930 research outputs found
Recycling of Water Treatment Plant Waste for Production of Soil-Cement Bricks
AbstractThe water treatment plants generate large amounts of municipal sludge that must be discarded. A crucial issue is to find an ecological destination for its final disposal. This work studies the possibility of incorporating water treatment plant waste into soil-cement bricks for civil construction. A sample of this waste material was analyzed for chemical composition, X-ray diffraction, particle size, plasticity, and organic matter. Mixtures of soil-cement containing up to 5wt.% of waste as a partial substitute of soil were pressed and cured for 28 days. The effects of the incorporation of the water treatment plant waste were determined by evaluating different physical properties such as compressive strength, apparent density, and water absorption. The results indicated that the water treatment plant waste is a plastic material composed mainly of kaolinite particles. The results also showed that the water treatment plant waste could be used for production of soil-cement bricks, helping to reduce the environmental impacts of the water treatment plants
Anisotropy of the space orientation of radio sources. I: The catalog
A catalog of the extended extragalactic radio sources consisting of 10461
objects is compiled based on the list of radio sources of the FIRST survey. A
total of 1801 objects are identified with galaxies and quasars of the SDSS
survey and the Veron-Veron catalog. The distribution of the position angles of
the axes of radio sources from the catalog is determined, and the probability
that this distribution is equiprobable is shown to be less then 10^(-7). This
result implies that at Z equal to or smaller then 0.5, spatial orientation of
the axes of radio sources is anisotropic at a statistically significant level.Comment: 8 pages, 7 figure
Glued laminated timber beams reinforced with sisal fibres
The current appeal for sustainable building materials has expanded the use of timber in construction. However, due to timber be a raw material, natural defects are present, what reduce its strength capacity and cause, in particular, brittle failures in the tensile region of timber beams. In order to increase the mechanical properties of these beams, fibre reinforcement can be applied. In this context, natural fibres, such as Sisal fibres, already used in various fields of construction, are an alternative for reinforcement of timber structural elements, by taking into account their adequate mechanical properties and, in special, for low-mechanical resistance wood species, such as Pinu sp, a species used widely in timber construction. This paper deals with an experimental analysis glued laminated timber beams (Glulam) of Pinus sp species, reinforced by Sisal fibres. Bending tests were performed on six beams with the following dimensions, 53 mm-width by 180 mm-height by 3000 mm-length, which were prepared with eight lamellas by 8 mm-thickness. These beams were reinforced with Sisal strips that were glued by Epoxy adhesive on the bottom part of these beams. In addition, comparisons of result with non-reinforced Glulam were carried out. From the analyses of the experimental results, a decrease of 20 to 30% for the normal stresses, 5 to 10% for the shear stresses and 8 to 12 % for the displacements in relation to non-reinforced beams were verified8439039
VV124 (UGC4879): A new transitional dwarf galaxy in the periphery of the Local Group
We present the first resolved-star photometry of VV124 (UGC4879) and find
that this is the most isolated dwarf galaxy in the periphery of the Local
Group. Based on imaging and spectroscopic follow up observations with the 6m
BTA telescope, we resolve VV124 into 1560 stars down to the limiting magnitude
levels of V~25.6 and I~23.9. The young blue stellar populations and emission
gas are found near the core, but noticeably displaced from the center of the
galaxy as traced by dominant evolved red stars. The mean radial velocity
derived from the spectra of two Blue Supergiant stars, an HII region and
unresolved continuum sources is -80+/-10 km/s. The evolved ``red tangle''
stellar populations, which contains the red giant branch (RGB), are identified
at large galactocentric radii. We use the I-band luminosity function to
determine the distance based on the Tip of RGB method, 1.1+/-0.1 Mpc. This is
~10 times closer than the values usually assumed in the literature, and we
provide revised distance dependent parameters. From the mean (V-I) color of the
RGB, we estimate the mean metallicity as [Fe/H]~-1.37 dex. Despite of its
isolated location, the properties of VV124 are clearly not those of a galaxy in
formation, but rather similar to a transitional dIrr/dSph type.Comment: 4 pages, submitted to MNRAS Letter
The statistical properties of galaxy morphological types in compact groups of Main galaxies from the SDSS Data Release 4
In order to explore the statistical properties of galaxy morphological types
in compact groups (CGs), we construct a random group sample which has the same
distributions of redshift and number of member galaxies as those of the CG
sample. It turns out that the proportion of early-type galaxies in different
redshift bins for the CG sample is statistically higher than that for random
group sample, and with growing redshift z this kind of difference becomes more
significant. This may be due to the existence of interactions and mergers
within a significant fraction of SDSS CGs. We also compare statistical results
of CGs with those of more compact groups and pairs, but do not observe as large
statistical difference as Hickson (1982)'results.Comment: 12 pages, 9 figure
Getting Better Intestinal Health through the Addition of Yeast (Saccharomyces Cerevisiae) Combined with Threonine in Broilers Diets
