1,823 research outputs found

    Lessons learned about the diagnosis of pathologies in concrete dams: 30 years of research and practice

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    Studies on the diagnosis of pathologies of concrete dams are a valuable reference for professionals managing such assets. However, detailed information is rarely reported in the literature. This paper compiles the most important lessons learned during 30 years of practical experience in this area. The diagnostic procedure is illustrated through 4 of the most interesting dams analysed and monitored by the authors. All were subjected to a first stage that included inspection and analysis of historical documentation, leading to the proposal of a diagnose hypothesis. This was followed by a second stage that included an experimental programme with laboratory tests and, in some cases, numerical simulations to confirm or reject the hypothesis. The analysis of the information shows different pathologies and provide a wide spectrum of boundary conditions, symptoms and diagnoses (from internal sulphate attack and alkali-aggregate reaction to soil-structure interaction)

    A unified scenario for the origin of spiral and elliptical galaxy structural scaling laws

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    Elliptical (E) and spiral (S) galaxies follow tight, but different, scaling laws that link their stellar masses, radii, and characteristic velocities. Mass and velocity, for example, scale tightly in spirals with little dependence on galaxy radius (the 'Tully-Fisher relation'; TFR). On the other hand, ellipticals appear to trace a 2D surface in size-mass-velocity space (the 'Fundamental Plane'; FP). Over the years, a number of studies have attempted to understand these empirical relations, usually in terms of variations of the virial theorem for E galaxies and in terms of the scaling relations of dark matter halos for spirals. We use Lambda cold dark matter (ΛCDM) cosmological hydrodynamical simulations to show that the scaling relations of both ellipticals and spirals arise as the result of (i) a tight galaxy mass-dark halo mass relation and (ii) the self-similar mass profile of cold dark matter halos. In this interpretation, E and S galaxies of a given stellar mass inhabit halos of similar masses, and their different scaling laws result from the varying amounts of dark matter enclosed within their luminous radii. This scenario suggests a new galaxy distance indicator applicable to galaxies of all morphologies and provides simple and intuitive explanations for long-standing puzzles, such as why the TFR is independent of surface brightness, or what causes the 'tilt' in the FP. Our results provide strong support for the predictions of ΛCDM in the strongly non-linear regime, as well as guidance for further improvements to cosmological simulations of galaxy formation.Fil: Ferrero, Santiago Ismael. University of Oslo; NoruegaFil: Navarro, Julio F.. University of Victoria; CanadáFil: Abadi, Mario Gabriel. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Córdoba. Instituto de Astronomía Teórica y Experimental. Universidad Nacional de Córdoba. Observatorio Astronómico de Córdoba. Instituto de Astronomía Teórica y Experimental; ArgentinaFil: Benavides Blanco, Jose Antonio. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Córdoba. Instituto de Astronomía Teórica y Experimental. Universidad Nacional de Córdoba. Observatorio Astronómico de Córdoba. Instituto de Astronomía Teórica y Experimental; ArgentinaFil: Mast, Damian. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Córdoba. Instituto de Astronomía Teórica y Experimental. Universidad Nacional de Córdoba. Observatorio Astronómico de Córdoba. Instituto de Astronomía Teórica y Experimental; Argentin

    The epoxyketone-based proteasome inhibitors carfilzomib and orally bioavailable oprozomib have anti-resorptive and bone-anabolic activity in addition to anti-myeloma effects

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    PMCID: PMC3771507.-- et al.Proteasome inhibitors (PIs), namely bortezomib, have become a cornerstone therapy for multiple myeloma (MM), potently reducing tumor burden and inhibiting pathologic bone destruction. In clinical trials, carfilzomib, a next generation epoxyketone-based irreversible PI, has exhibited potent anti-myeloma efficacy and decreased side effects compared with bortezomib. Carfilzomib and its orally bioavailable analog oprozomib, effectively decreased MM cell viability following continual or transient treatment mimicking in vivo pharmacokinetics. Interactions between myeloma cells and the bone marrow (BM) microenvironment augment the number and activity of bone-resorbing osteoclasts (OCs) while inhibiting bone-forming osteoblasts (OBs), resulting in increased tumor growth and osteolytic lesions. At clinically relevant concentrations, carfilzomib and oprozomib directly inhibited OC formation and bone resorption in vitro, while enhancing osteogenic differentiation and matrix mineralization. Accordingly, carfilzomib and oprozomib increased trabecular bone volume, decreased bone resorption and enhanced bone formation in non-tumor bearing mice. Finally, in mouse models of disseminated MM, the epoxyketone-based PIs decreased murine 5TGM1 and human RPMI-8226 tumor burden and prevented bone loss. These data demonstrate that, in addition to anti-myeloma properties, carfilzomib and oprozomib effectively shift the bone microenvironment from a catabolic to an anabolic state and, similar to bortezomib, may decrease skeletal complications of MM.This research was supported by grants from the National Institutes of Health (T32CA113275:MAH; P01CA100730:KNW; P50CA94056:DP-W), the St Louis Men’s Group Against Cancer (KNW), the Holway Myeloma Fund (KNW), the Spanish MICINN-ISCIII (PI081825), the Fundación de Investigación Médica Mutua Madrileña (AP27262008), the Centro en Red de Medicina Regenerativa y Terapia Celular de Castilla y León, the Spanish Myeloma Network Program (RD06/0020/0006 and RD06/0020/0041) and Spanish FIS (PS09/01897).Peer Reviewe

