Browsing
     by title


0-9 A B C D E F G H I J K L M N O P Q R S T U V W X Y Z

or enter first few letters:   
OK
Full Text
Peer Reviewed
See detailLe Mésolithique du Bassin pannonien et la formation du Rubané
Otte, Marcel ULg; Noiret, Pierre ULg

in Anthropologie (L') (2001), 105(3, JUL-SEP), 409-419

The LBK appears as the result of acculturation of local Mesolithic Populations, beginning in the Pannonian Basin following a trans-Balkan colonisation. Economy, architecture and ceramic proceed from an ... [more ▼]

The LBK appears as the result of acculturation of local Mesolithic Populations, beginning in the Pannonian Basin following a trans-Balkan colonisation. Economy, architecture and ceramic proceed from an adaptation to local means, which explains the chronological disjunction between acculturation and geographic expansion. The whole is placed within a context already Indo-European, since the Late Palaeolithic. (C) 2001 Editions scientifiques et medicales Elsevier SAS. [less ▲]

Detailed reference viewed: 45 (2 ULg)
Full Text
See detailLe Mésolithique récent du Trou Al’Wesse (comm. de Modave, Prov. de Liège) Découverte de tessons de type non rubanés ou «Bereitkeramiek»
Miller, Rebecca ULg; Otte, Marcel ULg; Stewart, John

in Notae Praehistoricae (2009), 29

On the terrace of the site of Trou Al'Wesse, commun of Modave (province of Liège, Belgium), stratum 4b-δ, excavated in 2008, has been attributed to the Late Mesolithic. Ceramic sherds of La Hoguette type ... [more ▼]

On the terrace of the site of Trou Al'Wesse, commun of Modave (province of Liège, Belgium), stratum 4b-δ, excavated in 2008, has been attributed to the Late Mesolithic. Ceramic sherds of La Hoguette type have been recovered from near the top of this Mesolithic context, which contains lithic artifacts, a charcoal lens, wild fauna including an aurochs astragalus with cutmarks, and a sawn red deer crown antler. LBK sherds of the type found in overlying stratum 4a, are absent in facies 4b-δ. This is the first time that La Hoguette sherds have been found instratified context associated with material that can be radiometrically dated, and also the first time that such sherds have been discovered south of the Meuse and Sambre in Belgium. New dates from this stratum contribute to placing these sherds and the other elements in chronological context. [less ▲]

Detailed reference viewed: 47 (4 ULg)
See detailMeson modes in Nuclear Matter in the Nambu – Jona-Lasinio Model
Jaminon, Martine ULg; Mendez Galain, Ramon; Stassart, Pierre

Conference (2001)

Detailed reference viewed: 6 (0 ULg)
Full Text
See detailMesopelagic C mineralization at the Southern Ocean’s scale
Jacquet, S.; Dehairs; Elskens, M. et al

Conference (2007, April)

Detailed reference viewed: 11 (0 ULg)
Full Text
Peer Reviewed
See detailMesophilic biohydrogen production by Clostridium butyricum CWBI1009 in trickling biofilter reactor
Puhulwella, Rathnasiri G.; Beckers, Laurent; Delvigne, Frank ULg et al

in International Journal of Hydrogen Energy (2014), 39

This study investigates the mesophilic biohydrogen production from glucose using a strictly anaerobic strain, Clostridium butyricum CWBI1009, immobilized in a trickling bed sequenced batch reactor (TBSBR ... [more ▼]

