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Espina J.,University of Nottingham | Ortega C.,Escola Universitaria Salesiana de Sarria | De Lillo L.,University of Nottingham | Empringham L.,University of Nottingham | And 2 more authors.
IEEE Transactions on Industrial Electronics | Year: 2014

This paper presents the study of an alternative space vector modulation (SVM) implementation for matrix converters (MCs), which reduces the output common mode (CM) voltage. The strategy is based on replacing the MC zero vectors with rotating ones. In doing this, the CM voltage (CMV) can be reduced, which, in turn, reduces the CM leakage current. By reducing the CM current, which flows inside the motor through the bearings and windings, the induction motor (IM) deterioration can be slowed down. This paper describes the SVM pattern and analyzes the CMV and the leakage current paths. Simulation and experimental results based on an MC-IM drive are provided to corroborate the presented approach. © 1982-2012 IEEE.

Calas-Blanchard C.,University of Perpignan | Cortina-Puig M.,Escola Universitaria Salesiana de Sarria | Barthelmebs L.,University of Perpignan | Noguer T.,University of Perpignan
Current Analytical Chemistry | Year: 2012

Reactive oxygen species (ROS) are very unstable molecules generated during the metabolism. They can be produced in excess, contributing to cellular dysfunctions. Antioxidants are substances that play an important role as a health-protecting factor, limiting the lesions caused by ROS. Two kinds of electrochemical biosensors based on ROS have been described to evaluate the antioxidant capacity in the food industry. The first one involves hydroxyl radicals and studies their effect on DNA alterations. The second one consists of the superoxide radicals scavenging ability, radicals being essentially generated by the xanthine/xanthine oxidase system. These sensors are commonly based on either cytochrome c or superoxide dismutase, even though recent strategies are emerging. Whatever the involved ROS, all the described biosensors possess similar advantages such as simplicity, rapidity and low cost and are successfully applied for the assessment of antioxidant properties in various foods, additives or beverages. © 2012 Bentham Science Publishers.

Prehn R.,CSIC - National Center of Microelectronics | Cortina-Puig M.,Escola Universitaria Salesiana de Sarria | Munoz F.X.,CSIC - National Center of Microelectronics
Journal of the Electrochemical Society | Year: 2012

We report a non-enzymatic glucose sensor that is based on a gold micropillar array electrode and was fabricated by using a combination of photolithographic techniques and electroplating. The electrode exhibits (a) a larger electroactive area, (b) enhanced surface roughness, and (c) enhanced catalytic activity toward the electro-oxidation of glucose. We demonstrate its potential application in sensing glucose with high operational stability, high sensitivity and relatively high selectivity. The response to glucose is linear in the 0.5 to 9 mM concentration range, the sensitivity is 13.2 μA mM -1 cm -2, and the detection limit is 60 μM. The simplicity of the sensor preparation makes gold micropillar array electrodes a good candidate for easy glucose determinations. © 2012 The Electrochemical Society.

Prehn R.,Autonomous University of Barcelona | Gonzalo-Ruiz J.,Autonomous University of Barcelona | Cortina-Puig M.,Escola Universitaria Salesiana de Sarria
Current Analytical Chemistry | Year: 2012

Polyphenolic compounds, which are widely distributed in plant-derived foods, recently attracted much attention because of their possible health benefits arising from their antioxidant activity, such as free radical scavengers and inhibition of lipoprotein oxidation. The detection of phenolic substances in food samples has been performed for many methods among them electrochemical sensors and biosensors approaches. Polyphenolic compounds are good substrates for oxidases enzymes, then biosensors modified with tyrosinase, laccase and peroxidase have been developed for detection of phenolic compounds since phenols can act as electron donors for these enzymes. Furthermore, as polyphenols are electroanalytically active compounds that can be easily oxidized at inert electrodes, electrochemical sensors have also been used as tools for estimating the total phenolic content (TPC). This paper critically reviews both electrochemical sensors and biosensors developed for the evaluation of polyphenolic compounds in foods and beverages. Due to the ability of these devices to perform simple, fast and reliable analysis, they are promising tools for the assessment of antioxidant properties. © 2012 Bentham Science Publishers.

Cortina-Puig M.,Escola Universitaria Salesiana de Sarria | Gallart-Ayala H.,University of Barcelona | Lacorte S.,CSIC - Institute of Environmental Assessment And Water Research
Current Analytical Chemistry | Year: 2012

Phenolic compounds are important components of many fruits, vegetables and beverages, contributing to their flavor, color and sensory properties. Besides, they are associated with prevention of diseases thought to be induced by oxidative stress, such as cardiovascular diseases, cancer and inflammation. Due to their bioactive functions, phenolic compounds have received particular attention in recent years. Amongst the different analytical methods reported to determine the polyphenol content and composition of food and beverages, liquid chromatography (LC) is the preferred option compared to gas chromatography (GC) since no derivatization is needed. UV detectors have been commonly used for the determination of phenolic compounds, but they lack of sensitivity and/or specificity. LC coupled with electrochemical detection (ECD) or coupled to mass spectrometry (MS) detectors are the most sensitive, selective and reproducible methods for quantifying phenolic compounds. This manuscript reviews the main applications of LC coupled to ECD or MS for the analysis of phenolic compounds in food and beverages. © 2012 Bentham Science Publishers.

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