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Johannes H C Cornelissen - One of the best experts on this subject based on the ideXlab platform.
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similar growth performance but contrasting biomass allocation of root flooded terrestrial plant alternanthera philoxeroides mart griseb in response to nutrient versus dissolved Oxygen stress
Frontiers in Plant Science, 2019Co-Authors: Bo Zeng, Kang Yang, Xiaoping Zhang, Peter M Van Bodegom, Johannes H C CornelissenAbstract:Terrestrial plants may experience nutrient and Oxygen stress when they are submerged, and increases in flooding are anticipated with climate change. It has been well reported that plants usually shift biomass allocation and produce more roots in response to nutrient Deficiency. However, it is unclear whether plants experiencing Oxygen Deficiency stimulate biomass allocation to roots to enhance nutrient absorption, similar to how plants experiencing nutrient Deficiency behave. We investigated the responses of the terrestrial species Alternanthera philoxeroides, upon root flooding, to nutrient versus dissolved Oxygen Deficiency in terms of plant growth, biomass allocation, root production, root efficiency (plant growth sustained per unit root surface area), and root aerenchyma formation. Both nutrient and dissolved Oxygen Deficiency hampered the growth of root-flooded plants. As expected, plants experiencing nutrient Deficiency increased biomass allocation to roots and exhibited lower root efficiency; in contrast, plants experiencing dissolved Oxygen Deficiency decreased biomass allocation to roots but achieved higher root efficiency. The diameter of aerenchyma channels in roots were enlarged in plants experiencing dissolved Oxygen Deficiency but did not change in plants experiencing nutrient Deficiency. The widening of aerenchyma channels in roots could have improved the Oxygen status and thereby the nutrient absorption capability of roots in low Oxygen environments, which might benefit the plants to tolerate flooding.
Bo Zeng - One of the best experts on this subject based on the ideXlab platform.
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similar growth performance but contrasting biomass allocation of root flooded terrestrial plant alternanthera philoxeroides mart griseb in response to nutrient versus dissolved Oxygen stress
Frontiers in Plant Science, 2019Co-Authors: Bo Zeng, Kang Yang, Xiaoping Zhang, Peter M Van Bodegom, Johannes H C CornelissenAbstract:Terrestrial plants may experience nutrient and Oxygen stress when they are submerged, and increases in flooding are anticipated with climate change. It has been well reported that plants usually shift biomass allocation and produce more roots in response to nutrient Deficiency. However, it is unclear whether plants experiencing Oxygen Deficiency stimulate biomass allocation to roots to enhance nutrient absorption, similar to how plants experiencing nutrient Deficiency behave. We investigated the responses of the terrestrial species Alternanthera philoxeroides, upon root flooding, to nutrient versus dissolved Oxygen Deficiency in terms of plant growth, biomass allocation, root production, root efficiency (plant growth sustained per unit root surface area), and root aerenchyma formation. Both nutrient and dissolved Oxygen Deficiency hampered the growth of root-flooded plants. As expected, plants experiencing nutrient Deficiency increased biomass allocation to roots and exhibited lower root efficiency; in contrast, plants experiencing dissolved Oxygen Deficiency decreased biomass allocation to roots but achieved higher root efficiency. The diameter of aerenchyma channels in roots were enlarged in plants experiencing dissolved Oxygen Deficiency but did not change in plants experiencing nutrient Deficiency. The widening of aerenchyma channels in roots could have improved the Oxygen status and thereby the nutrient absorption capability of roots in low Oxygen environments, which might benefit the plants to tolerate flooding.
A A Yaremchenko - One of the best experts on this subject based on the ideXlab platform.
