scholarly journals The Acoustic Nature of “Storm Nose”, “Supercell” Vortices and Tornadoes

2022 ◽  
Vol 16 (2) ◽  
pp. 71-80
Author(s):  
V. I. Pinakov
Keyword(s):  
Dynamic Balance ◽  
Dew Point ◽  
Sound Channel ◽  
Thermal Inversion ◽  
Acoustic Channel ◽  
Compression Waves ◽  
Middle Latitudes ◽  
Decompression Wave ◽  
Speed Level ◽  
Real Atmosphere

The process of cumulonimbus cloud Cb calvus formation in the middle latitudes of real atmosphere is analyzed in this work. Its transformation from initial lifecycle stage to “maturity” undergoes due to the formation of the waveguide called “aerial acoustic channel” in the troposphere near the level of temperature minimum that is close to 2 km altitude. This “aerial acoustic channel” can be considered as analog of “deep sound channel” that corresponds to the minimal sound speed level. Tropospheric “channel” related to the thermal inversion zone is almost unlimited horizontally. Synchronous generation of two compression waves (ascending one above Cb and descending one inside Cb) is caused by Cb calvus dome ascension. The first one can provoke the aerodynamic draft previously unexplained. The second one results in the growth of its “storm nose” and in the axial and peripheral descending mechanisms in Cb. The penetration of Cb into stratosphere results in the destruction of dynamic balance around Cb top and hence in its unloading in the descending decompression wave. Here the air cools down to the “dew point” in the place of conjugation with parental cloud – due to Snellius law it results in the formation of aerosol “vortex” as condensation front; this “vortex” has calculated value of its generatrix against vertical. Due to D. Snow’s criterion, this vortex forms either “supercell” vortex or tornado vortex.

A correction to sonic boom theory

2009 ◽  
Vol 113 (1149) ◽  
pp. 739-745 ◽  
Author(s):  
T. Cain
Keyword(s):  
Ambient Temperature ◽  
Acoustic Impedance ◽  
Aircraft Design ◽  
Sonic Boom ◽  
Sonic Booms ◽  
Compression Waves ◽  
Supersonic Aircraft ◽  
Real Atmosphere ◽  
Weak Shocks ◽  
The Waves

Abstract Current sonic boom theory is based on linear midfield solutions coupled with acoustic propagation models. Approximate corrections are made within the theory to account for non-linearities, in particular for the coalescence of compression waves and the formation of weak shocks. A very large adjustment is made to account for the increasing acoustic impedance that the waves encounter as they propagate from the low density air at cruise altitude to the high density air at sea level. Typically this correction reduces the calculated over pressure levels by a factor of three. Here the method of characteristics (MOC) is used to prove that the density gradient within a hydrostatic atmosphere has no direct effect on the propagation or intensity of the wave. However gravity and ambient temperature both affect the wave propagation and the combined pressure level attenuation is not dissimilar to that previously attributed to acoustic impedance. Although the flawed acoustic theory has given reasonable predictions of measured sonic booms, the omission of gravity from the equation of motion and the inclusion of a false impedance modification, makes the model unreliable for prediction of future designs, particularly those focused on boom minimisation. As an aid to quiet supersonic aircraft design, Whitham’s theory is extended to include gravity and ambient temperature variation and shown to be in good agreement with a MOC solution for the real atmosphere.

Use of Vestibular Rehabilitation in the Pediatric Population

2019 ◽  
Vol 4 (6) ◽  
pp. 1399-1405 ◽  
Author(s):  
Jennifer Christy
Keyword(s):  
Pediatric Population ◽  
Dynamic Balance ◽  
Vestibular Rehabilitation ◽  
Rehabilitation Program ◽  
Gross Motor ◽  
Gaze Stabilization ◽  
Motor Delay ◽  
Rehabilitation Programs ◽  
Motor Practice ◽  
Balance Exercises

Purpose The purpose of this article was to provide a perspective on vestibular rehabilitation for children. Conclusion The developing child with vestibular dysfunction may present with a progressive gross motor delay, sensory disorganization for postural control, gaze instability, and poor perception of motion and verticality. It is important that vestibular-related impairments be identified early in infancy or childhood so that evidence-based interventions can be initiated. A focused and custom vestibular rehabilitation program can improve vestibular-related impairments, enabling participation. Depending on the child's age, diagnosis, severity, and quality of impairments, vestibular rehabilitation programs may consist of gaze stabilization exercises, static and dynamic balance exercises, gross motor practice, and/or habituation exercises. Exercises must be modified for children, done daily at home, and incorporated into the daily life situation.

