Periodica Polytechnica (Budapest University of Technology and Economics)
Not a member yet
22160 research outputs found
Sort by
Lead-Free Conductors with a Surface Treatment Ensuring a Low Melting Temperature
Get PDFIn order to protect the environment and to ensure sustainability, it is prohibited to use lead materials in the production of automotive components. As part of soldering, busbars are used that usually have a copper core and a coating made of tin, but the melting point of such material is high, which poses a problem during soldering. This article discusses the case where a busbar is interconnected with another conductor in a sealable pressure vessel where high temperatures and pressures are reached. The product is heated to a certain temperature and the melting temperature of the given bus coating is exceeded, resulting in soldering and an ideal connection of the wires. The problem is that the temperatures reached by the processor during this operation are lower than the melting temperatures of the busbar with a tin coating. In the article, the authors focus on the production and development of new types of busbars with a coating consisting of tin, bismuth and indium and discuss possible formulations and their effect on the melting temperature of the busbars
The EU Logistics Sector
Get PDFLogistics and efficient transportation are crucial for the European Union economy. For economies to thrive and remain competitive, logistics and transportation networks must operate in an organized, economical and ecological manner. They facilitate the movement of goods within and outside the EU, giving businesses access to bigger markets and a wider range of consumer items. As a result, there were more prospects for employment and greater success in trade and the economy. An outline of the fundamental trends in the European logistics industry is given in this study. We anticipate the current study will add to our knowledge of the EU logistics industry
Small Robot Vehicle Developed for Multi-purpose Industrial Use
Get PDFThe small robotic vehicle presented in this article is a special, multifunctional vehicle that can perform diagnostic tasks in several different areas. Examination of heat release and heat losses, which characterizes the efficiency of processes in many technical areas. A device that penetrates into small spaces may be needed. In this area, an important task is to navigate the device to the right place under trucks and cars to perform thermal camera diagnostics. The examination of excessive heat emission is extremely important to filter out faulty transmission systems, faulty engines, and to detect excessively hot brake drums, which are unfortunately also responsible for causing many serious accidents and fires.The remote-controlled navigation robot with a camera presented in the article is perfectly suited for the above task, as it can also transmit the image of the thermal camera to a remote display. In addition to automotive applications, the device can also be used for other industrial purposes and machine diagnostic tasks. I According to the current European Union building energy regulations, new buildings must have almost zero energy requirements. The so-called thermal bridges must be calculated for both old and new buildings under construction.A useful solution to this problem can be the quick and cost-effective energetic measurement and classification of thermal bridges, factors, and structural elements that cause heat loss. The Heat Spotter robotic vehicle presented and built in the article is suitable for the above tasks, ready to be manufactured and quickly paying for itself
The European Union's Global Goods Transport and Trade Relations and their Implications
Get PDFTrade and transit have always played an important and prominent role in the life of humanity. Trade was already of great importance in ancient times, and the Industrial Revolution brought about significant changes, with the invention of the steam engine revolutionising transport and allowing goods to be transported not only in response to seasonal needs (e.g. after harvest, harvesting, etc.). The development of waterways and railways, in addition to roads, made it possible to transport goods over long distances more easily and quickly. From this point onwards, goods were constantly moved for trade by the various modes of transport, giving rise to the development of transport as a new service industry. All these processes played an integral role in developing the supply chains and trade routes we know today. In the present research, to map global trade trends and linkages, the trade relations between the European Union, China and the USA were first examined, and then, using correlation analysis and linear regression, the typical economic and trade indicators in the European Union were analysed
Experimental and Numerical Investigation of Cold Joint Effects on Intermediate Concrete Moment Frame Under Cyclic Loading
Get PDFThis study investigates the seismic behavior of reinforced concrete flexural frames with a focus on the impact of cold joints (CJs). Three one-bay concrete frames, scaled to 2:3 according to ACI 318-19(22), were tested under axial and cyclic loading. The frames included a control frame without CJs, a frame with CJs, and a frame with CJs reinforced with fiber-reinforced polymer (FRP) sheets. Initially, the difference between the frame without CJs and the frame with CJs was examined, revealing a 10% reduction in cumulative energy dissipation, a 24% reduction in ductility, and an 18% reduction in lateral load capacity for the frame with CJs. Additionally, the stiffness in frames with CJs has decreased. Subsequently, the frame with CJs was reinforced with FRP sheets, leading to a 33% increase in cumulative energy dissipation and a 54% increase in lateral load capacity. However, the FRP sheets, while increasing load capacity, introduced brittleness, which reduced ductility. Crack patterns varied, with the frame without CJs showing vertical cracks near connections at 3% drifts, and the frame with CJs exhibiting tension and compression vertical cracks at 1% drifts. After validating the numerical models, two structural designs have been proposed to mitigate the negative effects of CJs in reinforced concrete structures. These designs are intended to improve seismic performance and enhance the structure's resistance to cyclic loads
Effect of Polypropylene Fibers on the Behavior of Dune Sand Concrete Subjected to Elevated Temperatures
Get PDFIn the field of civil engineering, concrete is one of the most used materials. Above a particular temperature, concrete can exhibit thermal instability during fire events. Improving the safety of buildings and structures is an important issue of this study. This paper investigates the effects of adding polypropylene fibers to dune sand concrete at high temperatures. Prismatic specimens (4 x 4 x 16 cm3) are produced, and stored until the concrete is hardened. The samples are then subjected to a heating-cooling cycle, starting from room temperature and increasing by 0.1 °C/min until reaching 600 °C. The length and the rate of polypropylene fibers are examined to determine their impact on compressive strength, porosity, and weight loss at temperatures of 80, 150, 300, 450, and 600 °C. Also, the partial replacement of dune sand (DS) with river sand (RS) is investigated. The results show that, for temperatures below 450 °C, the strengths of dune sand concretes varied from 29 to 39% compared to those obtained with concretes subjected to an ambient temperature (20 °C). However, it should be noted that residual compressive strength values decrease at most temperatures with the addition of polypropylene fibers. Furthermore, sand concrete with 50% DS and 50% RS shows an increase in compressive strength of 43.77% compared to that obtained by 100% DS concrete