Caractérisation et évaluation des fibres de grains d'Asclépias Syriaca pour le développement d'isolants thermiques durables et le renforcement de matrices thermodurcissables

Abstract: The seed fibers or comas of Asclepias Syriaca, also known as milkweed floss, distinguish themselves from other natural fibers due to their gloss, softness, and hollow structure. Their abundance and unique microstructure suggest that these fibers could serve as sustainable and lightweight materials for various applications, including clothing, construction, thermal insulation, polymer reinforcement, water treatment, and oil absorption. With these potential applications in mind, this research study aimed to characterize and understand the properties of milkweed floss, as well as explore its prospective uses as a sustainable material for developing thermo-acoustic insulation systems and lightweight reinforced thermosetting matrices. To fully understand the advantages and potential applications of milkweed floss in insulation and polymer reinforcement, the first part of the project was focused on evaluating the microstructure, thermo-acoustic insulating properties, and mechanical and thermal resistances of the fibers. Additionally, a portion of the fibers was treated with acetone, and their properties were measured to analyze the effect of this treatment. Milkweed floss exhibited an average elastic modulus of 3.0 GPa, a thermal resistance comparable to that of other natural fibers, and superior thermo-acoustic insulation capacity than a traditional insulator such as expanded polystyrene. It was observed that the acetone treatment had no impact on the microstructure or acoustic insulation capacity of the fibers. The acetone treatment improved the thermal resistance and thermal conductivity of the fibers but decreased their elastic modulus. The second part of the project comprised the study of the combined effect of temperature, relative humidity, and fiber content on the specific heat capacity of milkweed floss, as well as the thermal conductivity and thermal diffusivity of nonwoven mats made of milkweed floss. The specific heat capacity of milkweed and thermal conductivity of the nonwovens increased with temperature. The thermal conductivity and thermal diffusivity of the nonwovens displayed significant variations only at relative humidity levels above 30%. Additionally, the thermal diffusivity and thermal conductivity decreased as the fiber content in the nonwovens increased. The optimal balance between good insulation properties and fiber consumption was achieved using nonwoven mats with a fiber content ranging from 20 to 25 kg/m3. In the third and final section of the project, native and acetone-treated milkweed floss were used to produce milkweed floss-reinforced epoxy composites. The microstructure, thermal conductivity, and thermos-mechanical behavior of the composites were analyzed to assess the reinforcing effect of milkweed floss. It was found that the composites reinforced with native or acetone-treated milkweed floss were 7.4% and 10.3% lighter than the epoxy resin alone, respectively. The specific elastic modulus of the resin increased by 9.6% and 20.1% with the addition of native or acetone-treated fibers, respectively. The thermal conductivity of the epoxy decreased by 7.8% and 15.6% with the use of native and acetone-treated fibers, respectively. The results of this study demonstrated several technical advantages of using milkweed floss as a sustainable and lightweight option for thermal insulation and polymer reinforcement.Les fibres de graines ou comas d'Asclepias Syriaca, aussi connues sous le nom de soie d'asclépiade, se distinguent des autres fibres naturelles par leur douceur et leur structure creuse. Leur abondance et leur microstructure unique suggèrent que ces fibres pourraient être utilisées comme matériaux durables et légers pour diverses applications, notamment dans l'industrie textile, la construction, l'isolation thermique, le renforcement de polymères, le traitement de l'eau et l'absorption d'huile. Cette étude visait à caractériser et comprendre les propriétés des fibres d'asclépiade, ainsi qu'à explorer leurs utilisations potentielles en tant que matériau durable pour le développement de systèmes d'isolation thermo-acoustique et de renforcement léger pour des matrices thermodurcissables. Pour comprendre les avantages et les applications potentielles de la soie d'asclépiade dans l'isolation et le renforcement de polymères, la première partie de ce projet s'est concentrée sur l'évaluation de la microstructure, des propriétés d'isolation thermo-acoustique, ainsi que des résistances mécaniques et thermiques des fibres d’asclépias. Une partie des fibres a été traitée avec de l'acétone, et leurs propriétés ont été mesurées afin de comprendre l'effet de ce traitement. Les résultats de la première étude ont montré que la soie d'asclépiade présente un module d'élasticité moyen de 3,0 GPa, une résistance thermique comparable à celle d'autres fibres naturelles, et une capacité d'isolation thermo-acoustique supérieure à celle d'un isolant traditionnel tel que le polystyrène expansé. Il a été observé que le traitement à l'acétone n'avait aucun impact sur la microstructure ou la capacité d'isolation acoustique des fibres. Le traitement à l'acétone a amélioré la résistance thermique et la conductivité thermique des fibres, mais a diminué leur module d'élasticité. La deuxième partie du projet a porté sur l'étude de l'effet combiné de la température, de l'humidité relative et de la teneur en fibres sur la capacité calorifique spécifique de la soie d'asclépiade, ainsi que sur la conductivité thermique et la diffusivité thermique des mats non tissés composées de soie d'asclépiade. La capacité calorifique spécifique de la soie d'asclépiade et la conductivité thermique des mats non tissés augmentaient avec la température. La conductivité thermique et la diffusivité thermique des non tissés présentaient uniquement des variations significatives à des niveaux d'humidité relative supérieurs à 30 %. De plus, la diffusivité thermique et la conductivité thermique diminuaient avec l'augmentation de la teneur en fibres dans les non tissées. Un équilibre optimal entre de bonnes propriétés d'isolation et une consommation de fibres a été atteint en utilisant des mats non tissés avec une teneur en fibres comprise entre 20 et 25 kg/m3. Dans la troisième partie du projet, des fibres d'asclépiade naturelles et traitées à l'acétone ont été utilisées comme renfort pour des composites époxy. La microstructure, la conductivité thermique et le comportement thermomécanique des composites ont été analysés pour comprendre l'effet de renforcement de la soie d'asclépiade sur la résine époxy. Il a été observé que les composites renforcés par des fibres d'asclépiade naturelles ou traitées à l'acétone étaient respectivement 7,4 % et 10,3 % plus légers que la résine époxy seule. Le module élastique spécifique de la résine a augmenté de 9,6 % et 20,1 % avec l'ajout de fibres naturelles ou traitées à l'acétone, respectivement. La conductivité thermique de l'époxy a diminué de 7,8 % et 15,6 % avec l'utilisation de fibres naturelles et traitées à l'acétone, respectivement. Les résultats de cette étude ont démontré plusieurs avantages techniques de l'utilisation de la soie d'asclépiade comme une option durable et légère pour l'isolation thermique et le renforcement de polymères thermodurcissables

