A general four-layer structure linear theory for predicting the effects of arbitrarily distributed roughness change on the variations of wind speed and shear stress in the surface layer of 3D and 2D atmospheres was pr...A general four-layer structure linear theory for predicting the effects of arbitrarily distributed roughness change on the variations of wind speed and shear stress in the surface layer of 3D and 2D atmospheres was presented.The results derived by the theory were agreeable to the previous ones.展开更多
Petroleum and Natural Gas still represent a considerable share in terms of energy consumption in the current global matrix, so that its exploration/exploitation is present in the market and driving activities in locat...Petroleum and Natural Gas still represent a considerable share in terms of energy consumption in the current global matrix, so that its exploration/exploitation is present in the market and driving activities in locations of specific complexities, as the ones along unconventional hydrocarbon resources from the Brazilian pre-salt. The daily cost of well drilling under harsh conditions can exceed US $1 million a day, turning any type of downtime or necessary maintenance during the activities to be very costly, moment in which processes optimization starts to be a key factor in costs reduction. Thus, new technologies and methods in terms of automating and optimizing the processes may be of great advantages, having its impact in total related project costs. In this context, the goal of this research is to allow a computation tool supporting achieving a more efficient drilling process, by means of drilling mechanics parameters choosiness aiming rate of penetration (ROP) maximization and mechanic specific energy (MSE) minimization. Conceptually, driven by the pre-operational drilling test curve trends, the proposed system allows it to be performed with less human influences and being updateable automatically, allowing more precision and time reduction by selecting optimum parameters. A Web Operating System (Web OS) was designed and implemented, running in online servers, granting accessibility to it with any device that has a browser and internet connection. It allows processing the drilling parameters supplied and feed into it, issuing outcomes with optimum values in a faster and precise way, allowing reducing operating time.展开更多
The Asian Network on Climate Science and Technology （www.ancstorg）, in collaboration with Tsinghua University, held a conference on environmental and climate science, air pollution, urban planning and transportation...The Asian Network on Climate Science and Technology （www.ancstorg）, in collaboration with Tsinghua University, held a conference on environmental and climate science, air pollution, urban planning and transportation in July 2015, with over 40 Asian experts participating and presentation. This was followed by a meeting with local government and community experts on the practical conclusions of the conference. Of the papers presented at the conference a selection are included in this special issue of ]ournal of Environmental Science, which also reflects the conclusions of the Paris Climate meeting in Dec 2015, when the major nations of the world agreed about the compelling need to reduce the upward trend of adverse impacts associated with global climate change. Now is the time for urban areas to work out the serious consequences for their populations, but also how they should work together to take action to reduce global wanning to benefit their own communities and also the whole planet!展开更多
文摘A general four-layer structure linear theory for predicting the effects of arbitrarily distributed roughness change on the variations of wind speed and shear stress in the surface layer of 3D and 2D atmospheres was presented.The results derived by the theory were agreeable to the previous ones.
文摘Petroleum and Natural Gas still represent a considerable share in terms of energy consumption in the current global matrix, so that its exploration/exploitation is present in the market and driving activities in locations of specific complexities, as the ones along unconventional hydrocarbon resources from the Brazilian pre-salt. The daily cost of well drilling under harsh conditions can exceed US $1 million a day, turning any type of downtime or necessary maintenance during the activities to be very costly, moment in which processes optimization starts to be a key factor in costs reduction. Thus, new technologies and methods in terms of automating and optimizing the processes may be of great advantages, having its impact in total related project costs. In this context, the goal of this research is to allow a computation tool supporting achieving a more efficient drilling process, by means of drilling mechanics parameters choosiness aiming rate of penetration (ROP) maximization and mechanic specific energy (MSE) minimization. Conceptually, driven by the pre-operational drilling test curve trends, the proposed system allows it to be performed with less human influences and being updateable automatically, allowing more precision and time reduction by selecting optimum parameters. A Web Operating System (Web OS) was designed and implemented, running in online servers, granting accessibility to it with any device that has a browser and internet connection. It allows processing the drilling parameters supplied and feed into it, issuing outcomes with optimum values in a faster and precise way, allowing reducing operating time.
基金supported by Asian Network for Climate Science and Technology, Malaysian Commonwealth Studies Centre (Cambridge)the Tsinghua-Cambridge-MIT Centre for Future Transport at Tsinghua University
文摘The Asian Network on Climate Science and Technology （www.ancstorg）, in collaboration with Tsinghua University, held a conference on environmental and climate science, air pollution, urban planning and transportation in July 2015, with over 40 Asian experts participating and presentation. This was followed by a meeting with local government and community experts on the practical conclusions of the conference. Of the papers presented at the conference a selection are included in this special issue of ]ournal of Environmental Science, which also reflects the conclusions of the Paris Climate meeting in Dec 2015, when the major nations of the world agreed about the compelling need to reduce the upward trend of adverse impacts associated with global climate change. Now is the time for urban areas to work out the serious consequences for their populations, but also how they should work together to take action to reduce global wanning to benefit their own communities and also the whole planet!
