Adoption of human metabolic processes as Data Quality Based Models

The Journal of Supercomputing - The buildup of huge data within business intelligence is essential because such data includes complete conceptual and technological stack in addition to raw and...     

Scalar models for the generalized Chaplygin gas and the structure formation constraints

The generalized Chaplygin gas model represents an attempt to unify dark matter and dark energy. It is characterized by a fluid with the equation of state p = −A/ρ ^α . It can be obtained from a generalization of the Dirac-Born-Infeld (DBI) action for a scalar, tachyonic field. At a background level, this model gives very good results, but it suffers from many drawbacks at the perturbative level. We show that, while for background analysis it is possible to consider any value of α, the perturbative analysis must be restricted to positive values of α. This restriction can be circumvented if the origin of the generalized Chaplygin gas is traced back to a self-interacting scalar field, instead of the DBI action. But, in doing so, the predictions coming from formation of large-scale structures reduce the generalized Chaplygin gas model to a kind of quintessence model, and the unification scenario is lost if the scalar field is the canonical one. However, if the unification condition is imposed from the beginning as a prior, the model may remain competitive. More interesting results concerning the unification program are obtained if a non-canonical self-interacting scalar field, inspired by Rastall’s theory of gravity, is invoked. In this case, an agreement with the background tests is possible.     

Inhomogeneous universe in f(T) theory

We obtain the equations of motions of the f(T) theory considering the Lemaître-Tolman-Bondi’s metric for a set of diagonal and non-diagonal tetrads. In the case of diagonal tetrads, the equations of motion of the f(T) theory impose a constant torsion or the same equations as in general relativity (GR), while in the case of a non-diagonal set, the equations are quite different from that obtained in GR. We show a simple example of a universe dominated by matter for the two cases. The comparison of the masses in the non-diagonal case shows a sort of increase with respect to the diagonal case. We also find two examples for the non-diagonal case. The first one concerns a Schwarzschild-type black hole solution, which presents a temperature higher than that of Schwarzschild, and a black hole in a dust-dominated universe.     

Modelling and experimental validation of high performance low platinum multilayer cathode for polymer electrolyte membrane fuel cells (PEMFCs)

The aim of this paper is to demonstrate numerically the feasibility of using a sputtering technique for the design of Polymer Electrolyte Membrane Fuel Cell cathodes having low platinum loading and offering high performance. A two-dimensional steady state model accounting for electrochemical reactions, momentum, saturation, species and charge conservation equations have been developed. It has been applied to three different cathode configurations where the platinum is assumed to be sputtered one, two and three times on the same number of carbon–Nafion layers (CNL). The predicted polarization curves were validated with the experimental data obtained in our laboratory. Our results showed that the best performance is obtained with a three Pt sputtered layer cathode. A parametric study proved the dependence of the PEM fuel cell cathode performance on the CNL porosity, the (Pt/C) agglomerate radius and the thickness of this agglomerate structure.     

Characterisation of volatile compounds in Tunisian fenugreek seeds

In this study, we intend to develop a simple and fast analytical procedure to identify the volatile compounds implicated in the odour of Tunisian fenugreek (Trigonella foenum-graceum L.) seeds. Two procedures, solvent extraction and static headspace solid-phase microextraction (SHS-SPME), have been used under different conditions. The volatile compounds extracted were systematically identified using gas chromatography–mass spectrometry, based on their mass spectrum and Kovats index on two columns of different polarity. A total of 67 compounds were identified, some of them being reported for the first time in fenugreek seeds (e.g. several pyrazines, 2,5-dimethyl-4-hydroxy-3(2H)-furanone or 1-epi-cubenol). Methanol was found to be the preferred solvent for high and medium boiling point volatile compounds, such as sotolone and nitrogen compounds. For SHS-SPME, the fibre coated with divinylbenzene/carboxen/polydimethylsiloxane 2 cm was the most suitable for extracting volatile compounds from ground seeds. The efficiency of this fibre was confirmed by direct gas chromatography–olfactometry, with a global odour similar to that of fenugreek seeds.     

Continuous and multidimensional assessment of resilience based on functionality analysis for interconnected systems

The increasing number of disruptions to critical infrastructure, like natural disasters, terrorist attacks or internal failure is today a major problem of society. Concern is even greater when considering the interconnected nature of critical infrastructure, which might lead to failure propagation, causing domino and cascade effects. To mitigate such outcomes, critical infrastructure must recover its capacity to function with regard to several criteria. Stakeholders must therefore analyse and improve the resilience of critical infrastructure before any disruption occurs, and base this analysis on different models so as to guarantee society’s vital needs. Current resilience assessment methods are mainly oriented toward the context of a single system, thus narrowing their criteria metrics, limiting flexibility and adaptation to other contexts and overlooking the interconnected nature of systems. This article introduces a new tool-equipped approach that makes it possible to define a model to evaluate the functionalities of interconnected systems. The model is then used to assess the resilience of these systems based on simple and generic criteria that can be extended and adapted. Several assertions related to the concept of resilience and some resilience indicators are also introduced. A case study provides the validation performed by experts from several domains.     

Improving the application of gibberellic acid to prolong dormancy of yam tubers (Dioscorea spp)

With the aim of reducing the cost and time needed to treat yam tubers with gibberellic acid (GA₃), this study compared several new methods of application with the established dipping procedure (150 mg kg^?1 for 1 h). Both GA₃‐containing soil paste (25 mg kg^?1) and gelatinized starch (860 mg kg^?1) were applied to tuber heads of Dioscorea alata and D cayenensis‐rotundata in the Ivory Coast. Soil paste, gelatinized starch and dipping consistently prolonged dormancy and reduced fresh matter losses by 23–39% in D cayenensis‐rotundata 3‐year means. Although dipping reduced the storage losses most efficiently, soil paste and gelatinized starch used considerably less GA₃. Both new treatments were easily prepared and quickly applied. Soil paste was most effective when the treatment was repeated before the end of dormancy. The third new method, spraying the tubers with a GA₃ solution (150 mg kg^?1), was not effective. In general, the optimal time of application was immediately post‐harvest. For D alata, treatment only 1 month after harvest was particularly ineffective, whereas D cayenensis‐rotundata tubers could be treated with some effect up to the end of dormancy. To achieve extended storage periods of healthy tubers of D cayenensis‐rotundata, GA₃ application may be recommended as post‐harvest practice. Copyright © 2003 Society of Chemical Industry     

Dégradation des eaux de rejets issues d’une raffinerie d’huile de coton par plasma d’arc électrique rampant à pression atmosphérique

Wastewater samples from liquid effluents of cotton oil refinery in Far-Northern Cameroon were exposed to a gliding arc discharge for various exposure times in a cold plasma reactor. The analysed results showed high levels of organic pollution parameters (TOC = 4635 mg/L, COD = 6943, 98 mg/L) before treatment. More than 56% TOC and 75% COD abatement were obtained after 30 min treatment in batch conditions with a laboratory reactor. The resultant pollution abatement is attributed both to strong oxidizing effects of °OH and NO° radicals formed in the plasma and their derivatives (H₂O₂, ONO₂H and NO₃H). The conductivity and TDS increase linearly and the pH, TOC and COD decrease with increasing exposure time to the discharge. The oxidation obeys a pseudo first-order kinetics law (kinetic rate: k_1DCO = 0, 0381 min^?1 and k_1COT = 0, 0245 min^?1).     

SDLER: stacked dedupe learning for entity resolution in big data era

The Journal of Supercomputing - In the Big Data Era, Entity Resolution (ER) faces many challenges such as high scalability, the coexistence of complex similarity metrics, tautonymy and synonym, and...