cometadata/datacite-rtg-text-other-reclassification-records huggingface dataset:
title: Sofia – sCO2 facility for supercritical Brayton cycle research
Creators: name: Frýbort, Otakar
name: Dočkal, Karel
name: Vlček, Petr
name: Hájek, Petr
name: Melichar, Tomáš
name: Kapic, Miroslav
name: Živný, Antonín
name: Pátý, Marek
name: Macálka, Aleš
name: Hanzal, Vilém
name: Hájek, Petr
Publisher: name: DuEPublico: Duisburg-Essen Publications online, University of Duisburg-Essen, Germany
Year: 2021
Subjects: subject: 620

description: In the frame of national project sCO2 Efekt supported by Czech technological agency TAČR, Research Centre Rez (CVR) is developing an innovative, effective and flexible energy storage system. This system is based on the P2H2P (Power to Heat to Power) technology also called Carnot battery, with the utilization of a sCO2 Brayton cycle for heat to power conversion. In frame of the project, the key components of the storage system will be developed and experimentally verified. The key components are mainly the compressors and turbines and the storage tank. To be able to test the compressor and turbine, an experimental test facility called Sofia is also being developed. The main parameters of the Sofia facility are temperature up to 550°C, maximal test pressure of 25MPa and flow rate of about 25kg/s. The highest possible power of the turbine to be tested is up to 1.5MW electrical. In this paper, the conceptual design of the large scale experimental facility is described including its main components.
description: Conference Proceedings of the European sCO2 Conference4th European sCO2 Conference for Energy Systems: March 23-24, 2021, Online Conference, p. 185
The effect of fire on forest soils and hydrologic responces : a review
Creators: name: Hallaway, Marissa
Publisher: name: The University of British Columbia
Year: 2012

description: The goal of this review was to investigate the correlation of wildfires with decreased infiltration and increased runoff. Research suggested that wildfires can alter several forest soil properties affecting infiltration and runoff, including the formation of a fire-induced water repellent layer, the addition of a surface ash layer, and the removal of surface cover. The combination of these effects can lead to serious hydrologic and geomorphic events such as flooding, large-scale erosion and water sedimentation problems. The pre-fire soil condition is a determining factor to the overall influence of the fire, in particular, soil moisture content and amount of soil organic substances. Soil moisture content can either promote heat transfer or prevent extreme high temperatures depending on its level. Soil temperature combined with the amount of soil organic substances determines the strength of the fire-induced water repellent layer within the soil profile. Ash was found to have somewhat contradicting short-term effects with respect to infiltration and runoff. It is either seen as a natural way of mitigating water repellency and loss of surface cover by increasing infiltration capacity and protecting underlying mineral soil from raindrop impact. However, some studies also suggest that it adds to reduced infiltration by causing soil sealing. The case study from South Interior Forest Region of British Columbia describes a Risk Analysis report for the Sitkum Creek Fire (number N70347) in 2007 that includes useful management strategies developed to mitigate the effects of wildfire in community watersheds.
Flow regime and the National Ecological Observatory Network (NEON) wadeable stream sites
Creators: name: Manning, David
name: Shogren, Arial
name: Loveless, Zacharie
Publisher: name: QUBES Educational Resources
Year: 2024

description: This resource uses discharge data from three of NEON's wadeable stream sites to illustrate how streams can differ in their flow regimes using graphical analysis of annual hydrographs.
Maximum likelihood degree of the $β$-stochastic blockmodel
Creators: name: Bortner, Cashous
name: Garbett, Jennifer
name: Gross, Elizabeth
name: McClain, Christopher
name: Krawzik, Naomi
name: Young, Derek
Publisher: name: arXiv
Year: 2024
Subjects: subject: Statistics Theory (math.ST)
subject: FOS: Mathematics

description: Log-linear exponential random graph models are a specific class of statistical network models that have a log-linear representation. This class includes many stochastic blockmodel variants. In this paper, we focus on $β$-stochastic blockmodels, which combine the $β$-model with a stochastic blockmodel. Here, using recent results by Almendra-Hernández, De Loera, and Petrović, which describe a Markov basis for $β$-stochastic block model, we give a closed form formula for the maximum likelihood degree of a $β$-stochastic blockmodel. The maximum likelihood degree is the number of complex solutions to the likelihood equations. In the case of the $β$-stochastic blockmodel, the maximum likelihood degree factors into a product of Eulerian numbers.
title: Environmental assessment of a 25 MWe fossil-fired supercritical CO2 cycle
Creators: name: Maquart, Victor
name: Valentin, Benoît
name: Cagnac, Albannie
Publisher: name: DuEPublico: Duisburg-Essen Publications online, University of Duisburg-Essen, Germany
Year: 2021
Subjects: subject: 620

