21. Fine particulate matter (PM2.5) exposure assessment among active daily commuters to induce behaviour change to reduce air pollutionAnja Ilenič, Alenka Mauko Pranjić, Nina Zupančič, Radmila Milačič, Janez Ščančar, 2023, izvirni znanstveni članek Povzetek: Fine particulate matter (PM2.5), a detrimental urban air pollutant primarily emitted by traffic and biomass burning, poses disproportionately significant health risks at relatively limited exposure during commuting. Previous studies have mainly focused on fixed locations when assessing PM2.5 exposure, while neglecting pedestrians and cyclists, who often experience higher pollution levels. In response, this research aimed to independently validate the effectiveness of bicycle-mounted low-cost sensors (LCS) adopted by citizens, evaluate temporal and spatial PM2.5 exposure, and assess associated health risks in Ljubljana, Slovenia. The LCS quality assurance results, verified by co-location field tests by air quality monitoring stations (AQMS), showed comparable outcomes with an average percentage difference of 21.29 %, attributed to humidity-induced nucleation effects. The colder months exhibited the highest air pollution levels (μ = 32.31 μg/m3) due to frequent thermal inversions and weak wind circulation, hindering vertical air mixing and the adequate dispersion of pollutants. Additionally, PM2.5 levels in all sampling periods were lowest in the afternoon (μ = 12.09 μg/m3) and highest during the night (μ = 61.00 μg/m3) when the planetary boundary layer thins, leading to the trapping of pollutants near the surface, thus significantly affecting diurnal and seasonal patterns. Analysis of exposure factors revealed that cyclists were approximately three times more exposed than pedestrians. However, the toxicological risk assessment indicated a minimal potential risk of PM2.5 exposure. The collaborative integration of data from official AQMS and LCS can enhance evidence-based policy-making processes and facilitates the realignment of effective regulatory frameworks to reduce urban air pollution.
Ključne besede: air pollution monitoring, PM2.5 exposure, citizen science, bicycle-mounted low-cost sensors
Objavljeno v DiRROS: 30.01.2024; Ogledov: 181; Prenosov: 72
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22. Electrochemical corrosion tests on steel in alkali-activated materialsNina Gartner, Miha Hren, Tadeja Kosec, Andraž Legat, 2021, objavljeni znanstveni prispevek na konferenci Povzetek: One of the potential alternatives to Ordinary Portland Cement (OPC) are Alkali-Activated Materials (AAMs). The service life of reinforced concrete structures greatly depends on the corrosion resistance of embedded steel reinforcement. Due to the wide range of AAMs and their diverse properties, corrosion processes of steel in these materials are relatively unknown. Corrosion monitoring methods or their interpretations in certain cases cannot be directly transferred from the ones for OPC materials. The chemical compositions of pore solution in different AAMs influence the results of electrochemical measurements and their interpretations. Within this research, three different alkali-activated mortar mixes were prepared, based on fly ash, slag or metakaolin. Pore solutions were extracted from each mortar andchemical analysis was acquired. Different electrochemical corrosion measurements were performed on steel submerged to synthetic pore solutions. In parallel, ordinary carbon steel reinforcing bar was installed in the same types of alkali-activated mortar mixes. Specimens were exposed to wet/dry cycles with saline solution and periodic measurements of electrochemical impedance spectroscopy (EIS) were performed. Measured parameters in both systems were analysedand compared. It was concluded that electrochemical measurements in pore solutions can provide basic overview on corrosion behaviour in different AAMs environments. Periodic EIS measurements enabled monitoring of corrosion initiation and propagation on steel reinforcement in AAMs, although the information on the corrosion type is missing. Interpretation of results depends on visual analysis of corrosion damages after the end of exposure, providing information on corrosion type and intensity. The continuation of research on corrosion monitoring techniques will be performed by using Electrical Resistance (ER) sensors and Coupled Multi-Electrode Array (CMEA) sensors.
