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Griselda Castruita-de León Claudia Y. Yeverino-Miranda Angel de J. Montes-Luna Hector Iván Meléndez-Ortiz German Alvarado-Tenorio Luis Alfonso García-Cerda 《应用聚合物科学杂志》2020,137(3):48286
Flat mixed matrix membranes (MMMs) comprising polysulfone and clinoptilolite-type natural zeolite were prepared by casting. Zeolite was modified with three alkylamines: ethanolamine (EA), bis(2-hydroxypropyl)amine (BHPA), and polyethylenimine (PEI) by the impregnation method. Impregnated zeolite samples were characterized by X-ray diffraction, Fourier transform infrared spectroscopy, and N2 adsorption–desorption. The alkylamine loading extent determined by thermogravimetric analysis was 5.2, 4.8, and 8.5% for EA, BHPA, and PEI, respectively. Analyses of MMMs showed that the incorporation of impregnated zeolite affected the glass-transition temperature (Tg) and mixed-gas transport properties. In this regard, a decreasing trend of the Tg values from 185.5 °C for the polymeric membrane up to 176.6 °C for Clino-EA-based MMM was recorded. In addition, the gas separation performance was evaluated at two different feed pressures. At 50 psi, MMMs showed an enhancement up to 30% on the CO2 permeability (22.79 Barrer) and 55% on the CO2/CH4 selectivity (45.78) in comparison with the polymeric membrane (CO2 permeability 17.34 Barrer; CO2/CH4 selectivity 29.38). These values varied depending on the alkylamine, BHPA being the most selective. © 2019 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2020 , 137, 48286. 相似文献
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Laura R. Turcer Amanda R. Krause Hector F. Garces Lin Zhang Nitin P. Padture 《Journal of the European Ceramic Society》2018,38(11):3905-3913
The high-temperature (1500?°C) interactions of two promising dense, polycrystalline EBC ceramics, YAlO3 (YAP) and γ-Y2Si2O7, with a calcia-magnesia-aluminosilicate (CMAS) glass have been explored as part of a model study. Despite the fact that the optical basicities of both the EBC ceramics and the CMAS are similar, they both react with the CMAS. In the case of the Si-free YAlO3, the reaction zone is small and it comprises three regions of reaction-crystallization products, including Y-Ca-Si apatite solid-solution (ss) and Y3Al5O12 (YAG)(ss). In contrast, only Y-Ca-Si apatite(ss) forms in the case of Si-containing γ-Y2Si2O7, and the reaction zone is an order-of-magnitude thicker. These CMAS interactions are analyzed in detail, and are found to be strikingly different than those observed in Y-free EBC ceramics (β-Yb2Si2O7 and β-Sc2Si2O7) in the accompanying Part II paper. This is attributed to the presence of the Y in the YAlO3 and γ-Y2Si2O7 EBC ceramics. 相似文献
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Amir Mowla Mehrez Agnaou Tanyakarn Treeratanaphitak Hector M. Budman Nasser M. Abukhdeir Marios A. Ioannidis 《American Institute of Chemical Engineers》2020,66(6):e16959
We quantify the ability of the two-fluid Euler–Euler model to predict the overall gas hold-up during two-phase flow in vertical columns using a combination of experiments and simulations. Gas hold-up in a bubble column and gas hold-up in the less-frequently studied co-current flow are investigated. For homogeneous flow characterized by nearly uniform bubble size, Euler–Euler model predictions are within 10% of the experimental values for both modes of operation, if the bubble diameter supplied as input to the model is the average bubble diameter in the physical system. This also holds true for heterogeneous flow in bubble columns despite the presence of a broad distribution of bubble sizes, if turbulence and bubble swarm effects on momentum exchange between phases are properly accounted for. Swarm corrections adequate for bubble columns, are less successful for co-current heterogeneous flow, for which gas hold-up predictions are least accurate (average error of 22%). 相似文献
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Taller Hector Barroso 《世界建筑导报》2019,(4)
<正>在墨西哥Valle de Bravo一处茂密的丛林中,五栋假日住宅散布于此。它们顺应着场地的环境,在松树林与风的回声中静静屹立。五栋住宅采用完全相同的内部结构,其内部六个功能区相互连接围合出中央天井。该中庭享有良好的视野,静谧的氛围,和亲密的舒适感。位于北侧的建筑内部空间相对私密,而南侧则向自然充分开放。低层坐落着客厅,餐厅,厨房和一间融入外部露台、中庭和花园的卧室。顶层三间卧室面向松树林迎接美丽的自然景观。建筑材料源自于当地的砖,木和泥土。 相似文献
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Transient Electronics: Thermally Triggered Degradation of Transient Electronic Devices (Adv. Mater. 25/2015) 下载免费PDF全文