description: In a global effort to decrease human sourced Greenhouse Gas (GHG emissions, the operation of GHG emitting plants is only justified if they offer a sufficient flexibility to satisfy a highly variable net electric demand in electric grids with a significant share of intermittent renewable power plants. The EU funded project sCO2 Flex aims at designing a highly flexible 25 MWe supercritical CO 2 cycle s uitable for such a complementarity with renewable energies, and testing its main components. However the performance of such a cycle should not be reached at the expense of its environmental impact. Therefore the present paper focuses on the analysis of the environmental impact of such a plant, following most of the guidelines of the Life Cycle Assessment (LCA) method, as described in the ISO 14040 14044 standards. The assessment described in this paper was conducted on the open source software OpenLCA usi ng the database Ecoinvent, both acknowledged by the LCA community. It encompasses four major steps: goal and scope definition of the project, inventory analysis of the data, impact analysis and interpretation. Data was picked directly from the Ecoinvent database, gathered from the project’s contributors, or extrapolated from hypotheses if data was to be missing in the inventory analysis. To compensate the uncertainties due to lack of data on equipment scaling and operation practices, an extensive sensitivity analysis has been carried out to bring additional robustness to the study. Considering the two impact categories selected in this paper (global warming potential at 100 years scope and abiotic resource depletion), the sCO2 Flex plant outperforms the reference water/steam plant for global warming potential thanks to its higher efficiency. This is however at the expense of a considerably higher abiotic resource depletion. Regarding the latter impact category, the most significant uncertainties arise from the amount of nickel based alloys used in the boiler.
description: Conference Proceedings of the European sCO2 Conference4th European sCO2 Conference for Energy Systems: March 23-24, 2021, Online Conference, p. 194
title: Optimal design of supercritical CO2 (S-CO2) cycle systems for internal combustion engine (ICE) waste-heat recovery considering heat source fluctuations
Creators: name: Song, Jian
name: Wang, Yaxiong
name: Wang, Jiangfeng
name: Markides, Christos
Publisher: name: DuEPublico: Duisburg-Essen Publications online, University of Duisburg-Essen, Germany
Year: 2021
Subjects: subject: 620

description: Supercritical CO2 (S-CO2) cycle systems have emerged as an attractive alternative for internal combustion engine (ICE) waste heat recovery thanks to the advantages offered by CO2 as a working fluid , incl uding robust performance and system compactness. The engine exhaust gases are the main available heat source from ICEs with promising thermodynamic potential for further utilisation, and whose conditions, i.e., temperature and mass flow rate, vary based on the ICE operating strategy load. These heat source variations have a critical influence on the performance of a bottoming S-CO2 cycle system, which needs to be carefully considered in the design stage. This paper explore s the optimal design of S-CO2 cycle system s for ICE waste heat recovery considering heat source fluctuations as well as the probability of their occurrence as arising from actual ICE operation. A variety of heat source conditions are selected for separate design s of an S-CO2 cycle system and performance prediction under all possible scenarios is evaluated via detailed design and off design models, so as to select the optimal design that is able to match the heat source fluctuations and exhibit the best performance from thermodynamic and economic perspectives. The advantage of this approach relative the conventional ones that only consider one specific design condition is that it avoid s either over or under sizing of the S-CO2 cycle system, which also achieves comprehensive insight of the interplay between the bottoming heat recovery system and the ICE, and provides valuable guidance for further system optimisation.
description: Conference Proceedings of the European sCO2 Conference4th European sCO2 Conference for Energy Systems: March 23-24, 2021, Online Conference, p. 205
title: Study of the influence of additives to CO2 on the performance parameters of a sCO2-cycle
Creators: name: Rath, Sebastian
name: Mickoleit, Erik
name: Gampe, Uwe
name: Breitkopf, Cornelia
name: Jäger, Andreas
Publisher: name: DuEPublico: Duisburg-Essen Publications online, University of Duisburg-Essen, Germany
Year: 2021
Subjects: subject: 620

description: Compared to existing technologies, thermodynamic cycles based on supercritical carbon dioxide (sCO2 ) are leading to higher efficiencies and a more compact design of the components. However, it is possible to improve the performance of sCO2-based power cycles by using mixtures of CO2 with suitable additives, as also discussed in the literature for some applications such as concentrated solar power plants or the usage of geothermal heat. The large variety of possible fluid combinations makes an experimental investigation of all conceivable additives considerably difficult. Therefore, a more viable alternative is to set up a model for the power cycle and conduct a screening in order to identify promising candidates for working fluid mixtures. In a next step these could subsequently be experimentally verified. In order to carry out a screening, a preferably accurate and likewise predictive mixture model is needed. This work investigates the potential to optimize the characteristics of sCO2 power cycles by selectively adding different substances in varying amounts to CO2. For the theoretical screening, the reference equation of state for CO2 was applied in combination with a multi fluid mixture model. In the literature studies were mainly limited to mixtures for which adjusted mixture models are available. In contrast, in this work the use of a predictive mixture model allows a screening of additional fluids for which multi parameter equations of state are available (e.g. alkanes, alkenes, alcohols, and hydrofluorocarbons). The predictive model, which was recently developed at our institute, allows the use of the excess Gibbs energy model COSMO-SAC in combination with the multi fluid mixture model. Applied to an exemplary thermodynamic cycle, changes in efficiency compared to the use of pure CO2 have been evaluated. Several pro mising mixture candidates have been identified. Additionally, shifts of the critical point have been investigated and are discussed.
description: Conference Proceedings of the European sCO2 Conference4th European sCO2 Conference for Energy Systems: March 23-24, 2021, Online Conference, p. 212
title: Numerical analysis of a centrifugal compressor operating with supercritical CO2
Creators: name: Karaefe, Renan
name: Post, Pascal
name: Sembritzky, Marwick
name: Schramm, Andreas
name: Di Mare, Francesca
name: Kunick, Matthias
name: Gampe, Uwe
Publisher: name: DuEPublico: Duisburg-Essen Publications online, University of Duisburg-Essen, Germany
Year: 2021
Subjects: subject: 620

