Kombineeritud sool-geel ja aatomkihtsadestatud struktuurid

Väitekirja elektrooniline versioon ei sisalda publikatsioone.Vedela materjali tahkestamise võimalused on mitmete teiste rakenduste seas omandanud tehnoloogilise tähtsuse kuna nad võimaldab valmistada vedelatest lähteainejugadest tahkeid fiibrilisi kehandeid ehk kiudusid. Käesolevates teesides keskendutakse metallialkoksiidide põhiste vedelikjugade tahkestumisele eesmärgiga sünteesida metalloksiidseid seest õõnsaid fiibreid ehk mikrotorusid. Uuringute põhiobjektiks on 8% üütriumoksiidiga faasistabiliseeritud tsirkooniumi oksiid (8%YSZ), mis on teada-tuntud tehnoloogiline materjal. Sünteesitud materjalid on ligemale 100%liselt tetragonaalses faasis, materjalidel on hea mehaaniline-termiline vastupidavus, kannatades kuumutamist 1000 ˚C ja enam, ning võimaldades näiteks rakenda toru sees 1000 atm ülerõhku. Tulenevalt neist omadustest pakume me torudele välja rea erinevaid rakendusi. Optiline kvaliteet – nanohomogenne materjali struktuur – võimaldab kasutada materjale vastavate lainejuhtidena, näiteks optilise lainejuhtivuse põhiste sensoritena. 8%YSZ torude ioonjuhtivus lubab asuda konstrueerima nende põhiseid ioonmembraanseadmeid, nagu näiteks tahkeoksiidsed kütuselemendid ja gaasisensorid. Teesides on demonstreeritud üksiku toru põhist mikroplasmaseadet, mis võimaldab plasma teket üleatmosfäärirõhulistes tingimustes ja perspektiivis plasmaergastud aktiivsete osakeste suunamist lokaalsesse pinnapunkti. Viimane rakendus võiks olla huvipakkuv näiteks meditsiinis. Keraamiliste mikrotorustruktuuride täiendavaks funktsionaliseerimiseks on näidatud aatomkihtsadestamistehnoloogiate sobilikkust. Magneesiumoksiidkiled sadestati mikrotorude pinnale kasutades β-diketonate tüüpi lähteainet 2,2,6,6-tetramethyl-heptanedionato-3,5magnesium(II). Aatomkihtsadestmine on torude funktsionaliseerimiseks oluline, kuna ta võimaldab torude ühtlast katmist nii seest, kui väljast.Curing processes enabling transformation of liquid threads into solid fiber material have gained technological importance. The theis are focusing on curing mechanisms for metal alkoxide-derived liquid threads in order to prepare novel structures metal oxide hollow fibres (microtubes). The focus is on YSZ (8% Y2O3 stabilized ZrO2), which exhibits a stable 100% tetragonal phase nanocrystalline structure up to 1000 ˚C. These tubes have excellent mechanical characteristics and can withstand 1000atm pressure inside the tubes. Owing to these and other physical, chemical and mechanical properties, there are many potential applications for these tubes, one example being that the high optical quality of the YSZ tubes could be useful for guiding of light. Ionic conductivity with no electronic component makes these tubes suitable for ionic membrane applications like solid oxide fuel cells (SOFCs) or corresponding gas sensors. We demonstrate a single-tube-based miniature plasma jet device potentially applicable as an ion source for local surface treatment. For the purpose of functionalization, deposition of MgO thin film on nanocrystalline YSZ microtubes was investigated. MgO films were atomic layer deposited from β-diketonate-type precursor 2,2,6,6-tetramethyl-heptanedionato-3,5-magnesium(II)

WEB-BASED DOCUMENT EDITOR FOR TIFF AND PDF FILES

V diplomskem delu bomo opisali in raziskali lastnosti PDF in TIFF formata, ta formata dokumentov bomo uporabili v spletnem urejevalniku, ki bo deloval brez predhodne namestitve. Primerjali in raziskali bomo tudi različna ogrodja, ki so primerna za obdelavo PDF in TIFF datotek, poudarek bo na ogrodju ImageEN, ki deluje v programskem jeziku Delphi, ter na ogrodju PDF Focus, ki deluje v programskem jeziku C#. Prikazali bomo razvoj in testiranje obeh ogrodij, ki nam bosta služili za primerjavo hitrosti in zasedenosti pomnilnika obeh tehnologij. Na koncu bomo izdelali spletni pregledovalnik PDF in TIFF datotek, ki bo deloval v najprimernejšem ogrodju.The purpose of this work is to describe and research the properties of the PDF and TIFF format. The aforementioned document formats will be used in a web-based document editor, operating with no preliminary setup. We will also compare and research different frameworks, suitable for editing PDF and TIFF files, focusing on the ImageEN framework, which operates in the Delphi programming language, and the PDF Focus framework, operating in the C# programming language. The developments and tests of both frameworks will also be presented, serving as a comparison of both technologies’ speed and memory occupation. In the end, an online PDF and TIFF viewer will be made, operating in the most suitable framework

Alkoxide-based precursors for direct drawing of metal oxide micro- and nanofibres

The invention of electrospinning has solved the problem of producing micro- and nanoscaled metal oxide fibres in bulk quantities. However, until now no methods have been available for preparing a single nanofibre of a metal oxide. In this work, the direct drawing method was successfully applied to produce metal oxide (SnO2, TiO2, ZrO2, HfO2 and CeO2) fibres with a high aspect ratio (up to 10 000) and a diameter as small as 200 nm. The sol–gel processing includes consumption of precursors obtained from alkoxides by aqueous or non-aqueous polymerization. Shear thinning of the precursors enables pulling a material into a fibre. This rheological behaviour can be explained by sliding of particles owing to external forces. Transmission (propagation) of light along microscaled fibres and their excellent surface morphology suggest that metal oxide nanofibres can be directly drawn from sol precursors for use in integrated photonic systems