Zhang¹ WD, DS Liu², JC Tian^1*, FL He¹

Phyton-International Journal of Experimental Botany, Vol.78, pp. 147-154, 2009, DOI:10.32604/phyton.2009.78.147

Abstract Soil arsenic contamination becomes a potential agricultural and environmental hazard worldwide, and has been a serious problem for safe food production. A field experiment on soil contamination was conducted on four wheat varieties (Jimai, Gaoyou, Weimai and Wennong) in Eastern China, using 50 or 100 mg arsenic/kg soil. Biomass production and yield components were determined and arsenic concentrations were measured in plant tissues. Differential arsenic effects on wheat varieties were determined at maturity. Results showed that addition of arsenic significantly (p<0.05) reduced root, stem and spike dry weight and yield components, which resulted in the… More >

Janja Kramer, Renata Jecl, Leopold Skerget

The International Conference on Computational & Experimental Engineering and Sciences, Vol.12, No.4, pp. 147-148, 2009, DOI:10.3970/icces.2009.012.147

Abstract A numerical study of double diffusive natural convection in porous media due to opposing buoyancy forces is reported, using the Boundary Domain Integral Method (BDIM). There have been several reported studies dealing with natural convection in porous media, mainly because of its importance in several industrial and technological applications. Less attention, however, has been dedicated to the so-called double diffusive problems, where density gradients occur due to the effects of combined temperature and concentration buoyancy. The current investigation is focused on the special problem, where the thermal and solutal buoyancy forces are opposing each other.
The… More >

M.R. Arab^1,2, E. Semma³, B. Pateyron¹, M. El Ganaoui¹

FDMP-Fluid Dynamics & Materials Processing, Vol.5, No.2, pp. 161-176, 2009, DOI:10.3970/fdmp.2009.005.161

Abstract In this work, flows in porous media are simulated by using a Lattice Boltzmann Method (LBM). A model D2Q9 with a single collision operator is proposed. This method is applied on 2D digital images obtained by a Scanning Electron Microscope technique (SEM), and followed by a special treatment in order to obtain an image of synthesis that is finally read by the numerical code. The first results tested on two-dimensional configurations show the reliability of this strategy in simulating with a good accuracy phenomena of heat and mass transport. The numerical study is extended to More >

Aouachria Z¹

FDMP-Fluid Dynamics & Materials Processing, Vol.5, No.2, pp. 137-148, 2009, DOI:10.3970/fdmp.2009.005.137

Abstract This work treats heat and mass transfer by natural convection along a vertical wall in porous media imbibed by fluid, using an integral method. The problem governing parameters are the buoyancy ratio,N, and the Lewis number, Le The results for the local Nusselt and Sherwood numbers are presented for a large range of these parameters. The concentration and thermal boundary layer thickness are also determined. We observe that our results are in good agreement with those obtained by Bejan and Khair (1985). More >

Sang-Hyun Lee¹, Sung-Sik Woo¹, Seung-Ho Cho¹, Lan Chung¹

The International Conference on Computational & Experimental Engineering and Sciences, Vol.8, No.3, pp. 115-120, 2008, DOI:10.3970/icces.2008.008.115

Abstract In this study, based on the results from the sinusoidal base excitation analyses of a single degree of freedom system with a tuned mass damper (TMD), the optimal friction is computed so that the rail friction improve the performance of the TMD. The magnitude of the optimal friction increases with increasing mass ratio of the TMD and decreases with increasing structural damping. Particularly, it is observed that the optimized friction force gives better control performance than the optimized viscous damping of the TMD. However, because the performance of the TMD considerably deteriorates when the friction More >

L. Bennamoun¹, A. Belhamri²

FDMP-Fluid Dynamics & Materials Processing, Vol.4, No.4, pp. 221-230, 2008, DOI:10.3970/fdmp.2008.004.221

Abstract This work focuses on tyipical heat and mass transfer phenomena during the processing of products in the context of the packed-bed drying method (products arranged in thick layers into dryers working in forced convection mode). The dryers are modeled as porous media at the macroscopic level. The simulations are carried out using the mass, momentum (written in the framework of the Darcy's law approximation) and energy equations applied for the different components. A diffusion model based on Fick's law is also used to take into account the drying kinetics. This approach allows monitoring of the More >

A.A. Ivanova¹, V.G. Kozlov^1,2,3, D.A. Polezhaev¹, D. Pareau³, M. Stambouli³

FDMP-Fluid Dynamics & Materials Processing, Vol.4, No.3, pp. 211-220, 2008, DOI:10.3970/fdmp.2008.004.211

Abstract The problem for the optimization of mass-transfer on the interface of two immiscible liquids by means of vibrational hydromechanics is studied experimentally. A new vibrational cell of Lewis's type expressly conceived for such purposes is described. Flow is generated by activators in the form of disks inducing translational axial oscillations near the opposite end faces of the cavity. It is shown that such vibrating disks can lead to the onset of a large-scale toroidal whirlwind effectively mixing the liquid throughout the volume. According to the experiments, in particular, axisymmetrical radial flows are generated on both More >

JOÃO PAULO MARDEGAN ISSA^*, RODRIGO TIOSSI^*, MAMIE MIZUSAKI IYOMASA^**

BIOCELL, Vol.31, No.3, pp. 375-382, 2007, DOI:10.32604/biocell.2007.31.375

Abstract The aim of this study was to evaluate alterations in the masseter muscle of 30 male guinea-pigs submitted to occlusal alteration. The animals were divided into 2 equal groups, the control group (C) only submitted to surgical stress, and the occlusal altered group (T) submitted to teeth extraction. Each group was subdivided into 3 groups, with 5 animals, for the following studies: macroscopy and vessels distribution, light microscopy and histochemical analysis, with animals’ perfusion 2 months after surgery. Data were submitted to statistical analysis. Macroscopically, an anteroposterior orientation of the muscular fibers was found and More >

J. Gajdošík¹, M. Šejnoha¹, J. Zeman¹

The International Conference on Computational & Experimental Engineering and Sciences, Vol.4, No.2, pp. 129-136, 2007, DOI:10.3970/icces.2007.004.129

Abstract Rock masses with relatively high concentration of discontinuities or joints are considered. Being aware of limitations of various averaging techniques such as the self consistent or Mori-Tanaka methods in providing reliable estimates of generally nonlinear macroscopic response of jointed rock masses, the paper introduces a notion of statistically equivalent periodic unit cell (SEPUC). Such a unit cell contains, in order to reduce the problem complexity, of the orders of magnitude less number of joints in comparison with the actual material system. In analogy with two-phase composites, the SEPUC is expected to be found in a More >

Rincón-Tuexi¹, Sergio Castro-Nava², José Alberto López-Santillán², Alfredo J Huerta³, Carlos Trejo-López⁴, Florencio Briones-Encinia

Phyton-International Journal of Experimental Botany, Vol.75, pp. 31-40, 2006, DOI:10.32604/phyton.2006.75.031

Abstract Effects of water and high temperature stresses, either separately or in combination, over biomass accumulation, grain yield and its direct components grain number per ear and individual grain weight], as well as harvest index were determined in four tropical maize populations. Results indicated that water stress do not significantly affect the studied variables, due to the absence of a severe water stress during flowering. This was the result of the fallen precipitation at this time. The most important factor in this study was high temperature, which significantly reduced all studied variables, except individual grain weight.… More >