In the relatively short time since its introduction, the technique of electron microscopy has tended to acquire an aura of mystique such that the process of specimen preparation for the electron microscope and the production of a micrograph from this may be compared with an inflexible religious ceremony. Dr. Hayat's book, together with the first volume in this series, should do much to dispel t...

Nozzle clogging is a serious productivity and quality problem in continuous casting. This work reviews the causes, effects, and solutions to clogging in continuous casting nozzles. The results of a one-dimensional, steady state analysis of the heat loss from the molten steel stream through the nozzle wall are discussed. The analyses show that steel may freeze within the clog matrix for a relati...

The improvement of pharmaceutical dosage forms, such as tablets, towards drug delivery control and cost efficiency is of great importance in formulation technologies. Here, three examples: in situ coating, freeze casting and protein-based biocomposites are presented that address the above mentioned issues and contribute to further developments in formulation technologies. The in situ coating in...

The effect of gravity on directional solidification was investigated in solution-based freeze casting. A preceramic siloxane-based polymer freeze-cast with a cyclohexene solvent from two different directions: that against the direction gravitational force and concert force. Because density is higher than solvent, segregated creates denser solution ahead freezing front underlying when same as di...

Porous hydroxyapatite (HA) scaffolds with porosity-graded structures were fabricated by sequential freeze-casting. The pore structures, compressive strengths, and biocompatibilities of the fabricated porous HA scaffolds were evaluated. The porosities of the inner and outer layers of the graded HA scaffolds were controlled by adjusting the initial HA contents of the casting slurries. The interfa...

Fiber alignment is the defining architectural characteristic of discontinuous fiber composites and is dictated by shear-dominated processing techniques including flow-injection molding, tape-casting, and mold-casting. However, recent colloidal assembly techniques have started to employ additional forces in fiber suspensions that have the potential to change the energy landscape of the shear-dom...

Coal fly ash with the addition of Al₂O₃ was recycled to produce mullite/alumina composites and the camphene-based freeze casting technique was processed to develop a controlled porous structure with improved mechanical strength. Many rod-shaped mullite crystals, formed by the mullitization of coal fly ash in the presence of enough silicate, melt. After sintering at 1300-1500 °C with the initial...

Vacuum-induced surface freezing has been used to produce uni-directional freezing of colloidal aluminum oxide dispersions. It leads to zones of different structure within the resulting sintered monoliths that are highly similar to those known for freeze casting using a cryogen cold source. A more-or-less dense surface layer and a cellular sub-surface region are formed, beneath which is a middle...