KCS34 evaluation for WHR in cement industry

The simple Kalina cycle system 34 (KCS34)- has been studied to perform energy cogeneration from the waste heat recovery (WHR) in preheater cement industries. The preheater available energy was considered from a 5000 tc/day cement production capacity. Thermodynamic and simplified exergoeconomic models were developed in the Engineering Equation Solver (EES) software. Several cycle thermodynamic parameters as ammonia-water mixture concentration and turbine operating pressure were wide-ranging in order to maximize the cycle thermal efficiency aiming to minimize the electricity generation cost. The temperature-entropy KCS34schematics were shown for different best results aiming to understand which set of parameters targets the maximum KCS34performance. The produced power, the thermal cycle efficiency, the exergetic efficiency and the exergoeconomic electricity specific cost were plotted for the different ranges of the independent parameters. The optimum results for a range specific investment price were presented. The main conclusions indicate that in the range of the studied parameters the turbine operating pressure caused a generated power variation greater than the ammonia-water mixture concentration in the KCS34performance. It was also possible to conclude that the KCS34is competitive with the existing electricity prices. In this case the KC proved to be applicable for WHR in the cement industry

Spectral analysis of the biharmonic operator subject to Neumann boundary conditions on dumbbell domains

We consider the biharmonic operator subject to homogeneous boundary conditions of Neumann type on a planar dumbbell domain which consists of two disjoint domains connected by a thin channel. We analyse the spectral behaviour of the operator, characterizing the limit of the eigenvalues and of the eigenprojections as the thickness of the channel goes to zero. In applications to linear elasticity, the fourth order operator under consideration is related to the deformation of a free elastic plate, a part of which shrinks to a segment. In contrast to what happens with the classical second order case, it turns out that the limiting equation is here distorted by a strange factor depending on a parameter which plays the role of the Poisson coefficient of the represented plate.Comment: To appear in "Integral Equations and Operator Theory

Study of Different Aging Conditions for Analysis of Microstructure and Mechanical Properties of F357 Alloy Fabricated in LPBF Printer

Aluminum F357 is a widely used material for casting in aerospace and additive manufacturing industry. Heat treatments are commonly applied to some aluminum alloys to modify its properties. With a further study on the aging and performance of the F357 with 3D printing technology, several industries benefit of this, military, automotive and aerospace are some examples, because the numerous components casted in service. This work presents mechanical properties of F357 specimens fabricated with EOS technology and subjected to heat treatments. Heat treatments conditions were applied to tensile specimens and tested. Furthermore, the specimens were subjected to artificial thermal aging for 100 h and 1000 h at two different temperatures (285 ºF and 350 ºF), and their mechanical properties were also determined. Finally, remarks on the comparison between the heat treatments and the effect of thermal aging on the microstructures and mechanical properties of the specimens will be presented.Mechanical Engineerin

Consideraciones microbiológicas y bioquímicas referentes al llamado hongo del té

Se describe la naturaleza microbiológica de una bebida fermentada obtenida a partir de infusiones edulcoradas de té. Los microorganismos predominantes en los cultivos obtenidos en Chile son Acetobacter xylinum, Sacchharomycodes ludwigii y Lactobacillus sp.Se compara la actividad biológica atribuida a esta bebida (obtenida por recopilación de la medicina popular) con su composición bioquímica y los datos científicos disponibles en literatura acerca de su actividad terapéutica comprobada

Genomes-based phylogeny of the genus Xanthomonas

<p>Abstract</p> <p>Background</p> <p>The genus <it>Xanthomonas </it>comprises several plant pathogenic bacteria affecting a wide range of hosts. Despite the economic, industrial and biological importance of <it>Xanthomonas</it>, the classification and phylogenetic relationships within the genus are still under active debate. Some of the relationships between pathovars and species have not been thoroughly clarified, with old pathovars becoming new species. A change in the genus name has been recently suggested for <it>Xanthomonas albilineans</it>, an early branching species currently located in this genus, but a thorough phylogenomic reconstruction would aid in solving these and other discrepancies in this genus.</p> <p>Results</p> <p>Here we report the results of the genome-wide analysis of DNA sequences from 989 orthologous groups from 17 <it>Xanthomonas </it>spp. genomes available to date, representing all major lineages within the genus. The phylogenetic and computational analyses used in this study have been automated in a Perl package designated Unus, which provides a framework for phylogenomic analyses which can be applied to other datasets at the genomic level. Unus can also be easily incorporated into other phylogenomic pipelines.</p> <p>Conclusions</p> <p>Our phylogeny agrees with previous phylogenetic topologies on the genus, but revealed that the genomes of <it>Xanthomonas citri </it>and <it>Xanthomonas fuscans </it>belong to the same species, and that of <it>Xanthomonas albilineans </it>is basal to the joint clade of <it>Xanthomonas </it>and <it>Xylella fastidiosa</it>. Genome reduction was identified in the species <it>Xanthomonas vasicola </it>in addition to the previously identified reduction in <it>Xanthomonas albilineans</it>. Lateral gene transfer was also observed in two gene clusters.</p

Viewing the Steklov eigenvalues of the Laplace operator as critical Neumann eigenvalues

