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1.
Prispevek zunanjih in notranjih virov ogljičnih delcev v različnih tipih stanovanjskih stavb : magistrsko delo
Klemen Levičnik, 2024, master's thesis

Abstract: Ogljični delci (del PM2,5) pomembno vplivajo na kakovost zraka. Sestavljeni so iz dveh frakcij, črnega ogljika (BC) in organskih delcev in so v večji meri posledica človeških aktivnosti, saj nastajajo pri nepopolnem zgorevanju ogljičnih goriv. Glede na optične lastnosti ločimo črni ogljik (BC), ki najbolj efektivno absorbira svetlobo preko celotnega spektra, in rjavi ogljik (BrC), ki absorbira v UV in modrem delu spektra. Kakovost zraka v notranjih prostorih zavisi od infiltracije delcev iz zunanjega zraka in notranjih virov. V kurilnih sezonah med leti 2021 in 2023 smo na jugovzhodnem delu Ljubljanske kotline merili koncentracije BC v zunanjem in notranjem zraku v treh različnih stanovanjskih stavbah (Novogradnja – NG, Kmečka hiša – KH, Povprečna hiša – SV) in na podlagi optičnih lastnosti določili delež BC iz prometa (%BCFF) in zgorevanja lesa (%BCWB). Preko sočasnih meritev CO2 smo ocenili tesnost stavbnega ovoja. Ugotovili smo, da kurjenje lesa v hladnejših mesecih pomembno vpliva na kakovost zunanjega zraka. Največjo tesnost stavbnega ovoja smo pričakovali pri NG, kjer sklepamo, da onesnažila v stavbo prihajajo preko rekuperacijskega sistema. Kljub temu smo v NG zabeležili najnižje povprečne urne koncentracije BC v notranjem zraku (1 µg/m3, 40 % BC glede na koncentracije v zunanjem zraku). Največjo tesnost stavbnega ovoja smo izmerili pri SV, kjer smo v prvem obdobju zabeležili 1 µg/m3 BC (60 % glede na zunanji zrak) in 1,7 µg/m3 (20 %) v drugem obdobju. Najvišje koncentracije BC smo izmerili v kmečki hiši (4 µg/m3 - 10 % in 2,8 µg/m3 - 60 %), kjer so višje koncentracije posledica slabe tesnosti stavbnega ovoja in prisotnosti intenzivnih notranjih virov delcev. Za vzdrževanje kakovosti zraka v stavbah odsvetujemo uporabo zastarelih kurilnih naprav, priporočeno pa je zračenje okoli poldneva, ko so zunanje koncentracije najnižje. Pri starejših stavbah je smiselna zamenjava dotrajanih oken in vrat, kar bi zmanjšalo potrebo po ogrevanju, pri novogradnjah z rekuperacijskim sistemom pa je smiselno poskrbeti za ustrezno filtriranje zunanjega zraka.
Keywords: ogljični aerosoli, črni ogljik, stanovanjske stavbe, viri onesnaženja, zrakotesnost, magistrske naloge
Published in RUNG: 09.02.2024; Views: 579; Downloads: 5
.pdf Full text (3,23 MB)

2.
Investigation of Aerosol Types and Vertical Distributions Using Polarization Raman Lidar over Vipava Valley
Longlong Wang, Marija Bervida, Samo Stanič, Klemen Bergant, Asta Gregorič, Luka Drinovec, Zhenping Yin, Yang Yi, Detlef Müller, Xuan Wang, 2022, original scientific article

