| | SLO | ENG | Cookies and privacy

Bigger font | Smaller font

Search the digital library catalog Help

Query: search in
search in
search in
search in
* old and bologna study programme

Options:
  Reset


1 - 8 / 8
First pagePrevious page1Next pageLast page
1.
Characterisation of a new dental alloy with high Au content
Rebeka Rudolf, Tjaša Zupančič Hartner, Ivan Anžel, Primož Mrvar, Jože Medved, Dragoslav Stamenković, 2007, original scientific article

Abstract: The basis for developing a new dental alloy with high Au content is appropriate chemical composition and manufacturing technology. This new Au dental alloy is based on the ternary system of Au-Pt-Zn with a nominal composition of 88.5Au-8.7Pt-1.5Zn-0.5In-0.4Ir-0.3Rh. The alloy was melted and cast in a vacuum-induction melting furnace in Zlatarna Celje. Casting was followed with subsequent thermo-mechanical treatment (procedures of profile and polish milling, thermal treatment) and cutting-off strips to form a regular shape. The heat treatments of Au alloy samples were carried out in a tube furnace under different temperatures, and over different times. Testing of the new Au dental alloy included examining the initial cast, and the different heat treated conditions of the Au alloy. The optical properties of Au-dental alloy were investigated by means of spectrophotometric colourimetry. Finally the test of cytotoxicity of new Au based dental alloys using standard in vitro assays for testing the biocompatibility with establishing new, more sensitive, in vitro tests on cell lines was done.Osnovo razvoja nove dentalne zlitine z visoko vsebnostjo Au predstavljata pravilna določitev kemijske sestave in tehnologije izdelave. Nova dentalna zlitina temelji na ternarnem sistemu of Au-Pt-Zn z nominalno kemijsko sestavo 88,5Au-8,7Pt-1,5Zn-0,5In-0,4Ir-0,3Rh. Izdelava dentalne zlitine je potekala s pretaljevanjem zelo čistih komponent v vakuumski indukcijski peči v Zlatarni Celje. Temu je sledilo odlivanje taline v ustrezno formo, postopek termo-mehanske obdelave odlitka in razrez zlitine v ustrezno obliko. Toplotna obdelava je bila izvedena pri različnih temperaturah in za različne čase. Testiranje dentalne zlitine je vključevalo določitev lastnosti začetnega stanja in stanja po različnih toplotnih obdelavah. Optične lastnosti dentalne zlitine so bile raziskane s spektro-fotometrično kolorimetrijo. Na novi Au dentalni zlitini so bili narejeni še testi citotoksičnosti z uporabo standardain vitro analize za testiranje biokompatibilnosti z uvajanjem novih, bolj občutljivih in vitro testov na celični liniji.
Keywords: dental alloy, characterisation, microstructure, properties
Published: 31.05.2012; Views: 1323; Downloads: 34
URL Link to full text

2.
Layered additive manufacturing in clinical medicine
Igor Drstvenšek, Nataša Ihan Hren, Tadej Strojnik, Vojko Pogačar, Tjaša Zupančič Hartner, Andreja Sinkovič, 2008, original scientific article

Abstract: The use of contemporary technologies of Computer Assisted Design (CAD), combined with latest rapid prototyping, tooling and manufacturing, with traditional CT scanning techniques and high medical skills are used as instruments for better diagnostic visualization, simulation of procedures and treatment of patients with craniofacial deformities. They also improve the overall performances of medical and nursing staff thus influencing the quality of medical service. Patients with congenital defects, orthognathic deformities, deformities after malignancy treatment or after craniofacial traumatic injuries of different severities are of particular interests due to both aesthetic and functional alterations. The paper presents two clinical cases - a patient with scull bone defect after brain hemorrhage and brain edema as well as a patient with hemifacial microsomia treated by surgery followed by implantation of titanium angular implant prepared by means of computer tomography scans, Computer Aided Design and Rapid Manufacturing technologies.
Keywords: rapid prototyping, computer assisted design, maxilla, scull, reconstructive surgery
Published: 31.05.2012; Views: 1436; Downloads: 92
URL Link to full text

3.
4.
5.
6.
Development of a 3D printer for thermoplastic modelling
Bogdan Valentan, Dušan Pogačar, Tomaž Brajlih, Tjaša Zupančič Hartner, Ana Pilipović, Igor Drstvenšek, 2012, original scientific article

Abstract: Additive technologies are entering the market in all price segments and the development of new machines and materials is rapidly growing. Machines under 2000 EUR are more and more interesting for home and educational use. This paper presents the development of a 3D printer that shapes the parts layer by layer by depositing the material on a predefined position. The development is presented from the engineering point of view. The construction steps, the control and the actuator solutions are presented. The ABS plastic was analysed for its material properties. The 3D printer evolved from a prototype to the pre-production phase.
Keywords: polymers, rapid prototyping, additive technologies, 3D print
Published: 10.07.2015; Views: 694; Downloads: 86
.pdf Full text (1,37 MB)
This document has many files! More...

