1000 resultados para power draft


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O presente estudo teve como objetivo avaliar parâmetros operacionais de um conjunto mecanizado envolvendo trator e semeadora, assim como o rendimento da cultura do milho semeada nas diferentes configurações das máquinas e combinações com o ambiente de produção. Os tratamentos consistiram de tipos de sulcadores (discos duplos e hastes), os quais foram avaliados em experimentos em que a operação de semeadura direta do milho foi efetuada transversalmente ao declive (em nível) e em aclive e declive. A semeadura contra o declive e o uso de haste sulcadora implicaram maior demanda de esforço de tração, patinagem do trator e consumo de combustível por área trabalhada e não influenciaram o volume de solo mobilizado, a população de plantas e a produtividade de grãos do milho, em relação à operação realizada em declive e uso de sulcador de discos duplos, respectivamente. A utilização de sulcador do tipo haste resultou em menor número de plantas acamadas e quebradas, em relação ao uso de discos duplos, independentemente do sentido da operação. A principal diferença entre semear em nível ou em declive é a formação de sulcos orientados no sentido do terreno, pela ação de sulcadores do tipo haste e elevada patinagem dos rodados do trator, já que o consumo de combustível por área trabalhada e capacidade operacional não foram afetados por aquelas variáveis.

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In ultra-low data rate wireless sensor networks (WSNs) waking up just to listen to a beacon every superframe can be a major waste of energy. This study introduces MedMAC, a medium access protocol for ultra-low data rate WSNs that achieves significant energy efficiency through a novel synchronisation mechanism. The new draft IEEE 802.15.6 standard for body area networks includes a sub-class of applications such as medical implantable devices and long-term micro miniature sensors with ultra-low power requirements. It will be desirable for these devices to have 10 years or more of operation between battery changes, or to have average current requirements matched to energy harvesting technology. Simulation results are presented to show that the MedMAC allows nodes to maintain synchronisation to the network while sleeping through many beacons with a significant increase in energy efficiency during periods of particularly low data transfer. Results from a comparative analysis of MedMAC and IEEE 802.15.6 MAC show that MedMAC has superior efficiency with energy savings of between 25 and 87 for the presented scenarios. © 2011 The Institution of Engineering and Technology.

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Despite previous attempts at codification of international law regarding international responses to natural and human-made disasters, there is currently no binding international legal framework to regulate the provision of humanitarian assistance outside armed conflicts. Nevertheless, since the International Law Commission (ILC) included the protection of persons in the event of disasters on its programme of work in 2006, it has provisionally adopted eleven draft articles that have the potential to create binding obligations on states and humanitarian actors in disaster settings. Draft articles adopted include the definition of ‘a disaster’, the relationship of the draft articles to the international humanitarian law of armed conflict, recognition of the inherent dignity of the human person, and the duty of international cooperation. However, the final form of the draft articles has not been agreed. The Codification Division of the UN Office of Legal Affairs has proposed a framework convention format, which has seen support in the ILC and the UN General Assembly Sixth Committee. The overall aim of this article is to provide an analysis of the potential forms of international regulation open to the ILC and states in the context of humanitarian responses to disasters. However to avoid enchanting the ILC draft articles with unwarranted power, any examination of form requires an understanding of the substantive subject matter of the planned international regulation. The article therefore provides an overview of the international legal regulation of humanitarian assistance following natural and human-made disasters, and the ILC’s work to date on the topic. It then examines two key issues that remain to be addressed by the ILC and representatives of states in the UN General Assembly Sixth Committee. Drawing on the UN Guiding Principles on Internal Displacement, the development and implications of binding and non-binding international texts are examined, followed by an analysis of the suggested framework convention approach identified by the Special Rapporteur as a potential outcome of the ILC work.

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The recent proposals presented by EPA aimed to reduce the dependency of fossil fuels and to lower current emissions levels, hoping to gradually shift electric generation units to renewable energy sources. Actually, the Final Rule Proposal announcement day exhibited a negative Abnormal Return on Fossil Fuels but the following days had positive Abnormal Returns, mostly due to legislative change perceived by financial markets which eased up implementation periods of the proposed measures in the Final Rule when compared to the Draft Rule. Oppositely, Renewables and Solar Portfolios exhibited negative Cumulative Abnormal Returns over the period surrounding the Final Rule.

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A new approach to the determination of the thermal parameters of high-power batteries is introduced here. Application of local heat flux measurement with a gradient heat flux sensor (GHFS) allows determination of the cell thermal parameters in di_erent surface points of the cell. The suggested methodology is not cell destructive as it does not require deep discharge of the cell or application of any charge/discharge cycles during measurements of the thermal parameters of the cell. The complete procedure is demonstrated on a high-power Li-ion pouch cell, and it is verified on a sample with well-known thermal parameters. A comparison of the experimental results with conventional thermal characterization methods shows an acceptably low error. The dependence of the cell thermal parameters on state of charge (SoC) and measurement points on the surface was studied by the proposed measurement approach.

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