Abstract: Aerosol direct radiative forcing is strongly dependent on aerosol distributions and aerosol types. A detailed understanding of such information is still missing at the Alpine region, which currently undergoes amplified climate warming. Our goal was to study the vertical variability of aerosol types within and above the Vipava valley (45.87◦ N, 13.90◦ E, 125 m a.s.l.) to reveal the vertical impact of each particular aerosol type on this region, a representative complex terrain in the Alpine region which often suffers from air pollution in the wintertime. This investigation was performed using the entire dataset of a dual-wavelength polarization Raman lidar system, which covers 33 nights from September to December 2017. The lidar provides measurements from midnight to early morning (typically from 00:00 to 06:00 CET) to provide aerosol-type dependent properties, which include particle linear depolarization ratio, lidar ratio at 355 nm and the aerosol backscatter Ångström exponent between 355 nm and 1064 nm. These aerosol properties were compared with similar studies, and the aerosol types were identified by the measured aerosol optical properties. Primary anthropogenic aerosols within the valley are mainly emitted from two sources: individual domestic heating systems, which mostly use biomass fuel, and traffic emissions. Natural aerosols, such as mineral dust and sea salt, are mostly transported over large distances. A mixture of two or more aerosol types was generally found. The aerosol characterization and statistical properties of vertical aerosol distributions were performed up to 3 km.
Keywords: valley air pollution, aerosol vertical distributions, lidar remote sensing, aerosol identification
Published in RUNG: 21.07.2022; Views: 1320; Downloads: 28
.pdf Full text (5,57 MB)

3.
Progressive pedagogies for innovation among art, science and technology : the case of mastmodule.eu
Peter Purg, N. Castillo-Rutz, Sergi Bermúdez i Badia, C. Csíkszentmihályi, Jurij V. Krpan, F. Hedeer, D. L. Sousa, Klemen Širok, 2022, original scientific article

Abstract: Even if aiming at technical innovation, an interdisciplinary curriculum can and should include social values. The Master Module in Art, Science and Technology project attempted to do so by developing the innovation catalyst profile, a graduate who critically reflects on the creation process by combining art thinking and design thinking. Within a pilot of the MAST module students from three universities responded to timely challenges such as ‘The Future of Work’ and ‘Solidarity,’ through which the project staff tested progressive pedagogical solutions like cross-disciplinary mentoring and situated knowledge sharing. Introducing European social values in both artistic and technical education, the article presents models, experiments and inspirations discussed against discursive analysis and course evaluation data. In order to support not only inclusive but also sustainable teaching and learning approaches, novel methods and tools may become daringly innovative as well as critical of both their pedagogical and the wider social setting.
Keywords: art thinking, curriculum design, social values, innovation catalyst, design thinking
Published in RUNG: 27.06.2022; Views: 1296; Downloads: 29
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4.
Characterization of electrochemical processes in metal-organic batteries by X-ray Raman spectroscopy
Ava Rajh, Iztok Arčon, Klemen Bučar, Matjaž Žitnik, Marko Petric, Alen Vižintin, Jan Bitenc, Urban Košir, Robert Dominko, Hlynur Gretarsson, Martin Sundermann, Matjaž Kavčič, 2022, original scientific article

Abstract: X-ray Raman spectroscopy (XRS) is an emerging spectroscopic technique that utilizes inelastic scattering of hard Xrays to study X-ray absorption edges of low Z elements in bulk material. It was used to identify and quantify the amount of carbonyl bonds in a cathode sample, in order to track the redox reaction inside metal−organic batteries during the charge/ discharge cycle. XRS was used to record the oxygen K-edge absorption spectra of organic polymer cathodes from different multivalent metal−organic batteries. The amount of carbonyl bond in each sample was determined by modeling the oxygen K-edge XRS spectra with the linear combination of two reference compounds that mimicked the fully charged and the fully discharged phases of the battery. To interpret experimental XRS spectra, theoretical calculations of oxygen K-edge absorption spectra based on density functional theory were performed. Overall, a good agreement between the amount of carbonyl bond present during different stages of battery cycle, calculated from linear combination of standards, and the amount obtained from electrochemical characterization based on measured capacity was achieved. The electrochemical mechanism in all studied batteries was confirmed to be a reduction of double carbonyl bond and the intermediate anion was identified with the help of theoretical calculations. X-ray Raman spectroscopy of the oxygen K-edge was shown to be a viable characterization technique for accurate tracking of the redox reaction inside metal−organic batteries.
Keywords: X-ray Raman spectroscopy, meta-organic batteries, oxygen K-edge XANES, electrochemical processes
Published in RUNG: 24.03.2022; Views: 1622; Downloads: 20
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5.
6.
Bora flow characteristics in a complex valley environment
Marija Bervida, Samo Stanič, Griša Močnik, Longlong Wang, Klemen Bergant, Xiaoquan Song, 2021, original scientific article

