Numerical investigation of low Prandtl number effect on mixed convection in a horizontal channel by the lattice Boltzmann method

The main purpose of this study is to numerically investigate the Prandtl number effect on mixed convection in a horizontal channel heated from below using the thermal lattice Boltzmann method (TLBM). The double-population model with two different lattices is used, in particular, the D2Q9 for the velocity field and D2Q5 for the thermal field. The developed lattice Boltzmann method code to simulate the fluid flow and heat transfer in the channel was validated with available literature results based on classical numerical methods, especially the finite volume method for Pr = 6.4 and the finite difference method for Pr = 0.667. The results obtained with the TLBM have shown good agreement with the conventional methods cited. The dynamic and thermal characteristics of the fluid flow were examined in the field of low Prandtl number, such that 0.05 ≤ Pr ≤ 0.667, and also compared to Pr = 6.4; for Ra = 2420 and 7400, the Reynolds number was fixed at 1. The results showed that the influence is relatively significant for the dynamic structure of flow convection for Pr ≤ 0.3 and is little influential beyond this value.     

Example-based model-transformation testing

A major concern in model-driven engineering is how to ensure the quality of the model-transformation mechanisms. One validation method that is commonly used is model transformation testing. When using this method, two important issues need to be addressed: the efficient generation/selection of test cases and the definition of oracle functions that assess the validity of the transformed models. This work is concerned with the latter. We propose a novel oracle function for model transformation testing that relies on the premise that the more a transformation deviates from well-known good transformation examples, the more likely it is erroneous. More precisely, the proposed oracle function compares target test cases with a base of examples that contains good quality transformation traces, and then assigns a risk level to them accordingly. Our approach takes inspiration from the biological metaphor of immune systems, where pathogens are identified by their difference with normal body cells. A significant feature of the approach is that one no longer needs to define an expected model for each test case. Furthermore, the detected faulty candidates are ordered by degree of risk, which helps the tester inspect the results. The validation results on a transformation mechanism used by an industrial partner confirm the effectiveness of our approach.     

Metabolization of the Polycyclic Aromatic Hydrocarbon Benzo( A )Pyrene by a Non-White Rot Fungus ( Fusarium Solani ) in a Batch Reactor

To investigate metabolization of benzo[ a ]pyrene (B a P), a high-molecular-weight polycyclic aromatic hydrocarbon consisting of five aromatic rings, by a Deuteromycete Fusarium solani , a culture with [7,10- 14 C]benzo[ a ]pyrene was carried out in a batch fermentor under cometabolic conditions. In spite of drastic culture conditions with a high load of B a P (302 mg in a 1.6 liters), analysis of the growth and substrate depletion kinetics showed a classical pattern. The evolution of 14 CO 2 release demonstrated that B a P mineralization by the non-white rot fungus F. solani occurred rapidly at early stages of fermentation (15 hr) during the germination process. At the end of fermentation, 1.2% of the B a P was evolved as 14 CO 2 and 5.3% was incorporated in biomass. B a P metabolization was also confirmed by isolating metabolic products, extracted from mycelia and identified as 1,6-benzo[ a ]pyrene quinone and 3,6-benzo[ a ]pyrene quinone, by mass and ultraviolet (UV) spectroscopic analyses.     

Changes of the cutaneous micro-relief in superficial radiation-induced fibrosis: a qualitative study

Cutaneous radiation-induced fibrosis (RIF) is characterized by a skin retraction or atrophy, toughness to the palpation and often entails functional limitation. Its clinical evaluation remains poorly quantified. The aim of this study was to propose an analytical method to quantify RIF skin surface with the replica technique. In this preliminary study, we report the qualitative and quantitative evaluation of the cutaneous microrelief in 44 healthy controls and in four patients presenting a superficial RIF, 3 to 20 years after radiotherapy for cancer. The microrelief of these RIF presented an abnormal anisotropy with a parallel reorganization of cutaneous valleys in three cases out of four, suggesting a premature radiation-induced ageing of the skin. Each subject being his own control, the relative vertical amplitude of the skin microrelief was +/-15% in control skin. Vertical amplitude was respectively increased by 84% in one inflammatory fibrosis (3 years after RT), decreased by 18% in one evolutive fibrosis (6 years after RT), decreased by 26% in one voluminous stabilized fibrosis (8 years after RT) and decreased by 53% in one atrophic fibrosis (20 years after RT). The present study suggests that the variations of the microrelief parameters could reflect the RIF evolution. This technique requires a validation in a larger series of patients, including patients with telangiectasia.     

Empirical studies to assess the understandability of data warehouse schemas using structural metrics

Data warehouses are powerful tools for making better and faster decisions in organizations where information is an asset of primary importance. Due to the complexity of data warehouses, metrics and procedures are required to continuously assure their quality. This article describes an empirical study and a replication aimed at investigating the use of structural metrics as indicators of the understandability, and by extension, the cognitive complexity of data warehouse schemas. More specifically, a four-step analysis is conducted: (1) check if individually and collectively, the considered metrics can be correlated with schema understandability using classical statistical techniques, (2) evaluate whether understandability can be predicted by case similarity using the case-based reasoning technique, (3) determine, for each level of understandability, the subsets of metrics that are important by means of a classification technique, and assess, by means of a probabilistic technique, the degree of participation of each metric in the understandability prediction. The results obtained show that although a linear model is a good approximation of the relation between structure and understandability, the associated coefficients are not significant enough. Additionally, classification analyses reveal respectively that prediction can be achieved by considering structure similarity, that extracted classification rules can be used to estimate the magnitude of understandability, and that some metrics such as the number of fact tables have more impact than others.

Study of thermal parameters' temperature dependence in solids using photothermal radiometry

A photothermal radiometry configuration that allows the measurement of the temperature dependence of thermal parameters of solid materials is described. Two procedures are proposed. The first one is based on a combination of phase and amplitude signal data collected at a single frequency and the second one makes use of the information contained in the phase signal data, obtained at two different chopping frequencies. The methods are recommended for calorimetric studies requiring temperature scans at a constant chopping frequency.     

Degradation of Benzo[a]Pyrene as Sole Carbon Source by a Non White Rot Fungus,Fusarium Solani

Non white rot fungi isolated from fuel-contaminated soil were screened for their ability to grow with benzo[a]pyrene as sole carbon source. The capacity of one isolate identified as F. solani F33 was further investigated by studying the mineralization of [7,10-¹⁴C]benzo[a]pyrene. Spores of F. solani were able to germinate in presence of benzo[a]pyrene and growing mycelium mineralized [7,10-¹⁴C]benzo[a]pyrene (0.2% over a period of 10 days). The amount of ¹⁴CO₂ released decreased of 66% in 10 days culture in the presence of the inhibitor of cytochrome P-450 1-aminobenzotriazole, suggesting that such enzymes are involved in benzo[a]pyrene degradation by F. solani. This hypothesis was also enhanced by observing, in F. solani grown on benzo[a]pyrene, the presence of small vesicles with high