The Experts below are selected from a list of 33 Experts worldwide ranked by ideXlab platform
Minchin, Frank R. - One of the best experts on this subject based on the ideXlab platform.
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Oxygen diffusion in lupin nodules: I.visualization of diffusion Barrier Operation
'Oxford University Press (OUP)', 2020Co-Authors: Iannetta P. P. M., Cristina De ,lorenzo, James E. K., Fernández-pascual Mercedes, Sprent, Janet Irene, Lucas M. Mercedes, Witty J. F., Mª Rosario De ,felipe, Minchin, Frank R.Abstract:Root nodules of Lupinus albus (L.) cv. Multolupa were subjected to short- and medium-term stresses by lowering rhizosphere temperature from 25 to 16°C (2 h), detopping plants (3 h), darkening plants (21 h) or exposing roots to 20 mol m-3 KNO3 for 4 d. All experimental treatments produced increases in oxygen diffusion resistance, compared with control plants. These correlated with structural changes in the nodule cortex, which is described in detail for the first time. The most noticeable change is the occlusion of intercellular spaces by a glycoprotein which was identified using the monoclonal antibody MAC236. This glycoprotein was also found surrounding bacteria in intercellular spaces of the cortex of control nodules
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Oxygen diffusion in lupin nodules: II. Mechanisms of diffusion Barrier Operation
'Oxford University Press (OUP)', 2020Co-Authors: Cristina De ,lorenzo, Iannetta P. P. M., James E. K., Fernández-pascual Mercedes, Sprent, Janet Irene, Lucas M. Mercedes, Witty J. F., Minchin, Frank R., Mª Rosario De ,felipeAbstract:The oxygen diffusion resistance of Lupinus albus (L.) cv. Multolupa root nodules was increased by subjection to short-term stresses; lowering rhizosphere temperature from 25 to 16 °C (2 h), detopping plants (3 h), darkening plants (21 h) or exposing roots to 20 mol m-3 KN03 for 2, 4 or 6 d. Microscopic observations and measurements showed that this resulted in the area of open intercellular spaces within the inner cortex being reduced due to both cell expansion and increased production of an occluding glycoprotein. Electrophoretic and Western Blot analysis using the monoclonal antibodies MAC236 and MAC265 showed two distinct glycoprotein antigens with molecular weights of 240 and 135 kDa, respectively. Both antigens are localized within intercellular spaces of the inner cortex. The amount of glycoprotein was determined using either ELISA, with MAC265, or quantification of immunolabelling with MAC236. This immunolabelling also localized the glycoprotein within globules adhering to the inside of the inner cortical cell walls
Mª Rosario De ,felipe - One of the best experts on this subject based on the ideXlab platform.
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Oxygen diffusion in lupin nodules: I.visualization of diffusion Barrier Operation
'Oxford University Press (OUP)', 2020Co-Authors: Iannetta P. P. M., Cristina De ,lorenzo, James E. K., Fernández-pascual Mercedes, Sprent, Janet Irene, Lucas M. Mercedes, Witty J. F., Mª Rosario De ,felipe, Minchin, Frank R.Abstract:Root nodules of Lupinus albus (L.) cv. Multolupa were subjected to short- and medium-term stresses by lowering rhizosphere temperature from 25 to 16°C (2 h), detopping plants (3 h), darkening plants (21 h) or exposing roots to 20 mol m-3 KNO3 for 4 d. All experimental treatments produced increases in oxygen diffusion resistance, compared with control plants. These correlated with structural changes in the nodule cortex, which is described in detail for the first time. The most noticeable change is the occlusion of intercellular spaces by a glycoprotein which was identified using the monoclonal antibody MAC236. This glycoprotein was also found surrounding bacteria in intercellular spaces of the cortex of control nodules
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Oxygen diffusion in lupin nodules: II. Mechanisms of diffusion Barrier Operation
