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See detailImproved separation of the 209 PCBs using GCxGC-TOFMS
Focant, Jean-François ULg; Sjödin, Andreas; Patterson, Donald G.

in Organohalogen Compounds (2004), 66

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See detailImproved separation of the 209 polychlorinated biphenyl congeners using comprehensive two-dimensional gas chromatography-time-of-flight mass spectrometry
Focant, Jean-François ULg; Sjödin, Andreas; Patterson, Donald G.

in Journal of Chromatography. A (2004), 1040(2), 227-238

The separation of the 209 polychlorinated biphenyl (PCB) congeners has been studied using comprehensive two-dimensional gas chromatography coupled to time-of-flight mass spectrometry (GC x GC-TOFMS). Four ... [more ▼]

The separation of the 209 polychlorinated biphenyl (PCB) congeners has been studied using comprehensive two-dimensional gas chromatography coupled to time-of-flight mass spectrometry (GC x GC-TOFMS). Four column combinations based on thermally stable phases, DB-1/HT-8, DB-XLB/HT-8, DB-XLB/BPX-50, and HT-8/BPX-50, have been investigated. The HT-8/BPX-50 set produced the best separation. The distribution of the 100 to 150 ms wide peaks was highly structured in the chromatographic space and based on the degree of ortho-substitution within each separated homologue series. A total of 192 congeners were resolved in 146 min (1.3 analyte per min) using this column set. Eight coelutions involved 17 congeners. Among them, seven congeners were present in Aroclors at levels >1.0 wt.% (CBs 33, 47, 48, 95, 97, 163, 187). Except for CBs 47 and 48, none of the major constituents of commercial mixtures were coeluting. CB 138 was well separated from CBs 163 and 164 in the second dimension. For all column sets, CBs 20, 33, and 109 always coeluted with other PCBs. The 12 toxic dioxin-like congeners (CBs 77, 81, 105, 114, 118, 123, 126, 156, 157, 167, 169, 189), and the seven European Union marker PCBs (CBs 28, 52, 101, 118, 138, 153, 180) were separated from any interfering congeners. This was not the case for the other investigated column sets. [less ▲]

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See detailImproved shimming for fMRI specifically optimizing the local BOLD sensitivity
Balteau, Evelyne ULg; Hutton, Chloe; Weiskopf, Nikolaus

in NeuroImage (2010), 49

In functional MRI, magnetic field inhomogeneities due to air-tissue susceptibility differences may lead to severe signal dropouts and geometric distortions in echo-planar images. Therefore, the ... [more ▼]

In functional MRI, magnetic field inhomogeneities due to air-tissue susceptibility differences may lead to severe signal dropouts and geometric distortions in echo-planar images. Therefore, the inhomogeneities in the field are routinely minimized by shimming prior to imaging. However in fMRI, the Blood Oxygen Level Dependent (BOLD) effect is the measure of interest, so the BOLD sensitivity (BS) should be optimized rather than the magnetic field homogeneity. The analytical expression for an estimate of the BOLD sensitivity has been recently developed, allowing for the computation of BOLD sensitivity maps from echo-planar images and field maps. This report describes a novel shimming procedure that optimizes the local BOLD sensitivity over a region of interest. The method is applied in vivo and compared to a standard global shimming procedure. A breath-holding experiment was carried out and demonstrated that the BS-based shimming significantly improved the detection of activation in a target region of interest, the medial orbitofrontal cortex. [less ▲]

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See detailImproved stability and transient behaviour of generalized-alpha time integrators for constrained flexible systems
Arnold, Martin; Bruls, Olivier ULg; Cardona, Alberto

Conference (2011, November)

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See detailAn improved synthesis of 9-[(3)-[F-18]fluoro-1-hydroxy-2-propoxy)methyl]guanine ([F-18]FHPG).
SHIUE, CY.; SHIUE, GG.; HUSTINX, Roland ULg et al

in Journal of Nuclear Medicine (The) (1999), 40

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See detailAn Improved Test to Study the Changes in Membrane Permeability During Rehydration of Freeze-Dried Weissella paramesenteroides LC11
Soro, Amenan Anastasie; Djè, K. M.; Thonart, Philippe ULg

in The Open Biotechnology Journal (2010), 4

The objective of this study was to assess changes in membrane permeability during rehydration of freeze-dried Weissella paramesenteroides LC11. Viability was assessed using the electrical conductivity ... [more ▼]