New Electro-Dynamic Balance

1882 ◽  
Vol 14 (355supp) ◽  
pp. 5665-5665
Author(s):  
M. Debrun
Keyword(s):  
Dynamic Balance

The Dynamic Balance of Machines

1916 ◽  
Vol 82 (2129supp) ◽  
pp. 262-263
Author(s):  
Chas. L. Clarke
Keyword(s):  
Dynamic Balance

Physical exercise protects dynamic balance and motor coordination of rats treated with vincristine

2020 ◽  
Vol 19 (5) ◽  
pp. 336
Author(s):  
Luiza Minato Sagrillo ◽  
Viviane Nogueira De Zorzi ◽  
Luiz Fernando Freire Royes ◽  
Michele Rechia Fighera ◽  
Beatriz Da Silva Rosa Bonadiman ◽  
...  
Keyword(s):  
Oxidative Stress ◽  
Locomotor Activity ◽  
Physical Exercise ◽  
Motor Coordination ◽  
Dynamic Balance ◽  
Exercise Group ◽  
Adult Rats ◽  
The Central Nervous System ◽  
Stress Damage ◽  
Training Protocol

Physical exercise has been shown to be an important modulator of the antioxidant system and neuroprotective in several diseases and treatments that affect the central nervous system. In this sense, the present study aimed to evaluate the effect of physical exercise in dynamic balance, motor coordination, exploratory locomotor activity and in the oxidative and immunological balance of rats treated with vincristine (VCR). For that, 40 adult rats were divided into two groups: exercise group (6 weeks of swimming, 1h/day, 5 days/week, with overload of 5% of body weight) and sedentary group. After training, rats were treated with 0.5 mg/kg of vincristine sulfate for two weeks or with the same dose of 0.9% NaCl. The behavioral tests were conducted 1 and 7 days after each dose of VCR. On day 15 we carried out the biochemical analyzes of the cerebellum. The physical exercise was able to protect against the loss of dynamic balance and motor coordination and, had effect per se in the exploratory locomotor activity, and neutralize oxidative stress, damage DNA and immune damage caused by VCR up to 15 days after the end of the training protocol. In conclusion, we observed that previous physical training protects of the damage motor induced by vincristine.Key-words: exercise, oxidative stress, neuroprotection, cerebellum.

Effects of Balance Training through Various Ankle Inclination on Dynamic Balance in Healthy Adults

2018 ◽  
Vol 25 (3) ◽  
pp. 61-67
Author(s):  
Nuri Kim ◽  
Kangmi Kim ◽  
Jeongeun Lee ◽  
Hakyeong Lee ◽  
Yuri Cha
Keyword(s):  
Dynamic Balance ◽  
Balance Training ◽  
Healthy Adults

S-TEN1

Alloy Digest ◽  
2005 ◽  
Vol 54 (8) ◽  
Keyword(s):  
Corrosion Resistance ◽  
High Temperature ◽  
Physical Properties ◽  
Tensile Properties ◽  
Carbon Steels ◽  
Dew Point ◽  
Steel Alloy ◽  
Temperature Performance ◽  
Nippon Steel Corporation ◽  
Steel Corporation

Abstract S-TEN1 is a steel alloy containing copper and antimony to make it more resistant to dew-point corrosion than conventional carbon steels. It is used as tubing in economizers. This datasheet provides information on composition, physical properties, hardness, elasticity, and tensile properties. It also includes information on high temperature performance and corrosion resistance as well as forming and joining. Filing Code: SA-550. Producer or source: Nippon Steel USA Inc., Nippon Steel Corporation.

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