Examining the validity of the Athlete Engagement Questionnaire (AEQ) within a Portuguese sport setting

Sport psychology literature suggests that understanding engagement levels is pivotal to promote positive sporting experiences among athletes. The purpose of this study was to examine the psychometric properties of the Athlete Engagement Questionnaire among Portuguese sport athletes. Two distinct samples of Portuguese athletes from different competitive levels were collected, and the results of a confirmatory factor analysis demonstrated a good fit of the model to the data. A review of the psychometric properties indicated that all factors showed good composite reliability, convergent validity, and discriminant validity. In addition, a multi-groups analysis showed the invariance of the model in two independent samples providing evidence of cross validity. Implications of these results for scholars and coaches are discussed and guidelines for future studies are suggested

SiC for microwave power applications: present status and future trends

A variety of RF and microwave electronic devices can be fabricated from SiC. MESFET's and SIT's fabricated from 4H-SiC grown on 6H- or 4H-SiC substrates with very good dc and RF performance have been demonstrated. These devices are being developed for microwave power amplifiers for short pulse, high power RADAR applications at C, S, and X-bands, and for communications amplifiers for base station transmitters at L and S band. These devices have the potential to produce RF power densities in excess of that possible from Si or GaAs based devices, with power-added efficiency approaching theoretical limits for class A and B operation. SiC MESFET's can produce RF power density on the order of 4 W/mm and experimental devices are rapidly approaching the theoretical potential