'Oxford University Press (OUP)', 2020Co-Authors: Cristina De ,lorenzo, Iannetta P. P. M., James E. K., Fernández-pascual Mercedes, Sprent, Janet Irene, Lucas M. Mercedes, Witty J. F., Minchin, Frank R., Mª Rosario De ,felipeAbstract:The oxygen diffusion resistance of Lupinus albus (L.) cv. Multolupa root nodules was increased by subjection to short-term stresses; lowering rhizosphere temperature from 25 to 16 °C (2 h), detopping plants (3 h), darkening plants (21 h) or exposing roots to 20 mol m-3 KN03 for 2, 4 or 6 d. Microscopic observations and measurements showed that this resulted in the area of open intercellular spaces within the inner cortex being reduced due to both cell expansion and increased production of an occluding glycoprotein. Electrophoretic and Western Blot analysis using the monoclonal antibodies MAC236 and MAC265 showed two distinct glycoprotein antigens with molecular weights of 240 and 135 kDa, respectively. Both antigens are localized within intercellular spaces of the inner cortex. The amount of glycoprotein was determined using either ELISA, with MAC265, or quantification of immunolabelling with MAC236. This immunolabelling also localized the glycoprotein within globules adhering to the inside of the inner cortical cell walls
Vos Thomas - One of the best experts on this subject based on the ideXlab platform.
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Tidal control in the Lower Ems: An indicative study into the effects of controlled Barrier Operation on the tidal asymmetry in the Lower Ems river
2021Co-Authors: Vos ThomasAbstract:The lower Ems river suffers from hyper-turbid conditions. These conditions are caused by channel deepening over the last 50 years, resulting in an asymmetrical tidal wave. This asymmetry has resulted in an increasedimport of sediment into the Ems river. Recently some effort has gone into determining whether or not the local tidal Barrier (Emssperrwerk) can be used to alter the asymmetry of the tidal waves propagating through the Ems estuary. Previous modelling studies, using state-of-the-art models, have been able to reproduce prototype tests involving the same tidal Barrier but very little effort has thus far gone into determining what the optimal Barrier control regime is and what the restriction imposed on the Barrier Operation mean for the overalleffectiveness of the Barrier. The Operation of the tidal Barrier was schematised and described using two factors: closure percentage and closure duration. The effectiveness of a broad spectrum of combinations determining the tidal Barrier Operation is modelled using a simple one-dimensional model which takes only into account the (simplified) hydrodynamics in the lower Ems river. The results of the model indicate that only in part of the Lower Ems the tide can be adjusted to become symmetrical or slightly ebb-dominant. This requires a closure duration longer than approximately 240 minutes. The length of this stretch of river is increase further by increasing the closure percentage. Similarly, increasing the closure percentage also leads to a decrease in the tidal volume and the amplitude of the M4 component. For this reason, the closure percentage should be kept as low as possible, as long as the Barrier Operation is able to reduce the sediment import into the Lower Ems. The required length of the stretch of the Lower Ems with a symmetric tide is estimated to be around 12 km. Applying restrictions to the Barrier Operations showed that shorter Barrier Operations should be preferred, since short Operations allow a larger number oftidal waves to be altered, increasing the effectiveness in a realistic setting. Based on these considerations an optimal Barrier Operation consists of a closure duration of approximately 300 minutes and a closure percentage of approximately 60%. The results showed that the method used for evaluating the Barrier Operation is unable to distinguish between water levels signals consisting of altered and unaltered waves. The effectiveness of the Barrier Operation isstill estimated by considering the whole water level signal. The impact of the Barrier Operation in the model interfered with the seaward model boundary. This error increases in magnitude with increasing closure percentages. Making the results for those combinations unreliable. In order to make more reliable conclusions about the effect of the tidal Barrier Operation, subsequent models should encompass a larger domain and include a more detailed schematisation of the channel geometry, river discharge and the tidal Barrier itself.Civil Engineering | Hydraulic Engineering | Coastal Engineerin
Iannetta P. P. M. - One of the best experts on this subject based on the ideXlab platform.
