Direct electron transfer of glucose oxidase at glassy carbon electrode modified with functionalized carbon nanotubes within a dihexadecylphosphate film

A glassy carbon electrode modified with functionalized multiwalled carbon nanotubes (CNTs) immobilized by 1-ethyl-3-(3-dimethylaminopropyl) carbodiimide/N-hydroxysuccinimide (EDC/NHS) in a dihexadecylphosphate film was prepared and characterized by cyclic voltammetry and scanning electron microscopy. It was used as a support for FAD or glucose oxidase (GOx) immobilization with EDC/NHS crosslinking agents. Cyclic voltammetry of GOx immobilized onto the surface of CNTs showed a pair of well-defined redox peaks, which correspond to the direct electron transfer of GOx, with a formal potential of −0.418 V vs. Ag/AgCl (3 M KCl) in 0.1 M phosphate buffer solution (pH 7.0). An apparent heterogeneous electron transfer rate constant of 1.69 s⁻¹ was obtained. The dependence of half wave potential on pH indicated that the direct electron transfer reaction of GOx involves a two-electron, two-proton transfer. The determination of glucose was carried out by square wave voltammetry and the developed biosensor showed good reproducibility and stability. The proposed method could be easily extended to immobilize and evaluate the direct electron transfer of other redox enzymes or proteins.     

Design of a service oriented architecture for efficient resource allocation in media environments

In many business domains, Grids and Service Oriented Architectures are considered to improve application design, integration and execution. In the audiovisual industry, applications are very data-intensive, time-constrained and computationally demanding, and design of a Service Oriented Architecture in this domain is no straightforward task. Efficient resource allocation-especially in terms of network usage-is paramount to meet users’ requirements in terms of deadlines and responsiveness, and offer high scalability at the same time. We present a resource- and network-aware management architecture addressing the issues in media environments, incorporating a number of scheduling algorithms and advance reservation systems to ensure efficient resource usage.     

RFID malware: Design principles and examples

This paper explores the concept of malware for Radio Frequency Identification (RFID) systems — including RFID exploits, RFID worms, and RFID viruses. We present RFID malware design principles together with concrete examples; the highlight is a fully illustrated example of a self-replicating RFID virus. The various RFID malware approaches are then analyzed for their effectiveness across a range of target platforms. This paper concludes by warning RFID middleware developers to build appropriate checks into their RFID middleware before it achieves wide-scale deployment in the real world.     

Globilization and regional scenarios: EU and mediterranean from marginalization to co-development

Despite globalization a progressively increasing economic and financial concentration in the cores of the world economy (e.g. EU) as well as the rise of new socioeconomic marginalization of peripheries (e.g. Maghreb and Mashraq) has been observed since the early 1980s. Marginalization has produced its own models of specialization in production which reflect in various countries and regions the needs of the cores economy forces. A regional strategy for regional co-operation, so called co-development, is advanced to overcome the current economic and social problems faced by marginalized regions in relation to world economic trends.     

Algorithms for Fuzzy Segmentation

Fuzzy segmentation is an effective way of segmenting out objects in pictures containing both random noise and shading. This is illustrated both on mathematically created pictures and on some obtained from medical imaging. A theory of fuzzy segmentation is presented. To perform fuzzy segmentation, a ‘connectedness map’ needs to be produced. It is demonstrated that greedy algorithms for creating such a connectedness map are faster than the previously used dynamic programming technique. Once the connectedness map is created, segmentation is completed by a simple thresholding of the connectedness map. This approach is efficacious in instances where simple thresholding of the original picture fails. Received: 22 October 1998?Received in revised form: 22 November 1998?Accepted: 2 December 1998     

Relation between formability and precipitates in Ti-IF enamelling steels

The influence of steel composition and processing conditions on the nature of precipitates in Ti interstitial free (IF) steels for enamelling were investigated in detail. Steels designed for enamelling applications require a higher amount of precipitates than conventional deep drawing IF steels, e.g. for automotive applications. Formable IF grades for enamelling applications have high Ti, S and C contents and the properties have hitherto not been investigated in detail. This work focused on the correlation between precipitate nature, texture development and deep drawability. It was found that a low reheating temperature, a high coiling temperature and a C/S ratio in the range of 0.4–0.5, favoured the beneficial precipitation of Ti₄C₂S₂. Furthermore, it is shown that for a steel with a given C/S ratio, a high Ti₄C₂S₂/Ti₄S₅-ratio resulted in improved deep drawability. The deep drawability decreases with increasing C/S ratio. This is due to the decrease in γ-fibre intensity, caused by an increased amount of TiC-precipitates.     

Dynamic security corrective control by UPFCs

This paper deals with the development of a nonlinear programming methodology for evaluating corrective actions to improve the dynamic security of power systems when transient instability is detected. Remedial actions are implemented by exploiting the fast response of unified power flow controllers (UPFCs). The algorithm is implemented and tested on the Italian grid     

Influence of laminate thickness on composite durability for long term utilisation at intermediate temperature (100–150 °C)

To increase the utilisation of composite material, new domain of application should be investigated such as intermediate temperature (up to 150 °C) for long term utilisation. Under these conditions, oxidation could not be neglected.