128 research outputs found

    Comportamiento de elementos estructurales de compuestos híbridos base cemento frente a impacto de torre de caída

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    The performance, under drop-weight impact load, of hybrid cement composite (HCC) elements, consisting of a top layer of plain concrete (PC) and a bottom layer of fibre reinforced concrete (FRC), in comparison with full-depth FRC and PC was studied. Apart from improving the tensile capacity of PC and saving fibre steel reinforcements of FRC, the results showed that HCC can effectively control the deformations and enhance the impact performance of the structural members as its outcomes were similar to that of a full-depth FRC. The analytical studies using Hughes empirical formulae (HEF) and yield line theory (YLT) adopted to investigate the practical use of HCC showed that they are applicable for design such HCC elements against impacts.Se estudió el comportamiento, frente a impacto de torre de caída, de elementos híbridos base cemento (HCC), formados por una capa superior de hormigón en masa (PC) y una capa inferior de hormigón reforzado con fibras (FRC) en comparación con elementos análogos íntegramente fabricados con FRC y PC. Además de proporcionar una mejora en la resistencia frente a flexo-tracción de los PC y un ahorro en refuerzo usando fibras de acero en el caso de los FRC, los resultados mostraron que el HCC puede controlar eficazmente las deformaciones y mejorar el rendimiento frente a impacto de los elementos estructurales ya que sus resultados fueron análogos a la de los FRC. Los estudios analíticos, utilizando HEF e YLT, adoptados para investigar el uso práctico de los HCC mostraron que los mismos son aplicables para el diseño de estos elementos frente a impacto

    Failure and impact behavior of facade panels made of glass fiber reinforced cement(GRC)

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    GRC is a cementitious composite material made up of a cement mortar matrix and chopped glass fibers. Due to its outstanding mechanical properties, GRC has been widely used to produce cladding panels and some civil engineering elements. Impact failure of cladding panels made of GRC may occur during production if some tool falls onto the panel, due to stone or other objects impacting at low velocities or caused by debris projected after a blast. Impact failure of a front panel of a building may have not only an important economic value but also human lives may be at risk if broken pieces of the panel fall from the building to the pavement. Therefore, knowing GRC impact strength is necessary to prevent economic costs and putting human lives at risk. One-stage light gas gun is an impact test machine capable of testing different materials subjected to impact loads. An experimental program was carried out, testing GRC samples of five different formulations, commonly used in building industry. Steel spheres were shot at different velocities on square GRC samples. The residual velocity of the projectiles was obtained both using a high speed camera with multiframe exposure and measuring the projectile’s penetration depth in molding clay blocks. Tests were performed on young and artificially aged GRC samples to compare GRC’s behavior when subjected to high strain rates. Numerical simulations using a hydrocode were made to analyze which parameters are most important during an impact event. GRC impact strength was obtained from test results. Also, GRC’s embrittlement, caused by GRC aging, has no influence on GRC impact behavior due to the small size of the projectile. Also, glass fibers used in GRC production only maintain GRC panels’ integrity but have no influence on GRC’s impact strength. Numerical models have reproduced accurately impact tests

    El efecto del humo de sílice y el metacaolín en el proceso de envejecimiento de los morteros de cemento reforzados con fibras de vidrio (GRC)

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    The deterioration of the mechanical properties of glassfibre reinforced concrete (GRC) over time rules out the use of this material in load-bearing structures. While one possible solution to this problem is the addition of pozzolans or metakaolin to the cement mortar, the amounts needed to ensure GRC integrity raise its price to non-competitive levels. Experimental research has been conducted to analyze whether the addition of small amounts of silica fume or metakaolin can prevent or mitigate the ageing issue. Unfortunately, the findings indicate that the addition of small proportions of metakaolin or silica fume to GRC are ineffective in improving its long-term performance.Para el uso del mortero de cemento reforzado con fibras de vidrio (GRC) en estructuras portantes se han de solucionar los problemas de reducción de las propiedades mecánicas que aparecen con el paso del tiempo. Estos problemas pueden ser solucionados mediante la adición de puzolanas o de metacaolín, a la pasta de mortero de cemento. Sin embargo, la cantidad de metacaolín que ha de ser añadida es elevada y el precio del GRC fabricado está fuera del mercado. Se ha realizado una campaña experimental que analiza si la adición de humo de sílice o de metacaolín en proporciones reducidas consigue evitar o paliar el problema del envejecimiento, que supone un freno al uso del GRC en elementos estructurales. Desgraciadamente, los resultados experimentales muestran que proporciones bajas de metacaolín o de humo de sílice no son efectivas para reducir el problema de pérdida de propiedades mecánicas

