J.S. Lowengrub¹, J-J. Xu², A. Voigt³

FDMP-Fluid Dynamics & Materials Processing, Vol.3, No.1, pp. 1-20, 2007, DOI:10.3970/fdmp.2007.003.001

Abstract We introduce and investigate numerically a thermodynamically consistent simple model of a drop or vesicle in which the interfacial surface contains multiple constitutive components (e.g. amphiphilic molecules). The model describes the nonlinear coupling among the flow, drop/vesicle morphology and the evolution of the surface phases. We consider a highly simplified version of the Helfrich model for fluid-like vesicle membranes in which we neglect the effects of bending forces and spontaneous curvature but keep the effects of inhomogeneous surface tension forces. Thus, this model may also describe liquid drops. To solve the highly nonlinear, coupled system More >

Jui-Ming Yang^*, Philip R. LeDuc^∗,†

Molecular & Cellular Biomechanics, Vol.3, No.2, pp. 69-78, 2006, DOI:10.3970/mcb.2006.003.069

Abstract Inorganic and organic integrated systems detect, process, and respond to signals from solid media. Advances in fluidic systems have offered an alternative to traditional signaling methods through the development of aqueous signaling systems. Here, we show an experimentally simple mechanically governed fluidic system that creates three-dimensional molecular multiphase separation in a combination of discrete and continuous gradients analogous to digital and analog signals that can be used for controlled spatiotemporal cellular stimulation. We accomplish the pattern formation by fabricating a compartmentalized multi-level fluidics device where a network of capillaries converges into a main channel. Simultaneous More >

T. J Jaber¹, M. Khawaja¹, M.Z. Saghir¹

FDMP-Fluid Dynamics & Materials Processing, Vol.2, No.4, pp. 271-286, 2006, DOI:10.3970/fdmp.2006.002.271

Abstract This paper numerically investigates the interaction between thermodiffuion and buoyancy driven convection in a laterally heated vertical porous cavity for different permeability. The Firoozabadi model is applied to binary hydrocarbon mixtures: (i) the mixture of 1,2,3,4 tetrahydronaphtalene (THN) and dodecane (C12) with mass fraction of 50% for each component, (ii) 1,2,3,4 tetrahydronaphtalene and isobutylbenzene (IBB) with mass fraction of 50% for each component, and (iii) isobutylbenzene and dodecane with mass fraction of 50% for each component. The thermal and molecular diffusion coefficients, which are functions of the temperature and other properties of mixture, are calculated More >

W. Brocks¹

Structural Durability & Health Monitoring, Vol.1, No.4, pp. 233-244, 2005, DOI:10.3970/sdhm.2005.001.233

Abstract A review on phenomenological fracture criteria is given, based on the energy balance for cracked bodies, and the respective toughness parameters are related to micromechanical processes. Griffith's idea of introducing a "surface energy" and Barenblatt's concept of a "process zone" ahead of the crack tip build the foundation of modern cohesive models, which have become versatile tools for numerical simulations of crack extension. The cohesive strength and the separation energy used as phenomenological material parameters in these models appear to represent a physically significant characterisation of "fracture toughness". Micromechanical interpretations of these parameters can be More >

Shouqin Lü¹, Mian Long^1,2

Molecular & Cellular Biomechanics, Vol.2, No.4, pp. 161-178, 2005, DOI:10.3970/mcb.2005.002.161

Abstract Selectin-ligand interactions are crucial to such biological processes as inflammatory cascade or tumor metastasis. How transient formation and dissociation of selectin-ligand bonds in blood flow are coupled to molecular conformation at atomic level, however, has not been well understood. In this study, steered molecular dynamics (SMD) simulations were used to elucidate the intramolecular and intermolecular conformational evolutions involved in forced dissociation of three selectin-ligand systems: the construct consisting of P-selectin lectin (Lec) and epidermal growth factor (EGF)-like domains (P-LE) interacting with synthesized sulfoglycopeptide or SGP-3, P-LE with sialyl Lewis X (sLe^X), and E-LE with sLe^X. SMD… More >