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Ahmed M.,NESCOM | Badshah S.,International Islamic University, Islamabad | Khan R.U.,International Islamic University, Islamabad | sajjad M.,International Islamic University, Islamabad | Jan S.,International Islamic University, Islamabad
International Journal of Engineering and Technology | Year: 2015

This paper illustrates the theory behind computational fluid dynamics (CFD) of flow though a gas turbine engine low pressure compressor. The goal of study is to develop a tool to perform shape optimization of low speed airfoils. Mathematical model and computational tool are developed using programming software. Analytical solution is developed to create airfoil geometry. The NACA 4 digits library is used with design parameters that control camber and the thickness of the airfoil. Solver is capable of providing derivatives of the objective function and limiting constraints with the solution for each set of parameters.

Shah M.,Quaid-i-Azam University | Ali S.,Quaid-i-Azam University | Tariq M.,Quaid-i-Azam University | Khalid N.,Pakistan Institute of Nuclear Science and Technology | And 2 more authors.
Fuel | Year: 2014

The transesterification of jojoba oil with methanol has been studied in the presence of various catalysts i.e., sodium hydroxide (NaOH), potassium hydroxide (KOH), dibutyltin diacetate (C4H9)2Sn (OOCCH3)2, dioctyltin diacetate (C8H 17)2Sn (OOCCH3)2, dibutyltin oxide (C4H9)2SnO, dioctyltin oxide (C 8H17)2SnO, diphenyltin oxide (C 6H5)2SnO, monobutyltin chloride dihydroxide ((C4H9)Sn(OH)2Cl) and monobutyltin hydroxide oxide hydrate ((C4H9)Sn(=O)OH×xH2O), with % age conversion of oil into biodiesel was 84.5%, 61.3%, 92.6%, 25.4%, 22.0%, 23.3%, 12.0%, 2.15% and 1.05%, respectively. The optimization of experimental parameters was established to achieve maximum yield of the product by using dibutyltin diacetate (C4H9)2Sn (OOCCH 3)2. The physical and fuel properties of jojoba biodiesel like density, dynamic viscosity, kinematic viscosity, pour point, cloud point, flash point, and acid number were determined by ASTM procedures and were found to be comparable to ASTM standards for diesels. The synthesis of jojoba seed oil biodiesel (JSOB) was confirmed by FT-IR and NMR (1H and 13C) analyses of both oil and biodiesel. Chemical composition of fatty acid methyl esters (FAMEs) in jojoba biodiesel was established by GC-MS analysis and verified by retention time data and mass fragmentation pattern. © 2013 Elsevier Ltd. All rights reserved.

Waris G.,Quaid-i-Azam University | Waris G.,University of Shefield | Siddiqi H.M.,Quaid-i-Azam University | Twyman L.J.,University of Shefield | And 3 more authors.
Turkish Journal of Chemistry | Year: 2013

The synthesis and polymerization of a novel diamine monomer, 1,1-(sulfonylbis (4,1-phenylene)) bis (thiourea) (SPT), with various aromatic dianhydrides were carried out. In addition, the fabrication of poly(thiourea-sulfone-imide)s (PTSIs) with noble thermal properties and ame retardancy was conducted. The structures of SPT and polymers were characterized by FT-IR, 1H NMR, and 13C NMR spectroscopy along with elemental analysis. Crystallinity, organosolubility, inherent viscosity, and gel permeation chromatographic measurements were taken as well. The amorphous nature was exhibited by PTSIs containing C=S and -SO2 - moieties in the backbone that were readily soluble in highly polar organic solvents. The inherent viscosities of PTSIs were 0.89-1.13 dL g -1 and molecular weights were 87,000-96,550 g mol -1 , respectively. Their thermal stability was studied in terms of temperature at 10% weight loss, which ranged between 478 and 526 °C under inert atmosphere. Polyimides had a glass transition temperature around 253-268 °C depending on the dianhydrides used. The flame retardant properties of PTSIs were studied in terms of limiting oxygen index values and were measured in the range of 50-56.© TÜBITAK.

