Anodizing of Aluminium and Its Alloys

Bakalářská práce se zaměřuje na tvrdou anodickou oxidaci hliníku a jeho slitin. Jako experimentální materiály byly použity různé hliníkové materiály, vyrobené tvářením za studena a odléváním. Práce obsahuje údaje o chemickém složení jednotlivých základních materiálů, fotografie jejich mikrostruktury, výsledky drsnosti povrchů před a po anodické oxidaci, fotografie anodizovaných vrstev, měření tvrdosti vrstev oxidu. Pro studium byly použity metody světelné mikroskopie, rastrovací elektronové mikroskopie, povrchové profilometrie a měřeni mikrotvrdosti.This thesis focuses on the hard anodic oxidation of aluminum and its alloys. As an experimental materials were used various aluminum materials, produced by cold forming and casting. The work contains information about chemical composition of the base materials, photographs of their microstructure, the results of surface roughness before and after anodic oxidation, photo anodized layer, measurements hardness oxide layers. For study were used methods light microscopy, scanning electron microscopy, surface profilometry and microhardness measurements.

Technology of Galvanic Anodization of Non-ferrous Materials and Its Alloys

Diplomová práce se zaměřuje na teoretický popis technologie anodické oxidace hliníku, hořčíku, zinku a jejich slitin. V práci jsou podrobně popsány metody tvorby oxidické vrstvy a chemické procesy, ke kterým během anodizace dochází. Experimentální část práce se zabývá tvorbou oxidických vrstev na hliníku, hořčíku a zinku o vysoké čistotě za různých podmínek. U všech tří materiálů byly vytvořeny oxidické vrstvy různých tlouštěk. Hliník byl anodizován v lázni 10% H2SO4, hořčík v lázni 1 mol/dm3 NaOH a zinek 0,5 mol/dm3 NaOH. Procesy probíhaly za laboratorní teploty. Na hliníku byla vytvořena souvislá oxidická vrstva. Dále bylo ověřeno pravidlo „312“, které lze orientačně použít pro výpočet tloušťky vzniklé oxidické vrstvy na hliníku. V případě hořčíku použitím nižšího proudu 0,08 a 0,2 A vznikají tmavě zabarvené vrstvy než při volbě vyššího proudu 0,5 A. S rostoucím napětím dochází u hořčíku ke vzniku členitější struktury oxidické vrstvy. Dále bylo u hořčíku pozorováno, že výsledná vrstva se skládá ze dvou subvrstev. U zinku lze vytvořit černě zabarvenou vrstvu při použití napětí 20 V a proudu 0,4–0,5 A. Ve vrstvě byly pozorovány opět dvě subvrstvy. Za nižšího proudu a napětí (0,05 A, 0,17 V) nedochází u zinku ke tvorbě vrstvy, ale dochází ke krystalografickému leptání.The thesis is focused on the theoretical description of the technology of anodizing of aluminium, magnesium, zinc and their alloys. In this work, methods for formation of oxide layers and the used chemical processes are described in detail. The experimental part of this work deals with formation of oxide layers on aluminium, magnesium and zinc of high purity under different conditions. Oxide layers of different thicknesses were created on all three experimental materials. Aluminium was anodized in a bath of 10% H2SO4, magnesium in the bath of 1 mol/dm3 NaOH, and zinc in the bath of 0.5 mol/dm3 NaOH. Processes were carried out at laboratory temperature. On the aluminium, continuous oxide layer was formed. Furthermore rule "312" was verified, that can indicatively be used for calculating the thickness of the resulting oxide layer on the aluminium. When using lower current of 0.08 and 0.2 A for magnesium anodizing, dark colored layer was created comparing to higher current of 0.5 A. More rough appearance of the oxide layer was produced with increasing voltage. Further, it was observed for magnesium that the resulting layer comprises of two sublayers. For zinc, black colored layer was created when the voltage 20 V and current from 0.4 to 0.5 A were used. In the layer, two sublayers were also observed. For lower voltage and current (0.05 A, 0.17 V), formation of the oxide layer on the zinc does not occur, but the crystallographic etching was observed.

