The theoretical period-luminosity relation for Cepheids was deduced from stellar evolution and pulsation computations. Questions concerning the metallicity dependence of the relation as well as the constancy of the pulsation ‘constant’ Q in the instablility strip were addressed. We found no significant metallicity dependence of either the slope or of the zero-point of the period-luminosity rela...

We have obtained time-resolved ultraviolet spectroscopy for the pulsating DAV stars G226-29 and G185-32 and for the pulsating DBV star PG 1351]489 with the Hubble Space T elescope Faint Object Spectrograph to compare the ultraviolet to the optical pulsation amplitude and determine the pulsation indices. We Ðnd that for essentially all observed pulsation modes, the amplitude rises to the ultravi...

We suggest that the observed long-period Alfvén waves in the solar wind may be generated in the solar interior due to the pulsation of the Sun in the fundamental radial mode. The period of this pulsation is about 1 hour. The pulsation causes a periodical variation of density and large-scale magnetic field, this affecting the Alfvén speed in the solar interior. Consequently the Alfvén waves with...

The artery pulsation has a strong correlation with the blood flow in the newborn baby head and tissuemotion has a relationship with artery pulsation. In this paper, we propose a novel method to estimate the tissuemotion quantitatively by combining local and global motion estimation methods, namely combined local-global (CLG) optical flow technique in cranial ultrasonogram of newborn babies. Tis...

Bombardier beetles (Brachinini) use a rapid series of discrete explosions inside their pygidial gland reaction chambers to produce a hot, pulsed, quinone-based defensive spray. The mechanism of brachinines' spray pulsation was explored using anatomical studies and direct observation of explosions inside living beetles using synchrotron x-ray imaging. Quantification of the dynamics of vapor insi...

background: mechanical torque limiting devices (mtlds) are necessary tools to control a peak torque and achieving target values of screw component of dental implants. due to probable effect of autoclaving and number of use on the accuracy of these devices, this study aimed to evaluate the effect of sterilization and number of use on the accuracy of friction-style mechanical torque limiting devi...

A long flexible material called the web is converted into final product through various processes such as printing, drying, coating, and laminating using a handling system. The transported from an unwind roller to rewind some guide drive rollers in servo motors control regulate their rotation velocity or torque system, where tension transportation controls play important role achieving high qua...

the linear adiabatic pulsation-periods of mira variable stars have been derived. approximately 2701[1]models were calculated for m = 0.7 mθ to 2 mθ stars with radii from 180 rθ to 340 rθ and luminosities from 2800 lθ to 10,000 lθ. the chemical composition of all models is (x,z) = (0.7,0.02). from the result of this study, linear relations on luminosity-period-mass relationship and luminosity-pe...