MHD stagnation flow of nanofluid past a permeable shrinking surface with various conditions

The purpose of the present study is to analyze the effects of slip and heat source/sink on magnetohydrodynamic stagnation-point flow and heat transfer past a permeable shrinking surface with convective boundary condition. The velocity and temperature profiles are analyzed with respect to the involved parameter such as slip parameter, magnetic parameter, heat source/sink parameter, Brownian motion parameter, thermophoresis parameter, suction parameter, shrinking parameter, Prandtl number, Biot number and Lewis number. Using a similarity transformation, the governing partial differential equations are transformed into nonlinear ordinary differential equations and the numerical solutions are solved by bvp4c in Matlab software. The numerical results indicate that the velocity increases with the increase in the values of slip parameter and suction parameter. The temperature profile increases as the increase of the Biot number and heat generation parameter whereas the increases of the heat absorption reduce the temperature

Magnetohydrodynamic Viscous Flow Over a Shrinking Sheet With Second Order Slip Flow Model

In this paper, we investigate the magnetohydrodynamic viscous flow with second order slip flow model over a permeable shrinking surface. We have obtained the closed form of exact solution of Navier-Stokes equations by using similarity variable technique. The effects of slip, suction and magnetic parameter have been investigated in detail. The results show that there are two solution branches, namely lower and upper solution branch. The behavior of velocity and shear stress profiles for different values of slip, suction and magnetic parameters has been discussed through graphs.Comment: 13 Pages, 8 Figures. Accepted for Publication in Heat Transfer Researc

Axisymmetric stagnation-point flow over a stretching/shrinking plate with second-order velocity slip

AbstractThe axisymmetric stagnation point flow over a stretching/shrinking surface with second-order slip and temperature jump is studied numerically. The governing partial differential equations are transformed into ordinary (similarity) differential equations. These equations along with the corresponding boundary conditions are solved numerically using a boundary value problem solver bvp4c in Matlab software. It is observed that dual (first and second) solutions exist for the similarity equations. The effects of different parameters on the velocity and the temperature distributions as well as the skin friction coefficient and the Nusselt number are analyzed and discussed

MHD free convection-radiation interaction in a porous medium - part I : numerical investigation

A numerical investigation of two dimensional steady magnetohydrodynamics heat and mass transfer by laminar free convection from a radiative horizontal circular cylinder in a non-Darcy porous medium is presented by taking into account the Soret/Dufour effects. The boundary layer conservation equations, which are parabolic in nature, are normalized into non-similar form and then solved numerically with the well-tested, efficient, implicit, stable Keller–Box finite-difference scheme. We use simple central difference derivatives and averages at the mid points of net rectangles to get finite difference equations with a second order truncation error. We have conducted a grid sensitivity and time calculation of the solution execution. Numerical results are obtained for the velocity, temperature and concentration distributions, as well as the local skin friction, Nusselt number and Sherwood number for several values of the parameters. The dependency of the thermophysical properties has been discussed on the parameters and shown graphically. The Darcy number accelerates the flow due to a corresponding rise in permeability of the regime and concomitant decrease in Darcian impedance. A comparative study between the previously published and present results in a limiting sense is found in an excellent agreement

Bio-nanotechnology application in wastewater treatment

The nanoparticles have received high interest in the field of medicine and water purification, however, the nanomaterials produced by chemical and physical methods are considered hazardous, expensive, and leave behind harmful substances to the environment. This chapter aimed to focus on green-synthesized nanoparticles and their medical applications. Moreover, the chapter highlighted the applicability of the metallic nanoparticles (MNPs) in the inactivation of microbial cells due to their high surface and small particle size. Modifying nanomaterials produced by green-methods is safe, inexpensive, and easy. Therefore, the control and modification of nanoparticles and their properties were also discussed

Pengaruh zikir terhadap kesihatan mental dan tekanan psikologi dalam mendepani cabaran revolusi industri 4.0