The hematopoietic stem-cell niche in health and leukemia

Research in the last decade has shown that hematopoietic stem cells (HSCs) interact with and are modulated by a complex multicellular microenvironment in the bone marrow, which includes both the HSC progeny and multiple non-hematopoietic cell types. Intense work is gradually throwing light on the composition of the HSC niche and the molecular cues exchanged between its components, which has implications for HSC production, maintenance and expansion. In addition, it has become apparent that bidirectional interactions between leukemic cells and their niche play a previously unrecognized role in the initiation and development of hematological malignancies. Consequently, targeting of the malignant niche holds considerable promise for more specific antileukemic therapies. Here we summarize the latest insights into HSC niche biology and recent work showing multiple connections between hematological malignancy and alterations in the bone marrow microenvironment.We thank members of the SM-F group for helpful discussions. This work was supported by core support grants from the Wellcome Trust and MRC to the Cambridge Stem Cell Institute, the Spanish Ministry of Economy and Competitiveness (SAF-2011-30308), Pro-CNIC Foundation, Severo Ochoa Center of Excellence award SEV-2015-0505 to CNIC, TerCel (Spanish Cell Therapy Network), Ramon y Cajal Program grants RYC-2011-09726 to AS-A and RYC-2009-04703 to SM-F), Marie Curie Career Integration Program grants (FP7-PEOPLE-2011-RG-294262/294096) to AS-A and SM-F; and a ConSEPOC-Comunidad de Madrid grant (S2010/BMD-2542) and Horizon2020 (ERC-2014-CoG-64765 grant to SM-F. This research was partly funded by a European Hematology Association Research Fellowship awarded to AS-A and an International Early Career Scientist Grant from the Howard Hughes Medical Institute to SM-F.S

