117 research outputs found
Un procedimiento nuevo para adaptar cualquier tipo de suelo para la construcción y consolidación de estructuras de tierra: Sistema de Tierra Proyectada
The “projected earth system” is put forward as an alternative construction method. The soil from each site is adapted following a specific protocol to make it suitable for spraying. The type of construction and the receiving surface determine the machinery and spraying system used (dry or wet mix). The result will be similar in texture and colour to the original material (in the case of earth walls) or to the surrounding material.Un procedimiento nuevo para adaptar cualquier tipo de suelo para la construcción y consolidación de estructuras de tierra: Sistema de Tierra Proyectada. Se plantea la “tierra proyectada” como nuevo sistema constructivo. Se adecuará la tierra de cada intervención con un protocolo para poder ser proyectada. El tipo de intervención y el soporte sobre el que se proyectará determinarán la maquinaria y el sistema de proyección (vía seca o húmeda). El resultado tendrá similar textura y color que el soporte restaurado (en muros de tierra) o que el material del entorno (en taludes carreteros u obras de tierra de nueva construcción)
Recycled aggregate in road construction following the Spanish General Technical Specifications for Roads and Bridge Works (PG-3): a case study
Diagnosis of stoneware pathology placed on bonded façade
Esta investigación analiza las causas del desprendimiento de un revestimiento de gres porcelánico colocado en fachada. En el momento de abordar este trabajo comprobamos que hay métodos normalizados para la determinación de las características de los adhesivos para las baldosas cerámicas y de las propias baldosas, pero en ambos casos, son métodos a aplicar durante el proceso de fabricación. No existen métodos normalizados para la determinación de las características de aplacados en servicio, cuestión que aborda este trabajo. Las técnicas de diagnosis empleadas han consistido en la comprobación de la capacidad de adherencia del adhesivo, la localización de juntas de movimiento, el análisis de las juntas de colocación y la detección de anclajes mecánicos ocultos.
Finalmente, los resultados obtenidos tras la aplicación de dicha metodología para el análisis de la patología han permitido establecer las causas que han originado los daños, proponiéndose como método de diagnosis del desprendimiento de un aplacado cerámico en servicio.This research examines the causes of the detachment of stoneware placed on façade cladding. In dealing with this work we see that there are standard methods for the determination of the characteristics of adhesives for ceramic tiles and own tiles, but in both cases, the methods are to be applied during the manufacturing process. There are no standard methods for the determination of the characteristics of facings in service, which deals with this work. Employed diagnosis techniques have consisted of checking the capacity of adhesion of adhesive, the location of movement joints, joints of positioning analysis and detection of hidden mechanical anchors.
Finally, the results obtained after the application of this methodology to the analysis of Pathology have allowed establishing the causes that have given rise to the damage; we propose a method of diagnosis of the evolution of a ceramic covering
Un estudio para la aplicación del árido reciclado en obras de carreteras en España siguiendo las especificaciones del Pliego de Prescripciones Técnicas Generales para Obras de Carreteras y Puentes (PG-3)
This research characterizes four samples of recycled aggregate for their potential use in road construction projects in consonance with the Spanish General Technical Specifications for Roads and Bridge Works (PG-3). Although some fractions were of sufficient quality for the construction of embankments, backfills, and quarry-run fills, they were ultimately found to be unsuitable for the construction of underground drainage, granular structural layers, soil stabilization and concrete pavements. They were negatively evaluated because of their particle size distribution and sulfate content. Nevertheless, the quality of this recycled aggregate could be substantially improved by manually removing the gypsum before the crushing process at the plant or by selecting the material with greater care at the beginning of the process. Finally, we suggest that Construction and Demolition (C&D) waste plant managers should modify the manufacturing process to obtain a suitable particle size distribution in accordance with PG-3 requirements and the projected use of the aggregate.En esta investigación se han caracterizado cuatro muestras de árido reciclado para su potencial uso en obras de carreteras en España siguiendo el Pliego de Prescripciones Técnicas Generales para Obras de Carreteras y Puentes (PG-3). Aunque algunas fracciones presentaron suficiente calidad para la construcción de terraplenes, rellenos localizados y rellenos todo en uno, resultaron inadecuadas para la construcción de drenes subterráneos, zahorras, suelos estabilizados y pavimentos de hormigón. Obtuvieron una evaluación negativa en cuanto a distribución granulométrica y contenido en sulfatos. No obstante, la calidad de este árido reciclado podría mejorar sustancialmente eliminando manualmente el yeso antes de la trituración en planta o seleccionando el material con un mayor cuidado al inicio del proceso. Finalmente, recomendamos que los empresarios de las plantas de residuos de construcción y demolición modifiquen el procedimiento de fabricación para obtener una distribución granulométrica adecuada, de acuerdo con los requisitos del PG-3 y el uso previsto del árido
