پروفیسر سید حسن مرحوم
افسوس کہ ۱۸؍ نومبر ۸۸ء کی صبح ۳۰:۸ بجے اردو اور فارسی کے نامور معلم محقق جناب پروفیسر سید حسن کا پٹنہ میڈیکل کالج میں انتقال ہوگیا، اناﷲ وانا الیہ راجعون۔ چند دنوں پہلے ان پر فالج کا حملہ ہوا تھا، انتقال کے وقت ان کی عمر تقریباً ۷۸ برس کی تھی۔
وہ ۱۹۱۱ء میں اپنے نانہالی گاؤں شیخ پورہ ضلع مونگیر میں پیدا ہوئے، اسی ضلع کا الہرہ گاؤں ان کا آبائی وطن تھا، یہاں کے سادات کا تعلق حضرت سید احمد جاجنیریؒ سے ہے، پروفیسر سید حسن کا خاندان بھی جاجنیری تھا، والدہ کا سلسلہ نسب حضرت مخدوم شیخ شعیبؒ برادر عم زاد حضرت شیخ شرف الدینؒ احمد یحییٰ منیری سے ملتا ہے، جب وہ ۷؍۸ سال کے تھے تو ان کے والد کا انتقال ہوگیا، لیکن ماں کی شفقت و تربیت نے یتیمی اور محرومی کا احساس نہ ہونے دیا اور نامساعد حالات کے باوجود وہ تعلیمی مراحل طے کرتے رہے اور مڈل، میڑک، انٹر اور پھر گریجویشن کے سارے امتحانات میں اول آئے، ۳۵ء میں اردو میں ۳۷ء میں فارسی میں ایم اے کیا، ۳۶ء میں انھوں نے ایجوکیشن میں ڈپلوما بھی لیا، بعد میں ۱۹۰۶ء میں انھوں نے دانش گاہ تہران ایران سے فارسی جدید، زبان پہلوی اور فارسی قدیم میں ڈپلوما حاصل کیا، طہران میں ڈاکٹر نذیر احمد اور پروفیسر سید امیر حسن عابدی وغیرہ بھی ان کے ساتھ تھے۔تعلیم ختم ہونے کے بعد ان کے مشغلہ تدریس کا آغاز ہوا، ۳۷ء میں بہار نیشنل کالج میں وہ فارسی اردو کے لکچرر مقرر ہوئے، ۷ سال کے بعد ۴۴ء میں پٹنہ کالج میں لکچرر مقرر ہوئے اور اسی کالج میں وہ ۵۰ء میں اسسٹنٹ پروفیسر اورچھ سال کے بعد ترقی کرکے ۶۱ء تک پروفیسر رہے، اسی عرصہ میں حکومت بہار نے عربی و فارسی میں مطالعہ و...
The ancient 5000 BCyears old Indus Valley Civilization, widely recognized as one of the most important early cities of South Asia. It is one of the world’s first cities and contemporaneous with ancient EgyptianCivilizations and Mesopotamian civilizations. Mohenjo-Daro is located west of the Indus Riveraround 28 kilometres (17 miles) from the town of LarkanaDistrict, Sindh, Pakistan. The Indus Valley civilization was entirely unknown until 1921. It was discovered in 1922 by R. D. Banerji, an officer of the Archaeological Survey of India, under the direction of John Marshall, K. N. Mohenjo-Daro does mean 'Mound of the dead'. It is the name given by the locals to the place. The total area of Mohenjo-daro is 620 acres. Numerous objects found in excavation include seated and standing figures, copper and stone tools, carved seals, balance-scales and weights, gold and jasper jewellery, and children's toys. Many important objects from Mohenjo-daro are conserved at the National Museum of India in Delhi and the National Museum of Pakistan in Karachi. In 1939, a representative collection of arteffacts excavated at the site was transferred to the British Museum by the Director-General of the Archaeological Survey of India.
This dissertation presents the effect of terbium substitution on the structural, magnetic, electrical and dielectric properties of ferrites of nominal compositions Ni1−xTbxFe2O4 and Mg1-xTbxFe2O4 (where x = 0, 0.02, 0.04, 0.06, 0.08, 0.10, 0.12, 0.14, 0.16, 0.18 and 0.20). The samples were initially sintered at 1000 °C and final sintering was performed at 1230 °C in order to prepare homogeneous ferrites. The said ferrites were characterized by X-ray Diffractometry, Fourier Transform Infrared Spectroscopy, Scanning Electron Microscopy, Energy Dispersive X-ray Spectroscopy, Vibrating Sample Magnetometery and Ferromagnetic Resonance. Phase analysis from XRD patterns reveals that the samples have a cubic spinel structure along with a few traces of second phase recognized as orthorhombic phase (TbFeO3) and this phase becomes more conspicuous as the terbium (Tb) is substituted in Ni1−xTbxFe2O4 and Mg1- xTbxFe2O4 ferrites. The lattice parameter changes non-linearly as a function of Tb content in both series that was attributed to the differences in ionic radii of the cations involved and the solubility limit of terbium ions. A gradual increase in the bulk density was observed with the increase of terbium concentration in both series. FTIR absorption spectra of Ni1−xTbxFe2O4 and Mg1- xTbxFe2O4 ferrites exhibited two main absorption bands in the wave number range 370 cm-1 to 1500 cm-1, thereby confirming the spinel structure. The particle size measured from XRD analysis found to decrease with the increase of Tb substitution. The morphology of the samples indicates that samples are crack free along with a few agglomerates. The inclusion of Tb caused the magnetization index to drop which is due to redistribution of cations on the tetrahedral and octahedral sites. The coercivity is observed to decrease and this trend is deviated at higher concentrations of terbium ions in Ni1−xTbxFe2O4 and Mg1-xTbxFe2O4 ferrites. Ferromagnetic resonance linewidths are ≤ 1000 Oe for most of the samples. The nominal composition Ni.94Tb.06Fe2O4 have minimum linewidth, ΔH = 593 Oe, which is minimum of the reported linewidths for spinel ferrites. Hence these ferrites have potential in high frequency applications. The relative initial permeability generally decreases for all the Tb-substituted samples and these are attributed to the decrease in magnetization. The magnetic loss factor is damped with respect to frequency and has very low values in the high frequency region. The electrical resistivity increases and it is attributed to the hinderence in the hopping mechanism caused by the presence of Tb-ions in these ferrites which enhance hopping length between the cations involved in the conduction mechanism. The study on resistivity as a function of temperature shows that all the samples obey semiconducting behaviour. The drift mobility drops while the activation energy increases in a similar manner as that of resistivity. The samples NiFe2O4 and MgFe2O4 have high dielectric constant as compared to the substituted samples. Hence, introduction of Tb-ions in Ni1−xTbxFe2O4 and Mg1-xTbxFe2O4 decrease the dielectric constant. All the substituted samples indicate small values of dielectric loss. These features make these ferrites suitable for various applications.