Many asteroids and comets orbit the inner solar system; among them Near Earth Objects (NEOs) are those celestial bodies for which the orbit lies close, and sometimes crosses, the Earth’s orbit. Over the last decades the impact hazard they pose to the Earth has generated heated discussions on the required measures to react to such a scenario. The aim of the research presented in this dissertatio...

This paper presents a failure analysis on a failed intake valve in a gasoline engine. During an endurance test, an intake valve was broken and caused some damages on the piston. Material examinations (by a light microscope and also a scanning electron microscope) were conducted on the fracture surface of the intake valve shaft. Results showed that no pores or defects could be observed and the m...

in this paper, the finite element analysis of stability problem of vehicle composite drive shafts subjected to torsional loading is studied. first, using the minimum total potential energy principle, the governing equations are derived and then they are solved by finite element method. the initial geometrical imperfection which is usually in the form of radial displacement, is taken into consid...

Details of 93 roll shaft breakages which have occurred at eight selected sugar mills in Natal since 1979 have been collated and analysed to determine the most likely causes of failure. Theoretical analyses of shaft stresses and fatigue stress concentration factors have been carried out to determine whether present shaft design, machining practices, material specifications and shell assembly tec...

A deflection routing algorithm that can be applied to a novel self-routing address scheme for networks with arbitrary topology is proposed. The proposed deflection routing algorithm can be implemented all-optically using bitwise optical logic gates. Besides the primary output link selection, alternate output link choices by a packet at each node in case of deflection are also encoded in the add...

introduction the aim of this study was to compare the characteristics of deflection load of three kinds of nickel titanium closed coil springs. methods and materials this research was an experimental study. research sample contains three kinds of niti closed coiled springs (heavy, medium, light) from gac, 3m, and rmo factories. 10 springs with 9 mm length for each group (totally 90 springs) wer...

The last phase of the proton transfer cycle of bacteriorhodopsin calls for a passage of a proton from D38 to D96. This reaction utilizes a narrow shaft approximately 10-A long that connects the two carboxylates that cross through a very hydrophobic domain. As the shaft is too narrow to be permanently hydrated, there are two alternatives for the proton propagation into the channel. The proton ma...

In this paper, a modular designed automatic screw tightening shaft system, which is based on enhanced variable gain PID control, is proposed. Designed for the autonomous screw tightening operation, the screw tightening shaft enjoys huge potential for industry application. The screw tightening shaft and the screw tightening process are both mathematically modeled as an uncertain feedback system ...

It is generally accepted that nuclei degrade in developing hair shafts but the point at which such occurs has not been investigated. The fate of mitochondria in the keratinizing hair shaft has been less clear. This study uses transmission electron microscopy to investigate when nuclei and mitochondria are no longer visible in the developing hair shaft. Serial sections were obtained from anagen ...