The impact of high-voltage-high-frequency (HVHF) amplifiers on echo-signal quality is greater with very-high-frequency (VHF, ≥100 MHz) ultrasound transducers than with low-frequency (LF, ≤15 MHz) ultrasound transducers. Hence, the bias voltage of an HVHF amplifier must be stabilized to ensure stable echo-signal amplitudes. We propose a bias-voltage stabilizer circuit to maintain stable DC volta...

A graphene Schottky contact was fabricated on an AlGaN/GaN heterostructure and subsequently analyzed. The calculated experimentally measured barrier heights (SBHs) determined using the theoretical Schottky–Mott model, thermionic emission temperature-dependent current–voltage measurement, capacitance–voltage measurement were observed to be inconsistent, which attributed ambiguities in both area ...

We classify and analyze bit errors in the current measurement mode of the Kirchhoff-law– Johnson-noise (KLJN) key distribution. The error probability decays exponentially with increasing bit exchange period and fixed bandwidth, which is similar to the error probability decay in the voltage measurement mode. We also analyze the combination of voltage and current modes for error removal. In this ...

Series of blackouts encountered in recent years in power system have been occurred because either of voltage or angle instability or both together was not detected within time and progressive voltage or angle instability further degraded the system condition, because of increase in loading. This paper presents the real-time assessment methodology of voltage stability using Phasor Measurement Un...

One of the most primitive but elusive current-voltage (I-V) responses of a superconductor is when its supercurrent grows steadily after a voltage is first applied. The present work employed a measurement system that could simultaneously track and correlate I(t) and V(t) with subnanosecond timing accuracy, resulting in the first clear time-domain measurement of this transient phase where the qua...

Moisture content is an important factor in corn breeding and cultivation. A corn breed with low moisture at harvest is beneficial for mechanical operations, reduces drying and storage costs after harvesting and, thus, reduces energy consumption. Nondestructive measurement of kernel moisture in an intact corn ear allows us to select corn varieties with seeds that have high dehydration speeds in ...

We report details of an amperometric method for measurement of hydrogen (H2) in the aqueous phase and its application to hydrogen evolution by an alga. Although amperometric measurement of hydrogen is not common, we wondered whether the conventional Clark electrode for measurement of oxygen could be applied to measurement of hydrogen simply by proper choice of voltage. Initial tests were encour...

This paper presents a frequency modulation based readout circuit for the measurement of skin conductance or resistance. A charge pump based frequency-to-voltage converter circuit with adjustable sensitivity is used to convert the frequency shifts due to skin resistance changes into voltage variations. The readout circuit improves the measurement accuracy and artifact rejection in measurements o...

Partial Discharge (PD) measurement and characterization provide vital information on insulation condition, different aspects of insulation ageing useful for equipment integrity verification and diagnosis. The work demonstrates standard test methods which employs capture of PD parameters with the aid of discharge detector. This paper investigates on the voltage amplitude at which PD of a specifi...