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See detailEffect of surface preparation techniques on the cohesion of superficial concrete: comparison between jack-hammering and water-jetting
Courard, Luc ULg; Bissonnette, Benoît; Belair, Normand

in Beushausen, H.; Dehn, F.; Alexander, M. G. (Eds.) Concrete Repair, Rehabilitation and Retrofitting (2006)

The aim of concrete surface preparation is to obtain a surface with properties similar to those of the bulk concrete. Superficial concrete must be sound, dry, cohesive and contaminant-free. Particularly ... [more ▼]

The aim of concrete surface preparation is to obtain a surface with properties similar to those of the bulk concrete. Superficial concrete must be sound, dry, cohesive and contaminant-free. Particularly, the preparation must be performed in such a way that sound and homogeneous concrete is reached. The most widespread surface preparation techniques are sandblasting, jack-hammering, milling and other water hydro-jetting. Evaluation of the effect of surface preparation is often based upon surface roughness or specific sur-face. It is necessary however to investigate further within the first few centimetres from the surface to verify the concrete homogeneity and soundness. Pull-off test is a destructive method that can be useful for such evaluation, but it only gives an indication; the observation of the failure mode is more instructive. This paper summarizes the results of a microscopy investigation performed to quantify the number and length of cracks. The analysis leads to the comparison of jack-hammering and water-jetting techniques in terms of their poten-tial effect on superficial cohesion of concrete. [less ▲]

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See detailEffect of surfactants and biomass on the gas/liquid mass transfer in an aqueous-silicone oil two-phase partitioning bioreactor using Rhodococcus erythropolis T902.1 to remove VOCs from gaseous effluents
Aldric, Jean-Marc ULg; Gillet, Sébastien ULg; Delvigne, Frank ULg et al

in Journal of Chemical Technology & Biotechnology (2009), 84

BACKGROUND: The two-phase partitioning bioreactor (TPPB) has become a new strategy in the context of waste gas treatment. However, the impact of biomass and surfactants on gas/liquid (G/L) mass transfer ... [more ▼]

BACKGROUND: The two-phase partitioning bioreactor (TPPB) has become a new strategy in the context of waste gas treatment. However, the impact of biomass and surfactants on gas/liquid (G/L) mass transfer needs to be better evaluated because the impact of these factors on the mass transfer coefficient “ ” and the interfacial area “ ”, respectively, remains misunderstood. RESULTS: Our study showed that, firstly, the surfactant extract produced by Rhodococcus erythropolis reduced the surface hydrophobicity of the biomass. Secondly, an optimal concentration appeared to exist for both of the components, respectively 0.5 g.L-1 and 0.7 g.L-1 for biomass (B) and surfactant extract (SE) when the global mass transfer coefficient ( ) of oxygen was measured in a silicone oil/water TPPB. However, the combination of B and SE was found to induce a negative synergism. In particular, SE improved the interfacial area “ ” by increasing the bubble diameter, while B reduced it as soon as a concentration of 1g.L-1 was exceeded. By contrast, the SE acted negatively on the , while B improved it overall. CONCLUSION: Better consideration is needed of the effect of biotic components in order to understand the phenomenon of G/L mass transfer in a TPPB. The behaviour of biomass growth and surfactants may strongly influence the mathematical models suggested in the literature. [less ▲]

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See detailThe effect of symmetric/asymmetric TAG ratio on the crystallization properties and storage stability of fat blends
De Graef, V.; Vereecken, J.; Danthine, Sabine ULg et al

Conference (2011, September)

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See detailThe effect of symmetric/asymmetric TAG ratio on the crystallization properties and storage stability of fat blends
DeGraef, V.; Vereecken, J.; Danthine, Sabine ULg et al

Conference (2011)

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See detailEffect of synthesis process and substrate on electrical and thermal transport properties of Bi-2212
Dorbolo, Stéphane ULg; Ausloos, Marcel ULg; Bougrine, Hassan ULg et al

in Journal of Superconductivity (1999), 12(5), 623-629

Resistivity, thermoelectric power, and thermal conductivity have been measured for a Bi-2212 system synthesized from a glassy precursor, either with a commercially Al2O3 substrate or with a homemade ... [more ▼]