Sultan M.,University of Agriculture at Faisalabad | Zia K.M.,Government College University at Faisalabad | Bhatti H.N.,University of Agriculture at Faisalabad | Jamil T.,University of Punjab | And 2 more authors.
Carbohydrate Polymers | Year: 2012

Polyurethane (PU) prepolymers were prepared by using two different diisocyanates i.e., toluene-2,4-diisocyanate (TDI) and or isophorone diisocyanate (IPDI), and poly (2-methyl-1,3-propylene glutarate), hydroxyl terminated group. PU prepolymer was reacted with 2-hydroxyethylacrylate (HEA) to form vinyl terminated PU prepolymer. Vinyl terminated PU prepolymers were further copolymerized with butyl acrylates (BuA) by emulsion process. The structure of proposed PUACs samples was confirmed by FT-IR, and their physicochemical properties were studied determining solid contents (%), emulsion stability and its appearance, tackiness and film appearance. Their acids and base chemical resistance was also studied and discussed. The synthesized PUACs samples were applied using dip-padding techniques on mill un-desized poly-cotton plain weave fabrics. The results emphasis that PUACs based on toluene-2,4-diisocyanate (TDI) have shown excellent performance against physical and chemical resistance as compared to isophorone diisocyanate (IPDI) based PUACs, however vice versa results were found in some studies. © 2011 Elsevier Ltd. All Rights Reserved.

Tabasum S.,Government College University at Faisalabad | Zuber M.,Government College University at Faisalabad | Jamil T.,University of Punjab | Shahid M.,University of Agriculture at Faisalabad | Hussain R.,NESCOM
International Journal of Biological Macromolecules | Year: 2013

Polyurethane acrylate copolymers (PACs) were synthesized by three step synthesis process via emulsion polymerization using toluene-2,4-diisocyanate, hydroxy terminated poly (caprolactone) diol (PCL), 2-hydroxyethylacrylate (HEA) and butyl acrylate (BuA). The proposed structure of the synthesized polyurethane acrylate copolymer (PAC) was confirmed using Fourier transform infrared (FTIR) spectrophotometer. The pilling characteristic and antimicrobial activities of the plain weave poly-cotton grey, white, printed and dyed fabric swatches after application of PAC were evaluated. The results revealed that by increasing the molecular weight of PCL in the synthesized PAC samples, the antimicrobial activities increased and this behavior was interpreted in term of increasing hydrophilic character. An increase in pilling ratings of the treated samples has been observed by increasing the molecular weight of the polycaprolactone diols in the synthesized PAC samples. © 2013 Elsevier B.V.

Zia K.M.,Government College University at Faisalabad | Zuber M.,Government College University at Faisalabad | Barikani M.,Iran Polymer And Petrochemical Institute | Hussain R.,NESCOM | And 2 more authors.
International Journal of Biological Macromolecules | Year: 2011

Chitin based polyurethane bio-nanocomposites (PUBNC) were prepared using chitin, Delite ® HPS bentonite nanoclay enriched in montmorillonite (MMT), 4,4'-diphenylmethane diisocyanate (MDI) and polycaprolactone polyol CAPA 231 (3000g/mol -1). The prepolymers having different concentration of Delite HPS bentonite nanoclay were extended with 2moles of chitin. The structures of the resulted polymers were determined by FT-IR technique. The effect of nanoclay contents on mechanical properties and in vitro biocompatibility was investigated. The mechanical properties of the synthesized materials were improved with increase in the Delite HPS ® bentonite nanoclay contents. Optimum mechanical properties were obtained from the PU bio-nanocomposite samples having 4% Delite HPS ® bentonite nanoclay. The results revealed that the final PU bio-nanocomposite having 2% Delite HPS ® bentonite nanoclay contents is ideal contenders for surgical threads with on going investigations into their in vitro biocompatibility, non-toxicity, and mechanical properties. © 2011 Elsevier B.V.

