Nirupama Devi - Academia.edu (original) (raw)
Papers by Nirupama Devi
Spontaneous giant pseudoaneurysm of right occipital artery: a case report
Indian Journal of Thoracic and Cardiovascular Surgery, 2021
Occipital artery pseudoaneurysm is a rare entity and few cases have been reported worldwide. Here... more Occipital artery pseudoaneurysm is a rare entity and few cases have been reported worldwide. Here, we are presenting a case of 32-year young lady with headache and a large swelling on the right side of the neck, without any history of trauma. Computed tomography (CT) angiogram revealed pseudoaneurysm of third part of the occipital artery. Excision of the pseudoaneurysm was performed with ligation of the occipital artery.
Journal of Evidence Based Medicine and Healthcare, 2020
BACKGROUND Incidence of Coronary Artery Disease (CAD) is increasing day by day. Cardiac rehabilit... more BACKGROUND Incidence of Coronary Artery Disease (CAD) is increasing day by day. Cardiac rehabilitation is an important aspect of management of Coronary Artery Disease. Anuloma Viloma Pranayama is beneficial to cardiac patients as it increases parasympathetic activity and lowers blood pressure and respiratory rate. This study was designed to assess the benefit of Anuloma Viloma Pranayama as rehabilitation therapy in post Coronary Artery Bypass Grafting (CABG) surgery patients. Parameters of pulmonary function test (PFT) were measured before and after 3 months of performing CABG. METHODS The study was carried out in the Department of Cardiothoracic and Vascular Surgery, CARE Hospital, Visakhapatnam, Andhra Pradesh, in collaboration with Department of Psychology and Parapsychology and yoga village of Andhra University. CAD patients admitted to the hospital for CABG procedure were included in the study. Thirty patients were selected for performing pranayama (cases) and 30 patients were ...
Studies of solitary waves in plasma
Nonlinear Wave Modulation and Stability Criteria for Strongly Dispersive Ion-Acoustic Waves
AIP Conference Proceedings, 2008
We have derived the Nonlinear Schrödinger Equation (NLSE) for strongly dispersive ion-acoustic pl... more We have derived the Nonlinear Schrödinger Equation (NLSE) for strongly dispersive ion-acoustic plasma waves taking into consideration the electron inertia effect through the parameter Q ( = me/mi, the ratio of electron to ion mass). In the present studies, the NLS equation is obtained by the modified reductive perturbation method and the derived equation is studied for the nonlinear wave modulation and the stability criteria. The parameter Q leads to higher dispersion compared to the case of electrons considered as Maxwellian. Consequently stronger nonlinearity comes into play for the studies of solitary wave propagation. In short it can be said that electron inertia effect modifies the nonlinear and dispersive coefficients of the NLS equation. The coefficient of the nonlinear term in the NLS equation turns to be complicated owing to the presence of electron mobility. A parametric range is obtained for angular frequency (omega) and the wave number k in order to get the stable region. It is found that instability occurs for small values of k due to electron inertia effect. A progressive wave type of solution of the NLS equation is obtained and plotted numerically to observe the modulation of nonlinear wave structure. Also a steady state solution of the NLS equation is derived.
Indian Journal of Pure Applied Physics, 2004
Mathe mati cal Scie nces Di vis ion, In stitute o f Ad vanced Stud7 in Sc ie nce
Studies on the formation of large amplitude kinetic Alfvén wave solitons and double layers in plasmas
Physics of Plasmas, 2007
... 70, 594 1994. 8A. Hasegawa and K. Mima, Phys. Rev. Lett. ... Peratt, Physics of the Plasma Un... more ... 70, 594 1994. 8A. Hasegawa and K. Mima, Phys. Rev. Lett. ... Peratt, Physics of the Plasma Universe Springer, New York, 1992, p. 120. FIG. 8. Amplitude N and width vs kz is plotted for different values of Q 1, respectively. 012107-5 Studies on the formation of large amplitude??? ...
