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Background: Demineralization of the enamel surface, which appears as white spot lesions during and after removal of the fixed orthodontic appliance, is the most common disadvantage of the orthodontic treatment course. Using the remineralizing agents during and after orthodontic treatment helps to avoid those enamel defects., Objective: The present study aims to assess the remineralizing effect of the chicken eggshell powder on the demineralized enamel surfaces after debonding the orthodontic bracket system., Materials and Methods: The current study was performed on 80 prepared premolar crowns embedded into acrylic molds. The samples were prepared to receive routine steps of the bonding process for the bracket system. The paste of the chicken eggshell powder was added to the samples after the debonding process. Scanning electron microscopy (SEM) and energy-dispersive X-ray (EDX) were used to evaluate the remineralization effect of the chicken eggshell powder. Also, the Vickers microhardness tester was used to assess the enamel surface microhardness., Results: It was found that the mean value of the Ca/P ratio for the samples before bonding of the orthodontic bracket system was (4.17 ± 2.2). This value significantly decreased to (2 ± 1.3) after debonding of the orthodontic bracket system and then showed a significant increase to (4.79 ± 2.65) after remineralization. These results were assured by the values of the Vickers microhardness tester., Conclusion: The chicken eggshell powder has an excellent remineralization effect for the demineralized enamel surface after debonding the orthodontic enamel surface., Competing Interests: There are no conflicts of interest., (Copyright: © 2024 Journal of Orthodontic Science.)

The magnetic coupler is the most vital component for charging EV wirelessly. Through it, the output power can be transported from the transmitter to the receiver by means of electromagnetic fields. Therefore, this manuscript presents a proposed design of a magnetic coupler in the form of Double-D (DD) on both sides, which is suitable for in-motion inductive charging. This charger is capable of transferring power of 200-kW through an airgap of 250 mm with an efficiency of 91.88% and an operating frequency of 85 kHz. Computational modeling is conducted to obtain the magnetic coupler and the compensation parameters of the proposed system. The appropriate dimensions of the coils, magnetic and metallic shielding are obtained by using the finite element model (FEM). The effect of misalignments on the self and mutual inductances of the two coils (L p , L s , M), the output power (P o ), and the transmission efficiency (η) is studied in case of one and two coils at transmitter side. The output power in the distance between the two transmitter coils (d) is improved by controlling the operating frequency, adding magnetizable concrete (MC), or both together. These techniques have proven effectiveness in improving the output power by 45.15% for small d and 72.51% for large d. In addition, the efficiency improved by 15.95% for small d and 60.76% for large d. Moreover, these improvement cases were compared in terms of size, weight and cost for a 100-m driving track., (© 2023. Springer Nature Limited.)

Inductive power transfer (IPT) technology is a promising solution for charging the electric vehicles (EVs) by enabling an EV to charge its energy storage system (battery) without any connecting wires through magnetic coupling. This paper proposes a new receiver design named Hollow Solenoid receiver that is compatible with the standard double-D transmitter defined by the SAE J2954 standard. A deep design analysis for the proposed Hollow Solenoid receiver is presented to define the optimum design parameters for coil (inductances, number of turns, dimensions, wires, etc.) and ferrite core (dimensions, number, arrangement, etc.). Several WPT3 (11.1kVA) solenoid receiver (SR) designs were presented and analyzed based on efficiency, weight, size, volume, and cost. The performance of the proposed SR was compared with the global Double-D receiver (DDR) presented by the SAE J2954 standard under different lateral and rotational alignment and loading conditions considering coupling factor, transmission power and efficiency, and stray electromagnetic fields (EMFs). The entire IPT system including coils, compensation network, power converters, controls, and battery load was modeled and analyzed for both SR and DDR coils. The results reveal that the proposed SR is compatible with the global DD transmitter at different alignment and loading conditions and is able to transmit the desired power (11 kW) at an efficiency > 85%. Hollow SR design shows the highest efficiency and lowest size, weight, and cost compared to DDR and other designs., (© 2023. The Author(s).)