Dyes decolorization using silver nanoparticles supported on nanometric diamond as highly efficient photocatalyst under natural Sunlight irradiation

[EN] Herein we report that silver nanoparticles supported on commercial diamond nanoparticles functionalized with hydroxyl groups (D3) is a cost-effective heterogeneous catalyst for the decolorization of different synthetic dyes (Methylene Blue, Orange II, Acid Red 1 or Rhodamine B) using H2O2 as oxidant under natural Sunlight irradiation. Importantly, the photocatalytic activity of Ag/D3 is higher than that of analogous catalysts based on Ag NPs supported on graphite or activated carbon and similar to that of costly Au/D3 catalyst or the benchmark Ag/TiO2 material. Ag/D3 stability was established by performing consecutive reuses, without observing either decrease of the catalytic activity or metal leaching, while particle size increase occurs in a low extent. Productivity tests allow determining a minimum TON for dyes and H2O2 of about 500 and 6000, respectively. © 2016 Elsevier B.V. All rights reserved. All rights reserved.Financial support by the Spanish Ministry of Economy and Competitiveness (Severo Ochoa, CTQ2012-32315 and CTQ2014-53292-R) is gratefully acknowledged. Generalidad Valenciana is also thanked for funding (Prometeo 2012/013). European Commission has been gratefully acknowledged for granting Erasmus Mundus Action-2 (SVAAGATA) fellowship to the first author for carrying out this work in Department of Chemistry, Universitat Politecnica de Valencia, Valencia, Spain.Manickam-Periyaraman, P.; Espinosa, SM.; Espinosa-López, JC.; Navalón Oltra, S.; Subramanian, S.; Alvaro Rodríguez, MM.; García Gómez, H. (2016). Dyes decolorization using silver nanoparticles supported on nanometric diamond as highly efficient photocatalyst under natural Sunlight irradiation. Journal of Environmental Chemical Engineering. 4(4):4485-4493. https://doi.org/10.1016/j.jece.2016.10.011S448544934

Graphenes as Efficient Metal-Free Fenton Catalysts

[EN] Reduced graphene oxide exhibits high activity as Fenton catalyst with HO. radical generation efficiency over 82 % and turnover nos. of 4540 and 15023 for phenol degrdn. and H2O2 consumption, resp. These values compare favorably with those achieved with transition metals, showing the potential of carbocatalysts for the Fenton reaction.Financial support by Generalidad Valenciana (GV/2013/040 and Prometeo 2012/2013) is gratefully acknowledged. Spanish Ministry of Economy and Competitiveness is also thanked for funding (Severo Ochoa and CTQ2012-32315).Espinosa, JC.; Navalón Oltra, S.; Primo Arnau, AM.; Moral, M.; Fernandez Sanz, J.; Alvaro Rodríguez, MM.; García Gómez, H. (2015). Graphenes as Efficient Metal-Free Fenton Catalysts. Chemistry - A European Journal. 21(34):11966-11971. https://doi.org/10.1002/chem.201501533S11966119712134Stratakis, M., & Garcia, H. (2012). Catalysis by Supported Gold Nanoparticles: Beyond Aerobic Oxidative Processes. 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D. (2010). Preparation and Evaluation of Graphite Oxide Reduced at 220 °C. Chemistry of Materials, 22(19), 5625-5629. doi:10.1021/cm102005mJin, M., Jeong, H.-K., Kim, T.-H., So, K. P., Cui, Y., Yu, W. J., … Lee, Y. H. (2010). Synthesis and systematic characterization of functionalized graphene sheets generated by thermal exfoliation at low temperature. Journal of Physics D: Applied Physics, 43(27), 275402. doi:10.1088/0022-3727/43/27/275402Primo, A., Atienzar, P., Sanchez, E., Delgado, J. M., & García, H. (2012). From biomass wastes to large-area, high-quality, N-doped graphene: catalyst-free carbonization of chitosan coatings on arbitrary substrates. Chemical Communications, 48(74), 9254. doi:10.1039/c2cc34978gPrimo, A., Sánchez, E., Delgado, J. M., & García, H. (2014). High-yield production of N-doped graphitic platelets by aqueous exfoliation of pyrolyzed chitosan. Carbon, 68, 777-783. doi:10.1016/j.carbon.2013.11.068Konios, D., Stylianakis, M. M., Stratakis, E., & Kymakis, E. 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Sociological analysis of sexual risk factors in the academic population. A comparative study

