Digitalni repozitorij raziskovalnih organizacij Slovenije

Iskanje po repozitoriju
A+ | A- | Pomoč | SLO | ENG

Iskalni niz: išči po
išči po
išči po
išči po

Možnosti:
  Ponastavi


Iskalni niz: "ključne besede" (materials) .

1 - 10 / 49
Na začetekNa prejšnjo stran12345Na naslednjo stranNa konec
1.
Advanced materials and research for the green future
Bojan Podgornik, 2023, izvirni znanstveni članek

Ključne besede: environment, pollution, advanced materials, surface engineering, research
Objavljeno v DiRROS: 08.03.2024; Ogledov: 55; Prenosov: 34
.pdf Celotno besedilo (3,78 MB)
Gradivo ima več datotek! Več...

2.
Evaluation of fly ash-based alkali activated foams at room and elevated temperatures
Katja Traven, Mark Češnovar, Srečo D. Škapin, Vilma Ducman, 2020, objavljeni znanstveni prispevek na konferenci

Povzetek: Alkali activated materials (AAM) are, in their broadest classification, any binder systems derived by the reaction of an alkali metal source (silicates, alkali hydroxides, carbonates , sulphates) with a solid, amorphous alumosilicate powder (found in precursors such as slag, fly ash and bottom ash). A wide variety of products can be obtained by the alkali activation process and could replace traditional construction products. Among the se, alkali activated foams (AAF) represent one of the most promising materials, owing to their economically accessible alumosilicate rich source materials, including industrial waste materials, clean processing, higher added value and most importantly, pro ducts with competitive properties. In the present study, the properties of alkali activated fly ash - based foam materials were studied at room temperature as well as at elevated temperatures (up to 1200 °C ) in order to develop a durable material in terms o f mechanical properties and suitability for high temperature applications.
Ključne besede: lightweight porous insulating material, alkali activated materials, microstructural analysis
Objavljeno v DiRROS: 05.03.2024; Ogledov: 80; Prenosov: 36
.pdf Celotno besedilo (970,74 KB)
Gradivo ima več datotek! Več...

3.
Foundry wastes as a potential precursor in alkali activation technology
Barbara Horvat, Alenka Sešek Pavlin, Vilma Ducman, 2020, objavljeni znanstveni prispevek na konferenci

Povzetek: In this study the amount of amorphous phase of elements useful in alkali activation of waste materials produced by the foundry industry was determined. Waste foundry sands, foundry flue gas and waste casting cores were alkali activated, and waste green ceramics and bottom ash were added to one of the foundry sand samples to shorten the time for producing measurable compressive strength from 1.5 years to 1 week.
Ključne besede: alkali activated materials, foundry wastes, compressive strength, upcycling, circular ecnomy
Objavljeno v DiRROS: 01.03.2024; Ogledov: 91; Prenosov: 32
URL Povezava na datoteko
Gradivo ima več datotek! Več...

4.
The deformation of alkali-activated materials at different curing temperatures
Mark Češnovar, Katja Traven, Vilma Ducman, 2020, objavljeni znanstveni prispevek na konferenci

Povzetek: Alkali activation is a chemical process whereby materials rich in aluminosilicate, which dissolves in basic media at room temperature, form binding phases by polycondensation. The alkali- activated materials (AAM) are a promising alternative to binding materials such as cement or other products in civil engineering (van Deventer et al., 2012). This study investigates the early age shrinkage behavior of Slovenian ladle and electric arc furnace slag - based alkali activated materials at different curing temperatures. The dimensions of specimens cured at room temperature and elevated temperatures up to 90 °C were measured over the first 7 hours (every 10 min). The results show that the most shrinkage occurred at the highest temperature, owing to the highest rate of evaporation of liquid content. Loss of mass follows from the drying shrinkage.
Ključne besede: alkali activated materials, shrinkage, compressive strength
Objavljeno v DiRROS: 01.03.2024; Ogledov: 88; Prenosov: 56
.pdf Celotno besedilo (670,52 KB)
Gradivo ima več datotek! Več...

