4,700 research outputs found
Performance analysis of PV modules of various technologies after more than one year of outdoor exposure in Rome
The paper deals with an extensive PV modules monitoring activity carried out at the outdoor
station ESTER of the University of Rome Tor Vergata. The purpose of the work was to
evaluate and compare the performances of PV silicon modules of polycrystalline and
amorphous technologies during a medium term outdoor exposure at optimized tilt angle, facing
south. Two PV modules, one polycrystalline by Kyocera and one double junction amorphous
by EPV Solar have been exposed since May 2009. A complete characterization of the weather
conditions at the site during the test has been performed and the most relevant parameters for
the performance comparison of the two technologies have been derived. In order to compare
different technologies and power productions, the energy Yield (Y) and Performance Ratio
(PR) for the two modules have been evaluated on a monthly and yearly basis. The typical
seasonal trend of PR has been observed for the polycrystalline module, essentially due to the
temperature influence on the module performances. For the EPV module, instead, a
degradation trend has been observed for the first months of operation. Subsequently a
significant recovery in the PR and energy production has been registered
Multiphase PC/PL Relations: Comparison between Theory and observations
Cepheids are fundamental objects astrophysically in that they hold the key to
a CMB independent estimate of Hubble's constant. A number of researchers have
pointed out the possibilities of breaking degeneracies between Omega_Matter and
H0 if there is a CMB independent distance scale accurate to a few percent (Hu
2005). Current uncertainties in the distance scale are about 10% but future
observations, with, for example, the JWST, will be capable of estimating H0 to
within a few percent. A crucial step in this process is the Cepheid PL
relation. Recent evidence has emerged that the PL relation, at least in optical
bands, is nonlinear and that neglect of such a nonlinearity can lead to errors
in estimating H0 of up to 2 percent. Hence it is important to critically
examine this possible nonlinearity both observationally and theoretically.
Existing PC/PL relations rely exclusively on evaluating these relations at mean
light. However, since such relations are the average of relations at different
phases. Here we report on recent attempts to compare theory and observation in
the multiphase PC/PL planes. We construct state of the art Cepheid pulsations
models appropriate for the LMC/Galaxy and compare the resulting PC/PL relations
as a function of phase with observations. For the LMC, the (V-I) period-color
relation at minimum light can have quite a narrow dispersion (0.2-0.3 mags) and
thus could be useful in placing constraints on models. At longer periods, the
models predict significantly redder (by about 0.2-0.3 mags) V-I colors. We
discuss possible reasons for this and also compare PL relations at various
phases of pulsation and find clear evidence in both theory and observations for
a nonlinear PL relation.Comment: 5 pages, 8 figures, proceeding for "Stellar Pulsation: Challenges for
Theory and Observation", Santa Fe 200
H-BIM – Innovative and Digital Tools to Improve the Management of the Existing Buildings
With the introduction of the BIM methodology, the digitalization is consolidating mostly the process of new building design defining new standardized working procedures in order to optimize the data flow. On the contrary, pertaining to existing buildings, the rules are still dictated by the traditional methodology leading to fragmented and disaggregated information flow. However, some tools have been recently developed and are quickly upgrading to meet the specific aim to pursue progress, dynamism and experimentation in order to stay in tune with market demands. One common issue, is due to the fact that the documents are paper, hard to find and numerous so that the digitalization represents the best real solution to improve their management.
In this regard, the heart of the informative flow is represented by the Common Data Environment (CDE), a cloud storage in which the documents are collected once uploaded and easily manageable with specific platforms. By way of example, a case study is developed in the paper in which the management process of the H-BIM of the XV century’s structure placed in the old town of Naples is carried out in a digital way, through the usBIM.platform (released by ACCA software company) using specific tools, like links, markers and tags. The goal of the paper is to define both a new organization for the data archive, in which the documents are structured and easily traceable, both a new way of conceiving the BIM model that it is thought as an informative vehicle and a key access to the information rather than a mere geometric representation
Influence of dietary conjugated linoleic acid (CLA) and L-Lysine on heavy pigs performances and meat quality
Conjugated linoleic acid (CLA) refers to a group of positional and geometric fatty acid isomers derived from linoleic acid. Dietary CLA supplementation has been shown to increase feed efficiency and may reduce body fat content in swine as recently reviewed by Corino et al., (2005). There was only one research conducted in heavy pig in which the authors did not observed any significant effect of dietary CLA on growth performances and lean tissue (Corino et al., 2003)
Efficacy and toxicity of bevacizumab in recurrent ovarian disease: an update meta-analysis on phase III trials
Background: To analyze the efficacy and toxicity of bevacizumab on survival outcomes in recurrent ovarian cancer.