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Oxygen diffusion in lupin nodules: I.visualization of diffusion Barrier Operation
'Oxford University Press (OUP)', 2020Co-Authors: Iannetta P. P. M., Cristina De ,lorenzo, James E. K., Fernández-pascual Mercedes, Sprent, Janet Irene, Lucas M. Mercedes, Witty J. F., Mª Rosario De ,felipe, Minchin, Frank R.Abstract:Root nodules of Lupinus albus (L.) cv. Multolupa were subjected to short- and medium-term stresses by lowering rhizosphere temperature from 25 to 16°C (2 h), detopping plants (3 h), darkening plants (21 h) or exposing roots to 20 mol m-3 KNO3 for 4 d. All experimental treatments produced increases in oxygen diffusion resistance, compared with control plants. These correlated with structural changes in the nodule cortex, which is described in detail for the first time. The most noticeable change is the occlusion of intercellular spaces by a glycoprotein which was identified using the monoclonal antibody MAC236. This glycoprotein was also found surrounding bacteria in intercellular spaces of the cortex of control nodules
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Oxygen diffusion in lupin nodules: II. Mechanisms of diffusion Barrier Operation
'Oxford University Press (OUP)', 2020Co-Authors: Cristina De ,lorenzo, Iannetta P. P. M., James E. K., Fernández-pascual Mercedes, Sprent, Janet Irene, Lucas M. Mercedes, Witty J. F., Minchin, Frank R., Mª Rosario De ,felipeAbstract:The oxygen diffusion resistance of Lupinus albus (L.) cv. Multolupa root nodules was increased by subjection to short-term stresses; lowering rhizosphere temperature from 25 to 16 °C (2 h), detopping plants (3 h), darkening plants (21 h) or exposing roots to 20 mol m-3 KN03 for 2, 4 or 6 d. Microscopic observations and measurements showed that this resulted in the area of open intercellular spaces within the inner cortex being reduced due to both cell expansion and increased production of an occluding glycoprotein. Electrophoretic and Western Blot analysis using the monoclonal antibodies MAC236 and MAC265 showed two distinct glycoprotein antigens with molecular weights of 240 and 135 kDa, respectively. Both antigens are localized within intercellular spaces of the inner cortex. The amount of glycoprotein was determined using either ELISA, with MAC265, or quantification of immunolabelling with MAC236. This immunolabelling also localized the glycoprotein within globules adhering to the inside of the inner cortical cell walls
Chicgoua Noubactep - One of the best experts on this subject based on the ideXlab platform.
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Modeling the permeability loss of metallic Iron water filtration Systems
CLEAN - Soil Air Water, 2013Co-Authors: Sabine Caré, Richard Crane, Paolo S. Calabro, Antoine Ghauch, Chicgoua NoubactepAbstract:Over the past 30 years the literature has burgeoned with in situ approaches for groundwater remediation. Of the methods currently available, the use of metallic iron (Fe0) in permeable reactive Barrier (PRB) systems is one of the most commonly applied. Despite such interest, an increasing amount of experimental and field observations have reported inconsistent Fe0 Barrier Operation compared to contemporary theory. In the current work, a critical review of the physical chemistry of aqueous Fe0 corrosion in porous media is presented. Subsequent implications for the design of Fe0 filtration systems are modeled. The results suggest that: (i) for the pH range of natural waters (>4.5), the high volumetric expansion of Fe0 during oxidation and precipitation dictates that Fe0 should be mixed with a non-expansive material; (ii) naturally occurring solute precipitates have a negligible impact on permeability loss compared to Fe0 expansive corrosion; and (iii) the proliferation of H2 metabolizing bacteria may contribute to alleviate permeability loss. As a consequence, it is suggested that more emphasis must be placed on future work with regard to considering the Fe0 PRB system as a physical (size-exclusion) water filter device.
