Showing papers in "Powder Technology in 2004"

TL;DR: In the pharmaceutical industry, an even greater number of products are in the form of particulate solids, and their formation, formulation and the control of their user properties are still not well understood and mastered as mentioned in this paper.

TL;DR: In this article, the extent of mixing and segregation induced by a single bubble injected in a monodisperse and bidisperse fluidised bed at incipient fluidisation conditions and in freely bubbling fluidised beds was studied both with well-defined experiments and with a 3D Euler?Lagrangian model.

TL;DR: In this article, a new and accurate empirical correlation for the drag coefficient, C D, of variously shaped particles has been developed, based on the particle nominal diameter, Re, the ratio of the surface-equivalent-sphere to the nominal diameters, d A / d n, and the particle circularity, c.

TL;DR: In this article, the direct quadrature method of moments (DQMOM) is implemented in a multi-fluid CFD code to simulate particle aggregation and breakage in a fluidized-bed (FB) reactor.

TL;DR: A critical review of the literature on fluidization using the kinetic theory of granular flow is presented in this article, where an equation of state for the particles relating solids pressure to granular temperature and the solids volume fraction, similar to the van der Waals equation for gases, has been verified experimentally to be reasonably correct.

TL;DR: In this paper, a critical comparison of a hard-sphere discrete particle model, a two-fluid model with kinetic theory closure equations and experiments performed in a pseudo-two-dimensional gasfluidized bed is made.

TL;DR: In this article, a semi-empirical model incorporating slurry rheology, solids concentration, particle size and slurry temperature was described, and on-line measurement for the slurry Rheology control was also discussed.

TL;DR: Claims and suggestions in the literature that verification or validation of CFD numerical models has been achieved for fluidized beds are shown to be inconsistent with objective criteria and accepted usage of terminology.

TL;DR: In this article, the effect of particle size, particle size distribution and milling time on the rheological behaviour and particle packing of silica suspensions was investigated using slurries containing total solids loading of 46 vol%.

TL;DR: In this paper, the importance of sticky behavior of amorphous food powders has been recognized over many decades in the food industry due to its influence on process and handling abilities and quality of the powders.

TL;DR: The influence of polyethylene glycol (PEG) on the adsorption at zinc oxide/polymer solution interface has been determined in this paper, where the authors measured the thickness of adsorbed polymer layer on ZnO nanoparticles and determined the main factors responsible for the changes in zeta potential.

TL;DR: In this article, the shape and roughness of granules were evaluated using a high-scale high-shear mixer with a set of shape factors, including the aspect ratio, the mass shape factor, OPCS, eR and the radial shape factor.

TL;DR: In this article, a 2D soft-sphere discrete particle model (DPM) was used to study the fluidization behavior of Geldart A particles in both the homogeneous and bubbling regime.

TL;DR: In this article, the effect of sound on the fluidization behavior of hydrophobic fumed silica nanoparticles (Degussa Aerosil® R974, having a primary particle size of 12 nm) was investigated.

TL;DR: In this paper, a series of placebo powders for inhalation was characterized regarding bulk density and powder flowability using different techniques, and a modified Hausner ratio was obtained by measurement of the poured and the compressed bulk densities.

TL;DR: In this paper, a method of manufacturing heat-sensitive pharmaceutical powder is described, where the original pharmaceutical substances are dissolved in a solution or suspended in a suspension, which is sprayed through an atomizing nozzle and frozen in a cold gas phase or liquid nitrogen atomized directly in the spray-freeze chamber or gas jacket at the same time.

TL;DR: In this article, the shape characteristics of talc particles produced by ball, rod and autogenous mills were investigated using Scanning Electron Microscope (SEM) and expressed by the shape descriptors such as elongation, flatness, roundness and relative width by measuring on the particle projections in two dimensions (2D).

TL;DR: In this paper, the influence of microwave pre-treatment on mineral ore breakage has been investigated using a multimode microwave cavity, and it was found that strength could be significantly reduced in 0.5 s when using 15 kW of microwave power.

TL;DR: In this article, the authors investigated on a particulate level the flow properties of dry powder mixtures consisting of cornstarch and a second nanoscaled material, and paid attention to the question on the working mechanism of glidants.

TL;DR: In this paper, the authors demonstrate that cohesive primary particles that fluidize as aggregates in a fluidized bed can be individually coated with a nano-thick ceramic film using ALD.

TL;DR: In this paper, solid dispersion particles of tolbutamide (TBM) were prepared by formulating nonporous (Aerosil 200), Aerosil R972 (hydrophobic), or porous (Sylysia 350, Sylophobic 200), and applying the spray-drying (SD) or evaporation (Eva) method.

TL;DR: In this paper, the effect of particle size on the light diffusion of NIR spectra was investigated and a chemo-infometrical method for quantitative determination of the particle size of phenacetin crystalline powder based on Fourier-transformed near-infrared (FT-NIR) spectroscopy was established.

TL;DR: In this article, structural and optical characterization of mechanically milled ZnO powders is presented, showing that the application of mechanical milling is a very effective and simple technique to produce nanocrystalline powders, with the possibility of obtaining large quantities of materials.

TL;DR: In this article, the authors used the discrete element method (DEM) for computer simulation of particle damping, which is a technique of providing damping with granular particles embedded within small holes in a vibrating structure.

TL;DR: In this paper, the effects of inlet type on cyclone performance characteristics, including the collection efficiency and pressure drop, were investigated and compared as a function of particle size and flow rate.

TL;DR: In this paper, the authors focus on identifying the physical processes that lead to fracture in a polydisperse cuboidal agglomerate impacting with a target wall and show that fracture is the result of the manner in which strong interparticle forces are transmitted into the agglomate and the consequent development of a heterogeneous distribution of primary particle velocities.

TL;DR: In this article, NiO nanoparticles were successfully prepared by Triton X-100/n-hextnol/cyclohexane/water W/O microemulsion system.

TL;DR: In this article, a rotating fluidized bed coater was used for fine cornstarch fine particle coating by using a horizontal porous cylindrical air distributor, which rotates around its axis of symmetry inside the plenum chamber.

TL;DR: In this article, the glidant properties of compacted hydrophilic and hydrophobic colloidal silicon dioxides were compared with respect to mixing time and mixer type using microcrystalline cellulose, pregelatinized starch and α-lactose-monohydrate as model excipients.

TL;DR: In this article, a novel solids-stabilized emulsion (Pickering emulsion) route for the first time was used to produce polyaniline (PANI)/nano-ZnO composites.