Recursos de colección

Archivo Digital UPM (109.492 recursos)

This is an institutional repository providing access to the research output of the institution. Primarily contains thesis.

Materia = Química

Mostrando recursos 1 - 20 de 637

  1. Morphology and thermal properties of biodegradable poly(hydroxybutyrate-co-hydroxyvalerate)/tungsten disulphide inorganic nanotube nanocomposites

    Silverman, Tyler; Naffakh Cherradi Hadi, Mohammed; Marco, Carlos; Ellis, Gary
    Promising biodegradable and renewable poly(hydroxybutyrate-co-hydroxyvalerate) (PHBV) nanocomposites based on tungsten disulphide inorganic nanotubes (INT-WS2) were efficiently prepared by a simple solution blending method. The structure, morphology, thermal stability and crystallization behavior of the nanocomposites were investigated by ultra-high field-emission scanning electron microscope (FESEM), thermogravimetric analysis (TGA), differential scanning calorimetry (DSC), wide-angle X-ray scattering (WAXS) and polarized optical microscopy (POM) techniques. As previously observed in poly(3-hydroxybutyrate) (PHB) hybrid systems, the dispersion, morphology and thermal properties of PHBV/INT-WS2 nanocomposites could be tuned by the introduction of small amounts of INT-WS2. The results revealed that a good dispersion of INT-WS2 in the PHBV...

  2. Polymer blend nanocomposites based on poly(L-lactic acid), polypropylene and WS2 inorganic nanotubes

    Naffakh Cherradi Hadi, Mohammed; Díez-Pascual, Ana M.; Marco, Carlos
    Tungsten disulphide inorganic nanotubes (INT-WS2) have been incorporated into poly(L-lactic acid) (PLLA)/ polypropylene (PP) blends compatibilized with polypropylene-grafted-maleic anhydride (PP-g-MAH), and their effects on the morphology, thermal and mechanical properties of the resulting nanocomposites have been investigated. The nanofillers were uniformly dispersed at the nanoscale via a melt-blending process. The addition of 1.0 wt% INT-WS2 to the PLLA/PP blends hardly affected their thermal stability or their degradation mechanism. Differential scanning calorimetry (DSC) thermograms revealed the nucleating role of INT-WS2 on both polymeric components, reflected not only in an increase in the crystallization temperature from the melt but also in a rise...

  3. Optical Sensing to Determine Tomato Plant Spacing for Precise Agrochemical Application: Two Scenarios

    Martínez Guanter, Jorge; Garrido Izard, Miguel; Valero Ubierna, Constantino; Slaughter, David; Pérez Ruiz, Manuel
    The feasibility of automated individual crop plant care in vegetable crop fields has increased, resulting in improved efficiency and economic benefits. A systems-based approach is a key feature in the engineering design of mechanization that incorporates precision sensing techniques. The objective of this study was to design new sensing capabilities to measure crop plant spacing under different test conditions (California, USA and Andalucía, Spain). For this study, three different types of optical sensors were used: an optical light-beam sensor (880 nm), a Light Detection and Ranging (LiDAR) sensor (905 nm), and an RGB camera. Field trials were conducted on newly...

  4. Libro de Actas del VI Congreso de estudiantes universitarios de Ciencia, Tecnología e Ingeniería Agronómica

    ETSIA, UPM
    Compendio de los trabajos presentados en el VI Congreso de estudiantes universitarios que organiza la Escuela de Agrónomos

  5. High resolution emission estimation in hot-spots of Madrid (Spain)

    Quaassdorff, Christina Violetta; Borge García, Rafael; Paz Martín, David de la; Pérez Rodríguez, Javier; Andrés Almeida, Juan Manuel de; Lumbreras Martin, Julio
    This work aims at obtaining high resolution NOx and PM10 emissions from road traffic at hot-spots in Madrid (Spain). For that, 12 1-hour representative scenarios are simulated with the traffic microsimulation model VISSIM. Measured traffic data (fluxes and fleet composition) are used as input for the model to obtain speed-time profiles for each vehicle. These profiles are used to predict representative emission factors for different vehicle classes in the VERSIT+micro model through the ENVIVER interface. Emission factors are compared with the ones of COPERT 4, a widely used average-speed model, as a preliminary model assessment. The results are strongly influenced...

