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Investigation on Double Oxide Film Initiated Pore Formation in Aluminum Casting Alloys
141-153Views:316The most common, and in fact, the most deleterious defects of aluminum casting alloys are the so-called double oxide films or bifilms, which have a central role in porosity formation, as they can easily unfurl and inflate into pores during the solidification of the alloys. Sr addition is generally used in the foundry industry for the modification of the eutectic Si phase of hypoeutectic Al-Si alloys. However, Sr microalloying usually leads to an increased pore formation tendency. As bifilms are preferred sites for pore formation, it should be expected that Sr additions have a significant effect on the number and/or the structure of double oxide films present in the melt. In this work, the relationship between Sr-concentration and the susceptibility to pore formation has been investigated through the evaluation of melt quality of melts which had different levels of Sr. The bifilm content of the melts was investigated by the analysis of K-mold specimens and X-ray computed tomography (CT) of reduced pressure test (RPT) samples. It was found that liquid alloys with a higher Sr concentration had a significantly greater tendency to pore formation, which can be explained by the presence of a larger number of bifilm defects in the liquid alloy.
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Maintenance Strategies and Life Cycle Costs of Renewable Energy Systems
106-116Views:113Life cycle costs are important factors in decisions on renewable energy investments. Since maintenance costs generally constitute a high portion of the life cycle costs, the maintenance strategy applied in a project can affect the bottom line significantly. The effective maintenance tools used in the production industry (e.g., diagnostics, condition monitoring, data management, integrated information systems, machine learning, and automated decision making) can be involved in planning and maintenance of renewable energy systems to gain the benefits of these approaches. In this paper the effects of maintenance strategies on life cycle costs are investigated and the benefits of up-to-date condition monitoring techniques are presented through case studies.
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Improvement of High Strength Automotive Steels Wettability Properties Using CO2 Laser Surface Treatment
422-427Views:147As a result of stricter environmental and safety standards, vehicle manufacturers have to reduce the weight of the vehicles, because 10% weight loss cause 8-10% reduction of fuel consumption. To reduce car’s weight and increase safety, vehicle manufacturers use high-strength steels. Further weight reduction can be achieved by using corresponding bonding technology (soldering, sticking) and optimizing these technologies can increase the strength of the joints. According to literature research, the improvement of interface properties has a large effect on bonding technologies. In order to improve interface properties, we can use multiple surface treatments. In our research we investigate the effects of CO2 laser surface treatment on high strength steels, because CO2 lasers are often used in the vehicle industry. In order to detect the effect of surface treatment, we investigate the wettability of the treated and untreated steels. In our research we measure the surface tension of treated and untreated steels. Our main goal is to improve wettability properties thus the bonding technology. In our research we used DP 600 high strength steel sheet with the thickness of 1 mm. We cut the steel sheet to 25mm wide and 55mm long workpieces. Before the surface treatment, the workpieces had to be cleaned and degreased using methanol. We searched for parameters that do not cause any visible changes on the surfaces. Among the parameters of the treatment we were able to change the output power of the laser. We used contact angle measurement to examine the wettability.
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How Implementing Space Capabilities can Realize the Directives of Hungary’s National Security Strategy
120-141Views:315The Hungarian Government has released its decree on Hungary’s National Security Strategy, which provides a comprehensive picture of Hungary’s present state of security, sets out the country’s goals and directives to be achieved as well as the necessary government tools and tasks. Significant contributions can be made to the implementation of many of these directives by national space capabilities based on a Hungarian satellite system. In this study we intend to show the validity of this statement by presenting an overview of the legitimacy, features and possible benefits of national space-based capabilities as well as the necessary tasks involved in their implementation.
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Evolution of Lean Management and the Organizational Learning
251-259Views:591In industry, service and public sector lean approach is gaining ground. However, there is a significant difference between the organizations applying lean concept in case of their lean transformation maturity level as well as their lessons learned. There is a huge variety of methods and techniques which can be used but there are two conditions in case of every organization regardless their sector or their lean maturity level which determine the success of their lean development: lean approach leader and learning organization. Lean leadership is not based on a particular sector or method and a ready-made lean organization is not needed either. The concept of the top management has a huge effect on the characteristics of theorganization but whether the will of the management is enough for the complete transformation or not is the question. Is the target the lean organization itself or how a unit of an organization or the whole organization can react to the change of the environment? The attitudes and behaviors of lean approach leadership can be applied every day, everywhere and support the aim of creating a real lean organization.
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Presentation of Employment and Economic effects of the Covid-19 Epidemic between March and November 2020 among Companies Dealing with Car and Parts Trade in Szabolcs-Szatmár-Bereg County
80-92Views:419The outbreak of the COVID-19 pandemic during the spring of 2020 entailed major economic and social changes all over the world. In this study, we aim to investigate the impacts of the COVID-19 pandemic on the labor market and the economy with relation to the automotive industry in Szabolcs-Szatmár-Bereg County. Apart from secondary data collection, this research also relies on primary data collection methods, including self-administered questionnaires and in-depth interviews, all conducted with several employees and finance directors employed by the automotive companies present in the county. The focus of this research is to study how the pandemic affected the balance sheets and the gross revenue of these companies; how it altered the repayment obligation of their current loans and how it influenced their willingness to enter into new loan agreements or relief options offering financial assistance. Apart from these factors, this research also studies how the pandemic restrictions affected the work schedule and the benefits of the employees.
