cometadata/datacite-rtg-text-other-reclassification-records huggingface dataset:
title: Experimental investigations on the heat transfer characteristics of supercritical CO2 in heated horizontal pipes
Creators: name: Theologou, Konstantinos
name: Mertz, Rainer
name: Laurien, Eckart
name: Starflinger, Jörg
Publisher: name: DuEPublico: Duisburg-Essen Publications online, University of Duisburg-Essen, Germany
Year: 2021
Subjects: subject: 620

description: In the frame of the sCO2-QA (qualification of analysis tools for the evaluation of a residual heat-driven, self-sufficient system for decay heat removal) project, a residual heat-driven self-sufficient sCO2-operated decay heat removal system based on a Brayton cycle is simulated with the German thermal-hydraulics system code ATHLET (analysis of thermal-hydraulics of leaks and transients). The heat removal system consists of a compact heat exchanger in the containment, a turbo-compressor system located in the reactor building and a gas cooler in the outdoor area. The validation of ATHLET and other numerical codes as well as understanding the heat transfer characteristics of sCO2 near the critical point requires experimental data. At IKE (Institute of Nuclear Technology and Energy Systems), the SCARLETT (supercritical carbon dioxide loop at IKE Stuttgart) test facility is available for various experiments with sCO2. This publication includes an experimental investigation of the thermal stratification in heated horizontal sCO2 pipe flows. For this investigation, eight test series with overall 48 experiments were carried out in two pipes with inner diameters of 4 mm and 8 mm. The experiments were carried out at a pressure of approximately 7.75 MPa. The target values of mass flux were set at 400 kg/m2s and 800 kg/m2s and those of heat flux at 50, 90 and 130 kW/m2, resulting in a heat to mass flux ratio of 62.5-225 J/kg. The inlet Reynolds numbers are between 16000 and 120000. The measured parameters are the flow rate, the pressure, the inlet and outlet fluid temperature as well as the outer surface temperature along the test pipe in three different radial angles. The results show the influence of the pipe diameter, Reynolds number, mass and heat flux on the temperature stratification. Also, inflow lengths were determined for a fully developed temperature stratification. This data set can be used for the validation of computer codes.
description: Conference Proceedings of the European sCO2 Conference4th European sCO2 Conference for Energy Systems: March 23-24, 2021, Online Conference, p. 38
title: Modeling and study of a printed circuit heat exchanger for Brayton power cycles using supercritical CO2 mixtures as working fluid
Creators: name: Valencia-Chapi, Robert
name: Fierros-Peraza, Olmo
name: Coco-Enríquez, Luis
name: Muñoz-Antón, Javier
Publisher: name: DuEPublico: Duisburg-Essen Publications online, University of Duisburg-Essen, Germany
Year: 2021
Subjects: subject: 620

description: Brayton power cycle using supercritical carbon dioxide (s-CO2) as a working fluid is a high-efficiency trend technology that has been under study for improvement. As most of the heat transfer in these cycles occurs in the regenerator, printed circuit heat exchangers (PCHE) have proved to be a useful device solution for this application because of their high surface-area-to-volume ratio. Moreover, recent studies have corroborated the improvement in the efficiency of a supercritical Brayton cycle by mixing components that raise the critical point of s-CO2. This study focuses on the CFD modeling and analysis of a PCHE for fully turbulent conditions. The device's performance with straight channels regarding essential parameters such as heat recuperator conductance (UA), temperature, pressure drop, or turbulence is studied, as well as different configurations. A comparison between pure supercritical carbon dioxide and s-CO2 mixtures (s-CO2 /COS, s-CO2 /H2S, s-CO2 /NH3, and s-CO2 /SO2) is carried out.
description: Conference Proceedings of the European sCO2 Conference4th European sCO2 Conference for Energy Systems: March 23-24, 2021, Online Conference, p. 48
title: Advanced thermodynamic power cycles utilizing carbon dioxide based mixtures as working fluids for high temperature waste heat recovery
Creators: name: Ayub, Abubakr
name: Di Marcoberardino, Gioele
name: Invernizzi, Costante
name: Iora, Paolo
Publisher: name: DuEPublico: Duisburg-Essen Publications online, University of Duisburg-Essen, Germany
Year: 2021
Subjects: subject: 620

