738 research outputs found

    Evoking the Mechanoreflex Using Static and Dynamic Approaches: The Influence of Free Radicals and Sex

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    Robots Liability: A Use Case and a Potential Solution

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    In this chapter, a system of distribution of responsibility for damages caused by robots is introduced, and its practical application on the results obtained in the real experiences at the University of Almería (Spain) is analyzed. The attribution of liability for damages produced by autonomous agents usually focuses the theoretical discussion on legal and ethical fields on robotics. The European Parliament adopted the report with recommendations to the Commission on Civil Law Rules on Robotics (2015/2103(INL)) in February 2017. This work includes the master guidelines that the European Commission should take into account to legislate this technology. In its attempt to attribute responsibility for damages caused by robots, the Committee considers that once responsible parties have been identified, their liability level should range, looking the robot’s learning capability and the knowledge learned from its owner. This work proposes the use of responsibility setting matrix as a mechanism to distribute liabilities between the robot, the manufacturer, and the owner, depending on the knowledge programmed by the manufacturer and the one acquired by the robot (through its learning ability and the adjustments made by the owner), that would distribute the responsibility for damages among the three agents involved

    Outstanding aspects on the use of spent FCC catalyst in binders

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    4 pages, 3 fiures, 7 tables.-- En: 1st Spanish National Conference on Advances in Materials Recycling and Eco – Energy Madrid, 12-13 November 2009.-- Editors: F. A. López, F. Puertas, F. J. Alguacil and A. Guerrero.FCC is a waste material from petrochemical plants which has interesting properties for preparing binders. FCC is lightly grey in color, and white FCC-portland cements with L*≥85 can be prepared. FCC reactivity is enhanced by grinding and it is attributed to pozzolanic reaction towards lime. Stratlingite is the main hydrated product from pozzolanic reaction, and CSH and CAH are also formed. Reactivity of FCC is high, and low curing temperature does not affect this contribution to strength in hardened mixtures. Additionally, high strength concrete can be easily prepared, and compressive strength greater 100MPa can be reached. Mixtures with low w/b ratio showed good behaviour in carbonation tests.Authors thank to Ministerio de Ciencia y Tecnología of Spain and FEDER the financial support of MAT 2001-2694 and BIA 2004-0052 projects.Peer reviewe

    Técnicas de biopsia para el diagnóstico de lesiones mamarias no palpables

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    Facing a non-palpable mammary lesion requiring a diagnostic biopsy, consideration must be given to the most suitable guiding method for obtaining the latter. Three methods are employed at present: stereotaxy (basically in cases of microcalcifications), echography (above all in the nodules), and magnetic resonance (for lesions not made visible through the previous systems). The next step is to select the most suitable biopsy technique. The most classical and reliable technique is the surgical biopsy with prior marking using a metallic harpoon, but, besides its high cost, it has the drawback of being an aggressive technique for the diagnosis of a benign pathology. Numerous systems of puncture have been developed as alternatives. Puncture with a fine needle is technically simple to carry out and can provide good results in the mammary nodules, but the existence of positive and negative false results has progressively limited its use. As an alternative, the systems of biopsy with a broad needle have made it possible to obtain multiple cylinders with a high diagnostic reliability, above all in the case of mammary nodules. However, their use in microcalcifications continues to show negative false results. The arrival of systems of vacuum-assisted biopsy has made it possible to obtain cylinders of greater quality, above all in cases of microcalcifications. Finally, the systems of percutaneous resection biopsy by means of cannulas with a diameter of 22 mm make it possible to completely extract lesions of a size below that of the cannula, with a reliability similar to that of the surgical biopsy

    Técnicas de imagen para la valoración del estado ganglionar axilar en el cáncer de mama

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    The axillary lymph node status is the most important prognostic factor in breast cancer, and the axillary dissection as the gold standar for staging. It requires radical surgery, which is accompanied by importants postoperaive problems. Axillary lymph nodes can be imaged with a wide variety of available diagnostic radiological test (ultrasonography, mammography, computed tomography and magnetic resonance imaging). In these anatomic imaging, the limph nodes whit metastatic disease appear dense, enlarged or spiculated. Difficulties arise, not in visualization of the axillary lymph nodes, but in reliably separating normal from those involved with metastatic disease. Radionucleide studies and positron emisión tomography provide biochemical information, but are limited by resolution constrains

    Study of Melamine-Formaldehyde/Phase Change Material Microcapsules for the Preparation of Polymer Films by Extrusion

