A 3D CFD analysis of flow past a hipped roof with comparison to industrial building standards

Khalid Khalil,Huzafa Khan,Divyansh Chahar,Jamie F. Townsend,Zeeshan A. Rana 한국풍공학회 2022 Wind and Structures, An International Journal (WAS Vol.34 No.6

Three-dimensional (3D) computational fluid dynamics (CFD) analysis of flow around a hipped-roof building representative of UK inland conditions are conducted. Unsteady simulations are performed using three variations of the k–ϵ RANS turbulence model namely, the Standard, Realizable, and RNG models, and their predictive capability is measured against current European building standards. External pressure coefficients and wind loading are found through the BS 6399-2:1997 standard (obsolete) and the current European standards (BS EN 1991-1-4:2005 and A1:20101). The current European standard provides a more conservative wind loading estimate compared to its predecessor and the k–ϵ RNG model falls within 15% of the value predicted by the current standard. Surface shear stream-traces and Q-criterion were used to analyze the flow physics for each model. The RNG model predicts immediate flow separation leading to the creation of vortical structures on the hipped-roof along with a larger separation region. It is observed that the Realizable model predicts the side vortex to be a result of both the horseshoe vortex and the flow deflected off it. These model-specific aerodynamic features present the most disparity between building standards at leeward roof locations. Finally, pedestrian comfort and safety criteria are studied where the k–ϵ Standard model predicts the most ideal pedestrian conditions and the Realizable model yields the most conservative levels.

Non Darcy Mixed Convection Flow of Magnetic Fluid over a Permeable Stretching Sheet with Ohmic Dissipation

A. Zeeshan,A. Majeed 한국자기학회 2016 Journal of Magnetics Vol.21 No.1

This paper aims to discuss the Non Darcy boundary layer flow of non-conducting viscous fluid with magnetic ferroparticles over a permeable linearly stretching surface with ohmic dissipation and mixed convective heat transfer. A magnetic dipole is applied “a” distance below the surface of stretching sheet. The governing equations are modeled. Similarity transformation is used to convert the system of partial differential equations to a system of non-linear but ordinary differential equations. The ODEs are solved numerically. The effects of sundry parameters on the flow properties like velocity, pressure, skin-friction coefficient and Nusselt number are presented. It is deduced the frictional resistance of Lorentz force decreases with stronger electric field and the trend reverses for temperature. Skin friction coefficient increase with increase in ferromagnetic interaction parameter. Whereas, Nusselt number decrease.

Simultaneous Effects of Slip and Wall Stretching/Shrinking on Radiative Flow of Magneto Nanofluid Through Porous Medium

A. Zeeshan,H. F. Ismael,M. A. Yousif,T. Mahmood,S. U. Rahman Korean Magnetics Society 2018 Journal of Magnetics Vol.23 No.4

Effects of the uniform magnetic field on aqueous magneto-Nanofluid confined in a porous domain with wall stretching/shrinking non-linearly is analyzed via this communication. The problem is modeled using continuity, momentum and energy equation along with linear thermal radiation. The effects of physical quantities are observed for Cu, Al₂O₃, TiO₂ and Ag particles in water. The coupled boundary layer PDE’s are reduced into the system of ODEs by utilizing similarity transformation and solved using shooting and Runga-Kutta fourth order technique. Stability of the obtained results are also analyzed. The results are displayed through graphs. It is observed that the momentum boundary layer is thicker when silver particles are introduced in water. Whereas, temperature profile has the minimum value for silver nanoparticles and maximum for Titanium dioxide. Also, in case of shrinking sheet dual solutions are obtained along with smallest Eigen values.

A new genus and new species of diplurid spider (Araneae: Mygalomorphae: Dipluridae) from northeast India

Zeeshan A. Mirza,Rajesh V. Sanap,Krushnamegh Kunte 국립중앙과학관 2017 Journal of Asia-Pacific Biodiversity Vol.10 No.1

A new diplurid genus and species is described from northeast India based on a single female specimen from Jampui hills. Orientothele gen. nov. is placed in the subfamily Diplurinae based on the presence of one row of teeth on the chelicerae. The new genus and species can be diagnosed from most diplurid genera in lacking lyra on the prolateral face of maxilla, paired claw with one row of teeth, maxilla with numerous cuspules, scopulae absent on all legs, and spermathecae consisting of two elongate stalks with bulbous receptacles at their tips which are bent inwards. Ischnothele indicola Tikader, 1969 is here treated as incertae sedis with regards to its generic placement in light of the discovery of Orientothele gen. nov.

Effects of External Magnetic Field on non-Newtonian Two Phase Fluid in an Annulus with Peristaltic Pumping

A. Riaz,A. Zeeshan,S. Ahmad,A. Razaq,M. Zubair 한국자기학회 2019 Journal of Magnetics Vol.24 No.1

This paper comprises the exact solutions of Non-Newtonian multiphase fluid through peristaltic pumping characteristics in an annulus having complaint walls and applied magnetic field. The mechanics of the geometry are defined cylindrical due to its large number of utilizations in medicine and biological apparatus. The external cylinder is having sinusoidal waves travelling along its walls. The problem is simplified by some suitable and valid approximations. The authors have obtained the accurate solutions of the velocities of two phases. The effects of appertaining parameters have been displayed through graphs of velocity for v and particulate phases and the behavior of curves are manipulated accordingly. It is concluded that applied magnetic field decreases the velocity of both the fluid and the particles flow.

