640 research outputs found

    Tripod-shaped penta (p-phenylene)s for the functionalization of silicon surfaces

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    In order to obtain nanostructured thin films to be used in biosensor devices, several chemical functionalization methods have been developed, such as Click chemistry or Suzuki carbon-carbon coupling reactions on surfaces.1 With the aim to control the orientation and spacing between grafted functional groups on a surface, tripodal oligo (p-phenylene)s have become the ideal anisotropic adsorbates due to their shape-persistent and self-standing characteristics.2 Here we report the synthesis and characterization of several tripod-shaped oligo(p-phenylene)s molecules with legs composed of five phenylene units, compounds 1, 2 and 3. In these structures, each leg is end-capped with an NH-Boc, NH2 and N3 group, respectively. The functional arm contains an acetylene group. The presented synthesis has as key step the Pd-catalyzed Suzuki cross-coupling reaction. In particular, a iodine derivative from the silicon core molecule reacts with the appropriate tetra(p-phenylene) boron derivative, thus generating the final tripod-shaped structure. The azide end-capped leg in 3 is specifically designed for its covalent incorporation on alkynyl terminated silicon surfaces by an easy and reproducible way. As a preliminary study, we present the alkynyl-functionalized silicon wafers nanostructuration with tripod 3 through the cooper catalyzed alkyne-azide cycloaddition (CuAAC) click reaction.Universidad de Málaga. Campus de Excelencia Internacional Andalucía Tech

    Caracterización de la agitación local y la respuesta oscilatoria de un buque mediante el uso de técnicas de visión artificial : aplicación al análisis de los umbrales operativos en líneas de atraque y amarre

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    El desarrollo de actividades de carga y descarga son parte de la esencia de la naturaleza funcional de un puerto, de las cuales derivan en gran medida los ingresos del mismo y la eficiencia de la cadena logística en su conjunto. Las oscilaciones en el interior de una dársena y en un línea de atraque disminuyen la calidad de la estancia de las embarcaciones en puerto, reducen el rendimiento de la estiba de los buques y solicitan y fatigan las estructuras y los cuerpos flotantes amarrados. Si los parámetros que definen la agitación local se aproximan a regiones de fallo 0 parada, el subsistema pierde rendimiento, fiabilidad y finalmente se paralizan las operaciones, produciéndose de este modo tiempos de inactividad. Estas paradas operativas conllevan pérdidas económicas para la terminal y, consecuentemente, para el puerto. Hoy día se dispone vastas redes de monitorización destinadas a la caracterización del medio físico en el entorno de los puertos. Paralelamente, las operaciones de manipulación de cargas en las terminales se están dirigiendo hacia modelos de automatización o semi automatización, que permiten no sólo la sistematización de procesos, sino también un profundo conocimiento del flujo de tareas. En este contexto hay un déficit de información sobre cómo afectan los diferentes forzadores del medio físico al rendimiento, la seguridad funcionalidad del proceso de manipulación de carga y descarga. Esto se debe en gran medida a la falta de registros dilatados en el tiempo que permitan correlacionar todos los aspectos mencionados de un modo particularizado para cada línea de atraque y amarre de un puerto. En esta tesis se desarrolla una metodología de vídeo monitorización no intrusiva y de bajo coste basada en la aplicación de técnicas "pixel tool' y la obtención de los parámetros extrínsecos de una observación monofocal. Con ello pretende poner en valor las infraestructuras de vídeo vigilancia de los puertos y de los laboratorios de experimentación a escala reducida, con el objeto de facilitar el estudio los umbrales operativos de las áreas de atraque y amarre. The development of loading and unloading activities is an essential part of he functional nature of a port, which derive largely from he same income and the efficiency of he supply chain as a whole. The oscillations inside a dock and a mooring line diminish he quality of the stay of vessels in port reducing the performance of the stowage of ship and asking and fatigued structures and moored floating bodies. If the parameters defining the local al agitation regions are close to areas of failure or shutdown, he subsystem looses performance, reliability and eventually paralyzes the operations, thereby producing downtime. These operational stops entail economic 1osses to the terminal and, consequently for the port. Today vast networks of monitoring, aimed at he characterization of the physical environment in the vicinity of he ports, are available. In parallel, the cargo handling operations at terminals are moving towards automation or semi-automation models that allow not only the systematization of processes, but also a deep understanding of he workflow. In this context, there is a lack of information about how the different forcing agents of the physical environment affect the performance and he functional safety of the loading and unloading process. This is due largely to the lack of spread-over-time records which would allow to correlate all aspects mentioned, specifically, for each berthing and mooring of a port. This thesis develops a methodology for non-intrusive and low cost monitoring video based on the application of "pixel tool" techniques and on obtaining the extrinsic parameters of a monofocal observation. It seeks an enhancement of the video monitoring infrastructure at ports and at experimental laboratories of reduced scale, in order to facilitate the study of operational thresholds berthing and mooring areas

