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Three Wave Interactions in Non- Degenerate and Degenerate Magneto-Plasmas

Thesis Info

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Author

Shahid, Muhammad

Program

PhD

Institute

Government College University

City

Lahore

Province

Punjab

Country

Pakistan

Thesis Completing Year

2008

Thesis Completion Status

Completed

Subject

Physics

Language

English

Link

http://prr.hec.gov.pk/jspui/bitstream/123456789/2194/1/2755S.pdf

Added

2021-02-17 19:49:13

Modified

2024-03-24 20:25:49

ARI ID

1676727609719

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In this thesis we study the parametric decay instability problem (three wave interactions) in classical andquantummagneto‐plasmas.Twocombinationsofthethreewaveinteractionshavebeen investigated.First,theparametricdecayinstabilityofupperhybridwaveintolow‐frequency electromagnetic shear Alfven wave and Ordinary mode radiation has been solved in an electron‐ion plasma immersed in uniform external magnetic field. Incorporating quantum effect due to electron spin, the fluid model has been used to investigate the linear and nonlinear response of the plasma species. It is shown that the spin of electrons has considerable effect on the three‐wave coupling interactions even in classical regime. Secondly,theelectronspin‐1/2effectsontheparametricdecayinstabilityofobliqueLangmuir waveintolow‐frequencyelectromagneticshearAlfvenwaveandleft‐handedcircularlypolarized wave(LHCP)hasbeeninvestigatedinanelectron‐ionquantumplasmaimmersedinuniform external magnetic field. Incorporating the quantum effects due to electron spin, Fermi pressure and Bohmpotentialterm,thequantummagneto‐hydrodynamic(QMHD)modelhasbeenusedto investigatethelinearandnonlinearresponseoftheplasmaspeciesforthree‐wavecoupling interactionina quantummagneto‐plasmas.Nonlineardispersionrelationsandgrowthrateshave been derived analytically. It has been shown that the spin of electrons has considerable effect on the growth rate of parametric instability problem even when the external magnetic field B0 is below the quantum critical magnetic field strength BQ = 4.4138 ×1013 G. Finally,theparametricdecayinstabilityofobliqueLangmuirwaveintolow‐frequency electromagnetic shear Alfven wave and LHCP have also been investigated in high density (quantum) and low density (classical) magneto‐plasma environments. QMHD model has been used to find the linear and non‐linear response of the high density quantum magneto‐plasma, and to compare the (h → 0, Pe → Pte ) results with the low density classical plasma we have used classical limit in the results of QMHD model. Nonlinear dispersion relations and growth rates of the problem have been derived analytically. The growth rate both for quantum and classical magneto‐plasma environments has been plotted. The normalized growth rate as a function of number density in the high density degeneratemagneto‐plasmasincreasesexponentiallywhileinthelowdensityclassicalmagneto‐ plasmas it increases logarithmically.
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خودی نہ بیچ غریبی میں نام پیدا کر

خودی نہ بیچ غریبی میں نام پیدا کر
نحمدہ ونصلی علی رسولہ الکریم امّا بعد فاعوذ بااللہ من الشیطن الرجیم
بسم اللہ الرحمن الرحیم
معززصدر ومیرے ہم مکتب ساتھیو!
آج مجھے جس موضوع پر اظہار خیال کرنا ہے وہ ہے:’’خودی نہ بیچ غریبی میں نام پیدا کر‘‘
جنابِ صدر!
مجدی و سروری ہر ایک کی خواہش رہی ہے، ہر ایک نے اس کی تمنا کی ہے، ہر ایک نے اس کے شجر سایہ دار میں بیٹھنے کا عندیہ ظاہر کیا ہے، ہر ایک کے دل میں اس کی آواز نے انگڑائیاں لی ہیں ، یہ ایک ایسی تمنا ہے جس کے کئی متمنی نظر آتے ہیں، یہ خواہش قبر تک پیچھا کرتی ہے۔
صدرِ ذی وقار!
نام پیدا کرنا کوئی بڑی بات نہیں ہے، نا موری کے تاج کو اپنے سر پر سجا نا عظمت ہے معروف ہو نا قابل صد تحسین ہے، اس کو بنظر تحسین دیکھا جاتا ہے، اس تصور کے حامل افراد قابلِ قدر ہوتے ہیں، اس کی تمنا عظیم لوگوں کا شیوہ رہا ہے۔
محترم صدر!
وہ ناموری جوذلت کا باعث ہو ، وہ سروری جوتحقیر کا باعث ہو، وہ رفعت جس سے پاؤں کٹتے ہوں ، وہ اُولوالعزمی جس سے لمحات زیست ظلمت کدہ ہوں ، وہ ناخدائی جو آب میں غرق ہونے کا سبب بنے ، وہ عزت جو کسی کو ذلیل کر ے، اس سے کنارکشی ہی بہتر ہے۔
اے طائر لاہوتی اس رزق سے موت اچھی
جس رزق سے آتی ہو پرواز میں کوتاہی
صدرِذی وقار!
خود دار انسان معاشرے کے ماتھے کا جھومر ہوتا ہے، خوددار انسان کی نشست و برخاست معیاری ہوتی ہے۔ خوددار انسان کی گفت و شنید میں ایک تنوع ہوتا ہے، خوددار پر انسانیت ناز کرتی ہے، خوددارلوگ ملک وقوم کی ترقی میں ایک اہم کردار ادا کرتے ہیں ،...

