Implications of Fermi-LAT observations on the origin of IceCube neutrinos

The IceCube (IC) collaboration recently reported the detection of TeV-PeV extraterrestrial neutrinos whose origin is yet unknown. By the photon-neutrino connection in $pp$ and $p\gamma$ interactions, we use the \fermi-LAT observations to constrain the origin of the IC detected neutrinos. We find that Galactic origins, i.e., the diffuse Galactic neutrinos due to cosmic ray (CR) propagation in the Milky Way, and the neutrinos from the Galactic point sources, may not produce the IC neutrino flux, thus these neutrinos should be of extragalactic origin. Moreover, the extragalactic gamma-ray bursts (GRBs) may not account for the IC neutrino flux, the jets of active galactic nuclei may not produce the IC neutrino spectrum, but the starburst galaxies (SBGs) may be promising sources. As suggested by the consistency between the IC detected neutrino flux and the Waxman-Bahcall bound, GRBs in SBGs may be the sources of both the ultrahigh energy, $>10^{19}$eV, CRs and the $1-100$~PeV CRs that produce the IC detected TeV-PeV neutrinos.Comment: JCAP accepted version; 8 pages, 2 figs; discussion on blazar origin added; conclusion unchange

Origin of the GeV Emission During the X-ray Flaring Activity in GRB 100728A

Recently, Fermi-LAT detected GeV emission during the X-ray flaring activity in GRB 100728A. We study various scenarios for its origin. The hard spectrum of the GeV emission favors the external inverse-Compton origin in which X-ray flare photons are up-scattered by relativistic electrons in the external forward shock. This external IC scenario, with anisotropic scattering effect taken into account, can reproduce the temporal and spectral properties of the GeV emission in GRB 100728A.Comment: Minor revisions, 6 pages, 2 figures, accepted for publication in Ap

2-(3-Methyl-2-nitro­phen­yl)-4,5-dihydro-1,3-oxazole

In the title compound, C10H10N2O3, an inter­mediate in the synthesis of anthranilamide insecticides, all the non-H atoms except the nitro-group O atom lie on a crystallographic mirror plane. The H atoms of the methyl group are disordered over two sets of sites with equal occupancies. In the crystal structure, C—H⋯N links lead to chains of mol­ecules propagating in [100]

Impacts of CO2-brine-rock interaction on sealing efficiency of sand caprock: A case study of Shihezi formation in Ordos basin

Large anthropogenic emission of CO2 causes earth temperature becoming higher and higher, which may lead to the melting of glaciers, the rising of sea levels, extreme weather and so on. An effective way of reducing emissions is to capture and sequestrate CO2 while not giving up the fossil fuels. Caprock seal is critical for CO2 long term storage. CO2-brine-rock interaction will change minerals composition and pore structure of both reservoir and caprock. This paper analyzes the variation trend of porosity and permeability due to CO2-brine-rock interaction in caprock of Shihezi formation in Ordos basin, where TOUGHREACT is used as simulation tool. Geological data of numerical model are acquired from core samples. Simulations show that minerals interaction plays an important role on sealing efficiency of caprock. Overall, porosity and permeability of caprock decrease with CO2 sequestration, which indicates that main mineral reaction in caprock is precipitation, and caprock sealing efficiency is enhanced.Cited as: Liu, B., Fu, X., Li, Z. Impacts of CO2-brine-rock interaction on sealing efficiency of sand caprock: A case study of Shihezi formation in Ordos basin. Advances in Geo-Energy Research, 2018, 2(4): 380-392, doi: 10.26804/ager.2018.04.0