  6. Modeling of the behavior of H2 vehicle users. A bilevel model for the location of hydrogen refueling stations.

    Clemente Jul, María del Carmen; Fúnez Guerra, Carlos; García-Ródenas, Ricardo; Sánchez-Herrera, Angulo; Verastegui Rayo, Doroteo
    This paper addresses the problem of estimating the infrastructure to be made available for refueling alternative fuel vehicles as a function of the profitability thresholds required by the investment. A methodology has been devised based on sales forecasts for alternative fuel vehicles. These methods use discrete choice models in which the factor of refueling infrastructure, rather than being considered simply as one more attribute of the model, acts as a constraint on the choice set for vehicle buyers. This methodology is used to estimate the infrastructure of hydrogen refueling stations and electricity charging stations for Spain (8; 112 population centers)...

  7. Activated carbon from flash pyrolysis of eucalyptus residue

    Grima Olmedo, Carlos; Ramírez Gómez, Álvaro; Clemente Jul, María del Carmen; Gómez-Limón, Dulce
    Forestry waste (eucalyptus sp) was converted into activated carbon by initial flash pyrolysis followed carbonization and CO2 activation. These residues were obtained from a pilot plant in Spain that produces biofuel, the biochar represented 10–15% in weight. It was observed that the highest activation was achieved at a temperature of 800 °C, the specific surface increased with time but, on the contrary, high loss of matter was observed. At 600 °C, although there was an important increase of the specific surface and the volume of micropores, at this temperature it was observed that the activation time was not an influential...

  8. La monitorización del CO2 difuso superficial para evaluar la seguridad de un almacenamiento geológico de CO2

    Clemente Jul, María del Carmen; Rodrigo Naharro, Julio; Pérez de Villar, Luis
    En el marco de un proyecto de investigación sobre análogos naturales españoles de almacenamiento y escape de CO2, se eligieron tres zonas de la cuenca terciaria de Gañuelas- Mazarrón (Murcia) para medir el flujo superficial difuso de CO2, utilizando el método de la cámara de acumulo. La cuenca se caracteriza por la presencia de un acuífero profundo, termal (~ 47º C), salino, rico en CO2, y atravesado por dos sondeos de exploración geotérmica. Los datos de flujo se trataron mediante un método gráfico-estadístico, Kriging y simulación Gaussiana secuencial. Los resultados sugieren que las margas de la cuenca actúan como un...

  9. Diseño teórico del sistema Surfactante Polímero para la mejora en la recuperación del petróleo.

    González García, Héctor
    El objetivo de este Trabajo de Fin de Grado es la correcta localización de un posible yacimiento petrolífero, determinar las propiedades del crudo, diseñar de forma teórica el sistema Alkali-Surfactante-Polimero acorde con las necesidades del proyecto y compatible con el crudo y suelo. Debido a los fuertes impactos, sobretodo medioambiental, se realizará una evaluación de impactos ambientales (apoyado con la Ley 21/2013), sociales y económicos. Por último, se desarrollará una planificación temporal, donde se incluye la distribución del trabajo y el tiempo dedicado al mismo, y presupuestaria. Con la gran demanda de energía que hay actualmente y con un crecimiento...

  10. Material properties of evolutionary diverse spider silks described by variation in a single structural parameter

    Madurga, Rodrigo; Plaza Baonza, Gustavo Ramon; Blackledge, Todd A; Guinea Tortuero, Gustavo Víctor; Elices Calafat, Manuel; Pérez Rigueiro, José
    Spider major ampullate gland silks (MAS) vary greatly in material properties among species but, this variation is shown here to be confined to evolutionary shifts along a single universal performance trajectory. This reveals an underlying design principle that is maintained across large changes in both spider ecology and silk chemistry. Persistence of this design principle becomes apparent after the material properties are defined relative to the true alignment parameter, which describes the orientation and stretching of the protein chains in the silk fiber. Our results show that the mechanical behavior of all Entelegynae major ampullate silk fibers, under any conditions,...