We consider the Steklov eigenvalues of the Laplace operator as limiting Neumann eigenvalues in a problem of boundary mass concentration. We discuss the asymptotic behavior of the Neumann eigenvalues in a ball and we deduce that the Steklov eigenvalues minimize the Neumann eigenvalues. Moreover, we study the dependence of the eigenvalues of the Steklov problem upon perturbation of the mass density and show that the Steklov eigenvalues violates a maximum principle in spectral optimization problems.Comment: This is a preprint version of a paper that will appear in the Proceedings of the 9th ISAAC Congress, Krak\'ow 201

Análisis preliminar de los efectos causados por la exposición al herbicida glifosato roundup en testículo de neonatos de caiman yacare

El presente estudio aporta datos preliminares acerca de las alteraciones testiculares en neonatos de Caiman yacare expuestos al herbicida glifosato (Roundup®) durante el desarrollo embrionario. Para tal estudio se colectaron nidos de huevos de yacaré, se trasladaron al laboratorio y luego se dividieron los huevos en tres grupos para comenzar con el ensayo de toxicidad: un primer grupo como control con agua corriente, un segundo grupo experimental tratado con 250 μg/huevo de dicho herbicida y un tercer grupo experimental tratado con 1000 μg/huevo del herbicida. Los huevos se incubaron a 33ºC de temperatura hasta la eclosión y luego se procesaron los testículos para realizar el análisis histológico. Los neonatos del grupo control presentaron túbulos seminíferos bien definidos, con espermatogonias y células de Sertoli, rodeados por la membrana basal. El tejido intersticial consistió en células de Leydig y abundantes capilares sanguíneos. Por otro lado, los neonatos de los grupos expuestos a 250 y 1000 μg/egg del herbicida presentaron alteraciones a nivel de los túbulos seminíferos, como ser desorganización del epitelio germinal y la membrana basal pobremente definida. Si bien estos resultados son preliminares demuestran que existen alteraciones a nivel gonadal posiblemente causadas por la exposición al herbicidaFil: Delssin, Andrea R.. Universidad Nacional del Nordeste. Facultad de Ciencias AgrariasFil: Arrieta, M. Belén. Universidad Nacional del Nordeste. Facultad de Ciencias AgrariasFil: Alvarez, B. Beatriz. Universidad Nacional del Nordeste. Facultad de Ciencias AgrariasFil: Siroski, Pablo A.. Universidad Nacional del NordesteFil: Lombardo, Daniel M.. Universidad Nacional del Nordest

Detection of variable VHE gamma-ray emission from the extra-galactic gamma-ray binary LMC P3

Context. Recently, the high-energy (HE, 0.1-100 GeV) $\gamma$-ray emission from the object LMC P3 in the Large Magellanic Cloud (LMC) has been discovered to be modulated with a 10.3-day period, making it the first extra-galactic $\gamma$-ray binary. Aims. This work aims at the detection of very-high-energy (VHE, >100 GeV) $\gamma$-ray emission and the search for modulation of the VHE signal with the orbital period of the binary system. Methods. LMC P3 has been observed with the High Energy Stereoscopic System (H.E.S.S.); the acceptance-corrected exposure time is 100 h. The data set has been folded with the known orbital period of the system in order to test for variability of the emission. Energy spectra are obtained for the orbit-averaged data set, and for the orbital phase bin around the VHE maximum. Results. VHE $\gamma$-ray emission is detected with a statistical significance of 6.4 $\sigma$. The data clearly show variability which is phase-locked to the orbital period of the system. Periodicity cannot be deduced from the H.E.S.S. data set alone. The orbit-averaged luminosity in the $1-10$ TeV energy range is $(1.4 \pm 0.2) \times 10^{35}$ erg/s. A luminosity of $(5 \pm 1) \times 10^{35}$ erg/s is reached during 20% of the orbit. HE and VHE $\gamma$-ray emissions are anti-correlated. LMC P3 is the most luminous $\gamma$-ray binary known so far.Comment: 5 pages, 3 figures, 1 table, accepted for publication in A&

Characterizing the gamma-ray long-term variability of PKS 2155-304 with H.E.S.S. and Fermi-LAT

Studying the temporal variability of BL Lac objects at the highest energies provides unique insights into the extreme physical processes occurring in relativistic jets and in the vicinity of super-massive black holes. To this end, the long-term variability of the BL Lac object PKS 2155-304 is analyzed in the high (HE, 100 MeV 200 GeV) gamma-ray domain. Over the course of ~9 yr of H.E.S.S observations the VHE light curve in the quiescent state is consistent with a log-normal behavior. The VHE variability in this state is well described by flicker noise (power-spectral-density index {\ss}_VHE = 1.10 +0.10 -0.13) on time scales larger than one day. An analysis of 5.5 yr of HE Fermi LAT data gives consistent results ({\ss}_HE = 1.20 +0.21 -0.23, on time scales larger than 10 days) compatible with the VHE findings. The HE and VHE power spectral densities show a scale invariance across the probed time ranges. A direct linear correlation between the VHE and HE fluxes could neither be excluded nor firmly established. These long-term-variability properties are discussed and compared to the red noise behavior ({\ss} ~ 2) seen on shorter time scales during VHE-flaring states. The difference in power spectral noise behavior at VHE energies during quiescent and flaring states provides evidence that these states are influenced by different physical processes, while the compatibility of the HE and VHE long-term results is suggestive of a common physical link as it might be introduced by an underlying jet-disk connection.Comment: 11 pages, 16 figure