Effect of Time Factor on the Battery Voltage State of Charge from Foot Beats Piezoelectric System

Aim: The study examined the effect of time on amount of voltage generated in a foot beat electricity generating system stored in a battery. Study Design: A system made of piezoelectric materials was designed such that the foot beats of dancers on a platform would cause a mechanical deformation that would lead to conversion of mechanical energy due to pressure from the foot beats to electrical energy; and can be stored in a rechargeable lead acid battery for future use. Place and Duration of Study: Awka Anambra State, Nigeria, between November 2018 and April 2020. Methodology: A sheet of plywood measuring 300 mm x 300 mm x 3 mm thick was placed on a hard wooden board of 300 mm x 300 mm x 25 mm thick where twelve piezoelectric sensors were connected in series with foam spring inserted as separators and to aid in returning after deformation. As the dancers step on the platform, multimeter was used to take the voltage and current readings, while Lead acid rechargeable battery could be connected at the output point to store energy generated in the system and or Light Emitting Diodes (LED) and Universal Serial Bus (USB) outputs. A stop clock was also used to take the time. Results: The study revealed that it would require 901 seconds for a 50kg dancer to increase a unit voltage state of charge in a battery. It also found that it would require 749 seconds for a 60 kg dancer; and 595 seconds for an 80kg dancer respectively to increase the same 1-unit voltage state of charge in a battery. The study showed that the voltage in the battery would continue to increase until the battery is fully charged at which point it is expected that there would no longer be any increase in charge in the battery irrespective of increase in the number of foot beats or time. Conclusion: The result implies that the charge in battery caused by pressure from the foot beats is subject to the maximum voltage capacity of the battery in the system. Likewise, the amount of time and number of foot beats required to add a unit voltage state of charge in a battery in the system is subject to the applied pressure from the foot beats. In view of this, the study craves for popularisation of this technology through large scale research supported by government, corporate organisations or international organisations and institutions that will support new products development in the building and construction industry as it is the case in India and other developed countries.

Network-specific synchronization of electrical slow-wave oscillations regulates sleep in Drosophila

Slow-wave rhythms characteristic of deep sleep oscillate in the delta band (0.5-4 Hz) and can be found across various brain regions in vertebrates. Across systems it is however unclear how oscillations arise and whether they are the causal functional unit steering behavior. Here, for the first time in any invertebrate, we discover sleep-relevant delta oscillations in Drosophila. We find that slow-wave oscillations in the sleep-regulating R2 network increase with sleep need. Optical multi-unit voltage recordings reveal that single R2 neurons get synchronized by sensory and circadian input pathways. We show that this synchronization depends on NMDA receptor (NMDARs) coincidence detector function and on an interplay of cholinergic and glutamatergic inputs setting a resonance frequency. Genetically targeting the coincidence detector function of NMDARs in R2, and thus the uncovered mechanism underlying synchronization, abolished network-specific slow-wave oscillations. It also disrupted sleep and facilitated light-induced wakening, directly establishing a causal role for slow-wave oscillations in regulating sleep and sensory gating. We therefore propose that the synchronization-based increase in oscillatory power likely represents an evolutionarily conserved, potentially optimal, strategy for constructing sleep-regulating sensory gates.

Active Structural Acoustic Control for Rectangular Plate with a Line Moment Excitation

Active control of noise radiation from vibrating plate excited by a harmonic line moment is analytically investigated. This study model of simple supported rectangular plate with a line moment excitation is used to simulate the vibration of ship hull or fuselage from the flutter of ship deck or aircraft wing respectively. The control is achieved by various configurations of piezoelectric actuators. The strategy of radiated power minimization is used to obtain the optimal control input unit voltage. The numerical results show that the significant attenuation of noise radiated power for volumetric modes in the low frequency range can be achieved with one control actuator located at the center of plate, irrespective of whether the excitation is on or off resonance. The efficiency of the active control is dependent on the location of the line moment and the actuators. It is also shown that the modal suppression and modal restructuring are two physical mechanisms of radiated power attenuation.

Disorder-Delineated AlGaAs/GaAs Quantum-Well Phase Modulator

Modeling is used to investigate waveguide phase modulators, with 0.5 μm and 1 μm quantum well active regions which are defined by implantation induced disordering. By controlling the extent of the interdiffusion in the lateral claddings, the refractive index difference between the core and claddings is used to provide single mode operation. The performance of the phase modulator is studied in terms of optical confinement, phase change per unit voltage per unit length, chirping property and absorption loss. Our result shows that the 0.5 μm one is a more efficient structure and its absorption loss can be reduced by increasing the applied field from 50 kV/cm to 100 kV/cm.