ACTRIS ACSM intercomparison – Part 2: Intercomparison of ME-2 organic source apportionment results from 15 individual, co-located aerosol mass spectrometers

Chemically resolved atmospheric aerosol data sets from the largest intercomparison of the Aerodyne aerosol chemical speciation monitors (ACSMs) performed to date were collected at the French atmospheric supersite SIRTA. In total 13 quadrupole ACSMs (Q-ACSM) from the European ACTRIS ACSM network, one time-of-flight ACSM (ToF-ACSM), and one high-resolution ToF aerosol mass spectrometer (AMS) were operated in parallel for about 3 weeks in November and December~2013. Part 1 of this study reports on the accuracy and precision of the instruments for all the measured species. In this work we report on the intercomparison of organic components and the results from factor analysis source apportionment by positive matrix factorisation (PMF) utilising the multilinear engine 2 (ME-2). Except for the organic contribution of mass-to-charge ratio m/z 44 to the total organics (f44), which varied by factors between 0.6 and 1.3 compared to the mean, the peaks in the organic mass spectra were similar among instruments. The m/z 44 differences in the spectra resulted in a variable f44 in the source profiles extracted by ME-2, but had only a minor influence on the extracted mass contributions of the sources. The presented source apportionment yielded four factors for all 15 instruments: hydrocarbon-like organic aerosol (HOA), cooking-related organic aerosol (COA), biomass burning-related organic aerosol (BBOA) and secondary oxygenated organic aerosol (OOA). ME-2 boundary conditions (profile constraints) were optimised individually by means of correlation to external data in order to achieve equivalent / comparable solutions for all ACSM instruments and the results are discussed together with the investigation of the influence of alternative anchors (reference profiles). A comparison of the ME-2 source apportionment output of all 15 instruments resulted in relative standard deviations (SD) from the mean between 13.7 and 22.7 % of the source's average mass contribution depending on the factors (HOA: 14.3 ± 2.2 %, COA: 15.0 ± 3.4 %, OOA: 41.5 ± 5.7 %, BBOA: 29.3 ± 5.0 %). Factors which tend to be subject to minor factor mixing (in this case COA) have higher relative uncertainties than factors which are recognised more readily like the OOA. Averaged over all factors and instruments the relative first SD from the mean of a source extracted with ME-2 was 17.2 %.JRC.H.2-Air and Climat

Childhood leukaemia: long-term excess mortality and the proportion ‘cured'

Survival from childhood leukaemia has increased, but the proportion of children cured is unknown. The proportion ‘cured' is defined as the proportion of survivors for whom, as a group, there is no longer excess mortality compared to the general population. Average time to cure is defined as the time since diagnosis at which the excess mortality rate has declined to or below a predetermined small value. Data on children diagnosed with leukaemia during 1971–2000 in Great Britain were used to estimate trends in survival, the proportion cured and the average time to cure. Five-year survival for all types of leukaemia combined rose from 33 to 79% by 2000. The percentage cured rose from 25 to 68% by 1995; it is predicted to increase to 73% for those diagnosed more recently. Average time to cure increased from 12 years (95% confidence interval (CI): 11–14) to 19 years (95% CI: 14–26) for lymphoid leukaemia (average annual increase of 0.3 years; P<0.001), but remained at about 5 years for acute nonlymphoblastic leukaemia. The proportion of children cured of leukaemia has risen dramatically, but the period of excess mortality associated with lymphoid leukaemia has also increased, possibly because of late relapse, secondary malignancy and toxicity from treatment

ACTRIS ACSM intercomparison – Part 1: Reproducibility of concentration and fragment results from 13 individual Quadrupole Aerosol Chemical Speciation Monitors (Q-ACSM) and consistency with co-located instruments