description: This paper proposed CO2 mixtures as working fluids in closed Brayton power cycles using flue gases at relatively high temperature (400-450 °C) as waste heat source. Firstly, a comprehensive selection criterion is defined for choice of working fluids to be employed as additives in CO2 mixtures. Secondly, the thermodynamic properties of the mixtures are calculated at different molar compositions using an appropriate equation of state. The binary interaction parameters involved in the equation of state are obtained with the help of available experimental VLE data or by estimation method in case of non-availability of the VLE data. As a benchmark, the study also investigates the thermodynamic performance of advanced sCO2 cycle layouts to compare with the performance of cycles operating with CO2 mixtures. Sensitivity analysis reveals that the power cycles operating with CO2-Novec5110 mixture (with 0.2 mole fraction of Novec fluids) show 3 percentage points rise in cycle thermodynamic efficiency (0.219 versus 0.252) with lower cycle operating pressures as compared to recuperative with mass split sCO2 cycle. In case of CO2-R134a mixture working fluid (with 0.3 mole fraction of R134a), total efficiency of about 0.15 is obtained at cycle maximum pressure of 200 bars compared to simple recuperative sCO2 cycle with total efficiency of 0.13 at rather higher maximum pressure of 400 bars.
description: Conference Proceedings of the European sCO2 Conference4th European sCO2 Conference for Energy Systems: March 23-24, 2021, Online Conference, p. 58
title: Mean-line analysis for supercritical CO2 centrifugal compressors by using enthalpy loss coefficients
Creators: name: Ren, Haikun
name: Hacks, Alexander
name: Schuster, Sebastian
name: Brillert, Dieter
Publisher: name: DuEPublico: Duisburg-Essen Publications online, University of Duisburg-Essen, Germany
Year: 2021
Subjects: subject: 620

description: In order to develop the technology of carbon dioxide at so-called supercritical state (sCO2) further, quick and reliable design tools for the different system components, e.g. centrifugal compressors, are required. In this study, a computer program is developed to predict the performance of centrifugal compressors with sCO2 as working fluid. This computer program is based on mean-line analysis, calculates the fluid parameters at selected sections of the meridional plane and plots the performance maps. So-called enthalpy loss coefficients are utilized to describe the difference between the isentropic and the polytropic process. In addition to previous studies, the presented model intends to predict the performance of sCO2 centrifugal compressor with a shrouded impeller and a vaneless diffuser. For this purpose, corresponding loss coefficients are incorporated. Subsequently, the predicted results of this work are compared and validated with computational fluid dynamics (CFD) and experimental results from the EU-project sCO2-HeRo. The prediction of the computer program fits within 5% deviation to the CFD results, and about 4% to the experimental results regarding to pressure ratio.
description: Conference Proceedings of the European sCO2 Conference4th European sCO2 Conference for Energy Systems: March 23-24, 2021, Online Conference, p. 68
Ensembl and Ensembl Genomes: genomic resources at EMBL-EBI workshop
Creators: name: Carvalho-Silva, Denise
Publisher: name: F1000Research
Year: 2016

description: The European Bioinformatics Institute exists to deliver freely available data and to provide bioinformatics services to all facets of the scientific community in ways that promote scientific progress and to offer advanced bioinformatics training to scientists at all levels, from PhD students to independent investigators. The EBI provides a pipeline of tools and services to support the assembly and annotation of new genomes, in addition to facilitating the deposition of new knowledge into the public domain at the time of publication. The Ensembl project (http://www.ensembl.org) seeks to enable genomic science by providing high quality, integrated annotation on chordate and selected eukaryotic genomes. All supported species include comprehensive, evidence-based gene annotations and a selected set of genomes includes additional data focused on variation, comparative, evolutionary, functional and regulatory annotation. Ensembl Genomes (http://www.ensemblgenomes.org) extend genomic resources across the taxonomic space and consists of five sub-portals (for bacteria, protists, fungi, plants and invertebrate metazoa) designed to complement the genomes available in Ensembl. Once the initial sequencing, assembly and gene prediction work has been completed, it is then necessary to move on to the next phase of genome annotation. Through talks and demonstrations, this workshop will introduce the users to the resources available at the EBI to enable genome annotation and access to data generated from ‘Omics experiments. Finally, we will describe Train Online (www.ebi.ac.uk/training/online/), a free, web-based learning resource for life scientists.
Browsing genes, variation and regulation data with Ensembl
Creators: name: Carvalho-Silva, Denise
Publisher: name: F1000Research
Year: 2016

description: Workshop presentation at University College Dublin on the 2nd June 2016. The workshop had a combination of talks, live tutorials and hands-on activities. The foucs was on the annotation of genes, genetic variants and regulatory elements and how to visualise them using the Ensembl browser. I also covered many of the Ensembl tools, such as BioMart, the VEP, BLAST/BLAT, and assembly converter. Finally I covered custom data upload of NGS and other data files.
Evaluation of emotional expressions viewers
Creators: name: Golubov, Andrey
Publisher: name: F1000Research
Year: 2016

description: With the evolution of television and Internet began to appear more and more audiovisual information is available to the end user. In the modern world of information overload, people do not have time to perform the whole flow,  to highlight relevant and interesting content for yourself. Thus, systematic semantic metadata provide valuable information to the user. They can allow him to choose a program according to the nature of the emotional impact on the person that will interest people from his group. The aim of this work is to study the emotional expression of the user when viewing audiovisual programs, and development of a method for the automatic creation of such responses for the enrichment of semantic metadata.
Perceiving the stereo depth of simple figures isn’t simple: the case of gratings
Creators: name: Farell, Bart
name: Cherlyn Ng
Publisher: name: F1000Research
Year: 2016

description: When one grating serves as the reference stimulus for another, the perceived stereo depth between the two gratings can't generally be predicted from the disparities of the stimuli. Orientation, both relative and absolute, also matters, and variation between observers is strikingly large, even when the disparities of both stimuli are zero. This depth ambiguity was predicted and here we measure it, showing the very large change in depth and depth order that accompanies changes in relative orientation.
k-BOOM: A Bayesian approach to ontology structure inference, with applications in disease ontology construction
Creators: name: Mungall, Chris
Publisher: name: F1000Research
Year: 2016

