Hamiltonian theory of the generalized oscillation-centre transformation

1988 ◽  
Vol 39 (1) ◽  
pp. 81-102 ◽  
Author(s):  
B. Weyssow ◽  
R. Balescu
Keyword(s):  
High Frequency ◽  
Ponderomotive Force ◽  
Hamiltonian Formalism ◽  
Larmor Frequency ◽  
Static Field ◽  
Canonical Variables ◽  
Hamiltonian Theory ◽  
External Frequency ◽  
High Frequency Electromagnetic Field ◽  
Physical Quantities

The theory of the slow reaction of a charged particle in the combined presence of a strong quasi-static magnetic field and a high-frequency electromagnetic field (generalized oscillation-centre motion) is constructed by using a Hamiltonian formalism with non-canonical variables and pseudo-canonical transformations. The theory combines the features studied in our previous works for the case in which only one of the previously mentioned fields is present. The new averaging transformation is based on the fact that the Larmor frequency of the quasi-static field is of the same order as the external frequency of the high-frequency field. Our theory is manifestly gauge-invariant and involves only physical quantities (particle velocity and electromagnetic fields). Explicit expressions for the drift velocity of the oscillation centre and for the ponderomotive force are derived.

A manifestly gauge-invariant Hamiltonian theory of the oscillation-centre dynamics

1987 ◽  
Vol 37 (3) ◽  
pp. 467-486 ◽  
Author(s):  
B. Weyssow ◽  
R. Balescu
Keyword(s):  
High Frequency ◽  
Ponderomotive Force ◽  
Hamiltonian Formalism ◽  
Gauge Invariant ◽  
Canonical Variables ◽  
Hamiltonian Theory ◽  
Special Cases ◽  
High Frequency Electromagnetic Field ◽  
Particle Velocities ◽  
Field Oscillation

The theory of the slow reaction of charged particles in the presence of a high-frequency electromagnetic field (oscillation-centre motion) is developed by using a Hamiltonian formalism with non-canonical variables and pseudo-canonical transformations. The flexibility introduced by the latter features allows us to construct a theory which is manifestly gauge-invariant and involves only physical concepts (electromagnetic fields and particle velocities instead of potentials and canonical momenta). A complete description of the oscillation-centre dynamics is derived. The known expressions of the ponderomotive force are derived as special cases of our theory.

The ponderomotive force of a high-frequency electromagnetic field in a cold magnetized plasma

1982 ◽  
Vol 27 (2) ◽  
pp. 215-224 ◽  
Author(s):  
V. I. Karpman ◽  
A. G. Shagalov
Keyword(s):  
Electromagnetic Field ◽  
Liquid Medium ◽  
Magnetic Moment ◽  
High Frequency ◽  
Ponderomotive Force ◽  
Frequency Dispersion ◽  
Magnetized Plasma ◽  
Complete Agreement ◽  
Microscopic Approach ◽  
High Frequency Electromagnetic Field

An expression is derived for the ponderomotive force acting in a cold collisionless magnetized plasma in a high-frequency electromagnetic field. Some related topics, such as the magnetic moment and solenoidal currents induced by the HF field are considered. A microscopic approach is used. The results are in complete agreement with the general expression for the ponderomotive force in a liquid medium with frequency dispersion obtained earlier by Washimi & Karpman by means of phenomenological considerations.

Method of high frequency therapy at cows' mastitis during machine milking

2020 ◽  
pp. 9-12
Author(s):  
Viktor E. Lyubimov ◽  
Keyword(s):  
Dairy Cows ◽  
Electromagnetic Fields ◽  
High Frequency ◽  
High Efficiency ◽  
Environmentally Friendly ◽  
Ultrahigh Frequency ◽  
Machine Milking ◽  
High Frequency Electromagnetic Field ◽  
Milking Machine ◽  
Methods Of Treatment

Health of dairy cows ensures human health, so it is important that dairy products do not contain antibiotics that are used to treat any inflammation, including mastitis. In Russia at present, the problem of mastitis in cows exists with both attached and loose housing of cows. Mastitis of dairy cows are the great problem in milking husbandry. Losses from mastitis in milk yield can reach 15-20%. The main reasons for the occurrence of nonspecific mastitis of cows are the shortcomings of the working components of the milking machine: the degree of deterioration of the nipple rubber and the violation of machine milking technology (the reduction in pre-milking time and vacuum fluctuations account for 70% of all causes). Treatment of mastitis with antibiotics is effective, but not environmentally friendly and unacceptable. For the treatment of inflammation of the udder, it is necessary to use more environmentally friendly methods of treatment, one of which is the exposure to ultra-high frequency electromagnetic field tested by medicine. Use of three types of medical-mobile milking machines with the same method of exposure to ultrahigh-frequency electromagnetic fields on cow's nipples through electrodes in milking cups: LPDA-1-UHF, LPDA-2-UHF and LPDA-UHF-30 M, is described in the article. Author proved that cows with subclinical forms of mastitis recovered faster during milking with exposure to the ultrahigh frequency than when treated by antibiotics, and milking with the ultrahigh frequency device helps to recover 82% of the affected quarters with clinical forms and 100% of cows with subclinical forms of mastitis or with udder irritation. The high efficiency of the method of exposure to electromagnetic fields of the ultrahigh frequency during machine milking by means of medical-mobile milking machines LPDA-UHF for the prevention and treatment of mastitis of cows was shown.

scholarly journals Effect of high-frequency electromagnetic field on microstructure of mold flux

