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1 – 3 of 3Tian Fang and Daiyong Ye
This paper aims to prepare good waterborne light-diffusion dip-coatings (WLDDC) for the glass lampshade inner walls of LED lamp tubes, the effects of viscosities and viscous flow…
Abstract
Purpose
This paper aims to prepare good waterborne light-diffusion dip-coatings (WLDDC) for the glass lampshade inner walls of LED lamp tubes, the effects of viscosities and viscous flow activation energies on these dip-coatings were investigated.
Design/methodology/approach
The WLDDC were prepared using white pigments, light-diffusion agents, additives and an acrylic emulsion. The dip-coatings were characterized by Fourier transform infrared spectroscopy, scanning electron microscopy and a digital rotational viscometer, respectively. The effects of shear rates, temperatures and solids contents on the viscosities of the dip-coatings were studied. The viscous flow activation energies of these dip-coatings and the emulsion were calculated, compared and studied, respectively.
Findings
The results showed that the non-Newtonian behaviors of these dip-coatings were more prominent than that of the acrylic emulsion. When the temperature was maintained to be a constant and the shear rate was increased, the viscosity decreased and the shear stress increased. When the shear rate was maintained to be a constant, the viscosity decreased with increasing temperatures. The viscous flow activation energies of these dip-coatings decreased with the increasing shear rates. The higher solid contents of WLDDC were, the more its viscosity would decrease with the increasing shear rates, the more prominent its non-Newtonian behaviors would show.
Practical implications
A sample of good WLDDC with balanced properties was illustrated.
Originality/value
This investigation benefits to investigate waterborne environment-friendly dip-coatings for the inner glass walls of lamp tubes. This research provides an approach to optimize the viscosity parameters of light-diffusion dip-coatings.
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W.M. Yu, S.C. Harlock, G.A.V. Leaf and K.W. Yeung
Describes the setting up of a moiré topographic system to measure three‐dimensional convex and concave surfaces of moulded brassière cups. The essential features of the system…
Abstract
Describes the setting up of a moiré topographic system to measure three‐dimensional convex and concave surfaces of moulded brassière cups. The essential features of the system consisted of a photographic instrument which precisely controlled the position of the light source, the camera, the grid and the cup sample. As the uniformity of the grid was most crucial to produce a high contrast moiré picture, a photochemical‐machined grid plate was developed, and a pneumatic grid translation device was incorporated into the system to produce a clear image. The tolerance of the instrumental error was derived by the law of error propagation and the confidence with the moiré set‐up was assured.
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Diana Pineda-Vázquez and Augusto García-Valenzuela
This study aims to propose and study a refractive index sensor based on measuring variations of the internal diffuse reflectance from a glass interface in a functional design. The…
Abstract
Purpose
This study aims to propose and study a refractive index sensor based on measuring variations of the internal diffuse reflectance from a glass interface in a functional design. The device is uncomplicated to assemble with simple optical elements and it can be built as a robust and stable sensor.
Design/methodology/approach
This study presents a simplified theoretical model of the signal obtained with the proposed device and perform a detailed analysis of its potential resolution and merits.
Findings
The authors report proof-of-principle experiments with a home-made device to evaluate its performance as a refractometer and index of refraction sensor.
Originality/value
The main novelty of the device is the use of a diffusing surface to couple light into a glass plate with a wide range of angles of refraction, including angles larger than the critical angle with the external medium, and using the same diffusing surface to couple reflected light out of the glass plate, including light that suffered total internal reflection.
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