Abstract
The discovery (Fabbiano et al. 2001) of two active black holes in the Seyfert galaxy NGC 3393, which are separated by about 490 light years, has revealed a merging event. This has led us to ...look for other evidence of galaxy collision and merging, using an analysis of the observed spectra in different frequency ranges. In the narrow-line region (NLR) of NGC 3393, we have found pre-shock densities that are higher by a factor of about 10 than in other active galactic nuclei, and we have found patches of ionized matter beyond the observed NLR bulk. These can be explained by the compression and heating of the gas downstream of the shock waves created by the collision. Metallicity, in terms of the O/H relative abundance, is about 0.78 solar. The Mg/H depletion by a factor of about 3, compared with solar, cannot be explained by Mg trapping into dust grains, as a result of high shock velocities. The low O/H and Mg/H abundances indicate mixing with external matter during the collision. Twice solar N/H is predicted by modelling the spectra of high-shock-velocity clouds reached by a T
* ≤ 105 K blackbody flux. This suggests that Wolf-Rayet stars could be created by galaxy collision in the central region.
ABSTRACT
We employ MUSE/VLT data to study the ionized and highly ionized gas phases of the feedback in Circinus, the closest Seyfert 2 galaxy to us. The analysis of the nebular emission allowed us to ...detect a remarkable high-ionization gas outflow beyond the galaxy plane traced by the coronal lines Fe vii λ6089 and Fe x λ6374, extending up to 700 and 350 pc NW from the nucleus, respectively. This is the first time that the Fe x emission is observed at such distances from the central engine in an active galactic nucleus (AGN). The gas kinematics reveals expanding gas shells with velocities of a few hundred km s−1, spatially coincident with prominent hard X-ray emission detected by Chandra. Density and temperature sensitive line ratios show that the extended high-ionization gas is characterized by a temperature reaching 25 000 K and an electron density >102 cm−3. We found that local gas excitation by shocks produced by the passage of a radio jet leads to the spectacular high-ionization emission in this object. This hypothesis is fully supported by photoionization models that account for the combined effects of the central engine and shocks. They reproduce the observed emission line spectrum at different locations inside and outside of the NW ionization cone. The energetic outflow produced by the radio jet is spatially located close to an extended molecular outflow recently reported using ALMA which suggests that they both represent different phases of the same feedback process acting on the AGN.
The line and continuum spectra of the merger galaxy Arp 220 are analysed with the aim of investigating the ionizing and heating sources. We refer to radio, optical, infrared and X-ray spectra. The ...results show that in agreement with other merger galaxies, the optical lines are emitted from gas photoionized by the active galactic nucleus (AGN) and heated by the shocks in the extended narrow-line region (ENLR). The infrared lines are better explained by the emission from gas close to the starburst. The starburst dominates the infrared emission. O i and C i lines in the far-infrared are formed in the internal region of extended clouds and are therefore absorbed, while C ii lines are emitted from the external edges of outflowing clouds. The O/H relative abundances are about solar and N/H are higher than solar by a factor of ∼1.5, throughout the starburst region, while in the AGN ENLR the O/H ratio is half-solar. A relatively high dust-to-gas ratio is indicated by modelling the dust-reprocessed radiation peak consistently with bremsstrahlung emitted from the blackbody radiation-dominated clouds. The observed radio emission is thermal bremsstrahlung, while synchrotron radiation created by the Fermi mechanism at the shock front is absorbed.
Abstract
We have calculated the physical conditions throughout the merger Seyfert galaxy NGC 6240 by modelling the observed optical and infrared line ratios. We have found that the optical spectra ...are emitted by clouds photoionized by the power-law radiation flux from the active galactic nucleus/nuclei (AGN/AGNs), and heated mainly by the shock accompanying the propagation of the clouds outwards. The infrared line ratios are emitted from clouds ejected from a starburst which photoionizes the gas by the blackbody radiation flux corresponding to a stellar colour temperature of about 5 × 104 K. Both the flux from the AGN and the ionization parameters are low. The most characteristic physical parameters are the relatively high shock velocities (≥500 km s−1) and low pre-shock densities (∼40-60 cm−3) of the gas. The C/H, N/H, O/H relative abundances are higher than solar by a factor ≤1.5. We suggest that those relative abundances indicate trapping of H into H2 molecules rather than high metallicities. Adopting an initial grain radius of 1 μm, the dust temperatures calculated in the clouds reached by the power-law radiation and by the blackbody radiation are 81 and 68 K, respectively.
