Periodica Polytechnica (Budapest University of Technology and Economics)
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Objective Measurement Method for Assessing Plank Test Among Female Basketball Players
Full text linkTrunk muscle strength plays a crucial role in the sport-specific movements of basketball players. While the plank test is widely used to assess trunk muscle endurance, its lack of standardization limits its effectiveness in high-performance environments. The study aimed to establish objective criteria for determining when the plank position was no longer maintained and introduced a new variable, postural error (PE). This study involved 23 (age = 15.22 years, weight = 66.3 kg, height = 174 cm) healthy female basketball players from the Hungarian U16 first league. Using optical motion capture, the thoracic kyphosis (TK) and lumbar lordosis (LL) were monitored during the test. The cutting point (CP) was determined based on four mathematical formulas and the estimation of two independent experts. PE was determined based on the area under the curves, which characterizes the magnitude of displacements until the endpoint. According to the difference between the expert-estimated and the calculated CP, the initial angles were calculated as the average of the first 15 seconds, and the CP was set at a ±25° deviation. Additionally, PE was introduced to assess the strategy of maintaining the plank posture, revealing differences in performance even among participants with similar CP times. The present study introduces a new method for determining the test's objective starting angle endpoint and introduces a new variable, PE, to characterize trunk stability, distinguishing between different execution strategies. The findings suggest that this approach provides a more reliable and objective way to assess trunk muscle endurance and core stability
Cellulose Xanthate–alginate Beads from Empty Palm Fruit Bunches: Synthesis, Characterization, and Application in Remazol Red Dye Degradation
Full text linkAlginate has been extensively employed as a biomaterial, but its practical applications are constrained by inherent drawbacks such as limited solubility, structural instability, brittleness, and inadequate mechanical strength. Empty palm fruit bunches (EPFB), an abundant lignocellulosic residue rich in cellulose, represent a renewable precursor for the synthesis of cellulose xanthate. In the present study, cellulose xanthate–alginate composite beads were fabricated via structural modification and intermolecular interactions to overcome the intrinsic limitations of alginate. The influence of NaCl as a porogen was investigated, and the applicability of the beads in the degradation of remazol red textile dye was evaluated. Beads were prepared using a mass ratio of alginate to cellulose xanthate of 1:3, with NaCl incorporated at concentrations of 3, 6, and 9% (w/v). Characterization techniques included Fourier transform infrared spectroscopy, optical microscopy, and scanning electron microscopy-energy dispersive X-ray spectroscopy analysis. This study demonstrated that increasing NaCl concentration up to 9% enhanced the porosity and swelling capacity to 80% and 48.50%, respectively. Application tests revealed that TiO2/cellulose xanthate–alginate beads achieved a maximum degradation efficiency of 85.59% for Remazol Red under UV irradiation with 0.8 g TiO2. These findings highlight the potential of EPFB-derived cellulose xanthate–alginate beads as eco-friendly materials for textile dye wastewater treatment
High-Quality Bio-Oil Production from Co-Pyrolysis of Acetic Acid Pretreated Nypa Fronds and High-density Polyethylene with Ni–Cu Modified Fly Ash Catalyst
Full text linkCo-pyrolysis has emerged as a promising thermochemical approach to enhance both the yield and quality of bio-oil compared to conventional pyrolysis. In this study, Nypa fruticans frond (NFF) was initially pyrolyzed following pretreatment with acetic acid diluted in peat water (AAPW) at concentrations of 2.5, 5, 7.5, and 10 w/w% to identify the optimal pretreatment condition for bio-oil production. Subsequently, co-pyrolysis was conducted using NFF pretreated at the selected AAPW concentration (2.5 w/w%) with high-density polyethylene (HDPE) at feed ratios of 30:70, 50:50, and 70:30 (NFF/HDPE, w/w). Finally, catalytic co-pyrolysis was performed at the optimal feed ratio (70:30) by adding Ni–Cu/FA catalyst loadings of 5%, 10%, and 15% (w/w). All experiments were conducted at 500 °C for 60 min. Results showed that increasing AAPW concentration enhanced the bio-oil yield, while the incorporation of HDPE significantly improved both yield and quality. Catalytic co-pyrolysis provided the greatest upgrading effect, with 15% Ni–Cu/FA catalyst achieving the highest bio-oil yield (71.87 ± 2.21%), heating value (45.55 MJ/kg), energy yield (89.61%), and superior physicochemical properties, including near-neutral pH (6.82), high density (0.78 g/cm3), and 98.43% hydrocarbon content. Overall, the combination of AAPW pretreatment, plastic co-feeding, and catalytic upgrading proved effective in producing high-quality bio-oil characterized by elevated hydrocarbon content and near-neutral acidity
Improving Plate Performance Under Dynamic and Axial Loads Through Pre-Formed Pyramidal Structures: A Numerical Method