Bulletin of Mathematical Sciences and Applications, 2012
Nonlinear wave structure of ion acoustic disturbances is investigated in magnetized plasma consis... more Nonlinear wave structure of ion acoustic disturbances is investigated in magnetized plasma consisting of warm ions and two electron components, namely hot and cold. The basic set of fluid equations for the flow variables is reduced to a single equation known as Sagdeev Potential (SP) equation using non perturbative approach. The properties of solitary wave structures are studied by pseudo potential method, which is valid for arbitrary amplitude. The amplitude of the solitary waves and the depth of the potential well are found to decrease with the increase of the direction-cosine of the wave propagation. The ranges of temperature ratios (ion to electrons) for the existence of solitary waves and their effects on the plasma medium are studied in detail and presented graphically for different sets of plasma parameters.
Nonlinear waves to study the evolution of collapsed soliton and its radiation
Planetary and Space Science, 2004
It has been shown that the Korteweg–de Vries equation, derived in inhomogeneous plasma, finds dif... more It has been shown that the Korteweg–de Vries equation, derived in inhomogeneous plasma, finds difficulty in obtaining the complete soliton solution and its propagation in plasma and thus fails to exhibit the actual nature of plasma acoustic-wave. The key here lies in the use of an approach, known as sine-Gordon method, which describes successfully soliton propagation along with its precursor.
Stability analysis and investigation of higher order Schrödinger equation for strongly dispersive ion-acoustic wave in plasma
Journal of Physics: Conference Series, 2010
Much interest was shown towards the studies on nonlinear stability in the late sixties. Plasma in... more Much interest was shown towards the studies on nonlinear stability in the late sixties. Plasma instabilities play an important role in plasma dynamics. More attention has been given towards stability analysis after recognizing that they are one of the principal obstacles in the way of a successful resolution of the problem of controlled thermonuclear fusion. Nonlinearity and dispersion are the two important characteristics of plasma instabilities. Instabilities and nonlinearity are the two important and interrelated terms. In our present work, the continuity and momentum equations for both ions and electrons together with the Poisson equation are considered as cold plasma model. Then we have adopted the modified reductive perturbation technique (MRPT) from Demiray [1] to derive the higher order equation of the Nonlinear Schrödinger equation (NLSE). In this work, detailed mathematical expressions and calculations are done to investigate the changing character of the modulation of ion acoustic plasma wave through our derived equation. Thus we have extended the application of MRPT to derive the higher order equation. Both progressive wave solutions as well as steady state solutions are derived and they are plotted for different plasma parameters to observe dark/bright solitons. Interesting structures are found to exist for different plasma parameters. Bibtex entry for this abstract Preferred format for this abstract (see Preferences) Find Similar Abstracts: Use: Authors Title Abstract Text Return: Query Results Return items starting with number Query Form Database: Astronomy Physics arXiv e-prints
One-dimensional motion of positive ions, negative ions and electrons leading to the propagation o... more One-dimensional motion of positive ions, negative ions and electrons leading to the propagation of K-dV soliton has been considered. Different aspects of soliton amplitude and width have been studied in relation to density ratio (r), mass ratio (Q') of the plasma medium. The role played by the temperature of the negative ions is critically considered to find possible regions of soliton radiation. It is also observed that there are two mutually opposite directions of wave propagation due to the presence of negative ions.
Non-linear coherent structures of kinetic Alfvén waves in plasmas with non-Maxwellian electrons and their relevance for space plasmas
Physics of Plasmas
Arbitrary amplitude double layers in warm dust kinetic Alfv�n wave plasmas
Phys Plasmas, 2008
Large amplitude electrostatic structures associated with low-frequency dust kinetic Alfvénic wave... more Large amplitude electrostatic structures associated with low-frequency dust kinetic Alfvénic waves are investigated under the pressure (temperature) gradient indicative of dust dynamics. The set of equations governing the dust dynamics, Boltzmann electrons, ions and Maxwell's equation have been reduced to a single equation known as the Sagdeev potential equation. Parameter ranges for the existence of arbitrary amplitude double layers are
Spontaneous giant pseudoaneurysm of right occipital artery: a case report
Indian Journal of Thoracic and Cardiovascular Surgery, 2021
Occipital artery pseudoaneurysm is a rare entity and few cases have been reported worldwide. Here... more Occipital artery pseudoaneurysm is a rare entity and few cases have been reported worldwide. Here, we are presenting a case of 32-year young lady with headache and a large swelling on the right side of the neck, without any history of trauma. Computed tomography (CT) angiogram revealed pseudoaneurysm of third part of the occipital artery. Excision of the pseudoaneurysm was performed with ligation of the occipital artery.
