Sol-gel is a promising deposition technique for the fabrication of silica-on-silicon photonic components. Silica-titania compositions provide large index differences, and thus strong mode confinement, and are suitable hosts for Er-doped optical amplifiers. We have developed channel waveguides based on phosphosilicate strip loads over high index titania-doped guiding layers. Here we demonstrate ...

Silica-based thulium-doped fiber devices operating around 810 nm would extend the spectral range covered by highpower fiber devices. Using a comprehensive numerical model of the fiber we have shown that efficient lasing at 810 nm can be achieved for specific ranges of the laser cavity parameters in silica-based thulium-doped fibers with enhanced 3 H4 lifetime up to 58 !s as measured in our high...

A literature survey was performed to evaluate the state-of-the-art membrane systems for CO2/CH4 separation which is critical in the natural gas industry. The systems that were reviewed included zeolite, carbon, polymeric, mixed matrix, amorphous silica, and supported ionic liquid membranes. Supported ionic liquid CO2/CH4 selective membranes were synthesized in our laboratory by applying room te...

Work in this laboratory on the adsorption behavior of vitamin A and related substances was initiated in 1929-30 when two of us (H. N. H., V. G. L.) attempted the concentration of this vitamin from the non-saponifiable portion of cod liver oil. Almost from the first we directed our efforts to adsorption methods of separating vitamin A in order to minimize oxidation or other undesired chemical re...

At present, the most commonly used building material is ordinary Portland cement (OPC). However, OPC has a negative environmental effect during synthesis, with the release of significant amount of CO2 greenhouse gas. The cement industry is responsible for 5-8% of total global anthropogenic CO2 emissions. Geopolymerization is a technology capable of turning industrial wastes into strong and chem...

In methane combustion, water tolerance of Pd-based catalysts is quite critical for stable performance, because produced in situ and a water-containing feed used under real conditions. Herein, water-tolerant mesoporous silica-alumina (H-MSA) was prepared by solvent deficient precipitation (SDP) using triethoxy(octyl)silane (TEOOS) aluminum isopropoxide (AIP). The H-MSA more tolerant to than ?-al...

PURPOSE The purpose of this in vitro study is to examine the effects of a nano-structured alumina coating on the adhesion between resin cements and zirconia ceramics using a four-point bending test. MATERIALS AND METHODS 100 pairs of zirconium bar specimens were prepared with dimensions of 25 mm × 2 mm × 5 mm and cementation surfaces of 5 mm × 2 mm. The samples were divided into 5 groups of 2...

Introduction Most dyes used in the pigmentation of textiles, paper, leather, ceramics, cosmetics, inks and food-processing products are derived from azo dyes, which are characterised by the presence of one or more azo groups (-N=N-) in their structure. Approximately 15% of the dyes produced worldwide are lost within waste water during synthesis and processing. This waste represents a great haza...

Four samples of MFI zeolites with silica to alumina ratio 100 and using different carbon mass ratios (1:1, 1:4, 1:8 1:12) were synthesized by black particles. Silica-alumina molar imposes the framework structure zeolites. In general an increase in silica-alumina gel ratio, thermal stability, acid resistance hydrophobicity product increases ion-exchange capacity decreases. A higher (as high as 1...