7,346 research outputs found
Linker-mediated self-assembly of mobile DNA-coated colloids
Developing construction methods of materials tailored for given applications
with absolute control over building block placement poses an immense challenge.
DNA-coated colloids offer the possibility of realising programmable
self-assembly, which, in principle, can assemble almost any structure in
equilibrium, but remains challenging experimentally. Here, we propose an
innovative system of linker-mediated mobile DNA-coated colloids (mDNACCs), in
which mDNACCs are bridged by the free DNA linkers in solution, whose two
single-stranded DNA tails can bind with specific single-stranded DNA receptors
of complementary sequence coated on colloids. We formulate a mean-field theory
efficiently calculating the effective interaction between mDNACCs, where the
entropy of DNA linkers plays a nontrivial role. Particularly, when the binding
between free DNA linkers in solution and the corresponding receptors on mDNACCs
is strong, the linker-mediated colloidal interaction is determined by the
linker entropy depending on the linker concentration
Kalman filter based estimation of neutral-axis position of bridge deck sections using strain monitoring data
The neutral-axis position has been recognized as a damage indicator for bridge deck assessment because of its high sensitivity to local damage on deck sections. It can be estimated when strain responses at the top and bottom of a deck cross-section under traffic loading are measured. However, the accuracy of neutral-axis position estimation directly using the measured strain responses might be significantly distorted in the presence of measurement noise and varying traffic load patterns. In this study, a Kalman filter (KF) estimator is formulated to locate the neutral-axis position from measured strain responses under traffic loading. Its capability for consistently locating the neutral-axis position under varying traffic load patterns is verified using the field monitoring data of traffic-induced strain responses acquired from the suspension Tsing Ma Bridge under diverse load scenarios (highway traffic, railway traffic, and their combination). The results indicate that the proposed KF estimator gives rise to consistent neutral-axis position estimation results which are independent of load conditions and patterns
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