Export 9189 results:
Sort by: Author Title Type [ Year  (Desc)]
2014
Miguel, Catarina, Joana V. Pinto, Mark Clarke, and Maria J. Melo. "The alchemy of red mercury sulphide: The production of vermilion for medieval art." Dyes and Pigments. 102 (2014): 210-217. AbstractWebsite

Vermilion red, mercury sulphide (α-HgS), was one of the most important reds in art and its use as a pigment dates back to Antiquity. In medieval Europe, it could be mined as cinnabar, or produced as vermilion by heating mercury with sulphur. This work aims to study the production of synthetic vermilion as a medieval pigment and to confirm which was the source (mineral or artificial) of the reds used in Portuguese medieval illuminations. The production of synthetic vermilion was based on the process described in the Judaeo-Portuguese medieval treatise “The book on how to make colours”, using materials and technologies as close as possible to the medieval ones. The reaction mechanism was studied by following the heating process by X-ray diffraction, and it was possible to conclude that the transformation from black cubic β-HgS into red hexagonal α-HgS is a solid-state phase transition, occurring at 235 °C. This result is contrary to what published in technical art literature, in which this process is described as a sublimation. Moreover, Scanning Electron Microscopy evidenced a sinterization effect on the artificial vermilion, not found in medieval original samples nor in paints prepared with mineral cinnabar from Almadén (Spain). Red mercury sulphide, natural and synthetic, was then prepared as a parchment-glue paint and compared to proteinaceous red paints from 12th–13th century miniatures produced in important medieval monasteries, previously fully characterized by a multi-analytical approach (μ-Energy dispersive X-ray fluorescence, μ-Fourier Transform Infrared Spectroscopy, Raman microscopy). A comparative Electron probe microanalysis of the red paints point to a mineral provenance for medieval vermilion found in Portuguese illuminations.

Valério, P., A. M. Monge Soares, M. Fátima Araújo, R. J. C. Silva, E. Porfírio, and M. Serra. "Arsenical copper and bronze in Middle Bronze Age burial sites of southern Portugal: The first bronzes in Southwestern Iberia." Journal of Archaeological Science. 42.1 (2014): 68-80. AbstractWebsite
n/a
Baltazar, Luis G., Fernando MA Henriques, Fernando Jorne, and M. T. Cidade. "Combined effect of superplasticizer, silica fume and temperature in the performance of natural hydraulic lime grouts." 50 (2014): 584-597. Abstract
n/a
Silva, Manuel A. G., Maria T. Cidade, Hugo Biscaia, and Rui Marreiros. "Composites and FRP-strengthened beams subjected to dry/wet and salt fog cycles." 26.12 (2014): 04014092. Abstract
n/a
Fliedel, C., V. Rosa, C. I. M. Santos, P. J. Gonzalez, R. M. Almeida, C. S. B. Gomes, P. T. Gomes, M. A. N. D. A. Lemos, G. Aullón, R. Welter, and T. Avilés. "Copper(ii) complexes of bis(aryl-imino)acenaphthene ligands: Synthesis, structure, DFT studies and evaluation in reverse ATRP of styrene." Dalton Transactions. 43.34 (2014): 13041-13054. AbstractWebsite
n/a
Pereira, Sónia, Alexandra Gonçalves, Nuno Correia, Joana Pinto, LuÍs Pereira, Rodrigo Martins, and Elvira Fortunato. "Electrochromic behavior of NiO thin films deposited by e-beam evaporation at room temperature." Solar Energy Materials and Solar Cells. 120, Part A (2014): 109-115. AbstractWebsite

In this work we report the role of thickness on electrochromic behavior of nickel oxide (NiO) films deposited by e-beam evaporation at room temperature on ITO-coated glass. The structure and morphology of films with thicknesses between 100 and 500 nm were analyzed and then correlated with electrochemical response and transmittance modulation when immersed in 0.5 M LiClO4–PC electrolyte. The NiO exhibits an anodic coloration, reaching for the thickest film a transmittance modulation of 66% between colored and bleached state, at 630 nm, with a color efficiency of 55 cm2 C−1. Very fast switch between states was obtained, where coloration and bleaching times are 3.6 s cm−2 and 1.4 s cm−2, respectively.

Goswami, Sumita, Tiago Brehm, Sergej Filonovich, and Maria Teresa Cidade. "Electrorheological properties of polyaniline-vanadium oxide nanostructures suspended in silicone oil." 23.10 (2014): 105012. Abstract
n/a
Cismasiu, Corneliu, Filipe Amarante dos Santos, and Ana Rodrigues. "Experimental and FE updating techniques for the unseating vulnerability assessment of a footbridge structure." The 4th International Conference on Dynamics, Vibration and Control. Shanghai, China: Shanghai Institute of Applied Mathematics and Mechanics, 2014.
Acker, Arnold Van, Carlos Chastre, Barry Crisp, David Fernandez, Válter Lúcio, Kim S. Elliott, Simon Hughes, George Jones, Holger Karutz, Ronald Klein-Holte, Stef Maas, Marco Menegotto, Spyros Tsoukantas, and Pieter van der Zee fib Bulletin 74. Planning and design handbook on precast building structures. fib bulletin. Lausanne: International Federation for Structural Concrete (fib), 2014. AbstractWebsite

