This paper presents a novel method for transient and steady state mixed gas permeation measurements, using a quadrupole residual gas analyser for the on-line determination of the permeate composition. The on-line analysis provides sufficiently quick response times to follow even fast transient phenomena, enabling the unique determination of the diffusion coefficient of the individual gases in a gas mixture. Following earlier work, the method is further optimised for higher gas pressures, using a thin film composite and a thick dense styrene-butadiene-styrene (SBS) block copolymer membrane. Finally, the method is used to calculate the CO₂/CH₄ mixed gas diffusion coefficients of the spirobisfluorene-based polymer of intrinsic microporosity, PIM-SBF-1. It is shown that the modest pressure dependence of the PIM-SBF-1 permeability can be ascribed to a much stronger pressure dependence of the diffusion coefficient, which partially compensates the decreasing solubility of CO₂ with increasing pressure, typical for the strong sorption behaviour in PIMs. The characteristics of the instrument are discussed and suggestions are given for even more versatile measurements under stepwise increasing pressure conditions. This is the first report on mixed gas diffusion coefficients at different pressures in a polymer of intrinsic microporosity.
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http://www.ncbi.nlm.nih.gov/pmc/articles/PMC6161161 | PMC |
http://dx.doi.org/10.3390/membranes8030073 | DOI Listing |
Sci Rep
December 2024
Department of Organic Chemistry, Faculty of Chemistry and Petroleum Sciences, Bu-Ali Sina University, Hamedan, Iran.
In recent two decades, considerable efforts have been devoted to the room-temperature green syntheses of metal-organic frameworks (MOFs) to reduce energy consumption and increase safety. It could improve some properties (e.g.
View Article and Find Full Text PDFJ Nutr
December 2024
Nottingham NIHR Biomedical Research Centre and Nottingham Digestive Disease Centre, School of Medicine, University of Nottingham, Nottingham, United Kingdom. Electronic address:
Background: Recent studies show that the increase in breath hydrogen (BH) and symptoms after ingestion of inulin is reduced by co-administering psyllium.
Objectives: To determine if slowing delivery of inulin to the colon by administering it in divided doses would mimic the effect of psyllium. Primary endpoint was the BH area under the curve AUC.
Sci Rep
December 2024
Faculty of Mechanical Engineering, Tarbiat Modares University, P.O. Box 14115-143, Tehran, Iran.
Porous combustion has drawn vast attention over the last few decades leading to a variety of progressing applications particularly in industrial kitchens and household appliances that require time sensitive heating. The present study experimentally investigates the relationship between cooking duration and the thermal efficiency of a cooking pot heated on a porous burner providing a valuable insights into the effectiveness of the heating process in terms of both time and fuel consumption. To facilitate this investigation, a dedicated test bench is designed and constructed, equipped with thermometers and timer to effectively monitor the temporal/thermal behavior of the heating process.
View Article and Find Full Text PDFRisk Anal
December 2024
Department of Electrical Engineering, Shahreza Campus, University of Isfahan, Isfahan, Iran.
This article presents a planning framework to improve the weather-related resilience of natural gas-dependent electricity distribution systems. The problem is formulated as a two-stage stochastic mixed integer linear programing model. In the first stage, the measures for distribution line hardening, gas-fired distributed generation (DG) placement, electrical energy storage resource allocation, and tie-switch placement are determined.
View Article and Find Full Text PDFJ Adv Res
December 2024
College of Agronomy and Biotechnology, China Agricultural University/ The Innovation Center (Beijing) of Crop Seeds Whole-Process Technology Research of Ministry of Agriculture and Rural Affairs/ Beijing Key Laboratory of Crop Genetic Improvement, Beijing 100193, China. Electronic address:
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