Showing papers by "International Islamic University, Islamabad published in 2015"
TL;DR: In this paper, the effect of thermal radiation on magnetohydrodynamics nanofluid flow between two horizontal rotating plates is studied and the significant effects of Brownian motion and thermophoresis have been included in the model of Nanofluide.
802 citations
TL;DR: In this paper, the effects of Brownian motion on the effective viscosity and thermal conductivity of nanofluid were investigated. And the results were presented graphically in terms of streamlines, isotherms and isokinetic energy.
604 citations
TL;DR: The main uses of natural food ingredients derived from mango by-products are presented and discussed, and the mainstream sectors of application for these by- products, such as in the food, pharmaceutical, nutraceutical and cosmetic industries, are highlighted.
395 citations
TL;DR: In this article, a mathematical model is analyzed in order to study the natural convection boundary layer flow along an inverted cone, where the shape of nanosize particles on entropy generation with based fluid is considered.
394 citations
TL;DR: Cadmium bioaccessibility and bioavailability were found to be significantly higher in yellow soil (YS) rice than calcareous soil (CS) rice, and toxicity assays showed an initial toxicity in YS rice at 6 mg kg(-1) Cd, whereas CS rice did not show any significant change due to low Cd concentrations.
Abstract: Cadmium (Cd) enters the food chain from polluted soils via contaminated cereals and vegetables; therefore, an understanding of Cd bioaccessibility, bioavailability, and toxicity in humans through rice grain is needed. This study assessed the Cd bioaccessibility, bioavailability, and toxicity to humans from rice grown on Cd-contaminated soils using an in vitro digestion method combined with a Caco-2/HL-7702 cell model. Cadmium bioaccessibility (18.45-30.41%) and bioavailability (4.04-8.62%) were found to be significantly higher in yellow soil (YS) rice than calcareous soil (CS) rice with the corresponding values of 6.89-11.43 and 1.77-2.25%, respectively. Toxicity assays showed an initial toxicity in YS rice at 6 mg kg(-1) Cd, whereas CS rice did not show any significant change due to low Cd concentrations. The acidic soils of Cd-contaminated areas can contribute to a higher dietary intake of Cd. Therefore, it is imperative to monitor Cd concentration in rice to minimize human health risk.
135 citations
TL;DR: The integrated waqf-based Islamic micro-finance model (IWIMM) as discussed by the authors was earlier developed using literature and intellectual discussions to overcome the financial, ethical and human capital deficiencies faced by the conventional financial institutions.
Abstract: Purpose – This paper aims to develop an integrated waqf-based Islamic microfinance (IsMF) for poverty reduction in Bangladesh. Microfinance institutions (MFIs) have been constrained by the high cost of funds, high interest rate charges and poor human resource quality of the recipients. Islamic MFIs have recently evolved with the hope of overcoming these financial, ethical and human capital deficiencies faced by the conventional financial institutions. Moreover, a good number of integrated models have been proposed to enhance the role played by Islamic MFIs. Most of these models, however, lack empirical justifications. Design/methodology/approach – The research uses survey techniques. A total of 381 respondents were included in the survey. The integrated waqf-based Islamic microfinance model (IWIMM) was earlier on developed using literature and intellectual discussions. There are six constructs presenting the IWIMM, namely, waqf resources, IsMF, takaful, project financing, human resource development and po...
123 citations
TL;DR: In this article, the closed-form solutions of peristaltic flow of Jeffery fluid under the simultaneous effects of magnetohydrodynamics (MHD) and partial slip conditions in a rectangular duct are studied.
123 citations
TL;DR: The proposed scheme is evaluated on two initial value problems of the Riccati fractional order equation with integer and non-integer derivatives and is validated using results of statistical analysis based on a sufficiently large number of independent runs.
114 citations
TL;DR: This paper analyzed the security of the proposed scheme in random oracle model which confirms the robustness of the scheme against all known attacks and proposed a supplemented scheme to overcome security weaknesses of Kumari et al.
