1,361 research outputs found
Being Opposite. On the translation of antikeimena in Aristotle's De anima
The main concern of this article is the interpretation of De Anima II.4 415a14-23, and the
particular way by which it is generally translated by modern editors.
Almost all modern translations adopt the two locutions - \emph{objects} and \emph{correlative objects} - to translate the Greek word \antikeimena.
But this choice is not neutral, nor it is without consequences for the
understanding of the text
Gaia Data Release 1. Cross-match with external catalogues - Algorithm and results
Although the Gaia catalogue on its own will be a very powerful tool, it is
the combination of this highly accurate archive with other archives that will
truly open up amazing possibilities for astronomical research. The advanced
interoperation of archives is based on cross-matching, leaving the user with
the feeling of working with one single data archive. The data retrieval should
work not only across data archives, but also across wavelength domains. The
first step for seamless data access is the computation of the cross-match
between Gaia and external surveys. The matching of astronomical catalogues is a
complex and challenging problem both scientifically and technologically
(especially when matching large surveys like Gaia). We describe the cross-match
algorithm used to pre-compute the match of Gaia Data Release 1 (DR1) with a
selected list of large publicly available optical and IR surveys. The overall
principles of the adopted cross-match algorithm are outlined. Details are given
on the developed algorithm, including the methods used to account for position
errors, proper motions, and environment; to define the neighbours; and to
define the figure of merit used to select the most probable counterpart.
Statistics on the results are also given. The results of the cross-match are
part of the official Gaia DR1 catalogue.Comment: 18 pages, 8 figures. Accepted for publication by A&
Studying the evolution of AGB stars in the Gaia epoch
We present asymptotic giant branch (AGB) models of solar metallicity, to
allow the interpretation of observations of Galactic AGB stars, whose distances
should be soon available after the first release of the Gaia catalogue. We find
an abrupt change in the AGB physical and chemical properties, occurring at the
threshold mass to ignite hot bottom burning,i.e. . Stars with
mass below reach the C-star stage and eject into the
interstellar medium gas enriched in carbon , nitrogen and . The higher
mass counterparts evolve at large luminosities, between and . The mass expelled from the massive AGB stars
shows the imprinting of proton-capture nucleosynthesis, with considerable
production of nitrogen and sodium and destruction of and . The
comparison with the most recent results from other research groups are
discussed, to evaluate the robustness of the present findings. Finally, we
compare the models with recent observations of galactic AGB stars, outlining
the possibility offered by Gaia to shed new light on the evolution properties
of this class of objects.Comment: 21 pages, 11 figure, 3 tables, accepted for publication in MNRAS
(2016 July 11
Avalanche boron fusion by laser picosecond block ignition with magnetic trapping for clean and economic reactor
After the very long consideration of the ideal energy source by fusion of the
protons of light hydrogen with the boron isotope 11 (boron fusion HB11) the
very first two independent measurements of very high reaction gains by lasers
basically opens a fundamental breakthrough. The non-thermal plasma block
ignition with extremely high power laser pulses above petawatt of picosecond
duration in combination with up to ten kilotesla magnetic fields for trapping
has to be combined to use the measured high gains as proof of an avalanche
reaction for an environmentally clean, low cost and lasting energy source as
potential option against global warming. The unique HB11 avalanche reaction is
are now based on elastic collisions of helium nuclei (alpha particles) limited
only to a reactor for controlled fusion energy during a very short time within
a very small volume.Comment: 11 pages, 6 figures, Submitted to Proceedings 2nd Symposium High
Power Laser Science and Engineering, 14-18 MARCH 2016, Suzhou/Chin
Investigating halo substructures with annual modulation signature
Galaxy hierarchical formation theories, numerical simulations, the discovery
of the Sagittarius Dwarf Elliptical Galaxy (SagDEG) in 1994 and more recent
investigations suggest that the dark halo of the Milky Way can have a rich
phenomenology containing non thermalized substructures. In the present
preliminary study, we investigate the case of the SagDEG (the best known
satellite galaxy in the Milky Way crossing the solar neighbourhood) analyzing
the consequences of its dark matter stream contribution to the galactic halo on
the basis of the DAMA/NaI annual modulation data. The present analysis is
restricted to some WIMP candidates and to some of the astrophysical, nuclear
and particle Physics scenarios. Other candidates such as e.g. the light bosonic
ones, we discussed elsewhere, and other non thermalized substructures are not
yet addressed here.Comment: 17 pages, 10 figures, to appear in Eur. Phys. J.
Molecular mechanisms of photosensitization induced by drugs XIV: Two different behaviours in the photochemistry and photosensitization of antibacterials containing a fluoroquinolone like chromophore
This paper deals with the photosensitizing activity of FLQs towards two different biosubstrates, membrane and DNA. Thein vitrophototoxic activity of these drugsvs.DNA presents peculiar features with respect to thatvs.membranes, probably due to a specific binding of the drugs to the double helix and to the operativeness of different photosensitization mechanisms with the two types of biosubstrates. A description of the UVA photochemistry and the photosensitizing properties of two significant examples in the FLQ family is reported. The investigated compounds are Enoxacin, 1-ethyl-6-fluoro-1,4-dihydro-4- oxo-7-[1-piperazinyl]-1,8-naphtyridine-3-carboxilic acid and Rufloxacin, 9-fluoro-2,3-dihydro-10-4´-methyl- 1´-piperazinyl-7-oxo-7H-pyrido[1,2,3−de]-1,4-benzothiazine-6-carboxylic acid
Techno-economic assessment of SEWGS technology when applied to integrated steel-plant for CO2 emission mitigation
Mitigation of CO2 emissions in the industrial sector is one of the main climate challenges for the coming decades. This work, carried out within the STEPWISE H2020 project, performs a preliminary techno-economic assessment of the Sorption Enhanced Water Gas Shift (SEWGS) technology when integrated into the iron and steel plant to mitigate CO2 emissions. The SEWGS separates the CO2 from the iron and steel off-gases with residual energy content (i.e. Blast Furnace Gas, Basic Oxygen Furnace Gas and Coke Oven Gas) and the produced H2 is sent to the power generation section to produce the electricity required by the steel plant, while the CO2 is compressed and transported for storage. Detailed mass and energy balances are performed together with a SEWGS cost estimation to assess the energy penalty and additional costs related to CO2 capture. Results demonstrates the potential of SEWGS to capture over 80 % of CO2 in the off-gases, which results in entire plant CO2 emission reduction of 40 % with a Specific Energy Consumptions for CO2 Avoided (SPECCA) around 1.9 MJ/kgCO2. SEWGS outperforms a commercial amine scrubbing technology which has a SPECCA of 2.5 MJ/kgCO2 and only 20 % of CO2 avoided. The cost of CO2 avoided calculated on the basis of a fully integrated steel plant is around 33 €/tCO2 compared to 38 €/tCO2 of the amine technology
- …