97 research outputs found

    Arquitectura e innovación. Las claves de la obra de Antonio Lamela y Estudio Lamela. Su aportación a los siglos XX y XXI

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    This paper makes a review of the joint trajectory of my father, the Architect Antonio Lamela, and “Estudio Lamela”. The relationship with the journal “Informes”, essential reference and sometimes only vehicle of diffusion of Architecture and construction in Spain, is pointed out. The relationship with the journal has been close and very productive. A timeline is made from the first moments of the office, with a more personal role of my father, until the period when its name changed to “Estudio Lamela” to convey a concept of multidisciplinary company and teamwork, once added to the team my uncle Amador Lamela. I have also tried to give my personal vision as a result of joining the Office and directing the development of important works of those moments, such as the expansion of the Santiago Bernabéu Stadium or Terminal T4. We also establish a reflection on our internationalization process.En el artículo se realiza un repaso de la trayectoria conjunta de mi padre, el Arquitecto Antonio Lamela, y de Estudio Lamela. Se señala la relación con la revista Informes, imprescindible referente y a veces único vehículo de difusión de la Arquitectura y la construcción en España. La relación con la revista ha sido estrecha y muy productiva. Se realiza un recorrido desde la primera época del Estudio, con un protagonismo más personal de mi padre, hasta el periodo del acuñamiento del nombre “Estudio Lamela” para transmitir un concepto de empresa multidisciplinar y trabajo en equipo, una vez sumado al equipo mi tío Amador Lamela. He intentado transmitir también mi visión personal a raíz de incorporarme a la Oficina y dirigir el desarrollo de obras importantes de esos momentos, como la ampliación del Estadio Santiago Bernabéu o la Terminal T4. También establecemos una reflexión sobre nuestro proceso de internacionalización

    Novel thermal annealing methodology for permanent tuning polymer optical fiber Bragg gratings to longer wavelengths

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    The Bragg wavelength of a polymer optical fiber Bragg grating can be permanently shifted by utilizing the thermal annealing method. In all the reported fiber annealing cases, the authors were able to tune the Bragg wavelength only to shorter wavelengths, since the polymer fiber shrinks in length during the annealing process. This article demonstrates a novel thermal annealing methodology for permanently tuning polymer optical fiber Bragg gratings to any desirable spectral position, including longer wavelengths. Stretching the polymer optical fiber during the annealing process, the period of Bragg grating, which is directly related with the Bragg wavelength, can become permanently longer. The methodology presented in this article can be used to multiplex polymer optical fiber Bragg gratings at any desirable spectral position utilizing only one phase-mask for their photo-inscription, reducing thus their fabrication cost in an industrial setting

    Caracterización probabilística de vidrio mediante diferentes tipos de ensayos

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    El vidrio no puede ser tratado como un material estructural convencional desde el punto de vista de la resistencia mecánica. Su naturaleza, como material frágil, junto con la inevitable presencia de microfisuras en su superficie y las consecuencias de accidentes por posibles fallos, exigen métodos rigurosos que garanticen un cálculo seguro de los elementos estructurales de vidrio, cuya resistencia a rotura depende en gran medida del tamaño del elemento y del tipo de carga a la que está sometido. Por lo tanto, su cálculo debe basarse en conceptos probabilísticos y en criterios de mecánica de la fractura, en sustitución de un cálculo convencional de vidrio según tablas deducidas de programas experimentales y posterior aplicación del concepto de tensiones admisibles. Con el fin de analizar y comparar las características mecánicas de vidrios templados, termoendurecidos y recocidos, se realizó un amplio programa experimental de ensayos de flexión a cuatro puntos y de anillos concéntricos de pequeña superficie, seguido de un ajuste de los resultados mediante una función de distribución triparamétrica de Weibull. Glass cannot be handled as a conventional structural material from the point of view of the mechanical strength. Its nature as brittle material, together with the inevitable presence of micro-cracks on its surface and the consequences of eventual failures, demand rigorous methods to achieve a safe design for glass elements, whose stress resistance is very much dependent on the integrity of its surface, element size and loading pattern. Thus, its design must rely on probabilistic concepts and fracture mechanics criteria, substitutive of the conventional glass design based on charts derived from experimental programs and subsequent application of the admissible stress concept. In order to analyze and compare the strength characteristics of tempered, heat-strengthened and annealed glass, a large experimental programme based on four-point bending and coaxial double ring tests was performed and the results were fitted using a three-parameter Weibull cumulative distribution function

    SNOM characterization of a potential low cost thin gold coated micro-structured grating using a commercial CD substrate

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    In this work near-field optical measurements of a corrugated grating coated with a 30 nm thick gold film are presented. The grating was made using the polycarbonate corrugated substrate of a commercially available recordable CD as template. This has been proved to be a versatile and low cost technique in producing large 1.6 μm period gratings. The study was carried out using a Scanning Near-Field Optical Microscope (SNOM) working in both collection and reflection modes at two different wavelengths, 532 nm and 633 nm. The results illustrate that the intensity patterns of near-field images are strongly polarization-dependent, even showing different periodicity of the localized fields for orthogonal polarization states. When electric field of the light is polarized parallel to the grooves, the periodicity of the SNOM images is coincident with the grating period, whereas when the light is polarized perpendicular to the grooves the SNOM pattern shows a periodicity twice that of the corresponding topography of the grating. Numerical simulations of the SNOM data based on a two-dimensional Finite Difference Time-Domain (2D-FDTD) model have been realized. The results of the simulations are in good agreement with the experimental data, emphasizing the need of performing numerical simulation for the correct interpretation of SNOM data

