C. Xu¹, X. Jia², R. A. Williams², E. H. Stitt³, M. Nijemeisland³, S. El-Bachir⁴, A. J. Sederman⁴, L. F. Gladden⁴

CMES-Computer Modeling in Engineering & Sciences, Vol.23, No.2, pp. 117-126, 2008, DOI:10.3970/cmes.2008.023.117

Abstract Existing theories and computer models for packed columns are either incapable of handling complex pellet shapes or based on over-simplified packing geometry. A digital packing algorithm, namely DigiPac, has recently been developed to fill the gap. It is capable of packing of particles of any shapes and sizes in a container of arbitrary geometry, and is a first step towards a practical computational tool for reliable predictions of packed column properties based on the actual pellet shapes. DigiPac can operate in two modes: a Monte Carlo mode in which particles undergo directional diffusive motions; and… More >

A.Z. Lorbiecka¹, R.Vertnik², H.Gjerkeš¹, G. Manojlovič², B.Senčič², J. Cesar², B.Šarler^1,3

CMC-Computers, Materials & Continua, Vol.8, No.3, pp. 195-208, 2008, DOI:10.3970/cmc.2008.008.195

Abstract A numerical model is developed for the simulation of solidification grain structure formation (equiaxed to columnar and columnar to equiaxed transitions) during the continuous casting process of steel billets. The cellular automata microstructure model is combined with the macroscopic heat transfer model. The cellular automata method is based on the Nastac's definition of neighborhood, Gaussian nucleation rule, and KGT growth model. The heat transfer model is solved by the meshless technique by using local collocation with radial basis functions. The microscopic model parameters have been adjusted with respect to the experimental data for steel 51CrMoV4. More >

García-Suárez¹ F, L Carreto-Montoya², R Cárdenas-Navarro³, JC Díaz-Pérez⁴, R López-Gómez

Phyton-International Journal of Experimental Botany, Vol.76, pp. 19-26, 2007, DOI:10.32604/phyton.2007.76.019

Abstract In this work we contribute to the knowledge of the reproductive phenology of Stenocereus stellatus (Pfeiffer,Riccobono), a columnar cactus that produces fruits of high commercial perspectives known as “pitayas”. This kind of pitayas are produced for local commercialization in back orchards in some regions of the Mexican dry tropics. These fruits are produced only in the apical part of the cactus “arms”. Our results show that fruit development of pitayas is highly associated to the rainy season of the year. This behavior is different from the reproductive strategy of other columnar cactus species that produce other More >

L. Nobile¹, C. Carloni¹

Structural Durability & Health Monitoring, Vol.2, No.2, pp. 83-90, 2006, DOI:10.3970/sdhm.2006.002.083

Abstract The analysis of buckling of elastic columns is one of the first problem in structural engineering that was historically solved. Critical loads of perfect columns with various end restrains have been derived. Nevertheless, the perfect column is an idealized model. In reality, unavoidable imperfections should be considered. Solutions for transversal disturbing load, crookedness or load eccentricity have been proposed. Another frequent imperfection to be taken into account is the weakness at an interior location due to a partial edge crack. In this paper the influence of this type of imperfection on the critical load is More >

T. Ishizawa¹, M. Iura¹

CMES-Computer Modeling in Engineering & Sciences, Vol.11, No.3, pp. 121-130, 2006, DOI:10.3970/cmes.2006.011.121

Abstract A one-dimensional model is proposed for numerical analysis of partially concrete-filled steel tubular (PCFST) columns subjected to cyclic loadings. The present formulation does not require experimental results nor shell analysis to obtain the constitutive equation of the model. The material properties and dimensions of PCFST columns are required for numerical analysis of the present model. The PCFST columns are assumed to consist of elastic beam and base plastic-hinge region in which steel local buckling is observed. Two parameters are introduced in order to express hardening phenomena of PCFST columns subjected to cyclic loading. Resisting forces More >