CO2 permeation properties of poly(ethylene oxide)-based segmented block copolymers

This paper discusses the gas permeation properties of poly(ethylene oxide) (PEO)-based segmented block copolymers containing monodisperse amide segments. These monodisperse segments give rise to a well phase-separated morphology, comprising a continuous PEO phase with dispersed crystallised amide segments. The influence of the polyether phase composition and of the temperature on the permeation properties of various gases (i.e., CO2, N2, He, CH4, O2 and H2) as well as on the pure gas selectivities were studied in the temperature range of −5 °C to 75 °C. The CO2 permeability increased strongly with PEO concentration, and this effect could partly be explained by the dispersed hard segment concentration and partly by the changing chain flexibility. By decreasing the PEO melting temperature the low temperature permeabilities were improved. The gas transport values were dependant on both the dispersed hard segment concentration and the polyether segment length (length between crosslinks). The gas selectivities were dependant on the polyether segment length and thus the chain flexibility

Reducing the Memory Complexity of Type-Inference Algorithms

In the Java Virtual Machine, the byte-code verifier checks low-level security properties that ensure that the downloaded code cannot bypass the virtual machine's security mechanisms. One of the statically ensured properties is type safety. The type-inference phase is the overwhelming resource-consuming part of the verification process

Untersuchungen zur Auslegung katalytischer Rekombinatoren

In recent years, LiDAR technology has provided accurate forest aboveground biomass (AGB) maps in several forest ecosystems, including tropical forests. However, its ability to accurately map forest AGB changes in high-biomass tropical forests has seldom been investigated. Here, we assess the ability of repeated LiDAR acquisitions to map AGB stocks and changes in an old-growth Neotropical forest of French Guiana. Using two similar aerial small-footprint LiDAR campaigns over a four year interval, spanning ca. 20km2, and concomitant ground sampling, we constructed a model relating median canopy height and AGB at a 0.25-ha and 1-ha resolution. This model had an error of 14% at a 1-ha resolution (RSE=54.7Mgha-1) and of 23% at a 0.25-ha resolution (RSE=86.5Mgha-1). This uncertainty is comparable with values previously reported in other tropical forests and confirms that aerial LiDAR is an efficient technology for AGB mapping in high-biomass tropical forests. Our map predicts a mean AGB of 340Mgha-1 within the landscape. We also created an AGB change map, and compared it with ground-based AGB change estimates. The correlation was weak but significant only at the 0.25-ha resolution. One interpretation is that large natural tree-fall gaps that drive AGB changes in a naturally regenerating forest can be picked up at fine spatial scale but are veiled at coarser spatial resolution. Overall, both field-based and LiDAR-based estimates did not reveal a detectable increase in AGB stock over the study period, a trend observed in almost all forest types of our study area. Small footprint LiDAR is a powerful tool to dissect the fine-scale variability of AGB and to detect the main ecological controls underpinning forest biomass variability both in space and time.CNESAgence Nationale de la RechercheGordon and Betty Moore FoundationERC - Advanced Grant (Tropical Forests in the Changing Earth System)Royal Society - Wolfson Research Merit Awar

Le radon 222 et ses descendants à vie courte dans l'environnement atmosphérique : origine et méthodes de mesure

Pour l'homme, le radon est la source permanente principale d'exposition naturelle aux rayonnements ionisants. Ce document synthétise les connaissances générales sur l'origine du radon 222 et son évolution dans différents milieux atmosphériques. Il présente diverses méthodes de mesure de l'activité volumique radon et de la concentration, en énergie alpha potentielle de ses descendants à vie courte. Il a été élaboré dans le cadre de la commission M60-3 du Bureau de Normalisation d'Équipements Nucléaires (BNEN) qui dépend de l'Association Française de Normalisation (AFNOR)

Effect of recombinant activated factor VII on perioperative blood loss in patients undergoing retropubic prostatectomy: a double-blind placebo-controlled randomised trial

BACKGROUND: Recombinant activated factor VII (factor VIIa) has prohaemostatic effects in bleeding patients with coagulation abnormalities. We aimed to test the hypothesis that recombinant factor VIIa could reduce perioperative blood loss in patients with normal coagulation systems. Therefore, we assessed safety and efficacy of this drug in patients undergoing retropubic prostatectomy, which is often associated with major blood loss and need for transfusion. METHODS: In a double-blind, randomised placebo-controlled trial, we recorded blood loss and transfusion requirements in 36 patients undergoing retropubic prostatectomy, who were randomised to receive an intravenous bolus of recombinant factor VIIa (20 microg/kg or 40 microg/kg) or placebo in the early operative phase. FINDINGS: Median perioperative blood loss was 1235 mL (IQR 1025-1407) and 1089 mL (928-1320) in groups given recombinant factor VIIa 20 microg/kg and 40 microg/kg, respectively, compared with 2688 mL (1707-3565) in the placebo group (p=0.001). Seven of twelve placebo-treated patients were transfused, whereas no patients who received 40 microg/kg recombinant factor VIIa needed transfusion. The odds ratio for receiving any blood product in patients treated with recombinant factor VIIa compared with control patients was 0 (95% CI 0.00-0.33) No adverse events arose. INTERPRETATION: An injection of recombinant factor VIIa can reduce perioperative blood loss and eliminate the need for transfusion in patients undergoing major surger