570 research outputs found

    BIM Approach in Construction Safety-A Case Study on Preventing Falls from Height

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    The construction industry has one of the highest occupational accident incidence rates among all economic sectors. Currently, building information modelling (BIM) appears to be a valuable tool for analysing occupational safety issues throughout the construction life cycle of projects, helping to avoid hazards and risks and, consequently, increasing safety. This work investigates BIM methodology and the application of related technologies for building safety planning and demonstrates the potential of this technology for the integrated implementation of safety measures during the design phase and construction site management. The first step consisted of a literature review on applying BIM-related technologies for safety in the design and planning phases. Following this, to show the potentialities of construction simulation, a case study based on BIM 4D to prevent falls from height was developed. With BIM 4D, it is possible to follow the construction process over time, giving the construction safety technicians, designers, supervisors and managers the capability to analyse, in each phase, the potential risks and identify which safety measures should be implemented. BIM can effectively integrate safety measures from the design phase to the construction and use phase and enable integrated safety planning within construction planning, leading to reliable safety management throughout the construction process

    X-ray image separation via coupled dictionary learning

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    In support of art investigation, we propose a new source sepa- ration method that unmixes a single X-ray scan acquired from double-sided paintings. Unlike prior source separation meth- ods, which are based on statistical or structural incoherence of the sources, we use visual images taken from the front- and back-side of the panel to drive the separation process. The coupling of the two imaging modalities is achieved via a new multi-scale dictionary learning method. Experimental results demonstrate that our method succeeds in the discrimination of the sources, while state-of-the-art methods fail to do so.Comment: To be presented at the IEEE International Conference on Image Processing (ICIP), 201

    Decomposition analysis: when to use which method?

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    Structural and index decomposition analyses allow identifying the main drivers of observed changes over time of energy and environmental impacts. These decomposition analyses have become very popular in recent decades and, many alternative methods to implement them have become available. Several of the most popular methods have been developed earlier in index number theory, a context in which each particular method is defined by adhering to a set of properties. The goal of the present paper is to review the main results of index number theory and discuss its connection to decomposition analyses. By doing so, we can present a decision tree that allows users to choose a decomposition method that meets desired properties. We report as hands-on example an empirical case study of the carbon footprint of the Netherlands in the period 2004–2005

    Learning the Fuzzy Phases of Small Photonic Condensates

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    Phase transitions, being the ultimate manifestation of collective behaviour, are typically features of many-particle systems only. Here, we describe the experimental observation of collective behaviour in small photonic condensates made up of only a few photons. Moreover, a wide range of both equilibrium and non-equilibrium regimes, including Bose-Einstein condensation or laser-like emission are identified. However, the small photon number and the presence of large relative fluctuations places major difficulties in identifying different phases and phase transitions. We overcome this limitation by employing unsupervised learning and fuzzy clustering algorithms to systematically construct the fuzzy phase diagram of our small photonic condensate. Our results thus demonstrate the rich and complex phase structure of even small collections of photons, making them an ideal platform to investigate equilibrium and non-equilibrium physics at the few particle level

    Enzymatic production of ethyl oleate ester using a lipase from Candida antarctica B

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    Lipases são biocatalisadores de grande importância em diferentes áreas, sendo capazes de catalisar reações em meios aquosos ou orgânicos. Além disso, estas enzimas são capazes de utilizar vários substratos sendo estáveis numa vasta gama de pH e temperatura. Lipases promovem a esterificação entre ácidos graxos e etanol produzindo ésteres oleatos. O objetivo deste trabalho é produzir o éster oleato de etila por esterificação enzimática do ácido oleico com etanol. Uma lipase de Candida antarctica tipo B foi utilizada a uma temperatura de 55 °C. A reação foi realizada utilizando o ácido oleico, sulfato de sódio anidro, lipase e etanol, na proporção de ácido oleico (0.03 mol ou 10 ml), lipase (0.1 mol ou 0.01 g), sulfato de sódio anidro (5 g) e etanol 99 % (100 ml). Diversos tempos de reação foram estudados, nomeadamente, 48, 72, 96 e 120 horas. Ressonância Magnética Nuclear (1 H e 13C) e espectros de Infravermelho confirmaram a produção do éster oleato de etila para as condições estudadas. O maior rendimento da produção do oleato de etila foi obtido no tempo de reação de 96 horas. Os ésteres oleato de etila foram reportados por possuirem aplicações interessantes em vários campos industriais, tais como, alimentos, produtos aromáticos, cosméticos, detergentes, saborizantes e produtos farmacêuticos.Lipases are biocatalysts of great importance in different areas, being able to catalyze reactions in aqueous or organic media. Furthermore, these enzymes are capable of using several substrates being stable in a wide range of pH and temperatures. Lipases promote the esterification between fatty acids and ethanol producing oleate esters. The aim of this work is to produce ethyl oleate ester by enzymatic esterification of oleic acid with ethanol. A lipase from Candida antarctica type B was used at a temperature of 55 °C. The reaction was conducted using oleic acid, sodium sulfate anhydrous, lipase and ethanol, with a ratio of oleic acid (0.03 mol or 10 ml), lipase (0.1 mol or 0.01 g), sodium sulfate anhydrous (5 g) and ethanol 99 % (100 ml). Several reaction times were studied, namely 48, 72, 96 and 120 hours. Nuclear Magnetic Resonance (1 H and 13C) and Infrared spectra confirmed the production of ethyl oleate ester for the studied conditions. The highest ethyl oleate production yield was obtained for 96 hours reaction time. Ethyl oleate esters have been reported to possess interesting applications in several industrial fields, such as food, aromatics, cosmetics, detergents, flavors and pharmaceuticals