The technique of underpinning with micropiles in conserving a compacted earth wall using "tapial-technic"
Durante el proceso de ejecución de un aparcamiento público subterráneo en la ciudad de Granada (España) se descubrió una obra de ingeniería hidráulica periurbana de 55 m de longitud con tres tajamares (declarado BIC en el 2007) ligado a la margen izquierda del río Genil. Se detectaron tres fases constructivas, muro monolítico (s. XI), tapia real (s. XII-XIII) y una reparación posterior (s. XIX) a base de cajones de mampostería con machones e hiladas de ladrillo. Para la conservación de este elemento en su posición original se ejecutaron: micropilotes verticales en su perímetro; otros horizontales en su base; viga riostra de encepado y bulones con barra Gewi pasantes a la viga de arriostramiento. Durante la excavación, se ejecutó un entramado de perfiles metálicos laminados «L» soldados entre sí y a los micropilotes. El elemento está totalmente integrado en la obra subterránea y en el entorno del Paseo del Violón.In this paper, the discovery of a peri-urban work of hydraulic engineering is presented. A wall-dike was found during the excavation for an underground public parking on the left bank of the Genil River in Granada city (Spain). Those consist in a compacted earth wall (using “Tapial-technic”) of 55 m length with three cutwaters. Three different construction methodologies were detected in the wall-dike: monolithic-wall (s. XI), royal wall (s. XII-XIII) and contemporary reparation (s. XIX). These elements were conserved in the original position with the help of the micropiles technique. The consolidation stages were as follows: vertical micropiles in its perimeter; horizontals micropiles in the base of the wall; brace beam and thought bolts with Gewi rod. After the digging, also, laminated metal sections with an “L” were welded together and to vertical micropiles. That element is fully integrated with both underground construction and its environment, “Paseo del Violón”.Queremos agradecer la colaboración de las empresas Ges-pad-Al-Andalus.S.L. y SITE S.A
Study of potential advantages of pre-soaking on the properties of pre-cast concrete made with recycled coarse aggregate
Consensus on complementary feeding from the Latin American Society for Pediatric Gastroenterology, Hepatology and Nutrition: COCO 2023
Abstract Complementary feeding (CF) is defined as infant feeding that complements breastfeeding or, alternatively, breastfeeding with a breast milk substitute, and is a process that goes beyond simply providing guidance on what and how to introduce foods. The information provided by health professionals should be up-to-date and evidence-based. There are different guidelines or position papers at the international level, which, although most of the recommendations may be applicable, there are some others that require regionalization or adaptation to the conditions and reality of each area. The Nutrition working group of the Latin American Society of Pediatric Gastroenterology, Hepatology and Nutrition convened a group of experts, representatives from each of the countries that make up the society, with the objective of developing a consensus on CA, incorporating, when possible, local information that adapts to the reality of the region. The purpose of this document is to show the results of this work. Through Delphi methodology, a total of 34 statements or statements regarding relevant aspects of CA were evaluated, discussed and voted upon.Resumen La alimentación complementaria (AC) se define como la alimentación de los lactantes que complementa a la lactancia materna o en su defecto, a la lactancia con un sucedáneo de la leche materna, y es un proceso que va más allá de simplemente una guía sobre qué y cómo introducir los alimentos. La información brindada por parte de los profesionales de la salud debe ser actualizada y basada en evidencia. Existen diferentes guías o documentos de posición a nivel internacional, que, aunque la mayoría de las recomendaciones pueden ser aplicables, hay algunas otras que requieren una regionalización o adecuación a las condiciones y realidad de cada zona. El grupo de trabajo de Nutrición de la Sociedad Latinoamericana de Gastroenterología, Hepatología y Nutrición Pediátrica convocó a un grupo de expertos, representantes de cada uno de los países que conforman la sociedad, con el objetivo de desarrollar un consenso sobre la AC, que incorporó cuando así fue posible, información local que se adapte a la realidad de la región. El objetivo de este documento es mostrar los resultados de dicho trabajo. A través de metodología Delphi, se evaluaron, discutieron y votaron un total de 34 declaraciones o enunciados con respecto a aspectos relevantes de la AC
Elective Cancer Surgery in COVID-19-Free Surgical Pathways During the SARS-CoV-2 Pandemic: An International, Multicenter, Comparative Cohort Study.
