Plasma gun with coaxial powder feed and adjustable cathode

An improved plasma gun coaxially injects particles of ceramic materials having high melting temperatures into the central portion of a plasma jet. This results in a more uniform and higher temperature and velocity distribution of the sprayed particles. The position of the cathode is adjustable to facilitate optimization of the performance of the gun wherein grains of the ceramic material are melted at lower power input levels

Morphology of zirconia particles exposed to D.C. arc plasma jet

Zirconia particles were sprayed into water with an arc plasma gun in order to determine the effect of various gun operating parameters on their morphology. The collected particles were examined by XRD and SEM techniques. A correlation was established between the content of spherical (molten) particles and the operating parameters by visual inspection and regression analysis. It was determined that the composition of the arc gas and the power input were the predominant parameters that affected the melting of zirconia particles

The effect of Al2O3, CaO, Cr2O3 and MgO on devitrification of silica

The effect of doping on devitrification of vitreous silica was studied at 1100, 1200, and 1300 C. Dispersion of dopants on a molecular scale was accomplished via a sol-gel technique. All dopants accelerated the devitrification of silica but to different degrees. The most active was CaO followed by MgO, Al2O3, and Cr2O3. Pure silica and silica containing Cr2O3 and Al2O3 devitrified to alpha-cristobalite only, whereas silica doped with CaO and MgO produced alpha-quartz and alpha-cristobalite. It appears that prolonged heat treatment would cause alpha-quartz to transform to alpha-cristobalite

Primers resultats de l’estudi ELAN.cat: el català en el multilingüisme de les empreses catalanes

La Càtedra de Multilingüisme Linguamón-UOC, amb el suport de la Generalitat de Catalunya, està realitzant l’estudi ELAN.cat, sobre el multilingüisme de les empreses catalanes. Aquest estudi és l’adaptació a Catalunya de l’informe europeu ELAN, que va posar en evidència que moltes empreses de la UE desaprofitaven oportunitats de negoci per manca de capacitats multilingües. L’estudi ELAN.cat es troba en aquests moments en la fase d’anàlisi de les dades quantitatives obtingudes d’un miler d’empreses de Catalunya. En aquest article oferim un avanç de resultats, centrats sobretot en el lloc que ocupa el català en el multilingüisme de les empreses catalanes