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See detailCellulose bioavailability in waste
Rodriguez, Ch.; Hiligsmann, Serge ULg; Lardinois, M. et al

Poster (2002, October)

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See detailCellulose enzymatic availability in Municipal solid waste
Rodriguez, C.; Hiligsmann, Serge ULg; Ongena, MARC ULg et al

in Christensen; Cossu; Stegmann (Eds.) Proceedings Sardinia 03, Ninth International Waste Management and Landfill Symposium (2003)

We recently developed a new and rapid method to evaluate the biological reactivity of cellulose in Municipal Solid Waste (MSW). This test is based on the enzymatic hydrolysis of cellulose in MSW and can ... [more ▼]

We recently developed a new and rapid method to evaluate the biological reactivity of cellulose in Municipal Solid Waste (MSW). This test is based on the enzymatic hydrolysis of cellulose in MSW and can be related to the digestibility of this polymer in MSW. In this work, we showed that the enzymatic cellulose degradation test (ECD) correlated well with a Biochemical Methane Potential (BMP) assay so that the ECD test can be reliably applied to estimate cellulose bioavailability in various waste samples. These tests have also been used to evaluate the influence of some important parameters that could affect the extent and the rate of cellulose degradation in waste. It appeared that cellulose enzymatic hydrolysis is related to the moisture content but no clear relationship could be established with the cellulose content. Moreover, it is shown that acetic acid produced by the anaerobic degradation of organic matter, and responsible for high COD in young leachates, may slow down or inhibit the enzymatic hydrolysis step and the methanogenesis. [less ▲]

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See detailCellulose enzymatic availability in waste refuse
Rodriguez, C.; Hiligsmann, Serge ULg; Lardinois, M. et al

in Christensen; Cossu; Stegmann (Eds.) Proceedings Sardinia 01, Eight International Waste Management and Landfill Symposium (2001)

This work presents an original method for testing the biological reactivity of cellulose. This test specifically targets one of the limiting steps of cellulose bioconversion into biogas, i.e. the ... [more ▼]

This work presents an original method for testing the biological reactivity of cellulose. This test specifically targets one of the limiting steps of cellulose bioconversion into biogas, i.e. the cellulose hydrolysis. From this point of view, enzymes-mediated hydrolysis has been performed to evaluate cellulose bioavailability in refuse samples from different layers of an old landfill. The relationship between the cellulose enzymatic accessibility and the lignin contents has also been studied. Similarly, the correlation between cellulose, lignin and humic acid contents has been investigated. On the other hand, moisture content in landfills is considered as one of the most important factors that favours methanogenesis. In this respect, the influence of moisture content on cellulose enzymatic hydrolysis has also been evaluated. [less ▲]

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See detailCellulose Hydrolysis of papermill sludge
Paquot, Michel ULg; Herman, L.

Book (1983)

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See detailCellwise robust regularized discriminant analysis
Aerts, Stéphanie ULg; Wilms, Ines

Conference (2017, June 02)

Quadratic and Linear Discriminant Analysis (QDA/LDA) are the most often applied classification rules under normality. In QDA, a separate covariance matrix is estimated for each group. If there are more ... [more ▼]

Quadratic and Linear Discriminant Analysis (QDA/LDA) are the most often applied classification rules under normality. In QDA, a separate covariance matrix is estimated for each group. If there are more variables than observations in the groups, the usual estimates are singular and cannot be used anymore. Assuming homoscedasticity, as in LDA, reduces the number of parameters to estimate. This rather strong assumption is however rarely verified in practice. Regularized discriminant techniques that are computable in high-dimension and cover the path between the two extremes QDA and LDA have been proposed in the literature. However, these procedures rely on sample covariance matrices. As such, they become inappropriate in presence of cellwise outliers, a type of outliers that is very likely to occur in high-dimensional datasets. We propose cellwise robust counterparts of these regularized discriminant techniques by inserting cellwise robust covariancematrices. Ourmethodologyresultsinafamilyofdiscriminantmethods that are robust against outlying cells, cover the gap between LDA and QDA and are computable in high-dimension. [less ▲]