The objective of this study was to assess changes in membrane permeability during rehydration of freeze-dried Weissella paramesenteroides LC11. Viability was assessed using the electrical conductivity measurement (ms cm-1 g-1 dry weight) and the plate count method (cfu g-1 dry weight). The symptoms of injury included an increase in the electrolyte leakage during the first 4 h of rehydration in Milli Q water and a decrease in the survival rate (about 64%), suggesting an increase in membrane permeability during dehydration. During rehydration of the freeze-dried strain, an increase in the temperature, NaCl or monosodium glutamate concentration and a decrease in H+ concentration resulted in an increase in the electrolyte leakage and a decrease in the survival rate (from about 5% to 97%, with respect to the treatment made). However, a decrease in the electrolyte leakage was observed with increasing glycerol, sucrose or maltodextrin and resulted in the maintenance of cell viability. Change in membrane permeability might lead to electrolyte leakage during rehydration and, ultimately, cell death. The electrolyte leakage assay associated with the plate count method, a quick and inexpensive method, could be used to evaluate dried bacteria resistance to dehydration. [less ▲]

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See detailImproved use of serial laboratory data in acute myocardial infarction
Albert, Adelin ULg; Chapelle, Jean-Paul ULg; Heusghem, C. et al

in Clinical Chemistry (1983), 28

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See detailImproved use of serial laboratory data in acute myocardial infarction
Albert, Adelin ULg; Chapelle, Jean-Paul ULg; Heusghem, C. et al

Poster (1982, August)

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See detailImproved vitrification method allowing direct transfer of goat embryos
Guignot, F.; Bouttier, A.; Baril, G. et al

in Theriogenology (2006), 66(4), 1004-1011

The aim of this study was to design a vitrification method suited to field embryo transfer experiments in goat. In a first experiment, a standard vitrification protocol, previously designed for sheep ... [more ▼]

The aim of this study was to design a vitrification method suited to field embryo transfer experiments in goat. In a first experiment, a standard vitrification protocol, previously designed for sheep embryos was compared to slow freezing of goat embryos. No significant difference was observed on kidding rate (48% versus 69%, respectively), nor on embryo survival rate (35% versus 45%). Second experiment: all embryos were vitrified. After warming, embryos were either transferred directly (direct transfer), or after in vitro dilution of the cryoprotectants (conventional transfer). The kidding rate was not affected by the transfer method (38% versus 23%, respectively). However, embryo survival rate tended to be higher after direct transfer (26% versus 14%). Third experiment: OPS vitrification was compared to standard vitrification. The kidding rate was not affected (22% versus 39%, respectively), but the embryo survival rate was lower after OPS (14% versus 28%). Fourth experiment: 0.4 M sucrose was added with cryoprotectants in vitrification. The kidding rate after direct transfer was significantly enhanced after addition of sucrose (56% versus 27%, respectively), whereas embryo survival rate was not significantly affected (32% versus 18%). Fifth experiment: vitrification with sucrose supplementation was compared to slow freezing. No significant difference was observed after direct transfer on kidding rate (52% versus 31%, respectively), but embryo survival rate tended to be higher after vitrification (34% versus 2 1 %). In conclusion, our results indicate that addition of 0.4 M sucrose in association with direct transfer improves significantly the viability of goat vitrified embryos. [less ▲]

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See detailAn improved weighting method with multibounds formulation and convex programming for multicriteria structural optimization
Zhang, W. H.; Domaszewski, M.; Fleury, Claude ULg

in International Journal for Numerical Methods in Engineering (2001), 52(9), 889-902

This paper presents an improved weighting method for multicriteria structural optimization. By introducing artificial design variables, here called as multibounds formulation (MBF), we demonstrate ... [more ▼]