  11. Migración de productos de degradación de poli(ácido láctico) de envases a simulantes de alimentos. Estudio espectroscópico

    Alarcón Martínez, Ana Inés
    Cada día surgen nuevos e interesantes avances en la producción de polímeros enfocados a mejorar nuestra calidad de vida. Sin embargo, la excesiva explotación de los polímeros producidos en masa para envases desechables ha provocado que, en todo el mundo, la contaminación por plásticos se haya convertido en un grave problema. Desde que comenzó a abordarse el tema de la lucha contra el cambio climático, la reducción de las reservas de petróleo y la preocupación por la acumulación de residuos plásticos en océanos y suelos, se ha impulsado una reciente investigación sobre el desarrollo de nuevos polímeros obtenidos de fuentes...

  12. Software para el dimensionamiento de condensadores y evaporadores en bombas de calor aire/aire

    Fraile Valdés, Marta
    El control de la temperatura siempre ha sido muy importante a lo largo de la historia, y con el desarrollo de la industria y de la tecnología lo es aún más. Existen multitud de equipos que necesitan para trabajar adecuadamente una determinada temperatura del ambiente o un calentamiento o refrigeración de los fluidos con los que operan. Por ejemplo en la industria química es esencial mantener la temperatura constante en determinadas reacciones para obtener algunos productos. O en la industria alimenticia, en la cual es necesario refrigerar las sustancias o aplicar calor para que se produzca la transformación de unas...

  13. Persistence and variation in microstructural design during the evolution of spider silk

    Madurga, Rodrigo; Blackledge, Todd A; Perea, B.; Plaza Baonza, Gustavo Ramón; Riekel, Christian; Burghammer, Manfred; Elices, Margarita L.; Guinea Tortuero, Gustavo V.; Pérez Rigueiro, José
    The extraordinary mechanical performance of spider dragline silk is explained by its highly ordered microstructure and results from the sequences of its constituent proteins. This optimized microstructural organization simultaneously achieves high tensile strength and strain at breaking by taking advantage of weak molecular interactions. However, elucidating how the original design evolved over the 400 million year history of spider silk, and identifying the basic relationships between microstructural details and performance have proven difficult tasks. Here we show that the analysis of maximum supercontracted single spider silk fibers using X ray diffraction shows a complex picture of silk evolution where some...

  14. Levels and gas-particle partitioning of POPs in urban ambient air.

    Barbas Bernao, Beatriz; Torre, Adrián de la; Sanz, Paloma; Navarro, Irene; Artíñano, Begoña; Martínez, María Á.
    Air pollution continues to be a major health, environmental, and economic issue in Europe, because it leads to health problems, premature deaths and damage to ecosystems, crops and buildings1. Despite progress in reducing air pollution, certain pollutants such as particulate matter (PM) remain a significant threat. PM is a complex and heterogeneous mixture of inorganic and organic substances, and constitutes the greatest risk in terms to harm the human health, especially in urban areas where the majority of the European population lives. Persistent Organic Pollutants (POPs), and emerging pollutants as flame retardants, are some of the wide extent of dangerous...

  15. Fraccionamiento de contaminantes orgánicos persistentes en aire urbano de Madrid: fase gas y fase particulada.

    Barbas Bernao, Beatriz; Torre, Adrián de la; Sanz, Paloma; Navarro, Irene; Artíñano, Begoña; Martínez, María Á.
    En el presente trabajo se evaluó la presencia de algunos Contaminantes Orgánicos Persistentes (COP) en muestras de aire de la ciudad de Madrid (España), discriminando entre la fase gas (FG) y la materia particulada en suspensión (MPS). Para ello se utilizaron captadores activos de alto volumen (CAV) equipados con espumas de poliuretano y filtros de microfibra de vidrio. Los policlorobifenilos resultaron los contaminantes mayoritarios (104.6 ± 86.6 pg/Nm3, media ± desviación estándar), seguidos de polibromodifenil éteres (20.4 ± 11.6 pg/Nm3), declorane plus (0.8 ± 0.5 pg/Nm3) y finalmente policlorodibenzo-p-dioxinas y policlorodibenzofuranos (0.3 ± 0.1 pg/Nm3). Los resultados, en concordancia con...