description: This study investigates the performance of a centrifugal compressor stage operating with supercritical CO2. The candidate geometry comprises a channel diffuser and is based on main dimensions of a test-loop compressor operated by Sandia National Laboratories. A non-dimensional performance curve is derived through three-dimensional RANS calculations performed with an in-house compressible CFD solver and is compared to experimental data as well as a meanline analysis that is conducted applying a single-zone modelling approach, including internal and external loss models. Within the CFD simulations, real gas thermophysical properties of carbon dioxide are assessed through an accurate and efficient tabulation procedure, the Spline-Based Table Look-Up Method (SBTL), which is optimised for the density-based solver architecture. The conducted RANS calculations show an ideal head rise of up to 41%through the channel diffuser compared to an ideal head assessment considering the impeller. The applied meanline methodology provides good agreement with the impeller performance characteristics derived from RANS calculations over the entire investigated flow range. Except for flow coefficients exceeding values of φ ≈ 0.043, where an abrupt decrease of the ideal head recovery is identified in the CFD assessments, which is not resembled by the meanline diffuser model, also satisfactory agreement of the meanline stage performance characteristics with the CFD results is obtained. Hence, applicability of the corresponding meanline loss models for sCO2 compressor analysis is indicated.
description: Conference Proceedings of the European sCO2 Conference4th European sCO2 Conference for Energy Systems: March 23-24, 2021, Online Conference, p. 230
title: Transient analysis of the super-critical carbon dioxide cycle coupled to pressurized water reactor for nuclear powered ships
Creators: name: Baek, Jeong
name: Lee, Jae
name: Lee, Jeong
Publisher: name: DuEPublico: Duisburg-Essen Publications online, University of Duisburg-Essen, Germany
Year: 2021
Subjects: subject: 620

description: Recently, nuclear-powered ships have attracted attention due to international regulations on greenhouse gas emissions and the trend of rapid and large-scale ships. In order for a nuclear system to be used in marine propulsion, it is important to achieve small in size and should be able to respond to rapid load demand changes. In this study, a super-critical carbon dioxide (S-CO2) cycle is proposed as a power conversion system for pressurized water reactors (PWR) for marine propulsion. The S-CO2 cycle has been attracting attention as the next-generation power conversion system that can be an alternative to the steam Rankine cycle due to its small system size and higher efficiency. The conceptual design of the S-CO2 power conversion system is first performed under the reference reactor conditions, including cycle design and component design. To conduct system analysis, MARS-KS code, one of the nuclear thermal-hydraulic safety analysis codes developed by Korea Atomic Energy Research Institute (KAERI) and actively used for the safety review calculation of a nuclear power plant by Korea Institute of Nuclear Safety, is improved to accurately simulate the S-CO2 power conversion system combined with PWR. The PID controller based automatic control strategy of the entire system is designed to respond to rapid load changes. Transient analyses are performed with the newly developed system analysis code under various scenarios.
description: Conference Proceedings of the European sCO2 Conference4th European sCO2 Conference for Energy Systems: March 23-24, 2021, Online Conference, p. 241
Generative AI Meets Adventure: Elevating Text-Based Games for Engaging Language Learning Experiences
Creators: name: DaCosta, Boaventura
Publisher: name: figshare
Year: 2025
Subjects: classificationCode: 460299
subject: Artificial intelligence not elsewhere classified

description: This work explores generative AI-enhanced text-based games for language learning. Utilizing ChatGPT, the study modifies an early version of Colossal Cave Adventure to generate contextually appropriate responses, making the game more interactive and engaging. The method involved creating a tailored model to emulate the original game, followed by iterative refinements. Playthrough-based comparisons revealed that the model successfully reproduced the game’s core mechanics while introducing dynamic content and contextual hints, enhancing the overall gaming experience. At the same time, the model’s nondeterministic nature showed benefits in the context of language generation while introducing challenges, such as inconsistencies in the progression of language complexity. Altogether, generative AI holds promise for improving educational, text-based games by increasing engagement and adaptability; thus, educators are encouraged to consider AI-enhanced gaming as an innovative tool for language instruction and interactive learning. However, further research is also needed to address AI limitations to ensure learning consistency, alongside the value of exploring broader applications beyond language acquisition.
A decision support system for harvest scheduling and log processing at the Malcolm Knapp Research Forest in Maple Ridge, British Columbia
Creators: name: Huang, Ye
Publisher: name: The University of British Columbia
Year: 2012

