We experimentally examine the primary rainbow created by the illumination of a coated cylinder. We present a simple technique for varying the coating thickness over a wide range of values, and we see evidence for two different scattering regimes. In one, where the coating thickness is large, twin rainbows are produced. In the second, where the coating is thin enough to act as a thin film, a sin...

the synthesis of titania via sol-gel method has been widely studied. in the present work, titania was deposited onto a titanium substrate via sol-gel method. different processing parameters such as the repetition number of dipping/heat treatment process and dipping time have been studied to obtain the homogenous titania coating. phase and microstructural evaluation of the powder and coating sam...

Zeolites/molecular sieves with uniform, molecular-sized pores are important for many adsorption-based separation processes. Pore size gaps, however, exist in the current zeolite family. This leads to a great challenge of separating molecules with size differences at ~0.01 nm level. Here, we report a novel concept, pore misalignment, to form a continuously adjustable, molecular-sieving "gate" at...

nanostructured alumina thin films were coated on stainless steel by sol-gel dip coating method. in order to prevent crack formation, al2o3 films were kept in a solvent bath immediately after coating to reduce the rate of drying. effects of calcination temperature and withdrawal speed on structural properties were analyzed using xrd and sem. topography and thickness of coatings were analyzed by ...

Uniform nanostructure coating of TiO2 was prepared on 316L stainless steel by sol-gel method using Tetra-n-Butyle Titanat (TBT) as alkoxide material. 316L specimens were coated with the mentioned sol by dip coating method. The influences of preparation condition, pH of sol on TiO2 nanostructure coating were investigated. Their structural properties were examined at var...

In this study different sized sustained-release coated pellets (6, 2.5 and 1 mm in diameter) were investigated using terahertz pulsed imaging (TPI). Ten pellets from each batch of metoprolol succinate layered sugar starter cores coated with a 75:25 (w/w) polymer blend of Kollicoat SR and Kollicoat IR (approximate coating thickness of 60 μm, according to the weight gain) were mapped individually...

In this research, tribological characteristics of Ni-P electroless coating and double-layered Ni-P/Ni-B electroless coating were studied. For this purpose, Ni-P electroless coating with 25 μm thickness was initially applied to the surface of steel Ck45 samples; then, a double-layered Ni-P/Ni-B electroless coating, including inner layer of Ni-P with 15 μm thickness and outer layer of Ni-B with 1...

We discuss a method to control the coating thickness deposited onto large and strongly curved optics by ion beam sputtering. The technique uses an original design of the mask used to screen part of the sputtered materials. A first multielement mask is calculated from the measured two-dimensional coating thickness distribution. Then, by means of an iterative process, the final mask is designed. ...

objective: a clinical challenge of using zirconia frameworks is to achieve adequate bond with different substrates. this study aimed to evaluate the effect of bioglass and silica coating of zirconia substrates on microshear bond strength of resin cement to tetragonal zirconia. methods: this laboratory experimental study was conducted on zirconia discs. a total of 120 ytzp zirconia (zirkonzahn) ...

A new method for catalyst deposition on the inner walls of capillary microreactors is proposed which allows exact control of the coating thickness, pore size of the support, metal particle size, and metal loading. The wall-coated microreactors have been tested in a selective hydrogenation reaction. Activity and selectivity reach values close to those obtained with a homogeneous Pd catalyst. The...