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Current density


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Effect of current density on the microstructure and morphology of the electrodeposited nickel coatings

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This behavior may be explained by a change of the growth mechanism with current density. However, grain refinement was observed with decreasing deposition current density.. In conclusion, the current density has a remarkable influence on the surface morphology of electrodeposited nickel coatings..

Effect of Substrate Temperature on the Critical Current Density in the YBa2Cu3O7-x Superconducting Films

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More interestingly, the critical current density of the YBCO films measured at 65 K also depended on the substrate temperature. The highest value of critical current density of ~ 5.7 MA/cm 2 was also found at the YBCO film deposited at 780 o C.

Scalable activated carbon/graphene based supercapacitors with improved capacitance retention at high current densities

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The gravimetric capacitance values varying cycle number at the current density of 1 A/g and the coulombic efficiencies of the pouch size hybrid electrodes..

Evaluation of the fuel cell performances of TiO2/PAN electrospun carbon-based electrodes

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Finally, TiO 2 +PAN/PGE electrode showed 62.54 mA cm -2 current density and 20.94 mW cm –2 power density (Figure 4D).. To further investigate the catalytic effect of the initial charging conditions the voltages between 3.5 and 9 V intervals were examined. PGE cathode using FC showed 0.95 A cm –2 current density and 2.01 W cm –2 power density values (Figure 5B), whereas TiO 2 +PAN/DBC showed 0.68 A cm –2 current.

Electrodeposition of tin(II) from citrate complexes

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The particular polarization curves of the parallel processes of metal and hydrogen evolution were calculated from the dependence at each particular point:. where j i is the partial current of tin or hydrogen. f CCE (j Σ ) is the current output function of the polarizing current density.. The dependence of the current efficiency of tin on polarizing current density is shown in Figure 4a.

Handbook of Corrosion Engineering P2

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Exchange current density depends upon the composition of the electrode and the solution (Table 1.1). For redox reactions, the exchange current density would depend on the composi- tion of the electrode supporting an equilibrium reaction (Table 1.2).. TABLE 1.1 Exchange Current Density (i 0 ) for M z. Table 1.3 contains the approximate exchange current density for the reduction of hydrogen ions on a range of materials.

Electromagnetic Field Theory: A Problem Solving Approach Part 38

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If we had orientated our loop in the xz or yz planes, the current density components would similarly obey the relations. so that in general. where we subscript the current density with an m to represent the magnetization current density, often called the Amperian current density..

Electromagnetic Field Theory: A Problem Solving Approach Part 23

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At the earth's surface the current density is then. The surface charge density on the earth's surface is. The potential difference between the upper atmosphere and the earth's surface is.

Enhanced electrocatalytic efficiency of C/MWNTs for methanol oxidation using Ni deposited on MWNTs

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As seen in Figure 9a, oxidation current density rose with the rising temperature, which shows the acceleration of the electrochemical reaction. The highest oxidation peak current density was obtained at 318 K. It was not studied above 318 K because of the boiling temperature of methanol. Activation energies of the MOR at the Ni@MWNTs catalyst were calculated (Figure 9b)..

Modeling

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A schematic representation of the current flow in the cell during discharge is illustrated in Figure 6. From the continuity of current on the electrodes, the following equations can be derived. in the positive and negative electrodes, respectively, and J is the current density (current per unit area (A m 2.

Process optimization and mechanism study of acid red G degradation by electro-FentonFeox process as an in situ generation of H2O2

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(a) The influence of current density on the removal ratio of the ARG. (b) The influence of current density on the generation of •OH. Effect of the initial pH. Under the conditions of the current density of 20 mA /cm 2 , electrolyte concentration of 0.2 M, and electrode spacing of 2 cm, the pH of the reaction was changed and its effect on ARG degradation efficiency and •OH, Fe 2.

