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See detailHigh spatial resolution of late-Holocene human activities in the moist forests of central Africa using soil charcoal and charred botanical remains
Morin, Julie ULg; Biwolé, Achille; Gorel, Anaïs ULg et al

in Holocene (2016), 26(12), 1954-1967

Palaeoecological and archaeological studies have demonstrated that human populations have long inhabited the moist forests of central Africa. However, spatial and temporal patterns of human activities ... [more ▼]

Palaeoecological and archaeological studies have demonstrated that human populations have long inhabited the moist forests of central Africa. However, spatial and temporal patterns of human activities have hardly been investigated with satisfactory accuracy. In this study, we propose to characterize past human activities at local scale by using a systematic quantitative and qualitative methodology based on soil charcoal and charred botanical remains. A total of 88 equidistant test-pits were excavated along six transects in two contrasting forest types in southern Cameroon. Charred botanical remains were collected by water-sieving and sorted by type (wood charcoals, oil palm endocarps, and unidentified seeds). A total of 50 Accelerator Mass Spectrometry 14C dates were also obtained. Results showed that charred macroremains were found at multiple places in the forest, suggesting scattered human activities, which were distributed into two main periods (Phase A: 2300-1300 BP – Phase B: 580 BP to the present). Charred botanical remains indicated two types of land use: (i) domestic, with oil palm endocarps most often associated with potsherds (villages) and (ii) agricultural, with charcoal as probable remnant of slash-and-burn cultivation (fields). Oil palm endocarp abundance decreased with distance from the identified human settlements. Our methodology allowed documenting, at high resolution, the spatial and temporal patterns of human activities in central African moist forests and could be applied to other tropical contexts. [less ▲]

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See detailHigh spatial resolution of late-Holocene human activities in the moist forests of Central Africa using soil charcoal and charred botanical remains
Morin, Julie ULg; Biwolé, Achille; Gorel, Anaïs ULg et al

Conference (2015, April 27)

Palaeoecological and archaeological studies have demonstrated that human populations have long inhabited the moist forests of central Africa. However, spatial and temporal patterns of human activities ... [more ▼]

Palaeoecological and archaeological studies have demonstrated that human populations have long inhabited the moist forests of central Africa. However, spatial and temporal patterns of human activities have hardly been investigated with satisfactory accuracy. In this study, we propose to characterize past human activities at local scale by using a systematic quantitative and qualitative methodology based on soil charcoal and charred botanical remains. A total of 88 equidistant test-pits were excavated along six transects in two contrasting forest types in southern Cameroon. Charred botanical remains were collected by water-sieving and sorted by type (wood charcoals, oil palm endocarps, and unidentified seeds). A total of 50 Accelerator Mass Spectrometry 14C dates were also obtained. Results showed that charred macroremains were found at multiple places in the forest, suggesting scattered human activities, which were distributed into two main periods (Phase A: 2300-1300 BP – Phase B: 580 BP to the present). Charred botanical remains indicated two types of land use: (i) domestic, with oil palm endocarps most often associated with potsherds (villages) and (ii) agricultural, with charcoal as probable remnant of slash-and-burn cultivation (fields). Oil palm endocarp abundance decreased with distance from the identified human settlements. Our methodology allowed documenting, at high resolution, the spatial and temporal patterns of human activities in central African moist forests and could be applied to other tropical contexts. [less ▲]

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See detailHigh spectral resolution monitoring of Nova V339 Delphini with TIGRE
De Gennaro Aquino, I.; Schröder, K.-P.; Mittag, M. et al

in Astronomy and Astrophysics (2015), 581

We investigate the early development of the classical nova V339 Del (Nova Delphini 2013) through high-resolution optical spectroscopy. To study the structure of the ejecta, we focus on the evolution of ... [more ▼]

