scholarly journals A geometrical optics-based numerical method for high frequency electromagnetic fields computations near fold caustics—Part I

2003 ◽  
Vol 156 (1) ◽  
pp. 93-125 ◽  
Author(s):  
J.-D. Benamou ◽  
O. Lafitte ◽  
R. Sentis ◽  
I. Solliec
2020 ◽  
pp. 9-12
Author(s):  
Viktor E. Lyubimov ◽  

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.


2009 ◽  
Vol 131 (3) ◽  
Author(s):  
Mario Durán ◽  
Jean-Claude Nédélec ◽  
Sebastián Ossandón

An efficient numerical method, using integral equations, is developed to calculate precisely the acoustic eigenfrequencies and their associated eigenvectors, located in a given high frequency interval. It is currently known that the real symmetric matrices are well adapted to numerical treatment. However, we show that this is not the case when using integral representations to determine with high accuracy the spectrum of elliptic, and other related operators. Functions are evaluated only in the boundary of the domain, so very fine discretizations may be chosen to obtain high eigenfrequencies. We discuss the stability and convergence of the proposed method. Finally we show some examples.


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 ◽  
...  

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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