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Ključne besede: nano manganese oxide, deep eutectic solvent, phenol, catalytic wet air oxidation
Objavljeno v DiRROS: 22.06.2026; Ogledov: 177; Prenosov: 120
Celotno besedilo (1,68 MB)
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Povzetek: Background and Objectives: This study aimed to investigate the risk and mechanisms of air entry into the extracorporeal membrane oxygenation (ECMO) circuit through the central venous catheter (CVC) in a veno-venous configuration. The primary goal was to assess the impact of different air volumes on ECMO circuit performance at varying pump speeds. Material and Methods: The study utilized a circuit model to simulate ECMO conditions and evaluate the potential entry points of air, specifically through the unprotected lumen of the CVC. Various interventions, such as the use of a closed three-way stopcock or clave, were implemented to assess their efficacy in preventing air entry. Results: The unprotected lumen of the central venous catheter posed a significant risk for air entry into the ECMO circuit. The introduction of a closed three-way stopcock or clave proved effective in preventing air ingress through the central venous catheter. Auditory cues, such as a distinct hissing sound, served as an early warning sign of air presence in the circuit. The study demonstrated that even small volumes of air, as minimal as 1 mL, could pass through the oxygenator at specific pump speeds, and larger volumes could lead to pump dysfunction. Conclusions: The study identified the unprotected lumen of the central venous catheter as a potential entry point for air into the ECMO circuit. The use of a closed three-way stopcock or one-way valve was found to be a reliable protective measure against air infiltration. Early detection through the observation of a hissing sound in the circuit provided a valuable warning sign. These findings contribute to enhancing the safety and performance of ECMO systems by minimizing the risk of air embolism.
Ključne besede: air embolism, complications, extracorporeal membrane oxygenation, simulation
Objavljeno v DiRROS: 12.06.2026; Ogledov: 168; Prenosov: 118
Celotno besedilo (1,59 MB)
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Povzetek: The study presents 8-years long dataset (2017–2025) of high-resolution radon concentration measurements in Županova Jama and 2-years long dataset (2022–2024) in Postojnska Jama. Radon concentrations from two show caves were compared with outside and cave air temperature as well as atmospheric pressure to assess diurnal and seasonal variability. Županova Jama showed consistently higher radon levels with a 2023 mean of 4030 Bq/m³, compared to 2278 Bq/m³ in Postojnska Jama. Diurnal variations occurred in both caves, with night values typically higher in Županova Jama, while Postojnska Jama displayed day and night concentrations more balanced depending on ventilation regimes. In Postojnska Jama, summer radon maxima followed outside air temperature peaks with a 12–18 h lag. Seasonally, both caves showed higher radon concentrations in summer and lower in winter. Long-term monitoring near Županova Jama revealed an increase in mean outside air temperature (+0.86 °C from 2018 to 2024) and a parallel rise in radon, particularly in 2023–2024. The influence of atmospheric pressure was found to be seasonally dependent at both sites, with higher radon concentrations during periods of stable summer pressure and lower values during higher winter oscillations. Exposure limits indicate safe annual times of 512 h for Postojnska Jama and 284–289 h for Županova Jama, values not hazardous for visitors but important for cave guides. The findings underline the importance of continuous monitoring and cave-specific ventilation management to mitigate long-term health risks.
Ključne besede: radon concentration, air temperature, atmospheric pressure, radiation exposure levels, Postojnska jama, Županova Jama, Slovenia
Objavljeno v DiRROS: 24.05.2026; Ogledov: 205; Prenosov: 224
Celotno besedilo (10,50 MB)
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Povzetek: This review highlights a significant gap in the multi-pollutant characterisation of ultrafine particulate matter (PM <0.1 µm), focusing on metal(oid)s and polycyclic aromatic hydrocarbons (PAHs). Fractionation mechanisms, sampling protocols and analytical methods are examined with an emphasis on integrating quality assurance measures to ensure high-quality data and facilitate cross-study comparability. Based on studies published between 2010 and 2025, research has largely focused on the analysis of pollutants bound to PM2.5 or PM10. Only 5% of the studies addressed ultrafine particles (UFPs), which have the greatest toxicological impacts. The measurement of both pollutant groups within a single sampling campaign was rare (14% of the studies). The reliability of analytical data was rarely evaluated. Only 33% of the studies employed certified reference materials for quality control and method validation. Microwave-assisted digestion and ultrasound-assisted extraction were commonly used for sample preparation prior to the determination of metal(oid)s and PAHs, by inductively coupled plasma mass spectrometry and gas chromatography–mass spectrometry, respectively. Both pollutant groups exhibited strong seasonal variability, with elevated concentrations observed during heating periods in cold seasons, as well as associated with fine PM and UFPs, fractions that exhibit high bioaccessibility. Smaller PM fractions were associated with anthropogenic sources, including fossil fuel and biomass combustion, traffic and industrial emissions, while coarse PM reflected naturally-derived crustal material. Overall, these findings highlight the importance of uniform and comprehensive protocols for sampling UFPs and quantifying associated pollutants, which are essential for reliable data and effective urban air quality control strategies aimed at mitigating emissions.
Ključne besede: particulate matter, urban air quality, sampling protocols, analytical methods, metal(oid)s, polycyclic aromatic hydrocarbons
Objavljeno v DiRROS: 15.05.2026; Ogledov: 243; Prenosov: 301
Celotno besedilo (2,27 MB)
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Povzetek: Frost hollows are areas where cold air pools frequently form due to relief, resulting in specific microclimatic conditions. The different microclimate also manifests itself in specific ecological conditions where only adapted plant communities develop. These unique areas are of high conservation impor-tance as they can provide suitable habitats for cold-adapted plant species that are not found in the surrounding landscape. Such microrefugia are known to maintain relict populations of some endemic species. It can be concluded that frost hollows are special areas in terms of both geodiversity and biodiversity. The chapter discusses the climatological and vege-tation characteristics of frost hollows from the Slovenian alpine areas.
Ključne besede: Mountain climate, topoclimate, temperature inversion, vegetation inversion, cold air pools, mountain species adaptation
Objavljeno v DiRROS: 05.03.2026; Ogledov: 389; Prenosov: 250
Celotno besedilo (2,46 MB)
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