Ruiz¹ MA, AD Golberg^1,2, O Martínez²

Phyton-International Journal of Experimental Botany, Vol.77, pp. 7-20, 2008, DOI:10.32604/phyton.2008.77.007

Abstract Tetrachne dregei, Panicum coloratum and Eragrostis curvula are perennial forage C4 grasses, introduced from South Africa to the pampean semiarid region. This work was carried out to compare water stress tolerance; forage production and quality of T. dregei, P. coloratum and E. curvula. Studies were conducted under greenhouse and field conditions. In the greenhouse, watering was stopped after eighty one days of plant emergency in the water stress treatment. Water potential (ψ), stomatal resistance (SR) and shoot and root weights were evaluated. Under water stress, ψ diminished earlier and SR increases were higher in P. coloratum than in T. dregei and E.… More >

P. Ramamurty Raju¹, B. Satyanarayana², K. Ramji³

Structural Durability & Health Monitoring, Vol.4, No.3, pp. 161-172, 2008, DOI:10.3970/sdhm.2008.004.161

Abstract This paper presents the details of method of sample size determination to estimate the characteristic fatigue life of aluminum alloy. The characteristic fatigue life of Aluminum alloy A356.2-T6 has been estimated by assuming a two parameter Weibull distribution model. A stepwise procedure is outlined to determine the number of specimens required at a predetermined stress amplitude to estimate the fatigue life within an acceptable error at a given probability and confidence level. The percentage of error is calculated at various probabilities and confidence levels (C.L). The probabilities considered are 50%, 90% and 95% whereas C.Ls More >

B.K.Raghuprasad¹, N.Lakshmanan², N.Gopalakrishnan², K.Muthumani²

Structural Durability & Health Monitoring, Vol.4, No.3, pp. 117-144, 2008, DOI:10.3970/sdhm.2008.004.117

Abstract The reduction in natural frequencies, however small, of a civil engineering structure, is the first and the easiest method of estimating its impending damage. As a first level screening for health-monitoring, information on the frequency reduction of a few fundamental modes can be used to estimate the positions and the magnitude of damage in a smeared fashion. The paper presents the Eigen value sensitivity equations, derived from first-order perturbation technique, for typical infra-structural systems like a simply supported bridge girder, modelled as a beam, an end-bearing pile, modelled as an axial rod and a simply… More >

J. Sladek, V. Sladek¹, P. Solek, P.H. Wen

The International Conference on Computational & Experimental Engineering and Sciences, Vol.8, No.4, pp. 165-170, 2008, DOI:10.3970/icces.2008.008.165

Abstract A meshless local Petrov-Galerkin (MLPG) method is applied to solve thermal bending problems described by the Reissner-Mindlin theory. Functionally graded material properties with continuous variation in the plate thickness direction are considered too. A weak formulation for the set of governing equations in the Reissner-Mindlin theory is transformed into local integral equations on local subdomains in the mean surface of the plate with using a unit test function. The meshless approximation based on the Moving Least-Squares (MLS) method is employed for the implementation. More >

Q.W. Ma¹

The International Conference on Computational & Experimental Engineering and Sciences, Vol.5, No.1, pp. 1-6, 2008, DOI:10.3970/icces.2008.005.001

Abstract In the MLPG_R (Meshless Local Petrove-Galerkin based on Rankine source solution) method, one needs a meshless interpolation scheme for an unknown function to discretise the governing equation. A new scheme, called simplified finite difference interpolation (SFDI) has been recently devised by the author, which is more efficient and has better convergent property than others. This paper will discuss about how the convergent property is affected by different weight functions. More >

E. Schnack¹, K. Kolk², A. Dimitrov³

The International Conference on Computational & Experimental Engineering and Sciences, Vol.8, No.3, pp. 107-114, 2008, DOI:10.3970/icces.2008.008.107

Abstract In fracture mechanics, corner and wedge singularities have to be considered for two- and three-dimensional problems in isotropic and layered anisotropic continua. To investigate the behaviour of crack propagation starting from corners and edges the information about stress asymptotics in the vicinity of three-dimensional corner points is needed [1]. Thus, in this paper two aspects are studied: the interface crack in layered anisotropic materials with re-entrant corners and surface cracks in homogeneous isotropic continua. Moreover a strategy is presented to model such surface breaking cracks efficiently within a numerical 3D simulation [2]. To study the… More >

Y. Shimamura¹, Y. Shibata², K. Tohgo³, H. Araki⁴

The International Conference on Computational & Experimental Engineering and Sciences, Vol.6, No.3, pp. 189-194, 2008, DOI:10.3970/icces.2008.006.189

Abstract Polylactic acid (PLA) is a biodegradable plastic made from lactic acid, and can be produced by renewable raw materials. The mechanical properties of PLA are, however, not sufficient for structural materials. In our study, carbon nanofiber reinforced PLA was fabricated to overcome the deficiency of PLA and the mechanical properties were measured at room and elevated temperatures. Vapor grown carbon fiber (VGCF) was used for reinforcement. Three point bending specimens were fabricated by using injection molding, and then bending stiffness, bending strength and fracture toughness were measured for amorphous and crystallized specimens. As a result, More >

Vedula S.R.K.^*, Lim T.S.^†, Hunziker W.^‡, Lim C.T.^§

Molecular & Cellular Biomechanics, Vol.5, No.3, pp. 169-182, 2008, DOI:10.3970/mcb.2008.005.169

Abstract Intercellular adhesion molecules play an important role in regulating several cellular processes such as a proliferation, migration and differentiation. They also play an important role in regulating solute diffusion across monolayers of cells. The adhesion characteristics of several intercellular adhesion molecules have been studied using various biochemical assays. However, the advent of single molecule force spectroscopy as a powerful tool to analyze the kinetics and strength of protein interactions has provided us with an opportunity to investigate these interactions at the level of a single molecule. The study of interactions involving intercellular adhesion molecules has More >

R. Martin¹, D. Komatitsch^1,2, S. D. Gedney³

CMES-Computer Modeling in Engineering & Sciences, Vol.37, No.3, pp. 274-304, 2008, DOI:10.3970/cmes.2008.037.274

Abstract In the context of the numerical simulation of seismic wave propagation, the perfectly matched layer (PML) absorbing boundary condition has proven to be efficient to absorb surface waves as well as body waves with non grazing incidence. But unfortunately the classical discrete PML generates spurious modes traveling and growing along the absorbing layers in the case of waves impinging the boundary at grazing incidence. This is significant in the case of thin mesh slices, or in the case of sources located close to the absorbing boundaries or receivers located at large offset. In previous work… More >

Chein-Shan Liu¹, Satya N. Atluri²

CMES-Computer Modeling in Engineering & Sciences, Vol.36, No.3, pp. 261-286, 2008, DOI:10.3970/cmes.2008.036.261

Abstract The inverse Sturm-Liouville problem finds its applications in the identification of mechanical properties and/or geometrical configurations of a vibrating continuous medium; however, this problem is hard to solve, either theoretically or numerically. Previously, Liu (2008a) has constructed a Lie-group shooting method to determine the eigenvalues, and the corresponding eigenfunctions, for the direct Sturm-Liouville problem. In this study, we are concerned with solving the inverse Sturm-Liouville problem, by developing a Lie-group of SL(2,R) to construct nonlinear algebraic equations (NAEs), when discrete eigenvalues are specified. Our purpose here is to use these NAEs to solve the unknown function More >