Major requirements for building Smart Homes in Smart Cities based on Internet of Things technologies

The recent boom in the Internet of Things (IoT) will turn Smart Cities and Smart Homes (SH) from hype to reality. SH is the major building block for Smart Cities and have long been a dream for decades, hobbyists in the late 1970s made Home Automation (HA) possible when personal computers started invading home spaces. While SH can share most of the IoT technologies, there are unique characteristics that make SH special. From the result of a recent research survey on SH and IoT technologies, this paper defines the major requirements for building SH. Seven unique requirement recommendations are defined and classified according to the specific quality of the SH building blocks

Variabilidad de la colección nuclear española de judía para compuestos vinculados con el valor nutricional y sensorial

The common bean (Phaseolus vulgaris L.) is one of the most important legumes worldwide because of its high proportion of protein, dietary fibre, minerals and vitamins. However, genetic improvement is necessary to obtain new varieties with higher yields, more resistant to environmental changes and improved nutritional and sensory qualities, which can meet the needs and demands of consumers. To make this improvement possible, gene banks have spent decades collecting plant genetic resources but devoting little effort to characterization, which would undoubtedly encourage their use by plant breeders. This project aims: i) to characterize the Spanish core collection of beans (Phaseolus vulgaris L.) from the chemical point of view, describing the variability existing for compounds present in the seed-coat and cotyledon related to sensory and nutritional value, and ii) to identify valuable accessions from their nutritional value or high content of molecules linked to sensory characteristics. The chemical evaluation of accessions of the core collection was performed by Near Infrared (NIR) spectroscopy methodology. High genetic variability has been observed in the chemical characteristics of the seed-coat and somewhat lower in the cotyledon. Correlations of chemical characters with each other show high values: ash vs. calcium and apparent amylose vs. amylose, with a high negative correlation between protein and starch. Meanwhile, sensory values correlated with chemical properties show high antagonistic values between floury texture vs. ash, calcium and uronic acids; while they show positive correlations, with high values, between shininess vs. ash, calcium, dietary fibre and uronic acids. The Principal Component Analysis shows great dispersion of accessions in the plane determined by the first two axes, which account for over 50% of the total variation. This is positive from the viewpoint of the breeder since there are few "impossible" combinations between traits, or in other words, there are few major genetic correlations between the traits studied. Finally, we have identified several accessions that stand out for their high protein, magnesium, starch or dietary fibre content, although they suffer deficiencies of other components. Keywords: Spanish core collection, common bean, chemical composition, cotyledon, seed-coat, nutritional value, characterization.La mongeta seca (Phaseolus Vulgaris L.) és una de les lleguminoses més importants a escala mundial degut a la seva elevada proporció de proteïnes, fibra dietètica, minerals i vitamines. No obstant això és necessària la seva millora genètica per obtenir noves varietats amb elevats rendiments, més resistents a canvis ambientals i qualitats nutricionals i sensorials millorades, que puguin satisfer les necessitats i exigències dels consumidors. Per poder fer possible aquesta millora, els bancs de germoplasma porten dècades recopilant recursos fitogenètics però dedicant poc esforç a la caracterització, que indubtablement afavoriria el seu ús per part dels fito-milloradors. En aquest projecte es pretén: i) caracteritzar la col·lecció nuclear espanyola de mongetes (Phaseolus vulgaris L.) des del punt de vista químic, descrivint la variabilitat que existeix per als compostos presents en la pell i el cotiledó vinculats al valor sensorial i nutricional, i