Y. C. Hon¹, L. Ling², K. M. Liew³

CMC-Computers, Materials & Continua, Vol.2, No.1, pp. 39-50, 2005, DOI:10.3970/cmc.2005.002.039

Abstract In this paper we investigate a thermal driven Micro-Electrical-Mechanical system which was originally designed for inkjet printer to precisely deliver small ink droplets onto paper. In the model, a tiny free-ended beam of metal bends and projects ink onto paper. The model is solved by using the recently developed radial basis functions method. We establish the accuracy of the proposed approach by comparing the numerical results with reported experimental data. Numerical simulations indicate that a light (low composite mass) beam is more stable as it does not oscillate much. A soft (low rigidity) beam results More >

Jessica E. Koehne, Jun Li¹, Alan M. Cassell, Hua Chen, Qi Ye, Jie Han, M. Meyyappan

Molecular & Cellular Biomechanics, Vol.1, No.1, pp. 69-80, 2004, DOI:10.3970/mcb.2004.001.069

Abstract Vertically aligned multi-walled carbon nanotubes (MWCNTs) have been reported in fabricating nanoelectrode arrays. Further studies on optimizing this system for the development of ultrasensitive DNA sensors are reported here. The mechanical stability of the as-grown MWCNT array can be improved by polymer coating or SiO₂ encapsulation. The latter method provides excellent electronic and ionic insulation to the sidewall of MWCNTs and the underlying metal layer, which is investigated with electrochemical impedance spectroscopy. The insulation ensures well-defined nanoelectrode behavior. A method is developed for selectively functionalizing biomolecules at the open end of MWCNTs while keeping the SiO₂ More >

Huajian Gao^1,1, Baohua Ji^1,1, Markus J. Buehler^1,1, Haimin Yao^1,1

Molecular & Cellular Biomechanics, Vol.1, No.1, pp. 37-52, 2004, DOI:10.3970/mcb.2004.001.037

Abstract Bone-like biological materials have achieved superior mechanical properties through hierarchical composite structures of mineral and protein. Gecko and many insects have evolved hierarchical surface structures to achieve extraordinary adhesion capabilities. We show that the nanometer scale plays a key role in allowing these biological systems to achieve their superior properties. We suggest that the principle of flaw tolerance may have had an overarching influence on the evolution of the bulk nanostructure of bone-like materials and the surface nanostructure of gecko-like animal species. We demonstrate that the nanoscale sizes allow the mineral nanoparticles in bone to More >

Shengping Shen¹, S. N. Atluri¹

CMES-Computer Modeling in Engineering & Sciences, Vol.6, No.1, pp. 91-104, 2004, DOI:10.3970/cmes.2004.006.091

Abstract An atomistic level stress tensor is defined with physical clarity, based on the SPH method. This stress tensor rigorously satisfies the conservation of linear momentum, and is appropriate for both homogeneous and inhomogeneous deformations. The formulation is easier to implement than other stress tensors that have been widely used in atomistic analysis, and is validated by numerical examples. The present formulation is very robust and accurate, and will play an important role in the multiscale simulation, and in molecular dynamics. An equivalent continuum is also defined for the molecular dynamics system, based on the developed More >

C. Luna, P. Sansberro*, L. Mroginski, J. Tarragó

BIOCELL, Vol.27, No.2, pp. 205-212, 2003, DOI:10.32604/biocell.2003.27.205

Abstract Micropropagation of Ilex dumosa var. dumosa R. (“yerba señorita”) from nodal segments containing one axillary bud was investigated. Shoot regeneration from explants of six-year-old plants was readily achieved in ¹/₄ strength Murashige and Skoog medium (¹/₄ MS) plus 30 gr·L^-1 sucrose and supplemented with 4.4 µM BA. Further multiplication and elongation of the regenerated shoots were obtained by subculture in a fresh medium of similar composition with 1.5 gr·L^-1 sucrose. Rooting induction from shoots were achieved in two steps: 1) 7 days in ¹/₄ MS (30 gr·L^-1 sucrose, 0.25 % Phytagel^®) with 7.3 µM IBA and 2) 21 days in More >

Gabriela Perdigón^1,2, Mónica Locascio¹, Marta Medici¹, Aida Pesce de Ruiz Holagado^1,2, Guillermo Oliver¹

BIOCELL, Vol.27, No.1, pp. 1-9, 2003, DOI:10.32604/biocell.2003.27.001

Abstract Bifidobacteria are predominant in the lumen of the large intestine and confer various health benefits on the host. They are also used in the preparation of new fermented milks (bioyogurts) or added to conventional yogurt to generate probiotic effects. The colonization of the gut by bacteria tends to be host specific due partly to the way in which bacteria adhere to the intestinal wall. Using a homologous strain of Bifidobacterium animalis in an experimental mouse model, we analyzed by immunofluorescence labelledbacteria and transmission electronic microscopy the importance of this bacterial interaction with epithelial an immune cells… More >

Leone Corradi¹, Francesco Genna²

CMES-Computer Modeling in Engineering & Sciences, Vol.4, No.3&4, pp. 381-396, 2003, DOI:10.3970/cmes.2003.004.381

Abstract A critical comparison of several Finite Element models is presented, with reference to the analysis of the stress and strain states around a tooth or a fixed dental implant. Such an analysis, if performed on a full, three-dimensional geometry of the jaw-tooth/dental implant system, requires significant computational resources, and it is therefore often done on simplified models, whose validity can be questionable. On the other side, the use of simplified models is adequate --- almost mandatory --- when detailed results are needed, or when geometrical and material nonlinearities, as well as other complicating factors, are… More >

Adnan Ibrahimbegovic¹, Catherine Knopf-Lenoir²

CMES-Computer Modeling in Engineering & Sciences, Vol.4, No.2, pp. 337-344, 2003, DOI:10.3970/cmes.2003.004.337

Abstract In this work we present an unconventional procedure for combining the optimal shape design and nonlinear analysis in mechanics. The main goal of the presented procedure is to enhance computational efficiency for nonlinear problems with respect to the conventional, sequential approach by solving the analysis and design phases simultaneously. A detailed development is presented for the chosen model problem, the 3d rod undergoing large rotations. More >

Yansong Wang¹, Q. Jane Wang¹, Chih Lin²

CMES-Computer Modeling in Engineering & Sciences, Vol.3, No.4, pp. 517-530, 2002, DOI:10.3970/cmes.2002.003.517

Abstract Many mechanisms, such as computer hard drives, gear trains, and machine tool spindle systems, operate under both axial and radial loads, which should be respectively supported by a thrust and a journal bearing. By utilizing the end face of the shaft of a journal bearing as a thrust bearing, a coupled journal-thrust bearing system can be formed. This paper presents a mixed lubrication model developed to investigate the lubrication of this coupled bearing system. A conformal-mapping method is used in the model formulation to facilitate a universal flow description. The performance of typical coupled bearing More >

Yuanzhong Hu¹, Yuchuan Liu, Hui Wang

CMES-Computer Modeling in Engineering & Sciences, Vol.3, No.4, pp. 447-454, 2002, DOI:10.3970/cmes.2002.003.447

Abstract Scuffing, a major cause of failure in automobile engines, is considered as a dynamic process in this study. Local adhesions may occur randomly in lubricated contacts due to the existence of asperity contact and breakdown of lubricating films. Scuffing would take place if the local events develop rapidly into a large-scale plastic deformation and catastrophic failure. A system dynamic model established in the present paper allows one to predict dynamic behavior of a tribological system through numerical solutions of a group of differential equations. Results show that a transition to adhesion begins when the surface More >