276 research outputs found
Comparison of Mechanical Properties of Hemp-Fibre Biocomposites Fabricated with Biobased and Regular Epoxy Resins
[EN] Bio- and green composites are mainly used in non-structural automotive elements like interior panels and vehicle underpanels. Currently, the use of biocomposites as a worthy alternative to glass fibre-reinforced plastics (GFRPs) in structural applications still needs to be fully evaluated. In the current study, the development of a suited biocomposites started with a thorough review of the available raw materials, including both reinforcement fibres and matrix materials. Based on its specific properties, hemp appeared to be a very suitable fibre. A similar analysis was conducted for the commercially available biobased matrix materials. Greenpoxy 55 (with a biocontent of 55%) and Super Sap 100 (with a biocontent of 37%) were selected and compared with a standard epoxy resin. Tensile and three-point bending tests were conducted to characterise the hemp-based biocomposite.The authors acknowledge financial support from the Spanish Government, Project PID2019-108807RB-I00.Colomer Romero, V.; Rogiest, D.; García Manrique, JA.; Crespo, J. (2020). Comparison of Mechanical Properties of Hemp-Fibre Biocomposites Fabricated with Biobased and Regular Epoxy Resins. Materials. 13(24):1-8. https://doi.org/10.3390/ma13245720181324Mohanty, A. K., Misra, M., & Hinrichsen, G. (2000). Biofibres, biodegradable polymers and biocomposites: An overview. Macromolecular Materials and Engineering, 276-277(1), 1-24. doi:10.1002/(sici)1439-2054(20000301)276:13.0.co;2-wLa Mantia, F. P., & Morreale, M. (2011). Green composites: A brief review. Composites Part A: Applied Science and Manufacturing, 42(6), 579-588. doi:10.1016/j.compositesa.2011.01.017Hansen, O., Habermann, C., & Endres, H.-J. (2019). BIO-BASED MATERIALS FOR EXTERIOR APPLICATIONS – PROJECT BIOHYBRIDCAR. Zukunftstechnologien für den multifunktionalen Leichtbau, 189-200. doi:10.1007/978-3-662-58206-0_18Gholampour, A., & Ozbakkaloglu, T. (2019). A review of natural fiber composites: properties, modification and processing techniques, characterization, applications. Journal of Materials Science, 55(3), 829-892. doi:10.1007/s10853-019-03990-yPatil, N. V., Rahman, M. M., & Netravali, A. N. (2017). «Green» composites using bioresins from agro‐wastes and modified sisal fibers. Polymer Composites, 40(1), 99-108. doi:10.1002/pc.24607Verma, D., & Senal, I. (2019). Natural fiber-reinforced polymer composites. Biomass, Biopolymer-Based Materials, and Bioenergy, 103-122. doi:10.1016/b978-0-08-102426-3.00006-0Adekomaya, O. (2020). Adaption of green composite in automotive part replacements: discussions on material modification and future patronage. Environmental Science and Pollution Research, 27(8), 8807-8813. doi:10.1007/s11356-019-07557-xKim, Y. K., & Chalivendra, V. (2020). Natural fibre composites (NFCs) for construction and automotive industries. Handbook of Natural Fibres, 469-498. doi:10.1016/b978-0-12-818782-1.00014-6Potluri, R., & Chaitanya Krishna, N. (2020). Potential and Applications of Green Composites in Industrial Space. Materials Today: Proceedings, 22, 2041-2048. doi:10.1016/j.matpr.2020.03.218Mann, G. S., Singh, L. P., Kumar, P., & Singh, S. (2018). Green composites: A review of processing technologies and recent applications. Journal of Thermoplastic Composite Materials, 33(8), 1145-1171. doi:10.1177/0892705718816354Standard Test Method for Tensile Properties of Polymer Matrix Composite Materials https://www.astm.org/Standards/D3039https://www.pecepoxy.co.uk/data-sheets/TDS_100_1000_v4.pdfhttp://www.matrix-composites.co.uk/prod-data-sheet/old/greenpoxy-55-ft-uk.pdfCzłonka, S., Strąkowska, A., & Kairytė, A. (2020). The Impact of Hemp Shives Impregnated with Selected Plant Oils on Mechanical, Thermal, and Insulating Properties of Polyurethane Composite Foams. Materials, 13(21), 4709. doi:10.3390/ma13214709Madhu, P., Mavinkere Rangappa, S., Khan, A., Al Otaibi, A., Al‐Zahrani, S. A., Pradeep, S., … Siengchin, S. (2020). Experimental investigation on the mechanical and morphological behavior of
Prosopis juliflora
bark fibers/E‐glass/carbon fabrics reinforced hybrid polymeric composites for structural applications. Polymer Composites, 41(12), 4983-4993. doi:10.1002/pc.2576
