scholarly journals Noise spectra of K+ and NH4+ ions at over-limiting current in an electrochemical system with a cation exchange membrane

2013 ◽  
Vol 3 (3) ◽  
pp. 291-296
Author(s):  
K. Oulmi ◽  
K. E. Bouhidel ◽  
G. M. Andreadis
Keyword(s):  
Limiting Current ◽  
Electrical Noise ◽  
Singular Behaviour ◽  
Counter Ion ◽  
Power Spectral ◽  
Counter Ions ◽  
Voltage Curve ◽  
Current Voltage ◽  
Current Voltage Curve ◽  
Exchange Membrane

The present work investigates the effect of the counter ion nature on the noise of the over-limiting current (Iov). Moreover, the electrochemical methods, current voltage curve (I–V) and the chronopotentiometry (V–t) measurements are applied. The over-limiting current is always accompanied by a neat electrical noise. It is a well accepted experimental phenomenon. The study of this noise may contribute to a better understanding of the Iov and the feasibility of electrodialysis operation at this current in terms of energy consumption. The electrical noise depends directly on the counter ion nature. The power spectral density of the membrane's potential fluctuation was obtained via Fourier analysis of the time series recorded during the transport of counter ions (K+ and NH4+). The spectra are evaluated above the limiting current indicating the differences between the K+ and the NH4+. It is found that the cation NH4+ presents a singular behaviour and the noise is minimal.

scholarly journals Modeling Asymmetry of a Current–Voltage Curve of a Novel MF-4SC/PTMSP Bilayer Membrane

Membranes ◽  
2021 ◽  
Vol 12 (1) ◽  
pp. 22
Author(s):  
Anatoly N. Filippov ◽  
Natalia A. Kononenko ◽  
Natalia V. Loza ◽  
Daria A. Petrova
Keyword(s):  
Good Accuracy ◽  
Thick Layer ◽  
Physicochemical Characteristics ◽  
Porous Membrane ◽  
Bilayer Membrane ◽  
Voltage Curve ◽  
Current Voltage ◽  
Current Voltage Curve ◽  
Exchange Membrane ◽  
A Current

A novel bilayer cation-exchange membrane—consisting of a thick layer of a pristine perfluorinated membrane MF-4SC (Russian equivalent of Nafion®-117) and a thinner layer (1 μm) of the membrane, on a base of glassy polymer of internal microporosity poly(1-trimethylsilyl-1-propyne) (PTMSP)—was prepared and characterized. Using the physicochemical characteristics of one-layer membranes MF-4SC and PTMSP in 0.05 M HCl and NaCl solutions, the asymmetric current–voltage curves (CVC) of the bilayer composite were described with good accuracy up to the overlimiting regime, based on the “fine-porous membrane” model. The MF-4SC/PTMSP bilayer composite has a significant asymmetry of CVC that is promising for using it in electromembrane devices, such as membrane detectors, sensors, and diodes.

scholarly journals Influence of Surface Modification of MK-40 Membrane with Polyaniline on Scale Formation under Electrodialysis

Membranes ◽  
2020 ◽  
Vol 10 (7) ◽  
pp. 145 ◽  
Author(s):  
Marina A. Andreeva ◽  
Natalia V. Loza ◽  
Natalia D. Pis’menskaya ◽  
Lasaad Dammak ◽  
Christian Larchet
Keyword(s):  
Potential Drop ◽  
Limiting Current ◽  
Limiting State ◽  
Simultaneous Control ◽  
Voltage Curve ◽  
Current Voltage ◽  
Current Voltage Curve ◽  
Modified Membrane ◽  
Mineral Scale ◽  
Surface Modified

A comprehensive study of the polyaniline influence on mineral scaling on the surface of the heterogeneous MK-40 sulfocationite membrane under electrodialysis has been conducted. Current-voltage curves and chronopotentiograms have been obtained and analyzed for the pristine MK-40 membrane and the MK-40 membrane which is surface-modified by polyaniline. The study of the electrochemical behavior of membranes has been accompanied by the simultaneous control of the pH of the solution outcoming from the desalination compartment. The mixture of Na2CO3, KCl, CaCl2, and MgCl2 is used as a model salt solution. Two limiting states are observed on the current-voltage curve of the surface-modified membrane. There is the first pseudo-limiting state in the range of small values of the potential drop. The second limiting current is comparable with that of the limiting current for the pristine membrane. It is shown that chronopotentiometry cannot be used as a self-sufficient method for membrane scaling identification on the surface-modified membrane at high currents. A mineral scale on the surfaces of the studied membranes has been found by scanning electron microscopy. The amount of precipitate is higher in the case of the surface-modified membrane compared with the pristine one.

