S. H. Kwon¹, B. R. Kim², H. K. Lee^2,3

CMC-Computers, Materials & Continua, Vol.21, No.1, pp. 65-86, 2011, DOI:10.3970/cmc.2011.021.065

Abstract The electromagnetic shielding effectiveness of grid-mesh films made of polyaniline was numerically investigated, and the optimal size of the polyaniline grid was determined through numerical analyses. The permittivity of polyaniline was first determined from an inverse analysis based on experimental data. A series of numerical analyses were carried out with 225 polyaniline grid-mesh films of different thickness, spacing, and width, and the shielding effectiveness of every grid was examined. In addition to the numerical analysis, the transparency of the grid-mesh films and the amount of polyaniline material required to manufacture the unit grid area (1mx1m) More >

Dye-Zone A. Chen, Gang Chen^*

Frontiers in Heat and Mass Transfer, Vol.1, No.2, pp. 1-6, 2010, DOI:10.5098/hmt.v1.2.3005

Abstract We present a calculation of the thermally generated electromagnetic flux propagating along the in-plane direction of a polar, thin film. The approach is based on fluctuational electrodynamics and the fluctuation-dissipation theorem. We find that for silicon carbide films between 5 nm and 100 nm thick, the thinner films transport more in-plane flux due to the long propagation length of the anti-symmetric surface phonon-polariton mode. Comparison of results obtained from the fluctuation-dissipation approach and the kinetic theory approach shows favorable agreement. More >

Je-Chin Han^*, Akhilesh P. Rallabandi

Frontiers in Heat and Mass Transfer, Vol.1, No.1, pp. 1-21, 2010, DOI:10.5098/hmt.v1.1.3001

Abstract Film cooling is widely used to protect modern gas turbine blades and vanes from the ever increasing inlet temperatures. Film cooling involves a very complex turbulent flow-field, the characterization of which is necessary for reliable and economical design. Several experimental studies have focused on gas turbine blade, vane and end-wall film cooling over the past few decades. Measurements of heat transfer coefficients, film cooling effectiveness values and heat flux ratios using several different experimental methods have been reported. The emphasis of this current review is on the Pressure Sensitive Paint (PSP) mass transfer analogy to More >

I-L. Chang¹, W.-C. Ding

CMES-Computer Modeling in Engineering & Sciences, Vol.68, No.3, pp. 297-312, 2010, DOI:10.3970/cmes.2010.068.297

Abstract Molecular dynamics method incorporating with parallel computing technique was employed to study the mechanical properties of textured polycrystalline nanofilms with fixed out-of-plane normal direction. The grain size and film thickness effects on both the elastic and plastic properties of the copper nanofilm were examined. It is shown from the simulation that the elastic and plastic properties (i.e., Young’s modulus, Poisson’s ratio, biaxial yield stress, etc) of textured polycrystalline nanofilms depend on the grain size and the film thickness. As the grain size of the nanofilm become larger, the Young’s modulus and biaxial yield stress increase More >

P.H. Gaskell¹, Y.C. Lee², H.M. Thompson¹

CMES-Computer Modeling in Engineering & Sciences, Vol.62, No.1, pp. 77-112, 2010, DOI:10.3970/cmes.2010.062.077

Abstract The three-dimensional flow of a gravity-driven continuous thin liquid film on substrates containing micro-scale features is modelled using the long-wave lubrication approximation, encompassing cases when surface topography is either engulfed by the film or extends all the way though it. The discrete analogue of the time-dependent governing equations is solved accurately using a purpose designed multigrid strategy incorporating both automatic error-controlled adaptive time stepping and local mesh refinement/de-refinement. Central to the overall approach is a Newton globally convergent algorithm which greatly simplifies the inclusion of further physics via the solution of additional equations of the More >

Shadia J Ikhmayies¹, Naseem M. Abu El-Haija², Riyad N. Ahmad-Bitar³

FDMP-Fluid Dynamics & Materials Processing, Vol.6, No.2, pp. 219-232, 2010, DOI:10.3970/fdmp.2010.006.219

Abstract Large area and highly uniform polycrystalline ZnO thin films have been produced by a spray pyrolysis (SP) technique resorting to a customized system (spraying) on glass substrates at temperature Ts= 450℃. This study deals with the related investigation about the influence of heat treatment (in nitrogen atmosphere) on the resulting properties (electrical, optical and structural) of such films. Properties are analyzed by means of I-V plots, transmittance curves, X-Ray diffractograms (XRD) and scanning electron microscope (SEM) micrographs. Results show that the resistivity of the films decreases from about 200W.cm for the as-deposited films to about… More >

ShadiaJ. Ikhmayies¹, Naseem M. Abu El-Haija¹, Riyad N. Ahmad-Bitar¹

FDMP-Fluid Dynamics & Materials Processing, Vol.6, No.2, pp. 165-178, 2010, DOI:10.3970/fdmp.2010.006.165

Abstract Undoped polycrystalline ZnO thin films were produced on glass substrates at a substrate temperature Ts= 450 C by the spray pyrolysis (SP) technique. The films were characterized by analyzing their I-V curves, transmittance, X-ray diffractograms (XRD) and their scanning electron microscope (SEM) images. The I-V plots are all linear and the resistivity was found to be about 200W.cm. The transmittance in the visible and near infrared regions is as high as 85% which is suitable for solar cell applications. The absorption coefficient which is deduced from the transmittance measurements is continuously increasing with the photon's… More >

S. N.V.R.K. Kurapati¹, Y. C. Lu¹, F. Yang²

CMC-Computers, Materials & Continua, Vol.20, No.1, pp. 1-18, 2010, DOI:10.3970/cmc.2010.020.001

Abstract The spherical indentation of elastic film /substrate structures is analyzed using the finite element method. The load-displacement curves of the film /substrate structures of various configurations are obtained and analyzed. A generalized power law relation is established, which can be used to analyze the load-displacement curve of elastic film /substrate systems under spherical indentations. The indentation load is dependent on the modulus ratio of the film to the substrate and film thickness. A semi-analytical expression for the power of the power law relation is also obtained as a function of the normalized film thickness and More >

Pavel Grinfeld¹

CMC-Computers, Materials & Continua, Vol.19, No.3, pp. 239-254, 2010, DOI:10.3970/cmc.2010.019.239

Abstract We model viscosity in the framework of the exact nonlinear equations of fluid film dynamics. The proposed approach yields monotonic dissipation of energy and guarantees that viscous forces are not engaged when the film undergoes rigid motion. With the addition of viscosity, the governing system has all the essential elements - inertia, surface tension, interaction with the ambient medium, influence of external fields and, now, viscosity - for accurate prediction and interpretation of experimental observations. The fluid film is modelled as a two-dimensional manifold. The film's thickness is represented by a surface density function. The More >

Veturia Chiroiu¹, Ligia Munteanu² and Antonio S. Gliozzi³

CMC-Computers, Materials & Continua, Vol.19, No.1, pp. 1-16, 2010, DOI:10.3970/cmc.2010.019.001

Abstract This paper develops a mechanical model for multifunctional reinforced carbon nanotube (CNT) beams. The model is obtained by introducing the couple stresses into the constitutive equations of linear viscoelastic theory. The material functions are determined using the homogenization method. More >