|
|
Rheological properties of gelatin-based gels for ultrasound brain phantom
Bojňanská, Terézia Marianna ; Šnejdrová, Eva (advisor) ; Holas, Ondřej (referee)
CHARLES UNIVERSITY IN PRAGUE FACULTY OF PHARMACY IN HRADEC KRALOVE DEPARTMENT OF PHARMACEUTICAL TECHNOLOGY Author: Terezia Marianna Bojnanska Supervisor: PharmDr. Eva Snejdrova, Ph.D. Title of diploma thesis: Rheological properties of gelatin-based gels for ultrasound brain phantom The diploma thesis deals with the evaluation of the viscoelastic properties of gelatin gels modified by addition of glutaraldehyde and glycerol using a rheometer with goal to verify the suitability of tested materials for their intended use as ultrasound brain phantoms. The theoretical part deals with gels in general and is focused on gelatin gels as a possible basic component of ultrasound phantoms, and the possibilities of characterizing gels as viscoelastic systems using methods of oscillatory rheometry. Gelatin gels of different concentrations (5; 7,5 and 10%) with the addition of glutaraldehyde and glycerol were characterized by complex modulus, complex viscosity, yield stress, phase angle. Temperature stability of the samples in the range from 20 to 50řC was tested. All tested gels were viscoelastic solids with a clearly defined linear-viscoelastic region, which is confirmed by phase angle values close to 0ř. With the increasing concentration of gelatin the values of the complex modulus increased, increasing...
|
|
|
Hydromechanic characteristics of clay suspensions
Sedláčková, Markéta ; Mls, Jiří (advisor) ; Císlerová, Milena (referee) ; Šembera, Jan (referee)
A mathematical model of two-phase systems, such as clay suspensions, consists of a set of partial differential equations which reflect both the general laws of mechanics and the relations connecting the involved characteristics of the particular system under consideration. The latter equations are known as constitutive relations. The aim of this study was to find the constitutive relations for kaolin suspensions that are necessary when solving forward problems of fine sludge thickening processes. The task was to design and carry out experimental research of the given suspension and to find a convenient method of utilizing the results for the sake of getting the sought relationships. It follows from the applied mathematical theory of two-phase systems that the sought relationships are hydraulic conductivity of the suspension as a function of the solid-phase concentration and the dependence of the solid-phase concentration on the solid-phase stress. The first part of this study describes the experimental research. Since both the characteristics are difficult to measure, it was necessary to analyze the suspension's characteristics and their measurability. Subsequently, the process of the suspension preparation and the method of laboratory measurements were determined. The following sections present...
|
|
|
Hydromechanic characteristics of clay suspensions
Sedláčková, Markéta ; Mls, Jiří (advisor) ; Císlerová, Milena (referee) ; Šembera, Jan (referee)
A mathematical model of two-phase systems, such as clay suspensions, consists of a set of partial differential equations which reflect both the general laws of mechanics and the relations connecting the involved characteristics of the particular system under consideration. The latter equations are known as constitutive relations. The aim of this study was to find the constitutive relations for kaolin suspensions that are necessary when solving forward problems of fine sludge thickening processes. The task was to design and carry out experimental research of the given suspension and to find a convenient method of utilizing the results for the sake of getting the sought relationships. It follows from the applied mathematical theory of two-phase systems that the sought relationships are hydraulic conductivity of the suspension as a function of the solid-phase concentration and the dependence of the solid-phase concentration on the solid-phase stress. The first part of this study describes the experimental research. Since both the characteristics are difficult to measure, it was necessary to analyze the suspension's characteristics and their measurability. Subsequently, the process of the suspension preparation and the method of laboratory measurements were determined. The following sections present...
|
guest ::
