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Comparison of ML and ASM models for effluent nutrient estimation in the Hias Process
Full text linkThe aim of this article is to develop and compare machine learning (ML) methods with activated sludge models (ASM) for estimation of effluent nutrients in the Hias Process. The Hias Process is a novel moving bed bioreactor with enhanced biological phosphorus removal and simultaneous nitrification and denitrification (MBBR-EBPR-SND). As the main energy cost of the nutrient removal process is aeration, it is necessary to design of energy-efficient control strategies that ensure compliance with legal requirements for nutrient removal in real-time while optimizing the aeration rates. The first step in control strategy design is development of models that represent the main process dynamics.The case study data set of four months was collected from a 192 000 PE municipal MBBR process at Hias water resource recovery facility in Norway. The online measurements include used water flowrate, aeration rates, dissolved oxygen, suspended solids, and soluble nutrients PO4, COD, NO2 and NO3. Reduced ASM model, support vector regression (SVR) and long short-term memory neural network (LSTM), with and without dynamic time-delay, were developed to predict the effluent PO4 in the Hias process. The model prediction accuracies were compared using correlation coefficients and trend figures. The SVR model with fine gaussian kernel gave best results with strong R index of 0.9. The LSTM model reached a sufficient R index of 0.6 and the reduced ASM2d model a weak R index of 0.2. Including the dynamic time-delay improved the model accuracy. Models with dynamic time-delay will be developed further for energy-efficient control strategy development
Process simulation for biogas upgrading and biomethane recovery using biofilm-based reactors
Full text linkMicrobial biofilm matrices offer numerous benefits in bioprocessing and are crucial in various industrial and remediation processes. They facilitate electron exchange from solid surfaces when they interact with the environment. Emerging technologies such as biofilm-containing trickle bed reactors (TBR) and bioelectrochemical systems (BESs) for carbon dioxide (CO2) utilization, mostly rely on microbial biofilm matrices. Metabolic modeling of biofilm-based reactors enables detailed analysis of CO2 reduction within microorganisms, enhancing reactor efficiency. This study employed simulation models to analyze biomethane synthesis within TBR and BES systems. AQUASIM simulation tool was used for conducting the simulation. Parameters such as non-stoichiometric and stoichiometric ratios of substrates, hydraulic retention time (HRT), biofilm surface area, and applied voltage in BES were varied to evaluate methane (CH4) production and microbial biomass growth in TBR and BES. Results demonstrated that 1 day HRT resulted in methanation process failure due to biomass development problem in both TBR and BES. The substrate ratio 1:4 of CO2 to H2 increased CH4 production in the investigated reactors. In BES, in-situ CO2 and proton (H+) generation from oxidation reactions can increase CH4 production. Whereas in TBR, external H2 (hydrogen) should be supplied to consume higher amount of CO2. The lag phase in TBR was shorter than that in BES because of the greater surface area in TBR. In BES, higher voltage increased the current generation because of development of more biomass on the cathode. The simulation underlines the influence of different variables on biofilm-based reactors, offering critical insights for experimental process design
Performance of direct air capture process in honeycomb channel configuration: A CFD study
Full text linkThis study presents a kinetic reaction modeling method for direct air capture (DAC) process of CO2 adsorption using computational fluid dynamics (CFD). Here, CO2 is adsorbed by amine coated air surface contact area. The Langmuir model is employed to represent the kinetics of CO2 adsorption. Despite neglecting the diffusive phase of the adsorption, which is dominant only in the later stages of adsorption, the surface reaction model gives a satisfactory representation of the adsorption for a major part of the process. Honeycomb reactors with coated adsorbent may yield a better control of reaction rate and pressure drop compared to commonly used packed bed adsorption columns. Their enhanced performance in distributing the flow homogeneously between and within channels creates unique features for the reactor. In this study, we have analyzed mechanical and electrical energy demand for adsorbing CO2 per unit mass of adsorbed CO2 as a function of air flow rate. Adsorption performance of honeycomb structure is anticipated to significantly improve in comparison to the packed beds
