Detection of Neodymium-Rich Phase for Development of Coercivity in Neodymium-Iron-Boron-Based Alloys with Submicron-Sized Grains Using Positron Lifetime Spectroscopy

In order to evaluate the relationship between positron lifetime and microstructure, which contributes to the development of coercivity in hydrogenation-disproportionation-desorption-recombination (HDDR)-processed Nd-Fe-B-based alloys, detailed studies of positron lifetime spectroscopy were performed on HDDR-processed Nd-Fe-B-based alloys during desorption-recombination (DR) treatment. After the onset of coercivity, the change in positron lifetime closely corresponded to the change in intrinsic coercivity (H cJ ) with the progress of DR treatment. This result can be explained in terms of the grain size of the recombined Nd 2 Fe 14 B phases and the diffusion length of positrons, which annihilate in the matrix before reaching the grain boundary. Furthermore, positron lifetime spectroscopy was able to detect small changes in the grain boundary region very sensitively compared with thermal desorption spectroscopy (TDS) and X-ray diffraction (XRD). These changes in the grain boundary region caused the onset of coercivity attributed to the formation of Nd-rich intergranular phases. These results indicate that formation of a small amount of the Nd-rich intergranular phase during the DR process, which could be detected by positron lifetime spectroscopy, contributes to the onset of coercivity, even if NdH x phases remain

Polar Patrol Balloon experiment in Antarctica during 2002-2003

The first scientific campaign of the Polar Patrol Balloon (PPB) experiment (1st-PPB) was performed at Syowa Station in Antarctica during 1990-1991 and 1992-1993. Based on the fruitful results of the 1st-PPB experiment, the next campaign (2nd-PPB) will be carried out in the austral summer of 2002-2003. This paper summarizes the 2nd-PPB experiment. Four balloons in total will be launched to make astrophysics observations (1 balloon) and upper atmosphere physics observations (3 balloons). The first payload will carry a very sophisticated instrument that will observe primary cosmic-ray electrons in the energy range of 10 GeV - 1 TeV. The payloads of the latter 3 flights are identical to each other. They will be launched in as rapid a succession as weather conditions permit to form a cluster of balloons during their flights. Such a "Balloon Cluster" is suitable for observing the temporal evolution and spatial distribution of various phenomena in the various magnetospheric and ionospheric regions and their boundaries that the balloons will traverse during their circumpolar trajectory. The expected flight duration of each balloon is 20 days. Observation data will be obtained mainly by a satellite communication system with a much higher temporal resolution than that used in the 1st-PPB experiment

Effects of unilateral neck muscle vibration on standing postural orientation and spatial perception in healthy subjects based on stimulus duration and simultaneous stimulation of trunk muscles

Neck muscle vibration (NMV) influences proprioceptive sensations and modulates standing postural orientation and spatial perception. However, the effects of NMV in healthy participants would vary based on the influence of stimulus duration and combination with trunk muscle vibration. Therefore, this study with a cross-over design clarified these effects. Twenty-four healthy participants (mean age, 25.7±3.7 years) were enrolled. To assess standing postural orientation, standing center-of-pressure (COP) measurements were recorded on a COP platform, starting with closed eyes and then with open eyes. The mean mediolateral (ML) and anteroposterior (AP) position [mm] of COP and other parameters were calculated. To assess spatial perception, subjective straight ahead (SSA) measurements were recorded, wherein participants were instructed to point and project the position of the manubrium of sternum on the touch panel using their right index finger with their eyes closed. Measurements were taken before and after four conditions: no vibration (control), left NMV for 30 s, left NMV for 10 min, and left NMV and left lumbar back vibration for 10 min. Vibratory stimulation was performed with the eyes closed at 80 Hz. The measurements under the four conditions were conducted with random cross-over and 5-min resting period between the conditions. COP and SSA values were subtracted before and after each condition for standardized variation and compared. NMV combined with trunk muscle vibration for 10 min resulted in significant deviations of the ML-COP toward the stimulation side and AP-COP toward the anterior side compared to the control condition with closed eyes. SSA showed no significant differences. These findings suggest that NMV-induced nervous system modulation would be amplified by proprioceptive sensory input to trunk muscles. Therefore, this method could provide a new option for clinical trials on postural orientation using NMV. SSA based on proprioceptive sensation may not be biased without visual illusions

立位における上肢運動時の腰部多裂筋深層線維および浅層線維の筋反応時間の検討

Based on the current literature, it remains unclear whether electromyographic onset of the deep fibers of the multifidus (DM) is dependent on the direction of shoulder movement and the position of the center of foot pressure (CFP). In the present study, we re-examined the electromyographic onset of the DM during shoulder flexion and extension and investigated the influence of the CFP position before arm movement. Intramuscular and surface electrodes recorded the electromyographic onset of the DM, superficial fibers of the multifidus (SM), rectus abdominis, and anterior and posterior deltoid. Eleven healthy participants performed rapid, unilateral shoulder flexion and extension in response to audio stimuli at three CFP positions: quiet standing, extreme forward leaning, and extreme backward leaning. It was found that the electromyographic onset of the DM and SM relative to the deltoid was dependent on the direction of arm movement. Additionally, of all electromyographic onsets recorded, only that of the DM occurred earlier in the extreme forward leaning position than in the extreme backward leaning position during shoulder flexion. These results suggest that the electromyographic onset of DM was influenced by the biomechanical disturbance such as shoulder movement and CFP position.首都大学東京, 2015-09-30, 博士（理学療法学）, 甲第619号首都大学東

Movement patterns of the functional reach test do not reflect physical function in healthy young and older participants

東京都立大学Tokyo Metropolitan University博士（理学療法学）doctoral thesi

Difference in the electromyographic onset of the deep and superficial multifidus during shoulder movement while standing.

Based on the current literature, it remains unclear whether electromyographic onset of the deep fibers of the multifidus (DM) is dependent on the direction of shoulder movement and the position of the center of foot pressure (CFP). In the present study, we re-examined the electromyographic onset of the DM during shoulder flexion and extension and investigated the influence of the CFP position before arm movement. Intramuscular and surface electrodes recorded the electromyographic onset of the DM, superficial fibers of the multifidus (SM), rectus abdominis, and anterior and posterior deltoid. Eleven healthy participants performed rapid, unilateral shoulder flexion and extension in response to audio stimuli at three CFP positions: quiet standing, extreme forward leaning, and extreme backward leaning. It was found that the electromyographic onset of the DM and SM relative to the deltoid was dependent on the direction of arm movement. Additionally, of all electromyographic onsets recorded, only that of the DM occurred earlier in the extreme forward leaning position than in the extreme backward leaning position during shoulder flexion. These results suggest that the electromyographic onset of DM was influenced by the biomechanical disturbance such as shoulder movement and CFP position