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Publications - 6374

Aerodynamic Effect of Shallow Circumferential Grooves in the Shroud of a Centrifugal Compressor

Pavel Novotny Márk Pesthy Jiří Vacula Richárd Takács Johan Prinsier

Publication Name: Journal of Turbomachinery

Publication Date: 2026-01-01

Volume: 148

Issue: 1

Page Range: Unknown

Description:

The standard aerodynamic design of a centrifugal compressor features an unshrouded impeller with a smooth shroud. However, the shape of the shroud significantly influences the final compressor parameters. Previous research has shown that even small geometric changes in the shroud, referred to as casing treatment, can substantially affect the operating characteristics of a rotating machine. This article presents a novel casing treatment for a centrifugal compressor, involving the creation of ten circumferential grooves with a semi-circular profile in a meridional section. The radius of these grooves is approximately equal to the tip clearance. Experimental results demonstrate that the presence of these grooves shifts the surge line toward lower flowrates, increases efficiency in a narrow region between the best efficiency point and the surge line and shifts the choke line toward lower flowrates. External sound pressure measurements indicate a reduction in amplitudes at sub-synchronous frequencies, suggesting a potential link between the compressor map's influence and the suppression of aerodynamic instabilities. Computational fluid dynamics analysis supports the experimental observations, revealing a significant influence of energy dissipation caused by the applied grooves. This study highlights the considerable impact of shroud geometry on centrifugal compressors with unshrouded impellers and offers valuable insights for further research into casing treatments.

Open Access: Yes

DOI: 10.1115/1.4069422

Minorities and the free press in Hungary after 1867

MihÁly RÉvÉsz

Publication Name: Parliaments Estates and Representation

Publication Date: 2003-01-01

Volume: 23

Issue: 1

Page Range: 123-130

Description:

The study analyses the status and the standard of freedom of the press in Hungary in the first decade of the Austro-Hungarian monarchy. Special attention is paid to libel cases against nationality papers attacking the government in Pest. The author's main purpose is to discuss the limits on the freedom of the press drawn by criminal law, and in addition, to examine the accusations against the oppositional papers and the court practices involved. As a result, the study emphasizes that the picture of ‘the press under a state of siege’ could hardly be verified from the criminal procedures examined. The author does not, however, paint an idealized picture of the freedom of the press. The government in Pest was biased against the nationality papers. Yet even so, in the first ten years of Dualism juries adjusted the official criminal law policy by acquittals of authors and editors. The prosecuting magistracy therefore accepted the independence of the jury and the unreliability of the lay judges, and often withstood the demands of government departments. The members of the government of Hungary accepted the practice instituted by the prosecuting magistracy and ‘instead of strict laws and even more strict courts’ they gave up trying to rule the press by means of the criminal law. The first half of the 1870s thus became a period of a free press, indicating to what extent the parliamentary system and its government in Dualism could ‘practise liberalism without risking its own existence’. © 2003, Taylor & Francis Group, LLC. All rights reserved.

Open Access: Yes

DOI: 10.1080/02606755.2003.9522171

Modelling of the Torsional Simple Shear Test with Randomized Tresca Model Properties in Midas GTS NX

Majd Ahmad R. P. Ray

Publication Name: Geotechnical and Geological Engineering

Publication Date: 2023-05-01

Volume: 41

Issue: 3

Page Range: 1937-1946

Description:

The dynamic properties of soil obtained from the torsional simple shear test (TOSS) are assumed to be uniform throughout the specimen. For some exceptional soils, this may hold true, but for the most majority of soils that we examine, it is obviously not the case, and this level of non-uniformity depends on the conditions in which the soil was formed. In this paper, we discuss a method of modelling inherently non-uniform soil specimens by representing them with elements that have an elasto-plastic simple Tresca material model with different properties (Elastic young modulus and yield stresses). The combination of properties that can simulate the nonlinear behaviour of the soil is found and calibrated using a model of the TOSS test built in the finite element software Midas GTS NX. Furthermore, the influence of rigid inclusions in the soil is studied and the results show an increase in stiffness with the increasing percentage of inclusion in the soil.

