In the past decade,several efforts around the world were started with the goal of introducing "smart metering" capabilities into the power grid.These efforts have spurred renewed interest in the design of ne...In the past decade,several efforts around the world were started with the goal of introducing "smart metering" capabilities into the power grid.These efforts have spurred renewed interest in the design of next generation Narrowband Power Line Communications(NB-PLC) transceivers.In the past few years,ITU-T and IEEE have standardized a family of next generation OFDM-based NB-PLC transceivers some of which are today being considered for massive deployments in Europe and Asia.This paper addresses the important role that PLC has not only for smart metering but also for many other Smart Grid applications,and also gives an overview of the main differences between these next generation NB-PLC standards.展开更多
The present study aims at environmental protection through the use of plastic wastes in the production of mortar. The behavior of siliceous sand-based mortars from Togo and binders of plastic bags of the kind “voltic...The present study aims at environmental protection through the use of plastic wastes in the production of mortar. The behavior of siliceous sand-based mortars from Togo and binders of plastic bags of the kind “voltic” is analyzed. Mortar samples from a mixture of siliceous sand and binder of plastic bags are prepared and subjected to physical and mechanical tests after immersion in the hydrocarbon from 0 hour to 504 hours. The result demonstrates that hydrocarbons have no influence on mechanical properties of mortars for an immersion time below 3 hours. Between 3 hours and 24 hours the presence of hydrocarbon increases their physical and mechanical properties. After 24 hours mortars generally lose the mechanical properties of around 8% to 24% due to the loss of viscosity and cohesiveness of the binder caused by the fuel. The behavior in the face of hydrocarbons shows that the material can be used in the surface of roads by carefully avoiding that hydrocarbons remain on the roads for a period of time beyond 24 hours.展开更多
The purpose of this study is to analyze the behavior of mortars from the sands of Togo in order to optimize their traction resistance. 3660 4 cm × 4 cm × 16 cm test tubes of mortars are prepared from the san...The purpose of this study is to analyze the behavior of mortars from the sands of Togo in order to optimize their traction resistance. 3660 4 cm × 4 cm × 16 cm test tubes of mortars are prepared from the sands of 20 extraction sites in Togo with variations in water and cement while keeping the water-cement ratio constant (<i>E</i>/<i>C</i> = 0.5). It emerges a quadratically increasing evolution of resistance in flexural at 28 days of age (<i>σ<sub>f</sub></i>) for cement-sand (<i>C</i>/<i>S</i>) and water-sand (<i>E</i>/<i>S</i>) ratios varying respectively by the interval [0.0370, 0.3580] to [0.1977, 0.5120] and [0.0185, 0.1792] to [0.0988, 0.2605]. The resistances become stationary beyond these values (<i>σ<sub>f</sub></i> ≈ 3.4750 MPa to 7.9010 MPa). For structures whose resistance in traction is desired, three formulas of sand mortars from Togo are therefore defined: rich mortars (<i>C</i>/<i>S</i> > 0.5120 and <i>E</i>/<i>S</i> > 0.2605), lean (<i>C</i>/<i>S</i> < 0.0370 and <i>E</i>/<i>S</i> < 0.0185) and normal (0.0370 < <i>C</i>/<i>S</i> < 0.5120 and 0.0185 < <i>E</i>/<i>S</i> < 0.2605).展开更多
文摘In the past decade,several efforts around the world were started with the goal of introducing "smart metering" capabilities into the power grid.These efforts have spurred renewed interest in the design of next generation Narrowband Power Line Communications(NB-PLC) transceivers.In the past few years,ITU-T and IEEE have standardized a family of next generation OFDM-based NB-PLC transceivers some of which are today being considered for massive deployments in Europe and Asia.This paper addresses the important role that PLC has not only for smart metering but also for many other Smart Grid applications,and also gives an overview of the main differences between these next generation NB-PLC standards.
文摘The present study aims at environmental protection through the use of plastic wastes in the production of mortar. The behavior of siliceous sand-based mortars from Togo and binders of plastic bags of the kind “voltic” is analyzed. Mortar samples from a mixture of siliceous sand and binder of plastic bags are prepared and subjected to physical and mechanical tests after immersion in the hydrocarbon from 0 hour to 504 hours. The result demonstrates that hydrocarbons have no influence on mechanical properties of mortars for an immersion time below 3 hours. Between 3 hours and 24 hours the presence of hydrocarbon increases their physical and mechanical properties. After 24 hours mortars generally lose the mechanical properties of around 8% to 24% due to the loss of viscosity and cohesiveness of the binder caused by the fuel. The behavior in the face of hydrocarbons shows that the material can be used in the surface of roads by carefully avoiding that hydrocarbons remain on the roads for a period of time beyond 24 hours.
文摘The purpose of this study is to analyze the behavior of mortars from the sands of Togo in order to optimize their traction resistance. 3660 4 cm × 4 cm × 16 cm test tubes of mortars are prepared from the sands of 20 extraction sites in Togo with variations in water and cement while keeping the water-cement ratio constant (<i>E</i>/<i>C</i> = 0.5). It emerges a quadratically increasing evolution of resistance in flexural at 28 days of age (<i>σ<sub>f</sub></i>) for cement-sand (<i>C</i>/<i>S</i>) and water-sand (<i>E</i>/<i>S</i>) ratios varying respectively by the interval [0.0370, 0.3580] to [0.1977, 0.5120] and [0.0185, 0.1792] to [0.0988, 0.2605]. The resistances become stationary beyond these values (<i>σ<sub>f</sub></i> ≈ 3.4750 MPa to 7.9010 MPa). For structures whose resistance in traction is desired, three formulas of sand mortars from Togo are therefore defined: rich mortars (<i>C</i>/<i>S</i> > 0.5120 and <i>E</i>/<i>S</i> > 0.2605), lean (<i>C</i>/<i>S</i> < 0.0370 and <i>E</i>/<i>S</i> < 0.0185) and normal (0.0370 < <i>C</i>/<i>S</i> < 0.5120 and 0.0185 < <i>E</i>/<i>S</i> < 0.2605).
