77823 research outputs found
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Surface roughness prediction in turning processes for grey cast iron: A hybrid machine learning approach integrating infrared thermography
No full textWorkpiece surface quality is a critical control parameter in machining processes, influencing functional performance, dimensional precision, and wear resistance. However, accurately predicting surface roughness is complex, often limited by the computational demands of traditional high-precision methods and the reliance of existing models solely on cutting parameters, hindering real-time monitoring. This research introduces a hybrid Artificial Neural Network (ANN) methodology specifically developed for predicting surface roughness of grey cast iron GG-25 workpieces machined in turning processes, a material previously unstudied in this context. The methodology integrates real-time infrared thermal measurements from multiple defined regions of interest (ROIs) within the tool-workpiece contact zone, along with cutting parameters.
Experimental results demonstrated that feed rate (f) is the most significant cutting parameter (effect = 0.43) affecting surface quality, followed by its combination with cutting speed (Vc) (effect = −0.25) and cutting speed (effect = 0.18). Correlation and non-linear regression analyses revealed complex, often exponential relationships between temperature and surface roughness, showing temperature an upward trend as machining progressed. The developed ANN achieves a correlation coefficient (R) value of 0.99 both when predicting the roughness arithmetic mean deviation (Ra) parameter in training conditions and when using data from experiments not used in training (validations data). Moreover, the model reaches a correlation coefficient value of 0.85 (test data) under cutting conditions different from those used in experiments, demonstrating robustness, significantly outperforming Support Vector Regression (SVR). This model represents a highly potential tool for real-time online inspection
Symptoms of distress, anxiety, and depression during COVID-19 confinement: the mediating role of rumination and sleep problems
No full textConfinement due to the COVID-19 outbreak is a stressful situation that can lead to the development of mental disorders such as distress, depression and anxiety. In this study, we investigated rumination and sleep problems as possible mechanisms in the development of distress, anxiety and depression related to home-confinement due to the COVID-19 outbreak. One thousand and fifty-two people (women 78.6%; age range 18 to 82 years old), confined for more than seven days, were recruited during the COVID-19 outbreak between March 21 and April 10, 2020, filled in a survey about depression, anxiety, and distress symptoms (DASS-21); state (BSRI) and trait rumination (RRS); sleep problems (SCOPA); and other control questions (e.g., experience with COVID-19 and psychiatric medication intake). More days of confinement were related to greater use of rumination, which in turn was related to more depression, anxiety, and distress (single mediation). Furthermore, more days of confinement were related to greater use of rumination, leading to more sleep problems, which in turn were related to more depression, anxiety, and distress (double mediation). These results confirm that confinement is a risk for mental health and that sleep problems and, especially, rumination are crucial mechanisms in understanding the relationship between the number of days of confinement and symptoms of depression, anxiety, and distress. Our results suggest that in situations of confinement, individuals may benefit from interventions aimed at reducing rumination and sleep problems to prevent distress, depression and anxiety
The Impact of Social Media Disorder, Family Functioning, and Community Social Disorder on Adolescents’ Psychological Distress: The Mediating Role of Intolerance to Uncertainty
No full textBackground/Objectives: Adolescent levels of psychological distress are strongly influenced by community, individual, social, and family factors. Family functioning, social media use, and community disorder have shown high predictive value for psychological distress during this critical stage of development. However, these relationships are not always direct and are often mediated by individual-level variables, such as intolerance of uncertainty. Adolescent psychological well-being is not solely determined by contextual factors; the coping skills developed during this critical stage also play a significant role. Our study aims to analyze how these factors are directly and indirectly related by developing a predictive model of psychological distress in adolescents. Methods: The study included 908 adolescents (46.9% female) aged between 14 and 21 years (M = 16.29, SD = 1.5). Participants completed self-administered questionnaires in a school setting. Structural equation modeling was used to estimate total, direct, and indirect effects. Results: The model showed a good fit to the data. Social media disorder and family functioning showed statistically significant direct and indirect effects on psychological distress. Social media disorder was associated with higher psychological distress, while positive family functioning was protective. Community social disorder was only indirectly linked to higher psychological distress through the increase of intolerance of uncertainty. Conclusions: Intolerance of uncertainty is a critical predictor of adolescent distress, often overlooked despite its significant mediating role. Direct effects of family functioning and social media use also strongly influence distress levels. Impaired family functioning and community disorder interact bidirectionally, creating a cycle that exacerbates distress. Adolescents in these contexts face compounded negative effects from these reinforcing environments
Singularly perturbed convection-diffusion elliptic problems with a non-smooth forcing term