In 1994 fib Commission 6: Prefabrication edited a successful Planning and Design Handbook that ran to approximately 45,000 copies and was published in Spanish and German.Nearly 20 years later Bulletin 74 brings that first publication up to date. It offers a synthesis of the latest structural design knowledge about precast building structures against the background of 21st century technological innovations in materials, production and construction. With it, we hope to help architects and engineers achieve a full understanding of precast concrete building structures, the possibilities they offer and their specific design philosophy. It was principally written for non-seismic structures.

The handbook contains eleven chapters, each dealing with a specific aspect of precast building structures.
The first chapter of the handbook highlights best practice opportunities that will enable architects, design engineers and contractors to work together towards finding efficient solutions, which is something unique to precast concrete buildings.
The second chapter offers basic design recommendations that take into account the possibilities, restrictions and advantages of precast concrete, along with its detailing, manufacture, transport, erection and serviceability stages.
Chapter three describes the precast solutions for the most common types of buildings such as offices, sports stadiums, residential buildings, hotels, industrial warehouses and car parks. Different application possibilities are explored to teach us which types of precast units are commonly used in all those situations.
Chapter four covers the basic design principles and systems related to stability. Precast concrete structures should be designed according to a specific stability concept, unlike cast in-situ structures.
Chapter five discusses structural connections.
Chapters six to nine address the four most commonly used systems or subsystems of precast concrete in buildings, namely, portal and skeletal structures, wall-frame structures, floor and roof structures and architectural concrete facades.
In chapter ten the design and detailing of a number of specific construction details in precast elements are discussed, for example, supports, corbels, openings and cutouts in the units, special features related to the detailing of the reinforcement, and so forth.
Chapter eleven gives guidelines for the fire design of precast concrete structures. The handbook concludes with a list of references to good literature on precast concrete construction.

Dall'Agnol, L. T., C. M. Cordas, and JJG Moura. "Influence of respiratory substrate in carbon steel corrosion by a Sulphate Reducing Prokaryote model organism." Bioelectrochemistry. 97 (2014): 43-51. AbstractWebsite
n/a
Veigas, Bruno, Rita Branquinho, Joana V. Pinto, Pawel J. Wojcik, Rodrigo Martins, Elvira Fortunato, and Pedro V. Baptista. "Ion sensing (EIS) real-time quantitative monitorization of isothermal DNA amplification." Biosensors and Bioelectronics (2014). Abstract
n/a
Fliedel, C., V. Faramarzi, V. Rosa, B. Doudin, and P. Braunstein. "Janus microspheres for visual assessment of molecular interconnects." Chemistry - A European Journal. 20.5 (2014): 1263-1266. AbstractWebsite
n/a
Chastre, Carlos. "Materiais e tecnologias de reforço de estruturas de betão - potencialidade e limitações." REHABEND 2014 - Congresso Latinoamericano "Patología de la construcción, Tecnología de la rehabilitacíon y gestión del patrimonio". Santander 2014. Abstractcarlos_chastre__-_rehabend2014_-_santander.pdf

O desenvolvimento da engenharia de estruturas tem tido grandes avanços nas últimas décadas, baseados em novos meios de cálculo e na investigação em novos materiais e tecnologias a eles associadas. Por sua vez, as atividades de reparação e reforço têm vindo a incrementar devido ao envelhecimento e à degradação das estruturas de betão, o que consequentemente tem dado origem ao aparecimento de novos materiais e tecnologias de reparação e reforço de estruturas. A utilização destes novos materiais na construção tem vindo a substituir outros materiais e técnicas existentes, requerendo, no entanto, mais estudos sobre o seu real comportamento quer em termos de caracteristicas mecânicas quer em termos de durabilidade.

Hendrickx, Christophe, Ricardo Araújo, and Octávio Mateus. "The nonavian theropod quadrate II: systematic usefulness, major trends and cladistic and phylogenetic morphometrics analyses." PeerJ PrePrints. 2 (2014): e380v2. AbstractWebsite