    Chagas Disease in the Yucatan Peninsula, Mexico

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    American trypanosomiasis or Chagas disease is caused by the protozoan Trypanosoma cruzi, which affects a wide variety of hosts including the man, until now treatment options or vaccines developed are not enough to control or prevent infected cases. The main way of transmission is vectorial, through insects of the Reduviidae family, as well by congenital transmission, blood/organ transplants or oral transmission. Chagas disease are considered as endemic in many areas due to the presence and lack of control of insect vectors. Many touristic places in Latin America are located in endemic areas; however, there is a nonexistence of knowledge by touristic service providers about the theme. For that reason, there is a latent risk that tourists who come to vacation in endemic areas are exposed get the infection. The risk factors are well identified, and this allows that well-defined prevention strategies can be established in order to avoid the presentation of cases in visitors to the tourist zones. This chapter aimed to describe the situation of Chagas disease in touristic areas of the Caribbean of America Latina as and to provide a brief review of information that allows visitors to know about the epidemiology and potential risks of this infection

    High-pressure greenschist to blueschist facies transition in the Maimón Formation (Dominican Republic) suggests mid-Cretaceous subduction of the Early Cretaceous Caribbean Arc

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    The Maimón Formation (Cordillera Central, Dominican Republic) is formed of metamorphosed bi-modal mafic-felsic volcanic rocks and sedimentary horizons of Early Cretaceous age deposited in the forearc of the nascent Caribbean island arc. Two structural-metamorphic zones depict an inverted metamorphic gradient: the Ozama shear zone, which records intense mylonitic and phyllonitic deformation and ubiquitous metamorphic recrystallization, tectonically overlies the much less deformed and variably recrystallized rocks of the El Altar zone. The presence of ferri-winchite and high-Si phengite, first reported in this paper, in the peak metamorphic assemblage of rocks of the Ozama shear zone (actinolite + phengite + chlorite + epidote + quartz + albite ± ferri-winchite ± stilpnomelane) point to subduction-related metamorphism. Pseudosection calculations and intersection of isopleths indicate peak metamorphic conditions of ~ 8.2 kbar at 380 °C. These figures are consistent with metamorphism in the greenschist/blueschist facies transition, burial depths of ~ 25-29 km and a thermal gradient of ~ 13-16 °C/km. Our new data dispute previous models pointing to metamorphism of Maimón rocks under a steep thermal gradient related to burial under a hot peridotite slice. Instead, we contextualize the metamorphism of the Maimón Formation in a subduction scenario in which a coherent slice of the (warm) Early Cretaceous forearc was engulfed due to intra-arc complexities and regional-scale-driven tectonic processes operating in the late Early Cretaceous. Integration of our findings with previous studies on metamorphic complexes in Hispaniola suggests that a major tectonic event affecting the whole arc system took place at c. 120-110 Ma

    Feasibility study of biogas upgrading coupled with nutrient removal from anaerobic effluents using microalgae-based processes

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    Producción CientíficaThe present research was conducted to simultaneously optimize biogas upgrading and carbon and nutrient removal from centrates in a 180-L high-rate algal pond interconnected to an external CO2 absorption unit. Different biogas and centrate supply strategies were assessed to increase biomass lipid content. Results showed 99 % CO2 removal efficiencies from simulated biogas at liquid recirculation rates in the absorption column of 9.9 m3 m−2 h−1, concomitant with nitrogen and phosphorus removal efficiencies of 100 and 82 %, respectively, using a 1:70 diluted centrate at a hydraulic retention time of 7 days. The lipid content of the harvested algal–bacterial biomass remained low (2.9–11.2 %) regardless of the operational conditions, with no particular trend over time. The good settling characteristics of the algal–bacterial flocs resulted in harvesting efficiencies over 95 %, which represents a cost-effective alternative for algal biomass reutilization compared to conventional physical–chemical techniques. Finally, high microalgae biodiversity was found regardless of the operational conditions.Junta de Castilla y León (programa de apoyo a proyectos de investigación – Ref. (Project GR76, VA024U14, and RTA2013-00056-C03-02

