Classical methods offer many possibilities to generate powders. Where very small particle sizes especially in spherical shape are required, or highly viscous substances have to be reduced, the limits of traditional processes are reached soon. The solution can be found in high-pressure processes. The PGSS (Particles from Gas Saturated Solutions) process e.g. is suitable for the micronisation of ...

Sol–gel synthesis of powders consisting of regularly shaped submicron silica spheres (∅400–600 nm) is described. IR and absorption spectra of such powders have been obtained. The IR spectra demonstrate that the silica spheres heated at 800 °C are hydroxyl-free. The TEM measurements show that the dimensions of silica nanoparticles do not change during heating. Films of self-organized silica nano...

The functional, nutritional, and antioxidative properties of hydrolyzed herring and herring byproducts (head and gonad) were evaluated. All freeze-dried herring fish protein hydrolysate (FPH) powders were light yellow and contained 77% to 87% protein. The degree of hydrolysis was 18.3%, 13%, 13%, and 10.1%, respectively, for head, whole fish, body, and gonad after 75 min digestion. All FPH powd...

Mechanical alloying (MA) is a solid-state powder processing technique involving repeated cold welding and fracturing of powder particles in a high-energy ball mill. It has been used to obtain nanocrystalline binary system FeNi. Fe and Ni elemental powders have been ball milled in a planetary mill (Pulverisette5, Fritsch) for various times up to several hours. The morphology of the powders was e...

The dielectric nanosize dependence of BaTiO₃ powders was investigated by the slurry method, where two series of BaTiO₃ slurries with 10 vol% and 30 vol% solids loadings were prepared as model samples. Applying the Bruggeman-Hanai equation, the high-frequency limiting permittivity (ε(h)) of the slurries was extracted from the dielectric spectra. The ε(h) of the 10 vol% slurry showed abnormal siz...

Variances in the measurement of properties used to characterize ceramic powders are discussed in the context of the International Energy Agency's study, Annex II, Subtask 2, which includes chemical and physical measurements for five powders: two grades of silicon nitride, and one grade each of silicon carbide, silicon, and zirconia. The analysis presented here includes results for 39 properties...

In this paper, we report the synthesis, the characterization and the scintillation properties of sol-gel derived Lu 2 SiO 5 (LSO) powders. Ce 3+ , Eu 3+ and Tb 3+ doped LSO powders have been synthesized by an original sol-gel process. The purity of the materials has been checked by X-Ray diffraction, confirming the elaboration of monophasic powders even for doped samples. Finally, the scintilla...

We fabricate nanosized superconducting YBa(2)Cu(3)O(7-δ) (Y-123) and nonsuperconducting Y(2)BaCuO(5) (Y-211) powders using carbon nanotubes as template. The mean particle size of Y-123 and Y-211 is 12 and 30 nm, respectively. The superconducting transition temperature of the Y-123 nanopowder is 90.9 K, similar to that of commercial, micrometer-scale powders fabricated by conventional processing...

strict and expensive processes, which were commonly required for the removal of free CO2 present in the atmosphere. The prepared powders were found to be crystalline, pure, and contained no BaCO3 as an impurity phase. Pure and Dy-doped BaTiO3 powders synthesized at 90 8C had the pseudocubic (space group: Pm-3m) crystal structure. Grain growth characteristics of pure and Dy-doped BaTiO3 pellets ...