The Experts below are selected from a list of 126606 Experts worldwide ranked by ideXlab platform
Miguel Angel Quinones - One of the best experts on this subject based on the ideXlab platform.
-
limiting co2 levels induce a blue light dependent hco3 uptake system in monoraphidium braunii
Journal of Experimental Botany, 2000Co-Authors: Nuria Giraldez, Pedro J Aparicio, Miguel Angel QuinonesAbstract:The in situ photoactivation of an HCO3 uptake system in the green alga Monoraphidium braunii requires the irradiation of the cell suspensions with short wavelength radiation (blue, UVA and/or UVC). Plasma membrane ATPase inhibitors block the uptake of this monovalent anion at pH 9. M. braunii cells grown in high CO 2 lack an HCO 3 - uptake system in their plasma membrane, but those grown in low CO 2 can take up this anion at high rates. Cells grown in high CO 2 , transferred to CO 2 -limiting conditions in the light, start taking up HCO 3 - in 30 min, although they take 90 min to reach maximum rates of HCO 3 - transport. Therefore, this Induction Process seems to be triggered by low external CO 2 concentration. In fact, increasing or decreasing the external HCO 3 - concentration does not induce the uptake system and only a decrease in CO 2 concentration in the medium triggers the Induction Process. The appearance of the HCO 3 - transport activity is sensitive to cycloheximide, indicating that cytoplasmic protein biosynthesis is necessary for the Induction of the uptake system. Photosynthetically active radiation, but not particularly blue light, is essential for Induction of the uptake system to occur and the inhibition of photosynthesis by DCMU blocks it. From these results it can be inferred that when M. braunii cells detect a drop in CO 2 concentration, they induce a blue light-dependent HCO 3 - uptake system.
-
Limiting CO2 levels induce a blue light‐dependent HCO3− uptake system in Monoraphidium braunii
Journal of Experimental Botany, 2000Co-Authors: Nuria Giraldez, Pedro J Aparicio, Miguel Angel QuinonesAbstract:The in situ photoactivation of an HCO3 uptake system in the green alga Monoraphidium braunii requires the irradiation of the cell suspensions with short wavelength radiation (blue, UVA and/or UVC). Plasma membrane ATPase inhibitors block the uptake of this monovalent anion at pH 9. M. braunii cells grown in high CO 2 lack an HCO 3 - uptake system in their plasma membrane, but those grown in low CO 2 can take up this anion at high rates. Cells grown in high CO 2 , transferred to CO 2 -limiting conditions in the light, start taking up HCO 3 - in 30 min, although they take 90 min to reach maximum rates of HCO 3 - transport. Therefore, this Induction Process seems to be triggered by low external CO 2 concentration. In fact, increasing or decreasing the external HCO 3 - concentration does not induce the uptake system and only a decrease in CO 2 concentration in the medium triggers the Induction Process. The appearance of the HCO 3 - transport activity is sensitive to cycloheximide, indicating that cytoplasmic protein biosynthesis is necessary for the Induction of the uptake system. Photosynthetically active radiation, but not particularly blue light, is essential for Induction of the uptake system to occur and the inhibition of photosynthesis by DCMU blocks it. From these results it can be inferred that when M. braunii cells detect a drop in CO 2 concentration, they induce a blue light-dependent HCO 3 - uptake system.
Nuria Giraldez - One of the best experts on this subject based on the ideXlab platform.
-
limiting co2 levels induce a blue light dependent hco3 uptake system in monoraphidium braunii
Journal of Experimental Botany, 2000Co-Authors: Nuria Giraldez, Pedro J Aparicio, Miguel Angel QuinonesAbstract:The in situ photoactivation of an HCO3 uptake system in the green alga Monoraphidium braunii requires the irradiation of the cell suspensions with short wavelength radiation (blue, UVA and/or UVC). Plasma membrane ATPase inhibitors block the uptake of this monovalent anion at pH 9. M. braunii cells grown in high CO 2 lack an HCO 3 - uptake system in their plasma membrane, but those grown in low CO 2 can take up this anion at high rates. Cells grown in high CO 2 , transferred to CO 2 -limiting conditions in the light, start taking up HCO 3 - in 30 min, although they take 90 min to reach maximum rates of HCO 3 - transport. Therefore, this Induction Process seems to be triggered by low external CO 2 concentration. In fact, increasing or decreasing the external HCO 3 - concentration does not induce the uptake system and only a decrease in CO 2 concentration in the medium triggers the Induction Process. The appearance of the HCO 3 - transport activity is sensitive to cycloheximide, indicating that cytoplasmic protein biosynthesis is necessary for the Induction of the uptake system. Photosynthetically active radiation, but not particularly blue light, is essential for Induction of the uptake system to occur and the inhibition of photosynthesis by DCMU blocks it. From these results it can be inferred that when M. braunii cells detect a drop in CO 2 concentration, they induce a blue light-dependent HCO 3 - uptake system.
