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CUIDAR DOS MAIS VULNERÁVEIS EM TEMPOS DE PANDEMIA: AS POLÍTICAS PÚBLICAS E O APOIO ASSOCIATIVO A ANTIGOS COMBATENTES
No full textThe global pandemic caused by the SARS-CoV-2 virus, and the circumstances that accompanied it, have had significant effects on both a collective and individual level. The pervasive feelings of fear and loneliness were particularly pronounced among the older population and those with underlying health conditions, a phenomenon that is frequently observed among war veterans. The objective of this article is to examine the way support was furnished to veterans during the period of the global pandemic, which also saw the implementation of the Former Combatant Statute, in 2020. A qualitative approach based on documentary sources was employed to assess the implementation of this latest public policy, and the activity of six associations of veterans was analysed. The results indicate both progress and limitations in the implementation of public policies. The work of the associations in question demonstrates the identification of problems and the endeavour to adapt to the conditions necessitated by social isolation
Enhancing Proton Conductivity of SPEEK Based Membranes by Incorporation of Graphene Oxide / Bisphosphonic acid dopant
Get PDFThe most commercially successful membrane for applications in fuel cell and electrolyzers, perfluorinated
sulfonic NafionR, exhibits relevant performance limitations due to its dependence on water content with
consequent proton mobility restrictions, environmental concerns and very high cost. Poly(etheretherketone)
(SPEEK) polymer appears as a versatile non-fluorinated alternative for a low-cost and a more environmentally
friendly membrane. Our previous studies showed that the incorporation of biphosphonic acid dopants (BPs) into
the mentioned polymeric matrices, improves membrane proton conduction and durability1-5. In this work, we
prepared and evaluated new doped SPEEK membranes using graphene oxide (GO) with bisphosphonic acid
functionalities as dopant (GOBP), anticipating superior membranes properties, including proton conductivity
IMU-CDC-VLP (International Mathematical Union-Commission for Developing Contries-Volunteer Lecture Program) Report on the VLP Lecture “Modelling with PDEs, their Mathematical and Numerical Analysis”
No full textThis is an IMU-CDC-VLP (International Mathematical Union-Commission for Developing Contries-Volunteer Lecture Program) report on the VLP lecture "Partial Differential Equations: Modelling and their Mathematical and Numerical Analysis", February 03-14, 2025, held at Silpakorn University, Nakhon Pathom, Thailan
Quiet Quitting -Perspectives of Silent Disengagement in Current Work Dynamics
Get PDFQuitting quietly has become a common difficulty for organizations in today's work environment because many employees no longer give their jobs their all and merely perform the bare minimum. The purpose of this paper is to conduct an analysis of this trend in the dynamics of the modern workplace, drawing on relevant references. It was determined that this is not a recent labor movement and has been occurring in the workplace subtly for a considerable amount of time; that certain circumstances can encourage employees to practice quiet quitting, and that this tendency affects employees of all ages and is not just present in younger generations. In addition, a "safety zone" chart was drawn, and a SWOT analysis carried out. It was observed that the main mitigating organizational strategies include the implementation of physical and mental health programs, training, professional development and recognition, open communication, and organizational flexibility
Perspectives and Realities of Disengagement Among Younger Generation Y and Z Workers in Contemporary Work Dynamics
Get PDFThe disengagement of younger workers, particularly from Generations Y and Z,
is a growing concern in contemporary organizational environments. This study analyzes
the factors influencing disengagement and the organizational strategies that can reduce
its impact. A literature review was conducted, covering studies published between 2014
and 2024, with the selection of publications based on relevance, indexing, and thematic
alignment. The findings indicate that disengagement results from a combination of factors.