    Analysis of the influence of the different variables involved in a damage progression probability model

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    Motivated by these difficulties, Castillo et al. (2012) made some suggestions on how to build consistent stochastic models avoiding the selection of easy to use mathematical functions, which were replaced by those resulting from a set of properties to be satisfied by the model

    Main determinants of efficiency and implications on banking concentration in the European Union

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    AbstractThis study aims to measure the main determinants influencing bank efficiency. We suggest that the bank efficiency ratio, obtained from the income statement, is positively related to the size of a bank in terms of total assets. However, we believe that such a relationship cannot be maintained for banks over a certain size. By the use of the regression analysis method, we analyze the link between bank efficiency and bank size, using a sample of 3952 banks in the European Union. Our results show that the efficiency ratio stops improving for banks with total assets over $25 billion. Previous literature, using different analysis techniques, does not reach an agreement on this point. Furthermore, our study identifies further variables which negatively affect the efficiency of banks, such as competition and lending diversification, or affect them positively, such as the wholesale funding ratio and income diversification. Our findings imply the need for different bank policies depending on total assets, in order to limit the size and activities of banks

    Study and characterization of modified silicon surfaces with organic molecules

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    Nanostructured thin films and subsequent biofunctionalization of silicon substrates are essential for the development of biosensors devices. The formation of organic monolayers on silicon substrates via Si-C bound allows specific interactions with biomolecules and presents several advantages like greater detection sensitivity and stability against hydrolytic cleavage.1 In this sense, to control the orientation and spacing between grafted functional moieties on the surface, tripodal oligo (p-phenylene)s have become ideal anisotropic adsorbates due to their shape-persistent and selfstanding characteristics.2 On the other hand, biomolecules such as tehtahydro[3]benzazepines are well-known to contain in their structure a phenetylamine skeleton, which is also present in dopaminergic receptors and drugs, therefore these molecules have a remarkable interest in medicinal chemistry. Here we report the synthesis and characterization of several tetrahydro[3]benzazepines and tripod-shaped oligo(p-phenylene)s which were suitably functionalized for its subsequent adsorption on silicon surfaces by hydrosilylation and/or CuAAc click reaction. X-ray photoemission spectroscopy (XPS) and atomic force microscopy (AFM) analysis were also carried out to reveal the presence of the grafted molecules on the different Si surfaces.Universidad de Málaga. Campus de Excelencia Internacional Andalucía Tech

    Combining Attention-based Multiple Instance Learning and Gaussian Processes for CT Hemorrhage Detection

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    This work has received funding from the European Union's Horizon 2020 research and innovation programme under the Marie Sklodowska Curie grant agreement No 860627 (CLARIFY Project) and also from the Spanish Ministry of Science and Innovation under project PID2019-105142RB-C22.Intracranial hemorrhage (ICH) is a life-threatening emer- gency with high rates of mortality and morbidity. Rapid and accurate de- tection of ICH is crucial for patients to get a timely treatment. In order to achieve the automatic diagnosis of ICH, most deep learning models rely on huge amounts of slice labels for training. Unfortunately, the manual annotation of CT slices by radiologists is time-consuming and costly. To diagnose ICH, in this work, we propose to use an attention-based multiple instance learning (Att-MIL) approach implemented through the combi- nation of an attention-based convolutional neural network (Att-CNN) and a variational Gaussian process for multiple instance learning (VGP- MIL). Only labels at scan-level are necessary for training. Our method (a) trains the model using scan labels and assigns each slice with an at- tention weight, which can be used to provide slice-level predictions, and (b) uses the VGPMIL model based on low-dimensional features extracted by the Att-CNN to obtain improved predictions both at slice and scan levels. To analyze the performance of the proposed approach, our model has been trained on 1150 scans from an RSNA dataset and evaluated on 490 scans from an external CQ500 dataset. Our method outperforms other methods using the same scan-level training and is able to achieve comparable or even better results than other methods relying on slice- level annotations.European Commission 860627Spanish Government PID2019-105142RB-C2

    Mechanical behavior of low density concrete mixtures with thermally expanded clay from the metropolitan area of Cúcuta: Comportamiento mecánico de mezclas de concreto de baja densidad con arcilla expandida térmicamente del área metropolitana de