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See detailCellwise Robust regularized discriminant analysis
Aerts, Stéphanie ULg; Wilms, Ines

E-print/Working paper (2016)

Quadratic and Linear Discriminant Analysis (QDA/LDA) are the most often applied classification rules under normality. In QDA, a separate covariance matrix is estimated for each group. If there are more ... [more ▼]

Quadratic and Linear Discriminant Analysis (QDA/LDA) are the most often applied classification rules under normality. In QDA, a separate covariance matrix is estimated for each group. If there are more variables than observations in the groups, the usual estimates are singular and cannot be used anymore. Assuming homoscedasticity, as in LDA, reduces the number of parameters to estimate. This rather strong assumption is however rarely verified in practice. Regularized discriminant techniques that are computable in high-dimension and cover the path between the two extremes QDA and LDA have been proposed in the literature. However, these procedures rely on sample covariance matrices. As such, they become inappropriate in presence of cellwise outliers, a type of outliers that is very likely to occur in high-dimensional datasets. In this paper, we propose cellwise robust counterparts of these regularized discriminant techniques by inserting cellwise robust covariance matrices. Our methodology results in a family of discriminant methods that (i) are robust against outlying cells, (ii) cover the gap between LDA and QDA and (iii) are computable in high-dimension. The good performance of the new methods is illustrated through simulated and real data examples. As a by-product, visual tools are provided for the detection of outliers. [less ▲]

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See detailCem anos com Saussure. Tomo 1
Badir, Sémir ULg; Beividas, Waldir; Lopes, Ivã Carlos

Book published by Anna Blume (2016)

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See detailCem anos com Saussure. Tomo 2
Badir, Sémir ULg; Beividas, Waldir; Lopes, Ivã Carlos

Book published by Anna Blume (2016)

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See detailLa "Cène" de Léonard de Vinci
Fagnart, Laure ULg

in Catalogue de l'exposition Leonardo da Vinci. The european genius (Bruxelles, Basilique de Koekelberg) (2007)

Detailed reference viewed: 62 (22 ULg)
See detailLa "Cène" de Léonard de Vinci. Une passion française ?
Fagnart, Laure ULg

Conference given outside the academic context (2007)

Detailed reference viewed: 9 (0 ULg)
See detailThe Cenomanian marine reorganization
Fischer, Valentin ULg

Poster (2011, January)

The middle Cretaceous is usually associated with numerous climatic and oceanic perturbations, and a minor to intermediate extinction event at the Cenomanian-Turonian (CTB) boundary. Amongst marine ... [more ▼]

The middle Cretaceous is usually associated with numerous climatic and oceanic perturbations, and a minor to intermediate extinction event at the Cenomanian-Turonian (CTB) boundary. Amongst marine vertebrate palaeontologists, the CTB is mostly known as the extinction of the last ichthyosaurs (Reptilia), after a long period of decline (e.g. Bardet, 1992; Bardet, 1994; Sander, 2000; Lingham-Soliar, 2003). However, new data from France, Canada and Russia indicates that the diversity of late Early Cretaceous ichthyosaurs was far higher than previously thought, both in terms of taxonomical and ecological diversity, but the Cenomanian ichthyosaur diversity remains extremely low. This suggests that the ichthyosaur extinction is far more severe than initially thought and took place during the whole duration of the Cenomanian, in a diachronic fashion. Additionally, a compilation of the current data on the diversity of other marine vertebrates groups shows that the Cenomanian is a peculiar stage within the Cretaceous, with the radiation burst of marine squamates, such as dolichosaurs and mosasauroids (Bardet et al., 2007; Bardet et al., 2008), as well as chondrichtyans, polycotylid plesiosaurs and teleost fishes (e.g. Cumbaa et al., 2010; Schultze et al., 2010). This profound reorganisation of the marine ecosystems (coeval with the onset of the “Chalk sea”) was probably driven by external, physical factors given the diversity of biotic responses. The numerous potential causes for that major reorganisation renders the identification of its precise mechanisms difficult. [less ▲]