Firstly, job demand factors were identified, such as the misalignment between well-being
policies and employee needs, excessive workloads, the absence of remote work and flexible
schedules, challenges associated with digitalization and new technologies, economic
insecurity, job instability, and frequent organizational changes. Secondly, job resource
factors were also highlighted, including inadequate leadership, ineffective communication,
limited professional development opportunities, and poorly structured evaluation and
reward systems. These findings align with the Job Demands-Resources (JD-R) Model. In
addition, psychological factors were observed, namely, a lack of autonomy, experiences
of injustice and inequality in the workplace, misalignment between personal values and
organizational culture, and the presence of hostile or toxic environments, which correspond
to the theoretical assumptions of the Self-Determination Theory (SDT).To address
disengagement, organizations should implement organizational strategies, such as physical
and mental well-being programs, encourage regular breaks, promote healthy lifestyle
campaigns, provide psychological support, and create ergonomic work environments. Additionally,
they should foster professional growth through continuous training, mentoring,
and transparent recognition and reward systems. Organizational communication must be
open and effective, ensuring transparency and active employee participation. The adoption
of remote work policies and flexible schedules, along with investments in technology and
collaboration tools, also helps maintain engagement. These strategies promote employee
satisfaction, motivation, and organizational commitment among workers, particularly
those from Generations Y and Z, so organizations must adapt to the evolving expectations
of the workforce to prevent long-term negative effects, such as decreased productivity and
higher turnover, compromising their competitiveness and sustainability
Unlocking improved hydrogen storage: Thermodynamic tuning and ionic conductivity boost in Fe-doped Mg2NiH4
Get PDFMg2Ni is considered a promising candidate for hydrogen storage materials due to its reasonable hydrogenation and dehydrogenation kinetics and cost-effectiveness. However, the high thermodynamic stability of Mg2NiH4
poses a significant challenge in terms of the operating temperature required for hydrogen release. This study investigates the crystal and electronic structure, and thermodynamic stability of Iron-doped Mg2NiH4 and their
alloys using first-principles calculations based on density functional theory. The results demonstrate that by replacing one in sixteen Mg atoms and one in eight Ni atoms with Fe, the enthalpy of hydrogen desorption can be
reduced from 65.173 to 57.58 and 50.72 kJ/mol H2, respectively. Furthermore, the study clarifies the crystal structure and electron properties of Fe-doped Mg2Ni and Mg2NiH4, highlighting the significant role of weakened
covalent interactions in the H–Ni bonding that contribute to the reduced thermodynamic stability of the hydrides. This study demonstrates that ionic conductivity improves with the destabilization of Mg2NiH4, achieving
up to 5 × 91.10 1 S/cm for Mg15FeNi8H32 at 400 K. Substituting magnesium (Mg) with iron (Fe) significantly impacts the electronic structure of the material. The additional d-electrons from Fe enhance the density of electronic states near the Fermi level, leading to increased charge carrier mobility and, consequently, higher conductivity. In contrast, replacing nickel (Ni) with Fe has a less pronounced effect, as both Ni and Fe are transition metals with similar electronic configurations and d-electrons near the Fermi level. This results in fewer new electronic states and a smaller increase in conductivity compared to Mg substitution
Strain engineering of LiFePO4 cathodes: Effects on voltage, energy density, and electronic structure for lithium-ion batteries
Get PDFImproving cathodes in commercial battery applications is one of the current trends aimed at achieving optimal
performance for energy storage and reuse. In this study, triaxial tensile/compressive strains were applied to
LiFePO4 and FePO4 structures, which are the main components of the cathode in lithium batteries. The goal is to
control the open-circuit voltage (OCV) and energy density (Ed) under the influence of these strains, as well as to
study the structural, electronic, and electrochemical properties. The study is based on density functional theory
(DFT) and uses the generalized gradient approximation (GGA) developed by Perdew-Wang 1991 (PW91). The
results show that the voltage of the undeformed systems is 3.92 V, and the energy density is 666.83 Wh/kg for
the undeformed systems. Under a maximum tensile strain of ε = +6 % applied to LiFePO4, the voltage decreases
to 3.32 V, and the energy density drops to 564.42 Wh/kg. In contrast, for FePO4, subjected to the same strain, the
voltage decreases to 2.99 V and the energy density to 507.71 Wh/kg. When the LiFePO4 system is subjected to a
maximum compressive strain of ε = 6 %, the voltage and energy density decrease to 3.08 V and 523.28 Wh/kg,
respectively. Similarly, when these strains are applied to FePO4, the voltage drops to 2.82 V and the energy
density to 478.46 Wh/kg. On the other hand, the interatomic distance of the studied features, as well as the
volume and electronic charge density, vary depending on the intensity of the applied strains. The analysis of the
total density of states showed that the characteristics of LiFePO4 and FePO4, in the absence of strain, behave as
semiconductors, with a band gap of 2.265 eV and 1.831 eV, respectively. However, these characteristics undergo