Objetivo principal: El objetivo de la presente investigación es identificar los factores de riesgo sexual y su relación con la estructura familiar de la que forman parte los estudiantes universitarios según el grado que cursan. Metodología: Se aplicó un cuestionario a 220 alumnos de los dos títulos de grado de la Universidad de Alicante (España). Resultados principales: Los resultados muestran que el 70.1% de los estudiantes se inició en la sexualidad entre los 16-18 años. El 95.5% ha utilizado métodos anticonceptivos en su primera relación sexual. Los estudiantes de enfermería recibieron la información sexual a través de los centros educativos y los estudiantes de Administración y Dirección de Empresas (ADE) la obtuvieron de los amigos. Conclusión principal: Se concluye que en la población universitaria siguen presentes conductas que conllevan riesgos para la salud, no encontrándose influenciados por la estructura familiar de origen. Actualmente, existe cierta disociación entre la información que reciben los estudiantes y las conductas inseguras que llevan a cabo.Objective: The objective of this investigation is identify the sexual risk factors and their relationship with the family structure which university students form part depending the degree they are studying. Methods: To 220 students of two degrees from the University of Alicante (Spain) were applied a questionnaire. Results: The results show that the 70’1% of the students began their sexual relationship among the years of 16-18. The 95’5% used contraceptive methods in their first sexual relationship. The sexual information was given nursing students from school and to the Administration and Direction of Business’ students from friends. Conclusions: Conclude that behaviors which entail health risk are still present in the university population. These behaviors are not influenced by the family structure for origin. Nowadays, there is a certain dissociation between the sexual information that the students receive and the insecure behaviors that they carry out

Substance use associated with academic performance. A research about secondary education students

Objetivo. Este artículo pretende analizar la asociación existente entre los hábitos de ocio nocturno, el consumo de drogas y el rendimiento y absentismo escolar en los adolescentes de Alicante (España). Metodología. La muestra estuvo compuesta por un total de 738 estudiantes de Educación Secundaria Obligatoria (ESO). Los datos se recogieron mediante un cuestionario anónimo y auto-administrado durante el curso académico 2013/2014. Se realizó un análisis descriptivo de las variables cuantitativas; se estudió la correlación entre las variables con el coeficiente de correlación de Pearson, y por último se llevó a cabo un análisis de regresión lineal múltiple mediante el método de paso a paso adelante. Resultados. El 65,5% de los estudiantes afirmó que había consumido alcohol alguna vez y el 25% cannabis. El consumo de esta última sustancia alcanzó el 42,3% en estudiantes del Programa de Cualificación Profesional Inicial (PCPI). El análisis de regresión mostró el consumo de drogas y la hora de regreso a casa como variables predictoras del rendimiento académico y del absentismo escolar. Conclusiones. A tenor de los resultados se puede concluir que el rendimiento académico y el absentismo escolar se encuentran influenciados por el consumo de drogas, y a su vez el consumo de psicoestimulantes se ve incrementado cuanto más se retrasa la hora de regreso a casa.Objective. This article aims to analyze the association between nightlife habits, the drug use and the achievement and truancy in teenagers Alicante (Spain). Methodology. The sample was composed by a total of 738 Secundary Education students, which is compulsory in Spain. A descriptive analysis of quantitative variables was performed; the correlation between variables were studied with the Pearson correlation coefficient, and finally a multiple linear regression analysis was performed using the method of step forward. Results. 65,5% of the students stated they had ever consumed alcohol, 25% reported that they used cannabis. The consumption of this last substance reached the 42,3% in students of the Program of Initial Professional Qualification. The regression analysis showed that the predictors of performance and school absenteeism are drugs use and homecoming time. Conclusion. The academic performance and school absenteeism is influenced by drug use, and at the same time the consumption of psychostimulants is increased however much it is delayed the time back home.Este artículo se enmarca y presenta resultados del proyecto de investigación “Consumo de drogas entre jóvenes de enseñanza secundaria de la ciudad de Alicante” (Ref. AYTOALICANTE3-13I), financiado por el Ayuntamiento de Alicante (España), llevado a cabo entre el mes de junio de 2013 y diciembre de 2014 y dirigido por la doctora Rosario Ferrer Cascales, directora del Departamento de Psicología de la Salud de la Universidad de Alicante

Estudio experimental de la influencia del estado tensional en las expansiones por Reacción Álcali-Sílice en hormigón