القاضي عياض: حياته وآرائه في علم الحديث

ABSTRACT: Qazi Ayaz was one of the great scholars in the Knowledge of Hadith. He enjoys a unique status in his memory, narration and understanding of Hadith. He has vast knowledge of chains of Hadith, its transmitters, and their biographies. For acquiring this high position he always travelled to get the Hadith from its well-known experts, and used utmost care in getting the authentic chains of transmitters, so much so that he is considered an authority among the great scholars ofHadith. The methodology of Ayaz in the science of the transmission of Hadith is based upon research, accuracy and authentication ofthe text. He considers the science of transmission and narration. The origin and essence in authenticating the Hadith. He was strict in the criticism of the text of Hadith and emphasized on the narration of the Prophet’s words instead of allowing the narration of the meanings, unlike the other scholars of Hadith. Hence he held some special views, due to his long experience in Hadith. Some of his views are about: The comparison with the original hearing. The appropriate age while transmitting Hadith toothers. The omitting ofrepeated words in Hadith. The usage of the marks of dialect in the text ofHadith. The permission in narration ofthose Hadith about which he himselfdoes not have permission

Expression Profiling of Cotton Fiber Genes and Evaluation of Some Regulatory Sequences for Gene Expression in Dicots

Cotton fiber is the most important raw material used in textile industry throughout the world. Due to demand of good quality fiber for manufacture of fabrics, there is need to develop cotton varieties with improved fiber characteristics. Through conventional breeding, a number of cotton varieties have been developed. However, this technique has disadvantage of narrow germplasm and requirement of longer time period for selection of best lines. Using genetic engineering techniques, fiber genes may be directly introduced in cotton which may express under the control of certain promoters. Through gene expression profiles, tissue and developmental stage specific expression level of genes can be determined. Gene those have been expressed specifically in fibers or other tissues may be transformed to alter various characters. Upstream regulatory regions of theses gene may also be evaluated as promoter. Fully characterized promoters can be used as component of expression cassette for crop improvement through molecular breeding. Cotton fibers are unicellular seed trichomes and the largest known plant cells. Fiber development in cotton is a complex process involving a large number of genes expressed during each fiber development stage. The objective of the study was to determine expression level of fiber related genes in cotton. The expression level of eight fiber related genes (EXPANSIN, tubulins, LTP1, LTP3, LTP7, E6, SPS, and susy) was determined in cotton tissues using reverse transcriptase real time PCR. Three cotton (Gossypium hirsutum) lines of varying fiber length were used to study the effect of genotypes on gene expression. The results revealed that transcription level of most of genes elevated from 5 to 20 DPA fibers. All genes showed similar expression pattern in all three genotypes. However, EXPANSIN was found to be highly expressed in long fiber variety during rapid elongation period than in medium and short fiber length. Sucrose synthase showed high expression in 15-20 DPA fibers and roots. Expression data may help also to explore the role of particular gene in fiber development. On the basis of expression profiles, two genes (SPS and LTP7) were selected. Upstream sequences of both genes were retrieved through high through put genomic sequences (HTGS) and analyzed using bioinformatics tool. About 2 kb region upstream of SPS and 1.8 kb upstream of LTP7 gene were selected for promoter isolation. Patent BLAST results of SPS and LTP7 promoter sequences confirmed that both were novel regulatory regions. Analysis of both promoter sequences using plantCARE revealed basal promoter elements including TATA box and CAAT box. There were various light regulated motifs, MYB binding sites and stress related motifs. Various motifs related to transcription activation and tissue specific expression were also identified in both promoters. Analysis of promoter sequences using plantPAN identified binding sites for transcription factors including MYBS, ERELEE4, GAREAT, ABRELATERD1 and WBOXNTERF3. Both SPS and LTP7 promoters along with their deletion fragments were isolated from genomic DNA of cotton leaves. A 1.5 kb deletion fragment for SPS promoter was cloned in expression vector. Two 5′ deletion fragments for LTP7 promoter (1 kb and 1.5 kb) were also cloned. Transient GUS expression assay revealed that full length SPS and LTP7 promoters were active in fiber tissues. Deletion derivatives (1.5 kb) of both promoters showed relatively weak GUS expression in fiber tissues. However, 1 kb LTP7 promoter was highly active in fiber tissues. No GUS expression was detected in root, shoot and leaf tissues. Agrobacterium mediated transformation in tobacco revealed that SPS promoter exhibited GUS stain in tobacco leaves in the form of patches while its 1.5 kb deletion fragment showed much low expression. Full length LTP7 promoter along with 1 kb LTP7 showed high vascular tissues specific expression in tobacco leaves. The novel promoters may be used to derive fiber specific expression in cotton and vascular tissues specific expression in heterologous system. The indigenous promoters can be used for specific expression of transgenes without IPR issues.