Exergy analysis of the diesel pre-reforming solid oxide fuel cell system with anode off-gas recycling in the SchIBZ project. Part I: Modeling and validation

Solid oxide fuel cell (SOFC) systems with anode off-gas recirculation (AGR) and diesel pre-reforming are advantageous because they can operate with the current fuel infrastructure. In the SchIBZ-project, the prototype of such a SOFC system for maritime applications has already been commissioned. In this first paper, we model the system devices to conduct an exergy analysis of this real SOFC plant and validate them with experimental values from experiments in laboratory scale. The results of our simulation agree well with the experimental values. The calculations with the validated results may be closer to the real thermodynamic behavior of such system components than previous literature.     

Fast-switching-speed,low-forward-voltage-drop static induction (SI) thyristor

A static induction (SI) thyristor using a normally-off planar-gate structure in a low power class has been developed to be used as a power switching device in a three-phase inverter circuit. A 600 V-15 A class SI thyristor with very fast switching time (tgt, tgq) and low forward voltage drop (V_TM) was designed and created. This design was performed with a reasonable wafer structure (n^?/n/p⁺), an n^? base carrier concentration and thickness, and a gate structure (gate diffusion length and gate-gate pitch). Microscopic processing was used to obtain this SI thyristor. The performance trade-off between turn-off time and forward voltage drop is controlled by a lifetime control process using proton irradiation that results in a very fast switching time with tgt of 500 ns and tgq of 500 ns with V_TM of 1.5 V (at I_T= 18 A). At a current level of I_T = 18 A, the current density in the active area becomes 200 A/cm², which indicates that the performance of the SI thyristor is superior to that of conventional IGBTs and MOSFETs.     

The social side of gaming: How playing online computer games creates online and offline social support

Online gaming has gained millions of users around the globe, which have been shown to virtually connect, to befriend, and to accumulate online social capital. Today, as online gaming has become a major leisure time activity, it seems worthwhile asking for the underlying factors of online social capital acquisition and whether online social capital increases offline social support. In the present study, we proposed that the online game players’ physical and social proximity as well as their mutual familiarity influence bridging and bonding social capital. Physical proximity was predicted to positively influence bonding social capital online. Social proximity and familiarity were hypothesized to foster both online bridging and bonding social capital. Additionally, we hypothesized that both social capital dimensions are positively related to offline social support. The hypotheses were tested with regard to members of e-sports clans. In an online survey, participants (N = 811) were recruited via the online portal of the Electronic Sports League (ESL) in several countries. The data confirmed all hypotheses, with the path model exhibiting an excellent fit. The results complement existing research by showing that online gaming may result in strong social ties, if gamers engage in online activities that continue beyond the game and extend these with offline activities.     

Structural Characterization of Metallurgical Coke by Raman Spectroscopy

To investigate the factors influencing the structural order of metallurgical coke, several coke samples were treated by temperatures between 850 °C and 1300 °C and analyzed by Raman Spectroscopy. A quantitative Raman-parameter is proposed to reflect the structural state of a coke sample.