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See detailCenomanian sands and clays north of the Vesdre valley: the oldest known Cretaceous deposits in eastern Belgium
Demoulin, Alain ULg; Quesnel, Florence; Dupuis, Christian et al

in Geologica Belgica (2010), 11(3), 241-256

A number of motored auger holes have been drilled in 2002 and 2006 in four sand-clay deposits preserved in dissolution pockets within the Dinantian limestones of the watershed north of the Vesdre valley ... [more ▼]

A number of motored auger holes have been drilled in 2002 and 2006 in four sand-clay deposits preserved in dissolution pockets within the Dinantian limestones of the watershed north of the Vesdre valley. These deposits of unknown age are currently classified as (Tertiary) SBL in the new geological map of Wallonia. We present detailed lithostratigraphic logs of the deposits and describe the results of sedimentological and mineralogical analyses. In particular, K-Ar dating of neoformed Mn oxides found at the base of one augerhole at Rechain yielded ages ranging from Cenomanian to Santonian, allowing us to place the Rechain and Andrimont deposits within the early Late Cretaceous. This is fully consistent with their topographic location very close beneath the trace of the pre-Cretaceous erosion surface and makes them the westernmost remains of the Hergenrath Member of the Late Cretaceous Aachen Formation. To the west, the Magnée deposit is more “typical SBL”, probably corresponding to the Late Neogene filling of a dissolution pocket by reworked weathering products of the local Cretaceous cover. [less ▲]

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See detailCenozoic and Devonian carbonate mound systems – comparisons of magnetic susceptibility behaviour between recent and ancient systems.
Da Silva, Anne-Christine ULg; Foubert, Anneleen; De Mol, Ben

in Travaux Géophysiques (2010), XXXIX

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See detailThe Cenozoic evolution of the strontium and carbon cycles: Relative importance of continental erosion and mantle exchanges
Godderis, Y.; François, Louis ULg

in Chemical Geology (1995), 126(2), 169-190

The past variations of the seawater Sr-87/Sr-86 isotopic ratio are related to changes in the relative contribution of the mantle Sr input to the ocean and the Sr supply from continental weathering ... [more ▼]

The past variations of the seawater Sr-87/Sr-86 isotopic ratio are related to changes in the relative contribution of the mantle Sr input to the ocean and the Sr supply from continental weathering. Recently, it has been postulated that the Cenozoic increase in the seawater Sr-87/Sr-86 isotopic ratio was associated with the uplift of the Himalayan and Andean mountains at that time. These orogenies may have changed the Sr isotopic ratio of the continental rocks undergoing weathering (as a result of extensive metamorphism), increased the river flux of Sr through enhanced weathering in these regions and possibly caused the global climatic cooling trend of the Cenozoic. A model of the major geochemical cycles coupled to an energy balance climate model is used to explore the possible causes of the Mesozoic-Cenozoic fluctuations in the seawater Sr-87/Sr-86 isotopic ratio. The contribution of the mantle exchanges at mid-ocean ridges, of the recycling of seafloor carbonates through plate margin volcanism and of the alteration of seafloor basalts to the fluctuations of the seawater Sr-87/Sr-86 isotopic ratio are studied. Finally, this model tentatively describes the impact of the Himalayan orogeny on the geochemical cycles of Sr and C. Some possible effects of the extensive metamorphism associated with the India-Asia collision and of the Himalayan uplift are modelled. The model reproduces the Cenozoic increase of the seawater Sr-87/Sr-86 isotopic ratio. However, the impact of the Himalayan orogeny on the C cycle appears to be limited and insufficient to generate the global climatic cooling of the Cenozoic. Rather, in the model, the Cenozoic cooling is mostly due to the reduction of the CO2 emission from mid-ocean ridge volcanism and to changes in the chemical weathering rates in the rest of the world excluding the Himalayas. [less ▲]

