We both theoretically and experimentally examine the behavior of the first- and the second-order rainbows produced by a normally illuminated glass rod, which has a nearly elliptical cross section, as it is rotated about its major axis. We decompose the measured rainbow angle, taken as a function of the rod's rotation angle, into a Fourier series and find that the rod's refractive index, average...

The special variable ratio transmission characteristics and complex tooth profile curve of elliptic gears make it difficult to analyse their characteristics, which restrict the application development elliptical gears. Given that, a characteristic analysis method based on testing is proposed in this paper. By building high-precision gear test rig, distribution laws dynamic lost motion, static b...

Recently, bicycles are used as exercising machines and traffic vehicles. Planetary gear trains can be used as the transmission systems with multi-speed for bicycles. The purpose of this work is to propose a design methodology for the design of automatic three-speed gear hubs with planetary gear trains for bicycles. First, applying the check list method (combining and extending methods), the des...

Large quasi-elliptical cylinders are extensively used in ocean engineering. To enhance a better understanding of the hydrodynamic wave force on such during extreme events, series experiments interaction with cylinder were conducted. A waves various heights, periods, and incident directions tested to investigate parameter effect directionality forces structure. The experimental results indicate ...

Balance shafts are often used to improve the engine vibration characteristics of three-cylinder engines. The balance damping gear with a ring is an important part connecting crankshaft and shaft transmission. stiffness unbalance have influence on its suppression performance, but coupled unbalanced unknown. In this paper, multi-body dynamic bending–torsional coupling model transmission system co...

We measured the supernumerary spacing parameter of the first- and second-order rainbows of two glass rods, each having an approximately elliptical cross section, as a function of the rod's rotation angle. We attribute large fluctuations in the supernumerary spacing parameter to small local inhomogeneities in the rod's refractive index. The low-pass filtered first-order rainbow experimental data...

With the continuous development of national economy, big gear was widely applied in metallurgy and mine domains. So, big gear plays an important role in above domains. In practical production, big gear abrasion and breach take place often. It affects normal production and causes unnecessary economic loss. A kind of intelligent test method was put forward on worn big gear mainly aimed at the big...

In-line skating injuries and protective gear use were explored in a sample of college students (n = 217). A minority of respondents wore protective gear. One third of skaters had experienced at least one minor injury, and a smaller percentage had experienced fractures or head injuries. Most minor injuries occurred during the first 1-2 times skating, while more serious injuries tended to occur a...