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Home > Synthesis and Characterization of Some Spiroimidazolidine-2, 4-Dione Derivatives from 2-Arylchroman-4-Ones

Synthesis and Characterization of Some Spiroimidazolidine-2, 4-Dione Derivatives from 2-Arylchroman-4-Ones

Thesis Info

Author

Muhammad Assad Ali

Department

Department of Chemistry, QAUid-I-Azam University

Program

Mphil

Institute

Quaid-i-Azam University

Institute Type

Public

City

Islamabad

Province

Islamabad

Country

Pakistan

Thesis Completing Year

2013

Thesis Completion Status

Completed

Page

84

Subject

Chemistry

Language

English

Other

Call No: Diss M. Phil / CHE / 1118

Added

2021-02-17 19:49:13

Modified

2023-02-19 12:33:56

ARI ID

1676717187708

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شری مشرو والا

شری مشرو والا
افسوس ہے کہ گزشتہ مہینہ گاندھی جی کے مشہور چیلے شری مشرو والا نے انتقال کیا، وہ ہریجن کے اڈیٹر اور گاندھی جی کے مشن کے سچے حامل و مبلغ تھے اور اس زمانہ میں جب کہ کانگریس اپنے اصولوں سے عملاً بالکل ہٹ گئی ہے اور کانگریسیوں کی اکثریت اقتدار کی ہوس، ذاتی اغراض اور فرقہ پرستی میں مبتلا ہے اور فرقہ پرستوں اور خود غرضوں کی قوت اتنی بڑھ گئی ہے کہ سچے کانگریسی بھی مشکل سے ان کے مقابلہ میں زبان کھولنے کی جرأت کرسکتے ہیں، مشرووالاجی اپنے اصولوں پر قائم تھے اور آخر دم تک نہایت دلیری کے ساتھ گانگریس کی غلط روی پر تنقید اور گاندھی جی کے اصولوں کی تبلیغ و اشاعت کا فرض انجام دیتے رہے انھوں نے ان کی تعلیمات پر متعدد کتابیں لکھی ہیں، اس خود غرضی اور فرقہ پرستی کے دور میں ایسے مخلص اور سچے کانگریسی کا اٹھ جانا ایک ناقابل تلافی نقصان ہے، ان کی موت سے متحدہ قومیت کا ایک بڑا ستون گرگیا، جس کی جگہ مدتوں نہ بھر سکے گی۔ (شاہ معین الدین ندوی، اکتوبر ۱۹۵۲ء)

 

Analysis of Factors Influencing Procurement Fraud in Government Agencies Environment (Case Study at Regional Apparatus in “XYZ” Regency)

This study aims to examine factors such as the Quality of the Procurement Committee, Goods/Services Procurement Systems and Procedures, Goods/Services Procurement Ethics, and Goods/Services Procurement Environment against Fraud in the Procurement of Goods/Services in Government Agencies. The research method used in this study is a quantitative method. The population in this study was the Head of Service, Treasurer, and Head of Sub-Division of Finance, and the sample in this study was the Regional Work Unit in “XYZ” Regency. The source of the data used in this research is the main/primary data obtained directly from the questions/statements (questionnaires) distributed to the respondents. The data analysis method used in this study is the Statistical Program for Social Science (SPSS) to test the four hypotheses proposed in this study. The results of this study indicate that systems and procedures are proven to have a positive influence on procurement fraud in government agencies, while the quality of the Procurement Committee, Procurement Ethics, and the Procurement Environment are not proven to have a positive effect on procurement fraud in government agencies.  

Effect of Doping of Various Metal Cations on Structural, Electrical and Magnetic Properties of Nano Cobalt Ferrites

Cobalt ferrite, having an inverse spinel structure and the inherent properties of high coercivity, moderate saturation magnetization and high electrical resistivity, is a potential candidate for magnetic storage devices and high frequency applications. In the present study, cobalt ferrite has been doped with various dopants like Cr, rare earths (Sm, Ho, Er, Dy and Pr) and Zr co-doped with Mg, Mn and Ni, in order to improve the electrical and magnetic properties while maintaining a spinel structure and moderate saturation magnetization values a micro-emulsion method of preparation in which a cheap surfactant, namely polyethylene glycol, has been used. The formation of spinel phase occurs between 573 and 673K as indicated by the thermal analyses (TG/DTA), but a well crystalline and stable spinel phase is achieved at 1073K as evident from the powder X-ray diffraction studies of the synthesized samples. All the doped cobalt ferrite samples are in single spinel phase as confirmed by XRD and magnetic susceptibility measurements. The average crystallite sizes of the doped cobalt ferrite samples are in the range of 13 nm to 70 nm. The elemental composition of doped cobalt ferrites is confirmed by energy dispersive X-ray fluorescence analysis which shows an agreement between the theoretical and experimental compositions of the prepared samples. Electrical resistivity as measured at 293K the by two point probe method is found to have a value of 1.25 × 106 Ωm for un-doped cobalt ferrite which is enhanced by doping with Cr, Zr-Mg, Zr-Mn and Zr- Ni. For small contents of rare earth metal cations introduced into spinel lattice of cobalt ferrite the electrical resistivity (at 293K) increases to a larger extent due to insulating nature of rare earth oxides. The variation in electrical resistivity with composition and temperature has been discussed on the basis of hopping model of electron conduction in ferrites. The activation energy of hopping and drift mobility of the charge carrier is calculated from the resistivity data. The dielectric properties are measured by inductance capacitance resistance (LCR) meter in the frequency range of 100Hz – 1MHz and dielectric constant (έ), dielectric loss angle (tanδ) and dielectric loss factor ( ε ′′ ) are calculated from the capacitance data. These dielectric parameters are found to decrease with increasing frequency. This behaviour is typical of ferrites as explained by Koop’s model. The dielectric constant (έ) and the dielectric losses of the un-doped cobalt ferrite have been reduced by doping in the present work. Curie temperature has been determined from the low field AC-magnetic susceptibility measurements and was found to increase for specific contents of dopants as compared to the un-doped cobalt ferrite while for others a lower value of Curie temperature was observed. Saturation magnetization has been increased by doping with Cr up to x = 0.5, Zr-Mn content x = 0.1, Sm content x = 0.04 and Er content x = 0.08 while for the rest of compositions the saturation magnetization has been decreased as compared to the un-doped cobalt ferrite sample. Beside this, the coercivity of the materials prepared in the present study has been increased by doping rare earth metal cations, while it has been reduced by Cr and Zr co-doped with Mg, Mn and Ni, in cobalt ferrites. The reduction in magnetization has been discussed in terms of dilution of magnetization, crystallite size effects and the spin canting introduced by the dopants at octahedral sites.