The skull-bone quadrate in nonavian theropods is very diverse morphologically alongside the disparity of the group as a whole. However this disparity has been underestimated for taxonomic purposes. In order to evaluate the phylogenetic potential and investigate the evolutionary transformations of the quadrate, we conducted a Catalano-Goloboff phylogenetic morphometric analysis as well as a cladistic analysis using 98 discrete quadrate related characters. The cladistic analysis provides a fully resolved tree mirroring to some degree the classification of nonavian theropods. The quadrate morphology by its own provides a wealth of data with strong phylogenetic signal and allows inference of major trends in the evolution of this bone. Important synapomorphies include: for Abelisauroidea, a lateral ramus extending to the ectocondyle; for Tetanurae, the absence of the lateral process; for Spinosauridae, a medial curvature of the ventral part of the pterygoid ramus occurring just above the mandibular articulation; for Avetheropoda, an anterior margin of the pterygoid flange formed by a roughly parabolic margin; and for Tyrannosauroidea, a semi-oval pterygoid flange shape in medial view. The Catalano-Goloboff phylogenetic morphometric analysis reveals two main morphotypes of the mandibular articulation of the quadrate linked to function. The first morphotype, characterized by an anteroposteriorly broad mandibular articulation with two ovoid/subcircular condyles roughly subequal in size, is found in Ceratosauria, Tyrannosauroidea and Oviraptorosauria. This morphotype allows a very weak displacement of the mandible laterally. The second morphotype is characterized by an elongate and anteroposteriorly narrow mandibular articulation and a long and parabolic/sigmoid ectocondyle. Present in Megalosauroidea, Carcharodontosauridae and Dromaeosauridae, this morphotype permits the lower jaw rami to be displaced laterally when the mouth opened.

Restani, Rita B., Joao Conde, Pedro V. Baptista, Maria Teresa Cidade, Ana M. Bragança, Jorge Morgado, Ilídio J. Correia, Ana Aguiar-Ricardo, and Vasco D. B. Bonifácio. "Polyurea dendrimer for efficient cytosolic siRNA delivery." 4.97 (2014): 54872-54878. Abstract
n/a
Domingo, A., D. Specklin, V. Rosa, S. Mameri, V. Robert, and R. Welter. "Probing the influence of the ligands on the magnetism of dinuclear manganese, iron, and chromium complexes supported by aroylhydrazone." European Journal of Inorganic Chemistry.15 (2014): 2552-2560. AbstractWebsite
n/a
Ceia, T. F., A. G. Silva, C. S. Ribeiro, JV Pinto, MH Casimiro, A. M. Ramos, and J. Vital. "PVA composite catalytic membranes for hyacinth flavour synthesis in a pervaporation membrane reactor." Catalysis Today. 236 (2014): 98-107. Abstract
n/a
Figueiredo, Maria-Ondina, Teresa P. Silva, Joao P. Veiga, Maria-Joao Batista, Eduardo Salas-Colera, and Daniel P. de Oliveira. "Selenium Speciation in Waste Materials From an Exhausted Iberian Pyrite Belt Mine." Journal of Materials Science Research. 3.4 (2014): p22. Abstract

n/a

Duarte, A. G., C. M. Cordas, JJG Moura, and I. Moura. "Steady-state kinetics with nitric oxide reductase (NOR): New considerations on substrate inhibition profile and catalytic mechanism." Biochimica et Biophysica Acta - Bioenergetics. 1837.3 (2014): 375-384. AbstractWebsite
n/a
Passos, F., M. H. Fino, and E. R. Moreno. "Analytical Characterization of Variable Width Integrated Spiral Inductors." International Journal of Electronics and Telecommunications (2014): 7377.
Gião, Rita, Válter Lúcio, and Carlos Chastre. "Assessing the behaviour of RC beams subject to significant gravity loads under cyclic loads." Engineering Structures. 59 (2014): 512-521. AbstractWebsite

Gravity loads can affect a reinforced concrete structure’s response to seismic actions, however, traditional procedures for testing the beam behaviour do not take this effect into consideration. An experimental campaign was carried out in order to assess the influence of the gravity load on RC beam connection to the column subjected to cyclic loading. The experiments included the imposition of a conventional quasi-static test protocol based on the imposition of a reverse cyclic displacement history and of an alternative cyclic test procedure starting from the gravity load effects. The test results are presented, compared and analysed in this paper. The imposition of a cyclic test procedure that included the gravity loads effects on the RC beam ends reproduces the demands on the beams’ critical zones more realistically than the traditional procedure. The consideration of the vertical load effects in the test procedure led to an accumulation of negative (hogging) deformation. This phenomenon is sustained with the behaviour of a portal frame system under cyclic loads subject to a significant level of the vertical load, leading to the formation of unidirectional plastic hinges. In addition, the hysteretic behaviour of the RC beam ends tested was simulated numerically using the nonlinear structural analysis software – OpenSees. The beam–column model simulates the global element behaviour very well, as there is a reasonable approximation to the hysteretic loops obtained experimentally.

de Melo, J. L. A., Querido F., Paulino N., and Goes J. A 0.4-V 410-nW opamp-less continuous-time ΣΔ modulator for biomedical applications. IEEE International Symposium on Circuits and Systems (ISCAS). Melbourne, Australia: IEEE, 2014.
Polcyn, M. J., LL Jacobs, C. Strganac, O. Mateus, TS Myers, S. May, R. Araújo, AS Schulp, and ML Morais. "Geological and paleoecological setting of a marine vertebrate bonebed from the Lower Maastrichtian at Bentiaba, Angola." Secondary Adaptation of Tetrapods to Aquatic Life. Washington DC, USA 2014.