A detailed study on all stages associated with the reaction mechanisms for the denitrogenation of 2,3-diazabicyclo[2.2.1]hept-2-ene derivatives (DBX, with X substituents at the methano-bridge carbon atom, X = H and OH) is presented. In particular, we have characterized the processes leading to cycloalkene derivatives through migration-type mechanisms as well as the processes leading to cyclopen...

The dissociative ionization of N2O by near-single-cycle laser pulses is studied using phase-tagged ion–ion coincidence momentum imaging. Carrier–envelope phase (CEP) dependences are observed in the absolute ion yields and the emission direction of nearly all ionization and dissociation pathways of the triatomic molecule. We find that laser-field-driven electron recollision has a significant imp...

Curved π-conjugated molecules and open-shell structures have attracted much attention from the perspective of fundamental chemistry, as well materials science. In this study, chemistry 1,3-diradicals (DRs) embedded in curved cycloparaphenylene (CPPs) structures, DR-(n+3)CPPs (n = 0–5), was investigated to understand effects curvature system size on spin–spin interactions singlet versus triplet ...

Because intubation can potentially become a lengthy procedure, the risk of arterial oxygen (O2) desaturation during intubation must be considered. Preoxygenation should be routine, as oxygen reserves are not always sufficient to cover the duration of intubation. Three minutes of spontaneous breathing at FiO2=1 allows denitrogenation with FAO2 close to 95% in patients with normal lung function. ...

Although differences exist, hypobaric and hyperbaric exposures share common physiological, biochemical, and clinical features, and their comparison may provide further insight into the mechanisms of decompression stress. Although altitude decompression illness (DCI) has been experienced by high-altitude Air Force pilots and is common in ground-based experiments simulating decompression profiles...

Introduction: To reduce denitrogenation time to prevent decompression sickness to support frequent extravehicular activities on the Moon, and to limit the risk of fire, a hypobaric (PB = 414 mmHg) and mildly hypoxic (ppO2 = 132 mmHg, 32% O2 68% N2) living environment is being considered during lunar missions for the Crew Exploration Vehicle (CEV) and Lunar Surface Access Module (LSAM). If the v...

Abstract In this study, bimetallic catalysts based on transition metals CuFe 2 O 4 , CoFe and NiFe are proposed for catalyzing aquathermolysis reaction during steam-based EOR method to improve in-situ heavy oil upgrading. All upgrading experiments were carried out under a nitrogen atmosphere 24 h in 300-ml batch Parr reactor at 250 300 °C high pressure 35 75 bar, respectively. To evaluate the c...

The performance of MSU-S and its forms modified with phosphotungstic acid (HPW) and nickel (Ni) for the desulfurization and denitrogenation of model diesel fuel were studied. According to the results of the characteristic tests (N2 adsorption-desorption, XRD, SEM, and NH3-TPD), heteropoly acid incorporation causes higher acidity along with a negligible loss of structural a...