15 research outputs found

    Quantification of Viscosity for Solvents−Heavy Oil/Bitumen Systems in the Presence of Water at High Pressures and Elevated Temperatures

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    In this study, a new and pragmatic methodology has been developed to accurately predict the viscosity for light solvents (i.e., methane, ethane, propane, n-butane, n-pentane, N2, and CO2)–heavy oil/bitumen/water systems as a function of pressure in the temperature range of 287.9–463.4 K. The LV and ALV (L is the oleic phase, V is the vapor phase, and A is the aqueous phase) phase equilibria of the aforementioned systems are calculated using the Peng–Robinson equation of state (PR EOS) with modified alpha functions and binary interaction parameters (BIPs). The six widely used mixing rules for predicting viscosity of solvents−heavy oil/bitumen systems pertaining to vapor–liquid equilibria are compared and evaluated, while the linear mixing rule is used for hydrocarbons−water mixtures. Plus, effective density is for the first time successfully introduced into the volume-based mixing rules. The volume-based power law, weight-based power law, and weight-based Cragoe’s mixing rules are found to well reproduce the viscosity for the aforementioned systems with AARDs of 15.5%, 19.0%, and 32.6%, respectively. Effective density rather than real density of dissolved gas(es) should be used for all of the volume-based mixing rules, while the adjustable parameter in the power law mixing rule has a potential to achieve high generalization if adequate measurements are made available. Although water has a lower diluting ability than other solvents in the same amount of dissolution, it can outperform methane and CO2 in diluting heavy oil/bitumen at high temperatures due to its high solubility. Addition of water can reduce or increase the viscosity of a solvents–heavy oil/bitumen mixture, depending on the ability of solvents and water to dilute heavy oil/bitumen and effects of water on the solvent dissolution. Water molar fraction in feed can exert an effect on the mixture viscosity in LV equilibria through affecting the solvent dissolution but cannot impose an impact on the mixture viscosity at ALV equilibria

    Introducing the VIMSSQ: Measuring susceptibility to visually induced motion sickness

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    Visually induced motion sickness (VIMS) is a specific form of motion sickness caused by dynamic visual content such as Virtual Reality applications. Predicting individual susceptibility to VIMS has proven to be difficult and a reliable method has yet to emerge. Here, we introduce the Visually Induced Motion Sickness Susceptibility Questionnaire (VIMSSQ), a modification of the Motion Sickness Susceptibility Questionnaire uniquely designed to predict the susceptibility to VIMS specifically. Scores on the VIMSSQ are based on incidences of nausea, headache, fatigue, dizziness, and eyestrain during the past use of visual devices. In this proof-of-concept study, 71 adult participants (34 younger, 37 older) engaged in a simulated driving task and VIMS was measured using the Fast Motion Sickness Scale. Strong correlations with the reported level of VIMS were found for the nausea aspects of the VIMSSQ, suggesting that the VIMSSQ may be a useful tool to estimate individuals’ susceptibility to VIMS

    Comparison of outcomes and complications in conventional versus ultrasound-accelerated catheter directed thrombolysis for treatment of pulmonary embolism: A systematic review and meta-analysis

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    Background: Acute submassive a massive pulmonary embolism are known as leading causes of cardiovascular morbidity and mortality in emergency departments. Choosing the optimal type of catheter directed thrombolysis (CDT) for treatment of pulmonary embolism presents a quandary to the practitioners. To the best of our knowledge, there is no meta-analysis comparing superiority of conventional CDT and ultrasound-accelerated catheter directed thrombolysis (USACDT). Therefore, in this meta-analysis, we aimed to compare conventional CDT with USACDT regarding clinical outcomes and safety profile. Methods: A systematic literature search of previous published studies comparing conventional CDT with USACDT regarding clinical outcomes and safety profile was carried out in the electronic databases including MEDLINE, Scopus, EBSCO, Google Scholar, Web of Science, and Cochrane from inception to December 2021. Data were analyzed by comprehensive meta-analysis software (CMA, version 3). Results: The meta-analysis included nine studies with a total of 705 patients. Our meta-analysis showed that there is no significant difference between two groups with respect to pulmonary arterial systolic pressure (SMD: �0.084; 95 CI: �0.287 to 0.12; p: 0.41), RV/LV (SMD: �0.003; 95 CI: �0.277 to 0.270; p: 0.98), and Miller score (SMD: �0.345; 95 CI: �1.376 to 0.686; p: 0.51). Similarly, we found no statistically significant differences between two groups regarding major and minor bleeding (p >.05). Conclusion: Our meta-analysis showed that when compared with USACDT, conventional CDT provides similar clinical and hemodynamic outcomes or safety for treatment of pulmonary embolism without the need for very expensive technologies. However, randomized clinical trials are required to further investigate cost-effectiveness of USACDT in comparison with conventional CDT. © The Author(s) 2022
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