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high temperature characterization of Oxygen deficient k2nif4 type nd2 xsrxnio4 δ x 1 0 1 6 for potential sofc soec applications
Journal of Materials Chemistry, 2015Co-Authors: Ekaterina Kravchenko, D D Khalyavin, Kiryl Zakharchuk, Jekabs Grins, Gunnar Svensson, V V Pankov, A A YaremchenkoAbstract:Previously unexplored Oxygen-deficient Ruddlesden–Popper Nd2−xSrxNiO4−δ (x = 1.0–1.6) nickelates were evaluated for potential use as Oxygen electrode materials for solid oxide fuel and electrolysis cells, with emphasis on structural stability, Oxygen nonstoichiometry, dimensional changes, and electrical properties. Nd2−xSrxNiO4−δ ceramics possess the K2NiF4-type tetragonal structure under oxidizing conditions at 25–1000 °C. Acceptor-type substitution by strontium is compensated by the generation of electron–holes and Oxygen vacancies. Oxygen Deficiency increases with temperature and strontium doping reaching ∼1/8 of Oxygen sites for x = 1.6 at 1000 °C in air. Strongly anisotropic expansion of the tetragonal lattice on heating correlated with Oxygen nonstoichiometry changes results in an anomalous dilatometric behavior of Nd2−xSrxNiO4−δ ceramics under oxidizing conditions. Moderate thermal expansion coefficients, (11–14) × 10−6 K−1, ensure however thermomechanical compatibility with common solid electrolytes. Reduction in inert atmosphere induces Oxygen vacancy ordering accompanied by a contraction of the lattice and a decrease of its symmetry to orthorhombic. Nd2−xSrxNiO4−δ ceramics exhibit a p-type metallic-like electrical conductivity at 500–1000 °C under oxidizing conditions, with the highest conductivity (290 S cm−1 at 900 °C in air) observed for x = 1.2. The high level of Oxygen Deficiency in Sr-rich Nd2−xSrxNiO4−δ implies enhanced mixed ionic–electronic transport favorable for electrode applications.
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high temperature characterization of Oxygen deficient k nif type nd ₓsrₓnio δ x 1 0 1 6 for potential sofc soec applications
Journal of Materials Chemistry, 2015Co-Authors: Ekaterina Kravchenko, D D Khalyavin, Kiryl Zakharchuk, Jekabs Grins, Gunnar Svensson, V V Pankov, A A YaremchenkoAbstract:Previously unexplored Oxygen-deficient Ruddlesden–Popper Nd₂₋ₓSrₓNiO₄₋δ (x = 1.0–1.6) nickelates were evaluated for potential use as Oxygen electrode materials for solid oxide fuel and electrolysis cells, with emphasis on structural stability, Oxygen nonstoichiometry, dimensional changes, and electrical properties. Nd₂₋ₓSrₓNiO₄₋δ ceramics possess the K₂NiF₄-type tetragonal structure under oxidizing conditions at 25–1000 °C. Acceptor-type substitution by strontium is compensated by the generation of electron–holes and Oxygen vacancies. Oxygen Deficiency increases with temperature and strontium doping reaching ∼1/8 of Oxygen sites for x = 1.6 at 1000 °C in air. Strongly anisotropic expansion of the tetragonal lattice on heating correlated with Oxygen nonstoichiometry changes results in an anomalous dilatometric behavior of Nd₂₋ₓSrₓNiO₄₋δ ceramics under oxidizing conditions. Moderate thermal expansion coefficients, (11–14) × 10⁻⁶ K⁻¹, ensure however thermomechanical compatibility with common solid electrolytes. Reduction in inert atmosphere induces Oxygen vacancy ordering accompanied by a contraction of the lattice and a decrease of its symmetry to orthorhombic. Nd₂₋ₓSrₓNiO₄₋δ ceramics exhibit a p-type metallic-like electrical conductivity at 500–1000 °C under oxidizing conditions, with the highest conductivity (290 S cm⁻¹ at 900 °C in air) observed for x = 1.2. The high level of Oxygen Deficiency in Sr-rich Nd₂₋ₓSrₓNiO₄₋δ implies enhanced mixed ionic–electronic transport favorable for electrode applications.
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Oxygen nonstoichiometry of bi2v0 9cu0 1o5 5 δ solid electrolyte by coulometric titration technique
Electrochimica Acta, 2002Co-Authors: V N Tikhonovich, E N Naumovich, V V Kharton, A A Yaremchenko, A V Kovalevsky, A A VecherAbstract:Abstract Oxygen Deficiency of Bi 2 V 0.90 Cu 0.10 O 5.5− δ (BICUVOX.10) solid electrolyte was studied by the coulometric titration technique and thermogravimetric analysis at Oxygen partial pressures from 1×10 −7 to 0.5 atm (atmospheric air) in the temperature range 650–1050 K. Within the phase stability domain, the nonstoichiometry ( δ ) varies in the narrow range from 0.150 to 0.155. Increasing Oxygen Deficiency leads to a greater n -type electronic conductivity, which can be described by common models for other solid electrolytes. The partial molar enthalpy and entropy for Oxygen incorporation into Bi 2 V 0.9 Cu 0.1 O 5.5− δ lattice linearly decrease with increasing δ . Further reduction of the Oxygen partial pressure results in decomposition of Bi 2 V 0.90 Cu 0.10 O 5.5− δ , forming a mixture of an Aurivillius-type phase and binary metal oxides, which is accompanied with decreasing ionic conductivity. The results of the coulometric titration and ion transference number measurements suggest that BICUVOX.10 ceramics can be used as electrolyte only at atmospheric or higher Oxygen pressures, preferably at temperatures below 900–950 K.
