Spotlight waste processing: Transpaille, compost, lagooning

Mis au point par le CIRAD et développé par Agriforce, le procédé Transpaille récupère et traite des déchets organiques par fermentation méthanique en produisant du gaz et du compost. Le dispositif a été mis en place à l'abattoir de Thiès au Sénégal en 1988-1989. Le compost produit constitue un bon amendement organique. Néanmoins son coût de production élevé nécessite une commercialisation plus adaptée à la qualité du produit telle que la filière de production de plants en mottes. Autre valorisation des déchets de l'abattoir de Thiès : le lagunage qui permet l'épuration des effluents liquides et qui permet également de tester en grandeur réelle les performances des différentes techniques de lagunag

Dossier traitement des déchets : Transpaille, plant en mottes, lagunage

Mis au point par le CIRAD et développé par Agriforce, le procédé Transpaille récupère et traite des déchets organiques par fermentation méthanique en produisant du gaz et du compost. Le dispositif a été mis en place à l'abattoir de Thiès au Sénégal en 1988-1989. Le compost produit constitue un bon amendement organique. Néanmoins son coût de production élevé nécessite une commercialisation plus adaptée à la qualité du produit telle que la filière de production de plants en mottes. Autre valorisation des déchets de l'abattoir de Thiès : le lagunage qui permet l'épuration des effluents liquides et qui permet également de tester en grandeur réelle les performances des différentes techniques de lagunag

Dossier tratamientos de los residuos : transpaille, compuesto, depuracion en laguna

Mis au point par le CIRAD et développé par Agriforce, le procédé Transpaille récupère et traite des déchets organiques par fermentation méthanique en produisant du gaz et du compost. Le dispositif a été mis en place à l'abattoir de Thiès au Sénégal en 1988-1989. Le compost produit constitue un bon amendement organique. Néanmoins son coût de production élevé nécessite une commercialisation plus adaptée à la qualité du produit telle que la filière de production de plants en mottes. Autre valorisation des déchets de l'abattoir de Thiès : le lagunage qui permet l'épuration des effluents liquides et qui permet également de tester en grandeur réelle les performances des différentes techniques de lagunag

Integrability as a consequence of discrete holomorphicity: the Z_N model

It has recently been established that imposing the condition of discrete holomorphicity on a lattice parafermionic observable leads to the critical Boltzmann weights in a number of lattice models. Remarkably, the solutions of these linear equations also solve the Yang-Baxter equations. We extend this analysis for the Z_N model by explicitly considering the condition of discrete holomorphicity on two and three adjacent rhombi. For two rhombi this leads to a quadratic equation in the Boltzmann weights and for three rhombi a cubic equation. The two-rhombus equation implies the inversion relations. The star-triangle relation follows from the three-rhombus equation. We also show that these weights are self-dual as a consequence of discrete holomorphicity.Comment: 11 pages, 7 figures, some clarifications and a reference adde

A SAURON view of galaxies

We have measured the two-dimensional kinematics and line-strength distributions of 72 representative nearby early-type galaxies, out to approximately one effective radius, with our panoramic integral-field spectrograph SAURON. The resulting maps reveal a rich variety in kinematical structures and linestrength distributions, indicating that early-type galaxies are more complex systems than often assumed. We are building detailed dynamical models for these galaxies, to derive their intrinsic shape and dynamical structure, and to determine the mass of the supermassive central black hole. Here we focus on two examples, the compact elliptical M32 and the E3 galaxy NGC4365. These objects represent two extreme cases: M32 has very regular kinematics which can be represented accurately by an axisymmetric model in which all stars rotate around the short axis, while NGC4365 is a triaxial galaxy with a prominent kinematically decoupled core, with an inner core that rotates about an axis that is nearly perpendicular to the rotation axis of the main body of the galaxy. Our dynamical models for these objects demonstrate that two-dimensional observations are essential for deriving the intrinsic orbital structure and dark matter content of galaxies.Comment: 7 pages (3 figures, full resolution Fig. 1 available at http://www.strw.leidenuniv.nl/~verolme/M32.ps). Contributed talk to the Athens Workshop on Galaxies and Chaos, Theory and Observations; Proceedings to appear in "Galaxies and Chaos", eds. G. Contopoulos and N. Vogli

