The membrane potential of frog single muscle fibers in solutions containing tetrodotoxin was controlled with a two-electrode voltage clamp. Local contractions elicited by 100-ms square steps of depolarization were observed microscopically and recorded on cinefilm. The absence of myofibrillar folding with shortening to striation spacings below 1.95 microm served as a criterion for activation of ...

A striation pattern can emerge in high-frequency acoustic signals interacting with dynamic surface waves. The striation pattern is analyzed using a ray tracing algorithm for both a sinusoidal and a rough surface. With a source or receiver close to the surface, it is found that part of the surface on either side of the specular reflection point can be illuminated by rays, resulting in time-varyi...

Failure analysis of fractured components provides some information about the causes and conditions of fracture. Fractography is an indispensable part of the failure analysis as it is usually the only means by which the failure mechanism can be established. By using fractography, some information such as component’s life, values of the stress intensity factor and the applied stress can be calcul...

We present a new image processing strategy that enables an automated extraction of signatures from striation patterns. To this end, a signal model is proposed that allows a suitable description of the interesting features of forensically relevant striation marks. To provide for a high image quality, several images of the same surface area are recorded under systematically varying conditions. Th...

The element–frequency acoustic intensity of a horizontal line array with sufficient aperture exhibits interference striation patterns, which can be used for source range estimation without prior environmental information. Under multisource scenarios, the striations sources overlap each other, leading to great difficulty in utilizing information striations. In this paper, wavenumber filtering me...

In the presence of ATP, recA protein forms a presynaptic complex with single-stranded DNA that is an obligatory intermediate in homologous pairing. Presynaptic complexes of recA protein and circular single strands that are active in forming joint molecules can be isolated by gel filtration. These isolated active complexes are nucleoprotein filaments with the following characteristics: (i) a con...