Journal of Evidence Based Medicine and Healthcare, 2020
BACKGROUND Incidence of Coronary Artery Disease (CAD) is increasing day by day. Cardiac rehabilit... more BACKGROUND Incidence of Coronary Artery Disease (CAD) is increasing day by day. Cardiac rehabilitation is an important aspect of management of Coronary Artery Disease. Anuloma Viloma Pranayama is beneficial to cardiac patients as it increases parasympathetic activity and lowers blood pressure and respiratory rate. This study was designed to assess the benefit of Anuloma Viloma Pranayama as rehabilitation therapy in post Coronary Artery Bypass Grafting (CABG) surgery patients. Parameters of pulmonary function test (PFT) were measured before and after 3 months of performing CABG. METHODS The study was carried out in the Department of Cardiothoracic and Vascular Surgery, CARE Hospital, Visakhapatnam, Andhra Pradesh, in collaboration with Department of Psychology and Parapsychology and yoga village of Andhra University. CAD patients admitted to the hospital for CABG procedure were included in the study. Thirty patients were selected for performing pranayama (cases) and 30 patients were ...
Studies of solitary waves in plasma
Nonlinear Wave Modulation and Stability Criteria for Strongly Dispersive Ion-Acoustic Waves
AIP Conference Proceedings, 2008
We have derived the Nonlinear Schrödinger Equation (NLSE) for strongly dispersive ion-acoustic pl... more We have derived the Nonlinear Schrödinger Equation (NLSE) for strongly dispersive ion-acoustic plasma waves taking into consideration the electron inertia effect through the parameter Q ( = me/mi, the ratio of electron to ion mass). In the present studies, the NLS equation is obtained by the modified reductive perturbation method and the derived equation is studied for the nonlinear wave modulation and the stability criteria. The parameter Q leads to higher dispersion compared to the case of electrons considered as Maxwellian. Consequently stronger nonlinearity comes into play for the studies of solitary wave propagation. In short it can be said that electron inertia effect modifies the nonlinear and dispersive coefficients of the NLS equation. The coefficient of the nonlinear term in the NLS equation turns to be complicated owing to the presence of electron mobility. A parametric range is obtained for angular frequency (omega) and the wave number k in order to get the stable region. It is found that instability occurs for small values of k due to electron inertia effect. A progressive wave type of solution of the NLS equation is obtained and plotted numerically to observe the modulation of nonlinear wave structure. Also a steady state solution of the NLS equation is derived.
Indian Journal of Pure Applied Physics, 2004
Mathe mati cal Scie nces Di vis ion, In stitute o f Ad vanced Stud7 in Sc ie nce
Studies on the formation of large amplitude kinetic Alfvén wave solitons and double layers in plasmas
Physics of Plasmas, 2007
... 70, 594 1994. 8A. Hasegawa and K. Mima, Phys. Rev. Lett. ... Peratt, Physics of the Plasma Un... more ... 70, 594 1994. 8A. Hasegawa and K. Mima, Phys. Rev. Lett. ... Peratt, Physics of the Plasma Universe Springer, New York, 1992, p. 120. FIG. 8. Amplitude N and width vs kz is plotted for different values of Q 1, respectively. 012107-5 Studies on the formation of large amplitude??? ...
