Search
Search Results
-
Future Power Plant Portfolio Analysis from the Point of View of Minimum Cost and Emission Optimization
61-77Views:253The article examines the expected composition of the power plant portfolio in Hungary by 2030. The indicators considered are the life-cycle unit costs (LCOE) and the life-cycle specific carbon dioxide emissions (LCA(CO2)) of the power plant types. The minimum of these two indicators, as objective functions, is determined by a linear programming method for the power plant portfolio. The results show that the LCOE minimum for the power plant portfolios in 2030 is worse in absolute terms and better in specific terms than in 2021. In both absolute and specific terms, the LCA(CO2) minimum is more favourable in 2021. These results are met under the thirty and twenty-five percent electricity import scenarios. With twenty percent imports, the absolute values are worse and the specific values are better for both indicators. On the other hand, the results of the calculations for 2030 fall short of the 2030 Agenda of the Institute for a Green Transition. This is due to the delay in commissioning a new nuclear power plant and the transformation of industry with increasing electricity demand. For the portfolios under review, a minimum of thirty percent of domestic generation from renewable sources is met. This contributes significantly to the European Union's ambition for the sector to be net greenhouse gas-free by 2050.
-
Optimization of Automotive Industry’s Manufacturing Process with Lean Tools
81-89Views:537Lean plays i mportant role in industrial environment. Automotive industries use lean tools in order to reduce cost and i mprove productivity. To achieve the company's objectives and so lve the detected problems I also used lean tools. By using lean tools we want to decrease total process cost (TPC). In order to achieve this target, the three-shift production has to reduce in two-shift production, which result decrease in the human resource costs and production costs. In order to reduce shifts we have to increase overall equipment efficiency (OEE) and eliminate minimum 50% of wastes by implementing 5s methodology, using Poka-yoke and scheduled maintenance.
-
The Location of Energy Plantations in the Sowing Structure and Its Evaluation with Linear Programming
255-269Views:230The research is examining traditional arable crops and woody plants on the basis of their marginal contribution. Calculations of income, expenditure and revenue were made on the grounds of sectoral technologies, which were the basis of the value of marginal contribution of the given sectors. As the linear programming model is quite comprehensive, we used this method for our calculations. To compile our model, we have gathered all the necessary information from farmers of the region of the Northern Great Plain. The missing data was completed from the databases of the Hungarian Central Statistical Office (KSH), Institute for Agricultural Economics Research and Information Technologies (AKII) and the Statistical Office of the European Communities (EUROSTAT). In some cases, we also used data of the Agricultural Administration Office and the Ministry of Agricultural and Rural Development. Our goal is to compile a 12-year production structure that suits for the characteristics of the region of the Northern Great Plain by achieving the maximum marginal contribution of a feature-farm.
-
Comparative Study of Surface Treatment Procedures for Dental Implants
12-32Views:322Nowadays, the most common type of implant in dentistry is a partial tooth replacement, such as a crown, or a complete tooth replacement. Today, many manufacturers offer implants made of a wide variety of materials and designs. These restorations must meet strict standards, one of the most stringent being surface roughness. Since proper bone-to-implant contact only occurs with adequate surface roughness, several methods are used to achieve the correct value. After reviewing the results of experiments carried out by several research groups, it is concluded that the surface roughness, the shape of the implant fixation screw, the shape of the thread and the thread elevation used to achieve the desired roughness together determine the success of the implantation. The average surface roughness required for osseointegration is considered to be optimal for values between 1 and 100 µm. In most cases, the surface roughness of commercially available dental prostheses is Ra 1-2 µm, but this can be modified by various grinding, acid etching and polishing processes to suit the application. Acid etching is a common technique for roughness reduction, which is the most effective in reducing surface roughness of dental restorative materials (mostly titanium alloys), thus bringing the roughness within the desired range. The result of acid etching is influenced by the concentration of acid, the temperature of the acid bath and the time spent in the acid. The acid used for the surface treatment is important and is most commonly sulphuric acid, hydrochloric acid or hydrogen fluoride (HF) and combinations of these. The study shows that the most optimal results are obtained with HF. Replacements are nowadays largely made by additive manufacturing, which allows for customised replacements and, due to dimensional accuracy, reduces the time and cost of post-processing, i.e. the surface treatment can be used to achieve the desired surface roughness and size at the same time. As a result, newer materials are being used for clinical prostheses and surface treatment should be applicable to all materials. The most optimal solution is a combination of grit blasting and acid etching. With this technology, the surface roughness for all materials reaches the optimum value of 1-100 µm, sometimes 1-2 µm, but can be further reduced below 1 µm by polishing. The study investigates the role of surface roughness, the surface roughness should only be reduced up to a certain value, approximately 0.5 µm, as smooth surfaces have limited or no potential for osseointegration.
