Search or add a thesis

Advanced Search (Beta)
Home > Solitary Structures in Space Plasmas With Non-Maxwellian Electron Distributions

Solitary Structures in Space Plasmas With Non-Maxwellian Electron Distributions

Thesis Info

Access Option

External Link

Author

Khalid, Saba

Program

PhD

Institute

Government College University

City

Lahore

Province

Punjab

Country

Pakistan

Thesis Completing Year

2020

Thesis Completion Status

Completed

Subject

Physics

Language

English

Link

http://prr.hec.gov.pk/jspui/bitstream/123456789/12109/1/Saba%20khalid%20physics%202020%20gcu%20lhr%20prr.pdf

Added

2021-02-17 19:49:13

Modified

2024-03-24 20:25:49

ARI ID

1676727186911

Similar


The objective of this study is to investigate linear and nonlinear propagation of kinetic Alfven waves (KAWs) and coupled kinetic Alfven-acoustic (CKAA) waves in non Maxwellian plasmas. Theoretical frame works that employed Maxwellian, kappa and Cairns distributions could not explain observations of flat top and spiky distributions. Generalized (?, ?) distribution function encompasses both low energy and high energy parts of the observed velocity distributions and provides good quantitative fits of the observed data. KAWs has been observed to play an important role in acceleration and heating of plasma particles in space and laboratory plasmas. The study is carried out by using two-potential theory and solitary structures are obtained by applying Sagdeev potential approach. A comprehensive study has been carried out to ascertain how the formation of compressive and rarefactive solitary structures of KAWs and CKAA waves depend on the low and high energy parts of the electron distribution function. It has been shown that out results agree well with Fast and Freja observations of the nonlinear KAWs. An important feature of our study is the formation of rarefactive solitary structures. The analysis of compressive and rarefactive solitary structures of CKAA waves reveals that flat top at low energies of the electron distribution are responsible for the formation of compressive solitary structures whereas the spikes at low energies allow the formation of both compressive and rarefactive solitary structures. We have extended our investigations of CKAA waves for electron-positron-ion (e-p-i) plasmas, particularly highlighting the role of nonthermal electrons and positrons following generalized (?, ?) distribution. The significance of this study is to emphasize the existence of density dip solitons for spiky distribution at low energy. The relevance of the study presented in this thesis with reference to astrophysical, space and laboratory plasmas has also been discussed.
Loading...
Loading...

Similar Books

Loading...

Similar Chapters

Loading...

Similar News

Loading...

Similar Articles

Loading...

Similar Article Headings

Loading...

47. Muhammad/The Prophet Muhammad

47. Muhammad/The Prophet Muhammad

I/We begin by the Blessed Name of Allah

The Immensely Merciful to all, The Infinitely Compassionate to everyone.

47:01
a. Those who disbelieve and obstruct others from pursuing the Path of Allah,
b. HE will let all of their good deeds go waste,
c. so they will find no reward for these in the realm of the Hereafter.

47:02
a. While HE will erase impieties and sinful trespasses of those who:
- believe, and
- practice righteousness, and
- believe in what has been sent on to Muhammad The Prophet - The Qur’an, and
- that it is the Truth from their Rabb - The Lord, and
b. HE will absolve them of their evil deeds and also set aright their hearts and improve their
spiritual situation.

47:03
a. That is so because those who disbelieve they follow the falsehood,
b. while those who believe they follow The Truth - The Qur’an - from their Rabb - The Lord.
c. That is how Allah gives people precepts of wisdom by similitudes of themselves.

47:04
a. Whenever you encounter in the battlefield those who disbelieve, then strike their necks,
until, when you have overpowered them, then hold them firmly as prisoners of war.
b. Thereafter, you can either free them graciously or hold them to ransom against payment or in exchange of Muslim captives, until the battle lays down its burdens.
c. That is the rule!
d. Yet if Allah so willed, HE alone would have defended HIMSELF against them,
e. but HE allows fighting so that some of you may be tested by means of others in the
battlefield.
f. As for those who would...

