118 research outputs found

    Lectures on the Statutes of the Sacred Order of St. John of Jerusalem : at the University (of Studies) of Malta 1792

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    The Statutes of the Order of Malta were compiled anew in 1776; they are still valid as subsidiary. Micallef, a Maltese Conventual Chaplain of the Order and professor at the Order\u27s University of Malta, delivered lectures on the Statutes which were printed in a very limited number in 1791. Edited in English is included with the lectures\u27 text .a brief history of the Order and of the University together with a short biography on Micallef; in appendix: the present Constitution and Code of the Order

    Achieving electrical conductive tracks by laser treatment of non-conductive polypropylene/polycarbonate blends filled with MWCNTs

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    Electrical non-conductive polymer blends consisting of a polypropylene (PP) matrix and dispersed particles of polycarbonate (PC) were melt compounded with 3 wt.% multiwalled carbon nanotubes (MWCNTs) loading and processed into plates by injection molding. The morphological analysis confirmed the selective localization of the MWCNTs in the PC component. By local irradiation with a CO2 laser beam, depending on the laser conditions, conductive tracks with dimensions of about 2 mm width, 80 to 370 μm depth and line resistances as low as 1.5 kΩ · cm-1 were created on the surface of the non-conductive plates. The factors affecting the line resistance are the PC content, the laser speed and laser power, as well as laser direction with respect to the melt flow direction. After the irradiation an enrichment of MWCNTs in the laser lines was detected indicating that conductive paths were generated by percolation of nanotubes selectively within these lines in otherwise non-conductive plates. © 2014 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim

    Investigating the Usability of a Head-Mounted Display Augmented Reality Device in Elementary School Children

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    Augmenting reality via head-mounted displays (HMD-AR) is an emerging technology in education. The interactivity provided by HMD-AR devices is particularly promising for learning, but presents a challenge to human activity recognition, especially with children. Recent technological advances regarding speech and gesture recognition concerning Microsoft’s HoloLens 2 may address this prevailing issue. In a within-subjects study with 47 elementary school children (2nd to 6th grade), we examined the usability of the HoloLens 2 using a standardized tutorial on multimodal interaction in AR. The overall system usability was rated “good”. However, several behavioral metrics indicated that specific interaction modes differed in their efficiency. The results are of major importance for the development of learning applications in HMD-AR as they partially deviate from previous findings. In particular, the well-functioning recognition of children’s voice commands that we observed represents a novelty. Furthermore, we found different interaction preferences in HMD-AR among the children. We also found the use of HMD-AR to have a positive effect on children’s activity-related achievement emotions. Overall, our findings can serve as a basis for determining general requirements, possibilities, and limitations of the implementation of educational HMD-AR environments in elementary school classrooms

    Digital ink and differentiated subjective ratings for cognitive load measurement in middle childhood

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    Background: New methods are constantly being developed to adapt cognitive load measurement to different contexts. However, research on middle childhood students' cognitive load measurement is rare. Research indicates that the three cognitive load dimensions (intrinsic, extraneous, and germane) can be measured well in adults and teenagers using differentiated subjective rating instruments. Moreover, digital ink recorded by smartpens could serve as an indicator for cognitive load in adults. Aims: With the present research, we aimed at investigating the relation between subjective cognitive load ratings, velocity and pressure measures recorded with a smartpen, and performance in standardized sketching tasks in middle childhood students. Sample: Thirty-six children (age 7–12) participated at the university's laboratory. Methods: The children performed two standardized sketching tasks, each in two versions. The induced intrinsic cognitive load or the extraneous cognitive load was varied between the versions. Digital ink was recorded while the children drew with a smartpen on real paper and after each task, they were asked to report their perceived intrinsic and extraneous cognitive load using a newly developed 5-item scale. Results: Results indicated that cognitive load ratings as well as velocity and pressure measures were substantially related to the induced cognitive load and to performance in both sketching tasks. However, cognitive load ratings and smartpen measures were not substantially related. Conclusions: Both subjective rating and digital ink hold potential for cognitive load and performance measurement. However, it is questionable whether they measure the exact same constructs
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