شاہ نادر خان
حادثۂ افغانستان
اکتوبر ۱۹۳۳ء میں افغانستان کو جاتے ہوئے، نومبر کے لئے جب میں شذرات قلمبند کررہا تھا تو یہ خیال نہ تھا کہ میری واپسی اس قدر جلد ہوگی اور اسی طرح ۳۰؍ اکتوبر کی صبح کو کابل سے روانہ ہوتے ہوئے یہ خیال بھی نہ تھا کہ ۸؍ نومبر ۱۹۳۳ء کو سہ پہر کو افغانستان میں یہ عظیم الشان واقعہ پیش آئے گا، ۳؍ نومبر کی رات کو غزنین و قندھار و چمن ہوکر میں اور ڈاکٹر سر اقبال کوئٹہ پہنچے اور میں ملتان میں دو روز ٹھہر کر ۸ کی دوپہر کو لکھنؤ پہنچا اور ۹ کی صبح کو شاہ نادر خاں کی شہادت کی وہ خبر سنی جس کا وہم و گمان بھی نہ تھا۔
افغانستان کی سرزمین ناگہانی سیاسی واقعات کے ظہور کے لیے ہمیشہ سے مشہور ہے، مگر آج جب دشمن ہر قدم پر کمین میں ہیں، اس قسم کے واقعہ کا پیش آنا حد درجہ افسوسناک ہے، افسوس اشخاص کی حیات و موت کا اتنا نہیں، جتنا افغان قوم کی حیات و موت کا ہے۔
ہم کو معلوم ہے کہ اس وقت ملک کی ترقی کے لئے وہاں کیا کیا تدابیر زیر غور تھیں، مگر افسوس کہ واقعات نے اب نیا پہلو بدلا ہے تاہم ہم کو امید ہے کہ موجودہ کار فرمایان حکومت کی دانشمندی سے مصیبت کی وہ بلائیں افغانستان کے سرسے دور ہوجائیں گی، جو اس وقت منڈلا رہی ہیں۔
دعا ہے کہ شاہ شہید کو مغفرت اور ملک کو امن و امان نصیب ہو۔
(سید سلیمان ندوی، نومبر ۱۹۳۳ء)
In sahih Bukhari the reform’s of Imam Bukhari are present in various styles and artistically sahih Bukhari is an eximious book. But in this present confab we want to disuses such a topic which is about the colligation of sahih Bukhari’s parts and order. The intellectual advisability and sequences called the order of the parlance, and some time many points are practical and various expediencies recondite in this order. With identity the object of the speaker is explicated e.g, he started the book with incipiency and it is brought first because the inspiration the provenance of admonition. He arranges “kitab-ul-Emam” of on the second because to have belief on Allah as “Rab” is the most preeminent and also the prerequisite. In the first Hdith انما الاعمال بالنيات is in the same order and we understand that candidness is not only enough in the outset but it should be obsessive on both the commencement and the verge. The advisability we understood is the deserts starts form intentness and suppress on the left. Imam Bukhari to words both radicals in the inception and completion of the book.
In the modern era of industrialization, power electronic converters have gained key importance due to their wide range of applications such as; use in arc furnaces, in duction heating systems, variable speed drives of motors, power supplies of various electronic systems, fluorescent lamps, elevators and cooling systems. Furthermore, the low-cost proliferation of power electronic devices due to the technological de velopments in the semiconductor industry has made them an attractive choice for integrating renewable energy resources. They are the essential and integral part of the systems providing solutions to issues like voltage sag, swell, frequency reg ulation, current sharing among different renewable energy resources, power factor correction and voltage regulation in different types of micro-grids. In all the above-mentioned applications, the robustness of the system under dif ferent load and line conditions depend upon the control algorithm of the power electronic converters. This is why the research in the field of power electronics has been focused on the control of power converters during the last decade. Among different types of control techniques, Sliding Mode Control (SMC) is renowned for its disturbance rejection and parameter invariant nature which makes it an irre sistible choice for controlling such systems. However due to physical constraints of the switching components, ideal condition of infinite frequency cannot be sat isfied. This causes the system to operate at finite but time varying switching frequency which is a serious issue for power electronic converters as they consist of passive components whose size and value depends upon the switching frequency. Moreover, the time varying switching frequency degrades the power quality and causes electromagnetic interference (EMI) issues in case of grid connected power converters. In the first phase of this research, a fixed frequency sliding mode controller uti lizing an integral sliding manifold is designed to improve the dynamic response of the power converter regulating the grid voltage, in the presence of unknown x load condition and uncertain network parameter of the micro-grid. A special purpose test rig is designed to experimentally validate the results in comparison with conventional PI controllers. In the second phase of the research, the power quality issues regarding DC micro grids are addressed. Power quality issues have been widely discussed regarding AC power systems but discussion regarding DC power quality in micro-grids is rare in research community because in past power transmission was carried out using AC systems only. However, in the recent years DC grids and transmission has emerged as an attractive solution to integrate renewable energy resources. Hence, to enhance the power quality, a fixed frequency SMC is proposed with harmonic cancellation and chattering reduction, using a PI type sliding manifold. Experimental results are presented to validate the theoretical derivations using the test rig. Finally, a new method based upon filter extraction of the equivalent control is proposed to fix the switching frequency in power converters controlled by SMC. The technique is implemented on a boost converter and the results are presented in comparison with PWM-SMC. Rigorous mathematical analysis is provided along with experimental results to validate the proposed technique.