91. Smernice za zagotavljanje gozdnega reprodukcijskega materiala : predlog pripravljen v okviru projekta LIFEGENMONKristina Sever, Boris Rantaša, Marijana Vidrih Minić, Natalija Dovč, Janez Kermavnar, Marjana Westergren, Gregor Božič, Matjaž Guček, Andrej Breznikar, Aleš Poljanec, Hojka Kraigher, 2021, treatise, preliminary study, study Keywords: gozdni reprodukcijski material, gozdni semenski objekti, provenienčna območja, vrste, genetska pestrost
Published in DiRROS: 14.11.2023; Views: 399; Downloads: 131
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93. Evolution of surface functional groups and aromatic ring degradation upon treatment of polystyrene with hydroxyl radicalsAlenka Vesel, Rok Zaplotnik, Gregor Primc, Miran Mozetič, 2023, original scientific article Abstract: The surface properties of hydrocarbon polymers are inadequate for numerous applications. Hence, they require alteration via functionalisation with desired functional groups. Hydroxyl groups are often preferred, since they enable appropriate polarity for the irreversible grafting of desired molecules. In this study, the surface kinetics resulting from the treatment of polystyrene with hydroxyl (OH) radicals from the gas phase was fundamentally investigated through a precisely-designed experiment. Polystyrene samples were exposed to various known fluences of OH radicals, and the evolution of surface functional groups versus the OH fluence was monitored using high-resolution X-ray photoelectron spectroscopy (XPS). The fluences of OH radicals varied between 1 × 1018 and 4 × 1023 m−2 in the process of finding a threshold fluence for the formation of specific groups. The surface concentration of carbonyl (C=O) groups could be measured using XPS at a fluence of approximately 5 × 1020 m−2. The C=O groups became measurable at a fluence of approximately 1.5 × 1021 m−2, and carboxyl (COOH)/ester groups at approximately 4 × 1021 m−2. As deduced from the XPS, a concentration of C=O groups at approximately 5 % occurred before the degradation of the aromatic ring. The formation of other oxygen-functional groups required opening of the aromatic ring. The results have been explained using a two-step process, considering available theories vis-a-vis initial stages in the functionalisation of PS with polar functional groups.
Keywords: polistiren, kinetika površinske funkcionalizacije, OH radikali, vpliv doze radikalov, časovni razvoj, polystyrene, surface functionalisation kinetics, OH radicals
Published in DiRROS: 09.11.2023; Views: 297; Downloads: 124
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94. Optimization method based on simplex for surface area improved photocatalytic performance of ▫$g-C_3N_4$▫Matevž Roškarič, Janez Zavašnik, Dániel Dániel Zámbó, Tomaž Kotnik, Sebastijan Kovačič, Gregor Žerjav, Albin Pintar, 2023, original scientific article Abstract: The main objective of the present study was to increase the specific surface area (SBET) of graphitic carbon nitride (g-C3N4) prepared from dicyandiamide by effectively modifying the synthesis procedure using the Simplex optimization method. A remarkable increase in SBET was achieved in only a few steps, with the highest value of 86 m2/g. Compared to the reference material, the improved photocatalyst exhibited enhanced and unique structural, textural, optical, and electronic properties, reflected in the improved ability of the photocatalyst to degrade a variety of organic pollutants dissolved in water. By performing scavenger and spin-trapping experiments, it was confirmed that the major reactive oxygen species formed under visible-light illumination of the enhanced photocatalyst were singlet oxygen (1O2) and superoxide anion radicals (O2–•) with a purposed formation mechanism. The enhanced formation of 1O2 enabled high activity and stability of the optimized materials as well as selective response to degradation of the pharmaceutical compounds studied. By using the simple and fast Simplex optimization algorithm to determine new synthesis parameters, we obtained an improved g-C3N4 that completely degrades bisphenol A under the conditions studied.
Published in DiRROS: 08.11.2023; Views: 264; Downloads: 144
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95. Impact of dye encapsulation in ZIF-8 on ▫$CO_2$▫, water, and wet ▫$CO_2$▫ sorptionAljaž Škrjanc, Mojca Opresnik, Matej Gabrijelčič, Andraž Šuligoj, Gregor Mali, Nataša Zabukovec Logar, 2023, original scientific article Published in DiRROS: 06.11.2023; Views: 245; Downloads: 145
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97. Models for forecasting the traffic flow within the city of LjubljanaGašper Petelin, Rok Hribar, Gregor Papa, 2023, original scientific article Abstract: Efficient traffic management is essential in modern urban areas. The development of intelligent traffic flow prediction systems can help to reduce travel times and maximize road capacity utilization. However, accurately modeling complex spatiotemporal dependencies can be a difficult task, especially when real-time data collection is not possible. This study aims to tackle this challenge by proposing a solution that incorporates extensive feature engineering to combine historical traffic patterns with covariates such as weather data and public holidays. The proposed approach is assessed using a new real-world data set of traffic patterns collected in Ljubljana, Slovenia. The constructed models are evaluated for their accuracy and hyperparameter sensitivity, providing insights into their performance. By providing practical solutions for real-world scenarios, the proposed approach offers an effective means to improve traffic flow prediction without relying on real-time data.
Keywords: traffic modeling, time-series forecasting, traffic-count data set, machine learning, model comparison
Published in DiRROS: 28.09.2023; Views: 355; Downloads: 151
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