131 research outputs found
Modelling long-term morphodynamic evolution of mega-nourishments
Peer ReviewedPostprint (published version
The potential risk induced by climate change in the context of mega-nourishments
Peer ReviewedPostprint (published version
Long-term and large-scale modeling of mega-nourishments
The Sand Engine, ZM (Zandmotor), is a hook-shaped mega-nourishment (21.5 millions m³) located on the
Dutch coast with an alongshore length of 2.4 km and an offshore extension of 1 km. The mega-nourishment project was
initiated as a coastal protection measure on decadal time scales to maintain the coastline under predicted sea level rise.
It follows the philosophy of working in harmony with the forces of nature by taking advantage of the longshore
transport as the main distributor of sand along the adjacent coast (Stive et al., 2013).
In the present contribution we use the Q2Dmorfo model (van den Berg, et al., 2012) to predict the long-term
dynamics of the ZM.Peer ReviewedPostprint (published version
Marketing estratégico y captación de clientes en una entidad financiera, San Martin de Porres, 2022
La investigación tuvo como objetivo establecer la relación entre el marketing
estratégico y la captación de clientes en una entidad financiera, San Martin de
Porres, 2022. Se trabajo con una población de 23 colaboradores, la técnica utilizada
para la obtención de datos se dio mediante la encuesta, la cual fue elaborada a
través de un cuestionario con escala de Likert conformado por 18 preguntas. Los
resultados fueron procesados mediante el método estadístico y se usó el programa
SPSS 24. La metodología de la investigación fue hipotético deductivo con un
enfoque cuantitativo, el tipo de investigación fue aplicada de nivel correlacional, el
diseño no experimental y de corte transversal. Se concluye que existe una relación
positiva alta de 0.830 (p<0,05) entre las variables marketing estratégico y captación
de clientes. De los resultados obtenidos se planteó una propuesta para implementar
el marketing estratégico y de esta forma aumentar la cantidad de clientes en una
entidad financiera, eso mediante actividades y estrategias
Emotional Impact and Perceived Effectiveness of Text-Only versus Graphic Health Warning Tobacco Labels on Adolescents
The study of smoking in adolescence is of major importance as nicotine dependence often
begins in younger groups. Tobacco health warnings have been introduced to inform people
of the negative consequences of smoking. This study assessed the emotions and perceived
effectiveness of two formats of tobacco warnings on adolescents: Text-only versus graphic
warning labels. In addition, we analyzed how emotions predicted their perceived
effectiveness. In a cross-sectional study, 413 adolescents (131 smokers, 282 non-smokers)
between 13–20 years of age rated their emotions (valence and arousal) and perceived
effectiveness towards a set of tobacco warnings. Results showed that graphic warnings
evoked higher arousal than text-only warning labels (p = .038). Most of the warning labels
also evoked unpleasantness with smokers reporting higher unpleasantness regarding text only
warnings compared to non-smokers (p = .002). In contrast, perceived effectiveness of
the warnings was lower in smokers than in non-smokers (p = .029). Finally, high arousal and
being a non-smoker explained 14% of the variance of perceiving the warnings more effective.
