تعلیمی نظام کی اصلاح کے بارے میں امام بخاری کا نظریہ

 Bukhari was an exemplary teacher. His teaching experiments, advices, and valuable analysis are beneficent even today. As he is famous for being expert in Ahaadeth (Muhadis), he is being ignored in the field of education.  His thoughts, described in Kitabul Ilm of Sahi Bukhari can be used to reform an education system. According to his advices, a teacher should be vocal, should understand and consider psychology of students. He should make groups of students on the basis of their intelligence, and should assign assignments to students to make them more confident. About questions asked by students during teaching, Imam says this is not beneficial. Teachers also should not be upset with proper questions asked by students. No one can become expert with his own study without consultation with an expert of the field.  Reading without the guidance of a teacher may be unhealthy.  Imam stressed even beginner students to do hard work and travel for research, and academic work.  To get knowledge and access to reliable teachers admission in an institution and fulfilling of all the requirements are necessary.  Imam Also considered women education necessary.  According to him women can get benefits only when their system is separate from men. Kitabul Ilm of Bukhari consists of advices for education system reforms. These advices can be used to reform the present education system. Purpose of this article is to analyze Imam Bukhari’s thoughts about education for understanding good and bad things in education.

Reflect Arrays for High Gain Applications

This research work focuses on design and analysis of low-cost, single-layer broadband reflectarrays for X-band applications. Traditionally, parabolic reflectors and phased arrays were introduced to obtain the high gain. The disadvantages associated with traditional antenna types include: narrow bandwidth, high fabrication cost and complex feed networks. Recently, reflectarray antennas have been developed to overcome the disadvantages associated with parabolic reflectors and phased arrays. High gain reflectarray antennas are typically employed in radars, satellite communication and direct broadcasting applications. Four different type of delay-lines integrated reflectarray elements which include: single circular delay-line, pair of circular delay-lines, quad-meander and T-shape delay-lines are designed to obtain a broad linear phase range, high gain and good aperture efficiency. The reflectarray unit element performance is investigated in terms of phase range, Transverse Electric (TE) and Transverse Magnetic (TM) modes and far-field radiation patterns. The reflectarray unit element is analyzed by using circuit model technique and equivalent circuit results are verified through High Frequency Structure Simulator (HFSS™). The circuit model technique replaces the lengthy full-wave simulation of FEM method. This method provides fast and accurate calculation of electromagnetic parameters i.e. magnitude and phase range. The unit element shape and configurations are used to extract the lumped parameters and reflection characteristics. The reflectarray antenna system contains a feed horn antenna and an arrangement of phase shifting array elements. A hybrid Finite Element Boundary Integral (FEBI) method is used for electromagnetic modeling of reflectarray antenna system. The FEBI method provides accurate electromagnetic analysis of complex and medium-to-large sized structures. The reflectarray far-field radiation characteristics are obtained by using the hybrid FEBI method. The reflectarray antenna system model comprises of feed horn antenna and array of phase shifting elements. The feed horn antenna and array elements are designed separately. The effect of the incident angle, feed-to-diameter ratio and transmission modes can easily be considered in the FEBI based system simulations. The proposed reflectarray prototypes are fabricated and measured on a low-cost FR-4 substrate. The reflectarray antenna measurements are made in anechoic chamber. A gain of more than 20 dBi is realized for the proposed reflectarray configurations. The simulated and measured cross polarizations and side-lobe-levels are below -20 dB in all design configurations. More importantly, simulated results are in good agreement with the measured results.