As part of the European ACTRIS project, the first large Quadrupole Aerosol Chemical Speciation Monitor (Q-ACSM) intercomparison study was conducted in the region of Paris for 3 weeks during the late-fall – early-winter period (November–December 2013). The first week was dedicated to the tuning and calibration of each instrument, whereas the second and third were dedicated to side-by-side comparison in ambient conditions with co-located instruments providing independent information on submicron aerosol optical, physical, and chemical properties. Near real-time measurements of the major chemical species (organic matter, sulfate, nitrate, ammonium, and chloride) in the non-refractory submicron aerosols (NR-PM1) were obtained here from 13 Q-ACSM. The results show that these instruments can produce highly comparable and robust measurements of the NR-PM1 total mass and its major components. Taking the median of the 13 Q-ACSM as a reference for this study, strong correlations (r2 > 0.9) were observed systematically for each individual Q-ACSM across all chemical families except for chloride for which three Q-ACSMs showing weak correlations partly due to the very low concentrations during the study. Reproducibility expanded uncertainties of Q-ACSM concentration measurements were determined using appropriate methodologies defined by the International Standard Organization (ISO 17025, 1999) and were found to be 9, 15, 19, 28, and 36 % for NR-PM1, nitrate, organic matter, sulfate, and ammonium, respectively. However, discrepancies were observed in the relative concentrations of the constituent mass fragments for each chemical component. In particular, significant differences were observed for the organic fragment at mass-to-charge ratio 44, which is a key parameter describing the oxidation state of organic aerosol. Following this first major intercomparison exercise of a large number of Q-ACSMs, detailed intercomparison results are presented, along with a discussion of some recommendations about best calibration practices, standardized data processing, and data treatment.JRC.H.2-Air and Climat

L'about inscrit du musée national du Cambodge (K. 943) : nouveaux éléments sur le bouddhisme tantrique à l'époque angkorienne

Registered by the National Museum of Cambodia in 1933 and still unpublished, the inscription K. 943, engraved on a bronze end-piece, provides interesting information about the date of the object as well as the religious history of the Khmer country and, more specifically, Buddhism. Although it is difficult to understand, this unusually long inscription for a metal Khmer object mentions a single deity, the Kamrateṅ Jagat Chpār Ransī, who appears in a dozen Khmer inscriptions, suggesting that he was an important deity during the Angkor period. Several elements of the text indicate a late Angkorian date, as opposed to a hasty analysis of the object which could lead one to believe otherwise, and thus supply the most recent evidence of this renowned Buddhist deity. Moreover, by virtue of the deity it bears — a Vajrasattva — this finial links the Kamrateṅ Jagat Chpār Ransī with Tantric Buddhism and, by doing so, raises some new questions about the development of this specific way of Buddhism in Khmer history.Estève Julia, Vincent Brice. L'about inscrit du musée national du Cambodge (K. 943) : nouveaux éléments sur le bouddhisme tantrique à l'époque angkorienne. In: Arts asiatiques, tome 65, 2010. pp. 133-158

A Recovering Beam Search algorithm for the single machine Just-in-Time scheduling problem

International audienceWe consider the Just-in-Time scheduling problem where the Just-in-Time notion is captured by means of multiple conflicting criteria. The calculation of any non-dominated solution for these criteria is achieved by solving an extension of the single machine problem of minimising the mean weighted deviation from distinct due dates. In the extended problem each job to schedule is also given by a release date and a deadline. This problem is NP-Hard in the strong sense and we propose heuristic algorithms to solve it. Computational experiments show that, among those algorithms, the most effective heuristic is a Recovering Beam Search algorithm

Preparation of bactericidal cationic PDMS surfaces using a facile and efficient approach

