Lacunarity as a quantitative measure of mixing—a micro-CT analysis-based case study on granular materials

In practically every industry, mixing is a fundamental process, yet its 3D analysis is scarce in the literature. High-resolution computed tomography (micro-CT) is the perfect X-ray imaging tool to investigate the mixing of granular materials. Other than qualitative analysis, 3D micro-CT images provide an opportunity for quantitative analysis, which is of utmost importance, in terms of efficiency (time and budget), and environmental impact of the mixing process. In this work, lacunarity is proposed as a measure of mixing. By the lacunarity calculation on the repeated micro-CT measurements, a temporal description of the mixing can be given in three dimensions. As opposed to traditional mixing indices, the lacunarity curve provides additional information regarding the spatial distribution of the grains. Discrete element method simulations were also performed and showed similar results to the experiments

Albumin adsorption study onto hydroxyapatite-multiwall carbon nanotube based composites

Abstract Albumin is one of the most abundant protein in the circulatory system, and has a fundamental role in the formation of the contact between the inorganic surface (implant) and the biological environment. Thus it is important to study the albumin sorption capacity and efficiency of a new implant base material. Carboxyl functionalized multiwall carbon nanotube, hydroxyapatite or silica substituted hydroxyapatite with different content of chitosan were synthesized and characterized by several characterization methods. During the experiments, the effect of chitosan and/or silica on the material physical-chemical properties were studied, such as: morphology, thermal stability, crystallinity, specific surface area, adsorption capacity and efficiency. Two initial BSA concentrations (0.5; 1 g/l) at two defined pH values (7.5; 8) were used for studying the BSA sorption onto hydroxyapatite (HAP). It was demonstrated that the sorption capacity and efficiency showed a correlation with the specific surface area of the composite. It was demonstrated that 10%CS-fMWCNT-HAP has the highest adsorption capacity at 7.5 pH

Environmental-Friendly Economical Cordierite-Mullite-based Ceramics for Kiln Furniture Production and Supports for CO2 Hydrogenation towards C5+ fuels

In this study, lightweight cordierite-mullite ceramics with high strength and high thermal-shock resistance were successfully synthesized by solid-state method with the usage of hollow ceramic microspheres. After careful physico-chemical and mechanical characterization, we gained an economical cordierite material with a low bulk density of 1.40 g/cm3 with an apparent porosity of 44.78%, a flexural strength of 20.17 MPa and a coefficient of thermal expansion of 2.26 × 10−6 oC−1 compared to the bulk counterpart with a bulk density of 2.00 g/cm3 with an apparent porosity of 25.75%, a flexural strength of 23.69 MPa and a coefficient of thermal expansion of 2.47 × 10−6 oC−1. As a catalyst support of Na-FeOx, the economical cordierite has proved the same stability and activity in CO2 hydrogenation towards C5+ fuels as bulk cordierite-based catalyst counterparts