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Povzetek: Arginine-vasopressin peptide (AVP) plays a critical role in water balance and osmoregulation. However, emerging evidence suggests that AVP’s actions may expand beyond its traditional role, significantly influencing metabolic regulation, including glucose homeostasis, insulin sensitivity, lipid metabolism and energy balance. Elevated AVP levels are seen in various metabolic conditions, such as insulin resistance, metabolic syndrome, type 2 diabetes (T2D) and obesity, further highlighting its potential role as a metabolic regulator. As AVP levels are regulated by hydration status, studies have proposed that chronic hypohydration and persistently elevated AVP levels may contribute to metabolic dysfunction, where increased hydration and therefore AVP suppression may lead to potential metabolic improvements. By analyzing data from animal studies, human observational research and interventional trials, this review evaluates the current evidence on the potential causal relationships and impact of AVP on metabolic regulation, as well as exploring the role of hydration in AVP-mediated metabolic outcomes.
Ključne besede: arginine-vasopressin (AVP), hydration, glucose regulation
Objavljeno v DiRROS: 27.02.2026; Ogledov: 489; Prenosov: 314
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Povzetek: The incorporation of recycled tyre polymer fibres (RTPF) in cementitious composites provides an effective and sustainable approach in tyre waste management while offering potential benefits in mitigating early-age volume deformations. This study evaluates the influence of RTPFs, used in dry (RTPFd) and pre-wetted (RTPFw) states, on key hydration processes governing autogenous shrinkage in cement pastes with w/c of 0.4 and 0.22. The results show that RTPF reduced workability and altered the setting process due to the fibre–matrix mechanical interactions. Incorporation of RTPFs induced changes in water distribution at the fibre surface, delaying self-desiccation and maintaining higher internal relative humidity. While RTPFs offer a beneficial reduction in autogenous shrinkage by 12–41% in mixtures with w/c of 0.4 and by 15–34% in mixtures with w/c of 0.22, RTPFs also increased porosity, which contributed to a reduction in 28-day compressive strength of up to 16%. These findings highlight the dual effect of RTPF on early-age performance and provide insight into their potential application in sustainable cementitious composites.
Ključne besede: recycled tyre polymer fibre, hydration kinetics, self-desiccation, autogenous shrinkage
Objavljeno v DiRROS: 13.01.2026; Ogledov: 457; Prenosov: 381
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Povzetek: The EU prioritizes transitioning to a circular economy, aiming to boost sustainable resource management through policies promoting recycling and reuse, benefiting both the environment and the economy. Many successful case studies demonstrate using various incineration waste by-products (ashes) as substitutes for natural materials, yielding environmental advantages and showcasing sustainable resource management practices. While extensive literature covers ash characterization and applications, the direct links between the properties of the main components, the amorphous phase, and research findings remain elusive. Analysis predominantly centers on microstructural phase development, influencing mechanical, physical, and chemical properties and guiding research interpretations. Existing standards for ash use primarily address coal-derived fly ash, with SIST EN 13282-2 allowing alternative sources like circulating fluidized bed and paper sludge incineration residues. Yet, beyond this standard, no regulations mandate using different ash types. Nonetheless, the applicability of ashes for the geotechnical composite materials has already been confirmed in the field since numerous geotechnical projects have been carried out in Slovenia. Such composites have been recognized as beneficial practices, and the majority of them also possess legal permission for usage according to the Slovenian Technical Approvals. Given the varying value and complexity of ashes, detailed characterization before use is crucial. Assessing the recycling potential of different ashes requires a precise definition of basic properties such as microstructure, minerals, and chemical composition. Emphasis should be placed on characterizing the hydraulic properties and gaining detailed insights into the amorphous phase, ensuring informed decision-making regarding their recycling processes.
Ključne besede: waste by-products from incineration processes, ashes, recycling, amorphous phase, (latent) hydraulic properties, hydration
Objavljeno v DiRROS: 22.07.2024; Ogledov: 1306; Prenosov: 981
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Povzetek: The influence of different curing temperatures on the hydration of belite-calcium sulfoaluminate cement was investigated at 20, 40 and 60 °C. The hydration kinetics and the hydrated phase assemblages were studied by isothermal calorimetry, X-ray powder diffraction, differential thermal analysis and thermogravimetric analysis, as well as field emission scanning electron microscopy. The compressive strength development of the cement pastes was also determined. Results showed that, at early ages, hydration was faster and early compressive strength was higher at elevated temperatures than at ambient temperature. On the other hand, at late ages in cement pastes cured at 60 °C, the amount of ettringite decreased, leading to lower compressive strength, indicating that the degree of hydration was lower at higher temperatures. Moreover, at elevated temperatures prismatic ettringite crystals became smaller due to faster hydration. Other hydration products present were aluminium hydroxide, which is formed together with ettringite from the hydration of calcium sulfoaluminate and gypsum, and C–S–H which precipitates as a main hydration product of belite. Belite hydrated in a lesser amount, especially at 60 °C, when the lowest amount of C–S–H was observed.
Ključne besede: hydration, cement, temperature, belite, calcium sulfoaluminate, open access, hidratacija, cement, temperatura, belit, kalcijev sulfoaluminat
Objavljeno v DiRROS: 04.08.2023; Ogledov: 2279; Prenosov: 1298
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Povzetek: The influence of temperature on the early hydration of belite-calcium sulfoaluminate cements with two different calcium sulfate to calcium sulfoaluminate molar ratios was investigated. The phase composition and phase assemblage development of cements prepared using molar ratios of 1 and 2.5 were studied at 25, 40 and 60 ◦C by in situ X-ray powder diffraction. The Rietveld refinement method was used for quantification. The degree of hydration after 24 h was highest at ambient temperatures, but early hydration was significantly accelerated at elevated temperatures. These differences were more noticeable when we increased the temperature from 25 ◦C to 40 ◦C, than it was increased from 40 ◦C to 60 ◦C. The amount of calcium sulfate added controls the amount of the precipitated ettringite, namely, the amount of ettringite increased in the cement with a higher molar ratio. The results showed that temperature also affects full width at half maximum of ettringite peaks, which indicates a decrease in crystallite size of ettringite at elevated temperatures due to faster precipitation of ettringite. When using a calcium sulfate to calcium sulfoaluminate molar ratio of 1, higher d-values of ettringite peaks were observed at elevated temperatures, suggesting that more ions were released from the cement clinker at elevated temperatures, allowing a higher ion uptake in the ettringite structure. At a molar ratio of 2.5, less clinker is available in the cement, therefore these differences were not observed.
Ključne besede: in situ X-ray diffraction, hydration, temperature, cement, rietveld analysis
Objavljeno v DiRROS: 26.06.2023; Ogledov: 1874; Prenosov: 1085
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