893 research outputs found
A new sample of bright galaxy pairs in UZC
We present a new sample of bright galaxy pairs extracted applying an
objective selection code to UZC catalog.The sample is volume limited to
M = -18.9 +5 log and contains 89 galaxy pairs.We analyze the
kinematical, morphological and photometrical properties of galaxies belonging
to this sample. We show that velocity separation, , between
pair members is significantly lower in spiral type (S+S) pairs than in
early-type (E+E) and mixed (E+S) pairs.This indicates that truly isolated
galaxy pairs are more likely to be found among S+S pairs. We show that
ellipticals are rare and underluminous in B and that late spirals (T 4)
are overluminous. We confirm that the formation of bright ellipticals is a
phenomenon linked to group/cluster environment, while galaxy-galaxy interaction
may enhance blue luminosity of disk galaxies through SF phenomena. This last
statement is supported by the presence of strong FIR emission from early
spirals in this sample and by the high frequency of AGN/SB phenomenon, revealed
mainly in pairs of low relative radial velocity separation and showing signs of
interaction.Comment: A & A accepted, 6 pages, 6 figure
Numerical assessment of integrated thermal management systems in electrified powertrains
Temperatures in internal combustion engines (ICE) impact fuel consumption and pollutant emissions, especially under transient operating conditions. In hybrid powertrains, where the reciprocating internal combustion engine has intermittent operating conditions, a optimum control of these temperatures is critical. In this work, a detailed methodology for studying integrated thermal management systems for hybrid propulsion system was presented. Both experimental measurements and 0D/1D models were implemented and validated for the different components of the hybrid vehicle powertrain. The novelty of this work consists in the extensive experimental measurements involved for the development of the different models, specially the ICE, in order to study the integration of the different thermal flows of a hybrid powertrain. Furthermore, the simulation methodology used in this work integrates different modelling tools and takes advantage of their strengths when compared to using a single modelling tool. Two different thermal management systems have been evaluated under different Real Driving Emission (RDE) cycles at two different temperatures (at 20 °C and -20 °C). Results have shown that during the ICE warming up, the integrated thermal management system improved energy consumption by 1.74% and 3% for warm and cold conditions, respectively. This was because, the integrated TMS allows to avoid the temperature drop of the ICE when the propulsive system is in pure electric mode. © 2022 Elsevier Lt
Selection and micropropagation of valuable caper genotypes
The high quality of the various biotypes present in the natural or cultivated state is one of the main features for caper production. Up to now, however, no selection activity has been carried out in order to identify the most suitable accessions for providing better quality products. In this paper, we report the first results of a selection of caper genotypes characterised by significant qualitative traits. A micropropagation protocol was evaluated in order to improve and allow the multiplication of the most promising Capparis spinosa L. subsp. spinosa genotypes, selected in Salina (Aeolian Islands), Sicily (Italy), in collaboration with the most important local growers
Studying the evolution of large-scale structure with the VIMOS-VLT Deep Survey
The VIMOS-VLT Deep Survey (VVDS) currently offers a unique combination of
depth, angular size and number of measured galaxies among surveys of the
distant Universe: ~ 11,000 spectra over 0.5 deg2 to I_{AB}=24 (VVDS-Deep),
35,000 spectra over ~ 7 deg2 to I_{AB}=22.5 (VVDS-Wide). The current ``First
Epoch'' data from VVDS-Deep already allow investigations of galaxy clustering
and its dependence on galaxy properties to be extended to redshifts ~1.2-1.5,
in addition to measuring accurately evolution in the properties of galaxies up
to z~4. This paper concentrates on the main results obtained so far on galaxy
clustering. Overall, L* galaxies at z~ 1.5 show a correlation length r_0=3.6\pm
0.7. As a consequence, the linear galaxy bias at fixed luminosity rises over
the same range from the value b~1 measured locally, to b=1.5 +/- 0.1. The
interplay of galaxy and structure evolution in producing this observation is
discussed in some detail. Galaxy clustering is found to depend on galaxy
luminosity also at z~ 1, but luminous galaxies at this redshift show a
significantly steeper small-scale correlation function than their z=0
counterparts. Finally, red galaxies remain more clustered than blue galaxies
out to similar redshifts, with a nearly constant relative bias among the two
classes, b_{rel}~1.4, despite the rather dramatic evolution of the
color-density relation over the same redshift range.Comment: 14 pages. Extended, combined version of two invited review papers
presented at: 1) XXVIth Astrophysics Moriond Meeting: "From Dark Halos to
Light", March 2006, proc. edited by L.Tresse, S. Maurogordato and J. Tran
Thanh Van (Editions Frontieres); 2) Vulcano Workshop 2006 "Frontier Objects
in Astrophysics and Particle Physics", May 2006, proc. edited by F.
Giovannelli & G. Mannocchi, Italian Physical Society (Editrice Compositori,
Bologna
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