scholarly journals Evaluation of the microwave power of a buncher in a repeated magnetic field

2020 ◽  
pp. 98-104
Author(s):  
Konstantin Anatolyevich Kuzmin ◽  
Sergey Mikhaylovich Morozov ◽  
Igor Valentinovich Pavlov ◽  
Vladimir Antonovich Reut ◽  
Elena Vitalyevna Balmashnova ◽  
...  

The article considers the klystron method of grouping in a repeated magnetic field. In the long-wavelength range, in addition to gyrocon and magnicon, microwave tetrodes and multi-cavity klystrons are used. Conventional klystrons in the decimeter range have significant dimensions, and their application becomes problematic, and microwave tetrodes have a significant power level, but low efficiency and gain ratio.

2019 ◽  
Author(s):  
Maurizio Milano ◽  
Maurizio Fedi ◽  
J. Derek Fairhead

Abstract. In the European region, the magnetic field at satellite altitudes (~ 350 km) is mainly defined by a long-wavelength magnetic-low called here the Central Europe Magnetic Low (CEML), located to the southwest of the Trans European Suture Zone (TESZ). We studied this area by a joint analysis of the magnetic and total gradient (∇T) anomaly maps, for a range of different altitudes of 5 km, 100 km and 350 km. Tests on synthetic models showed the usefulness of the joint analysis at various altitudes to identify reverse dipolar anomalies and to characterize areas in which magnetization is weak. By this way we identified areas where either reversely or normally magnetized sources are locally dominant. At a European scale these anomalies are sparse, with a low degree of coalescence effect. The ∇T map indeed presents generally small values within the CEML area, indicating that the Palaeozoic Platform is weakly magnetized. At 350 km altitude, the TESZ effect is largely dominant: with intense ∇T highs above the East European Craton (EEC) and very small values above the Palaeozoic Platform, this again denoting a weakly magnetized crust. Small coalescence effects are masked by the trend of the TESZ. Although we identified sparsely located reversely magnetized sources in the Palaeozoic Platform of the CEML, the joint analysis does not support a model of a generally reversely magnetized crust. Instead, our analysis strongly favors the hypothesis that the CEML anomaly is mainly caused by a sharp contrast between the magnetic properties of EEC and Palaeozoic Platform.


2020 ◽  
pp. 108201322098133
Author(s):  
Sagar Nagvanshi ◽  
Subbarao Kotra Venkata ◽  
TK Goswami

Microwave drying works on the volumetric heating concept promoted by electromagnetic radiation at 0.915 or 2.450 GHz. In this study, banana ( Musa Cavendish) was taken as the sample and treated under microwave drying. The effect of two process variables, namely slice thickness (2, 3.5, and 5 mm) and microwave power (180 W, 360 W, and 540 W), were studied on drying kinetics and color kinetics. It was observed that the inverse variation relationship exists between drying time and microwave power level while drying time and slice thickness exhibited a direct variation relationship. A Computer Vision System (CVS) was developed to measure the color values of banana in CIELab space using an algorithm written in MATLAB software. Once the color parameters were obtained, they were fitted in First and Zero-order kinetic models. Both models were found to describe the color values adequately. This study concludes that microwave drying is a promising dehydration technique for banana drying that reduces the significant time of drying. Application of CVS is an excellent approach to measure the surface color of banana.


2021 ◽  
Vol 104 (3) ◽  
pp. 003685042110336
Author(s):  
Safia Akram ◽  
Maria Athar ◽  
Khalid Saeed ◽  
Alia Razia

The consequences of double-diffusivity convection on the peristaltic transport of Sisko nanofluids in the non-uniform inclined channel and induced magnetic field are discussed in this article. The mathematical modeling of Sisko nanofluids with induced magnetic field and double-diffusivity convection is given. To simplify PDEs that are highly nonlinear in nature, the low but finite Reynolds number, and long wavelength estimation are used. The Numerical solution is calculated for the non-linear PDEs. The exact solution of concentration, temperature and nanoparticle are obtained. The effect of various physical parameters of flow quantities is shown in numerical and graphical data. The outcomes show that as the thermophoresis and Dufour parameters are raised, the profiles of temperature, concentration, and nanoparticle fraction all significantly increase.


