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See detailInfluence of ostacles on the development of gravity current prior to backdraft
Pérez-Jiménez, Christian; Guigay, Georges Jan; Horvat, Andrej et al

in Fire Technology (2009)

The phenomenon of backdraft is closely linked to the formation of a flammable region due to the mixing process between the unburned gases accumulated in the compartment and the fresh air entering the ... [more ▼]

The phenomenon of backdraft is closely linked to the formation of a flammable region due to the mixing process between the unburned gases accumulated in the compartment and the fresh air entering the compartment through a recently created opening. The flow of incoming fresh air is called the gravity current. Gravity current prior to backdraft has already been studied, Fleischmann (1993, Backdraft phenomena, NIST-GCR-94-646. University of California, Berkeley) and Fleischmann (1999, Numerical and experimental gravity currents related to backdrafts, Fire Safety Journal); Weng et al. (2002, Exp Fluids 33:398–404), but all simulations and experiments found in the current literature are systematically based on a perfectly regular volume, usually parallelipedic in shape, without any piece of furniture or equipment in the compartment. Yet, various obstacles are normally found in real compartments and the question is whether they affect the gravity current velocity and the level of mixing between fresh and vitiated gases. In the work reported here, gravity current prior to backdraft in compartment with obstacles is investigated by means of three-dimensional CFD numerical simulations. These simulations use as a reference case the backdraft experiment test carried out by Gojkovic (2000, Initial Backdraft. Department of Fire Safety Engineering, Lunds Tekniska Ho¨ gskola Universitet, Report 3121). The Froude number, the transit time and the ignition time are obtained from the computations and compared to the tests in order to validate the model. [less ▲]

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See detailInfluence of ovarian hormones on cortical spreading depression and its suppression by L-kynurenine in rat.
Chauvel, Virginie ULg; Schoenen, Jean ULg; Multon, Sylvie ULg

in PLoS ONE (2013), 8(12), 82279

Migraine is sexually dimorphic and associated in 20-30% of patients with an aura most likely caused by cortical spreading depression (CSD). We have previously shown that systemic L-kynurenine (L-KYN), the ... [more ▼]

Migraine is sexually dimorphic and associated in 20-30% of patients with an aura most likely caused by cortical spreading depression (CSD). We have previously shown that systemic L-kynurenine (L-KYN), the precursor of kynurenic acid, suppresses CSD and that this effect depends on the stage of the estrous cycle in female rats. The objectives here are to determine the influence of ovarian hormones on KCl-induced CSD and its suppression after L-KYN by directly modulating estradiol or progesterone levels in ovariectomized rats. Adult female rats were ovariectomized and subcutaneously implanted with silastic capsules filled with progesterone or 17β-estradiol mixed with cholesterol, with cholesterol only or left empty. Two weeks after the ovariectomy/capsule implantation, the animals received an i.p. injection of L-KYN (300 mg/kg) or NaCl as control. Thirty minutes later CSDs were elicited by applying KCl over the occipital cortex and recorded by DC electrocorticogram for 1 hour. The results show that both estradiol and progesterone increase CSD frequency after ovariectomy. The suppressive effect of L-KYN on CSD frequency, previously reported in normal cycling females, is not found anymore after ovariectomy, but reappears after progesterone replacement therapy. Taken together, these results emphasize the complex role of sex hormones on cortical excitability. The CSD increase by estradiol and, more surprisingly, progesterone may explain why clinically migraine with aura appears or worsens during pregnancy or with combined hormonal treatments. [less ▲]

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See detailInfluence of oven-drying temperature on physico-chemical and functional properties of date fibre concentrates
Borchani, C.; Besbes, S.; Masmoudi, M. et al

in Food and Bioprocess Technology (2011)

Agri-food by-products rich in dietary fibres may be used as feeds and health foods. Owing to its high fibre content, date flesh could be useful in human nutrition. It is interesting to study the influence ... [more ▼]

Agri-food by-products rich in dietary fibres may be used as feeds and health foods. Owing to its high fibre content, date flesh could be useful in human nutrition. It is interesting to study the influence of oven-drying temperatures of date fibre concentrates (DFC) on their physicochemical and functional properties for possible use as a potential fibre source in the enrichment of food. DFC from 11 Tunisian date cultivars were dried at different temperatures (40, 50 and 60 °C) and analysed regarding proximate composition (moisture, ash, protein and lipids), physicochemical (water activity (aw), pH) and functional properties (water holding capacity (WHC), swelling capacity (SC), oil holding capacity (OHC) and emulsifying capacity (EC)). DFC dried at different temperatures showed interesting functional characteristics such as hydration properties, high OHC (2.73–4.60 g oil/g dry fibre) and EC (5.93–12.87%) values. Although drying temperatures promoted little modifications affecting the physicochemical properties of DFC, significant decreases in WHC, SC and EC of DFC were noticed at the highest temperature (60 °C) for most of the date varieties. The observed influence of drying temperature on functional DFC properties calls for the use of low temperature in order to obtain DFC as suitable food ingredient. [less ▲]

