The smart grid is the next generation of power and distribution systems. The integration of advanced network, communications, and computing techniques allows for the enhancement of efficiency and reliability. The smar...The smart grid is the next generation of power and distribution systems. The integration of advanced network, communications, and computing techniques allows for the enhancement of efficiency and reliability. The smart grid interconnects the flow of information via the power line, intelligent metering, renewable and distributed energy systems, and a monitoring and controlling infrastructure. For all the advantages that these components come with, they remain at risk to a spectrum of physical and digital attacks. This paper will focus on digital vulnerabilities within the smart grid and how they may be exploited to form full fledged attacks on the system. A number of countermeasures and solutions from the literature will also be reported, to give an overview of the options for dealing with such problems. This paper serves as a triggering point for future research into smart grid cyber security.展开更多
In this study, a detailed evaluation was performed about the advancements in the renewable energy capacity （especially wind and solar energy） depending on progressive technological developments. Total energy consump...In this study, a detailed evaluation was performed about the advancements in the renewable energy capacity （especially wind and solar energy） depending on progressive technological developments. Total energy consumption as well as renewable energy production from natural sources is statistically evaluated in the basis of leading countries for the period of 2000-2010. The variation of energy mix, future trend of wind energy installations, cumulative capacities in daily wind and solar energy per person are worldwide investigated in this period.展开更多
Estimating CO2 emission factor of the electricity system is a key aspect in the calculation of the baseline emissions for projects certified as CDM （Clean Development Mechanism）, which replace energy from the grid. ...Estimating CO2 emission factor of the electricity system is a key aspect in the calculation of the baseline emissions for projects certified as CDM （Clean Development Mechanism）, which replace energy from the grid. Currently, Uruguay is driving the expansion of the electricity system based on domestic renewable energies, in addition to replacing oil-based fuels for others with lower emission factors. This implies a substantial change of the generation park in the next decade and of the associated CO2 emissions. In this paper, a calculation methodology of the baseline emissions is adapted for its incorporation in the software SimSEE （Electric Energy Systems Simulator）, which is used for modeling the Uruguayan electric system, and therefore, allows modeling the current energy generator park and the future one. Using this tool, the CO2 emission factor＇s evolution is evaluated in the 2012-2020 period. The 2020 scenario is based on an optimal expansion of the electric system. The results indicate a strong reduction of the emission factor between 2012 and 2020, going from average values （for 100 simulations） around 0.60 tCO2/MWh to 0.15 tCO2/MWh. In this possible future scenario, CDM certification will probably not act as a strong incentive in Uruguay for the development of projects based on non-traditional renewable energies.展开更多
Background:Endoscopic cyanoacrylate(glue)injection of fundal varices may result in life-threatening embolic adverse events through spontaneous gastrorenal shunts(GRSs).Balloon-occluded retrograde transvenous occlusion...Background:Endoscopic cyanoacrylate(glue)injection of fundal varices may result in life-threatening embolic adverse events through spontaneous gastrorenal shunts(GRSs).Balloon-occluded retrograde transvenous occlusion(BRTOcc)of GRSs during cyanoacrylate injection may prevent serious systemic glue embolization through the shunt.This study aimed to evaluate the efficacy and safety of a combined endoscopic–interventional radiologic(BRTOcc)approach for the treatment of bleeding fundal varices.Methods:We retrospectively analysed the data of patients who underwent the combined procedure for acutely bleeding fundal varices between January 2010 and April 2018.Data were extracted for patient demographics,clinical and endoscopic findings,technical details,and adverse events of the endoscopic–BRTOcc approach and patient outcomes.Results:We identified 30 patients(13[43.3%]women;median age 58[range,25–92]years)with gastroesophageal varices type 2(53.3%,16/30)and isolated gastric varices type 1(46.7%,14/30)per Sarin classification,and median clinical and endoscopic follow-up of 151(range,4–2,513)days and 98(range,3–2,373)days,respectively.The median volume of octylcyanoacrylate:Lipiodol injected was 7(range,4–22)mL.Procedure-related adverse events occurred in three(10.0%)patients,including transient fever,non-life-threatening pulmonary glue embolism,and an injection-site ulcer bleed.Complete gastric variceal obturation was achieved in 18 of 21 patients(85.7%)at endoscopic follow-up.Delayed variceal rebleeding was confirmed in one patient(3.3%)and suspected in two patients(6.7%).Although no procedure-related deaths occurred,the overall mortality rate was 46.7%,primarily from liver-disease progression and co-morbidities.Conclusion:The combined endoscopic–BRTOcc procedure is a relatively safe and effective technique for bleeding fundal varices,with a high rate of variceal obturation and a low rate of serious adverse events.展开更多
文摘The smart grid is the next generation of power and distribution systems. The integration of advanced network, communications, and computing techniques allows for the enhancement of efficiency and reliability. The smart grid interconnects the flow of information via the power line, intelligent metering, renewable and distributed energy systems, and a monitoring and controlling infrastructure. For all the advantages that these components come with, they remain at risk to a spectrum of physical and digital attacks. This paper will focus on digital vulnerabilities within the smart grid and how they may be exploited to form full fledged attacks on the system. A number of countermeasures and solutions from the literature will also be reported, to give an overview of the options for dealing with such problems. This paper serves as a triggering point for future research into smart grid cyber security.