Abstract: This paper complements the existing studies of Bora flow properties in the Vipava valley with the study of Bora turbulence in a lower region of the troposphere. The turbulence characteristics of Bora flow were derived from high resolution Doppler wind lidar measurements during eight Bora wind episodes that occurred in November and December 2019. Based on the vertical profiles of wind velocity, from 80 to 180 m above the valley floor, the turbulence intensity related to all three spatial directions and the along-wind integral length scales related to three velocity components were evaluated and compared to the approximations given in international standards. The resulting turbulence characteristics of Bora flow in a deep mountain valley exhibited interesting behaviour, differing from the one expected and suggested by standards. The intensity of turbulence during Bora episodes was found to be quite strong, especially regarding the expected values for that particular category of terrain. The specific relationship between along-wind, lateral and vertical intensity was evaluated as well. The scales of turbulence in the along-wind direction were found to vary widely between different Bora episodes and were rather different from the approximations given by standards, with the most significant deviations observed for the along-wind length scale of the vertical velocity component. Finally, the periodicity of flow structures above the valley was assessed, yielding a wide range of possible periods between 1 and 10 min, thus confirming some of the previous observations from the studies of Bora in the Vipava valley.
Keywords: doppler wind lidar, Bora wind, turbulence intensity, complex terrain, turbulence integral length scale
Published in RUNG: 05.11.2021; Views: 1935; Downloads: 42
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7.
What else needs to be said on Climate Change and Droughts: Future Chalanges
Klemen Bergant, unpublished conference contribution

Abstract: Extreme weather events, including droughts, and a failure of climate-change mitigation and adaptation are the most urgent global risks taking into account their likelihood and impact. The economic loss related to extreme weather events is increasing. Observations show that droughts became more frequent and severe in the last decades across the entire Europe, and according to the climate projections the drought risk will continue to increase in 21st century, therefore we need to take action now. Efficient drought monitoring and early warning system is the basic climate change adaptation measure. Different drought monitoring and warning systems are available on local, regional and global level and for efficient management of drought risk we need to connect those tools and integrate them into multi-hazard early warning systems.
Keywords: climate change, extreme weather events, droughts, monitoring, early warnings
Published in RUNG: 07.01.2021; Views: 2363; Downloads: 0
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8.
New Data Policy in South-East Europe : (related to the SEE-MHEWS-A project)
Klemen Bergant, unpublished conference contribution

Abstract: Conference contribution presents the process of development of a new data policy for the South-East European Multi-Hazard Early Warning Advisory System project (SEE-MHEWS-A Project). The project, led by the World Meteorological Organization, is currently in a demonstration phase. National meteorological and hydrological services (NMHSs) from 17 countries in the South-East Europe are involved in the project. With common SEE-MHEWS Data Policy Agreement the involved NMHSs express their willingness and provide legal framework for the exchange of all available meteorological and hydrological data with a main purpose to improve their meteorological and hydrological forecasts and warnings. The project data policy could be seen as a first step towards the open data policy in the region.
Keywords: Multi-Hazard Early Warning System, Meteorological and Hydorlogical Warnings, Data Exchnage, Data Policy
Published in RUNG: 06.01.2021; Views: 2232; Downloads: 0
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9.
Projekcije podnebnih sprememb za Slovenijo - kako so lahko v pomoč gospodarstvu?
Klemen Bergant, 2019, published professional conference contribution