We investigate the early development of the classical nova V339 Del (Nova Delphini 2013) through high-resolution optical spectroscopy. To study the structure of the ejecta, we focus on the evolution of the absorption and emission features and the changes within the line profiles. We obtained spectra with the robotic 1.2 m telescope TIGRE equipped with the HEROS spectrograph (R = 20 000, wavelength coverage from 3800 to 8800 Å). Our data set covers the outburst from 3 until 121 days after discovery. We provide a qualitative analysis of the spectra, describing the line profiles evolution and providing a rich list of identified lines. During the optically thick phase, we detected several blue-shifted absorption features from s-processed elements, whose origin is unclear. The presence of strong lines from C/O and the absence of Neon features confirm that the nature of the central white dwarf is a CO type. The later "nebular" phase spectra show evidence of the non-spherical, inhomogeneous structure of the ejecta. The detailed evolution of the line profiles and appearance of high ionization species (e.g. N III, O III, He II, [Fe VII]) are direct consequences of the re-ionization of the ejecta during the peak of the soft X-ray emission. [less ▲]

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See detailHigh spectral resolution monitoring of Nova V339 Delphini with TIGRE (Corrigendum)
De Gennaro Aquino, I.; Schröder, K.-P.; Mittag, M. et al

in Astronomy and Astrophysics (2016), 589

The tags in Table 2, indicating the positions of the most prominent spectral features in Figs. 2a and b, were not corrected during the revision process. We include here the corrected table. The lines ... [more ▼]

The tags in Table 2, indicating the positions of the most prominent spectral features in Figs. 2a and b, were not corrected during the revision process. We include here the corrected table. The lines observed and identified in the spectra and the respective phases remain unchanged. [less ▲]

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See detailHigh Speed Astronomical Photometry -- Brian Warner
Manfroid, Jean ULg

in Ciel et Terre (1989), 105

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See detailHigh strength steel in seismic resistant building frames (HSS-SERF)
Dubina, Dan; Vulcu, Cristian; Stratan, Aurel et al

Book published by Commission Européenne (2015)

The aim of “HSS-SERF” project was to investigate and evaluate the seismic performance of dual-steel building frames, realized from two different steel grades: Mild Carbon Steel (MCS) and High Strength ... [more ▼]

The aim of “HSS-SERF” project was to investigate and evaluate the seismic performance of dual-steel building frames, realized from two different steel grades: Mild Carbon Steel (MCS) and High Strength Steel (HSS). A comprehensive set of dual-steel frames (moment resisting, concentrically and eccentrically braced) were designed, which allowed the identification of realistic member sizes for both MCS and HSS components. Several practical solutions for bolted and welded beam-to-column joints were identified and designed. Further, an extensive numerical program was carried out for the seismic performance evaluation of frames. The ductility and over-strength demands, and q-factors associated with different performance levels were evaluated. Furthermore, experimental and numerical investigations were carried out on joint assemblies and components. Guidelines were elaborated for the conceptual design and PBD of dual-steel frames under seismic actions, and the technical and economic efficiency of dualsteel structures vs. conventional ones were finally evaluated. The main outcomes of the project consist in: (i) development and characterisation in terms of global ductility and over-strength demands of dual-steel frames with composite columns (innovative solutions in European context); (ii) development of design recommendations; (iii) proposal of innovative solutions for beam-to-column joints with composite columns; (iv) recommendation for weld details and appropriate component method design approaches; (v) evaluation of technical and economic efficiency of the dual-steel approach. [less ▲]

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See detailHigh temperature catalysts through sol-gel synthesis
Lecloux, A. J.; Pirard, Jean-Paul ULg

in Journal of Non-Crystalline Solids (1998), 225

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See detailHIGH TEMPERATURE CORROSION RESISTANCE OF METALLIC MATERIALS IN HARSH CONDITIONS
Novello, Frederic; Dedry, Olivier ULg; De Noose, Vincent et al

in Lecomte-Beckers, Jacqueline; Dedry, Olivier; Oakey, John (Eds.) et al Proceedings of the 10th Conference on Materials for Advanced Power Engineering 2014 (2014, September)

Highly efficient energy recovery from renewable sources and from waste incineration causes new problems of corrosion at high temperature. A similar situation exists for new recycling processes and new ... [more ▼]

