This Ph. D. dissertation deals with the synthesis of metallic nanoparticles with P2VP homo- and block copolymers (BCP) as stabilizing agent, their characterization, and applications. As a summary of the research conducted during the course of Ph. D., a series of homopolymers of poly(2-vinylpyridine) and amphiphilic block copolymers of poly(2-vinylpyridine), includingpoly(2-vinylpyridine)-block-poly(methyl methacrylate) andpolystyrene-blockpoly(2-vinylpyridine) were used to stabilize metallic nanoparticles (gold and silver). Polymers containing pyridine moiety have been utilized as a stabilizing agent for the metallic nanoparticles. Among them poly(2-vinylpyridine) (P2VP) is the excellent candidates because nitrogen atoms of the pyridine moiety have a strong affinity for the metal ions and metallic nanoparticles that restrains the aggregation of the metal nanoparticles through steric stabilization. Furthermore, P2VP prompts the reaction at ambient temperature and reduction of the particle size with the increase in its molar mass. AuNPs stabilized by P2VP ligands were designed to offer atomic level control and an efficient scale-up production through control of the molar mass of P2VP. Molar mass of the P2VP has enormous effect on the stabilization, size and size distribution of AuNPs. The reducing activity of P2VP increased with the increase in its molar mass. The P2VP stabilized AuNPs are evaluated for their stability and applications using UV-visible spectrophotometry, FTIR, DLS and AFM. Moreover, the drug encapsulation efficiency of P2VP-stablized AuNPs increased with the molar mass of P2VP. P(S-VP)-AgNPs were used as nanosensor for the rapid quantitative assay of pesticide, cartap. P(S-VP)-AgNPs and its interaction with cartap was studied using UV-visible spectroscopy, FTIR, zetasizer and AFM. The synthesized nanosensor is selective towards cartap in the presence of other interfering pesticides in real samples. The LoD of the nanosensor for cartap is far below already reported sensors for cartap. Furthermore, P(2VP-MMA)-AuNPs modified GCE electrode was used as a novel electrochemical sensor for nicotine. It was found that sensitivity of bare GCE is significantly enhanced by coating with P(2VP-MMA)-AuNPs. The P(2VP-MMA)AuNPs modified GCE is more sensitive towards nicotine and gave more intense electrochemical response with reference to bare GCE. In addition, the morphology of P(2VP-MMA) copolymer thin films was studied using AFM. It was observed that both P2VP and PMMA block lengths, total molar mass of block copolymer, solvent used for casting, and substrate play an important role in the morphology of block copolymer thin film. Gold nanoparticles incorporated with the polymer are completely shielded by P2VP chains and influenced the morphology of block copolymer organization by enlarging the polymer domain. Furthermore, surface roughness and thickness increased with the increase in molar mass of the block copolymers.
تخضع الإجارة لضوابط محددة تسمى الشروط، وهذه الشروط تنقسم إلى أربعة أقسام، شرط يكون مقتضى للعقد، وهو صحيح بالاتفاق، وشرط فيه مصلحة، سواء كانت مصلحة لأحد المتعاقدين أو للعقد، وشرط وصف في المبيع أو الثمن، وهو صحيح أيضاً، وشرط منفعة وهو من المختلف فيه، لذا فإن شروط العقود معظمها تكون جائزة. واعتمد الباحث على المنهج التحليلي، فتناول اللفظ الخاص بمحل الدراسة وعرفه لغة واصطلاحا، مستدلا عليه من مراجعه الأصلية، ثم عرَّج على أقوال الفقهاء لتعزيز ما ترجح منها، وذلك بعد أن بيَّنه بالتحليل والتوثيق. توصلت الدراسة إلى مجموعة من النتائج، أهمها: هنالك ضوابط لحالات العقود الجائزة، منها ما يتعلق بالأحكام ومنها ما يتعلق بالمعنى ومنها ما يتعلق بالشكل ومنها ما يتعلق بالزمان، كما سيتبين لنا في مواطن البحث. وأوصى الباحث بمجموعة من التوصيات أهمها ضرورة أن يلتزم المتعاقدون في معاملاتهم بالضوابط الشرعية لكل عقد وعدم الإعراض عن تلك الضوابط؛ لأن في ذلك مفسدة في أمورهم الدينية والدنيوية، واضطراب في أحوالهم ومعاشاتهم.
Unless we compare we cannot identify? So for all those who propagate the theme of ''leave the army alone'' or ''stop army bashing'' in the name of patriotism I can only say that this will do no good to an institution whose identity is undergoing a change and which needs to be debated. After all here was an army that not very long ago, created maintained and executed proxies to try and achieve its strategic ends. If it is now growing up to realize the fruitlessness of this failed strategy and the harm that it has brought to the country than is it not a sign of change? For the army and its senior military leadership it will be no mean task to break away from the ideological and strategic frontiers that has taken it decades to build, consolidate and reside within. Drawing comparison between the army of the past and today will only help army to build on its resolve and ability to bring about a change in its character and functions; from an army accused of periodical political interference''s and running the governments to the army now ready to cede to the civilian control. The question that I investigate is ‘Will military cede to civilian control?’ The army may have finally realized that subordinating itself to the civilian control is actually the best method to both win public approval as well as safeguard its institutional interests. Subordination to civilian authority will not be easy if the officer corps especially the senior military officers don''t accept that, ‘civilians too can make mistakes’. If our military has learnt from its history than today it definitely has an opportunity to build on the good work it has done so far on the matter of civilian and democratic rehabilitation by distancing itself from the politics. In fact an important benchmark on the change in the future behavior of the army would be the difficulty to distinguish on important policy matters, the views of the army from those of the civilian rulers. On termination of General Musharaf’s military rule two important measures were taken by the civilian government; it appointed a President that belonged and was leading a ruling party; the separation of the post of Prime Minister and the Defence Minister. The presidency which in the past was military compliant when worn as a crown by the leadership of the party became an important stabilizing factor to combat all crisis situations. The separation of the post of Defence Minister ensured bringing in an intermediary only through whom the army chief now reported to the Prime Minister, to whom he previously reported directly. These were institutionalized methods of control exercised by the government unlike some other dreadful efforts like bringing ISI under the ministry of interior and imposing the Kerry Lugar conditioned formalities on the army. These actions by the government amply demonstrate how well planned as well as poorly conducted methods employed to control the military by the civilian government could be. These had far reaching strategic and political consequences for the country in the past and if managed poorly they will continue to adversely affect the nature of civil-military relationship in future as well. Institutionalization of control that the civilians may exercise over the military in Pakistan will stretch over a long duration. Both civilians as well as military leaders will have to understand the benefits of this process. Democracy is still in a state of infancy in Pakistan but it is the only system of government that can help Pakistan to combat the many problems it faces today. For democracy to consolidate in Pakistan the military must subordinate to the civilian authority. The Dissertation suggests the ways and means to achieve it.