| 1. |
- Bianchi, F., et al.
(författare)
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Differentiation of the volatile profile of microbiologically contaminated canned tomatoes by dynamic headspace extraction followed by gas chromatography-mass spectrometry analysis
- 2009
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Ingår i: Talanta. - : Elsevier BV. - 0039-9140 .- 1873-3573. ; 77:3, s. 962-970
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Tidskriftsartikel (refereegranskat)abstract
- The aromatic profile of microbiologically contaminated canned tomatoes was analyzed by the dynamic headspace extraction technique coupled with gas chromatography-mass spectrometry. Canned tomatoes contaminated with Escherichia coli, Saccharomyces cerevisiae and Aspergillus carbonarius were analyzed after 2 and 7 days. About 100 volatiles were detected, among which alcohols, aldehydes and ketones were the most abundant compounds. Gas chromatographic peak areas were used for statistical purposes. First, principal component analysis was carried out in order to visualize data trends and clusters. Then, linear discriminant analysis was performed in order to detect the set of volatile compounds ables to differentiate groups of analyzed samples. Five volatile compounds, i.e. ethanol, beta-myrcene,o-methyl styrene, 6-methyl-5-hepten-2-ol and 1-octanol, were found to be able to better discriminate between uncontaminated and contaminated samples. Prediction ability of the calculated model was estimated to be 100% by the "leave-one-out" cross-validation. An electronic nose device was then used to analyze the same contaminated and not contaminated canned tomato samples. Preliminary results were compared with those obtained by dynamic headspace gas chromatography-mass spectrometry, showing a good agreement.
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| 2. |
- Concina, Isabella, et al.
(författare)
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Early detection of microbial contamination in processed tomatoes by electronic nose
- 2009
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Ingår i: Food Control. - : Elsevier BV. - 0956-7135 .- 1873-7129. ; 20:10, s. 873-880
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Tidskriftsartikel (refereegranskat)abstract
- Microbial contamination can easily affect processed tomato, thus determining both organoleptic adulterations and potential health risks for customers. Innovative techniques for a rapid and reliable diagnose of spoilage, such as electronic nose technology, are highly requested in order to guarantee food safety and to improve production. In this work canned peeled tomatoes were artificially spoiled with different kinds of microbial flora and then were analyzed by means of an electronic nose based on thin film metal oxide gas sensors. Preliminary analyses by dynamic-headspace gas chromatographic-mass spectrometry showed significant differences in the semi-quantitative volatile compounds profile of spoiled tomato samples just after few hours from contamination, thus suggesting to employ the electronic nose for an early diagnose of microbial presence. The electronic nose was indeed able to reveal contamination, even at early stages depending on the type of contaminant (e.g. for Saccharomyces cerevisiae and Escherichia coli), and to recognize spoiled tomato samples with good classification performances.
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| 3. |
- Ponzoni, Andrea, et al.
(författare)
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Metal oxide nanowire and thin-film-based gas sensors for chemical warfare simulants detection
- 2008
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Ingår i: IEEE Sensors Journal. - 1530-437X .- 1558-1748. ; 8:6, s. 735-742
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Tidskriftsartikel (refereegranskat)abstract
- This work concerns with metal oxide (MOX) gas sensors based on nanowires and thin films. We focus on chemical warfare agents (CWAs) detection to compare these materials from the functional point-of-view. We work with different chemicals including simulants for Sarin nerve agents, vescicant gases, cyanide agents, and analytes such as ethanol, acetone, ammonia, and carbon monoxide that can be produced by everyday activities causing false alarms. Explorative data analysis has been used to demonstrate the different sensing performances of nanowires and thin films. Within the chosen application, our analysis reveal that the introduction of nanowires inside the array composed by thin films can improve its sensing capability. Cyanide simulants have been detected at concentrations close to 1 ppm, lower than the Immediately Dangerous for Life and Health (IDLH) value of the respective warfare agent. Higher sensitivity has been obtained to simulants for Sarin and vescicant gases, which have been detected at concentrations close or even lower than 100 ppb. Results demonstrate the suitability of the proposed array to selectively detect CWA simulants with respect to some compounds produced by everyday activities. © 2008 IEEE.
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| 4. |
- Bianchi, Nicola, et al.
(författare)
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The steering effect - PM motor drives for automotive systems
- 2008
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Ingår i: IEEE Industry Applications Magazine. - 1077-2618 .- 1558-0598. ; 14:2, s. 40-48
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Tidskriftsartikel (refereegranskat)abstract
- This paper presents the analysis and design of asteer-by-wire drive system, developed in the frame of a two-years inter-university research project. The application requires fault-tolerance capability, effective steering control, and torque feedback control. The study focuses on the details of the PM motor used in the steering mechanism, which features innovative design concepts. Experimental results are included in the paper.
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| 5. |
- Vomiero, Alberto, et al.
(författare)
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Controlled growth and sensing properties of in2O3 nanowires
- 2007
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Ingår i: Crystal Growth & Design. - : American Chemical Society (ACS). - 1528-7483 .- 1528-7505. ; 7:12, s. 2500-2504
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Tidskriftsartikel (refereegranskat)abstract
- Single-crystalline nanowires of indium oxide were produced under controlled conditions via condensation from the vapor phase. Seeding of the substrate through dispersion of metallic indium nanoparticles was proven effective in promoting a nanowire nucleation driven by the vapor-solid process. Nanowires with as small an average lateral dimension as 110 nm were produced, allowing the exploitation of size reduction effects on the electrical properties and the response to gases. Preparation and microstructural and electrical characterization of nanowires are presented, and the peculiarities of these innovative structures for the development of nanodevices are highlighted. © 2007 American Chemical Society.
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