Bulletin of Mathematical Sciences and Applications, 2012
Nonlinear wave structure of ion acoustic disturbances is investigated in magnetized plasma consis... more Nonlinear wave structure of ion acoustic disturbances is investigated in magnetized plasma consisting of warm ions and two electron components, namely hot and cold. The basic set of fluid equations for the flow variables is reduced to a single equation known as Sagdeev Potential (SP) equation using non perturbative approach. The properties of solitary wave structures are studied by pseudo potential method, which is valid for arbitrary amplitude. The amplitude of the solitary waves and the depth of the potential well are found to decrease with the increase of the direction-cosine of the wave propagation. The ranges of temperature ratios (ion to electrons) for the existence of solitary waves and their effects on the plasma medium are studied in detail and presented graphically for different sets of plasma parameters.
Nonlinear waves to study the evolution of collapsed soliton and its radiation
Planetary and Space Science, 2004
It has been shown that the Korteweg–de Vries equation, derived in inhomogeneous plasma, finds dif... more It has been shown that the Korteweg–de Vries equation, derived in inhomogeneous plasma, finds difficulty in obtaining the complete soliton solution and its propagation in plasma and thus fails to exhibit the actual nature of plasma acoustic-wave. The key here lies in the use of an approach, known as sine-Gordon method, which describes successfully soliton propagation along with its precursor.
Stability analysis and investigation of higher order Schrödinger equation for strongly dispersive ion-acoustic wave in plasma
Journal of Physics: Conference Series, 2010
Much interest was shown towards the studies on nonlinear stability in the late sixties. Plasma in... more Much interest was shown towards the studies on nonlinear stability in the late sixties. Plasma instabilities play an important role in plasma dynamics. More attention has been given towards stability analysis after recognizing that they are one of the principal obstacles in the way of a successful resolution of the problem of controlled thermonuclear fusion. Nonlinearity and dispersion are the two important characteristics of plasma instabilities. Instabilities and nonlinearity are the two important and interrelated terms. In our present work, the continuity and momentum equations for both ions and electrons together with the Poisson equation are considered as cold plasma model. Then we have adopted the modified reductive perturbation technique (MRPT) from Demiray [1] to derive the higher order equation of the Nonlinear Schrödinger equation (NLSE). In this work, detailed mathematical expressions and calculations are done to investigate the changing character of the modulation of ion acoustic plasma wave through our derived equation. Thus we have extended the application of MRPT to derive the higher order equation. Both progressive wave solutions as well as steady state solutions are derived and they are plotted for different plasma parameters to observe dark/bright solitons. Interesting structures are found to exist for different plasma parameters. Bibtex entry for this abstract Preferred format for this abstract (see Preferences) Find Similar Abstracts: Use: Authors Title Abstract Text Return: Query Results Return items starting with number Query Form Database: Astronomy Physics arXiv e-prints
One-dimensional motion of positive ions, negative ions and electrons leading to the propagation o... more One-dimensional motion of positive ions, negative ions and electrons leading to the propagation of K-dV soliton has been considered. Different aspects of soliton amplitude and width have been studied in relation to density ratio (r), mass ratio (Q') of the plasma medium. The role played by the temperature of the negative ions is critically considered to find possible regions of soliton radiation. It is also observed that there are two mutually opposite directions of wave propagation due to the presence of negative ions.
Non-linear coherent structures of kinetic Alfvén waves in plasmas with non-Maxwellian electrons and their relevance for space plasmas
Physics of Plasmas
Arbitrary amplitude double layers in warm dust kinetic Alfv�n wave plasmas
Phys Plasmas, 2008
Large amplitude electrostatic structures associated with low-frequency dust kinetic Alfvénic wave... more Large amplitude electrostatic structures associated with low-frequency dust kinetic Alfvénic waves are investigated under the pressure (temperature) gradient indicative of dust dynamics. The set of equations governing the dust dynamics, Boltzmann electrons, ions and Maxwell's equation have been reduced to a single equation known as the Sagdeev potential equation. Parameter ranges for the existence of arbitrary amplitude double layers are