Waris G.,Quaid-i-Azam University | Siddiqi H.M.,Quaid-i-Azam University | Florke U.,University of Paderborn | Hussain R.,NESCOM | Butt M.S.,Quaid-i-Azam University
Acta Crystallographica Section E: Structure Reports Online | Year: 2013

The molecule of the title compound, C19H13Br2N3O2, lies about a twofold rotation axis. The benzene ring makes dihedral angles of 8.9 (2) and 16.4 (2)° with the central pyridine ring and the second benzene ring, respectively. An intramolecular N - H⋯N contact occurs. In the crystal, molecules are connected by pairs of N - H⋯O hydrogen bonds into chains along the c axis. © 2013 Waris et al.

Waris G.,Quaid-i-Azam University | Siddiqi H.M.,Quaid-i-Azam University | Florke U.,University of Paderborn | Hussain R.,NESCOM | Butt M.S.,Quaid-i-Azam University
Acta Crystallographica Section E: Structure Reports Online | Year: 2013

The molecular structure of the pyridine derivative, C19H 15N3O4·C3H7NO, shows almost planar geometry with dihedral angles of 6.9 (1) and 13.4 (1)° between the pyridine ring and the two benzene rings. This conformation is stabilized by two intramolecular N - H⋯N(pyridine) bonds. In the crystal, strong O - H⋯O(carboxamide) and N - H⋯O(hydroxyphenyl) hydrogen bonds link the molecules, forming a three-dimensional structure. The dimethylformamide solvent molecules are not involved in the hydrogen bonding. The structure shows pseudosymmetry, but refinement in the space group Pbcn leads to significantly worse results and a disordered dimethylformamide molecule. © Waris et al. 2013.

Nigar A.,Quaid-i-Azam University | Akhter Z.,Quaid-i-Azam University | McKee V.,Loughborough University | Hussain R.,NESCOM
Acta Crystallographica Section E: Structure Reports Online | Year: 2012

The asymmetric unit of the title compound, C17H 18N2O4, contains two independent molecules (A and B) differing principally in the conformations of the alkyl chains, anti for molecule A and gauche for molecule B. The dihedral angles between the aromatic rings are 82.51 (6) and 82.25 (6)° in the two molecules. In the crystal, amide-amide interactions (as N - H⋯O=C) results in distinct chains of A and B molecules running parallel to the a-axis direction. C - H⋯O interactions also occur.

Bahadar A.,National University of Sciences and Technology | Khan M.B.,National University of Sciences and Technology | Mehran T.,NESCOM
Industrial and Engineering Chemistry Research | Year: 2013

Diminishing fossil fuel resources, unstable/increasing prices of oil, environmental issues, global warming/climatic shifts, and allied problems have led the world to focus on alternate, environmental friendly, and renewable energy sources. Among many experimental candidates, production of biodiesel from Jatropha curcas L. has gained significant importance. More than 40 countries in the world are evaluating the potential of using this pure plant oil for manufacturing diesel. USEPA's action sets the 2013 volume at 1.28 billion gallons under the Energy Independence and Security Act of 2007. With this premise, it is imperative to identify innovative technologies to handle Jatropha biomass and its efficient oil extraction for economical biofuel production. This study is aimed to make efficient screw expeller to cater massive Jatropha biomass for its oil extraction. A computational flow dynamics (CFD) simulation is performed to estimate the pressure developed inside the barrel through screw pressing when the feedstock is Jatropha seed. This CFD study has helped to determine the optimum values of important operating variables like rotations per minute (rpm), backpressure caused by frictional forces, and effect of changing feed flow rate on the performance of the expeller. The performance of the expeller is measured by power consumption, yield, and efficiency. Experimental validation of the simulation is used to improve oil expeller for Jatropha seed by fabricating the expeller after the analysis of design by ANSYS FLUENT codes. An oil yield in excess of 98%, as compared to a maximum 75% for existing screw expellers, was achieved in practical runs which is very promising. © 2013 American Chemical Society.

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