H Robertson - One of the best experts on this subject based on the ideXlab platform.
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investigation of personal and fixed head Oxygen Deficiency hazard monitor performance for helium gas
Advances in cryogenic engineering, 2002Co-Authors: D Arenius, D Curry, A Hutton, K Mahoney, S Prior, H RobertsonAbstract:On May 14, 2001, the Thomas Jefferson National Accelerator Facility (JLAB) conducted a planned liquid helium release into its accelerator tunnel to study the effectiveness of the JLAB facility to vent the helium and therefore limit the Oxygen Deficiency hazard (ODH). During the test, it was discovered that a wide range of various Oxygen Deficiency monitors, of different manufacturers, were providing substantial conflicting measurements of the true Oxygen level where health effects are of concern. Yet, when tested separately with nitrogen gas as the diluting gas into air, the same models performed very well. This problem, which is associated with helium displacement of air, was found for both personal Oxygen monitors and fixed installation monitors from many different manufacturers. By informing other facilities of its findings, JLAB became aware this problem also exists among other national laboratories and facilities. Many manufacturers do not have data on the effects of helium displacing air for their d...
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investigation of personal and fixed head Oxygen Deficiency hazard monitor performance for helium gas
Advances in cryogenic engineering, 2002Co-Authors: D Arenius, D Curry, A Hutton, K Mahoney, S Prior, H RobertsonAbstract:On May 14, 2001, the Thomas Jefferson National Accelerator Facility (JLAB) conducted a planned liquid helium release into its accelerator tunnel to study the effectiveness of the JLAB facility to vent the helium and therefore limit the Oxygen Deficiency hazard (ODH). During the test, it was discovered that a wide range of various Oxygen Deficiency monitors, of different manufacturers, were providing substantial conflicting measurements of the true Oxygen level where health effects are of concern. Yet, when tested separately with nitrogen gas as the diluting gas into air, the same models performed very well. This problem, which is associated with helium displacement of air, was found for both personal Oxygen monitors and fixed installation monitors from many different manufacturers. By informing other facilities of its findings, JLAB became aware this problem also exists among other national laboratories and facilities. Many manufacturers do not have data on the effects of helium displacing air for their devices. Some manufacturers have now duplicated the test results conducted at JLAB. Since both fixed installation and personal Oxygen monitors have become standard safety device in many research facilities and industries in the United States and abroad, it is important that these facilities are aware of the problem and how it is being addressed at JLAB. This paper discusses the methods, procedures and materials used by JLAB to qualify its ODH sensors for helium. Data and graphs of JLAB’s findings are provided.
Kang Yang - One of the best experts on this subject based on the ideXlab platform.
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similar growth performance but contrasting biomass allocation of root flooded terrestrial plant alternanthera philoxeroides mart griseb in response to nutrient versus dissolved Oxygen stress
Frontiers in Plant Science, 2019Co-Authors: Bo Zeng, Kang Yang, Xiaoping Zhang, Peter M Van Bodegom, Johannes H C CornelissenAbstract:Terrestrial plants may experience nutrient and Oxygen stress when they are submerged, and increases in flooding are anticipated with climate change. It has been well reported that plants usually shift biomass allocation and produce more roots in response to nutrient Deficiency. However, it is unclear whether plants experiencing Oxygen Deficiency stimulate biomass allocation to roots to enhance nutrient absorption, similar to how plants experiencing nutrient Deficiency behave. We investigated the responses of the terrestrial species Alternanthera philoxeroides, upon root flooding, to nutrient versus dissolved Oxygen Deficiency in terms of plant growth, biomass allocation, root production, root efficiency (plant growth sustained per unit root surface area), and root aerenchyma formation. Both nutrient and dissolved Oxygen Deficiency hampered the growth of root-flooded plants. As expected, plants experiencing nutrient Deficiency increased biomass allocation to roots and exhibited lower root efficiency; in contrast, plants experiencing dissolved Oxygen Deficiency decreased biomass allocation to roots but achieved higher root efficiency. The diameter of aerenchyma channels in roots were enlarged in plants experiencing dissolved Oxygen Deficiency but did not change in plants experiencing nutrient Deficiency. The widening of aerenchyma channels in roots could have improved the Oxygen status and thereby the nutrient absorption capability of roots in low Oxygen environments, which might benefit the plants to tolerate flooding.