This study investigates the mesophilic biohydrogen production from glucose using a strictly anaerobic strain, Clostridium butyricum CWBI1009, immobilized in a trickling bed sequenced batch reactor (TBSBR) packed with a Lantec HD Q-PAC® packing material (132 ft2/ft3 specific surface). The reactor was operated for 62 days. The main parameters measured here were hydrogen composition, hydrogen production rate and soluble metabolic products. pH, temperature, recirculation flow rate and inlet glucose concentration at 10 g/L were the controlled parameters. The maximum specific hydrogen production rate and the hydrogen yield found from this study were 146 mmol H2/L.d and 1.67 mol H2/mol glucose. The maximum hydrogen composition was 83%. Following a thermal treatment, the culture was active without adding fresh inoculum in the subsequent feeding and both the hydrogen yield and the hydrogen production rate were improved. For all sequences, the soluble metabolites were dominated by the presence of butyric and acetic acids compared to other volatile fatty acids. The results from the standard biohydrogen production (BHP) test which was conducted using samples from TBSBR as inoculum confirmed that the culture generated more biogas and hydrogen compared to the pure strain of C. butyricum CWBI1009. The effect of biofilm activity was studied by completely removing (100%) the mixed liquid and by adding fresh medium with glucose. For three subsequent sequences, similar results were recorded as in the previous sequences with 40% removal of spent medium. The TBSBR biofilm density varied from top to bottom in the packing bed and the highest biofilm density was found at the bottom plates. Moreover, no clogging was evidenced in this packing material, which is characterized by a relatively high specific surface area. Following a PCA test, contaminants of the Bacillus genus were isolated and a standard BHP test was conducted, resulting in no hydrogen production. [less ▲]

Detailed reference viewed: 123 (16 ULg)
Full Text
Peer Reviewed
See detailMesoporosity of Zeolite Y – 3D Quantitative Study by Image Analysis of Electron Tomograms
Zecevic, Jovana; Gommes, Cédric ULg; friedrich, Heiner et al

in Angewandte Chemie International Edition (2012), 51

Detailed reference viewed: 31 (3 ULg)
Full Text
Peer Reviewed
See detailMesoporous amorphous tungsten oxide electrochromic films: a Raman analysis of their good switching behavior
Chatzikyriakou, Dafni ULg; Krins, Natacha ULg; Gilbert, Bernard ULg et al

in Electrochimica Acta (2014), 137

The intercalation and de-intercalation of lithium cations in electrochromic tungsten oxide thin films are significantly influenced by their structural and surface characteristics. In this study, we ... [more ▼]

The intercalation and de-intercalation of lithium cations in electrochromic tungsten oxide thin films are significantly influenced by their structural and surface characteristics. In this study, we prepared two types of amorphous films via the sol-gel technique: one dense and one mesoporous in order to compare their response upon lithium intercalation and de-intercalation. According to chronoamperometric measurements, Li+ intercalates/de-intercalates faster in the mesoporous film (24s/6s) than in the dense film (48s/10s). The electrochemical measurements (cyclic voltammetry and chronoamperometry) also showed worse reversibility for the dense film compared to the mesoporous film, giving rise to important Li+ trapping and remaining coloration of the film. Raman analysis showed that the mesoporous film provides more accessible and various W-O surface bonds for Li+ intercalation. On the contrary, in the first electrochemical insertion and de-insertion in the dense film, Li+ selectively reacts with a few surface W-O bonds and preferentially intercalates into pre-existing crystallites to form stable irreversible LixWO3 bronze. [less ▲]

Detailed reference viewed: 58 (19 ULg)
Full Text
Peer Reviewed
See detailMesoporous Lithium Vanadium Oxide as Thin Film Electrode for Lithium-Ion Batteries: Comparison between Direct Synthesis of LiV2O5 and Electrochemical Lithium Intercalation in V2O5
Caes, Sébastien ULg; Arrebola, Jose Carlos; Krins, Natacha ULg et al

in Journal of Materials Chemistry A (2014), 2

Research in the field of lithium-ion batteries favours electrode materials with high surface area. In this context, this paper is dedicated to mesoporous thin films (MTFs) and compares the electrochemical ... [more ▼]

Research in the field of lithium-ion batteries favours electrode materials with high surface area. In this context, this paper is dedicated to mesoporous thin films (MTFs) and compares the electrochemical performance of g-LiV2O5 MTFs with post-synthesis electrochemical lithium intercalation in a-V2O5 MTFs. Formation of vanadium oxide MTFs by soft-chemistry is notoriously difficult. However, it is shown that wormlike vanadium oxide (V–O) and lithium vanadium oxide (Li–V–O) MTFs can be obtained on silicon substrates by a direct sol–gel soft-templating route (evaporation-induced micelle assembly) using a polystyrene-block-poly(ethylene oxide) (PS-b-PEO) structuring agent. Heat treatment for 1 minute at 400 C (Li–V–O system) or 30 minutes at 350 C (V–O system) leads to the crystallization of g-LiV2O5 or a-V2O5, respectively. These calcination conditions ensure the degradation of the structuring agent while preventing the collapse of the mesostructure, yielding MTFs with pore size diameter in the 30–35 nm range. Using the same set of synthesis conditions, films can be deposited on conductive glass substrates for electrochemical investigation: the a-V2O5 films display better specific capacities, while the cyclability is good for both compositions, even at a current density as high as 30 C-rate. [less ▲]