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Analysis of Vibration During Turning Process of Different Materials
200-205Views:105In this article, we would like to introduce the problems caused by vibrations in case of polymer turning processes. Nowadays there is a lot of research in this topic, to avoid the unnecessary phenomena of vibrations. The two most common methods are the Spindle Speed Variation (SSV), and the Vibration Assisted Machining (VAM). In case of SSV, the CNC machine can increase and decrease the speed of spindle continuously during turning which can significantly reduce the effects of chatter. This method is beneficial for longer workpieces when there is not any support except the chuck. Vibration-assisted machining can be used to minimise the problems caused by vibrations. VAM combines precision machining with small-amplitude tool vibration to improve the fabrication process. It has been applied to some processes ranging from turning, drilling to grinding. Based on the enumerated above we made some trial measurements about the basic vibrations of the turning tool shank. The tests were done on an NCT EUROturn-12B CNC machine which can found in the workshop of our institute. The tested material was Polyamide 6 because this is the most commonly used polymer in the industry. In the future, we would like to test some other basic and composite polymer materials too. The equipment was served by a specialist from SPM Budapest Kft. With these tests, our goal was to make sure that the equipment and the measuring setup are suitable for our future research.
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Literature Overall of Fatigue Analysis Approaches of Vehicle Components Made of Rubber
130-140Views:144Generally, the most frequently used structural materials are metals which have high strength and stiffness. However, there are many cases when other important properties come to the front, as well as high deformation capacity with elastic behavior, high viscosity namely good damping effect. Due to its above mentioned properties, rubber is widely used in vehicle and automotive industry. Vehicle components made of rubber usually exhibit large deformations. Cyclic finite deformations generate temperature in hyperelastic materials. Furthermore it is necessary to take into consideration the effects of ambient temperature. The mechanical properties of rubber depend on temperature and temperature changes can accelerate chemical alteration processes which lead to the material deterioration and fatigue processes. Research on fatigue behavior and fatigue properties of rubber has a great significance for predicting fatigue life and improving durability of rubber products. There are several studies on the fatigue behavior of rubber-based materials, but there is less research in the fatigue life prediction considering the influence of temperature and temperature changes. First purpose of this paper is summarizing the influence of temperature and temperature changes on the fatigue behavior of rubber. The second purpose of this study is to provide an overview of the state of the art on the fatigue life prediction of rubber with primary focus on the different methods available for prediction of fatigue life under the influence of temperature and temperature changes.
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Defect Analysis of Bearings with Vibration Monitoring and Optical Methods
1-12Views:148Diagnosis of bearings with advanced methods gained remarkable roles in the previous years. This article focuses on the manufacturing defects and methods to reveal and classify them. During manufacturing several faults could emerge because of the grinding operation, tool wear and chatter vibration. Inproper handling of the bearing parts because of the collosion to each other and the storing box that causes deformation. To reveal these problems several methods are applied in industry. For deeper surface analysis nitric acid can be used to initate the finished surface of the roller then natrium-carbonate that nautralize the elements. Vibration analysis in its standard Fourier form is not a new achivement but other mathematical tools could be applied to condition monitoring such as wavelet transform. It is an efficient tool for analyzing the vibration signal of the bearings because it can detect the sudden changes and transient impulses in the signal caused by faults on the bearing elements. In this article five different wavelets, Daubechies, Gaussian, Coiflet, Mexican hat, Meyer are compared according to the Energy to Shannon Entropy ratio criteria to reveal their efficiency for fault detection.
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The Impact of Electrical Vehicles on Sustainability: Jordan as a Case Study
393-403Views:173The Global concern is moving toward making a revolution in favor of exploitation of renewable energy in order to improve environment conditions, limit emissions and minimizes consumption of non-renewable resources within the planet. In this context, it is necessary to focus on the transport sector as it contributes of at least 30% of the total primary energy consumption. Therefore, a set of rules must be developed to maintain economic, environmental and social sustainability to address the problems so as not to increase their severity and these cannot be done unless there are joint measures and regulations from governments, companies, manufacturers and users. Unfortunately, the Jordanian transport system mostly depend on the individual transport which supported by cars, and that because of the weak role played by the public transport sector, especially at the capital, Amman. Buying hybrid cars (internal combustion engine + electric motor) and Electrical Vehicles (EV), in the past few years in Jordan is increasing, which is compatible with the global trend to use Electrical Vehicles (EV) instead of Internal Combustion Engine vehicles (ICE) powered by fossil fuels, this issue will have a direct and indirect impact on gas stations companies, also it will have direct impact on labor sector and the current car industry since electric charging stations as well as EV manufacturing is not labor intensive. The main purpose of the study is to show how much it is necessary now to start theoretical assumptions through studying the expected annual increase in passenger cars and its impact on sustainability and predicting the future fuel consumption and emissions and compare them with the base situation.