ii) identificar entrades valuoses pel seu valor nutricional o pel seu elevat contingut en molècules vinculades a característiques sensorials. L'avaluació química de les accessions de la col·lecció nuclear s'ha efectuat mitjançant la metodologia de l'Espectroscòpia en l'Infraroig Proper (NIR). S'ha observat elevada variabilitat genètica en els caràcters químics de la pell i més baix en els de cotiledó. Les correlacions de caràcters químics entre si, mostren valors elevats: cendres vs calci i amilosa aparent vs la amilosa, i una elevada correlació negativa entre proteïna i midó. D'altra banda, els valors sensorials correlacionats amb els caràcters químics, mostren valors elevats antagònics entre la farinositat vs cendres, calci i els àcids urònics; contràriament presenten correlacions positives, amb valors elevats, entre la lluentor vs cendres, calci, fibra dietètica i àcids urònics. L'Anàlisi de Components Principals mostra una gran dispersió de les accessions en el plànol determinat pels dos primers eixos, que expliquen més del 50% de la variació total. Això és favorable des del punt de vista del millorador donat que existeixen poques combinacions "impossibles" entre caràcters, o el que és el mateix, existeixen poques correlacions genètiques importants entre els caràcters estudiats. Finalment, s'han identificat diverses entrades que destaquen pels seus elevats continguts en proteïna, magnesi, midó o fibra dietètica, pencara que patint deficiències d'altres components. Paraules clau: Col·lecció nuclear espanyola, mongeta comuna, composició química, cotiledó, pell, valor nutricional, caracterització.La judía común (Phaseolus Vulgaris L.) es una de las leguminosas más importantes a nivel mundial debido a su elevada proporción de proteínas, fibra dietética, minerales y vitaminas. Sin embargo es necesaria su mejora genética para obtener nuevas variedades con elevados rendimientos, más resistentes a cambios ambientales y cualidades nutricionales y sensoriales mejoradas, que puedan satisfacer las necesidades y exigencias de los consumidores. Para poder hacer posible esta mejora, los bancos de germoplasma llevan décadas recopilando recursos fitogenéticos pero dedicando poco esfuerzo a la caracterización, que indudablemente favorecería su uso por parte de los fito-mejoradores. En este proyecto se pretende: i) caracterizar la colección nuclear española de judías (Phaseolus vulgaris L.) desde el punto de vista químico, describiendo la variabilidad que existe para los compuestos presentes en la piel y el cotiledón vinculados al valor sensorial y nutricional, y ii) identificar entradas valiosas por su valor nutricional o por su elevado contenido en moléculas vinculadas a características sensoriales. La evaluación química de las accesiones de la colección nuclear se ha efectuado mediante la metodología de la Espectroscopia en el Infrarrojo Cercano (NIR). Se ha observado elevada variabilidad genética en los caracteres químicos de la piel y algo menor en los del cotiledón. Las correlaciones de caracteres químicos entre sí, muestran valores elevados: cenizas vs calcio y amilosa aparente vs la amilosa, y una elevada correlación negativa entre proteína y almidón. Por otra parte, los valores sensoriales correlacionados con los caracteres químicos, muestran valores elevados antagónicos entre la harinosidad vs cenizas, calcio y los ácidos urónicos; contrariamente presentan correlaciones positivas, con valores elevados, entre el brillo vs cenizas, calcio, fibra dietética y ácidos urónicos. El Análisis de Componentes Principales muestra una gran dispersión de las accesiones en el plano determinado por los dos primeros ejes, que explican más del 50% de la variación total. Ello es favorable desde el punto de vista del mejorador puesto que existen pocas combinaciones "imposibles" entre caracteres, o lo que es lo mismo, existen pocas correlaciones genéticas importantes entre los caracteres estudiados. Finalmente, se han identificado varias entradas que destacan por sus altos contenidos en proteína, magnesio, almidón o fibra dietética, pero sufriendo deficiencias de otros componentes. Palabras clave: Colección nuclear española, judía común, composición química, cotiledón, piel, valor nutricional, caracterización

