Estudio y revisión de técnicas no destructivas (termografía, ultrasonidos y resistógrafo) aplicadas a la inspección e intervención de forjados de madera

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Análisis sobre la influencia de la densidad en la termografía de infrarrojos y el alcance de esta técnica en la detección de defectos internos en la madera

This paper shows the results of a laboratory phase for the determination of the 1limits of infrared thermography in detecting internal defects in wood and, furthermore, it analyses how the density of this material can influence the surface temperature displayed in a thermogram. To this end, experimental work is carried out whereby a series of work and environmental parameters are monitored (such as environmental temperature, relative humidity, distance to target), and the process is systematized by using pieces of different wood species (different densities) and by devising a set of samples for which various possible cases are analysed in terms of size and internal position of the damage. Similarly, using these samples, a study has been conducted on the effect on the thermal image produced by an increase of humidity inside the defect phenomena normally associated with wood decay.En el presente artículo se muestran los resultados obtenidos en una fase de laboratorio al tratar de determinar el alcance de la termografía de infrarrojos en la detección de defectos internos en la madera y, por otro lado, cómo interviene la densidad de este material sobre la temperatura superficial mostrada en un termograma. Para ello se ha desarrollado un trabajo experimental donde se han controlado una serie de parámetros ambientales y de trabajo (temperatura ambiente, humedad relativa, distancia al objetivo…), y se ha sistematizado el proceso utilizando piezas de distintas especies de madera (distintas densidades) y diseñando una serie de probetas donde se han analizado varias casuísticas posibles en cuanto a tamaño y posición interna de los daños. Análogamente, sobre estas probetas se ha estudiado el efecto que produce sobre la imagen termográfica un incremento de humedad interna en el defecto asociada normalmente a los fenómenos de pudrición de la madera

Characterisation of recycled ceramic mortars for use in prefabricated beam-filling pieces in structural floors

This study analyses a procedure to manufacture mortars with different percentages of ceramic waste as partial replacement for aggregates. The study also examines the physical, chemical and mechanical properties of the new mortars, analysing substitution ratios that range from 10% to 50%. Prior to this, all the materials used in the production of the mortar were characterised using X-ray diffraction (XRD) and fluorescence (XRF). The objective was to determine the similarity between different types of ceramic waste, as well as the differences in the minerology and chemical composition with the aggregate. The results of the study show that it is possible to obtain mortars with lower densities compared to the same product with no recycled content. The product’s characteristics make it ideal for the manufacture of prefabricated components for structural floors for rehabilitation works. Finally, the pieces are used in a real rehabilitation case study, highlightining the structural advantages.Caracterización de morteros con cerámica reciclada y su uso en piezas prefabicadas para entrevigado de forjados. Este trabajo analiza morteros con diferentes porcentajes de cerámica reciclada como sustituto parcial de la arena. Además el estudio examina las propiedades físicas, químicas y mecánicas de los nuevos morteros, empleando diferentes porcentajes de sustitución (10% - 50%). Con anterioridad, se caracterizaron todos los materiales empleados en este trabajo mediante difracción y fluorescencia de rayos-X. El objetivo fue determinar las diferencias y similitudes en la composición química y mineralógica de los distintos tipos de residuos cerámicos y del resto de áridos utilizados. Los resultados muestran que es posible obtener morteros con menor densidad frente a las muestras sin contenido reciclado. Sus características los hacen idóneos para la creación de piezas prefabricadas de entrevigado para rehabilitación de forjados. Finalmente. Las piezas se usaron en un caso de estudio real, destacando las ventajas estructurales que conlleva su uso

Impact of Wetting–Drying Cycles on the Mechanical Properties and Microstructure of Wood Waste–Gypsum Composites

Large amounts of wood waste are generated each year in the world. In an attempt to identify a good recovery option for those residues, wood waste from construction and demolition works were used as raw materials in gypsum plasters. However, wood is a biodegradable material which implies that the products or materials that contain it are susceptible to su ering an important deterioration, due to exposure in certain environments. For that reason, the aim of this work was to simulate the e ects that, in the long term, the atmospheric exposure of wood waste–gypsum composites would have. To do that, the plasters were subjected to 5, 10, and 15 wetting–drying cycles in a climatic chamber. In this study, the density, flexural and compressive strength, and ultrasonic velocity of these composites were determined by the influence of the aging process on their mechanical properties. Furthermore, in order to detect changes on their internal structure, scanning electron microscopy tests (SEM) were used. The results showed that they were suitable to be used as indoor coverings of buildings. However, a treatment to reduce the moisture absorption of the wood waste must be studied if mixtures with high percentages of wood shavings (WS20) are used in wet rooms

