11. Impact of Open-Loop Systems on Groundwater Temperature in NE SloveniaSimona Adrinek, Mitja Janža, Mihael Brenčič, 2023, original scientific article Abstract: To achieve sustainable and efficient use of shallow geothermal resources, it is important to understand the heat transfer in the subsurface of the planned geothermal system. In the City Municipality of Murska Sobota, NE Slovenia, the use of geothermal open-loop systems has increased in recent years. Their high spatial density raises the question of possible mutual interference between the systems. By compiling geological, hydrogeological, and thermal data, obtained from the monitoring network, fieldwork, and knowledge of regional hydrogeological conditions, we have developed a transient groundwater flow and heat transfer model to evaluate the impact of the open-loop systems on the subsurface and surrounding systems. The transient simulation showed that the thermal state in the observed area is restored over the summer, when the systems are not in operation. Also, the systems do not have significant mutual interference that would affect their efficiency. However, as interest in installing new systems in the area increases, simulations of the thermal plumes of new geothermal systems are needed to ensure sustainable and efficient use of shallow geothermal energy in the future. Keywords: geothermal energy, open-loop system, groundwater heat pump, intergranular aquifer, numerical modelling, thermal plume Published in DiRROS: 19.09.2023; Views: 649; Downloads: 164
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12. Effects of specific parameters on simulations of energy use and air temperatures in offices equipped with radiant heating/cooling panelsSabina Jordan, Jože Hafner, Martina Zbašnik-Senegačnik, Andraž Legat, 2019, original scientific article Abstract: When creating a simulation model to assess the performance of buildings, there is usually a lack of feedback information. Only in the case of measurements of a real building is a direct comparison of the measured values and simulated results possible. Parameter data related to users’ behavior or other events can also be obtained. Their evaluated frequency, magnitude and duration, along with boundary conditions, are crucial for the results. It is clear that none of them can be predicted very accurately. Most of them, however, are needed for computer modeling. In this paper we analyzed the well-defined TRNSYS simulation model of offices equipped with radiant ceiling panels for heating and cooling. The model was based on real case offices and was validated based on measurements for 1 year. The analysis included simulations in order to define what effect the parameters related mainly to users have on the energy use and the indoor air temperatures. The study confirmed that specific human activities influence the annual energy use to a relatively small degree and that their effects often counteract. It also confirmed the even more important fact that although small, these activities can influence the thermal comfort of users. It is believed that despite the fact that this research was based on an analysis of offices equipped with radiant ceiling panels, most of the results could be applied generally. Keywords: measurements, modeling, simulation, validation, analysis, energy use, temperature Published in DiRROS: 15.09.2023; Views: 522; Downloads: 251
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13. Rotational dynamics of a protein under shear flow studied by the eckart frame formalismPetra Papež, Franci Merzel, Matej Praprotnik, 2023, original scientific article Keywords: energy, kinetics, molecules, protein structure, rotational dynamics, molecules, protein structure, rotational dynamics Published in DiRROS: 06.09.2023; Views: 495; Downloads: 261
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14. Mechanical performance of timber connections made of thick flexible polyurethane adhesivesJaka Gašper Pečnik, Igor Gavrić, Václav Sebera, Meta Kržan, Arkadiusz Kwiecień, BogusŁaw Zając, Boris Azinović, 2021, original scientific article Abstract: This study investigates timber connections with flexible polyurethane adhesives, which prove to have the po-tential for timber-adhesive composite structures without mechanical connections for seismic regions. Results of conducted cyclic double lap-shear adhesive timber joints tests were compared with available experimental re-sults on timber connections with standard mechanical dowel-type fasteners and with results of numerical finite element analysis. The study found that the shear strength, elastic stiffness and strength degradation capacity of the flexible adhesive connections were significantly higher compared to mechanical fasteners commonly used in seismic-resistant timber connections. The latter, however, manifested larger ultimate displacements but also yielded at lower displacements. Keywords: flexible adhesive, timber connection, polyurethane, double lap-shear, cyclic loading, energy dissipation, open access Published in DiRROS: 19.05.2023; Views: 578; Downloads: 337
