Periodica Polytechnica (Budapest University of Technology and Economics)
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Numerical Investigation of Enhanced Efficiency in CIGS Solar Cells with 3C-SiC and PEDOT:PSS Integration
Full text linkCopper indium gallium selenide (CIGS)-based thin-film solar cells continue to lead advancements in the efficiency of thin-film technologies. In this study, we propose cubic silicon carbide (3C-SiC) as a viable alternative to cadmium sulfide (CdS) for use as a buffer layer in CIGS solar cells. 3C-SiC offers superior transparency, higher electron mobility, and non-toxicity, making it a promising candidate for enhancing device efficiency. In this paper, we present a computational analysis of a thin-film solar cell utilizing a ZnO/3C-SiC/CIGS/ poly(3,4-ethylenedioxythiophene) (PEDOT): polystyrene sulfonate (PSS)/Mo heterostructure with PEDOT:PSS as the back surface field (BSF) layer. Simulations conducted using SCAPS-1D software demonstrate impressive photoconversion efficiencies, achieving an ideal efficiency (η) of 32.83%, an open circuit voltage (VOC) of 0.86 V, a short circuit current density (JSC) of 56.40 mA cm−2, and a fill factor (FF) of 80.79%. The study systematically examines the influence of key parameters, including CIGS absorber thickness, PEDOT:PSS thickness, 3C-SiC thickness, and temperature, demonstrating a strong correlation with previous experimental results. These findings offer valuable insights for enhancing the performance of CIGS solar cells and highlight promising avenues for future advancements in thin-film photovoltaics
Study on the Pile-soil Interaction of Large-diameter Piles Under the Wave Loading
Full text linkLarge-diameter pile is the main foundation type of offshore wind power engineering, which needs to withstand the long-term wave loadings. The pile-soil interaction is of great significance to the safety and stability of the foundation. In this study, numerical analyses with a two-dimensional model were employed to simulate the wave loading pile in layered soils. The results revealed that the pile-soil interaction shows a positive correlation with the wave loading, present a reciprocal trend, the displacement ranging from −9.3 mm to 10.7 mm in front of the pile and from −9.7 mm to 10.4 mm behind it, the plastic strain initially arises in the soil proximate to the point of rotation, rather than at the mudline, primarily occurs in the clay layer, gradually progressing from the bottom upward and expanding outward. The soil maximum stress is 23.9 kPa in sand layer, while 15.2 kPa in the clay layer, the stress does not correlate with depth in the clay layer, but significantly influenced by the clay layer's distribution
Rock Mass Characterization and Non-destructive In-situ Testing of a Rock-cut Tomb: Theban Necropolis (Egypt)
Full text linkThe current study describes the engineering geological properties of a rock-cut tomb that is located near Luxor, forming a part of the Theban necropolis in Egypt. The studied Theban Tomb no. 25 (TT 25) was excavated during the New Kingdom and served as a funeral site. The host limestone belongs to the Late Paleocene Tarawan Chalk Formation. The site investigations included the detection of the joint system, the measurements of relative humidity and temperature cycles, and moisture content. The rock mass parameters were also outlined considering the strength (obtained from Schmidt hammer rebounds) and the orientation and frequency of joints. Five joint sets were identified: three sub-vertical and one bedding-controlled sub-horizontal. The results of temperature, relative humidity, and moisture content measurements support the observations, namely that salts accumulate at the sloping passage and burial chamber, where higher humidity provokes salt efflorescence
Development of an Alternative Bitumen Rejuvenator Consisting of Waste Oils and Reacted and Activated Rubber (RAR)
Full text linkAfter a long-term in service on pavement, bituminous material exposure to environmental conditions and traffic loads leads to inevitable aging, causing an increase in binder viscosity and making it stiffer. On the other hand, the absence of proper elimination and illegal dumping of waste oil and tire rubber can lead to serious environmental risks. This research aims to investigate the possibility of using waste engine oil (WEO) and waste cooking oil (WCO) separately combined with reactive and activated rubber (RAR) as new alternative rejuvenating agents. In this study, 5% of waste oil (WCO, WEO) and 15% of RAR were added to the aged bitumen with a penetration grade of 20/30. The virgin, aged, and rejuvenated bitumen were investigated for their physical and chemical properties using penetration, softening point, and Fourier transform infrared spectroscopy (FTIR) tests, as well as the effect of thermal cycles (heating and cooling) on the cracking resistance of bituminous mixtures containing regeneration bitumen using the Fénix test. The study outcome indicated that these rejuvenators could effectively soften and restore the basic properties of the aged bitumen to a normal level of 40/50. Meanwhile, the bituminous mixture with the aged bitumen rejuvenated with both oils and tire rubber (AB-WRCO and AB-WREO) showed the best cracking behavior. Therefore, these alternative solutions involve not only reusing the aged bitumen but also reusing the waste oil and tire rubber in order to attain environmental protection and economic benefits
Numerical Analysis of Temperature Stress Generated by Hydration Heat in Massive Concrete Pier
Full text linkThermal crack induced by the hydration heat of massive concrete is the main problem that needs to be strictly controlled during the pouring process of concrete. In this study, the hydration heat of massive concrete pier and its influencing factors are studied numerically. The stress of massive concrete pier caused by the hydration heat of concrete is analytically derived. The influences of adiabatic temperature rise, ambient temperature and convection coefficient between the pier outer surface and environment on the temperature and stress of pier are studied. The results show that the peak values of temperature and stress of the pier increase with the increase of the maximum adiabatic temperature rise, the reaction rate coefficient and the ambient temperature. The peak value of stress reduces with the decrease of convection coefficient because the heat dissipation and the temperature change on the cross-section of the pier are reduced
Cybersecurity in Aviation: Exploring the Significance, Applications, and Challenges of Cybersecurity in the Aviation Sector
