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Linear and Quasilinear Analysis of Parallel Propagating Electromagnetic Modes

Thesis Info

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Author

Sarfraz, Muhammad.

Program

PhD

Institute

Government College University Lahore

City

Lahore

Province

Punjab

Country

Pakistan

Thesis Completing Year

2017

Thesis Completion Status

Completed

Subject

Physics

Language

English

Link

http://prr.hec.gov.pk/jspui/bitstream/123456789/9520/1/Muhammad_Sarfraz_Physics_HSR_2017_GCU_Lahore_11.01.2018.pdf

Added

2021-02-17 19:49:13

Modified

2024-03-24 20:25:49

ARI ID

1676726585345

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In solar wind, the charged particles like electrons, protons, and alpha particles are detected to possess anisotropies in their temperatures. This skewness in their particles distributions acts as a source of free energies to excite di erent modes. These microinstabilities are known to be responsible for checking and limiting the upper levels of anisotropies, speci cally near 1 AU, and thus explains the observations made with spacecrafts more accurately. Previously, threshold conditions for these unstable modes operative under di erent circumstances were presented as an inverse correlation between temperature anisotropy, T?=Tk, and parallel plasma beta,k. These relations were deduced on the basis of linear theory combined with observationalttings, or by simulations like Particle in Cell methods. In present study, a macroscopic quasilinear approach is adopted in which these correlations naturally emerge. A set of self-consistent quasilinear kinetic equations is formulated for dynamical temperatures and wave energy densities, separately, for homogeneous and inhomogeneous solar wind medium. The solutions of these equations are not only giving us a dynamical picture of temperatures and wave energy densities, but also con rm inverse correlation between temperature anisotropy and parallel plasma beta atnal stages of numerical solutions. A bi-Maxwellian form of particle''s distribution is assumed all the time except that temperatures of solar wind species may vary in time t. The validity of same approximation is justi ed based on theoretical and simulations studies. Firstly, we have studied right-hand polarized electromagnetic electron cyclotron instability conditioned for T?e > Tke based on core/halo components model. The time asymptotic states of core and halo electrons temperatures along with wave energy density are displayed. Marginal stability curves, separately, for core and halo electrons populations are con rmed at the saturation stages of particles trajectories in ( k; T?=Tk) phase space. Secondly, a detailed quasilinear analysis of electronsrehose mode is carried out assuming dynamical ions. This left-hand polarized electromagnetic mode becomes excited for excessive parallel temperature i.e Tke > T?e, and is important for an upper check of solar wind temperatures along the ambient magneticeld. Time history of parallel electron anisotropy regulation, variations in ions heating, and associated wave energy density saturation is shown. Final stages of numerical plots of dynamical equations are corresponded to electronrehose and electromagnetic ion cyclotron marginal stability curves. Thirdly, in quasilinear frame-work, assuming dynamical ions and electrons in an inhomogeneous solar wind medium, an interplay of electron and proton instabilities is studied. We point it out as one of the mechanisms of an outstanding issue that, the majority of data points are observed in near isotropic state in phase space for protons species. In fact, this interplay of proton-cyclotron and electron rehose instabilities is leading a counter-balancing e ect which, in turn, prevents a further progression of solar wind protons towards marginalrehose state. At the end, the spatial damping for parallel propagating modes is also looked in degenerate environments employing a linear kinetic model. Foreld free case, a comparison of skin depth is made for degenerate and non-degenerate environments in di erent relativistic regimes. The role of ambient magneticeld is also characterized for these anomalous skin e ects.
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مولانا محمد ناظم ندوی

