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See detailInfluence of dipole-dipole interactions decoherence-free states
Damanet, François ULg; Martin, John ULg

Poster (2014, March 18)

Decoherence, known as the consequence of the coupling of any quan- tum system to its environment, causes information loss in the system and represents a major problem in the physical realization of quan ... [more ▼]

Decoherence, known as the consequence of the coupling of any quan- tum system to its environment, causes information loss in the system and represents a major problem in the physical realization of quan- tum computers [1]. Decoherence-Free States (DFS) are considered as a possible solution to this problem. A set of trapped cold atoms placed in a DFS state will be immune against decoherence due to sponta- neous emission. However, because of dipole-dipole interactions between atoms, induced dephasing effects are likely to destroy the coherence and drive the system out of its DFS [1-2]. In this work, we study nu- merically the dynamics of a set of two-level atoms initially in a DFS with respect to dissipative processes by solving the master equation in- cluding both dissipative dynamics and dipole dipole interactions. We focus our attention on the influence of dipolar coupling on the radiated energy rate and coherence of the system as in [3]. In particular, by av- eraging over many realizations of close randomly distributed atomic positions, we show the formation of a superradiant-like pulse and we study its properties as a function of the dipolar coupling strength. [1] D. A. Lidar & K. B. Whaley, Lectures Notes in Phys., Vol. 622, p83-120, Springer (2003). [2] M. Gross & S. Haroche, Physics reports 93, 301-396 (1982). [3] W. Feng, Y. Li & S. -Y. Zhu, arXiv :1302.0957. (2013). [less ▲]

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See detailInfluence of dipole-dipole interactions on superradiance
Damanet, François ULg; Martin, John ULg

Poster (2013, September 02)

Superradiance, known as the cooperative spontaneous emission of a directional light pulse by excited atoms placed in vacuum, has recently regained attention in the context of photon localization [1] and ... [more ▼]

Superradiance, known as the cooperative spontaneous emission of a directional light pulse by excited atoms placed in vacuum, has recently regained attention in the context of photon localization [1] and single photon cooperative emission [2]. The dissipative dynamics of the atoms is known to depend dramatically on the ratio between the typical inter- atomic distance and the atomic transition wavelength, notably because of dipole-dipole interactions [3]. In this work, we study the effects of these interactions on superradiance as in [4] by solving numerically the corresponding master equation. In particular, by averaging over many realizations of the randomly distributed atomic positions, we show that the decay of the radiated energy pulse height with the intensity of the dipolar coupling follows a power law. [1] E. Ackermans, A. Gero & R. Kaiser, Phys. Rev. Lett. 101, 103602 (2008). [2] R. Friedberg & J. T. Manassah, J. Phys. B 43, 035501 (2010). [3] M. Gross & S. Haroche, Physics reports 93, 301-396 (1982). [4] B. Coffey & R. Friedberg, Phys. Rev. A 17, 1033 (1978). [less ▲]

Detailed reference viewed: 56 (6 ULg)
See detailInfluence of dipole-dipole interactions on the superradiant pulse
Damanet, François ULg; Martin, John ULg

Poster (2013, May 23)

Superradiance, known as the cooperative spontaneous emission of a directional light pulse by excited atoms placed in vacuum, has recently regained attention in the context of photon localization [1] and ... [more ▼]

Superradiance, known as the cooperative spontaneous emission of a directional light pulse by excited atoms placed in vacuum, has recently regained attention in the context of photon localization [1] and single photon cooperative emission [2]. The dissipative dynamics of the atoms is known to depend dramatically on the ratio between the typical inter-atomic distance and the atomic transition wavelength, notably because of dipole-dipole interactions [3]. In this work, we study the effects of these interactions on superradiance as in [4] by solving numerically the corresponding master equation. In particular, by averaging over many realizations of the randomly distributed atomic positions, we show that the decay of the radiated energy pulse height with the intensity of the dipolar coupling follows a power law. [1] E. Ackermans, A. Gero & R. Kaiser, Phys. Rev. Lett. 101, 103602 (2008). [2] R. Friedberg & J. T. Manassah, J. Phys. B 43, 035501 (2010). [3] M. Gross & S. Haroche, Physics reports 93, 301-396 (1982). [4] B. Coffey & R. Friedberg, Phys. Rev. A 17, 1033 (1978). [less ▲]

