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mass and charge number are given by = =10 and =10 − 10 ,
respectively [113, 143]. The dependence of the characteristics of the soli-
ton pulses such as wave phase velocity solitary pulse amplitude and
0
solitary pulse width ∆ on various plasma parameters (population of non-
thermal ions) (the negative charge number of hot dust )and (the
negative charge number of cold dust ) are studied. Also, the effect of
the cylindrical geometry on the acoustic solitary waves must be taken into
account. Figure (4.1) shows the variation of phase velocity with the
population of nonthermal ions and hot dust charge . It is clear that
increases with but decreases with . Plot of the soliton amplitude
against and is depicted in Fig. (4.2). Figure (4.2a) shows that
0
the compressive soliton amplitude decreases with both and This
0
means that the parameters and lead to the reduction of the solitary
pulse amplitude Also, , as shown in Fig. (4.2b). has a slight increase
0
0
with . On the other hand, Fig. (4.3) shows the dependence of soliton
width ∆ on and . It is seen that ∆ increases with both and
while decreases with .It is obvious that and make the soli-
tary potential profile much wider. According to the soliton picture, Fig.
(4.4) and Fig. (4.5) display the dust acoustic solitary profile in equa-
tion (4.12) with Θ, and at different time . It must be noted that
the soliton profile swerves towards the positive radial direction with the
increase of time. This behavior cannot be explored on neglecting and
Θ coordinates. However, it is noted that increasing the nonthermality of
ions produces positive-negative DA solitons as shown in Fig. (4.6). The
DA soliton profile is plotted in Figs. (4.7) with and Θ for two values of
=015 and =025. We see that negative DA soliton can exist for =015,
while =025 leads to the appearance of positive DA soliton. Also, these
figures show that how the position of pulse changes in the plane ( Θ)
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