore wind farm is many times larger than onshore due to large water depths and harsh offshore environments. Hence, the needs for fast and automatic data…
Palazzo Floridia-Bertini a Ragusa. Il restauro dei serramenti lignei della facciata barocca
2021
Per la “rimarchevole testimonianza dell’esuberante genialità espressa nell’arte e nell’architettura del tardo barocco” nella Val di Noto, nel 2002 il palazzo Floridia-Bertini è inserito dall’UNESCO nella World Heritage List ed inizia a prendere corpo la volontà di intervenire sulla sua facciata. Dopo avere richiamato le riflessioni che hanno condotto alle scelte operative, il contributo espone le più significative fasi di cantiere relative al restauro dei serramenti lignei esterni, con particolare riguardo all’intervento compiuto su un serramento settecentesco. For the “remarkable testimony of the exuberant genius expressed in the art and architecture of the late Baroque” in the Val di Noto…
The role of slabs and oceanic plate geometry in the net rotation of the lithosphere, trench motions, and slab return flow
2012
[1] Absolute plate motion models with respect to a deep mantle reference frame (e.g., hot spots) typically contain some net rotation (NR) of the lithosphere. Global mantle flow models for the present-day plate setting reproduce similarly oriented NRs but with amplitudes significantly smaller than those found in some high NR Pacific hot spot reference frames. It is therefore important to understand the mechanisms of NR excitation, which we attempt here with two-dimensional cylindrical models of an idealized Pacific domain. We study the influence of slab properties, oceanic ridge position, continental keels, and a weak asthenospheric layer on NR and trench migration. Fast slab return flow dev…
Small Wind Turbines: Specification, Design, and Economic Evaluation
2016
In this work, we consider various aspects of small wind turbines' (SWTs) design and operation. First, an extensive literature study is presented by considering SWTs specification, market statistics, the smart grid, and the prosumer concepts as well as the most important parameters affecting the efficiency of wind turbines. Then, both the literature review and series of coupled numerical simulations investigating impact of the chosen design solutions on small wind turbine operation are performed. It allowed objective evaluation of different design approaches, which in turn enabled the systematic identification of actual limitations as well as the opportunities for specific design solutions o…
Mean Interplanetary Magnetic Field Measurement Using the ARGO-YBJ Experiment
2011
The sun blocks cosmic ray particles from outside the solar system, forming a detectable shadow in the sky map of cosmic rays detected by the ARGO-YBJ experiment in Tibet. Because the cosmic ray particles are positive charged, the magnetic field between the sun and the earth deflects them from straight trajectories and results in a shift of the shadow from the true location of the sun. Here we show that the shift measures the intensity of the field which is transported by the solar wind from the sun to the earth.