Our society has made significant advancements in technology as it continues to grow in size which in turn has led to an accumulating amount of toxic threats. Some types of harmful pollution our society is currently facing includes industrial waste such as non biodegradable organic compounds, heavy metals and pathogens. Therefore, it is imperative to develop green and efficient technologies to control and reduce the growth of environmental hazards. In recent years, photocatalysis using titanium dioxide (TiO2) has become a promising route to degrading organic pollutants. However, Anatase phase of TiO2 has a band gap of 3.2 eV. This limits its practical application under sunlight because the light with energy greater than 3.2 eV constitutes only 3 ~ 4 % of the total solar energy reaching the earth. Therefore, modifications of TiO2 are needed to allow TiO2 to efficiently utilize the solar spectrum. Electrospun TiO2 nanofibers present a unique class of active materials with optimized photoactivity and cost efficiency due to ease of synthesis and fabrication in bulk. The high aspect ratios of these nanostructured materials shorten the transportation length of electrons and holes from the crystal interface to the surface, thus accelerating their migration to the active surface sites. The primary goal of this dissertation is to develop TiO2 nanofibers as an efficient and cost-effective catalyst for practical and multi-purpose application in water remediation. To achieve this, various strategies were employed including doping, photosensitization with a low bandgap material, modification of the surface chemical states, and incorporating second-phase materials in TiO2 nanofibers. The detailed characterization of the prepared nanofibers was carried out by SEM, TEM, XRD, XPS, UV-vis DRS, FTIR and PL. TiO2 nanofibers were prepared through sol-gel solution followed by electrospinning and calcination treatment. The electrospun nanofibers were successfully doped by phosphorus and the surface of nanofibers were decorated by silver nanoparticles. The synergistic effect of P-doping and Ag NPs resulted in a decrease in the bandgap and enhanced charge separation. Consequently, the rate constant of Cr(VI) photoreduction by Ag-PTNFs was 96 % higher than unmodified nanofibers and the rate constant of MB photoreduction was 83 % higher than that of the unmodified nanofibers. Another strategy was to make composite TiO2 nanofibers by incorporation of g-C3N4 in TiO2 nanofibers and the effect of making heterojunctions with Ag NPs was studied. The prepared composite nanofiber exhibited remarkable photocatalytic activity for degradation of MB, reduction of Cr(VI) and antibacterial activity against E. coli and S. aureus under simulated solar irradiation. TiO2 nanofibers were also successfully photosensitized with low bandgap Ag2S nanoparticles of 11, 17, 23 and 40 nm mean sizes. 17 nm Ag2S@TiO2 nanofibers exhibited optimal activity in the photodegradation of methylene blue and photoreduction of Cr(VI) under simulated sunlight. Whereas, 11 nm Ag2S@TiO2 nanofibers displayed excellent bactericidal activity under dark and simulated solar irradiation. Furthermore, a UV-O3 surface treatment induced excess Ti3+ surface states and oxygen vacancies which synergistically enhanced the photocatalytic activity. This was attributed to the efficient charge separation and transfer driven by increased visible-light absorption, bandgap narrowing and reduced electron-hole recombination rates. This dissertation demonstrates the potential utilization of modified TiO2 nanofibers in multifunctional filtration membranes for remediation of pollutants from wastewater under solar irradiation.
مولانا عبدالسلام نیازی افسوس ہے پچھلے دنوں دہلی میں اسّی (۸۰) نوے(۹۰) برس کی عمرمیں مولانا عبدالسلام نیازی کابھی انتقال ہوگیا۔مولانا عجیب وغریب خصوصیات کے بزرگ تھے اورکم ازکم راقم کی نظر سے آج تک کبھی کوئی شخص اس انداز اورادا کا نہیں گزرا۔ صورت شکل کے لحاظ سے ڈاڑھی مونچھ صاف، دراز قامت، کسرتی اور دُہرابدن۔مگر منطق وفلسفہ میں درک وبصیرت اس درجہ کہ صدرا اور شمس بازغہ، حمداﷲ اورقاضی ناخنوں میں پڑی ہوئی۔قرآن سے غیر معمولی شغف ،حضور پُرنورؐ کے ساتھ عشق کایہ عالم کہ نامِ نامی زبان پرآیا نہیں کہ جی بھر آیا اورآنکھیں نم ہو گئیں۔ زورِ تقریر وخطابت اس بلا کاکہ فقرہ فقرہ پرفصاحت وبلاغت صدقہ۔ عرفیؔ، جامیؔاورخاقانیؔ وغیرہم کے ہزاروں اشعار برنوکِ زبان، جھوم جھوم کر پڑھتے اوران کی تشریح کرتے تھے ۔اقلیدس سے حضورؐ کی ختمِ نبوت کے اثبات پر جب تقریر کرتے تھے تواﷲ اکبر! جوش وخروش اورزور وروانی کاکیا منظر ہوتاتھا! محسوس ہوتاتھا کہ ہر شے پر سکتہ طاری ہوگیااور دم بخود ہوکر رہ گئی ہے۔ خود داری اور استغنا اس درجہ کاکہ سراکبر حیدری ایسے لوگ آتے تھے اوریہ شخص تعظیم تک کے لیے کھڑا نہ ہوتا تھا۔ ہمیشہ مجرد رہے۔ عطربناکر گزربسر کرتے تھے۔تحفہ یا نذرانہ قلیل ہویاکثیر، امیر پیش کرے یاغریب کبھی ہرگز قبول نہیں کرتے تھے، اور اگر کبھی کوئی اصرار کرتاتھا توغصّہ میں بھبک کراُس کونہایت مغلظ گالیاں دینے لگتے تھے ۔نماز بے حد خشوع وخضوع سے پڑھتے اورتہجد تک کی پابندی کرتے تھے کبھی کسی کے مکان پرنہیں گئے، ہمیشہ خانہ نشین رہے۔ الھمّ اغفرلہ وارحمہ۔ [جولائی ۱۹۶۶ء]
