Periodica Polytechnica (Budapest University of Technology and Economics)
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Materials Challenges of the New Nuclear Power Plant in Hungary
Get PDFHaving the experience accumulated during close to twenty thousand reactor years worldwide one may say that enough knowledge is available on the behavior of nuclear structural materials. In recent years however new questions emerge in close association with the long-term operation of nuclear power plants. The questions are in relation with both the operating and the future plants. Hungary operates four Russian designed VVER-440 nuclear units, and currently, two VVERs are under construction. The new, VVER-1200 type reactors represent the generation 3+ which is the latest and the safest version of the world's reactor fleet in operation. Service life of VVER-1200 reactors is 60 years, and operation beyond this term is foreseen. The structural materials of the main and usually non replaceable pressurized components such as reactor pressure vessel, steam generator and so on have to resist load and environment during the long operation period to ensure the components' structural integrity. It is right to say that the long-term, safe operation of the current and future reactors is ultimately governed by the performance of the structural materials in the mechanical technological systems. After introduction of the evolution process of the VVER structural materials performance the article reviews the major loading and environmental parameters of the operation and the ageing effects induced by the operation. Then the most important materials aspects and challenges are presented and discussed
Decomposition of Carbon Dioxide (CO2) Emissions in Hungary: A Case Study Based on the Kaya Identity and LMDI Model
Get PDFElevated levels of global greenhouse gases (GHGs), primarily produced through fossil fuel combustion, present environmental risks such as prolonged droughts, global warming, and catastrophic floods. Despite raising awareness and international efforts to combat climate change, fossil fuel and GHGs demand persists. At this juncture, this study investigates Hungary's transportation sector, a notable CO2 emitter. Using the Kaya Identity and Log Mean Divisia Index method, this study decomposes the primary components of CO2 emissions in Hungary's transport sectors from 2001-2021. This analysis is done in two decomposition levels, annual and periodic decomposition analysis for each of the five years starting from 2001. The analysis reveals that the economic activity effect ∆CGPE is the predominant driver of CO2 emissions, while the energy intensity effect ∆CEIE improvements have substantially mitigated these increases. Population changes affect ∆CPOPE, and the carbon emission intensity effect ∆CCEIE has had minimal impacts. The study provides insights and recommendations for policy and strategic interventions to reduce emissions and promote sustainable transportation practices in Hungary
Egy fogalom diadalútja (?): Entitások a könyvtárinformatikában és a könyvtárosképzésben
No full textIn the second half of the 90s, a new trend appeared in the library and information science: it is about thinking about the bibliographic universe as a network of entities and their connections. Today there are many publications on this topic, however, according to the literature, the concept of entity has not only one but at least three definitions, that hardens the discourse between the experts and the library and information science education. There are authors who define entities as if they were equal to bibliographic resources, others think that they are unique and discrete things. And some of the authors think that the entities are sets or categories of unique things. In this study, in order to mitigate this heterogeneity, I try to strengthen the category view, and I examine the problem from the viewpoint of the metadata librarians and also of the LIS educators.Az entitás fogalma és a bibliográfiai univerzum új szempontú felfogása az 1990-es évek második felében jelent meg a könyvtártudományban. Az azóta eltelt csaknem 25 évben az új irányzat egyre nagyobb teret követelt magának, eleinte az elméleti publikációk, később már a gyakorlati implementációk területén is. Ma már nem csupán fogalmi modell (LRM), hanem katalogizálási szabályzat (RDA), illetve az új típusú metaadat-leírásokat hordozni képes technológia (RDF) is rendelkezésre áll, az esettanulmányok száma pedig azóta is örvendetesen növekszik. Maga az entitásfogalom azonban, a szakirodalom tanúsága alapján nem rendelkezik egyetlen, széles körben elfogadott definícióval, amely a könyvtári szakemberek közötti párbeszédet, illetve az új kollégák képzését is megnehezíti. Egyes szerzők bibliográfiai egységként, mások egyedi létezőként, megint mások elemeket tömörítő halmazként hivatkoznak rá. Írásomban e nehézkes heterogenitás mérséklése céljából az entitás kategóriaként történő értelmezésének népszerűsítésére teszek kísérletet, s bemutatom, hogy ennek a megközelítésnek milyen előnyei mutatkoznak a közgyűjteményi informatika, valamint a könyvtárosképzés területén
Development of Green Extraction Using Natural Deep Eutectic Solvent (NADES) for Separation Polyphenolic Compounds from Spilanthes acmella
Get PDFNatural deep eutectic solvent (NADES) is an alternative to conventional solvents in polyphenol extraction. Its composition of choline chloride combined with fructose, choline chloride with lactic acid, choline chloride with glycerol, choline chloride with propylene glycol, and choline chloride with proline have been sucessfully set using the thermal mixing method. Choline chloride served as the hydrogen bond acceptor (HBA), while the others acted as hydrogen bond donors (HBDs) at a mole ratio of 1:2. This study aimed to extract polyphenols from the flowers, stalks, stems, and leaves of Spilanthes acmella, using NADESs. The extraction process was conducted by adding 20% water to the mixture with a ratio of the sample to solvent of 1:10 (w/v), for 60 min. The extract concentration was assessed through spectroscopic photometry using the Folin-Ciocalteu method. The result showed that the choline chloride-glycerol NADES was the most appropriate solvent for the extraction of polyphenols from the flowers of the plant. Meanwhile, the best NADES for the extraction from the stems, stalks, and leaves, was the mixture of choline chloride and fructose. The highest polyphenol concentration was obtained in the stems at 2545.192 mg/L. The yield obtained in the stems, leaves, stalks, and flower were 25.452, 6.284, 3.111 and 2.415 mg gallic acid equivalent/g (GAE/g), respectively. These findings suggest that NADES can be used as an eco-friendly alternative solvent for green extraction processes of active compounds from natural materials, especially polyphenols from S. acmella