The Alkali-Silica Reaction is the combination of certain forms of silica present in determinate aggregates, and the alkalis (sodium and potassium) and calcium usually present in the water of the concrete pores. This reaction might form an expansive gel inside the microstructure of the concrete, which causes important expansions in the material and propagation of cracks in the worst cases. As a result, the ASR effect can damage de general deterioration of the structure and his durability. The types of structures usually affected by the RAS are bridges and dams. This experimental study is part of a bigger research carried out by the group MECMAT (UPC), which is focussed on the development of tests for the investigation of ASR. This thesis took part with the realization of experiments to study the influence of the stress state in the expansions of concrete test cubes. The tests are developed in the AAR-Triaxial Machine, a special device that allows applying a determinate stress conditions during the confinement of the test cube. The originality respect other experiments is the possibility of consider different value of load for each axis simultaneously. The main goal is contribute a consistent basis of experimental results in order to complete many numerical models that have been developed previously. Moreover, it is also realized an additional tests with a particular type of basaltic aggregate of natural origin. The purpose is applying this basaltic aggregate in future tests cubes for the AAR-TM, so it is needed to carry out tests of free expansion in order to typify the aggregate behaviour against the ASR. Along this thesis are exposed all the steps executed in the achievement of this experiments. It is explained the complete procedure of specimen preparation (materials, elaboration of test cubes, process, data acquisition and results). Also each part of the experimental methodology is defined and finally, it is shown the discussion of the results.La Reacción Álcali-Sílice es la combinación de ciertas formas de sílice presentes en determinados áridos, y los iones álcalis (sodio y potasio) y calcio normalmente presentes en el agua de los poros del hormigón. Esta reacción puede formar un gel expansivo en la microestructura del hormigón, causando importantes expansiones en el material y propagación de fisuras, en los peores casos. Como resultado, el efecto de la RAS puede perjudicar el deterioro global de la estructura y su durabilidad. Los tipos de estructuras normalmente afectadas por la RAS son puentes y presas. Este estudio experimental forma parte de una investigación más amplia llevada a cabo por el grupo MECMAT (UPC), el cual se centra en el desarrollo de ensayos para la investigación de la RAS. Esta tesis participa en la realización de experimentos para el estudio de la influencia de los estados tensionales en las expansiones de probetas cúbicas. Los ensayos se desarrollan en la AAR-Triaxial Machine, un aparato especial que permite aplicar un determinado estado tensional durante el confinamiento de la probeta cúbica. La originalidad respecto otros experimentos es la posibilidad de considerar diferentes valores de carga para cada eje simultáneamente. El objetivo principal es contribuir a una base consistente de resultados experimentales con el objetivo de completar los numerosos modelos numéricos desarrollados previamente. Además, se han realizado ensayos adicionales con un particular tipo de árido basáltico de origen natural. El propósito es utilizar este árido basáltico en futuras probetas cúbicas para la AAR-TM, por eso es necesario llevar a cabo ensayos de expansión libre para caracterizar el comportamiento del árido ante la RAS. A lo largo de este trabajo, son expuestos todos los pasos ejecutados para la realización de los experimentos. Se explica el procedimiento completo de elaboración de probetas (materiales, proceso, etc.). También, cada parte de la metodología experimental es definida y finalmente, se muestra la discusión de los resultados

Sociodemography of food habits. An investigation about Young university students in Alicante

Objetivo principal: el objetivo de esta investigación es describir los hábitos de consumo alimentario y determinar qué variables sociodemográficas, dentro del colectivo de los estudiantes jóvenes universitarios, están implicadas en la elección de los alimentos. Metodología: se aplicó un cuestionario ad hoc, anónimo y auto-administrado a 599 estudiantes de la Universidad de Alicante, matriculados en el curso académico 2018/2019. Resultados principales: los resultados muestran que los jóvenes universitarios concentran sus ingestas en la comida (90,2%) y la cena (82%). Se evidenció, además, que los alimentos incluidos en la dieta mediterránea se consumen dos o tres veces por semana en esta población, pero en porcentajes diferentes. Los datos confirman que los educados en un estilo democrático consumen, en un 59%, alimentos enriquecidos con vitaminas y minerales por encima de otros estilos educativos familiares. De los estudiantes que afirmaban consumir alimentos precocinados un 51,9% pertenecen a un estilo educativo democrático, un 32,3% al permisivo, un 14,6% al autoritario y un 1,2% al negligente, lo que confirma la influencia de la cultura educativa familiar en los hábitos de alimentación de este grupo etario para esta variable. Conclusión principal: se concluye que las pautas definitorias de la dieta mediterránea han perdido protagonismo en este grupo poblacional, al comparar sus resultados con los de otros momentos históricos. Además, los resultados obtenidos muestran que los estilos de crianza no influyen de forma determinante en la elección de la alimentación en la etapa universitaria, a excepción del consumo alimentos precocinados.Objective: the objective of this research is to describe food consumption habits and determine which sociodemographic variables, within the group of young university students, are involved in the choice of food. Methods: an ad hoc, Anonymous and self-administered questionnaire was applied to 599 students from the University of Alicante, enrolled in the 2018/2019 academic year. Results: the results show that university students concentrate their intakes at lunch (90.2%) and dinner (82%). It was also shown that the foods included in the Mediterranean diet are consumed two or three times a week in this population, but in different percentages. The data confirm that those educated in a democratic style consume, in 59%, foods enriched with vitamins and minerals above other family educational styles. Of the students who claimed to consume precooked foods, 51.9% belong to a democratic educational style, 32.3% to permissive, 14.6% to authoritarian and 1.2% to negligent, which confirms the influence of family educational culture in the eating habits of this ade group for this variable. Conclusions: it is concluded that the defining guidelines of the Mediterranean diet have lost prominence in this population group, when comparing their results with those od other historical moments. In addition, it is confirmed that the defining guidelines of the Mediterranean diet have been losing prominence along the years