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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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نجیب الرحمن عثمانی

آہ!ہماراچھوٹا بھائی
نجیب الرحمان عثمانی کاانتقال پر ملال
دل ودماغ رنج وغم اورصدمہ میں ڈوباہوا،ہاتھ کانپ رہاہے،قلم لرزرہاہے یہ لکھتے ہوئے کہ میرا پیارالاڈلا چھوٹابھائی نجیب الرحمن عثمانی اس دنیا میں نہیں رہا موت کے ظالم ہاتھوں نے اس کی روح قبض کرلی ہے اور وہ زندگی سے لڑتا ہوا بالآخر موت کی آغوش میں ہمیشہ ہمیشہ کی نیند سوگیا ہے۔انا ﷲ وانا الیہ راجعون۔
اب کیا لکھوں کیا نہ لکھوں طبیعت سخت پریشان ہے اورگہرے رنج میں ڈوبی ہوئی ہے کہ میرا چھوٹا بھائی کس طرح مسلسل دوسال تک بستر علالت پر اور تقریباً۸ماہ تک ڈائیلاسسز پرموت وزندگی کی کشمکش میں مبتلا رہا اور پھر ۲۷/ ستمبر۱۹۹۹ء کی شب کوہم کوروکتا بلکتا ہواچھوڑ کر اس دنیا سے اس دنیا میں چلا گیا۔ہر زندگی کے لیے موت مقدرہے کسی کو آگے جانا ہے اورکوئی پیچھے چلاجاتاہے جانا سب ہی کوہے مگر بہت سی موتیں زندوں کے لیے ہمیشہ کے لیے رنج وصدمہ کاباعث بن جاتی ہیں۔برادرخوردنجیب الرحمان عثمانی ہم سب کاپیارا تھا، چہیتا تھا،ماں باپ کا توتھا ہی لاڈلا،ماں باپ کے بعد ہم سب نے اس کی محبت اپنے سینوں میں بٹھا لی تھی وہ ہماری آنکھوں کاتارا بن گیا تھا۔ یہ کیاخبر تھی کہ موت اسے اس قدر جلدہم سے چھین لے جائی گی کہ ہم دیکھتے رہ جائیں گے روتے بلکتے ہوئے اس کی موت کے صدمہ سے بلبلا کر چیخ پڑیں گے۔
نجیب الرحمان عثمانی عرف بڑے میاں قبلہ اباجان حضرت مفکر ملت مفتی عتیق الرحمان عثمانی ؒ کے سب سے چھوٹے اورلاڈلے بیٹے تھے اﷲ پاک نے خوبصورت بنایاتھا ماں کا بھی چہیتا تھا اورپھر اس کے ظاہری حسن کے ساتھ باطن میں خوبیاں ہی خوبیاں بھررکھی تھیں۔عجز وانکساری میں اپنے قابل احترام باپ ہی کی طرح تھے۔علم وقابلیت میں نمایاں جوہر تھے، جامعہ ملیہ اسلامیہ سے نمایاں نمبروں کے ساتھ ایم ۔اے...

حضرت مولانا حماد اللہ ہالیجوی کی زندگی کا علمی جائزہ

Allah Almighty is the creator of the whole universe. He bestowed wisdom and intellect to humanbeings. He sent his prophets for their guidance. Prophets taught how to worship Almighty Allah by heart and serve humanity. After Prophets, it is the responsibility of religious scholars to guide people to the right way. Islam also explicitly encourages inward reform. Sub continent Indo-Pak has the privilege of being the gateway of Islam, as well as the benefit of great Islamists and brave people. The great scholars of Islam, Ulama, Hufaaz, Writers, Researchers, Intellectuals, Scientists and saints got birth on this pure land. These great personalities served their religion Islam with their self-determinations and eliminated the darkness of ignorance and eliminated the darkness of misguidance. Such great human lives and their educational, religious and literary activities have been documented, as the next generation could be aware of their great hostilities, writings and made their lives and their experiences as a model for themselves. Maulānā Ḥamadullah Ḥālajwī is one of them. He was a prominent pious Islamic scholar, researcher and a saint. He spent his whole life to follow the commands of Almighty Allah and the teachings of Holy Prophet (PBUH). He adapted his life according to the Sunnah. He used to do everything according to the Sunnah. He was a master of good personality and good character. His words were full of wisdom. During his meeting or statement, it seemed as if there was a sea of ​​knowledge, whose ripples were visible in his sermons. He used to make great arrangements for payment of religious duties. He was very pious and devout. His life is an ideal life and his religious and academic services are unpredictable. Practicing the Sunnah had become his mark and identity. He urged others to follow the commands of Allah and His Messenger (PBUH). Sitting in the company of such pious saints is also considered in worship. The bigger his personality, the more humble and controversial he was. This is actually the identity of a mediator and scholar. He was oceans of knowledge and action. The vacuum created by his death takes a long time to fill. Such individuals survive for centuries.

