SONIA ROSENFELDT, BEATRIZ G. GALATI

BIOCELL, Vol.31, No.1, pp. 13-21, 2007, DOI:10.32604/biocell.2007.31.013

Abstract Pollen morphology and the degree of pollen variability within nine species and two varieties of Oxalis species from Buenos Aires Province (Argentina) were studied using light microscopy (LM), scanning electron microscopy (SEM) and transmission electron microscopy (TEM).
Oxalis pollen grain is generally 3-colpate and the shape is prolate spheroidal, oblate spheroidal or spheroidal. The exine is microreticulate. The brochi are circular to polygonal; brochi sizes decrease near the colpi. The colpus membrane observed in unacetolysed material, is crustate or granular. The colpus length varies within a species; the largest grains are produced in stamens with long filaments More >

WALTER MANUCHA

BIOCELL, Vol.31, No.1, pp. 1-12, 2007, DOI:10.32604/biocell.2007.31.001

Abstract Congenital obstructive nephropathy is the primary cause of end-stage renal disease in children. Rapid diagnosis and initiation of the treatment are vital to preserve function and/or to slow down renal injury. Obstructive uropathy effects -decline in the plasmatic renal flow and glomerular filtration rate, interstitial infiltrate of leukocytes, significant decrease of the urine concentration, loss of the capacity to concentrate urine as well as fibrosis and apoptosis- are a consequence of a variety of factors that work in complex ways and are still not fully understood. Mediators as angiotensin II, transforming growth factor-β (TGF-β) and… More >

C. Bisagni¹

The International Conference on Computational & Experimental Engineering and Sciences, Vol.1, No.3, pp. 93-98, 2007, DOI:10.3970/icces.2007.001.093

Abstract The research here presented shows the numerical results for progressive failure of stiffened composite panels into the post-buckling field. In particular, a strength reduction procedure is implemented in the commercial finite element code ABAQUS where the stiffness properties of the material are removed in the failed areas. The results show a good correlation with experimental data obtained from a post-buckling test of a stiffened panel with a notch, that can be found in literature. More >

L. Susmel^1,2, D. Taylor², R. Tovo¹

The International Conference on Computational & Experimental Engineering and Sciences, Vol.1, No.2, pp. 81-86, 2007, DOI:10.3970/icces.2007.001.081

Abstract This paper investigates some practical aspects related to the use of the Theory of Critical Distances (TCD) when employed to estimate notch fatigue limits. The accuracy of different formalisations of the theory was checked by using experimental data taken from the literature. This exercise allowed us to confirm that the simplest formalisation of the TCD, in which both critical distance and critical stress are material constants [1], is also the most accurate one, giving predictions falling within an error interval of about ±20%. The TCD is also accurate when applied to notches having large opening More >

Jae-Sang Park¹, SangJoon Shin²

The International Conference on Computational & Experimental Engineering and Sciences, Vol.4, No.4, pp. 265-270, 2007, DOI:10.3970/icces.2007.004.265

Abstract This paper presents the preliminary design effort of a brand new integral twist-actuated blade incorporating single crystal piezoelectric fiber composites. Although the previous integral twist-actuated blade was able to reduce the vibration and acoustic noise of rotorcrafts significantly, a quite high input-voltage was unavoidably required. Therefore, in this paper, it is suggested to develop a new active blade using single crystal piezoelectric composites to reduce the vibration and acoustic noise of helicopters more efficiently. For the preliminary design of a new blade, the characteristics of the sectional properties and the twist actuation frequency responses in More >

K. Hashiguchi¹

The International Conference on Computational & Experimental Engineering and Sciences, Vol.4, No.4, pp. 257-264, 2007, DOI:10.3970/icces.2007.004.257

Abstract General corotational rate of tensors in arbitrary order having the objectivity is shown first, and then it is verified that the material-derivative of yield condition can be replaced generally to the corotational derivative, i.e. the consistency condition. More >

T. Tanaka¹

The International Conference on Computational & Experimental Engineering and Sciences, Vol.4, No.4, pp. 251-256, 2007, DOI:10.3970/icces.2007.004.251

Abstract The viscoplastic constitutive relations with kinematic strain hardening-softening model for geomaterials are developed. The constitutive models include strain-rate dependent properties based on the thoery by Duvaut-Lions. The dynamic relaxation method for static problems and the dynamic analysis for earthquake responses are applied to boundary value problems using finite element methods. More >

K. Hashiguchi¹ and T. Ozaki²

The International Conference on Computational & Experimental Engineering and Sciences, Vol.4, No.4, pp. 243-250, 2007, DOI:10.3970/icces.2007.004.243

Abstract The overstress model is improved by incorporating the novel variable "overstress tensor" reaching the current stress from the subloading stress evolving in an imaginary quasi-static process of elastoplastic deformation due to the extended subloading surface model with the tangential inelastic strain rate. More >

E.T.R. Dean¹

The International Conference on Computational & Experimental Engineering and Sciences, Vol.4, No.4, pp. 231-242, 2007, DOI:10.3970/icces.2007.004.231

Abstract The shapes of yield envelopes for soils and other materials are generally taken as the starting point of a macroscopic plasticity model. This paper shows that these shapes can be accurately predicted using recent advances in thermodynamics and the new concept of multi-scale patterns. Some implications for future models are discussed. More >

R. Matsumoto¹, N. Miyazaki¹, M. Nakagaki²

The International Conference on Computational & Experimental Engineering and Sciences, Vol.4, No.4, pp. 223-230, 2007, DOI:10.3970/icces.2007.004.223

Abstract The mechanical properties of amorphous metals and metallic glasses are remarkably changed by precipitated crystalline particles. In this paper, the effects of crystal particle size and volume fraction on the flow stress of the metallic glass are evaluated by molecular dynamics simulations. The investigated volume fraction ranges from 0% (metallic glass) to 100% (nanocrystalline metal), and the average particle diameter ranges from 1nm to 12nm. It is revealed that the dispersed particle effects on the flow stress are very small in the entire volume fraction range when the average particle diameter is smaller than 3 More >