مولانا محمد ناظم ندوی
اخباروں سے یہ افسوس ناک خبر ملی کہ ماہ جون ۲۰۰۰؁ء مین مشہور عالم اور عربی زبان و ادب کے قابل ادیب و شاعر جناب مولانا محمد ناظم ندوی کا پاکستان میں انتقال ہوگیا۔ اِنا ﷲ وَاِنا اِلیہ رَاجِعونْ۔
وہ دارالعلوم ندوۃ العلماء کے اس روشن دور کی آخری نشانی تھے جو حضرت مولانا سید سلمان ندوی کی سرپرستی اور مولانا حیدر حسن خاں ٹونکی اور علامہ تقی الدین ہلالی مراکشی کی تربیت و محنت سے سب سے زیادہ فیضیاب ہوا، گزشتہ صدی کی تیسری، چوتھی دہائی میں مولانا مسعود عالم ندوی، مولانا سید ابوالحسن علی ندوی، مولانا عبدالسلام قدوائی ندوی، مولانا ابواللیث اصلاحی ندوی، مولانا محمد عمران خاں ندوی اور مولانا محمد اویس ندوی رحمہم اﷲ جیسے سیارگان علم و فضل ایک ہی وقت میں برج سلیمانی میں جمع ہوگئے تھے، مولانا محمد ناظم ندوی بھی اس مجموعہ نجوم کے تابناک ستارے تھے۔ انہوں نے خاص طور پر علامہ ہلالی مراکشی سے استفادہ کیا۔ اس باب میں وہ مولانا مسعود عالم ندوی اور مولانا سید ابوالحسن ندوی کے بعد ثالث ثلثہ ہوئے۔
بہار کا مردم خیز خطہ مونگیر ان کا وطن تھا، گھر اور پٹنہ کے مدرسہ شمس الہدیٰ میں تعلیم حاصل کرنے کے بعد وہ انیس بیس سال کی عمر میں دارالعلوم ندوہ میں اعلیٰ تعلیم کے لئے داخل ہوئے، فراغت حاصل کرنے کے بعد وہ ڈابھیل کی اس درس گاہ میں درس و تدریس کے لئے منتخب کئے گئے جو اس وقت مولانا شبیر احمد عثمانی اور مولانا محمد یوسف بنوری جیسے جلیل القدر علماء کی موجودگی سے مرکز نگاہ بنی ہوئی تھی، کئی سال گزارنے کے بعد وہ حضرت سید صاحب کی خواہش پر ندوہ میں عربی زبان و ادب کے استاد کی حیثیت سے واپس تشریف لائے اور تقسیم ہند تک یہیں رہے، پاکستان بنا تو انہوں نے...

العلوم الطبيعية في القرآن الكريم

Quran has deep relation with science. For Example Quran teaches us about the creation of the world, human being, all the living and nonliving things and its advantages and disadvantages. Quran also tells us about the different diseases and its cure. Now in the modern time the scientist are following the Quran for their scientific research. There are 13 hundred verses in Quran belongs to human thoughts. Just like this there are different explanation about the human’s health and food and these things are related to science. The Quran has presented knowledge about mountains, sea, water, air environment etc.

Production and Characterization of Pectinases by Aspergillus Niger for Industrial Use

Two hundred and sixteen fungal strains were isolated from two hundred fifty soil samples collected from different localities of Punjab and subjected to screening for their pectinolytic ability using submerged fermentation. One hundred and fifty one pectinolytic strains were subjected to secondary screening and isolate IIB-13 gave the maximum pectinase yield (10.78±0.45U/ml/min) and identified as Aspergillus niger using morphological characteristics. Random mutagenesis (physical and chemical) was used to improve the pectinolytic activity of strain IIB-13. Nitrous acid mutant H-97 resulted in three fold increase (32.16 + 0.05U/ml/min) in pectinase production. This H-97strain was further subjected to optimization of media, carbon and nitrogen sources, temperature and pH. Maximum pectinase (37.01±0.11 U/ml/min) was produced using medium containing K2HPO4 (4.0 g), yeast extract (0.6 g), KH2PO4 (1.28 g), (NH4)2SO4 (2.0 g), MgSO4 (1.1 g) and pectin (10 g) per 1.0 L of distilled water at pH and temperature (7.0 and 30°C) respectively after 60 hours of fermentation. Fermenter studies (7.5 L) resulted in increased pectinase activity (40.31±0.07 U/ml/min) with decreased incubation time of 48 h using 1% inoculums with optimized reaction conditions i.e. temperature (30°C), pH (07), agitation (200 rpm) and aeration (1vvm). Fermentation kinetics was applied to validate the results. The crude enzyme was subjected to purification by applying ammonium sulfate precipitation and Ion exchange chromatography which resulted in 44.20 % yield with increased activity i.e. 75.18±0.04 U/mg. Km value of 2.30 mg/ml using pectin as substrate showed its maximum specificity for the enzyme. Activation energy (Ea) i.e. -28.95 KJ/mol and enthalpy of activation (ΔH) i.e. -26.73 KJ/mol were calculated employing thermodynamic studies. Characterization of enzyme revealed catalytic activity optimum temperature and pH as 25°C and pH 7. The enzymes catalytic activity was observed to be reduced by some heavy metals such as Hg2+, Pb2+, Cu+ and Cd2+.