  16. Envases activos para productos alimentarios: estudio de los sistemas autocalentables

    González Bautista, Raquel
    En las últimas décadas, uno de las mayores innovaciones desarrolladas en el área del empaquetado de comida ha sido el denominado “activo e inteligente” (A&I), basado en la interacción entre el alimento y la atmósfera que lo envuelve. El propósito del “empaquetado activo” es el aumento de la vida útil de la comida y el mantenimiento o la mejora de su calidad, mientras que el propósito del “empaquetado inteligente” es dar una indicación y una monitorización de la frescura de la comida. Los envases activos incluyen sistemas que absorben, eliminan o regulan sustancias como el oxígeno, radicales, etileno, agua y...

  17. Identifying ground-robot impedance to improve terrain adaptability in running robots

    Arévalo Martín, Juan Carlos; Sanz Merodio, Daniel; Cestari Soto, Manuel; García Armada, Elena
    To date, running robots are still outperformed by animals, but their dynamic behaviour can be described by the same model. This coincidence means that biomechanical studies can reveal much about the adaptability and energy efficiency of walking mechanisms. In particular, animals adjust their leg stiffness to negotiate terrains with different stiffnesses to keep the total leg-ground stiffness constant. In this work, we aim to provide one method to identify ground-robot impedance so that control can be applied to emulate the aforementioned animal behaviour. Experimental results of the method are presented, showing well-differentiated estimations on four different types of terrain. Additionally,...

  18. Crop row detection in maize for developing navigation algorithms under changing plant growth stages

    Reiser, David; Garrido Izard, Miguel; Vázquez Arellano, Manuel; Griepentrog, Hans W.; Paraforos, Dimitris S.
    To develop robust algorithms for agricultural navigation, different growth stages of the plants have to be considered. For fast validation and repeatable testing of algorithms, a dataset was recorded by a 4 wheeled robot, equipped with a frame of different sensors and was guided through maize rows. The robot position was simultaneously tracked by a total station, to get precise reference of the sensor data. The plant position and parameters were measured for comparing the sensor values. A horizontal laser scanner and corresponding total station data was recorded for 7 times over a period of 6 weeks. It was used...

  19. Dispersion of metals and arsenic from the tailings of an abandoned mine in Sierra of Madrid

    Sanchís Pérez, Inés; Pérez Esteban, Javier; Masaguer Rodríguez, Alberto; Moliner Aramendia, Ana María
    The extraction and processing of minerals produce significant environmental impacts that last long after mining operations have ended. Abandoned mines provide obvious sources of contamination by metals and arsenic in surrounding areas. These areas typically support sparse vegetation, so weather events, typical of Mediterranean environments such as heavy rains, can drag metals and metalloids, in a more or less available form for vegetation, as in solution and suspension to accumulate in lower lands. In this study, the area affected by a copper mine, abandoned early last century in the Sierra de Madrid, was sampled. Soil properties such as pH, EC,...

  20. Using Assembled 2D LiDAR Data for Single Plant Detection

    Reiser, David; Vázquez Arellano, Manuel; Garrido Izard, Miguel; Griepentrog, Hans W.; Paraforos, Dimitris S.
    A 2D laser scanner was mounted on the front of the small 4-wheel autonomous robot with differential steering, in an angle of 30 degrees pointing downwards. The machine was able to drive between maize rows and collect timestamped data simultaneously. The position of the vehicle was tracked by a highly precise total station. The data of the total station and the laser scanner was fused to generate a 3D point cloud. This 3D representation was used to search for single plant positions, what could later be used for additional applications like single plant treatment and precision weeding. First all points...

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