Lagunage naturel de lixiviat de décharge

Dans le cadre d'un traitement par lagunage naturel des lixiviats d'une décharge d'ordures ménagères broyées, nous avons procédé au cours d'un cycle annuel (mai 1998 à mai 1999) à des analyses biologiques et physicochimiques des eaux à l'entrée (lixiviat brut), dans les quatre bassins successifs et à la sortie du dispositif (lixiviat traité) avant son rejet dans le milieu récepteur (ruisseau Mont Bonnet). L'évolution spatiotemporelle de la qualité des lixiviats a été approchée par le suivi des fluctuations saisonnières de divers paramètres (température, conductivité électrique, pH, oxygène dissous, potentiel redox, chlorures, fer, manganèse, nickel, zinc, azote total, phosphore total, ammonium, DBO, DCO et chlorophylle a). Les résultats montrent deux périodes de dysfonctionnement de la station durant l'année. Un dysfonctionnement estival marqué par une chute du rendement épuratoire du fer, du manganèse et de la DBO, sous l'effet d'une diminution du potentiel redox et du surplus de matières organiques autochtones. Le deuxième dysfonctionnement, observé en hiver et au début du printemps, est caractérisé par une chute des rendements épuratoires pour l'ensemble des éléments chimiques suivis. Cette chute des rendements épuratoires est vraisemblablement liée à la diminution importante des valeurs de pH durant cette période.The Etueffont municipal landfill waste (Northeast of Belfort, France) possesses a mode of exploitation by grinding wastes without compaction, to facilitate the aerobic degradation. This technique leads to a leachate production. The leachate was treated by natural lagoons consisting of 4 decantation basins then released in the brook (of Mont Bonnet). Efficiency of the epuration was estimated by calculation the net budget of elements (=Input-Output). The results showed that lagoons eliminated the quasi-totality of organic matters (about 80% of BOD) and dissolved substances (about 50 to 90%). Nevertheless, a decrease of epuration efficiency that has been observed in winter of all elements (temperature, electric conductivity, pH, dissolved oxygen, redox potential, chloride, iron, manganese, nickel, zink, total nitrogen, total phosphorus, ammonia, BOD, COD), was due to the decrease of pH (pH=4,5). However, in the begining of summer only Cu2+ and Fe2+ decreased. The collapse of BOD removel (- 8% observed in September 1998) was linked to the excedentary stock of organic matter products in the basins during the summer. The analysis of the monthly evolution of the efficiency epuration of NH4+, total nitrogen (TN) and total phosphorus (TP) indicate similary features. The net budget fluctuates between 50% in winter and 70% in summer. The weak values are noted in January 1999 (19% for NH4+ , 13% for TN and 14% for TP). This work showed that the natural lagooning is weakly efficient for this kind of landfill leachates

Apports des traçages artificiel et naturel à la connaissance des circulations et des zones de recharge en région semi-aride: cas de l'Atlas de Beni Mellal (Maroc)