Segmentación de imágenes de células cervicovaginales con aprendizaje profundo
Este estudio explora el uso de técnicas de aprendizaje profundo para la segmentación y clasificación de imágenes de células cervicales. Las imágenes provienen de citologías de cuatro clases de anormalidad según el sistema Bethesda 2014. Los métodos utilizados son redes completamente convolucionales para la segmentación semántica, que etiquetan cada píxel como núcleo, citoplasmas o fondo, y redes neuronales convolucionales para la clasificación de imágenes, que asignan cada imagen de célula a una de las cuatro clases. Los resultados muestran que las máscaras de segmentación mejoran el rendimiento de la clasificación. Los mejores modelos son U-Net para segmentación y una concatenación de dos redes neuronales convolucionales para clasificación. El estudio concluye que la inteligencia artificial puede ayudar a patólogos en el diagnóstico de cáncer cervical al proporcionar una segmentación y clasificación precisas y eficientes de las imágenes de células.Ingeniería, Industria y Construcció
Educación y equidad en la primera infancia : el caso de las aulas de 2 años en los centros públicos de la Comunidad Valenciana
En este trabajo analizamos la evolución de la provisión de educación y atención de la primera infancia (EAPI) en el primer ciclo de la Educación Infantil en el contexto de la Comunidad Valenciana, con particular atención al caso de la implantación de las aulas de 2 años en centros públicos. Durante las últimas dos legislaturas, la Comunidad Valenciana ha pasado de estar en la vanguardia del fomento y desarrollo del modelo de oferta privada a ser de las regiones pioneras en el desarrollo de las aulas de 2 años en la enseñanza pública. Enmarcamos estos cambios en el contexto español, y discutimos su alcance para la equidad del sistema educativo en esta etapa desde el enfoque de los derechos humanos y el marco europeo de calidad actual.En aquest treball analitzem l'evolució de la provisió d'educació i atenció de la primera infància (EAPI) en el primer cicle de l'Educació Infantil en el context de la Comunitat Valenciana, amb particular atenció al cas de la implantació de les aules de 2 anys en centres públics. Durant les últimes dues legislatures, la Comunitat Valenciana ha passat d'estar en l'avantguarda del foment i desenvolupament del model d'oferta privada a ser de les regions pioneres en el desenvolupament de les aules de 2 anys en l'ensenyament públic. Emmarquem aquests canvis en el context espanyol, i discutim el seu abast per a l'equitat del sistema educatiu en aquesta etapa des de l'enfocament dels drets humans i el marc europeu de qualitat actual.In this paper we analyse the development of early childhood education and care provision (ECEC) in the first cycle of childhood education in the Valencian Community region, with particular attention to the implementation of "classrooms for two-year-olds" in public nurseries. During the last two legislatures, the Valencian Community region has gone from being at the forefront of promoting and developing the private supply model to being one of the pioneering regions in developing "classrooms for two-year-olds" in public education. We place these changes within the Spanish context, and discuss their scope for the equity of the education system at this age, from a human rights perspective and within the current European quality framework
Influence of Skin-Contact Treatment on Aroma Profile of Malvasia <em>Aromatica</em> Wines in D.O. “Vinos de Madrid”
The effects of prefermentative cold skin-contact technique using Malvasia aromatica were studied as a first step to adapt to the climate change related effects in order to intensify the aroma potential of white wines of the D.O. “Vinos de Madrid” keeping the organoleptic characteristics of the region. Major volatile compounds were extracted by liquid–liquid extraction and quantified by GC-FID. Minor volatile compounds were determined by HS-SPME/GC–MS. Sensory analysis were also carried out to describe and quantify attributes of the wines. A total of 37 components were identified and quantified. Volatile components showed mixed behavior depending on the skin-contact time. Skin-contact for longer helps to enhance the floral character provided by some compounds contained in the skin, especially linalool and 2-phenyl etanol and were impact odorants of Malvasia aromatica wine based on odor activity values (OAVs)
