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Sealing Performance of Beam Tube Flange Connections Under Internal Pressure and External Bending Loads
52-70Views:145Pipe flange connections are critical components in nuclear and petrochemical facilities, where reliable sealing and structural integrity are essential for safe operation. In research on open-pool reactors, ion beam tubes represent a specialized application of flange-connected pressure boundaries. This study investigated the structural response and sealing performance of a beam tube–flange assembly using three-dimensional nonlinear finite element analysis. The beam tube was evaluated under two operating conditions: an empty configuration and a configuration subjected to externally applied mechanical loads. Stress analysis indicated that the maximum Von Mises stress in the beam tube remained well below the material yield strength and satisfied the design deformation limit of 3 mm for both loading scenarios. Sealing performance assessment of the flange joint showed a bolt stress variation of 23 MPa, which remained within acceptable design limits. The corresponding gasket stress variation was 0.49 MPa, with maximum and minimum gasket stresses were within the recommended operating range of 1.4–8 MPa. Time-dependent analysis revealed gasket stress relaxation of 3.5% for the empty beam tube and 3.78% for the externally loaded case. The finite element results were validated using analytical models, demonstrating good agreement with discrepancies ranging from 0.01% to 5.8%. The findings confirmed the structural adequacy and sealing reliability of the beam tube–flange assembly under the investigated operating conditions, providing a robust basis for safe design and operation in research reactor applications.
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Experiences of Innovation Projects in the Light of the „European Paradox”
563-578Views:284Corporate innovation can be a major factor in economic development and long-term high-level corporate performance. The position of the EU in international innovation rankings has not improved since the 2000 2009 period; though there has been a more positive trend since 2010, meeting the Lisbon goals, the EU is still not at the forefront in terms of R&D&I. Behind this process is the rapid progress of some industrially developing nations in R&D&I, as well as the relatively slow institutional development of national innovation systems in Europe. The relative lag in Europe can be explained by the frequently referred to “European paradox”, which is still unclear for methodological reasons. Firstly we consider the international ranking in innovation, then discuss one of the explanations put forth to explain this rather weak performance. We present case study that represent Hungarian experiences with corporate innovation.
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Role of Biomass in Urban Energy Management
62-76Views:362When making decisions on the use of energy, both on building and on city level, biomass plays certainly a role in looking for sustainable solutions. This study starts with highlighting some key points regarding urban energy management, including world urbanization trends, heat island effect of big cities and energy hierarchy in energy management. With these in mind, it is worth considering, how the shading effect of surrounding biomass can mitigate the heating needs as a wind barrier in the winter or decrease the cooling load as shadowing element in the summer, both for buildings and whole cities. These can be further enhanced by biomass integrated in the buildings’ envelope: green roofs and green walls can have significant energy conservation effects, according the characteristics of their different types. Lastly, urban disposal of biomass can lead to renewable energy generation, both in case of biogas production and waste incineration. These shading, covering and fuel possibilities all underline the importance of biomass in urban energy management.
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Effect of Heat Input on the Toughness Properties of S690QL Steel during Hardfacing
1-13Views:171In recent years, the use of high-strength steels in hardfacing process has become increasingly common. One typical industrial example is the case of hydraulic shears used in building demolition operations, where the components are exposed not only to significant abrasive wear but also to intense dynamic loading. The use of quenched and tempered high-strength steel grade S690QL has become particularly widespread in this field, primarily as the base material for the hardfacing applied to the most heavily loaded regions of demolition shears. However, quenched and tempered high-strength steels are highly sensitive to the effects of the welding thermal cycle, which typically cause detrimental changes in the microstructure and mechanical properties of the heat-affected zone. The thermal cycles occurring during hardfacing differ from those typical of fusion welding, and consequently, the structure and mechanical properties of the resulting heat-affected zone may also vary. In addition, the penetration depth of the hardface layer can differ, which may significantly alter the load-bearing cross-section of the high-strength steel and, thus, the in-service behavior of the component. In the experimental work, hardfaced samples were performed on S690QL base material using different levels of heat input, thereby producing varying penetration depths. The aim of the study was to determine the effect of penetration depth on the resistance of the hardfaced component to dynamic loading. The tests were carried out at both +20 °C and –40 °C. The results clearly demonstrated that samples with deeper penetration exhibited reduced toughness at both investigated temperatures.
