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31.
32.
Felipe A. Perdomo Siti H. Khalit Claire S. Adjiman Amparo Galindo George Jackson 《American Institute of Chemical Engineers》2021,67(3):e17194
The SAFT-γ Mie group-contribution equation of state is used to represent the fluid-phase behavior of aqueous solutions of a variety of linear, branched, and cyclic amines. New group interactions are developed in order to model the mixtures of interest, including the like and unlike interactions between alkyl primary, secondary, and tertiary amine groups (NH2, NH, N), cyclic secondary and tertiary amine groups (cNH, cN), and cyclic methine-amine groups (cCHNH, cCHN) with water (H2O). The group-interaction parameters are estimated from appropriate experimental thermodynamic data for pure amines and selected mixtures. By taking advantage of the group-contribution nature of the method, one can describe the fluid-phase behavior of mixtures of molecules comprising those groups over broad ranges of temperature, pressure, and composition. A number of aqueous solutions of amines are studied including linear, branched aliphatic, and cyclic amines. Liquid–liquid equilibria (LLE) bounded by lower critical solution temperatures (LCSTs) have been reported experimentally and are reproduced here with the SAFT-γ Mie approach. The main feature of the approach is the ability not only to represent accurately the experimental data employed in the parameter estimation, but also to predict the vapor–liquid, liquid–liquid, and vapor–liquid–liquid equilibria, and LCSTs with the same set of parameters. Pure compound and binary phase diagrams of diverse types of amines and their aqueous solutions are assessed in order to demonstrate the main features of the thermodynamic and fluid-phase behavior. 相似文献
33.
An ecofriendly and biodegradable porous structure was prepared from drying aqueous foams based on nano fibrillated cellulose (NFC), extracted from softwood pulp by subcritical water/CO2 treatment (SC-NFC). The primary aim of this work was to use the modified SC-NFC as stabilizer for a water-based Pickering emulsion which upon drying, yielded porous cellulosic materials, a good dye adsorbent. In order to exploit the carboxymethylated SC-NFC (CMSC-NFC, with a degree of substitution of 0.35 and a charge density of 649 μeqv/g) as a stabilizer for water-based Pickering emulsion in subsequent step, an optimized quantity of octyl amine (30 mg/g of SC-NFC) was added to make them partially hydrophobic. A series of dry foam structures were prepared by varying the concentrations of treated CMSC-NFCs and 4 wt% was found to be the optimum concentration to yield foam with high porosity (99%) and low density (0.038 g/cc) along with high compression strength (0.24 MPa), superior to the conventionally extracted NFC. The foams were applied to capture as high as 98% of methylene blue dyes, making them a potential green candidate for treating industrial effluent. In addition, the dye adsorption kinetics and isotherms were found to be well suited with second order kinetics and Langmuir isotherm models. 相似文献
34.
《International Journal of Hydrogen Energy》2022,47(14):8716-8728
In this study, lignin was gasified in supercritical water with catalysis of CuO–ZnO synthesized by deposition precipitation, co-precipitation and sol-gel methods. Sol-gel synthesized CuO–ZnO showed the highest catalytic performance, and the gasification efficiency was increased by 37.92% with it. The XRD, SEM-EDS and N2 adsorption/desorption analysis showed that the priority of the sol-gel catalyst was the smallest crystallite size, largest specific surface area and high dispersion. For sol-gel synthesized CuO–ZnO, the increase of CuO/ZnO ratio improved the gasification efficiency but reduced H2 selectivity. And the catalytic activity was reduced with the calcination temperature above 600 °C due to enlarged crystallites and reduced pores. During sol-gel preparation, both the addition of ethanol and PEG in the solvent reduced the agglomeration and improved the catalytic activity. With CuO–ZnO prepared with 1 g PEG + water as the solvent, the highest H2 yield of 6.86 mol/kg was obtained, which was over 1.5 times of that without catalyst. 相似文献
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针对赤泥等固体废弃物对环境危害性大且利用率低等问题,以碱激发赤泥-矿渣基地聚物注浆材料为
研究对象,研究了不同掺量的聚羧酸(PA)减水剂、醛酮缩合物(AKC)减水剂和萘系(N)减水剂对材料凝结时间、流动
性及强度等的影响,并通过 XRD、傅里叶红外光谱及 SEM 等设备对减水剂的作用机理进行研究。 结果表明:减水剂增
强了材料的流动性但降低了材料的剪切应力;N 和 PA 减水剂能缩短材料的凝结时间,但 AKC 减水剂会延长材料的凝
结时间;N 和 AKC 减水剂能提高材料的强度,但 PA 减水剂会降低材料的强度;N 减水剂对材料的综合性能提升效果
更加明显,其最优掺量为 0. 7%;减水剂对赤泥-矿渣基地聚物性能提升的作用机理主要是促进地聚合物凝胶的形成。
研究成果为拓展赤泥在工程上的使用途径和效率提供了理论指导。 相似文献
37.
《Advanced Powder Technology》2022,33(6):103628
The charge sources, as well as the charging mechanism of the contact electrification (CE) of polymers, are still debatable. Since CE is accompanied by destruction, it is considered that “hard contacting” via ball milling can induce covalent bond scission and produce naked-activated-charge sources. Regarding “soft contacting” via nano-scale sliding, which does not induce covalent bond scission, a frontier-electron, “f-electron,” of the naked-activated-charge source is crucial to electron transfer among the naked-activated-charge sources. Here, we configure naked-activated-charge-source models, naked-activated-mechano-anion, and naked-activated-mechano-cation, which are produced by mechanical energy induced heterogeneous covalent bond scission, as well as naked-activated-mechano-radicals that are produced by homogeneous covalent bond scission. Regarding “soft contacting” among naked-activated-charge sources in a vacuum, f-electron can be transferred from a donor to an acceptor if the energy level of the donor is higher than that of the acceptor. The net amount of the normalized transferred-f-electrons is obtained by adopting settings in which the average energy level of the naked-activated-charge sources (as the donors) is higher than that of the sources employed as acceptors. Thus, the surfaces comprising the donors and acceptors will exhibit positive and negative net surface charges, respectively. We conclude that net surface charges depend on the average energy level of naked-activated-charge sources. Further, we observe that the alignment of polyethylene (PE)-polyvinyl chloride (PVC)-polytetrafluoroethylene (PTFE) to the average energy level is identical to that of the triboelectric series. 相似文献
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40.
Against the background of smart manufacturing and Industry 4.0, how to achieve real-time scheduling has become a problem to be solved. In this regard, automatic design for shop scheduling based on hyper-heuristics has been widely studied, and a number of reviews and scheduling algorithms have been presented. Few studies, however, have specifically discussed the technical points involved in algorithm development. This study, therefore, constructs a general framework for automatic design for shop scheduling strategies based on hyper-heuristics, and various state-of-the-art technical points in the development process are summarized. First, we summarize the existing types of shop scheduling strategies and classify them using a new classification method. Second, we summarize an automatic design algorithm for shop scheduling. Then, we investigate surrogate-assisted methods that are popular in the current algorithm field. Finally, current problems and challenges are discussed, and potential directions for future research are proposed. 相似文献