Historical reconstruction of the population dynamics of southern right whales in the southwestern Atlantic Ocean
Understanding the recovery of whale populations is critical for developing population-management and conservation strategies. The southern right whale (SRW) Eubalena australis was one of the baleen whale species that has experienced centuries of exploitation. We assess here for the first time the population dynamics of the SRW from the southwestern Atlantic Ocean at the regional level to measure numerically the effect of whaling and estimate the population trend and recovery level after depletion. We reconstructed the catch history of whaling for the period 1670–1973 by an extensive review of different literature sources and developed a Bayesian state-space model to estimate the demographic parameters. The population trajectory indicated that the pre-exploitation abundance was close to 58,000 individuals (median = 58,212; 95% CI = 33,329–100,920). The abundance dropped to its lowest abundance levels in the 1830s when fewer than 2,000 individuals remained. The current median population abundance was estimated at 4,742 whales (95% CI = 3,853–6,013), suggesting that the SRW population remains small relative to its pre-exploitation abundance (median depletion P2021 8.7%). We estimated that close to 36% of the SRW population visits the waters of the Península Valdés, the main breeding ground, every year. Our results provide insights into the severity of the whaling operation in the southwestern Atlantic along with the population´s response at low densities, thus contributing to understand the observed differences in population trends over the distributional range of the species worldwide.Fil: Romero, Maria Alejandra. Universidad Nacional del Comahue. Centro de Investigación Aplicada y Transferencia Tecnológica en Recursos Marinos "Almirante Storni". - Provincia de Río Negro. Ministerio de Agricultura, Ganadería y Pesca. Centro de Investigación Aplicada y Transferencia Tecnológica en Recursos Marinos "Almirante Storni". Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet Centro Nacional Patagónico. Centro de Investigación Aplicada y Transferencia Tecnológica en Recursos Marinos "Almirante Storni"; Argentina. Universidad Nacional del Comahue. Escuela de Ciencias Marinas; ArgentinaFil: Coscarella, Mariano Alberto. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Centro Nacional Patagónico. Centro para el Estudio de Sistemas Marinos; Argentina. Universidad Nacional de la Patagonia "San Juan Bosco"; ArgentinaFil: Adams, G. A.. University of Washington; Estados UnidosFil: Pedraza, Juan C.. Universidad de Buenos Aires. Facultad de Ciencias Exactas y Naturales; ArgentinaFil: González, Raul Alberto Candido. Universidad Nacional del Comahue. Centro de Investigación Aplicada y Transferencia Tecnológica en Recursos Marinos "Almirante Storni". - Provincia de Río Negro. Ministerio de Agricultura, Ganadería y Pesca. Centro de Investigación Aplicada y Transferencia Tecnológica en Recursos Marinos "Almirante Storni". Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet Centro Nacional Patagónico. Centro de Investigación Aplicada y Transferencia Tecnológica en Recursos Marinos "Almirante Storni"; Argentina. Universidad Nacional del Comahue. Escuela de Ciencias Marinas; ArgentinaFil: Crespo, Enrique Alberto. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Centro Nacional Patagónico. Centro para el Estudio de Sistemas Marinos; Argentin
La observación de la brecha salarial de género ajustada. En busca de la discriminación directa en España