A new large trapdoor spider species of the genus Heligmomerus Simon 1892 (Araneae, Mygalomorphae, Idiopidae) from Western Ghats, India

Rajesh V. Sanap,Zeeshan A. Mirza 국립중앙과학관 2015 Journal of Asia-Pacific Biodiversity Vol.8 No.3

A new species of trapdoor spider, Heligmomerus maximus sp. nov. is described from southern Western Ghats of Kerala state, India. The new species differs from known species of the genus from India and Sri Lanka in possessing a band of thorn-like spinules on coxa IV. Moreover it is the largest species of the genus with adult females reaching a length up to 32 mm and the burrows are shallow compared with other species of the genus.

Double threshold based optimal device selection scheme for D2D or Sidelink network

Shamganth Kumarapandian,Qasim Zeeshan Ahmed,Faheem A. Khan 한국통신학회 2023 ICT Express Vol.9 No.1

Device-to-device (D2D) or Sidelink aided communication is regarded as one of the most promising technologies to improve the spectral efficiency of the 5G and beyond communication system. However, two main challenges exist: 1) the selection of the optimal number of devices for improving the spectral efficiency, and 2) improving the physical layer security of such a communication system. The optimal device improves the secrecy capacity, and the selection of optimal devices enhances the physical layer security. Therefore, in this paper, we propose a double threshold-based optimal device selection (ODS) scheme for a cooperative wireless network with amplify and forward (AF) protocol in the presence and absence of an eavesdropper to enhance the physical layer security for the D2D network. The proposed scheme is analyzed with different distance cases, device scenarios, and modulation schemes. The bit error rate (BER) performance analysis concludes that a performance gain of more than 4 dB is achieved at the BER of 0.004 for the proposed double threshold-based ODS scheme compared to the existing ODS scheme at a high signal to noise ratio (SNR). Furthermore, the proposed scheme enhances the physical layer security.

Impact of Cattaneo-Christov Heat Flux Model on the Flow of Maxwell Ferromagnetic Liquid Along a Cold Flat Plate Embedded with Two Equal Magnetic Dipoles

S. U. Rehman,A. Zeeshan,A. Majeed,M. B. Arain 한국자기학회 2017 Journal of Magnetics Vol.22 No.3

The target of the current study is to inspect theoretically two-dimensional boundary layer flow of a Maxwell ferromagnetic fluid toward a flat plate. An external magnetic field due to two equal line dipole which are equidistant from the wall and perpendicular to the flow plane is applied. Cattaneo-Christov heat flux model is utilized in modified form of Fourier’s Law to disclose the heat transfer characteristic. Governing flow problem is normalized into ordinary differential equation by adopting similarity transform procedure. The solution of resulting non-linear ODE’s are solved by shooting technique based on Runge-Kutta algorithm with the help of MATLAB. Characteristic of sundry parameter like magneto-thermomechanical (ferrohydrodynamic) interaction parameter, dimensionless thermal relaxation, Prandtl number and Debora number on velocity and temperature profile are displayed via graphs and in tabular form. It is also pointed out that temperature profile suppresses by varying values of the thermal relaxation time and Prandtl number and increasing behaviour is seen against ferrohydrodynamic interaction. Present numerical results are compared with those published previously in the literature for the case of Newtonian fluid (α₁ → 0) and found an excellent agreement.

Computational modeling and biomarker studies of pharmacological treatment of Alzheimer's disease

Hassan, Mubashir,Abbas, Qamar,Seo, Sung-Yum,Shahzadi, Saba,Ashwal, Hany Al,Zaki, Nazar,Iqbal, Zeeshan,Moustafa, Ahmed A. SPANDIDOS PUBLICATIONS 2018 MOLECULAR MEDICINE REPORTS Vol.18 No.1

<P>Alzheimer's disease (AD) is a complex and multifactorial disease. In order to understand the genetic influence in the progression of AD, and to identify novel pharmaceutical agents and their associated targets, the present study discusses computational modeling and biomarker evaluation approaches. Based on mechanistic signaling pathway approaches, various computational models, including biochemical and morphological models, are discussed to explore the strategies that may be used to target AD treatment. Different biomarkers are interpreted on the basis of morphological and functional features of amyloid β plaques and unstable microtubule-associated tau protein, which is involved in neurodegeneration. Furthermore, imaging and cerebrospinal fluids are also considered to be key methods in the identification of novel markers for AD. In conclusion, the present study reviews various biochemical and morphological computational models and biomarkers to interpret novel targets and agonists for the treatment of AD. This review also highlights several therapeutic targets and their associated signaling pathways in AD, which may have potential to be used in the development of novel pharmacological agents for the treatment of patients with AD. Computational modeling approaches may aid the quest for the development of AD treatments with enhanced therapeutic efficacy and reduced toxicity.</P>

Current Distribution Dynamics in Microstrip Patch Antenna Arrays

Ali W. Azim,Shahid A. Khan,Zeeshan Qamar,K. S. Alimgeer,S. M. Ali 보안공학연구지원센터 2011 International Journal of Future Generation Communi Vol.4 No.3