Gap voltage

To study the electrical transport properties of this double-barrier system Pd nanoclusters have been trapped in this gap. Figure 14 shows a typical l(U) curve. The most pronounced feature at 4.2 K is the Coulomb gap at a voltage of about 55 mV, which disappears at 295 K. Above the gap voltage, the l(U) curve is not linear, but increases exponentially, which was explained by a suppression of the effective tunnel barrier by the applied voltage. 

The differential resistance of mesoscopic ferromagnet/superconductor junctions shows a number of features associated with the injection of spin-polarized carriers into the superconductor. In particular, large peaks are observed at currents corresponding to the superconducting gap voltage. These peaks are... 

Figure 6. Low-resolution STM survey image of a partly oxidized graphite flake. The asymmetric V-shape of the deep trenches is a tip artefact. Conditions Burleigh AR1S 6000, air, W tip, constant current mode, gap voltage 200 mV.

Figure 16. STM images (Burleigh ARIS 6000. air, W tip. constant current mode, 200 mV gap voltage, graphite natural single crystals, oxidation in air at 900 K) of (a) pristine and (b) oxidized graphite surfaces.

In a next step the possibility to image sub-surface impurities in metal surfaces by STM has been investigated [102]. The STM images were calculated for room temperature in the Tersoff and Hamann [105] approximation to determine the tunneling current I(r, U) for a gap voltage U. The local density of states (LDOS) of the sample is expressed in n(r , z, Sp+ s) [106] at the position... 

Radiative Transition Probabilities for X-Ray Lines Radioactive Tracer Diffusion Data for Pure Metals Recommended Daily Dietary Allowances Reduction of Barometer to Sea Level Refractory Materials Resistance of Wires Resistivity of Semiconducting Minerals Solvents for Liquid Chromatography Spark-Gap Voltages... 

The torque Tf, developed in the rotor shaft can be expressed as a function of the air-gap voltage Vm.-... 

Where R2 and X2 are both functions of the slip as explained above. The air-gap voltage can be found from the supply voltage Vs by noting that a voltage divider circuit exists which consists of the series components of the stator and the parallel combination of the magnetising branch and the rotor circuit. Hence becomes -... 

A 250 kW three-phase, fonr-pole, 50 Hz, 415 V, indnction motor is fed from a voltage source inverter. The motor has the following parameters for its star-wonnd windings. Find the cnrrents and air-gap voltage in the circnit. 

Harmonic number Stator current Rotor current Magnetising current Air-gap voltage ... 

Figure 15.12 shows the synthesised currents and air-gap voltage using the first 61 harmonics. 

The same motor as used in the worked example of sub-section 15.4.3.1 is fed from a cnrrent source inverter. Find the currents and air-gap voltage in the circuit. 

When the equivalent circuit is suitable it can be treated as a passive circuit in that no differential equations need to be solved for the currents or voltages in the circuit. The only differential equation associated with the circuit is the torque necessary to accelerate the rotor and its coupled load. For this purpose the standard form of equations for the electrical torque are appropriate, in which the air-gap voltage V , should be used. 

The maximal possible current flowing through an atomically sharp tip is of the order /q = 17/Rk with gap voltage U and Klitzing constant Rr = hle 25 kJ2. Actual tunnel currents are of the order 1 nA. The saturation of preamplifiers used in STM is typically reached with 50 nA. 

This is the simplest, qualitative extension of Eq. (49) when ignoring the variation of the transmission T with energy. With semiconductors and higher gap voltages the normalized differential conductance Psampie( ) oc dlldU)/ I/U) is used [208]. Such Psampie( ) curves reproduce pronounced features of the real... 

It can be seen from Fig. 13 that the surface potential decreases to a value lower than 360V for all values of the initial surface potential and all air gap thicknesses. With the air gap decrease and the initial surface potential increase the minimal value to which the electret surface potential decays is reduced. It decreases to a value of 33.5V at a gap of 0.10mm and initial surface potential 950V. This value of the surface potential corresponds to an electret-electrode gap voltage of 30.7V. This is considerably lower than the minimal value according... 

These curves have a minimum corresponding to the easiest breakdown conditions. The breakdown conditions, for example, pressure, treatment gas, discharge gap, voltage, and frequency, define the operating mode of DBD plasma [6,7,28]. 

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