    A Multi-Omics Analysis Pipeline for the Metabolic Pathway Reconstruction in the Orphan Species Quercus ilex

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    Holm oak (Quercus ilex) is the most important and representative species of the Mediterranean forest and of the Spanish agrosilvo-pastoral “dehesa” ecosystem. Despite its environmental and economic interest, Holm oak is an orphan species whose biology is very little known, especially at the molecular level. In order to increase the knowledge on the chemical composition and metabolism of this tree species, the employment of a holistic and multi-omics approach, in the Systems Biology direction would be necessary. However, for orphan and recalcitrant plant species, specific analytical and bioinformatics tools have to be developed in order to obtain adequate quality and data-density before to coping with the study of its biology. By using a plant sample consisting of a pool generated by mixing equal amounts of homogenized tissue from acorn embryo, leaves, and roots, protocols for transcriptome (NGS-Illumina), proteome (shotgun LC-MS/MS), and metabolome (GC-MS) studies have been optimized. These analyses resulted in the identification of around 62629 transcripts, 2380 protein species, and 62 metabolites. Data are compared with those reported for model plant species, whose genome has been sequenced and is well annotated, including Arabidopsis, japonica rice, poplar, and eucalyptus. RNA and protein sequencing favored each other, increasing the number and confidence of the proteins identified and correcting erroneous RNA sequences. The integration of the large amount of data reported using bioinformatics tools allows the Holm oak metabolic network to be partially reconstructed: from the 127 metabolic pathways reported in KEGG pathway database, 123 metabolic pathways can be visualized when using the described methodology. They included: carbohydrate and energy metabolism, amino acid metabolism, lipid metabolism, nucleotide metabolism, and biosynthesis of secondary metabolites. The TCA cycle was the pathway most represented with 5 out of 10 metabolites, 6 out of 8 protein enzymes, and 8 out of 8 enzyme transcripts. On the other hand, gaps, missed pathways, included metabolism of terpenoids and polyketides and lipid metabolism. The multi-omics resource generated in this work will set the basis for ongoing and future studies, bringing the Holm oak closer to model species, to obtain a better understanding of the molecular mechanisms underlying phenotypes of interest (productive, tolerant to environmental cues, nutraceutical value) and to select elite genotypes to be used in restoration and reforestation programs, especially in a future climate change scenario

    PARÁSITOS HELMINTOS EN Boa constrictor, Epicrates cenchria y Corallus caninus (Ophidia: Boidae) CRIADAS EN CAUTIVERIO

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    Los boideos pertenecen a la familia Boidae, cuyos representantes más conocidos son las boas y los pitones. Estos reptiles no son venenosos, pero sí peligrosos por la cantidad de dientes que poseen y por su hábito constrictor. Las especies Boa constrictor (“Boa” o “Mantona”), Epicrates cenchria (“Mantona roja”o “Arco iris”) y Corallus caninus (“Boa verde” o “Boa esmeralda”) se crían en cautiverio con fines comerciales, orientadas a un mercado para mascotas. La zoocría de boideos es una actividad poco desarrollada en el país por lo que se conoce poco acerca de su estado sanitario; aunque los parásitos, principalmente intestinales, son reportados como casuística de mortalidad y morbilidad.Fecal samples for the identification of helminthes were collected from three species of snakes (Boa contrictor “boa” or “mantona”, Epicrates cenchria “mantona roja” or “arco iris”, Corallus caninus “boa verde” or “boa esmeralda”) reared in captivity. The identified parasites, either through eggs or larva were: Kalicephalus sp., Ophiotaenia sp., Rhabdias sp., Ophidascaris sp., and Hymenolepis diminuta. The results indicated that 79% of adult female Boa constrictor and 46% of their offspring, 71% of E. cenchria and 70% of C. caninus were positive, either to single or multiple infections. These data showed that boas reared in captivity were highly parasitized with intestinal and pulmonary helminthes

    Situación de endeudamiento de las organizaciones de gestión de instalaciones deportivas de ocio no competitivo. Un estudio empírico

