3,186 research outputs found
Microwave-Assisted Organocatalytic Intramolecular Knoevenagel/Hetero Diels–Alder Reaction with O -(Arylpropynyloxy)-Salicylaldehydes: Synthesis of Polycyclic Embelin Derivatives
highly efficient and regioselective approach to new polycyclic embelin derivatives through a domino Knoevenagel condensation/intramolecular hetero Diels−Alder reaction using O-(arylpropynyloxy)-salicylaldehydes in the presence of ethylenediamine diacetate (EDDA) is reported. This organocatalyzed protocol is compatible toward a wide range of aryl-substituted alkynyl ethers with electron-donating and electron-withdrawing groups. When other active methylene compounds were subjected to this domino reaction the corresponding adducts were obtained in high yield.Fil: Martín-Acosta, Pedro. Universidad de La Laguna; EspañaFil: Feresin, Gabriela Egly. Consejo Nacional de Investigaciones Científicas y Técnicas; Argentina. Universidad Nacional de San Juan; ArgentinaFil: Tapia, Alejandro. Universidad Nacional de San Juan; ArgentinaFil: Estevez Braun, Ana. Universidad de La Laguna; Españ
Urban objects classification using Mueller matrix polarimetry and machine learning
Detecting and recognizing different kinds of urban objects is an important problem, in particular, in autonomous driving. In this context, we studied the potential of Mueller matrix polarimetry for classifying a set of relevant real-world objects: vehicles, pedestrians, traffic signs, pavements, vegetation and tree trunks. We created a database with their experimental Mueller matrices measured at 1550 nm and trained two machine learning classifiers, support vector machine and artificial neural network, to classify new samples. The overall accuracy of over 95% achieved with this approach, with either models, reveals the potential of polarimetry, specially combined with other remote sensing techniques, to enhance object recognition.European Regional Development Fund (POCI-01-0247-FEDER-037902); Fundação para a Ciência e a Tecnologia (UIDB/04650/2020).This work is supported by the European Structural and Investment Funds in the FEDER component, through the Operational Competitiveness and Internationalization Program (COMPETE 2020) [Project n°
037902; Funding Reference: POCI-01-0247-FEDER-037902] and partially supported by the Portuguese Foundation for Science and Technology (FCT) in the framework of the Strategic Funding UIDB/04650/2020. The authors acknowledge Alexandre Correia and Moisés Duarte (Bosch Car Multimedia Portugal S.A) and Dr. Rui Pereira and Dr. Stéphane
Clain (Minho University) for fruitful discussions on data analysis. The authors also acknowledge city council of Braga (Portugal) for the supply of samples
Effect of blanching, storage and drying conditions on the macro-composition, color and safety of mealworm Tenebrio molitor larvae
For food applications, the processing conditions applied to edible insects should present low energy requirements and environmental impact, while also assuring high quality and safety. The main goal of this study was to assess how different blanching, storage and drying conditions influence the quality and safety of Tenebrio molitor larvae. The different operations included blanching treatments (water-immersion or steaming), post-blanching storage (freezing or refrigeration) and drying methods (oven, microwave or freeze dryer). To monitor the impact on the quality of T. molitor dry matter content, water activity (aw), color and macro-nutrient composition were evaluated, while microbiological analyses were performed to assess the impacts on quality and safety. Blanching, particularly immersion-blanching, improved the lightness of the larvae, both before and after drying. Both blanching treatments reduced the Total Viable Count (TVC) and Enterobacteriaceae loads. Regarding the drying methods, freeze drying led to the best color conservation, while drying with an oven led to the lowest moisture content and aw. The application of drying methods further contributed to the reduction of TVC and Enterobacteriaceae, assuring low loads even after 3 months of storage, with the freeze dryer resulting in the lowest reductions, including an increase in yeast and mold count.info:eu-repo/semantics/publishedVersio
Microwave-assisted autohydrolysis of avocado seed for the recovery of antioxidant phenolics and glucose