-
Limiting CO2 levels induce a blue light‐dependent HCO3− uptake system in Monoraphidium braunii
Journal of Experimental Botany, 2000Co-Authors: Nuria Giraldez, Pedro J Aparicio, Miguel Angel QuinonesAbstract:The in situ photoactivation of an HCO3 uptake system in the green alga Monoraphidium braunii requires the irradiation of the cell suspensions with short wavelength radiation (blue, UVA and/or UVC). Plasma membrane ATPase inhibitors block the uptake of this monovalent anion at pH 9. M. braunii cells grown in high CO 2 lack an HCO 3 - uptake system in their plasma membrane, but those grown in low CO 2 can take up this anion at high rates. Cells grown in high CO 2 , transferred to CO 2 -limiting conditions in the light, start taking up HCO 3 - in 30 min, although they take 90 min to reach maximum rates of HCO 3 - transport. Therefore, this Induction Process seems to be triggered by low external CO 2 concentration. In fact, increasing or decreasing the external HCO 3 - concentration does not induce the uptake system and only a decrease in CO 2 concentration in the medium triggers the Induction Process. The appearance of the HCO 3 - transport activity is sensitive to cycloheximide, indicating that cytoplasmic protein biosynthesis is necessary for the Induction of the uptake system. Photosynthetically active radiation, but not particularly blue light, is essential for Induction of the uptake system to occur and the inhibition of photosynthesis by DCMU blocks it. From these results it can be inferred that when M. braunii cells detect a drop in CO 2 concentration, they induce a blue light-dependent HCO 3 - uptake system.
Noureddine Barka - One of the best experts on this subject based on the ideXlab platform.
-
Optimization of the edge effect of 4340 steel specimen heated by Induction Process with flux concentrators using finite element axis-symmetric simulation and experimental validation
The International Journal of Advanced Manufacturing Technology, 2019Co-Authors: Mohamed Khalifa, Noureddine Barka, Jean Brousseau, Philippe BocherAbstract:This research is performed by 2D axis-symmetric finite element simulation based on the coupling of electromagnetic fields and heat transfer applied on 4340 steel specimen with flux concentrators heated by Induction Process. The model is built using COMSOL software based on an adequate formulation taking into account the material properties and Process parameters. The obtained induced currents and temperature distributions are analyzed versus the geometrical dimensions of the model. The originality of this paper lies in the exploitation of simulation data using classical modeling and the optimization techniques to optimize the hardness profile according to geometrical factors. The proposed method is based on finite element simulations and adequate objective function able to converge to the optimal linear hardness profile. The results demonstrate that the final hardness profile can be quasi-uniform with a narrow flux concentrator gap when the gap between the master part and the inductor is larger. This overall study allows a good exploration of hardness profile linearity under various geometrical dimensions and permits a good comprehension of Induction heating with flux concentrator behavior.
-
Sensitivity study of hardness profile of 4340 specimen heated by Induction Process using axisymmetric modeling
The International Journal of Advanced Manufacturing Technology, 2013Co-Authors: Noureddine Barka, Philippe Bocher, Jean BrousseauAbstract:This present paper displays the sensitivity study of the hardness profile of flat cylinders heated by Induction-heating Process by the variation of machine parameters, such as the power (in kilowatts), the heating time (in seconds), and the generator frequency (in kilohertz). The overall work is realized only by using the simulation coupling electromagnetic field and heat transfer and it was performed in three distinguished steps. First, a COMSOL axisymmetric model was built using the adequate formulation and taking into account the material properties and the machine parameters. Second, the surface temperatures and the case depths are deeply analyzed in the function of the initial current density and the heating time in medium and high frequencies heating modes. The relationship between the initial current density in the coil and the power provided to the heated part is determined then. Finally, the sensitivity of hardness profile with the machine parameters variation was investigated using the obtained results and various statistical tools.
