Floating photovoltaic systems installed in water bodies such as natural lakes or dams reservoirs, have attracted increased worldwide attention since 2011 and have already been deployed in several countries, including ...Floating photovoltaic systems installed in water bodies such as natural lakes or dams reservoirs, have attracted increased worldwide attention since 2011 and have already been deployed in several countries, including Japan, South Korea and USA. In Brazil, pilot-projects were announced in the reservoirs of hydroelectric power plants of Balbina （State of Amazonas） and Sobradinho （State of Bahia）. Several advantages, not necessarily valid in Brazil, are mentioned for deploying this kind of technology, such as an increase in energy generation, reduction of water losses through evaporation, low environmental impact, no occupation of land etc. In this article, several of these allegations are analyzed preliminarily under the Brazilian point of view, and relevant considerations are presented. It is concluded that the technical and economic advantages of floating photovoltaic systems are not yet clear in Brazil and that pilot projects, such as those under way, should be used to clarify several important aspects related to them.展开更多
The traveling wave reactor （TWR） is a once-through reactor that uses in situ breeding to greatly reduce the need for enrichment and reprocessing. Breeding converts incoming subcritical reload fuel into new critical ...The traveling wave reactor （TWR） is a once-through reactor that uses in situ breeding to greatly reduce the need for enrichment and reprocessing. Breeding converts incoming subcritical reload fuel into new critical fuel, allowing a breed-burn wave to propagate. The concept works on the basis that breed-burn waves and the fuel move relative to one another. Thus either the fuel or the waves may move relative to the stationary observer. The most practical embodiments of the TWR involve moving the fuel while keeping the nuclear reactions in one place-sometimes referred to as the standing wave reactor （SWR）. TWRs can operate with uranium reload fuels including totally depleted uranium, natural uranium, and low-enriched fuel （e.g., 5.5% 23sU and below）, which ordinarily would not be critical in a fast spectrum. Spent light water reactor （LWR） fuel may also serve as TWR reload fuel. In each of these cases, very efficient fuel usage and significant reduction of waste volumes are achieved without the need for re- processing. The ultimate advantages of the TWR are realized when the reload fuel is depleted uranium, where after the startup period, no enrichment facilities are needed to sustain the first reactor and a chain of successor reactors. TerraPower＇s conceptual and engineering design and associated technolo- gy development activities have been underway since late 2006, with over 50 institutions working in a highly coordinated effort to place the first unit in operation by 2026. This paper summarizes the TWR technology： its development program, its progress, and an analysis of its social and economic benefits.展开更多
AIM: To investigate the use of the Gaumard's Noelle S550.100 Maternal and Neonatal Simulators for teaching forceps delivery.METHODS: Twenty two(n = 22) resident physicians were enrolled in a simulation course on o...AIM: To investigate the use of the Gaumard's Noelle S550.100 Maternal and Neonatal Simulators for teaching forceps delivery.METHODS: Twenty two(n = 22) resident physicians were enrolled in a simulation course on operative forceps deliveries. The physicians enrolled in the course were all part of an accredited Obstetrics and Gynecology residency program and ranged in their training from post graduate year(PGY) 1-4. Each participant received simulation based teaching on the indications, contraindications, proper application, delivery and removal of forceps by a single teacher. The Gaumard's simulator and Simpson forceps were used for this course. Statistical analysis using SPSS statistical software was performed after the completion of the simulation training program. A paired student t-test was performed to compare the cohort's mean pretest and post simulation training scores. Follow up skills assessment scores at one month, 3 mo and 6 mo were compared to thebaseline pretest score using a paired student t-test. RESULTS: There was statistically significant improvement in the post simulation training performance evaluations compared to the pretest, 13.7(SD = 3.14) vs 7.9(SD = 4.92), P < 0.05. Scores at 1 mo, 3 mo, and 6 mo were compared to the pretest score and showed retention of skills: 4.6(SD = 5.5, 95%CI: 2.21-7.07), 4.4(SD = 5.2, 95%CI: 2.13-6.70), and 5.6(SD = 4.8, 95%CI: 3.53-7.75) points, respectively. There were statistically significant differences between residents by post graduate training year on pretest scores, however these differences were not present after simulation training. Pretest scores for PGY 1, 2, 3, 4 were 3.5(SD = 2.27, 95%CI: 2.13-5.00), 7.25(SD = 6.70, 95%CI: 1.50-13.00), 10.75(SD = 1.5, 95%CI: 9.50-12.00), 12.17(SD = 2.57, 95%CI: 10.33-14.00). After simulation training PGY 1 residents did as well as well as the upper level residents. Posttest mean test scores for PGY 1, 2, 3, 4 were 13.75(SD = 1.49, 95%CI: 12.75-14.63), 10.25(SD = 0.24, 95%CI: 4.25-14.00), 15.00(SD = 1.16, 95%CI: 14.00-16.00), 15.17(SD = 0.75, 95%CI: 14.67-15.67). CONCLUSION: Our simulation based training program not only produced short term gains, but participants were able to retain the skills learned and demonstrate their knowledge months later.展开更多