Full text linkThis study presents a harnessed optimization process of pre-built pyramidal modifications at enhancing the response of AISI 1010 steel planar plates subjected to simultaneous axial-dynamic loading. Unlike conventional mass adding reinforcements for enhancing buckling resistance and vibration stability. ANSYS finite element analysis featured 25 plate arrangements (pyramid heights: 0 to 20 mm; thicknesses: 1 to 3 mm), considering the boundary conditions as clamped and compression load. At increased distortion, results indicate a marked improvement in performance, particularly for thinner plates (≤2 mm). At maximum in case of deformation (h = 20 mm), critical buckling loads were improved up to 237.3%, and fundamental natural frequencies were enhanced up to 328%. The enhancements are linked to a transition from global buckling and vibration to localized modes: pyramidal regions concentrate stresses via shear band redistribution, significantly diminishing the uniformly stressed area, and limit vibrational energy by confining kinetic energy to geometric protrusions. The augmentation of performance diminishes with increasing plate thickness, exhibiting losses of 86% in buckling and 98% in frequency gains as thickness escalates from 1 mm to 3 mm. Saturation effects occur beyond h = 15 mm for thicker plates. This geometric morphing approach provides a resource-efficient transformation for lightweight structural construction
Addressing the Urgent Need for E-scooter Regulation in Hungary
Full text linkThe role of electric scooters is becoming increasingly important for sustainable transport development. E-scooters and other light electric vehicles are generally more efficient in urban environments than electric cars, taking up less road space and resulting in lower energy consumption per trip. Our research involved a systematic literature review to investigate the integration of e-scooters into the existing transport infrastructure network. An online survey was conducted to explore public perceptions and usage patterns of e-scooters, assessing factors such as safety, comfort and preferred speeds. The survey presented five different scenarios in two locations, each illustrating different infrastructure solutions for e-scooters. A total of 137 valid responses were analyzed.Our study showed that infrastructure with dedicated space for bicycles should be preferred for e-scooters. Respondents indicated that the safest solution for e-scooters would be to use the bicycle facility where it is provided followed by the sidewalk, while using the traffic lane received a low rating. There were significant differences in the perception of safety and comfort by different user groups, with cyclists being the only group where we found the smallest deviation in safety and comfort ratings across scenarios. Speed limit preferences for e-scooters also depend on infrastructure provision. Speeds of 15 km/h or less are preferred for sidewalks, 15 km/h or more for bicycle infrastructure, and slightly higher for traffic lanes. In conclusion, our study highlights the need for proactive regulation to address the increasing presence of e-scooters on our existing infrastructure
Effect of PET Bottle Compaction on the Saturation of the Waste Container
Full text linkEngineers and users are being pushed by environmental concerns to maximize efficiency while minimizing ecological damage. Waste collection vehicles require fossil fuels during their collection route, as well as when lifting and emptying the containers, even if the design of separate waste collection islands has focused on the idea of recycling. Even in a computer plan–assisted collection, saturated containers may have low waste density, meaning that a sizable portion of the container becomes unusable due to the shape of the waste. To maximize container utilization, this study will investigate the type and compaction potential of each container. The simulation study will provide an answer to the question of how the density of waste placed in the various containers changes as a result of compressing each bottle.The research and development will optimize not only the saturation of the container but also the number of collection routes; in addition to the economic benefits, the environmental load will be reduced. The frequency of lifting and emptying the container will decrease, resulting in reduced maintenance and repair costs for the vehicle′s lifting system and container.It is a misconception that compaction by hand in one place, throughout the diameter of the PET bottle, is the optimum way to increase the efficiency of waste collection. Based on the tests carried out in this paper, foot diameter compaction at full height is considered to be the most appropriate method after the use of a costly compactor
Current trends in library and information science in the light of PhD research and studies – 5.: Interview with Andor Nagy
No full textThe editorial team of CELISR conducted a short interview with recent graduates of the Library and Information Science doctoral program at the ELTE Doctoral School of Literary Studies, in order to provide the journal’s readers with an insight into the current and future scientific activities of researchers, and to give an idea of the current research trends in the field. The following article contains a brief overview of the PhD research conducted by Andor Nagy, head of department at the Béla Hamvas Pest County Library, and university assistant professor at the University of Pécs, with background and future prospects
Deep Analysis of Higher Education Students' Attitudes Towards Artificial Intelligence
No full textThis paper synthesises research (Ribní, 2025a; Ribní, 2025b) focused on exploring the dynamics ofhuman-machine interaction, aiming to develop a deeper and more nuanced understanding of thecomplex processes involved and the relationship between humans and artificial intelligence (AI).The aim of our study is not only to map students' perceptions and practices regarding AI in highereducation, but also to demystify the concept of AI, i.e., to dispel misconceptions about thetechnology. AI is not viewed as a mystical entity, but rather as an extension of human knowledge andcreativity. This technology is not merely an innovation but also presents a cultural and philosophicalchallenge: how can we understand human nature and society through our relationship with AI? Thepresent paper seeks to explore AI as a new arena for modern education, based on students'perceptions