-
Simulation of Helical Gear Heated by Induction Process Using 3D Model
Advanced Materials Research, 2013Co-Authors: Noureddine Barka, Ahmed Chebak, Abderrazak El OuafiAbstract:This paper is devoted to develop a 3D model applied to helical gear heated by Induction Process. The global work is realised by multiphysicsimulation coupling electromagneticfields and heat transfer using Comsolsoftware. This model permits to establish the temperature distribution in function of simulation parameters. The results are very promising since they allow understanding the dissymmetry effect of heating that affect the real hardness profile. Finally, a global sensitivity study about nominal values of machine parameters is conducted to quantify the effect of power consumed by the part on the surface temperature.
-
Sensitivity Study of Temperature Profile of 4340 Spur Gear Heated by Induction Process Using 3D Model
Applied Mechanics and Materials, 2012Co-Authors: Noureddine Barka, Abderrazak El Ouafi, Philippe Bocher, Ahmed Chebak, Jean BrousseauAbstract:This paper presentsa sensitivity study using a Comsol3D model simulation for spur gear heated by Induction Process. Based on an adequate formulation and taking into account the material properties, a multi-physics 3D model is built to calculate the final temperature distribution determinate according the machine parameters and some geometrical factors (coil width and gap between coil and gear). Since the hardness profile is affected by thermal historic during heating, the surface temperatures are deeply analyzed versus the initial current density and the heating time using medium (MF) and high frequencies (HF). Finally, the sensitivity of hardness profile with the machine parameters variation isinvestigated using various statistical tools applied to the obtained results. The obtained results exhibits the main machine parameters and theirs effects on the hardness profile.
-
Effect of Dimensional Variation on Induction Process Parameters Using 2D Simulation
Advanced Materials Research, 2011Co-Authors: Noureddine Barka, Philippe Bocher, Jean Brousseau, Patrick ArkinsonAbstract:The Induction heating is a surface heat treatment that exhibits some relevant industrial advantages. In fact, the Process is not energy-consuming compared to thermo-chemical Processes such as carbonizing and nitriding because it allows generating high power and focusing it locally and during a short time to achieve hardness at the surface area without affecting the part core. Using no plating phase, the Induction heating Process is qualified as green and sustainable manufacturing Process but should be better understood to help developers to reach optimized recipes in a small number of Process iterations. Globally, for a given range of parts to be manufactured, one has to proper select the frequency and power of the equipment to be. This work will show how part geometry, generator frequency and power are closely linked. This work is carried principally by simulation efforts using computer-modeling software (COMSOL). A developed 2D model includes the coupling between electro-magnetic and thermal fields, and takes account of the non-linear behavior of material properties versus temperature. The simulation allows optimizing the machine according to the dimensions of gear. This paper also proposes a method to approximate the power amount required to achieve a desired hardness profile.
P D Nieuwkoop - One of the best experts on this subject based on the ideXlab platform.
-
The neural Induction Process; its morphogenetic aspects.
