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Tariq M.,Quaid-i-Azam University | Ali S.,Quaid-i-Azam University | Ahmad F.,National Engineering and Scientific Commission | Ahmad M.,Quaid-i-Azam University | And 3 more authors.
Fuel Processing Technology | Year: 2011

Biodiesel was synthesized from rocket seed oil by base-catalyzed transesterification with methanol. The synthesis of biodiesel was confirmed by FT-IR and NMR (1H and 13C) spectroscopy. Various fuel properties of the synthesized biodiesel were determined using ASTM methods and discussed accordingly. A total of eleven fatty acid methyl esters (FAMEs) were identified in rocket seed oil biodiesel (RSOB) by the retention time and the fragmentation pattern data of GC/MS analysis. The identified FAMEs were, methyl 9-hexadecenoate (C16:1), 14-methyl pentadecanoate (C16:0), methyl 9,12-octadecadienoate (C18:2), methyl 9-octadecenoate (C18:1), methyl octadecanoate (C18:0), methyl 11-eicosenoate (C20:1), methyl eicosanoate (C20:0), methyl 13-docosenoate (C22:1), methyl docosanoate (C22:0), methyl 15-tetracosenoate (24:1) and methyl tetracosanoate (C24:0). The percentage conversion of triglycerides to corresponding methyl esters determined by 1H NMR was 88.49%. © 2010 Elsevier B.V. All rights reserved.

Malik S.N.,University of Manchester | Mahboob S.,University of Manchester | Mahboob S.,Quaid-i-Azam University | Haider N.,National Engineering and Scientific Commission | And 2 more authors.
Nanoscale | Year: 2011

CuInSe2, CuGaSe2 and CuIn(1-x)Ga xSe2 (CIGS) nanoparticles were synthesised from the diisopropyldiselenophosphinatometal complexes Mx[iPr 2PSe2]n (M = Cu(i), In(iii), Ga(iii); n = 1, 3) by thermal decomposition of the precursors in HDA/TOP at 120-210 °C or 250 °C. The semiconductor nanoparticles obtained were characterized by powder X-ray diffraction (p-XRD), scanning electron microscopy (SEM), transmission electron microscopy (TEM) and energy dispersive X-ray (EDX) analysis. The diameters of the nanoparticles for CuInSe2, CuGaSe2 and CuIn0.7Ga0.3Se2 were found to be 4.9 ± 0.6 nm (at 180 °C), 13.5 ± 2.9 nm (at 250 °C) and 14 ± 2.22 nm (at 250 °C) respectively. The p-XRD patterns for the nanoparticulate samples were assigned to the corresponding ICDD patterns for tetragonal chalcopyrite phase. © 2011 The Royal Society of Chemistry.

Majid A.,Pakistan Institute of Engineering and Applied Sciences | Majid A.,Gwangju Institute of Science and Technology | Khan A.,Pakistan Institute of Engineering and Applied Sciences | Javed G.,National Engineering and Scientific Commission | Mirza A.M.,National University of Computer and Emerging Sciences
Computational Materials Science | Year: 2010

In the study of crystalline materials, the lattice constant (LC) of perovskites compounds play important role in the identification of materials. It reveals various interesting properties. In this study, we have employed Support Vector Regression, Artificial Neural Network, and Generalized Regression Neural Network based Computational Intelligent (CI) techniques to predict LC of cubic and monoclinic perovskites. Due to their interesting physiochemical properties, investigations in modeling the structural properties of perovskites have gained considerable attention. A dataset of a reasonable number of cubic and monoclinic perovskites are collected from the current literature. The CI techniques can efficiently correlate the LC of the perovskites materials with the ionic radii of constituent elements. A performance analysis of CI techniques is carried out with Multiple Linear Regression techniques, SPuDS software, and Density-Functional Theory. We have observed that the CI techniques yield accurate LC prediction as against the conventional approaches. Availability: Matlab based computer program developed for this work is available on request. © 2010 Elsevier B.V. All rights reserved.

Sappurd A.,National Engineering and Scientific Commission
Clean Technologies and Environmental Policy | Year: 2011

Oil Refineries surrounding the gulf are the largest source of environmental pollution in the region. Air dispersion models are powerful tools for assessing the consequences of environmental air pollutant concentrations. This study was carried out to investigate the transport and dispersion patterns of SO 2 originating from Mina Al-Fahal refinery, in the Sultanate Oman by employing California Puff (CALPUFF) dispersion modeling system. The major goal of this study is to make a comparison of the results produced by this modeling system with a previous study which was conducted for the same area using Industrial Source Complex Short Term (ISCST) model. In order to obtain the meteorological fields of the study area the CALPUFF modeling system was coupled with Weather Research and Forecasting (WRF), a prognostic meteorological model. The results indicated that the performance of the CALPUFF was better than that of ISCST; however, a difference in magnitudes of predicted and measured concentrations of SO2 was found. This difference can be reduced using high-resolution terrain elevation data, site-specific observational meteorological data and buoy data. The complex geography and variable wind regimes played an important role in distribution of SO2 in and around the refinery. The land-sea interaction also influenced the predicted results. © 2010 Springer-Verlag.

Khattak A.R.,National Engineering and Scientific Commission
Proceedings of the Institution of Mechanical Engineers, Part G: Journal of Aerospace Engineering | Year: 2013

Joints are an important source of vibration damping in built-up structures. Their mathematical modelling is, however, complex due to microslip with highly nonlinear nature. This is a major reason for developing a reduced-order model of dynamics in joints. The singular value decomposition is applied to decompose the time history and arrive at a linear model for joint dynamics while preserving the physics of the model at the same time. The model, which is a linearization of joint dynamics, is obtained by the introduction of certain functions of time which replace the nonlinear forces in the reduced space for harmonic excitation. A two-fold computational advantage is achieved by (1) increasing the size of the stable time step and (2) reducing the number of generalized coordinates substantially. Several configurations of joint, having different geometry and dynamic parameters, are studied with the help of the reduced-order model. The state of the system as well as the hysteretic behaviour is successfully modelled showing very good agreement with full model. © IMechE 2012.

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