Abstract: Prispevek za posamezne letne čase povzema zaznane spremembe podnebja v Sloveniji v preteklih šestih desetletjih ter projekcije podnebnih sprememb do konca 21. stoletja. Pri projekcijah podnebnih sprememb so upoštevani različni scenariji izpustov toplogrednih plinov. Obravnavane so spremembe temperature zraka, evapotranspriacije, količine padavine in prisotnosti snežna odeja ter njihov vpliv na različne gospodarske panoge.
Keywords: podnebne spremembe, temperatura zraka, evapotranspiracija, padavine, snežna odeja, gospodarstvo
Published in RUNG: 06.01.2021; Views: 2257; Downloads: 0
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10.
Household and road dust as indicators of airborne particulate matter elemental composition : dissertation
Klemen Teran, 2020, doctoral dissertation

Abstract: Household dust (HD) and road dust (RD) are widespread and easily accessible urban sediments, which are influenced by deposition of airborne particulate matter (PM). Since airborne PM is considered to be one of the most important pollutants in urban areas, with significant adverse effects on human health, a better understanding of its elemental composition and dispersion mechanisms is needed. The present study examines whether the HD and RD elemental composition can be used as a quick alternative method for the determination of corresponding PM elemental composition over a selected area. In summer 2016, HD, RD, and topsoil samples were collected from 249 sampling locations distributed across rural, urban, and industrial areas in Slovenia. The collected samples were sieved for particle diameters below 63 μm and analysed for 53 elements with ICP-MS after aqua regia digestion. SEM/EDS analyses were applied for the determination of characteristic particles at the microlevel. Finally, the elemental composition of HD and RD was compared with the PM10 elemental composition obtained from National Network for Ambient Air Quality Monitoring governed by Slovenian Environmental Agency (ARSO) to determine any potential connection between them. The results show that HD and RD are considerably enriched with a large set of elements compared to the topsoil. Correlations and factor analyses show that spatial distribution of factor scores in RD revealed strong regional trends, connected with soil resuspension (Al, Ce, Ga, K, La, Li, P, Rb, Sc and Y) or with anthropogenic sources such as traffic (Ag, Bi, Cu, Sb and Sn), steel mill emissions (Cr, Mo, Mn, Ni and W) and construction material decomposition (Ca and Sr). In contrast, HD elemental composition was highly variable between sampling locations. Variability was probably caused by indoor sources, such as smoking (Ce and La), biomass combustion (K, P and Rb), construction material decomposition (Ca and Sr) and residents’ professional occupation: dental care employees (Ag, Au, Pd) and employees in the metal-processing industry (Cr, Mo, Ni). Among deposited particles in RD, urbanization processes, such as fossil fuel combustion and traffic emissions, including brake pad abrasion and tyre wear, contributed the largest share of particles with anomalous elemental composition. Brake pad abrasion, for instance, contributed Ba-, Cu-, Sn-, and Zn-enriched irregular, angular and tabular particles, while tyre wear produced elongated rubber particles with traces of Ba, Cu, and Zn. RD from urban areas showed significantly higher elemental levels of Ag, Bi, Ca, Cd, Cr, Cu, Hg, Fe, Mo, Nb, Pb, Pt, Sb, Sn, Sr, Ti, Zn, and W in comparison to the rural environment, indicating the strong impact of urbanization on RD elemental composition. Another important anthropogenic source of deposited particles in RD were steel mills. Strong anomalies of Cr, Mo and Ni were detected in their vicinity. Their elemental levels decreased with distancing from the plan location, reaching urban background levels between 15 and 20 km from the mills. SEM/EDS analyses identified enrichments of Cr, Mn, Mo, Ni, V, and W in spherical particles and particles with partially melted surfaces, which were found only in the proximity of steel mills, indicating their influence of the PM deposition. Comparison of RD and the corresponding PM10 elemental composition showed that the RD fraction with particle diameters below 63 μm reflects PM10 elemental composition for the last 30 to 90 days for Cr, Cu, Mo and Zn and can be used as a predictor for PM10 elemental levels. This is not true for HD, as indoor particle sources prevail over the deposition of ambient PM10.
Keywords: household dust, road dust, particulate matter, PM10, pollution, Slovenia, steel mills, topsoil, traffic, urbanization
Published in RUNG: 02.12.2020; Views: 3614; Downloads: 182
.pdf Full text (17,40 MB)

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