Abstract: Very recently, Kumari et al. proposed a symmetric key and smart card-based remote user password authentication scheme to enhance Chung et al.'s scheme. They claimed their enhanced scheme to provide anonymity while resisting all known attacks. In this paper, we analyze that Kumari et al.'s scheme is still vulnerable to anonymity violation attack as well as smart card stolen attack. Then we propose a supplemented scheme to overcome security weaknesses of Kumari et al.'s scheme. We have analyzed the security of the proposed scheme in random oracle model which confirms the robustness of the scheme against all known attacks. We have also verified the security of our scheme using automated tool ProVerif. Copyright © 2015 John Wiley & Sons, Ltd.
92 citations
TL;DR: In this paper, Ni dopant induced excessive structural changes such as decrease in crystallite size as well as lattice constants and enhancement in oxygen vacancies in CeO 2 crystal structure.
92 citations
TL;DR: In this article, the structural and electronic properties of beryllium (Be) doped and Be and boron (B) co-doped graphene systems were investigated, and it was observed that not only the concentration of impurity atoms is important to tune the bandgap to some desired level, but also the specific substitution sites play a key role.
Abstract: First-principles density functional theory (DFT) calculations were carried out to investigate the structural and electronic properties of beryllium (Be) doped and Be and boron (B) co-doped graphene systems. We observed that not only the concentration of impurity atoms is important to tune the band-gap to some desired level, but also the specific substitution sites play a key role. In our system, which consists of 32 atoms, a maximum of 4Be and, in the co-doped state, 2Be and 3B atom substitutions are investigated. Both dopants are electron deficient relative to C atoms and cause the Fermi level to shift downward (p-type doping). A maximum band gap of 1.44 eV can be achieved on incorporation of 4Be atoms. The introduction of Be is more sensitive in terms of geometry and stability than B. However, in opening the energy gap, Be is more effective than B and N (nitrogen). Our results offer the possibility to modify the band-gap of graphene sufficiently for utilization in diverse electronic device applications.
TL;DR: In this paper, the effect of stress ratio or mean stress on fatigue delamination growth in composites is reviewed and classified according to their mode of fracture, using a unified correlating parameter.
TL;DR: The server can now authenticate the user on the request message received, rather than the response received upon sending the challenge message, saving another round-trip of exchanged messages and hence escapes a possible denial of service attack.
Abstract: The Session Initiation Protocol (SIP) has revolutionized the way of controlling Voice over Internet Protocol (VoIP) based communication sessions over an open channel. The SIP protocol is insecure for being an open text-based protocol inherently. Different solutions have been presented in the last decade to secure the protocol. Recently, Zhang et al. authentication protocol has been proposed with a sound feature that authenticates the users without any password-verifier database using smart card. However, the scheme has a few limitations and can be made more secure and optimized regarding cost of exchanged messages, with a few modifications. Our proposed key-agreement protocol makes a use of two server secrets for robustness and is also capable of authenticating the involved parties in a single round-trip of exchanged messages. The server can now authenticate the user on the request message received, rather than the response received upon sending the challenge message, saving another round-trip of exchanged messages and hence escapes a possible denial of service attack.
TL;DR: In this article, the blood flow of Prandtl fluid through a tapered stenosed arteries having permeable walls is modelled in cylindrical coordinates with the help of non-dimensional variables under the assumption of mild stenosis.
Abstract: This Communication deals with the blood flow of Prandtl fluid through a tapered stenosed arteries having permeable walls. The governing equations of two-dimensional Prandtl fluid model are modelled in cylindrical coordinates. The highly nonlinear equations are simplified with the help of non-dimensional variables under the assumption of mild stenosis. The solution of reduced nonlinear equation subject to boundary condition of porous walls having the effects of Darcy's number and slip parameter are computed analytically with the help of perturbation method. Effects of emerging parameters such as impedance λ, slip parameter α, stenosis height δ, magnetic parameter and stress component Srz on velocity are illustrated graphically. The streamlines have also been presented to discuss the trapping bolus discipline.
TL;DR: In this article, X-ray diffraction (XRD) results of the synthesized samples reveal the monoclinic structure of CuO without any impurity related phases and the micro-structural parameters such as crystallite size and microstrain have been strongly influenced by Zndoping.