description: One strategy for building ontologies covering domains such as disease or anatomy is to weave together existing knowledge sources (databases, vocabularies and ontologies) into single cohesive whole. A first step in this process is to generate mappings between the elements of these different sources. There are a number of well-known techniques for generating mappings (also known as ontology alignment), both manual and automatic. Sometimes mappings are seen as an end in themselves, with the sources remaining in a loosely connected state. However, if we want to take the next step and use the mappings to integrate the different sources into a cohesive reference ontology, then we need to translate the mappings into precise logical relationships. This will allow us to safely merge equivalent concepts, creating a unified ontology. This translation is a non-trivial step, as each mapping can be interpreted as multiple different logical relationships, with each interpretation affecting the likelihood of the others. There is a lack of automated methods to assist with this last step; this resolution is typically performed by expert ontologists.

Here we describe an ontology construction technique that takes two or more ontologies linked by hypothetical axioms, and estimates the most likely unified logical ontology. Hypothetical axioms can themselves be derived from semantically loose mappings. The method combines deductive reasoning and probabilistic inference and is called Bayesian OWL Ontology Merging (BOOM). We describe a special form k-BOOM that works by factorizing the probabilistic ontology into $k$ submodules.

We also briefly describe a supplemental lexical and knowledge-based technique for generating a set of hypothetical axioms from loose mappings.

We are currently using this technique to build a merged disease ontology (Monarch Disease Ontology; MonDO) that unifies a broad range of vocabularies into a consistent and coherent whole.
Investigating Media Selection through ChatGPT: An Exploratory Study on Generative Artificial Intelligence in the Aid of Instructional Design
Creators: name: DaCosta, Boaventura
name: Kinsell, Carolyn
Publisher: name: figshare
Year: 2024
Subjects: classificationCode: 460299
subject: Artificial intelligence not elsewhere classified

description: In instructional design (ID), the selection of appropriate media (in the facilitation of learning) is crucial yet complex. This study proposes that artificial intelligence (AI), particularly ChatGPT, an advanced large language model, holds the potential to streamline the media selection process. Aimed at assisting instructional designers and educators, this investigation explores the efficacy of ChatGPT in recommending suitable instructional delivery systems. A media selection tool built with ChatGPT was used to review a series of instructional tasks, mirroring the work of the authors who did the same using traditional methods. The results from both approaches were then compared and studied, revealing similarities and differences in their media decisions, showing that the AI and authors went “off script” from their training and guidance, respectively. The findings demonstrate ChatGPT’s capacity to expedite analyses and offer varied insights, thereby enriching the instructional process while also raising concerns regarding the need to evaluate its outputs, inputs (i.e., prompts), and potential biases in training data carefully. Overall, this research concludes that generative AI presents novel approaches and opportunities within ID, offering significant benefits. It underscores the transformative impact of AI tools like ChatGPT and advocates for continued exploration into their integration and influence within the field of ID.
title: Numerical investigation of a simple regenerative heat to power system with coupled or independent turbomachinery drives
Creators: name: Marchionni, Matteo
name: Bianchi, Giuseppe
name: Usman, Muhammad
name: Pesyridis, Apostolos
name: Tassou, Savvas
Publisher: name: DuEPublico: Duisburg-Essen Publications online, University of Duisburg-Essen, Germany
Year: 2021
Subjects: subject: 620

description: Supercritical CO2 (sCO2) power systems have the potential to revolutionise power generation. Among the possible layouts, the simple regenerative cycle is the most essential, yet potentially the most competitive for an industrial uptake of the sCO2 technology at small-scales (<0.5MWe) in high-grade waste heat to power applications (>400°C). To compensate for the efficiency downsides due to the basic architecture, this study investigates how turbomachinery could improve the design and part-load performance of sCO2 power systems. With reference to the 50kWe High Temperature Heat To power Conversion facility (HT2C) available at Brunel University London, this research numerically assesses pros and cons of a radial turbine and a compressor being simultaneously or independently driven. Two turbine designs with nominal total-static efficiency of 75% were developed using a mean-line methodology which further allowed to retrieve the operational and efficiency maps. These maps were later implemented in a one-dimensional simulation platform of the HT2C facility calibrated against equipment data. The differential performance of the coupled and independent turbomachinery drive solutions was assessed with reference to a broad range of industrial heat input conditions in terms of mass flow rate and temperature of the flue gas. The results show marginal benefits at design conditions due to the same turbine design specifics. The independent drive solution leads to worse performance for part load conditions below the nominal one. On the other hand, the dual optimisation of compressor and turbine speeds allows substantial benefits above the design point, particularly for deviations of the flue gas temperature. At 110% of the nominal heat source temperature, the independent drive solution increases the net thermal power output by 27%, namely from 75kW to 95kW. This is primarily due to a higher mass flow rate in the sCO2 loop as well as a slightly higher pressure ratio.
description: Conference Proceedings of the European sCO2 Conference4th European sCO2 Conference for Energy Systems: March 23-24, 2021, Online Conference, p. 78
title: Thermal design of latent heat thermal energy storage facility with supercritical CO2
Creators: name: Melichar, Tomáš
name: Dočkal, Karel
name: Frýbort, Otakar
name: Hájek, Petr
name: Filip, Radomír
Publisher: name: DuEPublico: Duisburg-Essen Publications online, University of Duisburg-Essen, Germany
Year: 2021
Subjects: subject: 620