Interoperability Challenges and Opportunities in Vehicle-in-the-loop Testings: Insights from NUVE Lab's Hybrid Setup
Full text linkResearch and innovation in Vehicle-in-the-loop (VIL) testing is garnering more attention than ever. Integrating cyber-physical systems into the VIL setups further enhances their functionality and hybridizes the testing. Setting up any VIL infrastructure involves substantial investments and critical analysis of the resources. This study focuses on such a VIL testing infrastructure development at NUVE-Lab, aiming to provide state-of-the-art facilities for hybrid automotive testing. The facility includes components such as a heavy tractor, dynamometers, an Actuators power need generation system (APGS) system, and battery emulators (BE), complemented by digital twins (DTs) of each physical machine, process and environment to automate the testing facilities. This research examines various interoperability challenges within the current VIL framework. Three distinct testing scenarios are created to assess the overall functionalities of the hybrid setup: dynamometer-in-the-loop, APGS-in-the-loop, and BE-in-the-loop. Analyzing individual cases highlighted the need for different modeling and simulation (M/S) tools to develop digital twins. Among the tools, SIMULINK is used to build and refine the models of DTs, whereas MATLAB is used to develop control algorithms. The study also explores the adoption of Functional Mock-up Interface (FMI) standards to facilitate seamless interoperability among modeling and simulation tools. Additionally, the potential integration of the Eclipse Arrowhead framework, an IoT-edge-based automation tool, is discussed to enhance efficient data management, service interoperability, and the integration of various cyber-physical system components. In conclusion, this paper outlines the interconnection of the digital and physical platforms to evolve a hybrid VIL test laboratory, envisioning the future trajectory of the NUVE-Lab
Integration of Optimization Methods into Simulation Technology for Manufacturing via Warehouse Optimization
Full text linkThe manufacturing industry is transitioning towards digital, intelligent, and sustainable practices. However, small and medium-sized enterprises (SMEs) often lack the resources and expertise to leverage digital tools in their research and development (R&D) activities. This paper demonstrates warehouse optimization using a Genetic algorithm to optimize pallet transfers within a flexible manufacturing system (FMS) cell. The simulation model, created with Visual Components software and an external Python application, includes a warehouse with nine Euro pallets and a stacker crane. The optimization reduced the total duration of pallet transfers by approximately 20 seconds (8.1%). Integrating simulation and optimization tools offers significant benefits, including enhanced production efficiency, reduced operational costs, and improved decision-making capabilities. This demonstration highlights the practical applications and advantages of these digital tools for SMEs, showcasing their potential to streamline processes and foster sustainable manufacturing practices. The results have sparked longer-term collaborations with local industry, emphasizing the practical applications and advantages of these digital tools in enhancing manufacturing efficiency
Baldomera´s Bray: The Transmediation of a Viral Story
Full text linkThis article examines the transmedial transformation of The Story of Baldomera, tracing its evolution from a viral video to a picturebook. The study highlights how the adaptation recontextualizes the original material through the interplay of visual and verbal elements, expanding its narrative to address contemporary environmental concerns and the emotional resonance of human-animal relationships. By introducing themes of climate change and the pandemic’s impact on human interaction with nature, the picturebook redefines the story as an ecomedial artifact, reflecting broader cultural changes and ecological anxieties. The analysis further explores intertextual connections to iconic literary representations of donkeys, including Dapple in Don Quixote and Platero in Platero and I, positioning Baldomera within a tradition that underscores the cultural significance of donkeys. In studying how the transmediation of the video introduces new layers of meaning to the book, this article reflects on the persistence of hierarchical views of animals and explores how children's literature and digital media can both express ecological crises and reimagine human-animal relationships in the digital age. 