No full textSingularly perturbed elliptic problems, of convection-diffusion type, with a non-smooth forcing term are examined. The lack of smoothness arises from the forcing term either containing an interior layer or being discontinuous across an interface. In addition to the presence of several different kinds of boundary and corner layers, this forcing term introduces an interior layer in the solution. For both problem classes, a decomposition of the continuous solution is constructed, whose components identify the various types of layer functions that can exist in the solution. Parameter-explicit pointwise bounds on the partial derivatives of these components are then established. An appropriate Shishkin mesh is identified and this is combined with upwinding to form a numerical method for each problem class. Parameter-uniform error bounds in the maximum norm are deduced. Numerical results are presented to illustrate the performance of both numerical methods
El desplazamiento activo al centro educativo como situación de aprendizaje
No full textEl marco educativo que ofrece la LOMLOE (2020) y, más concretamente, las situaciones de aprendizaje que propone, relacionadas con la adquisición de competencias clave y el Perfil de salida del alumnado, se presentan como una oportunidad única para trabajar programas interdisciplinares de desplazamiento activo que sean evaluados y calificados desde los centros escolares y representen aprendizajes significativos para la vida futura del alumnado
Novela y cine. Los géneros cinematográficos como herencia de la novela, Antonio Viñuales Sánchez (2025, Institución Fernando el Católico)
No full textStandardizing functional assessment in hospital rehabilitation: A proposal based on RASS, S5Q, and JH-HLM scales
No full textThe functional assessment performed by Rehabilitation Services for admitted patients represents a key component of our daily clinical practice. There is considerable intra- and inter-individual variability and subjectivity. This scientific letter aims to propose a standardized initial approach applicable to all inpatients functional assessed by the Rehabilitation Service, regardless of their reason for admission. This approach includes, in the following order: the Richmond Agitation-Sedation Scale (RASS), the Standardized 5 Questions Scale (S5Q), and the Johns Hopkins Highest Level of Mobility Scale (JH-HLM). The combined application of these scales allows for a rapid evaluation of the patient's consciousness level, capacity for cooperation and mobility level
Health Promoting Schools and Adolescent Health Behaviours: A Comparative Study of Network Affiliation Effects
No full textABSTRACTThe Health Promoting Schools (HPS) are actively committed to enhancing healthy lifestyles. Nevertheless, the evidence currently available regarding the role of the HPS accreditation status in a HPS network on students' health outcomes is uneven. The aim of this study was to compare different health behaviours of students enrolled in health promoting (HPS) and non‐health promoting schools (NHPS). This is a comparative cross‐sectional study. Validated instruments were used to measure dietary habits, physical activity, screen time‐based sedentary behaviours, and tobacco and alcohol consumption. Sleep time was also collected. A total of 840 students aged between 12 and 17 years participated in the study. In comparison with students enrolled in Non‐Health Promoting Schools, HPS students showed healthier levels in dietary habits, physical activity, screen time‐based sedentary behaviours, sleep duration, and alcohol consumption. No differences were found for tobacco consumption. Our findings suggest that the integration of schools into a HPS network could play a role in the adoption of better health behaviours among students. Further research is needed to analyse: a) the accreditation and evaluation procedures in the HPS networks, b) the degree of implementation of the HPSF in the HPS, and c) the effectiveness of HPS actions in promoting positive health outcomes in the long term
Digitisation and virtual restitution applied to the heritage of displaced mural painting: the case of the medieval mural painting of the church of Saints Julián and Basilisa of Bagüés (Spain)
No full textAbstract
This study presents an exploration of the digitisation of medieval mural paintings from the church of Saints Julián and Basilisa in Bagüés (Zaragoza, Spain), an Asset of Cultural Interest. These murals were removed in 1966, resulting in a disconnection between the artworks and their original architectural context. This removal raised concerns regarding decontextualisation and potential loss of heritage significance. To address these challenges, advanced digital techniques, such as laser scanning and photogrammetry, were employed to create highly accurate 3D models of both the church and the museum where the murals are now housed. These models facilitate a detailed geometric analysis, allowing a direct comparison of the two environments and an exploration of the spatial relationships that were lost over time. The digital data collected through these techniques play a vital role in the preservation, study, and dissemination of heritage, providing new possibilities for the virtual reintegration of the murals into their original context. Additionally, these 3D models offer an innovative tool for virtual restoration, allowing researchers, conservators, and the public to engage with the murals as they might have appeared within the church. This study demonstrates the potential of digital technologies in mitigating the effects of heritage displacement while offering new approaches to the interpretation and virtual presentation of relocated artworks. The research also suggests future applications in heritage conservation, including the development of interactive museum experiences and the integration of these models into virtual and augmented reality platforms, enhancing the public's understanding and appreciation of displaced cultural heritage