description: Conversion of electric power to heat and from the stored heat back to power is the energy storage concept that allows high temperature and high-capacity accumulation (hundreds of MWh stored in the heat). Combination of the high temperature heat storage with use of the sCO2 energy conversion cycle may provide highly efficient and very flexible energy storage system. An aluminum alloy was identified as a suitable accumulation material for the latent heat storage due to its high latent heat, appropriate melting point (577°C) and acceptable price. The energy storage system with Al-Si12 alloy as the heat storage material and the sCO2 conversion cycle is being developed at CVR. In this paper, design of a mock-up of the storage tank with the aluminum alloy, an electrical heating system and a sCO2 heat exchanger will be presented. The storage tank with capacity of 300 kWht will be fabricated, connected to the sCO2 experimental loop of CVR and operated at the relevant conditions to demonstrate capabilities of the energy storage concept. A thermal computational model that was developed to support design and optimization of the sCO2/metal heat exchanger will be also presented. Based on the computational model results, feasibility of this concept for the high capacity energy storage will be discussed.
description: Conference Proceedings of the European sCO2 Conference4th European sCO2 Conference for Energy Systems: March 23-24, 2021, Online Conference, p. 88
With Friends Like These, Who Needs Explanations? Evaluating User Understanding of Group Recommendations
Creators: name: Waterschoot, Cedric
name: Toledo, Raciel Yera
name: Tintarev, Nava
name: Barile, Francesco
Publisher: name: arXiv
Year: 2025
Subjects: subject: Human-Computer Interaction (cs.HC)
subject: FOS: Computer and information sciences

description: Group Recommender Systems (GRS) employing social choice-based aggregation strategies have previously been explored in terms of perceived consensus, fairness, and satisfaction. At the same time, the impact of textual explanations has been examined, but the results suggest a low effectiveness of these explanations. However, user understanding remains fairly unexplored, even if it can contribute positively to transparent GRS. This is particularly interesting to study in more complex or potentially unfair scenarios when user preferences diverge, such as in a minority scenario (where group members have similar preferences, except for a single member in a minority position). In this paper, we analyzed the impact of different types of explanations on user understanding of group recommendations. We present a randomized controlled trial (n = 271) using two between-subject factors: (i) the aggregation strategy (additive, least misery, and approval voting), and (ii) the modality of explanation (no explanation, textual explanation, or multimodal explanation). We measured both subjective (self-perceived by the user) and objective understanding (performance on model simulation, counterfactuals and error detection). In line with recent findings on explanations for machine learning models, our results indicate that more detailed explanations, whether textual or multimodal, did not increase subjective or objective understanding. However, we did find a significant effect of aggregation strategies on both subjective and objective understanding. These results imply that when constructing GRS, practitioners need to consider that the choice of aggregation strategy can influence the understanding of users. Post-hoc analysis also suggests that there is value in analyzing performance on different tasks, rather than through a single aggregated metric of understanding.
description: This article will be part of the UMAP 2025 conference. (33rd ACM Conference on User Modeling, Adaptation and Personalization (UMAP25), June 16-19, 2025, New York City, NY, USA)
title: Microstructural evaluation of preselected steels for turbine after supercritical CO2 exposure
Creators: name: Rozumová, Lucia
name: Melichar, Tomáš
name: Velebil, Ladislav
Publisher: name: DuEPublico: Duisburg-Essen Publications online, University of Duisburg-Essen, Germany
Year: 2021
Subjects: subject: 620

description: The energy conversion cycles with supercritical carbon dioxide (sCO2) are being considered as an innovative technology with potential for replacement of conventional steam cycles within various applications such as nuclear, fossil or renewable energy resources. Due to extreme operational conditions including temperatures above 550°C and pressures up to 25 MPa, proper selection of materials is essential for a suitable design of the thermal circuit. Several materials that were identified as potentially suitable for the main components of the sCO2 circuits were exposed in the sCO2 relevant conditions in the sCO2 experimental loop at Research Centre Rez (CVR). The experimental conditions were represented by the sCO2 temperature of 550°C, pressure of 25 MPa, flow conditions and 1000 hours of exposure. Moreover, an additional test section where the sCO2 flow velocity up to 100 m/s was achieved was designed and utilized to simulate turbine relevant conditions. Suitability of the materials preselected for the sCO2 turbomachinery will be evaluated and discussed in this paper. For the experiments, four types of materials (FB2, 17-4-PH, 625M, IN718) were selected. After the exposure, the corrosion behaviour and oxidation of the materials was investigated including surface analyses and cross sections examination. The paper presents the experimental parameters including the high velocity test section design. The materials degradation will be evaluated as well as the effect of the high velocity flow.
description: Conference Proceedings of the European sCO2 Conference4th European sCO2 Conference for Energy Systems: March 23-24, 2021, Online Conference, p. 98
The importance and influence of policy and partnerships in community forestry in developing countries
Creators: name: Shepherd, Allison
Publisher: name: The University of British Columbia
Year: 2012

