In this thesis we have discussed linear and nonlinear characteristics of drift waves, drift shock waves and coupled kinetic-acoustic Alfven waves in electron-ion plasma. Density of trapped electrons is calculated by using product bi (r,q) distribution. By using two potential theory for low ? assumption linear dispersion relation of coupled kinetic-acoustic Alfven wave is derived. The plot of linear dispersion relation of coupled kinetic-acoustic Alfven wave is compared for different distribution function. By employing Sagdeev potential approach solitary structures are observed only for sub Alfvenic mode. Considering inhomogeneity in electron-ion plasma linear dispersion relation drift wave is derived. The electrons follow product bi (r,q) distribution function. A comparison of the linear dispersion relation of ion drift wave is carried out for different electron distribution functions. It is observed that drift wave frequency is smaller for spiky distribution (? < 0), whereas its value is larger for flat topped distribution(? > 0). In the nonlinear regime solitary drift waves have also been investigated for different values of spectral indices ? ??? ?. For ? = 0 rarefactive solitary structures are are observed whose amplitude varies directly with the increase of high energy particles (increasing the value of ?). For flat topped distribution ? > 0 there exists only compressive solitons. For spiky distribution ? < 0 both compressive and rarefactive solitary strucures are observed. This is the unique characteristics of spiky distribution that is not observed with Maxwellian and Kappa distribution. Linear and nonlinear analysis of drift shock wave have also been done by considering dissipative effects. During linear analysis, it is observed that frequency of drift wave is significantly modified with the inclusion of disspative effects. Effect of variation high energy particle on the drift wave frequency is also observed. In the nonlinear regime, variation in the strength and steepness of positive and negative polarity drift shock waves are investigated for different values of ?, ?, temperature, magnetic field strength and collision frequency. The negative polarity drift shocks have been observed for only specific range of ? i.e. 0.5 > ? > −0.25 . For rest values of ? under condition ?(? + 1) > 3 positive polarity shocks have been observed. The strength and steepness of these positive polarity drift shocks have been found for different values of ?, different temperature and for different values of magnetic field strength. The results obtained in this thesis are general and can be applied to any region of space and interstellar medium.
پڑھائی خوشی دینے ، گفتگو کے نکھار اور قابلیت کو بڑھانے کے لیے مفید ہے۔ خوشی کے لیے اہم یہ ہے کہ آپ اپنے معمولات کی اچھی منصوبہ بندی کریں ، پھر یہ چاہے آپ کے فرصت کے اوقات کار ہوں، تنہائی ہو ، گفتگو کے نکھار کے لیے اپنی قابلیت کا بہتر استعمال ہو، آپ کو اس سے خوشی میسر آئے گی۔ اس لیے تجربہ کار انسان ہی اس پر عمل کر سکتےہیں اور شاید وہ انفردی معاملات کے بارے میں صحیح رائے رکھتے ہیں۔ لیکن پڑھے لکھے لوگ ہی معاملات کے بارے میں بہتر نصیحت، منصوبہ بندی اور انتظام کرتے ہیں۔ پڑھائی میں بہت زیادہ وقت صرف کرنا کاہلی ہے اور اس کا گفتگو کی سخاوت کے لیے بہت زیادہ استعمال بناوٹ ہے۔ فیصلہ کرنے کے لیے اس کے قوانین پر انحصار کرنا ایک سکالر کا مذاق اڑانا ہے ۔ وہ اس سے باشعور ہوتے ہیں اور تجربے سے ان کے شعور میں شگفتگی آتی ہے۔ فطری قابلیتوں کو پروان چڑھانے کے لیے ضروری کے کہ پودے کی طرح انسان کی بھی کانٹ چھانٹ کی جائے، پڑھائی سے ۔ خود سے پڑھ لینا کافی نہیں، یہ مبہم انداز میں آپ کی رہنمائی کرے گا ماسوائے اس کے کہ وہ تجربہ سے مل کر مفیدثابت ہوتا ہے۔ چالاک لوگ پڑھائی سے نفرت کرتے ہیں، سادہ لوگ اس کی تعریف کرتے ہیں اور عقل مند آدمی اس کا استعمال کرتے ہیں، کیونکہ پڑھائی نہیں سکھاتی کہ اسے کیسے استعمال کرنا ہے۔ لیکن یہ جو عقل ہے، یہ کتابوں میں نہیں ، ان سے بالاتر ہے اور یہ صرف مشاہدہ سے حاصل کی جاسکتی ہے۔ کتابوں کو نقطہ چینی یا رد کرنے کے لیے ، اہمیت دینے یا یقین کرنے کے لیے، اپنی گفتگو یا تقریر کے لیے مواد حاصل کرنے کے لیے نہیں بلکہ سمجھ کے لیے...
Allah Almighty has created everything in pairs. It is a scientific fact that these pairs exist in all things, in vegetable kingdom, even in inorganic matters. There is no doubt that these elements do not exist by themselves. The Holy Quran has mentioned repeatedly this fact in different verses. Marriage in Islam is a divine bond between husband and wife to enjoy the social relationship with each other and is a basic unit of Islamic family system. This article presents the structure of a Muslim Family in the light Islamic teachings.
Empirical research on the profitability of momentum investment strategies in emerging equity markets has presented mixed findings and therefore the momentum patterns in emerging equity markets have not been explained to the unanimous satisfaction of the researchers. This research examines the momentum returns and their determinants for stocks listed on Pakistan Stock Exchange using the data from 2001 to 2015. The analysis is also performed for the two sub-periods, from 2001 to 2007 and from 2009 to 2015, and the two sub-samples, financial firms and non- financial firms. Results show that over the complete sample period the momentum returns are positive and as high as the returns reported in early literature (for example, Jegadeesh & Titman, 1993), but they are not statistically significant. Similar results are obtained for the two sub-samples; however, for the two sub-periods, the momentum strategy yields completely contrasting results. For the first sub-period which experienced a high economic growth, low inflation and better governance, the momentum portfolios earned significant positive returns; whereas for the second sub-period which experienced a low economic growth, high inflation and poor governance, momentum returns are negative for most of the portfolios. Analysis also shows that momentum portfolios continue earning positive returns beyond the holding period indicating that the returns are not caused by temporary over- or under-reaction of investors in the market and they must be related to some systematic risk factors. However, the study does not find any evidence of relationship between beta and size factors and the momentum returns