SIMULATIONS OF HIGH-VELOCITY CLOUDS. II. ABLATION FROM HIGH-VELOCITY CLOUDS AS A SOURCE OF LOW-VELOCITY HIGH IONS

Abstract The well measured gas-phase abundances in the low halo suggest that this region of the Galaxy has total (gas plus dust) metal abundances which are close to those in the solar neighborhood. The gas-phase abundances in the halo are generally higher than those seen in the disk, however, this affect is likely due to the destruction of dust in the halo clouds. Observations of high velocity clouds (HVCs) in the halo suggest that these clouds have metal abundances which are substantially lower than those measured for the local interstellar medium. These determinations, however, are often of lower quality than those for the low halo because of uncertainties in the hydrogen abundances along the sightlines, in the incorporation of elements into dust, and in the partial ionization of the clouds.

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Detection of effort maximality in adults performing isokinetic wrist flexion and extension

Isokinetics and Exercise Science ◽

10.3233/ies-200274 ◽

2021 ◽

pp. 1-7

Author(s):

Mercè Torra ◽

Eduard Pujol ◽

Anna Maiques ◽

Salvador Quintana ◽

Roser Garreta ◽

...

Keyword(s):

High Velocity ◽

Healthy Male ◽

Wrist Flexion ◽

Low Velocity ◽

Wrist Extensor ◽

Submaximal Effort ◽

The Difference ◽

Muscle Groups ◽

Maximal Effort ◽

Flexion And Extension

BACKGROUND: The difference between isokinetic eccentric to concentric strength ratios at high and low velocities (DEC) is a powerful tool for identifying submaximal effort in other muscle groups but its efficiency in terms of the wrist extensors (WE) and flexors (WF) isokinetic effort has hitherto not been studied. OBJECTIVE: The objective of the present study is to examine the usefulness of the DEC for identifying suboptimal wrist extensor and flexor isokinetic efforts. METHODS: Twenty healthy male volunteers aged 20–40 years (28.5 ± 3.2) were recruited. Participants were instructed to exert maximal and feigned efforts, using a range of motion of 20∘ in concentric (C) and eccentric (E) WE and WF modes at two velocities: 10 and 40∘/s. E/C ratios (E/CR) where then calculated and finally DEC by subtracting low velocity E/CR from high velocity ones. RESULTS: Feigned maximal effort DEC values were significantly higher than their maximal effort counterparts, both for WF and WE. For both actions, a DEC cutoff level to detect submaximal effort could be defined. The sensitivity of the DEC was 71.43% and 62.5% for WE ad WF respectively. The specificity was 100% in both cases. CONCLUSION: The DEC may be a valuable parameter for detecting feigned maximal WF and WE isokinetic effort in healthy adults.

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Studying the Depth Structure of the Kyrgyz Tien Shan by Using the Seismic Tomography and Magnetotelluric Sounding Methods

Geosciences ◽

10.3390/geosciences11030122 ◽

2021 ◽

Vol 11 (3) ◽

pp. 122

Author(s):

Irina Medved ◽

Elena Bataleva ◽

Michael Buslov

Keyword(s):

Seismic Tomography ◽

High Velocity ◽

Fault Zones ◽

Magnetotelluric Sounding ◽

Tien Shan ◽

High Resistivity ◽

Low Velocity ◽

Low Resistivity ◽

Velocity Models ◽

Fluid Saturation

This paper presents new results of detailed seismic tomography (ST) on the deep structure beneath the Middle Tien Shan to a depth of 60 km. For a better understanding of the detected heterogeneities, the obtained velocity models were compared with the results of magnetotelluric sounding (MTS) along the Kekemeren and Naryn profiles, running parallel to the 74 and 76 meridians, respectively. We found that in the study region the velocity characteristics and geoelectric properties correlate with each other. The high-velocity high-resistivity anomalies correspond to the parts of the Tarim and Kazakhstan-Junggar plates submerged under the Tien Shan. We revealed that the structure of the Middle Tien Shan crust is conditioned by the presence of the Central Tien Shan microcontinent. It manifests itself as two anomalies lying one below the other: the lower low-velocity low-resistivity anomaly, and the upper high-velocity high-resistivity anomaly. The fault zones, limiting the Central Tien Shan microcontinent, appear as low-velocity low-resistivity anomalies. The obtained features indicate the fluid saturation of the fault zones. According to the revealed features of the Central Tien Shan geological structure, it is assumed that the lower-crustal low-velocity layer can play a significant role in the delamination of the mantle part of the submerged plates.

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