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51.
Electrochemical injection of organic corrosion inhibitors into carbonated cementitious materials: Part 1. Effects on pore solution chemistry 总被引:4,自引:0,他引:4
This series of investigations was intended to clarify phenomena associated with electrochemical injection of the organic base corrosion inhibitors, ethanolamine and guanidine, into carbonated concrete. In Part 1, experiments were conducted with laminated specimens of carbonated cement paste, that were specially designed to facilitate analysis with adequate spatial resolution to assess changes in their pore solution phase chemistry after they had been subjected to constant current electrolysis between embedded cathodes and external anodes. The anolyte solutions provided sources of ethanolamine or guanidine in contact with the exterior specimen surfaces. Effects of variations in the applied current density and duration of electrolysis on the concentration profiles of the two inhibitors and the other main constituents of the pore solution phase were determined. The results have been used to underpin the development of a mathematical model, which is described in Part 2. 相似文献
52.
Quantification of response time in poly(vinyl alcohol)–metal complex thermochromic polymeric systems
Thermochromic poly(vinyl alcohol) (PVA)‐based material was synthesized and an extensive study of its thermochromic behavior with respect to response time was carried out. It was observed that it is possible to manipulate the response time by keeping control over chemical and physical parameters. The response time, which is the most important property of a smart material, has in this case been found to be very much influenced by rate of heat transfer into the material. Different compositions of the thermochromic material and their corresponding response time with respect to rate of heat transfer were studied and correlated. First, a theoretical equation was derived and later on it was experimentally verified to quantify the response time in PVA–metal complex‐based thermochromic systems. © 2006 Wiley Periodicals, Inc. J Appl Polym Sci 100: 4832–4834, 2006 相似文献
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Gang Li Dan I. Enache Jennifer Edwards Albert F. Carley David W. Knight Graham J. Hutchings 《Catalysis Letters》2006,110(1-2):7-13
The oxidation of benzyl alcohol to benzaldehyde has been investigated in the absence of solvent using zeolite-supported Au
and Au–Pd catalysts. Three zeolites were investigated, ZSM-5, zeolite β and zeolite Y, and these were contrasted with the
titanoslicalite TS-1 and TiO2 as supports. For the Au catalysts the best results are obtained with zeolite β as the support and the conversions were comparable
or better than those observed with TiO2 in terms of turn over frequencies. However, the selectivities observed with the acidic zeolites were lower than the non-acidic
TS-1 and TiO2. This is due to the subsequent reaction of benzaldehyde via acid catalysed reactions to give benzyl benzoate and its dibenzyl
acetal, and, in some cases dibenzylether. Initial catalysts were evaluated with a gold loading of 2 wt% and increasing this
to 4 wt% showed the expected increase in activity, indicating that there is scope to improve the performance of these catalysts.
The most active catalysts were prepared by impregnation and catalysts prepared by deposition precipitation were considerably
less active. Introduction of Pd into the catalyst improved the activity without significantly affecting the selectivity. 相似文献
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Degree of crosslinking and mechanical properties of crosslinked poly(vinyl alcohol) beads for use in solid-phase organic synthesis 总被引:1,自引:0,他引:1
The limited swellability in polar media of the commonly used polystyrene/divinylbenzene (PS-DVB) support materials for solid-phase organic synthesis has led to the development of novel, highly swellable hydrophilic gels designed for use in aqueous or polar media. Poly(vinyl alcohol) beads crosslinked with epichlorohydrin (PVA-EP) were prepared by a two-step inverse-suspension polymerization method. While it is known that the morphology of the resulting beads can be controlled by the ratio of EP versus PVA as well as by the pre-crosslinking time, the actual degree of crosslinking of the beads and their mechanical properties remain unknown. It is therefore the purpose of this study to evaluate the actual degree of crosslinking of beads prepared with different quantities of crosslinker in the feed by spectroscopic (Raman, nuclear magnetic resonance) and chemical (functional group loading) methods. The mechanical properties of these swollen PVA-EP beads will be evaluated by single-bead unconfined compression in solvents such as water, N,N-dimethylformamide (DMF), and tetrahydrofuran (THF) and compared to model PS-DVB beads commonly used for solid phase synthesis. 相似文献
59.
《Expert systems with applications》2014,41(5):2574-2581
We describe in this paper a new methodology for blood alcohol content (BAC) estimation of a subject. Rather than using external devices to determine the BAC value of a subject, we perform a behaviour analysis of this subject using intelligent systems. We monitor the user’s actions in an ordinary task and label those data to various measured BAC values. The obtained data-set is then used to train learning systems to detect alcoholic consumption and perform BAC estimation. We obtain good results on a mono-user base, and lower results with multiple users. We improve the results by combining multiple classifiers and regression algorithms. 相似文献
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