Prospects for future very high-energy gamma-ray sky survey: impact of secondary gamma rays

Very high-energy gamma-ray measurements of distant blazars can be well explained by secondary gamma rays emitted by cascades induced by ultra-high-energy cosmic rays. The secondary gamma rays will enable one to detect a large number of blazars with future ground based gamma-ray telescopes such as Cherenkov Telescope Array (CTA). We show that the secondary emission process will allow CTA to detect 100, 130, 150, 87, and 8 blazars above 30 GeV, 100 GeV, 300 GeV, 1 TeV, and 10 TeV, respectively, up to $z\sim8$ assuming the intergalactic magnetic field (IGMF) strength $B=10^{-17}$ G and an unbiased all sky survey with 0.5 hr exposure at each Field of View, where total observing time is $\sim540$ hr. These numbers will be 79, 96, 110, 63, and 6 up to $z\sim5$ in the case of $B=10^{-15}$ G. This large statistics of sources will be a clear evidence of the secondary gamma-ray scenarios and a new key to studying the IGMF statistically. We also find that a wider and shallower survey is favored to detect more and higher redshift sources even if we take into account secondary gamma rays.Comment: 8 pages, 3 figures, accepted for publication in Astroparticle Physic

Why environmental management must become the new normal (2/4)

MP4 Video; Duration: 1:45:42Please cite as: Scientific Advisory Group on Emergencies (SAGE), (2021). Why environmental management must become the new normal (2/4). [Online] Available at: http://hdl.handle.net/20.500.11911/213SAGE hosted a webinar series in partnership with ASSAf, SAYAS and INR on “Why environmental management must become the new normal”. The series aimed at raising awareness on the importance of emergency risk mitigation in the context of environmental management. The series sought to answer the following questions: 1. How can we prevent future pandemics and human-driven environmental emergencies? 2. How should we manage the environment in a more pro-active and integrated fashion? The second webinar focused on the following topics: 1. South Africa's National Healthy Eating Guidelines Sustainable Diets the People and the Planet. 2. Environmental Management as the New Normal: Towards a Framework for the Covid 19 Pandemic Analysis. 3. Investing in Ecological Infrastructure for Water Security. 4. Pathway towards Climate Mitigation and Resilience requires a Transdisciplinary Approach.SAGE is supported by the National Research Foundation (NRF) of South Africa, the Canadian International Development Research Centre (IDRC), the Swedish International Development Cooperation Agency (SIDA), the United Kingdom (UK) Department for International Development (DFID), UK Research and Innovation (UKRI) through the Newton Fund, South Africa’s Department of Science and Innovation (DSI), and Fonds de Recherche du Québec (FRQ)

Development of a composite prototype with GFRP profiles and sandwich panels used as a floor module of an emergency house

A series of experimental tests carried out on a composite prototype to be used as a floor module of an emergency house is presented in this paper. The prototype comprises a frame structure formed by GFRP pultruded profiles, and two sandwich panels constituted by GFRP skins and a polyurethane foam core that configures the floor slab. The present work is part of the project “ClickHouse – Development of a prefabricated emergency house prototype made of composites materials” and investigates the feasibility of the assemblage process of the prototype and performance to support load conditions typical of residential houses. Furthermore, sandwich panels are also independently tested, analysing their flexural response, failure mechanisms and creep behaviour. Obtained results confirm the good performance of the prototype to be used as floor module of an emergency housing, with a good mechanical behaviour and the capacity of being transported to the disaster areas in the form of various low weight segments, and rapidly installed. Additionally, finite element simulations were carried out to assess the stress distributions in the prototype components and to evaluate the global behaviour and load transfer mechanism of the connections.Quadro de Referência Estratégica Nacional (QREN)FEDER funds through the Operational Program for Competitiveness Factors – COMPETE and the Portuguese National Agency of Innovation (ADI) - project no. 3896

Measurement of ϒ production in pp collisions at √s = 2.76 TeV

The production of ϒ(1S), ϒ(2S) and ϒ(3S) mesons decaying into the dimuon final state is studied with the LHCb detector using a data sample corresponding to an integrated luminosity of 3.3 pb−1 collected in proton–proton collisions at a centre-of-mass energy of √s = 2.76 TeV. The differential production cross-sections times dimuon branching fractions are measured as functions of the ϒ transverse momentum and rapidity, over the ranges pT < 15 GeV/c and 2.0 < y < 4.5. The total cross-sections in this kinematic region, assuming unpolarised production, are measured to be σ (pp → ϒ(1S)X) × B ϒ(1S)→μ+μ− = 1.111 ± 0.043 ± 0.044 nb, σ (pp → ϒ(2S)X) × B ϒ(2S)→μ+μ− = 0.264 ± 0.023 ± 0.011 nb, σ (pp → ϒ(3S)X) × B ϒ(3S)→μ+μ− = 0.159 ± 0.020 ± 0.007 nb, where the first uncertainty is statistical and the second systematic