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Thermal Desorption Spectroscopy (TDS) and its Application for Research of Surface Processes
Potoček, Michal ; Čech, Vladimír (referee) ; Pavlík, Jaroslav (referee) ; Dub, Petr (advisor)
ermal desorption spectroscopy (TDS) is a common method for surface analysis of adsorbed molecules. In chapter 1 the work deals with the theoretical background of this method and shows the principles of a desorption process influenced by subsurface diffusion. Chapter 2 first shows application of TDS for detection of surface molecules and determination of binding energy.Experiments were mainly focused on ditermination of surface adsorbents and impurities on Si wafers. The second part of chapter 2 describes desorption of atoms of a Ga layer on Si surface and their subsurface diffusion. A Ga diffusion process was also observed by with secondary ion mass spectrometry (SIMS) and numerically simulated.
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Effects of the addition of distillates in white sausage production on the sensory quality of the product
Horňan, Samuel ; Kovalčík, Adriána (referee) ; Mikulíková, Renata (advisor)
This diploma thesis deals with the production and sensory analysis of white sausages to which different types of distillates have been added. The aim of this thesis is to observe the effect of the added distillates on the overall sensory quality of the sausages. The theoretical part describes meat and meat products, meat and meat product legislation, characteristics of sausages and the technological process of white sausage production. Furthermore, it characterises alcoholic beverages, the legislation of spirits and distillates, and it includes the characteristics and description of raw materials for the production of distillates as well as substances occurring in distillates. In addition, it illustrates the basic principles of sensory perception and sensory analysis. The experimental part deals with the production of white sausages to which 5 selected types of distillates have been added. The result consisted of a total of 10 sausage samples produced in 2 batches, each batch varying in the volume of the added distillate. Together with the samples there was also produced a standard that contained no added distillate. These sausage samples were then further evaluated sensorially using general discrimination tests, a sensory profile evaluation method and the dynamic method Temporal Dominance of Sensations (TDS). Besides the sensory analysis all samples underwent gas chromatography that determines the percentage of their fatty acids content. The data obtained from the sensory analysis were subjected to the general descriptive statistics and graphically evaluated. The evaluation of the difference between the samples and the standard was performed statistically using the Thurston model and hypothesis tests. Analysis of variance (ANOVA) revealed the existence of statistically significant differences in some of the measured parameters, between the samples with lower and higher added volume of distillate. Correlations between the measured parameters were identified by covariance. Differences and similarities of the individual samples regarding their parameters were evaluated by Principal Component Analysis (PCA). Graphical analysis of the results from TDS described and clarified in more detail the variation of dominant flavours in the samples over time, which were not detected in the sensory profile evaluation.
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Effects of the addition of distillates in white sausage production on the sensory quality of the product
Horňan, Samuel ; Kovalčík, Adriána (referee) ; Mikulíková, Renata (advisor)
This diploma thesis deals with the production and sensory analysis of white sausages to which different types of distillates have been added. The aim of this thesis is to observe the effect of the added distillates on the overall sensory quality of the sausages. The theoretical part describes meat and meat products, meat and meat product legislation, characteristics of sausages and the technological process of white sausage production. Furthermore, it characterises alcoholic beverages, the legislation of spirits and distillates, and it includes the characteristics and description of raw materials for the production of distillates as well as substances occurring in distillates. In addition, it illustrates the basic principles of sensory perception and sensory analysis. The experimental part deals with the production of white sausages to which 5 selected types of distillates have been added. The result consisted of a total of 10 sausage samples produced in 2 batches, each batch varying in the volume of the added distillate. Together with the samples there was also produced a standard that contained no added distillate. These sausage samples were then further evaluated sensorially using general discrimination tests, a sensory profile evaluation method and the dynamic method Temporal Dominance of Sensations (TDS). Besides the sensory analysis all samples underwent gas chromatography that determines the percentage of their fatty acids content. The data obtained from the sensory analysis were subjected to the general descriptive statistics and graphically evaluated. The evaluation of the difference between the samples and the standard was performed statistically using the Thurston model and hypothesis tests. Analysis of variance (ANOVA) revealed the existence of statistically significant differences in some of the measured parameters, between the samples with lower and higher added volume of distillate. Correlations between the measured parameters were identified by covariance. Differences and similarities of the individual samples regarding their parameters were evaluated by Principal Component Analysis (PCA). Graphical analysis of the results from TDS described and clarified in more detail the variation of dominant flavours in the samples over time, which were not detected in the sensory profile evaluation.
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Thermal Desorption Spectroscopy (TDS) and its Application for Research of Surface Processes
Potoček, Michal ; Čech, Vladimír (referee) ; Pavlík, Jaroslav (referee) ; Dub, Petr (advisor)
ermal desorption spectroscopy (TDS) is a common method for surface analysis of adsorbed molecules. In chapter 1 the work deals with the theoretical background of this method and shows the principles of a desorption process influenced by subsurface diffusion. Chapter 2 first shows application of TDS for detection of surface molecules and determination of binding energy.Experiments were mainly focused on ditermination of surface adsorbents and impurities on Si wafers. The second part of chapter 2 describes desorption of atoms of a Ga layer on Si surface and their subsurface diffusion. A Ga diffusion process was also observed by with secondary ion mass spectrometry (SIMS) and numerically simulated.
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Influence of annealing to stress in CNx:(H) films observed by SLEEM
Mikmeková, Eliška ; Mikmeková, Šárka ; Müllerová, Ilona ; Sobota, Jaroslav
The effect of high residual stress on the quality of thin sputtered carbon nitride films has been studied by Scanning Low Energy Electron Microscopy (SLEEM). Basically, two different types of stress can be identified in thin films: compressive stress and tensile stress. Compressive stress leads to wrinkling and film delamination and tensile stress can cause the fracturing of thin films. Experiments were made in the Tescan TS 5130 MM equipped with the Cathode Lens system (CL), which enable us to observe samples at arbitrary landing energies of the illuminating electrons. Operating of a SEM at low energies offers several advantages: an increase of materials contrast via low energy, high ratio SE, BSE signal and noise, smaller interaction volume and elimination of charging effects. The effect of annealing in vacuum to residual stress (calculated from Stoney’s equation) was measured. The porous character of films was observed by thermal desorption spectroscopy (TDS).
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