Results 21 to 30 of about 12,436,754 (287)
Frontiers in Earth Science, 2023 Different air pressures are used to conduct an impact test based on the split Hopkinson pressure bar (SHPB) test system to study the crack evolution process and energy dissipation law of the cemented rock under impact load.
Chang-Xing Zhu +3 more
doaj +1 more source
IS THERE EVIDENCE FOR DARK ENERGY EVOLUTION? [PDF]
The Astrophysical Journal, 2015 Recently, Sahni, Shafielo o & Starobinsky (2014) combined two independent measurements of $H(z)$ from BAO data with the value of the Hubble constant $H_0 = H(z=0)$, in order to test the cosmological constant hypothesis by means of an improved version of the $Om$ diagnostic.
Xuheng Ding +4 more
openaire +2 more sources
Applied Sciences, 2023 This paper presents two experimental schemes, graded cyclic loading and unloading, and variable lower limit cyclic loading and unloading, to investigate the energy evolution and acoustic emission characteristics of rocks under different cyclic loading ...
Zhushuai Wang +5 more
semanticscholar +1 more source
Energies, 2020 The exploitation of deep resources is necessary for human development. At the same time, high-stress environments that are deep underground bring about great challenges vis-à-vis resource exploitation.
Chun Yang +5 more
doaj +1 more source
The continuing evolution of Energy Policy
Energy Policy, 2020 As the world confronts the Covid-19 pandemic, we hope that all of you are doing well. We know that many lives have been greatly disrupted, and that world economic activity is slowing and maybe declining in some places. We have read reports that energy consumption has been greatly affected by the slowdown in world economic activity—likely contributing ...
Brown, Stephen P.A. +8 more
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Cosmological Evolution with Negative Energy Densities
Astrophysics, 2022 For general number of spatial dimensions we investigate the cosmological dynamics driven by a cosmological constant and by a source with barotropic equation of state. It is assumed that for both those sources the energy density can be either positive or negative. Exact solutions of the cosmological equations are provided for flat models.
Saharian, A. A. +5 more
openaire +2 more sources
Parametric and nonparametric methods hint dark energy evolution [PDF]
Physics of the Dark Universe, 2021 We study dark energy through the viewpoints of parametric and nonparametric analyses of late-time cosmological data. We consider four Hubble parameter priors reflecting the Hubble tension and make use of two phenomenological functions, namely, a ...
R. C. Bernardo +3 more
semanticscholar +1 more source
Applied Sciences, 2023 In many underground engineering projects, rocks are often subjected to cyclic loading and unloading, such as repeated excavation of roadway surrounding rock, which will lead to damage to underground rocks, and the energy of rocks also changes. Therefore,
Xiaoyu Lu +3 more
doaj +1 more source
Mechanical and Energy Evolution Characteristics of Sandstone under True Triaxial Cyclic Loading
Applied Sciences, 2023 To study the mechanical and energy evolution characteristics of sandstone under true triaxial cyclic loading, a sandstone mechanical test with different intermediate principal stress under true triaxial loading was conducted using the rock true triaxial ...
Chun-liang Dong +5 more
semanticscholar +1 more source
Uncorrelated Estimates of Dark Energy Evolution [PDF]
, 2004 Type Ia supernova data have recently become strong enough to enable, for the first time, constraints on the time variation of the dark energy density and its equation of state.
Cooray, Asantha, Huterer, Dragan
core +2 more sources