ESI Group (Czechia)

Abstract NPHyCo (Nuclear Power and Hydrogen Cogeneration) is an EU research project dedicated to the production of hydrogen from nuclear power. The project is funded by the EU’s Euratom Research & Training program (2021–2025) dedicated to nuclear research and innovation. NPHyCo started in the Autumn of 2022 and will last for two and a half years. The EU hopes to fully decarbonize its economy by 2050 [1]. One of the solutions being put forward is hydrogen. Nevertheless, to date most of the hydrogen produced in Europe comes from fossil fuels [2]. So the question is how to increase the production of low-carbon hydrogen to ensure that enough is being produced — at an affordable cost — to meet the needs of hard to decarbonize sectors, such as industry? The article presents the structure of the project and the results achieved so far by the different working groups of the NPHyCo project, such as concept, technology, economics, licensing, implementation, selection of a suitable location for the hydrogen production plant (HPP) and communication. Particular attention is paid to the nuclear power plant (NPP) modification in the case of a hydrogen facility construction, its connection to the NPP resources and NPP safety assessment. The first results regarding Ukrainian NPPs were presented in [3], but since then new results have been obtained, which are presented in the next sections. Since the largest scope of information was collected for Ukrainian NPPs we use the Rivne NPP (RNPP) for the best tuning of all universal models in WP3, WP4 and WP5. Therefore, the results for this NPP in particular are presented below.

Critical flow Venturi nozzles (CFVNs) are a state-of-the-art secondary standard widely used for gas flow measurements with high precision. The flow rate correlates with the type and thickness of the boundary layer (BL) inside the nozzle throat. In the cylindrical type—one of the two standard designs of CFVNs—the nozzle throat encompasses a defined axial length in which the BL develops. This numerical study is concerned with the BL effects in a cylindrical CFVN by means of two turbulence models. Compared to experimental data, the k-ω\\documentclass[12pt]{minimal} \\usepackage{amsmath} \\usepackage{wasysym} \\usepackage{amsfonts} \\usepackage{amssymb} \\usepackage{amsbsy} \\usepackage{mathrsfs} \\usepackage{upgreek} \\setlength{\\oddsidemargin}{-69pt} \\begin{document}$$\\omega$$\\end{document} SST model predicts the discharge coefficient well for high and low Reynolds numbers, but not in the intermediate regime. The γ\\documentclass[12pt]{minimal} \\usepackage{amsmath} \\usepackage{wasysym} \\usepackage{amsfonts} \\usepackage{amssymb} \\usepackage{amsbsy} \\usepackage{mathrsfs} \\usepackage{upgreek} \\setlength{\\oddsidemargin}{-69pt} \\begin{document}$$\\gamma$$\\end{document}-Reθ\\documentclass[12pt]{minimal} \\usepackage{amsmath} \\usepackage{wasysym} \\usepackage{amsfonts} \\usepackage{amssymb} \\usepackage{amsbsy} \\usepackage{mathrsfs} \\usepackage{upgreek} \\setlength{\\oddsidemargin}{-69pt} \\begin{document}$$Re_{\ heta }$$\\end{document} model, on the contrary, agrees well with experimental data in the entire flow range. Relevant quantities and profiles of the BL are separately investigated in the laminar, turbulent, and transitional region. The calculated laminar and turbulent BL thicknesses correspond to predictions based on integral methods for solving the BL equations. Simple representations are proposed for the Zagarola-Smits scaled laminar and turbulent deficit BL profiles removing the effects of axial position, Reynolds number, and pressure gradient. Furthermore, the shape factor is investigated as a characteristic parameter for determining the transitional region.

This article deals with the comparison and review of two solvers from the open-source CFD tool, OpenFOAM®, in the field of compressible fluids: the explicit segregated density-based solver (rhoCentralFoam), and the PIMPLE algorithm solver (sonicFoam). In spite of the numerous studies showing both solvers, there are not yet been presented complete flowcharts. This work will expose the creation of two flowcharts based on bibliographic review. For the purpose of the demonstration of the application of the two solvers, the Mach number, and the mass flow rate in time in the current case analysis are numerically estimated in both cases in an ISO 9300 Venturi nozzle case analysis.

The processing of personal data is becoming a key business factor, especially for high-tech system industries such as automotive and healthcare service providers. To protect such data, the European Union (EU) has introduced the General Data Protection Regulation (GDPR), with the aim to standardize and strengthen data protection policies across EU countries. The GDPR defines stringent requirements on the collection and processing of personal data and imposes severe fines and penalties on data controllers and processors for non-compliance. Although the GDPR is enforce since 2018, many public and private organizations are still struggling to fully comply with the regulation. A main reason for this is the lack of usable methodologies that can support developers in designing of GDPR-complaint high-tech systems. This paper examines the growing literature on methodologies for the design of privacy-aware systems, and identifies the main challenges to be addressed in order to facilitate developers in the design of such systems. In particular, we investigate to what extent existing methodologies (i) cover GDPR and privacy-by-design principles, (ii) address different levels of system design concerns, and (iii) have demonstrated their suitability for the purpose. Our literature study shows that the domain landscape appears to be heterogeneous and disconnected, as existing methodologies often focus only on subsets of the GDPR principles and/or on specific angles of system design. Based on our findings, we provide recommendations on the definition of comprehensive methodologies tailored to designing GDPR-compliant high-tech systems.