The International journal of developmental biology, 1999Co-Authors: P D NieuwkoopAbstract:This posthumous review of early embryonic Inductions concludes: 1) the amphibian egg has only two distinct components, animal and vegetal. Interactions at their mutual boundary forms meso-endoderm. This is "meso-endoderm Induction", not just "mesoderm Induction". 2) The dorso-ventral polarity of the yolk mass implies a dorsally situated inducing centre. 3) Accumulation of cells into one, two, three or many cell masses [problastopores] along the circumference of the meso-endoderm results in as many axes, implying a self-organizing capacity of meso-endoderm. 4) Induction of the meso-endoderm is slow, spreading cell to cell through the animal moiety from the boundary of the vegetal yolk mass towards the animal pole. 5) Interaction between mesoderm and ectoderm is a separate step leading to cranio-caudal differentiation of the archenteron roof. 6) The initial invaginating endoderm and mesoderm, representing the future pharynx endoderm and prechordal plate mesoderm, first contacts the most posterior presumptive neurectoderm after having passed the still uninvaginated trunk mesoderm. At that moment an antero-posterior level neural Induction actually starts. 7) The ectoderm contraction wave coincides spatially and temporally with the induced neural plate. 8) Two successive homoiogenetic waves of inductive activity pass through the presumptive neurectoderm in the anterior direction, the first one, "activation", giving rise to neural differentiation and ultimately forebrain, the second one, "transformation", to more caudal CNS structures. These are separate, successive steps in CNS regional Induction. 9) The midbrain represents a secondary formation in the neural plate. 10) The observed changes in morphogenesis may depend upon separate, successive binary decisions via [cell and] nuclear state splitters [involving differentiation waves].
Pedro J Aparicio - One of the best experts on this subject based on the ideXlab platform.
-
limiting co2 levels induce a blue light dependent hco3 uptake system in monoraphidium braunii
Journal of Experimental Botany, 2000Co-Authors: Nuria Giraldez, Pedro J Aparicio, Miguel Angel QuinonesAbstract:The in situ photoactivation of an HCO3 uptake system in the green alga Monoraphidium braunii requires the irradiation of the cell suspensions with short wavelength radiation (blue, UVA and/or UVC). Plasma membrane ATPase inhibitors block the uptake of this monovalent anion at pH 9. M. braunii cells grown in high CO 2 lack an HCO 3 - uptake system in their plasma membrane, but those grown in low CO 2 can take up this anion at high rates. Cells grown in high CO 2 , transferred to CO 2 -limiting conditions in the light, start taking up HCO 3 - in 30 min, although they take 90 min to reach maximum rates of HCO 3 - transport. Therefore, this Induction Process seems to be triggered by low external CO 2 concentration. In fact, increasing or decreasing the external HCO 3 - concentration does not induce the uptake system and only a decrease in CO 2 concentration in the medium triggers the Induction Process. The appearance of the HCO 3 - transport activity is sensitive to cycloheximide, indicating that cytoplasmic protein biosynthesis is necessary for the Induction of the uptake system. Photosynthetically active radiation, but not particularly blue light, is essential for Induction of the uptake system to occur and the inhibition of photosynthesis by DCMU blocks it. From these results it can be inferred that when M. braunii cells detect a drop in CO 2 concentration, they induce a blue light-dependent HCO 3 - uptake system.
-
Limiting CO2 levels induce a blue light‐dependent HCO3− uptake system in Monoraphidium braunii
Journal of Experimental Botany, 2000Co-Authors: Nuria Giraldez, Pedro J Aparicio, Miguel Angel QuinonesAbstract:The in situ photoactivation of an HCO3 uptake system in the green alga Monoraphidium braunii requires the irradiation of the cell suspensions with short wavelength radiation (blue, UVA and/or UVC). Plasma membrane ATPase inhibitors block the uptake of this monovalent anion at pH 9. M. braunii cells grown in high CO 2 lack an HCO 3 - uptake system in their plasma membrane, but those grown in low CO 2 can take up this anion at high rates. Cells grown in high CO 2 , transferred to CO 2 -limiting conditions in the light, start taking up HCO 3 - in 30 min, although they take 90 min to reach maximum rates of HCO 3 - transport. Therefore, this Induction Process seems to be triggered by low external CO 2 concentration. In fact, increasing or decreasing the external HCO 3 - concentration does not induce the uptake system and only a decrease in CO 2 concentration in the medium triggers the Induction Process. The appearance of the HCO 3 - transport activity is sensitive to cycloheximide, indicating that cytoplasmic protein biosynthesis is necessary for the Induction of the uptake system. Photosynthetically active radiation, but not particularly blue light, is essential for Induction of the uptake system to occur and the inhibition of photosynthesis by DCMU blocks it. From these results it can be inferred that when M. braunii cells detect a drop in CO 2 concentration, they induce a blue light-dependent HCO 3 - uptake system.