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Publications - 6374

Intermediate-mass black hole binary evolution in nuclear star clusters: The effect of the stellar-mass black hole population

Andreas Just Fazeel Mahmood Khan Andrea V. Macciò Margaryta Sobolenko Kelly Holley-Bockelmann Rainer Spurzem Peter Berczik

Publication Name: Astronomy and Astrophysics

Publication Date: 2026-02-01

Volume: 706

Issue: Unknown

Page Range: Unknown

Description:

Aims. In this study, we investigate the dynamics of intermediate-mass black hole (IMBH) binaries within nuclear star clusters (NSCs) that contain a population of stellar-mass black holes (BHs). We examine how these stellar and BH populations influence the dynamics of the IMBH binary and, in turn, how the evolving IMBH binary affects the surrounding stellar and BH populations. Methods. We conducted high-resolution N-body simulations of NSCs constructed based on observational parameters from two local dwarf galaxies: NGC205 and NGC404. For the first time, we achieved a star particle mass resolution of 1 M⊙ and a BH mass resolution of 10 M⊙. This level of resolution is crucial for accurately modeling the collisional dynamics of these dense systems. Results. Including stellar-mass BHs within the stellar population significantly influences the IMBH binary dynamics, nearly doubling the sinking rate and halving the merger time. During the initial phase of the inspiral, the IMBH binary disrupts both the stellar and BH cusps. However, the BH cusp quickly regains its steep slope due to its shorter relaxation time and continues to dominate the evolution of the IMBH binary, despite being much less massive than the stellar component. We uncover an interesting mechanism in which BHs first efficiently extract energy from the IMBH binary and then transfer this energy to the surrounding stars, allowing the BHs to spiral back toward the center of the system and restart the process. Our results imply that although stellar-mass BHs are a minor component of a stellar population they can significantly facilitate IMBH growth within NSCs via mergers. We also notice that these dense systems can potentially boost intermediate-mass ratio inspirals (IMRIs) predominantly on radial orbits.

Open Access: Yes

DOI: 10.1051/0004-6361/202557283

Efficient Layer-by-Layer Processed Small-Molecule Donor/Polymer Acceptor Solar Cells: Morphology-Dependent Charge-Transfer Mechanisms

Gusztáv Fekete Hai Qiao Wang Shu Xu István Bíró Xingyu Liu Beining Wang Zhongle Chen Yuxuan Wang Chenghuan Chen

Publication Name: ACS Photonics

Publication Date: 2026-01-21

Volume: 13

Issue: 2

Page Range: 424-432

Description:

Small-molecule donor:polymer acceptor (SMD:PA) organic solar cells have garnered attention due to their excellent active layer stability, yet their efficiency remains significantly lower than other OSC types. This study addresses the challenge of morphology control in SMD:PA systems via a layer-by-layer (LBL) process to optimize the donor–acceptor interpenetrating network. Using small-molecule donor B1 and polymer acceptor PY-IT with chloroform as a universal solvent, we systematically investigated the impact of LBL processing on the active layer morphology and device performance. The inverted LBL device (ITO/ZnO/PY-IT/B1/MoO3/Ag) achieved a power conversion efficiency of 8.6%, significantly outperforming the bulk heterojunction devices (inverted 2.91% and normal 6.11%) and previously reported LBL SMD:PA cells (1.12%). Static and femtosecond transient absorption spectra, time-resolved photoluminescence, and grazing incidence X-ray diffraction analyses revealed that the LBL and nonorthogonal solvent strategy facilitated effective B1 infiltration into the PY-IT layer, forming an optimized active layer with refined phase separation and improved donor/acceptor interfaces, thus resulting in enhanced exciton dissociation and charge transport while reducing recombination losses. This work validates the feasibility of LBL processing for high-efficiency SMD:PA OSCs, offering a novel strategy to overcome the efficiency limitations of this class of OSCs.

