On the use of global sensitivity analysis for the numerical analysis of permeable pavements

The aim of this study is to investigate the use of different global sensitivity analysis techniques in conjunction with a mechanistic model in the numerical analysis of a permeable pavement installed at the University of Calabria. The Morris method and the variance-based E-FAST procedure are applied to investigate the influence of soil hydraulic parameters on the pavement’s behavior. The analysis reveals that the Morris method represents a reliable computationally cheap alternative to variance-based procedures for screening important factors and provides the first inspection of the model. The study is completed by a combined GSA-GLUE uncertainty analysis used to evaluate the model accuracy.     

KIDYAN: Computer-aided kinematic and dynamic analysis of planar mechanisms

The paper deals with a method of kinematic and dynamic analyses of planar linkages and describes a general program based on it. Both make use of a theorem saying that every planar mechanism consists of several Assur groups and of one or more driving links. Likewise, the corresponding program is composed of subprograms for the analysis of these groups.Two examples are presented.     

New frequency/voltage converters for ac-electrogravimetric measurements based on fast quartz crystal microbalance

A better understanding of the mechanisms located at the solid/electrolyte interface is becoming essential to the development of new applications in the electrochemical fields. The fast quartz crystal microbalance is an attractive and powerful gravimetric sensor which can be used in the dynamic regime to determine a mass/potential transfer function. The principle is equivalent to classical electrochemical impedance measurements; the only difference is the determination of mass changes given by the quartz crystal microbalance rather than current changes following sine wave modulations of the applied potential. This function appears very well adapted to characterize ionic exchanges at the electrochemical interface. Frequency/voltage converters are the key devices in translating the microbalance frequency response in terms of a continuous voltage change. The latter allows the transfer function to be obtained via a frequency response analyzer. Different converters were tested in this work in order to improve the performances of the experimental setup.     

Optically Immersed Bolometer IR Detectors Based on V<Subscript>2</Subscript>O<Subscript>5</Subscript> Thin Films with Polyimide Thermal Impedance Control Layer for Space Applications

Optically immersed bolometer IR detectors were fabricated using electron beam evaporated vanadium oxide as the sensing material. Spin-coated polyimide was used as medium to optically immerse the sensing element to the flat surface of a hemispherical germanium lens. This optical immersion layer also serves as the thermal impedance control layer and decides the performance of the devices in terms of responsivity and noise parameters. The devices were packaged in suitable electro-optical packages and the detector parameters were studied in detail. Thermal time constant varies from 0.57 to 6.0 ms and responsivity from 75 to 757 V W^?1 corresponding to polyimide thickness in the range 2 to 70 μm for a detector bias of 9 V in the wavelength region of 14–16 μm. Highest D* obtained was 1.2×10⁸ cmHz^1/2 W^?1. Noise equivalent temperature difference (NETD) of 20 mK was achieved for devices with polyimide thickness more than 32 μm. The figure of merit, NETD × τ product which describes trade-off between thermal time constant and sensitivity is also extensively studied for devices having different thickness of thermal impedance layers.     

Coupling an annotated corpus and a lexicon for state-of-the-art POS tagging

This paper investigates how to best couple hand-annotated data with information extracted from an external lexical resource to improve part-of-speech tagging performance. Focusing mostly on French tagging, we introduce a maximum entropy Markov model-based tagging system that is enriched with information extracted from a morphological resource. This system gives a 97.75?% accuracy on the French Treebank, an error reduction of 25?% (38?% on unknown words) over the same tagger without lexical information. We perform a series of experiments that help understanding how this lexical information helps improving tagging accuracy. We also conduct experiments on datasets and lexicons of varying sizes in order to assess the best trade-off between annotating data versus developing a lexicon. We find that the use of a lexicon improves the quality of the tagger at any stage of development of either resource, and that for fixed performance levels the availability of the full lexicon consistently reduces the need for supervised data by at least one half.     

Evaluation of colouring ability of main European elderberry (Sambucus nigra L.) varieties as potential resources of natural food colourants

Profiling and quantitative analysis of anthocyanins in five elderberry (Sambucus nigra L.) varieties, namely ‘Haschberg’, ‘Samocco’, ‘Samyl’, ‘Samident’ and ‘Sampo’, were performed in six different maturity stages from two consecutive years (2012 and 2013) and from two growing areas in Hungary. Cyanidin‐3‐O‐sambubioside‐5‐O‐glucoside, cyanidin‐3‐O‐sambubioside and cyanidin‐3‐O‐glucoside were found and identified by HPLC‐Q/TOF‐MS as major anthocyanins and were quantified by HPLC‐UV/Vis. In optimum maturity stage, ‘Samocco’ showed the highest anthocyanin content with an average of 1237 mg per 100 g dry weight in both growing areas and vintages. The dominant anthocyanin component of Samocco variety was cyanidin‐3‐O‐sambubioside, which is according to literature more stable against technology processing than cyanidin‐3‐O‐glucoside found in the other four investigated elderberry varieties in the highest concentration. ‘Samocco’, if grown under the climatic conditions of the Carpathian basin, might be a promising alternative variety for growing as raw material for natural food colourant processing industry.     

Numerical modeling of strain localization in engineering ductile materials combining cohesive models and X-FEM

The present work aims at numerically predicting the current residual strength of large engineering structures made of ductile metals against accidental failure. With this aim in view, the challenge consists in reproducing within a unified finite element-based methodology the successive steps of micro-voiding-induced damage, strain localization and crack propagation, if any. A key ingredient for a predictive ductile fracture model is the proper numerical treatment of the critical transition phase of damage-induced strain localization inside a narrow band. For this purpose, the strong discontinuity cohesive model and the eXtended Finite Element Method are combined. A propagation algorithm is proposed and studied in the context of ductile materials. Physics-motivated criteria to pass from the phase of more or less diffuse damage to strain localization and from strain localization to crack propoagation are proposed. Finally, a 2D numerical example is shown to study the performance of the failure analysis model when implemented into an engineering finite element computation code, namely Abaqus.     

Energy savings potential by integrating Phase Change Material into hollow bricks: The case of Moroccan buildings

The building sector in Morocco represents 25% of the country’s total energy consumption. The poor thermal performance of the building envelopes is one of the principal reasons for this consumption rate. In this study, the efficiency of integrating Phase Change Materials (PCM) into hollow bricks used in three typical housing types in the six climate zones in Morocco is investigated. The numerical model is based on the heat transfer equation and the apparent heat capacity formulation to model the phase change. A heat flux analysis is performed at the internal surface of the wall, giving a good understanding of the thermal behavior of hollow bricks with PCMs compared with hollow bricks with air. The results show that the heat flux density at the internal face of the wall is constant when the PCM is partially solid/liquid, and follows the outdoor conditions when the PCM is fully solid or fully liquid. Irrespective of the climate zone, the PCM with a 32 °C median melting temperature reduces the heat flux peak value in the hotel housing while the PCM with a 37 °C median melting temperature is better for the individual and collective housing. On the other hand, the PCM with a 27 °C median melting temperature is able to save up to 25% and 40% of energy consumption in the Saharan climate and oceanic climate, respectively.