The Transitional Layer in the Mantle

2013 ◽  
pp. 676-682
Author(s):  
V. A. Magnitsky
Keyword(s):  
Transitional Layer

scholarly journals Resonant Instability of Kink Oscillations in Magnetic Flux Tubes with Siphon Flow

Solar Physics ◽  
2021 ◽  
Vol 296 (6) ◽  
Author(s):  
Michael S. Ruderman ◽  
Nikolai S. Petrukhin
Keyword(s):  
Flow Velocity ◽  
Resonant Absorption ◽  
Tube Axis ◽  
Magnetic Tube ◽  
Transitional Layer ◽  
Threshold Velocity ◽  
Flux Tubes ◽  
Resonant Instability ◽  
Constant Magnitude ◽  
Magnetic Flux Tubes

AbstractWe study kink oscillations of a straight magnetic tube in the presence of siphon flows. The tube consists of a core and a transitional or boundary layer. The flow velocity is parallel to the tube axis, has constant magnitude, and confined in the tube core. The plasma density is constant in the tube core and it monotonically decreases in the transitional layer to its value in the surrounding plasma. We use the expression for the decrement/increment previously obtained by Ruderman and Petrukhin (Astron. Astrophys.631, A31, 2019) to study the damping and resonant instability of kink oscillations. We show that, depending on the magnitude of siphon-velocity, resonant absorption can cause either the damping of kink oscillations or their enhancement. There are two threshold velocities: When the flow velocity is below the first threshold velocity, kink oscillations damp. When the flow velocity is above the second threshold velocity, the kink oscillation amplitudes grow. Finally, when the flow velocity is between the two threshold velocities, the oscillation amplitudes do not change. We apply the theoretical result to kink oscillations of prominence threads. We show that, for particular values of thread parameters, resonant instability can excite these kink oscillations.

scholarly journals Decayless Kink Oscillations Excited by Random Driving: Motion in Transitional Layer

Solar Physics ◽  
2021 ◽  
Vol 296 (8) ◽  
Author(s):  
M. S. Ruderman ◽  
N. S. Petrukhin ◽  
E. Pelinovsky
Keyword(s):  
Coronal Loop ◽  
Radial Displacement ◽  
Oscillation Amplitude ◽  
Radial Distance ◽  
Magnetic Pressure ◽  
Pressure Perturbation ◽  
Transitional Layer ◽  
Thin Boundary Layer ◽  
Plasma Displacement ◽  
Thin Tube

AbstractIn this article we study the plasma motion in the transitional layer of a coronal loop randomly driven at one of its footpoints in the thin-tube and thin-boundary-layer (TTTB) approximation. We introduce the average of the square of a random function with respect to time. This average can be considered as the square of the oscillation amplitude of this quantity. Then we calculate the oscillation amplitudes of the radial and azimuthal plasma displacement as well as the perturbation of the magnetic pressure. We find that the amplitudes of the plasma radial displacement and the magnetic-pressure perturbation do not change across the transitional layer. The amplitude of the plasma radial displacement is of the same order as the driver amplitude. The amplitude of the magnetic-pressure perturbation is of the order of the driver amplitude times the ratio of the loop radius to the loop length squared. The amplitude of the plasma azimuthal displacement is of the order of the driver amplitude times $\text{Re}^{1/6}$ Re 1 / 6 , where Re is the Reynolds number. It has a peak at the position in the transitional layer where the local Alfvén frequency coincides with the fundamental frequency of the loop kink oscillation. The ratio of the amplitude near this position and far from it is of the order of $\ell$ ℓ , where $\ell$ ℓ is the ratio of thickness of the transitional layer to the loop radius. We calculate the dependence of the plasma azimuthal displacement on the radial distance in the transitional layer in a particular case where the density profile in this layer is linear.

The Effect of Charge Redistribution on Flat-Band Voltage Turnaround in 4H-SiC MOS Capacitors

2017 ◽  
Vol 897 ◽  
pp. 167-170
Author(s):  
Hamid Amini Moghadam ◽  
Sima Dimitrijev ◽  
Ji Sheng Han ◽  
Daniel Haasmann
Keyword(s):  
Room Temperature ◽  
Flat Band ◽  
Gate Bias ◽  
Charge Redistribution ◽  
Flat Band Voltage ◽  
Transitional Layer ◽  
Mos Capacitors ◽  
Voltage Instability ◽  
Polar Species ◽  
Different Temperatures

The existence of a turnaround in flat-band voltage shift of stressed MOS capacitors, fabricated on N-type 4H–SiC substrates, is reported in this paper. The turnaround is observed by room-temperature C–V measurements, after two minutes gate-bias stressing of the MOS capacitors at different temperatures. The existence of this turnaround effect demonstrates that a mechanism, in addition to the well-stablished tunneling to the near-interface oxide traps, is involved in the threshold voltage instability of 4H–SiC MOSFETs. This newly identified mechanism occurs due to charge redistribution of the compound polar species that exist in the SiO2–SiC transitional layer.

