117 research outputs found
Trans-Stilbenes in Commercial Grape Juices: Quantification Using HPLC Approaches
Trans-stilbenes belong to the group of polyphenolic phytoalexins, and occur in many plant foods. These compounds have received great attention by researchers due to their well-known beneficial health effects. In the present study a chromatographic method that comprises the use of variable wavelength (VWD) and fluorescence (FLD) detectors in series for the analysis of trans-stilbenes is presented. The relation of peak-area obtained with both detectors is proposed as an alternative and complementary approach for the rapid identification of these phenolic compounds. The proposed method was applied to determine trans-stilbenes in commercial fruit juices. Trans-piceid was the most common trans-stilbene found in the samples analyzed. The method was validated in terms of linearity, sensitivity and repeatability. Appropriate sensitivity and good linearity (r2 > 0.9991) were achieved.This work was financed under grant GRC2014/012 for consolidating and structuring of competitive research units do Galician University System, SpainS
3D exploration and navigation with optimal-RRT planners for ground robots in indoor incidents
Navigation and exploration in 3D environments is still a challenging task for autonomous robots that move on the ground. Robots for Search and Rescue missions must deal with unstructured and very complex scenarios. This paper presents a path planning system for navigation and exploration of ground robots in such situations. We use (unordered) point clouds as the main sensory input without building any explicit representation of the environment from them. These 3D points are employed as space samples by an Optimal-RRTplanner (RRT ∗ ) to compute safe and efficient paths. The use of an objective function for path construction and the natural exploratory behaviour of the RRT ∗ planner make it appropriate for the tasks. The approach is evaluated in different simulations showing the viability of autonomous navigation and exploration in complex 3D scenarios
UAVs formation approach using fast marching square methods
This article presents a novel method for the management of UAVs formations. Based on the fast marching square (FM2) technique, the proposed method allows the generation of soft realizable paths for a formation in leader-followers configuration, keeping a desired geometry among its different agents. The solution presented here also allows the UAVs formation to adapt its shape so that the obstacles can be avoided, at the same time that a flight level can be fixed with respect to the ground. Simulation results will be presented in different environments to show the validity and robustness of the approach.This research was supported by RoboCity2030-DIH-CM Madrid Robotics Digital Innovation Hub (Robótica aplicada a la mejora de la calidad de vida de los ciudadanos, Fase IV; S2018/NMT-4331), funded by Programas de Actividades I+D en la Comunidad de Madrid and cofunded by Structural Funds of the EU
Diseño y simulación de un actuador de rigidez variable
XIX Congreso Nacional de Ingeniería Mecánica (CNIM 2012), Castellón, 14-16 de noviembre de 2012Los actuadores de rigidez variable se han desarrollado como una alternativa a los actuadores convencionales en diversas aplicaciones, como son entre otras los robots de servicio y los robots caminantes. El diseño mecánico de estos actuadores debe dar solución a nuevas necesidades que no eran tenidas en consideración en los actuadores rígidos, como la reducción del daño en caso de impacto o el ajuste de la frecuencia natural del sistema. Han sido muy diversas las soluciones propuestas hasta el momento, caracterizadas por el tipo de mecanismo implementado para variar la rigidez y posición de la articulación. En este trabajo se presenta un nuevo diseño de actuador basado en transmisión por cables, en el que un primer motor controla la posición de equilibrio del eslabón y un segundo motor se encarga de variar la rigidez de la articulación. Además, se ha simulado una situación de impacto hombre-robot para estudiar su contribución en la reducción del daño en hombre y robot.This work has been supported by the CAM Project S2009/DPI-1559/ROBOCITY2030 II, developed by the research team RoboticsLab at the University Carlos III of Madrid
Modular and self-scalable origami robot: A first approach
This paper presents a proposal of a modular robot with origami structure. The proposal is based on a self-scalable and modular link made of soft parts. The kinematics of a single link and several links interconnected is studied and validated. Besides, the link has been prototyped, identified, and controlled in position. The experimental data show that the system meets the scalability requirements and that its response is totally reliable and robust.The research leading to these results has received funding from the project Desarrollo de
articulaciones blandas para aplicaciones robóticas, with reference IND2020/IND-1739, funded by
the Comunidad Autónoma de Madrid (CAM) (Department of Education and Research), and from
RoboCity2030-DIH-CM, Madrid Robotics Digital Innovation Hub (Robótica aplicada a la mejora de la
calidad de vida de los ciudadanos, FaseIV; S2018/NMT-4331), funded by “Programas de Actividades
I+D en la Comunidad de Madrid” and cofunded by Structural Funds of the EU
Mineral element contents in commercially valuable fish species in Spain