During the Arab Rule in Sindh, there had been great and featured research work in all fields of Islamic knowledge particularly in the field of Qurʾān, Hadīth and biography of Prophet Muḥammad PBUH. After the Arabs, The Kalhora’s period is known as the golden period of education, literature and civilization in the history of Sindh. Prior to this, the scholars of Sindh had written various voluminous works on Islamic knwoledge in Arabic and Persian. During this period, a movement initiated amongst the scholars of Sindh, which encouraged them for writing and compiling books in local Sindhi Language inspite of vernacular Arabian and Persian languages. As such, a remarkable work of authorship and compilation had been made in various fields including Islamic studies in general and in the field of biography of Hazrat Muḥammad PBUH, which thereafter remained continued in the days of Talpur’s, British Rule and till to date. This paper is the analytical survey of Sīrah Literature being produced in Sindh from 1947 to 2015 CE in local Sindhi Language.
Pakistan is blessed with a wide range of indigenous mango germplasm. These mango genotypes, growing at Punjab and Azad Jammu and Kashmir (AJK) and its vicinity are valuable resource for unique genetic diversity. This germplasm has declined drastically due to population pressure, deforestation and high incidence of insect pests and diseases including Mango Quick Wilt Disease (MQWD). Hence, the aim of this study was to develop DNA fingerprints and determine the genetic diversity of the availabale germplasm. On the other hand, better understanding about the varability of MQWD pathogen is also important for incorporating resistant traits in the plant. Therefore, DNA profiles of 232 genotypes of Pakistan were developed with 114 SSR markers to determine the population structure. SSR based genetic diversity analysis identified a total of 593 alleles ranging from 2 to 18 alleles per locus, which were able to distinguish almost all of these genotypes. The average polymorphism information content value was 0.665. The expected and observed heterozygosity values were 0.695 and 0.619, respectively, which exhibited moderate level of genetic diversity among mango genotypes. Thirty unique alleles were identified in commercial and some wild genotypes. This analysis identified 26 duplicate entries in the collected samples, though they were identified as different genotypes at the time of sampling. The remaining genotypes (203) were found to be genetically distinct from each other. The Bayesian cluster, principal coordinate and hierarchical clustering analyses divided the collected genotypes into three groups i.e. A, B and C. Groups A and C consisted of entirely indigenous genotypes, while all commercial genotypes were clustered in group B. The genotypes from AJK have relatively broader genetic base within their clusters as compared to the genotypes collected from Punjab. However, strong correlation between geographic distribution and genetic clustering suggested no extensive exchanges of mango germplasm across these geographic areas. The genetic diversity of Pakistani genotypes was found to be higher when compared with the genotypes of other mango growing countries of the world. No association could be established between the embryony and SSR markers analyzed. The analysis identified the mislabeling of the introduced genotypes from other countries. These markers also identified and confirmed the parentage of hybrid genotypes. Most of the genotypes collected from Rahim Yar Khan, Multan and Khanewal showed close relationship with ‘Chaunsa’, ‘Sindhri’ and ‘Langra’. Another aspect of this study was to assess the genetic diversity of the casual agent of the most notorious mango disease, MQWD, which is a major threat to mango production in Pakistan. Eighteen fungal isolates were sampled from infected mango decline trees from mango growing areas of Punjab. The genetic makeup of these isolates was determined by using various DNA marker genes like ITS, β-tubulin and EF-1α. The comparison of their nucleotide sequencing data showed that ‘RYK-147’ belongs to Ceratocystis manginecans; while, rest of the seventeen samples belong to Ceratocystis fimbriata. These results are contradictory to the previous reports, which showed that disease causing fungi belongs to solely C. manginecans. This study showed that the mango decline disease is caused by both fungal species. However, the C. manginecans, isolated in this study has the same genetic makeup as previously reported from Pakistan and Oman. This contradiction in results is likely due to sampling from the regions, which are different from the previous studies in Pakistan. The genetic diversity analysis of 18 isolates was also carried out through 20 SSR markers. The results indicated that the isolates collected from Multan, Khanewal and Muzaffargarh are genetically similar. While, low level of genetic diversity was observed among isolates sampled from Rahim Yar Khan. The analysis also screend out C. manginecans, as a causal agent of mango wilt disease in isolate of ‘RYK-147’. These all isolates were sampled from commercial mango genotypes, which have low level of genetic diversity. High level of genetic similarity in the disease causing fungi might be an evolutionary outcome of diversity relation between host and pathogen. The quantitative analysis of the genetic diversity and population structure would help cultivar improvement in the future mango breeding programs.