    Valorization of lignin side-streams into polyols and rigid polyurethane foams—a contribution to the pulp and paper industry biorefinery

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    Valorization of industrial low-value side-streams are of great interest, contributing to boosts in the circular economy. In this context, lignin side-streams of the pulp and paper industry were oxypropylated to produce biobased polyols and tested in the synthesis of rigid polyurethane (RPU) foams. E. globulus lignins, namely a lignin isolated from an industrial Kraft black liquor and depolymerized lignins obtained as by-products of an oxidation process, were used. RPU foams, synthesized with 100% lignin-based polyols and using a 1.1 NCO/OH ratio, were characterized concerning apparent density, morphology, thermal conductivity, thermal stability, and heat release rate (HRR). Foams containing the lignin-based polyols presented densities varying from 44.7 to 112.2 kg/m3 and thermal conductivity in the range of 37.2–49.0 mW/mK. For the reference foam (sample produced with 100% wt. Daltofoam TP 32015 polyol), values of 70.9 kg/m3 and 41.1 mW/mK were obtained, respectively. The achieved results point out the viability of using the generated lignin-based polyols at 100% content in RPU foams, mainly when depolymerized lignins are used. Moreover, fire retardancy was favored when the lignin-based polyols were introduced. The proposed strategies can contribute to establishing the integrated pulp and paper biorefinery concept where material synthesis (polyols and RPU foams) can be combined with chemical production (vanillin and syringaldehyde).Foundation for Science and Technology (FCT, Portugal) and FEDER under Program PT2020 for financial support to CIMO (UIDB/00690/2020), and to UIDB/50020/2020 of the Associate Laboratory LSRE-LCM—funded by national funds through FCT/MCTES (PIDDAC); national funding by FCT, PI, through the institutional scientific employment program contract for Isabel P. Fernandes. This work was carried out under the Project No. 33969 Bioblocks—Design of biobased products from renewable lignocellulosic sources as precursors for the bioindustry of chemical synthesis and biomaterials—financed by FEDER through the Operational Program for Competitiveness Factors (POFC) and QREN. To COST Action LignoCOST (CA17128) supported by COST (European Cooperation in Science and Technology).info:eu-repo/semantics/publishedVersio

    Adaptive-Rate Sparse Signal Reconstruction With Application in Compressive Foreground Subtraction

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    We propose and analyze an online algorithm for reconstructing a sequence of signals from a limited number of linear measurements. The signals are assumed sparse, with unknown support, and evolve over time according to a generic nonlinear dynamical model. Our algorithm, based on recent theoretical results for ℓ1-ℓ1 minimization, is recursive and computes the number of measurements to be taken at each time on-thefly. As an example, we apply the algorithm to compressive video background subtraction, a problem that can be stated as follows: given a set of measurements of a sequence of images with a static background, simultaneously reconstruct each image while separating its foreground from the background. The performance of our method is illustrated on sequences of real images: we observe that it allows a dramatic reduction in the number of measurements with respect to state-of-the-art compressive background subtraction schemes. Index Terms—State estimation, compressive video, background subtraction, sparsity, ℓ1 minimization, motion estimation

    Monitorização dos problemas fitossanitários e fauna auxiliar presentes em pomares de macieiras da ilha Terceira

