scholarly journals A New Simplified Model and Parameter Estimations for a HfO2-Based Memristor †

Technologies ◽  
2020 ◽  
Vol 8 (1) ◽  
pp. 16
Author(s):  
Valeri Mladenov
Keyword(s):  
Hafnium Dioxide ◽  
Step Function ◽  
Complete Analysis ◽  
Hyperbolic Function ◽  
Model Parameters ◽  
Parameter Estimations ◽  
Current Voltage ◽  
Highly Nonlinear ◽  
Relationship Of ◽  
Current Voltage Relationship

The purpose of this paper was to propose a complete analysis and parameter estimations of a new simplified and highly nonlinear hafnium dioxide memristor model that is appropriate for high-frequency signals. For the simulations; a nonlinear window function previously offered by the author together with a highly nonlinear memristor model was used. This model was tuned according to an experimentally recorded current–voltage relationship of a HfO2 memristor. This study offered an estimation of the optimal model parameters using a least squares algorithm in SIMULINK and a methodology for adjusting the model by varying its parameters overbroad ranges. The optimal values of the memristor model parameters were obtained after minimizing the error between the experimental and simulated current–voltage characteristics. A comparison of the obtained errors between the simulated and experimental current–voltage relationships was made. The error derived by the optimization algorithm was a little bit lower than that obtained by the used methodology. To avoid convergence problems; the step function in the considered model was replaced by a differentiable tangent hyperbolic function. A PSpice library model of the HfO2 memristor based on its mathematical model was created. The considered model was successfully applied and tested in a multilayer memristor neural network with bridge memristor–resistor synapses

scholarly journals Plasticity of calcium-permeable AMPA glutamate receptors in Pro-opiomelanocortin neurons

eLife ◽  
2017 ◽  
Vol 6 ◽  
Author(s):  
Shigetomo Suyama ◽  
Alexandra Ralevski ◽  
Zhong-Wu Liu ◽  
Marcelo O Dietrich ◽  
Toshihiko Yada ◽  
...  
Keyword(s):  
Food Deprivation ◽  
High Fat Diet ◽  
Receptor Complex ◽  
High Fat ◽  
Fasted State ◽  
Linear Current ◽  
Current Voltage ◽  
Relationship Of ◽  
Current Voltage Relationship ◽  
Voltage Relationship

POMC neurons integrate metabolic signals from the periphery. Here, we show in mice that food deprivation induces a linear current-voltage relationship of AMPAR-mediated excitatory postsynaptic currents (EPSCs) in POMC neurons. Inhibition of EPSCs by IEM-1460, an antagonist of calcium-permeable (Cp) AMPARs, diminished EPSC amplitude in the fed but not in the fasted state, suggesting entry of GluR2 subunits into the AMPA receptor complex during food deprivation. Accordingly, removal of extracellular calcium from ACSF decreased the amplitude of mEPSCs in the fed but not the fasted state. Ten days of high-fat diet exposure, which was accompanied by elevated leptin levels and increased POMC neuronal activity, resulted in increased expression of Cp-AMPARs on POMC neurons. Altogether, our results show that entry of calcium via Cp-AMPARs is inherent to activation of POMC neurons, which may underlie a vulnerability of these neurons to calcium overload while activated in a sustained manner during over-nutrition.

Capsaicin and nicotine both activate a subset of rat trigeminal ganglion neurons

1996 ◽  
Vol 270 (6) ◽  
pp. C1807-C1814 ◽  
Author(s):  
L. Liu ◽  
S. A. Simon
Keyword(s):  
Trigeminal Ganglion ◽  
Acetylcholine Receptors ◽  
Ganglion Cells ◽  
Whole Cell Patch Clamp ◽  
Current Voltage ◽  
Trigeminal Ganglion Neurons ◽  
Ganglion Neurons ◽  
Relationship Of ◽  
Current Voltage Relationship ◽  
Voltage Relationship

Nicotine and capsaicin produce many similar physiological responses that include pain, irritation, and vasodilation. To determine whether neuronal nicotine acetylcholine receptors (nAChR) are present on capsaicin-sensitive neurons, whole cell patch-clamp recordings were performed on rat trigeminal ganglion cells. It was found that approximately 20% of the total number of neurons tested was activated by both 100 microM nicotine and 1 nM capsaicin. Other subsets of neurons were activated by only one of these compounds, whereas a fourth subset was not activated by either compound. At -60 mV, the magnitude of the capsaicin-activated currents was about three times larger than the magnitude of the nicotine-activated currents. The current-voltage relationship of the nAChR exhibited marked rectification, such that for voltages > or = 0 mV the current was essentially zero. In contrast, the current-voltage relationship of the capsaicin-activated current was ohmic from +/- 60 mV. These data indicate the existence of subsets of capsaicin-sensitive afferent neurons.