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    n-Eicosane-melamine formaldehyde microcapsules of an average size of 1.1 µm and latent heat of fusion of 146.2 ± 5.3 J/g have been prepared. They have been characterized by scanning electron microscopy, FTIR spectroscopy, calorimetric techniques, and thermogravimetric analyses. Under processing conditions, the microcapsules apparently preserved their properties, also maintaining their n-eicosane loading and heat storage capacity under washing conditions (water with detergent at 60¿C). The microcapsules synthesis has been scaled up for the fabrication of functional films by extrusion. For that, polymer films containing 10 wt.% of microcapsules were prepared at a pilot plant level. In those films, even though a fraction of the n-eicosane loading was lost during the extrusion process, the microcapsules showed good compatibility within the polyamide. The percentage of PCM in the polyamide 6 films was estimated by TGA, verifying also the heat storage capacity predicted by DSC (2.6 ± 0.7 J/g). © 2022 by the authors. Licensee MDPI, Basel, Switzerland

    Función de apantallamiento de interferencia electromagnética de pastas de cemento con materiales carbonosos y cenizas volantes procesadas

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    The study described in this article explored the effect of adding different types of carbon materials (graphite powder and three types of carbon fibre), fly ash (with 5.6%, 15.9% and 24.3% Fe2O3), and a mix of both on electromagnetic interference (EMI) shielding in Portland cement pastes. The parameters studied included the type and aspect ratio of the carbonic material, composite material thickness, the frequency of the incident electromagnetic radiation and the percentage of the magnetic fraction in the fly ash. The findings showed that the polyacrylonitrile-based carbon fibres, which had the highest aspect ratio, provided more effective shielding than any of the other carbon materials studied. Shielding was more effective in thicker specimens and at higher radiation frequencies. Raising the magnetic fraction of the fly ash, in turn, also enhanced paste shielding performance. Finally, adding both carbon fibre and fly ash to the paste resulted in the most effective EMI shielding as a result of the synergies generated.En el presente trabajo se investiga la influencia de la adición de diferentes tipos de materiales carbonosos (polvo de grafito y 3 tipos de fibra de carbono), de una ceniza volante con diferentes contenidos de fase magnética (5,6%, 15,9% y 24,3% de Fe2O3) y de una mezcla de ambos, sobre la capacidad de apantallar interferencias electromagnéticas de pastas de cemento Pórtland. Entre los parámetros estudiados se encuentra: el tipo de material carbonoso, la relación de aspecto del material carbonoso, el espesor del material compuesto, la frecuencia de la radiación electromagnética incidente y el porcentaje de fracción magnética en la ceniza volante. Los resultados obtenidos indican que entre los materiales carbonosos estudiados son las fibras de carbono basadas en poliacrilonitrilo con una mayor relación de aspecto las que dan mejores resultados de apantallamiento. Al aumentar el espesor del material compuesto o la frecuencia de radiación también aumenta la eficacia del apantallamiento. En lo que respecta a la ceniza volante, el incremento de la fracción magnética de la ceniza incrementa el nivel de apantallamiento. No obstante, los resultados más eficaces se obtienen por la adición conjunta de fibras de carbono y ceniza volante debido a un efecto sinérgico

    A new geopolymeric binder from hydrated-carbonated cement

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    This paper evaluates the use of hydrated Portland cement as the raw material in the production of geopolymers. The silicon and aluminium oxides needed for the geopolymerization process were produced by the carbonation of hydrated Portland cement, which transforms CSH and CAH (Portland cement hydrates) into silica and alumina gels. Hydrated-carbonated Portland cement was alkali activated with a NaOH/waterglass solution. Pastes and mortars were prepared, and micro-structural and mechanical properties were analyzed. It has been noted that geopolymers are mechanically stable and yield compressive strength higher than 10 MPa when mortars are cured at 65 °C for 3 days. The results have shown that there are interesting possibilities for re-using the cement-rich fraction of construction and demolition waste. Alkaline activation of hydrated-carbonated Portland cement could be considered a low CO 2-emission binder. © 2012 Elsevier B.V. All rights reserved.Paya Bernabeu, JJ.; Borrachero Rosado, MV.; Monzó Balbuena, JM.; Soriano Martinez, L.; Mitsuuchi Tashima, M. (2012). A new geopolymeric binder from hydrated-carbonated cement. Materials Letters. 74:223-225. doi:10.1016/j.matlet.2012.01.132S2232257