5.
Characterization of hFOB 1.19 cell line for studying Zn-based degradable metallic biomaterials
Eva Jablonská, Lucie Mrázková, Jiří Kubásek, Dalibor Vojtěch, Irena Paulin, Tomáš Ruml, Jan Lipov, 2024, izvirni znanstveni članek

Povzetek: In vitro testing is the first important step in the development of new biomaterials. The human fetal osteoblast cell line hFOB 1.19 is a very promising cell model; however, there are vast discrepancies in cultivation protocols, especially in the cultivation temperature and the presence of the selection reagent, geneticin (G418). We intended to use hFOB 1.19 for the testing of Zn-based degradable metallic materials. However, the sensitivity of hFOB 1.19 to zinc ions has not yet been studied. Therefore, we compared the toxicity of zinc towards hFOB 1.19 under different conditions and compared it with that of the L929 mouse fibroblast cell line. We also tested the cytotoxicity of three types of Zn-based biomaterials in two types of media. The presence of G418 used as a selection reagent decreased the sensitivity of hFOB 1.19 to Zn2+. hFOB 1.19 cell line was more sensitive to Zn2+ at elevated (restrictive) temperatures. hFOB 1.19 cell line was less sensitive to Zn2+ than L929 cell line (both as ZnCl2 and extracts of alloys). Therefore, the appropriate cultivation conditions of hFOB 1.19 during biomaterial testing should be chosen with caution.
Ključne besede: zinc degradable materials, in vitro cytotoxicity testing, hFOB 1.19 osteoblasts
Objavljeno v DiRROS: 28.02.2024; Ogledov: 84; Prenosov: 38
.pdf Celotno besedilo (1,81 MB)
Gradivo ima več datotek! Več...

6.
Secondary deposits as a potential REEs source in South-Eastern Europe
Robert Šajn, Jasminka Alijagić, Ivica Ristović, 2024, izvirni znanstveni članek

Povzetek: The main objective of this manuscript is to collect, classify, and compile all available data about secondary mineral sources of REEs in the South-Eastern Europe (SEE). The material is generated from the extracting and processing sector, that might be possibly transformed in the business process becoming an important raw material for another industry. The management inventory guide will strengthen communication and dissemination efforts and simultaneously contribute to Europe’s self-sufficiency and support transitioning to green and digital technology. Identification of the knowledge gaps associated with secondary sources of REEs in SEE will contribute to connections between all partners being involved at the beginning, during the lifetime of products and at the end of the life cycle, represented with deposit owners, technology developers and potential processors, producers, and potential users. At the investigated area it was found 1835 individual landfills, most of them belonging to waste rocks. The total quantity of all material in SRM is about 3.2 billion tons on an area of about 100 km2. The largest 95 individual landfills were selected as potential prospective landfills, containing about 1600 million tons of material. The estimated total potential of REEs (ΣREE) is more than 200 Kt. The largest quantities are found in landfills for coal fly ash and Cu flotation, which correspond to more than 80% of the ΣREE. Most of the promising sites are located in Serbia and North Macedonia. It has been calculated that the valorisation potential and perspectivity of REE2O3 is about 32.5 billion USD (prices from December 2022). According to the average concentrations of REEs, the most prospective are the red mud dams but their total volume is limited compared to massive amounts of coal fly ash landfills. The REEs content in all type of investigated materials, especially in coal fly ash in North Macedonia is twice as high as in other countries.
Ključne besede: secondary raw materials, ESEE, rare elements, economic prospective
Objavljeno v DiRROS: 06.02.2024; Ogledov: 108; Prenosov: 27
.pdf Celotno besedilo (12,40 MB)

7.
Bio-solution for global sand crisis and sustainable organic agriculture in desert states
Darina Štyriaková, Iveta Štyriakova, Jaroslav Šuba, Felix Föhre, 2022, objavljeni znanstveni prispevek na konferenci

Povzetek: Sand is an important component of many everyday items, and currently sand is the second most extracted resource on earth after water, but it is not sustainable: we are running out of sand! The black market is booming, and the sand mafia is mining sand at any price. Desert sand is unusable, even Dubai must import it. The smooth surface and iron impurities prevent its industrial use. In this study, bacteria in the bioleaching test attacked the surface of the mineral grains and dissolved impurities including iron through organic acids. Furthermore, the liquid residue containing dissolved iron, organic acids and bacteria stimulated the growth plant what can be a valuable biofertilizer and biostimulant for organic agriculture. Desert states have fertility problems. Despite this, Qatar, for example, is aiming for self-sufficiency in vegetables “in five years”. Results showed that bioleaching combined with magnetic separation resulted in iron removal of 73.23%. The sand after treatment can be suitable to produce clear flat glass, coloured container glass, insulating glass fibres or ceramics. The integrated technology based ecological study revealed overall as utilization potential of the desert sand and the liquid residue could support glass and food production in desert states.
Ključne besede: materials, sand, bioleaching, sustainable organic agriculture, desert states
Objavljeno v DiRROS: 31.01.2024; Ogledov: 155; Prenosov: 92
.pdf Celotno besedilo (443,33 KB)
Gradivo ima več datotek! Več...

