K. Lahmer¹, R. Bessaïh¹, A. Scipioni², M. El Ganaoui²

FDMP-Fluid Dynamics & Materials Processing, Vol.10, No.1, pp. 149-162, 2014, DOI:10.3970/fdmp.2014.010.149

Abstract This paper summarizes the outcomes of a numerical study about the phenomenon of hydrogen absorption in an axisymmetric tank geometry containing magnesium hydride heated to 300˚C and at moderate storage pressure 1 MPa. The governing equations are solved with a fully implicit finite volume numerical scheme (as implemented in the commercial software FLUENT). Different kinetic reaction equations modeling hydrogen absorption are considered and the related numerical simulations are compared with experimental results. Spatial and temporal profiles of temperature and concentration in hydride bed are plotted. More >

F.Z. Ferahta^1,2, S. Bougoul¹, M. Médale², C. Abid²

FDMP-Fluid Dynamics & Materials Processing, Vol.8, No.3, pp. 339-352, 2012, DOI:10.3970/fdmp.2012.008.339

Abstract A numerical study is carried out to evaluate the thermal performances of a solar collector. As it is well known, that the thermal losses of such systems are mainly of a convective nature, the study is concentrated in particular on the features of natural convection that is activated in the air domain delimited by the upper glass and the lower absorber of the solar collector. The efficiency of such a system depends essentially on both the temperature difference and the distance between the absorber and the glass. Since the temperature difference remains an uncontrolled variable (because it depends on the… More >

Viveca Wallqvist¹, Per M. Claesson², Agne Swerin¹, Patrick A. C. Gane^3,4,3, Joachim Schoelkopf³

FDMP-Fluid Dynamics & Materials Processing, Vol.4, No.2, pp. 85-98, 2008, DOI:10.3970/fdmp.2008.004.085

Abstract It has been shown that talc powder can be compacted into tablets with a preferred orientation of the platelets. The tablets can be obtained with different controlled porosity depending on pressing methods and applied pressure. The tablets can be obtained with or without additives, which may, in turn, be adsorbed. The orientation of the high aspect ratio platy talc, the surface chemistry imparted by the additives and the transported fluid influence the imbibition and permeation rates. Non-polar hexadecane displays a higher imbibition and permeability than water for all particulate orientations during short timescale absorption, likely due to the oleophilic nature… More >

Jun Xie¹, Chong Wang¹, Jiaxiang Cai², Fuhong Cai^1,*

CMC-Computers, Materials & Continua, Vol.57, No.2, pp. 261-268, 2018, DOI:10.32604/cmc.2018.03669

Abstract The rapid quantification method of human serum glucose was established by using the Fourier transform infrared spectroscopy (FTIR) and attenuated total reflection (ATR). By the subtracted spectra between glucose aqueous solution and de-ionized water, absorption peaks are calculated in fingerprint area. Based on these absorption peaks and multiple linear regression (MLR) model, discrete band selection method of absorption peaks disturbance model (APDM) was developed. 5 absorption peaks 1150 cm^-1, 1103 cm^-1, 1078 cm^-1, 1034 cm^-1, 991 cm^-1 were found in fingerprint area. Used these absorption peaks to establish absorption peaks disturbance model, the optimal wavelength combinations are 1140 cm^-1, 1096… More >

Subashini I^{1, a}, Smitha Gopinath^{2, *}, Aahrthy R^{3, b}

CMC-Computers, Materials & Continua, Vol.53, No.4, pp. 291-306, 2017, DOI:10.3970/cmc.2017.053.291

Abstract Present paper proposes a methodology by combining finite element method with smoothed particle hydrodynamics to simulate the response of textile reinforced concrete (TRC) slabs under low velocity impact loading. For the constitutive modelling in the finite element method, the concrete damaged plasticity model was employed to the cementitious binder of TRC and Von-Mises criterion was used for the textile reinforcement. Strain dependent smoothed particle hydrodynamics (SPH) was used to assess the damage and failure pattern of TRC slabs. Numerical simulation was carried out on TRC slabs with two different volume fraction of glass textile reinforcement to predict the energy absorption… More >