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    The management of the debt in sports organizations are determinant variables for the survival of these, the lack of control can affect the proper functioning of an entity. According to the existing data, the organizations that manage golf courses enjoy a good economic situation. Therefore, the purpose of this study was to know the status and evolution of the debt of sports companies that participate in the sport of non-competitive golf. For this, a sample of 93 organizations throughout the Spanish territory was selected with an average age of 20,08 years. In order to obtain the data, the economic information of the Iberian Balance Sheet Analysis System of the past decade was used. From the findings obtained in the present study, an increase in the average debt of the organizations of 70,5% follows after a decade. In spite of the good economic health and the increase of its income by exploitation and total of assets in the period of study, we can affirm that the debt of these organizations has increased exponentially between 2005-2015.La gestión de la deuda en las organizaciones deportivas es una variable determinante para la supervivencia de éstas, la falta de control puede afectar al buen funcionamiento de una entidad. Según los datos existentes, las organizaciones que gestionan campos de golf gozan de una buena situación económica. Por ello, el propósito del presente estudio fue conocer el estado y evolución de la deuda de las empresas deportivas que participan en el deporte del golf no competitivo. Para ello, se seleccionó una muestra de 93 organizaciones de todo el territorio Español, con una antigüedad media de 20,08 años. Para la obtención de los datos se utilizó la información económica del Sistema de Análisis de Balances Ibéricos de la pasada década. Los hallazgos obtenidos en el presente estudio nos llevan a conocer que la deuda media de las organizaciones ha aumentado en el 70,5% de los casos después de una década. A pesar de la buena salud económica y al aumento de sus ingresos por explotación y total de activos en el período de estudio, podemos afirmar que la deuda de estas organizaciones ha aumentado exponencialmente entre el 2005-2015

    Functional recovery in patients with schizophrenia: recommendations from a panel of experts

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    emission and encompasses multiple aspects of the patient's life, making it difficult to settle on a definition and to develop reliable assessment criteria. In this consensus process based on a panel of experts in schizophrenia, we aimed to provide useful insights on functional recovery and its involvement in clinical practice and clinical research. Methods: After a literature review of functional recovery in schizophrenia, a scientific committee of 8 members prepared a 75-item questionnaire, including 6 sections: (I) the concept of functional recovery (9 items), (II) assessment of functional recovery (23 items), (III) factors influencing functional recovery (16 items), (IV) psychosocial interventions and functional recovery (8 items), (V) pharmacological treatment and functional recovery (14 items), and (VI) the perspective of patients and their relatives on functional recovery (5 items). The questionnaire was sent to a panel of 53 experts, who rated each item on a 9-point Liken scale. Consensus was achieved in a 2-round Delphi dynamics, using the median (interquartile range) scores to consider consensus in either agreement (scores 7-9) or disagreement (scores 1-3). Items not achieving consensus in the first round were sent back to the experts for a second consideration. Results: After the two recursive rounds, consensus was achieved in 64 items (85.3%): 61 items (81.3%) in agreement and 3 (4.0%) in disagreement all of them from section II (assessment of functional recovery). Items not reaching consensus were related to the concepts of functional recovery (1 item, 13%), functional assessment (5 items, 6.7%), factors influencing functional recovery (3 items, 4.0%), and psychosocial interventions (2 items, 5.6%). Conclusions: Despite the lack of a well-defined concept of functional recovery, we identified a trend towards a common archetype of the definition and factors associated with functional recovery, as well as its applicability in clinical practice and clinical research.This project was funded by Janssen. The funding body participated in study design and data interpretation

    Towards on line monitoring the evolution of the myocardium infarction scar with an implantable electrical impedance spectrum monitoring system.

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    The human heart tissue has a limited capacity for regeneration. Tissue and cellular therapies based on the use of stem cells may be useful alternatives to limit the size of myocardial infarction. In this paper, the preliminary results from an experimental campaign for on-line monitoring of myocardium scar infarction are presented. This study has been carried out under a research project that has as main objective the development and application of a bioactive patch implant for regeneration of myocardial infarction. Electrical Impedance Spectroscopy (EIS) has been chosen as a tissue state monitoring technique. What is presented in this communication is the first results of an implantable EIS measurement system which has been implanted in a subset of the animals corresponding to the control group, along one month. In all the animals, the myocardial infarction was induced by the ligation of the first circumflex marginal artery. In the animal group presented,the bioactive patch scaffold and the electrodes were implanted without the stem cells load. The scaffold is a piece of decellularized human pericardium, lyophilized and rehydrated with hydrogel RAD16-I. Nanogold particles were also placed near the electrodes to improve the electrode area conductivity. The results presented correspond to the subset of animals (n = 5), which had implanted the bioimpedance system monitoring the electrical impedance spectrum in vivo during 1 month. Two electrodes were connected to the bioactive patch implant. A total of 14 logarithmically spaced frequencies were measured every 5 minutes, from 100 Hz to 200 kHz. Results show a convergence of low-frequency and high frequency impedance magnitudes along the measurement period, which is coherent with the scar formation.Postprint (published version

