4,188 research outputs found

    Cu oxidation mechanism on Cu-Zr(O)N coatings: Role on functional properties

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    Zirconium oxynitride (Zr(O)N) and Copper-Zirconium oxynitrides (Cu-Zr(O)N) were deposited by a DC reactive magnetron sputtering technique on stainless steel substrates. A duty cycle controller was used to obtain different oxygen contents in the developed films and a chemical activation procedure was carried out to obtain copper oxides. The samples were chemical and structurally characterized by SEM, EDS, XRD and XPS. Additional functional features were evaluated according to colour variation and inhibition halo tests. Zr(O)N and Cu-Zr(O)N surfaces showed a wide colour variation from golden to black tones, progressing through intermediate tones such as purple, blue and bluish grey. An antibacterial effect was only obtained after the chemical activation of Cu-ZrON-DC100, which showed a Zr(O)N matrix incapable of catching more oxygen from deposition. After, with the additional availability of O2- ions, the Cu present in the coating reacted with these ions forming CuO. The antibacterial mechanism was associated with the aforementioned characterizations and ICP-OES spectroscopy. The Cu2+ ions release had no influence on the antibacterial effect although the presence of CuO was decisive in obtaining an antibacterial behaviour. The acquired results demonstrated a potential multifunctionality of Cu-Zr(O)N coatings, joining an aesthetical surface with an antibacterial effect.This research is sponsored by FEDER funds through the COMPETE program - Competitive Factors Operational Program - and by national funds through FCT - Foundation for Science and Technology - under the scope of the strategic funding of co-financed via UIDB/00285/2020 and UIDB/04650/2020 unit and BioTecNorte operation (NORTE-01-0145-FEDER-000004) funded by the European Regional Development Fund under the scope of Norte2020 - Programa Operacional Regional do Norte, On-SURF (co-financed via FEDER (PT2020) POCI-01-0247-FEDER 546024521; The authors also thank the financial support in the framework of HEALTHYDENT - POCI-01-0145-FEDER-030708) and ATRITO-0 (co-financed via FEDER (PT2020) POCI-01- 0145-FEDER-030446.info:eu-repo/semantics/publishedVersio

    Why are there defaulters in eye health projects?

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    PURPOSE: To identify barriers to attendance for eye examination of schoolchildren. METHODS: Cross-sectional study. Students in grades 1-4 in elementary school in Guarulhos (Brazil) were screened and referred for ophthalmic examination in 2006. Facilities offered in this project were: examination arranged during weekends, free transportation, spectacle donation and two different opportunities for exam. A questionnaire was applied, by interview, to a sample consisted of students' parents attended in a community project who missed the first call and attended the recall, to identify the reasons for non-attendance. RESULTS: The sample consisted of 767 parents or guardians, corresponding to an equal number of schoolchildren. Personal characteristics of the students: 49.2% male and 50.8% female, 60.2% of them had never received previous ophthalmologic evaluation. Reported reasons for no-show to the project: parents had not received appropriate orientation (35.6%), loss of working day (20.6%), illness (12.4%), had another appointment (10.0%). The need for eyeglasses was higher in the recall. CONCLUSIONS: A significant number of parents did not take their children for ophthalmological exams, even when a second opportunity was offered in projects with transportation facilities, free exams performed during weekends and spectacle donation. The main causes of absenteeism were lack of awareness and work. For 87.1% of the absenteeism cases, the difficulties could be overcome via improved structuring of the first call. A recall increases attendance coverage of target population by only 15.2% (59.3 to 74.5%). Notably, the eye exam campaign was the first exam for most of the absent students

    Perceived overqualification and contact center workers’ burnout: are motivations mediators?

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    Purpose – The purpose of this paper is to test the direct effect of the perceived overqualification on the burnout syndrome and the indirect effect through the workers’ autonomous and controlled motivation. Design/methodology/approach – The hypotheses were tested with a sample of 3,256 contact center operators from one Portuguese company and data were analyzed using the software package Mplus to conduct structural equation models. Findings – The results revealed that workers’ perceived overqualification is positively related to burnout and that both autonomous and controlled motivation partially mediates this relationship. Research limitations/implications – The cross-sectional design should be regarded as a limitation. Moreover, each variable was only assessed with self-reported measures, the sample comprised call center employees from only one company and one country (Portugal), and the workers were all employed in commercial services of telecommunications, energy, banking or insurance companies, which may constrain the generalization of these results. Practical implications – Workers’ perceived overqualification should be avoided to prevent their burnout. Furthermore, an increase in workers’ skills and competencies, enhanced decision latitude, and the task variety and quality should be crucial for employees to develop more autonomous motivation to work in a contact center and the promotion of their well-being at work. More precisely, as overqualification concerns the employees’ perceptions of surplus education, experience and knowledge, from a practical perspective, enhancing the decision latitude, task variety and quality of these individuals’ work may contribute to decreasing individuals’ perception of overqualification and, therefore, contribute to increasing workers’ autonomous motivations and well-being. Originality/value – This study provides evidence concerning the mediating role of both workers’ autonomous and controlled motivation to explain the relationship between perceived overqualification and burnout. Keywords Motivation, Conditions of employment, Employees, Human resource management, Well-being, human resource planning.info:eu-repo/semantics/acceptedVersio