Investigamos la brecha de género oculta, la desigualdad salarial inexplicable que podría relacionarse con la discriminación directa. Se estima un Modelo Lineal General combinando las variables de la Encuesta Española de Estructura Salarial de 2018 para construir tipologías con máxima brecha salarial. Construimos una matriz con todas las combinaciones de variables explicativas incluido el sexo (>3 millones de filas). Predecimos el salario con el modelo y calculamos la brecha salarial entre filas cuya única diferencia es el sexo. Ordenamos filas seleccionando aquellas con la máxima brecha salarial (≥ percentil 99) para identificar tipologías. Ajustamos así el cálculo de la brecha oculta (13,1%) e identificamos los tipos de ocupación donde se da mayoritariamente (puestos de trabajo fijos en empresas de 1 a 49 trabajadores del sector industrial del Noroeste de España). Adicionalmente, observamos las características de las mujeres que más la padecen (mujeres ≥ 50 años con educación media y alta)
Creencias sobre la pobreza relacionadas con la categorización social en la infancia.
The aim of this study was to determine whether the social categorization of poverty during childhood is based on essentialist beliefs. The study included 121 children, aged 5 to 7, from different socioeconomic backgrounds living in the city of Barranquilla, Colombia. The children stated that the nature of this social category is based on situations external to the individuals rather than essentialist reasons. No significant differences were found as regards age, gender or socioeconomic status (SES), except in the capacity of the respondents to self-categorize their social status. Children who find fewer differences between members and non-members of a given category tend to err in their self-categorization, which is important for the prevention of social exclusionEl objetivo de este estudio fue determinar si la categorización social de la pobreza durante la infancia se basa en creencias esencialistas. El estudio incluyó a 121 niños, de 5 a 7 años, de diferentes orígenes socioeconómicos que viven en la ciudad de Barranquilla, Colombia. Los niños declararon que la naturaleza de esta categoría social se basa en situaciones externas a los individuos en lugar de razones esencialistas. No se encontraron diferencias significativas en cuanto a la edad, el género o el estatus socioeconómico (SES), excepto en la capacidad de los encuestados para autocategorizar su estatus social. Los niños que encuentran menos diferencias entre los miembros y los no miembros de una categoría dada tienden a errar en su autoclasificación, lo cual es importante para la prevención de la exclusión social
Late presentation of chronic HBV and HCV patients seeking first time specialist care in Spain: a 2-year registry review
Chronic viral hepatitis infection affects an estimated 325 million people globally. People who initiate treatment after significant disease progression face increased risk of severe liver complications and death. Data are scarce on the characteristics and risk factors of people who present late to care in Spain and globally. Data were collected from January 2018 to December 2019 to report late presentation (LP) to specialist care at 11 large university hospitals in Spain to assess related risk factors using a multivariable logistic regression model. 2290 (CHB = 505, CHC = 1785) patients were analysed, with 581 (25.2%) presenting late. Hepatitis C patients more frequently reported LP compared to hepatitis B patients (28.1% vs 15.0%; p < 0.001). Older age (p < 0.001), being male
(p < 0.001), being Spanish‑born (p < 0.001), and having an unknown origin of referral (p = 0.08) were associated with a higher likelihood of LP. Advanced liver disease was identified in 533 (23%) patients and late‑stage liver disease in 124 (5.4%). LP, including with irreversible liver damage, to viral hepatitis
specialist care is frequent in Spain, despite being a country with unrestricted treatment access. Initiatives to reduce LP should specifically target men, older individuals, foreign‑born populations for CHB, and Spanish nationals for CHC
Creencias sobre la pobreza relacionadas con la categorización social en la infancia
El objetivo de este estudio es determinar si la categorización social sobre la pobreza en la
infancia está basada en creencias esencialistas. El estudio incluyó a 121 niños de entre 5 y
7 años de edad, de distinto nivel socioeconómico y residentes en la ciudad de Barranquilla,
Colombia. Los niños plantearon que la naturaleza de esta categoría social está basada en
situaciones externas a los individuos, en lugar de atribuirla a razones de tipo esencialista.