Pour mieux comprendre les modalités d'alimentation des sources de l'Atlas, des campagnes de coloration et d'analyses isotopiques ont été effectuées sur l'ensemble des sources. La disparité des circulations, la variabilité des vitesses et des taux de restitution, révèlent un aquifère complexe ou à plusieurs entrées. La majorité des écoulements convergent vers la source de Ain Asserdoune qui constitue une zone d'abaissement d'axe de plis. L'étude isotopique montre la variation des teneurs en 180 avec l'altitude des zones de recharge des différents exutoires et avec la saison. Les gradients définis autorisent la détermination de l'altitude moyenne des impluviums des systèmes jusqu'alors mal connus, en particulier celui de l'exutoire principal du massif, Ain Asserdoune.The chalky massif of Beni-Mellal, which supplies many springs, spreads over a 365 km2 area of 500 to 2400 meters elevation (average altitude, 1200 m). Rainfall in this sector varies between 400 mm and 700 mm/year. All springs emerge along the major coastal fault giving the Liassic massif overthrushing the Cenozoic lands of piemont. The most important is Ain Asserdoune spring with an average discharge of about 1.1 m3/s. The mainly chalky and dolomitic formations are very fractured according to preferential directions (N150-180 and N50-70) and show some karstification features at the surface. Some tracing experiments with fluorescein allowed the delimitation of the boundaries of the intake area of Ain Asserdoune Basin and the determination of the groundwater flow velocity. Two types of flow were identified with fast (100 to 231 m/h) and slow circulation (< 100 m/h). Most of circulations converge towards the spring of Ain Asserdoune (fig. 1) with an important intake area. This convergence results from an axis lowering. The variability of the circulation axes, the velocity and the rate of restitution suggest either a complex aquifer or an aquifer with several inputs.Two water samplings (the first for the Beni Mellal Atlas) were carriet out in March and in September 1993 on the several springs, in order to study the variations of the oxygen-18 isotope. The oxygen-18 contents range between - 5.5 per thousand and - 7.7 per thousand (table 2). The most depleted waters directly exit from the Liassic aquifer or emerge at high altitudes; those which are richer in oxygen-18 emerge at the level of foothills, either from the Tertiary or from Liassic scales. The relationship between the oxygen-18 and the H-2 content of some samples indicates that the points are aligned along the world meteoric line (Craig, 1961). Even if the waters of Dir (piemont) springs are slighly evaporated because they partly originate in seeping Liassic waters, oxygen-18 content is probably mainly controlled by an altitude effect. Oxygen-18 data for local precipitations are not available; however, a local relationship between oxygen-18 content and mean recharge altitude was etablished for eleven (11) springs with small recharge areas whose mean altitude may be estimated from topography and geology. Oxygen 18 ratio is very well correlated to recharge average elevation for spring samples ( [delta]per thousand (O - 18)=- 3 - 0,0026 x altitude, r=0,96, fig. 3), when it is not for autumn samples. This gradient is very close to the regional relationship proposed by Marce (1975) and Kabbaj et al. (1978) (slope: 3 per thousand in oxygen-18 per 1,000 m ). This difference is attributed to the seasonal variations in the origin of water that feeds the springs. In the high water season, the whole basin area contributes to the recharge. In contrast, during low water period, water mainly originates from altitudes higher than the mean altitude of the basin, probably with a longer transit time. The seasonal variations are particularly marked for the Dir (piemont) springs (with a lower flux and intake area range of 800 to 1,200 m). They are weaker for the Lias springs and even non-existent for the main spring of the massif, Ain Asserdoune. In this latter case, the smoothing (- 7.6 per thousand and - 7.5 per thousand) of seasonal variation (which is also observed for temperature: 15.5 to 16°C ) gives evidence of important water reserves. A mean recharge altitude higher than 1,700 m may be proposed for Ain Asseroune. Based on this analysis, some emergences which in the part were assigned to the same hydrologic system can now be discriminated. On the other hand, with a similar value of oxygen-18 ratio, rather distant springs can be considered as belonging to the same hydrogeological Atlasic unit. So the relationship which was quantified (slope: 2.6 per thousand in oxygen-18 per 1,000 m) is usable for the whole Atlasic range on account of regionaly similar weather. The methodology selected in this work corroborates the results obtained by hydrometric analysis concerning the very important groundwater reserves in the Beni Mellal aquifer

Group status drives majority and minority integration preferences

WOS:000300955100009 (Nº de Acesso Web of Science)“Prémio Científico ISCTE-IUL 2013”This research examined preferences for national-and campus-level assimilative and pluralistic policies among Black and White students under different contexts, as majority-and minority-group members. We targeted attitudes at two universities, one where 85% of the student body is White, and another where 76% of students are Black. The results revealed that when a group constituted the majority, its members generally preferred assimilationist policies, and when a group constituted the minority, its members generally preferred pluralistic policies. The results support a functional perspective: Both majority and minority groups seek to protect and enhance their collective identities

