39 research outputs found

    Scattering phase Function Spectrum Makes Reflectance Spectrum Measured from Intralipid phantoms and Tissue Sensitive to the Device Detection Geometry

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    Reflectance spectra measured in Intralipid (IL) close to the source are sensitive to wavelength -dependent changes in reduced scattering coefficient (μs′)and scattering phase function (PF). Experiments and simulations were performed using device designs with either single or separate optical fibers for delivery and collection of light in varying concentrations of IL. Spectral reflectance is not consistentl y linear with varying IL concentration, with PF -dependent effects observed for single fiber devices with diameters smaller than ten transport lengths and for separate source- detector devices that collected light at less than half of a transport length from the source. Similar effects are thought to be seen in tissue, limiting the ability to quantitatively compare spectra from different devices without compensation

    Scattering phase function spectrum makes reflectance spectrum measured from Intralipid phantoms and tissue sensitive to the device detection geometry

    Get PDF
    Reflectance spectra measured in Intralipid (IL) close to the source are sensitive to wavelength-dependent changes in reduced scattering coefficient (μ′s) and scattering phase function (PF). Experiments and simulations were performed using device designs with either single or separate optical fibers for delivery and collection of light in varying concentrations of IL. Spectral reflectance is not consistently linear with varying IL concentration, with PF-dependent effects observed for single fiber devices with diameters smaller than ten transport lengths and for separate source-detector devices that collected light at less than half of a transport length from the source. Similar effects are thought to be seen in tissue, limiting the ability to quantitatively compare spectra from different devices without compensation

    Extraction of Intrinsic Fluorescence from Single Fiber Fluorescence Measurements on a Turbid Medium: Experimental Validation

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    Abstract The detailed mechanisms associated with the influence of scattering and absorption properties on the fluorescence intensity sampled by a single optical fiber have recently been elucidated based on Monte Carlo simulated data. Here we develop an experimental single fiber fluorescence (SFF) spectroscopy setup and validate the Monte Carlo data and semi-empirical model equation that describes the SFF signal as a function of scattering. We present a calibration procedure that corrects the SFF signal for all system-related, wavelength dependent transmission efficiencies to yield an absolute value of intrinsic fluorescence. The validity of the Monte Carlo data and semi-empirical model is demonstrated using a set of fluorescent phantoms with varying concentrations of Intralipid to vary the scattering properties, yielding a wide range of reduced scattering coefficients (μ′s = 0–7 mm −1). We also introduce a small modification to the model to account for the case of μ′s = 0 mm −1 and show its relation to the experimental, simulated and theoretically calculated value of SFF intensity in the absence of scattering. Finally, we show that our method is also accurate in the presence of absorbers by performing measurements on phantoms containing red blood cells and correcting for their absorption properties

    Organizing knowledge transfer between university and agribusiness firms

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    The agribusiness sector represents an economic sector of particular importance and with the highest employment rate. The sector is very complex due to the characteristics of the organizations that are part of it and need to base their competitive advantage on innovations often obtained by sharing knowledge with third organizations. The study highlights the main theories of the key organizational factors that influence the knowledge transfer process between universities and firms and presents the first results of an exploratory analysis, aimed to understand what are the key organizational factors identified by the entrepreneurs of the agribusiness sector that affect knowledge transfer for innovation, in particular from universities and high educational institutions. The study can help agribusiness organizations to activate and manage their interorganizational relationships in order to improve their mechanism of knowledge sharing for innovation and shed light for scholars on an important business sector
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