Reduction of New Zealand Titanomagnetite Ironsand pellets in H₂ Gas at High Temperatures

To reduce the emission of the carbon dioxide (CO2) in New Zealand (NZ), it is proposed to perform direct reduction (DR) of NZ titanomagnetite ironsand pellets using H2 gas. However, there is limited pre-existing knowledge on the DR behaviour of NZ titanomagnetite ironsand pellets in hydrogen. This thesis addresses this through an experimental investigation of the H2 gas-based reduction of Ar-sintered and pre-oxidised pellets, and an analytical kinetic model is developed to describe the reduction rate. The reduction rate of both types of pellets is found to increase with increasing temperature, H2 gas flow rate, and H2 gas concentration. For both pellets reduced at 1443 K above the critical flow rate, the maximum reduction degree reaches ~97% with a similar reduction rate. However, in the lower temperature range (\u3c 1143 K), pre-oxidised pellets are reduced much faster than Ar-sintered ones. During reduction of both types of pellets, any TTH present is rapidly reduced first. After this step, TTM is then reduced to FeO, with Ti becoming enriched in the remaining unreduced TTM. FeO is further reduced to metallic Fe, which makes up to ~90% reduction degree. Eventually Ti-enrichment of the TTM leads to a change in the reduction pathway and it instead directly converts to metallic Fe and FeTiO3. Above ~90% reduction degree, reduction of the remaining Fe-Ti-O phases occurs (leading to the formation of TiO2 or (pseudobrookite) PSB/ferro-PSB). At the pellet-scale, both types of pellets present a single interface shrinking core phenomenon at higher temperatures. Metallic Fe is generated from pellet surface with a reaction interface moving inwards. However, at lower temperatures this pellet-scale interface becomes less defined in the pellets. Instead, grain-scale reaction fronts are observed

Network Orientation, Organisational Improvisation and Innovation: An Empirical Examination

In today\u27s highly competitive world market, businesses can hardly maintain their competitiveness without strong innovation abilities. In the past, many Chinese enterprises have enjoyed success through imitation. But to continue to succeed in a global marketplace, they must develop ambidextrous innovation abilities. The resource‐based theory eloquently posits that competitive advantage is associated with different and heterogeneous resources. To obtain such resources, firms must establish an external network to acquire necessary knowledge and skills. In this paper, we develop a theoretical model linking network orientation, organisational improvisation, ambidexterity and competitive tension. We postulate that organisational improvisation has a mediating effect and competitive tension is a moderator. Empirical results (N = 340) show that (1) network orientation leads to both exploratory and exploitative innovations, (2) the above effect is mediated by organisational improvisation and (3) competitive tension positively moderates the effect between network orientation and organisational improvisation

Magnus Force on Quantum Hall Skyrmions and Vortices

We have discussed here the Magnus force acting on the vortices and skyrmions in the quantum Hall systems. We have found that it is generated by the chirality of the system which is associated with the Berry phase and is same for both the cases.Comment: 5 page