description: This essay develops prototypes of linear programming-based models to project the harvesting level, lumber production, and net revenue of a harvesting plan in order to support forest operation decision-making in the Malcolm Knapp Research Forest (MFRF) in Maple Ridge, British Columbia. Field data were collected from 3 different biogeoclimatic zones within the research forest. Growth and yield of the forest was modeled by Table Interpolation Program for Stand Yields (TIPSY) which is a stand- and forest-level model developed by the British Columbia Ministry of Forest and Range. Then, the growth and yield data were imported into a forest estate linear programming model to forecast the volume of logs harvested from the forest. A sawing pattern model was used to design the sawing pattern and generate Lumber Recovery Factors by log diameter. Subsequently, a log-to-product linear programming model was used to estimate the final lumber production, mill working hours and the net profit for the forest. The results predict that the mill can earn $3,110,141 by producing 141,229 MBF of lumber and 298,818 m³ of chips over a 60-year planning horizon. Sensitivity analysis included different sawing patterns, price fluctuations and limited mill operating hours. Some potential improvements in model structure, efficiency, availability for big diameter log, and carbon credits are also discussed. Although the forest data and the sawmill configuration used in the models are different from reality, it will not be difficult to modify the model for MKRF.
title: Numerical dimensioning of a pre-cooler for sCO2 power cycles to utilize industrial waste heat
Creators: name: Unger, Sebastian
name: Müller, Jonas
name: Bangalore Mohankumar, Malini
name: Rath, Sebastian
name: Hampel, Uwe
Publisher: name: DuEPublico: Duisburg-Essen Publications online, University of Duisburg-Essen, Germany
Year: 2021
Subjects: subject: 620

description: The annual waste heat available from industry in the European Union is more than 2,700 PJ. Consequently, the utilization of the unexploited thermal energy will decisively contribute to a reduced overall power consumption and lower greenhouse gas emissions. Supercritical carbon dioxide (sCO2) power cycles offer a variety of advantages for that purpose compared to established power cycles. Such are a high conversion efficiency and a turbomachinery with high power density. The pre-cooler is one of the essential components in an sCO2 power cycle and the prediction of the flow and heat transfer characteristics is a challenging task. In the present investigation, cycle layouts were developed for one waste heat source: a gas compressor station. The pre-cooler design as well as the boundary conditions of the< numerical simulation were assessed by an analytical model. The most promising design was the printed circuit heat exchanger with inlet temperatures between 209 °C and 352 °C. Subsequently, these heat exchangers were examined in more detail by the numerical code ANSYS CFX for sCO2 mass fluxes between 100 kg/(m² s) and 900 kg/(m² s). The pressure drop along the sCO2 channel was found insensitive to the channel diameter, but increased with the channel length and mass flux. However, the pressure drop of the coolant stream significantly depends on the channel diameter and thus a larger coolant channel diameter is recommended to maintain a reasonably low pressure drop. The overall heat transfer coefficient is limited by the heat transfer on the coolant side. Ultimately, pre-cooler designs were proposed for a waste heat system of a gas compressor station, consisting of compact modular stainless steel plates with an sCO2 channel diameter of 0.5 mm, a coolant channel diameter of 0.8 mm, an sCO2 mass flux of 700 kg/(m² s) and a coolant mass flux of 1029 kg/(m² s). Based on these results more complex channels designs, including internal fins were studied. The fin height was optimized, in order to improve the heat transfer performance.
description: Conference Proceedings of the European sCO2 Conference4th European sCO2 Conference for Energy Systems: March 23-24, 2021, Online Conference, p. 249
title: Design and off-design analysis of a highly loaded centrifugal compressor for sCO2 applications operating in near-critical conditions
Creators: name: Romei, Alessandro
name: Gaetani, Paolo
name: Persico, Giacomo
Publisher: name: DuEPublico: Duisburg-Essen Publications online, University of Duisburg-Essen, Germany
Year: 2021
Subjects: subject: 620

description: The closed gas cycle based on supercritical carbon dioxide (sCO2) is a promising solution to realize highly efficient power systems arranged in compact devices. However, the technical feasibility of these so-called sCO2 power systems relies on the development of non-conventional components, whose features are dictated by the peculiar character of the working fluid. The compressor is a key component of the system and its design demands the set-up of novel guidelines, due to the nearcritical thermodynamic condition of the fluid, which (i) makes the machine operate with a very low flow function, (ii) experiences steep changes in properties across the machine, and (iii) is prone to phase-change in the intake part of the machine. In this study we revise the entire design workflow of a prototype sCO2 centrifugal compressor, from the preliminary definition of the machine, to the mean-line design, and finally to the detailed definition of the meridional channel and of the blade shape, highlighting the aspects making the machine alternative to conventional ones. The compressor aerodynamics is then analyzed by resorting to a high-fidelity Computational Fluid Dynamics (CFD) model in both design and off-design conditions, considering three speed-lines and low/high flow rate margins. Results show the capabilities and limitations of conventional low-fidelity design procedures for designing sCO2 compressors, especially at off-design conditions, and shed light on the technical implications of the thermodynamic character of the fluid, especially in connection to the onset of phase change in the intake region of the impeller and in the tip clearance.
description: Conference Proceedings of the European sCO2 Conference4th European sCO2 Conference for Energy Systems: March 23-24, 2021, Online Conference, p. 257
title: Investigation of material degradation and coolant chemistry for sCO2 power cycles
Creators: name: Berka, Jan
name: Hlinčík, Tomas
name: Purkarová, Eliška
name: Vagenknechtová, Alice
name: Rozumová, Lucia
Publisher: name: DuEPublico: Duisburg-Essen Publications online, University of Duisburg-Essen, Germany
Year: 2021
Subjects: subject: 620