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    In order to develop construction materials with greater efficiency and performance than conventional materials, mixtures of lightweight concrete (LWC) made from thermally expanded clay (TEC) have been generated. In this article we study the mechanical properties (equilibrium density, compressive strength) of the LWC mixtures produced with raw material from the metropolitan area of Cúcuta, contrasting their characteristics with conventional concrete (CC) mixtures. For this, the lightweight aggregates were developed by calcining clay pellets in a rotary kiln at a pilot plant scale at a temperature of 1050 ° C, generating an expansion of 1.60 times of its initial size. Following the methodology ACI 211.2-98 two concrete mixtures were designed: the first, with fine and coarse aggregate of TEC; and the second, with coarse aggregate of TEC and fine aggregate of sand. It was determined that the LWC mixture with the highest efficiency is the one that uses fine and coarse aggregate of TEC, since the density of the LWC decreased by 25% with respect to the density of the CC, maintaining the resistance to compression after 28 days Under the same conditions. In conclusion, LWC mixtures made from TEC with raw materials from the metropolitan area of Cúcuta have a lower equilibrium density and compressive strength similar to that of CC.In order to develop construction materials with greater efficiency and performance than conventional materials, mixtures of lightweight concrete (LWC) made from thermally expanded clay (TEC) have been generated. In this article we study the mechanical properties (equilibrium density, compressive strength) of the LWC mixtures produced with raw material from the metropolitan area of Cúcuta, contrasting their characteristics with conventional concrete (CC) mixtures. For this, the lightweight aggregates were developed by calcining clay pellets in a rotary kiln at a pilot plant scale at a temperature of 1050 ° C, generating an expansion of 1.60 times of its initial size. Following the methodology ACI 211.2-98 two concrete mixtures were designed: the first, with fine and coarse aggregate of TEC; and the second, with coarse aggregate of TEC and fine aggregate of sand. It was determined that the LWC mixture with the highest efficiency is the one that uses fine and coarse aggregate of TEC, since the density of the LWC decreased by 25% with respect to the density of the CC, maintaining the resistance to compression after 28 days Under the same conditions. In conclusion, LWC mixtures made from TEC with raw materials from the metropolitan area of Cúcuta have a lower equilibrium density and compressive strength similar to that of CC

    Mechanical behavior of low density concrete mixtures with thermally expanded clay from the metropolitan area of Cúcuta: Comportamiento mecánico de mezclas de concreto de baja densidad con arcilla expandida térmicamente del área metropolitana de

    Get PDF
    In order to develop construction materials with greater efficiency and performance than conventional materials, mixtures of lightweight concrete (LWC) made from thermally expanded clay (TEC) have been generated. In this article we study the mechanical properties (equilibrium density, compressive strength) of the LWC mixtures produced with raw material from the metropolitan area of Cúcuta, contrasting their characteristics with conventional concrete (CC) mixtures. For this, the lightweight aggregates were developed by calcining clay pellets in a rotary kiln at a pilot plant scale at a temperature of 1050 ° C, generating an expansion of 1.60 times of its initial size. Following the methodology ACI 211.2-98 two concrete mixtures were designed: the first, with fine and coarse aggregate of TEC; and the second, with coarse aggregate of TEC and fine aggregate of sand. It was determined that the LWC mixture with the highest efficiency is the one that uses fine and coarse aggregate of TEC, since the density of the LWC decreased by 25% with respect to the density of the CC, maintaining the resistance to compression after 28 days Under the same conditions. In conclusion, LWC mixtures made from TEC with raw materials from the metropolitan area of Cúcuta have a lower equilibrium density and compressive strength similar to that of CC.In order to develop construction materials with greater efficiency and performance than conventional materials, mixtures of lightweight concrete (LWC) made from thermally expanded clay (TEC) have been generated. In this article we study the mechanical properties (equilibrium density, compressive strength) of the LWC mixtures produced with raw material from the metropolitan area of Cúcuta, contrasting their characteristics with conventional concrete (CC) mixtures. For this, the lightweight aggregates were developed by calcining clay pellets in a rotary kiln at a pilot plant scale at a temperature of 1050 ° C, generating an expansion of 1.60 times of its initial size. Following the methodology ACI 211.2-98 two concrete mixtures were designed: the first, with fine and coarse aggregate of TEC; and the second, with coarse aggregate of TEC and fine aggregate of sand. It was determined that the LWC mixture with the highest efficiency is the one that uses fine and coarse aggregate of TEC, since the density of the LWC decreased by 25% with respect to the density of the CC, maintaining the resistance to compression after 28 days Under the same conditions. In conclusion, LWC mixtures made from TEC with raw materials from the metropolitan area of Cúcuta have a lower equilibrium density and compressive strength similar to that of CC

    Efecto de la aplicación de un progestágeno y dos tipos de destete sobre la respuesta a celo y dertilidad en vacas Cebuinas (Bos indicus) en el Trópico Húmedo.