modifications under the effect of the applied strains
The role of Al substitution in Na3AlH6 hydrides: Structural and thermodynamic insights for hydrogen storage technologies
Get PDFIn this work, the structural, thermodynamic, and electronic properties, as well as the diffusion kinetics and
volumetric and gravimetric capacities of sodium and aluminum hydride Na3AlH6, were evaluated and enhanced
by substituting the aluminum element with Be (Na3Al1-xBexH6), Si (Na3Al1-xSixH6), and Fe (Na3Al1-xFexH6) with
x = 0.25 and x = 0.5. All calculations were performed according to density functional theory (DFT), using the
generalized gradient approximation (GGA) developed by Perdew, Burke, and Ernzerhof for solids (PBEsol). The
results show an improvement in the thermodynamic properties. For instance, the formation enthalpy decreased
from 82.25 kJ/mol.H₂ for the unsubstituted hydride Na3AlH6 to 34.24 kJ/mol.H2 for (Na3Al0.75Be0.25H6) and
35.02 kJ/mol.H₂ for (Na3Al0.5Si0.5H6), values that closely align with those suggested by the U.S. Department of
Energy (DOE). The decomposition temperature (Td) dropped from 632.76 K for the unsubstituted hydride
Na3AlH6 to 392.21 K for (Na3Al0.5Fe0.5H6), corresponding to the operational temperature range of hydrogen fuel
cells (PEM) from 289 to 393 K. Furthermore, the gravimetric capacity of hydrogen increased from 5.93 wt% for
the unsubstituted hydride Na3AlH6 to 6.40 wt% for Na3Al0.5Be0.5H6, in line with the DOE’s recommended value
of 6 wt%. Analysis of the density of states of Na3AlH6 revealed that the bandgap is 2.98 eV, indicating that the
hydride Na3AlH6 is insulating. The activation energy of hydride Na3AlH6 varies between 0.8 and 3.05 eV
Evaluation of the level of contamination in sediments from watercourses of the Caveira Mining System (Grândola)
Get PDFThe following work is inserted in the GeoMatRe Project, in which
the conditions of the most updated physical and chemical parameters of an Acid
Mine Drainage are analysed. This study shows that the mining area of Caveira,
in Grândola, Portugal, which was abandoned since the 60’s, presents a critical
situation of contamination, with high levels of Potentially Toxic Elements
(PTE) present in the whole mining area and its surroundings. It is intended,
within the scope of the project, and through geochemical analysis, to observe
the conditions of contamination by PTE in native sediments from the mine
tailing, which occur either in mobile phases, dissolved in the interstitial water
of the sediments, or in more immobile phases. With that in mind, preparation
of methodologies for geochemical studies were carried out, namely Fusion for
further analysis of the element’s total forms, and Partial Digestion with Aqua Regia for quantification of the most easily extratable forms, which represent
the most contaminating fraction. Ultimately, Inductively Coupled Plasma Optical
Emission Spectrometer (ICP-OES) was used to analyse and quantify the
previously prepared samples. It is herein presented a general characterization
of the mining system, through analysis and understanding of the Geo-accumulation
Index (IGEO) and the Enrichment Factor (EF), tools that improve the
visualization of the previously obtained data on the ICP-OES, demonstrating
the content and chemical nature of the contaminating elements (As, Cu, Zn, Pb
and Hg) as main PTE’s in the region, presenting values, in some cases, thousands
of times higher than those stipulated by Nacional standards
pXRF skeletal measurements as an assessment tool for environmental exposure to Lajes Field–derived contaminants (Terceira Island, Azores, Portugal)
Get PDFLajes Field is an Atlantic Portuguese military air base that has been used by the USA since the Cold War, primarily for intercontinental refueling. For this purpose, large fuel tanks and an extensive pipeline network were constructed within the municipality of Praia da Vitória, on Terceira Island, Azores. Over the past two decades, fuel leaks were detected and confirmed to have contaminated soils and the aquifers that supply water for public use. For the latter, identified contaminants include TPH, PAH, BTEX, VOCs, and metals. Although risk assessment reports have identified unacceptable risks to human health, and journalistic investigations suggest unusually high cancer rates, no assessment on possible human exposure has been conducted to date. To address this gap, metals, serving as a proxy for overall contamination exposure, were measured using portable X-ray fluorescence (pXRF) in the First Identified Skeletal Collection of the Azores (CEI/Açores). A total of 64 skeletons with known places of last residence were selected (44 from Angra do Heroísmo, where no exposure risk is present, and 20 from Praia da Vitória, where risk is present). No significant differences in mean ages at death were observed between the groups, and sex distribution was similar. Additionally, soil samples from 46 graves were analyzed to assess potential diagenesis. Greater concentrations of Sb, As, Cd, Cr, Au, Mo, Sr, Sn, U, and Zr were found in individuals from Praia da Vitória (p < 0.05). Soil measurements, Pearson’s correlation test, and a principal component analysis suggest that the differences in Zr and As levels can be partially attributed to diagenesis. For the remaining metals, the observed differences likely result from other factors, including potential contamination exposure, particularly for Cd, Cr, and Mo. Although this pioneering study contributes to the ongoing discussion on the subject, further research should be conducted both in the CEI/Açores and the living population to further discuss this issue