Impact properties and water uptake behavior of old newspaper recycled fibers-reinforced polypropylene composites

Natural fiber-reinforced thermoplastic composites can be an alternative to mineral fiber-based composites, especially when economic and environment concerns are included under the material selection criteria. In recent years, the literature has shown how lignocellulosic fiber-reinforced composites can be used for a variety of applications. Nonetheless, the impact strength and the water uptake behavior of such materials have been seen as drawbacks. In this work, the impact strength and the water uptake of composites made of polypropylene reinforced with fibers from recycled newspaper have been researched. The results show how the impact strength decreases with the percentage of reinforcement in a similar manner to that of glass fiber-reinforced polypropylene composites as a result of adding a fragile phase to the material. It was found that the water uptake increased with the increasing percentages of lignocellulosic fibers due to the hydrophilic nature of such reinforcements. The diffusion behavior was found to be Fickian. A maleic anhydride was added as a coupling agent in order to increase the strength of the interface between the matrix and the reinforcements. It was found that the presence of such a coupling agent increased the impact strength of the composites and decreased the water uptake. Impact strengths of 21.3 kJ/m3 were obtained for a coupled composite with 30 wt % reinforcement contents, which is a value higher than that obtained for glass fiber-based materials. The obtained composites reinforced with recycled fibers showed competitive impact strength and water uptake behaviors in comparison with materials reinforced with raw lignocellulosic fibers. The article increases the knowledge on newspaper fiber-reinforced polyolefin composite properties, showing the competitiveness of waste-based materialsPostprint (published version

Topography of the interfacial shear strength and the mean intrinsic tensile strength of hemp fibers as a reinforcement of polypropylene

The strength of the interphase between the reinforcements and the matrix has a major role in the mechanical properties of natural ¿ber reinforced polyole¿n composites. The creation of strong interphases is hindered by the hydrophobic and hydrophilic natures of the matrix and the reinforcements, respectively. Adding coupling agents has been a common strategy to solve this problem. Nonetheless, a correct dosage of such coupling agents is important to, on the one hand guarantee strong interphases and high tensile strengths, and on the other hand ensure a full exploitation of the strengthening capabilities of the reinforcements. The paper proposes using topographic pro¿le techniques to represent the e¿ect of reinforcement and coupling agent contents of the strength of the interphase and the exploitation of the reinforcements. This representation allowed identifying the areas that are more or less sensitive to coupling agent content. The research also helped by ¿nding that an excess of coupling agent had less impact than a lack of this componentPostprint (published version

Women with low quality of life by cervantes-short form scale choose menopausal hormone therapy.

Objectives The aim of the study is to assess whether women who choose to use menopausal hormone therapy (MHT) have lower quality of life (QoL) than those who do not initiate it using Cervantes short form scale (C-SF), and analyze sociodemographic factors associated with lower QoL in women. Study design A cross-sectional descriptive observational study was made in four hundred and eighty women with climacteric symptoms. Results Mean age was 51.1 years. Two hundred and sixty-one women (54.3 %) started MHT. The sample´s global mean in C-SF score was 51.3 ± 13.9. Women who choose to use MHT have higher score in C-SF (lower QoL) than women who reject it (58.7 ± 15.9 vs 46.7 ± 12.8; p 30 BMI) (52.8 ± 13.5 vs 41.0 ± 8.2; p = 0.002); with previous malignancies (56.2 ± 18.2 vs 50.2 ± 13.5; p = 0.020) and without sexual activity (58.0 ± 25.4 vs 50.4 ± 13.1; p = 0.009. No differences were found in C-SF score with respect to tobacco habits or physical activity. In the multivariate analysis, the variable independently associated to lower QoL by C-SF (high score) was to be a woman who want to initiate MHT (p = 0.004). Conclusions Women who choose to use MHT due to menopausal symptoms have lower quality of life measured by C-SF scale. Women with early menopause, with no obesity (<30 BMI), without sexual activity and with previous malignances have lower quality of life measured by C-SF scale. Women with early menopause have more psychic symptoms like nervousness, fatigue and sleep complaints by C-SF scale than women with natural menopause.pre-print726 K

Impact of laser attacks on the switching behavior of RRAM devices

The ubiquitous use of critical and private data in electronic format requires reliable and secure embedded systems for IoT devices. In this context, RRAMs (Resistive Random Access Memories) arises as a promising alternative to replace current memory technologies. However, their suitability for this kind of application, where the integrity of the data is crucial, is still under study. Among the different typology of attacks to recover information of secret data, laser attack is one of the most common due to its simplicity. Some preliminary works have already addressed the influence of laser tests on RRAM devices. Nevertheless, the results are not conclusive since different responses have been reported depending on the circuit under testing and the features of the test. In this paper, we have conducted laser tests on individual RRAM devices. For the set of experiments conducted, the devices did not show faulty behaviors. These results contribute to the characterization of RRAMs and, together with the rest of related works, are expected to pave the way for the development of suitable countermeasures against external attacks.Postprint (published version