description: sCO2 power cycles are characterized by the enhanced efficiency of thermal to electric power conversion and more compact turbine size compared with the steam power cycle. The organizations from Czech Republic take part the extensive research activities in this field. The research infrastructure including sCO2 experimental loop was constructed. The sCO2 coolant chemistry and material degradation are among the solved topics. The objectives are to identify impurities in sCO2 medium and propose the purification and purity control system. Another objective is to gain data of structural material degradation in sCO2 medium. First results concerning impurities and materials were obtained during laboratory tests and the 1000 h operation of the sCO2 loop. The most important of them are presented in the paper and also conference presentation.
description: Conference Proceedings of the European sCO2 Conference4th European sCO2 Conference for Energy Systems: March 23-24, 2021, Online Conference, p. 267
Verification of Digital Twins using Classical and Statistical Model Checking
Creators: name: Gunasekaran, Raghavendran
name: Haverkort, Boudewijn
Publisher: name: arXiv
Year: 2025
Subjects: subject: Software Engineering (cs.SE)
subject: Emerging Technologies (cs.ET)
subject: FOS: Computer and information sciences

description: With the increasing adoption of digital techniques, the concept of digital twin (DT) has received a widespread attention in both industry and academia. While several definitions exist for a DT, most definitions focus on the existence of a virtual entity (VE) of a real-world object or process, often comprising interconnected models which interact with each other, undergoing changes continuously owing to the synchronization with the real-world object. These interactions might lead to inconsistencies at execution time, due to their highly stochastic and/or time-critical nature, which may lead to undesirable behavior. In addition, the continuously varying nature of VE owing to its synchronization with the real-world object further contributes to the complexity arising from these interactions and corresponding model execution times, which could possibly affect its overall functioning at runtime. This creates a need to perform (continuous) verification of the VE, to ensure that it behaves consistently at runtime by adhering to desired properties such as deadlock freeness, functional correctness, liveness and timeliness. Some critical properties such as deadlock freeness can only be verified using classical model checking; on the other hand, statistical model checking provides the possibility to model actual stochastic temporal behavior. We therefore propose to use both these techniques to verify the correctness and the fulfillment of desirable properties of VE. We present our observations and findings from applying these techniques on the DT of an autonomously driving truck. Results from these verification techniques suggest that this DT adheres to properties of deadlock freeness and functional correctness, but not adhering to timeliness properties.
description: In Proceedings ASQAP 2025, arXiv:2505.02873
title: Conceptual design and qualification of highly effective heat exchangers for heat removal sCO2 Brayton cycle to increase the safety of nuclear power plants
Creators: name: Tioual-Demange, Sarah
name: Voirin, Vivien
name: Hofer, Markus
name: Hecker, Frieder
name: Buck, Michael
name: Starflinger, Jörg
Publisher: name: DuEPublico: Duisburg-Essen Publications online, University of Duisburg-Essen, Germany
Year: 2021
Subjects: subject: 620

description: The sCO2 sCO2-4-NPP European project aims to develop an innovative technology based on supercritical CO2 (sCO2) for heat removal to improve the safety of current and future nuclear power plants. The heat removal from the reactor core will be achieved with multiple highly compact self self-prope llant, self self-launching, and self self-sustaining cooling system modules, powered by a sCO2 Brayton cycle. Heat exchangers are one of the key components required for advanced Brayton cycles using supercritical CO2. To this end, two compact and highly effective brazed plates and fins heat exchangers are designed: a main heat recovery heat exchanger (CHX), wh which allows the heat transfer directly from the steam generator to the sCO2 sCO2-4-NPP cycle, a heat sink exchanger (DUHS), which evacuate the remaining heat to the atmosphere. An important work has been achieved in the frame of this project to conceive the pre liminary design of these components, in close collaboration between Fives Cryo, a French brazed plates and fins heat exchangers manufacturer, the Institut für Kernenergetik und Energiesysteme (IKE) of University of Stuttgart and KSG/GFS Institute, a simula tor center, both in Germany. In fact, several constraints needed to be taken into account. For instance, for the DUHS, the low fans power available for the cycle and the necessary air flow for effective heat exchange implies considering almost inexisting pressure drops on the air side. To this end, very specific design ideas has been adressed to meet the desired thermal duty. Also, this project benefits from the recent results achieved among the european project sCO2-flex, related to the mechanical resistance of heat exchanger components, the assembly process and their thermal and hydraulic performances, along with Fives Cryo expertise and background. A second challenge of the sCO2-4-NPP project is to qualify the designed plates and fins heat exchangers, at cycle operating conditions, in order to meet with pressure vessels codes and regulations according to nuclear requirements. This paper presents the work achieved on the design of DUHS heat exchanger components and a preliminary part of the qualification of this equipment according to nuclear power plants regulations.
description: Conference Proceedings of the European sCO2 Conference4th European sCO2 Conference for Energy Systems: March 23-24, 2021, Online Conference, p. 274
Supplementary document for Flexible Graphene-based Metamaterial Sensor for Highly Sensitive Detection of Bovine serum albumin - 6139920.pdf
Creators: name: Xiao, Meiyu
name: Lang, Tingting
name: ren, zhe
name: Hong, Zhi
name: shen, changyu
name: Zhang, Jinhui
name: Cen, Wenyang
name: Yu, Zhenyu
Publisher: name: Optica Publishing Group
Year: 2025
Subjects: Uncategorized