Results: Bevacizumab was associated with significant improvement of PFS and OS compared with standard treatment with HRs of 0.53 (95% CI 0.44 - 0.63; p < 0.00001) and 0.87 (95% CI, 0.77 to 0.99; p = 0.03), respectively.
Bevacizumab increased the incidence of G3/G4 hypertension (RR 19.01, 95% CI 7.77 - 46.55; p < 0.00001), proteinuria (RR 17.31, 95% CI 5.42 - 55.25; p < 0.00001), arterial thromboembolic events (ATE) (RR 4.99, 95% CI 1.29 - 19.27; p = 0.02) and bleeding (RR 3.14, 95% CI 1.35 - 7.32; p = 0.008).
Materials and Methods: Three randomized phase III trials representing 1502 patients were identified.
Pooled hazard ratio (HR), odd ratio (OR), risk ratio (RR) with 95% confidence interval (CI) were calculated using fixed or random effects model.
Conclusions: Adding bevacizumab to standard chemotherapy improved ORR, PFS and OS, and it had a higher, but manageable, incidence of toxicities graded 3 to 4
Stellar Archaeology in the Galactic halo with the Ultra-Faint Dwarfs: VI. Ursa Major II
We present a B, V color-magnitude diagram (CMD) of the Milky Way dwarf
satellite Ursa Major II (UMa II), spanning the magnitude range from V ~ 15 to V
~ 23.5 mag and extending over a 18 {\times} 18 arcmin2 area centered on the
galaxy. Our photometry goes down to about 2 magnitudes below the galaxy's main
sequence turn-off, that we detected at V ~ 21.5 mag. We have discovered a
bona-fide RR Lyrae variable star in UMa II, which we use to estimate a
conservative dereddened distance modulus for the galaxy of (m-M)0 =
17.70{\pm}0.04{\pm}0.12 mag, where the first error accounts for the
uncertainties of the calibrated photometry, and the second reflects our lack of
information on the metallicity of the star. The corresponding distance to UMa
II is 34.7 {\pm} 0.6 ({\pm} 2.0) kpc. Our photometry shows evidence of a spread
in the galaxy subgiant branch, compatible with a spread in metal abundance in
the range between Z=0.0001 and Z=0.001. Based on our estimate of the distance,
a comparison of the fiducial lines of the Galactic globular clusters (GCs) M68
and M5 ([Fe/H]=-2.27 {\pm} 0.04 dex and -1.33 {\pm} 0.02 dex, respectively),
with the position on the CMD of spectroscopically confirmed galaxy members, may
suggest the existence of stellar populations of different metal abundance/age
in the central region of UMa II.Comment: To appear in Ap
Groups with many abelian subgroups
AbstractIt is known that a (generalized) soluble group whose proper subgroups are abelian is either abelian or finite, and finite minimal non-abelian groups are classified. Here we describe the structure of groups in which every subgroup of infinite index is abelian
A sensory study on loin quality from pigs slaughtered at 120 or 160 kg liveweight
Effects of different slaughter weights (160 vs. 120 kg) on chemical, physical and sensory characteristics of pig loin were investigated. Physical and chemical traits were similar for the two typologies of weight, whereas lower values of moisture (P<0.01) and higher fat content (P<0.05) were found in heavy pork loin; furthermore increased slaughter weight resulted in redder, more yellow and intensive colour (P<0.05). A selected and trained panel carried out difference from control test showing that heavy pig loin scored higher for appearance and taste parameters (P<0.05), but lower for tenderness (P<0.05). Heavy pig loin was redder, more marbling, wetter, sweeter, and saltier and had higher metallic flavour and lower tenderness
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