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2. Vpliv temperature in gostote na mehanske lastnosti ekspandiranega polistirena : magistrsko deloJaka Vaupot, 2023, magistrsko delo Ključne besede: ekspandiran polistiren, tlačna trdnost, natezna trdnost, temperaturno utrujanje materiala, povišana temperatura, mikrostruktura, dimenzijska stabilnost, magistrsko delo
Objavljeno v DiRROS: 27.02.2024; Ogledov: 142; Prenosov: 47
 Celotno besedilo (2,34 MB) |
3. Krmiljenje togosti in trdnosti recikliranega polipropilena (rPP) z dodatkom odpadnega papirja s postopkom brizganja : magistrsko deloDavid Črešnar, 2023, magistrsko delo Ključne besede: recikliranje, ogljični odtis, recikliran polipropilen, recikliran biokompozit, brizganje, togost, trdnost, magistrsko delo
Objavljeno v DiRROS: 22.02.2024; Ogledov: 160; Prenosov: 47
Celotno besedilo (9,21 MB) |
4. Influence of microwaves in the early stage of alkali activation on the mechanical strength of alkali-activated materialsBarbara Horvat, Majda Pavlin, Vilma Ducman, 2023, izvirni znanstveni članek Povzetek: This study focuses on the influence of microwave irradiation dosimetry on alkali-activated slurry in its early stages. The impact on the chemistry and mineralogy along with the mechanical properties were evaluated by changing the power of microwaves and their duration of exposure. This influenced the dissolution of amorphous content, diffusion, and self-assembly into an aluminosilicate network. The precursors used in this study were metakaolin, a non-waste material commonly used in geopolymerisation technology, and local fly ash and ladle furnace slag as secondary materials. Furthermore, they were chemically and mineralogically analysed, and their mixtures with NaOH and Na-water glass provided the optimal ratio of the amount of elements obtained using the pre-calculation approach. However, the potential extra addition of water was experimentally determined to allow complete wetting of the material and solid workability during moulding. Using Fourier-transform infrared spectroscopy, the influence of water was further investigated in alkali-activated slag and fly ash irradiated with microwaves, which resulted in the highest values of mechanical strength in the dosimetry-mapping part of the analysis. In addition to the time dependence of the expected mechanical strength on the ageing of the alkali- activated material, the synthesised material exhibited a significant dependence on the dose of microwave irra- diation, which was different for every precursor as well as every mixture with different chemistries.
Ključne besede: odpadni material, alkalijska aktivacija, obsevanje z mikrovalovi, mehanska trdnost, waste material, alkali activation, microwave irradiation, mechanical strength
Objavljeno v DiRROS: 12.07.2023; Ogledov: 361; Prenosov: 271
Celotno besedilo (8,99 MB)
Gradivo ima več datotek! Več... |
5. The preparation and characterization of low-temperature foams based on the alkali activation of waste stone woolMajda Pavlin, Barbara Horvat, Mark Češnovar, Vilma Ducman, 2022, izvirni znanstveni članek Povzetek: Waste mineral wool represents a huge amount of construction and demolition waste that is still not adequately returned into the value chain but needs to be landfilled. In the present study, waste stone wool (SW) was evaluated for the preparation of alkali-activated foams. For this purpose SW was milled and sieved below 63 μm, then the activator (sodium silicate) and different amounts of foaming agent (hydrogen peroxide, H2O2), varying between 1 wt% and 3 wt%, were added to the slurry and cured in moulds at an elevated temperature (70 ◦ C) for three days. In this way, foamed, highly porous materials were obtained whose density and mechanical properties were influenced by the amount of foaming agent used. The densities obtained ranged between 1.4 and 0.5 g/cm3, with corresponding mechanical properties of between 12.6 and 1.5 MPa and total porosities in the range 37.8–78.6%, respectively. In the most porous samples with the total porosity of 78.6%, a thermal conductivity of 0.092 W/(m∙K) was confirmed. The study confirmed the suitability of waste mineral wool (in our case SW) as a precursor for alkali-activated foams with potential use in the construction sector or other industrial applications.
Ključne besede: alkali activation, waste mineral wool, mechanical strength, open access, alkalijska aktivacija, odpadna volna, SEM, XRF, XRD, mehanska trdnost, odprti dostop
Objavljeno v DiRROS: 19.06.2023; Ogledov: 265; Prenosov: 205
Celotno besedilo (9,47 MB)
Gradivo ima več datotek! Več... |
6. Določanje strižne trdnosti vezi med kompozitnimi fasetami in ogrodjem iz kompozita na osnovi PEEK-a za izdelavo zobnih nadomestkov : magistrsko deloAnamarija Kuchler, 2022, magistrsko delo Ključne besede: BioHPP, BioHPP plus, CAD/CAM rezkanje BioHPP, stiskanje BioHPP plus, fasetirni kompozit, toplotni prehodi PEEK kompozitov, hrapavost, omočljivost, strižna trdnost, magistrsko delo
Objavljeno v DiRROS: 22.03.2023; Ogledov: 510; Prenosov: 108
Celotno besedilo (2,89 MB) |
7. Influence of beech particle size used in surface layer on bending strength of three-layer particleboardSergej Medved, Jože Resnik, 2003, izvirni znanstveni članek Povzetek: Znano je, da vrsta lesa in velikost iverja vplivata na upogibno trdnost trislojnih ivernih plošč. Namen posebej zasnovane raziskave je bil ugotoviti, kako velikost bukovega (Fagus Sylvatica L.) iverja vpliva na upogibno trdnost trislojnih ivernih plošč, če je velikost bukovega iverja spremenjena samo v zunanjem sloju. Uporabljeno je bilo bukovo iverje petih različnih velikosti. Iverje je bilo oblepljeno z UF lepilom. Rezultati meritev so pokazali, da upogibna trdnost ivernih plošč narašča z naraščanjem specifične površine iverja, faktorja zgostitve zunanjega sloja in prostorninske mase zunanjega sloja, medtem ko z naraščanjem oblepljenosti upogibna trdnost pada.
Ključne besede: iverne plošče, upogibna trdnost, bukovo iverje, velikost iverja, faktor zgostitve zunanjega sloja, stopnja oblepljenosti
Objavljeno v DiRROS: 12.07.2017; Ogledov: 4194; Prenosov: 1858
Celotno besedilo (196,77 KB) |
