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Drift Effects on Plasma Waves

Thesis Info

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External Link

Author

Bashir, Muhammad Fraz

Program

PhD

Institute

Government College University

City

Lahore

Province

Punjab

Country

Pakistan

Thesis Completing Year

2014

Thesis Completion Status

Completed

Subject

Physics

Language

English

Link

http://prr.hec.gov.pk/jspui/bitstream/123456789/2224/1/2774S.pdf

Added

2021-02-17 19:49:13

Modified

2024-03-24 20:25:49

ARI ID

1676725925802

Similar


The full kinetic dispersion relation for the Geodesic acoustic modes (GAMs) including diamagnetic effects due to inhomogeneous plasma density and temperature is derived by using the drift kinetic theory. The fluid model including the effects of ion parallel viscosity (pressure anisotropy) is also presented that allows to recover exactly the adiabatic index obtained in kinetic theory. We show that diamagnetic effects lead to the positive up-shift of the GAM frequency and appearance of the second (lower frequency) branch related to the drift frequency. The latter is a result of modification of the degenerate (zero frequency) zonal flow branch which acquires a finite frequency or becomes unstable in regions of high temperature gradients. By using the full electromagnetic drift kinetic equations for electrons and ions, the general dispersion relation for geodesic acoustic modes (GAMs) is derived incorporating the electromagnetic effects. It is shown that m=1 harmonic of the GAM mode has a finite electromagnetic component. The electromagnetic corrections appear for finite values of the radial wave numbers and modify the GAM frequency. The effects of plasma pressure βe, the safety factor q and the temperature ratio τ on GAM dispersion are analyzed. Using the quantum hydrodynamical model of plasmas, the stability analysis of self-gravitational electrostatic drift waves for a streaming non-uniform quantum dusty magneto-plasma is presented. For two different frequency domains i.e., Ω0d<<ω<Ω0i (unmagnetized dust) and ω<< Ω0d < Ω0i (magnetized dust), we simplify the general dispersion relation for self-gravitational electrostatic drift waves which incorporates the effects of density inhomogeneity ∇n0α, streaming velocity v0α due to magnetic field inhomogeneity ∇B0, Bohm potential and the Fermi degenerate pressure. For the unmagnetized case, the drift waves may become unstable under appropriate conditions giving rise to Jeans instability. The modified threshold condition is also determined for instability by using the intersection method for solving the cubic equation. We note that the inhomogeneity in magnetic field (equilibrium density) through streaming velocity (diamagnetic drift velocity) suppress the Jeans instability depending upon the characteristic scale length of these inhomogeneities. On the other hand, the dust-lower- hybrid wave and the quantum mechanical effects of electrons tend to reduce the growth rate as expected. A number of special cases are also discussed.
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دورِ حاضر میں فنی تعلیم کی ضرورت

دور حاضر میں فنی تعلیم کی ضرورت
نحمدہ ونصلی علی رسولہ الکریم امّا بعد فاعوذ بااللہ من الشیطن الرجیم
بسم اللہ الرحمن الرحیم
معزز سامعین اور میرے ہم مکتب شاہینو!
آج مجھے جس موضوع پر اظہار خیال کرنا ہے وہ ہے:’’دور حاضر میںفنی تعلیم کی ضرورت‘‘
صدرِذی وقار!
علم ایک نور ہے، علم ایک روشنی ہے، علم ایک دولت ہے، علم ہی سے گلشن ہستی کے گل وگلزار میں تازگی اور طراوت ہے، علم ہی سے میدانِ حیات و زیست میں شاہسواری کی جاتی ہے، علم ہی کی بدولت آسمانِ علم و دانش پر آفتاب و ماہتاب بن کر چمکتا ہے۔
صدرِ محترم!
علم نام ہے واقفیت کا، علم نام ہے ادراک کا ،علم نام ہے شعور اور قویٰ کو پروان چڑھانے کا، علم سے زندگی ہے، علم ہی بندگی کا انداز سکھاتا ہے ،علم ہی سے نشت و برخاست کا ڈھنگ آتاہے، علم ہی سے لغت حجازی کا فرہنگ بنتا ہے، علم ہی سے تہذیب و تمدن کی فضاء ہموار ہوتی ہے۔
معززصدر!
علم کی ضرورت ہر دور میں رہی ہے ،علم ہی کی بدولت آج ہم اپنی تاریخ سے باخبر ہیں، علم جو بھی ہو انسان کو انسانیت سکھاتا ہے، اگر علم نافع ہے تو صاحب علم کی قدریں بڑھ جاتی ہیں، اگر علم غیر نافع ہے تو صاحب علم اپنے آپ کو محفوظ و مامون رکھتا ہے۔
معززصدر!
علم جب عقل و شعور کو منور کر کے اپنی روشنی کی کرنیں خارجی طور پر ظاہر کرتا ہے، صاحب علم کے اعضاء سے اس کا اظہار ہوتاہے، ایک غنی کی شکل اختیار کرتا ہے۔ ایک ہنر کی صورت میں نظر آتا ہے۔ تو اس وقت اس کی اہمیت کو چار چاند لگ جاتے ہیں، معاشرے میں خوشحالی کے دروازوا ہو جاتے ہیں، غربت و افلاس کا خاتمہ...

