In recent years, the demand of polymers is growing progressively in a wide variety of fields extending from everyday life to medical and high technological applications due to their unique inherent properties like lightweight, flexibility, weather and corrosion-resistance and low cost. Considering the bulk properties of polymer an effort has been made to modify the structural, morphological, electrical and optical properties of near-surface layer of polymer by ion implantation. Indeed, it is a useful technique to modify surface properties of polymers without altering their bulk properties. In particular, with an improvement in electrical conductivity the implanted polymer can be utilized as a promising candidate for its future utilization in the field of plastic electronics. In the present study, the effects of 400 keV C+, Cr+ and Ag+ ion implantation on Polymethylmethacrylate (PMMA) have been examined at different ion fluences ranging from 5x1013 to 5x1015 ions/cm2. The ion penetration depths have been estimated with the help of SRIM simulation. The chemical and structural modifications in implanted PMMA are examined by Fourier Transform Infrared and Raman Spectroscopy (FTIR), respectively. The surface topographical examination of the implanted polymer has been performed using Atomic Force Microscope (AFM). The effects of ion implantation on electrical and optical properties of PMMA have been investigated by four probe apparatus and UV–Visible spectroscopic analysis. The FTIR spectra confirmed the formation of C = C bonds in C+ and Cr+ implanted PMMA at a fluence of 5 × 1015 ions/cm2 while for Ag+ implanted PMMA the peak for C=C is developed at relatively lower fluence of 1 × 1015 ions/cm2. Moreover, the Raman spectra justified the growth of sp2 carbon clusterization and transformation of C+, Cr+ and Ag+ implanted layer of PMMA into quasi-continuous amorphous carbon at implantation fluence of about ≥5x1014 ions/cm2. The AFM images showed the topographical modification due to ion implantation on PMMA. However, the extent of modification depends on the type of ions and increase in ion fluence. The roughness analysis revealed the smoothness of the surface of C+ and Cr+ implanted PMMA with increasing ion fluence. On the other hand, the implantation of Ag+ ions showed dominant effects on the surface of PMMA rather than C+ and Cr+ implantation. As a result, the surface of Ag+ implanted PMMA became rougher due to the formation of nano-hillocks and nano sized grainy structures above the surface. Due to ion-induced structural modifications the electrical conductivity of PMMA is increased to semiconducting range with a rise in ion fluence. After C+ ion implantation the electrical conductivity of PMMA is increased from 2.14 × 10-10 S/cm (pristine) to 1.46 × 10-6 S/cm. Similarly, for Cr+ and Ag+ ion implantation the electrical conductivity has improved to 7.21 × 10-6 S/cm and 9.60 × 10-6 S/cm, respectively. The results of UV-Visible analysis also confirmed an increase in sp2 carbon clusters in implanted PMMA in the favor of other results. Due to creation of carbonaceous clusters the optical absorption spectra of PMMA exhibit a shift towards higher wavelength after C+, Cr+ and Ag+ implantation along with a significant reduction in the optical band gap energies. For C+ implanted PMMA the optical band gap is reduced from 3.13 (pristine) to 0.66 eV whereas, after Cr+ and Ag+ ion implantation it shrinks to 0.85 and 0.81 eV, respectively.
The Concept of Collective Ijtihad and Introduction to Prominent Institutions in the Muslim World for resolving contemporary jurisprudential issues is a burning issue these days. Ijtihad is the effort made by the mujtahid in seeking knowledge of the ahkam (rules) of the Shariah through interpretation. It is a known fact the ahkam specifically and explicitly prescribed in the Holy Quran and Sunnah are limited, and as human society evolves, new problems come to the fore. This is the responsibility of mujtahid to present solution of the problems in the light of the rules and principles prescribed in the Holy Quran and Sunnah. This endeavor can take place in three shapes, first by an individual effort of a mujtahid, second by a group of in the form of collective ijtihad while its more advanced shape is the consensus (ijma’a) of all the mujtahidin of the time. In this article all the three modes of ijtihad have been discussed and it has been concluded and suggested that the best option for resolving the issues faced by the Muslim Ummah is collective Ijtihad due its easy implementation. This also helps in avoiding many complications while seeking consensus (Ijma’a) in present day time. In this article a list of the problems have been given which need immediate attention of the Muslim scholars, while in the last part introduction of some prominent institutions of the Muslim World have been given with elaboration of their objectives.
Corporate Governance is the mechanism by which companies are managed and controlled in the best interest of the shareholders. In order to eliminate the agency problems and to strive for goal congruence between the corporate managers and shareholders, different codes of corporate governance have been developed keeping in view the legal, social and economic structure of a particular country. In Pakistan code of Corporate Governance 2003 was initially adopted which was revised and updated in the form of Code of Corporate Governance 2012. This research study focuses on the relationship between corporate governance and market valuation in order to confirm that those companies that employ good corporate governance mechanism are valued more than other non-complying companies. For this purpose, two measures of value i.e. Tobin Q and MVA have been used while corporate governance is measures through six variables i.e.Ratio of Executive directors to Total Directors (Re), Ratio of Independent Directors to Total Directors (Ri), Role duality (Rd), Ratio of Management Remuneration to Total Salaries (Rm), Number of Board Meetings (Dm) and Ownership concentration (Ow) along-with four control variables i.e. Size of the firm (Sz), Sales Growth (Sg), Leverage of firm (Lev) and Return on Assets (ROA). In order to determine the relationship between the two variables sample of companies included in KSE-100 index of Pakistan Stock Exchange have been selected while multiple regression technique and Pearson?s correlation is used for the purpose of analysis. The result of data analysis shows significant relationship of corporate governance measures with both Tobin Q and MVA, which is consistent with the previous studies. The findings of the study recommend adoption of corporate governance practices to the Governments Agencies, Policy makers and Corporate managers as it will result in enhancing profitability, growth, market value at microeconomic level while it with lead to greater market stability by enhancing investor?s confidence, development of corporate and financial markets, improving FDI and GDP growth at macroeconomic level. Pakistan is the major emerging market of South Asia and being strategic partner of China in the China Pakistan Economic Corridor (CPEC) it will be the center of major economic and corporate activity in the near future. However in order to attract potential corporate investors the corporate governance framework requires further restructuring and improvement while financial, legal and economic environment needs to strengthen along with development of physical infrastructure to obtain maximum economic gains from the CPEC projects.