Johor Bahru, Malaysia
Johor Bahru, Malaysia

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Baharanchi A.A.,Florida International University | Darus A.N.,Technological University of Malaysia | Ansari M.,Islamic Azad University at Shahrood | Baharanchi E.A.,Islamic Azad University at Najafabad
ASME International Mechanical Engineering Congress and Exposition, Proceedings (IMECE) | Year: 2012

Numerical study of internal nozzle flow in simplex atomizer is now well established to represent features of the flow such as turbulence, swirl, and interface between phases. However, an attempt is still needed to introduce an optimum method to capture the interface between liquid and gas with satisfactory level of sharpness. Besides, a detailed study must be dedicated to quantify the influence of surface tension force on evolution of interface shape and flow variables and to determine the necessity of inclusion of this force in molding of this particular type of flow. In the present study RNG K-ε model has been used in Fluent 6.3 to compare performance of four interface schemes and introduce an optimum method in terms of computational effort and grid size requirement. Later, combination of the CSF model, RNG K-ε model and Implicit scheme has been used to introduce a threshold Weber number below which inclusion of surface tension will considerably influence the flow field during intermediate time steps. Copyright © 2012 by ASME.

Wetten A.C.,University of Reading | Thomas J.-L.,Laboratoire Of Biologie Moleculaire Of La Cellule | Wagiran A.,Technological University of Malaysia | Chiurugwi T.,Rothamsted Research
Methods in Molecular Biology | Year: 2012

A transgenesis programme has been developed for Impatiens balsamina that will allow elucidation of the roles played by individual genes in the flower reversion phenomenon shown by this model species. The lack of explants exhibiting adventitious shooting in I. balsamina hinders Agrobacterium-based transformation, but the multiple shoots that arise from cotyledonary nodes present a suitable target for biolistics. These tissues can be disrupted by the helium blast effect associated with conventional biolistic devices, so we have utilised modifications to the PDS 1000/He equipment originally developed for transformation of fragile insect tissues. By loading microcarriers on to a rigid, rather than flexible, macrocarrier, the blast effect is largely eliminated, and the use of a focussing nozzle allows the bombardment to be concentrated on the target tissues. This approach reduces waste of plasmid DNA and gold microcarriers and achieves transfection at lower, less disruptive helium pressures than would otherwise be necessary to efficiently penetrate below the shoot epidermis and generate heritable transgenic lines. © 2012 Springer Science+Business Media, LLC.

Ahmadi M.T.,Technological University of Malaysia | Johari Z.,Technological University of Malaysia | Chek D.C.Y.,Technological University of Malaysia | Amin N.A.,Technological University of Malaysia | Ismail R.,Technological University of Malaysia
Journal of Nanomaterials | Year: 2010

Graphene nanoribbon (GNR) is a promising alternative to carbon nanotube (CNT) to overcome the chirality challenge as a nanoscale device channel. Due to the one-dimensional behavior of plane GNR, the carrier statistic study is attractive. Research works have been done on carrier statistic study of GNR especially in the parabolic part of the band structure using Boltzmann approximation (nondegenerate regime). Based on the quantum confinement effect, we have improved the fundamental study in degenerate regime for both the parabolic and nonparabolic parts of GNR band energy. Our results demonstrate that the band energy of GNR near to the minimum band energy is parabolic. In this part of the band structure, the Fermi-Dirac integrals are sufficient for the carrier concentration study. The Fermi energy showed the temperature-dependent behavior similar to any other one-dimensional device in nondegenerate regime. However in the degenerate regime, the normalized Fermi energy with respect to the band edge is a function of carrier concentration. The numerical solution of Fermi-Dirac integrals for nonparabolic region, which is away from the minimum energy band structure of GNR, is also presented. Copyright © 2010 Zaharah Johari et al.

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