Semi Analytical Model For Heat Transfer In Liquid Fluidized Bed.

This paper presents a semi analytical model for heat transfer in liquid fluidized bed using big particles. The accuracy of the model and its validity are verified by experiments. Using a one dimensional general formulation of the energy equation, a system of coupled differential equations is obtained. This system represents the temperature distribution in the solid particles and in the fluid along the axis of the bed. These equations were solved numerically using an iterative finite difference technique. The heat transfer coefficient between the solid particles and fluid is obtained experimentally.167968

Fluorescence properties of surface-active styrylcyanine molecular rotors

This paper reports on some photophysical properties of a newly synthesized styrylcyanine chromogen 1 of electron donor—acceptor type, namely 1-cetyl-4-[4′-( N- N-dimethylamino)-styryl]-pyridinium bromide. The fluorescence properties of this self-organized surfactant chromogen were studied in non-homogeneous media. Its fluorescence shows a sensitivity to environmental factors which could be exploited profitably as a fluorescence probe in various systems of industrial and biological importance. A remarkable enhancement in its fluorescence efficiency was observed in a rigid ethanol matrix at 77 K and in micellar solutions. Moreover, a considerable edge-excitation red shift was observed in a PMMA matrix at room temperature similar to that found in glassy ethanol. The results provide some information on the free-volume distribution in a PMMA matrix. The changes noted can be rationalized, relative to the short-chain model compound 2 in terms of an enhanced sensitivity of the highly organized and tightly packed molecules 1 to viscocity—torsional reactions between solute and solvent

Synthesis of highly active thin film based on TiO2 nanomaterial for self-cleaning application

Highly active TiO2 self-cleaning thin film with porous structure and hybrid morphology was prepared from hydrothermally treated TiO2 nanomaterials for 24h at 200°C followed by calcinations at 450°C in air. •Highly active TiO2 self-cleaning surfaces were synthesized by hydrothermal method.•The hydrothermal treatments modified the photo-oxidative properties of TiO2.•The modified TiO2 nanomaterial was applied as a self-cleaning. Highly active self-cleaning surfaces were prepared from hydrothermally treated TiO2 nanomaterials for different times (0, 12, 24 and 36h) under acidic condition. TiO2 thin films were characterized by X-ray diffraction (XRD), transmission electron microscope (TEM) and scanning electron microscope (SEM). TiO2 thin film (hydrothermal 24h) exhibited hybrid morphology from accumulated plates, clusters, rods and spheres. The photo self-cleaning activity in term of quantitative determination of the active oxidative species (OH) produced on the thin film surfaces was evaluated using fluorescent probe method. The results show that, the highly active thin film is the hydrothermally treated for 24h at 200°C. The structural, morphology and photoactivity properties of nano-TiO2 thin films make it promising surfaces for self-cleaning application. Mineralization of commercial textile dye (Remazol Red RB-133, RR) from highly active TiO2 thin film surface was applied. Moreover, the durability of this nano-TiO2 thin film (hydrothermal 24h) was studied