Blood Vessels and Feature Points Detection on Retinal Images

In this paper we present a method for the automatic extraction of blood vessels from retinal images, while capturing points of intersection/overlap and endpoints of the vascular tree. The algorithm performance is evaluated through a comparison with handmade segmented images available on the STARE project database (STructured Analysis of the REtina). The algorithm is performed on the green channel of the RGB triad. The green channel can be used to represent the illumination component. The matched filter is used to enhance vessels w.r.t. the background. The separation between vessels and background is accomplished by a threshold operator based on gaussian probability density function. The length filtering removes pixels and isolated segments from the resulting image. Finally endpoints, intersections and overlapping vessels are extracted

Processing surface sizing starch using oxidation, enzymatic hydrolysis and ultrasonic treatment methods - preparation and application

The surface application of starch is a well-established method for increasing paper strength. In surface sizing, a solution of degraded starch is applied to the paper. Two procedures have proved valuable for starch degradation in the paper mill: enzymatic and thermo-oxidative degradation. The objective of this study was to determine achievable efficiencies of cavitation in preparing degraded starch for surface application on paper. It was found that ultrasonic-assisted starch degradation can provide a starch solution that is suitable for surface sizing. The molecular composition of starch solutions prepared by ultrasonic treatment differed from that of starch solutions degraded by enzymes or by thermo-oxidation. Compared to commercial degradation processes, this resulted in intensified film formation and in greater penetration during surface sizing and ultimately in a higher starch content of the paper. Paper sized with ultrasonically treated starch solutions show the same strength properties compared to commercially sized paper

Film properties of hydroxypropyl starch

The present study describes the preparation of low-substituted hydroxypropyl (HP) starches and investigation of their suitability for the development of flexible, highly transparent cast films. Changes in molecular composition due to processing conditions were identified by determining molar mass distribution. Molecular characterisation was performed both by static light scattering (SLS) and size-exclusion chromatography with multi-angle laser light scattering (SEC-MALLS) detection. The weight-average molar mass, mean square radius of gyration, second virial coefficient, and molar mass distribution were determined. Rheological characterisation of concentrated aqueous solutions included a study of flow behaviour as a function of shear rate and oscillatory measurement of viscoelastic properties. Significant differences in rheological properties due to hydroxypropylation conditions were established. Mechanical testing was carried out by measuring tensile strength and elongation and determining the elastic modulus. The tensile strength of cast films based on hydroxypropyl starches was 40-50 MPa. Elongation values were dependent on the type of starch, use of plasticiser and storage conditions

Physikalisch-chemische Charakterisierung von zuechterisch verbesserten Gersten-, Weizen- und Roggenstaerken

Available from TIB Hannover: F95B1383+a / FIZ - Fachinformationszzentrum Karlsruhe / TIB - Technische InformationsbibliothekSIGLEBundesministerium fuer Bildung, Wissenschaft, Forschung und Technologie, Bonn (Germany)DEGerman