separation system is one of the most important systems in rockets. the influence of this system on mission success cannot be ignored. in this paper, reliability of a sounding rocket separation system is determined using block diagram and fmea . this system is based on the flexible linear shape charge cross-section and a spring mechanism to accelerate separation. in this investigation, the relia...

A piezoelectric vibration feeder with a magnetic spring is discussed in this paper. The feeder can keep resonance frequency relatively stable under changing loading. Through the analysis on the working principle and magnetic spring stiffness characteristic of this feeder, the dynamic model was established and the relationship among system resonance frequency, loading and magnetic spring stiffne...

Abstract: It is difficult to weigh the light objects by weighing balance accurately when measured individually. If several light objects are weighed in groups rather than individually then the precision of the estimates increases quite considerably. There are two types of balances one is chemical balance and other is spring balance. Spring balance is similar when only one pan of chemical balanc...

We would like to welcome our readers to the twenty-eighth issue of 49 th Parallel and our second of 2012. In the last few months there have been some exciting developments at the journal and we hope that 49 th Parallel will continue to flourish in the future. We would like to welcome our new Articles Editor, Galateia Demetriou, to the 49 th Parallel team. Galateia is a second year doctoral rese...

THE RESPONSE of hitherto known practical forms of seismographs depends upon the relative motion of a pendulum and the moving ground to which ~ts supporting structure is fastened. The various kinds of seismographs differ in the type of pendulum used, such as gravity, spring, torsion, and/or they differ in the type of magnifying and recording elements which they employ. They all measure or indica...

Beijing’s mountainous areas have an important ecological significance because they are ecological conservation and water source protection areas of Beijing. The impact of precipitation on the vegetation coverage of Beijing’s mountainous areas is qualitatively analyzed using multi-temporal Landsat images obtained during the last 20 years. Firstly, the influence of external factors, such as pheno...

The controlling behaviour of a vehicle is influenced by the performance of its steering system. The steering system consists of steering wheel, steering column, rack and pinion, steering gearbox, and a linkage system. The vehicle is controlled by the behaviour of the steering gear with the spring loaded rack and pinion. This spring loading arrangement consists of yoke nut, spring, and plunger. ...

This article describes a mechanical vertical attenuation system capable to provide large attenuation factors above 1Hz. This system is derived from, and improves, the passive Geometric Anti-Spring seismic attenuation filters minimizing their vertical resonant frequency by means of a tunable electromagnetic spring mounted in parallel with the main spring. The tunable spring is also used to compe...

—The West Virginia Spring Salamander (Gyrinophilus subterraneus) is one of four obligate cave-dwelling species of plethodontid salamanders found east of the Mississippi River in the United States. This species is endemic to a single cave system; General Davis Cave, in Greenbrier Co., West Virginia, where it is syntopic with the closely-related Spring Salamander (G. porphyriticus). Accordingly, ...