Resistivity, thermoelectric power, and thermal conductivity have been measured for a Bi-2212 system synthesized from a glassy precursor, either with a commercially Al2O3 substrate or with a homemade BaZrO3 substrate. Those measurements show that the BaZrO3 substrate gives better superconducting properties to the Bi-2212 than the Al2O3 substrate. The effect of (1.0 T) weak magnetic field has been searched for. The thermal magnetoconductivity and the contributions of the magnetic field to the thermoelectrical power are studied and compared through fine measurements. An electronic contribution seems to appear already well above the critical temperature and to exist up to 200 degrees K. The onset temperature is thus deduced. [less ▲]

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See detailEffect of synthetic peptide thrombin receptor agonist encapsulated in microparticles based on lactic and glycolic acid copolymer on healing of experimental skin wounds in mice.
Dugina, T.N; Kiseleva, E.V; Lange, M.A et al

in Bulletin of Experimental Biology and Medicine (2004), 138(5), 463-466

PAR1 peptide thrombin receptor agonist (PAR1-AP) was encapsulated in microcorpuscles based on lactic and glycolic acid copolymer. The desorption profile of the preparation was studied in vitro and its ... [more ▼]

PAR1 peptide thrombin receptor agonist (PAR1-AP) was encapsulated in microcorpuscles based on lactic and glycolic acid copolymer. The desorption profile of the preparation was studied in vitro and its wound-healing effects were studied on a model of cut skin wound in mice. The study showed that 90% PAR1-AP was desorbed over 6 h, but the peptide was detected in eluates from the microparticle surface after 23 h. The desorbed peptide retained its physiological activity and was capable of activating PAR1 receptors on human platelets. The study of the dynamics of experimental skin wound healing in mice showed lower number of macrophages in the wounds treated with PAR1-AP microparticles compared to the control (open wounds and wounds covered with microparticles) and higher number of fibroblasts on day 3 of tissue reparation. Hence, PAR1-AP desorbed from microparticles shortened the inflammation phase in the wound. On day 7 the best healing parameters were also observed in wounds treated with PAR1-AP microparticles, which attests to shortening of the proliferation phase and acceleration of wound healing. [less ▲]

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See detailEffect of systemic kynurenine on cortical spreading depression and its modulation by sex hormones in rat.
Chauvel, Virginie ULg; Vamos, Eniko; Pardutz, Arpad et al

in Experimental Neurology (2012), 236(2), 207-14

BACKGROUND: The aura symptoms in migraine are most likely due to cortical spreading depression (CSD). CSD is favored by NMDA receptor activation and increased cortical excitability. The latter probably ... [more ▼]

BACKGROUND: The aura symptoms in migraine are most likely due to cortical spreading depression (CSD). CSD is favored by NMDA receptor activation and increased cortical excitability. The latter probably explains why migraine with aura may appear when estrogen levels are high, like during pregnancy. Kynurenic acid, a derivative of tryptophan metabolism, is an endogenous NMDA receptor antagonist whose cerebral concentrations can be augmented by systemic administration of its precursor l-kynurenine. OBJECTIVE: To determine if exogenous administration of l-kynurenine is able to influence KCl-induced CSD in rat, if the effect is sex-dependent and if it differs in females between the phases of the estrous cycle. METHODS: Adult Sprague-Dawley rats (n=8/group) received intraperitoneal (i.p.) injections of l-kynurenine (L-KYN, 300mg/kg), L-KYN combined with probenecid (L-KYN+PROB) that increases cortical concentration of KYNA by blocking its excretion from the central nervous system, probenecid alone (PROB, 200mg/kg) or NaCl. Cortical kynurenic acid concentrations were determined by HPLC (n=7). Thirty minutes after the injections, CSDs were elicited by application of 1M KCl over the occipital cortex and recorded by DC electrocorticogram. In NaCl and L-KYN groups, supplementary females were added and CSD frequency was analyzed respective to the phases of the estrous cycle determined by vaginal smears. RESULTS: In both sexes, PROB, L-KYN and L-KYN+PROB increased cortical kynurenic acid level. PROB, L-KYN and L-KYN+PROB with increasing potency decreased CSD frequency in female rats, while in males such an effect was significant only for L-KYN+PROB. The inhibitory effect of L-KYN on CSD frequency in females was most potent in diestrus. CONCLUSION: l-Kynurenine administration suppresses CSD, most likely by increasing kynurenic acid levels in the cortex. Females are more sensitive to this suppressive effect of l-kynurenine than males. These results emphasize the role of sex hormones in migraine and open interesting novel perspectives for its preventive treatment. [less ▲]

