Preparation and properties of magnetic iron oxide nanotubes

Magnetite (Fe3O4) nanotubes were prepared by reducing synthesized hematite (α-Fe2O3) nanotubes in 5% H2+95% Ar atmosphere,and then maghemite (γ-Fe2O3) nanotubes were obtained by re-oxidizing the Fe3O4 nanotubes.The nanotube structure was kept from collapsing or sintering throughout the high temperature reducing and re-oxidizing processes.The coercivities of the Fe3O4 and γ-Fe2O3 nanotubes synthesized were found to be 340.22 Oe and 342.23 Oe,respectively,both higher than other nanostructures with the same phase and of similar size.Both adsorbed phosphate and the nanotube structure are considered responsible for this high coercivity.     

Removal of dust from flue gas in magnetically stabilized fluidized bed

A magnetically stabilized fluidized bed (MSFB, φ 500mm x 2100mm) was designed to study dust removal from flue gas. Based on the mechanism of dust removal in a fixed bed, the effects on collection efficiency of magnetic field intensity, ratio of flue gas velocity to minimum fluidization velocity, bed height, and particle average diameter, were investigated. Then feasible methods for MSFB to better remove dust were proposed. Over 95% of dust removal with MSFB can be achieved, when stable fluidization is maintained and when magnetic particles are frequently renewed.     

Removal of dust from flue gas in magnetically stabilized fluidized bed

A magnetically stabilized fluidized bed （MSFB,Ф 500mm×2100mm） was designed to study dust removal from flue gas. Based on the mechanism of dust removal in a fixed bed, the effects on collection efficiency of magnetic field intensity, ratio of flue gas velocity to minimum fluidization velocity, bed height, and particle average diameter, were investigated. Then feasible methods for MSFB to better remove dust were proposed. Over 95 % of dust removal with MSFB can be achieved, when stable fluidization is maintained and when magnetic particles are frequently renewed.     

Nonisothermal moisture transport in hygroscopic building materials: modeling for the determination of moisture transport coefficients

A mathematical model for calculating the nonisothermal moisture transfer in building materials is presented in the article. The coupled heat and moisture transfer problem was modeled. Vapor content and temperature were chosen as principal driving potentials. The coupled equations were solved by an analytical method, which consists of applying the Laplace transform technique and the Transfer Function Method. A new experimental methodology for determining the temperature gradient coefficient for building materials was also proposed. Both the moisture diffusion coefficient and the temperature gradient coefficient for building material were experimentally evaluated. Using the measured moisture transport coefficients, the temperature and vapor content distribution inside building materials were predicted by the new model. The results were compared with experimental data. A good agreement was obtained.