The aim was to evaluate the association of Saccharomyces cerevisiae (Sc) with Threonine (T) in broiler diets, on performance, carcass quality and gut histomorphometric variables. One hundred Ross male broilers (1 to 43 days old) were distributed into four treatments. D1: commercial type, plus 5 g Sc/Kg food, D2: D1 plus 15% T, D3: D1 plus 30% T, D4: D1 plus 45% T. Performance productive were measured as Average Daily Weight Gain (ADWG) (g/broiler/day), Average Daily Consumption Feed (ADCF) (g/broiler/day) and Feed Conversion Ratio (FCR). Carcass quality was determined as Breast Weight (BW) (g), Thigh Weight (TW) (g) and Abdominal Fat Weight (AFW) (g). In gut were measured: Villus Height (VH) (”), Crypt Depth (CD) (”) and VH/CD Ratio. Results: BW and TW increased and AFW decreased in D3 and D4 groups (p ? 0.05). In gut, all groups received T decreased VH/CD Ratio (p ? 0.05) and increased goblet cells number producing higher mucus. Conclusion: Sc associate with T increased carcass quality of broiler through a healthy gut, that could be generated by more mature epithelia that enhancing absorptive function through the efficient use of nutrient and increasing protective function through mucosal hypersecretion by increased goblet cell number
Effect Of Ion Irradiation On The Structural Properties And Hardness Of A-c:h:si:o:f Films
Amorphous carbon-based thin films, a-C:H:Si:O:F, were obtained by plasma immersion ion implantation and deposition (PIIID) from mixtures of hexamethyldisiloxane, sulfur hexafluoride and argon. For PIIID the sample holder was biased with negative 25 kV pulses at 60 Hz. The main system parameter was the proportion of SF6 in the reactor feed, R-SF. To allow comparison to growth without intentional ion implantation, some films were also grown by plasma enhanced chemical vapor deposition (PECVD). The objectives were to investigate the effects of fluorine incorporation and ion implantation on the film's chemical structure, and principally on the surface contact angle, hardness and friction coefficient. Infrared and X-ray photo-electron spectroscopic analyses revealed that the films are essentially amorphous and polymer-like, and that fluorine is incorporated for any non-zero value of R-SF. Choice of R-SF influences film composition and structure but ion implantation also plays a role. Depending on R-SF, hydrophilic or hydrophobic films may be produced. Ion implantation is beneficial while fluorine incorporation is detrimental to hardness. For ion implanted films the friction coefficient falls about one third as R-SF is increased from 0 to 60%. Films prepared by PIIID without fluorine incorporation present fairly low friction coefficients and hardnesses greater than those of conventional polymers.59
Double Bars, Inner Disks, and Nuclear Rings in Early-Type Disk Galaxies
We present results from an imaging survey of an unbiased sample of
thirty-eight early-type (S0--Sa), low-inclination, optically barred galaxies in
the field. Our goal was to find and characterize central stellar and gaseous
structures: secondary bars, inner disks, and nuclear rings. Bars inside bars
are surprisingly common: at least one quarter of the sample galaxies (possibly
as many as 40%) are double-barred, with no preference for Hubble type or the
strength of the primary bar. A typical secondary bar is ~12% of the size of its
primary bar and 240--750 pc in radius. We see no significant effect of
secondary bars on nuclear activity. We also find kiloparsec-scale inner disks
in at least 20% of our sample, almost exclusively in S0 galaxies. These disks
are on average 20% the size of their host bar, and show a wider range of
relative sizes than do secondary bars. Nuclear rings are present in about a
third of our sample. Most are dusty, sites of current or recent star formation,
or both; such rings are preferentially found in Sa galaxies. Three S0 galaxies
(15% of the S0's) appear to have purely stellar nuclear rings, with no evidence
for dust or recent star formation. The fact that these central stellar
structures are so common indicates that the inner regions of early-type barred
galaxies typically contain dynamically cool and disklike structures. This is
especially true for S0 galaxies, where secondary bars, inner disks, and/or
stellar nuclear rings are present at least two thirds of the time. (abridged)Comment: LaTeX, 15 pages, 7 EPS figures; to appear in The Astronomical Journal
(July 2002
Effect of ion irradiation on the structural properties and hardness of A-C:H:SI:O:F films
Amorphous carbon-based thin films, a-C:H:Si:O:F, were obtained by plasma immersion ion implantation and deposition (PIIID) from mixtures of hexamethyldisiloxane, sulfur hexafluoride and argon. For PIIID the sample holder was biased with negative 25 kV pulses at 60 Hz. The main system parameter was the proportion of SF6 in the reactor feed, R-SF. To allow comparison to growth without intentional ion implantation, some films were also grown by plasma enhanced chemical vapor deposition (PECVD). The objectives were to investigate the effects of fluorine incorporation and ion implantation on the film's chemical structure, and principally on the surface contact angle, hardness and friction coefficient. Infrared and X-ray photo-electron spectroscopic analyses revealed that the films are essentially amorphous and polymer-like, and that fluorine is incorporated for any non-zero value of R-SF. Choice of R-SF influences film composition and structure but ion implantation also plays a role. Depending on R-SF, hydrophilic or hydrophobic films may be produced. Ion implantation is beneficial while fluorine incorporation is detrimental to hardness. For ion implanted films the friction coefficient falls about one third as R-SF is increased from 0 to 60%. Films prepared by PIIID without fluorine incorporation present fairly low friction coefficients and hardnesses greater than those of conventional polymers59115th Latin American Workshop on Plasma Physics (LAWPP) / 21st IAEA TM on Research Using Small Fusion Devices (RUSFD)2014-01COSTA RICAUniv Nacl Costa Rica, Instituto Tecnologico Costa Rica; Ad Astra Rocket Co; Int Atom Energy AgcySan Jos
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