2020 ◽  
Vol 39 (1) ◽  
pp. 368-376
Author(s):  
Xingjuan Wang ◽  
Hebin Jin ◽  
Liguang Zhu ◽  
Ran Liu ◽  
Tushun Song
Keyword(s):  
Electromagnetic Field ◽  
High Frequency ◽  
Mold Flux ◽  
Film Structure ◽  
Glass Layer ◽  
Slag Film ◽  
Flux Flow ◽  
Layer Form ◽  
Finite Element Software ◽  
High Frequency Electromagnetic Field

AbstractSoft-contact of molten steel can be achieved by applying a high-frequency electromagnetic field above the mold of continuous casting, which can effectively eliminate surface defects and achieve billets with no cracks and no oscillation marks. It also has some influence on the mold flux. In this study, the effect of a high-frequency electromagnetic field (20 kHz) on a mold flux flow field was simulated using a finite element software, and the slag film was extracted using a slag film simulator. The effect of the high-frequency magnetic field on the microstructure of the mold flux was analyzed using X-ray diffraction, Raman spectroscopy, and mineral phase testing. The results show that the high-frequency electromagnetic field disrupts the orderly movement and increases the movement rate of the liquid flux. The precipitate phase of the slag film did not change, but the silicate dimer Q1 decreased, the chain Q2 increased, and the network degree was increased. The slag film structure changed from the original two-layer form of crystalline layer–glass layer into a three-layer form of crystal layer–glass layer–crystal, and the crystallization ratio increased by 35% on average. The grain-size melilite granularity was reduced from the original 0.12 to 0.005 mm.

The Generation of Switchable Polarized Currents in Nodal Ring Semimetals Using High-Frequency Periodic Driving

2021 ◽  
Author(s):  
Pei-Hao Fu ◽  
Qianqian Lv ◽  
Xiang-Long Yu ◽  
Jun-Feng Liu ◽  
Jiansheng Wu
Keyword(s):  
High Frequency ◽  
Surface Currents ◽  
Switching Effect ◽  
Fermi Arc ◽  
Periodically Driven ◽  
Weyl Semimetal ◽  
Spin Polarized ◽  
High Frequency Electromagnetic Field ◽  
Polarized Surface ◽  
Lead Device

Abstract A nodal ring semimetal (NRSM) can be driven to a spin-polarized NRSM or a spin-polarized Weyl semimetal (SWSM) by a high-frequency electromagnetic field. We investigate the conditions in realizing these phases and propose a switchable spin-polarized currents generator based on periodically driven NRSMs. Both bulk and surface polarized currents are investigated. The polarization of bulk current is sensitive to the amplitude of the driving field and robust against the direction and polarization of the driving, the opaqueness of the lead-device interface and the misalignment between the nodal ring and the interface, which provides sufficient flexibility in manipulating the devices. Similar switchable polarized surface currents are also expected, which is contributed by the Fermi arc surface state associated with the Weyl semimetal (WSM) phases. The generation of polarized currents and the polarization switching effect offer opportunities to design periodic driving controlled topological spintronics devices based on NRSMs.

scholarly journals ЗМІНА ЕЛЕКТРИЧНИХ ВЛАСТИВОСТЕЙ НАСІННЯ ПІД ВПЛИВОМ ВИСОКОЧАСТОТНОГО ЕЛЕКТРОМАГНІТНОГО ОПРОМІНЕННЯ

2014 ◽  
pp. 151-155
Author(s):  
О. М. Петровський
Keyword(s):  
Electromagnetic Field ◽  
High Frequency ◽  
Electric Properties ◽  
Electric Resistance ◽  
Active Resistance ◽  
Exchange Processes ◽  
High Frequency Electromagnetic Field ◽  
Stimulation Of

Розглянуті питання передпосівної стимуляції на-сіння високочастотним електромагнітним полем.Запропоновано спосіб опромінення насіння і визна-чення його електричних характеристик. На основібудови клітин визначені електричні властивості біо-логічної тканини, з якої складається насіння. Пока-зана зміна складових активного опору в залежностівід частоти струму. Експериментально доведено,що еквівалентну електричну схему неможливо звес-ти до простих випадків з’єднання опорів і ємностей,а саме насіння не можна вважати нейтральнимдіелектриком. Розроблена методика оцінки інтенси-вності обмінних процесів залежно від електричногоопору насіння. The questions of stimulation of seed before sowing are considered by the high-frequency electromagnetic field considered. The method of irradiation of seed and determination of him is offered electric descriptions. On the basis of structure of cages electric properties of biological fabric which seed consist of are certain. The change of constituents of active resistance is shown depending on frequency of current. It is experimentally proved that it is impossible to erect an equivalent electric chart to the simple cases of connection of resistances and capacities, namely seed can not be considered a neutral dielectric. The method of estimation of intensity of exchange processes  is developed depending on electric resistance of seed.

scholarly journals Translocation of silica nanospheres through giant unilamellar vesicles (GUVs) induced by a high frequency electromagnetic field

RSC Advances ◽  
2021 ◽  
Vol 11 (50) ◽  
pp. 31408-31420
Author(s):  
Palalle G. Tharushi Perera ◽  
Nevena Todorova ◽  
Zoltan Vilagosh ◽  
Olha Bazaka ◽  
The Hong Phong Nguyen ◽  
...  
Keyword(s):  
Electromagnetic Field ◽  
Membrane Permeability ◽  
Electromagnetic Fields ◽  
High Frequency ◽  
Model Systems ◽  
Membrane Model ◽  
Silica Nanospheres ◽  
Giant Unilamellar Vesicles ◽  
High Frequency Electromagnetic Field ◽  
First Time

Membrane model systems capable of mimicking live cell membranes were used for the first time in studying the effects arising from electromagnetic fields (EMFs) of 18 GHz where membrane permeability was observed following exposure.

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