W.Xu¹, A.M. Waas²

CMC-Computers, Materials & Continua, Vol.46, No.3, pp. 165-194, 2015, DOI:10.3970/cmc.2015.046.165

Abstract Plastic deformation and splitting are two important mechanisms of energy dissipation when metal tubes undergo axial crushing. Isotropic J2 plasticity theory combined with a failure criterion is used to model axial splitting and curling of metal tubes undergoing axial crush. The proposed material model is implemented within a finite element (FE) framework using the user material subroutine VUMAT option available in the commercial code ABAQUS. Experimental results from literature are used to validate the model. The predicted splitting and curling patterns as well as the load-displacement response agree well with the experimental observations. The present material model is also used… More >

Shiv Narayan¹, Latha S.¹ and R M Jha¹

CMC-Computers, Materials & Continua, Vol.39, No.3, pp. 217-230, 2014, DOI:10.3970/cmc.2014.039.217

Abstract The EM analysis of multi-layered metamaterial based radar absorbing structure (RAS) with dual-band characteristics in millimeter wave frequency regime has been carried out in this paper using transmission line transfer matrix (TLTM) method for TE and TM polarizations. The proposed metamaterial-based RAS exhibits dual-band characteristics at centre frequencies 120 GHz and 175 GHz with very low power reflection. It absorbs more than 90% power of incidence wave over the frequency range from 111-131 GHz at first resonance and from 164.5-185 GHz at second resonance without metal backing plate, which is desirable for stealth applications. It also showed very low (<… More >

Balamati Choudhury¹, Sanjana Bisoyi¹, Pavani Vijay Reddy¹, Manjula S.¹ and R. M. Jha¹

CMC-Computers, Materials & Continua, Vol.39, No.3, pp. 179-215, 2014, DOI:10.3970/cmc.2014.039.179

Abstract The terahertz spectrum of electromagnetic waves is finding its position in various applications of day to day life because of its unique properties, including the penetration through opaque materials. Naturally occurring materials in this range are rare due to the display of a natural breakpoint of both electric, and magnetic resonances in these materials. However recent advances in artificially engineered materials, which show resonance in this region are able to harness desirable properties in the terahertz region. In this paper, terahertz design and fabrication issues have been explored along with their applications. A brief review of metamaterial terahertz applications has… More >

Balamati Choudhury¹, Pavani Vijay Reddy¹, Sanjana Bisoyi¹, R. M. Jha¹

CMC-Computers, Materials & Continua, Vol.37, No.3, pp. 135-146, 2013, DOI:10.3970/cmc.2013.037.135

Abstract The terahertz region of the electromagnetic spectrum plays a vital role in biomedical imaging because of its sensitivity to vibrational modes of biomolecules. Advances in broadband terahertz imaging have been emerging in the field of biomedical spectroscopy. Biomedical imaging is used to distinguish between the infected (cancer) and the non-infected tissue, which requires broad band and highly efficient radar absorbing material (RAM) designs (to obtain high resolution image of the tissue). In this paper, a metamaterial broadband RAM design is proposed towards biomedical spectroscopy applications in the THz region. The particle swarm optimization (PSO) algorithm is used for the design… More >

Shiv Narayan¹, Latha S.¹, R M Jha¹

CMC-Computers, Materials & Continua, Vol.34, No.2, pp. 131-142, 2013, DOI:10.3970/cmc.2013.034.131

Abstract The EM performance analysis of a multilayered metamaterial based radar absorbing structure (RAS) has been presented in this paper based on transmission line transfer matrix (TLTM) method for millimeter wave applications. The proposed metamaterial-RAS consists of cascaded DPS and MNG layers of identical configurations. It exhibits extremely low reflection (< 42 dB) at 95 GHz and absorbs more than 95% power of incident wave over the frequency range of 90.4- 100 GHz without metal backing for both TE and TM polarizations. In view of aerospace applications, the reflection, transmission, and absorption characteristics of the proposed metamaterial-RAS are also studied at… More >