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The ultrasonic velocities in a colloidal solution and a thixotropic hydrogel containing imogolite are measured. Our original experimental setup can detect the change of ultrasonic velocity caused by the mixing of imogolite and maleic acid in pure water. Using this setup, the ultrasonic velocity is found to remain unchanged during the macroscopic solid/liquid transition and viscoelastic change of a
Small ultrasonic motors are driven by the oscillation of piezoelectric transducers. They are primarily applied to equipment components that require precise movements, such as drivers for auto-focus lenses in cameras, and actuators in robots and positioning devices. While lubrication has been proven effective in improving the performance of ultrasonic motors, the friction materials still play a sig
A bidirectional non-contact rotary motor using a piezoelectric torsional vibrator and the giant electrorheological (GER) fluid is described in this paper. By applying the dynamic electric signal with a square waveform to the GER fluid, which is in phase with the vibration velocity of the torsional vibrator, bidirectional rotation at an excitation frequency of 118 Hz is achieved. This motor generat
Lubrication has been proven to be an effective approach to drastically improve the efficiency of ultrasonic motors without losing the output torque. This phenomenon is attributed to the effective modulation of the friction force by lubricant, according to the theory described in the Stribeck curve. Previous findings even show a potential to increase the motor output torque with lubrication. Here,
Ultrasonic motors have hit a bottleneck caused by low efficiency and short life, which limits their applications to some niche areas. We believe that lubrication is a promising candidate to solve these problems. In this paper, we clarify, both analytically and experimentally, that the performance of the hybrid transducer-type ultrasonic motor (HTUSM), including the transduction efficiency, can be
Ultrasonic motors (USMs) have been extensively studied for three decades, due to their attractive features, such as high torque at low speed, simple structure, and precise positioning capability. However, since USMs are driven by the friction force between the rotor and the stator in most cases, they inherently possess the friction loss and the wear of contact materials, which cause their low effi
Background and purpose: The treatment of biochemical recurrence (BCR) after prostatectomy is challenging as the site of the recurrence is often undetectable. Our aim was to test a personalised treatment concept for BCR based on PSA kinetics during salvage radiotherapy (SRT) combined with prostate-specific membrane antigen positron emission tomography (PSMA-PET).Materials and methods: This phase II
During the period 1920--30, there was a certain interest in north-westem Argentina's archaeology and ethnography at Etnografiska Museet. This interest had its roots in the so called "Expedition Chaco-Cordillera" led by Erland Nordenskiöld in 1901-1902. In 1932, Alfred Metraux visited Etnografiska Museet and inspired, among others, Stig Ryden, one of Erland Nordenskiöld's students. In the same ye
How does delay in the realization of a prosocial decision affect prosocial choice? This paper first provides a meta-analysis that collects existing evidence on the temporal consistency of prosocial behavior. I show that the evidence on the delay effect on prosocial choice is contradicting but appears reconcilable by a moderating factor: repeated interaction. Motivated by this finding, I conduct an
PURPOSE: The overall aim of this study was to describe experiences of discrimination due to inaccessibility among people using mobility devices.MATERIAL AND METHODS: We conducted a thematic qualitative analysis of 88 complaints about wheeled mobility device use, inaccessibility, and discrimination submitted to the Swedish Equality Ombudsman (DO) during 2015 and 2016.RESULTS: The analysis resulted