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Investigation of the Eigenfrequency of the Bending Vibration of the Beam Clamped at Both Ends Around the Principle Directions of Inertia Based on a Single-Degree Freedom Model and a Finite Element Method Analysis
69-79Views:431In this study, we have dealt with the calculation methods of the eigenfrequencies associated with the bending vibrations of rectangular-shaped beams clamped at both ends. Said eigenfrequencies were determined analytically in the single-degree of freedom model of the beam and the case of the three-dimensional solid and three-dimensional rod models by finite element modal vibration analysis. We presented the calculation method of the characteristics of the analytical model and then calculated the eigenfrequency for a concrete example. We have described the concept of modal characteristics, and in the following, we have determined its natural frequency based on the solid-beam and rod models of the former beam. We calculated and compared the solutions belonging to the models recorded in different ways in 11 additional cases of the presented methods.
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How Does Public Debt Change when the Next Crisis Comes - and It Will Come!/the Expected Evolution of Greece's State Debt in the Next Crisis Period/
91-104Views:404It has recently been announced that Greece may withdraw from the Euro-Zone permanent rescue fund's aid program because it has successfully met the conditions imposed on it. Creditors and credit qualifiers also agreed that the Greek economy was on a good growth path. That is why there is a chance that by 2030 the current sovereign gross debt of 182.7 per cent of GDP will fall to 123.3 per cent. The author finds this statement unfoundedly optimistic. He argues that the Greek debt ratio – despite the current optimum economic fundamentals – does not seem to be sustainable. He sees greater probability that in the near future it will again be necessary to release some of the Greek debt. Debt reduction will also mean a new orderly state bankruptcy. The study seeks to highlight how vulnerable and risked the sustainability of current Greek debt financing. Using a macroeconomic model, it shows and justifies how the Greek sovereign debt changes in the case of a crisis that is only half the extent of the previous subprime crisis. If this happens, by 2023, the state debt will rise to more than double the national product, and by 2030 only to the present, otherwise critical, level. It follows that the high risk of financing Greek state debt remains unchanged.
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Vállalkozói képzés a 21. században a felsőoktatásban – lehetőségek, módszerek, jó gyakorlatok
1-18Views:688Challenges of the 21st century require answers from higher education as well. In Europe, most of the entrepreneurship programmes on the higher education institutions are less than ten years old. Whilst business studies may battle for academic legitimacy, it has a clear advantage when it comes to graduate employability. The aim of this paper is to give answer to the following questions: why entrepreneurship education is important, what are the methods which are already used and what are the results of them. The answers to the questions are based on literature reviews, a case study and in-depth interviews with alumni carried out at the University of Debrecen, where since 2010 Team Academy Debrecen, a new education model from Finland is implemented. Tiimiakatemia education is an innovative Finnish model founded in 1993 by Johannes Partanen that develops team entrepreneurs. Based on the results some of the important elements of entrepreneurship teachability are: learning by doing, passion, learning in teams, coaching and mentoring.