Stability improvement by crosslinking of previously immobilized glucose oxidase on carbon nanotube-based bioanode

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Next, the effect of the buffer concentration on the immobilized enzyme system was considered by determining the current densities in the half-cell electrochemical system and the results are given in Figure 6. The current density increased at first with an increase in the buffer concentration before reaching a plateau value. A further increase in the salt concentration resulted in a decrease in the current density.

Electromagnetic Field Theory: A Problem Solving Approach Part 48

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Figure 6-28 (a) A conducting material moving through a magnetic field tends to pull the magnetic field and current density with it. (b) The magnetic field and current density are greatly disturbed by the flow when the magnetic Reynolds number is large, R. Since (41) is linear, the most general solution is just the sum of the two allowed solutions,. where the magnetic Reynold's number is defined as.

Electromagnetic Field Theory: A Problem Solving Approach Part 20

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The electric field and current density are inversely pro- portional to the square of the radius. so that the current density is constant at any radius r. 3-5-1 Parallel Plate Electrodes. The surface charge density does not distribute itself uni- formly, as illustrated by the fringing field lines for infinitely thin parallel plate electrodes in Figure 3-17a. Near the edges the electric field is highly nonuniform decreasing in magni- tude on the back side of the electrodes.

One-step potentiostatic codeposition and electrochemical studies of poly(1-pyrenyl)-2,5-di(2-thienyl)pyrrole-co-pyrrole) film for electrochemical supercapacitors

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According to the above equation, the specific capacitance values of P(PyrPy-co-Py)/PGE, P(Py)/PGE, and P(PyrPy)/PGE were found to be 178 F g − 1 , 65 F g − 1 , and 0.8 F g − 1 at 2 A g − 1 constant current density, respectively (Figure 7a). in 1 M H 2 SO 4 at a constant current density of 2 A g − 1 for 1000 cycles..

Low loaded Pt-Co catalyst surfaces optimized by magnetron sputtering sequential deposition technique for PEM fuel cell applications: Physical and electrochemical analysis on carbon paper support

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The exchange current density, j o , was a qualitative measure for the intrinsic activity of the catalyst. In order to calculate j o , firstly construction of the mass-transfer corrected Tafel slopes was necessary, which, in turn, required determination of the kinetic current density. Over 400 mV, the mass transfer corrected Tafel plots showed a wide linear range, which allowed determining the values of the Tafel slope and the apparent values of the exchange current density, j 0 ap .

Optimization of EC parameters using Fe and Al electrodes for hydrogen production and wastewater treatment

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Neutral and alkaline pH seems to be more effective towards the formation of the coagulants ( Garcia- Segura et al., 2018. 2 , pH range lies in alkaline me- dia for the Fe-Al combination of the electrodes operated under a current density of 1.25 mA cm − 2 for a fixed EC time of 30 minutes. Effect of the current density on the removal of organic matter. Two current densities of 1.25 mA cm − 2 and 2.09 mA cm − 2 were selected for the different combinations of the elec- trodes ( Anode -Cathode.

Stimulated Emission and Optical Gain in Semiconductors

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Because of the approximate relation described by Eq. (3.43), the shapes of the graphs for the current density dependence are somewhat different from those for the carrier density dependence shown in Fig. the slopes of the graphs for the current density dependence become smaller for the region of high injection currents. Figure 3.11 Dependence of the maximum amplification gain upon the injection current density..

Electromagnetic Field Theory: A Problem Solving Approach Part 19

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We multiply (35) by the charge densities that we assume to be constant so that the constitutive law relating the current. density to the electric field is. w,_/27r - 9 X 1010 Hz (37) If such a material is placed between parallel plate elec- trodes that are open circuited, the electric field and current density J= J++J must be perpendicular to the electrodes, which we take as the x direction.

The photostimulated quantum effect in rectangular quantum wire with an infinite potential for the case of electron-acoustic phonon scattering

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We obtain the expressions for the current density  j 0. (20) Equation (13) shows the dependent of the direct current density on the frequency  of the laser radiation field, the frequency  of the linearly polarized electromagnetic wave, the size of the wire.