On the study of catalytic membrane reactor for water detritiation: Membrane characterization.

Tritium waste recycling is a real economic and ecological issue. Generally under the non-valuable Q2Oform (Q = H, D or T), waste can be converted into fuel Q2for a fusion machine (e.g. JET, ITER) by isotopeexchange reaction Q2O + H2= H2O + Q2. Such a reaction is carried out over Ni-based catalyst bed packed ina thin wall hydrogen permselective membrane tube. This catalytic membrane reactor can achieve higherconversion ratios than conventional fixed bed reactors by selective removal of reaction product Q2bythe membrane according to Le Chatelier’s Law. This paper presents some preliminary permeation tests performed on a catalytic membrane reactor.Permeabilities of pure hydrogen and deuterium as well as those of binary mixtures of hydrogen, deu-terium and nitrogen have been estimated by measuring permeation fluxes at temperatures ranging from573 to 673 K, and pressure differences up to 1.5 bar. Pure component global fluxes were linked to perme-ation coefficient by means of Sieverts’ law. The thin membrane (150 �m), made of Pd–Ag alloy (23 wt.%Ag),showed good permeability and infinite selectivity toward protium and deuterium. Lower permeabilityvalues were obtained with mixtures containing non permeable gases highlighting the existence of gasphase resistance. The sensitivity of this concentration polarization phenomenon to the composition andthe flow rate of the inlet was evaluated and fitted by a two-dimensional model

Petri Net Reachability Graphs: Decidability Status of FO Properties

We investigate the decidability and complexity status of model-checking problems on unlabelled reachability graphs of Petri nets by considering first-order, modal and pattern-based languages without labels on transitions or atomic propositions on markings. We consider several parameters to separate decidable problems from undecidable ones. Not only are we able to provide precise borders and a systematic analysis, but we also demonstrate the robustness of our proof techniques

On adaptive wavelet estimation of a class of weighted densities

We investigate the estimation of a weighted density taking the form $g=w(F)f$, where $f$ denotes an unknown density, $F$ the associated distribution function and $w$ is a known (non-negative) weight. Such a class encompasses many examples, including those arising in order statistics or when $g$ is related to the maximum or the minimum of $N$ (random or fixed) independent and identically distributed (\iid) random variables. We here construct a new adaptive non-parametric estimator for $g$ based on a plug-in approach and the wavelets methodology. For a wide class of models, we prove that it attains fast rates of convergence under the $\mathbb{L}_p$ risk with $p\ge 1$ (not only for $p = 2$ corresponding to the mean integrated squared error) over Besov balls. The theoretical findings are illustrated through several simulations

Systemic thrombolytic therapy for acute pulmonary embolism: a systematic review and meta-analysis

Aim Thrombolytic therapy induces faster clot dissolution than anticoagulation in patients with acute pulmonary embolism (PE) but is associated with an increased risk of haemorrhage. We reviewed the risks and benefits of thrombolytic therapy in the management of patients with acute PE. Methods and results We systematically reviewed randomized controlled studies comparing systemic thrombolytic therapy plus anticoagulation with anticoagulation alone in patients with acute PE. Fifteen trials involving 2057 patients were included in our meta-analysis. Compared with heparin, thrombolytic therapy was associated with a significant reduction of overall mortality (OR; 0.59, 95% CI: 0.36-0.96). This reduction was not statistically significant after exclusion of studies including high-risk PE (OR; 0.64, 95% CI: 0.35-1.17). Thrombolytic therapy was associated with a significant reduction in the combined endpoint of death or treatment escalation (OR: 0.34, 95% CI: 0.22-0.53), PE-related mortality (OR: 0.29; 95% CI: 0.14-0.60) and PE recurrence (OR: 0.50; 95% CI: 0.27-0.94). Major haemorrhage (OR; 2.91, 95% CI: 1.95-4.36) and fatal or intracranial bleeding (OR: 3.18, 95% CI: 1.25-8.11) were significantly more frequent among patients receiving thrombolysis. Conclusions Thrombolytic therapy reduces total mortality, PE recurrence, and PE-related mortality in patients with acute PE. The decrease in overall mortality is, however, not significant in haemodynamically stable patients with acute PE. Thrombolytic therapy is associated with an increase of major and fatal or intracranial haemorrhag