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See detailINFLUENCE OF DISSOLVED MACROMOLECULES ON ADHERENCE OF PARTICULATE SOILS
Toure, Yetioman ULg; Sindic, Marianne ULg; Rouxhet, G. Paul

Conference (2013, June 12)

Polysaccharides, proteins, lipids and other biopolymers are the main components of food and pharmaceutical mixtures and may influence interactions at interfaces and thus fouling and cleaning. In this ... [more ▼]

Polysaccharides, proteins, lipids and other biopolymers are the main components of food and pharmaceutical mixtures and may influence interactions at interfaces and thus fouling and cleaning. In this study, quartz particles (10 to 30µm) were used as a model soil for examining the effect of dissolved proteins on the cleanability of substrates after soiling and drying. Glass and stainless steel pretreated by UV-Ozone (StSteel-UVO) were used as model hydrophilic substrates, while hydrophobic substrates were represented by stainless steel cleaned with ethanol (StSteel-Eth) and polystyrene. BSA and β-LGB were used as proteins. The quartz suspensions used for soiling (150g/L) were prepared in pure water and in a solution of each protein (8g/l). After soiling and drying, the cleanability was evaluated using a radial-flow cell, with pure water as the cleaning fluid. When soiling was made with a quartz suspension in pure water, the soil adherence increased with substrate hydrophilicity. This may be explained by better droplet spreading and increase of the capillary forces created upon drying. The presence of proteins in the suspension used for soiling hydrophilic substrates (Glass and StSteel-UVO), decreased the adherence of quartz particles. Its effect was less marked and tended to be opposite for less hydrophilic substrates (StSteel-Eth, Polystyrene). The comparison of different substrates and two proteins showed that the adherence cannot be explained by a simple relation with the contact angle. Other factors may be the solution surface tension itself and the protein behavior at the interfaces created by drying and by rehydratation during cleaning. When considering the influence of substrate on soiling, it must be kept in mind that high surface energy solids (metals, oxides) are readily contaminated in contact with air and lose their hydrophilicity. Amazingly this may improve the substrate behavior regarding cleanability with respect to particulate soil. [less ▲]

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See detailInfluence of DMM addition in light fuel oil on the flame emission in a domestic hot water boiler
Masy, Cédric; Ngendakumana, Philippe ULg

Conference (2004, August)

In order to investigate the soot reduction potentialities of DMM (called also methylal) addition in an overall lean diffusion flame, tests have been carried out on our experimental fuel oil boiler whose ... [more ▼]

In order to investigate the soot reduction potentialities of DMM (called also methylal) addition in an overall lean diffusion flame, tests have been carried out on our experimental fuel oil boiler whose burner is equipped with a spill-return atomizer. The tests have been performed in steady state regime without and with addition of DMM. During all the tests, the oxygen at the chimney was kept constant (around 3%) by adjusting the position of the burner air damper and thus the air combustion mass flow rate. The combustion chamber has two quartz windows through which the flame emission was registered by using a photodiode sensible in visible range. Classical gas analysers were used to measure the CO and NOx concentrations at the chimney. DMM percentages up to 15% (by mass) have been tested. [less ▲]

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See detailInfluence of DNA condensation state on transfection efficiency in DNA/polymer complexes: An AFM and DLS comparative study
Volcke, C.; Pirotton, S.; Grandfils, Christian ULg et al

in Journal of Biotechnology (2006), 125(1), 11-21

Atomic force microscopy (AFM) is used to describe the formation process of polymer/DNA complexes. Two main objectives of this research are presented. The first one is to apply AFM as an effective tool to ... [more ▼]

