Coupling finite elements for modelling fluid flow in fractured porous media

The presence of discontinuities such as cracks and faults in porous media can remarkably affect the fluid pressure distribution. This is due to considerable contrast between hydraulic properties of porous matrix and discontinuity. Several numerical techniques have been adopted to simulate the behaviour of fractured porous media subjected to fluid flow mostly in the context of discrete fracture- matrix models. Current approaches still have several shortcomings, namely in terms of computational costs from large number of additional degrees of freedom to capture the discontinuities, and the implementation of special integration procedures. The present work proposes a new technique to model fluid flow in saturated fractured porous media based on coupling finite elements to enable embedding the preferential paths of flow created by discontinuities in regular meshes. The discretisation of fracture and porous medium does not need to conform and the meshes are coupled without additional degrees of freedom. Two numerical examples are presented to assess the performance of the new method in comparison with other techniques available in the literature.ARC DE150101703, ARC DP170104192, ARC LP14010059

Transformational leadership contributions for employee autonomy

The performance of a company is affected by several variables and understanding them and knowing how they work is decisive for management. Therefore, this research aims to address and measure how transformational leadership impacts the employees work. To test the conceptual model, we used survey data from 174 active workers. Data was analyzed using PLS-SEM. Our results reveal that leaders who adopt a Transformational approach allow workers to be more autonomous in their work, the autonomy leverage the existence of efficiency in tasks and processes. Efficiency is also reached through cost savings, which translates into a reduction of unproductive work time. Furthermore, results indicate the mediating effect of efficiency and employee autonomy on the relation between transformational leadership and cost savings and between transformational leadership and unproductive work time.info:eu-repo/semantics/publishedVersio

Homogeneous metallicities and radial velocities for Galactic globular clusters. II. New CaT metallicities for 28 distant and reddened globular clusters

Although the globular clusters in the Milky Way have been studied for a long time, a significant fraction of them lack homogeneous metallicity and radial velocity measurements. In an earlier paper we presented the first part of a project to obtain metallicities and radial velocities of Galactic globular clusters from multiobject spectroscopy of their member stars using the ESO Very Large Telescope. In this paper we add metallicities and radial velocities for a new sample of 28 globular clusters, including in particular globular clusters in the MW halo and the Galactic bulge. Together with our previous results, this study brings the number of globular clusters with homogeneous measurements to $\sim 69$ \% of those listed in the W. Harris' catalogue. As in our previous work, we have used the CaII triplet lines to derive metallicities and radial velocities. For most of the clusters in this study, this is the first analysis based on spectroscopy of individual member stars. The metallicities derived from the CaII triplet are then compared to the results of our parallel study based on spectral fitting in the optical region and the implications for different calibrations of the CaII triplet line strengths are discussed. We also comment on some interesting clusters and investigate the presence of an abundance spread in the globular clusters here. A hint of a possible intrinsic spread is found for NGC 6256, which therefore appears to be a good candidate for further study.Comment: 13 pages, 9 figures, accepted for publication in Astronomy and Astrophysic

Fast and efficient method to evaluate the potential of eutectic solvents to dissolve lignocellulosic components

The application of eutectic solvents (ESs) in lignocellulosic biomass fractionation has been demonstrated as a promising approach to accomplish efficient and environmentally friendly biomass valorization. In general, ESs are a combination of two components, a hydrogen-bonding donor and a hydrogen-bonding acceptor, in which the melting point of the mixture is lower than that of the individual components. However, there are plenty of possible combinations to form ESs with the potential to apply in biomass processing. Therefore, the development of fast and effective screening methods to find combinations capable to dissolve the main biomass components—namely cellulose, hemicelluloses, and lignin—is highly required. An accurate and simple technique based on optical microscopy with or without polarized lenses was used in this study to quickly screen and monitor the dissolution of cellulose, xylose (a monomer of hemicelluloses), and lignin in several ESs. The dissolution of these solutes were investigated in different choline-chloride-based ESs (ChCl:UREA, ChCl:PROP, ChCl:EtGLY, ChCl:OXA, ChCl:GLY, ChCl:LAC). Small amounts of solute and solvent with temperature control were applied and the dissolution process was monitored in real time. The results obtained in this study showed that cellulose was insoluble in these ESs, while lignin and xylose were progressively dissolved.publishe

Network as a strategy to break silos and promote open innovation.

Abstract: Objectives: The central objective of this paper is to propose and test a model for the development of network governance structures to respond to the silo effect in the innovation management process in a large research organization. Method: A case study was used with the objective of building a governance model that could address the problems derived from the silo effect. To achieve the objective, validation workshops were held, with teams being challenged to reflect on the mechanisms and basic rules used to assemble the model. Results: The efforts made to inhibit the silo effect in the organization investigated were successful. Internal events were held to exchange knowledge between research centers, which resulted in greater stimulation of connections between these and other actors throughout the innovation ecosystem. Conclusions: The governance model adopted to mitigate the problems derived from the silo effect proved to be effective in promoting interaction between research centers on issues related to open innovation. The model, supported by mechanisms and basic rules inserted in the key actions, proved to be efficient in promoting a more intense relationship between the research units of the institution studied, resulting in new network actions