An Investigation into the Digital Construction Progress Monitoring Models
Get PDFConstruction exhibits relatively low efficiency and a modest annual productivity growth rate despite being one of the largest industries. As digitalizing the construction progress monitoring process and ensuring the objectivity of the obtained data is considered as a critical area for enhancing efficiency of the AEC (Architecture, Engineering, and Construction) industry, AEC companies invest in resources to extract and report construction data obtained from the site. This paper examines digitalization efforts in construction progress monitoring, focusing particularly on studies proposing new monitoring models. Articles focusing on studies proposing a specific model for digitalization of progress monitoring was searched in databases. A framed literature review study is conducted, bibliometric analysis is performed via keywords and the Vosviewer tool and finally semantic and methodological variations of models studied. An in-depth analysis of these studies reveals that the proposed models fundamentally consist of four different elements defined as: data collection methods, data processing methodologies, the specific construction areas they focus on, and the primary input objects they address. All studies were examined and categorized under these four distinct headings and mapped accordingly. The relationships between the emerging methods and their frequency of preference were also analyzed. Both more frequently and less commonly employed approaches have been identified in the literature. Additionally, this paper highlights potential research areas on possible data collection and processing ways, specific construction areas and input sources to focus in the literature by emphasizing the existing relationships and correlations between the mentioned categories
Polymer-based Bipolar Plates for Fuel Cells: Design, Simulation, and Manufacturing
Get PDFThis paper presents the optimization of bipolar plates for polymer-based fuel cells designed for small-scale applications like drones and portable devices. The fuel cell uses an open-cathode system, where air from the environment is the oxidant, reducing weight and complexity. Three initial design concepts were created, and the counter-flow design was selected for further development due to its higher performance potential. The plate geometry was optimized with semi-circular channels on the anode side to improve hydrogen flow and U-shaped channels on the cathode side for better water removal. Flow and pressure distributions were analyzed using Computational Fluid Dynamics (CFD). Although early results showed uneven distribution, further adjustments led to a new design, which improved manufacturability and reduced deformation. After testing different gas inlet configurations, a final design was developed, showing more uniform flow and better performance for lightweight applications
Satisfaction with Experiential Balloon Flights in the Context of Gender Groups: The Case Study of the Czech Republic
Get PDFChanges in visitor preferences and lifestyle are giving rise to new forms of tourism. Coming to the forefront are new, unique experiences, which significantly support the development of experiential tourism, including activities such as scenic hot air balloon flights. Balloon flying allows clients to create an emotional experience and also serves as an educational and entertaining element. Even in this segment there is significant competition, companies are forced to offer a product according to the requirements of the clientele, which differ significantly not only by age, but also by gender. The aim of the article was to define the level of experience and satisfaction with the services based on a web review analysis, which was determined through quantitative assessment (scoring), willingness to recommend, and qualitative content analysis of individual reviews conducted using NVIVO (14) software. The research focused on identifying differences between reviews and recommendations of women and men of Czech clientele (226 reviews). Overall, the participants of the balloon flight rated the experience as very positive, most clients associated it with the words great, wonderful or even romantic. A quarter of the participants further recommended this form of experience. As part of the statistical testing, the dependence between the gender of the reviewer and the scope of the review, recommendation, and satisfaction was not confirmed. On the contrary, the dependence between gender and the choice of place for publishing a customer review was confirmed
Innovatív könyvtári lakberendezés : Állományalakítás mint forgalomgenerálási eszköz a Gödöllői Városi Könyvtár és Információs Központban
No full textThe Municipal Library and Information Centre of Gödöllő uses non-traditional, marketing-oriented library solutions to increase reader activity and utilisation of information resources. The present study examines the effects of the implemented shop concept on library circulation statistics, with a special focus on acquisitions in 2022. The statistical analyses show that thematic groupings and highlights have significantly contributed to higher utilisation of library resources and increased reader satisfaction.A Gödöllői Városi Könyvtár és Információs Központ a nem hagyományos, marketingorientált könyvtári megoldásokkal növeli az olvasói aktivitást és az állomány kihasználtságát. Jelen tanulmány a bevezetett shop koncepció hatásait vizsgálja a könyvtári forgási statisztikákra, különös tekintettel a 2022-es beszerzésekre. A statisztikai elemzések alapján látható, hogy a tematikus csoportosítások és kiemelések jelentősen hozzájárultak a könyvtári állomány nagyobb kihasználtságához, valamint az olvasói elégedettség növeléséhez