The Malaysian government＇s vision to be a developed nation by 2020 has pushed forward the use of innovative technologies in most sectors and industries, including the construction industry. Through the ETP （Economic...The Malaysian government＇s vision to be a developed nation by 2020 has pushed forward the use of innovative technologies in most sectors and industries, including the construction industry. Through the ETP （Economic Transformation Programme）, major projects launched are expected to provide a great catalyst for the economy, and may become the platform for increasing the use of automation and highly enhanced plants and machineries in the construction industry. Innovations in most countries are mostly driven by the need to find revolutionary solutions to problems, such as a shortage of skilled labor, decreasing quality of product and processes, inferior working conditions, declining productivity and increasing costs of labor and materials. Automation and robotics technologies encompass a wide range of innovative technologies using technologically advanced machineries to improve the speed and efficiency of a given process. This paper discusses the readiness of a developing country in embracing construction automation and robotics, by exploring industry perception, suggested practices and barriers to its implementation using a questionnaire survey and semi-structured interviews directed at Malaysian construction finns of contractors, specialist sub-contractors, developers and consultants. The findings show that the Malaysian construction industry is ready, to a certain extent, for implementing the technologies in limited areas such as prefabrication and assembly and in the design, planning and costing phases.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
Giant earthquakes generate rich signals that can be used to explore the characteristics of the hierarchical structure of the Earth’s interior associated with the eigenfrequencies of the Earth.We employ the spectral e...Giant earthquakes generate rich signals that can be used to explore the characteristics of the hierarchical structure of the Earth’s interior associated with the eigenfrequencies of the Earth.We employ the spectral element method,incorporated with large-scale parallel computing technology,to investigate the characteristics of global seismic wave propagation excited by the2011 Mw9.0 Tohoku earthquake.The transversely isotropic PREM model is employed as a prototype of our numerical global Earth model.Topographic data and the effect of the oceans are taken into consideration.Wave propagation processes are simulated by solving three-dimensional elastic wave governing equations with the seismic moment tensor obtained from the Global Centroid Moment Tensor Catalog.Three-dimensional visualization of our computing results displays the nature of the global seismic wave propagation.Comparative analysis of our calculations with observations obtained from the Incorporated Research Institutions for Seismology demonstrates the reliability and feasibility of our numerical results.We compare synthetic seismograms with incorporated and unincorporated ocean models.First results show that the oceans have obvious effects on the characteristics of seismic wave propagation.The peak displacement and peak velocity of P waves become relatively small under the effect of the ocean.However,the effect of the ocean on S-waves is complex.The displacement and velocity of S waves decrease rapidly over time using an unincorporated ocean model.Therefore,the effects of the ocean should be incorporated when undertaking quantitative earthquake hazard assessments on coastal areas.In addition,we undertake comparative analysis on the characteristics of the Earth’s oscillation excited by the 2004 Sumatra-Andaman,2008 Wenchuan,and 2011Tohoku earthquakes that incorporate the effect of the Earth’s gravitational potential.A comparison of the amplitude spectra of the numerical records indicates that energy released by the three big earthquakes is different.Our comparative analysis realizes that the computing results can accurately reproduce some eigenfrequencies of the Earth,such as toroidal modes 0T2 to 0T13and spheroidal modes 0S7 to 0S31.These results demonstrate that numerical simulations can be successfully used to investigate the Earth’s oscillations.We propose that numerical simulations can be used as one of the major tools to further reveal how the Earth’s lateral heterogeneities affect the Earth’s oscillations.展开更多