    Anti-reflection coatings on 3D printed components

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    The use of anti-reflection coatings on 3D-printed components to reduce both Fresnel reflections and scattering is explored. Two similar photo-initiated acrylic commercial material structures, known as Standard Clear (SC: T~60% @ λ = 800 nm) and VeroClear (VC: T~90% @ λ = 800 nm), used specifically for optical components, are examined. The refractive indices for slab samples~(5 × 5 × 0.7) cm are measured at λ = 650 nm and averaged over the slab area: n(SC)~(1.49 ± 0.04) and n(VC)~(1.42 ± 0.03). Within experimental error, novel Shore D mapping is used to show hardness distribution across the surface flats, with VC slightly harder than SC, where VC = 85.9 ± 0.3 and SC = 84.4 ± 1.3, indicating uniform hardness. A TiO2/MgF2 anti-reflection twin-layer coating is deposited onto one side of an unpolished SC slab and binds well, passing standard peeling and humidity tests. Shore hardness increases to SCCOATED = 87.5 ± 1.5. It is found to reduce the measured Fresnel reflection and surface scatter by~65% without requiring major polishing, paving the way for lower-cost high-quality optics. The demonstration of successful anti-reflection coatings will benefit all 3D-printed component finishes, permitting viable film deposition more broadly

    A cumulative risk model of child physical maltreatment potential: findings from a community-based study

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    "Published online before print November 20, 2015"Previous studies have identified the predictive risk factors of child physical maltreatment (CPM). However, a significant number of these studies assessed risk factors in isolation. The cumulative risk hypothesis postulates that health problems are caused by the accumulation of risk factors, independently of the presence or absence of specific risk indicators. Few studies examined the effect of cumulative risk on CPM potential. This study aimed to test two concurrent models of cumulative risk of CPM potential by investigating whether CPM potential was better predicted by a threshold cumulative risk model or a linear cumulative risk model. Data from the National Representative Study of Psychosocial Context of Child Abuse and Neglect in Portugal were used. Parents of school-age children (N = 796) answered to self-report measures regarding sociodemographic variables, history of child maltreatment, psychological distress, and CPM potential. A cumulative risk index was computed, comprising 10 dichotomized risk factors. Evidence for a threshold cumulative effect was found. Additional bivariate logistic regressions revealed that the odds for high-potential CPM were dramatically higher for those parents with six or more risk factors when compared with parents with any one risk factor. By testing and confirming a threshold cumulative effect on CPM potential, it was possible to find a "trigger point" from which a dramatic increase in child physical maltreatment potential occurs.This study was supported by the Portuguese Foundation of Science and Technology through a research grant to the second author (POCTI/PSI/14276/1998

    Psychometric properties of the Portuguese version of the Posttraumatic Growth Inventory Short Form among divorced adults

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    The aim of this study was to develop and validate a Portuguese version of the Short Form of the Posttraumatic Growth Inventory (PTGI-SF). Using an online convenience sample of Portuguese divorced adults (N = 482), we confirmed the oblique five-factor structure of the PTGI-SF by confirmatory factor analysis. The results demonstrated the measurement invariance across divorce initiator status groups. Total score and factors of PTGI-SF showed good internal consistency, with the exception of the New Possibilities factor, which revealed an acceptable reliability. The Portuguese PTGI-SF showed a satisfactory convergent validity. In terms of discriminant validity, posttraumatic growth assessed by the Portuguese PTGI-SF was a distinct factor from posttraumatic psychological adjustment. These preliminary findings suggest the cultural adaptation and also psychometric properties of the present Portuguese PTGI-SF to measure posttraumatic growth after personal crisis

    AI-driven web API testing

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    Testing of web APIs is nowadays more critical than ever before, as they are the current standard for software integration. A bug in an organization’s web API could have a huge impact both in ternally (services relying on that API) and externally (third-party applications and end users). Most existing tools and testing ap proaches require writing tests or instrumenting the system under test (SUT). The main aim of this dissertation is to take web API testing to an unprecedented level of automation and thoroughness. To this end, we plan to apply artificial intelligence (AI) techniques for the autonomous detection of software failures. Specifically, the idea is to develop intelligent programs (we call them “bots”) ca pable of generating hundreds, thousands or even millions of test inputs and to evaluate whether the test outputs are correct based on: 1) patterns learned from previous executions of the SUT; and 2) knowledge gained from analyzing thousands of similar programs. Evaluation results of our initial prototype are promising, with bugs being automatically detected in some real-world APIs.Ministerio de Economía y Competitividad BELI (TIN2015-70560-R)Ministerio de Ciencia, Innovación y Universidades RTI2018-101204-B-C21 (HORATIO)Ministerio de Educación, Cultura y Deporte FPU17/0407

    Quantum Optics and Photonics

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    Contains reports on nine research projects.U.S. Air Force - Office of Scientific Research (Contract F49620-82-C-0091)U.S. Air Force - Rome Air Development CenterJoint Services Electronics Program (Contract DAAG29-83-K-0003)National Science Foundation Grant (Grant PHY 82-710369
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