description: Community management of forest and forest resources in developing countries has been a rising trend since the 1970s. This shift arose due to instability in communities, on social and economic scales, as well as high deforestation rates. Governments have the option to devolve rights and title to communities to empower them to access and manage the forest resources, giving communities a chance at better livelihoods. Partnerships with external actors also provide influential assistance to communities through building communities capacity and providing funding and infrastructure. Using case studies from North and Central America, South Asia and Africa, this essay examines the potential of policy and partnerships within the realm of community forestry. Impacts of policy and partnership are assessed, followed by a discussion on current successes and setbacks. The author makes suggestion for emerging community forests in developing countries and a look at the future of community forestry.
title: Design considerations of sCO2 turbines developed within the CARBOSOLA project
Creators: name: Glos, Stefan
name: Lippe, Patrik
name: Schlehuber, Dominic
name: Kobler, Simon
name: Wechsung, Michael
Publisher: name: DuEPublico: Duisburg-Essen Publications online, University of Duisburg-Essen, Germany
Year: 2021
Subjects: subject: 620

description: Due to the great potential in terms of compactness and efficiency, supercritical CO 2 (sCO 2 ) power systems are being investigated in the field of scientific and industrial energy technology. The German research project CARBOSOLA has been initiated in order to drive the sCO 2 technology development in Europe by providing a test loop for research programs and basic component tests followed by an initial system and component design for a future demo plant. In a first project phase, the economic potential of the sCO 2 technology is evaluated and optimized for different use cases based on initial component designs and corresponding cost assumptions. For the CO 2 turbine different design aspects have been investigated and assessed leading to first design concept.
description: Conference Proceedings of the European sCO2 Conference4th European sCO2 Conference for Energy Systems: March 23-24, 2021, Online Conference, p. 106
Revolutionizing Newcomers' Onboarding Process in OSS Communities: The Future AI Mentor
Creators: name: Tan, Xin
name: Long, Xiao
name: Zhu, Yinghao
name: Shi, Lin
name: Lian, Xiaoli
name: Zhang, Li
Publisher: name: arXiv
Year: 2025
Subjects: subject: Software Engineering (cs.SE)
subject: FOS: Computer and information sciences

description: Onboarding newcomers is vital for the sustainability of open-source software (OSS) projects. To lower barriers and increase engagement, OSS projects have dedicated experts who provide guidance for newcomers. However, timely responses are often hindered by experts' busy schedules. The recent rapid advancements of AI in software engineering have brought opportunities to leverage AI as a substitute for expert mentoring. However, the potential role of AI as a comprehensive mentor throughout the entire onboarding process remains unexplored. To identify design strategies of this ``AI mentor'', we applied Design Fiction as a participatory method with 19 OSS newcomers. We investigated their current onboarding experience and elicited 32 design strategies for future AI mentor. Participants envisioned AI mentor being integrated into OSS platforms like GitHub, where it could offer assistance to newcomers, such as ``recommending projects based on personalized requirements'' and ``assessing and categorizing project issues by difficulty''. We also collected participants' perceptions of a prototype, named ``OSSerCopilot'', that implemented the envisioned strategies. They found the interface useful and user-friendly, showing a willingness to use it in the future, which suggests the design strategies are effective. Finally, in order to identify the gaps between our design strategies and current research, we conducted a comprehensive literature review, evaluating the extent of existing research support for this concept. We find that research is relatively scarce in certain areas where newcomers highly anticipate AI mentor assistance, such as ``discovering an interested project''. Our study has the potential to revolutionize the current newcomer-expert mentorship and provides valuable insights for researchers and tool designers aiming to develop and enhance AI mentor systems.
title: Techno-economic optimization method and its application to a sCO2 gas turbine bottoming cycle
Creators: name: Gotelip, Thiago
name: Gampe, Uwe
name: Glos, Stefan
Publisher: name: DuEPublico: Duisburg-Essen Publications online, University of Duisburg-Essen, Germany
Year: 2021
Subjects: subject: 620