description: Supplementary Information
A Case Study on the Application of Digital Twins for Enhancing CPS Operations
Creators: name: Muntean, Irina
name: Frasheri, Mirgita
name: Munaro, Tiziano
Publisher: name: arXiv
Year: 2025
Subjects: subject: Robotics (cs.RO)
subject: Software Engineering (cs.SE)
subject: FOS: Computer and information sciences

description: To ensure the availability and reduce the downtime of complex cyber-physical systems across different domains, e.g., agriculture and manufacturing, fault tolerance mechanisms are implemented which are complex in both their development and operation. In addition, cyber-physical systems are often confronted with limited hardware resources or are legacy systems, both often hindering the addition of new functionalities directly on the onboard hardware. Digital Twins can be adopted to offload expensive computations, as well as providing support through fault tolerance mechanisms, thus decreasing costs and operational downtime of cyber-physical systems. In this paper, we show the feasibility of a Digital Twin used for enhancing cyber-physical system operations, specifically through functional augmentation and increased fault tolerance, in an industry-oriented use case.
description: In Proceedings ASQAP 2025, arXiv:2505.02873
Modular Properties of Generalised Gibbs Ensembles
Creators: name: Downing, Max
name: Karimi, Faisal
Publisher: name: arXiv
Year: 2024
Subjects: subject: High Energy Physics - Theory (hep-th)
subject: Statistical Mechanics (cond-mat.stat-mech)
subject: Mathematical Physics (math-ph)
subject: FOS: Physical sciences

description: We investigate the modular properties of Generalised Gibbs Ensembles (GGEs) in two dimensional conformal field theories. These are obtained by inserting higher spin charges in the expressions for the partition function of the theory. We investigate the particular case where KdV charges are inserted in the GGE. We first determine an asymptotic expression for the transformed GGE. This expression is an expansion in terms of the zero modes of all the quasi-primary fields in the theory, not just the KdV charges. While these charges are non-commuting they can be re-exponentiated to give an asymptotic expression for the transformed GGE in terms of another GGE. As an explicit example we focus on the Lee-Yang model. We use the Thermodynamic Bethe Ansatz in the Lee-Yang model to first replicate the asymptotic results, and then find additional energies that need to be included in the transformed GGE in order to find the exact modular transformation.
Modelling urban forest structure and services using the urban forest effects (UFORE) model
Creators: name: Langley, Benjamin
Publisher: name: The University of British Columbia
Year: 2012

description: Urban forests offer a variety of services, values and benefits to communities. Urban forest resource values include air quality improvements, carbon storage and sequestration, increased property values, energy savings for homeowners and a variety of environmental services. Effective urban forest management for these services and values requires at the very least an understanding of the structure, composition and state of urban forests. The Urban Forest Effects (UFORE) model uses urban forest inventories or sampling data to quantify urban forest structure. The forest structure data is then used to estimate pollution removal, carbon sequestration, pollen allergy ratings, and the effects of shading on building energy use within the urban forest. This paper outlines the UFORE model and its applications for urban forest managers and then discusses a series of recommendations. These include; the incorporation of additional output values in an expansion of the UFORE model; use of new technology to increase accuracy, efficiency and decrease cost of input data collection processes; and potential application of the UFORE model in Canadian cities.
Quantum Optics Applications of Hexagonal Boron Nitride Defects
Creators: name: Çakan, Aslı
name: Cholsuk, Chanaprom
name: Gale, Angus
name: Kianinia, Mehran
name: Paçal, Serkan
name: Ateş, Serkan
name: Aharonovich, Igor
name: Toth, Milos
name: Vogl, Tobias
Publisher: name: arXiv
Year: 2024
Subjects: subject: Quantum Physics (quant-ph)
subject: Mesoscale and Nanoscale Physics (cond-mat.mes-hall)
subject: Applied Physics (physics.app-ph)
subject: Optics (physics.optics)
subject: FOS: Physical sciences

description: Hexagonal boron nitride (hBN) has emerged as a compelling platform for both classical and quantum technologies. In particular, the past decade has witnessed a surge of novel ideas and developments, which may be overwhelming for newcomers to the field. This review provides an overview of the fundamental concepts and key applications of hBN, including quantum sensing, quantum key distribution, quantum computing, and quantum memory. Additionally, we highlight critical experimental and theoretical advances that have expanded the capabilities of hBN, in a cohesive and accessible manner. The objective is to equip readers with a comprehensive understanding of the diverse applications of hBN, and provide insights into ongoing research efforts.
description: 23 pages, 8 figures, 1 table
Towards Federated Digital Twin Platforms
Creators: name: Frasheri, Mirgita
name: Talasila, Prasad
name: Scherma, Vanessa
Publisher: name: arXiv
Year: 2025
Subjects: subject: Software Engineering (cs.SE)
subject: FOS: Computer and information sciences