8.
Alternative alkali activators based on waste bottle glass and waste cathode-ray tube glass
Katja Koenig, Katja Traven, Vilma Ducman, 2021, objavljeni znanstveni prispevek na konferenci

Povzetek: Alkali-activated binders are an environmentally friendly alternative to Portland cement, particularly when locally-available raw materials are used. It is well known that alkali activation with a sodium silicate activator generates a hardened binder with higher compressive strength than a binder hardened with sodium hydroxide. As the alkali-silicate activators are produced through energy extensive processes, and their use can significantly increase the carbon footprint of the final products, it is of great significance to develop alternative alkaline activators based on locally-available waste materials. This article assesses the potential to apply waste bottle glass and waste cathode-ray tube (CRT) glass to synthesise alternative alkali activators by the hydrothermal method. Inductively coupled plasma-optical emission spectrometry (ICP-OES) was used to determine silicon and aluminium content in the alternative activators. The influence of dissolution process parameters (time, temperature, particle size) on the concentrations of silicon and aluminium in the alternative activators was investigated. The alternative activators with silicon concentration up to 19 g/L and aluminium concentration up to 0.9 g/L were prepared at T = 120 °C and boiling time 24 h. The alternative alkali activators and, for comparison, also commercial sodium silicate were used in the alkali activation of fly ash powder. The formed pastes were cured at 70 °C for 72 h. Mechanical strength measurements indicated that alkali activation of fly ash with the optimal alternative activator yielded hardened paste with compressive strength of 33 MPa. However, the compressive strength of hardened paste prepared from fly ash and commercial sodium silicate reached 70 MPa. Part of this difference can be ascribed to the lower density of hardened pastes prepared with alternative activators.
Ključne besede: alkali -activated materials, alternative alkali activators, waste bottle glass, waste cathode -ray tube glass, fly ash, hydrothermal method
Objavljeno v DiRROS: 25.01.2024; Ogledov: 145; Prenosov: 96
.pdf Celotno besedilo (14,96 MB)
Gradivo ima več datotek! Več...

9.
10.
Detoxified spent pot lining from aluminum production as (alumino-)silicate source for composite cement and autoclaved aerated concrete
Arne Peys, Mateja Košir, Ruben Snellings, Ana Mladenovič, Liesbeth Horckmans, 2021, izvirni znanstveni članek

Povzetek: New sources of supplementary cementitious materials (SCMs) are needed to meet the future demand. A potential new source of SCM is spent pot lining, a residue from aluminum production. The present work showed that the refined aluminosilicate part of spent pot lining (SPL) has a moderate chemical reactivity in a cementitious system measured in the R3 calorimetry test, comparable to commercially used coal fly ash. The reaction of SPL led to the consumption of Ca(OH)2 in a cement paste beyond 7 days after mixing. At 28 and 90 days a significant contribution to strength development was therefore observed, reaching a relative strength, which is similar to composite cements with coal fly ash. At early age a retardation of the cement hydration is caused by the SPL, which should most likely be associated with the presence of trace amounts of NH3. The spent pot lining is also investigated as silica source for autoclaved aerated concrete blocks. The replacement of quartz by spent pot lining did not show an adverse effect on the strength-density relation of the lightweight blocks up to 50 wt% quartz substitution. Overall, spent pot lining can be used in small replacement volumes (30 wt%) as SCM or as replacement of quartz (50 wt%) in autoclaved aerated concrete blocks.
Ključne besede: spent pot lining, construction materials, recycling, autoclaved aerated conctrte, supplementary cementitious material
Objavljeno v DiRROS: 04.12.2023; Ogledov: 162; Prenosov: 68
.pdf Celotno besedilo (15,66 MB)
Gradivo ima več datotek! Več...

Iskanje izvedeno v 0.36 sek.
Na vrh