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See detailInfluence of overshooting and metallicity on the delta Scuti and gamma Doradus instability strips
Grigahcène, A.; Dupret, Marc-Antoine ULg; Garrido, R. et al

in Memorie della Società Astronomica Italiana : Journal of the Italian Astronomical Society (2006), 77

Computations of theoretical instability strips (IS) for delta Scuti (Sct) and gamma Dor (Dor) stars are presented. The Time-Dependent Convection (TDC) theory of Gabriel (1996) and Grigahcène et al. (2005 ... [more ▼]

Computations of theoretical instability strips (IS) for delta Scuti (Sct) and gamma Dor (Dor) stars are presented. The Time-Dependent Convection (TDC) theory of Gabriel (1996) and Grigahcène et al. (2005) is adopted in our models. We are able to obtain the delta Sct and gamma Dor IS. We present a prospective study on the influence of the overshooting and metallicity on the location of these IS in the HR diagram. [less ▲]

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See detailInfluence of oxygen tension on nitric oxide and prostaglandin E2 production by bovine chondrocytes
Burton, Sandrine; Mathy, Marianne ULg; Deby-Dupont, Ginette et al

in Osteoarthritis and Cartilage (2003, October), 11(Suppl.1), 58

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See detailInfluence of oxygen tension on nitric oxide and prostaglandin E2 synthesis by bovine chondrocytes.
Mathy, Marianne ULg; Burton, Sandrine; Deby, Ginette ULg et al

in Osteoarthritis and Cartilage (2005), 13(1), 74-9

OBJECTIVES: To determine the in vitro effects of oxygen tension on interleukin (IL)-1beta induced nitric oxide (*NO) and prostaglandin E(2) (PGE(2)) production by bovine chondrocytes. DESIGN ... [more ▼]

OBJECTIVES: To determine the in vitro effects of oxygen tension on interleukin (IL)-1beta induced nitric oxide (*NO) and prostaglandin E(2) (PGE(2)) production by bovine chondrocytes. DESIGN: Enzymatically isolated bovine chondrocytes were cultured for different periods in suspension in 21 (atmospheric), 5 or 1% (low) oxygen tension and in the absence or in the presence of increased amounts (0.01 to 1nM) of IL-1beta. Nitrite and nitrate concentrations in the culture supernatants were determined by a spectrophotometric method based upon the Griess reaction. PGE(2) production was quantified by a specific radioimmunoassay (RIA). Cyclooxygenase-2 (COX-2) and inducible nitric oxide synthase (iNOS) mRNA steady state levels were also quantified by real-time polymerase chain reaction (PCR). RESULTS: In the absence of IL-1beta, ()NO production remained stable whatever the oxygen tension used. IL-1beta dose-dependently increased *NO production in both atmospheric and low oxygen conditions but the effect was more pronounced in low (1 and 5%) than in atmospheric (21%) oxygen tension (P<0.001). Under low and atmospheric oxygen tension, iNOS gene expression was increased by IL-1beta, but to a lesser extent in 21% than in 1 or 5% oxygen (P<0.01). In the basal condition, bovine chondrocytes spontaneously produced PGE(2) whatever the oxygen tension used. At 21% oxygen, IL-1beta dose-dependently increased PGE(2) production while no significant effect was observed at 1 or 5% oxygen. COX-2 gene expression was significantly upregulated by IL-1beta in both low and atmospheric oxygen tension. No significant difference between oxygen tension conditions was observed. CONCLUSIONS: This study demonstrates that a hypoxic environment fully blocks COX-2 activity but favours iNOS gene expression in chondrocytes culture. These findings indicate that O(2) tension modulates cellular behaviour in culture and supports the concept of chondrocyte culture in low oxygen tension to reproduce in vitro the life conditions of chondrocytes. [less ▲]

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See detailInfluence of P-glycoprotein on the tissue distribution in rats of the 5-HT1A antagonist p-[18F]MPPF.
Plenevaux, Alain ULg; Lacan, G.; Defraiteur, C. et al

in Society for Neuroscience / Abstracts (2002)