description: Cycle architecture, fluid parameter selection, and component design of an exhaust/waste heat recovery cycle require an integral approach. The exhaust/waste heat shall be utilized to a maximum but at minimum costs. The bottoming cycle needs to be aligned with the topping cycle regarding operational behavior, especially for a part load. To analyze potentials of exhaust heat recovery in a combined gas turbine sCO2 cycle, the bottoming cycle's optimum cycle architecture and fluid parameters must be determined. A thermo-physical model of the sCO2 bottoming cycle, including knowledge of component design, component behavior, and costs, is based on the multiobjective optimization procedure. As part of the CARBOSOLA project, techno-economic optimizations for a use case of exhaust heat recovery have been carried out. The paper aims to present the optimization methodology followed by the specific use case's boundary conditions, investigated sCO2 cycle architectures, and results of optimum cycle architecture and fluid parameters for maximum heat recovery and minimum costs. Attention will also be paid to accurate modeling of heat exchangers operating near the critical point.
description: Conference Proceedings of the European sCO2 Conference4th European sCO2 Conference for Energy Systems: March 23-24, 2021, Online Conference, p. 113
title: An attempt for establishing pressure ratio performance maps for supercritical carbon dioxide compressors in power applications
Creators: name: Abd El Hussein, Ihab
name: Schuster, Sebastian
name: Brillert, Dieter
Publisher: name: DuEPublico: Duisburg-Essen Publications online, University of Duisburg-Essen, Germany
Year: 2021
Subjects: subject: 620

description: Carbon dioxide in the supercritical state (sCO2) has drawn much interest lately. It is considered as a promising fluid for next-gen power plants with many researchers investigating this technology. Cycle simulation and control requires compressor performance maps valid for variable inlet conditions. In this paper, an attempt is made for establishing a pressure ratio based performance map for sCO2 compressors in power applications. For that purpose the so-called Glassman approach is considered. This model has been originally established for fluids obeying the ideal gas law. Therefore, a modification is proposed to take into consideration the real gas equation of state and to allow wide variation of the isentropic volume exponent kv. Computational fluid dynamics (CFD) is used to predict the performance of a single stage radial compressor. Results for different kv values at the compressor inlet confirms the validity of the proposed model with both the polytropic efficiency and the reduced enthalpy deviations limited to 1 percent. On the other hand, predicted pressure ratio shows difference of around 3 percent from kv=7.1 to kv= 4.1. A further decrease of kv to 2.5 extends the difference up to 8 percent.
description: Conference Proceedings of the European sCO2 Conference4th European sCO2 Conference for Energy Systems: March 23-24, 2021, Online Conference, p. 124
title: Experiences of supercritical CO2 applications in refrigeration and air conditioning systems
Creators: name: Doerffel, Christian
name: Thomas, Christiane
name: Hesse, Ullrich
Publisher: name: DuEPublico: Duisburg-Essen Publications online, University of Duisburg-Essen, Germany
Year: 2021
Subjects: subject: 620

description: Carbon dioxide (CO2) is a working fluid, which is suitable for various applications. Excellent heat transfer properties, especially in the supercritical area, make it attractive for thermal systems. As it is an environmentally friendly and non-flammable fluid, it is used in larger stationary systems e.g. in supermarket refrigeration systems as well as in small cycles, e.g. for mobile air conditioning (A/C) systems. There is no risk of pollution or major environmental damage due to leakage or accidental release of fluid. In addition to power cycles, CO2 is suitable for cooling circuits for both subcritical (liquid-gas phase change) and transcritical applications. The latter includes supercritical heat rejection and subcritical heat absorption. Therefore, CO2 refrigeration systems and their components, e.g. compressors, have special design requirements. They need to be specially adapted to the fluid properties such as pressures above 10 MPa and pressure differences up to 8 MPa. The efficiencies of refrigeration systems must be competitive to those of conventional refrigerants. This requires advanced system designs, which will be presented. Finally, possible synergies between CO2 power systems and CO2 refrigeration and heat pump systems will be discussed.
description: Conference Proceedings of the European sCO2 Conference4th European sCO2 Conference for Energy Systems: March 23-24, 2021, Online Conference, p. 131
Postoperative herniation of Nissen fundoplication
Creators: name: Moujir SÃ¡Nchez, Alejandro
Publisher: name: EURORAD
Year: 2016
Subjects: subject: Gastrointestinal tract
subject: CT
subject: Plain radiographic studies
subject: Barium meal
subject: Diagnostic procedure
subject: Hernia

description: Clinical History Image Findings Discussion Find Diagnosis Differential Diagnosis
description: female, 60 years
description: Clinical History: A 60 year old woman with no clinical history of interest underwent scheduled surgery of hiatus hernia, without complications. During the hospital admission subsequent to surgery, the patient began with vomiting, nausea and chest pain. Final Diagnosis: Supra-diaphragmatic herniation of Nissen fundoplication
title: Adiabatic compressed CO2 energy storage
Creators: name: Manzoni, Matteo
name: Patti, Alberto
name: Maccarini, Simone
name: Traverso, Alberto
Publisher: name: DuEPublico: Duisburg-Essen Publications online, University of Duisburg-Essen, Germany
Year: 2021
Subjects: subject: 620

