44 research outputs found

    Fault management in an i.c. engine piezoelectric fuel injection system

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    A piezoelectric injection system 15, eg for a diesel engine, comprises a VDCpower supply 24 for supplying a power circuit 17 provided with a DC-DC converter having high-side and low-side drivers 20, 21 connected at a switching node 22, the drivers being electrically connected to at least a piezoelectric injector 16. The value of an electric parameter representative of the operation the injection system is monitored and compared with a predetermined reference parameter value, and emergency means 32 are activated when the monitored parameter value exceeds the respective reference value. The electric parameter may be the current flowing through the piezoelectric actuator 19 and/or the low-side driver 21, sensed by current sensor 30, or the voltage across the piezoelectric actuator. The emergency means 32 may interrupt the operation of the drivers 20, 21, discharge the piezoelectric injector or disconnect the injector form the power circuit 1

    Fault management in an i.c. engine piezoelectric fuel injection system

    Get PDF
    A piezoelectric injection system 15, eg for a diesel engine, comprises a VDCpower supply 24 for supplying a power circuit 17 provided with a DC-DC converter having high-side and low-side drivers 20, 21 connected at a switching node 22, the drivers being electrically connected to at least a piezoelectric injector 16. The value of an electric parameter representative of the operation the injection system is monitored and compared with a predetermined reference parameter value, and emergency means 32 are activated when the monitored parameter value exceeds the respective reference value. The electric parameter may be the current flowing through the piezoelectric actuator 19 and/or the low-side driver 21, sensed by current sensor 30, or the voltage across the piezoelectric actuator. The emergency means 32 may interrupt the operation of the drivers 20, 21, discharge the piezoelectric injector or disconnect the injector form the power circuit 17

    Prospective observational cohort study of the association between antiplatelet therapy, bleeding and thrombosis in patients with coronary stents undergoing noncardiac surgery

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    Background: The perioperative management of antiplatelet therapy in noncardiac surgery patients who have undergone previous percutaneous coronary intervention (PCI) remains a dilemma. Continuing dual antiplatelet therapy (DAPT) may carry a risk of bleeding, while stopping antiplatelet therapy may increase the risk of perioperative major adverse cardiovascular events (MACE). Methods: Occurrence of Bleeding and Thrombosis during Antiplatelet Therapy In Non-Cardiac Surgery (OBTAIN) was an international prospective multicentre cohort study of perioperative antiplatelet treatment, MACE, and serious bleeding in noncardiac surgery. The incidences of MACE and bleeding were compared in patients receiving DAPT, monotherapy, and no antiplatelet therapy before surgery. Unadjusted risk ratios were calculated taking monotherapy as the baseline. The adjusted risks of bleeding and MACE were compared in patients receiving monotherapy and DAPT using propensity score matching. Results: A total of 917 patients were recruited and 847 were eligible for inclusion. Ninety-six patients received no antiplatelet therapy, 526 received monotherapy with aspirin, and 225 received DAPT. Thirty-two patients suffered MACE and 22 had bleeding. The unadjusted risk ratio for MACE in patients receiving DAPT compared with monotherapy was 1.9 (0.93–3.88), P=0.08. There was no difference in MACE between no antiplatelet treatment and monotherapy 1.03 (0.31–3.46), P=0.96. Bleeding was more frequent with DAPT 6.55 (2.3–17.96) P=0.0002. In a propensity matched analysis of 177 patients who received DAPT and 177 monotherapy patients, the risk ratio for MACE with DAPT was 1.83 (0.69–4.85), P=0.32. The risk of bleeding was significantly greater in the DAPT group 4.00 (1.15–13.93), P=0.031. Conclusions: OBTAIN showed an increased risk of bleeding with DAPT and found no evidence for protective effects of DAPT from perioperative MACE in patients who have undergone previous PCI

    The necessity for a local level of gastronomic tourism standardization - The case of Torino's city branding

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    This study investigates the role and opportunities of gastronomy within the cultural re-branding of a city. Entrepreneurs and tourism authorities can emphasize the uniqueness of local cuisine but the common offer by different companies also requires alignment and standardization in order to define what they have in common, to assure product and service quality, and to communicate the service offer to potential customers. This creates a tension between standardization and authenticity: both concepts seem to contradict each other but these are needed in combination. This paradox is explored using the case of an alternative food network in the Italian city Torino. Our findings show the potential of this combined approach of authenticity and local standardization

    Need for a local level of standardisation: the case of Torino

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    Need for a local level of standardisation: the case of Torino

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