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Surface Activation of Polyamide 6 Nanocomposites by Atmospheric Plasma: Wettability and Chemical Changes for Type IV Pressure Vessel Liners

Eszter Kókai Dávid István Kis

Publication Name: International Journal of Automotive Science and Technology

Publication Date: 2025-01-01

Volume: 9

Issue: 1st Future of Vehicles Conf.

Page Range: 41-46

Description:

This study explores how atmospheric-pressure plasma treatments can modify the surface properties of polyamide 6 (PA6) and its nanocomposites reinforced with organomodified montmorillonite (OMMT), materials developed as potential liners for Type IV composite overwrapped pressure vessels (COPVs) designed for hydrogen storage. Four material compositions were examined: neat PA6 and composites containing 1, 2.5, 5, and 10 wt.% OMMT. Two different plasma systems—a piezoelectric plasma brush and a rotary plasma source—were used to activate the surfaces, and their effects were evaluated using water contact angle (WCA) measurements and Fourier transform infrared spectroscopy (FTIR). Both plasma treatments effectively increased the wettability of the tested materials, but the rotary plasma consistently produced the lowest WCA values across all compositions, reaching as low as 21° for neat PA6. These findings suggest that the rotary plasma’s higher power and dynamic exposure enhance the formation of polar functional groups and may increase micro-scale roughness, leading to improved surface activation. FTIR results confirmed the appearance and growth of oxidized functional groups, particularly carbonyl and hydroxyl species, which are linked to the increased surface polarity and hydrophilicity. Time-dependent contact angle tests revealed that the effects of plasma treatment were not permanent. Over several hours, the contact angles gradually increased, returning close to untreated values.

Open Access: Yes

DOI: 10.30939/ijastech..1753231

Comparative study of plasma, laser, and flame induced activation of HDPE liner surfaces of type 4 hydrogen vessels

Attila Bata Péter Kovács Erika Varga Ferenc Palásti

Publication Name: Journal of Adhesion

Publication Date: 2025-01-01

Volume: 101

Issue: 7

Page Range: 909-929

Description:

In our study, we compare the surface modifications of coarse HDPE surface induced by atmospheric air plasma, CO2 laser, and flame treatments. An order of WCA decrease of air plasma>flame>CO2 laser methods was detected. The improvement in adhesion strength measured 5 days after the activations followed the same trend. FT-IR and EDS proved that different oxygen compounds were formed after treatments, resulting in increased polar component of the total surface energy. Flame activation showed a saturation character regarding the O-moiety. Hydrophobic recovery showed a linear behavior, with a larger decreasing slope for the polar component than the total surface energy. Plasma treatments induced higher recovery rate; however, restore was not complete here either. The effects of the different CO2 irradiation intensities were nonlinear; SEM and roughness measurements revealed surface ablation or structure formation on the different samples, while after plasma and flame treatment a hilly microtexture appeared. With different mechanisms and intensities, all the tested methods are suitable for increasing the adhesion strength on HDPE surfaces.

Open Access: Yes

DOI: 10.1080/00218464.2024.2406813

Dynamic Modeling Possibilities of Embedded Rail Structures

Szabolcs Fischer Zoltán Major Attila Németh Vivien Jóvér Nándor Liegner

Publication Name: Acta Polytechnica Hungarica

Publication Date: 2025-01-01

Volume: 22

Issue: 4

Page Range: 29-43

Description:

In Hungarian design practice, the Zimmermann-Eisenmann quasi-static design method is employed to dimension track structures with embedded rails. This method determines the mean values of deformations and stresses using an infinitely long elastically embedded beam as the static frame. After establishing these mean values, the effects of track condition and speed are considered through Eisenmann multiplication, enabling the definition of design values. Conversely, international practices include methods that calculate deformations and stresses based on dynamic models incorporating viscoelastic embedding, directly accounting for speed but not dynamic effects due to track characteristics. This paper presents a solution to the dynamic problem, extending it to studying rotating frames beyond the commonly considered uniaxial solution. Each factor's effect is separately analyzed for track structures with embedded rail tracks, leading to a recommendation for the value of the "load multiplication factor".

