Decree S.,University of Namur |
Ruffet G.,CNRS Geosciences Laboratory of Rennes |
Putter T.D.,Musee Royal de lAfrique Centrale |
Baele J.-M.,Faculte Polytechnique de Mons |
And 2 more authors.
Journal of African Earth Sciences | Year: 2010
The Tamra mine, located in the Nefza mining district (NW Tunisia), exploits a 50m-thick layer of Mio-Pliocene sediments that are heavily mineralized with Fe and other metals (Mn, Pb, Zn), especially in its eastern part, which is highly mineralized in Mn and known as the "manganiferous zone". The textural and geochemical studies of manganiferous minerals in the Tamra mine have allowed the determination of four main paragenetic stages. Stages 1 and 2 relate to the main pedogenetic event that gave rise to the currently exploited Fe ore deposit. The last two stages relate to mineralizing events closely connected with hydrothermal circulation and leaching of underlying mineralization of the Sidi Driss Pb-Zn sedex deposit, with subsequent crystallisation in the supergene environment. Stage 3 is characterized by the formation of massive romanechite, hollandite and Sr-cryptomelane, while stage 4 results in the formation of coronadite and chalcophanite. 39Ar-40Ar analyses performed on hollandite (stage 3) and coronadite (stage 4) samples yielded ages of 4.7±0.1Ma and 3.35±0.07Ma, respectively. Tentative 39Ar-40Ar analyses on chalcophanite provided aberrant results, due to the poor argon retention in this layer-structure mineral. The youngest age corresponds to the late phase of the late Alpine extension event in northern Tunisia, evidenced through an increased regional thermal gradient as well as by a N-S set of normal faults and fractures. The Tamra mine is obviously a polyphase mineral deposit, recording several distinct metal inputs, part of them originating from the underlying Sidi Driss Pb-Zn deposit, while another part is provided by hydrothermal circulations forced by the high thermal gradient. Three springs flowing from the Tamra ore series are regular sources for drinking water used by the local population. Although the Alpine thermal gradient could have facilitated extensive mixing between subsurface oxidizing meteoric fluids and deep reducing hydrothermal tepid fluids, the springs flowing out in the Tamra mine are not significantly polluted with metallic elements (Fe, Pb, Zn, Mn), and can be regarded as drinking waters according to the World Health Organization (WHO) standards. 39Ar-40Ar ages suggest that complex Mn oxides formed early in the deposit history. These oxides incorporated metal ions in their mineral structure and/or acted as high-surface-area substrates favouring heavy metal adsorption (e.g. Pb on Mn oxides). Similar adsorption/co-precipitation processes are also exhibited by iron oxides, which form the major part of the Tamra sediments. These efficient trapping processes most probably account for a restricted migration of "pollutants" through the neighbouring sediments and the circulating fluids. © 2009 Elsevier Ltd.
Ferey G.,University of Versailles |
Serre C.,University of Versailles |
Devic T.,University of Versailles |
Maurin G.,Charles Gerhardt Institute |
And 6 more authors.
Chemical Society Reviews | Year: 2011
Hybrid porous solids, with their tunable structures, their multifunctional properties and their numerous applications, are currently topical, particularly in the domain of adsorption and storage of greenhouse gases. Most of the data reported so far concern the performances of these solids in this domain, particularly in terms of adsorbed amounts of gas but do not explain at the atomic level why and how adsorption and storage occur. From a combination of structural, spectroscopic, thermodynamic experiments and of molecular simulations, this tutorial review proposes answers to these open questions with a special emphasis on CO2 and CH4 storage by some rigid and flexible hybrid porous materials. © 2011 The Royal Society of Chemistry.
Faculte Polytechnique De Mons and Multitel Asbl | Date: 2012-12-03
A device for designing a sensor arrangement for an automated system, the device comprising a first input unit for receiving a specification of a plurality of sensor measurements to be carried out by the sensor arrangement, a second input unit for receiving a specification of a confidence region together with an associated confidence level for each of the specified sensor measurements, a third input unit for receiving a specification of a target confidence level for the automated system, and a configuration unit for configuring the plurality of sensor measurements and for configuring the combination of the sensor measurements in a manner to guarantee the target confidence level for the automated system.