The Current-Voltage Relationship Of Galvanic Anode Arrays in Cathodic Protection★

CORROSION ◽  
1958 ◽  
Vol 14 (6) ◽  
pp. 47-52
Author(s):  
L. J. WALDRON ◽  
M. H. PETERSON
Keyword(s):  
Cathodic Protection ◽  
Sheet Steel ◽  
Initial Current ◽  
Current Output ◽  
Specific Data ◽  
Ship Hulls ◽  
Current Voltage ◽  
Sea Wall ◽  
Relationship Of ◽  
Current Voltage Relationship

Abstract The current output of full-scale arrays of several anode sizes in use by the U. S. Navy for the cathodic protection of ship hulls were determined. Impressed-current anodes formed from sheet steel were substituted for conventional galvanic anodes to reduce the weight and number of arrays necessary to obtain the desired information. Five anode sizes were investigated. A 1500-foot steel sea wall located in water with a resistivity of 34 to 38 ohm-cm acted as an un-polarizable cathode. The output currents were determined for driving potentials of 0.1, 0.2, 0.5, 0.7, and 1.0 between the cathode and the anode arrays; hence the data can be used to estimate for any galvanic material both the initial current output of an anode array, and the continuing current output against a cathode polarized to a known potential. The anodes in all arrays investigated suffered mutual interference as indicated by decreased current outputs from individual anodes as the number of anodes in the array increased. It was found that the addition of anodes is more efficient than a moderate separation of anodes in increasing the total current output. An empirical equation was derived from the data of the continuous linear arrays which relates the current output to total anode area and driving potential. It may be used to estimate the current output of arrays for which more specific data have not been obtained, but these estimations should be confirmed by experimentation wherever possible. 5.2.2

On the current-voltage relationship of the magnetospheric generator at intermediate spatial scales

1986 ◽  
Vol 13 (6) ◽  
pp. 495-498 ◽  
Author(s):  
J. F. Vickrey ◽  
R. C. Livingston ◽  
N. B. Walker ◽  
T. A. Potemra ◽  
R. A. Heelis ◽  
...  
Keyword(s):  
Spatial Scales ◽  
Current Voltage ◽  
Relationship Of ◽  
Current Voltage Relationship ◽  
Voltage Relationship

scholarly journals Ionic mechanisms underlying the responses of off-center bipolar cells in the carp retina. I. Studies on responses evoked by light.

1983 ◽  
Vol 81 (4) ◽  
pp. 589-601 ◽  
Author(s):  
T Saito ◽  
A Kaneko
Keyword(s):  
Reversal Potential ◽  
Input Resistance ◽  
Bipolar Cells ◽  
Inward Rectification ◽  
Current Voltage ◽  
Ionic Mechanisms ◽  
Resistance Decrease ◽  
Relationship Of ◽  
Current Voltage Relationship ◽  
Receptive Field Center

Off-center bipolar cells show hyperpolarizing responses to spot illumination in the receptive field center and depolarization responses to an annulus in the surround. To understand the ionic mechanisms underlying these responses, we examined the current-voltage relationship of these bipolar cells, input resistance changes during their light-evoked responses, and the reversal potentials of these responses. Off-center bipolar cells generally showed inward rectification when they were hyperpolarized and outward rectification when they were strongly depolarized. The membrane potential at which the I-V relationship deviated from linearity varied in individual cells. Hyperpolarizing center responses were generally accompanied by a resistance increase, irrespective of signal inputs either from red-sensitive cones or from rods, and the response polarities reversed at greater than +50 mV. Depolarizing surround responses were accompanied by a resistance decrease with a reversal potential at about +28 mV (one case). From the above observations, it is suggested that the center responses are generated by a decrease in sodium conductance (gNa) and the surround response is generated by an increase in gNa.

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