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Agent-based modeling: Insights into consumer behavior, urban dynamics, grid management, and market interactions
Full text linkA future sustainable energy system is expected to be digital, de-central, de-carbonized, and democratized. As the transition unfolds, new and diverse actors of various sizes will emerge in different segments. Thereby, the future energy system could shift its attention to the actors’ behavior than finding an optimum based on the physical system. Agent based modeling tools can reflect decisions from several actors in a decentralized and digital market setting. Then, such tools can enable a sustainable energy transition. This work sets out to investigate how agent-based models could tackle various challenges in energy transition. This investigation covers four segments of the energy system — consumer, city, microgrid, and market. It starts with the consumer where consumer behavior is modeled. From there, expands to a city level where the dynamic characteristics of a city are simulated. The next step is distributed microgrids, particularly how to optimally plan the grid expansions. The final step in the investigation is simulating an energy market with national and international stakeholders. The selection of models presents how agent-based models can be applied to decision-making processes in the aforementioned segments. Then a novel framework with metrics for characterization is proposed and validated that addresses the challenge — which are the characteristics that make an agent-based model a better fit to tackle a modeling objective? Additionally, the framework identifies the existing knowledge gaps and the scope for further developments. In summary, this work outlines how far agent-based models have come to tackle energy system challenges to sustain the energy transition. This work specifically highlights the scope, advantages, challenges, and trends of the agent-based models in energy sector applications. Moreover, this study finds that agent-based models reflect what a solution could be more than the traditional modeling practice that focuses on what a solution should be.Agent-based modeling: Insights into consumer behavior, urban dynamics, grid management, and market interactionspublishedVersio
Experimental optimization of an absorption-compression heat pump with wet compression for large temperature glide industrial applications
Full text linkThe present work demonstrates the experimental optimization of a single-stage compression-absorption heat pump system for an application with a large temperature glide on the heat sink side using wet compression. The primary focus is weak solution injection to optimize the compressor discharge temperature and absorber heat sink temperature glide optimizations and their effect. With constant heat sink and source inlet temperatures at 60 °C and a mass flow rate of 0.25 kg/s, preliminary results show that the system delivers 50 kW of heating load and 26 kW of cooling load, respectively. Increasing the heat sink temperature glide between 28 °C and 48 °C reduces Lorenz COP and improves system efficiency. A weak solution mass flow rate of 0.015–0.25 kg/s with a minimum absorber pressure of 15 bar is recommended to achieve a higher heat sink temperature glide. Increasing the weak solution injection flow rate from 0 to 0.03 kg/s decreases the compressor discharge temperature from 139 °C to 122 °C, with a constant 0.0015 kg/s injection directed to the bearing and shaft seal. The results also highlight differences in the overall heat transfer coefficients and heat flux between absorbers 1 and 2. Absorber 1, operating in bubble mode, performs better with a maximum heat transfer coefficient of 1.39 kW/m2K compared to absorber 2, which operates in falling film mode. The system’s performance and behavior are comprehensively evaluated, providing a foundation for future improvements and advancements in oil-free absorption-compression heat pump technology.Experimental optimization of an absorption-compression heat pump with wet compression for large temperature glide industrial applicationspublishedVersio
The effect of temperature constraints on the treatment of tumors using focused ultrasound-induced acoustic streaming
Full text linkThe transport of drugs into tumor cells near the center of the tumor is known to be severely hindered due to the high interstitial pressure and poor vascularization. The aim of this work is to investigate the possibility to induce acoustic streaming in a tumor. Two tumor cases (breast and abdomen) are simulated to find the acoustic streaming and temperature rise, while varying the focused ultrasound transducer radius, frequency, and power for a constant duty cycle (1%). In the absence of perfusion, the simulated rise in temperature, despite the low duty cycle, never reaches a steady state and is fitted to a logarithmic equation, enabling predictions of the temperature for long treatment times. Higher frequencies and larger probe radii are found to result in shorter treatment times relative to the temperature rise, at the cost of a smaller treated area. Results from the simulations indicate that it may be possible to achieve reasonable acoustic streaming values in tumor without the temperature exceeding 50 °C. Treatment times for streaming a distance of 50 μm in the breast case are shown to range from less than one and a half hour to 93 h, depending on the probe settings. © The Author(s) 2024.publishedVersio
