http://localhost:80/xmlui/handle/123456789/19270 2026-04-22T22:34:43Z http://localhost:80/xmlui/handle/123456789/19825 Title: A FACILE AND EFFICIENT APPROACH TO THE SYNTHESIS OF 2,6-DIACETYLPYRIDINE Authors: Guangyong, Xie; Haitao AI; Lu Lei; Dongfang Zhang Abstract: 2,6-Diacetylpyridine was synthesized via esterification by using pyridine-2,6-dicarboxylic acid as precursor and successive Claisen condensation promoted by sodium for the first time. Compared with traditional sodium ethylate promoted Claisen condensation, the yield of 2,6-diacetylpyridine was improved greatly, and the procedures were simpler and convenient. 2009-08-20T00:00:00Z http://localhost:80/xmlui/handle/123456789/19824 Title: Comparative Vapour Phase FTIR Studies and Vibrational Assignment of Cyclopentadienyl-manganese-tricarbonyl and Methylcyclopentadienyl-manganese-tricarbonyl Authors: Zahid Mahmood; Syeda Robina, Gillani Abstract: The FTIR spectra in solution and vapour phase of the compounds, cyclopentadienyl manganese tricarbonyl (η-C₅H₅)Mn(CO)₃and methylcyclopentatadieny l manganese tricarbonyl (η-C₅H₄CH₃)Mn(CO)₃ were measured in the region 4000-400 cm⁻¹. An Assignment is offered in which the normal modes are described in term of "Local symmetry". This assignment has been discussed in terms of previous assignment given for (in Liquid phase and nujoll mull) other η-cyclopentadienyl and related compounds including ferrocene, dimethyl ferrocene, benzenechromium ticarbonyl and toulene chromium tricarbonyl. 2009-08-20T00:00:00Z http://localhost:80/xmlui/handle/123456789/19726 Title: Sewage Water Pollutants Removal Efficiency Correlates to the Concentration Gradient of Amendments Authors: Zulfiqar Ahmad, Bhatti; Qaisar Mahmood; Iftikhar Ahmad, Raja Abstract: Three coagulants viz. alum, FeClG₃, and Moringa oleifera seed extract were compared for treating municipal wastewater. The wastewater samples were collected from a drain near the Murree Road in Abbottabad city. The initial treatment depicted that alum was a suitable coagulant, while the other two caused color development and increased chemical oxygen demand in the effulent. Subsquently, wastewater samples were treated with graded concentrations (4-32 mg.L-¹) of alum in batch series, and shacked at 600-620 rpm for five minutes. The treated samples were analyzed for various water quality parameters to examine the effective coagulation and flocculation process in the wastewater. There was an increase in TDS and electrical conductivity with the increasing levels of alum above the optimized values (22 to 30 Mg L-¹). The proposed primary treatment strategy of wastewater treatment with alum is suitable for reducing the pollutants load in the sewer system. 2009-08-20T00:00:00Z 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