description: As the energy market is moving worldwide towards low-emission solutions, there is a growing interest in plants capable of storing non-dispatchable renewable power, contributing to maintain the high quality level of current electrical infrastructure and ensuring spinning-reserve capability, complementing the lack of frequency control by most of solar and wind technologies. CO2 cycles, including supercritical ones, could be a solution to achieve this goal. Most of current efforts on CO2 cycles are devoted to study the most promising configurations for power production, including supercritical CO2 plants for solar energy conversion. Basing on such extensive state of the art and growing knowledge, this paper aims to analyse innovative energy storage solutions involving closed cycles, employing different working fluids in sub-critical or supercritical conditions, including CO2. Different plant configurations and operating conditions at 10 MWe design point are compared in terms of Round Trip Efficiency (RTE) and preliminary costs, benchmarked against traditional large scale storage solution such as CAES. Subcritical CO2 cycles is shown to be a very promising solution with RTE>70% and attractive cost features, thus being a potential candidate for utility scale energy storage.
description: Conference Proceedings of the European sCO2 Conference4th European sCO2 Conference for Energy Systems: March 23-24, 2021, Online Conference, p. 137
title: Evaluation of deterioration in vertical sCO2 cooling heat transfer in 3 mm tube
Creators: name: Wahl, Andreas
name: Mertz, Rainer
name: Laurien, Eckart
name: Starflinger, Jörg
Publisher: name: DuEPublico: Duisburg-Essen Publications online, University of Duisburg-Essen, Germany
Year: 2021
Subjects: subject: 620

description: In the frame of EU-project sCO2-flex the design of a 25 MWe supercritical CO2 (sCO2) Brayton cycle will be designed. The system will be optimized to meet flexibility requirements, while reducing environmental impact and focusing on cost efficiency. In the context of a sCO2 Brayton cycle, the gas cooler is a key component to achieve a high overall efficiency. Close to the critical point, due to varying properties, heat transfer and pressure drop of carbon dioxide (CO2) are difficult to predict. In case of vertical flow, acceleration and buoyancy effects induced by strong density gradients can cause a significant deterioration of the heat transfer. In this publication, the cooling heat transfer coefficient (htc) is investigated in a 3 mm diameter tube with vertical flow orientation. Commonly used calculation methods of the heat transfer coefficient are presented. Although developed for heating of sCO2, the mixed convection criterion of Jackson and Hall [7] is used to evaluate the heat transfer deterioration. The effects of the CO2 mass flux of 141 − 354 kg/m2s and bulk fluid temperatures of 20 − 50 °C with a constant pressure of 80 bar on the heat transfer were examined. The transition between forced and mixed convection can be explained by the htc -values. The upwards flow shows a steady decrease in the htc with the reduction of the mass flux. However, the downwards flow shows significant effects of buoyancy. At low mass flux the distinct peak in the htc at the pseudocritical temperature (Tpc) disappears.
description: Conference Proceedings of the European sCO2 Conference4th European sCO2 Conference for Energy Systems: March 23-24, 2021, Online Conference, p. 146
Next-Generation Sequencing – Game of Thrones edition
Creators: name: McGrath, Ken
Publisher: name: F1000Research
Year: 2016

description: The “Next-Generation Sequencing” landscape is one of constant change, with new and emerging technologies always competing with established platforms – much like the different characters and families from the “Game of Thrones” universe. Using this analogy, Ken talks about the sequencing technologies that have had their day on the throne, and looks in detail at the current rulers – and who is best positioned to usurp them. In doing so, Ken will explain how the sequencing technologies work and give examples of projects that can be run on them, as well as hint at what’s “next” in Next-Gen.
title: Preliminary aerodynamic design of a supercritical carbon dioxide compressor impeller for waste heat recovery applications
Creators: name: Thada, Shantanu
name: Pradeep, A.
name: Sridharan, Arunkumar
Publisher: name: DuEPublico: Duisburg-Essen Publications online, University of Duisburg-Essen, Germany
Year: 2021
Subjects: subject: 620

description: Supercritical Carbon dioxide (S-CO2) Brayton cycles have garnered significant attention in the recent past as an alternative source for renewable energy. The present research provides a simplistic, yet robust methodology to appropriately size and design the impeller of a centrifugal compress or for a 12.5 MWe waste heat recovery S-CO2 power plant. Two prominent variants of the S-CO2 cycle are studied and optimized with the aim of maximizing the power output using genetic algorithm. To calculate the geometry from the inlet and exit thermodynamic conditions of the optimized cycle, conservation equations are solved. The impeller is sized and a brief study on condensation in the impeller throat is performed . The effect of multi staging on condensation is investigated. Further, the performance model is coupled with the design scheme to dynamically modify the impeller geometry. Using the developed model, the geometrical parameters of the S-CO2 impeller are calculated. In addition to the geometry, certain impeller performance parameters are reported and are observed to lie within the permissible limits.
description: Conference Proceedings of the European sCO2 Conference4th European sCO2 Conference for Energy Systems: March 23-24, 2021, Online Conference, p. 154
Efficacy of radial shock waves in physiotherapeutic treatment of myofascial trigger points: Review of clinical evidence
Creators: name: Voznesenskyy, Sergiy
name: Pulla, Nancy Gualpa
Publisher: name: F1000Research
Year: 2016