Atomic force microscopy (AFM) is used to describe the formation process of polymer/DNA complexes. Two main objectives of this research are presented. The first one is to apply AFM as an effective tool to analyse DNA molecules and different polycation/DNA complexes in order to evaluate their degree of condensation (size and shape). The other one is to search for a relationship between the condensation state of DNA and its transfection efficiency. In this study, linear methacrylate based polymers and globular SuperFect polymers are used in order to induce DNA condensation. Ternary complexes, composed of methacrylate based polymers and polyethylene glycol (PEG)-based copolymers, are also investigated. AFM allows us to confirm good condensation conditions and relate them (or not) to transfection efficiencies. These AFM results (obtained after drying in air) are compared with measurements deduced from Dynamic Light Scattering (DLS) experiments performed in water. This comparison allowed us to identify the structural modifications resulting from deposition on the mica surface. (c) 2006 Elsevier B.V. All rights reserved. [less ▲]

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See detailInfluence of domestication process on immune response to repeated emersion stressors in Eurasian perch (Perca fluviatilis L.)
Douxfils, Jessica; Lambert, S; Mathieu, Cédric et al

in Comparative Biochemistry and Physiology. A : Comparative Physiology (2014), 173

Detailed reference viewed: 17 (2 ULg)
Peer Reviewed
See detailInfluence of dominance relationships on the estimation of dominance variance with sire-dam subclass effects
Gengler, Nicolas ULg; VanVleck, L. D.; MacNeil, M. D. et al

in Journal of Animal Science (1997), 75(11), 2885-2891

Two data sets from the USDA Livestock and Range Research Laboratory mere analyzed to study dominance variance and the influence of dominance relationships. The first consisted of 4,155 birth weight (3,884 ... [more ▼]

Two data sets from the USDA Livestock and Range Research Laboratory mere analyzed to study dominance variance and the influence of dominance relationships. The first consisted of 4,155 birth weight (3,884 weaning weight) records of inbred USDA Line 1 Herefords. The second consisted of 8,065 birth weight (7,380 weaning weight) records from a line-cross experiment with five lines. Two models were used. Both included fixed effects of year-sex of calf and age of dam, and covariates for calving date, inbreeding of animal, and inbreeding of dam. For the second set, additional covariates were line composition and heterozygosity coefficients. Random effects were direct and maternal additive genetic, maternal permanent environment, sire-dam subclass, and residual. Model 1 considered sire-dam subclasses unrelated. Model 2 related sire-dam subclasses with a parental dominance relationship matrix. Variance components were estimated using REML. Differences between estimates with Model 1 and 2 were unimportant except for dominance variance. For the first data set, estimates with Model 2 of relative genetic direct and maternal variances, direct-maternal correlation, permanent environment, and dominance variances for birth weight were .35, .13, -.02, .03, and .25, respectively, and they were .39, .11, .04, .06 and .14 for the second data set. For weaning weight, the first data set estimates were .20, .15, -.37, .19, and .11, respectively, and they were .16, .20, -.07, .18, and .18 for the second data set. Changes, decreases and increases, in estimates of dominance variances may be due to increased information from relationships and family types other than full-sibs. The assumption of unrelated sire-dam subclasses might not be appropriate for estimation of dominance variance in populations with many dominance relationships among siredam classes. [less ▲]

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See detailInfluence of dose on the persistence of conditioned place preference induced by cocaine in C57BL/6J mice
Brabant, Christian ULg; Tirelli, Ezio ULg

in Behavioural Pharmacology (2003, September), 14(Suppl. 1), 54

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See detailInfluence of drospirenone on renin-angiotensin-aldosterone system evaluation
VROONEN, Laurent ULg; Cavalier, Etienne ULg; Vranken, Laura ULg et al

in Endocrine Abstracts - 13th European Congress of Endocrinology (2011)

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See detailInfluence of drying and hydrothermal treatment of corn on the denaturation of salt-soluble proteins and color parameters
Odjo, Sylvanus; Malumba Kamba, Paul ULg; Dossou, Joseph et al

in Journal of Food Engineering (2012), 109(3), 561-570

The effect of heat treatments (drying and hydrothermal treatment) on the extractability of salt-soluble protein (SSP) was assessed using Promatest methodology for corn kernels heated between 60 C and 120 ... [more ▼]