This paper presents an improved weighting method for multicriteria structural optimization. By introducing artificial design variables, here called as multibounds formulation (MBF), we demonstrate mathematically that the weighting combination of criteria can be transformed into a simplified problem with a linear objective function. This is a unified formulation for one criterion and multicriteria problems. Due to the uncoupling of involved criteria after the transformation, the extension and the adaptation of monotonic approximation-based convex programming methods such as the convex linearization (CONLIN) or the method of moving asymptotes (MMA)are made possible to solve multicriteria problems as efficiently as for one criterion problems. In this work, a multicriteria optimization tool is developed by integrating the multibounds formulation with the CONLIN optimizer and the ABAQUS finite element analysis system. Some numerical examples are taken into account to show the efficiency of this approach. [less ▲]

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See detailImprovement and validation of milk fatty acid predictions using mid-infrared spectrometry
Soyeurt, Hélène ULg; McParland, Sinead; Berry, Donagh et al

in Proceedings of the Bristish Society of Animal Science and the Agricultural Research Forum (2010)

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See detailImprovement in HSS grade for early stands of hot strip mills - Metallurgical features and mechanical properties assessment
Ernst, Roger; Breyer, Jean-Pierre; Tchuindjang, Jérôme Tchoufack ULg et al

in Proceedings of the 43rd Seminar of Rollings (2007)

Aurora and Kosmos grades are HSS alloys belonging to the complex Fe-Cr-C-X system, where X is a strong carbide former element of the V, Mo or W type. Both alloys were metallurgically characterised prior ... [more ▼]

Aurora and Kosmos grades are HSS alloys belonging to the complex Fe-Cr-C-X system, where X is a strong carbide former element of the V, Mo or W type. Both alloys were metallurgically characterised prior to their comparison. Metallurgical analyses involved phases identification and carbides quantification by using Scanning Electron Microscopy and Energy Dispersive X rays. Differential Thermal Analysis was performed to allow a better understanding of the solidification sequence of studied alloys while mechanical tests performed were compressive at room temperature and bulk hardness at usual service temperatures. An attempt was made in order to connect experimental results to the good behaviour in operation of Aurora grade. In fact Aurora grade appeared to exhibit strong metallurgical differences when compared to Kosmos grade, especially as concern in nature and amount of carbides. [less ▲]

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See detailImprovement in non-linear guitar loudspeaker sound reproduction
Schmitz, Thomas ULg; Embrechts, Jean-Jacques ULg

in International Conference on Systems, Signals and Image Processing (2014, May)

This paper proposes a study of the accuracy of a guitar amplifier loudspeaker simulation. The simulation is based on a non-linear convolution of a signal using Volterra kernels, which are measured in ... [more ▼]

This paper proposes a study of the accuracy of a guitar amplifier loudspeaker simulation. The simulation is based on a non-linear convolution of a signal using Volterra kernels, which are measured in anechoic conditions with a sine-sweep technique. In this paper, we propose an evaluation of the method to minimise the cost in CPU load, while keeping the best performance in the sound reproduction. To assess the performance of the method, we measure errors between the simulated and real sounds. Human listening tests are moreover proposed in order to determine the minimum level of accuracy leading to unaudible differences with the real loudspeaker.. [less ▲]

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See detailImprovement in the inflammatory aspect of androgenetic alopecia. A pilot study with an antimicrobial lotion
Pierard, Gérald ULg; Pierard-Franchimont, Claudine ULg; Tassoudji, Nazli ULg et al

in Journal of Dermatological Treatment (1996), 7

Androgenetic alopecia (AGA) is a common yet poorly understood condition. In particular, the significance of inflammatory cells close to the infrainfundibulum of transitional hairs remains obscure. This ... [more ▼]