description: Digital Twin (DT) technology has become rather popular in recent years, promising to optimize production processes, manage the operation of cyber-physical systems, with an impact spanning across multiple application domains (e.g., manufacturing, robotics, space etc.). DTs can include different kinds of assets, e.g., models, data, which could potentially be reused across DT projects by multiple users, directly affecting development costs, as well as enabling collaboration and further development of these assets. To provide user support for these purposes, dedicated DT frameworks and platforms are required, that take into account user needs, providing the infrastructure and building blocks for DT development and management. In this demo paper, we show how the DT as a Service (DTaaS) platform has been extended to enable a federated approach to DT development and management, that allows multiple users across multiple instances of DTaaS to discover, reuse, reconfigure, and modify existing DT assets.
description: In Proceedings ASQAP 2025, arXiv:2505.02873
title: Thermal efficiency gains enabled by using supercritical CO2 mixtures in Concentrated Solar Power applications
Creators: name: Crespi, Francesco
name: Rodríguez-de Arriba, Pablo
name: Sánchez, David
name: Ayub, Abubakr
name: Di Marcoberardino, Gioele
name: Invernizzi, Costante
name: Martínez, Gonzalo
name: Iora, Paolo
name: Di Bona, Daniele
name: Binotti, Marco
name: Manzolini, Giampaolo
Publisher: name: DuEPublico: Duisburg-Essen Publications online, University of Duisburg-Essen, Germany
Year: 2021
Subjects: subject: 620

description: Supercritical Carbon Dioxide (sCO2) power cycles have been proposed for Concentrated Solar Power (CSP) applications as a means to increase the performance and reduce the cost of state-of-the-art CSP systems. Nevertheless, the sensitivity of sCO2 systems to the usually hot ambient temperatures found in solar sites compromises the actual thermodynamic and economic gains that were originally anticipated by researchers of this innovative power cycle. In order to exploit the actual potential of sCO2 cycles, the utilization of dopants to shift the (pseudo)critical temperature of the working fluid to higher values is proposed here as a solution towards enabling exactly the same features of supercritical CO2 cycles even when ambient temperatures compromise the feasibility of the latter technology. To this end, this work explores the impact of adopting a CO2-based working mixture on the performance of a CSP power block, considering hexafluorobenzene (C6F6) and titanium tetrachloride (TiCl4) as possible dopants. Different cycle options and operating conditions are studied (250-300 bar and 550-700ºC) as well as molar fractions ranging between 10 and 25%. The results in this work confirm that CO2 blends with 15-25%(v) of the cited dopants enable efficiencies that are well in excess of 50% for minimum cycle temperatures as high as 50 or even 55ºC. It is also confirmed that, for these cycles, turbine inlet temperature and pressure hardly have any effect on the characteristics of the cycle that yields the best performance possible. In this regard, the last part of this work also shows that cycle layout should be an additional degree of freedom in the optimisation process inasmuch as the best performing layout changes depending on boundary conditions.
description: Conference Proceedings of the European sCO2 Conference4th European sCO2 Conference for Energy Systems: March 23-24, 2021, Online Conference, p. 291
Fast Feedforward 3D Gaussian Splatting Compression
Creators: name: Chen, Yihang
name: Wu, Qianyi
name: Li, Mengyao
name: Lin, Weiyao
name: Harandi, Mehrtash
name: Cai, Jianfei
Publisher: name: arXiv
Year: 2024
Subjects: subject: Computer Vision and Pattern Recognition (cs.CV)
subject: FOS: Computer and information sciences

description: With 3D Gaussian Splatting (3DGS) advancing real-time and high-fidelity rendering for novel view synthesis, storage requirements pose challenges for their widespread adoption. Although various compression techniques have been proposed, previous art suffers from a common limitation: for any existing 3DGS, per-scene optimization is needed to achieve compression, making the compression sluggish and slow. To address this issue, we introduce Fast Compression of 3D Gaussian Splatting (FCGS), an optimization-free model that can compress 3DGS representations rapidly in a single feed-forward pass, which significantly reduces compression time from minutes to seconds. To enhance compression efficiency, we propose a multi-path entropy module that assigns Gaussian attributes to different entropy constraint paths for balance between size and fidelity. We also carefully design both inter- and intra-Gaussian context models to remove redundancies among the unstructured Gaussian blobs. Overall, FCGS achieves a compression ratio of over 20X while maintaining fidelity, surpassing most per-scene SOTA optimization-based methods. Our code is available at: https://github.com/YihangChen-ee/FCGS.
description: Project Page: https://yihangchen-ee.github.io/project_fcgs/ Code: https://github.com/yihangchen-ee/fcgs/
title: Characterizing and modelling turbulence in supercritical fluids
Creators: name: Pecnik, Rene
name: Ren, Jie
name: Otero-Rodriguez, Gustavo
Publisher: name: DuEPublico: Duisburg-Essen Publications online, University of Duisburg-Essen, Germany
Year: 2021
Subjects: subject: 620

description: From concentrated solar power plants to rocket engines, energy conversion systems are continually reengineered to perform ever better. Often this involves fluids being pushed into the supercritical region, where highly non-ideal thermodynamic effects are at play. Yet, our fundamental understanding of flow physics at such conditions lags behind to successfully realize these exciting engineering applications. Especially, the sharp variations in all thermophysical properties close to the critical point and the high optical density at supercritical pressures lead to significantly richer flow physics and even more intricate phenomena in turbulence. In this talk we will present our recent fundamental on turbulence in supercritical fluids, which are relevant in all component of a supercritical power cycle. We will elucidate how and when flows with supercritical fluids transition to turbulence and how compressible effects can be characterized and modelled for turbulent heat transfer.
description: Conference Proceedings of the European sCO2 Conference4th European sCO2 Conference for Energy Systems: March 23-24, 2021, Online Conference, p. 301
MAKROSKOPIK ELEKTRODINAMIKANING ASOSIY TENGLAMALARINI FIZIKADA ASOSIY O'RNI
Creators: name: Quzratov, Shamsullo
name: Murodova, Zarnigor
name: Omonkeldiyeva, Dildora
Publisher: name: Zenodo
Year: 2024