Abstract: ZnxCu1−xO (where x= 0, 0.01, 0.03, 0.05, 0.07 and 0.1 mol%) hierarchical nanostructures have been prepared via soft chemical route. X-ray diffraction(XRD) results of the synthesized samples reveal the monoclinic structure of CuO without any impurity related phases. The micro-structural parameters such as crystallite size and microstrain have been strongly influenced by Zndoping.Scanning electron microscope(SEM) analyses depict the formation of hierarchical nanostructures having average particle size in the range of 26-43 nm. The surface area of CuO nanostructures has been reduced systematically with the increase in Zn content which is linked with the variations in particle size. An obvious decrease in the optical band gap energy of the synthesized CuO hierarchical nanostructures has been observed with Zndoping which is assigned to the formation of shallow levels in the band gap of CuO and combined transition from oxygen 2p states to d sates of Cu and Zn ions. The bactericidal potency of the CuO hierarchical nanostructures have been found to be enhanced remarkably with Zndoping.
TL;DR: In this article, a novel adaptive strategy is designed based on fractional least mean square (LMS) algorithm for parameter estimation of Hammerstein nonlinear autoregressive moving average system with exogenous noise (HN-ARMAX).
Abstract: In this study, a novel adaptive strategy is designed based on fractional least mean square (LMS) algorithm for parameter estimation of Hammerstein nonlinear autoregressive moving average system with exogenous noise (HN-ARMAX). The design scheme consists of parameterization of HN-ARMAX systems to obtain linear-in-parameter models and to use fractional LMS algorithm for adapting unknown parameter vectors. The performance analysis of the proposed method is carried out based on convergence to the desired values of HN-ARMAX systems, and comparison is made with state-of-the-art kernel LMS and Volterra LMS algorithms. The consistency in terms of accuracy and convergence is established through the results of statistical analysis based on sufficient large number of independent runs rather than single successful run of the algorithm. The performance of proposed scheme is superior due to its strong mathematical foundations, nonlinear weight updating mechanism and more convergence controlling variables but at the cost of bit more computational requirements.
TL;DR: In this paper, the authors studied the Joules heating effects on stagnation point flow of Newtonian and non-Newtonian fluids over a stretching cylinder by means of GA and found the analytical and numerical solutions for the said mathematical model.
Abstract: Purpose – The purpose of this paper is to study the Joules heating effects on stagnation point flow of Newtonian and non-Newtonian fluids over a stretching cylinder by means of genetic algorithm (GA). The main emphasis is to find the analytical and numerical solutions for the said mathematical model. The work undertaken is a blend of numerical and analytical studies. Effects of active parameters such as: Hartmann number, Prandtl number, Eckert number, Nusselt number, Skin friction and dimensionless fluids parameters on the flow and heat transfer characteristics have been examined by graphs and tables. Compression is also made with the existing benchmark results. Design/methodology/approach – Analytical solutions of non-linear coupled equations are developed by optimal homotopy analysis method (OHAM). A very effective and higher order numerical scheme hybrid GA and Nelder-Mead optimization Algorithms are used for numerical investigations. Findings – An excellent agreement with the existing results in limit...
TL;DR: The annual effective dose for all detected radionuclides for all study locations has been found to be within UNSCEAR acceptable limits as has the associated life-time cancer risk.
Abstract: The environment of the Straits of Malacca receives pollution as a result of various industrial and anthropogenic sources, making systematic studies crucial in determining the prevailing water quality. Present study concerns concentrations of natural radionuclides and heavy metals in marine fish (Rastrelliger kanagurta) collected from the Straits of Malacca, since aquatic stock form an important source of the daily diet of the surrouding populace. Assessment was made of the concentrations of key indicator radionuclides (226Ra, 232Th, 40K) and heavy metals (As, Mn, Fe, Cr, Ni, Zn, Cu, Co, Sr, Al, Hg and Pb) together with various radiation indices linked to the consumption of seafish. The annual effective dose for all detected radionuclides for all study locations has been found to be within UNSCEAR acceptable limits as has the associated life-time cancer risk. The overall contamination of the sampled fish from heavy metals was also found to be within limits of tolerance.
TL;DR: A comparison of structural and magnetic properties of as-prepared and annealed (900°C) Mg doped Zn ferrite nanoparticles (Zn 1− x Mg x Fe 2 O 4, with x = 0, 0.1, 0 2, 0 3, 0 4 and 0.5) is presented in this paper.