The effect of heat treatments (drying and hydrothermal treatment) on the extractability of salt-soluble protein (SSP) was assessed using Promatest methodology for corn kernels heated between 60 C and 120 C. During drying, the evolution of the grain moisture content is fitted using the analytical solution of Fick equation developed by Crank (1979) for spherical material. The decrease of extractible salt-soluble protein during heating is forecasted using a first and a second order ordinary differential equation. It was found that temperature; moisture content and time of processing greatly influence the kinetic denaturation of SSP of corn kernels. The evolution of extractible SSP content of corn kernels during drying at high temperature is more correctly described with second order kinetic than with the first order kinetic reaction. The Hunterlab color parameters of corn also vary during drying. Lightness and color intensity decrease while yellowness, redness, chroma and hue angle increase through drying time. Most of these Hunterlab color parameters are highly correlated with the salt-soluble proteins content and therefore could be used as indicators of excessive heat treatment and denaturation of salt-soluble proteins in corn kernels [less ▲]

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See detailInfluence of drying and hydrothermal treatments on the denaturation of corn proteins
Odjo, Djosse Psijus Sylvanus ULg; Malumba Kamba, Paul ULg; Bera, François ULg

Poster (2013, February 08)

Corn (Zea mays L.) is the most abundant cereal grain produced in the world. It also provides a significant amount of protein in human and animal diets. During drying corn grains undergo several ... [more ▼]

Corn (Zea mays L.) is the most abundant cereal grain produced in the world. It also provides a significant amount of protein in human and animal diets. During drying corn grains undergo several alterations including protein denaturation. A series of studies have been conducted in order to understand mechanisms behind denaturation of corn proteins during drying and heat moisture treatments. Using a laboratory fluidized-bed dryer, a flint corn variety have been dried between 54° and 130°C and subjected to different analyses from a qualitative point of view with a sequential extraction of corn protein fractions and from a quantitative point of view with the modeling of salt-soluble proteins using Promatest assay. Albumin, globulin and zein solubilities dropped significantly when the drying temperature increased. The electrophoretic patterns of zein and glutelin-G1 were not significantly modified, although the solubility of zein was affected by the drying temperature. The analysis of the different protein group solubilities suggested that denaturation mechanisms other than the creation of new disulfide bonds occurred during the drying of corn at high temperature. The study of the effect of heat treatments on the extractability of salt-soluble proteins shows that temperature; moisture content and time of processing greatly influence their kinetic denaturation. Modeling of salt-soluble proteins reveals that the evolution of extractible salt-soluble proteins content of corn kernels during drying at high temperature is more correctly described with a second order kinetic reaction. Investigations continue in order to understand protein denaturation and influence in functional properties and end-use of corn protein-based products. [less ▲]

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See detailInfluence of drying methods on yield and chemical composition
Dahak, K.; Wathelet, Jean-Paul ULg; Chechouani, H. et al

Poster (2009)

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See detailInfluence of drying temperature on functional properties of wet-milled starch granules
Malumba Kamba, Paul ULg; Massaux, Carine; Deroanne, Claude et al

in Carbohydrate Polymers (2009), 75

Relationships between swelling capacities, pasting properties, rotational flow behaviour and textural properties of hydro-thermally heated wet-milled starch granules from corn dried between 60 and 130°C ... [more ▼]

Relationships between swelling capacities, pasting properties, rotational flow behaviour and textural properties of hydro-thermally heated wet-milled starch granules from corn dried between 60 and 130°C were investigated. High-drying temperatures applied during the corn drying process conferred to the wet-milled starch granules (WSG) such a rigidity which reduced their swelling capacities, their water binding capacities and their water solubility index after gelatinization. These granules changes affected their pasting characteristics, their flow behaviour and several textural parameters of gel formed from the wet-milled starch granule after gelatinization. The rigidity of granules was a major factor determining the formation of either starch pastes or gels. [less ▲]

