National Repository of Grey Literature 11 records found  1 - 10next  jump to record: Search took 0.00 seconds. 
Investigation of Polyelectrolytes Interactions with Cationic Aminogroups-containing Amphiphiles
Zeman, Jan ; Běťák, Jiří (referee) ; Chytil, Martin (advisor)
The study deals with interactions of polyelectrolytes polystyrene sulfonate and hyaluronic acid with nitrogenic amphiphilic substances, represented by lysine and albumine. To study the interactions pH-metry, conductance, viscositic and turbidity measurement, DLS and reometry were used. All mixtures of different concentrations were measured and the data were compered with data obtained from measurement of samples with amphiphilic sumstances without polyelectrolytes. Observed interactions occured in the aminoacid concentrations between 0 to 20 mmoldm-3, then the PSS interaction groups were fully bonded by lysine and no more interactions were recognized. The same behaviour were observed in albumine solutions with concentration under 2 gdm-3.
Study on interactions of protonated aminoacids with low-molecular weight hyaluronan
Chlumská, Jana ; Kalina, Michal (referee) ; Chytil, Martin (advisor)
This bachelor thesis deals with interactions between hyaluronic acid (HA) of low molecular weight (110-130 kDa) and protonated aminoacids lysine and 6-aminocaproic acid. For investigation of these interactions, methods such as pH-metry, conductance measurement, viscometry and dynamic light scattering were used. The electrostacic interactions between carboxylic group of HA and the aminogroup of the aminoacids are presumed. Proving these interactions would allow us to physically modify HA and further more, using such a system as a carrier of pharmaceuticals. The interactions of protonated lysine with HA were studied in pure water or in the solution of NaCl (c = 15 mmol•dm-3). Interactions of 6-aminocaproic acid were studied only in pure water. Both aminoacids were in the concentration range 0.9-20 mmol•dm-3. The decrease in the viscosity of the solutions indicates the interactions for lysine; for 6-aminocaproic acid the interactions also occured, but not as signifciantly as for the system containing lysine.
Characterization of hyaluronan interactions with albumin
Valentová, Kristýna ; Kratochvílová, Romana (referee) ; Chytil, Martin (advisor)
This bachelor thesis focuses on the research of physical interactions between hyaluronic acid and a protein albumin. In order to investigate these interactions following methods were used: pH and conductivity measurement, viscosimetry, turbidimetry and rheometry. The interactions were observed in solutions of fixed albumin concentration 1.0 gdm-3 and varying concentrations of hyaluronic acid from 0.1 to 2.0 gdm-3. Results were compared with a solution of hyaluronic acid without the addition of albumin. The results show that there are interactions between hyaluronic acid and albumin solutions, especially for those containing high molecular weight hyaluronic acid. The interactions exhibited a change in viscosity of solutions. We can see a reduction in viscosity after adding albumin to the reference solutions. The reduction is noticeable even in the low molecular weight HA solutions, but is not so significant.
Ageing of cotton fabric as determined from polymerization degree change
Flimelová, Miroslava ; Nasadil, Petr (referee) ; Kučerík, Jiří (advisor)
The degree of polymerization (DP) is the main factor which plays a role in cellulose aging. The adverse consequence of cellulose fibers aging is the deterioration of mechanical and optical properties. Viscometry is a technique which is frequently used for determination of degree of polymerization of cellulose fibers. The aim of the work was to determine the degree of polymerization of cotton fabrics and to investigate the dependence of DP on number of washing and dying. Next task was to investigate if there exists a corellation between DP and results from thermal and thermo-oxidative degradation studied by methods of thermal analysis. First, the traditional viscometry was employed to determine DP of cellulose fibers. It has been demonstrated that number of washing and dying decreases the DP. In the second part the differential scanning calorimetry (DSC) and thermogravimetry (TG) were used. DSC provided values of combustion heat and TG allowed the detail evaluation of degradation steps; obtained results were further used for correlation with DP. Methods of thermal analysis revealed differences between cotton wool and treated fabrics. Combustion heat did not show any correlation with DP. In contrast, results from TG suggested some promising correlations which could be used for the prediction of cotton fabrics DP using thermal analysis in the future.
Hydrodynamic properties of hyaluronan-lysin systems
Kunert, Vojtěch ; Kratochvílová, Romana (referee) ; Chytil, Martin (advisor)
This bachelor’s thesis studies the interactions of hyaluronan with partly protonized amino acids lysine and arginine. Rheology and viscosimetry were used to analyze the interactions. pH-metry and conductance measurements were used to check the interactions. Individual mixtures were measured and the data was compared to each other, but also in terms of partly and complete protonization. The interactions have been observed in all selected concentrations.