Open Access: Yes

DOI: 10.12700/APH.22.4.2025.4.3

Hybrid work and HRM practice in a global south context: a job demands-resources perspective

Jessica Lichy Vincent Dutot Geshwaree Huzooree Jacqueline Brodie Sarita Hardin-Ramanan Melina Doargajudhur Zuberia Hosanoo

Publication Name: Journal of Management Development

Publication Date: 2025-01-01

Volume: Unknown

Issue: Unknown

Page Range: 1-21

Description:

Purpose – This study explores how hybrid work is implemented and experienced in a Global South (GS) context, with a focus on Mauritius, a small island developing state (SIDS) where remote work was virtually non-existent before the COVID-19 pandemic. It investigates how hybrid arrangements reshape job demands, resources and employee outcomes. Design/methodology/approach – Drawing on the job demands-resources (JD-R) model and a practice-oriented lens on Human Resource Management (HRM), the study examines hybrid work through two focus groups comprising professionals from 14 organisations across IT, finance, education and creative industries. Thematic analysis was used to identify key patterns in the data. Findings – Four interrelated themes emerged: technological enablers of performance, autonomy and flexibility, tensions in virtual collaboration and inequalities in hybrid work. The findings reveal how job resources such as autonomy, digital infrastructure and supportive leadership buffer demands such as technostress, role ambiguity and over-monitoring. Human resource (HR) professionals play a key role in mediating these dynamics through both formal and informal practices. Research limitations/implications – The study has limitations due to the focus on professionals in Mauritius, a SIDS, which limits the generalisability of its findings to other GS contexts with varying technological and cultural landscapes. The qualitative design, relying on a limited number of focus groups, further restricts the breadth and empirical generalisability of the insights. Additionally, the reliance on self-reported data, particularly from managerial-level participants, introduces a potential for social desirability bias. Finally, the exclusive theoretical grounding in the JD-R model may have inadvertently constrained the emergence of other relevant constructs beyond its framework. Practical implications – The study offers actionable insights for HR practitioners and organisational leaders designing hybrid work systems in digitally uneven environments. Emphasis is placed on the need to address equity in access, enhance virtual collaboration and support employee autonomy through tailored HRM practices. Social implications – The findings highlight that hybrid work exacerbates social inequalities and strains. HR must address the uneven distribution of job demands and resources across demographic lines. Older employees often struggle with digital tools, while younger staff face heightened monitoring and blurred work-life boundaries. The loss of informal connections and spontaneous interactions also risks social isolation and reduces organisational cohesion. Inclusive HRM practices are essential to mitigate these socio-technical divides and ensure sustainable transformation. Originality/value – This study extends the JD-R model to an under-researched GS setting and contributes to understanding how hybrid work evolves in contexts lacking a pre-existing culture of remote working, adding depth to theory and informing inclusive practice. A conceptual model is proposed to illustrate how hybrid work experiences are shaped by the interaction between structural enablers, job characteristics and HRM practices.

Open Access: Yes

DOI: 10.1108/JMD-10-2025-0546

Accident Risk Analysis of Road Accidents Involving Personal Injury

I. Lakatos Gergő Sütheö Brúnó Péter

Publication Name: Periodica Polytechnica Transportation Engineering

Publication Date: 2025-01-01

Volume: 53

Issue: 3

Page Range: 301-307

Description:

In both the European Union Member States and Hungary, a large number of people are killed in road traffic accidents. Reducing road collisions, personal injuries, and fatalities is a priority. To get an accurate picture of the situation, it is necessary to know the accident statistics of the European Union and the main EU directives that define a Safe Transport System. We then review the road safety situation in Hungary, using data from 2017 to 2020. In preparing the statistical overview, particular attention will be paid to the spatial distribution of severity, over time and by county, the distribution of accident participants by type of transport, the characteristics of the persons involved in the accident, the causes of the accidents and the distribution by type of accident. The analysis includes an explanation of the variables related to the vehicles involved in the accident and the causes of accidents related to human factors.

Open Access: Yes

DOI: 10.3311/PPtr.38004

Case Study on Kitchen Waste Collection Materials: Comparing the Effects of Biobased Bags on Anaerobic Digestion

Károly Kalauz Katalin Bélafi-Bakó Tamás Rózsenberszki Janka Bobek-Nagy Csilla Őze Veronika Kalauz-Simon Janka Bobek-Nagy Veronika Kalauz-Simon Katalin Kovács Nándor Nemestóthy Péter Komáromy

Publication Name: Chemical Engineering Transactions

Publication Date: 2025-01-01

Volume: 121

Issue: Unknown

Page Range: 109-114

Description:

Separate collection of household bio-waste became mandatory across the European Union in 2024, increasing the use of biodegradable paper and plastic liners for kitchen waste. While these materials improve source-separation and hygiene, their behavior during Anaerobic Digestion (AD) remains insufficiently understood and may affect plant performance and digestate quality. This study evaluated five commercially available collection bags – three paper-based and two biodegradable plastic types – under mesophilic batch AD conditions. Paper bags increased methane and biogas yields by approximately 5–20 %, while biodegradable plastics resulted in similar or slightly reduced yields compared to controls. Neither material showed substantial structural degradation, but paper provided additional substrate and surface area, supporting modest efficiency gains. In contrast, persistent plastic fragments in the digestate may limit its agricultural use under strict EU fertilizer regulations, leading to higher post-treatment costs. These findings highlight that paper liners are more compatible with AD-based waste management systems, informing municipalities, policymakers, and operators in selecting collection tools that optimize resource recovery and regulatory compliance.

