The Measurement of Silicon, Tin, and Titanium in Jet-Engine Oil
A wear metal profile is often prepared for each engine. Typically an early wear-in period of high metals concentration is observed, followed by a plateau of low metals concentration [2]. Impending component failure will be indicated by a rapid increase in wear metal concentration, or the sudden appearance of a metal. The metal type and concentration may also indicate to the analyst and engineers which part of an engine is failing. A change in the concentration of sodium for example, may indicate an antifreeze leakage, the increased presence of lead may indicate the wear of bearings in a diesel engine [3].
Effect of Calcite and Silica Content on Tribological Performance of Engine Oil Lubricants
Sand dust can enter into an engine lubrication system through the intake manifold. The effect of calcite and silica sand dust particles in an engine on oil particle contamination was investigated. The presence, amount, and size of silica and calcite particles in engine oil were determined using X-ray diffraction (XRD), inductively coupled plasma (ICP) spectroscopy, and energy dispersive X-ray spectroscopy (EDX). Four levels of silica and calcite particles were obtained through engine oil sampling from farm tractors at the east of Isfahan (Iran) then, used to investigate their effect on the wear of engine moving parts after 20 hours of engine operation. The ICP analysis showed the amount of iron, aluminum, chromium, copper, nickel, and lead increased in the engine oil with increasing silica content, whereas aluminum and copper increased as the calcite content increased. In zero, 1, 2, and 3 g/L of the silica content of the engine oil, there were 6.2, 136.7, 176.3, and 1758.6 mg/L of iron particles, 0.18, 27.38, 46.65 and 47.85 mg/L of aluminum particles, and 0, 3.54, 5.85, and 10.73 mg/L of chromium particles, respectively. Thus, the quality of filters in agricultural tractors is to be improved to prevent engine wear by sand dust.
12.2: Enhanced Electron Emission of the Cone‐Shaped Emitters with Carbon Nanostructures
We developed novel cone‐shaped emitters with individual carbon nanotips using the resist‐assisted patterning process. The novel cone‐shaped nanotip emitters were arranged in an array with many nano emitters in pre‐patterned diameters of 3 μm. The cone‐shaped nanotip emitters consist of a number of carbon‐based nanostructures such as nanotubes and/or nanofibers with silicon and nitrogen elements at the periphery of each element. The cone‐shaped nano‐emitters strongly adhered to the substrate due to the large area bottom contact which is covered with diffused silicon elements. The growth mechanism and enhanced electron emission of cone‐shaped nanotip emitters was discussed.