لسان العرب کا تعارفی و تحقیقی مطالعہ

The dictionaries have played a vital role in understating and preserving any language. Arabic is a Semitic language; it has a large, deep and rich history. The Arabs have always tried to keep the Arabic language safe, but all these efforts were verbal, they did not have a tradition of writing in pre Islamic era. After the Islam they focused on writing and began the writing activities such as: exegesis of Quranic verses, Hadith and explanation of some difficult words used in Quranic verses. In the 2nd century, the first initial stage of Arabic dictionary writing began with the efforts of Al-Khalil, who is considered as a founder of Arabic dictionary writing. After that, language scholars created a great work in promotion of Arabic dictionary. Of these scholars Ibn Manzoor who sacrificed his life for the preserving Arabic language through his writing and research. And his valuable and great benefit book (Lisan-al-Arab) which is considered one of the most important source on said subject. In this Paper, we have presented an introductory and detailed study of his said book, So that Urdu readers can benefit from this scholarly investment.

Synthesis of Calix[4]Arene Based Receptors for the Removal of Anoins from Aqueous Media

Anions play an important role in biology, medicine, catalysis, biomimetic receptors and the environment, but at the same time they are also considered as potentially toxic to human health at elevated concentrations. Particularly, perchlorate, dichromate and fluoride ion are highly persistent in water for decades and their exposure in humans includes ingestion of contamination through drinking water and food. In 1990 US EPA considered perchlorate as toxic material and in 1998 US EPA included perchlorate in Contaminant Candidate List (CCL) with a drinking water level upto 24.5 μg L-1. Dichromate with high solubility in water and oxidation potential exhibits carcinogenic effects on biological systems. The maximum permissible level for dichromate in potable and industrial wastewater is 0.05 mg·L-1. Flouride with concentration of >1.5 mg/L in natural water causes dental and skeletal fluorosis; renal and neuronal disorders Therefore, there is essential need of treatment of wastewater containing hazardous anions from aqueous environment to reduce the health risk. In the field of separation science, the calix[4]arene platform displays interesting organizing properties for the building of various ligating sites to recognize various species including cations, anions and neutral molecules. Our study is concerned with the design and synthesis of different calix[4]arene based materials, efficient for the removal of anions mainly perchlorate, dichromate and flouride ion present in water by optimizing different parameters. In the first part of study, the synthesis of two new calixarene based polymeric resins (Resin-4 and Resin-5) were conducted and characterized by different analytical techniques, i.e. TGA, FT-IR and elemental analyses. The synthesized resins were used for the selective removal of perchlorate. Results showed that the Resin-4 and Resin-5 have perchlorate removal efficiency from aqueous media. The isotherm models, breakthrough curves, kinetic and thermodynamic studies further confirm the experimental results. The maximum adsorption of perchlorate could be achieved at low pH. During the second part of study dichromate adsorption by synthesized compound and resins were carried out. The liquid and solid phase extraction methods have been applied to ascertain the extraction efficiency of both the calix[4]arene derivative and the resin. Analysis of experimental data has been carried out by log-log plot analyses and the determination of characteristic parameters of each isotherm model such as Freundlich, Langmuir and Dubinin-Radushkevich (D-R). The kinetic and thermodynamic parameters concluded that the resin has good capability to efficiently remove dichromate from aqueous media. Finally the third part of our study demonstrates a comparative equilibrium study of calix[4]arene based chitosan (Resin-3) and Ambelite XAD-4 (Resin-4) towards fluoride ion. In batch experiments different parameters were optimized such as pH, dosage and concentration to evaluate the adsorption efficiency. Maximum % adsorption (i.e 98% and 96 % for Resin-3 and Resin-4 respectively) was observed at pH 8.7 with 50 mg of each resin in 60 minutes time. Langmuir, Freundlich, Dubinin–Radushkevich (D-R), Temkin and Flory-Huggins equilibrium isotherms were used to validated the experimental data. The results show that Langmiur and D-R isotherms best fit to experimental data for Resin-3 and Resin-4 as compared to other isotherms models. The maximum adsorption capacity of Resin-3 and Resin-4 was observed as 1.0175 mol g-1.and 1.2097 mol g-1, respectively. The results show that the synthesized calixarene based materials have desired properties for the removal of anions from aqueous media as compared to other reported materials. The analytical work will be beneficial in terms of public health safety, laboratory and industrial application.