When the sample activity is measured for various reasonsseveral times, then with each measurement can be associated an individualdecision threshold and limit of detection. Each measurement canbe analyzed through its own decision threshold. The whole measurementscan sometimes present contradictory results, some measurements beinglower than the decision threshold and other higher. The problemthen arises to build a decision threshold and a detection limittaking into account all the individual results, and to decide ifthe radioactivity is finally detected or not. It is interestingto note that it is possible sometimes that the decision thresholdtaking account all results makes it possible to decide that the radioactivityis present whereas the totality of the individual results are negativein terms of individual decision threshold. The purpose of this articleis to show how these thresholds and these coherent limits cumulatedcan be determined in way according to the experimental conditions.In a general way a rigorous method of cumulating makes it possibleto systematically decrease the decision threshold and limit of detectionin terms of activity. This approach has interesting applicationsin gamma spectrometry with multi-emitters, discharge or periodicalenvironmental measurements. On the basis of measurements realizedby the IRSN within the framework of the national monitoring of theenvironment, we will see the potential impact of these methods onthe final assessments.

We report a novel finding of slither propagation of shear bands on the fracture surface of a Cu47.5Zr47.5Al5 bulk metallic glass (BMG). The nanoscale heterogeneities in the as-cast state are aggregated along shear bands with irregular morphology. Such heterogeneities create a fluctuating stress field during shear band propagation leading to a slither propagation mode. The slither propagation of 10 to 15 nm wide shear bands is effective to improve both the plasticity and the “work-hardening-like” behavior of BMGs if the size, the morphology, and the elastic properties of the heterogeneities are intimately intercalated during solidification.

We report the hydrogenation characteristics and mechanical properties of Ti50Zr25Cu25 in situ composite ribbons, composed of β-Ti crystalline phase dispersed in an amorphous matrix. Upon cathodic charging at room temperature, high hydrogen absorption up to ∼60 at.% (H/M = ∼1.2) is obtained. At such a high concentration, hydrogen-induced amorphization occurs. Mechanical tests conducted on the composite with varying hydrogen concentrations indicate that the Ti50Zr25Cu25 alloy is significantly resistant to hydrogen embrittlement when compared to conventional amorphous alloys. A possible mechanism that would contribute toward hydrogen-induced amorphization and hydrogen embrittlement is discussed.

Taenia solium cysticercosis is a parasitic disease frequently affecting human health and the pig industry in many developing countries. A synthetic peptide vaccine (designated S3Pvac) against porcine cysticercosis has been developed previously as an aid to interrupt transmission and has been shown to be effective. The results of the present study support the effectiveness of the vaccine under endemic field conditions. However, given the time-frame of the vaccination trial, no changes in the local levels of transmission were detectable before and after vaccination using sentinel pigs. Thus, this investigation shows the limited usefulness of single vaccination as the sole means of interrupting Taenia solium transmission in an endemic region.

Parasites often induce behavioural changes in their host. However, it is not necessarily easy to determine whether these changes are representative of an adaptation of the parasite (parasite manipulation), an adaptive response of the host or a side-effect of infection. In a solitary parasitoid of Drosophila larvae (Leptopilina boulardi), viral particles (LbFV) modify the host acceptance behaviour of infected females by increasing their tendency to superparasitize. This behavioural alteration allows for the horizontal transmission of the virus within superparasitized Drosophila larvae. To add support for or against the ‘manipulation hypothesis’, we investigated whether other behavioural components of the parasitoid are affected by viral infection, and whether other forms of horizontal transmission exist. Neither the ability of females to locate host kairomones nor their daily rhythm of locomotor activity was affected by viral infection. However, infected females showed a lower rate of locomotor activity, suggesting a physiological cost of infection. The searching paths of females were also unaffected. Males from infected and uninfected lines showed the same ability to locate females'sexual pheromones. Moreover, alternative modes of horizontal transmission (through food consumption and/or contact with the same Drosophila larvae) did not lead to viral contamination of the parasitoid. The overall specificity of behavioural alteration and of viral horizontal transmission is consistent with the hypothesis that the virus manipulates the behaviour of the parasitoid.