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See detailINFLUENCE OF DRYING TEMPERATURE ON THE CORN WET-MILLING PROCESS: REVIEW
Malumba Kamba, Paul ULg; Janas, Sébastien; Sindic, Marianne ULg et al

in Filipovic, Lovro, A. (Ed.) Milling: Operations, Applications and Industrial Effects (2011)

In order to separate its major components, corn kernel is processed using the wet-milling process during which steeping, milling and starch/gluten separations appear to be the most important operations ... [more ▼]

In order to separate its major components, corn kernel is processed using the wet-milling process during which steeping, milling and starch/gluten separations appear to be the most important operations. To improve the efficiency of this process, corn wet-milling industry expended considerable resources focusing on improved process control, more efficient process equipment and on the development of hybrids that decrease the variability and reduce production costs. However, important variability is still observed according to the thermal history of grain after harvesting. The present article reviews up-to-date literature on the effect of drying conditions on the corn wet-milling performance and the physicochemical and functional properties of corn wet-milled fraction. Literature in this topic shows that high drying temperature combined with high initial moisture content of grain impact significantly the wet-milling performance and the quality of recovered materials. Further studies on the influence of drying process on the quality of starch, gluten, germ and fiber recovered during the wet-milling process are needed and would help to develop more accurate engineering and economic models for the corn wet milling process. [less ▲]

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See detailInfluence of drying temperature on the solubility, the purity of isolates and the electrophoretic patterns of corn proteins
Malumba Kamba, Paul ULg; Vanderghem, Caroline ULg; Deroanne, Claude ULg et al

in Food Chemistry (2008), 111(3), 564-572

A sequential extraction of proteins from whole corn kernels dried between 54 and 130 degrees C was performed in order to elucidate the effect of the drying temperature on the solubility, the purity and ... [more ▼]

A sequential extraction of proteins from whole corn kernels dried between 54 and 130 degrees C was performed in order to elucidate the effect of the drying temperature on the solubility, the purity and the electrophoretic patterns of the different classes of corn proteins. It was observed that albumin, globulin and zein solubilities dropped significantly when the drying temperature increased, while fractions solubilised as glutelin-G(2) and glutelin-G3 increased until 110 degrees C before dropping slightly at 130 degrees C. The analysis of the solubility of different protein groups indicated that mechanisms other than the creation of new disulfide bonds between proteins occurred during the high temperature drying of corn. Except for glutelin-G1 and zein isolates, which were highly pure, the purities of albumin, globulin, glutelin-G2 and glutelin-G3 isolates after dialysis were influenced by the drying temperature. Sodium dodecyl sulphate-polyacrylamide gel electrophoresis (SDS-PAGE) showed the disappearance of some water and salt-soluble poly-peptides at high drying temperatures. The electrophoretic patterns of zein and glutelin-G, were not significantly modified, although the solubility of zein was affected by the drying temperature. (c) 2008 Elsevier Ltd. All rights reserved. [less ▲]

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See detailInfluence of drying temperature on the wet-milling performance and the proteins solubility indexes of corn kernels
Malumba Kamba, Paul ULg; Janas, Sébastien ULg; Masimango, Thaddée et al

in Journal of Food Engineering (2009), 95

The effects of air drying temperature on the wet-milling performance and the proteins solubility indexes were investigated for corn kernels dried between 54°C and 130°C. It was observed that when the ... [more ▼]

The effects of air drying temperature on the wet-milling performance and the proteins solubility indexes were investigated for corn kernels dried between 54°C and 130°C. It was observed that when the drying temperature increases, the starch yield drops significantly. The gluten recovered increased abruptly for drying temperatures up to 80 C. The albumin, globulin and zein solubility indexes decreased continuously when corn drying temperatures increased. According to the temperatures used, the starch yield, the gluten recovered and the salt-soluble proteins solubility indexes were adjusted satisfactorily by using a two asymptotic logistic model. This model has the advantage of supplying information on the dynamic of the variation of described parameters. The solubility index of total salt-soluble proteins was shown to be a suitable indicator of the severity of the drying treatment in regard to the corn wet-milling performance. [less ▲]

Detailed reference viewed: 39 (5 ULg)