Spectroscopic emission of lead plasma, generated by the fundamental （1064 nm） and second harmonics （532 nm） of a Q-switched pulsed Nd： YAG laser, is studied. The spectral lines of neutral atoms and singly ionized...Spectroscopic emission of lead plasma, generated by the fundamental （1064 nm） and second harmonics （532 nm） of a Q-switched pulsed Nd： YAG laser, is studied. The spectral lines of neutral atoms and singly ionized lead ions were shown predominantly. The profiles of neutral lead lines observed were used to extract the excitation temperature using Boltzmann plots, whereas electron number density was determined from the profile of Stark broadened line. The variations of excitation temperature and electron number density as a function of laser energy were studied.展开更多
The rheological features of an incompressible axi-symmetric Casson-Maxwell nanofluid flow between two stationary disks are examined.The lower permeable disk is located at z=-a,while the upper disk is placed at z=a.Bot...The rheological features of an incompressible axi-symmetric Casson-Maxwell nanofluid flow between two stationary disks are examined.The lower permeable disk is located at z=-a,while the upper disk is placed at z=a.Both the disks are porous and subjected to uniform injection.The fluid properties such as thermal conductivity vary with temperature.The Cattaneo-Christov thermal expression is implemented along with the Buongiorno nanofluid theory.By operating the similarity functions,the reduced form of the fluid model in terms of ordinary differential equations is obtained and solved by the bvp4 c numerical technique.The physical quantities are demonstrated graphically on the velocity and temperature fields.Three-dimensional flow arrangements and twodimensional contour patterns against several dimensionless variables are also sketched.The numerical values of the local Nusselt and Sherwood numbers for various quantities are presented in tabular set-up.The intensity of the linear relationship between the Nusselt and Sherwood numbers is assessed through Pearson’s product-moment correlation technique.The statistical implication of the linear association between variables is also examined by the t-test statistic approach.展开更多
We studied the spatial evolution of the Fe-Ni plasma generated by the fundamental （1064 nm） and second （532 nm） harmonics of a Q-switched Nd： YAG laser. The experimentally observed line profiles of the neutral ir...We studied the spatial evolution of the Fe-Ni plasma generated by the fundamental （1064 nm） and second （532 nm） harmonics of a Q-switched Nd： YAG laser. The experimentally observed line profiles of the neutral iron （Fe I） have been used to extract the plasma temperature （T e ） using the Boltzmann plot method, whereas the electron number density （N e ） has been deter- mined from the Stark broadening. In addition, we studied the spatial behavior of T e and N e with the variation of laser energy for iron plasma by placing the target material （iron-nickel alloy） in air at atmospheric pressure for both modes of the Nd： YAG laser.展开更多
基金financially supported by the Higher Education Commission (HEC) and Pakistan Science Foundation (PSF-134)MCS, National University of Sciences & Technology (NUST) for encouragement in terms of provision of time and financial support to carry out research work
文摘Spectroscopic emission of lead plasma, generated by the fundamental （1064 nm） and second harmonics （532 nm） of a Q-switched pulsed Nd： YAG laser, is studied. The spectral lines of neutral atoms and singly ionized lead ions were shown predominantly. The profiles of neutral lead lines observed were used to extract the excitation temperature using Boltzmann plots, whereas electron number density was determined from the profile of Stark broadened line. The variations of excitation temperature and electron number density as a function of laser energy were studied.
文摘The rheological features of an incompressible axi-symmetric Casson-Maxwell nanofluid flow between two stationary disks are examined.The lower permeable disk is located at z=-a,while the upper disk is placed at z=a.Both the disks are porous and subjected to uniform injection.The fluid properties such as thermal conductivity vary with temperature.The Cattaneo-Christov thermal expression is implemented along with the Buongiorno nanofluid theory.By operating the similarity functions,the reduced form of the fluid model in terms of ordinary differential equations is obtained and solved by the bvp4 c numerical technique.The physical quantities are demonstrated graphically on the velocity and temperature fields.Three-dimensional flow arrangements and twodimensional contour patterns against several dimensionless variables are also sketched.The numerical values of the local Nusselt and Sherwood numbers for various quantities are presented in tabular set-up.The intensity of the linear relationship between the Nusselt and Sherwood numbers is assessed through Pearson’s product-moment correlation technique.The statistical implication of the linear association between variables is also examined by the t-test statistic approach.
文摘We studied the spatial evolution of the Fe-Ni plasma generated by the fundamental （1064 nm） and second （532 nm） harmonics of a Q-switched Nd： YAG laser. The experimentally observed line profiles of the neutral iron （Fe I） have been used to extract the plasma temperature （T e ） using the Boltzmann plot method, whereas the electron number density （N e ） has been deter- mined from the Stark broadening. In addition, we studied the spatial behavior of T e and N e with the variation of laser energy for iron plasma by placing the target material （iron-nickel alloy） in air at atmospheric pressure for both modes of the Nd： YAG laser.