The aim of this study was to measure selected metal concentrations in Trachurus trachurus, Trachurus picturatus, and Trachurus mediterraneus, which are widely consumed in Spain. Principal component analysis suggested that the variable Cr was the main responsible variable for the identification of T. trachurus, the variables As and Sn for T. mediterraneus, and the rest of variables for T. picturatus. This well-defined discrimination between fish species provided by mineral element allows us to distinguish them on the basis of their metal content. Based on the samples collected, and recognizing the inferential limitation of the sample size of this study, the metal concentrations found are below the proposed limit values for human consumption. However, it should be taken into consideration that there are other dietary sources of these metals. In conclusion, metal contents in the fish species analyzed are acceptable for human consumption from a nutritional and toxicity point of view
Identification of Volatile and Semi-Volatile Compounds in Polymeric Coatings Used in Metal Cans by GC-MS and SPME
Polymeric coatings are used as a protective layer to preserve food or beverage quality and protect it from corrosion and avoid a metallic taste. These types of materials can contain some chemicals that are susceptible to migrate to food and constitute a risk for consumers’ health. This study is focused on the identification of volatile and semi-volatile low molecular weight compounds present in polymeric coatings used for metal food and beverage cans. A method based on solid–liquid extraction followed by gas chromatography–mass spectrometry (GC-MS) was optimized for the semi-volatile compounds. Different solvents were tried with the aim of extracting compounds with different polarities. Furthermore, a method based on solid-phase microextraction (SPME) in headspace (HS) mode and gas chromatography coupled with mass spectrometry (HSSPME-GC-MS) was developed for the identification of potential volatile migrants in polymeric coatings. Some parameters such as extraction time, equilibrium temperature, or the type of fiber were optimized. Different compounds, including aldehydes such as octanal or nonanal, alcohols such as α-terpineol or 2-butoxyethanol, ethers, alkenes, or phthalic compounds, among others, were identified and confirmed with analytical standards both via SPME analysis as well after solvent extractionThis research was funded by the Ministerio de Ciencia, Innovación y Universidades, by the Fondo Europeo de Desarrollo Regional (FEDER), and by the Agencia Estatal de Investigación Ref. No. PGC2018-094518-B-I00 “MIGRACOATING” (MICIU/FEDER, UE). The authors are grateful to the Ministerio de Ciencia, Innovación y Universidades for the predoctoral fellowship (ref. PRE2019-088195) awarded to P.V.-L.; A.L.-C. is grateful for her grant Programa de axudas á etapa predoutoral da Xunta de Galicia (Consellería de Cultura, Educación e Ordenación Universitaria)S
Diagnóstico microbiológico de la infección por el VIH
Producción CientíficaEn la actualidad se calcula que en España hay alrededor de 150.000 personas infectadas por el virus de la inmunodeficiencia humana (VIH). Este número, junto con el hecho de que esta enfermedad se haya convertido en una patología crónica gracias a los nuevos tratamientos antirretrovirales, condiciona una gran demanda asistencial en los laboratorios de microbiología de nuestros hospitales. Esta mayor demanda tiene lugar no sólo en el terreno del diagnóstico y tratamiento de las infecciones oportunistas, sino también en pruebas que ayudan en el diagnóstico y tratamiento terapéutico de la propia infección por el virus. Consciente de ello, la Sociedad Española de Enfermedades Infecciosas y Microbiología Clínica ha realizado una actualización de su procedimiento sobre el diagnóstico microbiológico de la infección por VIH. En dicho procedimiento se realiza una revisión de las principales novedades en el terreno del diagnóstico serológico, de la carga viral plasmática y de la detección de resistencias a los distintos retrovirales
Recopilación de métodos analíticos para la caracterización y determinación del quitosano y las principales aplicaciones del polímero en los envases activos alimentarios
Antimicrobial films for food packaging applications have received increasing attention from the industry in recent years. Due to their exceptional properties, such as non-toxicity, biodegradability, antimicrobial characteristics, and biocompatibility, chitosan has proven useful for the development of active materials. This review aims to provide anoverview of the main techniques used for the characterization of chitin and chitosan, including Fourier transforminfrared spectroscopy (FTIR), 1H and 13C nuclear magnetic resonance (NMR) spectroscopy, UV spectrophotometry, viscosimetry, elemental analysis, X-ray diffraction (XRD), thermogravimetric analysis (TGA), titrations, scanning electron microscopy (SEM) and size exclusion chromatography (SEC) among others. In addition, the main applications of the polymer in food packaging are also reportedEn los últimos años los films antimicrobianos han recibido una gran atención por parte de la industria para su aplicación en el envasado alimentario. Debido a sus excepcionales propiedades, no-tóxico, biodegradable, características antimicrobianas y biocompatible, el quitosano ha demostrado ser útil para el desarrollo de materiales activos. Este artículo de revisión tiene por objeto proporcionar una visión general de las principales técnicas usadas para la caracterización de quitina y quitosano incluidas la espectroscopia infrarroja (FTIR), la espectroscopia RMN de 1H y 13C, la espectrofotometría UV, viscosimetría, análisis elemental, difracción de rayos-X (XRD), análisis termogravimétrico (TGA), titulaciones, microscopía electrónica de barrido (SEM) y cromatografía de exclusión por tamaños (SEC)entre otras. Además, se describen las principales aplicaciones del polímero en el envasado de los alimentosThis work was funded under the Project no. 95935 from FONCICYT C002-2008-1/ALA 127 249S
Bibliografía
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