Determination of fireline intensity by oxygen consumption calorimetry

Fireline intensity is one of the most relevant quantities used in forest fire science. It helps to evaluate the effects of fuel treatment on fire behavior, to establish limits for prescribed burning. It is also used as a quantitative basis to support fire suppression activities. However, its measurement is particularly tricky for different reasons: difficulty in measuring the weight of the fuel consumed in the active fire front, difficulty to evaluate the rate of spread of the fire front, and uncertainty on combustion efficiency. In this study, an innovative and original approach to directly measure the fireline intensity at laboratory scale is proposed. Based on the oxygen consumption calorimetry principle, this methodology is applied here in case of spreading fires, for the first time. It allows for directly measuring the heat released by the fire front. The results are then used to test the famous Byram’s formulation that is generally applied to determine the fireline intensity. Combustion efficiency and effective heat of combustion results are provided. The uncertainty and the use of a full scale calorimeter instead of a bench scale calorimeter for this study are discussed.     

Contribution of heterogeneous strain field measurements and boundary conditions modelling in inverse identification of material parameters

The present paper aims at applying the Finite Element Updating inverse method to several sample geometries by the means of Digital Image Correlation. The full-field data are experimentally obtained from three geometries exhibiting increasing strain fields heterogeneities. For each test, a Finite Element model is built and boundary conditions are duplicated from the measured displacements at the sample borders. Field comparisons are performed at several time steps until fracture occurs and a Levenberg–Marquardt method is used to solve the optimization problem. Six parameters of an anisotropic elastic–plastic constitutive model are identified and validated through the simulation of a deep-drawing forming operation. Results show that identification quality is improved when heterogeneous strain fields are used.     

Anisotropy of the resistivity of normal hexagonal metals

Using the Mannari-Ziman-Baym theory we calculate the anisotropy in phonon scattering resistivity of normal hexagonal metals. We use a Born von Karman force constant fit to inelastic neutron and X-ray scattering experiments and both empirical and model form factors. U and N processes are explicitly separated. We get reasonable results for the anisotropy of Mg, Cd and Zn but not for Be.     

Thermopower calculation for magnesium single crystals

The thermopower of magnesium single crystals has been calculated in a 1-OPW model. The results are compared with the measurements of Rowe and Schroeder.     

Determination of (fluoro)quinolone antibiotic residues in pig kidney using liquid chromatography-tandem mass spectrometry. I. Laboratory-validated method

A new LC-MS/MS method has been developed for the multiresidue determination of 11 (fluoro)quinolone antibiotics (FQs), including acidic and amphoteric species, around their maximum residue level (MRL) in pig kidney. The procedure involves a common sample preparation by solid-phase extraction on disposable extraction cartridges followed by a fast reversed-phase liquid chromatography-tandem mass spectrometry analysis. The method was validated according to the Commission Decision 2002/657/CE. The accuracy of the method was satisfactory with recoveries included in the interval 80-100%. The precision results showed mean repeatability and reproducibility coefficients of 7.4% and 11.8%, respectively. Limits of quantification much lower than the MRLs could be obtained.     

Determination of (fluoro)quinolone antibiotic residues in pig kidney using liquid chromatography-tandem mass spectrometry. Part II: intercomparison exercise

A recently in-house validated method for the liquid chromatography-tandem mass spectrometry (LC-MS/MS) determination of eleven (fluoro)quinolone antibiotics (FQs) in pig kidney has been fully validated through an intercomparison exercise. This ring trial involved eight European laboratories and was based on the Commission Decision 2002/657/CE for validation of method and on the IUPAC protocol for method-performances studies. The laboratories data were submitted to a one-way analysis of variance. Satisfactory results were obtained for each FQ with regards to within- and between-laboratory reproducibility and accuracy. The method was validated for the simultaneous qualitative and quantitative determination of the eleven FQs in pig kidney around their maximum residue limit (MRL) as defined in the European Council Regulation 2377/90/EEC.     

Improved method for the iodine(III)-mediated preparation of aryl sulfonimidates

[reaction: see text] One-pot hypervalent iodine-mediated oxidations of arylsulfinamides to arylsulfonimidates is reported. Contrary to the case of alkylsulfinamides, use of iodosobenzene was not satisfactory. The reaction worked best with diacetoxyiodosobenzene (DIB) and a mild base (MgO). The influence of substituents on the iodine(III) reagent arene has been examined.     

Tunable magnetic properties of arrays of Fe(1 1 0) nanowires grown on kinetically grooved W(1 1 0) self-organized templates

We report a detailed magnetic study of a new type of self-organized nanowires discussed briefly previously [B. Borca et al., Appl. Phys. Lett. 90 (2007) 142507]. The templates, prepared on sapphire wafers in a kinetically limited regime, consist of uniaxially grooved W(1 1 0) surfaces, with a lateral period here tuned to 15 nm. Fe deposition leads to the formation of (1 1 0) 7 nm-wide wires located at the bottom of the grooves. The effect of capping layers (Mo, Pd, Au, Al) and underlayers (Mo, W) on the magnetic anisotropy of the wires was studied. Significant discrepancies with figures known for thin flat films are evidenced and discussed in terms of step anisotropy and strain-dependent surface anisotropy. Demagnetizing coefficients of cylinders with a triangular isosceles cross-section have also been calculated, to estimate the contribution of dipolar anisotropy. Finally, the dependence of magnetic anisotropy with the interface element was used to tune the blocking temperature of the wires, here from 50 to 200 K.