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Impacts of Digital Communication Tools on Fashion Brands Success –The NUDE Project
1-13Views:886The global scale, changing fashion industry can be characterised with low predictability, high volatility, seasonality, short life cycle products and highly impulse consumer purchasings decisions, addressing ethical and sustainability matters. Fashion as generic collecting name can be defined as styles of clothing and accessories worn at any time by different groups of people. One of the main opportunity and challenge for this complex, multi actors sector introducing digital solutions, which can provide significant contribution of restructuring the supply chains, optimising the production techniques, reducing its negative environmental externalities supporting the future sustainability. Possible reason beyond this digitization trend can be changing consumer attitudes and expectations. Majority of consumers have tendency using digital channels before, during and after their purchase, so fashion brands have to take into consideration this new reality. The convenience and accessibility of online enjoyable shopping opportunities have reshaped consumer expectations including personalized recommendations, and user-friendly online social media platforms (video channels, websites, mobile apps, and secure payment systems). Instagram, TikTok, YouTube and Pinterest have transformed the way fashion brands communicate and connect with their audience creating loyal social network. Digital transformation requires more than just implementing new technologies; it necessitates a cultural shift within fashion brands. Case study of the NUDE Project analysing its challenges and main competitors as well, can serve as an illustrative example how can the digital communication tools contribute to the fashion brand future success and prosperity.
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Analysis and Comparison of Forecast Methods for a Small Enterprise
14-21Views:577The application of forecasting models is an essential part of the profitable operations of every company. However, today’s small and medium sized enterprises (SMEs) does not pay enough attention to this field. This research presents a case study in which we tried to determine the sequence of a forecasting process, furthermore, determine the best applicable method to the dataset. Seven dissimilar forecasting method was applied: moving average and weighted moving averages with different periods (2-3-4 weeks), as well as exponential smoothing. The four-week-long weighted moving average served the best solution, which was tested by tracking signal as well.
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Battery Measurement Methods and Artificial Intelligence Applied in Energy Management Systems
428-436Views:348Diagnostics of batteries using advanced methods have gained remarkable roles in the past few years. This study focuses on the type of measurements, tests and methods to reveal and classify them. During manufacturing and operation several faults could emerge in batteries including non-optimal operation conditions, operators without experience, and finally, random changes in batteries under physical and nonphysical conditions. Improper handling of batteries and battery cells man cause operation failures or, in the worst case, accidents. To reveal these problems several methods are applied in industry and in scientific laboratories. For a comprehensive analysis of battery management, artificial intelligence and Industry 4.0 methods can be used very effectively. Big Data analysis in its standard form is not a new achievement, but other mathematical tools could be applied to control monitoring such as Fuzzy Logic or Support Vector Machine (SVM). They are efficient tools to analyse the deviation of batteries condition because it can detect sudden changes, parameter deviations and anomalies, and the user’s behaviour and habits. This article gives a description about the most important battery testing methods and the connection between Big Data and Operation Management with Artificial Intelligent (AI) methods.
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Adapting Open Innovation Model in Supplier Qualification Programs
155-167Views:517The development of innovative models fundamentally contribute to the changing the way of thinking in business context. Today, in this process, the impact of open innovation model is a kind of paradigm shift. The contents of this change has been mostly clear in the field of context of product-, innovation and technology, but not onm the field of organizational and management innovations. In this study, we sought to answer that in the case of knowledge transfer’s special field –the programs of suppliers - how to apply the principles of open innovation and how this may have positive effects. The motivation behind, was to look for commonly used models for the SME sector, that is fundamentally linked to large enterprises as suppliers, characterized by increasingly rapid technological development ecosystem to collaborate.
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Do Changes in the Economic Role of States through Privatization matter?: The Brazilian Case
125-136Views:351In market economies, the subject of scientific research is the extent to which the state can contribute to the sustainability of development. However, the question is to know where the boundaries of the market and the role of the state lie. The study briefly introduces different views of the state's economic role and how states have changed the proportion of their entrepreneurial assets. Among these, it highlights privatization, which is one of the significant segments of today's economic policy practice at both micro and macroeconomic levels. It then describes Brazil's economic circumstances that led to the formulation of a proper size privatization program. Finally, the socio-economic factors that, according to the author, make the realization of Brazilian privatization plans uncertain presented.