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    I Congresso de Fruticultura e Viticultura. Angra do Heroísmo 17-19 Abril 2008.Trabalho de investigação desenvolvido no projecto INTERFRUTA II, financiado pelo programa INTERREG III-B (05/MAC/3.1/A4).Nos objectivos do Projecto INTERFRUTA II, projecto desenvolvido nas Ilhas da Madeira, Tenerife (Canárias) e Terceira (Açores) destinado a contribuir para a promoção da fruticultura e viticultura nestas três regiões insulares, procurou-se atingir uma melhoria dos conhecimentos sobre diversas culturas abrangidas nos diversos trabalhos de investigação e de entre as quais a das macieiras, onde através deste trabalho, nas duas zonas de maior produtividade da Ilha Terceira (Biscoitos e São Sebastião), se procurou conhecer os seus problemas fitossanitários, de forma a determinar os períodos de maior actividade e risco principalmente das pragas que afectam a macieira e assim tentar encontrar a melhor forma de as poder combater através da aplicação prática dos conceitos da Protecção Integrada, o que contribuiu, decisivamente, para o conhecimento e procura de soluções inovadoras que conduziram ao acréscimo do rendimento dos produtores e a uma menor utilização e aplicação de pesticidas. Para além disso, pretendeuse identificar toda a fauna auxiliar presente nos pomares de macieira estudados. Nas macieiras, os principais problemas fitossanitários decorrem da presença de aranhiço vermelho (Panonychus ulmi Koch), traça-oriental (Cydia molesta) e bichado (Cydia pomonella L.). Nos fungos foram encontrados Alternaria mali Roberts, Aspergillium sp., Botryosphaeria lutea, Botryosphaeria ribis Gross.& Dungar, Phoma glomerata (Corda) Wolll. Rhizoctonia solani Kuhn, Verticillium sp. Nos vírus o único encontrado nas folhas de macieira foi o ACLSV – Apple chlorotic leafspot vírus. Da totalidade dos espécimes da fauna auxiliar encontrados nos pomares de macieira estudados foi elaborada uma tabela

    Development of pH-Sensitive magnetoliposomes containing shape anisotropic nanoparticles for potential application in combined cancer therapy

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    Late diagnosis and systemic toxicity associated with conventional treatments make oncological therapy significantly difficult. In this context, nanomedicine emerges as a new approach in the prevention, diagnosis and treatment of cancer. In this work, pH-sensitive solid magnetoliposomes (SMLs) were developed for controlled release of the chemotherapeutic drug doxorubicin (DOX). Shape anisotropic magnetic nanoparticles of magnesium ferrite with partial substitution by calcium (Mg0.75Ca0.25Fe2O4) were synthesized, with and without calcination, and their structural, morphological and magnetic properties were investigated. Their superparamagnetic properties were evaluated and heating capabilities proven, either by exposure to an alternating magnetic field (AMF) (magnetic hyperthermia) or by irradiation with near-infrared (NIR) light (photothermia). The Mg0.75Ca0.25Fe2O4 calcined nanoparticles were selected to integrate the SMLs, surrounded by a lipid bilayer of DOPE:Ch:CHEMS (45:45:10). DOX was encapsulated in the nanosystems with an efficiency above 98%. DOX release assays showed a much more efficient release of the drug at pH = 5 compared to the release kinetics at physiological pH. By subjecting tumor cells to DOX-loaded SMLs, cell viability was significantly reduced, confirming that they can release the encapsulated drug. These results point to the development of efficient pH-sensitive nanocarriers, suitable for a synergistic action in cancer therapy with magnetic targeting, stimulus-controlled drug delivery and dual hyperthermia (magnetic and plasmonic) therapy.This work was funded by the Portuguese Foundation for Science and Technology (FCT) within the framework of the Strategic Funding of Research Units UIDB/04650/2020 (CF-UM-UP), UIDB/00319/2020 (ALGORITMI), UIDB/04077/2020 (MEtRICs), UIDB/04436/2020 (CMEMS) and UIDB/00511/2020 (LEPABE). FCT, POCI, FEDER and NORTE2020 are acknowledged for funding through research projects PTDC/QUI-QFI/28020/2017, EXPL/EMD-EMD/0650/2021, PTDC/EEI-EEE/2846/2021 and NORTE-01-0145-FEDER-000054. MINECO (Spain) is acknowledged for project MAT2016-76824-C3-2-R. B.D.C. and V.M.C. acknowledge FCT for PhD grants SFRH/BD/141936/2018 (B.D.C.) and UI/BD/151028/2021 (V.M.C.). R.O.R. thanks FCT for contract 2020.03975.CEECIND
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