|
|
Biodegradable metal materials for bone tissue prosthetics
Panáková, Olga ; Vondrák, Jiří (referee) ; Sedlaříková, Marie (advisor)
This paper is focused on use of metal materials as a bone replacement. For coherence of this text is necessary theoretical preamble which is consisting of describing metal properties, aimed particularly at corrosion, valuation methods of disposition to corrosion and mainly corrosion itself. This paper also includes description of techniques of preparation, which involves selection of material and its procession. Furthermore there are stated results of experiments. Those are amended with pictures.
|
|
|
Characterization of scanning transmission electron microscopy images of thin biological sections
Novotná, Veronika ; Nebesářová,, Jana (referee) ; Krzyžánek, Vladislav (advisor)
Diplomová práce popisuje fyzikální principy mikroskopů TEM, SEM a STEM spolu s jejich vhodností pro pozorování vzorků citlivých na elektrony, jako jsou zalévací média či biologické vzorky. Dále je popsána příprava vzorků pro STEM (TEM) a popis interakcí, ke kterým dochází mezi primárním elektronovým svazkem a vzorkem. Součástí práce je také pojednání o zpracování mikroskopických obrazů s podkapitolou o metodách kvantitativního porovnání obrazů ze STEM. Praktická část práce je zaměřena zejména na měření úbytku hmoty zalévacích médií (Epon, Spurr, LR White) způsobený primárním svazkem elektronů v nízkonapěťovém STEM. Ultratenké řezy několika tlouštěk byly zkoumány při různých nastaveních mikroskopu (urychlovací napětí, celková dávka, proud svazku, čištění povrchu vzorku a komory mikroskopu) a zobrazovacích módech (světlé a tmavé pole). Dále jsou zkoumány také biologické vzorky Krásnoočka štíhlého (Euglena gracilis) zalitého v pryskyřicích Epon a Spurr. Nasbírané snímky, vytvořené algoritmy a získané výsledky jsou diskutovány a zhodnoceny.
|
|
|
Bone implants based on Fe
Bachmayer, Marek ; Vondrák, Jiří (referee) ; Sedlaříková, Marie (advisor)
This thesis deals with usage of metal materials in bone implats creation process. This work also includes information about structure and attributes of bones, body fluids and content of iron in human organism. Following part of the paper deals with osteosynthesis, therefore commonly used methods of treating bone defects. Next part of this bachelor’s thesis is discussing the issue of biomaterials, biocompatibility and biodegradability of metal materials. Sample preparion procedure and description of samples, electrochemical corrosion and microscopic observation is included altogether with a pictorial documentation at the last chapters of this paper.
|
|
|
Measurement of the properties of solid and liquid fuels (biofuels)
Horák, Jakub ; Štelcl, Otakar (referee) ; Moskalík, Jiří (advisor)
Nowadays there are large numbers of standard methods for measuring the properties of fuels. With the increasing number of new methods to an already confusing issue of measurement of fuel becomes even more confusing. This thesis therefore deals with the measurement of the energy properties of solid and liquid fuels (biofuels). The introduction is carried out searches of solid and liquid fuels (biofuels). Search is focused on the description of each type of fuel, their properties and adjustments to the final form suitable for combustion. The next part deals with the sampling of fuel, which divides the sampling and preparation of samples for laboratory testing. The last section describes the methods of measurement of selected energy fuel properties and selects appropriate methods. Methods of measurement of selected properties is then checked in the laboratory.
|
|
|
The study of various methods of preparation of the milk sample for milk analysis by ICP-OES technique
Kaňová, Veronika ; Vítová, Eva (referee) ; Diviš, Pavel (advisor)
The theoretical part of the thesis deals with the chemical composition of cow’s milk, with the description of chosen methods of sample pretreatment and with the description of the used technique ICP-OES. The practical part is aimed at individual preparations of samples and at analysis of chosen chemical elements (Ca, Na, K and Mg). Milk is a really complicated polydisperse system, that’s the reason why the preparation of samples with milk is very important step before the measurement itself. In addition to accuracy choosing the sample adjustment method, other factors such as time, work intensity, or cost need to be considered when. In the thesis a comparison of four selected methods of sample preparation was made: direct analyse of milk, dilution with addition of Triton X-100, wet microwave ashing and destruction of matrix with TMAH (tetramethylammonium hydroxide). Selected elements were analysed with the help of ICP-OES. This diploma thesis builds on the bachelor thesis, which deals with the same problem. Final concentrations were compared with certified values of skimmed powdered milk. Data showed that the most accurate are methods of preparation of wet microwave ashing and destruction of matrix with TMAH. By using these methods, the effect of the dairy matrix that caused problems in the analysis, was largely eliminated. The diluted samples with and without Triton X-100 showed a bigger anomaly of measuring than the mineralization of wet ashing which came to the loss of analyte because of fat elements contained in milk.
