1,957 research outputs found
Estudio de las construcciones de tapia en la zona norte de Monforte de Lemos
En Galicia predomina la construcción en piedra, aunque haya un gran número de patrimonio de tierra poco conocido, en áreas sedimentarias, como es el caso de Monforte de Lemos. Existe un vacío en el conocimiento sobre las edificaciones de tierra en Galicia, por parte de investigadores, constructores y agentes técnicos locales, teniendo como consecuencia directa la pérdida de información del patrimonio tangible. Por este motivo, la investigación se basa en la realización de un inventario de las construcciones en tierra en el patrimonio urbano de la zona norte de Monforte, y en el estudio de las edificaciones de tapia en función de su tipología y características constructivas.
Al no existir ningún catálogo que recopilase las construcciones de tierra de la zona norte de la ciudad, el primer objetivo se centra en inventariar su patrimonio urbano de tierra. Asimismo, el segundo objetivo de la investigación analiza las edificaciones de tierra en función de su tipología y sus características constructivas.
El profundo estudio del patrimonio urbano de la zona norte de Monforte de Lemos, posibilitó localizar e inventariar ochenta y cuatro edificaciones construidas con tierra y seleccionar y analizar en mayor profundidad, dieciseis casos de estudio.
El estudio ha contribuido a esclarecer, la existencia de un patrimonio urbano de tierra en Monforte de Lemos y comprender la tipología espacial, los materiales y los sistemas constructivos de las edificaciones de tierra.Traballo fin de mestrado (UDC.ETSA). Rehabilitación arquitectónic
Culturas constructivas de tierra en Monforte de Lemos, Galicia
En Galicia, noroeste de España, predomina la construcción en piedra, aunque haya un gran número de patrimonio de tierra poco conocido, en áreas sedimentarias, como es el caso de Monforte de Lemos. Existe un vacío en el conocimiento sobre las culturas constructivas en tierra en Galicia, por parte de investigadores, constructores y agentes técnicos locales, teniendo como consecuencia directa la pérdida de información del patrimonio tangible. Por este motivo, la investigación se basa en la realización de un inventario de las construcciones en tierra en el patrimonio urbano de Monforte, y en el estudio de las culturas constructivas locales.
Al no existir ningún catálogo que recopilase las construcciones de tierra en Monforte de Lemos, el primer objetivo se centra en inventariar su patrimonio urbano de tierra. Asimismo, el segundo objetivo de la investigación establece relaciones justificativas entre la tipología espacial, los materiales y los sistemas constructivos, en el patrimonio de tierra y el contexto local.
La investigación se estructura en la revisión de la literatura sobre la problemática establecida; el análisis de las tipologías espaciales y de las culturas constructivas, resultante de los nueve casos de estudio y de las doscientas edificaciones inventariadas; y en la correlación de la referida análisis con el estado del arte y la contextualización, los resultados obtenidos de la investigación desarrollada y su contribución para el conocimiento de las culturas constructivas.
El profundo estudio del patrimonio urbano de Monforte de Lemos, posibilitó localizar y inventariar doscientas edificaciones construidas con tierra y seleccionar y analizar en mayor profundidad, nueve casos de estudio. Como resultado, se constató la existencia de una tipología con pocas variantes espaciales, pero con diversas culturas constructivas en tapia. Se observa en la tapia, la presencia de cantos rodados, elementos horizontales de madera a lo largo del muro perimetral, así como láminas de pizarra. En definitiva, el estudio ha contribuido a esclarecer, la existencia de un patrimonio urbano de tierra en Monforte de Lemos y comprender la tipología espacial, los materiales y los sistemas constructivos de las edificaciones de tierra.Abstract: In Galicia, located in the northwest of Spain, stone construction prevails, even though there is a great amount of earth heritage in sedimentary areas like Monforte de Lemos, which is rarely known. There is a void in the knowledge about earth building cultures in Galicia by investigators, constructors and local technical agents that causes a loss of tangible information, as an immediate consequence. Therefore, this investigation is oriented to the creation of an inventory of earth structures belonging to the urban heritage of Monforte de Lemos, as well as the study of the local building cultures.
The first objective of this work is to make an inventory of the earth building urban heritage of Monforte de Lemos. Also, the second purpose of this investigation is to establish justifying relationships between spatial typology, materials and construction systems in earth heritage and the local context.
The methodology of the present investigation is based in the review of the literature about the already established difficulties, as well as the analysis of spatial typologies and building cultures which emerges from nine case studies and two hundred inventoried structures. This investigation also takes into account their interrelationship with the state of art, the results obtained from the research and their contribution to the knowledge of local building cultures.
