Removal of Pb(II) from aqueous solutions by using clinoptilolite and bentonite as adsorbents

In the present study, the ability of natural zeolite clinoptilolite and bentonite (clay) to remove Pb(II) from aqueous solutions has been investigated in batch reactors with a maximum contact time of 120 min. Adsorption tests of Pb(II) were carried out using a solution concentration of 1,036 ppm at initial pH = 4, and solid to liquid ratio of 2 g/100 mL. The effects of agitation speed (0, 100, 200, 500 rpm), temperature (28°C, 45°C, 60°C) and particle size (2.5–5.0 mm, dust) of the minerals were examined. The effect of acidity of the aqueous solution was also examined. Bentonite was found to be more effective for the removal of Pb(II) than clinoptilolite, under the experimental conditions used. The removal of Pb(II) using bentonite reached 100% at ambient temperature and mild agitation (100 rpm), while it was approximately 90% at 60°C without agitation. On the other hand, the highest removal level reached by clinoptilolite was 55%. Clinoptilolite dust is found to be more efficient than granular clinoptilolite. Agitation and temperature affected the uptake of Pb(II), especially in the case of granular clinoptilolite (2.5–5.0 mm). Finally, it can be seen that acidity of the aqueous solution influences the removal of lead by the minerals. The adsorption of lead increases with an increase in pH of the solution from 1 to 4.     

Store selection criteria and sales prediction in virtual worlds

Virtual worlds (VWs) have emerged as a new context for gaming, collaboration, social networking but also commercial activity. This paper focuses on the latter, and investigates how consumers behave in this virtual context when selecting stores they visit or buy from. The paper explores store selection criteria in virtual world stores and extends earlier research in both offline and online commercial environments, taking into account the novel IT capabilities that VWs exploit. Theoretical insights drawn from the marketing and information systems literature have been used to guide the design of a survey conducted in the virtual world Second Life. In addition to identifying the factors influencing store selection, the paper investigates how these differ between shoppers and non-shoppers, and identifies the factors that affect the amount of money spent in virtual world shopping environments. The findings suggest that “Core Store Features” and “Security and Privacy” constitute the most important store selection factors in virtual environments and that sales in VWs are predicted by the frequency of visiting and the time spent within VWs’ stores. Building on these findings, the paper discusses theoretical and practical implications and further research perspectives in the context of (3D) online commerce.     

Organisational Appropriation of Technology: A Case Study

This paper investigates how organisations – as joint cognitive systems – deal with change. This is explored in a case study into the use of web-based technology in an organisation and the ways in which its current and future use may be influenced by the local concerns of the actors with it. The paper looks at some of the factors that need to be taken into account for improving technology, and more specifically, in intranet development. In particular, the paper discusses the case experience in the light of previous research in IT-enabled organisational transformation and contributes to our understanding of human interaction with network technologies in an organisational context.     

Accommodating Practices During Episodes of Disillusionment with Mobile IT

This study investigates how tablet users react when technology falls short of their expectations. We deploy a data/frame model to study this process and investigate resistance-related reactions and the deployment of accommodating practices at the individual level. Analyzing user blogs that provide narratives on user interaction with tablets, we identify triggers of episodes of disillusionment and illustrate five sensemaking paths that users follow, eventually leading to one of three practices: 1) users choose to defer tasks until the situation changes, or they abandon the platform altogether; 2) they develop workarounds at different levels of proficiency; or 3) they proceed by reframing their expectations of the platform. By revealing user decision-making process during episodes of disillusionment, the findings contribute to information systems post-adoption research. At a practical level, the findings inform IT artifact and application design by offering insights on how users process discrepancies between their expectations and actual use experience.

     

A novel rapid method for the determination of frying oil quality: development of prototype and equations and examination with respect to legislation criteria

The present work presents a prototype apparatus developed for a novel method based on capillary penetration for the determination of frying oil quality and examines the method and the performance of the prototype. The work further assesses the method results in comparison with the results of established methods and proposes equations for calculating frying oil quality parameters relevant to legislation criteria. The examination of the method is performed by using 184 oil samples produced by frying different foods in different oils for forty-five successive batches. Equations relating the method output with the total polar compounds, total polymers and viscosity are proposed. High correlation coefficients between legislation criteria and the method result are obtained: R² = 0.96, R² = 0.91 and R² = 0.86 for correlation with the oil viscosity, the polymer compounds and the TPC of the fried oils, respectively. The false-positive and false-negative answers of the method are below 2.5% for all cases.     

Rapid Methods for Frying Oil Quality Determination: Evaluation with Respect to Legislation Criteria

This work focuses on the evaluation of commercially available rapid methods for determining frying oil quality. Five rapid methods differing in principle were selected: FOM320 (Ebro), PCT120 (3M), LRSM (3M), Fritest (Merck) and Viscofrit (Viscofrit). The performance of the methods was examined by use of 184 oil samples produced by controlled frying experiments. Twelve series of frying experiments (45 batches each) were performed in which the oil type (palm, sunflower and olive) and the food type (potatoes, zucchini and minced beef meat) varied. Control thermal oxidation experiments with the same oil types were also performed. Results of the rapid methods were compared to results of analytical methods determining legislation criteria. Namely, the total polar compounds and total polymer compounds were determined using High Pressure Size Exclusion Chromatography with and without prior separation of the polar fraction. Furthermore, determination of the free fatty acid concentration, acidity, viscosity and level of oxidation of the oils using UV spectroscopy were carried out. Principal component analysis and linear regression analysis were used in order to assess the obtained results. Comparison of the results of the rapid methods with the analytical ones showed differences in most examined cases. For many of the examined rapid methods the agreement of the results versus those of analytical methods depended on the food-oil combination used in the frying experiments.     

Symmetric and Asymmetric Decoration of Graphene: Bimetal‐Graphene Sandwiches

Low‐dimensional carbon materials, i.e., graphene and its functionalization with a number of semiconductor or conductor materials, such as noble metal nanostructures, have primary importance for their potential exploitation as electro‐active materials, i.e., as new generation catalysts. Here, low‐cost, solution chemistry‐based, two‐step functionalization of an individual, free‐standing, chemical vapor‐deposited graphene monolayer is reported, with noble metal (Au, Pt, Pd) nanoparticles to build up two‐side decorated graphene‐based metal nanoclusters. Either the same metal (symmetric decoration) or different metals (asymmetric decoration) are used for the preparation of bimetal graphene sandwiches, which are adsorbed at the liquid/liquid (organic/water) interface. The successful fabrication of such dual‐decorated graphene‐based metal nanocomposites is confirmed using various microscopic techniques (scanning electron and atomic force microscopies) and several spectroscopic methods (x‐ray photoelectron, energy dispersive x‐ray, mapping mode Raman spectroscopy, and electron energy loss spectroscopy). Taken together, it is inferred from these techniques that the location of deposited metal nanoparticles is on opposite sides of the graphene.     

Stakeholder identification in inter-organizational systems: gaining insights for drug use management systems

Inter-organizational systems operate in an area where there are many interested parties. If the views of these interested parties are not explored and taken into consideration before and during the development of an inter-organizational system, it is likely that the implementation of this system will be disappointing. This paper describes one approach to exploring these views through the use of stakeholder analysis. More specifically, it describes how to identify the stakeholders, a process that has been overlooked in the stakeholder analysis and inter-organizational systems literature, and examines the perceptions of a number of stakeholders in the drug use management field in the UK.