1,373 research outputs found

    Garadam, corbelled dome architecture in Azerbaijan

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    THE CHORÁ OF PATMOS (GREECE): ANALYSIS OF ARCHITECTURAL HERITAGE, IDENTIFICATION OF RISKS AND ASSESSMENT OF IMPACTS

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    Abstract. The Historic Center (Chorá) of Patmos, located in one of the Dodecanese Islands of Greece, was inscribed in the World Heritage List in 1999. The morphological feature, the housing typologies and the building techniques that characterize the Chorá provide an authentic and astonishing expression of the stylistic and typological models of the vernacular architecture of the Greek islands. This paper presents part of the research carried out on the Chorá of Patmos, within the 3D Past project, funded by the European Creative Europe program. The first part illustrates the results of the research concerning the analysis of the material components of the architectural heritage of Patmos: the urban structure, the evolution of the main architectural typologies, the feature of the main building systems. The second part of the paper presents the application of the Heritage Impact Assessment (HIA), a tool for the management of site transformations and in particular for identifying, forecasting and evaluating the impact of potential development on the Outstanding Universal Value (OUV) of the properties. In the case of Patmos the application of HIA can provide an important contribution to manage changes and future transformations in order to preserve the cultural significance of the site and ensure its sustainable development

    Direct Differential Photometric Stereo Shape Recovery of Diffuse and Specular Surfaces

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    This is the author accepted manuscript. The final version is available from Springer via http://dx.doi.org/10.1007/s10851-016-0633-0Recovering the 3D shape of an object from shading is a challenging problem due to the complexity of modeling light propagation and surface reflections. Photometric Stereo (PS) is broadly considered a suitable approach for high-resolution shape recovery, but its functionality is restricted to a limited set of object surfaces and controlled lighting setup. In particular, PS models generally consider reflection from objects as purely diffuse, with specularities being regarded as a nuisance that breaks down shape reconstruction. This is a serious drawback for implementing PS approaches, since most common materials have prominent specular components. In this paper, we propose a PS model that solves the problem for both diffuse and specular components aimed at shape recovery of generic objects with the approach being independent of the albedo values thanks to the image ratio formulation used. Notably, we show that by including specularities, it is possible to solve the PS problem for a minimal number of three images using a setup with three calibrated lights and a standard industrial camera. Even if an initial separation of diffuse and specular components is still required for each input image, experimental results on synthetic and real objects demonstrate the feasibility of our approach for shape reconstruction of complex geometries.The first author acknowledges the support of INDAM under the GNCS research Project “Metodi numerici per la regolarizzazione nella ricostruzione feature-preserving di dati.

    On the well-posedness of uncalibrated photometric stereo under general lighting

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    Uncalibrated photometric stereo aims at estimating the 3D-shape of a surface, given a set of images captured from the same viewing angle, but under unknown, varying illumination. While the theoretical foundations of this inverse problem under directional lighting are well-established, there is a lack of mathematical evidence for the uniqueness of a solution under general lighting. On the other hand, stable and accurate heuristical solutions of uncalibrated photometric stereo under such general lighting have recently been proposed. The quality of the results demonstrated therein tends to indicate that the problem may actually be well-posed, but this still has to be established. The present paper addresses this theoretical issue, considering first-order spherical harmonics approximation of general lighting. Two important theoretical results are established. First, the orthographic integrability constraint ensures uniqueness of a solution up to a global concave-convex ambiguity , which had already been conjectured, yet not proven. Second, the perspective integrability constraint makes the problem well-posed, which generalizes a previous result limited to directional lighting. Eventually, a closed-form expression for the unique least-squares solution of the problem under perspective projection is provided , allowing numerical simulations on synthetic data to empirically validate our findings

    An efficient Buchwald-Hartwig amination protocol enables the synthesis of new branched and polymeric hole transport materials for perovskite solar cells

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    Perovskite solar cells (PSCs) are experiencing tremendous interest due to compatibility with solution processing on a wide range of substrates and very high efficiency. The hole transport layer (HTL) plays a fundamental role in such multistack cells. We propose new branched and polymeric organic HTL derivatives with sustainable synthesis and performances exceeding those of Spiro-OMeTAD, the standard in the field

    The effect of ceramic YSZ powder morphology on coating performance for industrial TBCs

