964 resultados para Web-actor theory
Resumo:
In this paper we analyzed the adsorption of gases and vapors on graphitised thermal carbon black by using a modified DFT-lattice theory, in which we assume that the behavior of the first layer in the adsorption film is different from those of second and higher layers. The effects of various parameters on the topology of the adsorption isotherm were first investigated, and the model was then applied in the analysis of adsorption data of numerous substances on carbon black. We have found that the first layer in the adsorption film behaves differently from the second and higher layers in such a way that the adsorbate-adsorbate interaction energy in the first layer is less than that of second and higher layers, and the same is observed for the partition function. Furthermore, the adsorbate-adsorbate and adsorbate-adsorbent interaction energies obtained from the fitting are consistently lower than the corresponding values obtained from the viscosity data and calculated from the Lorentz-Berthelot rule, respectively.
Resumo:
A comparative study of carbon gasification with O-2 and CO2 was conducted by using density functional theory calculations. It was found that the activation energy and the number of active sites in carbon gasification reactions are significantly affected by both the capacity and manner of gas chemisorption. O-2 has a strong adsorption capacity and the dissociative chemisorption of O-2 is thermodynamically favorable on either bare carbon surface or even isolated edge sites. As a result, a large number of semiquinone and o-quinone oxygen can be formed indicating a significant increase in the number of active sites. Moreover, the weaker o-quinone C-C bonds can also drive the reaction forward at (ca. 30%) lower activation energy. Epoxy oxygen forms under relatively high O-2 pressure, and it can only increase the number of active sites, not further reduce the activation energy. CO2 has a lower adsorption capacity. Dissociative chemisorption of CO2 can only occur on two consecutive edge sites and o-quinone oxygen formed from CO2 chemisorption is negligible, let alone epoxy oxygen. Therefore, CO2-carbon reaction needs (ca 30%) higher activation energy. Furthermore, the effective active sites are also reduced by the manner Of CO2 chemisorption. A combination of the higher activation energy and the fewer active sites leads to the much lower reaction rate Of CO2-carbon.
Resumo:
This article presents a fairness theory-based conceptual framework for studying and managing consumers’ emotions during service recovery attempts. The conceptual framework highlights the central role played by counterfactual thinking and accountability. Findings from five focus groups are also presented to lend further support to the conceptual framework. Essentially, the article argues that a service failure event triggers an emotional response in the consumer, and from here the consumer commences an assessment of the situation, considering procedural justice, interactional justice, and distributive justice elements, while engaging in counterfactual thinking and apportioning accountability. More specifically, the customer assesses whether the service provider could and should have done something more to remedy the problem and how the customer would have felt had these actions been taken. The authors argue that during this process situational effort is taken into account when assessing accountability. When service providers do not appear to exhibit an appropriate level of effort, consumers attribute this to the service provider not caring. This in turn leads to the customer feeling more negative emotions, such as anger and frustration. Managerial implications of the study are discussed.