Comprehensive Study of τ-Phase Mn-Al-C Magnets: Corrosion Resistance, Structural Integrity, and Magnetic Properties.

This study investigates the chemical, physical, and magnetic properties of Mn-Al-C type magnets, focusing on their corrosion resistance. The hot compaction process is used for densification, producing isotropic magnets. Microstructural analysis reveals undesirable features, such as phase decomposition and deformation.

Postural adjustments upon arm movement during sinusoidal induced body oscillations.

Postural adjustments due to the fast forward right arm elevation, performed during sinusoidal induced body oscillations in the phase of platform-induced dorsal, as well as plantar flexion of the foot were studied. Start times of the changes in the cyclic way of the center-of-gravity position (SG) and right ankle goniogram (GG) as well as the EMG onsets of the right soleus (S), anterior tibial (AT) and femoral biceps (FB) muscles relative to the ipsilateral anterior deltoid muscle (AD) EMG onset were measured. The EMG onset of FB muscle was found to occur significantly before the EMG onset of the AD muscle during plantar flexion series, wherever during dorsal flexion series the EMG onset of the AT muscle was significantly before the AD muscle EMG onset.

Postural adjustments associated with a fast voluntary arm movement at various foot positions.

The aim of the study was to further investigate postural adjustments associated with a fast voluntary arm elevation at various foot positions. The subjects stood upright on a force platform and participated in 3 sessions according to foot position: horizontal position, dorsal and plantar flexion of 6 degrees. EMG activity of anterior deltoid muscle (DA) and of ipsilateral and contralateral soleus (SD, SS), biceps femoris (BFd, BFs) and ipsilateral anterior tibial (TAd) muscles, initial acceleration (Acc) and stabilogram change (Sg) were recorded.

Motor unit activity during different functional states of the neuromuscular system.

The study showed that the mean interspike interval (ISI) and the variability of ISIs increased with fatigue for both low and high threshold motor units (MUs). The recruitment threshold tension decreased for both the low and high threshold MUs while the recruitment threshold in % of maximal voluntary contraction changed selectively because of decrease of muscle force. During ischaemia after an initial decrease of mean ISI and ISIs' variability there was an essential increase of variability of ISIs at almost the same mean ISI followed by a considerable final increase of both parameters.