2021 ◽  
Vol 0 (0) ◽  
Author(s):  
Syeda Noureen

Abstract On employing linearized Vlasov–Maxwell equations the solution of relativistic electromagnetic extraordinary mode is investigated for the wave propagating perpendicular to a uniform ambient magnetic field (in the presence of arbitrary magnetic field limit i.e., ω > Ω > k.v) in partially degenerate (i.e., for T F ≥ T and T ≠ 0) electron plasma under long wavelength limit (ω ≫ k.v). Due to the inclusion of weak quantum degeneracy the relativistic Fermi–Dirac distribution function is expanded under the relativistic limit ( m 0 2 c 2 2 p 2 < 1 $\frac{{m}_{0}^{2}{c}^{2}}{2{p}^{2}}{< }1$ ) to perform momentum integrations which generate the Polylog functions. The propagation characteristics and shifting of cutoff points of the extraordinary mode are examined in different relativistic density and magnetic field ranges. The novel graphical results of extraordinary mode in relativistic quantum partially degenerate (for μ T = 0 $\frac{\mu }{T}=0$ ), nondegenerate (for μ T ≈ − 1 $\frac{\mu }{T}\approx -1$ ) and fully/completely degenerate (for μ T ≈ $\frac{\mu }{T}\approx $ 1) environments are obtained and the previously reported results are retraced as well.


2013 ◽  
Vol 25 (2) ◽  
pp. 107-118 ◽  
Author(s):  
A. M. Abd-Alla ◽  
S. M. Abo-Dahab ◽  
R. D. El-Semiry

2021 ◽  
Author(s):  
Muhammad Awais ◽  
Muhammad Shoaib ◽  
Muhammad Asif Zahoor Raja ◽  
Saba Arif ◽  
Muhammad Yousaf Malik ◽  
...  

Abstract In current study, analysis is presented for peristaltic motion of applied magnetic field and entropy generation within couple stress (Cu/H2O) nanofluid through an endoscope. An endoscope contains two coaxial cylindrical tubes in which the internal tube is nonflexible while the external tube has sinusoidal wave passing through the boundary. Influences of mixed convection along with applied magnetic field are encountered as well. Formulated governing model is fabricated introducing long wavelength and creeping Stokesian flow approximation which are then analyzed numerically by utilizing Adams Bashforth method. For a physical insight, results are demonstrated to examine the behaviors of flow profiles and entropy generation number for emerging flow parameters with the help of graphs, bar-charts and tables.


Author(s):  
И.А. Ларкин ◽  
Ю.Н. Ханин ◽  
Е.Е. Вдовин

The behavior of the photocurrent in GaAs / AlAs p-i-n heterostructures is studied in a magnetic field parallel to the heterolayers in the wavelength range from 395 to 650 nm. A strong dependence of the non-oscillating component of the photocurrent on the radiation wavelength associated with the suppression of the diffusion current by the magnetic field was found. It is shown that the behavior of the oscillating component of the photocurrent in a magnetic field does not depend on the wavelength of light and is determined by the transfer of electrons through the dimensional quantization level in a triangular near-barrier well. It is shown that the suppression of the oscillating component by the magnetic field is due to the smearing of the level in the triangular well due to the motion of electrons parallel to the walls of the well and perpendicular to the magnetic field.


1993 ◽  
Vol 155 ◽  
pp. 341-341
Author(s):  
K. Justtanont ◽  
M. J. Barlow ◽  
C. J. Skinner

We report 10 and 20μm spectroscopic observations of four C–rich post–AGB objects which exhibit the unidentified emission feature at 21μm. The observations were carried out in October 1990 and May 1991 using CGS3 on UKIRT. The spectral resolutions were 70 for the wavelength range of 7.4–13.3μm and 80 for the region between 15.4–24.1μm. Three of the sources reported here are from the list of Kwok, Volk & Hrivnak (1989), i.e., IRAS 04296+3429; IRAS 07134+1005 and IRAS 22272+5435. Figure 1 shows the full spectrum of IRAS 04296+3429 and IRAS 22272+5435. The 10μm spectra of these objects exhibit UIR bands whose peaks all fall longwards of the usual peak wavelengths associated with such features. This may be related to the fact that they are the lowest excitation objects so far found to exhibit UIR emission bands. We also found narrow emission features superimposed on the long wavelength wing of the 21μm emission bands of IRAS 04296+3429 and IRAS 22272+5435. The fourth object we observed, SAO 163075, was found to also exhibit a (weak) 21μm emission feature. However, there is no PAH features in the 10μm region, apart from the plateau at 12μm.


2000 ◽  
Vol 14 (16) ◽  
pp. 1633-1650
Author(s):  
K. SUGAWARA ◽  
N. ARAI ◽  
A. KOUZUKI ◽  
S. ICHIMURA ◽  
H. NAOI ◽  
...  

The non-resonant microwave absorption (NRMA) measurements have been intensively performed for superconducting thin films of YBa 2 Cu 3 O y fabricated on MgO (100) substrates and powder samples of LaSrCuO systems. In order to complement the study, we also review the NRMA of BiSrCaCuO system. A particular attention has been paid to the following phenomena: (i) phases, (ii) effect of current, (iii) directional effect of applied magnetic field, (iv) hysteresis, (v) microwave power absorbed as a function of magnetic field, (vi) linewidth in the vicinity of T c , and (vii) modulation amplitude effect. A preliminary study on ( La 0.98 Dy 0.02)1.85 Sr 0.15 CuO 4 was also reported.


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