A new eddy-current system based on low-noise magnetoresistive sensors has been developed to detect cracks and corrosion in thick, multi-layer metal structures. The new instrument has detected narrow slots as short as 6.3 mm, in the lowest layer of a stack of three aluminum plates totaling 25 mm in thickness. These flaws were detected through 19 mm of overlying aluminum, in spite of the presence...

Commissural axons are attracted to the midline intermediate target by chemoattractants, but upon crossing the midline they switch off responsiveness to attractants and switch on responsiveness to midline repellents, which expel the axons from the midline and enable them to move on. Here we show that midline exit also requires the stimulation of axon outgrowth by Stem Cell Factor (SCF, also know...

The friction and wear behaviour of ZrO*-Y203, Zr02-Y203--Ce02 and ZrQ--A1203 composite ceramics against hardened steel AISI-52100 were investigated using a pin on plate configuration under reciprocating motion. The reproducibility of the results was examined in this configuration. Wear characteristics were separated into system and material contributions. Under the conditions used, all the cera...

This paper presents a novel bolt-loosening detection technique using image information of bolted joints in steel bridges. Firstly, existing bolt-loosening detection techniques are reviewed and their benefits and limitations are analyzed. Secondly, a bolt-loosening detection algorithm using image processing techniques is newly proposed for bolted joints in steel bridges. It consists of 3 steps: ...

Progress Using mathematical models, we are investigating the influence of plate fixation on the internal stresses in long bones subjected to all known in vivo loading modes . The variables we are studying include : plate geometry, plate/bone fixity, and screw tightness. The mathematical models are based upon the finite element technique . The models will be subjected to all physiological loadin...

Metal Plate Shear Walls (MPSWs) represent an effective, practical and economical system for the seismic protection of existing RC framed buildings. They consist of one or more metallic thin plates, bolted or welded to a stiff steel frame, which are installed in the bays of RC framed structures. A case study of an existing RC residential 5-storey building, designed between the ‘60s and ‘70s of t...

A monitoring solution was developed for detection of material loss in metals such as carbon steel using the force generated by permanent magnets in addition to the optical strain sensing technology. The working principle of the sensing system is related to the change in thickness of a steel plate, which typically occurs due to corrosion. As thickness decreases, the magnetostatic force between t...

According to the different construction forms of PBL shear connectors in steel-concrete composite beam and steel-concrete joint section, eight finite element models in two groups of the two construction forms are conducted to study different mechanical properties of PBL shear connectors. Following conclusions can be drawn from the finite element method calculation results. The load-slip curve, ...

This paper presents a finite element analysis on the tensile stiffness of steel bolted connections, which are fabricated from thin-walled cold-formed steel strips and members. This type of bolted connection is usually used to assemble the diagonal bracing member in the light steel structure. Unlike the architectural steel structure, thin walled steel bolted connection cannot be simplified into ...