The central parsecs of M87: jet emission and an elusive accretion disc

We present the first simultaneous spectral energy distribution (SED) of M87 core at a scale of 0.4 arcsec ($\sim 32\, \rm{pc}$) across the electromagnetic spectrum. Two separate, quiescent, and active states are sampled that are characterized by a similar featureless SED of power-law form, and that are thus remarkably different from that of a canonical active galactic nuclei (AGN) or a radiatively inefficient accretion source. We show that the emission from a jet gives an excellent representation of the core of M87 core covering ten orders of magnitude in frequency for both the active and the quiescent phases. The inferred total jet power is, however, one to two orders of magnitude lower than the jet mechanical power reported in the literature. The maximum luminosity of a thin accretion disc allowed by the data yields an accretion rate of $< 6 \times 10^{-5}\, \rm{M_\odot \, yr^{-1}}$, assuming 10% efficiency. This power suffices to explain M87 radiative luminosity at the jet-frame, it is however two to three order of magnitude below that required to account for the jet's kinetic power. The simplest explanation is variability, which requires the core power of M87 to have been two to three orders of magnitude higher in the last 200 yr. Alternatively, an extra source of power may derive from black hole spin. Based on the strict upper limit on the accretion rate, such spin power extraction requires an efficiency an order of magnitude higher than predicted from magnetohydrodynamic simulations, currently in the few hundred per cent range.Comment: 18 pages, 6 figures. Accepted for publication in MNRA

Long- term effects of fire and three fire-fighting chemicals on a soil-plant system.

The impacts of fire and fire-fighting chemicals (FFC) on soil properties and the soil-plant system were evaluated five years after treatment application. Unburnt soils (US) were compared with burnt soils treated with water alone (BS) or with foaming agent (BS+Fo), Firesorb polymer (BS+Fi), or ammonium polyphosphate (BS+Ap). Soils (0-2 cm depth) and foliar material (Ulex micranthus, Pterospartum tridentatum, Erica umbellata and Pinus pinaster) were analysed for total-C, total-N, δ 15N, nutrients (soil-available; plant-total), pH and inorganic-N (soils) and vegetation cover and height. No long-term effects of FFC on soil properties were found except for pH (BS+Fo > BS+Ap), inorganic-N and P (BS+Ap > other treatments). BS+Ap plants usually showed higher values of δ 15N, N, P and Na, but less K. Soil coverage by Pterospartum and Ulex was higher in BS+Ap than in other treatments, while the opposite was observed for Erica; shrubs were always taller in BS+Ap. After 3 years of growth, the size of pine seedlings followed the order BS+Ap > US > other treatments. Foliar N and P, scrub regeneration and growth of pines showed the long-term fertilizing effect of ammonium polyphosphate, although the second highest pine mortality was found in the BS+Ap treatment. The foaming agent did not affect vegetation cover, and Firesorb had no noticeable effect on shrubs but the highest pine mortality.Peer reviewe

Alteraciones de la superficie del cuerpo vertebral en una población medieval de Logroño (s. XI y XII)

X Congreso Nacional de Paleopatología. Univesidad Autónoma de Madrid, septiembre de 200

Energy Analysis of Control Measures for Reducing Aerosol Transmission of COVID‐19 in the Tourism Sector of the “Costa Daurada” Spain

In this paper, the use of HVAC systems and non‐HVAC control measures to reduce virus-laden bioaerosol exposure in a highly occupied indoor space is investigated. A simulation tool was used to model the fate and transport of bioaerosols in an indoor space in the hotel industry (bar or pub) with three types of HVAC system (central air handling system (CAHS), dedicated outdoor air system (DOAS), and wall unit system (WUS)). Non‐HVAC control measures such as portable air cleaners (PAC) and local exhaust fans were considered. Occupant exposure was evaluated for 1 μm bioaerosols, which transport SARS‐CoV‐2, for 3 h/day of continuous source and exposure. The combined effects of ventilation (400 l/s of outdoor air), recirculated air filtration (90% efficacy), and a PAC with a capacity up to 900 m3/h mitigated the (normalized) integrated exposure of the occupant by 0.66 to 0.51 (CAHS) and 0.43 to 0.36 (DOAS). In the case of WUS, the normalized integrated exposure was reduced by up to 0.2 when the PAC with a capacity of up to 900 m3/h was used. The corresponding electricity consumed increased by 297.4 kWh/year (CAHS) and 482.7 kWh/year (DOAS), while for the WUS it increased by 197.1 kWh/year.The research work presented in this paper is the outcome of a project funded by Diputació de Tarragona under the collaboration framework agreement between the Diputació de Tarragona and the Universitat Rovira i Virgili for the period 2020–2023 with the reference number 2020/19: reference number 2020/19

Interest and Applicability of Meta-Heuristic Algorithms in the Electrical Parameter Identification of Multiphase Machines

Multiphase machines are complex multi-variable electro-mechanical systems that are receiving special attention from industry due to their better fault tolerance and power-per-phase splitting characteristics compared with conventional three-phase machines. Their utility and interest are restricted to the definition of high-performance controllers, which strongly depends on the knowledge of the electrical parameters used in the multiphase machine model. This work presents the proof-of-concept of a new method based on particle swarm optimization and standstill time-domain tests. This proposed method is tested to estimate the electrical parameters of a five-phase induction machine. A reduction of the estimation error higher than 2.5% is obtained compared with gradient-based approaches.Plan Estatal 2013-2016 Retos - Proyectos I+D+i DPI2013-44278-RPlan Estatal 2013-2016 Retos - Proyectos I+D+i DPI2016-76144-

MALDI_TOF mass spectrometry does not differentiate between brucella species, suggesting that the may represent a single species

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