School of Systems and Technology (SST)
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One of the best in Pakistan, consisting Moreover about two dozen faculty members have doctoral degrees.
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Item Peristaltic flow of a carreau fluid in a channel with different wave forms(Wiley, 2009) Tasawar Hayat; Najma Saleem; Ali, N.This investigation deals with the peristaltic motion of a Carreau fluid in a planar channel by employing long wavelength approximation. Five wave forms are chosen. Explicit solutions of longitudinal velocity and pressure gradient are derived. The pumping and trapping phenomena are properly examined. Comparison is made for the flow characteristics of the various selected wave forms. © 2009Wiley Periodicals, Inc. Numer Methods Partial Differential Eq 26: 519–534, 2010Item Filament temperature of low power incandesecent lamps: stefan-boltzmann law(2010) Imtiaz Ahmad; Sidra Khalid; Ehsan KhawajaAn undergraduate experiment using commercially available low power incandescent lamps was performed. The results obtained, for higher temperature of the filament (say above 1000 K), were compared with those calculated using a simple model, based on transfer of electric power predominantly into Planck’s radiation channel through Stefan- Boltzmann law. The agreement between the results and the theory was quite satisfactory. Measurement of filament temperature to confirm theoretical results, included in the present work, is expected to give a student more confidence in the theory.Item Dielectric properties of vegetable oils(Journal of Scientific Research Publications, 2011) Zaheer Hussain Shah; Q. A TahirIn search of PCB (polychlorinated biphenyl) free mineral oil used in transformer, we have carried out the detailed study on dielectric properties of some vegetable oils, such as corn oil and cottonseed oil. Dielectric constant, dielectric loss factor have been determined for corn oil, cotton seed oil, and PCB free mineral transformer oil having International Electrotechnical Commission number IEC-60296 in the frequency range 330 Hz to 3 MHz and in temperature range 250C to 700C. The dielectric data of the vegetable oils is critically compared with that of the transformer oil and appropriate causes for similarities and differences have been discussed. Owing to comparable results in the vegetable oils and transformer oil studied, it is suggested that vegetable oils may also be used as transformer oil.Item A numerical technique for heat equation subject to integral specifications(Science International, 2011) Muhammad Aziz Ur Rehman; M. S. A. TajThis paper deals with numerical method for the approximate solution of one-dimensional heat equation with integral boundary conditions. The integral conditions are approximated by using Simpson’s 1/3 rule while the space derivatives are approximated by third-order finite difference approximations. Then method of lines, semidiscritization approach, is used to transform the model partial differential equation into a system of first-order linear ordinary differential equations whose solution satisfies a recurrence relation involving matrix exponential function. The method developed is L-acceptable, third-order accurate in space and time and do not require the use of complex arithmetic. A parallel algorithm is also developed and implemented on several problems from literature and found to be highly accurate when compared with the exact ones and alternative techniques.Item Isothermal plasma waves properties of the Schwarzschild de-sitter black hole in a veselago medium(Astrophysics Space Science, 2011) M. Sharif; Ifra NoureenIn this paper, we study wave properties of isothermal plasma for the Schwarzschild de-Sitter black hole in a Veselago medium. We use ADM 3 + 1 formalism to formulate general relativistic magnetohydrodynamical (GRMHD) equations for the Schwarzschild de-Sitter spacetime in Rindler coordinates. Further, Fourier analysis of the linearly perturbed GRMHD equations for the rotating (non-magnetized and magnetized) background is taken whose determinant leads to a dispersion relation. We investigate wave properties by using graphical representation of the wave vector, the refractive index, change in refractive index, phase and group velocities. Also, the modes of wave dispersion are explored. The results indicate the existence of the Veselago medium.Item Influence of induced magnetic field and heat transfer on peristaltic transport of a carreau fluid(Elsevier, 2011) Tasawar Hayat; Najma Saleem; S. Asghar; Mohammed Shabab Alhothuali; Adnan AlhomaidanThe effect of an induced magnetic field on peristaltic flow of an incompressible Carreau fluid in an asymmetric channel is analyzed. Perturbation solution to equations under long wavelength approximation is derived in terms of small Weissenberg number. Expressions have been constructed for the stream function, the axial induced magnetic field, the magnetic force function, the current density distribution and the temperature. Trapping phenomenonis examined with respect to emerging parameters of interest.Item Screening of aerial parts of abutilon bidentatum for hepatoprotective activity in rabbits(Academic Journals, 2011-02-04) Sammia Yasmin; Akram Kashmiri, Muhammad; Kalsoom AnwarThe objective of this investigation was to study the hepatoprotective activity of aqueous methanolic extracts of aerial parts of Abutilon bidentatum on carbon tetra chloride (CCl4) and paracetamol induced liver damage in rabbits. The extracts at different dosages, administered orally for three days, significantly decrease serum enzymes; Serum Glutamate Pyruvate Transaminase (SGPT), Serum Glutamate Oxaloacetate (SGOT), Alkaline Phosphate (ALKP), and direct bilirubin. Silymarin was used as a standard hepatoprotective agent. The biochemical observations were supplemented with histopathological examination of rabbit liver sections. The results of this study strongly indicated that aerial parts of A. bidentatum had potent hepatoprotective action against CCl4 and paracetamol induced hepatic damage in rabbits. These findings revealed A. bidentatum an indigenous plant to be a potentially valuable herb for liver diseases.Item Common fixed point theorem for a hybrid pair of mappings in hausdorff fuzzy metric spaces(University of Management and Technology, 2012) M Abbas; Basit Ali; A Amini-HarandiIn this paper, we prove a coupled fixed point theorem for a multivalued fuzzy contraction mapping in complete Hausdorff fuzzy metric spaces. As an application of the first theorem, a coupled coincidence and coupled common fixed point theorem has been proved for a hybrid pair of multivalued and single-valued mappings. It is worth mentioning that to find coupled coincidence points, we do not employ the condition of continuity of any mapping involved therein. Also, coupled coincidence points are obtained without exploiting any type of commutativity condition. Our results extend, improve, and unify some well-known results in the literature.Item Fusion higher -order parallel splitting methods for parabolic partial differential equations(2012) Muhammad Aziz Ur Rehman; S. A Mardan; M. S. A Taj; A Bhatti. A.A family of numerical methods, based upon a rational approximation to the matrix exponential function, was developed for solving parabolic partial differential equations. These methods were partially sixth-order precise in space and time, due to combination of sixth-order finite approximations and fifth-order pde’s approximations. These methods do not involve the use of complex computation. In these methods second-order spatial derivates were approximated by sixth-order finite difference approximations. Parallel algorithms were developed and tested on the one, two and three-dimensional heat equations, with constant coefficients, subject to homogeneous boundary conditions and time dependent boundary conditions. It was observed that the results obtained through these methods were highly accurate and can be easily coded on serial or parallel computers.Item Time-dependent flow and heat transfer over a stretching cylinder(The Physical Society of Republic of China, 2012) Sufian Munawar; Ahmer Mehmood; Asif AliThe unsteady laminar boundary-layer flow and heat transfer of a viscous fluid over a stretching cylinder is discussed in this work. To normalize the governing system of equations a proper set of similarity variables is used. Two types of thermal boundary conditions, prescribed surface temperature (PST) and prescribed heat flux (PHF), are taken into account for thermal analysis. The governing equations are solved using the homotopy analysis method, and the obtained series solution is found to be valid for the entire temporal and spatial domains and for certain ranges of the other physical parameters. The effects of various material parameters on different physical quantities, such as the coefficient of skin friction and the Nusselt number, are illustrated through graphs and tables.Item Effect of syngas and coal composition on performance of solid oxide fuel cell(2012) Ayesha Mohy-Ud-Din; Mehwish Mujahid; Muhammad Hassan Qayyum KhanGasification technology includes the conversion of fossil fuels into either combustible gas or synthesis gas (syngas) for subsequent utilization. It finds its applications in the production of clean power as well as chemicals. Coal is one of the world's important sources of energy fueling around 40% of the power stations around the world. It is commonly agreed that coal pits will be mined more intensively and in more numbers in the coming years and that lignite and hard coals will be the major energy suppliers until 2100. Integrated gasification fuel cell hybrid power generation system is a promising system for coal utilization. It combines clean coal gasification technology with high efficient fuel cell technology. In this paper, effect of syngas and coal composition on performance of solid oxide fuel cell was studied. It was observed that different ratios of H2 and CO affect the current and voltage of fuel cell. With higher molar fraction of H2 the better output voltage was obtained under the same working conditions. The trace species in coal also affect the performance of solid oxide fuel cell. Ni, Be, Cr, K and Na trace species present in coal also affect the performance to some extent.Item Chemical constituents, proximate composition and hepatoprotective activity of abutilon muticum(Asian Journal of Chemistry, 2012) Sammia Shahid; Muhammad Akram Kashmiri; A Adnan; B AliPhytochemical studies of the aerial parts of Abutilon muticum resulted in the isolation of eight new source compounds, which had not been isolated so far from this investigated source. The compounds isolated were: 3,4',5,6,7-pentahydroxy flavones; 3,3',4',5,7-penta hydroxy flavone-8-O-b-D-glucopyranoside, 3,3',4',5,7-pentahydroxy flavones; stigmasterol, benzoic acid, 1-tricosanol, cholesterol and triacontyl palmitate. Proximate composition of A. muticum revealed that the protein content was appreciable (23.5 %) and similar to that of cotton (28.72 %). As far as human nutritional aspects are concerned A. muticum had significant mineral contents. Potassium is most abundant (443.01 mg/100 g), followed by calcium (395.23 mg/100 g), phosphorus (327.13 mg/100 g) and magnesium (193.42 mg/100 g). In addition hepatoprotective activity of A. muticum was evaluated against hepatic