A Delayed Black and Scholes Formula I

In this article we develop an explicit formula for pricing European options when the underlying stock price follows a non-linear stochastic differential delay equation (sdde). We believe that the proposed model is sufficiently flexible to fit real market data, and is yet simple enough to allow for a closed-form representation of the option price. Furthermore, the model maintains the no-arbitrage property and the completeness of the market. The derivation of the option-pricing formula is based on an equivalent martingale measure

On the monotone stability approach to BSDEs with jumps: Extensions, concrete criteria and examples

We show a concise extension of the monotone stability approach to backward stochastic differential equations (BSDEs) that are jointly driven by a Brownian motion and a random measure for jumps, which could be of infinite activity with a non-deterministic and time inhomogeneous compensator. The BSDE generator function can be non convex and needs not to satisfy global Lipschitz conditions in the jump integrand. We contribute concrete criteria, that are easy to verify, for results on existence and uniqueness of bounded solutions to BSDEs with jumps, and on comparison and a-priori $L^{\infty}$-bounds. Several examples and counter examples are discussed to shed light on the scope and applicability of different assumptions, and we provide an overview of major applications in finance and optimal control.Comment: 28 pages. Added DOI https://link.springer.com/chapter/10.1007%2F978-3-030-22285-7_1 for final publication, corrected typo (missing gamma) in example 4.1

Low-Noise Ku-Band Receiver Frontend with Switchable SIW Filters for Cubesat Applications

This paper proposes a low-noise receiver frontend for nanosatellite and Cubesat platforms. The frontend is composed by a Low-Noise Amplifier (LNA) and two Substrate Integrated Waveguide (SIW) filters, providing a frequency reconfigurability to the system. The two filters operate in the 13 and in the 14 GHz uplink bands, and are selected by means of a pair of solid-state SPDT switches. As a results, 15.5 dB gain with 2.4 dB noise figure for the 13 GHz configuration and 17.8 dB gain with 2.3 dB noise figure for the 14 GHz configuration are obtained. This work is important since demonstrates a low-cost solution for satellite radio apparatuses based on commercial components on a standard PCB

The ArDM experiment

The aim of the ArDM project is the development and operation of a one ton double-phase liquid argon detector for direct Dark Matter searches. The detector measures both the scintillation light and the ionization charge from ionizing radiation using two independent readout systems. This paper briefly describes the detector concept and presents preliminary results from the ArDM R&D program, including a 3 l prototype developed to test the charge readout system.Comment: Proceedings of the Epiphany 2010 Conference, to be published in Acta Physica Polonica

Precision measurement of the neutrino velocity with the ICARUS detector in the CNGS beam

During May 2012, the CERN-CNGS neutrino beam has been operated for two weeks for a total of 1.8 10^17 pot in bunched mode, with a 3 ns narrow width proton beam bunches, separated by 100 ns. This tightly bunched beam structure allows a very accurate time of flight measurement of neutrinos from CERN to LNGS on an event-by-event basis. Both the ICARUS-T600 PMT-DAQ and the CERN-LNGS timing synchronization have been substantially improved for this campaign, taking ad-vantage of additional independent GPS receivers, both at CERN and LNGS as well as of the deployment of the "White Rabbit" protocol both at CERN and LNGS. The ICARUS-T600 detector has collected 25 beam-associated events; the corresponding time of flight has been accurately evaluated, using all different time synchronization paths. The measured neutrino time of flight is compatible with the arrival of all events with speed equivalent to the one of light: the difference between the expected value based on the speed of light and the measured value is tof_c - tof_nu = (0.10 \pm 0.67stat. \pm 2.39syst.) ns. This result is in agreement with the value previously reported by the ICARUS collaboration, tof_c - tof_nu = (0.3 \pm 4.9stat. \pm 9.0syst.) ns, but with improved statistical and systematic errors.Comment: 21 pages, 13 figures, 1 tabl