Operating Characteristic Analysis and Verification of Short-Stroke Linear Oscillating Actuators Considering Mechanical Load

Linear oscillating machines are electric devices that reciprocate at a specific frequency and at a specific stroke. Because of their linear motion, they are used in special applications, such as refrigerators for home appliances and medical devices. In this paper, the structure and electromagnetic characteristics of these linear oscillating machines are investigated, and the stroke is calculated according to voltage and motion equations. In addition, static and transient behavior analysis is performed, considering mechanical systems such as springs, damping systems, and mover mass. Furthermore, in this study, the magnetic force is analyzed, experiments are conducted according to the input power, and the current magnitude and stroke characteristics are analyzed according to the input frequency. Finally, the study confirmed that the most efficient operation is possible when the electrical resonance frequency matches the resonance frequency of the linear oscillating machines.

Signatures of Transient Overvoltages in Low Voltage Power Systems in Tea Factories and Their Implications on Insulation Deterioration and Allied Power Quality Issues

Electrical equipment and supply cables demand a better quality of supply, with the recent advancements in integrated sensitive solid-state controls. Divergently, proliferated heavy inductive motors and some performance additions based on power electronics have introduced power quality issues to the network. Thus, this study mainly investigates the impact of switching transients generated by electromechanical machines in industrial power systems on insulation deterioration while taking transient overvoltages due to capacitor bank switching also to support. Transients with a high rate of rise are likely to catalyze the degradation of the insulation quality and break down the insulating material through ionization. These steeply passing overvoltage stresses let partial discharges ensue, which can attack the insulation over long service. To unveil this danger, 314 common-mode transient waveforms were measured in the electrical machines of five tea factories in Sri Lanka, in a 50 ms measurement window, taken in 55 measuring attempts. Most of the transients observed are in the form of a damped oscillatory waveform tailed by fast exponential collapse. That correlates to insulation degradation having a very steep rise as 30.04 V/ns, the highest at the withering section. When machines are heavily loaded, situations tend to generate transients with high amplitudes. There were transient bursts that spread as 426.3 ms, while 14 ns fast rise times were recorded from withering motors. Unlike electrical resonance and power-frequency overvoltages, electromagnetic switching transients last even less than 100 ms. To underline this, an analysis of the frequency domain of transients was also presented, which proves high density of high-frequency components reaching 107 kHz range. Accepting the fact that frequency and amplitude are always under the influences of innumerable dynamics, the observational evidence of the study endorses that electrical stress built by the transient nature of the factories reduces the life expectancy of electrical insulation.

Low Frequency Electrical Resonance in Water

We report the observation of sharp electrical resonance of water with width ~2 neV in the low radiofrequency range at room temperature. Various controlling factors, including temperature, pH level, biasvoltage, and boundary conditions are found to impact on the resonance frequency and intensity. The neVlevel of the resonant width is not expected under room temperature (~25 meV), within any existingmolecular theory of the dielectric properties of water, strongly suggesting that a macroscopic long-rangecoherent quantum mechanical excited state is responsible for the resonance.

Calcium induced calcium release in proximity to hair cell BK channels revealed by PKA activation

Large conductance calcium-activated potassium (BK) channels play a critical role in electrical resonance, a mechanism of frequency selectivity in chicken hair cells. We determine that BK currents are dependent on inward flow of Ca2+, and intracellular buffering of Ca2+. Entry of Ca2+ is further amplified locally by Ca2+ induced Ca2+ release (CICR) in close proximity to plasma membrane BK channels. Ca2+ imaging reveals peripheral clusters of high concentrations of Ca2+ that are suprathreshold to that needed to activate BK channels. PKA activation increases BK currents likely by recruiting more BK channels due to spatial spread of high Ca2+ concentrations in turn from increasing CICR. STORM imaging confirms the presence of nanodomains with ryanodine and IP3 receptors in close proximity to the Slo subunit of BK channels. Together, these data require a rethinking of how electrical resonance is brought about and suggest effects of CICR in synaptic release. Both genders were included in this study.

Hearing and hair cells

“Hearing and hair cells” is the sixth chapter of the book Sensory Transduction and begins with hearing in insects, describing the anatomy and physiology of tympanal organs and Johnston’s organ. It reviews the literature on vertebrate hair cells, which are the sensory receptors of the inner ear. It begins with the anatomy of hair cells and then describes tip links, hair cell transduction proteins, and our present understanding of the nature and identity of the mechanoreceptive channels, including the role of channel gating in bundle stiffness and adaptation of hair cells. A review is given of the anatomy and physiology of the organs of the lateral line, the vestibular system, and the cochlea, together with a description of endolymph and the endocochlear potential, outer hair cells and tuning in mammals, and the role of electrical resonance in tuning in the turtle basilar papilla.