    DEBATES Y PERSPECTIVAS DEL PROCESO DE FORMACIÓN Y DESARROLLO DE LAS COMPETENCIAS MATEMÁTICAS EN LAS CARRERAS DE INGENIERÍA

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    The purpose of this article is to assess the various existing theories about the concept of mathematical competence, due that this topic is analyzed from different perspectives and epistemological conceptions of the general theory about competences and properly from the didactic perspective of mathematics. This led a consensus on its definition, as well as those requirements that are essential for the achievement of an efficient and effective learning of them. To get the result there were used methods and techniques essentially of theoretical character as analysis-synthesis, induction-deduction and concretionabstraction characteristic of this type of study.  El presente artículo tiene como propósito valorar las diversas teorías existentes acerca del concepto competencia matemática, ya que el mismo ha sido visualizado desde diversas perspectivas y concepciones epistemológicas de la teoría general sobre el tema y propiamente desde la perspectiva didáctica de las matemáticas. Ello propició llegar a consensos acerca de su definición, así como de aquellos requisitos que son esenciales para el logro de un aprendizaje eficiente y eficaz de las mismas. Para la elaboración del artículo fueron utilizados esencialmente métodos y técnicas de carácter teórico como el análisis-síntesis, la inducción-deducción y la concreción-abstracción, característicos de este tipo de estudio

    Tunable magneto-photonic response of nickel nanostructures

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    In this letter, we present both experimental and numerical studies of the magneto-optical (MO) properties of nickel infiltrated opals. Ni can show interesting MO properties that can be controlled by nanostructuration through colloidal crystals templating. Nanostructuration allows the coupling of light to surface plasmon modes of Ni, and a clear dependence of the MO response as a function of the structural parameters of the template has been observed. This dependence can be used in future tunable devices such as switchers or MO modulators. © 2011 American Institute of Physics.This work has been partially supported by EU FP7 (NoE Nanophotonics 4 Energy Grant No. 248855 and NMP3-SL-2008-214107-Nanomagma); the CSIC PIF08-016, the Spanish MICINN (CSD2007-0046-Nanolight.es, CSD2008-00023-Funcoat, MAT2009-07841-GLUSFA, MAT2008-06765-C02-01/NAN-MAGPLAS) and Comunidad de Madrid (S2009/MAT-1756-PHAMA and S2009/TIC–1476- MICROSERES).Peer Reviewe

    EL DESARROLLO DE LA COMPETENCIA MODELAR PROBLEMAS DE PROGRAMACIÓN LINEAL COMO REQUISITO EN LA FORMACIÓN DEL INGENIERO INFORMÁTICO

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    Este artículo pretende realizar una valoración de la importancia que posee la competencia modelas problemas de programación lineal para el futuro ingeniero en informática, debido a que una de sus funciones profesionales se centrará en la utilización de los recursos informáticos para lograr optimizar procesos económicos y sociales. De la misma manera se establece una discusión sobre el proceso de desarrollo de esa competencia y de las más disimiles controversias para su definición e inserción en el proceso enseñanza-aprendizaje de la asignatura Investigación de Operaciones. Para la elaboración del artículo fueron utilizados esencialmente métodos y técnicas de carácter teórico como el análisis-síntesis, la inducción-deducción y la concreción-abstracción, característicos de este tipo de estudio.PALABRAS CLAVE: Competencias; competencia modelar; desarrollo de la competencia modelar problemas; programación lineal.THE DEVELOPMENT OF THE COMPETENCE MODELLING PROBLEMS OF LINEAR PROGRAMMING AS A REQUIREMENT TO EDUCATE THE COMPUTER ENGINEER IN PROGRESSABSTRACTThis article aims to assess the importance of the competence modelling linear programming problems for the future computer engineer, because one of its professional functions will focus on the use of computing resources to optimize economic and social processes. In the same way, a discussion is established about the development process of that competence and the most dissimilar controversies for its definition and insertion in the teaching-learning process of the subject Operations Research. To get the result there were used methods and techniques essentially of theoretical character as analysis-synthesis, induction-deduction and concretion-abstraction characteristic of this type of study.KEYWORDS: Competences; modelling competence; development of the competence modelling problems; linear programming
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