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See detailEffect of systemic nitroglycerin on CGRP and 5-HT afferents to rat caudal spinal trigeminal nucleus and its modulation by estrogen
Pardutz, A.; Multon, Sylvie ULg; Malgrange, Brigitte ULg et al

in European Journal of Neuroscience (2002), 15(11), 1803-1809

Systemic administration of nitroglycerin, a nitric oxide donor, triggers in migraine patients a delayed attack of unknown mechanism. After puberty migraine is more prevalent in women. Attacks can be ... [more ▼]

Systemic administration of nitroglycerin, a nitric oxide donor, triggers in migraine patients a delayed attack of unknown mechanism. After puberty migraine is more prevalent in women. Attacks can be triggered by abrupt falls in plasma estrogen levels, which accounts in part for sexual dimorphism, but lacks an established neurobiological explanation. We studied the effect of nitroglycerin on the innervated area of calcitonin gene-related peptide (CGRP) and serotonin-immunoreactive afferents to the superficial laminae of the spinal portion of trigeminal nucleus caudalis, and its modulation by estrogen. In male rats, nitroglycerin produced after 4 h a significant decrease of the area innervated by CGRP-immunoreactive afferents and an increase of that covered by serotonin-immunoreactive fibres. These effects were not observed in the superficial laminae of thoracic dorsal horns. The effect of nitroglycerin was similar in ovariectomized females. In estradiol-treated ovariectomized females the area in the spinal portion of trigeminal nucleus caudalis laminae I-II covered by CGRP-immunoreactive fibres was lower and that of serotonin-immunoreactive fibres was higher than in males and for both transmitters not significantly changed after nitroglycerin. The bouton size of CGRP profiles was smaller in estradiol-treated ovariectomized females, whereas after nitroglycerin it decreased significantly but only in males and ovariectomized females. Nitroglycerin, i.e. nitric oxide, is thus able to differentially influence afferent fibres in the superficial laminae of rat spinal trigeminal nucleus caudalis. Estradiol modulates the basal expression of these transmitters and blocks the nitroglycerin effect. These data may contribute to understanding the mechanisms by which estrogens influence migraine severity and the triggering of attacks by nitric oxide. [less ▲]

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See detailEffect of tank mixed adjuvants on the drift potential of phenmedipham formulations.
Stainier, Charles; Destain, Marie-France ULg; Schiffers, Bruno ULg et al

in Communications in agricultural and applied biological sciences (2005), 70(4), 979-987

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See detailEffect of task demands on phonological acquisition : the acquisition of phonemes in French speaking children aged 30 to 53 months in four different contexts.
Maillart, Christelle ULg; Vaucel, Cécile; Macleod, Andrea

Poster (2014, June)

When children first begin to produce the phonemes of their language, their productions are characterized by a high degree of variability (e.g., Ferguson & Farwell, 1975) and are influenced by task demands ... [more ▼]