Studies on the Removal of Pesticide Residues from Various Vegetables Through Traditional Processing Methods

Pesticides are used in agriculture to safe guard the crops and new vegetation/plantation against pests, diseases, and weeds. Vegetable crops are usually attacked by insect pests round the year from seedling stage up to maturity of the crop because of their attractive colors. The insects, pests cause high damage to the production. It is observed that these pests destroy nearly half of the world''s agricultural crops which not only affects the yield and economy but also leads to lesser economic returns to farmers coupled with decreased supply of food to huge population. It therefore warrants to enhance the yield of crops to feed the ever growing population particularly in developing countries. The study was conducted in two parts. In the first part, the selection of pesticides was carried out through the survey conducted in six districts of lower Sindh to assess the knowledge, perception and use of pesticides amongst farmers. It was observed that farmers were using 27 different types of pesticides belonging to different groups. Out of these, six were most commonly and frequently used. It was further observed that farmers were not applying pesticides in recommended doses, time, frequency, safety interval after last spray and were also not following safety measures during pesticides spray on the crops. Sixty dealers (10 from each district) were allowed to participate in the survey. Questions were asked from the pesticide dealers as per structured questionnaire and it was noticed that 2 dealers of total (3.34%) were postgraduate, 34 (56.66%) were graduate and 15 dealers (25%) had education up to secondary level and 9 dealers (15%) had education up to middle. Majority of the pesticide dealers were not agricultural graduates but these dealers got briefings periodically from pesticide sales representatives of different companies. These sales representatives are competent agriculture graduates with specialization in plant protection, entomology, plant pathology or agronomy. Pesticide companies and other agricultural representatives periodically visited pesticide dealers in different areas explained briefly and provided literature in the form of leaflets and brochures mostly in the local language (Sindhi/Urdu) and/or English of pesticide products. Twenty seven dealers (45%) of them on a quarry replied that they did nothing for the use or reuse of the expired products, whereas 19 dealers (31.67%) returned the pesticides to the respective companies after expiry date, 3 dealers (5%) of them threw them away, whereas 11dealers (18.33%) buried them in the soil. It was also observed that 66.67% farmers demanded the pesticides most frequently in the Kharif season (summer) than in Rabi season (winter) i.e., 33.33% from the pesticide dealers. About 22 dealers explained that there is a high demand of pesticides on cauliflower crop (36.67%) followed by brinjal (25%), tomato (16.67%), bitter gourd (11.66%) and onion (10%). Pesticide dealers further explained that most of the farmers demanded endosulfan (35%) followed by imidaclopride (21.67%), bifenthrin (20%), prefenofos (11.67%), emamectin benzoate (8.33%) and diafenthiuron (3.33%). Five (8.33%) famers brought slips for the pesticide purchase, while 95 (91.67% pesticides were purchased on the recommendation of pesticide dealers. Fifty seven (95%) dealers briefly explained the use of pesticides to the farmer regarding pesticide usage and 34 (56.67%) dealers informed the farmers regarding residual effects of pesticides. The spray of pesticide depended upon many factors such as the price of vegetable in the market, advice from the fellow farmers, pesticide sales representative, etc. 96 (80%) of farmers had their own decision to spray, but 4 (3.33%) farmers have other sources such as Neighbors, Agriculture extension workers, Agriculture Research and Pesticides agents. The time of spray by 49 farmers (40.83%) was in the morning, whereas 71 farmers (59.17%) sprayed in the evening. Only 5 farmers (4.17%) used the protective cloths in winter but in summer they did not use because of high temperature and high moisture and 115 farmers (95.83%) farmers did not use the protective clothes & tools in lower Sindh. They put off shoes deliberately while spraying. For increasing the effect of pesticides, farmers also used the mixed pesticides as suggested to them by different sources such as Agriculture extension department, Pesticides dealer or by their own decision. About 118 (98.33%) farmers had used the mixed pesticides on their crop in which 92 farmers (76.67%) farmers’ source was pesticides dealer. Answers about interval between pesticide application and harvest depended on farmer’s need of vegetables not on the kind of the pesticides. In the second part, in order to reduce the risk of vegetables poisoning due to residues, the study was conducted on farmer’s field to reduce the pesticide residues from vegetables through various traditional processing being practiced at various homes of Sindh province of Pakistan. Five vegetables i.e. onion, cauliflower, bitter gourd, brinjal and tomato were grown on farmers field and were sprayed with different insecticides/pesticides at recommended dosages. Onion was harvested one week after the application of pesticides, while cauliflower, bitter gourd, tomato and brinjal were harvested one day after the spray of pesticides. After harvesting, the samples were packed in polythene bags, labeled and brought to the laboratory of Institute of Food Sciences and Technology for traditional processing such as plain water washing, detergent washing, blanching, salt washing, drying under sun and in cabinet dehydrator and boiling/frying etc. The samples were further processed for extraction, clean up and analyses. The results revealed that some traditional processing methods were mildly effective and others were highly effective. Plain water washing reduced the residues up to 45% whereas, detergent water washing deceased it up to 50%. The blanching treatment of vegetable further removed the pesticide residues up to 60%. The washing was followed by sun drying, drying in cabinet and dehydrator and/or frying which reduced the pesticide residues by more than 80% from all the five vegetables and were found highly effective. The results further suggest that every traditional method played its significant role in reducing the residues depending upon the kind of vegetables and the type and nature of pesticides. Commercially produced samples of all the vegetables taken from Hyderabad market were found contaminated with residues of more than one pesticide and most of the samples contained residues above their respective MRLs. It is therefore, concluded from the study that traditional/house hold processing methods play a significant role in reducing the insecticides/pesticides. However, indiscriminate use of pesticides and lack of good agricultural practices lead to residue problems in vegetables and the consumption of pesticide residue contaminated vegetables may cause severe health haz