Cat vocal behavior, in particular, the vocal and social behavior of feral cats, is poorly understood, as are the differences between feral and fully domestic cats. The relationship between feral cat social and vocal b...Cat vocal behavior, in particular, the vocal and social behavior of feral cats, is poorly understood, as are the differences between feral and fully domestic cats. The relationship between feral cat social and vocal behavior is important because of the markedly different ecology of feral and domestic cats, and enhanced comprehension of the repertoire and potential information content of feral cat calls can provide both better understanding of the domestication and socialization process, and improved welfare for feral cats undergoing adoption. Previous studies have used conflicting classi- fication schemes for cat vocalizations, often relying on onomatopoeic or popular descriptions of call types （e.g., ＂miow＇）. We studied the vocalizations of 13 unaltered domestic cats that complied with our behavioral definition used to distinguish feral cats from domestic. A total of 71 acoustic units were extracted and visually analyzed for the construction of a hierarchical classification of vocal sounds, based on acoustic properties. We identified 3 major categories （tonal, pulse, and broadband） that further breakdown into 8 subcategories, and show a high degree of reliability when sounds are classified blindly by independent observers （Fleiss＇ Kappa K= 0.863）. Due to the limited behavioral contexts in this study, additional subcategories of cat vocalizations may be identified in the future, but our hierarchical classification system allows for the addition of new categories and new subcategories as they are described. This study shows that cat vocalizations are diverse and complex, and provides an objective and reliable classification system that can be used in future studies.展开更多
文摘Floating photovoltaic systems installed in water bodies such as natural lakes or dams reservoirs, have attracted increased worldwide attention since 2011 and have already been deployed in several countries, including Japan, South Korea and USA. In Brazil, pilot-projects were announced in the reservoirs of hydroelectric power plants of Balbina （State of Amazonas） and Sobradinho （State of Bahia）. Several advantages, not necessarily valid in Brazil, are mentioned for deploying this kind of technology, such as an increase in energy generation, reduction of water losses through evaporation, low environmental impact, no occupation of land etc. In this article, several of these allegations are analyzed preliminarily under the Brazilian point of view, and relevant considerations are presented. It is concluded that the technical and economic advantages of floating photovoltaic systems are not yet clear in Brazil and that pilot projects, such as those under way, should be used to clarify several important aspects related to them.
文摘The traveling wave reactor （TWR） is a once-through reactor that uses in situ breeding to greatly reduce the need for enrichment and reprocessing. Breeding converts incoming subcritical reload fuel into new critical fuel, allowing a breed-burn wave to propagate. The concept works on the basis that breed-burn waves and the fuel move relative to one another. Thus either the fuel or the waves may move relative to the stationary observer. The most practical embodiments of the TWR involve moving the fuel while keeping the nuclear reactions in one place-sometimes referred to as the standing wave reactor （SWR）. TWRs can operate with uranium reload fuels including totally depleted uranium, natural uranium, and low-enriched fuel （e.g., 5.5% 23sU and below）, which ordinarily would not be critical in a fast spectrum. Spent light water reactor （LWR） fuel may also serve as TWR reload fuel. In each of these cases, very efficient fuel usage and significant reduction of waste volumes are achieved without the need for re- processing. The ultimate advantages of the TWR are realized when the reload fuel is depleted uranium, where after the startup period, no enrichment facilities are needed to sustain the first reactor and a chain of successor reactors. TerraPower＇s conceptual and engineering design and associated technolo- gy development activities have been underway since late 2006, with over 50 institutions working in a highly coordinated effort to place the first unit in operation by 2026. This paper summarizes the TWR technology： its development program, its progress, and an analysis of its social and economic benefits.
