4,240 research outputs found
Reactor Searches for Neutrino Magnetic Moment as a Probe of Extra Dimensions
We present calculations of the magnetic moment contribution to neutrino
electron scattering in large extra dimension brane-bulk models (LED) with three
bulk neutrinos. We discuss the cases with two and three large extra dimensions
of sizes . The calculations are done using reactor flux from Uranium,
as the neutrino source. We find that if the electron neutrino mass is
chosen to be in the range of one eV, the differential cross section for
scattering for low electron recoil energy can be of the same
order as the presently explored values in reactor experiments. Furthermore the
spectral shape for the LED models is different from the four dimensional case.
Future higher precision reactor experiments can therefore be used to provide
new constraints on a class of large extra dimension theories.Comment: 8 pages; 3 figure
Resilient Wide-Area Damping Control Using GrHDP to Tolerate Communication Failures
This paper proposes a goal representation heuristic dynamic programming (GrHDP)-based resilient wide-area damping controller (WADC) for voltage source converter high voltage direct current (VSC-HVDC) employing redundant wide-area signals as input signals to tolerate communication failure. A supervisory fuzzy logic module is proposed and added in the resilient WADC to adjust the learning rate of GrHDP online when encountering communication failure. Moreover, the resilient WADC does not need the accurate model of the power system and has the adaptability to the variation of operation conditions and communication failures. Case studies are conducted in a 10-machine 39-bus system with one VSC-HVDC transmission line. Simulation results show that the resilient WADC can counteract the negative impact of communication failures on control performance under a wide range of system operating conditions
Energy Saving and Carbon Reduction in the Operation Stage of Cross Laminated Timber Residential Buildings in China
This paper focused on energy consumption and carbon emission for heating and cooling
during a building’s operation stage, and examined the energy effects of using Cross Laminated
Timber (CLT) as an alternative building material to reinforced concrete (RC) in China’s 31 key cities
located in different climate zones. The authors designed two seven-story residential buildings, which
were constructed with RC framed and CLT systems, separately. This was followed by simulating the
energy consumption using commercialized software IESTM under the different climate zones and
calculating the carbon emissions. Comparisons were made between RC and CLT systems buildings
on the basis of simulation data. The results show that the estimated energy consumption and carbon
emission in CLT buildings are much lower than that of RC buildings in all studied cities, which
indicates that CLT systems have good potential in reducing carbon emission and saving energy
consumption compared to RC. The energy consumptions and carbon emissions in both concrete and
CLT buildings are closely related to the climate zones. Buildings in Severe Cold and Cold Regions
consumed the most energy and released more carbon. At the national level, the estimated energy
consumption at the operation stage, in the studied building with RC frames and CLT system was
approximately 465.1 MJ/m2 and 332.6 MJ/m2 per annum, respectively. Despite vast differences in
China’s climate zones, the effects of energy saving and carbon reduction potentials of CLT buildings
show little relationship to the climate zone. CLT buildings may result in a weighted 29.4% energy
saving, which equals 24.6% carbon reductions, compared with RC buildings at the operation stage at
national level, although it may vary in different climate zones
Relationship between leaf physiologic traits and canopy color indices during the leaf expansion period in an oak forest
© The Author(s), 2015. This article is distributed under the terms of the Creative Commons Attribution License. The definitive version was published in Ecosphere 6, no. 12 (2015): 1-9, doi:10.1890/ES14-00452.1.Plant phenology has a significant impact on the forest ecosystem carbon balance. Detecting plant phenology by capturing the time-series canopy images through digital camera has become popular in recent years. However, the relationship between color indices derived from camera images and plant physiological characters are elusive during the growing season in temperate ecosystems. We collected continuous images of forest canopy, leaf size, leaf area index (LAI) and leaf chlorophyll measured by a soil plant analysis development (SPAD) analyzer in a northern subtropical oak forest in China. Our results show that (1) the spring peak of color indices, Gcc (Green Chromatic Coordinates) and ExG (Excess Green), was 18 days earlier than the 90% maximum SPAD value; (2) the 90% maximum SPAD value coincided with the change point of Gcc and ExG immediately after their spring peak; and (3) the spring curves of Gcc and ExG before their peaks were highly synchronous with the expansion of leaf size and the development of LAI value. We suggest it needs to be adjusted if camera-derived Gcc or ExG is used as a proxy of chlorophyll or gross primary productivity, and images observation should be complemented with field phenological and physiological information to interpret the physiological meaning of leaf seasonality.This research was funded by the Priority Academic Program Development of Jiangsu Higher Education Institutions in the Discipline of Environmental Science and Engineering at Nanjing Forest University, Changjiang River Delta Urban Forest Ecosystem Research of CFERN (to H. Hu) and Brown University Seed Funds for International Research Projects on the Environment (to J. Tang)
Use of parenteral caffeinum natrio-benzoicum: an underestimated risk factor for HCV transmission in China
Research on Issues Related to Virtual Reality Representation in Online Shopping System –Experimental Study on Spatial Location Relations among Objects Based on Visual Attention Theory
This article has studied influences of three factors namely flashing (FF), consistency (CF) and distance (DF) to spatial location array of commodity objects in online shopping system. The findings show that reaction time (RT) of subjects in still representation is shorter than that in live representation; faster in the setting of being inconsistency between commodities and their text description than that of being consistency; in the condition of both Flashing (FSH) level and Consistency (CON) level, Un-flashing (UNFSH) level and Inconsistency (INCON) level, subjects RT in the setting of commodity object being farther from its description is shorter than that in being near. The research finds no discrepancies that three factors have any impact on subjects’ accuracy rate. Further analysis finds that physical distance of commodities plays a major role in affecting spatial location array of objects, while conceptual distance ranks on the second place. Location-based visual attention has the biggest impact on spatial location relation of virtual reality setting, and object-based visual attention plays a second largest impact. The impact would be highly impressive when either physical distant or conceptual distance is conformed to experiences in real life, Singleton detection mode will play a role at the situation when coincidence of the said phenomenon and real life experience is less, which means distinct flashing (FSH) will lead to better effect at this particular situation, otherwise it is worse
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