    PRESENCE OF TRYPANOSOMA SP. IN COLLARED PECCARIES (TAYASSU TAJACU) REARED IN CAPTIVITY IN THE TROPICS OF PERU

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    El objetivo del presente estudio fue determinar la presencia de Trypanosoma sp. en sajinos en cautiverio de las zonas de Iquitos y Moyobamba. Se colectó muestras de sangre de 40 sajinos procedentes de tres zoocriaderos con edades entre 3 meses y 2 años. Las muestras se procesaron con las técnicas de microcapilar o técnica de Woo y del frotis sanguíneo delgado. No se halló la presencia de Trypanosoma sp. en las muestras examinadas, y, posiblemente, la baja sensibilidad de las técnicas afectó los resultados. La técnica de evaluación de riesgo por simulación Monte Carlo (programa @Risk) indicó que el 95% de las observaciones analizadas se encontraron en un intervalo de 0.006 a 0.854% y que la probabilidad de encontrar la infección real en sajinos provenientes de Iquitos y Moyobamba se encuentra en un rango promedio de infección de 0.02%.The objective of the present study was to determine the presence of Trypanosoma sp. in collared peccaries reared in captivity in Iquitos and Moyobamba area. Blood samples were collected from 40 animals from 3 months to 2 years of age. Samples were processed by the microcapillary or Woo technique and the blood smear. None of the samples resulted positive to Trypanosoma sp., and probably the low sensitivity of the techniques affected the results. The Monte Carlo risk analysis (@Risk) indicated that the probability to obtain an infected animal in the Moyobamba and Iquitos area was 0.02% and that 95% of the samples were within an interval of 0.006 a 0.854%

    Seropositivity rates for agents of canine vector-borne diseases in Spain : a multicentre study

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    Background: Controlling canine vector-borne diseases (CVBD) is a major concern, since some of these diseases are serious zoonoses. This study was designed to determine seropositivity rates in Spain for agents causing the following five CVBD: leishmaniosis (Leishmania infantum: Li), heartworm (Dirofilaria immitis: Di), ehrlichiosis (Ehrlichia canis: Ec), anaplasmosis (Anaplasma phagocytophilum/Anaplasma platys: An) and Lyme disease (Borrelia burgdorferi: Bb). Methods: Anti-An, -Bb, and -Ec antibodies and the Di antigen were determined using the 4DX SNAP® Test (IDEXX Laboratories) and anti-L. infantum (Li) antibodies using the Leishmania SNAP® Test (IDEXX Laboratories) in blood and/or serum samples. Results: Among 1100 dogs examined, overall seropositivity rates were: Li (15.7%), Ec (5%), An (3.1%), Di (1.25%) and Bb (0.4%). While seropositivity towards Bb and Di was similar in all geographic regions, rates were significantly higher in the east of Spain (8.3%) for An, significantly higher in the north (20%) for Ec, and significantly higher in the Southeast (46.6%) and South (27.4%), and significantly lower in the north (0%) for Li. No statistical associations were observed between sex and the CVBD analyzed (p ≥ 0.05) while the following associations with other variables were detected: a higher seropositivity to Ec (40%) and Bb (6.7%) in dogs under one year of age compared with adults (p < 0.05); and a higher seropositivity to An and Li in dogs that lived outdoors versus indoors (p = 0.01; p < 0.001, respectively). Seropositivity rates of 2.1%, 0%, 1.7%, 0.5% and 4.2% were recorded respectively for An, Bb, Ec, Di and Li in dogs with no clinical signs (n = 556) versus 3.8%, 0.6%, 7.5%, 1.8% and 25.9% for those with signs (n = 507) suggestive of a CVBD. Conclusion: The data obtained indicate a risk for dogs in Spain of acquiring any of the five CVBD examined. Veterinarians in the different regions should include these diseases in their differential diagnoses and recommend the use of repellents and other prophylactic measures to prevent disease transmission by arthropod vectors. Public health authorities also need to become more involved in the problem, since some of the CVBD examined here also affect humans
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