Detailed reference viewed: 102 (18 ULg)
Full Text
Peer Reviewed
See detailMesoporous SiO2 thin films containing ZnO photoluminescent nanoparticles. Simultaneous SAXS / WAXS / Ellipsometry investigations
Krins, Natacha ULg; Bass, J. D.; Julián-López, B. et al

in Journal of Materials Chemistry (2011), 21

Detailed reference viewed: 7 (1 ULg)
Full Text
See detailMesoporous TiO2 thin films for photovoltaic applications
Dewalque, Jennifer ULg; Mathieu, Xavier; Decroly, André et al

Poster (2008, August)

Thin films of nanocrystalline, mesostructured titanium dioxide are very promising materials to build low cost and efficient photovoltaic devices. TiO2 present a high chemical stability and electronic ... [more ▼]

Thin films of nanocrystalline, mesostructured titanium dioxide are very promising materials to build low cost and efficient photovoltaic devices. TiO2 present a high chemical stability and electronic properties such as photo-induced electronic transfer properties associated with the anatase phase. For many applications, highly porous nanostructured thin films with accessible pores are preferable to dense ones. Indeed, high accessible porosity leads to high surface area increasing the electron transfer surface. [less ▲]

Detailed reference viewed: 46 (4 ULg)
Full Text
See detailMesoporous TiO2 thin films for photovoltaic applications
Dewalque, Jennifer ULg; Cloots, Rudi ULg; Mathis, François ULg et al

Poster (2008, September 08)

Thin films of nanocrystalline, mesostructured titanium dioxide are very promising materials to build low cost and efficient photovoltaic devices. TiO2 present a high chemical stability and electronic ... [more ▼]

Thin films of nanocrystalline, mesostructured titanium dioxide are very promising materials to build low cost and efficient photovoltaic devices. TiO2 present a high chemical stability and electronic properties such as photoinduced electronic transfer properties associated with the anatase phase. For many applications, highly porous nanostructured thin films with accessible pores are preferable to dense ones. Indeed, high accessible porosity leads to high surface area increasing the electron transfer area. [less ▲]

Detailed reference viewed: 41 (5 ULg)
Full Text
Peer Reviewed
See detailMesoporous zirconium oxides: An investigation of physico-chemical synthesis parameters
Blin, J. L.; Gigot, L.; Léonard, Alexandre ULg et al

in Studies in Surface Science and Catalysis (2002), 141

A systematic kinetic study of mesoporous zirconia formation has been performed in order to optimize the synthesis conditions without addition of structure stabilizing agents such as sulfate or phosphate ... [more ▼]

A systematic kinetic study of mesoporous zirconia formation has been performed in order to optimize the synthesis conditions without addition of structure stabilizing agents such as sulfate or phosphate anions. We have investigated in particular the effect of synthesis time and temperature. On the basis of TEM, SEM XRD and N 2 adsorption-desorption results, a synthesis mechanism has been proposed. Low temperature or short duration afford supermicroporous materials and continuation of hydrothermal treatment makes the walls separating adjacent pores break down allowing the transformation to mesopores. The obtained materials have a uniform pore size and their surface can reach 400m 2/g. However, if hydrothermal treatment is performed at too high temperatures or for too long durations, mesoporous compounds are no longer obtained, but thermodynamically more stable crystalline zirconium oxides with very low specific surface area, namely the tetragonal and monoclinic forms, are the final phases that are more likely to appear. [less ▲]

Detailed reference viewed: 25 (9 ULg)
Full Text
Peer Reviewed
See detailMesoscale Characterization of Nanoparticles Distribution Using X-Ray Scattering
Gommes, Cédric ULg; Prieto, Gonzalo; Zecevic, Jovana et al

in Angewandte Chemie International Edition (2015), 54

The properties of many functional materials depend critically on the spatial distribution of an active phase within a matrix or support material. In the case of solid catalysts, controlling the spatial ... [more ▼]