This paper examines the ethical perception of tax evasion in the Republic of Macedonia. A survey consisting of 18 statements was distributed to 120 students; 107 responses were received. The results show that, in general, Macedonian students are intolerant towards tax evasion, perceiving it as an unethical behavior. However, only 45.3 % of the students did not justify tax evasion in any of the 18 cases. Furthermore, male students were more tolerant towards tax evasion than their female colleagues. Law students were more supportive of tax evasion than their colleagues from the faculty of economics.

<div class="section abstract"><div class="htmlview paragraph">In this work, an innovative piston bowl design that physically divides the combustion chamber into a central zone and a peripheral zone is employed to assist the control of the ethanol-diesel combustion process via heat release shaping. The spatial combustion zone partition divides the premixed ethanol-air mixture into two portions, and the combustion event (timing and extent) of each portion can be controlled by the temporal diesel injection scheduling. As a result, the heat release profile of ethanol-diesel dual-fuel combustion is properly shaped to avoid excessive pressure rise rates and thus to improve the engine performance. The investigation is carried out through theoretical simulation study and empirical engine tests. Parametric simulation is first performed to evaluate the effects of heat release shaping on combustion noise and engine efficiency and to provide boundary conditions for subsequent engine tests. In the engine tests, the engine performance is examined through emission measurements and efficiency analyses, and combustion characteristics are investigated focusing on the correlation between the combustion noise and heat release shaping. As demonstrated by the test results, the heat release profiles representing the combustion events in the central zone and peripheral zone can be actively controlled via diesel injections (fuelling amount and timing), towards the desired heat release shaping. The maximum pressure rise rates are substantially reduced to levels of 5~8 bar/°CA that are in the practical range of modern production diesel engines. The dual-chamber piston bowl along with the injection strategy using an early diesel pilot for the peripheral zone and a near-TDC diesel pilot for the central zone shows a great potential of achieving clean, efficient, and smooth ethanol-diesel combustion.</div></div>

Numerical tools are now used widely in the prediction of material properties necessary in order to gain a better understanding of the relationship between material properties and performance, to improve the reliability of processes and the quality of the final product, and to reduce costs, waste and energy use. In this paper, the solidification properties and the microstructure of some commercial Ni based alloys were analysed and predicted numerically using the ProCAST software. The microstructure of a sample obtained by the direct additive laser growth, a new additive manufacturing technique based on the selective laser melting, is presented and discussed. Numerical approaches and software packages that can be used to model additive manufacturing processes are discussed and critically analysed.

We review some ideas of Grothendieck and others on actions of the absolute Galois group {\Gamma} Q of Q (the automorphism group of the tower of finite extensions of Q), related to the geometry and topology of surfaces (mapping class groups, Teichm{\"u}ller spaces and moduli spaces of Riemann surfaces). Grothendieck's motivation came in part from his desire to understand the absolute Galois group. But he was also interested in Thurston's work on surfaces, and he expressed this in his Esquisse d'un programme, his R{\'e}coltes et semailles and on other occasions. He introduced the notions of dessin d'enfant, Teichm{\"u}ller tower, and other related objects, he considered the actions of {\Gamma} Q on them or on their etale fundamental groups, and he made conjectures on some natural homomorphisms between the absolute Galois group and the automor-phism groups (or outer automorphism groups) of these objects. We mention several ramifications of these ideas, due to various authors. We also report on the works of Sullivan and others on nonlinear actions of {\Gamma} Q , in particular in homotopy theory. The final version of this paper will appear as a chapter in Volume VI of the Handbook of Teichm{\"u}ller theory. This volume is dedicated to the memory of Alexander Grothendieck.

ABSTRACT Computation of constructive works needs complex structure analyses taking account of large displacements and including accurate material modeling. In this paper, a shell finite element family dedicated to reinforced concrete structures is presented. The numerical formulation is similar to the one of T1 element (in the case of 3 node triangle) described in [HUG 87]. The behavior of concrete couples elasticity and damage (La Borderie's model) and the reinforcement which is defined as layers at different heights, presents an elastic-plastic behavior with isotropic hardening. The way such a complex behavior is implemented in shell elements as well as the numerical algorithm used to solve the constitutive equations, including the calculation of the tangent stiffness, are detailed. Two applications validate the behavior of the proposed elements.