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Compte rendu de : Peter Mitchell, Horse Nations: The Worldwide Impact of the Horse on Indigenous Societies Post-1492, Oxford, Oxford University Press…
2019
International audience
Rotational effects on the oscillation frequencies of newly born proto-neutron stars
2003
In this paper we study the effects of rotation on the frequencies of the quasi-normal modes of a proto-neutron star (PNS) born in a gravitational collapse during the first minute of life. Our analysis starts a few tenths of seconds after the PNS formation, when the stellar evolution can be described by a sequence of equilibrium configurations. We use the evolutionary models developed by Pons et al. (1999; 2001) that describe how a non rotating star cools down and contracts while neutrino diffusion and thermalization processes dominate the stellar dynamics. For assigned values of the evolution time, we set the star into slow rotation and integrate the equations of stellar perturbations in th…
Toward farm-level health management of wind turbine systems: status and scope for improvements
2018
An outline of health management for OWFs has been detailed in this chapter with description of various important elements. The need for such farm level management is explained and benefits are discussed. Key gaps to be filled in order to realize such a system are identified. The proposed health management system is mainly based on the existing knowledge of fleet-level management in the aerospace sector. Health management is much broader than CM; there are a number of aspects beyond the prognostics capabilities that are to be designed in order to arrive at a comprehensive maintenance management scheme. A comprehensive maintenance program that is sensitive to the health of the assets and adap…
Recurrent pathologies in recently built schools in Palermo,
2006
This topic concerns the most significant pathologies noticed in the facilities being used as schools, which were built in Palermo in the last three decades. Many among these facilities already have undergone major restoration works, while the others are in poor conditions, which remarkably compromise the quality of their utilization. Sober elegance and safety are particularly important whenever a facility is to function as a school, especially if we consider the type of users and the ways of utilization. In order to achieve such goal, it is fundamental to analyse the most frequent pathologies, relating them to their causes, so as to have the tools for correcting previous errors and prevent …
Fault diagnosis of induction motors broken rotor bars by pattern recognition based on noise cancelation
2014
Current signal monitoring (CSM) can be used as an effective tool for diagnosing broken rotor bars fault in induction motors. In this paper, fault diagnosis and classification based on artificial neural networks (ANNs) is done in two stages. In the first stage, a filter is designed to remove irrelevant fault components (such as noise) of current signals. The coefficients of the filter are obtained by least square (LS) algorithm. Then by extracting suitable time domain features from filter's output, a neural network is trained for fault classification. The output vector of this network is represented in one of four categories that includes healthy mode, a 5 mm crack on a bar, one broken bar, …
Lapsen kehollisuuden esittäminen aikakauslehtien mainoskuvissa
2006
Lake size and fish diversity determine resource use and trophic position of a top predator in high-latitude lakes
2015
Prey preference of top predators and energy flow across habitat boundaries are of fundamental importance for structure and function of aquatic and terrestrial ecosystems, as they may have strong effects on production, species diversity, and food-web stability. In lakes, littoral and pelagic food-web compartments are typically coupled and controlled by generalist fish top predators. However, the extent and determinants of such coupling remains a topical area of ecological research and is largely unknown in oligotrophic high-latitude lakes. We analyzed food-web structure and resource use by a generalist top predator, the Arctic charr Salvelinus alpinus (L.), in 17 oligotrophic subarctic lakes…
Domestic resource mobilization by social movement organizations in Latin America : a case study of the Abrinq Foundation for children rights of Brazil
2008
The aim of this Master’s thesis is to study the feasibility and sustainability of mobilizing domestic resources to advance social movement causes in Latin America. The question is based on the understanding that Social Movement Organizations (SMO) can mobilize the resources –funds and labor- of domestic elite instances in order to favor their beneficiary bases. The thesis proposes a Domestic Resource Mobilization (DRM) approach and addresses various theoretical and practical concerns regarding the qualitative impact of that conception in the work of Social Movement Organizations. The specific focus of is centered on resource mobilization strategies and initiatives conducted by the SMO Abrin…