The properties of many functional materials depend critically on the spatial distribution of an active phase within a matrix or support material. In the case of solid catalysts, controlling the spatial distribution of metal (oxide) nanoparticles at the mesoscopic scale offers new strategies to tune their performance and enhance their lifetimes. However, such advanced control requires the development of suitable methods to characterize the spatial distribution of nanoparticles at the mesoscopic scale. Currently electron microscopy and more specifically electron tomography is close to being the only option. Here, we show how the background in x-ray scattering patterns can be analyzed to quantitatively access the distribution of metal nanoparticles within support materials displaying hierarchical porosity. Our approach is illustrated for copper catalysts supported on meso- and micro-porous silica, which display distinctly different metal spatial distributions. Results derived from the modeling of x-ray scattering patterns are in excellent agreement with electron tomography observations, while the amount of material being characterized at once is enhanced by twelve orders of magnitude. Our strategy opens unprecedented prospects to understand structure-property relationships and to guide the synthesis of advanced supported catalysts as well as a wide array of other functional nanomaterials. [less ▲]

Detailed reference viewed: 222 (14 ULg)
Full Text
Peer Reviewed
See detailMesoscale structures from magnetocapillary self-assembly
Vandewalle, Nicolas ULg; Obara, Noriko; Lumay, Geoffroy ULg

in European Physical Journal E -- Soft Matter (2013), 36

When identical soft ferromagnetic particles are suspended at some water-air interface, capillary attraction is balanced by magnetic repulsion induced by a vertical magnetic field. By adjusting the ... [more ▼]

When identical soft ferromagnetic particles are suspended at some water-air interface, capillary attraction is balanced by magnetic repulsion induced by a vertical magnetic field. By adjusting the magnetic field strength, the equilibrium interdistance between particles can be tuned. The aim of this paper is to study the ordering of particles for large assemblies. We have found an upper size limit above which the assembly collapses due to capillary effects. Before reaching this critical number of particles, defects are always present and limit the perfect ordering expected for that system. This is due to the curvature of the interface induced by the weight of the self-assembly. [less ▲]

Detailed reference viewed: 17 (2 ULg)
Full Text
Peer Reviewed
See detailMesoscale surface distribution of biogeochemical characteristics in the Crozet Basin frontal zones (South Indian Ocean)
Fiala, M.; Delille, Bruno ULg; Dubreuil, C. et al

in Marine Ecology. Progress Series (2003), 249

A mesoscale study was conducted in January and February 1999 in the Crozet Basin frontal zones (43degrees50' to 45degrees20'S, 61degrees00' to 64degrees30'E) within the southernmost and easternmost ... [more ▼]

A mesoscale study was conducted in January and February 1999 in the Crozet Basin frontal zones (43degrees50' to 45degrees20'S, 61degrees00' to 64degrees30'E) within the southernmost and easternmost convergence area of the Antarctic Circumpolar Current (ACC) and the Agulhas Return Current (ARC). Distribution of biogeochemical parameters was strongly linked to the merged Subtropical (STF) and Subantarctic (SAF) Fronts which mark the border between the cold and less saline subantarctic waters and the warm and more saline subtropical waters. This survey took place during a post-bloom period. Chlorophyll a concentrations were low throughout the study area ranging from 0.2 mug l(-1) in the Polar Frontal Zone (PFZ) to 0.4 mug l(-1) in the Subtropical Zone (STZ). Maximum chlorophyll a values (0.8 mug l(-1)) associated with an increase in biogenic silica concentration (from 0.03 to 0.34 muM) and a diatom peak (1.2 x 10(5) cells l(-1)) were encountered in the northeastern part of the STF edge. Despite northwardly decreasing concentrations of nitrates from 14 muM in the PFZ to 6 PM in the STZ, they were not the main factor limiting phytoplankton growth. Low silicic acid (mean = 0.6 muM) could have limited diatom development in the PFZ and the STZ where diatom numbers were low. In STZ waters, where average diatom numbers were highest, various species of Nitzschia and Thalassiothrix were common, but Pseudonitzschia spp. were dominant. Throughout the survey area, pico- and nano-sized cells dominated the phytoplankton assemblage, and their number was the highest in the STZ. Cyanobacteria, only present in subtropical waters >12.5degreesC, were the major component of the picoplankton size-fraction. While dinoflagellate numbers were low in the Subantarctic Zone (SAZ), their abundance and species numbers increased in the STZ, where Oxytoxum laticeps became dominant and several further large-size species of Prorocentrum, Ceratium and Gymnodinium appeared in addition to those at the STF. The distribution of different biogeochemical parameters suggests that the Crozet Basin frontal region is a non-exporting system at the end of summer. During this post-bloom period, biological activity is low and phytoplankton growth severely limited. This is evidenced by the weak dependence of the partial pressure of carbon dioxide (pCO(2)) on biological activity and the importance of the air-sea exchange in maintaining pCO(2) close to saturation. [less ▲]