The first solid-state route to luminescent Au(I)—glutathionate and its pH-controlled transformation into ultrasmall oligomeric Au10–12(SG)10–12 nanoclusters for application in cancer radiotheraphy

There is still a need for synthetic approaches that are much faster, easier to scale up, more robust and efficient for generating gold(I)–thiolates that can be easily converted into gold–thiolate nanoclusters. Mechanochemical methods can offer significantly reduced reaction times, increased yields and straightforward recovery of the product, compared to the solution-based reactions. For the first time, a new simple, rapid and efficient mechanochemical redox method in a ball-mill was developed to produce the highly luminescent, pH-responsive Au(I)–glutathionate, [Au(SG)]n. The efficient productivity of the mechanochemical redox reaction afforded orange luminescent [Au(SG)]n in isolable amounts (mg scale), usually not achieved by more conventional methods in solution. Then, ultrasmall oligomeric Au10–12(SG)10–12 nanoclusters were prepared by pH-triggered dissociation of [Au(SG)]n. The pH-stimulated dissociation of the Au(I)–glutathionate complex provides a time-efficient synthesis of oligomeric Au10–12(SG)10–12 nanoclusters, it avoids high-temperature heating or the addition of harmful reducing agent (e.g., carbon monoxide). Therefore, we present herein a new and eco-friendly methodology to access oligomeric glutathione-based gold nanoclusters, already finding applications in biomedical field as efficient radiosensitizers in cancer radiotherapy

Research and development of a technology of hard anodization of nonferrous alloys

Práce je zaměřena na výzkum a vývoj technologie přípravy tvrdých anodických vrstev na třech různých typech neželezných materiálů a to (i) hliníkové slitině (AA1050), (ii) čistém hořčíku (99.9% Mg) a (iii) zinkové slitině (ZnTi2). Vhodnou kombinací anodizačních podmínek (napětí, proudová hustota, teplota a složení elektrolytu atd.) lze vytvářet anodické vrstvy s rozdílnými vlastnostmi. V rámci předložené práce byl prokázán vliv předúpravy a anodizačních podmínek na vzhled, morfologii, tloušťku a tvrdost vytvořených anodických vrstev. Pro zvýšení tribologických vlastností a tvrdosti byly anodické vrstvy přímo dopovány Al2O3 částicemi nebo kombinací Al2O3 a PTFE částic během anodizačního procesu. Teoretická část práce popisuje základní principy anodizace, metody používané v průmyslové praxi a v práci je také popsán technologický proces. Experimentální část je rozdělena na tři základní části. První část se věnuje anodické oxidaci hliníkové slitiny AA1050. Druhá část je zaměřena na anodizaci čistého hořčíku a poslední část je zaměřena na anodizaci zinkové slitiny ZnTi2, která není tak známá jako anodizace hliníku.The thesis is focused on the research and development of the technological process for the preparation of hard anodic coatings on three different non-ferrous materials, namely (i) aluminium alloy (AA1050), (ii) pure magnesium (99.9% Mg), and (iii) zinc alloy (ZnTi2). Suitable combinations of anodizing conditions (voltage, current density, temperature and composition of the electrolyte, etc.) can produce anodic coatings with different properties. The effect of pre-treatment and anodizing conditions on the appearance, morphology, thickness and hardness of the produced anodic coatings was demonstrated in the present thesis. In order to increase tribological properties and hardness, the anodic coatings were directly doped with Al2O3 or with a mixture of Al2O3/PTFE particles during the anodizing process. The theoretical part describes the basic principles of anodization, the methods used in industry and the technological process. The experimental part is divided into three basic parts. The first part is devoted to anodizing of aluminium alloy. The second part is focused on anodizing of pure magnesium, and the last part is focused on anodizing of zinc alloy, which has not been researched as thoroughly as anodizing of aluminium.

Criminal liability in Czech environmental law

This thesis decribes the current state of criminal liability legislation in Czech environmental law. Relevant parts of the work focus on defining the frame for this topic through its essential terms, they also focus on the role played by sanctions in the area of environmental protection and furthermore they focus on one of their constitutive source, criminal liability of natural and legal persons. Special focus is given to criminal liability of natural persons, particularly on the evolution and description of the current state of legislation, the evaluation and de lege ferenda suggestions included. Lastly the text describes present Swedish criminal liability legislation in the field of the environmental protection and compares it with Czech legislation

Criminal liability in Czech environmental law

This thesis decribes the current state of criminal liability legislation in Czech environmental law. Relevant parts of the work focus on defining the frame for this topic through its essential terms, they also focus on the role played by sanctions in the area of environmental protection and furthermore they focus on one of their constitutive source, criminal liability of natural and legal persons. Special focus is given to criminal liability of natural persons, particularly on the evolution and description of the current state of legislation, the evaluation and de lege ferenda suggestions included. Lastly the text describes present Swedish criminal liability legislation in the field of the environmental protection and compares it with Czech legislation

Woman's and men's roles in the Iban tribe in Kalimantan

The doctoral thesis studies woman's and men's roles in the Iban tribe in Kalimantan. As a result of the growing influence of the majority society, these crofters, originally living in the heart of the primeval forest, have undergone many changes in the last 20 years. They have to cope with a different lifestyle and values hectically imposed upon them to a large extent. This process influences the structure of the whole society, and affects also the traditional system of male and female roles. Through deep study and analysis of female and male activities, I have studied penetrability of the assigned roles, which start to appear as impaired or non-functional, and which determine the creation of new structures