No se encontraron diferencias estadísticamente significativas relacionadas con la edad, el
sexo o el nivel socioeconómico, a excepción de la capacidad de autocategorizarse de acuerdoThe aim of this study was to determine whether the social categorization of poverty during
childhood is based on essentialist beliefs. The study included 121 children, aged 5 to 7, from
different socioeconomic backgrounds living in the city of Barranquilla, Colombia. The
children stated that the nature of this social category is based on situations external to the
individuals rather than essentialist reasons. No significant differences were found as
regards age, gender or socioeconomic status (SES), except in the capacity of the respondents
to self-categorize their social status. Children who find fewer differences between members
and non-members of a given category tend to err in their self-categorization, which is
important for the prevention of social exclusion
In Vitro Antibacterial Activity of Propyl-Propane-Thiosulfinate and Propyl-Propane-Thiosulfonate Derived from Allium spp. against Gram-Negative and Gram-Positive Multidrug-Resistant Bacteria Isolated from Human Samples
Background: The aim of this study was to compare the in vitro antibacterial activity of two compounds derived from Alliaceae, PTS (propyl-propane-thiosulfinate), and PTSO (propyl-propane-thiosulfonate), with that of other antibiotics commonly used against bacteria isolated from humans.
Materials and methods: A total of 212 gram-negative bacilli and 267 gram-positive cocci isolated from human clinical samples and resistant to at least one group of antibiotics were selected. In order to determine the minimum inhibitory concentration (MIC) and minimum bactericidal concentration (MBC) to various antibiotics as well as PTS and PTSO, all isolates underwent broth microdilution assay.
Results: PTS showed moderate activity against Enterobacteriaceae with MIC50 (and MBC50) and MIC90 (and MBC90) values of 256-512 mg/L, while PTSO showed greater activity with MIC50 and MIC90 values of 64-128 mg/L and MBC50 and MBC90 values of 128-512 mg/L. These data show the bactericidal activity of both compounds and indicate that PTSO was more active than PTS against this group of bacteria. Both compounds showed lower activity against P. aeruginosa (MIC50 = 1024 mg/L, MIC90 = 2048 mg/L, MBC50 = 2048 mg/L, and MBC90 = 2048 mg/L, for PTS; MIC50 = 512 mg/L, MIC90 = 1024 mg/L, MBC50 = 512 mg/L, and MBC90 = 2048 mg/L, for PTSO) compared to those obtained in others nonfermenting gram-negative bacilli (MIC50 = 128 mg/L, MIC90 = 512 mg/L, MBC50 = 128 mg/L, and MBC90 = 512 mg/L, for PTS; MIC50 = 64 mg/L, MIC90 = 256 mg/L, MBC50 = 64 mg/L, and MBC90 = 256 mg/L, for PTSO) and also indicate the bactericidal activity of both compounds against these groups of bacteria. Finally, the activity against S. aureus, E. faecalis, and S. agalactiae was higher than that observed against enterobacteria, especially in the case of PTSO (MIC50 = 8 mg/L, MIC90 = 8 mg/L, MBC50 = 32 mg/L, and MBC90 = 64 mg/L, in S. aureus; MIC50 = 4 mg/L, MIC90 = 8 mg/L, MBC50 = 8 mg/L, and MBC90 = 16 mg/L, in E. faecalis and S. agalactiae).
Conclusion: PTS and PTSO have a significant broad spectrum antibacterial activity against multiresistant bacteria isolated from human clinical samples. Preliminary results in present work provide basic and useful information for development and potential use of these compounds in the treatment of human infections
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