Open Access: Yes

DOI: 10.1021/acsphotonics.5c02041

A novel preparation method of polypropylene/natural rubber blends with improved toughness

László Lendvai

Publication Name: Polymer International

Publication Date: 2021-03-01

Volume: 70

Issue: 3

Page Range: 298-307

Description:

A novel melt compounding method – originally introduced for the preparation of nanocomposites – was adapted to produce polypropylene (PP) based blends toughened with up to 20 wt% natural rubber (NR). This water-assisted technique is based on batchwise melt mixing, where the additives are introduced as an aqueous dispersion into the matrix, drop by drop. The efficiency of this preparation technique was analyzed by comparing the resulting blends with reference samples produced by traditional melt mixing. Mechanical, thermomechanical and morphological properties were determined in order to investigate the structure–property relationships. According to SEM analyses, the average domain size of NR within the PP matrix became significantly smaller when the water-assisted method was applied. Charpy impact tests showed that the toughening efficiency of NR particles within the PP was enhanced as a result of their decreased size. This improvement was more prominent when the difference between the viscosity of PP and NR was higher. In addition, applying the water-assisted technique led to an enhanced deformability with similar strength and stiffness compared to common melt mixing. © 2020 The Author. Polymer International published by John Wiley & Sons Ltd on behalf of Society of Industrial Chemistry.

Open Access: Yes

DOI: 10.1002/pi.6133

Physical and numerical modelling of climate-change influenced, poorly-compacted glacial till embankments

Peter Hudacsek A. Leung

Publication Name: Geotechnical Engineering for Infrastructure and Development Proceedings of the Xvi European Conference on Soil Mechanics and Geotechnical Engineering Ecsmge 2015

Publication Date: 2015-01-01

Volume: 7

Issue: Unknown

Page Range: 3911-3916

Description:

Cutting and embankment slopes are subject to seasonally changing hydraulic boundary conditions. This results in repeated wetting and drying of the soil mass, which in certain combinations of slope geometry, soil type, fabric feared to induce significant swellshrink cycles raising serviceability issues and possibly lead to extensive down-slope displacements. Since the response of infrastructure embankments is particularly relevant in light of the current global climate change, numerical and centrifuge model studies focusing on saturated overconsolidated clay earthworks - mainly representing cutting slopes - have been carried out to investigate the above mentioned effects. Some of these tests suggested that, even a slope failure may be triggered after a number of cycles due to softening of the soil. More recent centrifuge model test results of compacted glacial till embankment with more shallow slopes reviled that the observed behaviour for heavily overconsolidated steep slopes representing cutting like conditions should not be directly adopted when investigating the behaviour of poorly compacted embankments with dominant inter-granular porosity influencing both hydraulic and mechanical response of the structure. The paper thus aims to improve the understanding by undertaking series of numerical modelling and analysis using Plaxis. The input parameters for the implemented advanced hypoplastic constitutive model that could capture the small-strain nonlinearity have been determined based on earlier and more recent advanced element test results. The boundary conditions were set to match those from the centrifuge tests, and finally the model has been refined to reproduce the experienced hydraulic and mechanical behaviour.

Open Access: Yes

DOI: DOI not available

Natural disaster as a means of nationalising public administration: the consequences of a flood in 1879

Balázs Pálvölgyi

Publication Name: Rechtskultur

Publication Date: 2024-01-01

Volume: Unknown

Issue: Unknown

Page Range: 467-482

Description:

After the Austro-Hungarian Compromise of 1867 and the restoration of constitutionalism, the government had to resolve not only the day-to-day tasks but also the question of the role of the state, the scope for government and the role of self-government in the civil transformation. The modernisation agenda of the civic transition presupposed the development of a modern public administration, marked by the aim of ‘nationalising’, i.e. centralising public administration. The flood disaster of 1879, which devastated the city of Szeged, was a great help to Prime Minister Kálmán Tisza in achieving these goals. By shelving the institutions of county and city self-government and reconstruction after the disaster through a royal commissioner, the position of the defenders of self-government became practically comparable with the aims of the government that wanted to create a modern administration.

Open Access: Yes

DOI: DOI not available

FACTORS EFFECTING FEMALE STARTUPPERS IN HUNGARY

Márta Konczos Szombathelyi Petra Kinga Kézai

Publication Name: Economics and Sociology

Publication Date: 2021-01-01

Volume: 14

Issue: 4

Page Range: 186-203

Description:

The present paper focuses on female startup founders in Hungary. Numerous studies examine female entrepreneurship, but the topic of female startups is a less explored area. The research was carried out in two stages: at first in 2019 through an online survey and in-depth interviews, and then in May 2021 with in-depth interviews due to the delays caused by the COVID-19 pandemic. Mixed research methodology was used and comprised of an online questionnaire administered in startup-themed closed social media groups (n=113) and in-depth interviews among experts and members of the ecosystem (n=7+7). The aim was to conclude how potential female startup founders could be encouraged and what form of support should be given to them, as well as to explore the effects of the Covid-19 pandemic on female startup entrepreneurs. The results show that 70 percent of respondents have their own business, these were set up by both sexes between the ages of 24 and 35. The respondents mostly use equity when starting their businesses. Although the proportion of women among startup founders is very low, a positive entrepreneurial attitude can be observed among them. The startup ecosystem is centralised in Hungary; it is only emerging in some major university cities outside the capital. The strengthening role of startup communities and social media is unquestionable. Furthermore, the results reveal limiting factors, especially complex ones hindering female start-ups, which can typically be traced back to family and social reasons. To overcome these obstacles governments should continue facilitating startup development. The pandemic was considered as an opportunity to promote new ideas and features, concentrate on design and finetune their startup businesses.

Open Access: Yes

DOI: 10.14254/2071-789X.2021/14-4/11

A specific selection programme is required in the autochthonous Cikta Sheep which is endangered by own frequent ARQ prion haplotype?

Petra Zenke Ákos Maróti-Agóts László Sáfár Károly Tempfli Endre Kovács Susanne Mitro András Gáspárdy Ágnes Bali Papp

Publication Name: Landbauforschung

Publication Date: 2017-01-01

Volume: 67

Issue: 3-4

Page Range: 141-146

Description:

The authors study the current status of Hungarian Cikta Sheep based on genetic background of scrapie resistance. The aim of this investigation was to estimate the relative frequency of prion haplotypes, -genotypes, and risk categories as well as to reveal the efficiency of scrapie eradication program achieved over the last decade. The authors confirmed based on larger sample size the previous knowledge, that the resistance against scrapie of Cikta breed is considered as low, and the classification of this breed according to risk category has not been improved. However, the frequent genotype ARQ and risk category 3 can also be considered for breed specificity. The careful use of these genotypes is permitted and will contribute to the maintenance of breed diversity according to other aspects.

Open Access: Yes

DOI: 10.3220/LBF1513065159000

The Role of Demand-Responsive Transport Systems in Sustainable Urban Mobility: A Systematic Literature Review and Stakeholder Analysis †

Adhie Prayogo Boglárka Eisingerné Balassa László Buics

Publication Name: Engineering Proceedings

Publication Date: 2024-01-01

Volume: 79

Issue: 1

Page Range: Unknown

Description:

On-demand transportation, such as demand-responsive public transit (DRT), is gaining prominence as a mobility service tailored to passengers’ needs, offering flexibility in routes, pick-up/drop-off locations, and timing. This study aims to delve into the challenges and technological advancements within the DRT system, focusing on its application and effectiveness in various European Union states. The research first applied a systematic literature review using the PRISMA methodology with a PEO framework. Then, the research aims to provide information on how demand-responsive transportation operates in Central Eastern European countries by collecting and analyzing the characteristics of DRT service processes with a business process modeling approach. The findings aim to inform policymakers and stakeholders about the effectiveness and potential of DRT systems, facilitating informed decision making and policy formulation.

Open Access: Yes

DOI: 10.3390/engproc2024079040

Inverse Perspective Mapping Correction for Aiding Camera-Based Autonomous Driving Tasks †

Péter Korös Miklos Unger Nobert Marko

Publication Name: Engineering Proceedings

Publication Date: 2024-01-01

Volume: 79

Issue: 1

Page Range: Unknown

Description:

Inverse perspective mapping (IPM) is a crucial technique in camera-based autonomous driving, transforming the perspective view captured by the camera into a bird’s-eye view. This can be beneficial for accurate environmental perception, path planning, obstacle detection, and navigation. IPM faces challenges such as distortion and inaccuracies due to varying road inclinations and intrinsic camera properties. Herein, we revealed inaccuracies inherent in our current IPM approach so proper correction techniques can be applied later. We aimed to explore correction possibilities to enhance the accuracy of IPM and examine other methods that could be used as a benchmark or even a replacement, such as stereo vision and deep learning-based monocular depth estimation methods. With this work, we aimed to provide an analysis and direction for working with IPM.

Open Access: Yes

DOI: 10.3390/engproc2024079067