The deep study of the urban heritage of Monforte de Lemos allowed the location and inventory of two hundred earth-built structures and a selection and more exhaustive analysis of nine case studies. As a result, the existence of a typology with few spatial variations but several building cultures in walls was verified. The presence of boulders, horizontal pieces of wood along the perimeter wall, as well as slate sheets can be seen in the walls. In conclusion, this study has contributed to the clarification of the existence of an earth-built urban heritage in Monforte de Lemos and to the comprehension of the spatial typology, the materials and the construction systems of earth structures
Simplifying the process to perform air temperature and UHI measurements at large scales: Design of a new APP and low-cost Arduino device
The main purpose of Urban Heat Island (UHI) studies and the monitoring of ambient temperatures at large scales is to gather temperature information in a certain area, so as to understand temperature heterogeneity and its drivers or detect locations that lack thermal comfort. However, these studies originate mostly from some research projects, with sufficient budget and manpower to carry out the measurements and the necessary calculations. Thus, there is a scarcity of air temperature information, making it difficult to implement appropriate mitigation actions worldwide. The present work aims to greatly simplify the process to monitor air temperatures and carry out UHI estimations through mobile transects. This is done by introducing the design of a low-cost device and a new APP, which performs automatically most necessary UHI calculations. A web tool based on the Inverse Distance Weighting interpolation method is also included to obtain heat maps. The methodology is illustrated using case studies in Seville (Spain) and New York city (USA). By introducing a straightforward and reproducible methodology, we aim to open the path for a more widespread availability of ambient temperature data anywhere in the world, without the need for costly equipment and many hours of dedication by the researcher
Analysis of the economic feasibility and reduction of a building’s energy consumption and emissions when integrating hybrid solar thermal/PV/micro-CHP systems
The aim of this paper is to assess the performance of several designs of hybrid systems composed of solar thermal collectors, photovoltaic panels and natural gas internal combustion engines. The software TRNSYS 17 has been used to perform all the calculations and data processing, as well as an optimisation of the tank volumes through an add-in coupled with the GENOPT® software. The study is carried out by analysing the behaviour of the designed systems and the conventional case in five different locations of Spain with diverse climatic characteristics, evaluating the same building in all cases. Regulators, manufacturers and energy service engineers are the most interested in these results.
Two major contributions in this paper are the calculations of primary energy consumption and emissions and the inclusion of a Life Cycle Cost analysis. A table which shows the order of preference regarding those criteria for each considered case study is also included. This was fulfilled in the interest of comparing between the different configurations and climatic zones so as to obtain conclusions on each of them. The study also illustrates a sensibility analysis regarding energy prices. Finally, the exhaustive literature review, the novel electricity consumption profile of the building and the illustration of the influence of the cogeneration engine working hours are also valuable outputs of this paper, developed in order to address the knowledge gap and the ongoing challenges in the field of distributed generation
Mitigating energy poverty: Potential contributions of combining PV and building thermal mass storage in low-income households
The issue of energy poverty has devastating implications for the society, and it has been aggravated in the past years due to the economic crisis and the increase of energy prices. Among the most affected are those with low incomes and living in inefficient buildings. Unfortunately, the bitter reality is that sometimes this part of the population are facing the next question: Heating, or eating? The declining prices of distributed energy technologies such as photovoltaics provides an opportunity for positive social change. Although their use does not address energy poverty directly, substantial contributions may be made.
Measurements of indoor temperatures in a social housing district of southern Spain in 2017 have revealed the unbearable temperatures that the occupants have to endure, both in summer and winter. Using this district as a case study, the present work aims to evaluate the benefits of exploiting its rooftop PV potential to cover part of the electricity consumption of the district (reducing the energy bills), and use the surplus electricity to supply power for the heat pumps in the district. Optimal alternatives regarding maximum PV production, maximum self-sufficiency ratio and minimum investment costs have been found, considering as well different options when sharing the available electricity surplus to improve the thermal comfort of the occupants. As far as the authors know, no previous study has followed an approach aimed at energy poverty alleviation such as the one presented in this work. The results show that using the surplus electricity to heat or cool the whole dwellings would improve the thermal comfort of the occupants in average up to 11% in winter and 26% in summer. If all the PV generation was used or more buildings in the area were employed to install PV modules, improvements up to 33% in winter and 67% in summer could be obtained, reducing at the same time the thermal comfort differences among the dwellings of the district
Contributions of heat pumps to demand response: A case study of a plus-energy dwelling
- Premio ETSI al mejor artículo científico del Trimestre. Junio 2018.
- Artículo subido a idUS con permiso de su primera autora (Laura Romero Rodríguez), que proporciona las versiones preprint y postprint.Demand Response programs are increasingly used in the electricity sector, since they allow consumers to play a significant role for balancing supply and demand by reducing or shifting their electricity consumption. For that purpose, incentives such as time-based rates have been proposed. The present study analyzes the potential benefits of operating the heat pump of a plus-energy dwelling which participates in a dynamic pricing market, benefitting from the thermal storage capacity of the building. The software TRNSYS 17 has been used to model the building and the supply system. A validation of the model was carried out by using available measurements of the dwelling.
Three setpoint temperature scenarios have been considered for sixteen different strategies which depend on temperature and electricity price thresholds, with the aim of determining which alternatives could lead to significant savings while maintaining an acceptable thermal comfort. Several factors such as cost savings, heat pump consumption, ratio of self-consumption of the dwelling and use of the heat pump during peak hours were also evaluated in every case.
