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Linear and Nonlinear Phenomena in Semiconductor Plasma Like Medium

Thesis Info

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Author

Noureen Ch, Uzma

Program

PhD

Institute

Government College University

City

Lahore

Province

Punjab

Country

Pakistan

Thesis Completing Year

2011

Thesis Completion Status

Completed

Subject

Physics

Language

English

Link

http://prr.hec.gov.pk/jspui/handle/123456789/1931

Added

2021-02-17 19:49:13

Modified

2024-03-24 20:25:49

ARI ID

1676726585134

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Linear and nonlinear phenomena in semiconductor plasma like medium have been discussed in this thesis. The first chapter starts with the brief account of plasma related media, waves in plasma, methods of treating weak nonlinearity and basic phenomena of parametric instability and ion-implantation. All of these have been employed in the research papers included in this thesis. In the second chapter the phenomena of stimulated Brillouin scattering (SBS) has been examined in an un-magnetized piezoelectric semiconductor using quantum- hydrodynamic (QHD) model. It is seen that Bohm potential plus Fermi pressure have significantly improved the growth rate of stimulated Brillouin scattering. It is further noted that the improvement in the growth rate of stimulated Brillouin scattering occurs at higher values of electron number density and wave number of electron-acoustic wave. The third chapter concerns with the detailed study of shielding static potential and oscillating far-field potential in an ion- implanted piezoelectric semiconductor. In this ion- implanted piezoelectric semiconductor the colloid ions act as test particles. The quantum effect introduced via Bohm potential associated with electrons and the electron-coupling effect, both contribute to the dielectric response function of semiconductor. The tighter binding of the electrons is noted because of the presence of quantum effect due to which the length of effective wake potential and radius of quantum Debby shielding both are found to be reduced. As a result, the formation of quasi-quantum lattice of colloid ions in semiconductor is reported on quantum scale. The formation of such quasi-quantum lattice can cause thorough changes in the properties of ion- implanted semiconductor. In forth chapter we deal with a composite medium and study the propagation of nonlinear coupled helicon-spin and Alfven-spin waves through the composite medium. Composite medium is a medium which exhibits the properties of both semiconductors and magnetic materials. Using reductive perturbation technique we find the nonlinear evolution equations for these coupled waves which are found to have soliton solutions. The limiting cases for the semiconducting and magnetic materials have also been discussed separately in this chapter. In the last chapter our medium of research is gaseous dusty plasma. We have investigated analytically the nonlinear decay instability of dust-acoustic wave (DAW) and low-frequency electromagnetic wave in a collision-less dusty plasma which is homogeneous as well as magnetized. We have derived the nonlinear response function for the plasma particles using coupled fluid and Maxwell’s equations and developed un-damped growth rate for three-wave parametric decay instability. It is found that in magnetized dusty plasma, a large amplitude dust-acoustic wave undergoes a considerable decay. The growth rate of the instability is found to be highly sensitive to the externally applied magnetic field, ion number density and electron/ion temperature etc. A vibrant application of this work has also been identified in the environment of dusty plasma in space. The references are in the end of the thesis.
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ہمایوں کبیر

ہمایوں کبیر
افسوس ہے کہ گذشتہ مہینہ ہمایوں کبیر صاحب نے انتقال کیا، وہ اس دور کے لائق ترین مسلمانوں میں تھے اور اپنے ذوق کے اعتبار سے علمی و تعلیمی لائن کے آدمی تھے لیکن انھوں نے سیاست کا پُر خار راستہ اختیار کیا، اس لیے اس میں کامیاب نہ ہوسکے، علمی و تعلیمی لائن میں وہ زیادہ مفید کام انجام دے سکتے تھے، ان میں بعض خامیوں کے باوجود اسلامی حمیت پوری طرح موجود تھی جس کا اظہار ان کی تقریروں میں ہوتا رہتا تھا، وہ مولانا ابوالکلام کے شعبۂ میں رہ چکے تھے، اس لیے دارالمصنفین سے بھی واقف اور اس کے بڑے قدردان تھے، چنانچہ انھوں نے مولانا کے بعد بھی دارالمصنفین کے کاموں میں بڑی مدد پہنچائی، اب جو اور جیسا مسلمان بھی اٹھتا ہے، اس کا بدل نہیں مل سکتا، اس لیے ان کی جگہ بھی خالی رہے گی، اﷲ تعالیٰ ان کی خامیوں اور خطاؤں سے درگذر کرکے ان کی مغفرت فرمائے۔ (شاہ معین الدین ندوی، ستمبر ۱۹۶۹ء)

 

An Empirical Evaluation of Budget Implementation on Economic Development in Nigeria

One of the primary goals of this study was to explore how a budget review approach may affect Nigeria's economic development. The reasoning was that the Nigerian economy was being challenged by a variety of imbalances in budget creation and implementation. The study strategy was based on events that occurred after the study was completed, and the data used in the study came from the Central Bank Statistical Bulletin and the Federal Ministry of Finance. A model was constructed based on both empirical and theoretical investigations in order to achieve this broad goal. The HDI, which was utilized as a measure of development, was the dependent variable in the model. The government's capital budget, recurrent budget, and the speed of annual budget implementation were the other independent variables in the model. They examined data using the Auto Regressive Distributed Lag (ARDL) Model, diagnostic tests such as the test of normality, auto correlation test, and heteroskedasticity test, which proved the validity and reliability of the model they chose; inferential results reveal that the use of budget evaluation had a positive and significant impact on the Nigerian economy. According to the study's suggestions, Nigeria's government should try to increase capital and recurrent expenditures in its annual budget, both of which have a significant impact on economic development. Finally, the government should work to build budget monitoring and review infrastructure that will aid in the effective implementation of large budget expenditures while also ensuring compliance with legal procedures.

Including the Excluded: A Case Study of an Inclusive Classroom in an Inclusive Education School in Karachi, Pakistan

The purpose of inclusive education is to value children with special needs, so that they can participate equally in all educational activities in a general school along with their peers without discrimination. There is a worldwide movement towards establishing inclusive educational settings for children who have not as yet received due attention from governments and the private sector. The Salamanca Conference (1994) focused on education of the child with special education needs. In this gathering, all governments of the world were to ensure the basic education of all children with and without special education needs (SEN) within the existing mainstream schools. Many developed countries have already worked on this critical issue. In the developing countries, much less initiatives have been taken to include children with SEN in the mainstream schooling systems. As a result, there is a dearth of research in this area (with the exception of studies on teachers' attitudes), and where efforts (have been) made, they lack enough support, direction and clarity towards inclusive education. In Pakistan, as in many other developing counties, the government has given more attention to the inclusion of girl child in the main stream educational system, as compared to inclusion of the child with SEN. Despite these difficulties, I found a private school in Karachi, Pakistan, which has taken initiatives for implement a policy of inclusion of all children in their school. This study set out to find the perceptions, classroom practices, interactions, facilitating and hindering factors within an inclusive classroom and their relationship with the practical steps that can be taken towards inclusive education. The study was a case study, where in- depth interviews and classroom observations were conducted. The class had three students with SEN, and the remaining 22 students had no special needs. It was found that the participants (teachers, co-ordinator, and principal) had positive attitudes towards inclusion. They perceived that inclusive education (IE) allows all children to share the same school and classroom. There was a two-sided interaction (negative and positive) between perceptions and practices. The study also found that more students with SEN could be accommodated in mainstream classroom than the current number through the existing practice, for example, students having physical handicaps or mild impairments are not particularly disruptive to the classroom. In the research questions, through this study, six major themes were extracted; and they have been analyzed and discussed in chapter four. The key findings