The oxidation behavior in air of gas atomized Al–Cu–Fe–Be powders was investigated during isothermal exposures at 750, 800, and 830 °C. Oxidation data obtained at 750 °C for Al–Cu–Fe and Al–Cu–Fe–Cr powders are also presented and used as references. Thermogravimetric analyses showed that Be significantly improved the oxidation resistance of the icosahedral phase at 750 °C. At this temperature the i-phase in Al–Cu–Fe–Be powders was found to be stable even after oxidation for 300 h, while oxidation at and beyond 800 °C led to the formation of a cubic β′-phase. Auger analyses suggested that, in addition to its role on the stability of the icosahedral phase, the presence of Be in the oxide layer provided efficient protection against air oxidation at high temperature.

Samples with a target composition of Al62.5Cu25Fe12.5 (at.%) have been produced from the repeated cold rolling and folding (R&F) process of Al, Cu and Fe elemental foils. Upon early increments of the R&F cycle, the mechanically-induced process led to the fragmentation of the initial foils, which resulted in the dispersion of elemental Fe layers through the refined Al and Cu layers. After 40 R&F cycles the Al2Cu phase was detected, while Fe did not contribute to the formation of compounds. Thermal analyses suggested that the formation and dissolution of the Al2Cu and Al7Cu2Fe phases are critical steps for the synthesis of the i-phase during post-R&F treatment. Annealing between 650° and 750°C enabled the formation of the stable i-phase and resulted in high values of the microhardness.

In this article, we present a laboratory astrophysics experiment on radiative shocks and its interpretation using simple modelization. The experiment is performed with a 100-J laser (pulse duration of about 0.5 ns) which irradiates a 1-mm3 xenon gas-filled cell. Descriptions of both the experiment and the associated diagnostics are given. The apparition of a radiation precursor in the unshocked material is evidenced from interferometry diagrams. A model including self-similar solutions and numerical ones is derived and fairly good agreements are obtained between the theoretical and the experimental results.

Phase formation and thermal stability for an Al–Mn–Be alloy have been investigated by melt-spinning and conventional casting. Significant differences in the phase formation and the thermal stability of the microstructure were found as a result of the different cooling rates. In the melt-spun ribbons, a large volume fraction of a metastable icosahedral phase was found to coexist with an Al solid solution. In the bulk cast ingots, the primary phase formed in the two-phase microstructure was a hexagonal approximant phase of quasicrystals. This phase that solidified in the form of faceted particles embedded in the Al solid matrix proved to be thermodynamically stable during annealing at 540 °C for 100 h. The effect of Be addition on the formation of the stable approximant phase is discussed in terms of the Hume–Rothery mechanism.

The microdynamics of water and oil in macroporous media with SiO2 or CaCO3 surfaces has been probed at various temperatures by magnetic field-cycling measurements of the spin-lattice relaxation rates. These measurements and an original theory of surface diffusion allowed us to obtain surface dynamical parameters, such as a coefficient of surface affinity of the liquid molecules and the surface diffusion coefficient. The water surface diffusion coefficients are compared to the volume self-diffusion coefficients of water in pores, measured by PGSE method, the latter values being more than an order of magnitude higher than the surface ones. Complementary information on the nature of the solid-liquid interface was given by NMR chemical shift experiments at high magnetic field.

In their pivotal 1986 volume, Converse and Pierce rekindle the debate over whether left-right ideological attachment or party identification serves as the psychological anchor of the French electorate. They argue that, much like Americans, French voters use partisanship to orient themselves to the political landscape. Our study, which employs the data used by Converse and Pierce, draws a different conclusion. We find that ideology, in terms of both scope and strength, clearly exceeds party in its importance for vote choice.

What is the “standing decision” rule that guides the French voter? Party or ideology? Converse and Pierce (1993), commenting on their 1986 volume, say that “the tilt of our diverse tests actually favored party.” Our tests point in the opposite direction, favoring ideology (Fleury and Lewis-Beck 1993). This disagreement is but a part of a larger debate in the literature on explanations of French electoral behavior. We hope, by reviewing key aspects of the disagreement, light will be cast on broader concerns. We begin with the modeling issue, then take up the matter of data and measures. We conclude with analysis of a newer, and perhaps better, data set from the 1988 elections. In that analysis, we offer a straightforward examination of the basic question: Are there more ideological identifiers or party identifiers in the French electorate? As shall be seen, there are many more ideological identifiers.