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Local Annealing of Cold Rolled Aluminum Sheets by LASER Treatment
21-26Views:296LASER treatment widely used in material processing technologies. The annealing is not the typical application of the LASER treatment, but this is possible to apply in case of cold deformed metals. In the article a cold rolled EN AW 8006 aluminum sheet is annealed by LASER treatment. The microstructure of the annealed sheets is observed by optical microscopy. An existing cellular automata simulation of recrystallization process is modified to study the LASER annealing. The observed microstructure and the simulated results are compared to determine the further development of the developed automaton.
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Organisational Culure and Academic Performance of Technical Management BSc Students
1-11Views:304Our study analyses the connection between perceived and ideal organizational cultures and academic results. A modified, self-managed OCAI questionnaire was used to measure perceived and ideal organizational cultures among engineering management students of the University of Debrecen Faculty of Engineering (N = 114). Our results reveal weak positive linear correlations between academic performance and perceived or ideal level of clan culture. In case of other culture types we did not find any consistent relationship. Based on our results students who consider clan culture ideal can expect better results than those who prefer other types. Among students who visit at least 61% of the classes those who reported fitting (or better fitting) perceived and ideal cultures tend to perform better in their studies.
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Cybersecurity Challenges in Agricultural Digitalization: A Systematic Review with Python-Based Analysis
33-47Views:519The intersection of agriculture and cybersecurity has become a prominent research focus in recent years, driven by the rapid adoption of IoT (Internet of Things) and precision farming technologies. These technological innovations have revolutionized agricultural processes, enhancing efficiency and sustainability while introducing significant security risks. This study conducts a systematic literature review (SLR) to address key cybersecurity issues in agriculture, with a particular emphasis on IoT vulnerabilities and threats. Using Python-based text analysis techniques, the research automated the analysis of abstracts and full texts, enabling rapid filtering and thematic categorization of relevant studies. From an initial pool of 1,039 publications, 40 relevant studies were identified based on rigorous screening criteria. The thematic analysis revealed that 44.9% of the publications focus on IoT device vulnerabilities, 32.7% on agricultural cybersecurity challenges, and 22.4% on the security issues of Agriculture 4.0 and precision farming. Methodological analysis indicated that machine learning, simulation models, and case studies dominate the research landscape, while surveys and experimental studies appear less frequently. The findings highlight the critical importance of developing robust cybersecurity strategies and technologies in the agricultural sector, particularly to mitigate the risks posed by IoT devices.
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Level of Digital Competences and the Examination the Relationship Between Unemployment and in Job-Trainings in the European Union
197-209Views:438In this study we examined the digital competences by the EU Member States between 2015 and 2017 based on data of OECD and EuroStat. We wanted to know, are there any relationship between the unemployment and the level of digital competences. We realised that, in these countries where the percentage of individuals with basic digital skills is higher, there the harmonized unemployment rate is lower, than in those states where the individuals have above-average digital skills. In the case of lower educated states (where the citizens do not have a general digital knowledge), the unemployment rate is higher. We researched the openness of companies towards individuals with different levels of digital knowledge. In these countries, where the more educated people live there provide the comapnies more chance to take part further trainings, than in the less educated countires. We found a moderately strong negative correlation between the group of individuals who have low overall digital skills and in-work trainings. It means, if a country has individuals with a few digital competences, there the organisations will not offer trainings them. According to the available data we could divide the EU Member States in three clusters. These groups are underdeveloped, developing, developed countries. The biggest difference is between these groups in the quantity of skilled people, however the distribution of individuals in the developed group also shows interesting features. We realised in these countries the so-called „reverse competence pyramid”. It means, as the level of skill grows, the number of individuals, who own it, grows as well. As a continuation of the research, it would be worth examining the countries regionally, so it would be clear where are, the "digital kingdoms" can be found. On the one hand this could help the state in the allocation of digital education, on the other hand, it would also improve the position of companies. They could create regional centers in less developed countries, thus outsourcing expensive high added value work.