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    Proyecto de Investigación. Instituto Tecnológico de Costa Rica. Escuela de Ingeniería en Agronomía. Centro de Investigación y Desarrollo en Agricultura Sostenible pata el Trópico Húmedo (CIDASTH), 2004Para determinar el efecto de la aplicación de un progestágeno sintético y dos tipos de destete sobre la respuesta a la sincronización, la actividad folicular y la tasa de preñez, se utilizaron 55 hembras cebuinas (multíparas) todas en lactación, con un promedio de 67 días posparto. Se les aplicó un implante auricular de Norgestomet más Valerato de Estradiol1 [1], el cual fue retirado nueve días después. Al momento de retirar el implante las hembras se dividieron en tres grupos, el A (n=20) en el cual las madres estaban separadas de sus crías, pero tenían contacto visual y olfativo con ellas (CCV); el B (n=20) donde la cría también fue separada y la madre no tenía contacto visual con ella (SCV); el C (n=15), donde las crías no fueron separadas (SSC). En estos grupos se mantuvieron dos toros con experiencia y evaluación reproductiva previa; las vacas fueron observadas por 72 horas consecutivas, para determinar conductas estrales. Durante el periodo experimental, se realizaron ultrasonografías y determinaciones del nivel de progesterona (P4) plasmática (dos veces por semana) por medio de sangrados. Antes de iniciar el periodo de empadre, la proporción de animales ciclando fue de 10 % para el grupo CCV; de 20% para el SCV y de 33,3% para el lote SSC. En la etapa de empadre, el nivel de animales ciclando se incrementó a 85% en el CCV; a 70% en el SCV y a 80% en el SSC. Los resultados indican que el 85,4% de los animales mostraron conducta de celo, como producto de la sincronización, pero solo el 69.1% ovularon. La duración del celo osciló entre 6,5 y 7,2 horas y las vacas recibieron entre 1,6 y 2,5 montas por hora en celo. Luego de retirar el implante el grupo SSC fue el que con más anticipación manifestó conducta estral (40,5 ± 10,4 h), seguido del CCV (44,6 ± 8,3 h) y del SCV (45,4 ±6,5 h), sin embargo no se estableció diferencias entre los grupos (p>0.05). La tasa de gestación global fue del 60%, resultando ser de 70 % para el grupo CCV; de 55% para el SCV y de 53,3% para el SSC, no se detectaron diferencias entre grupos (p>0,05). La mejor respuesta reproductiva se produjo en los animales sometidos a la separación de la cría con contacto visual (CCV), ya que estas vacas tienden a reiniciar la actividad ovárica más rápido, por lo que tienen oportunidad de quedar gestantes lo más pronto posible, después de la intervención. Se concluye que el tratamiento sincronizador es efectivo para inducir las vacas a mostrar conducta de celo, pero no lo es para llevarlas a ovular y preñarse; además la presencia de la cría no influye en los resultados obtenidos, luego de un tratamiento sincronizador.Instituto Tecnológico de Costa Rica

    Metástasis en hueso maxilar superior de adenocarcinoma de esófago: presentación de un caso clínico

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    Las metástasis en cavidad oral son lesiones raras que representan aproximadamente el 1% de todas las neoplasias malignas de cavidad oral. Las metástasis orales se localizan en un 80-90% en mandíbula, siendo mas raras en maxilar superior. Las metástasis en tejidos blandos de boca son raras, y es encía donde con mayor frecuencia se localizan las metástasis en tejidos blandos en boca. Los tumores primarios que metastatizan a boca son los más frecuentes pulmón, mama y riñón. Las metástasis en cavidad oral es como consecuencia de una diseminación a distancia de la enfermedad e indica un mal pronóstico, con una supervivencia corta. Aquí presentamos un caso clínico de un paciente diagnosticado de adenocarcinoma de esófago que presentó metastasis en hueso maxilar superior izquierdo.Metastases in the oral cavity are rare lesions which represent approximately 1% of all malignant neoplasms in the oral cavity. Oral metastases are located in the mandible 80-90% on average, the maxilla location being rarer. Metastases in mouth soft tissue are also rare, and within these it is on the gums where they more frequently occur. Primary tumours which metastasize to mouth are most commonly: lung, breast and kidney. Oral cavity metastases appear as a result of distant disease spreading and show wrong prognosis, with short survival. Here we present a clinical case of a patient diagnosed with esophagus adenocarcinoma which presented metastasis in upper-left maxillary bone
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