TL;DR: In this paper, the combined effects of partial slip and prescribed surface heat flux when the fluid is moving due to stretching cylinder were analyzed using Chebyshev Spectral Newton Iterative Scheme (CSNIS).
Abstract: This study is dedicated to analyze the combined effects of partial slip and prescribed surface heat flux when the fluid is moving due to stretching cylinder. A very moderate and powerful technique Chebyshev Spectral Newton Iterative Scheme is used to determine the solution of the present mathematical model. Involved physical parameters, namely the slip parameter, Casson fluid parameter, curvature parameter and Prandtl number are utilized to control the fluid moments and temperature distribution. The results show that the fluid velocity and the skin friction coefficient on the stretching cylinder are strongly influenced by the slip parameter. It is further analyzed that hydrodynamic boundary layer decreases and thermal boundary layer increases with the slip parameter. Influence of Casson fluid parameter on temperature profile provides the opposite behavior as compared to the slip parameter. The comparison of numerical values of skin friction coefficient and the local Nusselt number is made with the results available in the literature. The accuracy and convergence of Chebyshev Spectral Newton Iterative Scheme is compared with finite difference scheme (Keller box method) through tables. The CPU time is calculated for both schemes. It is observed that CSNIS is efficient, less time consuming, stable and rapid convergent.
TL;DR: An efficient lightweight signcryption scheme based on HECC which fulfills all the security requirements and reduced significant amounts of computation, communication costs and message size as compared to existing signc encryption schemes making it the good candidate for environments suffer from the resource limitation problems.
Abstract: The need for Lightweight cryptography is on the rise as transition has been made from wired to wireless network. Wireless systems inherently are insecure and resource (power) constrained, to deal with these constraints, many techniques for symmetric and asymmetric cryptography are defined. One such important developement is Signcryption to achieve message confidentiality, integrity, sender and message authentication, non repudiation, forward secrecy as well as unforgeability,and public verifiability. Since Signcryption combines the signature and encryption therefore the cost is very less in comparison to those schemes based on the signature then encryption. Many signcryption schemes have been proposed based on El-Gamal, RSA and ECC till today. This paper highlights limitations of the existing ECC based schemes using signcryption. These limitations include some missing security aspects as well as high computation power requirement, more communication overhead incurred and large memory requirements. Further it proposes an efficient lightweight signcryption scheme based on HECC which fulfills all the security requirements. The scheme reduced significant amounts of computation, communication costs and message size as compared to existing signcryption schemes making it the good candidate for environments suffer from the resource limitation problems.
TL;DR: In this article, the authors compared the accuracy of two logistic models; Multinomial Logistic Regression and Neural Network to create a model of rating probability from several financial variables.
Abstract: The development of Sukuk market as the alternative to the existing conventional bond market has risen the issue of rating the Sukuk issuance. These credit ratings fulfill a key function of information transmission in capital market. Moreover, Basel Committee for Banking Supervision has now instituted capital charges for credit risk based on credit ratings. Basel II framework allowed the bank to establish capital adequacy requirements based on ratings provided by external credit rating agencies or determine rating of its investment internally for more advance approach. For these reasons, ratings are considered important by issuers, investors, and regulators alike. This study provides an empirical foundation for the investors to estimate the ratings assigned using the approach from several rating agencies and past researches on bond ratings. It tries to compare the accuracy of two logistic models; Multinomial Logistic Regression and Neural Network to create a model of rating probability from several financial variables.
TL;DR: Initial results show that TH Rank can effectively identify the most prestigious authors, papers and journals related to a specific topic, which is a vital tool for identifying authorities of a given topic within a particular domain.
Abstract: Topic-based ranking of authors, papers and journals can serve as a vital tool for identifying authorities of a given topic within a particular domain. Existing methods that measure topic-based scholarly output are limited to homogeneous networks. This study proposes a new informative metric called Topic-based Heterogeneous Rank (TH Rank) which measures the impact of a scholarly entity with respect to a given topic in a heterogeneous scholarly network containing authors, papers and journals. TH Rank calculates topic-dependent ranks for authors by considering the combined impact of the multiple factors which contribute to an author's level of prestige. Information retrieval serves as the test field and articles about information retrieval published between 1956 and 2014 were extracted from web of science. Initial results show that TH Rank can effectively identify the most prestigious authors, papers and journals related to a specific topic.