CO2 electroreduction enhanced by transitional layer at cathode/electrolyte interface

2020 ◽  
Vol 451 ◽  
pp. 227743 ◽  
Author(s):  
Lixiao Zhang ◽  
Shiqing Hu ◽  
Wenping Li ◽  
Peng Zhang ◽  
Zhongwei Cao ◽  
...  
Keyword(s):  
Transitional Layer ◽  
Electrolyte Interface ◽  
Co2 Electroreduction

Laser Cladding of Ni-Based Alloy on Mg Alloy with Brass Transition

2011 ◽  
Vol 686 ◽  
pp. 197-201
Author(s):  
Qing Kun He ◽  
Hong Zhi Cui ◽  
Shao Hua Huang ◽  
Jin Quan Sun ◽  
Hong Guang Yang ◽  
...  
Keyword(s):  
Wear Resistance ◽  
Laser Cladding ◽  
Transition Layer ◽  
Corrosion Potential ◽  
Alloy Layer ◽  
Mg Alloy ◽  
Transitional Layer ◽  
Cladding Layer ◽  
Cu And Zn

Laser cladding of Ni-based alloy on Mg-alloy was achieved by using brass as transition layer on substrate. The Ni-based alloy layer free of cracks and porosities was bonded metallurgically with the Mg substrate using brass as the transitional layer. The Ni-based cladding layer was mainly composed of Cr2Ni3, FeNi3, AlNi3 while the content of Mg, Al, Cu and Zn is very low in the cladding layer. Microhardness and the wear resistance of the sample were tested, whose results indicated that microhardness and wear resistance increased 12.8 times and 13.3 times, respectively compared with the substrate. In addition, the corrosion potential (Ecorr) of the sample was much higher than that of untreated materials.

Analysis of Core-Candlestick Drill in Drilling Composite Materials

2009 ◽  
Vol 419-420 ◽  
pp. 337-340 ◽  
Author(s):  
Chung Chen Tsao ◽  
Kei Lin Kuo ◽  
I Chien Hsu ◽  
G.T. Chern
Keyword(s):  
Composite Materials ◽  
Thrust Force ◽  
Machining Process ◽  
Load Carrying Capacity ◽  
Reinforced Composites ◽  
Twist Drill ◽  
Cutting Mechanism ◽  
Transitional Layer ◽  
Ductile Metals ◽  
Load Carrying

Unlike ductile metals cutting mechanism, the interfaces between fiber and matrix as a transitional layer experience mismatched deformation in machining process. In general, the most frequent operation performed on composite materials is drilling with a twist drill to generate a hole owing to their versatility and low production cost. However, delamination is one of the most common defects in drilling laminated fiber-reinforced composites and can cause a significant reduction in the load-carrying capacity of a structure. At the periphery, using such special drills as saw drill, candlestick drill and core drill, reducible to causing delamination damage than the twist drill. Experimental results indicated that the diameter ratio and feed rate have statistical and physical significance on the thrust force obtained with a core-candlestick drill.

Study on the OLED with mutual doped transitional layer

2004 ◽  
Author(s):  
Meiping Jiang ◽  
Zhiyou Zhong ◽  
Dufang Shi
Keyword(s):  
Transitional Layer

Magnetotelluric response on vertically inhomogeneous earth having conductivity varying exponentially with depth

Geophysics ◽  
1982 ◽  
Vol 47 (1) ◽  
pp. 89-99 ◽  
Author(s):  
D. Kao
Keyword(s):  
Half Space ◽  
Apparent Resistivity ◽  
Bessel Functions ◽  
Homogeneous Layer ◽  
Modified Bessel Functions ◽  
Layer Model ◽  
Transitional Layer ◽  
Number Of Layers ◽  
Inhomogeneous Models ◽  
Electric And Magnetic Fields

Magnetotelluric (MT) response is studied for a vertically inhomogeneous earth, where conductivity (or resistivity) varies exponentially with depth as [Formula: see text]. Horizontal electric and magnetic fields in such an inhomogeneous medium are given in terms of modified Bessel functions. Impedance and apparent resistivity are calculated for (1) an inhomogeneous half‐space having conductivity varying exponentially with depth, (2) an inhomogeneous half‐space overlain by a homogeneous layer, and (3) a three‐layer model with the second layer as an inhomogeneous or transitional layer. Results are presented graphically and are compared with those of homogeneous multilayer models. In the case of resistivity increasing exponentially with depth, the results of the above inhomogeneous models are equivalent to those of Cagniard two‐layer models, with [Formula: see text]. In the case of resistivity decreasing exponentially with depth, the homogeneous multilayer approximation depends upon the number of layers and the layer parameters chosen; |Z/ωμ| as a function of frequency is more useful than the apparent resistivity in determining the values of p and [Formula: see text].

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