10 research outputs found
ACTIVITIES OF THE ITA WORKING GROUP ON SPRAYED CONCRETE USE
This paper describes the activities of the International Tunnelling and Underground Space Association (ITA) Working Group 12 on Sprayed Concrete Use. The Working Group has carried out tasks with the purpose of promoting information exchange between National Groups and planning, coordinating and releasing the results of testing programs in order to advance the state-of-the-art of sprayed concrete use for underground support. The intention of the Working Group is to explore and develop the idea that the rational use of sprayed concrete improves possibilities for design and construction of new underground works
APPLICATION OF BLENDED CEMENT IN SHOTCRETE TO
The application of blended cements in shotcrete is investigated to reduce the environmental burden. Reduction of the environmental burden and meeting the required properties of quick setting and strength development are achieved using blended cements with blast furnace slag and a powder accelerator with a main component of calcium sulfo-aluminate. The powder accelerator is hydro-reactive and promotes quick setting and strength development in shotcrete. The reduced environmental burden of shotcrete with blended cement and powder accelerator are calculated
石炭灰原粉高含有吹付けコンクリートのフレッシュ特性と強度発現特性
金沢大学大学院自然科学研究科環境創成金沢大学工学
Combined Pre-Supernova Alert System with Kamland and Super-Kamiokande
International audiencePreceding a core-collapse supernova, various processes produce an increasing amount of neutrinos of all flavors characterized by mounting energies from the interior of massive stars. Among them, the electron antineutrinos are potentially detectable by terrestrial neutrino experiments such as KamLAND and Super-Kamiokande via inverse beta decay interactions. Once these pre-supernova neutrinos are observed, an early warning of the upcoming core-collapse supernova can be provided. In light of this, KamLAND and Super-Kamiokande have been monitoring pre-supernova neutrinos since 2015 and 2021, respectively. Recently, we performed a joint study between KamLAND and Super-Kamiokande on pre-supernova neutrino detection. A pre-supernova alert system combining the KamLAND detector and the Super-Kamiokande detector is developed and put into operation, which can provide a supernova alert to the astrophysics community. Fully leveraging the complementary properties of these two detectors, the combined alert is expected to resolve a pre-supernova neutrino signal from a 15 M star within 510 pc of the Earth, at a significance level corresponding to a false alarm rate of no more than 1 per century. For a Betelgeuse-like model with optimistic parameters, it can provide early warnings up to 12 hours in advance
Combined Pre-Supernova Alert System with Kamland and Super-Kamiokande
International audiencePreceding a core-collapse supernova, various processes produce an increasing amount of neutrinos of all flavors characterized by mounting energies from the interior of massive stars. Among them, the electron antineutrinos are potentially detectable by terrestrial neutrino experiments such as KamLAND and Super-Kamiokande via inverse beta decay interactions. Once these pre-supernova neutrinos are observed, an early warning of the upcoming core-collapse supernova can be provided. In light of this, KamLAND and Super-Kamiokande have been monitoring pre-supernova neutrinos since 2015 and 2021, respectively. Recently, we performed a joint study between KamLAND and Super-Kamiokande on pre-supernova neutrino detection. A pre-supernova alert system combining the KamLAND detector and the Super-Kamiokande detector is developed and put into operation, which can provide a supernova alert to the astrophysics community. Fully leveraging the complementary properties of these two detectors, the combined alert is expected to resolve a pre-supernova neutrino signal from a 15 M star within 510 pc of the Earth, at a significance level corresponding to a false alarm rate of no more than 1 per century. For a Betelgeuse-like model with optimistic parameters, it can provide early warnings up to 12 hours in advance