Face seals operate by allowing a small volume of the sealed fluid to escape and form a thin film between the contacting parts. The thickness of this film must be optimised to ensure the faces are separated, yet the leakage is minimised. In this work the liquid film is measured using a novel ultrasonic approach with a view to developing a condition monitoring tool. The trials were performed in t...

STATEMENT OF PROBLEM For a luting agent to allow complete seating of prosthetic restorations, it must obtain an appropriate flow rate maintaining a minimum film thickness. The performance of recently introduced luting agents in this regard has not been evaluated. PURPOSE To measure and compare the film thickness and flow properties of seven resin-containing luting cements at different tempera...

We present the results of laboratory experiments that quantify the physical controls on the thickness of the falling film of liquid around a Taylor bubble, when liquid–gas interfacial tension can be neglected. We find that the dimensionless film thickness l′ (the ratio of the film thickness to the pipe radius) is a function only of the dimensionless parameter Nf = r √ gD3/m, where r is the liqu...

In this article, we report an alternative method for in situ monitoring of the thickness and refractive index of thin film during the growth process. We design a special structure with a thickness-controlled air film to simulate the process of thin film growth. The phase term of the reflected light coming from this multi-layer structure is modulated and has a strong correlation with the thickne...

This paper presents a unique optical technique that utilizes the reabsorption and emission of two fluorescent dyes to accurately measure film thickness while minimizing errors caused by variations in illumination intensity and surface reflectivity. Combinations of dyes are selected that exhibit a high degree of emission reabsorption and each dye concentration is adjusted to create an optically ...

Full-perovskite Pb0.87Ba0.1La0.02(Zr0.6Sn0.33Ti0.07)O3 (PBLZST) thin films were fabricated by a sol-gel method. These revealed both rhombohedral and tetragonal phases, as opposed to the full-tetragonal phase previously reported in ceramics. The fractions of tetragonal and rhombohedral phases are found to be strongly dependent on film thickness. The fraction of tetragonal grains increases with i...

ZnO nanoparticles were produced by flame spray pyrolysis (FSP) using zinc naphthenate as a precursor dissolved in toluene/acetonitrile (80/20 vol%). The particle properties were analyzed by XRD, BET, and HR-TEM. The sensing films were produced by mixing the particles into an organic paste composed of terpineol and ethyl cellulose as a vehicle binder and were fabricated by doctor-blade technique...

A general theoretical calculation is described for predicting the interference effect in the sum frequency generation (SFG) spectra from a model thin-film system as a function of film thickness. The calculations were carried out for a three-layer thin film consisting of an organic monolayer, a dielectric thin film of variable thickness, and a gold substrate. This system comprises two sources of...

In the context of conjugated polymers, especially those of the poly (phenylenevinylene) (PPV) family, which are promising candidates as emission material in light emitting devices such as LEDs, field effect transistors and photovoltaic devices, we have, in the present study, prepared MEH-PPV [Poly [2- methoxy-5-(2’-ethyl-hexyloxy)-1,4-phenylen-evinylene] of low molecular weight and low polydisp...

This paper deals with the design and fabrication of a quartz-crystal resonator used in a thickness-monitor unit, measuring film thickness in a film-depositing system. A purpose-grown quartz crystal is cut to form the desired wafer. Two gold electrodes are deposited on both surfaces of the wafer to provide electrical contacts. The resonance frequency of the resonator, at room temperature, and th...