812 research outputs found
Precompact noncompact reflexive abelian groups
We present a series of examples of precompact, noncompact, reflexive
topological Abelian groups. Some of them are pseudocompact or even countably
compact, but we show that there exist precompact non-pseudocompact reflexive
groups as well. It is also proved that every pseudocompact Abelian group is a
quotient of a reflexive pseudocompact group with respect to a closed reflexive
pseudocompact subgroup
Improved Search for Heavy Neutrinos in the Decay
A search for massive neutrinos has been made in the decay . No evidence was found for extra peaks in the positron energy spectrum
indicative of pion decays involving massive neutrinos (). Upper limits (90 \% C.L.) on the neutrino mixing matrix element
in the neutrino mass region 60--135 MeV/ were set, which are
%representing an order of magnitude improvement over previous results
Precision Measurement of the π+→e+νe Branching Ratio in the PIENU Experiment
The PIENU experiment at TRIUMF aims to measure the branching ratio of the pion decay modes Rπ=[π+→e+νe(γ)]/[π+→μ+νμ(γ)] with precision of <0.1%.
Precise measurement of RÏ€ provides a stringent test of electron-muon universality in weak interactions. The current status of the PIENU experiment and future prospects are presented
Status of the TRIUMF PIENU Experiment
The PIENU experiment at TRIUMF aims to measure the pion decay branching ratio
with precision % to provide a sensitive test of electron-muon
universality in weak interactions. The current status of the PIENU experiment
is presented.Comment: Talk presented CIPANP2015. 8 pages, LaTeX, 4 eps figure
Moored Vessel Station-Keeping in Ice-Infested Waters: An Assessment of Model Test Data for Various Structures and Ship Shapes
A wide range of ice model test data were assembled for the Kulluk, turret-moored drillships, semi-submersibles, and tankers or production vessels connected to loading terminals. These data were analyzed in combination to establish trends for sheet ice conditions and for broken ice conditions, with respect to ice concentration, thickness, and many other parameters.NRC publication: Ye
Assessment of post-tsunami disaster land use/land cover change and potential impact of future sea-level rise to low-lying coastal areas: A case study of Banda Aceh coast of Indonesia
© 2019 The objective of this study is to investigate the impact of the projected sea-level rise to the coastal land use/land cover (LULC) at a disaster-prone coastal area, encompassing an engineering time-scale, based on a couple of sea-level rise scenarios. We investigate the Banda Aceh coast, a low-lying coastal area vulnerable to multiple hazards such as tsunamis and co-seismic land subsidence, which is typical along the Indonesian coastlines. Three sets of multi-temporal Google Earth Engine images acquired in 2004 (pre-tsunami December 2004), 2011 and 2017 were utilized to obtain the areal coverage of various types of LULC. The scenarios of coastal inundation were pre-determined at elevation +1.0 m and +1.5 m projecting the sea-level rise in the next couple centuries. Aquaculture ponds, buildings and bare land are the top three most pre-dominant land covers in Banda Aceh coast. The finding of this study reveals that the aquaculture ponds are at the highest risk to the future sea-level rise, and potentially contribute to the unproductive seawater inundated area. The bare land which has a huge potential to be converted into settlement area (buildings, housing, etc.), experienced remarkable loss due to both future inundation scenarios. The coastal area of Banda Aceh in the next couple of centuries, thus, will be highly vulnerable to the projected sea-level rise, providing the fast-growing and ever-expanding built environment very close to the coastline. A sustainable coastal management taking into account the disaster risk should, therefore, be incorporated within the decision making for the protection of the coastal area
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