Detailed reference viewed: 42 (13 ULg)
Full Text
Peer Reviewed
See detailMesoscopic cross-film cryotrons: Vortex trapping and dc-Josephson-like oscillations of the critical current
Aladyshkin, A Yu; Ataklti, G. W.; Gillijns, W. et al

in Physical Review. B : Condensed Matter (2011), 83(14),

We investigate theoretically and experimentally the transport properties of a plain Al superconducting strip in the presence of a single straight current-carrying wire, oriented perpendicular to the ... [more ▼]

We investigate theoretically and experimentally the transport properties of a plain Al superconducting strip in the presence of a single straight current-carrying wire, oriented perpendicular to the superconducting strip. It is well known that the critical current of the superconducting strip, I(c), in such a cryotron-like system can be tuned by changing the current in the control wire, I(w). We demonstrated that the discrete change in the number of the pinned vortices/antivortices inside the narrow and long strip nearby the current-carrying wire results in a peculiar oscillatory dependence of I(c) on I(w). [less ▲]

Detailed reference viewed: 19 (3 ULg)
Full Text
Peer Reviewed
See detailMesoscopic fluctuations of the Loschmidt echo
Petitjean, Cyril ULg; Jacquod, P.

in PHYSICAL REVIEW E (2005), 71(3), 036223-6

We investigate the time-dependent variance of the fidelity with which an initial narrow wave packet is reconstructed after its dynamics is time reversed with a perturbed Hamiltonian. In the semiclassical ... [more ▼]

We investigate the time-dependent variance of the fidelity with which an initial narrow wave packet is reconstructed after its dynamics is time reversed with a perturbed Hamiltonian. In the semiclassical regime of perturbation, we show that the variance first rises algebraically up to a critical time t(c), after which it decays. To leading order in the effective Planck's constant h(eff), this decay is given by the sum of a classical term similar or equal to exp[-2 lambda t], a quantum term similar or equal to 2h(eff) exp[-Gamma t], and a mixed term similar or equal to 2 exp[-(Gamma+lambda)t]. Compared to the behavior of the average fidelity, this allows for the extraction of the classical Lyapunov exponent lambda in a larger parameter range. Our results are confirmed by numerical simulations. [less ▲]

Detailed reference viewed: 18 (0 ULg)
Full Text
Peer Reviewed
See detailMesoscopic model of intergranular cracks in low carbon steel during cooling of continuous casting
Castagne, S.; Pascon, Frédéric ULg; Lecomte-Beckers, Jacqueline ULg et al

in Lamberigts, M. (Ed.) Proceedings of the 2nd international conference of thermomechanical processing of steels (TMP 2004) (2004)

This paper addresses the problem of transverse cracking during the continuous casting of low carbon steel. The damage mechanisms occurring at high temperature during this process are identified and a ... [more ▼]

This paper addresses the problem of transverse cracking during the continuous casting of low carbon steel. The damage mechanisms occurring at high temperature during this process are identified and a numerical approach for the modelling of these phenomena at the grain scale is proposed. Experiments allowing the identification of the model’s parameters are described. Finally, the first results obtained with the model are presented. [less ▲]

Detailed reference viewed: 53 (5 ULg)
See detailMesoscopic physics of matter waves
Schlagheck, Peter ULg

Conference (2010, July)

Detailed reference viewed: 7 (2 ULg)