Browsing by Subject "Fluidics"

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Open Access
Bio-insprired optoelectronic digital nose for breath analysis
(2011) Bayındır, Mehmet; Yıldırım, Adem; Yaman, Mecit; Vural, Mert
A novel electronic nose device is presented that can be used in disease diagnostics by exhaled breath analysis. Exhaled breath contains more than a thousand organic compounds that can be analysed to insect various diseases and metabolic activity. The novel device is an electronic nose, based on photonic bandgap fibers that can selectively guide infrared radition inside a hollow core plastic fiber. Instead of a laser line source, a broadband balackbody source is used that exploits the filtering/ guiding properties of the fibers to scan the whole mid-infrared region, making it high selectivity of volatile organic compounds possible. In addition waveguiding inside the fiber enhances the electromagnetic radiation intensity, resulting in improved infrared absorption cross-section. The fiber electronic nose can be integrated and deployed as a portable electronics device to point-of-care institutes.
Open Access
Modeling of subsonic cavity flows by neural networks
(IEEE, 2004-06) Efe, M.Ö.; Debiasi, M.; Özbay, Hitay; Samimy, M.
Influencing the behavior of a flow field is a core issue as its improvement can yield significant increase of the efficiency and performance of fluidic systems. On the other hand, the tools of classical control systems theory are not directly applicable to processes displaying spatial continuity as in fluid flows. The cavity flow is a good example of this and a recent research focus in aerospace science is its modeling and control. The objective is to develop a finite dimensional representative model for the system with appropriately defined inputs and outputs. Towards the goal of reconstructing the pressure fluctuations measured at the cavity floor, this paper demonstrates that given some history of inputs and outputs, a neural network based feedforward model can be developed such that the response of the neural network matches the measured response. The advantages of using such a model are the representational simplicity of the model, structural flexibility to enable controller design and the ability to store information in an interconnected structure.