7.
Mechanical properties and microstructure characterisation of Au-Pt dental alloy
Rebeka Rudolf, Tjaša Zupančič Hartner, Ladislav Kosec, Aleksandar Todorović, Borut Kosec, Ivan Anžel, 2008, original scientific article

Abstract: Development of a dental alloy with high Au content is based on the ternary system of Au-Pt-Zn with a nominal composition of 86,9Au-9,9Pt-1,5Zn, and about 1,5 wt.% micro-alloying elements (In, Ir, Rh). The results analyses of different heat-treated states showed that the optimal mechanical properties and hardness of an Au-Pt-Zn alloy can be reached with combinations of heat treatment for 20 minutes at 723 K and then slowly cooling, if the alloy was annealed at 1223 K for 30 minutes and the water quenched. Research results confirmed that the microstructure of the Au-Pt-Zn alloy consists of two phases: α1-phase rich in Au (main phase) and α2-phase rich in Pt (minor phase). During XRD analysis and use of the Rietveld method, it was found that the α1-phase content is about 98,5 wt.% while the content of α2-phase is 1,5 wt.%. STA analyses show that the Au-Pt-Zn alloy has a solidus temperature of about 1292 K and a liquidus temperature of about 1412 K.
Keywords: Au dental alloy, properties, microstructure, characterization
Published: 03.07.2017; Views: 460; Downloads: 61
.pdf Full text (1,59 MB)
This document has many files! More...

8.
Notranja oksidacija mikrolegiranega zlata za medicinske aplikacije
Tjaša Zupančič Hartner, 2016, doctoral dissertation

Abstract: V doktorski disertaciji je obravnavana problematike izdelave mikrolegiranega disperzijsko utrjenega zlata z disperzijo oksidov (La2O3), redko zemeljskega elementa (La) s procesom notranje oksidacije ter študija biokompatibilnosti materiala.. V prvem delu raziskav smo izdelali zlitino Au – 0,5 ut.% La, s postopkom klasičnega litja. Rezultati karakterizacije so pokazali, da že zelo majhna količina mikrolegirnega elementa lantana v zlati zlitini, povzroči tvorbo intermetane faze Au6La, ki pomembno izboljša mehanske lastnosti mikrolegiranega zlata, v primerjavi s čistim zlatom. V drugem delu smo s tehnologijo hitrega strjevanja in valjanja, izdelali trakove z metastabilno mikrostrukturo. S hitrim strjevanjem zlitine Au - 0,5 ut.% La smo dosegli spremembo morfologije strjevanja. Mikrostruktura hitro strjenih trakov sestoji iz zelo finih zrn αAu, s premerom do nekaj mikrometrov ter homogeno razporejeno intermetalno fazo (Au6La), po celotnem preseku traku. Izmerjena trdota trakov je pokazala, da se je v primerjavi z litim stanjem, trdota povečala za skoraj 20 %. Valjane trakove smo rekristalizacijsko žarili in ugotovili, da že majhen dodatek 0,5 % La, zvišuje temperaturo rekristalizacije do 200 K in povzroči rekristalizacijski zastoj. Karakterizacija materiala, je pokazala, da intermetalna faza Au6La v valjanih trakovih tvori neprekinjeno mrežo po mejah zrn, ki dodatno niža hitrost rekristalizacije. Sledila je notranja oksidacija zlitine v litem, valjanem in hitro strjenem stanju. Rezultati notranje oksidacije zlitine v litem ter valjanem stanju so pokazale, da proces notranje oksidacije poteče le po mejah kristalnih zrn z oksidacijo lantana iz intermetalne faze (Au6La). Med tem ko notranja oksidacija hitro strjenih trakov poteče s oksidacijo lantana iz trdne raztopine in tvorbo CNO ter delno po mejah zrn s oksidacijo lantana iz intermetalne faze (Au6La) . Na osnovi rezultatov smo identificirali mehanizem notranje oksidacije in postavili model notranje oksidacije zlitine Au- 0,5 ut.% La, ki rezultira v disperzijskem utrjanju mikrolegirane zlate zlitine v površinskem sloju, kljub temu, da je topnost kisika v kristalni mreži zlata zelo majhna. V zaključni fazi smo potrdili, da je material Au-0,5 ut.% La biokompatibilen, kar daje možnost njegove uporabe v obliki tankih nanosov na medicinske implantate.
Keywords: notranja oksidacija, zlato, zlitine zlato-lantan, biokompatibilnost zlato-lantan zlitin
Published: 05.07.2016; Views: 1011; Downloads: 91
.pdf Full text (6,89 MB)

Search done in 0.1 sec.
Back to top
Logos of partners University of Maribor University of Ljubljana University of Primorska University of Nova Gorica