description: Ushbu annotatsiyada muallif makroskopik elektrodinamikaning asosiy tenglamalarini yoritib berdi.
title: Analysis of sCO2 Cycles for District Heating Applications
Creators: name: Penkuhn, Mathias
name: Tsatsaronis, George
Publisher: name: DuEPublico: Duisburg-Essen Publications online, University of Duisburg-Essen, Germany
Year: 2021
Subjects: subject: sCO2
subject: Brayton Cycle
subject: Analysis
subject: District Heating
subject: 620

description: Supercritical CO2 (sCO2) power cycles provide the possibility to significantly improve power generation from fossil fuels and renewable sources considering thermodynamic efficiency, economic feasibility, and operational flexibility. In addition to standalone power generation, the application of sCO2 cycles to cogeneration for combined heat and power processes can be a highly attractive option with respect to further development, and commercialization. In particular, the incorporation of a heat extraction option for district heating can be favorable regarding the overall cycle efficiency for temperate and cold climate regions because of the thermodynamic properties of sCO2. The current study thus focuses on the modeling, simulation, and thermodynamic analysis of different, simple sCO2 cycle designs for waste heat applications incorporating heat extraction for district heating. Different technological options, like backpressure turbines, split-flow recooling, as well as turbine extraction designs, and their effects on cycle design, operation, and efficiency are analyzed. The results show that sCO2 based cycles enable engineers to achieve high-efficiency power generation also in combination with heat extraction for district heating, comparable to conventional water-steam-based cycles. Furthermore, the split-flow recooling design provides the possibility to extract a significant amount of heat without affecting the power generation.
description: Conference Proceedings of the European sCO2 Conference4th European sCO2 Conference for Energy Systems: March 23-24, 2021, Online Conference, p. 307
Evaluation of the Effect of Chlorhexidine Mouthwash on Blood Pressure: A Narrative Literature Review
Creators: name: Yonezaki, Mayara
name: Almeida, Pollyanna
name: De Oliveira, Eduarda
name: Ramos, Giovanna
name: Bezerra, Giovanna
name: Da Silva, Marcos Vinícius
name: Moutinho, Raphael
name: Moreira, Cláudia Lúcia
name: Cruz, Adriana
Publisher: name: Scientific Letters
Year: 2025

description: This article presents a narrative review investigating the use of chlorhexidine mouthwash and its impact on blood pressure and cardiovascular health. Chlorhexidine, a widely used antimicrobial in Dentistry, has been associated with risks, such as increased blood pressure. The bibliographic research included articles published between 2014 and 2024, using the PubMed, SciELO, and the Virtual Library of the Ministry of Health databases, with keywords including “chlorhexidine”, “mouthrinse”, “mouthwash”, “nitrate” and “blood pressure”. The results indicate that chlorhexidine may disrupt nitric oxide homeostasis, essential for blood pressure regulation, by inhibiting oral microbiota bacteria that reduce nitrate to nitrite. Although effective in reducing pathogenic microorganisms, chlorhexidine should be prescribed with caution, considering its potential hypertensive effects. The study concludes that further research is needed regarding the contexts of chlorhexidine use and prescription, as well as the development of oral hygiene protocols that balance the elimination of pathogenic microorganisms with the preservation of beneficial microbiota.
description: Scientific Letters, Vol. 1 No. 1 (2025)
title: 10MW-Class sCO2 Compressor Test Facility at University of Notre Dame
Creators: name: Kang, Jeongseek
name: Vorobiev, Alex
name: Cameron, Joshua
name: Morris, Scott
name: Wackerly, Ryan
name: Sedlacko, Kyle
name: Miller, Jason
name: Held, Timothy
Publisher: name: DuEPublico: Duisburg-Essen Publications online, University of Duisburg-Essen, Germany
Year: 2021
Subjects: subject: 620

description: The compressor is a key component in closed loop Brayton Cycles and advanced electrothermal energy storage systems The use of sCO2 as the primary working fluid had many advantages for these systems. However, due to the unique operating conditions and fluid properties, there remains significant challenges for the development of high efficiency compression systems with sCO2. Detailed experimental measurements from sCO2 compressors are extremely difficult to obtain, given the small size and very high power requirements. This has limited the majority of current experimental results to very small scale, single stage, centrifugal compressors. Larger, multi stage axial compressors are of significant interest for sCO2 systems, but have not been subject to experimental investigations. The present communication describes the design and salient characteristics of a new, 10MW class closed loop sCO2 or CO2 compressor test facility. The 10MW drive system allows for a physical scale that allows testing of both axial and centrifugal compressor types with flow passages large enough to enable detailed experimental meas urements. including survey s through the flow passage, steady and unsteady performance measurements, and aeromechanical measurements on vanes or blades.
description: Conference Proceedings of the European sCO2 Conference4th European sCO2 Conference for Energy Systems: March 23-24, 2021, Online Conference, p. 316