Open Access: Yes

DOI: 10.1007/s10706-023-02382-z

Modelling and Sensitivity Analysis of Nonlinear Firefighting Systems Using Maple

F. Hajdu Rajmund Kuti G. Y. Molnarka

Publication Name: Communications in Computer and Information Science

Publication Date: 2021-01-01

Volume: 1414

Issue: Unknown

Page Range: 234-251

Description:

Mathematical modelling and numerical simulations have greatly contributed to the development of technical sciences in the recent decades. With powerful tools, like Maple, the examination of ever newer engineering applications in simulation environment was made possible. This paper gives an overview of mathematical modelling and numerical examination of nonlinear fire truck suspension systems using Maple. The examined models are the suspension system of a heavy-duty fire truck with different degrees of freedom and a special double-cabin fire truck suspension system with a crew compartment. The construction of mathematical models, their implementation to Maple and the numerical simulation results are explained. Detailed One-at-a-Time sensitivity analysis results using a novel fuzzy logic based evaluation method developed in Maple are also presented. With the proposed method an extended parameter range can be examined and the parameters can be easily compared. From the sensitivity analysis it was concluded that the spring characteristics and the road models greatly affect simulation results.

Open Access: Yes

DOI: 10.1007/978-3-030-81698-8_16

Assessing the impact of climate policy uncertainty on lobbying: An empirical analysis of European countries

Cristian Barra Pasquale Marcello Falcone Patrizio Giganti Grazia Errichiello

Publication Name: Ecological Economics

Publication Date: 2026-07-01

Volume: 245

Issue: Unknown

Page Range: Unknown

Description:

Climate policies are a key focus of the European Union's political agenda. Lobbyists aim to exert influence on these policies to advance their interests. This paper uses a panel dataset from 2011 to 2022 of European organizations to investigate the relationship between Climate Policy Uncertainty (CPU) and Lobbying Expenditure (LE). The dataset includes annual observations from organizations across eight European countries, incorporating both microeconomic and macroeconomic factors. The results indicate a positive association between CPU and LE, suggesting that higher levels of CPU are systematically linked to increased lobbying efforts within our sample. This relationship remains robust after addressing potential endogeneity concerns using the Two-Stage Least Squares (2SLS) approach. The effect is particularly pronounced in countries with high GDP or high CO₂ emissions, as well as for organizations with lower participation in European Commission meetings. The study also examined the presence of an exogenous shock, specifically the COVID-19 pandemic. While COVID-19 did not alter the existing relationship between CPU and LE, an analysis focused on the pandemic period revealed a reversal in the relationship. These findings carry important policy implications. Governments should prioritize transparency in lobbying activities and address the regulatory challenges posed by CPU to uphold accountability, balance diverse organizational interests, and safeguard the integrity of climate policymaking.

Open Access: Yes

DOI: 10.1016/j.ecolecon.2026.108996

THE IMPACT OF ARTIFICIAL INTELLIGENCE ON THE EUROPEAN LABOUR MARKET-POLARISATION, CHALLENGES AND OPPORTUNITIES

Balázs Fábián

Publication Name: Studia Iuridica Cassoviensia

Publication Date: 2025-12-19

Volume: 13

Issue: Special Issue

Page Range: 20-35

Description:

The rapid development and diffusion of artificial intelligence (AI) is having a major impact on the European labour market, transforming employment structures, skills, and ways of working. This technological revolution is both a challenge and an opportunity for workers, companies, and policy makers. This research is about to focus on the sectors, the depth, and the ethical use of AI, and will explore the labour law issues of new forms of employment generated by AI (e.g. platform work).Overall, the integration of AI into the labour market presents both opportunities and risks that require initiative-taking policy responses, ongoing research, and collaboration between governments, businesses, and social partners. By addressing the legal, social, and ethical implications of AI-driven work, Europe can harness the benefits of technological advancement while safeguarding workers' rights and promoting a more inclusive labour market.

Open Access: Yes

DOI: 10.33542/SIC2025-S-02

Sustainability in Railways – A Review

Szabolcs Fischer Szabolcs Szalai Szabolcs Kocsis Szurke András Brautigam Laszlo Ezsias

Publication Name: Chemical Engineering Transactions

Publication Date: 2023-01-01

Volume: 107

Issue: Unknown

Page Range: 7-12

Description:

This paper examines the sustainability of railways. A comprehensive international literature review was conducted on railway vehicles, traction, and railway permanent way. The main goal was to find the factors and parameters that affect railway sustainability the most. CO2 emissions from transportation, mining, raw material production, manufacturing, use, operation and maintenance, and demolition and restoration must be significantly reduced. Naturally, the attention will be on the considerable energy and financial savings. This article's main topics are sustainability, affordable and clean energy, industry, innovation, infrastructure, sustainable cities and communities, responsible consumption and production, climate action, and life on land. Building materials come from quarries and gravel pits, but availability is decreasing. Future pavement construction and maintenance require recycling demolition and industrial waste. Engineers must choose materials and technology that extend track lifetimes to ensure reliability, availability, maintainability, safety, sustainability, and economy in permanent railroad ways. Life-cycle costs can be reduced, e.g., by Building Information Modeling. Electric machinery is preferred for construction equipment, materials, and management. Sustainability, like grassed tracks and recyclable plastics, has improved urban life. Sheet metal forming using recycled materials and sustainability shows how important environmental protection is in car and train design. Electric road and rail propulsion are driven by environmental concerns, while supercapacitors and batteries are studied. In conclusion, by preferring rail for freight and passenger transport, both for private and public transport, energy savings and CO2 emissions can be up to 2-10 times higher than for other modes of transport.

Open Access: Yes

DOI: 10.3303/CET23107002

From Over-Tourism to Under-Tourism via COVID-19: Lessons for Sustainable Tourism Management

Irum Shahzadi Gagan Deep Sharma Mandeep Mahendru Ravi Chatterjee Vibha Arora Irum Shahzadi

Publication Name: Evaluation Review

Publication Date: 2024-02-01

Volume: 48

Issue: 1

Page Range: 177-210

Description:

With various strains of the novel coronavirus emerging during the last few years, there is a need to reinvent and manage the tourism industry by engaging various stakeholders. Industry and policymakers need to observe the shift and curate tourism-related products and offerings accordingly. In light of the increasing demand for innovations and future directions in the post-COVID-19 period, this article conducts a bibliometric analysis for sustainable tourism studies spanning the years 1990–2021. This paper presents an integrative review of tourism, environment and sustainable tourism to reveal geographical, contextual, and methodological directions for future research. The comprehensive analysis includes contributions on topics and methods, country collaborations, and thematic analysis. The findings are consistent with the Sustainable Development Goals of sustainable production and consumption (SDG-12), with a particular emphasis on sustainable tourism to promote local culture and create jobs (SDG-12.b) and on sustainable growth (SDG-13). The study’s findings can be used to inform future policies and directions; for example, the findings indicate that the hospitality industry is facing challenges that necessitate new regulations to address its socioeconomic and environmental impacts.

Open Access: Yes

DOI: 10.1177/0193841X231189805

Analysis of Human-Robot Interactions as a Sustainability Factor

Adam Csapo Csaba Hajdu

Publication Name: Chemical Engineering Transactions

Publication Date: 2023-01-01

Volume: 107

Issue: Unknown

Page Range: 85-90

Description:

Robotic systems are traditionally widespread in the efficient automatization of industrial processes. Recent applications include material handling, reconnaissance, and agricultural tasks, besides the more traditional assembly line tasks. On the other hand, the recent advancements of robotic systems aim at enhancing and even replacing the human workforce in traditional social service tasks, like nursery, clerk positions, eldercare, and catering – collectively called social robotics. Developed countries generally suffer from the decreased available workforce in these areas, threatening the long-term availability of such essential services. The robots providing such services are required to appear and behave human-like to some degree to interact with people seamlessly. Human-like behavior requires complex software and hardware systems with learning capabilities to solve social situations appropriately. This paper investigates the relationship between human-robot interactions and sustainability and identifies the foundational similarities between the aims of the two interdisciplinary fields. The paper proposes the effect of complex interaction capabilities on sustainable factors and their possible qualitative verification. The quantitative factors described in this paper are the social perception of different robots and their expected functions defined by the foundational human-robot interaction roles. The paper proposes the possible contribution of future social robot applications to sustainability factors, such as the effect of telepresence. The paper also presents the result of a qualitative survey of participating university students on the acceptance of different types of robots based on their visual appearance. The assumption of possible integration of robots into social roles and what appearance is perceived as acceptable. In summary, this paper highlights the sustainable factors in human-robot interactions by identifying the effects of social robot roles and mapping between corresponsive sustainability factors, most importantly resolving workforce deficit.

Open Access: Yes

DOI: 10.3303/CET23107015