A 60 pc counter-rotating core in NGC 4621

We present adaptive optics assisted OASIS integral field spectrography of the S0 galaxy NGC 4621. Two-dimensional stellar kinematical maps (mean velocity and dispersion) reveal the presence of a 60 pc diameter counter-rotating core (CRC), the smallest observed to date. The OASIS data also suggests that the kinematic center of the CRC is slightly offset from the center of the outer isophotes. This seems to be confirmed by archival HST/STIS data. We also present the HST/WFPC2 V-I colour map, which exhibits a central elongated red structure, also slightly off-centered in the same direction as the kinematic centre. We then construct an axisymmetric model of NGC 4621: the two-integral distribution function is derived using the Multi-Gaussian Expansion and the Hunter & Qian (1993) formalisms. Although the stellar velocities are reasonably fitted, including the region of the counter-rotating core, significant discrepancies between the model and the observations demonstrate the need for a more general model (e.g. a three-integral model).Comment: 9 pages, 8 figure

OASIS High-Resolution Integral Field Spectroscopy of the SAURON Ellipticals and Lenticulars

We present a summary of high-spatial resolution follow-up observations of the elliptical (E) and lenticular (S0) galaxies in the SAURON survey using the OASIS integral field spectrograph. The OASIS observations explore the central 8x10" regions of these galaxies using a spatial sampling four times higher than SAURON, often revealing previously undiscovered features. Around 75% (31/48) of the SAURON E/S0s with central velocity dispersion >= 120 km/s were observed with OASIS, covering well the original SAURON representative sample. We present here an overview of this follow-up survey, and some preliminary results on individual objects, including a previously unreported counter-rotating core in NGC 4382; the decoupled stellar and gas velocity fields of NGC 2768; and the strong age gradient towards the centre of NGC 3489.Comment: 4 pages, 5 figures. Accepted for publication in Astron. Nachr. as refereed proceedings of Euro3D Science Workshop, IoA Cambridge, May 200

The M 31 double nucleus probed with OASIS and HST. A natural m=1 mode?

We present observations with the adaptive optics assisted integral field spectrograph OASIS of the M 31 double nucleus at a spatial resolution better than 0.5 arcsec FWHM. These data are used to derive the two-dimensional stellar kinematics within the central 2 arcsec. Archival WFPC2/HST images are revisited to perform a photometric decomposition of the nuclear region. We also present STIS/HST kinematics obtained from the archive. The luminosity distribution of the central region is well separated into the respective contributions of the bulge, the nucleus including P1 and P2, and the so-called UV peak. We then show that the axis joining P1 and P2, the two local surface brightness maxima, does not coincide with the kinematic major-axis, which is also the major-axis of the nuclear isophotes (excluding P1). We also confirm that the velocity dispersion peak is offset by ~ 0.2 arcsec from the UV peak, assumed to mark the location of the supermassive black hole. The newly reduced STIS/HST velocity and dispersion profiles are then compared to OASIS and other published kinematics. We find significant offsets with previously published data. Simple parametric models are then built to successfully reconcile all the available kinematics. We finally interpret the observations using new N-body simulations. The nearly keplerian nuclear disk of M31 is subject to a natural m=1 mode, with a very slow pattern speed (3 km/s/pc for M_BH = 7 10^7~\Msun), that can be maintained during more than a thousand dynamical times. The resulting morphology and kinematics of the mode can reproduce the M~31 nuclear-disk photometry and mean stellar velocity, including the observed asymmetries. It requires a central mass concentration and a cold disk system representing between 20 and 40% of its mass. Abridged..Comment: 21 pages. accepted for publication in A&

The Nearby Supernova Factory

The Nearby Supernova Factory (SNfactory) is an ambitious project to find and study in detail approximately 300 nearby Type Ia supernovae (SNe~Ia) at redshifts 0.03<z<0.08. This program will provide an exceptional data set of well-studied SNe in the nearby smooth Hubble flow that can be used as calibration for the current and future programs designed to use SNe to measure the cosmological parameters. The first key ingredient for this program is a reliable supply of Hubble-flow SNe systematically discovered in unprecedented numbers using the same techniques as those used in distant SNe searches. In 2002, 35 SNe were found using our test-bed pipeline for automated SN search and discovery. The pipeline uses images from the asteroid search conducted by the Near Earth Asteroid Tracking group at JPL. Improvements in our subtraction techniques and analysis have allowed us to increase our effective SN discovery rate to ~12 SNe/month in 2003.Comment: 7 pages, 3 figures to be published in New Astronomy Review