|
|
Diffusion in humic gels.
Královič, Michal ; Pospíšilová, Ľubica (referee) ; Klučáková, Martina (advisor)
This bachelor thesis is focuses on study of heavy metals diffusion in humic gels. The objective of the work was to verify, whether the diffusion is influenced by methylation of humic acid. Cupric and nickel cation was used in this thesis. Absorbance of solutions in acceptor and donor diffusion cell part was measured spektrofotometrically.
|
|
|
influence of physical conditions on diffusion processes in humic gels
Marvan, Jan ; Pabst, Willi (referee) ; Klučáková, Martina (advisor)
Diploma thesis is based on diffusion processes of copper (II) ions to humic gels obtained from lignite. Solutions with various concentrations and acidity were exposed to diffusion for exact time 24 hours. After the diffusion was ended the copper (II) ionic concentration profiles of tubular gels were create and calculated total diffusion flux. The experiment showed that the higher acidity of copper (II) solution decrease an amount of immobilized Cu2+ ions to the humic gels. In comparison concentration/pH: concentration of the solution has higher influence on sorption metal ions than change of the pH.
|
|
|
Diffusion in humic gels with incorporated metal ions
Krpatová, Lenka ; Gregorová,, Eva (referee) ; Klučáková, Martina (advisor)
The main topic of this diploma thesis is the study of diffusion of humic gels with incorporation of copper ions. Humic gel was prepared by precipitation of humate sodium with 5 M copper dichloride. First, it was necessary to find a useful extraction of surfactant that would have extracted copper from humic gel. Magnesium chloride was chosen as optimal surfactant from obtain relation of concentration copper(II) ions on time. Magnesium chloride was used to elution of copper from the slices of the gel. In next part it was important to verify the diffusion method that reaction in gel was not proceed in. Elution from slices of the gel before and after diffusion were scaled on the UV/VIS spectrophotometer. Experiment was prepared for times 3, 12, 24, 48 and 72 hours. Coefficient of the diffusion was calculated from obtained results, but 72 hours was not counted to the result.¨ From the coeficient of diffusion theoretic concentration profiles were calculated and then they were compared with experimentally results. Profile for 72 hours shows that it was unusable because it was oblate and fringe and concentration was lower than in other profiles. Other theoretic profiles agree.
|
|
|
Chemical heat treatment of steel
Pišek, David ; Molliková, Eva (referee) ; Němec, Karel (advisor)
This bachelor thesis deals with methods of chemical and heat treatment of steel. This thesis incorporates basic findings and ways of the performance of the chemical and heat treatment with detailed specialization in cementation and nitration of steels. This study is also focused on property of surface layers and their use. The primary aim of this thesis is to evolve an overview of the most frequent methods of chemical and heat treatment of steel and to evaluate advantages and disadvantages of individual methods for a practical use in industry.
|
|
|
Influence of polyelectrolyte biopolymers on transport of ions
Kolesa, Pavel ; Kalina, Michal (referee) ; Klučáková, Martina (advisor)
This bachelor thesis was focused on the study of interaction of cationic biopolymer with model diffusion probe (basic organic dye) in the gel media by diffusion processes. The main aim was optimization of simply laboratory diffusion technique (unsteady diffusion in a cuvette) because of study on interactions of chosen biopolymer with model compound depending on temperature. Cationic chitosan was chosen as model biopolymer. The model diffusion compound was chosen organic anionic dye Acidal Black 10B (C.I. 20470). Diffusion processes in plastic cuvettes were realized by transport of dye in a hydrogel media based on thermoreversible polysaccharide – agarose. The important content of this method is a monitoring of the time progression of diffusion profile by UV-VIS spectrophotometry. Important part of this work was characterization of hydrogel medium and biopolymers by basic physical-chemical methods. This bachelor thesis is focused on reactivity of chitosan and its behavior in different systems. Unsteady diffusion in cuvettes appears to be a universal method for the study on reactivity of biopolymers.
