Mikro- és mezopórusos katalizátorok alkalmazása glicerin reaktív desztillációjában

Mészáros, Szilvia

doi:10.14232/phd.1977

Cited by 2 publications

(2 citation statements)

References 116 publications

(178 reference statements)

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“…The sources of these neutrinos are currently unknown, but they appear to be extragalactic in origin [9][10][11]. Gammaray bursts (GRBs), energetic supernovae (SNe), active galactic nuclei (AGNs), starburst and star-forming galaxies, galaxy groups and clusters, as well as some Galactic sources have been proposed as potential candidates (see reviews [12][13][14]). In particular, GRBs, which are believed to be caused by ultra-relativistic jets launched by the collapse of a massive star (i.e.…”

Section: Introductionmentioning

confidence: 99%

Choked jets and low-luminosity gamma-ray bursts as hidden neutrino sources

2016

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We consider gamma-ray burst (GRB) jets that are choked by extended material as sources of high-energy cosmic neutrinos. We take into account the jet propagation physics both inside the progenitor star and the surrounding dense medium. Radiation constraints, which are relevant for high-energy neutrino production are considered as well. Efficient shock acceleration of cosmic rays is possible for sufficiently low-power jets and/or jets buried in a dense, extended wind or outer envelope. Such conditions also favor GRB jets to become stalled, and the necessary conditions for stalling are explicitly derived. Such choked jets may explain transrelativistic supernovae (SNe) and low-luminosity (LL) GRBs, giving a unified picture of GRBs and GRB-SNe. Focusing on this unified scenario for GRBs, we calculate the resulting neutrino spectra from choked jets including the relevant microphysical processes such as multipion production in pp and pγ interactions, as well as the energy losses of mesons and muons. We obtain diffuse neutrino spectra using the latest results for the luminosity function of LL GRBs. Although uncertainties are large, we confirm that LL GRBs can potentially give a significant contribution to the diffuse neutrino flux. Our results are consistent with the present IceCube data and do not violate the stacking limits on classical highluminosity GRBs. We find that high-energy neutrino production in choked jets is dominated by pγ interactions. These sources are dark in GeV-TeV gamma-rays, and do not contribute significantly to the Fermi diffuse gamma-ray background. Assuming stalled jets can launch a quasi-spherical shock in the dense medium, "precursor" TeV neutrinos emerging prior to the shock breakout gamma-ray emission can be used as smoking gun evidence for a choked jet model for LL GRBs. Our results strengthen the relevance of wide field-of-view sky monitors with better sensitivities in the 1−100 keV range.PACS numbers: 95.85. Ry, 97.60.Bw, 98.70.Rz

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Section: Introductionmentioning

confidence: 99%

Choked jets and low-luminosity gamma-ray bursts as hidden neutrino sources

2016

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“…Ezért a fejlesztés fő iránya egy korszerű, széles körben elterjedt informatikai környezetben elkészített, lokálistól a globális skáláig alkalmazható terjedési modell elkészítése volt. A témaválasztás szorosan kapcsolódott az ELTE Meteorológiai Tanszékén a TREX révén már évekkel korábban elkezdődött modellfejlesztési tevékenységhez, amibe hallgatóként 2009-ben én is bekapcsolódtam (Leelőssy et al, 2012;Mészáros et al, 2012bMészáros et al, , 2012c. Diákköri munkám részeként megismerkedhettem különböző skálájú terjedési modellekkel (Leelőssy, 2011(Leelőssy, , 2012a(Leelőssy, , 2012b, valamint a fukushimai balesetre vonatkozó terjedési szimulációkat is végeztem (Leelőssy et al, 2011a(Leelőssy et al, , 2011b.…”

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Szennyezőanyagok légköri koncentrációját előrejelző modellrendszer fejlesztése és alkalmazása

Leelőssy¹

2017

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Atmospheric dispersion models have become important tools for air pollution meteorology for the last decades. Based on meteorological data, these models can simulate the transmission of pollutants released from accidental or normal industrial processes, traffic and households, as well as deflation and evaporation. The scale of the dispersion process can range from local air pollution events to globally detectable nuclear accidents. Simulation of atmospheric dispersion on different scales requires different modeling approaches.The aim of this research is to develop an atmospheric dispersion model applicable on a wide range of scales. A regional-to-global scale Lagrangian particle dispersion model and a local scale plume model have been developed, which can be used with data from several numerical weather prediction systems.The main application of the Lagrangian model was the simulation of the global dispersion of radionuclides released from the Fukushima Nuclear Power Plant. Measurement data from several sites in the Northern Hemisphere provided a resource to validate model results and to reconstruct the dispersion process in each region.The developed dispersion models have been applied for recent cases in Hungary that reached large public interest. Our plume model was used to simulate the long-term spatial distribution of deflated industrial dust from the Budapest Chemical Works site for a period of thirteen years. Radioiodine release from the Institute of Isotopes in Budapest was simulated with our Lagrangian model to reveal model uncertainties in a complex weather situation with low-level inversion and wind shear.Our Gaussian and Lagrangian models can simulate the dispersion of passive tracers or toxic substances with a simple chemical mechanism. Development of the model allows the flexible adaptation for special needs of users and its integration into complex decision support software. Development and testing provided valuable experience for future applications to select and set up the best possible modeling tool for atmospheric dispersion problems.

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Mikro- és mezopórusos katalizátorok alkalmazása glicerin reaktív desztillációjában

Cited by 2 publications

References 116 publications

Choked jets and low-luminosity gamma-ray bursts as hidden neutrino sources

Choked jets and low-luminosity gamma-ray bursts as hidden neutrino sources

Szennyezőanyagok légköri koncentrációját előrejelző modellrendszer fejlesztése és alkalmazása

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