Faculte Polytechnique De Mons and Acapela Group S.A. | Date: 2010-10-20
The present invention is related to a method for coding excitation signal of a target speech comprising the steps of:- extracting from a set of training normalised residual frames, a set of relevant normalised residual frames, said training residual frames being extracted from a training speech, synchronised on Glottal Closure Instant(GCI), pitch and energy normalised;- determining the target excitation signal of the target speech;- dividing said target excitation signal into GCI synchronised target frames;- determining the local pitch and energy of the GCI synchronised target frames;- normalising the GCI synchronised target frames in both energy and pitch, to obtain target normalised residual frames;- determining coefficients of linear combination of said extracted set of relevant normalised residual frames to build synthetic normalised residual frames close to each target normalised residual frames;wherein the coding parameters for each target residual frames comprise the determined coefficients.
El Gout R.,University Mohammed Premier |
Khattach D.,University Mohammed Premier |
Houari M.-R.,University Mohammed Premier |
Kaufmann O.,Faculte Polytechnique de Mons |
Aqil H.,University Mohammed Premier
Journal of African Earth Sciences | Year: 2010
Many years ago, geophysical surveys (gravity and aeromagnetic) were initiated for economic investigation and recently the analysis of gravity and magnetic anomalies are used as a powerful tool for the geological mapping. The present study is based on various filtered maps of gravity and aeromagnetic anomalies of north-eastern Morocco (NEM) in order to highlight its main structural features. Filtering techniques such as horizontal gradient, upward continuation and Euler deconvolution were used to map structural lineaments in NEM. The obtained structural map is consistent with many faults already recognized or supposed by traditional structural studies, and highlights new major accidents by specifying their layout and dips. © 2010 Elsevier Ltd.
Yans J.,University of Namur |
Gerards T.,University of Liège |
Gerrienne P.,University of Liège |
Spagna P.,Faculte Polytechnique de Mons |
And 4 more authors.
Palaeogeography, Palaeoclimatology, Palaeoecology | Year: 2010
Pedogenic nodules, calcitic shells, dispersed organic carbon and bulk rocks affected by low diagenesis are judged to be reliable tools for carbon-isotope chemostratigraphy. Up to now no systematic study has been carried out to check the reliability of fossil wood material for carbon-isotope chemostratigraphy in terrestrial settings. The 235-m thick Wealden facies sediments of the Danube-Bouchon quarry at Hautrage (Hautrage Clays Formation, Mons Basin, Belgium) encompass dark to grey clays and sands, rich in organic matter and coalified-charcoalified fragments of fossil wood, deposited in an alluvial plain during middle Barremian to earliest Aptian. We measured and compared the carbon-isotope ratios of 110 levels of the stratigraphic succession for dispersed organic carbon (δ13CDOC), and fossil wood (δ13CWOOD) collected in the same geological level. In the whole succession, the averages of δ13CDOC and δ13CWOOD have a significant difference of about 0.9‰. The δ13CWOOD is usually heavier than the δ13CDOC, which is consistent with measurements on different constituents of modern trees (branches versus leaves and tissues). In one single stratigraphic level, the variability of δ13CWOOD is much higher (up to 7.3‰) than that of δ13CDOC (0.4‰). Four main causes may explain these results. Firstly, the δ13CDOC averages the isotopic signal of different compounds and tissues (such as leaves, seeds, cuticles) as they become mixed and dispersed. The δ13CWOOD reflects the carbon-isotope ratio of a small part only of one single tree, which is a complex system with δ13C variations over a range of 4‰. Secondly, there is strong δ13C variability between different species of plants. In Hautrage, several gymnosperm genera were collected (including Podocarpoxylon, Taxodioxylon, Brachyoxylon, and Thujoxylon) and numerous fern taxa. Thirdly, coalification and charcoalification can affect the δ13C of the DOC and the various kinds of woods in a different way. Fourthly, the wood fragments may be reworked several times from more ancient geological levels, especially in the alluvial plain environment of Hautrage where thick levels of fluviatile coarse sand deposits are observed. However, in the whole succession, both δ13CWOOD and δ13CDOC curves show similar trends. This suggests that carbon-isotope curves on fossil wood can be matched to carbon-isotope curves on DOC. For the whole trend fossil wood is a relatively good chemostratigraphic tool when sufficient samples are measured in the succession. Whenever possible both control of the wood taxa, and estimation of degree of (char)coalification are however recommended. In one single level, charcoal has more stable δ13CWOOD values than δ13CWOOD of coalified fragments. The δ13C positive trend can be due to several causes, including global pCO2 variations and/or regional changes and/or local environmental conditions in the alluvial plain. If global, the dating of the Hautrage succession may be refined to the late Early Barremian-early Late Barremian by matching palynological and carbon-isotope chemostratigraphical data. © 2010 Elsevier B.V. All rights reserved.
