Diproline segments have been advanced as templates for nucleation of folded structure in designed peptides. The conformational space available to homochiral and heterochiral diproline segments has been probed by crystallographic and NMR studies on model peptides containing L-Pro-L-Pro and D-Pro-L-Pro units. Four distinct classes of model peptides have been investigated: a) isolated D-Pro-L-Pro ...

Motion tracking is an important step of the analysis of ow image sequences. However, Particle Image Velocimetry (PIV) techniques rarely use tracking methods developed in computer vision, they usually work with FFT and correlation based methods. Two major types of motion estimation algorithms exist: the optical ow and the feature based ones. Promising results have been obtained by applying optic...

Bäcklund transformations (BTs) for ordinary differential equations (ODEs), and in particular for hierarchies of ODEs, are a topic of great current interest. Here we give an improved method of constructing BTs for hierarchies of ODEs. This approach is then applied to fourth Painlevé (PIV ) hierarchies recently found by the same authors [Publ. Res. Inst. Math. Sci. (Kyoto) 37 327–347 (2001)]. We ...

An improved correlation based Particle Tracking Velocimetry (PTV) algorithm was proposed in the present paper. The path tracking of the tracer particles was achieved through a correlation operation of the small interrogation window around the studied tracer particles at two-time steps. The central positions of the tracer particles were determined by the correlation operation of the tracer parti...

Parainfluenza viruses (PIV) are common respiratory viruses that belong to the Paramyxoviridae family. PIV infection can lead to a wide variety of clinical syndromes ranging from mild upper respiratory illness to severe pneumonia. Severe disease can be seen in elderly or chronically ill persons and may be fatal in persons with compromised immune systems, particularly children with severe combine...

The background-oriented schlieren (BOS) technique with the physicsbased optical flow method (OF-BOS) is developed for measuring the pressure field of a laser-induced underwater shock wave. Compared to BOS with the conventional cross-correlation method in PIV (called PIV-BOS), by using the OF-BOS, the displacement field generated by the small density gradient in water can be obtained at the spat...

The main purpose of the present work is to correct errors occurring in a stereoscopic PIV system and caused by misalignments between the calibration plane and the measurement plane. The experimental measurements have been conducted using an angular stereoscopic system with Scheimpflug conditions and a PIV-calibration pattern has been mounted on stages which can translate in three dimensions and...

In Stereoscopic Particle Image Velocimetry (Stereo-PIV), the three velocity components are obtained by illuminating a planar region in the fl ow fi eld and recording the region of interest using two cameras at an angle. Calibration, planar velocity estimation, and velocity reconstruction are the three essential steps involved in the process. Earlier efforts to quantify the accuracy in a Stereo-...

The flow distribution in a silicon microchannel heat sink was studied using Infrared MicroParticle Image Velocimetry (IR PIV). The microchannel test piece consisted of seventy-six 110 m wide  371 m deep channels etched into a silicon substrate. Inlet and outlet manifolds, also etched into the substrate, were fed by 1.4 mm inner-diameter tubing ports. An image processing algorithm was develo...