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    The increasing turbine inlet temperatures in modern gas turbines have raised concerns about the corrosion of ceramic thermal barrier coatings (TBCs) caused by molten silicate deposits, commonly referred to as “CMAS” due to their main constituents (CaO-MgO-Al2O3-SiO2). The objective of this study was to investigate the combined influence of powder morphology and chemical composition on the CMAS resistance and thermal cycling resistance of ceramic monolayer and bi-layer coatings created through Atmospheric Plasma Spraying (APS). Three powder morphologies were examined: porous Agglomerated and Sintered (A&S) granules, Hollow Spherical (HOSP) powders, and dense, irregular Fused and Crushed (F&C) particles. Monolayer 7-8YSZ coatings with both porous and dense vertically cracked (DVC) microstructures, and bi-layer coatings consisting of a bottom layer of porous standard 7-8YSZ and a top layer composed of a porous high‑yttrium ZrO2–55 wt% Y2O3 were obtained using all three powder types (A&S, HOSP, or F&C). Furthermore, the bi-layer systems were deposited with different ratios between the individual layer thicknesses and/or different total thickness. FEG-SEM, EDX, and micro-Raman analyses, were conducted to assess the coatings' performance. Nanoindentation high-speed mapping and pillar splitting test were performed to evaluate the mechanical behaviour. The study on 8YSZ monolayers shows that coatings from a F&C feedstock exhibit higher density, reducing the CMAS penetration. However, these coatings demonstrate poorer thermal cycling performance due to increased stiffness and thermal stresses. Coatings from HOSP and A&S powders allow CMAS penetration but offer stress relief pathways, enhancing the coating's ability to withstand thermal stresses. Bi-layer coatings with a 55YSZ top coat show superior CMAS resistance compared to 7-8YSZ monolayer coatings, with limited penetration causing top coat peeling. The thickness ratio between the layers also affects thermal cycling resistance, where a thinner 55YSZ layer extends the TBC lifetime

    Ten-week lifestyle changing program reduces several indicators for metabolic syndrome in overweight adults

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    We aim to investigate the effectiveness of a 10-week lifestyle intervention focusing on physical activity and high fiber intake for reducing indicators for metabolic syndrome in overweight-obese individuals. A prospective study of 50 overweight (OW) adults (22 in the general educational group - G1; 28 in the high fiber nutrition group - G2) was performed. Both groups were offered dietary counseling and supervised exercise. Clinical, anthropometric, dietary and plasma biochemical tests were performed at baseline - time 0 (T0) and after 10 weeks - time 1 (T1). Both groups improved their dietary quality, but only G2 presented higher intake of fruit and vegetables (servings/day), higher plasma β-carotene levels and a 24% reduction of MetS incidence. Additionally G2 showed greater reductions in body fat (4%), and waist circumference (7%), obesity class III (2%) and obesity class II (14%) rate. Lifestyle intervention, including a high dietary fiber intake, improved healthy eating index and decreased body fat composition and plasma lipid concentrations leading to MetS incidence reduction

    A sensitivity study of triboson production processes to dimension-6 EFT operators at the LHC

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    We present the first parton-level study of anomalous effects in triboson production in both fully and semi-leptonic channels in proton-proton collisions at 13TeV at the Large Hadron Collider (LHC). The sensitivity to anomalies induced by a minimal set of bosonic dimension-6 operators from the Warsaw basis is evaluated with specific analyses for each final state. A likelihood-based strategy is employed to assess the most sensitive kinematic observables per channel, where the contribution of Effective Field Theory operators is parameterized at either the linear or quadratic level. The impact of the mutual interference terms of pairs of operators on the sensitivity is also examined. This benchmark study explores the complementarity and overlap in sensitivity between different triboson measurements and paves the way for future analyses at the LHC experiments. The statistical combination of the considered final states allows setting stringent bounds on five bosonic Wilson coefficients

    THE EUROPEAN PROJECT "VERSUS+ / HERITAGE FOR PEOPLE". OBJECTIVES AND METHODOLOGY

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    Abstract. The project "VerSus+ / Heritage for PEOPLE", founded by the European Commission as part of the Creative Europe Culture Programme (Ref. 607593-CREA-1-2019-1-ES-CULT-COOP1) during the period 2019–2023, focuses on the transmission of knowledge to all branches of society and the general public. Its aim is to raise awareness on what constitutes the basis for the conservation of the tangible and intangible heritage as well as for a more sustainable contemporary architecture. This in-depth transmission of the lessons from vernacular heritage to future society is to be carried out in specific defined contexts, such as islands and archipelagos (geographically limited territories that are accessible to collaborators and administrative, technical and social agents), where vernacular heritage is under pressure, subjected to the transformations of contemporary life, particularly mass tourism. These pilot experiences should serve as a real testing ground for the implementation of actions for social participation, dissemination, education, communication, and promotion in different contexts and through different media. This project aims to reach out to society in order to showcase the sustainable qualities of the examples identified, through the establishment of an operative approach that can be adjusted to different contexts. The experiences on each island are expected to have repercussions throughout the region and, in turn, throughout the country in question, improving the perspectives and opportunities starting from best practices, and promoting the development of local skills. In addition, promotion and support from partners and associate partners will allow these experiences to be applied in other similar European and international contexts
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