Teplotní závislost viskozity rostlinných olejů
Bureš, Václav
A large part of this bachelor thesis is focused on fats and oils, their usage and ef-fect on human health and organism, as well as industrially oil extraction and its final treatment before filling the packages and distribution to the end consumer through business network. There are three kinds of the most used vegetable oils, namely rape-seed, sunflower and olive oil, and then two kinds of less traditional, such as grape oil and rice oil. There are a characteristics, chemical composition and utilization of these oils described. Second part is practical and deals directly with the change of the viscos-ity of these oils within increasing the temperature. The viscosity is measured on rotary viscometer Brookfield DV2T. The measured values have been evaluated and processed into graphs and tables.
Investigation of Polyelectrolytes Interactions with Cationic Aminogroups-containing Amphiphiles
Zeman, Jan ; Běťák, Jiří (referee) ; Chytil, Martin (advisor)
The study deals with interactions of polyelectrolytes polystyrene sulfonate and hyaluronic acid with nitrogenic amphiphilic substances, represented by lysine and albumine. To study the interactions pH-metry, conductance, viscositic and turbidity measurement, DLS and reometry were used. All mixtures of different concentrations were measured and the data were compered with data obtained from measurement of samples with amphiphilic sumstances without polyelectrolytes. Observed interactions occured in the aminoacid concentrations between 0 to 20 mmoldm-3, then the PSS interaction groups were fully bonded by lysine and no more interactions were recognized. The same behaviour were observed in albumine solutions with concentration under 2 gdm-3.
Ageing of cotton fabric as determined from polymerization degree change
Flimelová, Miroslava ; Nasadil, Petr (referee) ; Kučerík, Jiří (advisor)
The degree of polymerization (DP) is the main factor which plays a role in cellulose aging. The adverse consequence of cellulose fibers aging is the deterioration of mechanical and optical properties. Viscometry is a technique which is frequently used for determination of degree of polymerization of cellulose fibers. The aim of the work was to determine the degree of polymerization of cotton fabrics and to investigate the dependence of DP on number of washing and dying. Next task was to investigate if there exists a corellation between DP and results from thermal and thermo-oxidative degradation studied by methods of thermal analysis. First, the traditional viscometry was employed to determine DP of cellulose fibers. It has been demonstrated that number of washing and dying decreases the DP. In the second part the differential scanning calorimetry (DSC) and thermogravimetry (TG) were used. DSC provided values of combustion heat and TG allowed the detail evaluation of degradation steps; obtained results were further used for correlation with DP. Methods of thermal analysis revealed differences between cotton wool and treated fabrics. Combustion heat did not show any correlation with DP. In contrast, results from TG suggested some promising correlations which could be used for the prediction of cotton fabrics DP using thermal analysis in the future.
Hydrodynamic properties of hyaluronan-lysin systems
Kunert, Vojtěch ; Kratochvílová, Romana (referee) ; Chytil, Martin (advisor)
This bachelor’s thesis studies the interactions of hyaluronan with partly protonized amino acids lysine and arginine. Rheology and viscosimetry were used to analyze the interactions. pH-metry and conductance measurements were used to check the interactions. Individual mixtures were measured and the data was compared to each other, but also in terms of partly and complete protonization. The interactions have been observed in all selected concentrations.
Characterization of hyaluronan interactions with albumin
Valentová, Kristýna ; Kratochvílová, Romana (referee) ; Chytil, Martin (advisor)
This bachelor thesis focuses on the research of physical interactions between hyaluronic acid and a protein albumin. In order to investigate these interactions following methods were used: pH and conductivity measurement, viscosimetry, turbidimetry and rheometry. The interactions were observed in solutions of fixed albumin concentration 1.0 gdm-3 and varying concentrations of hyaluronic acid from 0.1 to 2.0 gdm-3. Results were compared with a solution of hyaluronic acid without the addition of albumin. The results show that there are interactions between hyaluronic acid and albumin solutions, especially for those containing high molecular weight hyaluronic acid. The interactions exhibited a change in viscosity of solutions. We can see a reduction in viscosity after adding albumin to the reference solutions. The reduction is noticeable even in the low molecular weight HA solutions, but is not so significant.

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