文摘AIM: To investigate the use of the Gaumard's Noelle S550.100 Maternal and Neonatal Simulators for teaching forceps delivery.METHODS: Twenty two(n = 22) resident physicians were enrolled in a simulation course on operative forceps deliveries. The physicians enrolled in the course were all part of an accredited Obstetrics and Gynecology residency program and ranged in their training from post graduate year(PGY) 1-4. Each participant received simulation based teaching on the indications, contraindications, proper application, delivery and removal of forceps by a single teacher. The Gaumard's simulator and Simpson forceps were used for this course. Statistical analysis using SPSS statistical software was performed after the completion of the simulation training program. A paired student t-test was performed to compare the cohort's mean pretest and post simulation training scores. Follow up skills assessment scores at one month, 3 mo and 6 mo were compared to thebaseline pretest score using a paired student t-test. RESULTS: There was statistically significant improvement in the post simulation training performance evaluations compared to the pretest, 13.7(SD = 3.14) vs 7.9(SD = 4.92), P < 0.05. Scores at 1 mo, 3 mo, and 6 mo were compared to the pretest score and showed retention of skills: 4.6(SD = 5.5, 95%CI: 2.21-7.07), 4.4(SD = 5.2, 95%CI: 2.13-6.70), and 5.6(SD = 4.8, 95%CI: 3.53-7.75) points, respectively. There were statistically significant differences between residents by post graduate training year on pretest scores, however these differences were not present after simulation training. Pretest scores for PGY 1, 2, 3, 4 were 3.5(SD = 2.27, 95%CI: 2.13-5.00), 7.25(SD = 6.70, 95%CI: 1.50-13.00), 10.75(SD = 1.5, 95%CI: 9.50-12.00), 12.17(SD = 2.57, 95%CI: 10.33-14.00). After simulation training PGY 1 residents did as well as well as the upper level residents. Posttest mean test scores for PGY 1, 2, 3, 4 were 13.75(SD = 1.49, 95%CI: 12.75-14.63), 10.25(SD = 0.24, 95%CI: 4.25-14.00), 15.00(SD = 1.16, 95%CI: 14.00-16.00), 15.17(SD = 0.75, 95%CI: 14.67-15.67). CONCLUSION: Our simulation based training program not only produced short term gains, but participants were able to retain the skills learned and demonstrate their knowledge months later.
文摘The Malaysian government＇s vision to be a developed nation by 2020 has pushed forward the use of innovative technologies in most sectors and industries, including the construction industry. Through the ETP （Economic Transformation Programme）, major projects launched are expected to provide a great catalyst for the economy, and may become the platform for increasing the use of automation and highly enhanced plants and machineries in the construction industry. Innovations in most countries are mostly driven by the need to find revolutionary solutions to problems, such as a shortage of skilled labor, decreasing quality of product and processes, inferior working conditions, declining productivity and increasing costs of labor and materials. Automation and robotics technologies encompass a wide range of innovative technologies using technologically advanced machineries to improve the speed and efficiency of a given process. This paper discusses the readiness of a developing country in embracing construction automation and robotics, by exploring industry perception, suggested practices and barriers to its implementation using a questionnaire survey and semi-structured interviews directed at Malaysian construction finns of contractors, specialist sub-contractors, developers and consultants. The findings show that the Malaysian construction industry is ready, to a certain extent, for implementing the technologies in limited areas such as prefabrication and assembly and in the design, planning and costing phases.