Study of Pragmatic Losses in the English Translation of Surah Al Ikhlas: A Comparative Pragma-Linguistic Analysis

The comprehension of the message of the Holy Qur’ān is obligatory for the whole of humanity which is revealed in the Arabic language. Scholars all over the world, Muslims as well as non-Muslims have devoted their best efforts to translate the word of Allah Almighty in different languages of the world, although absolute translation is not possible. These translations from Arabic to other languages of the world result into pragmatic losses. Small wonder, these pragmatic losses cause problems in the process of understanding the actual message of the Holy Qur’ān enshrined in the source text. This study was conducted to analyze the pragmatic losses in the English translations of Sūrah Ikhlāṣ (chapter 112) through a comparative pragma-linguistic analysis. Three different translations have been selected for the study. A comparative and critical study of these translations has established the presence of certain pragmatic losses which are likely to bear upon the comprehension of the reader in more than one way. To the researchers, the presence of these losses calls for the greater sensitivity towards and understanding of the pragmatic aspects of interlingual translation, specifically for a text which in its primordial form was intended to be a Speech (Kalām). To retain the pragmatic value and meaning of the source text become all the more paramount when the text translated is sacred one with its own canonical conventions and discursive norms.

Comparative Effects of Salicylic Acid and Calcium Carbide on Some Morphological and Physiological Parameters of Sweet Pepper

Calcium carbide (CaC2) has occupied an important position among different sources of ethylene (C2H4) for improving growth and yield of vegetables. Calcium carbide dependent C2H4 can cause noteworthy improvements in growth, yield and fruit quality of vegetables but its effect on physiological and morphological parameters of vegetables is completely concentration dependent. Under critical environmental conditions, an abrupt release of C2H4 from CaC2 can impede growth and yield of a crop as it initiates leaf, flower and fruit senescence and finally great loss of yields. However, CaC2 dependent released C2H4 can be more constructive and worthwhile for non-conventional production of vegetables if it is applied along with salicylic acid (SA). Salicylic acid not only impedes C2H4 biosynthesis but also plays a crucial role in plant physiology as a stress hormone. As comparative effects of C2H4 released from CaC2 and SA are not thoroughly investigated particularly for production of vegetables with improved quality, therefore, a series of laboratory, pot and field studies were conducted to scrutinize the effectiveness of CaC2 dependent C2H4 with and without application of SA for seed germination, physiological, morphological, yield and quality parameters of sweet pepper. Experiments were conducted in three sections. Section I, II and III consisted of four laboratory, three wire-house/pot and two field experiments, respectively. From first experiment of section-I, polyethylene and paint were selected as the most effective materials for coating CaC2. In second experiment of section-I, it was observed that CaC2 up to 14 mg plate-1 induced early seed germination with 100% germination rate and better seedling growth parameters but application of CaC2 ˃16 mg plate-1 inhibited seed germination and seedling growth parameters of sweet pepper. Similarly, results of third experiment of section-I revealed that SA concentration ≤0.4 mM can be used to improve germination percentage and seedling vigor of sweet pepper. In last experiment of section-I, it was noted that SA alleviated injurious effects of CaC2 with ˃16 mg plate-1 on seed germination and seedling growth parameters. In section-II, data revealed that 20 mg CaC2 kg-1 soil while 0.3 mM SA can be used for maximization of sweet pepper productivity. In last pot trial, effect of CaC2 with and without SA was investigated on growth, yield and fruit quality of sweet pepper under salinity stress. It was observed that detrimental effects of excessive C2H4 from CaC2 on physiology, photosynthesis, growth and yield of sweet pepper were mitigated by the foliar application of SA under saline conditions. On the basis of preliminary trials of section I and II, two field experiments were conducted on two different locations (section-III). Results of both field experiments showed that application of CaC2 along with foliar application of SA improved photosynthetic activity by 7-77%, plant water use and carboxylation efficiency by 10-211%, antioxidant and enzyme activities by 15-53% and finally fruit yield by 5-34% with a significant increase in fertilizer use efficiency compared to that of plants without SA and CaC2 application (control). Additionally, quality parameters related to chemical composition of sweet pepper fruits were also improved by the application of CaC2 with foliar application of SA. These parameters are very much required for improvement in shelf life. In short, results confirm the synergistic role of SA and CaC2 for improving physiology, growth, yield and quality of sweet pepper. Our results suggest that application of 200 mg plant-1 polyethylene coated CaC2 with foliar application 0.1 or 0.3 mM SA is relatively more economically beneficial and effective than application of 200 mg plant-1 polyethylene coated CaC2 without foliar application of SA. Moreover, results also indicated that SA treated plants were tolerated abrupt release of C2H4 from applied CaC2 to a greater extent.