The observations of far-infrared line and continuum spectra throughout the Galactic Centre and in some regions of the disc are analysed in order to determine the physical conditions (densities, shock ...velocities, radiation parameters etc.) and the relative abundances of some elements (C, N and O). Consistent model calculations of the line and continuum spectra show that, although the radiation from the stars dominates, an active galactic nucleus (AGN) is clearly present, with a radiation maximum in the Sgr A* region. The models account for the coupled effect of photoionization and shocks. The flux, similar to that found in low-luminosity AGNs, is lower by a factor of ∼100 than that of AGN. Gas densities in the downstream line emission region range between 100 and 3000 cm−3, the shock velocities between 50 and 300 km s−1. Densities of ∼5 × 106 cm−3, close to the Sgr A* black hole, lead to self-absorption of free-free radiation in the radio frequency range, while X-ray data are explained by shock velocities of ∼3000 km s−1. A magnetic field of ∼10 −4 G shows relatively small fluctuations throughout the Galactic Centre. The dust-to-gas ratios range between 3 × 10−15 and ≤10−13 by number. Lower values are found far from the centre, suggesting that N and O, which are depleted from the gaseous phase, are included into molecules rather than trapped into grains.
The aim was to evaluate the analgesic efficacy and safety of the dexketoprofen/tramadol 25 mg/75 mg fixed-dose combination vs dexketoprofen (25 mg) and tramadol (100 mg) in moderate-to-severe acute ...pain after total hip arthroplasty.
This was a randomized, double-blind, parallel-group study in patients experiencing pain of at least moderate intensity on the day after surgery, compared with placebo at first administration to validate the pain model. The study drug was administered orally every 8 h throughout a 5 day period. Rescue medication, metamizole 500 mg, was available during the treatment period. The evaluation of efficacy was based on patient assessments of pain intensity and pain relief. The primary end point was the mean sum of the pain intensity difference values throughout the first 8 h (SPID8).
Overall, 641 patients, mean age 62 (range 29–80) yr, were analysed; mean (sd) values of SPID8 were 247 (157) for dexketoprofen/tramadol, 209 (155) for dexketoprofen, 205 (146) for tramadol, and 151 (159) for placebo. The primary analysis confirmed the superiority of the combination over dexketoprofen 25 mg (P+0.019; 95% confidence interval 6.4–73) and tramadol 100 mg (P+0.012; 95% confidence interval 9.5–76). The single components were superior to placebo (P<0.05), confirming model sensitivity. Most secondary analyses supported the superiority of the combination. The incidence of adverse drug reactions was low and similar among active treatment groups.
The efficacy results confirmed the superiority of dexketoprofen/tramadol over its single components, even at higher doses (tramadol), with a safety profile fully in line with that previously known for these agents in monotherapy.
EudraCT 2012-004548-31 (https://www.clinicaltrialsregister.eu/ctr-search/search?query=eudract_number:2012-004548-31);
ClinicalTrials.gov NCT01902134 (https://www.clinicaltrials.gov/ct2/show/NCT01902134?term=NCT01902134&rank=1).
This work aims to obtain recycled carbon fibre and develop an application for this new material. The carbon fibres were obtained by recycling aerospace prepreg waste via the pyrolysis process. The ...recycled fibres were combined with an Araldite LH5052/Aradur LY5053 epoxy resin/hardener system using manual lay-up and vacuum bagging processes. For comparison, the same resin/hardener system was used to produce a composite using commercial carbon fibre. The recycled and commercial composites were subjected to flexural, tensile and Mode I testing. Fracture aspects were analysed via scanning electron microscopy (SEM). The pyrolysis process did not affect the fibre surface as no degradation was observed. The fracture aspect showed a mixture of failure in the recycled composite laminate and interlaminar/translaminar failure near the surface of the commercial composite caused by flexural stress. Flexural and tensile tests showed a loss of mechanical strength due to the recycling process, but the tensile values were twice as high. The sand ladder platform was the project chosen for the development of a product made with recycled carbon fibres. The product was manufactured using the same manufacturing process as the specimens and tested with a 1243 kg car. The method chosen to design, manufacture and test the prototype sand ladder platform made of recycled carbon fibre was appropriate and gave satisfactory results in terms of high mechanical strength to bending and ease of use.