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.
基金supported by the National High Technology Research and Development Program (Grant No. 2010AA012402)the Ministry of Land and Resources Industry Fund (Grant No. SinoProbe-07)+1 种基金China Earthquake Administration Earthquake Industry-Scientific Research Fund (Grant No. 200808077)the Open Foundation of State Key Laboratory of Earthquake Dynamics.
文摘Giant earthquakes generate rich signals that can be used to explore the characteristics of the hierarchical structure of the Earth’s interior associated with the eigenfrequencies of the Earth.We employ the spectral element method,incorporated with large-scale parallel computing technology,to investigate the characteristics of global seismic wave propagation excited by the2011 Mw9.0 Tohoku earthquake.The transversely isotropic PREM model is employed as a prototype of our numerical global Earth model.Topographic data and the effect of the oceans are taken into consideration.Wave propagation processes are simulated by solving three-dimensional elastic wave governing equations with the seismic moment tensor obtained from the Global Centroid Moment Tensor Catalog.Three-dimensional visualization of our computing results displays the nature of the global seismic wave propagation.Comparative analysis of our calculations with observations obtained from the Incorporated Research Institutions for Seismology demonstrates the reliability and feasibility of our numerical results.We compare synthetic seismograms with incorporated and unincorporated ocean models.First results show that the oceans have obvious effects on the characteristics of seismic wave propagation.The peak displacement and peak velocity of P waves become relatively small under the effect of the ocean.However,the effect of the ocean on S-waves is complex.The displacement and velocity of S waves decrease rapidly over time using an unincorporated ocean model.Therefore,the effects of the ocean should be incorporated when undertaking quantitative earthquake hazard assessments on coastal areas.In addition,we undertake comparative analysis on the characteristics of the Earth’s oscillation excited by the 2004 Sumatra-Andaman,2008 Wenchuan,and 2011Tohoku earthquakes that incorporate the effect of the Earth’s gravitational potential.A comparison of the amplitude spectra of the numerical records indicates that energy released by the three big earthquakes is different.Our comparative analysis realizes that the computing results can accurately reproduce some eigenfrequencies of the Earth,such as toroidal modes 0T2 to 0T13and spheroidal modes 0S7 to 0S31.These results demonstrate that numerical simulations can be successfully used to investigate the Earth’s oscillations.We propose that numerical simulations can be used as one of the major tools to further reveal how the Earth’s lateral heterogeneities affect the Earth’s oscillations.
文摘Cat vocal behavior, in particular, the vocal and social behavior of feral cats, is poorly understood, as are the differences between feral and fully domestic cats. The relationship between feral cat social and vocal behavior is important because of the markedly different ecology of feral and domestic cats, and enhanced comprehension of the repertoire and potential information content of feral cat calls can provide both better understanding of the domestication and socialization process, and improved welfare for feral cats undergoing adoption. Previous studies have used conflicting classi- fication schemes for cat vocalizations, often relying on onomatopoeic or popular descriptions of call types （e.g., ＂miow＇）. We studied the vocalizations of 13 unaltered domestic cats that complied with our behavioral definition used to distinguish feral cats from domestic. A total of 71 acoustic units were extracted and visually analyzed for the construction of a hierarchical classification of vocal sounds, based on acoustic properties. We identified 3 major categories （tonal, pulse, and broadband） that further breakdown into 8 subcategories, and show a high degree of reliability when sounds are classified blindly by independent observers （Fleiss＇ Kappa K= 0.863）. Due to the limited behavioral contexts in this study, additional subcategories of cat vocalizations may be identified in the future, but our hierarchical classification system allows for the addition of new categories and new subcategories as they are described. This study shows that cat vocalizations are diverse and complex, and provides an objective and reliable classification system that can be used in future studies.
