Search Results (6)

Background: Tooth extraction techniques have been refined over the years in order to be less traumatic and to better preserve alveolar bone. A recently introduced extraction method involves the use of the Magnetic Mallet^®, which allows clinicians to be more precise and perform extractions faster. Moreover, the instrument enables the procedure to be less traumatic for patients. The aim of the present study was to clinically evaluate whether extractions performed using the Magnetic Mallet^® can lead to less buccolingual bone resorption. Methods: Between February 2023 and June 2023, nine patients with an average age of 62 years underwent 29 extractions using the Magnetic Mallet^®. Sectorial CBCTs were performed in order to measure buccolingual bone thickness at time 0 (T0, before extraction) and 3 months after extraction (T3M). All the extractions were performed by two different expert operators exclusively using the Magnetic Mallet^®. For statistical analysis, a two-sample t-test was performed to determine the difference between the measurements taken at T0 and those taken at T3M in the 29 dental elements and the difference in bone loss between the surgeries conducted by the two clinicians. Results: A total of 22 teeth were extracted in the upper jaw and 7 in the lower jaw. The average degree of mobility was 1. The average degree of force impressed by the instrument to extract the teeth was 2, while the average frequency of blows administered was 7. The average time taken for the extractions was 3½ min. After 3 months, the mean buccolingual bone resorption was 1.54 mm (SD: ±). The difference in buccolingual bone thickness between T0 and T3 was significant at an alpha significance level of 0.01. No difference in bone resorption was found between the surgeries conducted by the two clinicians. Conclusions: The use of the Magnetic Mallet^® results in bone loss in the buccolingual direction comparable with existing data in the literature on healing the post-extraction socket. This tool seems to be predictable in producing the same results between different operators. Full article

Background and Objectives: Traumatic Brain Injury (TBI) is a condition in which an external force, usually a violent blow to the head, causes functional impairment in the brain. Neuromodulation techniques are thought to restore altered function in the brain, resulting in improved function and reduced symptoms. Brain stimulation can alter the firing of neurons, boost synaptic strength, alter neurotransmitters and excitotoxicity, and modify the connections in their neural networks. All these are potential effects on brain activity. Accordingly, this is a promising therapy for TBI. These techniques are flexible because they can target different brain areas and vary in frequency and amplitude. This review aims to investigate the recent literature about neuromodulation techniques used in the rehabilitation of TBI patients. Materials and Methods: The identification of studies was made possible by conducting online searches on PubMed, Web of Science, Cochrane, Embase, and Scopus databases. Studies published between 2013 and 2023 were selected. This review has been registered on OSF (JEP3S). Results: We have found that neuromodulation techniques can improve the rehabilitation process for TBI patients in several ways. Transcranial Magnetic Stimulation (TMS) can improve cognitive functions such as recall ability, neural substrates, and overall improved performance on neuropsychological tests. Repetitive TMS has the potential to increase neural connections in many TBI patients but not in all patients, such as those with chronic diffuse axonal damage.Conclusions: This review has demonstrated that neuromodulation techniques are promising instruments in the rehabilitation field, including those affected by TBI. The efficacy of neuromodulation can have a significant impact on their lives and improve functional outcomes for TBI patients. Full article

Currently, research is being carried out on the performance improvement of permanent-magnet-synchronous motors (PMSM) used in air conditioning and blowing systems for marine, as well as structural research, regarding their high-speed operation. Surface-mounted permanent magnet (SPM) motors used in marine propulsion and air-conditioning systems have the advantages of easy rotor manufacturing and a simple structure. However, owing to the structural characteristics associated with attaching a permanent magnet to the surface of the rotor, there is a risk of permanent magnet scattering when turning a rated load at high speed, and the rotor assembly is directly affected by the heat generated in the stator winding. Therefore, in this study, additional protrusions were proposed to prevent rotor scattering during high-speed operations. Additionally, optimization was performed to reduce the torque ripple at the rated load and the total harmonic distortion (THD) of the no-load-induced electromotive-force waveform generated by the protrusion. Consequently, the risk of scattering at high speeds was improved by securing the bonding force of the permanent magnet using the proposed structure, and the THD and torque ripple were reduced compared with those of the basic model through optimization. In addition, rotor structural stress analyses were conducted to solve the problem of scattering at high speeds and eigenmode analysis. Full article

This study is aimed to explore the magneto-hydrodynamic Carreau fluid flow over a stretching/shrinking surface with a convectively heated boundary. Temperature-dependent variable thermophysical properties are utilized to formulate the problem. The flow governing equations are obtained with boundary layer approximation and constitutive relation of the Carreau fluid. The shooting method is utilized to obtain graphical and numeric outcomes. Additionally, initial guesses are generated with the help of Newton’s method. The effect of Weissenberg number, Magnetization, stretching ratio, Prandtl number, suction/blowing parameter, and Lewis number is obtained on velocity, temperature and species continuity profile and analyzed. Shear stress rates and Nusselt number outcomes under body forces influences are present in tabulated data and discussed. It is observed that in absence of magnetization force, B = 0 and strong mass suction $5\le S\le 7.5$ effect high rates of Nusselt number is obtained. It is concluded that under the influence of power law index and non-linearity parameter maximum heat transfer and reduced shear stress rates are obtained. Full article

The paper presents a modern method of computer modeling, concerning the low-voltage extinguishing chambers employed in modular apparatuses. The focus was put on presenting the phenomenon of increasing the blow-out, through the use of ferromagnetic plates, dividing the electric arc inside the electrical apparatus. The use of ferromagnetic material for the production of extinguishing chambers results in the distortion of the magnetic field generated by the electric arc. This creates a magnetic force that draws the arc towards the plate area of the extinguishing chamber. The authors presented a modern tool for the analysis of physical phenomena inside the extinguishing chamber. The presented material makes it possible to examine the influence of changes in the geometry and materials of the mentioned components on the process of switching off the current. The applied approach can be used to analyze physical phenomena in devices, not only for alternating current, but also for direct current. Moreover, the model is scaled to the various parameters of these devices. Full article

The multi-terminal direct current network is expected to commercialize while carrying out projects related to DC power systems worldwide. Accordingly, it is necessary to develop a DC circuit breaker required for the DC power system. A DC circuit breaker should be developed to protect the DC power system and the consumer from the transient state on the line in any case. Currently, the use of power semiconductors increases the performance of DC circuit breakers. However, power semiconductors are expensive and suffer series of losses from frequent failures. Therefore, the DC circuit breaker must have a reliable, stable, and inexpensive structure. We proposed a new type of arc-induction type DC circuit breaker. It consists of a mechanical blocking contact, an induction needle and a superconducting magnet. It blows the arc with an induction needle using the Lorentz force according to the high magnetic field of the superconducting magnet. The arc-induction needle absorbs the arc and flows through the ground wire to the ground to extinguish the arc. We established this principle of arc induction as a mathematical model. In addition, the Maxwell program was used to secure data of electric and magnetic fields and apply them to mathematical models. The results obtained through numerical analysis were analyzed and compared. As a result, we confirmed that the magnitude of the force exerted on the electrons between the mechanical contacts with the superconducting magnets increased about 1.41 times and reasoned the arc-induction phenomenon out numerically. Full article