    Tratamiento conservador del cáncer de mama: valoración de los resultados

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    Introducción: La asociación de cirugía limitada y radioterapia es el tratamiento de elección para un gran número de mujeres con cáncer de mama; no obstante esta opción terapéutica va asociada a un número no despreciable de recidivas sobre la mama tratada (1-1,5% por año de seguimiento). Material y Métodos: Se analizan 641 casos de mujeres con cáncer de mama, tratados mediante cirugía conservadora de la mama y radioterapia y seguidos durante una media de 50 meses. La técnica consistió preferentemente en la practica de una Resección Segmentaria de mama con vaciamiento axilar, al menos de los niveles I y II (excepto en los CIS a partir de 1997), complementada con la administración de Radioterapia (45-50 Gy sobre la mama y una sobreimpresión de 15-20 Gy). Resultados: La edad media fue de 52.3 años, con extremos en 21 y 82 años El tamaño medio tumoral fue pT: 1,7 cm y el 63,1% de los casos correspondieron a tumores pT1. En 41 casos no se realizó vaciamiento axilar (35 CIS y 6 pT1mic). En 4 casos existió afectación puntual de bordes (componente intraductal) que fueron sometidos a sobreimpresión radioterápica con 20Gy. Tras un seguimiento medio de 50 meses, el 91,4% están libres de enfermedad y en 12 casos (1,9%) se desconocía su estado. Se han producido 13 recidivas (2%) a nivel mamario (2 de ellas en un cuadrante distinto). Conclusiones: El estado de los bordes de resección en un factor fundamental en la cirugía conservadora del cáncer de mama. La resección del tumor debe ser suficientemente amplia e incluir el segmento mamario asiento del tumor, para asegurar un alto índice de control local, sin comprometer el resultado cosmético. El estudio histológico de los bordes de resección permite reducir significativamente la necesidad de una segunda cirugía.Introduction: Conservative surgery combined with radiotherapy is an effective treatment in many cases of breast cancer. Nevertheless this therapy is associated with a not inconsiderable number of recurrences in the remaining breast after excision (1-1.5% recurrences per year of follow-up). Material and Methods: We reviewed 641 cases of breast cancer (age average was 52.3 years (21-82) and tumour size average 1.7 cm, 3% corresponded to pT1 tumours) treated with conservative surgery combined with radiotherapy, average follow-up of 50 months. The technique consisted of segmentectomy and at least level I-II axilary dissection (excluding in situ carcinoma diagnosed since 1997, in which lymphadenectomy was not performed). Adjuvant radiotherapy was also indicated (giving a dose of 45-50 Gy to the breast, and another 15-20 Gy dose was given to tumour size). Results: In 41 cases lymphadenectomy was not performed (35 cases of Tis, and 6 pTmic). In 4 cases, 20 Gy radiotherapy was administered to the tumour excision site because of in situ carcinoma disease in the margins. During follow-up of 50 months, 91.4% of the patients were disease- free; in 12 cases we are not informed of the present status. 13 recurrences (2%) have been found, two of which were in a different quadrant. Conclusions: The status of the surgical margins is an important factor in the practice of conservative surgery. Tumour excision must be broad enough and must include the whole segment in which the tumour is located to obtain local control of the disease, maintaining an acceptable cosmetic appearance. The intraoperative study of specimen margins permits the reduction of cases in which a second operation is needed

    Alkali activated materials based on fluid catalytic cracking catalyst residue (FCC): Influence ofSiO2/Na2O and H2O/FCC ratio on mechanical strength and microstructure

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    Reuse of industrial and agricultural wastes as supplementary cementitious materials (SCMs) in concrete and mortar productions contribute to sustainable development. In this context, fluid catalytic cracking catalyst residue (spent FCC), a byproduct from the petroleum industry and petrol refineries, have been studied as SCM in blended Portland cement in the last years. Nevertheless, another environmental friendly alternative has been conducted in order to produce alternative binders with low CO2 emissions. The use of aluminosilicate materials in the production of alkali-activated materials (AAMs) is an on going research topic which can present low CO2 emissions associated. Hence, this paper studies some variables that can influence the production of AAM based on spent FCC. Specifically, the influence of SiO2/Na2O molar ratio and the H2O/spent FCC mass ratio on the mechanical strength and microstructure are assessed. Some instrumental techniques, such as SEM, XRD, pH and electrical conductivity measurements, and MIP are performed in order to assess the microstructure of formed alkali-activated binder. Alkali activated mortars with compressive strength up to 80 MPa can be formed after curing for 3 days at 65 C. The research demonstrates the potential of spent FCC to produce alkali-activated cements and the importance of SiO2/Na2O molar ratio and the H2O/spent FCC mass ratio in optimising properties and microstructure.Authors would like to thank to the Ministerio de Ciencia e Innovacion (MICINN) of the Spanish Government (BIA2011-26947) and to FEDER for funding, and also to the PROPG - UNESP "Universidade Estadual Paulista Julio de Mesquita Filho'', Brazil.Mitsuuchi Tashima, M.; Akasaki, JL.; Melges, J.; Soriano Martínez, L.; Monzó Balbuena, JM.; Paya Bernabeu, JJ.; Borrachero Rosado, MV. (2013). Alkali activated materials based on fluid catalytic cracking catalyst residue (FCC): Influence ofSiO2/Na2O and H2O/FCC ratio on mechanical strength and microstructure. Fuel. 108:833-839. https://doi.org/10.1016/j.fuel.2013.02.052S83383910
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