A semi-quantitative real-time RT-PCR assay was designed to measure gonococcal pilin antigenic variation (SQ-PCR Av assay). This assay employs 17 hybridization probe sets that quantitate subpopulations of pilin transcripts carrying different silent pilin copy sequences and one set that detects total pilE transcript levels. Mixtures of a DNA standard carrying the silent copy being detected and a ...

In this paper, pile behavior embedded in layered soil deposits subjected to seismic loadings is analyzed using a nonlinear fiber element for simulation of soil – pile interactions. In the created model, both pile and surrounding soil are modeled using fiber elements in a practical Beam on Nonlinear Winkler Foundation (BNWF) concept. Herein, the features of DRAIN–3DX finite element software are ...

A quasi-three-dimensional finite element method of analysis is proposed for the dynamic response analysis of pile foundations that is computationally feasible for practical applications. The method uses a simplified three-dimensional wave equation for describing the dynamic response of the soil. The response of the pile foundation is computed directly without having to use pile–soil–pile intera...

A new efficient and accurate hybrid reliability method is proposed to estimate risk of an axially loaded single pile considering pile-soil interaction effect. Uncertainties associated with all the design variables are considered appropriately. It intelligently integrates the concepts of the response surface method, the finite difference method, the first-order reliability method, and an iterati...

We investigate the collapse of granular rodpiles as a function of particle (length/diameter) and pile (height/radius) aspect ratio. We find that, for all particle aspect ratios below 24, there exists a critical height Hl below which the pile never collapses, maintaining its initial shape as a solid, and a second height Hu above which the pile always collapses. Intermediate heights between Hl an...

Many coastal and offshore construction activities require the driving of piles into the seabed, either using impact or vibratory pile drivers. Impact pile driving produces an intense impulsive underwater noise that has been associated with fish deaths at very short range, whereas vibratory pile driving produces a lower level continuous noise. Because of the high sound levels involved, noise fro...

In this study, a coupled model is developed to address the dynamic response of an offshore pile to linear water waves. In the coupled model, the pile and the seabed are treated as a saturated poro-elastic medium described by Biot’s dynamic theory, while the seawater is considered as a conventional acoustic medium. To establish the coupled model, boundary element formulations for saturated porou...

The bearing capacity of a single pile in granular soil was analyzed piles under vertical loads in the study of the mechanism of shaft fiiction. The effect of the deformation modulus on the bearing capacity of the single pile in granular materials, and especially in sand, was examined. By using the FLAC program for the finite element analysis it was possible to predict quite accurately the load ...

in this paper effect of pile-soil consideration in obtaining seismic response offshore structure is assessed due to earthquake loading. inducedseismic force is one of the most important excitations for the dynamic response of an offshore structure. according to api, seismic forces should be accounted in platform design for seismically active regions in order to determine the allowable seismic r...