Gooijer L.,National Institute for Public Health and the Environment |
Cornil N.,Faculte Polytechnique de Mons |
Process Safety and Environmental Protection | Year: 2012
In order to compare the quantitative risk assessment (QRA) methods for land use planning and licensing used in France, the United Kingdom, The Netherlands and the Walloon Region of Belgium, a benchmark exercise was performed. Based on a description of a fictitious LPG storage plant, INERIS from France, HSE from the United Kingdom, the Faculté Polytechnique de Mons from the Walloon Region of Belgium and the RIVM from The Netherlands used their own quantitative risk assessment approach to perform the exercise. The risk assessment approaches to determine third party risks of a LPG plant used by the four partners are very different. In France the assessment is based on a specific on-site analysis performed by experts. HSE uses a simple consequence based approach to determine safety distances. In The Netherlands and the Walloon Region a generic and standardized method for determining the risk contours is used. The differences relate to the calculation methodologies and the types of consequences that are calculated (such as lethal effects or irreversible effects). Despite the differences, the methods yield to similar safety distances between houses and companies: distances between 200 and 280 m. However, similar safety distances can still have different policy implications. For instance, the safety distances in The Netherlands and France are used as limit values, whereas in Belgium and the United Kingdom they are used to give an advice. © 2011 The Institution of Chemical Engineers. Published by Elsevier B.V. All rights reserved.
Darracq G.,National Graduate School of Chemistry, Rennes |
Darracq G.,European University of Brittany |
Couvert A.,National Graduate School of Chemistry, Rennes |
Couvert A.,European University of Brittany |
And 9 more authors.
Journal of Chemical Technology and Biotechnology | Year: 2010
BACKGROUND: Hydrophobic volatile organic compounds(VOCs), such as toluene,dimethyl sulfide (DMS)anddimethyldisulfide (DMDS), are poorly soluble inwater and classical air treatment processes like chemical scrubbers are not efficient.An alternative technique involving an absorption step in an organic solvent followed by a biodegradation phase was proposed. The solvent must fulfil several characteristics, which are key factors of process efficiency, andaprevious study allowedpolydimethylsiloxane (or PDMS, i.e. silicone oil) to be selected for this purpose. The aim of this paper was to determine some of its characteristics like absorption capacity and velocity performances (Henry's constant, diffusivity and mass transfer coefficient), and to verify its non-biodegradability. RESULTS: For the three targeted VOCs, Henry's constants in silicone oil were very low compared to those in water, and solubility was infinite. Diffusivity values were found to be in the range 10-10 to 10-11 m2 s-1 andmass transfer coefficients did not show significant differences between the values in pure water and pure silicone oil, in the range 1.0 × 10-3 to 4.0 × 10 -3 s-1 for all the VOCs considered. Silicone oil was also found to be non-biodegradable, since its biological oxygen demand (BOD5) value was zero. CONCLUSION: Absorption performances of silicone oil towards toluene, DMS and DMDSwere determined and showed that this solvent could be used during the first step of the process. Moreover, its low biodegradability and its absence of toxicity justify its use as an absorbent phase for the integrated process being considered. © 2010 Society of Chemical Industry.
David R.,Faculte Polytechnique de Mons |
Vande Wouwer A.,Faculte Polytechnique de Mons |
Vasel J.-L.,University of Liège |
Queinnec I.,CNRS Laboratory for Analysis and Architecture of Systems
2007 European Control Conference, ECC 2007 | Year: 2015
The Activated Sludge Model no. 1 (ASM1) , which is the most widely accepted model of wastewater treatment plants (WWTPs), is used to describe the biotrans-formation processes of nitrification-denitrification. Due to its complexity and nonlinearity, this model is however not well-suited to the design of a control structure. The objective of this work is threefold: (1) to reduce the ASM1, (2) to linearize the reduced model, and (3) to design a robust control algorithm, in order to improve the plant performance and reject disturbances. This procedure is illustrated with data from the COST benchmark . © 2007 EUCA.
Hoeffgen S.K.,Fraunhofer Institute for Technological Trend Analysis |
Henschel H.,Fraunhofer Institute for Technological Trend Analysis |
Kuhnhenn J.,Fraunhofer Institute for Technological Trend Analysis |
Weinand U.,Fraunhofer Institute for Technological Trend Analysis |
And 3 more authors.
IEEE Transactions on Nuclear Science | Year: 2011
The radiation sensitivity of type I FBGs written by four different manufacturers with different UV or IR lasers in two different Ge-doped H$2 loaded and unloaded fibers was investigated. The measured peak shifts agreed quite well. © 2011 IEEE.