Ključne besede: corrosion, alkali-activated mortars, pore solution extraction, electrochemical corrosion techniques, visual analysis
Objavljeno v DiRROS: 22.01.2024; Ogledov: 197; Prenosov: 109
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23. Ocena količinskega stanja podzemnih voda za Načrt upravljanja voda 2022–2027 (NUV III)Petra Souvent, Urška Pavlič, Mišo Andjelov, Nina Rman, Peter Frantar, 2023, izvirni znanstveni članek Povzetek: Ocena količinskega stanja podzemnih voda je del Načrta upravljanja voda 2022–2027 (NUV III). Z njo po določenih kriterijih ovrednotimo količinsko stanje na 21 vodnih telesih podzemnih voda v Sloveniji kot »dobro« ali »slabo«. Ocena je izvedena s štirimi preizkusi, kjer analiziramo vpliv odvzemov (črpanih količin) podzemne vode na: količine podzemne vode in vodno bilanco, ekološko stanje površinskih vodnih teles, kopenske ekosisteme odvisne od podzemne vode in vdore slane vode ali vode slabše kakovosti v vodonosnik. Končno skupno oceno, na podlagi opravljenih preizkusov, določa kriterij najslabše ocene. Na podlagi rezultatov izvedenih preizkusov imamo 20 vodnih teles ocenjenih s skupno oceno »dobro«. Vodno telo Dravska kotlina pa je ocenjeno kot »slabo«, ker črpanje podzemne vode povzroča vdore vode slabše kakovosti v vodonosnik. Zadnja obdobna ocena količinskega stanja 1991–2020 razkriva, da imamo v plitvih vodonosnikih podzemnih vodnih teles letno na razpolago dobrih 4 milijarde m3 podzemne vode. Odvzemi podzemne vode (črpane količine) so v obdobju 2014–2019 v plitvih vodonosnikih dosegali povprečno 135 milijonov m3/leto. Na območju globokega geotermalnega vodonosnika v Murski kotlini so odvzemi v tem obdobju ocenjeni na 2,5 milijona m3/leto. Numerični modeli simulirajo omejeno napajanje, ki se kaže kot izcejanje iz okoliških kamnin v geotermalni vodonosnik v višini približno 2,3 milijona m3 termalne vode na leto.
Ključne besede: podzemna voda, vodno telo, preizkus količinskega stanja, vodna bilanca, ekosistemi, odvzemi
Objavljeno v DiRROS: 16.01.2024; Ogledov: 158; Prenosov: 58
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24. Heavy minerals as indicators of source material in soils on carbonatesBarbara Čeplak, Miloš Miler, Nina Zupančič, Simona Jarc, 2023, izvirni znanstveni članek Povzetek: The origin of the soils formed on carbonate rocks remains uncertain, as they are probably of polygenetic origin. Of particular interest are the elevated contents of some trace elements detected in these soils, as they can hardly be attributed to insoluble residues of carbonate rock. The aim of this study was to uncover the relationship between heavy minerals in bedrock and soil and to identify other sources that influence the mineral and chemical composition of soil. We investigated representative samples of soils and dolomite bedrock as well as sandstones and marlstones from the nearby flysch basin as an expected source of the aeolian contribution. XRD and SEM/EDS showed that mineral diversity is higher in soils compared to the dolomites. Heavy minerals found in dolomite insoluble residue include sphalerite, Ti-oxide (probably rutile), zircon, fluorite, pyrite, minerals of REE phosphates and apatite group, interpreted as terrigenous detrital material. The mineral composition of soil heavy fraction is only partly following insoluble residues of bedrock and indicates possible aeolian contribution. Comparison with nearby flysch sandstones and marlstones showed similarities in mineralogical diversity by the presence of chromite and Fe-Cr(Mn) oxides (probably carmichaelite). Other minerals present in soils and flysch layers, such as Ti-oxide (probably rutile), zircon, REE phosphates, and pyrite grains, however, show similarities in mode of occurrence and transport indications. Signs of aeolian transport on the grains detected in soils were further confirmed by SEM/EDS.
