Quantitative analysis of PIN choices: a contribution to the establishment of authentication requirements

The authentication using a PIN number remains one of the most used ways to enter a system (mobile phone, ATM, etc.). Many people seem to dislike this form of authentication because they simply despise their use, placing unsafe PINs just because they have to put some. Some relevant results are the combination 1234, the combinations using only one digit (example: 1111), or the central line of the numerical keypad. On the other hand there is some understanding because it is proven that remember strong passwords is a difficult task for humans, and the tendency is to choose the simplest ones. This research had a sample of 497 participants and aimed to understand the preferred choice of the participants in relation to the number of digits used for a PIN number (a choice between four and/or six digits) and realized the amount of times that each of the available digits was used. To this end it was developed a web-based tool for entering the data. This application was intended only to the data collection process, being the information processed further. Through this application, the user was asked to enter four and/or six-digit PINs. The method does not raise any doubt on the participants, which were informed about the anonymity and confidentiality of the data, and never they were asked to identify themselves. Participants were asked to use the PINs that they normally use in other contexts. With the analysis of the data it was possible to understand the distribution of digits per position in a PIN, check which digits is more/less used in each position, and check which digit is more/less used regardless of its position. Among the conclusions it appears that the layout of the numeric keypad of the system influence the PIN choice.This work has been supported by FCT – Fundação para a Ciência e Tecnologia within the Project Scope UID/CEC/00319/201

Contact detection approach between wheel and rail surfaces

This work presents a general formulation to identify the contact points for the interaction between wheels and rails in the context of railway dynamics simulations. This formulation treats the wheel and rail as parametric surfaces and searches the contact between each wheel strip and the rail independently to avoid the numerical difficulties due to the wheel concave zone. This methodology assumes the rail as locally straight and takes advantage that its potential contacting surface is always convex. For the evaluation of contact forces, two Hertzian-based models are employed for normal and creep forces. A trailer vehicle running on a curved track is used to demonstrate the effectiveness of this methodology.The first authorissupported by the Portuguese Foundation for Science and Technology (FCT) under grant PD/BD/114154/2016.This work is also supported by FCT with the reference project UIDB/04436/202

Creative project oriented learning strategy: teaching information and communication technologies for future health professionals

Digital native learners arrived at Higher Education Institutions. Digital skills are fundamental to the future health professionals, improving their academic performance and prepares them for their integration into the labor market.info:eu-repo/semantics/publishedVersio

Spiral inertial microfluidics for size based microalgae separation

The identifcation of toxic microalgae is essential for the sustainable management of activities, such as aquaculture, being also relevant for environmental monitoring and marine research purposes [1]. For these reasons, there is an increasing demand for in situ, reliable, portable, autonomous, low-cost and of easy operation technologies and devices able to detect early signs of potential toxic algal populations within the context of long term monitoring programmes. To this aim, a multisensory platform for in-situ phytoplankton quantifcation and taxonomic identifcation designed for underwater deployment and based on lab-on-chip (LoC) technology has been developed. It combines fow cytometry with optical and electrical measurements. The separation of microalgae based on cell size prior to analysis is key to reduce the complexity and heterogeneous nature of seawater samples while also ofering a degree of distinction between taxonomic groups. This work investigates and develops a simple inertial microfuidic device based on a spiral microchannel that achieves size-based separation of microparticles/ cells. The theoretical principle of their separation was analysed trough numerical simulations and experimental tests were also performed. Using a 5-loop spiral (300 μm width and 100 μm height), 20 μm and 40 μm polystyrene (PS) microparticles were successfully separated for a fow rate of 2000 μl/min, showing its potential for microalgae size-based separation. Furthermore, the simple structure and high throughout makes this technique suitable for integration in LoC devices [2, 3].Peer Reviewe

The neural correlates of obsessive-compulsive disorder: a multimodal perspective

Obsessive-compulsive disorder (OCD) is one of the most debilitating psychiatric conditions. An extensive body of the literature has described some of the neurobiological mechanisms underlying the core manifestations of the disorder. Nevertheless, most reports have focused on individual modalities of structural/functional brain alterations, mainly through targeted approaches, thus possibly precluding the power of unbiased exploratory approaches. Eighty subjects (40 OCD and 40 healthy controls) participated in a multimodal magnetic resonance imaging (MRI) investigation, integrating structural and functional data. Voxel-based morphometry analysis was conducted to compare between-group volumetric differences. The whole-brain functional connectome, derived from resting-state functional connectivity (FC), was analyzed with the network-based statistic methodology. Results from structural and functional analysis were integrated in mediation models. OCD patients revealed volumetric reductions in the right superior temporal sulcus. Patients had significantly decreased FC in two distinct subnetworks: the first, involving the orbitofrontal cortex, temporal poles and the subgenual anterior cingulate cortex; the second, comprising the lingual and postcentral gyri. On the opposite, a network formed by connections between thalamic and occipital regions had significantly increased FC in patients. Integrative models revealed direct and indirect associations between volumetric alterations and FC networks. This study suggests that OCD patients display alterations in brain structure and FC, involving complex networks of brain regions. Furthermore, we provided evidence for direct and indirect associations between structural and functional alterations representing complex patterns of interactions between separate brain regions, which may be of upmost relevance for explaining the pathophysiology of the disorder

Release of volatile compounds from polymeric microcapsules mediated by photocatalytic nanoparticles

In this study we propose a suitable method for the solar-activated controlled release of volatile compounds from polymeric microcapsules bonded with photocatalytic nanoparticles. These reservoirs can find applications, for example, in the controlled release of insecticides, repellents, or fragrances, amongst other substances. The surfaces of the microcapsules have been functionalized with TiO2 nanoparticles.Upon ultraviolet irradiation, redox mechanisms are initiated on the semiconductor surface resulting in the dissociation of the polymer chains of the capsule wall and, finally, volatilization of the encapsulated compounds. The quantification of the output release has been performed by gas chromatography analysis coupled with mass spectroscopy.Strategic Project PEST-C/FIS/UI607/2011 and PTDC/CTMNAN/119979/2010 Projec

Eco-friendly methods for extraction and modification of cellulose: an overview

Cellulose is the most abundant renewable polymer on Earth and can be obtained from several different sources, such as trees, grass, or biomass residues. However, one of the issues is that not all the fractionation processes are eco-friendly and are essentially based on cooking the lignocellulose feedstock in a harsh chemical mixture, such as NaOH + Na2S, and water, to break loose fibers. In the last few years, new sustainable fractionation processes have been developed that enable the obtaining of cellulose fibers in a more eco-friendly way. As a raw material, cellulose’s use is widely known and established in many areas. Additionally, its products/derivatives are recognized to have a far better environmental impact than fossil-based materials. Examples are textiles and packaging, where forest-based fibers may contribute to renewable and biodegradable substitutes for common synthetic materials and plastics. In this review, some of the main structural characteristics and properties of cellulose, recent green extraction methods/strategies, chemical modification, and applications of cellulose derivatives are discussed.BDE 05|POCI-01-0247-FEDER021874; 2022.07519.PTDCinfo:eu-repo/semantics/publishedVersio