Viability analysis of using cellulose pulp recycled from cement sacks in the production of compressed earth blocks

This study concerns the development and analysis of the Kraftterra composite – raw earth stabilized with disperse fibers made with kraft paper from recycled cement sacks – for the production of CEBs and mortar for masonry infill elements. Its main goal is to define the behavior of small walls (prisms) of Kraftterra in relation to diagonal compression. The tests show that the prisms produced with Kraftterra CEBs and mortar show excellent bond strength between block and mortar. All the prisms tested presented fissure lines very close to the normal load line and the fissures occurred in the blocks and in the mortar in similar manner, without separation between these elements. The mortar produced with Kraftterra results in strong bonds between blocks and produces homogeneous construction elements with uniform performance, that is, with high monolithicity

KRAFTTERRA composite: Performance analysis of compressed earth blocks with and without cellulose pulp deriving from cement sacks recycling

This study presents part of the results of an experimental campaign on the mechanical behaviour of Kraftterra composite. This research was developed as a framework of collaboration between the University of Brasilia, in Brazil, and the University of Aveiro, in Portugal. The objective of this study involves the development and the performance evaluation of compressed earthen blocks for the construction incorporating recycled cement sacks. Research’s main goal is the hypothesis verification that the cellulose pulp that stem from cement sacks can be used to improve the characteristics, and particularly the mechanical properties, of the blocks with soil as raw material. This paper presents the Kraftterra mixture and production processes, as well as the performance analysis of compressed earth blocks – CEBs – produced with Kraftterra regarding the compressive strength

The Cuspy LINER Nucleus of the S0/a Galaxy NGC 2681

The nucleus of the bulge-dominated, multiply-barred S0/a galaxy NGC 2681 is studied in detail, using high resolution Hubble Space Telescope FOC and NICMOS imaging and FOS spectroscopy. The ionised gas central velocity dispersion is found to increase by a factor ~2 when narrowing the aperture from R~1.5" (ground) to R~0.1" (FOS). Dynamical modeling of these velocity dispersions suggests that NGC 2681 does host a supermassive black hole (BH) for which one can estimate a firm mass upper limit M_BH < 6*10^7 Solar Masses. This upper limit is consistent with the relation between the central BH mass and velocity dispersion M_BH - sigma known for other galaxies. The emission line ratios place the nucleus of NGC 2681 among LINERs. It is likely that the emission line region comes from a rather mild, but steady, feeding of gas to the central BH in this galaxy. The inner stellar population lacks any measurable color gradient (to a radius of 0.6 kpc) from the infrared to the ultraviolet, consistently with FOC, FOS and IUE data, all indicating that this system underwent a starburst ~1 Gyr ago that encompassed its whole interior, down to its very center. The most likely source of such a widely-distributed starburst is the dumping of tidally-extruded gas from a galaxy neighbor. If so, then NGC 2681 can be considered as the older brother of M82, seen face-on as opposed to the edge-on view we have for M82.Comment: 25 pages, LaTeX, with 10 PostScript figures, to appear in The Astrophysical Journa

Evaluation of performance under fire of compressed earth blocks

In this paper are presented and discussed the main results of fire resistance tests on walls made of soil-cement and Kraftterra compressed earth blocks (CEB). Within this research it was intended to evaluate the fire resistance of walls made with CEB, with and without cellulose pulp incorporation deriving from recycling of cement sacks. Firstly, it is described the Kraftterra production processes and the fire resistance test campaign. Then, the performance of the blocks under analysis in terms of fire resistance is compared

Galaxy evolution in nearby groups. II. Galaxy evolution in nearby loose groups. II. Photometric and kinematic characterization of USGC U268 and USGC U376 group members in the Leo cloud

We present the photometric and kinematic characterization of two groups, USGC U268 and USGC U376 located in different regions of the Leo cloud. U268, composed of 10 catalogued members and 11 new added members, has a small fraction (~24%) of early-type galaxies (ETGs). U376 has 16 plus 8 new added members, with ~38% of ETGs. We find the presence of significant substructures in both groups suggesting that they are likely accreting galaxies. U268 is located in a more loose environment than U376. For each member galaxy, broad band integrated and surface photometry have been obtained in far-UV and near-UV with GALEX, and in u,g, r, i, z (SDSS) bands. H_alpha imaging and 2D high resolution kinematical data have been obtained using PUMA Scanning Fabry-Perot interferometer at the 2.12 m telescope in San Pedro M\'artir, (Baja California, M\'exico). We improved the galaxy classification and we detected morphological and kinematical distortions that may be connected to either on-going and/or past interaction/accretion events or environmental induced secular evolution. U268 appears more active than U376, with a large fraction of galaxies showing interaction signatures (60% vs. 13%). The presence of bars among late-type galaxies is ~10% in U268 and ~$29% in U376. The cumulative distribution of (FUV - NUV) colours of galaxies in U268 is significantly different than that in U376 with galaxies in U268 bluer than those in U376. In the (FUV-r vs. M_r) and (NUV-r vs. M_r) planes no members of U268 are found in the `red sequence', even early-type galaxies lie in the `blue sequence' or in the `green valley'. Most (80%) of the early-type members in U376 inhabits the `red sequence, a large fraction of galaxies, of different morphological types, are located in the `green valley', while the `blue sequence' is under-populated with respect to U268.Comment: 27 pages, 11 figures, 8 tables, accepted for publication in MNRAS (abridged abstract