|
|
|
Influence of pH and ionic strength on barrier abilities of humic substances
Přítulová, Marie ; Kratochvílová, Romana (referee) ; Klučáková, Martina (advisor)
The main aim of this bachelor thesis is the study of humic acids and their barrier properties. The reactivity of humic acids was studied by simple laboratory diffusion techniques in plastic diffusion cells. This thesis is mainly focused on the through-diffusion processes in hydrogel media. Hydrogel media were based on the thermoreversible polysaccharide (agarose) with or without addition of humic acids. The rate of reactivity of humic acids was compared by the interactions with organic cationic dye – methylene blue. The influence of ionic strength and pH was tested as well.
|
|
|
Study on Reactivity of Cationic Biopolymer by Simple Diffusion Techniques
Tesařová, Barbora ; Kalina, Michal (referee) ; Smilek, Jiří (advisor)
This bachelor thesis is focused on study of chitosan reactivity by simple diffusion processes realized in hydrogel media based on agarose. Mechanical properties studied by oscilatory measurements and the pore size were determined at agarose gels with the addition of chitosan as the main parameters influenced the transport properties. The main goal of this work is the investigation the reactivity of chitosan. Agarose is used only as a supporting matrix for the formation of a hydrogel. The state of the art is aimed primarily on the study of chitosan reactivity based on already published scientific papers.
|
|
|
Reaction synthesis of bulk intermetallic materials in Ti Ni system form kinetic spraying deposits
Dyčka, Martin ; Moravčík, Igor (referee) ; Jan, Vít (advisor)
Bachelor’s thesis deals with intermetallic compounds which are formed in nickel-titanium binary system. The theoretical part of this thesis deals with the best known titanium based intermetallics, diffusion and possible processing technologies of intermetallic materials. In experimental part, a nickel-titanium coating created by cold spray technique was used. The changes in microstructure depending on annealing temperature were analysed. The results contain photographs of microstructure and fractures, values of microhardness and results of chemical analyses.
|
|
|
A method for the solution of non-spherical (fiber) particles deposition by means of the Fokker-Planck equation for ODF in a laminar flow
Kopečková, Barbora ; Knotek, Stanislav (referee) ; Jícha, Miroslav (advisor)
The Bachelor's thesis deals with a deposition efficiency for a fibers by various mechanisms of a deposition. It explains deposition efficiency by diffusion, by sedimentation and by impaction. The implementation of Peterlin's analytical solution for calculation of the ODF, which is used for individual efficiencies solution, is also mentioned. Afterwards, the thesis summarizes formulas for calculation of particular efficiencies derived for spherical particles and recomputation appropriate parameters for fibers. The purpose of the thesis is to create graphs, which illustrate deposition efficiencies dependence by various mechanisms on the aspect ratio of fibers. Another goal is the graphs creation, which shows juxtaposition for various breathing modes for given deposition mechanisms. The software MATLAB is used for the whole calculation process and graphs plotting.
|
|
|
Transport properties of agarose hydrogels
Vlasák, Jan ; Kalina, Michal (referee) ; Klučáková, Martina (advisor)
This thesis deals with the transportation processes of electrolytes using simple organic dyes as diffuse probes. The main goal of the work concerns a study of a diffusion mobility of the selected probes being in a form of simple organic dyes in a hydro-gel matrix based on a thermo-reversible linear polysaccharide, i.e., agaroses, functioning as semi-permeable membranes. The thesis describe diffusion processes used for determination of the basic diffusion parameters such as an efficient diffusion coefficient, reputed diffusion coefficient, separating coefficient, concentration of the dye in a gel and the time needed for the diffusion going throughout the entire layer of the gel. Attention is paid also to the environment in which the diffusion processes are implemented (in particular in view of the gel-like samples), porousness of the structure and its mechanical properties.
|
guest ::
