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Found 6341 publications
A Framework for Effective Virtual Commissioning: Guiding Principles for Seamless System Integration
Publication Name: Journal of Manufacturing and Materials Processing
Publication Date: 2024-08-01
Volume: 8
Issue: 4
Page Range: Unknown
Description:
Virtual commissioning (VC), defined as the simulation and testing of systems in a virtual environment before physical implementation, plays a key role in addressing the challenges of integrating and validating complex systems efficiently and effectively. This paper focuses on the topic of virtual commissioning, summarizing and organizing existing research in the field. The paper provides a comprehensive overview of various design methods and technologies currently in use. A case study of virtual commissioning is also presented within the area of the Cyber-Physical Manufacturing Systems Laboratory of the Széchenyi István University, detailing the solution steps taken. Drawing on both research and practical experience, the paper proposes a novel framework to support virtual commissioning design, referred to as the “Virtual Commissioning House” (VCH). The methodology is evaluated through comparisons with existing virtual commissioning solutions, demonstrating its effectiveness.
Open Access: Yes
DOI: 10.3390/jmmp8040165
Numerical Modeling and Optimization of a Quasi-Resonant Inverter-Based Induction Heating Process of a Magnetic Gear
Publication Name: Energies
Publication Date: 2024-08-01
Volume: 17
Issue: 16
Page Range: Unknown
Description:
Induction heating is a clear, cheap, and highly effective technology used for many industrial and commercial applications. Generally, a time-varying magnetic field produces the required heat in the workpiece with a specially designed coil. The efficiency of the heating process depends highly on the coil design and the geometrical arrangement. A detailed and accurate finite element analysis of the induction heating process usually needs to resolve a coupled thermoelastic–magnetic problem, whose parameters values depend on the solution of another field. The paper deals with a shrink-fitting process design problem: a gear should be assembled with an axe. The interesting part of this case study is given the prescribed low limits for critical stress, the temperature of the gear material, and the heat-treated wearing surfaces. A coupled finite-element-based model and a genetic algorithm-based parameter determination methodology were presented. A thermal imaging-based measurement validated the presented numerical model and parameter determination task. The results show that the proposed methodology can be used to calibrate and validate the numerical model and optimize an induction heating process.
Open Access: Yes
DOI: 10.3390/en17164130
Empowering energy transition: Green innovation, digital finance, and the path to sustainable prosperity through green finance initiatives
Publication Name: Energy Economics
Publication Date: 2024-08-01
Volume: 136
Issue: Unknown
Page Range: Unknown
Description:
This study delves into the intricate relationship between financial digitization and green innovation, aiming to shed light on their dynamic interplay within a global context. Spanning from 2003 to 2020, the study encompasses 15 diverse countries, encompassing both developed and emerging economies, including Australia, Brazil, Canada, China, France, Germany, India, Italy, Japan, Mexico, Russian Federation, South Africa, Turkey, the United Kingdom, and the USA. It not only explores the direct connection between financial digitization and green innovation but also takes into account various controlling factors such as economic growth, industrial value addition, research and development expenditure, and gross national expenditure. The key findings from quantile regression reveal financial digitization have a significant positive effect, indicating that in countries with lower green innovation levels, an increase in digital financial services significantly boosts green innovation. This positive impact persists across quantiles, even in countries with higher green innovation levels, albeit to a lesser degree. Economic growth consistently shows a negative association with green innovation across all quantiles. Research and development expenditure consistently demonstrate a positive relationship with green innovation across all quantiles, emphasizing that countries allocating a higher percentage of their economic growth to research and development expenditure activities experience substantial increases in green innovation. This underscores that countries allocating a higher percentage of their economic growth to research and development expenditure activities experience substantial increases not only in green innovation but also in the facilitation of green finance initiatives.
Open Access: Yes
Music-making in microgravity: across the first 63 years (1961-2024) of spaceflight. Academy transaction note
Publication Name: Acta Astronautica
Publication Date: 2024-08-01
Volume: 221
Issue: Unknown
Page Range: 85-89
Description:
Musical expression is a characteristic of humanity on Earth. This paper highlights the historical relationship between music and spaceflight, including its use in the representation of space, and its role in space culture. The paper documents circa 57 musical instruments: from a miniaturized harmonica to a 1.5 m Digeridoo that are known to have been taken into space – usually as part of a crew members personal allowance. Due to mass and volume restrictions numerous classical and ethnographic instruments have been ‘spaceflight-adapted’, in addition to the use of digital technologies for personal musical pleasure and public relations. Furthermore, it charts how access to personalised music playlists and shared musical experiences have been deemed to be vital by crew, promoting individual wellbeing including a connection to home, to each other and playing a part in the marking of success, and tragedy. The value of music making in space is briefly described leading to the proposition that as humanity ventures with greater regularity to Low Earth Orbit and beyond, consideration of how music can be effectively utilised to support individual and crew wellbeing, whilst contributing to the cannon of human artistic expression is warranted.