damage in rabbits. The substantially elevated enzyme levels were restored towards normalization significantly by the extracts. The biochemical observations were supplemented with histopathological examination of rabbit liver sections. These findings reveal A. muticum, indigenous to Pakistan to be potentially valuable herb for minerals, delivery of drugs and liver diseases.Item On fuzzy ideals in rings and anti-homomorphism(International Mathematical Forum, 2012) Tariq Shah; Saeed, MuhammadWe investigate anti- homomorphic images and pre images of semiprime, strongly primary, irreducible and strongly irreducible fuzzy ideals of a ring. We also prove that: For a surjective anti-homomorphism f : R → R/, if every fuzzy ideal of R is f-invariant and has a fuzzy primary (respectively, strongly primary) decomposition in R, then every fuzzy ideal of R/ has a fuzzy primary (respectively, strongly primary) decompsition in R/.Item Factorization properties and chain conditions on ideals: A linkage(2012) Saeed, Muhammad; Tariq Shah; Inayatur-Rehman; Waheed Ahmad KhanThe purpose of this study is to find relationship among the various domains. In particular, the domains possessing factorization properties and the domains which hold different chain conditions on ideals.Item Entropy generation in hydrodynamic slip flow over a vertical plate with convective boundary(Springer, 2012) Adnan Saeed Butt; Sufian Munawar; Asif Ali; Ahmer MehmoodThe present article aims to report the effects of hydrodynamic slip on entropy generation in the boundary layer flow over a vertical surface with convective boundary condition. Suitable similarity transformations are used to transform the fundamental equations of hydrodynamic and thermal boundary layer flow into ordinary differential equations. The governing equations are then solved numerically using the shooting method and the velocity and the temperature profiles are obtained for various values of parameters involved in the governing equations. The expressions for the entropy generation number and the Bejan number are presented and the results are discussed graphically and quantitatively for the slip parameter, the local Grashof number, the Prandtl number, the local convective heat transfer parameter, the group parameter and the local Reynolds number. It is observed that due to the presence of slip, entropy production in a thermal system can be controlled and reduced.Item Unsteady flow and heat transfer in a composite porous annulus with time-dependent injection(VERLAG Z NATURFORSCH, 2012) Muhammad Nasir; Sufian Munawar; Ahmer Mehmood; Asif AliIn the present study, we deal with the momentum and heat transfer analysis in a horizontal annulus of a composite porous medium. The Darcy–Brinkman model is used to develop the governing equations for the flow and heat transfer phenomenon. The annulus injects the time dependent oscillatory velocity normal to its surface. Both the regions of the flow have their own viscosities, and the heat transfer analysis is carried out by retaining viscous dissipation. The governing equations for flow and heat transfer are solved analytically using a perturbation series for solutions in both regions of the annulus. A brief parametric analysis is performed for the velocity and the temperature profiles through graphs.Item Fourth-order method for the solution of diffusion equation subject to the specification of energy(Society of Physics and Natural History of Geneva, 2012) Muhammad Aziz Ur Rehman; M. S. A. Taj; Muhammad Saeed; I. RehmanA fourth-order numerical technique is developed for the solution of the diffusion equation ( ut =uxx + s x, t),0 < x < X,0 < t £ T, subject to u(x,0) = f (x),0 < x < X,u(1, t) = g(t),0 < t £ T and the specification of energy 0 ( , ) ( ), 0 , 0 b u x t dx = M t < b < X < t £ T .Item Suzuki type fixed point theorems for generalized multi-valued mappings on a set endowed with two b-metrics(Elsevier, 2012) Ljubomir C´ iric´; Mujahid Abbas; Miloje Rajovic´; Basit AliIn this paper, we obtained Suzuki type fixed point results for a generalized multi-valued mapping on a set equipped with two b-metrics. As a consequence, existence and uniqueness of solution of functional equation arising in dynamical programming is also derivedItem Fuzzy transitivity and monotonicity of cardinality-based similarity measures(Springer, 2012) S. Ashraf; S. M. Husnine; Tabasam RashidThe interrelationship of notions is presented in fuzzy transitivity and monotonicity of fuzzy similarity measures. It is observed that the axiom of fuzzy transitivity may replace that of monotonicity in the definition of fuzzy similarity measures.Item Thermal analysis of the flow over an oscillatory stretching cylinder(IOP Publishing, 2012) Sufian Munawar; Asif Ali; Ahmer MehmoodAn investigation has been conducted on the convective heat transfer and the entropy production attributable to the presence of an infinitely long cylinder in a viscous fluid exhibiting oscillatory motion. The heat transfer analysis is carried out by assuming that the surface of the cylinder is isothermal. The entropy generation is caused by heat transfer attributable to the finite temperature difference MT and viscous effects produced in the fluid. The number of independent variables in the governing equations is reduced by using a proper set of similarity variables. To obtain the solution of the nonlinear partial differential equation, we use a well-known finite difference scheme by transforming the semi-infinite domain to a finite domain. The numerical results have been analyzed by means of a comprehensive parametric study. It is observed that the entropy production intensifies in the presence of the oscillatory motion of the cylinder.