Forjados de madera de entrevigado cuajado con residuos cerámicos de demolición

The present work is the continuity of the research carried out by the group TEP 205, "Analysis and evaluation of construction and structural systems in Architecture", focused on domestic architecture building typologies of cities as Seville or Cordoba from the seventeenth to the twentieth centuries. The aim of the study, mainly experimental, is to develop a new infill piece, from the reuse of ceramic waste generated in demolition works. This piece is intended to be used in the floors of this building typology. Different test models reproducing the geometry and structural characteristics of these slabs have been developed. In these models different dosages of mortars and geometries are studied, in order to achieve the necessary strength for their use on the building site. As a result, we have developed a piece in which resistance values reaches up to 137 Kgf, higher than the values required to prefabricated concrete slabs according to regulations.El trabajo realizado es una continuidad en la línea de investigación del grupo TEP-205, “Análisis y evaluación de sistemas constructivos y estructurales en la Arquitectura”, centrada en las tipologías edificatorias de la arquitectura doméstica de ciudades como Sevilla o Córdoba de los siglos XVII al XX. El objeto del trabajo, fundamentalmente experimental, consiste en desarrollar una nueva pieza de entrevigado, a partir del reaprovechamiento de los residuos cerámicos generados en las tareas de demolición. Esta pieza está destinada a emplearse en los forjados de entrevigado cuajado característicos de esta tipología edificatoria. Para la definición de este elemento se han elaborado diferentes modelos de ensayo reproduciendo la geometría y características constructivas de estos forjados. En estos modelos se estudian diferentes dosificaciones de morteros y geometrías, en aras de alcanzar la capacidad resistente necesaria para su utilización en obra. Como esultado, se ha desarrollado una pieza en la que se alcanzan valores resistentes de hasta 137 Kgf, superiores a los valores exigidos a las bovedillas prefabricadas de hormigón según normativa

Inspección with non destructive techniques of a historic building: oratorio San Felipe Neri (Cádiz)

El objetivo de este artículo es dar a conocer los resultados obtenidos al aplicar técnicas no destructivas de inspección (ultrasonidos y termografía) durante las obras de reparación de un edificio de gran valor histórico y artístico. Estas técnicas no destructivas se han aplicado en la inspección de la cubierta de madera del edificio para detectar distintos estados de deterioro, pérdidas de densidad y defectos, con el objetivo de evaluar su estado de conservación. Se ha realizado un trabajo de campo donde se ha aplicado ambas técnicas conjuntamente, los ultrasonidos, técnica eficaz para establecer el diagnóstico de una estructura de madera, y la termografía, técnica menos experimentada en la inspección in situ de este material. El objetivo es acotar el alcance y las posibilidades reales de utilización de cada una de las técnicas. En este sentido, se aplica la metodología de ultrasonidos desarrollada y publicada por las autoras y se estudia la termografía como herramienta de inspección in situ analizando las dificultades añadidas y parámetros de interferencia no detectados en laboratorio. Las conclusiones del trabajo ponen de manifiesto que la unión de la técnica de ultrasonidos y la termografía constituyen una buena herramienta para la inspección in situ de las estructuras de madera y para evaluar sus condiciones permitiendo establecer un diagnóstico adecuado. La termografía permite detectar distintos contenidos de humedad y distintos materiales y, por otro lado, los ultrasonidos los distintos grados de deterioro o pérdida de densidad en zonas localizadas con elevado contenido de humedad de las piezas.The main aim of this article is showing the results that have been obtained when non destructive techniques (ultrasound and thermography) are applied to a building with an important artistic and historical value. These non-destructive techniques have been applied in the inspection of the wooden roof structure to detect different states of deterioration, loss of density and defects. The aim is the assessment the state of the preservation of the wooden structure. A fieldwork has been carried out, where the two techniques have been applied together, ultrasound, an effective technique to establish the diagnosis of a wooden structure, and the thermography, a technique less tested in the in situ inspection of this material. The aim is checking the range and the real possibilities of using of each technique. In this sense, the methodology of ultrasound developed and published by the authors is applied and the thermography like in situ inspection tool, analysing additional difficulties and interference parameters not found in laboratory. The conclusions of this study show that the union of the ultrasound technique and the thermography is a good tool for on-site inspection of wooden structures and to assess their conditions allowing establishing a proper diagnosis. Thermography can detect different moisture contents and different materials and, on the other hand, ultrasound detects different states of deterioration or loss of density in specific areas with a high moisture content of the piece

Reuse of CD and DVD wastes as reinforcement in Gypsum Plaster Plates

The continuous and rapid evolution in the field of computing, and in particular in the field of storage devices, has led to the obsolescence of optical discs in favour of mass storage devices.In that sense, a large number of CDs and DVDs become obsolete each day in the world. In trying to create a recovery solution for those pieces, research in which polycarbonate (PC) waste from recycled discs have been used to develop new gypsum coating materials and products has beenconducted. In a previous study, the physical and mechanical properties of new gypsum plasters, with PC waste as aggregate, were studied. Following that study, this article aims at creating new gypsum plaster false ceiling plates, using CD and DVD residues in different scenarios: as crushed aggregatein the gypsum matrix, as full reinforcement pieces of the plates and as a combination of both. The mechanical behaviour and the thermal conductivity of the new pieces have been analysed in this paper. The results showed an important improvement in the mechanical and thermal properties ofthe plates when the PC waste was used in many scenario