Open Access: Yes
Effect of the Particle Size Distribution of the Ballast on the Lateral Resistance of Continuously Welded Rail Tracks
Publication Name: Infrastructures
Publication Date: 2024-08-01
Volume: 9
Issue: 8
Page Range: Unknown
Description:
While the effect of ballast degradation on lateral resistance is noteworthy, limited research has delved into the specific aspect of ballast breakage in this context. This study is dedicated to assessing the influence of breakage on sleeper lateral resistance. For simplicity, it is assumed that ballast breakage has already occurred. Accordingly, nine granularity variations finer than No. 24 were chosen for simulation, with No. 24 as the assumed initial particle size distribution. Initially, a DEM model was validated for this purpose using experimental outcomes. Subsequently, employing this model, the lateral resistance of different particle size distributions was examined for a 3.5 mm displacement. The track was replaced by a reinforced concrete sleeper in the models, and no rails or rail fasteners were considered. The sleeper had a simplified model with clumps, the type of which was the so-called B70 and was applied in Western Europe. The sleeper was taken into consideration as a rigid body. The crushed stone ballast was considered as spherical grains with the addition that they were divided into fractions (sieves) in weight proportions (based on the particle distribution curve) and randomly generated in the 3D model. The complete 3D model was a 4.84 × 0.6 × 0.57 m trapezoidal prism with the sleeper at the longitudinal axis centered and at the top of the model. Compaction was performed with gravity and slope walls, with the latter being deleted before running the simulation. During the simulation, the sleeper was moved horizontally parallel to its longitudinal axis and laterally up to 3.5 mm in static load in the compacted ballast. The study successfully established a relationship between lateral resistance and ballast breakage. The current study’s findings indicate that lateral resistance decreases as ballast breakage increases. Moreover, it was observed that the rate of lateral resistance decrease becomes zero when the ballast breakage index reaches 0.6.
Open Access: Yes
Ballast Settlement Accumulation in Zones with Unsupported Sleepers
Publication Name: Transportation Infrastructure Geotechnology
Publication Date: 2024-08-01
Volume: 11
Issue: 4
Page Range: 2598-2637
Description:
The high influence of impact and vibration on the behavior of crushed stone and ballast materials has been known for a long time. The zones with unsupported sleepers, which are always present in transition zones, crossings, welds, etc., are typically characterized by impact interaction, ballast full unloading, and additional preloading. However, no studies on ballast layer settlements consider impact vibration loading. Moreover, the influence of the cyclic loading on the ballast settlement intensity is considered ambiguously, with both decelerating and accelerating trends. The comprehensive literature review presents the influence of factors on settlement intensity. The present study aims to estimate the long-term processes of sleeper settlement accumulation depending on the loading factors: impact, cyclic loading, and preloading. The typical for a void zone ballast loading pattern was determined for various void sizes and the position along the track by using a model of vehicle-track interaction that was validated by experimental measurements. The loading patterns were parametrized with four parameters: maxima of the cyclic loading, impact loading, sleeper acceleration, and minimal preloading. A specially prepared DEM simulation model was used to estimate the ballast settlement intensity after initial settlement stabilization for more than 100 loading patterns of the void zone cases. The settlement simulation results clearly show that even a low-impact loading pattern causes many times increased settlement intensity than ordinary cyclic loading. Moreover, the initial preloading in the neighbor-to-void zones can cause even a decrease in the settlement intensity compared to the full ordinary or partial unloading. A statistical analysis using a machine learning approach and an analytic one was used to create the model for the intensity prediction regarding the loading patterns. The analytic approach demonstrates somewhat lower prediction quality, but it allows to receive plausible and simple analytic equations of the settlement intensity. The results show that the maximal cyclic loading has a nonlinear influence on the settlement intensity that corresponds to the 3–4 power function, and the impact loading is expressed by the linear to parabolic function. The ballast’s minimal preloading contributes to the reduction of the settlement intensity, especially for high cyclic loadings that are typical for neighbor-to-void zones. The results of the present study could be used for the complementing of the present phenomenological equations with the new factors and further application in the algorithms of the settlements accumulation prediction.