|
|
|
Analysis of milk by ICP-OES technique
Kaňová, Veronika ; Hrstka, Miroslav (referee) ; Diviš, Pavel (advisor)
The theoretical part of the thesis deals with the chemical composition of cow’s milk, with the description of chosen methods of sample pretreatment and with the description of the used technique ICP-OES. The practical part is aimed at individual preparations of samples and at analysis of chosen chemical elements (Ca, Na, K, Mg a P). Milk is a really complicated polydisperse system. The preparation of samples with milk is very important step before the measurement itself. In the thesis a comparison of four selected methods of sample preparation was made: bare dilution, dilution with addition of Triton X 100, wet ashing and sonication. Selected elements were analysed with the help of ICP-OES. Final concentrations were compared with CRM of dried milk. Data showed that the most accurate are methods of preparation of diluted sample and wet ashing. Four different types of milk were analysed with the help of those two selected methods. The diluted samples showed a bigger anomaly of measuring than the mineralization of wet ashing which came to the loss of analyte because of fat elements contained in milk.
|
|
|
Analysis of pesticides in the environment using the QuEChERS method
Vašinková, Alena ; Řezáčová, Veronika (referee) ; Mravcová, Ludmila (advisor)
This thesis focuses on pesticides in the environment, more specifically in cereals. Pesticides were monitored in various samples of cereals (barley, rye, oats, and wheat) within the thesis. The monitored substances were isolated in selected samples and concentrated using the QUECHERS method. Gas and liquid chromatography were used to determine pesticides. The theoretical part consists of the common types of pesticides, divided by the ease with which these substances into food and their impact on humans and environment. It also mentions current health protection legislation and environmental legislation.
|
|
|
Preparation of semiconductor samples for transmission electron microscopy
Bajo, Viktor ; Bukvišová, Kristýna (referee) ; Horák, Michal (advisor)
This bachelor thesis deals with the preparation of samples from semiconductors for transmission electron microscopy. In the theoretical part, the most common methods of pre-preparation and finishing methods used to create ultrathin regions transparent to the electron beam of the microscope are generally described. This is followed by an overview of the experimental equipment used in the practical part for the actual sample preparation. I prepared two single crystal silicon samples, one by mechanical preparation followed by ion polishing, the other in the form of a lamella fabricated using a scanning electron microscope equipped with a focused ion beam. Mechanical preparation is significantly more time-consuming, is performed on several specialised instruments and risks destruction of the whole object under investigation. Preparation of the lamellae is relatively fast and allows a very small area of interest to be selected, leaving the rest of the sample intact but, on the other hand, requires at least basic skills in scanning electron microscopy. Both methods can be used to prepare good quality samples suitable for analysis in a transmission electron microscope. I have documented the whole procedure in the practical section that can serve as a guide for the preparation of these samples.
|
|
|
Analysis of pesticides in the environment using the QuEChERS method
Vašinková, Alena ; Řezáčová, Veronika (referee) ; Mravcová, Ludmila (advisor)
This thesis focuses on pesticides in the environment, more specifically in cereals. Pesticides were monitored in various samples of cereals (barley, rye, oats, and wheat) within the thesis. The monitored substances were isolated in selected samples and concentrated using the QUECHERS method. Gas and liquid chromatography were used to determine pesticides. The theoretical part consists of the common types of pesticides, divided by the ease with which these substances into food and their impact on humans and environment. It also mentions current health protection legislation and environmental legislation.
|
|
|
Environmental characteristics of mineral waste from metallurgy
Vítková, Martina ; Ettler, Vojtěch (advisor) ; Bollinger, Jean-Claude (referee) ; Dijkstra, Joris J (referee)
Mineralogical and geochemical characteristics of metallurgical wastes from the Cu-Co smelters situated in the Zambian Copperbelt have been investigated. A number of instrumental analytical methods (XRD, SEM/EDS, EPMA, TEM/EDS) has been used to identify primary and secondary phases in smelter slags and dusts. A set of leaching experiments (CEN/TS 14997 pH-static test, EN 12457 batch test) in combination with geochemical modelling has been performed, with the emphasis on the leaching behaviour of potential contaminants and their release as a function of the pH. The effect of sample preparation on metal leachability from slag was also evaluated, considering the grain size reduction required by the standardised leaching protocols. Environmental and health risk assessments of the dust samples have been performed. It was shown that the main carriers of metals in the studied slags were Cu sulphides (bornite, digenite, chalcocite), Co sulphides (cobaltpentlandite), Co-bearing intermetallic phases and alloys. Copper and cobalt were detected in major silicates and spinels, substituting for Fe or Mg in their structures, and in glass. The presence of secondary metal-bearing phases observed on the slag surfaces indicated the reactivity of the slags on contact with water/atmosphere. It was reported that in...
|
guest ::