Improving the Advantages of Single Port in Right Hemicolectomy: Analysis of the Results of Pure Transumbilical Approach with Intracorporeal Anastomosis

Background. Single-port laparoscopic surgery has recently emerged as a method to improve patient recovery and cosmetic benefits of laparoscopic surgery. The evolution of our technique has led us to move from a periumbilical incision to a transumbilical one, avoiding the use of drain and maintaining a pure single-port approach with intracorporeal anastomosis in order to maintain the incision as smaller as possible. Method. We report a prospective clinical analysis of our first 38 patients. Oncological surgical steps were followed as during the standard laparoscopic approach, performing the anastomosis intracorporeally in all cases. Results. Mean age of 68,39 years old and an average BMI of 27,88%. (range 19,81–41,5). Most lesions were adenocarcinoma (65,8%), while the remaining were polyps (31,5%) and one a mucocele of the appendix. We moved from a periumbilical incision, initial 14 cases, into a transumbilical one, (medium size of the incision 3,25 cm). Average surgical time was 117,42 minutes. Drains was only used in our first 3 cases. Mean hospital stay was 5,2 days, (86,5% stayed less than 5 days). Total morbidity was 13%. Histological exams of the specimens showed that the oncological criteria were preserved. Conclusions. Single-port right hemicolectomy with intracorporeal anastomosis is feasible and safe. The advantages of a total intracorporeal anastomosis include that there is no need to enlarge the umbilical incision and avoid traction of the pedicle of the mesenterium of the transverse colon during the extracorporeal anastomosis. A transumbilical incision offers better cosmetic results, and the use of drains can be avoided, which increase, patient's satisfaction

Microstructure formation of cement mortars modified by superabsorbent polymers

The utilization of superabsorbent polymers (SAPs) in cement-based materials has been found to be a promising means of mitigating the autogenous propagation of shrinkage and cracks. On the other hand, the undesired effects of SAPs’ application on functional properties, including mechanical strength, microstructure formation, and the evolution of hydration heat are not properly understood, given the variety in SAPs’ characteristics. To contribute to the present state-of-theart, cement mortars, modified with two grades of SAPs by dosages of 0.3%, 0.6%, and 0.9%, were designed and studied with emphasis on the relationship between the materials’ porosities and mechanical strengths. The obtained results are interpreted by scanning electron microscopy analysis and hydration heat evolution to elucidate the major changes and their driving factors. Besides the benefits associated with the mitigation of autogenous shrinkage, the achieved results point to an adverse effect of supplementation with SAP on mechanical strength at an early age, and an even more pronounced increase at a later age. The employed scanning electron microscopy images, together with mercury-intrusion porosimetry data, depict distortion in the material porosity as a result of the filling of formed voids and the closing of open ends by swelled hydrogels. Only the minor benefit of a greater cross-linking density was obtained by the formation of dense structures and the gains in mechanical strength therefrom.Czech Science Foundatio

Melanoma and nevi subtype histopathological characterization with optical coherence tomography

Background: Melanoma incidence has continued to rise in the latest decades, and the forecast is not optimistic. Non-invasive diagnostic imaging techniques such as optical coherence tomography (OCT) are largely studied; however, there is still no agreement on its use for the diagnosis of melanoma. For dermatologists, the differentiation of non-invasive (junctional nevus, compound nevus, intradermal nevus, and melanoma in-situ) versus invasive (superficial spreading melanoma and nodular melanoma) lesions is the key issue in their daily routine. Methods: This work performs a comparative analysis of OCT images using haematoxylin-eosin (HE) and anatomopathological features identified by a pathologist. Then, optical and textural properties are extracted from OCT images with the aim to identify subtle features that could potentially maximize the usefulness of the imaging technique in the identification of the lesion?s potential invasiveness. Results: Preliminary features reveal differences discriminating melanoma in-situ from superficial spreading melanoma and also between melanoma and nevus subtypes that pose a promising baseline for further research. Conclusions: Answering the final goal of diagnosing non-invasive versus invasive lesions with OCT does not seem feasible in the short term, but the obtained results demonstrate a step forward to achieve this.This work has been funded by the Department of Economic Development, Sustainability and the Environment of the Basque Government (Spain) ELKARTEK projects ONKOTOOLS with grant numbers KK-2020/00069, the Spanish Ministry of Science and Education CERVERA project AI4ES with grant numbers CER-20211030, and by the ECSEL JU European project ASTONISH with the grant number 692470, UC Industrial Doctorate DI14