Ključne besede: Phaeozem, Upper Triassic dolomite, flysch layers, trace elements, SEM/EDS
Objavljeno v DiRROS: 04.01.2024; Ogledov: 220; Prenosov: 53
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28. Rak jajčnikov : ponovno nekaj novega2023, zbornik recenziranih znanstvenih prispevkov na domači konferenci Povzetek: Rak jajčnikov je najpogostejši vzrok smrti pri ženskah, ki zbolijo za ginekološkimi raki, saj je bolezen za večino bolnic v napredovalih fazah pogosto usodna. To je posledica težavne prepoznavnosti bolezni v zgodnjih fazah, ko je zdravljenje učinkovito. /// Na žalost preventivni program za zgodnje odkrivanje raka jajčnikov še ne obstaja, zato je pri več kot 75 % bolnic bolezen odkrita v napredovalih stadijih, kar posledično prinaša slabo prognozo. Tako pri zdravnikih kot pri ženskah je pomanjkljivo poznavanje zgodnjih znakov bolezni, kar lahko vodi v napačno diagnostiko in triažiranje bolnic v neprimerno zdravstveno ustanovo. /// Diagnoza se postavi s pomočjo ustreznih diagnostičnih preiskav, potrdi pa se s patohistološko preiskavo. 90 % rakov jajčnikov izvira iz epitelija, medtem ko so drugi tipi redki. Osnovno zdravljenje vključuje kirurški poseg, katerega cilj je popolnoma odstraniti bolezen in doseči stanje brez vidnega ostanka bolezni. Sledi sistemska terapija, medtem ko obsevanje pri zdravljenju raka jajčnikov nima ključnega pomena. /// Ugotovljeno je, da je zdravljenje raka jajčnikov najuspešnejše v specializiranih ustanovah, kjer delujejo strokovnjaki z usmerjenostjo v ginekološko-onkološko področje. V Sloveniji si nenehno prizadevamo za standardizirano in kakovostno obravnavo žensk z rakom jajčnikov.
Ključne besede: ginekološki raki, elektronske knjige
Objavljeno v DiRROS: 22.11.2023; Ogledov: 305; Prenosov: 143
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29. The corrosion properties of steel in pore solutions obtained from alkali‐activated mortarsNina Gartner, Tadeja Kosec, Stéphane Poyet, Andraž Legat, 2023, izvirni znanstveni članek Povzetek: Alkali‐activated materials (AAMs) are considered a promising alternative to materials made from ordinary Portland cement (OPC). Other than considering the durability of the material itself, the use of AAMs for reinforced concrete elements also raises the question of steel corrosion processes in these materials, which are still relatively unknown. Three different alkali‐activated mortars were prepared for this study, based on either fly ash, slag, or metakaolin. Pore solutions were then extracted from each mortar and chemically analyzed. Electrochemical techniques were used to study the corrosion of steel in synthetic pore solutions containing varying concentrations of chlorides. In parallel, the same corrosion tests were performed in a generic pore solution representing OPC mortar. It was shown that the chemical composition differed in each pore solution tested, thus affecting the corrosion properties of the steel. The addition of chloride also had a varying effect on the corrosion properties of the steel in each type of pore solution tested. This study provided a basic overview of the corrosion behavior and mechanisms of the various AAM environments in comparison to that of OPC.
Ključne besede: alkali-aktivated materials, corrosion, electrochemical corrosion techniques, extracted pore solution
Objavljeno v DiRROS: 20.11.2023; Ogledov: 236; Prenosov: 35
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30. Monitoring the galvanic corrosion of copper–steel coupling in bentonite slurry during the early oxic phase using coupled multielectrode arraysTadeja Kosec, Miha Hren, Klara Prijatelj, Bojan Zajec, Nina Gartner, Andraž Legat, 2023, izvirni znanstveni članek Povzetek: In the case of a two-part container for spent nuclear fuel, consisting of an iron-based inner structure with a copper coating, the potential perforation of copper through minor damage may result in intensive galvanic corrosion between copper and steel. The present work focuses on the corrosion of steel galvanically coupled to copper and exposed to a slightly saline environment under oxic conditions. The electrochemical processes on individual electrodes were monitored by coupled multielectrode arrays (CMEAs). The CMEAs were either in contact with groundwater saturated with bentonite or immersed in groundwater only. Very high galvanic corrosion currents were detected between carbon steel and pure copper in the early oxic phase. Additionally, the use of CMEAs further made it possible to monitor the distribution of cathodic currents around the steel electrode, which behaved anodically. Various microscopy and spectroscopy techniques were applied to identify the modes of corrosion and the type of corrosion products present at the end of the period of exposure.
Ključne besede: copper, steel, bentonite, Aspö groundwater, coupled multi electrode array, electrochemical properties, Raman analysis, corrosion
Objavljeno v DiRROS: 16.11.2023; Ogledov: 332; Prenosov: 52
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