Highly efficient energy recovery from renewable sources and from waste incineration causes new problems of corrosion at high temperature. A similar situation exists for new recycling processes and new energy storage units. These corrosions are generally considered to be caused by ashes or molten salts, the composition of which differs considerably from one plant to another. Therefore, for the assessment of corrosion-resistance of advanced materials, it is essential to precisely evaluate the corrosion rate under conditions close to industrial conditions. To be able to advise their customers in selecting the right material or the right protective coating, the present authors are developing testing equipment and related procedures to assess the high temperature corrosion rate of metallic materials. This paper describes the testing equipment developed so far and presents the first results obtained in two corrosive environments: the aggressive condensates that affect waste incinerators (mixture of liquid/solid salts in oxidising conditions) and heat transfer fluids of electric power generating plants based on solar towers (mixture of liquid salts). Temperatures range from 400 to 650°C. Tested materials include 16Mo3 (0.3% molybdenum steel alloy), Inconel 625 (austenitic nickel-chromium-based superalloys), Nickel 200, Ni-57CrMoSiB (nickel-base coating with high chromium content and boron as additional element) and Grade 91 (9% chrome- 1% molybdenum steel alloy). [less ▲]

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See detailHigh temperature crossover in paraconductivity of granular Y1Ba2Cu3O7-y
Ausloos, Marcel ULg; Gillet, François ULg; Laurent, Christian et al

in Zeitschrift für Physik. B, Condensed Matter (1991), 84(1), 13-16

We have examined the deviation from linearity of the temperature dependence of the electrical resistivity of a YBaCuO ceramics. We have observed at high temperature a crossover behavior toward a ... [more ▼]

We have examined the deviation from linearity of the temperature dependence of the electrical resistivity of a YBaCuO ceramics. We have observed at high temperature a crossover behavior toward a logarithmic temperature dependence at lower temperature. It seems relevant to attribute the origin of such a term to a pair breaking mechanism contribution, thus to give a lower bound to the existence of superconductivity fluctuations onset temperature. Our findings also implies that carriers are bosons above T(c). [less ▲]

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See detailHigh Temperature Ferromagnetism in a GdAg2 Monolayer
Ormaza, M.; Fernandez, L.; Ilyn, M. et al

in Nano Letters (2016), 0(0),

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See detailHigh temperatures limit plant growth but hasten flowering in root chicory (Cichorium intybus) independently of vernalisation.
Mathieu, Anne-Sophie; Lutts, Stanley; Vandoorne, Bertrand et al

in Journal of Plant Physiology (2013), in press

An increase in mean and extreme summer temperatures is expected as a consequence of climate changes and this might have an impact on plant development in numerous species. Root chicory (Cichorium intybus ... [more ▼]

An increase in mean and extreme summer temperatures is expected as a consequence of climate changes and this might have an impact on plant development in numerous species. Root chicory (Cichorium intybus L.) is a major crop in northern Europe, and it is cultivated as a source of inulin. This polysaccharide is stored in the tap root during the first growing season when the plant grows as a leafy rosette, whereas bolting and flowering occur in the second year after winter vernalisation. The impact of heat stress on plant phenology, water status, photosynthesis-related parameters, and inulin content was studied in the field and under controlled phytotron conditions. In the field, plants of the Crescendo cultivar were cultivated under a closed plastic-panelled greenhouse to investigate heat-stress conditions, while the control plants were shielded with a similar, but open, structure. In the phytotrons, the Crescendo and Fredonia cultivars were exposed to high temperatures (35 °C day/ 28 °C night) and compared to control conditions (17 °C) over 10 weeks. In the field, heat reduced the root weight, the inulin content of the root and its degree of polymerisation in non-bolting plants. Flowering was observed in 12% of the heat stressed plants during the first growing season in the field. In the phytotron, the heat stress increased the total number of leaves per plant, but reduced the mean leaf area. Photosynthesis efficiency was increased in these plants, whereas osmotic potential was decreased. High temperature was also found to induce flowering of up to 50% of these plants, especially for the Fredonia cultivar. In conclusion, high temperatures induced a reduction in the growth of root chicory, although photosynthesis is not affected. Flowering was also induced, which indicates that high temperatures can partly substitute for the vernalisation requirement for the flowering of root chicory [less ▲]

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See detailHigh temporal coverage of carbon dioxide measurements in the Southern Bight of the North Sea
Schiettecatte, L. S.; Thomas, H.; Bozec, Y. et al

in Marine Chemistry (2007), 106(1-2), 161-173

A monthly survey of the partial pressure of CO2 (pCO2) was carried in the Southern Bight of the North Sea (SBNS) from June 2003 to May 2004. The spatial variability of the surface distribution of the pCO2 ... [more ▼]

