Voltage dependence, electronic devices

In addition, very few observations are pristine and basic measurements such as angular deviation of a needle on a display, linear expansion of a fluid, voltages on an electronic device, only represent analogs of the observation to be made. These observations are themselves dependent on a model of the measurement process attached to the particular device. For instance, we may assume that the deviation of a needle on a display connected to a resistance is proportional to the number of charged particles received by the resistance. The model of the measurement is usually well constrained and the analyst should be in control of the deterministic part through calibration, working curves, assessment of non-linearity, etc. If the physics of the measurement is correctly understood, the residual deviations from the experimental calibration may be considered as random deviates. Their assessment is an integral part of the measurement protocol and the moments of these random deviations should be known to the analyst and incorporated in the model. 

The gate voltage dependence of the frequency is a stepwise function, as shown in the inset of Fig. 3. Steps occur whenever an additional electron tunnels onto the tube. For the E-nanotube, their height is MHz, which is measurable. Note, that the present submicron silicon devices are always in the weak-bending regime so that corrections due to the second term in Eq. (16) are too small to be measured. Furthermore, one should realize that frequency quantization is only observable if the frequency itself is greater than the inverse tunneling time for electrons. 

The model suggests that at higher voltages the electron and hole currents in PPV-based devices with low contact barriers (as expected for selective Ohmic contacts) are determined by the bulk conduction properties of the polymer and not by the injection properties of the contacts. The conduction of holes is governed by space-charge effects and field dependent mobility, while electron transport is limited by traps. 

Electroporation efficiency depends on the parameters of electric pulses that are delivered to the treated cells using specially designed electrodes and electronic devices. In vitro experiments usually employ parallel plate types of electrodes made of inert metals like stainless steel or platinum but needle types of electrodes are also used for tissue electroporation [24,25,27,28] as well as for tumor treatment apphcations [29-32]. There are two types of electroporator devices available devices with voltage output and those with current output. However, a voltage output device seems to be preferable, which is widely used for diverse applications. 

Schottky barriers are metal-semiconductor junctions that have the ability to rectify current, because the work fimction of the metal is greater than that of the semiconductor. The junction thus creates a barrier between the semiconductor and the metal that decreases when the junction is forward biased and vice versa. Conduction in Schottky devices is by majority carriers, principally electrons. In conventional p-n devices reverse conduction is predominately via minority carriers. In p- -junction devices, charge is stored in the junction during forward conduction and has to be removed if the jimction is reverse biased before the diode can switch off. The junction capacitance and the capacitive reactance are voltage dependent. 

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