The results show that dynamic price thresholds should be used instead of fixed price thresholds, which may cause low activations of the heat pump or overheat the building above the comfort limits. Cost savings up to 25% may be achieved by using optimal strategies, increasing the self-consumption ratio, having almost no influence on the thermal comfort and achieving significant peak reductions on the grid. The outcomes of this study show the importance of looking at the implications of such strategies on several criteria within a demand response framework.Ministerio de Economía y CompetitividadUniversidad de Sevilla. V Plan Propio de Investigación (VPPI-US)Unión Europea. Horizon2020. Grant agreement No. 69596
Basement membrane-rich Organoids with functional human blood vessels are permissive niches for human breast cancer metastasis
Metastasic breast cancer is the leading cause of death by malignancy in women worldwide. Tumor metastasis is a multistep process encompassing local invasion of cancer cells at primary tumor site, intravasation into the blood vessel, survival in systemic circulation, and extravasation across the endothelium to metastasize at a secondary site. However, only a small percentage of circulating cancer cells initiate metastatic colonies. This fact, together with the inaccessibility and structural complexity of target tissues has hampered the study of the later steps in cancer metastasis. In addition, most data are derived from in vivo models where critical steps such as intravasation/extravasation of human cancer cells are mediated by murine endothelial cells. Here, we developed a new mouse model to study the molecular and cellular mechanisms underlying late steps of the metastatic cascade. We have shown that a network of functional human blood vessels can be formed by co-implantation of human endothelial cells and mesenchymal cells, embedded within a reconstituted basement membrane-like matrix and inoculated subcutaneously into immunodeficient mice. The ability of circulating cancer cells to colonize these human vascularized organoids was next assessed in an orthotopic model of human breast cancer by bioluminescent imaging, molecular techniques and immunohistological analysis. We demonstrate that disseminated human breast cancer cells efficiently colonize organoids containing a functional microvessel network composed of human endothelial cells, connected to the mouse circulatory system. Human breast cancer cells could be clearly detected at different stages of the metastatic process: initial arrest in the human microvasculature, extravasation, and growth into avascular micrometastases. This new mouse model may help us to map the extravasation process with unprecedented detail, opening the way for the identification of relevant targets for therapeutic intervention
Improving the accessibility at home: implementation of a domotic application using a p300-based brain computer interface system
The aim of this study was to develop a Brain Computer Interface (BCI) application to control domotic devices usually present at home. Previous studies have shown that people with severe disabilities, both physical and cognitive ones, do not achieve high accuracy results using motor imagery-based BCIs. To overcome this limitation, we propose the implementation of a BCI application using P300 evoked potentials, because neither extensive training nor extremely high concentration level are required for this kind of BCIs. The implemented BCI application allows to control several devices as TV, DVD player, mini Hi-Fi system, multimedia hard drive, telephone, heater, fan and lights. Our aim is that potential users, i.e. people with severe disabilities, are able to achieve high accuracy. Therefore, this domotic BCI application is useful to increase their personal autonomy and independence, improving their quality of life.Peer Reviewe
QR-Factorization Algorithm for Computed Tomography (CT): Comparison With FDK and Conjugate Gradient (CG) Algorithms
[EN] Even though QR-factorization of the system matrix for tomographic devices has been already used for medical imaging, to date, no satisfactory solution has been found for solving large linear systems, such as those used in computed tomography (CT) (in the order of 106 equations). In CT, the Feldkamp, Davis, and Kress back projection algorithm (FDK) and iterative methods like conjugate gradient (CG) are the standard methods used for image reconstruction. As the image reconstruction problem can be modeled by a large linear system of equations, QR-factorization of the system matrix could be used to solve this system. Current advances in computer science enable the use of direct methods for solving such a large linear system. The QR-factorization is a numerically stable direct method for solving linear systems of equations, which is beginning to emerge as an alternative to traditional methods, bringing together the best from traditional methods. QR-factorization was chosen because the core of the algorithm, from the computational cost point of view, is precalculated and stored only once for a given CT system, and from then on, each image reconstruction only involves a backward substitution process and the product of a vector by a matrix. Image quality assessment was performed comparing contrast to noise ratio and noise power spectrum; performances regarding sharpness were evaluated by the reconstruction of small structures using data measured from a small animal 3-D CT. Comparisons of QR-factorization with FDK and CG methods show that QR-factorization is able to reconstruct more detailed images for a fixed voxel size.This work was supported by the Spanish Government under Grant TEC2016-79884-C2 and Grant RTC-2016-5186-1.Rodríguez-Álvarez, M.; Sánchez, F.; Soriano Asensi, A.; Moliner Martínez, L.; Sánchez Góez, S.; Benlloch Baviera, JM. (2018). QR-Factorization Algorithm for Computed Tomography (CT): Comparison With FDK and Conjugate Gradient (CG) Algorithms. IEEE Transactions on Radiation and Plasma Medical Sciences. 2(5):459-469. https://doi.org/10.1109/TRPMS.2018.2843803S4594692
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