This study aimed to investigate the associations between teachers’ flourishing at work, their perceived stress, their strategies to deal with stress, and their intention to leave their jobs. A convenience sample of teachers (n = 209) in South Africa participated in a survey. The Flourishing at Work Scale – Short Form, Perceived Stress Scale, Brief COPE Inventory, and Workplace Evaluation Questionnaire were administered.
Contributors:Filippo Masi, Ioannis Stefanou, Victor Maffi-Berthier, Paolo Vannucci
Masonry structures are often characterized by complex, non-planar geometries. This is also the case for historical and monumental structures. Here we investigate the dynamic behaviour of non-standard, curvilinear masonry geometries, such as vaults, subjected to blast loading.
We use the Discrete Element Method (DEM) for modelling the dynamic structural response to explosions. The approach allows considering the detailed mechanical and geometrical characteristics of masonry, as well as the inherent coupling between the in- and out-of-plane motion.
The proposed modelling approach is validated with existing experimental tests in the case of planar masonry geometries, walls. The DEM model well captures the dynamic response of the system and the form of failure within the masonry structure.
Then the response of a curved masonry structure subjected to blast loading is investigated. The influence of various micro-mechanical parameters, such as the dilatancy angle, the tensile strength and the cohesion of the masonry joints on the overall dynamic structural response of the system is explored. The effect of the size of the building blocks is also studied.
Finally, the common DEM assumption of rigid blocks is assessed through detailed comparisons with simulations involving deformable blocks.
Contributors:Maciej Spiegel, Karina Kapusta, Wojciech Kolodziejczyk, Beata Zbikowska, Glake A. Hill, Zbigniew Sroka
Phenolic acids are naturally occurring compounds that are known for their antioxidant and antiradical activity. This study was conducted in order to investigate the antioxidant potential of the set of 22 phenolic acids with different model of hydroxylation and methoxylation of aromatic ring both experimentally and theoretically. Ferric reducing antioxidant power assay was used for evaluating this property. 2,3-dihydroxybenzoic acid was found to be the strongest antioxidant, while mono hydroxylated and methoxylated structures had the lowest activities. A comprehensive structure-activity investigation with density functional theory methods elucidated the influence of compounds’ topology, resonance stabilization and intramolecular hydrogen bonding on the exhibited activity. The key factor was found to be a presence of two or more hydroxyl groups being located in ortho or para position to each other. Finally, the quantitative structure-activity relationship approach was used to build a multiple linear regression model describing the dependence of antioxidant activity on structure of compound, using purely features related to their topology. Coefficient of determination for training set was 0.9918 and the one for the test set 0.9993, with Q2 value for leave-one-out 0.9716. This model was used to predict activities of phenolic acids that haven’t been tested here experimentally.
This study aimed to investigate the relationships between job crafting, psychological need satisfaction/frustration, thriving, and job insecurity of academics in higher education institutions. A survey with a convenience sample of 276 academic staff at three higher education institutions in South Africa was used. The participants completed the Job Crafting Scale, Basic Psychological Need Satisfaction and Frustration Scale, High-Performance Human Resource Practices Questionnaire, and Thriving at Work Scale.
The data consist of an application, namely PyFEST, written in Python language, and a file with instructions to install and use the application. It can be used to estimate the frequencies of short-time signals with high accuracy. Along with the application, examples with generated signal (single-ton, multi-tone, noisy, damped etc.) and measured signals are delivered for testing purposes.
The frequencies of the harmonic components are evaluated one-by-one with high accuracy. Because the actions performed do not imply previous expertise, the results are not influenced by human intervention.