Open Access: Yes

DOI: 10.3303/CET25121019

Algorithmic Management in Traditional Workplaces: The Case of High vs. Low Involvement Working Practices: The Context of the Non-Inclusive Industrial Relations System in Hungary

László Imre Komlósi Miklós Illéssy József Pap Éva Farkas Csaba Makó

Publication Name: Journal of Labor and Society

Publication Date: 2025-01-01

Volume: 28

Issue: 3

Page Range: 394-422

Description:

Algorithmic management (am) has become a key research focus in the sociology of work, especially concerning platform work. However, am tools are also impacting traditional workplaces. This study investigates three main questions: the impact of ai on high vs. low-skilled jobs, its effect on employee's role, and the formation of collective voices around am, including non-traditional labour relations actors. The context is the Hungarian industrial relations system, known for low union membership and company-level bargaining. The study compares two cases: a medium-sized company in high-value-added business services and a Hungarian subsidiary of a multinational employing warehouse workers. Contrary to literature suggesting am reduces employee autonomy, the study finds its impact complex, decreasing employee's roles some areas while increasing it in others. Notably, transparency and wage predictability improved. The study also highlights the importance of considering new actors, such as clients and external consultants, in am analysis. Keywords

Open Access: Yes

DOI: 10.1163/24714607-bja10182

Case Report: From disordered eating to an eating disorder—a case study of an orienteering athlete with anorexia nervosa and the shortcomings of the multidisciplinary approach

Réka Erika Kovács Szilvia Boros

Publication Name: Frontiers in Psychology

Publication Date: 2025-01-01

Volume: 16

Issue: Unknown

Page Range: Unknown

Description:

This case study explores the transition from disordered eating (DE) to an eating disorder (ED) in a 23-year-old female orienteer. Despite her talent as an athlete, her eating habits and training practices led to significant health concerns. After following an ovo-lacto vegetarian diet for 3 years, she exhibited symptoms of DE, including low energy intake (1,200 kcal/day), low body weight (50.1 kg, BMI: 16.9), and amenorrhea. Her condition deteriorated over 2 years, resulting in a diagnosis of anorexia nervosa (AN) by February 2023. During the treatment process, the athlete utilized a multidisciplinary approach that included dietitians, psychologists, and physicians. Despite achieving some initial progress, including a slight increase in body weight and the return of menstruation in July 2022, her health declined after psychological consultations were halted, leading to a further decrease in body fat and persistent low serum iron levels. This case highlights the importance of continuous monitoring, timely intervention, and a coordinated multidisciplinary team in addressing DE and ED in athletes. It also highlights the significance of effective communication among healthcare professionals and the need for comprehensive treatment strategies that include psychological, nutritional, and medical support. This study highlights the significance of early detection, suitable intervention, and the prevention of long-term health complications, such as decreased bone density and cardiovascular issues, in athletes with DE and ED.

Open Access: Yes

DOI: 10.3389/fpsyg.2025.1537844

Practical stability design of general I-section members for combined forces

B. Vaszilievits-Sömjén Donald W. White

Publication Name: Proceedings of the Annual Stability Conference Structural Stability Research Council Ssrc 2025

Publication Date: 2025-01-01

Volume: Unknown

Issue: Unknown

Page Range: Unknown

Description:

Numerous situations occur in engineering practice where I-section members must be designed for a combination of flexure, shear, torsion, and/or axial loadings. Particularly in metal buildings and horizontally curved I-girder bridges, these member types may have variable web depth and stepped cross-section transitions along their length. Design guidance for handling combined loadings on these member types has been limited. Modern software systems that can accurately calculate combined second-order elastic demands and elastic buckling loads for general I-section members in general framing systems are increasingly available. This paper discusses new AISC 360 Chapter F provisions under consideration in the 2027 Specification development cycle. These provisions provide an improved, streamlined calculation of the flexural resistance of general I-section members. The calculations address recent research findings regarding the influence of moment gradient and corresponding web shear. The discussion of the new AISC 360 procedures is followed by a brief presentation of recommended ways to verify a design where the member is also subjected to axial compression and/or torsion based on experiences from European and American practice. The focus of the paper is on the essential concepts.

Open Access: Yes

DOI: DOI not available