Full text linkThe increasing reliance on digital technologies in the aviation industry has amplified the need for robust cybersecurity measures. This article examines the critical issue of cybersecurity in aviation, exploring its importance, applications, and associated challenges. Through an analysis of real-world examples of cyber-attacks against aviation, the article highlights the potential consequences of inadequate security measures. Various applications of cybersecurity in aviation are explored, including air traffic management (ATM) Security, blockchain technology, airports, and aircraft systems protection. Furthermore, the article delves into the challenges faced by the industry in implementing effective cybersecurity protocols, considering factors such as evolving cyber threats, system interconnectivity, and the need to balance security with operational efficiency. The findings underscore the vital role of cybersecurity in safeguarding critical systems, protecting passenger data, and maintaining the integrity of aviation operations. The article concludes by emphasizing the necessity for continuous collaboration, information sharing, and investment in research and development to address emerging threats and ensure a secure future for the aviation industry
Adapting the ITF's Transport Policy with a Focus on the EU's Strategy of Sustainable Mobility
Full text linkUrban regions worldwide face increasing challenges in mobility planning due to transformative developments such as climate change, energy crises, migration, digitalisation, and the rise of artificial intelligence. In Europe, frameworks like the European Union's Sustainable and Smart Mobility Strategy and the International Transport Forum's (ITF) policy measures aim to create sustainable, multimodal, and efficient urban transport systems. This paper explores how these frameworks can be integrated to enhance urban mobility governance, focusing on the Brussels-Capital Region’s Good Move plan. The plan emphasises shared mobility, digitalised multimodal systems like mobility as a Service (MaaS), and a regulatory framework that balances innovation with public oversight. Through a "learning by doing" approach, this study highlights the interplay between public and private actors, effective data governance, and market regulation to establish a viable MaaS ecosystem. Key findings underline the potential of MaaS to reduce urban emissions, improve accessibility, and promote sustainable travel while addressing regulatory challenges such as data-sharing, competition safeguards, and equitable mobility subsidies. The paper concludes with actionable recommendations to optimise MaaS integration and support urban regions in achieving resilient, livable cities through sustainable mobility solutions
250 éves a Klimo Könyvtár: VI. Tudomány és kutatás a Klimo Könyvtárban konferencia (beszámoló)
No full textBishop György Klimo of Pécs opened his library to the public 250 years ago.The events included guided tours of the building, guided walks, craft activities and exhibitions to introduce visitors to the history of the Klimo Library and the wide-ranging activities of Bishop Klimo in the field ofnational education.
This article contains the report about the „250th Anniversary of the Klimo Library VI: Science and Research in the Klimo Library” conference and the temporary exhibition „The Klimo Library Researchers. Exhibition at the 250 years old Klimo Library”.250 éve nyitotta meg Klimo György pécsi püspök könyvtárát a nyilvánosság előtt. A jubileumi évforduló emlékére a Pécsi Tudományegyetem Egyetemi Könyvtár és Tudásközpont programsorozatot rendezett „Klimo 250-emlékév” címmel. A rendezvények keretében a látogatók épületvezetéseken, várossétákon, kézműves-foglalkozásokon és kiállításokon ismerkedhettek meg a Klimo Könyvtár történetével és Klimo püspöknek a hazai művelődés terén kifejtett széles körű tevékenységével. Jelen cikk a „250 éves a Klimo Könyvtár VI. Tudomány és kutatás aKlimo Könyvtárban” konferenciáról és „A Klimo Könyvtár kutatói.Kiállítás a 250 éves Klimo Könyvtárban” időszaki kiállításról készültbeszámolót tartalmazza
Influence of Laser Cutting on the Functional Safety of Metallic Vascular Stents
Full text linkA new method for the determination of missing data from scientific publications were presented on stent cutting lasers, using a combination of computational methods available from different sources in the literature. Some of the setting parameters for pulsed laser cutting are not independent of each other, which gives the possibility to determine some missing data in scientific articles: this way, data from different articles can be better evaluated, compared and experiments can be repeated, which is a useful basis for further development of a manufacturing technology. For this purpose, a new method was developed that allows the determination and calculation of the entire parameter system required for laser stent cutting. Finally, an evaluation system including weighting factors has been developed to quantify the defects of laser stent cutting, to classify the functional safety of the product, and to calculate the missing dimension that characterizes the cutting quality of stent manufacturing
Urban Mobility Modeling in PTV Visum with Various Options for Bus Fare Structure
Full text linkThe study focused on applying linear and non-additive fare structure models to simulate flat fares with a set of constraints for each fare model that can be used on public transport in real-world conditions. To this end, a method for modeling flat fares using PTV Visum software, specifically the origin-destination fare model, has been developed. The impedance function, which is used in the public transport headway-based assignment, is determined to minimize deviations between actual and calculated passenger volumes for bus routes using SQV statistics. The case study aims to develop a method for modeling flat fares within PTV Visum to predict and analyze passenger traffic on municipal bus routes in the Ukrainian city of Kryvyi Rih in the case of implementing flat fares for these routes. Two options were modeled: the current situation with a flat fare of UAH 15 (EUR 0.35) for bus routes run by private operators and fare-free public transit for municipal bus routes, and an anticipated scenario with a flat fare of UAH 15 (EUR 0.35) for bus routes operated by private companies and a flat fare of 8 UAH (0.18 EUR) for municipal bus routes. These evaluations provide insight into passenger flows on municipal bus routes under the existing fare option and in the case of implementing a charge for municipal transport in Kryvyi Rih. Obtaining results of passenger volumes and devising an approach to fare modeling is crucial for transportation sector decision-makers, aiding in the development of effective fare strategies within the city