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| 2. |
- Bellani, Gabriele, et al.
(författare)
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Measurement-Integrated simulations and Kalman filter applied to a turbulent co-flowing jet
- 2010
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Rapport (övrigt vetenskapligt/konstnärligt)abstract
- This paper deals with the experimental evaluation of a flow analysis system based on the integration between an under-resolved Navier-Stokes simulation and experimental measurements with the mechanism of feedback (referred to as Measurement-Integrated simulation), applied to the case of a planar turbulent co-flowing jet. The experiments are performed with inner-to-outer-jet velocity ratio around 2 and the Reynolds number based on the inner-jet heights about 10000. The measurement system is a high-speed PIV, which provides timeresolved data of the flow-field, on a field of view which extends to 20 jet heights downstream the jet outlet. The experimental data can thus be used both for providing the feedback data for the simulations and for validation of the M-Isimulations over a wide region. The effect of reduced data-rate and spatial extent of the feedback was investigated. Then, to deal with the reduced data different feedback strategies were tested. It was found that for small data-rate reduction the results are basically equivalent to the case of full-information feedback but as the feedback data-rate is reduced further the error increases and tend to be localized in regions of high turbulent activity. Moreover, it is found that the spatial distribution of the error looks qualitatively different for different feedback strategies. Feedback gain distributions calculated by optimal control theory are presented and proposed as a mean to make it possible t operform MI-simulations based on localized measurements only. So far, we have not been able to low error between measurements and simulations by using these gain distributions.
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| 3. |
- Imagawa, A, et al.
(författare)
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High titres of IgA antibodies to enterovirus in fulminant type-1 diabetes.
- 2005
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Ingår i: Diabetologia. - : Springer Science and Business Media LLC. - 0012-186X .- 1432-0428. ; 48:2, s. 290-3
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Tidskriftsartikel (refereegranskat)abstract
- AIMS/HYPOTHESIS: We have recently proposed that fulminant type-1 diabetes is a novel subtype of type-1 diabetes with abrupt onset of insulin-deficient hyperglycaemia without islet-related autoantibodies. The pathogenesis is still unknown, but flu-like symptoms are frequently observed before the onset of disease of this subtype. Enterovirus infection is a candidate environmental factor causing type-1 diabetes. The aim of this study was to determine whether enterovirus infection contributes to the development of fulminant type-1 diabetes. METHODS: We investigated 19 patients with recent-onset fulminant type-1 diabetes, 18 patients with recent-onset typical type-1A diabetes, and 19 healthy controls. IgM, IgG, and IgA subclasses of antibodies to enterovirus were determined by ELISA. RESULTS: IgA antibody titres to enterovirus were significantly higher in fulminant type-1 diabetes than in typical type-1A diabetes (p=0.033) and controls (p=0.0003). IgM antibodies to enterovirus were not detected in any subject. IgG titres were lower in autoimmune diabetes than fulminant type and controls (p=0.014 and 0.019, respectively). CONCLUSIONS/INTERPRETATION: High titres of enterovirus IgA antibodies in serum suggest recurrent enterovirus infection in fulminant type-1 diabetic patients, indicating higher susceptibility to enteroviral infections among them. Such infections might have pathogenetic importance in the triggering of fulminant type-1 diabetes.
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| 4. |
- Imagawa, K., et al.
(författare)
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Measurement-Integrated simulations and Kalman filter applied to a co-flowing jet
- 2010
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Ingår i: 5th Flow Control Conference. - Reston, Virigina : American Institute of Aeronautics and Astronautics. - 9781600867453 ; , s. 2010-4420-
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Konferensbidrag (refereegranskat)abstract
- This paper deals with the experimental evaluation of a flow analysis system based on the integration between an under-resolved Navier-Stokes simulation and experimental measurements with the mechanism of feedback (referred to as Measurement-Integrated simulation), applied to the case of a planar turbulent co-flowing jet. The experiments are performed with inner-to-outer-jet velocity ratio around 2 and the Reynolds number based on the inner-jet heights about 10000. The measurement system is a high-speed PIV, which provides time-resolved data of the flow-field, on a field of view which extends to 20 jet heights downstream the jet outlet. The experimental data can thus be used both for providing the feedback data for the simulations and for validation of the MI-simulations over a wide region. The effect of reduced data-rate and spatial extent of the feedback (i.e. measurements are not available at each simulation time-step or discretization point) was investigated. At first simulations were run with full information in order to obtain an upper limit of the MI-simulations performance. The results show the potential of this methodology of reproducing first and second order statistics of the turbulent flow with good accuracy. Then, to deal with the reduced data different feedback strategies were tested. It was found that for small data-rate reduction the results are basically equivalent to the case of full-information feedback but as the feedback data-rate is reduced further the error increases and tend to be localized in regions of high turbulent activity. Moreover, it is found that the spatial distribution of the error looks qualitatively different for different feedback strategies. Feedback gain distributions calculated by optimal control theory are presented and proposed as a mean to make it possible to perform MI-simulations based on localized measurements only. So far, we have not been able to low error between measurements and simulations by using these gain distributions.
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