Modelación y simulación numérica de pruebas de trazadores en flujo bipolar vertical

Uno de los objetivos principales en las empresas petroleras es la exploración y explotación de yacimientos optimizando la producción de hidrocarburos. Para lograr esto es indispensable contar ante todo con una caracterización estática y dinámica adecuada del yacimiento, lo cual en general requiere de inversiones importantes en tiempo y dinero. Las técnicas de caracterización dinámica más importantes son las pruebas de presión y las pruebas de trazadores. Estas últimas son generalmente tardadas pues involucran tiempos largos de transito del trazador entre el pozo de inyección y los pozos productores, sin embargo, dan información contundente de los canales más importantes de flujo entre pozos. Las pruebas de trazadores pueden adicionalmente dar información de propiedades de la formación, como porosidad, saturación residual de aceite, espesor de la capa productora, dispersividad, etc. Las pruebas de trazadores de inyección-extracción en un solo pozo son atractivas pues dan información rápida de las propiedades de la formación en la zona cercana al pozo. En esta misma dirección, las pruebas de trazadores de un solo pozo tipo dipolo vertical, originalmente pensadas para acuíferos, empiezan a ser investigadas por su potencial también para caracterización dinámica de yacimientos petroleros. En esta tesis se hace el planteamiento de un modelo para analizar el potencial de una prueba de dipolo vertical en determinar características de las capas presentes regularmente en yacimientos areno arcillosos. En la tesis se presenta un modelo matemático para describir el comportamiento de un trazador en un yacimiento petrolero tipo areno-arcilloso. El trazador es introducido dentro del flujo monofásico tipo dipolo vertical estacionario establecido en un pozo para ser monitoreado en un intervalo de tiempo [0, T] para determinar algunas propiedades del yacimiento. Para analizar la dinámica del trazador en flujo bipolar vertical se considera un pozo con dos perforaciones (zona de disparos) a diferentes alturas. En la primera perforación se inyecta un fluido y se extrae en la segunda perforación generándose un flujo bipolar vertical que ser ‘a el medio de transporte del trazador. El problema se describe en tres partes Modelo A: Calculo de la presión del fluido, Modelo B: Evaluación del campo de velocidades del flujo bipolar vertical, Modelo C: Calculo de la dinámica de la concentración de trazador. En este trabajo se describe la modelación maten ática de cada uno de los modelos mencionados y se resuelve numéricamente empleando la técnica de elemento finito. El yacimiento considerado está compuesto de capas horizontales con diferentes espesores y valores de permeabilidad y porosidad. Finalmente se presentan los resultados numéricos del problema y se hace un análisis de resultados. Se encuentra que en general hay poca sensibilidad de la curva de surgencia de trazadores al espesor y propiedades de las capas, esto es debido a que la curva de surgencia es un reflejo del efecto integrado del medio poroso. En el análisis de resultados la obtención de información relevante del yacimiento se torna un problema complejo, es necesario involucrar información adicional complementaria de otras fuentes que reduzca la cantidad de parámetros de ajuste

Dictionary memory based software architecture for distributed bluetooth low energy host controllers enabling high coverage in consumer residential healthcare environments

Technology has been seen as a possible solution to the increasing costs of healthcare and the globally aging population. It is known that many elderly people prefer to stay in their homes for as long as possible and remote monitoring can be a solution, but often such systems lack useful information or are prohibitive due to cost, ease of use/deployment and wireless coverage. This work presents a novel gateway software architecture based on threads being managed by dictionary memory. The architecture has been deployed in a distributed interconnected set of low-cost consumer grade gateway devices using Bluetooth Low Energy (BLE) that are positioned around the home. The gateway devices can then be used to listen, monitor or connect to BLE based healthcare sensors to continually reveal information about the user with full residential coverage. A further novelty of this work is the ability to maintain handover connections between many sensors and many gateways as a user moves throughout their home, thus the gateways can route information to/from sensors across the consumer’s home network. The system has been tested in an experimental house and is now poised to be initially deployed to 100 homes for residential healthcare monitoring before any public mass consumer deployment