When children first begin to produce the phonemes of their language, their productions are characterized by a high degree of variability (e.g., Ferguson & Farwell, 1975) and are influenced by task demands (Khami, Catts, & Davis, 1984). As children’s phonological representations become more defined, their productions become more stable and less influenced by the task demands. Despite the clinical significance of phonological variability, there exists no normative data that can be used to objectively describe this variability in French. The goal of the present study was to describe variability and consistency among French-speaking children between the ages of 30 and 53 months, according to task demands. A total of 153 children participated in the present study and were equally distributed in four groups (aged 30-35, 36-41, 42-47, and 48-53 months). We created a picture identification task with 65 target words, which contained the consonants of French in word initial, medial and final position. The children were asked to produce these words in four different contexts : 1) picture naming ; 2) word repetition ; 3) sentence repetition ; 4) spontaneous language. Two measures of consistency were used. (1) A consonant level analysis that investigated the stability of phonological accuracy. (2) A word level analysis that investigated the consistency of productions across the four tasks. We predict that younger children will be more influenced by changes in task complexity than older children. [less ▲]

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See detailEffect of temperature and water activity on spore germination and mycelial growth of three fungal biocontrol agents against water hyacinth (Eichhornia crassipes)
Dagno, Karim ULg; Lahlali, Rachid; Diourté, M. et al

in Journal of Applied Microbiology (2011), 110

The fungi were grown in vitro on plates containing potato dextrose agar medium at different aw values (glycerol being added to adjust the aw). The percentage of viable conidia and radial growth rate ... [more ▼]

The fungi were grown in vitro on plates containing potato dextrose agar medium at different aw values (glycerol being added to adjust the aw). The percentage of viable conidia and radial growth rate decreased with decreasing water activity. Statistical analysis showed a significant effect of aw, temperature and the aw temperature interaction on mycelial growth (P < 0Æ0001). Water activity emerged as the factor exerting the greatest influence. Differences were observed between the fungi tested, the C. malorum appearing more tolerant to low aw and the F. sacchari more tolerant to high temperature (35 C). Growth models predicting the combined effect of aw and temperature were developed and response surfaces generated, showing fairly good agreement with the experimental values. Conclusions: Our results confirm the previous finding that aw has a greater influence than temperature on fungal growth. Under most conditions, variation of environmental factors has a detrimental influence on the percentage of viable conidia and mycelial growth rate of fungal isolates. [less ▲]

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See detailEffect of Temperature and Water Restriction On Piper aduncum L. Seed Germination
Silva, MHL; Costa, RCL; Lobato, AKS et al

in Journal of Agronomy (2007), 6(3), 472-475

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See detailEffect of temperature increase on the courtship behavior and the fitness in the Palmate newt
Galloy, Valérie ULg; Lo Presti, Wendy; Denoël, Mathieu ULg

Poster (2008)

A trend in global warming is now undeniable. Increases of global temperatures have resulted in measurable shifts in the distribution, phenology and survival of some plant and animal species. However, the ... [more ▼]

A trend in global warming is now undeniable. Increases of global temperatures have resulted in measurable shifts in the distribution, phenology and survival of some plant and animal species. However, the mechanisms showing the link between global warming and declines remain unclear. The aim of this study was to examine whether courtship displays and fitness could be affected by a temperature increase. To this end, we compared the sexual behavior and egg-laying traits at naturally occurring temperatures (14 C, 18 C and 22 C) in palmate newts (Triturus helveticus). First, our results underline the importance of female role in the male courtships. The majority of male behaviors are affected by the female responsiveness, which is temperature dependent. They also show that water temperature increase has a negative effect on the fecundity of female newts. Females lay half as many eggs at high temperatures as they do at low temperatures and of these only one third hatch. The demonstration of such a detrimental effect shows that more experimental studies are required to understand the proximate mechanisms of global warming. [less ▲]

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See detailEffect of Temperature on Growth of Psychrophilic and Psychrotrophic Members of Rhodotorula Aurantiaca
Sabri, Ahmed ULg; Jacques, Philippe; Weekers, Frederic et al

in Applied Biochemistry and Biotechnology (2000), 84-86(Spring), 391-9

The thermo-dependence of growth kinetic parameters was investigated for the Antarctic psychrophilic strain Rhodotorula aurantiaca and a psychrotrophic strain of the same species isolated in Belgium ... [more ▼]

