Oxydation du phenol sur un catalyseur à base de Fer supporté sur une argile marocaine

L'objectif du présent travail est l'étude de l'oxydation par voie humide du phénol en catalyse hétérogène, en présence de peroxyde d'hydrogène. Les catalyseurs choisis sont à base de fer et de cuivre; l'oxydation est effectuée dans des conditions normales de température et de pression. Les résultats expérimentaux montrent une oxydation complète du phénol et une diminution significative de la demande chimique en oxygène DCO. D'autre part ces catalyseurs manifestent une grande stabilité; on peut donc les utiliser sans causer des problèmes de pollution métallique.Mots-clés : Phénol, peroxyde d'hydrogène, catalyse hétérogène, Fe-argile, oxydation

Esophageal variceal ligation in the secondary prevention of variceal bleeding: Result of long term follow-up

Introduction: Long-term outcome of patients after band ligation have been poorly defined. Therefore, we conducted a long-term follow-up study to delineate the outcome of ligation in patients with portal hypertension in the Hassan II university hospital, Fes, Morocco. Methods: Over 118 months patients treated by endoscopic variceal ligation were received regular follow- up and detailed clinical assessment of at least 24 months.Results: One hundred twenty five patients were followed up for a mean of 31 months (range 12-107 months). Obliteration of the varices was achieved in 89.6 % (N=112) of patients, with 3 +/-1.99 (range 1-8) endoscopy sessions over a period of 14+/-6.8 weeks (range 3-28). The percentage of variceal recurrence during follow-up after ligation was 20.5 % (N=23). Recurrence were observed in a mean of 22 months +/- 7.3 (range 3-48). Bleeding rate from recurrent varices was 30.4 % (7/23). Rebleeding from esophageal ulcers occurred in 5.6 % (7/125) of patients. Portal hypertensive gastropathy before and after eradication of varices was 17.6% (N=22) and 44.6% (N=50) respectively; p< 0.05. Fundal gastric varices was 30.4% (N=38) and 35.7% (N=40) before and after eradication of varices respectively; p> 0.05. The overall mortality was 4 % (N=5).Conclusion: Band ligation was an effective technical approach for variceal obliteration with low rates of variceal recurrence, rebleeding and development of gastric varices. Furthermore, it was associated with frequent development of portal hypertensive gastropathy.Key words: Variceal hemorrhage, endoscopic band ligation, liver cirrhosis, complication of band ligation, esophageal varices, secondary preventio

Studies of new Higgs boson interactions through nonresonant HH production in the b¯bγγ fnal state in pp collisions at √s = 13 TeV with the ATLAS detector

A search for nonresonant Higgs boson pair production in the b ¯bγγ fnal state is performed using 140 fb−1 of proton-proton collisions at a centre-of-mass energy of 13 TeV recorded by the ATLAS detector at the CERN Large Hadron Collider. This analysis supersedes and expands upon the previous nonresonant ATLAS results in this fnal state based on the same data sample. The analysis strategy is optimised to probe anomalous values not only of the Higgs (H) boson self-coupling modifer κλ but also of the quartic HHV V (V = W, Z) coupling modifer κ2V . No signifcant excess above the expected background from Standard Model processes is observed. An observed upper limit µHH < 4.0 is set at 95% confdence level on the Higgs boson pair production cross-section normalised to its Standard Model prediction. The 95% confdence intervals for the coupling modifers are −1.4 < κλ < 6.9 and −0.5 < κ2V < 2.7, assuming all other Higgs boson couplings except the one under study are fxed to the Standard Model predictions. The results are interpreted in the Standard Model efective feld theory and Higgs efective feld theory frameworks in terms of constraints on the couplings of anomalous Higgs boson (self-)interactions

Simultaneous energy and mass calibration of large-radius jets with the ATLAS detector using a deep neural network

The energy and mass measurements of jets are crucial tasks for the Large Hadron Collider experiments. This paper presents a new calibration method to simultaneously calibrate these quantities for large-radius jets measured with the ATLAS detector using a deep neural network (DNN). To address the specificities of the calibration problem, special loss functions and training procedures are employed, and a complex network architecture, which includes feature annotation and residual connection layers, is used. The DNN-based calibration is compared to the standard numerical approach in an extensive series of tests. The DNN approach is found to perform significantly better in almost all of the tests and over most of the relevant kinematic phase space. In particular, it consistently improves the energy and mass resolutions, with a 30% better energy resolution obtained for transverse momenta pT > 500 GeV

Statistical Combination of ATLAS Run 2 Searches for Charginos and Neutralinos at the LHC

Statistical combinations of searches for charginos and neutralinos using various decay channels are performed using 139 fb^{-1} of pp collision data at sqrt[s]=13 TeV with the ATLAS detector at the Large Hadron Collider. Searches targeting pure-wino chargino pair production, pure-wino chargino-neutralino production, or Higgsino production decaying via standard model W, Z, or h bosons are combined to extend the mass reach to the produced supersymmetric particles by 30-100 GeV. The depth of the sensitivity of the original searches is also improved by the combinations, lowering the 95% C.L. cross-section upper limits by 15%-40%