Open Access: Yes
Examining Shape Dependence on Small Mild Steel Specimens during Heating Processes
Publication Name: Materials
Publication Date: 2024-08-01
Volume: 17
Issue: 16
Page Range: Unknown
Description:
With regard to the heating technology of small test specimens (D < 1 inch, i.e., 25.4 mm), only a limited amount of data and literature are available for making adequate technological decisions. Heating time of small geometric shapes is influenced by the technological parameters of the furnace, the temperature, the disposition technique in the furnace and the geometric characteristics of the workpiece. How to shorten heating time to achieve a suitable material structure is a vital question, while considerable energy is saved at the same time. Among the geometric characteristics, shape dependence is one of the important aspects that must be taken into account in terms of heating technology. Shape dependence is usually taken into account with empirically produced correction factors, which can result in significant oversizing of heating time, energy-wasting technology and material structure of insufficient fineness. In the course of our work, we investigated and compared the shape dependence of cylindrical and prismatic specimens with the same surface-to-volume ratios, which were combined with surface heat transfer analyses and geometric effect tests to formulate new approximate equations for determining heating time. As a result, we could mathematically derive a relationship between heating time, size and shape of the active surfaces, the correlation of which can shorten heating time by 20%. In addition, a shape factor (1.125) between cylinder and prismatic-shaped specimens was determined, which can be used with the new equation to calculate heating time for similar specimens. At last, a relationship is developed between the amount of heat that can be stored in the body during heat equalization and the complexity of the shape, which can be characterized through ratios depending on heating times and active surfaces in the function of total surface/volume ratio. Based on this relationship it can be determined more precisely when heat equalization occurs; therefore, shorter heating time can be achieved. In conclusion, with the help of this new method, optimal heating time for structural steel components, in the case of small cross-section and weight, can be determined.
Open Access: Yes
DOI: 10.3390/ma17163912
Exploratory analysis of zero waste theory to examine consumer perceptions of sustainability: A covariance-based structural equation modeling (CB-SEM)
Publication Name: Cleaner Waste Systems
Publication Date: 2024-08-01
Volume: 8
Issue: Unknown
Page Range: Unknown
Description:
Introduction: The analysis of corporate and consumer sustainability practices is currently the focus of several scientific disciplines due to their environmental impact and diversity. Objective: This research aims to create a hierarchy of consumer perceptions of zero waste thinking that can guide government decisions regarding university communities' sustainability efforts. To achieve the objectives of this study, Hungarian university citizens (students, faculty, staff) as potential zero waste consumers in Győr were involved in a purposive sampling approach. Methods: This study adopted the Covariance-Based Structural Equation Modeling (CB-SEM) methodology to prove the hypotheses related to the 7Rs regarding Zero Waste perceptions of university citizens. The rethink element of the hierarchy was defined as the default condition for the 7 R application and therefore remained at the top of the hierarchy as an endogenous variable. Results: The study concluded that it is possible to adapt a business 7 R framework for consumer use, but only 5Rs can be applied. The analysis was conducted at a 90% confidence level, under which condition the independent variables together explain 87% of the variance of the rethink factor. The results show that the four constructs, namely rot (β =0.12, ρ<0.1), reduce (β =0.21, ρ<0.1), recycle (β =0.26, ρ<0.05), and reuse (β =0.43, ρ<0.05) significantly affect rethinking. Based on these regression weights, a hierarchy of importance can be established. In line with the original 7 R business concept, rethink is at the top of the hierarchy, followed by the other elements. Conclusions: The results suggest that the zero waste attitudes of university citizens are currently limited to the 5Rs, which should require government leadership to strengthen these factors or a more consistent presence and support for the 2Rs that are missing from the established model. Governments can use the results of this research in their sustainability-related decisions.
Open Access: Yes
Graphical pinch analysis-based method for heat exchanger networks retrofit of a residuum hydrogenation process
Publication Name: Energy
Publication Date: 2024-07-15
Volume: 299
Issue: Unknown
Page Range: Unknown
Description:
Sustainable energy systems are crucial for reducing carbon emissions because renewable energy sources leave a footprint. The petrochemical industry often suffers from inefficient heat exchange network (HEN) systems, leading to substantial energy wastage. In the current work, a real case study of the residue hydrogenation process was analyzed to identify potential energy savings. A new method combining Pinch Analysis and Thot –Tcold diagram analysis methods was proposed. This graphical analysis method plots the cold-flow temperature of each heat exchanger unit on the x-axis and the hot-flow temperature on the y-axis. By applying the Thot –Tcold diagram to a practical case of residue hydrogenation in Zhejiang, the existing process energy state was evaluated, and HEN was retrofitted to achieve energy savings and carbon emission reduction. Following optimization, the energy recovery amounted to 202.71 GJ/h with an energy recovery rate of 14.3 %. The proposed method saves approximately 4.058 × 105 GJ/y compared to current operations, resulting in an annual cost saving of approximately $ 2.76 M/y, with an investment payback period of less than 0.36 y. This study offers a solution to the energy challenges of industrial residue hydrogenation by enhancing the economic and environmental sustainability of existing process flows.
Open Access: Yes