The thermo-dependence of growth kinetic parameters was investigated for the Antarctic psychrophilic strain Rhodotorula aurantiaca and a psychrotrophic strain of the same species isolated in Belgium (Ardennes area). Cell production, maximum growth rate (mu max), and half-saturation constant for glucose uptake (Ks) of both yeasts were temperature dependent. For the two yeasts, a maximum cell production was observed at about 0 degree C, and cell production decreased when temperature increased. The mu max values for both strains increased with temperature up to a maximum of 10 degrees C for the psychrophilic strain and 17 degrees C for the psychrotrophic strain. For both yeasts, Ks for glucose was relatively constant at low temperatures. It increased at temperatures above 10 degrees C for the psychrophilic strain and 17 degrees C for the psychrotrophic strain. Although its glucose affinity was lower, the psychrotrophic strain grew more rapidly than the psychrophilic one. The difference in growth rate and substrate affinity was related to the origin of the strain and the adaptation strategy of R. aurantiaca to environmental conditions. [less ▲]

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See detailEffect of Temporal Changes in Bone Turnover on the Bone Mineralization Density Distribution: A Computer Simulation Study
Ruffoni, Davide ULg; Fratzl, Peter; Roschger, Paul et al

in JOURNAL OF BONE AND MINERAL RESEARCH (2008), 23(12), 1905-1914

The heterogeneous distribution of mineral content in trabecular bone reflects the continuous renewal of bone material in bone remodeling and the subsequent increase in mineral content in the newly formed ... [more ▼]

The heterogeneous distribution of mineral content in trabecular bone reflects the continuous renewal of bone material in bone remodeling and the subsequent increase in mineral content in the newly formed bone packets. The bone mineralization density distribution (BMDD) is typically used to describe this nonuniform mineral content of the bone matrix. Our mathematical model describes changes of the BMDD of trabecular bone as a function of bone resorption and deposition rates and the mineralization kinetics in a newly formed bone packet. Input parameters used in the simulations were taken from experimental studies. The simulations of the time evolution of the BMDD after increase in bone turnover (perimenopausal period) resulted in a shift of the BMDD toward lower values of the mineral content. Transiently, there was a broadening of the BMDD configuration partly showing two peaks, which points to a strongly heterogeneous distribution of the mineral. Conversely, when the remodeling rate was reduced (antiresorptive therapy), the BMDD shifted toward higher values of the mineral content. There was a transient narrowing of the distribution before broadening again to reach the new steady state. Results from this latter simulation are in good agreement with measurements of the BMDD of patients after 3 and 5 yr of treatment with risedronate. Based on available experimental data on bone remodeling, this model gives reliable predictions of changes in BMDD, an important factor of bone material quality. With the availability of medications with a known effect on bone turnover, this knowledge opens the possibility for therapeutic manipulation of the BMDD. [less ▲]

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See detailEffect of the 2003 heatwave on Eryngium alpinum demography under different management regimes
Bizoux, Jean-Philippe ULg; Andrello, Marco; Till-Bottraud, Irène

Conference (2011, September 28)

In the summer of 2003, Europe was impacted by an extreme heatwave that altered ecosystem productivity and increased plant mortality in natural areas. We analyse the effect of this extreme climatic event ... [more ▼]

In the summer of 2003, Europe was impacted by an extreme heatwave that altered ecosystem productivity and increased plant mortality in natural areas. We analyse the effect of this extreme climatic event on the demography of the protected alpine plant Eryngium alpinum in relation to local ecological conditions and management regimes (mowing, grazing and unmanaged). Spatiotemporal variation in the vital rates of different plant life-stages (seedlings, juveniles, vegetative and reproductive adults) was estimated in seven sites of E. alpinum in the French Alps between 2001 and 2010. The effects on population dynamics (deterministic and stochastic population growth rates, λ and a) were studied using matrix population models and life table response experiments. Reductions in survival rates were observed following the extreme 2003 summer. λ was smaller during the heatwave and a decreased in simulations where the occurrence probability of a 2003-like event was increased. Adult survival rates and fecundity were negatively affected by heavy spring grazing, leading to lower λ and a. There were few differences in population dynamics between mowed and unmanaged sites. While greater rates of heatwave occurrence did increase extinction probability, only heavily grazed sites showed considerable extinction risk. As a consequence, heavy spring grazing must be discouraged in sites where the conservation of E. alpinum is a priority, while it is important to quantify acceptable levels of grazing in semi-natural areas where plant conservation has to be achieved in accordance with human development needs. [less ▲]