Dusty Nuclear Disks and Filaments in Early Type Galaxies

We examine the dust properties of a nearby distance-limited sample of early type galaxies using the WFPC2 of the Hubble Space Telescope. Dust is detected in 29 out of 67 galaxies (43%), including 12 with small nuclear dusty disks. In a separate sample of 40 galaxies biased for the detection of dust by virtue of their detection in the IRAS 100 micron band, dust is found in ~78% of the galaxies, 15 of which contain dusty disks. In those galaxies with detectable dust, the apparent mass of the dust correlates with radio and far infrared luminosity, becoming more significant for systems with filamentary dust. A majority of IRAS and radio detections are also associated with dusty galaxies rather than dustless galaxies. This indicates that thermal emission from clumpy, filamentary dust is the main source of the far-IR radiation in early type galaxies. Dust in small disk-like morphology tends to be well aligned with the major axis of the host galaxies, while filamentary dust appears to be more randomly distributed with no preference for alignment with any major galactic structure. This suggests that, if the dusty disks and filaments have a common origin, the dust originates externally and requires time to dynamically relax and settle in the galaxy potential in the form of compact disks. More galaxies with visible dust than without dust display emission lines, indicative of ionized gas, although such nuclear activity does not show a preference for dusty disk over filamentary dust. There appears to be a weak relationship between the mass of the dusty disks and central velocity dispersion of the galaxy, suggesting a connection with a similar recently recognized relationship between the latter and the black hole mass.Comment: 17 pages, including 10 figures & 7 tables, to be published in the Astronomical Journa

Star formation and figure rotation in the early-type galaxy NGC2974

We present Galaxy Evolution Explorer (GALEX) far (FUV) and near (NUV) ultraviolet imaging of the nearby early-type galaxy NGC2974, along with complementary ground-based optical imaging. In the ultraviolet, the galaxy reveals a central spheroid-like component and a newly discovered complete outer ring of radius 6.2kpc, with suggestions of another partial ring at an even larger radius. Blue FUV-NUV and UV-optical colours are observed in the centre of the galaxy and from the outer ring outward, suggesting young stellar populations (< 1Gyr) and recent star formation in both locations. This is supported by a simple stellar population model which assumes two bursts of star formation, allowing us to constrain the age, mass fraction and surface mass density of the young component pixel by pixel. Overall, the mass fraction of the young component appears to be just under 1per cent (lower limit, uncorrected for dust extinction). The additional presence of a nuclear and an inner ring (radii 1.4 and 2.9kpc, respectively), as traced by [OIII] emission, suggests ring formation through resonances. All three rings are consistent with a single pattern speed of $78\pm6$ km/s/kpc, typical of S0 galaxies and only marginally slower than expected for a fast bar if traced by a small observed surface brightness plateau. This thus suggests that star formation and morphological evolution in NGC2974 at the present epoch are primarily driven by a rotating asymmetry (probably a large-scale bar), despite the standard classification of NGC2974 as an E4 elliptical.Comment: 13 pages, 10 figures, Changed content, Accepted for publication in MNRA

The Cool ISM in S0 Galaxies. I. A Survey of Molecular Gas

Lenticular galaxies remain remarkably mysterious as a class. Observations to date have not led to any broad consensus about their origins, properties and evolution, though they are often thought to have formed in one big burst of star formation early in the history of the Universe, and to have evolved relatively passively since then. In that picture, current theory predicts that stellar evolution returns substantial quantities of gas to the interstellar medium; most is ejected from the galaxy, but significant amounts of cool gas might be retained. Past searches for that material, though, have provided unclear results. We present results from a survey of molecular gas in a volume-limited sample of field S0 galaxies, selected from the Nearby Galaxies Catalog. CO emission is detected from 78 percent of the sample galaxies. We find that the molecular gas is almost always located inside the central few kiloparses of a lenticular galaxy, meaning that in general it is more centrally concentrated than in spirals. We combine our data with HI observations from the literature to determine the total masses of cool and cold gas. Curiously, we find that, across a wide range of luminosity, the most gas rich galaxies have about 10 percent of the total amount of gas ever returned by their stars. That result is difficult to understand within the context of either monolithic or hierarchical models of evolution of the interstellar medium.Comment: 26 pages of text, 15 pages of tables, 10 figures. Accepted for publication in the Astrophysical Journa

The Herschel Virgo Cluster Survey: VI. The far-infrared view of M87

The origin of the far-infrared emission from the nearby radio galaxy M87 remains a matter of debate. Some studies find evidence of a far-infrared excess due to thermal dust emission, whereas others propose that the far-infrared emission can be explained by synchrotron emission without the need for an additional dust emission component. We present Herschel PACS and SPIRE observations of M87, taken as part of the science demonstration phase observations of the Herschel Virgo Cluster Survey. We compare these data with a synchrotron model based on mid-infrared, far-infrared, submm and radio data from the literature to investigate the origin of the far-infrared emission. Both the integrated SED and the Herschel surface brightness maps are adequately explained by synchrotron emission. At odds with previous claims, we find no evidence of a diffuse dust component in M87, which is not unexpected in the harsh X-ray environment of this radio galaxy sitting at the core of the Virgo Cluster.Comment: Letter accepted for publication in A&A (Herschel special issue

AGB Connection and Ultraviolet Luminosity Excess in Elliptical Galaxies

Relying on infrared surface brightness fluctuactions to trace AGB properties in a sample of elliptical galaxies in the Virgo and Fornax clusters, we assess the puzzling origin of the "UV-upturn" phenomenon, recently traced down to the presence of a hot horizontal branch stellar component. We find that the UV-upturn actually signals a profound change in the c-m diagram of stellar populations in elliptical galaxies, involving both the hot stellar component and red-giant evolution.Comment: 13 pages & 13 figures -- To appear in the Astrophysical Journal (Sep '08 issue). Further info on SBF models at http://www.bo.astro.it/~eps/home.htm