Seiko (United States)

An air turbine handpiece is a dental abrasive device that rotates at high speed and uses compressed air as the driving force. It is characterized by its small size, light weight, and painless abrading due to its high-speed rotation, but as compared to an electric handpiece that uses a motor as the driving force, its torque is small and noise level is high. However, it is difficult to form the flow influenced by the rotor or the nozzle inside the turbine, and determine the shape by trial and error. In this study, we optimized the nozzle by applying the optimization design method to the model which extracted only the turbine part. As a result, the torque increased when the tip of the blade was located near the nozzle. This is thought to be caused by the nozzle inwardly and colliding widely due to the inward inclination of the jet.

The purpose of this study is to clarify the performance characteristics and internal flow of dental air turbine handpiece. Therefore, the performance test by the actual machine and the numerical analysis by the handpiece model were carried out. The calculated values and the experimental values were compared for the torque and turbine output, and it was confirmed that the two agree well. In the numerical analysis, it was confirmed that the fluid loss in the turbine section was large. Focusing on the flow in the nozzle and the rotor, investigating the internal flow for each rotational speed and blade phase angle revealed the mechanism of torque generation and factors of torque fluctuation.

This study discusses how to use information on mindfulness and its applications as a method for coping with difficult emotions in order to prevent a relapse of drug addiction. Mindfulness practices, while supporting healthy development, also reduce stress, improve well-being, and provide emotional balance. Its use in substance abuse treatment is quite new. Mindfulness helps one to be able to cope with their state of mind in the moment of stress related to substance withdrawal by supporting learning and well-being, and by enabling a direct relationship to be established among self-awareness, self-control, and emotion regulation. In the working group of this study on the prevention of substance abuse relapse, sessions consisted of experimental exercises and discussions. The objective is to keep key points such as the person’s current experiences, relapse, improvement or lifestyle in the center of the discussion. The attention of the participants, through mindfulness application, is a continual in “the moment” review of their surroundings and can prevent them from getting lost in their history. As another strong side of the program, the importance of an individual addressing one’s self before judging or being made to feel guilty is gently encouraged in these applications. In this way, difficulties that emerge in the practice are assessed not as failures but as a sign of tendencies related to the mind, and people’s motivations are protected by normalizing the difficulties they experience. Perhaps the most crucial point of the mindfulness-based relapse prevention program, unlike other therapies, is that labeling in any manner is not performed. Instead of people experiencing the worth of being forgiven, people are required to only observe and accept. Through all of these practices, the target is to ensure a person becomes more aware and accepting towards their actions.

The fatigue property of shape memory alloy (SMA) is one of the most important subjects in view of evaluating functional characteristics of SMA elements. In the present study, ultrasonic shot peening (USP) was applied to induce compressive residual stress on the surface layer of TiNi SMA tape and the influence of USP on the bending fatigue life was investigated. The fatigue life of USP-treated tape is longer than that of the asreceived tape. The fatigue life of the tape USP-treated with high coverage is longer than that with low coverage. The fatigue life of the USPtreated tape increases in proportion to the hardness on the surface of the tape. [doi:10.2320/matertrans.MBW201408]