scholarly journals Variation of mean value of velocity of ion with different obliqueness of magnetized plasma sheath

2020 ◽  
pp. 53-59
Author(s):  
B.R. Adhikari ◽  
H.P. Lamichhane ◽  
R. Khanal

Plasma sheath, which forms between a material wall and incoming plasma, plays an important role in controlling particle and energy fluxes to the wall. The problem of plasma sheath is one of the oldest in plasma and still draws attention, especially in magnetized plasmas. In this work velocity of ions in a magnetized plasma sheath has been studied using a kinetic trajectory simulation model for varying obliqueness of the field. Any change in obliqueness of the field causes the velocities to change. The change in mean value of the component normal to the wall is comparatively small whereas the other two components of velocity vary sinusoidally, nearly complementary to each other with nearly equal amplitudes.

AIP Advances ◽  
2019 ◽  
Vol 9 (5) ◽  
pp. 055123 ◽  
Author(s):  
Bhesha Raj Adhikari ◽  
Suresh Basnet ◽  
Hari Prasad Lamichhane ◽  
Raju Khanal

2019 ◽  
Vol 23 (1) ◽  
pp. 88-92
Author(s):  
B. R. Adhikari ◽  
S. Basnet ◽  
H. P. Lamichhane ◽  
R. Khanal

 Beat frequency and velocity variation of ions in a magnetized plasma sheath has been numerically investigated by using a kinetic trajectory simulation (KTS) model for varying obliqueness of the external magnetic field in presence of an electric field. Angular dependence of mean value, maximum amplitude, damping constant, frequency of oscillation and beat frequency have been studied. As the obliqueness of the field changes the mean values, beat frequency as well as the maximum amplitude of the velocity components also change but frequency of oscillation remains almost the same.


BIBECHANA ◽  
2021 ◽  
Vol 18 (1) ◽  
pp. 58-66
Author(s):  
R Chalise ◽  
S K Pandit ◽  
G Thakur ◽  
R Khanal

The understanding of the properties of magnetized plasma sheath has been various beneficial applications in surface treatment, electron emission gun, ion implantation, and nuclear fusion, etc. The effect of electron temperature on the magnetized plasma sheath has been studied for a fixed magnetic field and ion temperature. It has been observed that various plasma sheath parameters can be prominently altered by the varying temperature of the electron. The density of ion is influenced more by the change in electron temperature rather than the electron density. The temperature of the electron has a great effect at the wall, when electron temperature increases, the ion and electron densities at the wall decreases. This shows the potential at the wall also decreases follows the Poisson’s equation. Similarly, the electric field also decreases but total charge density increases when the electron temperature is increased. BIBECHANA 18 (2021) 58-66


1970 ◽  
Vol 6 (6) ◽  
pp. 4-7
Author(s):  
R Khanal

The effect of ion-induced electrons emission on the plasma sheath voltage for different values of ion induced electrons emission coefficients has been studied. Using a Kinetic Trajectory Simulation model of plasma sheaths, we calculate the particle densities reaching the wall and for given ion induced electrons emission coefficient the additional electrons emitted from the wall is obtained. Finally, the plasma sheath voltage (wall potential) is obtained by solving the Poisson equation. It has been observed that the potential decreases as the ion-induced electron emission coefficient increases as expected theoretically.Key words: Plasma; Quasineutrality; Debye Shielding; Sheath; Presheath; Bohm criterion.DOI: 10.3126/sw.v6i6.2625Scientific World, Vol. 6, No. 6, July 2008 4-7


2010 ◽  
Vol 26-28 ◽  
pp. 862-869
Author(s):  
Tao Peng ◽  
Zhi Peng Li ◽  
Chang Shu Zhan ◽  
Xiang Luo ◽  
Qian Wang

Through analyzing the process of brake, a dynamic model of automobile and a model of the relationship between braking distance and adhesion coefficient were formed; also a simulation calculating model of braking distance was established with the use of Matlab. Finally, a research was done toward the braking distance of a type of a car running on a road after using snow-melting agent. On one hand, with the application of the simulation model which has been established, calculations have been done to the braking distance of Bora vehicles running on roads after using deicing salt; on the other hand, by experiments, Bora vehicles’ braking distance and maximum braking deceleration under the same road condition were measured, meanwhile, the established simulation model was verified.


Author(s):  
Erfan Kazemi ◽  
Reihane Soldoozi Nejat ◽  
Fatemeh Ashkan ◽  
Hossein Sheibani

Abstract Background Abnormal laboratory findings are common in patients infected with severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2). The aim of this systematic review was to investigate the effect of the level of some laboratory factors (C-reactive protein (CRP), creatinine, leukocyte count, hemoglobin, and platelet count) on the severity and outcome of coronavirus disease 2019 (COVID-19). Methods We searched PubMed, Web of Science, Scopus, and Google Scholar. We collected the articles published before May 26, 2020. We gathered the laboratory factors in groups of patients with COVID-19, and studied the relation between level of these factors with severity and outcome of the disease. Results Mean CRP level, creatinine, hemoglobin, and the leukocytes count in the critically ill patients were significantly higher than those of the other groups (non-critical patients); mean CRP = 54.81 mg/l, mean creatinine = 86.82 μmol/l, mean hemoglobin = 144.05 g/l, and mean leukocyte count = 7.41 × 109. The lymphocyte count was higher in patients with mild/moderate disease (mean: 1.32 × 109) and in the invasive ventilation group (mean value of 0.72 × 109), but it was considerably lower than those of the other two groups. The results showed that the platelet count was higher in critically ill patients (mean value of 205.96 × 109). However, the amount was lower in the invasive ventilation group compared with the other groups (mean level = 185.67 × 109). Conclusion With increasing disease severity, the leukocyte count and the level of CRP increase significantly and the lymphocyte count decreases. There seems to be a significant relation between platelet level, hemoglobin, and creatinine level with severity of the disease. However, more studies are required to confirm this.


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