ملت ابراہیمی کے احیاء کےلیے حضرت عبدالمطلب کی کاوشیں قرآن کی روشنی میں : ایک تحقیقی مطالعہ Efforts of Hazrat Abd al-Muṭṭalib for the Revival of Millat-e-Ibrāhimī in the Light of the Qur’ān: An Exploratory Study

This exploratory study delves into the remarkable efforts of Hazrat Abd al-Muttalib, the revered grandfather of the Holy Prophet Muhammad, in rejuvenating the Millat-e-Ibrahimi, the Abrahamic faith, in pre-Islamic Arabia. This study investigates the pivotal role played by Hazrat Abd al-Muttalib in preserving and strengthening the monotheistic beliefs of his forefathers, Abraham and Ishmael, against the backdrop of a polytheistic society. Drawing from historical accounts, oral traditions, and early Islamic sources, the research uncovers the strategies and initiatives employed by Hazrat Abd al-Muttalib to foster unity among the disparate Arabian tribes and uphold the principles of monotheism. This study sheds light on a crucial yet often understudied period in Islamic history, exploring the legacy of Hazrat Abd al-Muttalib as a precursor to the prophethood of his grandson, the Holy Prophet Muhammad. By examining his actions and their impact, it provides valuable insights into the early foundations of the Islamic faith and the broader context of religious development in the Arabian Peninsula. Keywords: Hazrat Abd al-Muṭṭalib, Millat-e-Ibrāhimī, Abrahamic faith, Pre-Islamic Arabia, Monotheism, Revival efforts, Arabian tribes۔

Studies on Synchronization of Estrus and Timed Artificial Insemination Protocols in Non-Descript Cattle Bos Indicus of Azad Jammu and Kashmir

Artificial insemination (AI) after estrus induction is one of the best reproductive bio-techniques that will help in progressing animal agriculture into the new era. Reproductive efficiency of cow and heifer is an important factor that influence the profitability of any dairy enterprise. Different experiments were conducted to compare the efficacy of estrus synchronization protocols through estrus response and fertility rate in cattle during non-breeding and breeding seasons. Determination of time of ovulation and ovulatory response through peripheral LH surge, progesterone (P4) rise and follicular dynamics were also studied during non-breeding season. A total of 312 non-descript cows and heifers (averaging 3 to 4 years) with body condition score (BCS) ranges between 3.0 to 3.5 were randomly assigned to receive Ovsynch, CIDR alone and CO-Synch+CIDR protocols. Animals were inseminated at 16 h after the injection of second GnRH in Ovsynch, and 48 h after CIDR removal in CIDR inserted groups. The duration of induced estrus in non-descript cows was similar (P = 0.79) to natural estrus whereas, the duration of standing heat was significantly (P < 0.05) increased in induced cows (9.69 ± 0.62 h) compared to non-induced cows (6.66 ± 0.80 h). The results revealed that the Ovsynch protocol was slightly better in terms of inducing heat and enhanced the conception rate (CR) in indigenous cows under farm (87.5%) and field (50.0%) conditions during non-breeding season. In case of non-descript heifers, duration of induced estrus with an average of 18.63 ± 1.03 h, similar (P > 0.05) to natural estrus (18.00 ± 1.58 h). However, a significant difference (P < 0.05, t(18)= 2.515) was observed between the duration of induced (10.63 ± 0.60 h) and natural (8.25 ± 0.73 h) standing heat. It was observed that treatment with CO-Synch+CIDR enhanced the CR at timed artificial insemination (TAI; P > 0.05) in indigenous heifers under farm (50.0%) and field (33.33%) conditions during non-breeding season. To achieve further improvements in results, hormonal analysis and ultrasonography were performed to determine the time of ovulation and to establish the AI at a fixed time without the need for estrus detection. A better synchronous LH peak was observed in Ovsynch group (48.40 ± 0.40 h post PGF2α administration) compared to CIDR alone (71.67 ± 9.74 h) and CO-Synch+CIDR (54.86 ± 4.71 h) protocols. The ovulatory response was induced in 100% cows with Ovsynch and CO-Synch+CIDR protocols as indicated by LH surge and progesterone level; only 83.33% cows responded to CIDR alone treatment during non-breeding season (P > 0.05). The mean follicular diameter (13.98 ± 1.15), growth rate (1.43 ± 0.15) and ovulation rate was highest (100%) with Ovsynch treatment compared to CIDR alone and CO-Synch+CIDR, but the difference was non-significant (P > 0.05). The interval between PGF2α and ovulation was shorter in Ovsynch (77.0 ± 6.0 h) group compared to CIDR alone (93.60 ± 10.32 h) and CO-Synch+CIDR (79.20 ± 2.93 h) groups. The interval between LH surge and ovulation was 28.50 ± 5.85 h, 24.80 ± 7.31 h and 22.0 ± 5.55 h in Ovsynch, CIDR alone and COSynch+ CIDR groups respectively. During breeding season, CR/TAI was similar (47%) in all groups of non-descript cows under field conditions. It was observed that CO-Synch+CIDR treatment yielded the satisfactory (P < 0.05) conception rates under farm conditions compared to field conditions in non-descript heifers. The application of estrus synchronization protocols significantly (P < 0.0001) reduced the service period in non-descript cows and age at first calving in crossbred cows. It is concluded that during non-breeding season, Ovsynch can be an advantageous protocol for non-descript cows and CO-Synch+CIDR for heifers which showed good estrus expression and fertility, and thus, reduce the maintenance cost of dry animals, which in fact is of economic importance to the farmers. During breeding season conception rates at TAI were satisfactory in all groups of cows under field conditions. Treatment of cows and heifers with estrus induction protocols will yield acceptable pregnancy rates.