Search results for " wind"
showing 10 items of 403 documents
100 Million Filipinos
2017
The Philippine archipelago, with more than 100 million inhabitants, is the 12th most populous in the world, one the fastest growing and youngest countries in Asia, and will soon overtake an aging Japan. Causes of the high rate of population growth include the teachings of the influential Philippine Catholic Church (no divorce, contraception or abortion) and the active sexual life of young Filipinos. Many women become pregnant at a very early age, soon after puberty. The country has not developed population control policies as some other countries (Thailand, China) have. Therefore it has a very young population with few elderly people, a situation that may be good for the economy (demographi…
Ultra-fast intensified frame images from an electron cyclotron resonance hydrogen plasma at 2.45 GHz: some space distributions of visible and monochr…
2014
First results from an ultra-fast frame image acquisition diagnostic coupled to a 2.45 GHz microwave hydrogen discharge are presented. The plasma reactor has been modified to include a transparent doubled shielded quartz window allowing to viewing the full plasma volume. Pictures describing the breakdown process at 1μs exposure time have been obtained for integrated visible light signal, Balmer-alpha, Balmer-beta lines, and Fulcher-band. Several different plasma emission distributions are reported. The distribution depends on the magnetic field configuration, incident microwave power, and neutral gas pressure. peerReviewed
Boron-Doped Diamond Electrodes for Electroorganic Chemistry
2011
Boron-doped diamond (BDD) electrodes provide an unusually wide electrochemical window in protic media, since there exist large offset potentials for the evolution of molecular hydrogen and oxygen, respectively. At the anode, alcohols are specifically converted to alkoxyl radicals. These can be used for chemical synthesis. When the enormous reactivity of such intermediate spin centers is not controlled, mineralization or electrochemical incineration dominates. Efficient strategies include either high substrate concentrations or fluorinated alcohols which seem to stabilize the spin centers in the course of reaction.
Addressing subphthalocyanines and subnaphthalocyanines features relevant to fluorescence imaging
2018
International audience; A series of new synthetic subphthalocyanines bear structural features aimed at allowing either fluorescence activation or a bathochromic shift of the absorption band towards the near-infrared window, relevant to optical imaging. X-ray diffraction studies of four subphthalocyanines are reported. Spectrofluorimetric studies on subnaphthalocyanines and activatable subphthalocyanine pro-fluorophores are reported.
Evaluation of the ERA5 reanalysis-based Universal Thermal Climate Index on mortality data in Europe
2021
Air temperature has been the most commonly used exposure metric in assessing relationships between thermal stress and mortality. Lack of the high-quality meteorological station data necessary to adequately characterize the thermal environment has been one of the main limitations for the use of more complex thermal indices. Global climate reanalyses may provide an ideal platform to overcome this limitation and define complex heat and cold stress conditions anywhere in the world. In this study, we explored the potential of the Universal Thermal Climate Index (UTCI) based on ERA5 – the latest global climate reanalysis from the European Centre for Medium-Range Weather Forecasts (ECMWF) – as a h…
A general procedure for the construction of Gorges polygons for multi-phase windings of electrical machines
2018
This paper presents a simple and effective procedure for the determination of the Gorges polygon, suitable for all possible winding configurations in electrical machines. This methodology takes into account the determination of a Winding Distribution Table (WDT), in which all the information about the distribution of the currents along the stator periphery is computed and from which the Görges polygon are easily derived. The proposed method can be applied to both symmetrical and asymmetrical multi-phase windings, including concentrated, fractional, reduced and dead-coil ones. The examples provided in this paper demonstrate the versatility of the proposed method.
A framework for data integration of offshore wind farms
2013
Abstract Operation and maintenance play an important role in maximizing the yield and minimizing the downtime of wind turbines, especially offshore wind farms where access can be difficult due to harsh weather conditions for long periods. It contributes up to 25–30% to the cost of energy generation. Improved operation and maintenance (O&M) practices are likely to reduce the cost of wind energy and increase safety. In order to optimize the O&M, the importance of data exchange and knowledge sharing within the offshore wind industry must be realized. With more data available, it is possible to make better decisions, and thereby improve the recovery rates and reduce the operational costs. This …
Proactive maintenance of offshore wind turbine blades using knowledge-based force analysis
2013
The operation and maintenance (O&M) costs of wind turbines constitute approximately 10-15% of the lifecycle cost in onshore installations and up to 30% in offshore installations. The O&M costs for offshore wind power plants are higher than the onshore ones due to greater logistical challenges of maintaining and servicing, and the less mature state of offshore wind energy technology. Wind turbine blades suffer from various faults, for example, blade angle asymmetry, icing, and bends. These faults may cause wind turbines to a standstill. Replacement of rotor blades will normally result in a long downtime since the replacement process involves heavy transportation (vessel, crane) and dependenc…
A hemispherical dynamo model : Implications for the Martian crustal magnetization
2014
Abstract Mars Global Surveyor measurements revealed that the Martian crust is strongly magnetized in the southern hemisphere while the northern hemisphere is virtually void of magnetization. Two possible reasons have been suggested for this dichotomy: a once more or less homogeneously magnetization may have been destroyed in the northern hemisphere by, for example, resurfacing or impacts. The alternative theory we further explore here assumes that the dynamo itself produced a hemispherical field ( Stanley et al., 2008 , Amit et al., 2011 ). We use numerical dynamo simulations to study under which conditions a spatial variation of the heat flux through the core–mantle boundary (CMB) may yiel…
Is the tourism–economic growth nexus time-varying? Bootstrap rolling-window causality analysis for the top 10 tourist destinations
2017
This article explores the time-varying causal nexus between tourism development and economic growth for the top 10 tourist destinations in the world, namely China, France, Germany, Italy, Mexico, t...