International audienc

Fast circuit breaker based on integration of Al/CuO nanothermites

International audiencePyroswitches and circuit breakers play an important safety role in electrical systems. A miniature one-shot circuit breaker based on the violent reaction of a nanothermite is presented for safety application as protection against overcurrent, external perturbation and short circuit of a broad range of equipment and systems. This device consists of two circuits assembled together to define a cavity. An ignition chip is placed into this cavity and ignites, within less than 100 µs, a few milligrams of nanothermites powder. The resulting violent reaction interrupts a thick copper connection within 1 ms. After the presentation of the device design, fabrication and assembly, we demonstrate the good operation and reproducibility of the device (100 % of success rate) with a response time much lower than that of classical mechanical circuit breakers, which are slow. The response time can be tuned from 1.02 ms to 0.57 ms just by adjusting the mass of nanothermites from 5.59 to 13.24 mg, i.e., adjusting the volumetric solid loadings from 5.6 to 19 %. The nanothermite-based circuit breaker presented in this paper offers unprecedented advantages: it is built using only safe substances and is based on a low-2 cost mass fabrication process that is compatible with electronics. The proposed concept is generic and can be applied to a large number of applications (electrical storage, aerospace manufacturing, human safety, demolition parachute opening, road vehicles, battery powered machines…)

Ultra-rapid and fully integrated active pyrotechnic safety switches integrating nanothermites

International audienceTraditional technologies used to manufacture current pyrotechnic switches are based on synthesis, pressing/casting and injection of macroscopic organic energetic materials (explosive or highly energetic materials), which leads to bulky and dangerous systems. We propose, instead, a nanothermite-based safety switch, which provides a compact circuit breaker, ideally suited to protect against overcurrent, external perturbation and short circuit of a broad range of equipments and systems. This new switch is miniaturized based on the integration of a few mg of nanothermites by additive manufacturing methods directly on electronic circuitry. The concept is simple and adaptable to many applications: two printed board circuit (PCB) are bonded together to form a hermetic cavity of 38 mm 3 in volume. The bottom PCB contains the electronic circuitry and ignitor element to trigger the switching. A second PCB supports the copper connection as part of the circuitry that must be disconnected. Once ignited, the nanothermite generates the high gas pressure burst sufficient to safely terminate the electrical connections of the circuit in less than 2 ms, well before a short-circuit can occur that could lead to an uncontrolled action, i.e. an accident or catastrophe. We show that the pressure (up to 1.5 MPa) or force level (up to 50 N) and switching time (from 0.9 to 5 ms) can all be controlled by tailoring the nanothermite composition (type and dimension of oxide particles), stoichiometry and compaction rate, so that the response of the actuator can be tuned. Therefore it can be applied in a broad variety of applications, such as electric storage, aerospace manufacturing (rod and bolt pyrotechnic cutters), human safety, demolition, parachute opening, road vehicles, boats and battery powered machines. We focus our presentation on the vaporization of a 100 µm-thick copper connection to rapidly disconnect a battery unit (in less than milliseconds) regardless of the magnitude of the fault-current. For example, we demonstrate that varying the compaction rate from 3.3 to 7.1 % of the TMD (Theoretical Maximun Density), the switching time decreases from 3 to 1.5 ms. Tuning the Al/CuO stoichiometric ratio also impacts greatly the switching time. The design, fabrication process as well as switching performances will be presented. The proposed concept is innovative and offers unprecedented advantages: (1) harmless manipulation of products of substances and processes for human; (2) an integrated fabrication framework enabling low cost and mass fabrication, reliability, and nanoscale precision; (3) increased environmental protection: only safe and environmental friendly substances and components can now be chosen and combined to produce the energetic layer; and (4) a versatile design that can be applied to a large number of applications

Etude pour l’amélioration d’un système d’identification nommée du locuteur

National audienceAutomatic speaker segmentation and classification produce generic labels rather than the true identity of the speakers. The proposed approach is based on the use of a semantic classification tree using lexical rules to extract the true identity of the speakers from the transcription. In this paper, experiments are carried out on French broadcast news from ESTER 2005 to evaluate this approach, focusing on the impact of the various combinations of automatic vs. manual transcription with automatic vs. manual speaker segmenta-tion/classification. We also study the errors generated by the system.La segmentation et la classification automatique des locuteurs produisent des étiquettes génériques plutôt que la véritable identité des locuteurs. L'approche proposée est basée sur l'utilisation d'un arbre de classification sémantique utilisant des règles lexicales pour extraire la véritable identité des locuteurs de la transcription. Dans cet article, des expériences sont effectuées sur des journaux français du corpus ESTER 2005