Androgenetic alopecia (AGA) is a common yet poorly understood condition. In particular, the significance of inflammatory cells close to the infrainfundibulum of transitional hairs remains obscure. This study was conducted in 20 men who used a lotion containing the antimicrobials, piroctone olamine and triclosan, regularly for 18 months. At entry, mild pruritus and abnormal hair loss were reported by the volunteers. During treatments, pruritus resolved rapidly. Comparison of clinical photographs and trichograms taken at 3-month intervals suggested signs of hair regrowth with moderate increase in density of transitional hairs. Biopsies taken at 6-month intervals were processed for immunohistochemistry. There was a decrease in the density of activated T cells in the region of the follicular infrainfundibulum and isthmus over time. UgG deposits found within the epithelial sheaths at entry to the study were absent in the subsequent biopsies. The volume of the sebaceous glands, as assessed by computerized morphometry, was not modified by the treatment. It was concluded that inflammation associated with AGA transitional hairs may be driven by the presence of microorganisms harboured in the infrainfundibulum. They may modulate the severity of AGA and may potentially be controllable. This offers a new possibility of prevention and partial reversal of hair loss in AGA. [less ▲]

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See detailImprovement in the methylene blue adsorption capacity and photocatalytic activity of H2-reduced rutile-TiO2 caused by Ni(II)porphyrin preadsorption
Páez Martínez, Carlos ULg; Lambert, Stéphanie ULg; Poelman, Dirk et al

in Applied Catalysis B : Environmental (2011), 106

H2-reduced rutile-TiO2 xerogel (Ti-700), obtained via the sol–gel process, was found to strongly adsorb the Ni(II)-5,10,15,20-tetrakis(4-carboxyphenyl)-porphyrin (NiTCPP) from a methanolic solution ... [more ▼]

H2-reduced rutile-TiO2 xerogel (Ti-700), obtained via the sol–gel process, was found to strongly adsorb the Ni(II)-5,10,15,20-tetrakis(4-carboxyphenyl)-porphyrin (NiTCPP) from a methanolic solution, despite its very low specific surface area (SBET ≈ 2 m2 g−1). UV/vis spectroscopy analysis showed that after calcination at 700 ◦C and reduction under H2 flow at 400 ◦C, the TiO2-xerogel increased its NiTCPP-adsorption capacity by surface area unit by up to 120 times. The effect of the porphyrin presence in the catalytic performances of TiO2-xerogels was studied through three kinetics models: (i) the pseudo-first-order kinetic model; (ii) the pseudo-second-order kinetic model, which are used to describe the adsorption rate based on the adsorption capacity of the catalysts; and (iii) the Langmuir–Hinshelwood kinetic model which is used to describe the photocatalytic degradation rate of methylene blue (MB). A significant improvement in the efficiency of Ti-700 was observed after the porphyrin-adsorption process (NiTCPP/Ti-700): MB-adsorption capacity at equilibrium and the apparent MB-photoconversion constant, kapp, of NiTCPP/Ti-700 were both up to 2 times higher than those observed for the Ti-700. [less ▲]

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See detailImprovement in the results in sixty-four ulnar nerve sections associated with arterial repair.
LECLERCQ, Daniel ULg; CARLIER, Alain ULg; KHUC, Toan ULg et al

in Journal of Hand Surgery (The) (1985), 10(6 Pt 2), 997-9

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See detailImprovement in Thixoforging of 7075 Aluminium Alloys at High Solid Fraction
Vaneetveld, Grégory ULg; Rassili, Ahmed ULg; Pierret, Jean-Christophe ULg et al

in Solid State Phenomena (2008), 141-143

Thixoforging is a type of semi-solid metal processing at high solid fraction (0.5<1). 7075 aluminium alloys have been used as a feedstock for thixoforging in order to investigate thixoformability of a ... [more ▼]

Thixoforging is a type of semi-solid metal processing at high solid fraction (0.5<1). 7075 aluminium alloys have been used as a feedstock for thixoforging in order to investigate thixoformability of a high performance aluminium alloy at high solid fraction. Higher solid fraction of 7075 alloy is less sensitive to temperature, avoids metal splash at high speed and allows laminar flow at high speed. Hot tool combined with lubricant tool coating are used to slow down the solidification rate of the high solid fraction metal by decreasing thermal exchanges with the tool. Improved thermal and forming parameters [1-2] will be applied to produce an automotive component by thixoforging and mechanical properties have been measured from tensile samples. High mechanical properties are obtained after T6 thermal treatment. [less ▲]

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