scholarly journals Ion Transport through Diffusion Layer Controlled by Charge Mosaic Membrane

2012 ◽  
Vol 2012 ◽  
pp. 1-7 ◽  
Author(s):  
Akira Yamauchi
Keyword(s):  
Ion Transport ◽  
Current Density ◽  
Membrane Surface ◽  
Transition Time ◽  
Limiting Current ◽  
Water Dissociation ◽  
Limiting Current Density ◽  
Voltage Curve ◽  
Current Voltage Curve ◽  
Exchange Membrane

The kinetic transport behaviors in near interface of the membranes were studied using commercial anion and cation exchange membrane and charge mosaic membrane. Current-voltage curve gave the limiting current density that indicates the ceiling of conventional flux. From chronopotentiometry above the limiting current density, the transition time was estimated. The thickness of boundary layer was derived with conjunction with the conventional limiting current density and the transition time from steady state flux. On the other hand, the charge mosaic membrane was introduced in order to examine the ion transport on the membrane surface in detail. The concentration profile was discussed by the kinetic transport number with regard to the water dissociation (splitting) on the membrane surface.

ATP-activated chloride channel inhibited by an antibody to P glycoprotein

1994 ◽  
Vol 267 (4) ◽  
pp. C1095-C1102 ◽  
Author(s):  
J. J. Zhang ◽  
T. J. Jacob
Keyword(s):  
Single Channel ◽  
Disulfonic Acid ◽  
Fiber Cells ◽  
Cl Channel ◽  
P Glycoprotein ◽  
Voltage Curve ◽  
Current Voltage ◽  
Single Channel Activity ◽  
Current Voltage Curve

In this report, we present the characteristics of a Cl- channel found in lens fiber cells. The single channel has a conductance of 17 pS, a linear current-voltage curve, is activated by ATP or strong depolarization and is blocked by verapamil, quinidine, 4,4'-diisothiocyanostilbene-2,2'-disulfonic acid, 5-nitro-2-(3- phenylpropylamino)benzoate, dideoxyforskolin, and tamoxifen. These properties are similar to those reported for a volume-activated Cl- channel associated with the multidrug resistance (MDR) gene product, P glycoprotein (24). Confirming this connection, we demonstrate that our lens Cl- channel is inhibited by an antibody to P glycoprotein. The data we present here may, therefore, be the first characterization of the single channel activity of the Cl- channel associated with P glycoprotein.

Evidence of Hysteresis in a New p-i-n-i-p-i-n Amorphous Silicon Device

1997 ◽  
Vol 467 ◽  
Author(s):  
D. Caputo ◽  
G. De Cesare ◽  
F. Palma
Keyword(s):  
Charge Trapping ◽  
Bistable Behavior ◽  
Novel Device ◽  
Voltage Curve ◽  
Current Voltage ◽  
Recombination Processes ◽  
Current Voltage Curve ◽  
Numerical Device ◽  
Silicon Device

ABSTRACTA novel device based on a-Si:H p+-i-n−-i-p−-i-n+ structure, showing a hysteresis in its current-voltage curve is reported. A numerical device model allows to investigate in detail the fundamental role of the two lightly doped n− and p− layers, where charge trapping determines the bistable behavior of the device. The ON condition is mantained until the ambipolar charge injection overcomes the fixed charge. The transition OFF-ON starts when, increasing the applied voltage, one of the two lightly doped layers becomes completely depleted. The transition ON-OFF is, instead, mainly dependent on the recombination processes occurring in the central doped layers. Devices with hysteresis around 2 V and tum-on voltage around 12 are presented.

scholarly journals The Cardiac Electrophysiology Web Lab

2015 ◽  
Author(s):  
Jonathan Cooper ◽  
Martin Scharm ◽  
Gary R Mirams
Keyword(s):  
Cardiac Electrophysiology ◽  
Computational Modelling ◽  
Cell Types ◽  
Virtual Experiments ◽  
Online Resource ◽  
Voltage Curve ◽  
Current Voltage ◽  
Wide Range ◽  
Current Voltage Curve ◽  
The Mathematical Model