description: Myofascial trigger points are one of the most common causes of acute and chronic pain in the general population. The acceptance of their treatment by means of shock wave therapy is ever-growing. The aim of this study was to assess current clinical evidence of efficacy of radial shock wave therapy in reducing pain and disability related to myofascial trigger points. A structured bibliographic search without language or geographical restrictions was performed in 5 databases (MEDLINE, EMBASE, CENTRAL, PEDro, and AMED, 1985-2014) and was complemented with grey literature search. Jadad scoring was used to assess methodological quality of the clinical trials included in the review. The overall quality of evidence was categorised using the GRADE approach. Of the 26 unique records identified, 4 clinical trial reports met the eligibility criteria. Despite 2 studies showing big treatment effect of radial shock wave therapy in comparison to other medical and physiotherapeutic interventions, small sample sizes, study design limitations and inconsistency among study results decreased the overall quality of evidence. Low quality evidence based on randomised controlled clinical trials was found as to the efficacy of radial shock wave therapy of myofascial trigger points in comparison to some conventional medical and physiotherapeutic interventions. A cost-benefit analysis of radial shock wave therapy of myofascial trigger points is necessary.
title: Binary interaction uncertainty in the optimisation of a transcritical cycle: consequences on cycle and turbine design
Creators: name: Aqel, Omar
name: White, Martin
name: Sayma, Abdulnaser
Publisher: name: DuEPublico: Duisburg-Essen Publications online, University of Duisburg-Essen, Germany
Year: 2021
Subjects: subject: 620

description: Conference Proceedings of the European sCO2 Conference4th European sCO2 Conference for Energy Systems: March 23-24, 2021, Online Conference, p. 164
title: sCO2 power cycle design without heat source limitations: Solar thermal particle technology in the CARBOSOLA project
Creators: name: Heller, Lukas
name: Glos, Stefan
name: Buck, Reiner
Publisher: name: DuEPublico: Duisburg-Essen Publications online, University of Duisburg-Essen, Germany
Year: 2021
Subjects: subject: 620

description: Supercritical CO2 power cycles have been proposed to lower the levelized cost of electricity generated by Concentrating Solar Power (CSP) plants due to their high thermal efficiency and low equipment cost. In this study, a simplified techno-economic model was developed to compare the performance of molten salt and solid particle CSP technologies with various sCO2 cycle layouts and parameters. It was found that systems employing particle technology consistently have a lower levelized cost than molten salt systems, mainly due to the latter’s high storage system cost, caused by a low temperature spread. Furthermore, less complex process layouts without reheat or intercooling and even without recompression render lower levelized cost, which is caused by increasing costs for compressors, motors and recuperators in high-performance layouts. Compared with the reference system based on a steam power block, the best sCO2 processes achieve similar LCOE values but not the often-proposed significant improvements. These findings are highly dependent on some of the cost models, mainly for the primary heat exchanger and for indirect power block costs, which will be refined in a next step.
description: Conference Proceedings of the European sCO2 Conference4th European sCO2 Conference for Energy Systems: March 23-24, 2021, Online Conference, p. 177
Understanding cell fate decisions through integrative analyses of multi-dimensional genome-wide sequencing data
Creators: name: MS Vijayabaskar
name: Goode, Debbie
name: Obier, Nadine
name: Lie-A-Ling, Michael
name: Lilly, Andrew
name: Hannah, Rebecca
name: Lichtinger, Monika
name: Batta, Kiran
name: Florowska, Magdalena
name: Patel, Rahima
name: Challinor, Mairi
name: Wallace, Kirstie
name: Gilmour, Jane
name: Assi, Salam
name: Cauchy, Pierre
name: Hoogenkamp, Maarten
name: Westhead, David
name: Lacaud, Georges
name: Kouskoff, Valerie
name: Göttgens, Berthold
name: Bonifer, Constanze
Publisher: name: F1000Research
Year: 2016

description: Cellular differentiation is a tightly controlled process that is essential for the development of a single celled embryo into a multicellular organism. This process is regulated primarily through changes in the dynamics of gene differentiation and is orchestrated by the interplay of various biological mechanisms such as chromatin accessibility, modifications and most importantly, binding of transcription factors. In this study we have generated, integrated and analysed a large multi-dimensional dataset for the in-vitro differentiation of mouse embryonic stem cells to macrophages. At the first step we successfully associate gene expression changes with important cell fate decisions that determine lineage specification. By interrogating DNaseI accessibility, active histone marks such as H3K27ac, H3K9ac and H3K4me3, repressive H3K27me3 histone mark and 16 transcription factors, in a unified manner, we show that we can map this four dimensional data to gene expression events, vis-a-vis cellular differentiation. Here, we also show how we systematically build up the complexity of the analysis and derive a simple yet highly informative core gene regulatory network for the transcriptions factors important in our developmental pathway. Follow-up experiments driven by the new hypotheses derived from our analyses shows that this dataset can be powerful in implicating new biological gene networks and pathways in definitive hematopoiesis. We have also provided these analyses as a user friendly website for the access of general scientific community.
Supplementary document for Extended angular-spectrum modeling (EASM) of light energy transport in scattering media - 6139066.pdf
Creators: name: Yan, Meng
name: Gong, Mali
name: Ma, Jianshe
Publisher: name: Optica Publishing Group
Year: 2025
Subjects: Uncategorized

description: This document provides supplementary information to “Extended angular-spectrum modeling (EASM) of light energy transport in scattering media”. It includes the detailed description of EASM, detailed data in figures and experimental setup.