Slab track structures become deformed under the effects of differential subgrade settlement. According to properties China Railway Track System (CRTS) II slab on a subgrade, three-dimensional (3D) coupled model based both discrete element method (DEM) and finite difference (FDM) was developed. The were simulated using FDM DEM, respectively. verified. deformation contact forces gravel grains in ...

Bioadhesives produced by marine macroalgae represent a potential source of inspiration for the development of water-resistant adhesives. Assessing their adhesion strength, however, remains difficult owing to low volumes of adhesive material produced, low solubility and rapid curing time. These difficulties can be circumvented by testing the adhesion strength of macroalgae propagules attached to...

Microbial biofilms induce larval settlement for some invertebrates, including corals; however, the chemical cues involved have rarely been identified. Here, we demonstrate the role of microbial biofilms in inducing larval settlement with the Caribbean coral Porites astreoides and report the first instance of a chemical cue isolated from a marine biofilm bacterium that induces complete settlemen...

The boundary element technique is a practical problem-solving tool and useful in comparison to other currently popular alternatives. In this paper, a circular tunnel of a diameter 3.4 m is to be excavated through a clayey soil and surrounded by concrete lining of a thickness 0.2 m, so the clear internal diameter is 3.0 m. A plane strain analysis is adopted for such problem and the soil is assum...

The preparation of side group modified polystyrene-based surface-active block copolymers (SABC) for use as marine fouling resistance/release applications is described. Modifying moieties such as poly(ethylene glycol) (PEG) and semifluorinated segments were used. A novel bilayer methodology has been employed that provides both suitable mechanical properties through the use of an elastomeric prim...

Tunnelling through cities underlain by soft soil, commonly associated with soil movement around the tunnels and subsequent surface settlement. The predication of ground movement during the tunnelling and optimum support pressure could be based on analytical, empirical or the numerical methods. The commonly used Earth pressure balance (EPB) tunneling machines, uses the excavated soil in a pressu...

Compared with straight tunnels, over-excavation occurs on the inner side of curved section during shield construction small radius and disturbance to ground surface mechanical properties surrounding rock segment are more severe. This paper establishes numerical models curve tunnels study characteristics deformation caused by excavation influence parameters settlement, deformation, force. The ma...

Gregarious settlement in barnacle larvae (cyprids) is induced by a contact pheromone, the settlement-inducing protein complex (SIPC). The SIPC has been identified both in the cuticle of adult barnacles and in the temporary adhesive secretion (footprint) of cyprids. Besides acting as a settlement inducer, the presence of the SIPC in footprints points to its additional involvement in the adhesion...

The barnacle Balanus ( = Amphibalanus) amphitrite is a major marine fouling animal. Understanding the molecular mechanism of larval settlement in this species is critical for anti-fouling research. In this study, we cloned one isoform of p38 MAPK (Bar-p38 MAPK) from this species, which shares the significant characteristic of containing a TGY motif with other species such as yeast, Drosophila a...

This paper presents the results of a recent study about the following aspects relevant to tunneling in soft grounds:e) The domain of deformations due to tunneling in soft ground can be specified within a boundary of a parabolic shape. This boundary is defined by a parabolic formula as a function of a central angle which depends on the soil type i.e., either cohesive or cohesionless. This para...