La enseñanza del Derecho a través de la técnica del storytelling

El objetivo de este trabajo es explicar la técnica del storytelling a los no especialistas en derecho o estudiantes como instrumento de enseñanza desde el relato de historias concretas que sirvan para introducir temas jurídicos complejos. En este trabajo analizamos la técnica en sí y su aplicabilidad práctica, utilizando casos concretos para explicarlo. THE TEACHING OF LAW THROUGH THE TECHNIQUE OF STORYTELLINGThe objective of this paper is to explain the technique of storytelling to non-specialists in law or students as a teaching tool from the telling of specific stories that serve to introduce complex legal issues. In this paper we analyze the technique itself and its practical applicability, using specific cases to explain it

Development of Artistic Competition in the Family

Recepción: 2 de noviembre de 2016 | Revisión: 3 de noviembre de 2016 | Aceptado: 7 noviembre de 2016Correspondencia: Mª Ángeles Hernández Prados | Email: [email protected] | ORCID: 0000-0002-3617-2015XLa complementariedad entre el contexto escolar y familiar es uno de los objetivos educativos del siglo XXI, especialmente por la diversidad de competencias esenciales del desarrollo humano. En este trabajo se analiza la percepción que tienen 86 alumnos y alumnas de Educación Secundaria Obligatoria sobre el desarrollo de la competencia artística en el contexto familiar. Los resultados permiten concluir que la actitud que mantiene su familia hacia la transmisión de conocimientos artísticos es ambigua, que en el contexto familiar existen recursos artísticos pero no se potencia la competencia artística como profesionalización, sino como actividad complementaria de ocio.Abstract: The complementarity between the school and familiar context is one of the educational aims of the 21st century, specially because of the diversity of the essential competences of the human development. This research analyzes the perception of 86 students of Compulsory Secondary Education on the development of the artistic competence in the familiar context. The results lead to the conclusion that the attitude of the family towards the transmission of artistic knowledges is ambiguous, and that in the familiar context exists artistic resources but the artistic competence is not enhanced as professionalization, but as a complementary leisure activity.Universidad de Granada. Departamento de Psicología Social. Proyecto de Innovación Docente ReiDoCre

Análisis comparativo del uso de nanosílice y ceniza volante en el concreto hidráulico

Context: Nowadays, nanomaterials constitute an innovative alternative for the construction sector. This study evaluates the benefits of adding nanosilica and fly ash to Portland cement concrete in terms of its mechanical strength properties. Methodology: 45 specimens were used to compare the compressive strength and durability of concrete mixtures with nanosilica and fly ash. The specimens were studied after 7, 14, and 21 days to determine their maximum resistance. Results: The addition of small amounts of nanosilica (up to 1%) significantly improved the compressive strength of the concrete. In contrast, a large amount of fly ash (up to 8%) was required for a noticeable effect. Conclusions: Concrete with nanosilica yielded the best results in terms of mechanical strength. The key to improving concrete through nanosilica and fly ash is to reduce the water-to-cement ratio using chemical agents that reduce porosity and increase resistance.Contexto: Hoy en día, los nanomateriales representan una alternativa innovadora para el sector de la construcción. Este estudio evalúa los beneficios de añadir nanosílice y ceniza volante al concreto de cemento Portland en función de sus propiedades de su resistencia mecánica. Método: Se utilizaron 45 especímenes para comparar la resistencia a la compresión y la durabilidad de mezclas de concreto con nanosílice y ceniza volante. Los especímenes fueron estudiados a los 7, 14 y 21 días para determinar su máxima resistencia. Resultados: La adición de cantidades pequeñas de nanosílice (hasta 1 %) mejoraron significativamente la resistencia a la compresión del concreto. En contrate, se necesitó una gran cantidad de ceniza volante (hasta 8 %) para lograr un efecto notable. Conclusiones: El concreto con nanosílice dio los mejores resultados en cuanto a resistencia mecánica. La clave para mejorar el concreto con nanosílice y ceniza volante es reducir la relación cemento-agua utilizando agentes químicos que reduzcan la porosidad y aumenten la resistencia

Diseño de 6,500 metros lineales de estructura de pavimento flexible tramo de carretera Ochomogo – Macarrón, municipio de Belén, Rivas

Presenta el diseño de 6,500 metros lineales de estructura de pavimento flexible tramo de carretera Ochomogo – Macarrón, municipio de Belén, Rivas, por medio de la elaboración de una análisis del tránsito vehicular que determino las cargas que actuaran en la estructura, así como un estudio de suelo para con el objetivo de evaluar la calidad del mismo para su utilización en el diseño

An overview of the CPRI specification and its application to C-RAN-based LTE scenarios

The CPRI specification has been introduced to enable the communication between radio equipment and radio equipment controllers, and is of particular interest for mobile operators willing to deploy their networks following the novel cloud radio access network approach. In such a case, CPRI provides an interface for the interconnection of remote radio heads with a baseband unit by means of the so-called fronthaul network. This article presents the CPRI specification, its concept, design, and interfaces, provides a use case for fronthaul dimensioning in a realistic LTE scenario, and proposes some interesting open research challenges in the next-generation 5G mobile network.The authors would like to acknowledge the support of projects CRAMnet (grant no. TEC2012-38362-C03-01) and EU H2020 5G-Crosshaul Project (grant no. 671598) to the development of this work.European Commissio