Cause Of Synchronization Research Articles

Research on the Synchronization Problem in the Combustion of Candles

In 2020, IYPT question 5 “synchronized candles” describes an interesting common phenomenon in life. The so-called synchronous candle refers to the flame that can be observed to oscillate when several adjacent candles are burning. Two such oscillations can be coupled with each other, leading to in-phase or reverse phase. In this paper, the control variable method is used to study the reason of the oscillation of a single oscillator and the phenomenon of inphase or anti phase oscillation of candles with different separation distance. It is found that the phenomenon of the oscillation coupling of regular candles is related to the distance between candles. Considering that the gas diffusion coefficient of the air is too low and the isotherm of the candle is relatively stable, the most likely cause of synchronization or inverse synchronization is thermal radiation. Finally, FDS software is used to simulate the combustion of the flame, and the results of in-phase and inverse vibration are also obtained.

Synchronization among Pedestrians in Footbridges due to Crowd Density

AbstractCrowding is a critical condition for footbridges that are prone to vibration problems from pedestrian loads. Synchronization of pedestrian movements has been identified as the cause of the excessive lateral vibration in some footbridges. Two conditions have been named as the cause of synchronization: increase in crowd density and pedestrian-structure interaction. The former would be related to the onset of the phenomenon; the latter takes place after structural vibration reaches a certain level. This paper focuses on the former condition. A test program to investigate whether this condition occurs was carried out for a range of pedestrian densities, complementing data previously published on this subject. The head movement of pedestrians walking both in groups and in a flow was recorded by a video camera, and the examination of the video indicated no synchronization from densification. However, it was observed that the lateral sway of the pedestrians’ bodies increased with the increase of density....

Possible ozone influence on the quasi-biennial oscillation in the equatorial stratosphere

Crossspectral analysis between the time series of zonal wind velocity in the equatorial stratosphere and the flux of solar UV radiation revealed high coherence between the variations of these two parameters on a quasibiennial scale (24-30 months) in the atmo� spheric layer 500-1 hPa (~6-48.5 km). A lag of the quasibiennial variations in wind velocity behind the quasibiennial variations in the solar radiation flux, the maximum (~ 24 months) of which is located at a level of 100 hPa (16.5 km), decreases with height, and in the stratopause region (~1 hPa), the wind velocity variations are approximately in phase with the varia� tions in the solar radiation flux. This points at the pos� sibility of the influence of quasibiennial variations in the shortwave solar radiation on the quasibiennial oscillation of the zonal wind in the neighborhood of the equatorial stratopause. It has been shown that the meridional gradient and the curvature degree of the meridional profile of ozone concentration in this layer undergo quasibiennial variations such that could be a cause of synchronization between the quasibiennial variations in the wind velocity and thermal variations according to the solar wind equation. 1. The quasibiennial oscillation (QBO) manifests itself most clearly in the change of the direction of the

The relation between 5-amino uracil-induced mitotic synchronization and DNA synthesis

The effect of the pyrimidine analogue 5-amino uracil (5AU) on DNA synthesis in Vicia faba lateral roots has been studied. Earlier reports had suggested that 6 m M 5AU synchronizes nuclear divisions (mitotic index of 40 instead of 10 in controls) in Vicia 12–14 hr after removal from a 24-hr treatment through interference with DNA synthesis at the time of treatment. It was shown in the present study that the mitotic synchronization induced by 5AU can occur while the seedlings are in 5AU, and that even a 2-hr treatment with 12 m M 5AU is sufficient to produce the synchrony. Furthermore, synchronization could not be eliminated by the addition of thymidine to the 5AU, as would have been expected if interference with thymidine synthesis were a cause of synchronization. Autoradiographic studies of 3H-thymidine and 3H-deoxycytidine incorporation into the DNA of the meristematic nuclei of the root tip showed that DNA synthesis goes on in the presence of 4 m M to 6 m M 5AU. The rate of DNA synthesis, however, is slowed down, and S is at least 25–40 per cent longer than in the control. This suggests an extension of S from the normal 7.5 hr to at least 11 hr. After removal of the roots from 4 m M 5AU, the rate of DNA synthesis of the root meristem continues to be slow for about 6 hr and then approaches the control level by 9 hr. The slowing down of DNA synthesis is probably not causally related to the mitotic synchronization. A block in G2 as a possible cause of 5AU-induced mitotic synchronization has been discussed.