This study describes the valorization of avocado seed (AS) within a green biorefinery concept using microwave-assisted autohydrolysis. After the treatment at temperatures of 150–230 ◦C for 5 min, the resulting solid and liquor were characterized. The temperature of 220 ◦C led to the simultaneous optimal values of antioxidant phenolics/flavonoids (42.15 mg GAE/g AS, 31.89 RE/g AS, respectively) and glucose + glucooligosaccharides (38.82 g/L) in the liquor. Extraction with ethyl acetate allowed the recovery of the bioactive compounds while maintaining the polysaccharides in the liquor. The extract was rich in vanillin (99.02 mg/g AS) and contained several phenolic acids and flavonoids. The solid phase and the phenolic-free liquor were subjected to enzymatic hydrolysis to produce glucose, reaching values of 9.93 and 105 g glucose/L, respectively. This work demonstrates that microwave-assisted autohydrolysis is a promising technology to obtain fermentable sugars and antioxidant phenolic compounds from avocado seeds following a biorefinery scheme.Universidade de Vigo/CISUGXunta de Galicia | Ref. ED431C 2017/62-GRCXunta de Galicia | Ref. ED431F 2020/03Xunta de Galicia | Ref. ED481B-2022-020Ministerio de Ciencia, Innovación y Universidades | Ref. FPU21/02446Ministerio de Ciencia, Innovación y Universidades | Ref. FJC2021-046978-IMinisterio de Ciencia, Innovación y Universidades | Ref. RYC2018-024846-IMinisterio de Ciencia, Innovación y Universidades | Ref. RYC2018-026177-
Título: Epidecio sacro panegyrico, a las inmortales memorias de la V. Madre Sor Manuela de la Trinidad / dixole en sus exequias ... Fr. Gabriel de Noboa, del Orden de N. P. S. Francisco ... con port. pag. y sign. propias
Copia digital. Valladolid : Junta de Castilla y León. Consejería de Cultura y Turismo, 2009-2010La h. de grab. calc. imagen de Nª Sª de la Limpia Concepció
Eye-to-hand calibration of an industrial robotic arm with structured light 3D cameras
[EN] Computer vision is gaining more and more importance in the world of industrial robotics, since it is necessary to carry out increasingly precise and autonomous tasks, which is why a more exact positioning of the robot is needed. This requires the support of a vision system that is the one that gives the robot precision in its pose, calibrating said system with respect to the robot. This work presents a simple methodology to approach this form of calibration, called hand-eye, using a structured light 3D camera that obtains information from the real world and a six-axis industrial robotic arm. The method uses the RANSAC algorithm for the determination of the planes, which represents a notable reduction in errors, since the coordinates of the points sought come from planes adjusted to thousands of points. This allows the system to always have the ability to obtain a transformation matrix from the coordinates of the camera to the base of the robot. In addition, the proposed method is ideal for making a precision comparison between cameras, due to its simplicity and speed of use. In this study, the resulting error analysis was performed using two dfferent 3D cameras: a basic one (Kinect 360) and an industrial one (Zivid ONE + M).[ES] La visión artificial está cobrando cada día más auge en el mundo de la robótica industrial, ya que es necesario realizar tareas cada vez más precisas y autónomas, por lo que se necesita un posicionamiento del robot más exacto. Para ello se precisa del apoyo de un sistema de visión que sea el que preste al robot precisión en su pose, calibrando dicho sistema con respecto al robot. Este trabajo presenta una metodología sencilla para abordar esta forma de calibración, llamada ojo a mano, empleando una cámara 3D de luz estructurada que obtiene la información del mundo real y un brazo robótico industrial de seis ejes. Esto permite utilizar el algoritmo RANSAC para la determinación de los planos, cuya intersección nos da las coordenadas de los puntos,lo que supone una reducción notable de los errores, ya que las coordenadas proceden de planos ajustados a miles de puntos, lo cual hace que el sistema sea más robusto y capaz de obtener una matriz de transformación de las coordenadas de la cámara a la base del robot, que le permitirá abordar cualquier tarea que precise con una precisión eficiente. Se ha realizado el análisis de errores resultante utilizando dos cámaras 3D diferentes: una básica (Kinect 360) y otra industrial (Zivid ONE+ M).Este trabajo ha sido realizado parcialmente gracias al apoyo del Plan Estatal de Investigación Científica y Técnica y de Innovación 2017-2020 (AUROVI) EQC2018-005190-P.
Fernando M. Quintana agradece al Ministerio de Ciencia, Innovación y Universidades de España su apoyo a través de la ayuda FPU (FPU18/04321).Diaz-Cano, I.; Quintana, FM.; Galindo, PL.; Morgado-Estevez, A. (2022). Calibración ojo a mano de un brazo robótico industrial con cámaras 3D de luz estructurada. Revista Iberoamericana de Automática e Informática industrial. 19(2):154-163. https://doi.org/10.4995/riai.2021.16054OJS15416319
Click chemistry of multi-walled carbon nanotubes-G-1,3-diazido-2-isopropanol with alkyne groups
The click chemistry was employed on oxidized multiwall carbon nanotubes for their functionalization with 1,3-diazido-2-isopropanol (2N3OH). Phenylacetylene and propargylamine are used as alkyne groups, catalyzed with copper iodide (I). The chemical and structural characterization are described starting from the Raman and infrared spectroscopy as well as the realization of an elemental combustion analysis, transmission electron microscopy and nuclear magnetic resonance (NMR)CONACY
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