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15. Tailoring water adsorption capacity of APO-TricSuzana Mal, Alenka Ristić, Amalija Golobič, Nataša Zabukovec Logar, 2021, original scientific article Keywords: APO-Tric, water adsorption capacity, thermal energy storage, green ionothermal synthesis, single-crystal structure determination Published in DiRROS: 16.11.2022; Views: 663; Downloads: 500
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16. The effect of cultivation practices on agronomic performance, elemental composition and isotopic signature of spring oat (Avena sativa L.)Aleš Kolmanič, Lovro Sinkovič, Marijan Nečemer, Nives Ogrinc, Vladimir Meglič, original scientific article Keywords: oat, cultivation practice, yield, energy dispersive X-ray fluorescence (EDXRF), elements, isotopic signature Published in DiRROS: 06.09.2022; Views: 739; Downloads: 274
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17. Determining the thermal energy required to heat a biogas plant fermenterSlavica Prvulović, Milica Josimovic, Dragica Radosav, Jasna Tolmac, Sasa Jovanovic, Ivica Micic, 2022, original scientific article Keywords: fermenter, biogas, thermal energy, heating Published in DiRROS: 22.06.2022; Views: 753; Downloads: 335
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18. Nutritional intake of Slovenian semi-professional handball playersKaja Teraž, Cécil J. W. Meulenberg, 2019, original scientific article Abstract: Aim: Handball is a highly popular team sport, both in Slovenia and globally. The performance during team sport matches is influenced by numerous factors, amongst others there is nutrition whose influence is lesser known, particularly since diet is often uncontrolled. The purpose of this paper is to investigate whether Slovenian handball players, on basis of their anthropometric data and nutritional recommendations, have adequate nutritional intakes of energy and macronutrients.
Methods: Two Slovenian handball teams with male and female players (17 males and 9 females) who are part of the 1A national league, were assessed through a 7-day food diary to define their nutritional intake in three different conditions for males (on their training days, match days and days off) and in two conditions for females (on their training days and days off). Basal anthropometric data were measured by standard methods and the body composition by a bioelectrical impedance scale. The results were statistically analysed with IBM SPSS programme, using the repeated measures ANOVA model.
Results: Both female and male handball players show insufficient amounts of energy intake, based on the most recent nutritional intake recommendations for team sports. Moreover, the intake of carbohydrates is too low for both female and male handball players, and the intake of fat is too high.
Conclusion: The analysis of the initial nutritional intake and the comparison with the recommendation shows that the male handball players do not have an optimal diet with proper intake of both energy and macronutrients. The energy intake is insufficient also in female players. Adjusting the nutritional intake in a way to make it more balanced and tuned to the training schedule, would support a better health and performance. Keywords: energy intake, macronutrients, nutrition, body composition, handball, team sport Published in DiRROS: 17.12.2020; Views: 1522; Downloads: 766
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19. A comparison of models for forecasting the residential natural gas demand of an urban areaRok Hribar, Primož Potočnik, Jurij Šilc, Gregor Papa, 2019, original scientific article Abstract: Forecasting the residential natural gas demand for large groups of buildings is extremely important for efficient logistics in the energy sector. In this paper different forecast models for residential natural gas demand of an urban area were implemented and compared. The models forecast gas demand with hourly resolution up to 60 h into the future. The model forecasts are based on past temperatures, forecasted temperatures and time variables, which include markers for holidays and other occasional events. The models were trained and tested on gas-consumption data gathered in the city of Ljubljana, Slovenia. Machine-learning models were considered, such as linear regression, kernel machine and artificial neural network. Additionally, empirical models were developed based on data analysis. Two most accurate models were found to be recurrent neural network and linear regression model. In realistic setting such trained models can be used in conjunction with a weather-forecasting service to generate forecasts for future gas demand. Keywords: demand forecasting, buildings, energy modeling, forecast accuracy, machine learning Published in DiRROS: 15.03.2019; Views: 2482; Downloads: 1144
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20. Elemental composition of wheat, common buckwheat, and tartary buckwheat grains under conventional productionLea Orožen, Katarina Vogel-Mikuš, Matevž Likar, Marijan Nečemer, Peter Kump, Marjana Regvar, 2012, original scientific article Keywords: dietary reference intake, energy dispersive X-ray fluorescence spectrometry, metals, minerals, trace elements, total reflection X-ray fluorescence spectrometry Published in DiRROS: 11.07.2017; Views: 4439; Downloads: 1531
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