European cities in globalization: a comparative analysis based on the location strategies of advanced producer services

Today there is a key question that lurks behind any consideration of Europe and its cities: is this foundation core zone of the modern world-system showing symptoms of dropping out of the contemporary core zone? It certainly appears that in the period of crises since 2008, Europe has been falling behind other major world-regions. Dubbed the “austerity region” of the world, such an interpretation sees Europe as the first part of the world-economy core to be subject to what are effectively structural adjustment programmes, largely self-imposed but still resulting in a process of peripheralization. Although uneven in impact, this is clearly a result of Europe’s states failing to adequately manage and regulate the economic activities within their territories. However it is far too soon to say whether such a monumental global economic shift is happening but we can investigate the current unevenness of economic globalization amongst European states. We compare three of these states that represent different degrees of potential peripheralization: Spain showing the stronger symptoms, Germany with least symptoms, and Britain somewhere in between. Our study is based upon an original analysis of advanced producer services that combines comparisons between countries and relations between cities

Citizens as Sensors for Crisis Event: Sensor Web Enablement for Volunteered Geographic Information

A set of developments within the field of geosensors is to engage citizens to act as sensors, thus providing so-called Volunteered Geographic Information (VGI). There is a long tradition of non specialists contributing to the collection of geo-referenced information. Furthermore thanks to recent convergence of greater access to broadband connections, the availability of Global Positioning Systems at affordable prices, and more participative forms of interaction on the Web (Web 2.0) vast numbers of individuals are able to create and share geographic information. The potential of up to 6 billion human sensors to monitor the state of the environment, validate global models with local knowledge, contribute to crisis situations awareness and provide information that only humans can capture (e.g. emotions and perceptions like fear of crime) is vast and has yet to be fully exploited. However, integrating VGI into Spatial Data Infrastructures (SDI) is a major challenge, as it is often regarded as insufficiently structured, documented or validated according to scientific standards. Early instances of SDIs used to have limited ability to manage and process geosensor-based data (beyond remotely sensed imagery snapshots), which tend to arrive in continuous streams of real-time information. The current works on standards for Sensor Web Enablement (SWE) aim to fill this gap. This paper shows how such SWE standards can be applied to VGI, thus converting it in a timely, cost-effective and valuable source of information for SDIs. By doing so, we extend previous works describing a workflow for VGI integration into SDI and further advance an initial set of VGI Sensing and event detection techniques. In particular, an example of how such VGI Sensing techniques can support crisis information system is provided.JRC.DDG.H.6-Spatial data infrastructure

A conceptual view at microtubule plus end dynamics in neuronal axons

AbstractAxons are the cable-like protrusions of neurons which wire up the nervous system. Polar bundles of microtubules (MTs) constitute their structural backbones and are highways for life-sustaining transport between proximal cell bodies and distal synapses. Any morphogenetic changes of axons during development, plastic rearrangement, regeneration or degeneration depend on dynamic changes of these MT bundles. A key mechanism for implementing such changes is the coordinated polymerisation and depolymerisation at the plus ends of MTs within these bundles. To gain an understanding of how such regulation can be achieved at the cellular level, we provide here an integrated overview of the extensive knowledge we have about the molecular mechanisms regulating MT de/polymerisation. We first summarise insights gained from work in vitro, then describe the machinery which supplies the essential tubulin building blocks, the protein complexes associating with MT plus ends, and MT shaft-based mechanisms that influence plus end dynamics. We briefly summarise the contribution of MT plus end dynamics to important cellular functions in axons, and conclude by discussing the challenges and potential strategies of integrating the existing molecular knowledge into conceptual understanding at the level of axons