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See detailEffect of the 585 Nm Flashlamp-Pumped Pulsed Dye Laser for the Treatment of Keloids
Paquet, Philippe ULg; Hermanns, Jean-François ULg; Pierard, Gérald ULg

in Dermatologic Surgery (2001), 27(2), 171-4

BACKGROUND: Due to its potential effects on skin microcirculation and collagen metabolism, the 585 nm flashlamp-pumped pulsed dye laser has been proposed for treating abnormal scars. Indeed, one of the ... [more ▼]

BACKGROUND: Due to its potential effects on skin microcirculation and collagen metabolism, the 585 nm flashlamp-pumped pulsed dye laser has been proposed for treating abnormal scars. Indeed, one of the main problems with keloidal scars is their disfiguring erythematous color. OBJECTIVE: To assess the efficacy of the 585 nm pulsed dye laser on the appearance of keloids. METHODS: Eleven patients with skin phototypes II-IV and keloids were treated with the 585 nm pulsed dye laser. After one to three treatment sessions, clinical assessments of the scars were performed in combination with remittance spectroscopy measurements of the redness and melanin pigmentation. A group of nine keloids covered by silicone gel sheeting served as controls. Data were compared statistically. RESULTS: During laser treatments, a discrete decrease in redness of the scars was clinically reported. However, this improvement was not confirmed by the objective spectrophotometric data. No side effects, especially hyperpigmentation, were disclosed. The keloids redness was not improved in the control group. CONCLUSION: The 585 nm pulsed dye laser yields only minimal effects, if any, on the erythema of keloids. Similarly silicone gel sheeting does not modify the keloids redness. [less ▲]

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See detailEffect of the activating agent on physico-chemical and electrical properties of activated carbon cloths developed from a novel cellulosic precursor
Ramos, ME; Bonelli, PR; Blacher, Silvia ULg et al

in Colloids and Surfaces A : Physicochemical and Engineering Aspects (2011), 378(1-3), 87-93

Different chemical reagents (phosphoric acid, boric acid, ammonium citrate, sodium dihydrogen phosphate, potassium dihydrogen phosphate, disodium hydrogen phosphate and trisodium phosphate) were employed ... [more ▼]

Different chemical reagents (phosphoric acid, boric acid, ammonium citrate, sodium dihydrogen phosphate, potassium dihydrogen phosphate, disodium hydrogen phosphate and trisodium phosphate) were employed to develop activated carbon cloths (ACC) by chemical activation of a lyocell precursor, in an attempt to explore their effect on main physico-chemical characteristics and electrical behaviour of the resulting ACC. The activating agent markedly influenced yield, elemental composition, and textural properties of the ACC. The ACC obtained with phosphoric and boric acids were essentially microporous, whereas those developed with the other reagents presented mesoporosity development. Phosphoric acid-derived samples showed the highest specific surface area (976 m2/g). The results also highlight the relevance of correcting the external surface adsorption in order to obtain reliable estimates of micropore volume. All the ACC were electrically conductive, their resistivity being also strongly dependent on the nature of the activating agent. The electrical resistivity of the ACC obtained with all the phosphorous compounds was successfully correlated with their C/H ratio and micropore volume [less ▲]

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See detailEffect of the addition of deffated date seeds on wheat dough performance and bread quality.
Bouaziz, M. A.; Besbes, Souhail; Blecker, Christophe ULg et al

in Journal of Texture Studies (2010), 41

Detailed reference viewed: 51 (7 ULg)