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See detailThe influence of palaeophytogeography on the zosterophyllopsid diversity
Cascales - Miñana, Borja ULg; Meyer-Berthaud, Brigitte

Conference (2013, October)

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See detailThe influence of palm oil addition on sunflower halva stability and texture
Mure şan, V.; Danthine, Sabine ULg; Racolţa, E. et al

Scientific conference (2013, September 26)

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See detailThe Influence of Palm Oil Addition on Sunflower Halva Stability and Texture
MUREŞAN, Vlad; Danthine, Sabine ULg; RACOLŢA, Emil et al

in Bulletin UASVM Food Science and Technology (2014), 71(1), 51-56

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See detailInfluence of parameters during induction heating cycle of 7075 aluminium alloys with RAP process
Vaneetveld, Grégory ULg; Rassili, Ahmed ULg; Atkinson, Helen

in Solid State Phenomena (2008), 141-143

Thixoforging involves shaping alloys with a globular microstructure in the semi-solid state. To reach this kind of material, the Recrystallisation and Partial Melting (RAP) process can be used to obtain a ... [more ▼]

Thixoforging involves shaping alloys with a globular microstructure in the semi-solid state. To reach this kind of material, the Recrystallisation and Partial Melting (RAP) process can be used to obtain a globular microstructure from extruded material with liquid penetrating the recrystallised boundaries. Induction heating is used to apply the RAP process to slugs. One of the benefits of using this method of heating is the fast heating rate (20°C/s). This paper will help to improve heating parameters by showing their influence on 7075 aluminium alloy recrystallisation. These parameters are the heating rate; heating frequencies-power; presence or not of protective gas; position of the slug in the inductor; energy stored inside the slug; oxide layer on the slug side; chamfer of the slug upper corner. [less ▲]

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See detailInfluence of Parenteral Multivitamins Concentration on Neonatal Lung
Senterre, Thibault ULg

in Pediatric Research (2004, April), 55(4), 445

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See detailInfluence of particle flatness and elongation on size distributions obtained from laser diffraction, static and dynamic image analysis.
Califice, Arnaud ULg; Michel, Frédéric ULg; Dislaire, Godefroid et al

in World Congress on Particle Technology (2010, April)

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See detailInfluence of Particle Packing on Elastic Properties of Concrete
He, Huan ULg; Stroeven, Piet; Stroeven, Martijn et al

in Magzine of Concrete Research (2012), 64(2), 163-175

Concrete is a complex composite material. Hence, the main components of concrete on meso-scale should be considered when studying its global elastic properties. As a main ingredient of concrete, aggregate ... [more ▼]

Concrete is a complex composite material. Hence, the main components of concrete on meso-scale should be considered when studying its global elastic properties. As a main ingredient of concrete, aggregate will exert influences on the elastic properties of concrete. In the present study, particularly particle shape and particle packing are considered of relevance. The densely packed structure of arbitrary shaped aggregate is simulated by a concurrent algorithm-based discrete element modelling (DEM) system. A comparison is pursued of data, produced by numerical models, either based on arbitrary angular-shaped particles or on spherical ones. This will be accomplished by means of the finite element method (FEM). The results can be used to evaluate the adequacy for this purpose of conventional numerical or analytical models based on spherical aggregates. The influences exerted on the elastic properties of concrete by other factors, such as the mechanical and physical properties of the aggregate, the ITZ and the matrix will also be addressed in this study. [less ▲]

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See detailInfluence of Particle Packing on Fracture Properties of Concrete
He, Huan ULg; Stroeven, Piet; Stroeven, Martijn et al

in Computers and Concrete (2011), 8(6), 677-692

Particle packing on meso-level has a significant influence on workability of fresh concrete and also on the mechanical and durability properties of the matured material. It was demonstrated earlier that ... [more ▼]

Particle packing on meso-level has a significant influence on workability of fresh concrete and also on the mechanical and durability properties of the matured material. It was demonstrated earlier that shape exerts but a marginal influence on the elastic properties of concrete provided being packed to the same density, which is not necessarily the case with different types of aggregate. Hence, elastic properties of concrete can be treated as approximately structure-insensitive parameters. However, fracture behaviour can be expected structure-sensitive. This is supported by the present study based on discrete element method (DEM) simulated three-phase concrete, namely aggregate, matrix and interfacial transition zones (ITZs). Fracture properties are assessed with the aid of a finite element method (FEM) based on the damage materials model. Effects on tensile strength due to grain shape and packing density are investigated. Shape differences are shown to have only modest influence. Significant effects are exerted by packing density and physical-mechanical properties of the phases, whereby the ITZ takes up a major position. [less ▲]

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