Abstract
This work proposes a new control framework for power converters with a dual half bridge (DHB) configuration. The new framework exploits the multi-port structure of the DHB to simultaneously: i) regulate the current in the primary side of the DIM and ii) equalize the voltage in the two secondary ports of the DHB. To implement these functions, we combine input-output linearization methods with pragmatic voltage balance algorithms. We then apply this framework to a hybrid energy storage system composed of a battery pack and two supercapacitor modules. Numerical simulation results demonstrate the effectiveness of the proposed approach in regulating the power between the energy storage units and balancing the supercapacitors' voltages.

Abstract
<p><em>Investment in research and development is a key factor in increasing countries' competitiveness. However, its impact can potentially be broader and include other socially relevant elements like job quality. In effect, the quantity of generated jobs is an incomplete indicator since it does not allow to conclude on the quality of the job generated. In this sense, this paper intends to explore the relevance of R&amp;D investments for the job quality in the European Union between 2009 and 2018. For this purpose, we investigate the effects of R&amp;D expenditures made by the business sector, government, and higher education sector on three dimensions of job quality. Three research methods are employed, i.e. univariate linear analysis, multiple linear analysis, and cluster analysis. The findings only confirm the association between R&amp;D expenditure and the number of hours worked, such that the European Union countries with the highest R&amp;D expenses are those with the lowest average weekly working hours.</em></p>

Abstract
The growth of social media as an information medium without restrictive measures on the creation of new accounts led to the rise of malicious agents with the intend to diffuse unreliable information in the network, ultimately affecting the perception of users in important topics such as political and health issues. Although the problem is being tackled within the domain of bot detection, the impact of studies in this area is still limited due to 1) not all accounts that spread unreliable content are bots, 2) human-operated accounts are also responsible for the diffusion of unreliable information and 3) bot accounts are not always malicious (e.g. news aggregators). Also, most of these methods are based on supervised models that required annotated data and updates to maintain their performance through time. In this work, we build a framework and develop knowledge-based metrics to complement the current research in bot detection and characterize the impact and behavior of a Twitter account, independently of the way it is operated (human or bot). We proceed to analyze a sample of the accounts using the metrics proposed and evaluate the necessity of these metrics by comparing them with the scores from a bot detection system. The results show that the metrics can characterize different degrees of unreliable accounts, from unreliable bot accounts with a high number of followers to human-operated accounts that also spread unreliable content (but with less impact on the network). Furthermore, evaluating a sample of the accounts with a bot detection system shown that bots compose around 11% of the sample of unreliable accounts extracted and that the bot score is not correlated with the proposed metrics. In addition, the accounts that achieve the highest values in our metrics present different characteristics than the ones that achieve the highest bot score. This provides evidence on the usefulness of our metrics in the evaluation of unreliable accounts in social networks.

Abstract

Abstract
The combination of marine origin biopolymers for tissue engineering (TE) applications is of high interest, due to their similarities with the proteins and polysaccharides present in the extracellular matrix of different human tissues. This manuscript reports on innovative collagen-chitosan-fucoidan cryogels formed by the simultaneous blending of these three marine polymers in a chemical-free crosslinking approach. The physicochemical characterization of marine biopolymers comprised FTIR, amino acid analysis, circular dichroism and SDS-PAGE, and suggested that the jellyfish collagen used in the cryogels was not denatured (preserved the triple helical structure) and had similarities with type II collagen. The chitosan presented a high deacetylation degree (90.1%) that can strongly influence the polymer physicochemical properties and biomaterial formation. By its turn, rheology, and SEM studies confirmed that these novel cryogels present interesting properties for TE purposes, such as effective blending of biopolymers without visible material segregation, mechanical stability (strong viscoelastic character), as well as adequate porosity to support cell proliferation and exchange of nutrients and waste products. Additionally,in vitrocellular assessments of all cryogel formulations revealed a non-cytotoxic behavior. The MTS test, live/dead assay and cell morphology assessment (phalloidin DAPI) showed that cryogels can provide a proper microenvironment for cell culturing, supporting cell viability and promoting cell proliferation. Overall, the obtained results suggest that the novel collagen-chitosan-fucoidan cryogels herein presented are promising scaffolds envisaging tissue engineering purposes, as both acellular biomaterials or cell-laden cryogels.

Abstract