ABSTRACT
We study the ionized and highly ionized gas phases in the Seyfert 2 galaxy IC 5063 by means of the Very Large Telescope (VLT)/Multi-Unit Spectroscopic Explorer (MUSE) integral field ...spectroscopy. Our analysis allowed us to detect a high-ionization gas outflow traced by the coronal lines Fe vii λ6087 and Fe x λ6375. Both emissions are found to be extended. The former up to 1.2 kpc and 700 pc north-west (NW) and south-east (SE) from the nucleus, respectively. The latter reaches 700 pc NW of the nucleus. This is the first time that Fe x emission is observed at such distances from the central engine in an active galactic nucleus. The Fe vii λ6087 emission peaks at the nucleus, with two secondary peaks at the position of the NW and SE radio lobes. The gas kinematics is complex, with the coronal emission displaying split line profiles along the radio jet and line widths of several hundred km s−1. Velocity shifts of up to 600 km s−1 in excess of the systemic velocity of the galaxy are found very close to the radio lobes and along the jet propagation. The extended coronal gas is characterized by temperatures reaching 20 000 K and electron densities >102 cm−3, with the larger values associated with the regions of larger turbulence, likely due to the passage of the radio jet. This hypothesis is supported by photoionization models that combine the effects of the central engine and shocks. Our work highlights the strong relationship between extended coronal emission and the radio jet, with the former suitably tracing the latter, which in the case of IC 5063, propagates very close to the galaxy disc.
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•Frugivorous and nectarivorous bats have high islet density.•Insectivorous and hematophagous bats have low islet density.•Hematophagous bat has more α- than β-cell proportion per ...islet.•Carbohydrate-rich diets are associated with a high β/α-cells ratio.
Whether there is a relationship between bats' dietary patterns and evolutionary endocrine pancreas adaptation is not clearly understood. Aiming to contribute to this topic, we evaluated some metabolic and structural parameters in the following adult bats: the frugivorous Artibeus lituratus, the nectarivorous Anoura caudifer, the hematophagous Desmodus rotundus, and the insectivorous Molossus molossus. A. lituratus and A. caudifer diets consist of high amounts of simple carbohydrates, while D. rotundus and M. molossus diets consist of high amounts of proteins or protein and fat, respectively. In our results, A. lituratus and A. caudifer bats exhibited the highest values of relative islet mass (%), islet density (number of islets per pancreas area), and the lowest values of intestinal length among the four species. When adjusted by the body mass (mg/g of body mass), both D. rotundus and A. caudifer bats exhibited the highest islet mass values among the groups. Blood glucose was similar between A. lituratus, D. rotundus, and M. molossus, with the lowest values for the A. caudifer bats. M. molossus bats had the highest plasma cholesterol values among the studied species but exhibited similar plasma triacylglycerol with D. rotundus and A. caudifer bats. β- and α-cell distribution within A. lituratus, A. caudifer, and M. molossus islets achieved an approximate average value of ∼ 66% and ∼ 28%, respectively, a pattern inverted in D. rotundus islets (53% of α cells and 40% of β cells). A. caudifer and D. rotundus exhibited the highest and the lowest β/α-cells ratio per islet, respectively. We conclude that the macronutrient predominance in each bat-eating niche correlates with the morphophysiological pancreas features being the nectarivorous A. caudifer the species with the highest islet mass per body mass and β/α-cells ratio, while the hematophagous D. rotundus showed the highest α-cells apparatus.
Inconel 718 is a Ni superalloy with superior mechanical properties, even at high temperatures. However, due to its high hardness and low thermal conductivity, it is considered a difficult-to-machine ...material. This material is widely used in applications that require good dimensional stability, making the milling process the most used in machining this alloy. The wear resulting from this process and the quality of the machined surface are still challenging factors when it comes to Inconel 718. TiAlN-based coating has been used on cutting tools with Yttrium as a doping element to improve the process performance. Based on this, this work evaluated the machined surface integrity and wear resistance of cutting tools coated using Physical Vapor Deposition (PVD) HiPIMS with TiAlYN in the end milling of Inconel 718, varying the process parameters such as cutting speed (
), feed per tooth (
), and cutting length (
). It was verified that the
is the parameter that exerts the most significant influence since, even at small distances, Inconel 718 already generates high tool wear (TW). Furthermore, the main wear mechanisms were abrasive and adhesive wear, with the development of a built-up edge (BUE) under a125 m/min feed rate (
) and a
= 15 m. Chipping, cracking, and delamination of the coating were also observed, indicating a lack of adhesion between the coating and the substrate, suggesting the need for a good interlayer or the adjustment of the PVD parameters.
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