文摘In this study, a detailed evaluation was performed about the advancements in the renewable energy capacity （especially wind and solar energy） depending on progressive technological developments. Total energy consumption as well as renewable energy production from natural sources is statistically evaluated in the basis of leading countries for the period of 2000-2010. The variation of energy mix, future trend of wind energy installations, cumulative capacities in daily wind and solar energy per person are worldwide investigated in this period.
文摘Estimating CO2 emission factor of the electricity system is a key aspect in the calculation of the baseline emissions for projects certified as CDM （Clean Development Mechanism）, which replace energy from the grid. Currently, Uruguay is driving the expansion of the electricity system based on domestic renewable energies, in addition to replacing oil-based fuels for others with lower emission factors. This implies a substantial change of the generation park in the next decade and of the associated CO2 emissions. In this paper, a calculation methodology of the baseline emissions is adapted for its incorporation in the software SimSEE （Electric Energy Systems Simulator）, which is used for modeling the Uruguayan electric system, and therefore, allows modeling the current energy generator park and the future one. Using this tool, the CO2 emission factor＇s evolution is evaluated in the 2012-2020 period. The 2020 scenario is based on an optimal expansion of the electric system. The results indicate a strong reduction of the emission factor between 2012 and 2020, going from average values （for 100 simulations） around 0.60 tCO2/MWh to 0.15 tCO2/MWh. In this possible future scenario, CDM certification will probably not act as a strong incentive in Uruguay for the development of projects based on non-traditional renewable energies.
文摘Background:Endoscopic cyanoacrylate(glue)injection of fundal varices may result in life-threatening embolic adverse events through spontaneous gastrorenal shunts(GRSs).Balloon-occluded retrograde transvenous occlusion(BRTOcc)of GRSs during cyanoacrylate injection may prevent serious systemic glue embolization through the shunt.This study aimed to evaluate the efficacy and safety of a combined endoscopic–interventional radiologic(BRTOcc)approach for the treatment of bleeding fundal varices.Methods:We retrospectively analysed the data of patients who underwent the combined procedure for acutely bleeding fundal varices between January 2010 and April 2018.Data were extracted for patient demographics,clinical and endoscopic findings,technical details,and adverse events of the endoscopic–BRTOcc approach and patient outcomes.Results:We identified 30 patients(13[43.3%]women;median age 58[range,25–92]years)with gastroesophageal varices type 2(53.3%,16/30)and isolated gastric varices type 1(46.7%,14/30)per Sarin classification,and median clinical and endoscopic follow-up of 151(range,4–2,513)days and 98(range,3–2,373)days,respectively.The median volume of octylcyanoacrylate:Lipiodol injected was 7(range,4–22)mL.Procedure-related adverse events occurred in three(10.0%)patients,including transient fever,non-life-threatening pulmonary glue embolism,and an injection-site ulcer bleed.Complete gastric variceal obturation was achieved in 18 of 21 patients(85.7%)at endoscopic follow-up.Delayed variceal rebleeding was confirmed in one patient(3.3%)and suspected in two patients(6.7%).Although no procedure-related deaths occurred,the overall mortality rate was 46.7%,primarily from liver-disease progression and co-morbidities.Conclusion:The combined endoscopic–BRTOcc procedure is a relatively safe and effective technique for bleeding fundal varices,with a high rate of variceal obturation and a low rate of serious adverse events.