PURPOSE: As cancer surgery restarts after the first COVID-19 wave, health care providers urgently require data to determine where elective surgery is best performed. This study aimed to determine whether COVID-19-free surgical pathways were associated with lower postoperative pulmonary complication rates compared with hospitals with no defined pathway. PATIENTS AND METHODS: This international, multicenter cohort study included patients who underwent elective surgery for 10 solid cancer types without preoperative suspicion of SARS-CoV-2. Participating hospitals included patients from local emergence of SARS-CoV-2 until April 19, 2020. At the time of surgery, hospitals were defined as having a COVID-19-free surgical pathway (complete segregation of the operating theater, critical care, and inpatient ward areas) or no defined pathway (incomplete or no segregation, areas shared with patients with COVID-19). The primary outcome was 30-day postoperative pulmonary complications (pneumonia, acute respiratory distress syndrome, unexpected ventilation). RESULTS: Of 9,171 patients from 447 hospitals in 55 countries, 2,481 were operated on in COVID-19-free surgical pathways. Patients who underwent surgery within COVID-19-free surgical pathways were younger with fewer comorbidities than those in hospitals with no defined pathway but with similar proportions of major surgery. After adjustment, pulmonary complication rates were lower with COVID-19-free surgical pathways (2.2% v 4.9%; adjusted odds ratio [aOR], 0.62; 95% CI, 0.44 to 0.86). This was consistent in sensitivity analyses for low-risk patients (American Society of Anesthesiologists grade 1/2), propensity score-matched models, and patients with negative SARS-CoV-2 preoperative tests. The postoperative SARS-CoV-2 infection rate was also lower in COVID-19-free surgical pathways (2.1% v 3.6%; aOR, 0.53; 95% CI, 0.36 to 0.76). CONCLUSION: Within available resources, dedicated COVID-19-free surgical pathways should be established to provide safe elective cancer surgery during current and before future SARS-CoV-2 outbreaks
Elective cancer surgery in COVID-19-free surgical pathways during the SARS-CoV-2 pandemic: An international, multicenter, comparative cohort study
PURPOSE As cancer surgery restarts after the first COVID-19 wave, health care providers urgently require data to determine where elective surgery is best performed. This study aimed to determine whether COVID-19–free surgical pathways were associated with lower postoperative pulmonary complication rates compared with hospitals with no defined pathway. PATIENTS AND METHODS This international, multicenter cohort study included patients who underwent elective surgery for 10 solid cancer types without preoperative suspicion of SARS-CoV-2. Participating hospitals included patients from local emergence of SARS-CoV-2 until April 19, 2020. At the time of surgery, hospitals were defined as having a COVID-19–free surgical pathway (complete segregation of the operating theater, critical care, and inpatient ward areas) or no defined pathway (incomplete or no segregation, areas shared with patients with COVID-19). The primary outcome was 30-day postoperative pulmonary complications (pneumonia, acute respiratory distress syndrome, unexpected ventilation). RESULTS Of 9,171 patients from 447 hospitals in 55 countries, 2,481 were operated on in COVID-19–free surgical pathways. Patients who underwent surgery within COVID-19–free surgical pathways were younger with fewer comorbidities than those in hospitals with no defined pathway but with similar proportions of major surgery. After adjustment, pulmonary complication rates were lower with COVID-19–free surgical pathways (2.2% v 4.9%; adjusted odds ratio [aOR], 0.62; 95% CI, 0.44 to 0.86). This was consistent in sensitivity analyses for low-risk patients (American Society of Anesthesiologists grade 1/2), propensity score–matched models, and patients with negative SARS-CoV-2 preoperative tests. The postoperative SARS-CoV-2 infection rate was also lower in COVID-19–free surgical pathways (2.1% v 3.6%; aOR, 0.53; 95% CI, 0.36 to 0.76). CONCLUSION Within available resources, dedicated COVID-19–free surgical pathways should be established to provide safe elective cancer surgery during current and before future SARS-CoV-2 outbreaks
Biased-corrected richness estimates for the Amazonian tree flora
Amazonian forests are extraordinarily diverse, but the estimated species richness is very much debated. Here, we apply an ensemble of parametric estimators and a novel technique that includes conspecific spatial aggregation to an extended database of forest plots with up-to-date taxonomy. We show that the species abundance distribution of Amazonia is best approximated by a logseries with aggregated individuals, where aggregation increases with rarity. By averaging several methods to estimate total richness, we confirm that over 15,000 tree species are expected to occur in Amazonia. We also show that using ten times the number of plots would result in an increase to just ~50% of those 15,000 estimated species. To get a more complete sample of all tree species, rigorous field campaigns may be needed but the number of trees in Amazonia will remain an estimate for years to come
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