model-based analysis and experimental assessment of key design parameters for an integrated unglazed metallic thermal collector façade,

The building sector presents poor performance in terms of energy efficiency and is looking for effective alternatives aimed at reducing the use of fossil fuels. The facade is a key element able to harness renewable energy as an Active Solar Thermal Facade (ASTF). The main purpose of this study is the assessment of a novel design concept based on a steel sandwich panel technology. The performance of the active system will be first addressed by a parametric study in order to analyze its behavior and secondly, by describing a real case based on an experimental test by connecting the active panels to a heat pump. The study shows the impact of solar irradiation and mass flow on the thermal jump achieved, while ambient and fluid inlet temperatures are the most influencing parameters in the efficiency of the facade. When coupled to the heat pump, results from a measurement campaign demonstrate a remarkable improvement in the performance of the ASTF. The results presented provide significant proof about the benefits of a synergetic combination of both technologies—solar facades and heat pumps—as efficient alternatives for the building sector, aiming to improve energy efficiency as well as reduce their dependence on non-renewable sources.

ARIEL LÓPEZ Réflexions à propos de R. Bagnall (éd.), Egypt in the Byzantine World, 300-700 (Cambridge, 2007) Ces lignes proposent le compte rendu d'un ouvrage collectif issu du Dumbarton Oaks Spring Symposium in Byzantine Studies tenu en 2004 et consacré à « l'Égypte dans le monde byzantin, 450-700 ». Deux principaux thèmes régissent l'ensemble du volume : l'un concerne les effets des changements et/ou des permanences qu'a manifestementconnus le V e siècle mais qui n'ont laissé que très peu de témoignages ; l'autre le potentiel qu'offre une histoire comparative qui inscrit l'Égypte dans contexte élargi du Proche-Orient romain tardif.

AINHOA RODRÍGUEZ LÓPEZ Universidad del País Vasco (UPV/EHU) FERNANDO BAZETA GOBANTES Universidad del País Vasco (UPV/EHU)1 El presente artículo forma parte del proyecto "Estudio de técnicas pictóricas en relieve en el País Vasco" fi nanciado por el programa de Becas Postdoctorales del Gobierno Vasco y desarrollado en 2011 en el Straus Center for Conservation and Technical Studies-Harvard Art Museum y la Facultad de Letras de la Universidad del País Vasco (UPV/EHU).Resumen: El término brocado de estaño en relieve aplicado (comúnmente conocido como brocado aplicado) se refi ere a una decoración polícroma que imita los brocados de terciopelo y seda hechos con hilos de oro y plata, los cuales dominan el mundo de la moda de Europa en los siglos XV y XVI. Esta técnica reproduce mecánicamente a través de una matriz, lámina de estaño y masa de relleno motivos en relieve de brocados textiles, que, una vez recortados, son aplicados sobre la obra, pudiendo estar en ocasiones dorados y pintados. El hallazgo de más ejemplos de esta decoración en el Norte de España nos ha conducido a analizar las fuentes documentales, especialmente las españolas, con el objetivo de ampliar nuestro conocimiento sobre la técnica en cuestión, su evolución histórica y material y sus diferentes tipologías. Asimismo, dicho estudio nos ha proporcionado un importante glosario de técnicas pictóricas en relieve por adición precursoras del brocado de estaño en relieve aplicado. Abstract:The term applied tin-relief brocade (commonly called applied brocade) refers to painted decoration that simulates the velvet and silk brocades made of gold and silver threads commonly used in Europe in the fi fteenth and sixteenth centuries. This technique uses a mould, tin leaf, and fi lling mass to reproduce in a mechanical way the relief motifs of textile brocades. Once cut, they are applied to artwork, and then sometimes gilded or painted. The discovery of many examples of this type of decoration in northern Spain has led us to the study of the documentary sources, especially Spanish ones, with the purpose of improving our understanding of the technique, its historic and material development, and the typology of standardized patterns. Furthermore, this study has provided us with an important glossary of the relief painting additive techniques that culminated in applied tinrelief brocade. INTRODUCCIÓNEl brocado de estaño en relieve aplicado se ha empleado en una gran variedad de obras de arte, entre las cuales se incluyen: retablos de madera, esculturas de madera, esculturas de piedra (por ejemplo, caliza), relieves de madera, pinturas sobre tabla, pinturas murales, pinturas sobre lienzo y artesonados de madera.El objetivo de este artículo es presentar una revisión detallada del brocado de estaño en relieve aplicado desde una perspectiva histórica, material y estilística, con atención a los casos hallados en España. En el artículo, mediante el análisis de la documentación (publicada y sin publicar) sobre brocados de estaño en relieve aplicados, localizados en retablo...

The building sector has a poor performance in terms of energy efficiency and is looking for alternatives to reduce the use of fossil fuels on building use stage. Renewables are unlimited and solar thermal energy is a technology with a demonstrated potential. The façade is a key element able to harness renewable energy coming from the sun becoming in an Active Solar Thermal Façade (ASTF). The main purpose of this study is the development of a parametric study using a numerical model to analyze the behavior of an unglazed solar collector. Thus, evaluating different design and meteorological parameters to show their influence on the heat transfer and the efficiency. The study shows that solar irradiation and mass flow are the most influential on thermal difference. However, for the efficiency ambient temperature and inlet temperature both are the most influencing ones. In brief, a set of parameters have a significant influence on the behavior of the ASTF that are fully governed by environmental conditions. Nevertheless, there are some other parameters that can be controlled during the operation. The challenge is to make a continuous configuration of this adaptable values depending on the external situation to achieve a higher performance for the ASTF.