TL;DR: In this paper, undoped and Co-doped CeO 2 nanoparticles have been prepared by facile, cost effective and easily reproducible chemical co-precipitation technique.
TL;DR: In this paper, an analysis of the peristaltic pumping of a non-Newtonian Ellis fluid in a planar channel was carried out, and the coupled nonlinear partial differential equations governing the problem were simplified under the widely used assumption of long wavelength and low Reynolds number.
Abstract: An analysis is carried out to investigate the peristaltic pumping of a non-Newtonian Ellis fluid in a planar channel. The coupled nonlinear partial differential equations governing the problem are simplified under the widely used assumption of long wavelength and low Reynolds number. A semi- analytical approach is adopted to obtain the expressions for stream function, longitudinal velocity, pressure gradient and pressure rise per wavelength. The important characteristics of the peristaltic motion are explained graphically for several values of the material parameter of the Ellis fluid.
TL;DR: In this article, a conceptual model for mentors and discusses that an entrepreneur may need different mentoring support and skills depending on the type of entrepreneurs, personality traits, or decision-making style and phase at which entrepreneurs are at that moment.
Abstract: A mentor plays an important role in entrepreneurial development of an individual. He guides entrepreneurs from conception of business to product development and business growth. Previous literature on entrepreneurial learning is disseminated and not properly organized; it is difficult to even find pertinent and comprehensive articles on entrepreneurial learning. The research proposed in this article helps mentors to understand and find out what type of entrepreneurs need what kind of mentoring support. This article proposes a conceptual model for mentors and discusses that an entrepreneur may need different mentoring support and skills depending on the type of entrepreneurs, personality traits, or decision-making style and phase at which entrepreneurs are at that moment. This article will also help mentors in understanding what type of skills entrepreneurs need at each stage of mentoring relationship, that is, initiation, cultivation, separation, and redefinition stage.
TL;DR: The accuracy and convergence of the proposed scheme is analyzed on large data set generated through statistical analysis based on sufficient number of independent runs of the algorithm and result in term of performance measures established the worth of the scheme.
TL;DR: In this article, modified fractional least mean square (FrLMS) algorithms are formulated for parameter estimation of Hammerstein nonlinear control autoregressive system (HNCAR) by exploiting the fractional calculus concepts in weight adaptation mechanism of the algorithm.
Abstract: In this study, modified fractional least mean square (FrLMS) algorithms are formulated for parameter estimation of Hammerstein nonlinear control autoregressive system (HNCAR) by exploiting the fractional calculus concepts in weight adaptation mechanism of the algorithm. In modified FrLMS (MFrLMS) of first kind, forgetting factor is applied to exploit the strength of both standard LMS and FrLMS algorithms. The MFrLMS algorithm of second kind is based on single fractional weight adaptation term in cost function for finding the optimal values instead of considering both fractional and first derivative terms as in FrLMS approach. Performance analysis of the proposed methods are carried out on the basis of optimization ability to the true values of HNCAR system, and comparison is made in terms of accuracy, convergence and complexity. Reliability and effectiveness of the proposed scheme is validated through performance indices based on mean square error, variance account for and Nash Sutcliffe efficiency for sufficient large number of independent runs.
TL;DR: In this paper, the mediating role of leader-member exchange in the relationship between organizational justice and job performance was examined and a series of separate hierarchical regression analysis was used to test the hypothesis.
Abstract: Purpose – The purpose of this paper is to examine the mediating role of leader-member exchange in the relationship between organizational justice and job performance. The study primarily focused on the perception of university libraries personnel regarding organizational justice practices and the quality of their relationship with their supervisors and how such perceptions predict their job performance. Design/methodology/approach – This study tested a sample of 15 university libraries of Islamabad, Pakistan. Data were accumulated through questionnaire and analyzed on SPSS. Descriptive and correlation analysis showed the positive and significant relationship between all variables. Series of separate hierarchical regression analysis were used to test the hypothesis. Findings – The result revealed that all three kinds of organizational justices (distributive justice, procedural justice and interactional justice) predict the job performance but interactional justice along with leader-member exchange impacts ...