INO OptiFLEX 22MW FWT - Definition and modelling of the INO OptiFLEX 22MW floating wind turbine - 2025:00067 A
No full textThis report presents the open INO OptiFLEX 22MW floating wind turbine design, used as a case study in the OptiFLEX project.INO OptiFLEX 22MW FWT - Definition and modelling of the INO OptiFLEX 22MW floating wind turbine - 2025:00067 ApublishedVersio
Hamlet – Limited laboratory study - In comparison with existing weathering properties of oils from neighbouring fields
Full text linkA limited laboratory study of Hamlet crude oil (a re-check approach) has been conducted on Hamlet crude oil to compare the obtained data with the existing weathering properties of crude oils from the neighbouring field in the North Sea (Cerisa, Ofelia, Duva, and Gjøa). The limited laboratory study was performed at 13 °C.Hamlet – Limited laboratory study - In comparison with existing weathering properties of oils from neighbouring fieldspublishedVersio
A new method for placental volume measurements using tracked 2D ultrasound and automatic image segmentation
Full text linkBackground: Placental volume measurements can potentially identify high-risk pregnancies. We aimed to develop and validate a new method for placental volume measurements using tracked 2D ultrasound and automatic image segmentation.
Methods: We included 43 pregnancies at gestational week 27 and acquired placental images using a 2D ultrasound probe with position tracking, and trained a convolutional neural network (CNN) for automatic image segmentation. The automatically segmented 2D images were combined with tracking data to calculate placental volume. For 15 of the included pregnancies, placental volume was also estimated based on MRI examinations, 3D ultrasound and manually segmented 2D ultrasound images. The ultrasound methods were compared to MRI (gold standard).
Results: The CNN demonstrated good performance in automatic image segmentation (F1-score 0.84). The correlation with MRI-based placental volume was similar for tracked 2D ultrasound using automatically segmented images (absolute agreement intraclass correlation coefficient [ICC] 0.58, 95% CI 0.13–0.84) and manually segmented images (ICC 0.59, 95% CI 0.13–0.84). The 3D ultrasound method showed lower ICC (0.35, 95% CI −0.11 to 0.74) than the methods based on tracked 2D ultrasound.
Conclusions: Tracked 2D ultrasound with automatic image segmentation is a promising new method for placental volume measurements and has potential for further improvement.publishedVersio
A mixed-method approach to understand energy-related occupant behavior and everyday practices in multi-story residential buildings☆
Full text linkIn recent decades, attention has increased to investigating energy-related occupant behavior and everyday practices to contribute to bridging buildings’ well-known energy performance gap. Understanding some of the mechanisms behind this gap, such as, the energy-related decisions and/or shared heating practices among occupants, could foster effective strategies for promoting energy efficiency. However, such mechanisms are not yet well identified, especially in residential contexts and low-energy buildings, where the relative impact of occupants’ behavior is predominant. Aiming to contribute to tackling this knowledge gap, this article presents the results of a sequential mixed-method approach, combining quantitative and qualitative methods to study the energy-related practices of six occupants in five households of a multi-story low-energy household block located in Denmark. The households are monitored with sensors measuring heating use, room temperature, and heating setpoint temperature, enabling to capture human-building interactions at a high resolution. The quantitative analyses (data analyses) showed substantial differences in heating behavior and practices and thermal comfort preferences across households and over the seasons (from 90 to 301 heating days a year). Nevertheless, the qualitative analysis (semi-structured interviews) indicates shared practices regarding the use of the feedback display installed in each dwelling. This suggests that despite individual differences in preferences and habits, households living in the same building still share heating practices. The findings underpin the importance of the building managers’ support and trust in improving feedback implementation and ensuring heating practices to support building energy efficiency.publishedVersio
Lov- og regelverket for bruk av råvarer fra dagligvare til fôr og gjødsel
Full text linkArrangement: Dagligvare matsvinn prosjekt workshop
Type arrangement: Workshop
Sted: Trondheim
Tidspunkt: 16.06.25draf