http://localhost:80/xmlui/handle/123456789/19273 2026-04-23T00:17:30Z http://localhost:80/xmlui/handle/123456789/19712 Title: The Distances of the Closest Approach and of the Reaction Site-From the Electrode-for Adiabatic Heterogeneous Electron Transfer. The Case of Pyridinium (Mono) Cations Authors: MAHBOOB MOHAMMAD Abstract: In investigating the heterogeneous electron transfer process in some pyridinium compounds, those physical (distance) parameters were investigated which could be relevant to the adiabaticity of a heterogeneous electron transfer process. These distance parameters are: the closest approach, the position of the interfacial potential-energy barrier maximum and the reaction site. The pyridinium (mono) cations were treated as charged Shard) sphere with the reaction site at the center of the sphere. With this assumption the distance of the closest approach and the distance of the-reaction-site - from the electrode surface - were investigated under the constraint Kel (electronic transmission coefficient) = 1. Various models were considered and the Khan model was found to be quite sound, versatile as well as convenient to use. Results of these calculations are presented the reaction site as calculated through Khan model came close to the sum of radii of the solvent and the pyridinium cations under study. 2009-12-20T00:00:00Z http://localhost:80/xmlui/handle/123456789/19711 Title: Secondary Metabolites from Alhagi maurorum Authors: SAEED AHMAD; IRSHAD AHMAD; MUHAMMAD SALEEM; ABDUL JABBAR; NISAR-UR-REHMAN; SYED SAEED-UL-HASSAN; KANWAR SALEEM AKHTAR; MUHAMMAD IQBAL CHOUDHARY Abstract: Eight compounds have been isolated for the first time from Alhagi maurorum namely, β- sitosterol, cinnamic acid, p-coumaric acid, 4-hydroxybenzoic acid, 3'-O-methylorobol, Methyl β-D-glucopyranoside, β-sitosterol 3-0-β-D-glucopyranoside and quercetin 3-O-β-D-glucopyranoside, respectively. Their structures have been elucidated by various spectroscopic techniques. 2009-12-19T00:00:00Z http://localhost:80/xmlui/handle/123456789/19706 Title: Chemical Composition of Volatile Fraction of Pakistani Peanut and its Antiradical Activities Authors: MUHAMMAD ATHAR ABBASI; TAUHEEDA RIAZ; FARHAN MEHMOOD KHAN; AZIZ-UR-REHMAN; DURRE SHAHWAR; NAEEM AHMAD; TAYYABA SHAHZADI; MUHAMMAD AJAIB; VIQAR UDDIN AHMAD Abstract: Arachis hypogaea Linn. (peanut or groundnut) is an economically important crop. Thousands of peanut cultivars are grown in the world and studies have been carried out on these but, to the best of our knowledge, no salient work has been done on Pakistani cultivar so far. Here, we report the chemical composition of volatile fraction of Pakistani cultivar of peanut and its antiradical activities using 1,1-Dipheny1-2-picrylhydrazyl radical (DPPH) scavenging and phosphomolybdenum complex (PC) method. This study revealed that Pakistani cultivar exhibited an almost equal antioxidant potential to that of standard, butylated hydroxytoluene (BHT), which was obvious from their IC50 values. The IC50 value of peanut extract was found to be 13.42 ± 26 μL/ML, relative to butylated hydroxytoluene, having 12.1 ± 0.92 μL/ML. 2009-12-18T00:00:00Z http://localhost:80/xmlui/handle/123456789/19705 Title: Gas Chromatography Mass Spectrometric Quantitative Determination of Product Distribution of Paper Pyrolysis with Solid Acids at Low Temperature Authors: SHAHNAZ PERVEEN; ZAHID HUSSAIN; KHALID MOHAMMED KHAN Abstract: Paper was pyrolyzed at low temperature (300 "C) both in the absence and presence of catalysts. The liquid products were collected and characterized by using GC/MS. Boric acid and aluminum sulphate acting as catalysts were found to alter the relative concentration and nature of the product due to depolymerizing, polarizing and free radical stabilizing properties. Boric acid was found to decrease the amount of anhydrosugars and favors the formation of esters, ketones and carboxylic acids. Aluminum sulphate favored the formation of furan carboxaldehyde, phenols and other cyclic compounds. The cracking of paper and formation of new compounds was facilitated by vacant orbital of the catalyst. Therefore change in concentration of catalyst also changed the nature and concentration of rite products. These observations are explained on the basis of the chemical nature of these compounds in this paper. 2009-12-17T00:00:00Z