Human-Fish Relationship in Medieval Literature for Younger Audiences
Full text linkThe present chapter analyses the representations of water-borne animals (which all were categorised as ‘fish’ in the pre-Linnean taxonomies) appearing in medieval literature for younger audiences. While childhood and children’s literature have been traditionally perceived as later societal constructs, this article demonstrates that certain narratives were considered suitable and were potentially consumed by younger audiences. The article starts by addressing the current academic discussions on medieval childhood and which medieval sources can be identified as narratives potentially intended for children. It then argues that three types of dynamics are visible in the representations of fish in medieval stories for young audiences. First, fish are portrayed as food. Second, fish are represented as containers carrying objects, which are sent to humans by God. Finally, fish can be shown as imaginary monstrous creatures. The article analyses these narratives within the contexts of medieval Christian worldview and modern research into human – nonhuman relationships. 
In the Mind of the Dog: Anthropomorphism and Othering in Uno Modin’s Zorro, the Police Dog
Full text linkIn this article, the main focus is on the use of narrative and stylistic strategies contributing to anthropomorphism and othering in the depiction of the dog in Uno Modin’s Zorro, the Police Dog (1953). The analysis shows that both crude and critical anthropomorphism are used when describing Zorro. The dog is assigned philosophical thinking and trans-species affinity that goes beyond the plausible, but he is also described as involved in companionship with his human handler. Othering is also used, portraying the dog as superior to the human at certain instances and diametrically different and wild at other. When the instinct of the dog is at the center, the divide between nature and culture is accentuated, leaving no room for what Haraway terms natureculture or companion species. The narrative is read through an ecocritical lens with support of animal studies and posthumanist perspectives and the article shows how internal focalization on the canine contribute to a normalizing of stereotypical depictions of other species and the white human explorer’s other, embodied by members of the Roma community or by Native Americans
Integrating the IEEE/CIGRE DLL Modeling Standard to Use “Real Code” Models for Power System Analysis in Modelica Tools
Full text linkVendors of power system simulation tools are investigating the incorporation of actual controller code into specialized simulation environments. To facilitate this, IEEE and CIGRE have collaboratively created the IEEE/CIGRE DLL Modeling Standard. However, adoption by simulation tool providers has been minimal. The limited adoption is because 'real code' models per the IEEE/CIGRE DLL Modeling Standard must be provided as DLLs by equipment vendors. Thus, to support the standard, tools need to support a standard-specific interface and provide additional functions to execute the models.
This paper presents a method for integrating 'real controller code' models (RCMs) built according to the IEEE/CIGRE DLL Modeling Standard into Modelica-based tools. This is achieved by linking precompiled C code to Modelica models and using components from the OpenIPSL library. The approach is demonstrated with an RCM of a simplified silicon-controlled rectifier excitation system (SCRX). The paper discusses the details of the implementation, challenges, and solutions. The findings show that this method allows RCMs to be used in Modelica tools for power system simulations, providing a valuable alternative to specialized simulation tools
Decentralised Hydrogen Fuelled Gas Engine CHP Units: A Feasibility Study with Modelica
Full text linkThe use of hydrogen gas as an alternative fuel to power energy systems has been a topic of research over the last few decades and is currently gaining importance, even more due to current circumstances related to decarbonising energy supply. One focus of research is the use of hydrogen gas in combined heat and power gas engines, as this type of energy conversion is known for its high efficiency. For this reason, a cross-border project between France and Germany is developing a living laboratory in the Upper Rhine region to investigate the feasibility of hydrogen gas as an alternative fuel in a holistic decentralised energy system. It consists of several energy components, including a polymer electrolyte membrane electrolyser (PEMEC), gas engine combined heat and power (CHP) unit, photovoltaic (PV) panels, hydrogen storage, thermal and electrical energy storage. To enable and demonstrate multiple what-if scenarios of possible variations of the energy system, a simulation model was developed using Modelica. Users, e.g. local authorities, landlords, businessmen, etc., of this simulation model could utilize it as a decision support tool for designing a carbon-neutral energy system for their own use. This paper describes the development of the model and its application with real measured data from municipal buildings in the city of Offenburg, Germany. The results indicate that the suitability of the model and the use of hydrogen CHPs can be beneficial for this specific use case