A Study of the Waves Processes in Inhomogeneous Cylindrical Waveguides

2021 ◽  
pp. 317-329
Author(s):  
A. O. Vatulyan ◽  
V. Yurov
Keyword(s):  
Cylindrical Waveguides ◽  
The Waves

scholarly journals HIGHER RADIAL MODES OF AZIMUTHAL SURFACE WAVES ABOVE THE UPPER-HYBRID FREQUENCY IN CYLINDRICAL WAVEGUIDES PARTIALLY FILLED BY PLASMA

2020 ◽  
pp. 22-25
Author(s):  
I. Girka ◽  
V. Kondratenko
Keyword(s):  
Surface Waves ◽  
Plasma Column ◽  
Particle Density ◽  
Low Frequency ◽  
Magnetoactive Plasma ◽  
Cylindrical Metal ◽  
Cylindrical Waveguides ◽  
Waveguide Design ◽  
The Waves ◽  
Metal Wall

Azimuthal surface waves (ASWs) are known to be eigen waves of cylindrical metal waveguides partially filled by magnetoactive plasma. Zeroth radial modes were under study earlier. Their dispersion properties are known to be significantly influenced by the plasma column properties: its particle density, external axial static magnetic field, geometric dimensions, – rather than properties of the dielectric layer which separates the plasma column from the metal wall. Application of higher order ASWs in the low-frequency range was shown earlier to make it possible to get advantage of exciting ASWs with higher frequency than in the case of zeroth order ASWs without no change in the waveguide design. The present study generalises those investigation for the case of the waves above the upperhybrid frequency.

The Waves

1986 ◽  
Author(s):  
Virginia Woolf ◽  
Warner
Keyword(s):  
The Waves

How physics is rocked by the waves of history

Nature ◽  
2020 ◽  
Vol 580 (7802) ◽  
pp. 183-184
Author(s):  
Sabine Hossenfelder
Keyword(s):  
The Waves

Iguanas ride the waves

Nature ◽  
1998 ◽  
Author(s):  
Eleanor Lawrence
Keyword(s):  
The Waves

Racing the waves [wave and tidal energy technology]

2004 ◽  
Vol 18 (3) ◽  
pp. 24 ◽  
Author(s):  
J. Wood
Keyword(s):  
Tidal Energy ◽  
Energy Technology ◽  
The Waves

From Missionary Translation to Local Theological Inquiry: A Narrative History of the Lisu Bible

2019 ◽  
Vol 25 (2) ◽  
pp. 202-219
Author(s):  
Aminta Arrington
Keyword(s):  
Minority Group ◽  
Local Leadership ◽  
Bible Translation ◽  
Narrative History ◽  
History Of ◽  
Christian Practices ◽  
Village Elders ◽  
The Village ◽  
The Waves ◽  
Bible Reading

The Lisu are a largely Christian minority group in south-west China who, as an oral culture, express their faith more through a set of Christian practices done as a group and less through bible reading as individuals. Even so, the Lisu practice of Christianity specifically, and Lisu culture more generally, was profoundly impacted by the written scriptures. During the initial evangelisation of the Lisu by the China Inland Mission, missionaries created a written script for the Lisu language. Churches were constructed and organised, which led to the creation of bible schools and the work of bible translation. In the waves of government persecution after 1949, Lisu New Testaments were hidden away up in the mountains by Lisu Christians. After 1980, the Lisu reclaimed their faith by listening to the village elders tell the Old Story around the fires and reopening the churches that had been closed for twenty-two years. And they reclaimed their bible by retrieving the scriptures from the hills and copying them in the evening by the light of a torch. The Lisu bible has its own narrative history, consisting of script creating, translating, migrating, and copying by hand. At times it was largely influenced by the mission narrative, but at other times, the Lisu bible itself was the lead character in the story. Ultimately, the story of the Lisu bible reflects the Lisu Christian story of moving from missionary beginnings to local leadership and, ultimately, to local theological inquiry.