Computational modelling of cardiac cellular electrophysiology has a long history, with many models now available for different species, cell types, and experimental preparations. This success brings with it a challenge: how do we assess and compare the underlying hypotheses and emergent behaviours, in order to choose a model as a suitable basis for a new study, or characterize how a particular model behaves in different scenarios? We have created an online resource for the characterization and comparison of electrophysiological cell models under a wide range of experimental scenarios. The details of the mathematical model (quantitative assumptions and hypotheses formulated as ordinary differential equations) are separated from the experimental protocol being simulated. Each model and protocol is then encoded in computer-readable formats. A simulation tool runs virtual experiments on models, and a website – https://chaste.cs.ox.ac.uk/FunctionalCuration – provides a friendly interface, allowing users to store and compare results. The system currently contains a sample of 36 models and 23 protocols, including current-voltage curve generation, action potential properties under steady pacing at different rates, restitution properties, block of particular channels, and hypo-/hyper-kalaemia. This resource is publicly available, open source, and free; and we invite the community to use it and become involved in future developments. Those interested in comparing competing hypotheses using models can make a more informed decision; those developing new models can upload them for easy evaluation under the existing protocols, and even add their own protocols.

scholarly journals Self-Cascode Current-Voltage Curve-Construction Algorithm from Single MOSFET Measurements for Analog Figures-of-Merit Extraction

2019 ◽  
Vol 14 (1) ◽  
pp. 1-6
Author(s):  
Li�gia Martins d'Oliveira ◽  
Valeriya Kilchytska ◽  
Denis Flandre ◽  
Michelly De Souza
Keyword(s):  
Threshold Voltage ◽  
Extraction Method ◽  
New Technologies ◽  
Experimental Measurements ◽  
Saturation Regime ◽  
Figures Of Merit ◽  
Voltage Curve ◽  
Current Voltage ◽  
Current Voltage Curve ◽  
Self Cascode

This paper proposes a curve extraction method for I-V curves and analog figures-of-merit of self-cascode MOSFET associations (SC) using a code that exploits I-V curves of single transistors as input. The method was validated by using experimental measurements of fabricated SC and the very single transistors that compose them. The results indicate a very low error between the SC generated by the code and the measured reference for operation in saturation regime and above threshold voltage, for both the I-V curves and their derivatives. This method is then valid for the assessment of the SC structures in new technologies, avoiding experimental dedicated layouts or complex set-ups.

scholarly journals Measurement of the Current-Voltage Curve of Photovoltaic Cells Based on a DAQ and Python

2018 ◽  
Vol 1 ◽  
pp. 94-98
Author(s):  
Israel Reyes-Ramírez ◽  
◽  
Jorge Fonseca-Campos ◽  
Juan Luis Mata Machuca
Keyword(s):  
Photovoltaic Cells ◽  
Voltage Curve ◽  
Current Voltage ◽  
Current Voltage Curve

Ab Initio Study of the Sub-threshold Electron Transport Properties of Ultra-scaled Amorphous Phase Change Material Germanium Telluride

2014 ◽  
Vol 1697 ◽  
Author(s):  
Jie Liu ◽  
Xu Xu ◽  
M. P. Anantram
Keyword(s):  
Electron Transport ◽  
Ab Initio ◽  
Transport Properties ◽  
Defect States ◽  
Germanium Telluride ◽  
Voltage Curve ◽  
Current Voltage ◽  
Current Voltage Curve ◽  
Electron Transport Properties ◽  
Change Material

ABSTRACTThe sub-threshold electron transport properties of amorphous (a-) germanium telluride (GeTe) phase change material (PCM) ultra-thin films are investigated by using ab initio molecular dynamics, density function theory, and Green’s function simulations. The simulation results reproduce the trends in measured electron transport properties, e.g. current-voltage curve, intra-bandgap donor-like and acceptor-like defect states, and p-type conductivity. The underlying physical mechanism of electron transport in ultra-scaled a-PCM is unraveled. We find that, though the current-voltage curve of the ultra-scaled a-PCM resembles that of the bulk a-PCM, their physical origins are different. Unlike the electron transport in bulk a-PCM, which is governed by the Poole-Frenkel effect, the electron transport in ultra-scaled a-PCM is largely dominated by tunneling transport via intra-bandgap donor-like and acceptor-like defect states.

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