180 research outputs found
Corporate sustainability reporting index and baseline data for the cruise industry
Sustainability policies and corporate reports demonstrate the impacts cruise companies acknowledge as their responsibility, and the actions put in place to address them. This paper develops a corporate social responsibility index based on the Global Reporting Initiative, with industry specific additions including labor and human rights, health and safety, and environmental and economic aspects. Companies disclose more management than performance data, which is typical of early stages of development. Companies disclosing less information focus on soft indicators which are easy to mimic and demonstrate posturing. Items disclosed tend to be marginal to the core of the business, have a positive economic impact or pre-empt sector regulation. Reports echo the voice of the corporations and not the demands of stakeholders. Institutional isomorphism has not influenced a homogenization in reporting, with only the largest firms reporting at this stage
A study of different supports for the catalytic reduction of nitrates from natural water with a continuous reactor
[EN] The aim of this work is to study the activity for the nitrate catalytic reduction in natural water, using a
continuous stirred tank reactor, of Pd/Cu and Pd/Sn catalysts supported on different materials. The studied
supports are: -Al2O3 (commercial), active carbon, graphite, hydrotalcite and alumina synthesized in
our laboratory with a high surface area. The activity and selectivity of the catalysts supported on these
materials have been compared. The best results have been obtained with the Pd/Sn catalysts supported on
alumina. These results show thatthe surface area ofthe supportis notthe only important characteristic for
an active catalyst in this reaction, but also its acidâbase properties, electrical conductivity and interaction
with the metallic active sites are very significant. The adequate combination of these characteristics is
necessary to obtain an active catalyst. The influence of the Pd/Sn content on the activity of the alumina
supported catalysts was studied, observing that the best activity was obtained when the Pd/Sn ratio was
higher than 1. This result clearly indicates that it is necessary to have both Pd and PdâSn centers in order
to obtain an active catalyst.The authors thank the Spanish Government(projects MAT2009-14528-C02-01 and CONSOLIDER INGENIO 2010) and the European Union (European Communityâs Seventh Framework Programme FP7/2007-2013 under Grant Agreement No. 226347 Project)for the financial support.Franch MartĂ, C.; Palomares Gimeno, AE.; Corma CanĂłs, A. (2011). A study of different supports for the catalytic reduction of nitrates from natural water with a continuous reactor. Catalysis Today. 172(1):90-94. https://doi.org/10.1016/j.cattod.2011.05.015S9094172
Recommended from our members
Organising the process of knowledge integration: The benefits of structural ambiguity
In this article we examine how loose coupling between units and people can benefit a firm's ability to combine and recombine knowledge-based resources continuously in a creative and flexible way. An in-depth study of Oticon A/S suggests that loose coupling can be deliberately brought into the design of the organisation by introducing a certain structural ambiguity into the configuration of role systems and authority relationships. In the first part of the paper, we show how loose coupling among units and people is a distinctive feature of the way Oticon organises its administrative activities. In the second, we explore the structural properties of a loosely coupled arrangement. We develop the concepts of multipolarity, fluidity and interconnectedness and we show how these properties conduce to an increase in the effectiveness, efficiency and flexibility of the processes of knowledge integration. Structural ambiguity is thus proposed as a viable design principle for organisations operating in hypercompetitive environment, where flexible knowledge integration represents a critical condition of survival
Generalized predictive modeling for facilitated transport membranes accounting for fixed and mobile carriers
The present work expands previous modeling knowledge on facilitated transport membranes for olefin/paraffin separation. A new robust and practical mathematical model for the description of light olefin flux in composite polymer/ionic liquid/Ag+ membranes is reported. The model takes into account three different transport mechanisms, i.e., solution-diffusion, fixed-site carrier and mobile carrier transport mechanisms. Fixed-site carrier contribution that appears thanks to the bounding of silver cations with the polymer chains is described through a âhopping parameterâ. Furthermore, given that the addition of an ionic liquid to the membrane composition promotes carrier mobility, the inclusion of a dedicated expression is necessary for a realistic description of mobile-carrier transport phenomena. The contribution of each mechanism in weighted based on the membrane composition.
In order to check the model suitability, simulated values have been matched to experimental data obtained by continuous flow propane/propylene permeation experiments through PVDF-HFP/BMImBF4/AgBF4 composite membranes, working with 50:50 gas mixtures at different temperature and pressure. The resultant model offers good predictions for olefin flux and provides a very useful tool for process optimization and scaling-up. To our knowledge, this is the first time that mobile and fixed site carrier mechanisms performance are simultaneously modeled considering the influence of temperature, pressure and carrier loading.Financial support from projects CTQ2015-66078-R and CTQ2016-75158-R (MINECO, Spain-FEDER 2014â2020) is gratefully acknowledged. RaĂșl Zarca also thanks the Universidad de Cantabria for a postgraduate fellowship
Recommended from our members
Redirecting research efforts on the diversification-performance linkage: The search for synergy
We review the literature on the diversification-performance (D-P) relationship to a) propose that the time is ripe for a renewed attack on understanding the relationship between diversification and firm performance, and b) outline a new approach to attacking the question. Our paper makes four main contributions. First, through a review of the literature we establish the inherent complexities in the D-P relationship and the methodological challenges confronted by the literature in reaching its current conclusion of a non-linear relationship between diversification and performance. Second, we argue that to better guide managers the literature needs to develop along a complementary path â whereas past research has often focused on answering the big question of does diversification affect firm performance, this second path would focus more on identifying the precise micro-mechanisms through which diversification adds or subtracts value. Third, we outline a new approach to the investigation of this topic, based on (a) identifying the precise underlying mechanisms through which diversification affects performance; (b) identifying performance outcomes that are âproximateâ to the mechanism that the researcher is studying, and (c) identifying an appropriate research design that can enable a causal claim. Finally, we outline a set of directions for future research
Catalytic membrane in reduction of aqueous nitrates: operational principles and catalytic performance
The catalytic membrane with palladium-copper active component supported over the macroporous ceramic membrane, and a series of Îł-Al 2O 3 supported Pd-Cu catalysts were prepared and investigated. In reduction of nitrate ions by hydrogen in water at ambient temperature, pronounced internal diffusion limitations of the reaction rate were observed for Pd-Cu/Al 2O 3 catalysts. The catalytic membrane with Pd-Cu active component deposited over the macroporous ceramic membrane support was employed to minimize the diffusion limitations. Multifold increase in the observed catalytic activity was registered for the catalytic membrane operated with the forced flow of the reaction solution through the membrane, as compared to the value achieved at the same conditions, but in the absence of the forced flow (i.e. when the membrane porous space was accessible to the reactants due to diffusion only). These improvements are attributed to the intensification of the intraporous mass transfer attainable with the reactants forced flow in the membrane pores. The concept of catalytic membrane reactors explored in this study offers a new means to improve catalytic performance in the processes where internal diffusion limitations must be minimized and the use of finely dispersed catalysts is not desired
- âŠ