Revolusi Industri 4.0 (IR4) telah memberi implikasi negatif terhadap kesihatan mental dan psikologi dalam masyarakat seperti kemurungan, kebimbangan dan tekanan perasaan. Masalah-masalah ini mampu diatasi dengan amalan zikir sebagai terapi psikospiritual berunsur kerohanian Islam. Kajian ini berbentuk kualitatif dengan menggunakan kaedah temu bual separa-berstruktur serta analisis secara deduktif, induktif dan tematik untuk mengetahui kesan sebelum dan selepas berzikir secara berjemaah. Pendekatan Lataif Qur’aniyyah digunakan untuk memaknakan kedudukan al-zikr dan pengamalannya lebih meluas. Peserta-peserta majlis zikir bulanan dalam kajian ini terdiri daripada 83 orang dan diadakan di Kediaman Rasmi Menteri Besar Selangor. Hasil kajian menunjukkan ‘zikir bersanad’ yang diamalkan secara konsisten merupakan santapan rohani terbaik dalam mempengaruhi jiwa dan emosi individu ke arah celik akal yang menjadi matlamat kemuncak dalam kaunseling. Hal ini berkesan dalam membantu perubahan minda dan tingkah laku manusia dalam pembentukan keluarga dan masyarakat yang bersahsiah dan harmoni. Justeru, zikir yang bersanad, yakni dalam bimbingan bersama guru rohani (Mursyid), dengan fokus niat untuk mencapai ‘keterhubungan kerohanian’ dengan Nabi Muhammad (s.a.w.) dan ‘jiwa fakir’ kepada Allah (s.w.t.), serta memenuhi adab-adab dan syarat-syarat takwa adalah terapi psikospiritual yang mujarab dalam merawat pelbagai masalah mental

Gagasan negara zikir negara Brunei Darussalam: kejayaan dan cabaran

Gagasan Negara Zikir sebagai sebuah modul melahirkan masyarakat yang mempunyai kekuatan peribadi sebagaimana peribadi Nabi Muhammad s.a.w. Ia penting bagi melahirkan tamadun material dan kerohanian dalam kehidupan moden menjelang Wawasan Brunei 2035. Gagasan negara Zikir bukan bermaksud membentuk masyarakat mengejar ukhrawi semata tetapi ia memperkukuh dan mempertinggikan keupayaan masyarakat Islam Brunei mengurus hal ehwal yang bersangkutan dengan kehidupan duniawi dan ukhrawi. Oleh itu kertas kerja ini membincangkan beberapa faktor kejayaan pelaksanaan Negara Zikir Negara Brunei Darussalam di antaranya Polisi Asas Pembagunan Negara Zikir, Falsafah Negara Melayu Islam Beraja (MIB) dan lain-lain. Di samping itu kertas kerja ini juga menjelaskan bahawa terdapat banyak faktor dalaman dan luaran yang berkait rapat dengan cabaran dan halangan yang boleh menghalang proses pelaksanaan Negara Zikir secara berkesan. Ia meliputi soal kurangnya kefahaman dan penghayatan keagamaan, keruntuhan institusi kekeluargaan serta penguatkuasaan hukuman yang kurang memberikan kesan. Kesimpulannya, Negara Zikir adalah kerajaan Islam bukan kerajaan agama (teokrasi) atau kependetaan. Buktinya adalah sebuah kerajaan sivil dan moden yang menjadikan syariat Islam sebagai dasar dan landasan perundangan yang tertinggi

Effects of Heat Transfer on the Stagnation Flow of a Third-Order Fluid over a Shrinking Sheet

This paper is devoted to the study of a stagnation point flow of an incompressible third-order fluid towards a shrinking sheet (with heat transfer). The governing nonlinear partial differential equations are reduced into nonlinear ordinary differential equations by means of a similarity transformation and then solved by the homotopy analysis method. Two types of flow problems, namely, (i) two dimensional stagnation flow toward a shrinking sheet and (ii) axisymmetric stagnation flow towards an axisymmetric shrinking surface have been discussed. Also, two types of boundary conditions are taken into account: (i) prescribed surface temperature (PST) and (ii) prescribed heat flux (PHF) case. The effects of various emerging parameters of non-Newtonian fluid have been investigated in detail and shown pictorically. The convergence of the solutions have been discussed through h-curves and residual error. For further validity, the homotopy Pade approximation is also applied