A monthly survey of the partial pressure of CO2 (pCO2) was carried in the Southern Bight of the North Sea (SBNS) from June 2003 to May 2004. The spatial variability of the surface distribution of the pCO2 was relatively small (within a range of 10–70 μatm) compared to the amplitude in the seasonal signal (∼260 μatm). On an annual scale, the pCO2 dynamics appeared to be controlled by biological processes (primary production in springtime and respiratory processes in summer), rather than temperature (in summer). The comparison with measurements carried out in 2001 and 2002 (13 cruises) shows that the inter-annual variability of pCO2 was close to the range of the spatial variability and mostly observed in spring, associated to biological processes (primary production). Net ecosystem production estimated from dissolved inorganic carbon (DIC) temporal variations showed that the SBNS is autotrophic, at an annual rate of 6.3 mol C m−2 yr−1. The decoupling in time between autotrophy in spring and heterotrophy in summer, associated to the relatively rapid flushing time of the water mass in the area (∼70 days), might allow the export of a fraction of the springtime synthesized organic matter to the adjacent areas of the North Sea. The SBNS was on a yearly basis a sink of atmospheric CO2 at a rate of −0.7 mol C m−2 yr−1. [less ▲]

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See detailHigh Throughput determination of Levonorgestrel in human plasma using a Sensitive LC-MS/MS method
Hubert, Cédric ULg; Streel, Bruno; Sibenaler, Renilde et al

Poster (2011, June 19)

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See detailHigh throughput sequencing analysis reveals genetic variability and selection pressure in different murine norovirus genomic regions during in vitro replication
Mauroy, Axel ULg; Taminiau, Bernard ULg; Nezer, Carine et al

Poster (2014, July)

Murine norovirus (MuNoV), a single stranded positive sense RNA virus belonging to the Caliciviridae family, is considered as a representative model for human norovirus infections, one of the most ... [more ▼]

Murine norovirus (MuNoV), a single stranded positive sense RNA virus belonging to the Caliciviridae family, is considered as a representative model for human norovirus infections, one of the most important etiological cause of both epidemic and sporadic gastroenteritis cases worldwide. Four open reading frames are described into its genome: ORF1 codes the non-structural (NS) proteins, including the viral RNA dependent RNA polymerase (RdRp); ORF2 codes the single capsid protein (VP1), wherein two domains are present: a relatively conserved domain (“shell”) and a more variable domain (“protruding”); ORF3 codes a minor structural protein; and ORF4, currently only found in viruses genetically related to MuNoV codes a virulence factor. In this study, we demonstrated by high throughput sequencing that, during serial passages of MuNoV in cell culture, the substitution rates, estimated by Bayesian inferences, did not significantly differ across the five targeted genomic regions except one. These rates were similar in four genomic regions encompassing partial non-structural 1-2 protein (NS1-2)-, NS5-, NS6-, NS7 (RdRp)- and VP1-coding sequences (coding the conserved part of the protein also including the ORF4 region). In the partial minor structural protein-coding region, this substitution rate was however estimated to be at least one log higher when expressed as substitution/site/day. The precise localisation of the detected nucleotide point mutations (substitution, deletion and insertion) were reported as well as the quantitative increase or decrease of the sequences harbouring them along ten cell culture passages. The non-silent amino acid mutations were also depicted in 3D models for four out of the five studied regions. These results have important implications for different norovirus research fields, especially in terms of diagnosis, classification methodology and genetic evolution. [less ▲]

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See detailHigh Throughput sequencing and biological research: Paradigm switches from genetics to ecophysiology
Massart, Sébastien ULg

Scientific conference (2014, June)

A technological revolution is ongoing in sequencing and is deeply impacting biological research. This leads to paradigm switches in traditional « sequencing-friendly » areas, like genetic or microbiology ... [more ▼]

A technological revolution is ongoing in sequencing and is deeply impacting biological research. This leads to paradigm switches in traditional « sequencing-friendly » areas, like genetic or microbiology, but also expands the usefulness of sequencing in other areas such as ecophysiology or ecology. [less ▲]

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See detailHigh throughput sequencing of aphid haemolymph reveals endosymbiont diversity
De Clerck, Caroline ULg; Leonard, Simon; Joncour, Pauline et al

Conference (2014, May 20)

Detailed reference viewed: 25 (4 ULg)