Waste polymers recycling in high performance asphalt mixtures

Building a road pavement requires large amounts of constituent materials, whose extraction can lead to the devastation of natural resources and causes negative impacts on the environment. As aggregates comprise nearly 90% of asphalt mixtures, their partial substitution by waste thermosetting polymers (12 million tons of waste polymers are presently mislaid into landfills, every year, in Europe) can be considered as a sustainable technology, given that an equivalent performance can be assured. Thus, this study aims on evaluating possible advantages of introducing polyethylene based wastes in asphalt mixtures, namely high density polyethylene (HDPE) and cross-linked polyethylene (PEX), incorporating HDPE as a bitumen modifier and PEX as partial substitute of the aggregates. The laboratory tests carried out in this work showed that the use of HDPE significantly improves the behavior of the asphalt binder/mixture. The use of PEX considerably decreases the density of the mixtures, which can be attractive to lighten structures. The mixtures with PEX have similar performance to the conventional one in terms of water sensitivity, improving the permanent deformation resistance and reducing the temperature susceptibility. In brief, the mixtures incorporating waste polymers could be considered a good technical and environmental alternative for paving works.Portuguese Foundation for Science and Technology (FCT) in the scope of the Strategic Project UI 4047 2011‐201

Estudo para produção de misturas com betume borracha a menores temperaturas

As misturas com betume borracha precisam de temperaturas mais elevadas no seu processo de fabrico e compactação devido à maior viscosidade deste ligante betuminoso modificado com borracha granulada de pneus usados. Caso contrário, o betume borracha poderá não garantir o correto envolvimento dos agregados e a necessária trabalhabilidade da mistura para a sua correta compactação. As consequências previsíveis relacionam-se com uma maior sensibilidade à água, o que reduz a durabilidade destas misturas e potencia a ocorrência de desagregações superficiais no pavimento. No entanto, o uso de tecnologias temperadas que permitem reduzir as temperaturas de produção e compactação das misturas betuminosas, pode ser uma solução mais sustentável para produção das misturas com betume borracha a menores temperaturas, desde que isso não afete o seu desempenho. Este trabalho consiste no estudo da utilização de uma dessas tecnologias para produzir misturas com betume borracha a menores temperaturas. Assim, estudou-se o efeito que a aplicação de um aditivo surfactante tem nas propriedades dos ligantes com e sem borracha. Em seguida estudou-se a redução de temperatura de produção. Por fim comparou-se o desempenho de misturas betuminosas com betume borracha normais e temperadas. No estudo concluiu-se que é possível reduzir bastante a temperatura de fabrico sem comprometer o desempenho da mistura com betume borracha

Utilization of waste materials to improve asphalt mixtures performance

This study aims to develop an innovative bitumen with large quantities of waste materials to improve asphalt mixtures performance. Different amounts of waste motor oil and waste HDPE were added to a new bitumen. The bitumen modified with 10% of waste motor oil and 5% of HDPE showed promising characteristics (high softening point temperatures and penetration slightly higher than the conventional bitumen). After the selection of the most promising modified bitumen, three asphalt mixtures were produced with different bitumens (namely conventional bitumen, commercial modified bitumen and the selected modified bitumen). Beyond that, this modified bitumen improved some mechanical characteristics of the asphalt mixture where it was used, in comparison to conventional and modified asphalt mixtures.Portuguese Government and EU/FSE within a PhD fellowship (SFRH/BD98379/2013) of the FCT, in the scope of POPH/QREN, by FEDER through the Competitiveness Factors Operational Programme (COMPETE) and by national funds through the Portuguese Foundation for Science and Technology (FCT) in the scope of PLASTIROAD Project (PTDC/ECM/119179/2010

Anti-LRP/LR specific antibody IgG1-iS18 impedes adhesion and invasion of liver cancer cells.

Two key events, namely adhesion and invasion, are pivotal to the occurrence of metastasis. Importantly, the 37 kDa/67 kDa laminin receptor (LRP/LR) has been implicated in enhancing these two events thus facilitating cancer progression. In the current study, the role of LRP/LR in the adhesion and invasion of liver cancer (HUH-7) and leukaemia (K562) cells was investigated. Flow cytometry revealed that the HUH-7 cells displayed significantly higher cell surface LRP/LR levels compared to the poorly-invasive breast cancer (MCF-7) control cells, whilst the K562 cells displayed significantly lower cell surface LRP/LR levels in comparison to the MCF-7 control cells. However, Western blotting and densitometric analysis revealed that all three tumorigenic cell lines did not differ significantly with regards to total LRP/LR levels. Furthermore, treatment of liver cancer cells with anti-LRP/LR specific antibody IgG1-iS18 (0.2 mg/ml) significantly reduced the adhesive potential of cells to laminin-1 and the invasive potential of cells through the ECM-like Matrigel, whilst leukaemia cells showed no significant differences in both instances. Additionally, Pearson's correlation coefficients suggested direct proportionality between cell surface LRP/LR levels and the adhesive and invasive potential of liver cancer and leukaemia cells. These findings suggest the potential use of anti-LRP/LR specific antibody IgG1-iS18 as an alternative therapeutic tool for metastatic liver cancer through impediment of the LRP/LR- laminin-1 interaction.National Research Foundation.NCS201