Recording of the Cavitation Phenomena when Modeling Flows in the Trunk Pipelines

2020 ◽  
pp. 7-14
Author(s):  
A.M. Sverchkov ◽  
◽  
S.I. Sumskoy ◽  
Keyword(s):  
Occupational Safety ◽  
Linear Part ◽  
Simple Wave ◽  
Pressure Profile ◽  
Real Problem ◽  
Flow Modeling ◽  
Oil Pipeline ◽  
Emergency Situations ◽  
Hydraulic Shocks ◽  
The Waves

In the article, it is proposed to use a numerical method based on the approach of S.K. Godunov to simulate boiling in a pipeline. The paper presents a statement of the real problem of modeling a water hammer, considering possible boiling of the transported liquid on a real object — an oil pipeline. When solving the problem, two variants of flow modeling when closing the valve installed at the end of the pipeline were carried out. In the first Наука и техника 14 Безопасность Труда в Промышленности • Occupational Safety in Industry • № 11'2020 • www.safety.ru case, the possibility of liquid boiling was not considered. In the second case, this opportunity was considered. The performed numerical simulation showed that in the pipeline in emergency situations, liquid columns can be formed, separated by the cavitation zones and oscillating in different phases, respectively, at the collapse of the cavitation zones, which serve as a kind of pressure dampers, the collisions of liquid columns occur, which can lead, depending on the ratio of velocities, to hydraulic shocks that occur not on the valves, but on the linear part of the pipeline (local hydraulic shocks). The waves from these collapses, interacting with each other, create the new pressure peaks that do not coincide with the pattern of simple wave circulation, which are predicted in the simulations that do not consider possible liquid boiling. As a resul t, the pressures reached in the pipeline during fluid hammer is significantly different from what it would be in the absence of boiling. When boiling is considered, the maximum reached pressures are 40 % higher. Moreover, this excess is repeated. The detailed analysis of the pressure profile in the pipeline is given in the article. Based on the results of solving this problem, it is concluded that when modeling pre–emergency and emergency situations in the pipeline, it is necessary to consider the process of possible liquid boiling, since sometimes, as in the presented case, the values of the pressure surges can be higher than the values of the pressure surges in the liquid without considering boiling, which increases the likelihood of emergency depressurization.

Observations for the Role of Flux rope Eruption in a Geoeffective Solar Flare

2014 ◽  
Vol 4 (2) ◽  
pp. 555-564
Author(s):  
A.M Aslam
Keyword(s):  
Solar Flare ◽  
Flux Rope ◽  
Magnetic Configuration ◽  
Solar Dynamics Observatory ◽  
Multi Wavelength ◽  
Solar Dynamics ◽  
Halo Coronal Mass Ejection ◽  
Mass Ejection ◽  
The Waves

On September 24, 2011 a solar flare of M 7.1 class was released from the Sun. The flare was observed by most of the space and ground based observatories in various wavebands. We have carried out a study of this flare to understand its causes on Sun and impact on earth. The flare was released from NOAA active region AR 11302 at 12:33 UT. Although the region had already produced many M class flares and one X- class flare before this flare, the magnetic configuration was not relaxed and still continued to evolve as seen from HMI observations. From the Solar Dynamics Observatory (SDO) multi-wavelength (131 Ã…, 171 Ã…, 304 Ã… and 1600Ã…) observations we identified that a rapidly rising flux rope triggered the flare although HMI observations revealed that magnetic configuration did not undergo a much pronounced change. The flare was associated with a halo Coronal Mass Ejection (CME) as recorded by LASCO/SOHO Observations. The flare associated CME was effective in causing an intense geomagnetic storm with minimum Dst index -103 nT. A radio burst of type II was also recorded by the WAVES/WIND. In the present study attempt is made to study the nature of coupling between solar transients and geospace.

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