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See detailCenozoic Structure and Tectonic Evolution of the Kuqa Foldbelt, southern Tianshan, China
Wang, X.; Suppe, J.; Guan, S. et al

in American Association of Petroleum Geologists Memoir (2011), 94

The east–west-trending late Cenozoic Kuqa fold belt is a part of the compressive southern margin of the Tianshan Mountains in western China. Approximately 20,000 km (12,000 mi) of two-dimensional seismic ... [more ▼]

The east–west-trending late Cenozoic Kuqa fold belt is a part of the compressive southern margin of the Tianshan Mountains in western China. Approximately 20,000 km (12,000 mi) of two-dimensional seismic reflection profiles are integrated with surface geology and well data to examine the deformation style and structural evolution of the Kuqa fold belt. Mesozoic through Holocene strata in the northern Tarim Basin have been deformed in a thrust system that roots northward into the Paleozoic basement of the southern Tianshan. The south-vergent deformation is characterized by a series of forward-breaking thrust faults, fault-related folds, and detachment folds. Two major decollement levels exist: an upper detachment in salt-gypsum lithologies in the Paleogene–Miocene Kumgeliem, Suweiyi, and Jidike formations, and the lower detachment mostly within Jurassic coal and mudstone strata. Fault-propagation folds developed above both detachments and have been refolded in some cases by displacement on the lower thrust faults. Imbricate thrust faults and duplex structures linking the two detach- ments developed with salt that apparently flowed into the cores of the duplex structure. Near the high Tianshan mountain front, Mesozoic and Cenozoic strata are involved in deformation that began at approximately 25–26 Ma as documented by growth strata north of Kuqa. To- ward the southward limit of the fold belt, Miocene through Holocene strata are folded in the Quilitage and Yaken anticlines, which began growing above a thrust system that propagated at about 5.5 Ma. The Yaken anticline at the south edge of the eastern Kuqa fold belt has only emerged as a topographic anticline in the last 0.2 – 0.3 Ma associated with an acceleration of the Quilitage-Yaken thrust system. Structural restoration suggests a shortening of 15–20 km (9– 12 mi) across the eastern Kuqa fold belt. Considering that this shortening began about 25 Ma, the average shortening rate was about 0.7 mm/yr (0.03 in./yr). Because the frontal thrust system underlying the Quilitage and Yaken anticlines has a shortening of 6 km (3.7 mi) that began approximately 5.5 Ma, their average shortening rate is about 1.1 mm/yr (0.04 in./yr). However, the shortening rate on this frontal system from about 5.5 Ma to about 0.2–0.3 Ma is approximately 0.6 mm/yr (0.02 in./yr) followed by an acceleration to about 4–5 mm/yr (0.16–0.19 in./yr) at approximately 0.2–0.3 Ma, causing the topographic emergence of these structures. These results indicate that shortening rates in the Kuqa fold belt have increased in the late Pleistocene, which is consistent with more regional present-day geodetic shortening rates of about 9 mm/yr (0.35 in./yr) across the southern Tianshan, which also indicate a substantial acceleration relative to Neogene shortening rates. [less ▲]

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See detailCenozoic vegetation gradients in the mid- and higher latitudes of central Eurasia and climatic implications
Popova, S.; Utescher, T.; Gromyko, D. V. et al

in Palaeogeography, Palaeoclimatology, Palaeoecology (2017), 467

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See detailCensparreg
Heuchenne, Cédric ULg; Van Keilegom, Ingrid

Software (2010)

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See detailLa censure a-t-elle disparu ?
Durand, Pascal ULg

Article for general public (2007)

Detailed reference viewed: 24 (2 ULg)