Bismuth Molybdate-Based Catalysts for Selective Oxidation of Hydrocarbons

Bismuth molybdate materials (α-Bi2Mo3O12, β-Bi2Mo2O9, and γ-Bi2MoO6) are well-known in the field of catalysis due to their excellent activity for one of the most important industrial processes: the oxidation/ammoxidation of lower olefins. These processes play an important role in society since the production of one quarter of the most important industrial organic chemicals and intermediates (such as acrolein, acrylic acid, propylene oxide, etc.) used in the manufacture of industrial products and consumer goods is based on these reactions. Although the materials were developed since the 1960s, the topic still attracts many attentions; new catalysts with different additive elements to enhance catalytic activity are still explored. Advanced researches on bismuth molybdate-based catalysts have been performed not only with the change in composition but also in the synthesis methods. This book chapter summarizes recent researches on the development of bismuth molybdate-based catalysts with new achievements in catalysis field

Addressing the Rare Word Problem in Neural Machine Translation

Neural Machine Translation (NMT) is a new approach to machine translation that has shown promising results that are comparable to traditional approaches. A significant weakness in conventional NMT systems is their inability to correctly translate very rare words: end-to-end NMTs tend to have relatively small vocabularies with a single unk symbol that represents every possible out-of-vocabulary (OOV) word. In this paper, we propose and implement an effective technique to address this problem. We train an NMT system on data that is augmented by the output of a word alignment algorithm, allowing the NMT system to emit, for each OOV word in the target sentence, the position of its corresponding word in the source sentence. This information is later utilized in a post-processing step that translates every OOV word using a dictionary. Our experiments on the WMT14 English to French translation task show that this method provides a substantial improvement of up to 2.8 BLEU points over an equivalent NMT system that does not use this technique. With 37.5 BLEU points, our NMT system is the first to surpass the best result achieved on a WMT14 contest task.Comment: ACL 2015 camera-ready versio

CeO2 based catalysts for the treatment of propylene in motorcycle's exhaust gases

In this work, the catalytic activities of several single metallic oxides were studied for the treatment of propylene, a component in motorcycles' exhaust gases, under oxygen deficient conditions. Amongst them, CeO2 is one of the materials that exhibit the highest activity for the oxidation of C3H6. Therefore, several mixtures of CeO2 with other oxides (SnO2, ZrO2, Co3O4) were tested to investigate the changes in catalytic activity (both propylene conversion and CO2 selectivity). Ce0.9Zr0.1O2, Ce0.8Zr0.2O2 solid solutions and the mixtures of CeO2 and Co3O4 was shown to exhibit the highest propylene conversion and CO2 selectivity. They also exhibited good activities when tested under oxygen sufficient and excess conditions and with the presence of co-existing gases (CO, H2O)

Risk Factors for IN-Hospital Seizure and New-Onset Epilepsy in Coiling and Clipping Treatment of Aneurysmal Subarachnoid Hemorrhage

OBJECTIVE: To identify risk factors associated with in-hospital seizures and new-onset epilepsy in patients with aneurysmal subarachnoid hemorrhage (SAH) who underwent coiling embolization or clipping surgery. METHODS: This retrospective descriptive study included 195 patients diagnosed with aneurysmal SAH and treated with coiling embolization or clipping surgery between January 2018 and June 2022. RESULTS: Among the 195 patients meeting inclusion criteria, 9 experienced an onset seizure at the time of SAH. In-hospital seizures were observed in 33 patients, of which 24 were electrographic seizures detected in 24 patients with suspected subclinical seizures. After 12 months of follow-up, 11 patients met criteria for diagnosis of epilepsy. The incidence of epilepsy after discharge at 12 months was 2.41% in the coiling group and 8.03% in the clipping group. The risk of in-hospital seizures was significantly higher in the clipping group (P = 0.007), although the difference was not statistically significant after 12 months of follow-up (P = 0.121). CONCLUSIONS: Epilepsy following aneurysmal SAH was relatively common. Clipping surgery and brain edema emerged as independent predictive factors for in-hospital seizures, while onset seizures and in-hospital seizures were identified as independent predictors of epilepsy during follow-up. Patients presenting with these risk factors may benefit from long-term electroencephalogram monitoring and should be considered for prophylactic antiepileptic drugs. Additionally, lumbar drainage proved effective in improving both early and late epileptic outcomes in the group with Fisher grades 3 and 4