    Stellar equilibrium configurations of white dwarfs in the f(R,T)f(R,T) gravity

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    In this work we investigate the equilibrium configurations of white dwarfs in a modified gravity theory, na\-mely, f(R,T)f(R,T) gravity, for which RR and TT stand for the Ricci scalar and trace of the energy-momentum tensor, respectively. Considering the functional form f(R,T)=R+2λTf(R,T)=R+2\lambda T, with λ\lambda being a constant, we obtain the hydrostatic equilibrium equation for the theory. Some physical properties of white dwarfs, such as: mass, radius, pressure and energy density, as well as their dependence on the parameter λ\lambda are derived. More massive and larger white dwarfs are found for negative values of λ\lambda when it decreases. The equilibrium configurations predict a maximum mass limit for white dwarfs slightly above the Chandrasekhar limit, with larger radii and lower central densities when compared to standard gravity outcomes. The most important effect of f(R,T)f(R,T) theory for massive white dwarfs is the increase of the radius in comparison with GR and also f(R)f(R) results. By comparing our results with some observational data of massive white dwarfs we also find a lower limit for λ\lambda, namely, λ>−3×10−4\lambda >- 3\times 10^{-4}.Comment: To be published in EPJ

    Occupational safety & ergonomics training of future industrial engineers: a project-based learning approach

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    As industries push for continuous technological innovation, the need to balance work demands and human capabilities and to ensure the workers' safety is now more pressing than ever. Therefore, the training of future industrial engineers must promote the development of different skills, including in the Occupational Safety & Ergonomics (OS&E) domain. Based on this assumption, Project-Based Learning (PjBL) is an active learning methodology where students develop projects in teams as a means of building effective professional skills and knowledge. The current study aims at evaluating the impact of PjBL in effective learning on OS&E, based on the participants' perceptions. PjBL has been applied in the 7th semester of the Integrated MSc in Industrial Engineering and Management at a Portuguese University. In the last years, different companies in the northern region of Portugal have participated in this PjBL, welcoming the students to develop the projects. The current study included a documental analysis that was also developed, considering the final technical reports developed by the students during a scholar semester. In addition, a questionnaire for data collection was developed and applied to the participants. The sample (n=64) included university students who participated in the referred PjBL, their teachers, and the supervisors of the companies where the Project was developed. Globally, the participants' perceptions reveal that the PjBL participants attribute a positive evaluation to this learning methodology, concerning the development of technical (on OS&E) and transversal skills.FCT - Fundação para a CiĂȘncia e a Tecnologia(UIDB/00319/2020

    Improving hospital operations management to reduce ineffective medical appointments

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    The main objective of this study is to meet management aspirations by promoting waste reduction and consequently improving patients` experience in a Portuguese public hospital. These aspirations include increasing hospital service quality in a continuous and efficient way. This management mindset uncovered divergences between medical appointment and magnetic resonance imaging (MRI) exam scheduling that were generating waste for both the hospital and patients. The main aspects considered in this study were the patients’ medical expectations, the quality, and cost of service provided. One-year retroactive encrypted data from medical appointments and MRI requisitions were provided for the algorithm development. Outcomes obtained from the algorithm revealed a high percentage of medical appointments occurring without the respective MRI exam results. These outcomes exposed waste existence that was hitherto unknown by the administration. Thus, the main algorithm function is to analyze future data to previously alert ineffective medical appointments. This progress contributes to reducing wasted medical and patient time. In summary, the main contribution of this article is to allow hospital managers to cross-check data from different sectors to identify divergences in future medical consultations that require exams or results of clinical analysis.This work was supported by the Fundacao para a Ciencia e a Tecnologia [POCI-01-0145-FEDER-030299]; Fundacao para a Ciencia e a Tecnologia [UIDB/00319/2020]
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