Given the role that warnings may play in increasing health awareness, these findings
highlight how smoking status and emotions are important predictors of the way adolescents
consider tobacco health labels to be effective.This study was funded by Fundação Calouste Gulbenkian (grant number: 95476) and by the
Portuguese Foundation for Science and Technology through the Research Center CIS-IUL
(Ref. UID/PSI/03125/2013)
Self-organized kilometer-scale shoreline sand wave generation: sensitivity to model and physical parameters
The instability mechanisms for self-organized kilometer-scale shoreline sand waves have been extensively explored by modeling. However, while the assumed bathymetric perturbation associated with the sand wave controls the feedback between morphology and waves, its effect on the instability onset has not been explored. In addition, no systematic investigation of the effect of the physical parameters has been done yet. Using a linear stability model, we investigate the effect of wave conditions, cross-shore profile, closure depth, and two perturbation shapes (P1: cross-shore bathymetric profile shift, and P2: bed level perturbation linearly decreasing offshore). For a P1 perturbation, no instability occurs below an absolute critical angle ¿c0˜ 40-50°. For a P2 perturbation, there is no absolute critical angle: sand waves can develop also for low-angle waves. In fact, the bathymetric perturbation shape plays a key role in low-angle wave instability: such instability only develops if the curvature of the depth contours offshore the breaking zone is larger than the shoreline one. This can occur for the P2 perturbation but not for P1. The analysis of bathymetric data suggests that both curvature configurations could exist in nature. For both perturbation types, large wave angle, small wave period, and large closure depth strongly favor instability. The cross-shore profile has almost no effect with a P1 perturbation, whereas large surf zone slope and gently sloping shoreface strongly enhance instability under low-angle waves for a P2 perturbation. Finally, predictive statistical models are set up to identify sites prone to exhibit either a critical angle close to ¿c0 or low-angle wave instability.Postprint (author's final draft
Modeling the long-term diffusion and feeding capability of a mega-nourishment
A morphodynamic model based on the wave-driven alongshore sediment transport, including cross-shore transport in a simplified way and neglecting tides, is presented and applied to the Zandniotor mega-nourishment on the Dutch Delfiand coast. The model is calibrated with the bathymetric data surveyed from January 2012 to March 2013 using measured offshore wave forcing. The calibrated model reproduces accurately the surveyed evolution of the shoreline and depth contours until March 2015. According to the long-term modeling using different wave climate scenarios based on historical data, for the next 30-yr period, the Zandmotor will display diffusive behavior, asymmetric feeding to the adjacent beaches, and slow Migration to the NE. Specifically, the Zandmotor amplitude will have decayed from 960 m to about 350 m with a scatter of only about 40 m associated to climate variability. The modeled coastline diffusivity during the 3-yr period is 0.0021 m(2)/s, close to the observed value of 0.0022 m(2)/s. In contrast, the coefficient of the classical one-line diffusion equation is 0.0052 m(2)/s. Thus, the lifetime prediction, here defined as the time needed to reduce the initial amplitude by a factor 5, would be 90 yr instead of the classical diffusivity prediction of 35 yr. The resulting asymmetric feeding to adjacent beaches prodtices 100 m seaward shift at the NE section and 80 m seaward shift at the SW section. Looking at the variability associated to the different wave climates, the migration rate and the slight shape asymmetry correlate with the wave power asymmetry (W vs N waves) while the coastline diffusivity correlates with the proportion of high-angle waves, suggesting that the Dutch coast is near the high-angle wave instability threshold.Peer ReviewedPostprint (published version
Mineralization enhancement of a recalcitrant pharmaceutical pollutant in water by advanced oxidation hybrid processes
ABSTRACT: Degradation of the biorecalcitrant pharmaceutical micropollutant ibuprofen (IBP) was carried out by means of several advanced oxidation hybrid configurations. TiO2 photocatalysis, photo-Fenton and sonolysis – all of them under solar simulated illumination – were tested in the hybrid systems: sonophoto-Fenton (FS), sonophotocatalysis (TS) and TiO2/Fe2+/sonolysis (TFS). In the case of the sonophoto-Fenton process, the IBP degradation (95%) and mineralization (60%) were attained with photo-Fenton (FH). The presence of ultrasonic irradiation slightly improves the iron catalytic activity. On the other hand, total removal of IBP and elimination of more than 50% of dissolved organic carbon (DOC) were observed by photocatalysis with TiO2 in the presence of ultrasound irradiation (TS). In contrast only 26% of mineralization was observed by photocatalysis with H2O2 (TH) in the absence of ultrasound irradiation. Additional results showed that, in the TFS system, 92% of DOC removal and complete degradation of IBP were obtained within 240 min of treatment. The advanced oxidation hybrid systems seems to be a promising alternative for full elimination/mineralization for the recalcitrant micro-contaminant IBP
Tecnologías para el desarrollo, y la educación del ingeniero.
El texto analiza las necesidades y oportunidades en la formación de los ingenieros en Tecnologías Apropiadas al progreso del Desarrollo Humano en las Comunidades Rurales Aisladas, en el marco de los cambios en las relaciones internacionales -globalización-, en los objetivos y metodologías educativas -proceso de "Bolonia"- y en la recomposición de los tradicionales códigos deontológicos o de las orientaciones filantrópicas a los modelos de acreditación y certificación de su implementación y aplicación desde la visión y la misión de las instituciones universitarias. Muestra ejemplos prácticos y establece recomendaciones para su incorporación en la enseñanza universitaria
Formation and destruction of shoreline sand waves: observations and modelling
Peer ReviewedPostprint (published version
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