Tomas Bata University in Zlín
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Optimized 8-parameter relay-based delayed thermal process model identification via saturated relay and artificial delay
No full textThis study aims at an extension and substantial improvement of the recently published relay-feedback parameter identification of an infinite-dimensional system thermal process model. The original procedure has applied the standard on/off relay to get a simplified model. Then, the dominant pole assignment has given rise to the process model characteristic quasi-polynomial via the Levenberg-Marquardt algorithm. Finally, the same optimization tool has been used to determine transfer function numerator parameters. On the contrary, a saturated relay is used to receive an improved initial simplified-model estimation in this contribution. As the process model in question has eight unknown parameters, a doubled relay test with artificial delay is made, which enables the estimation of all the parameters simultaneously. Moreover, the Nelder-Mead algorithm is used as the optimization tool. A numerical example validates an enhanced estimation in time and frequency domains.INT/2022/0002; GAČR 21-45465LCollege of Polytechnics Jihlava [INT/2022/0002]; Czech Science Foundation [R21-45465L
Competitive algae biodiesel depends on advances in mass algae cultivation
No full textThe aim of this review was to study why, despite large investments in research and development, algae biodiesel is still not price competitive with fossil fuels. Microalgal production was confirmed to be a critical cost item (84 up to 93 %) for biodiesel regardless of the production technology. Techno-economic assessment revealed the main cost drivers during mass cultivation. It is argued that a breakthrough in the cultivation efficiency of microalgae is identified as a necessary condition for achieving price-competitive microalgal biodiesel. The key bottlenecks were identified as follows: (1) light and O2 concentration management; (2) overnight respiratory loss of oil. It is concluded that most of the research on microalgae biodiesel yields economically over-optimistic presumptions because it has been based on laboratory scale experiments with a low level of interdisciplinary overlap
Evaluation of selected properties and surface quality of cured pre-impregnated carbon-fiber fabrics after exposure to sulphuric acid
Get PDFThis paper deals with changes in selected properties of composite material and surface degradation after exposure to an acidic environment. A carbon fiber-reinforced composite (CFRP) produced from prepregs was tested. The weight change, micro-hardness, and surface degradation of the CFRP composite made of cured pre-impregnated laminates were evaluated in this study. Material consisting of a DT121R epoxy resin matrix with high reactivity and high viscosity, with two reinforcing carbon fabrics layers, is characterized by a low value of tensile strength. Evaluation of changes in the material properties was performed before and after exposure to specific environmental conditions, which are achieved by using a chemical solution of 15% H(2)SO(4 )at various temperatures. Subsequently, the effect of 15% H2SO4 at various temperatures on the material properties was monitored. The specimens were immersed in the solution for up to 3 and 6 weeks at the temperatures of 23 degrees C, 40 degrees C, and 60 degrees C. It was found out, that the degradation of the composite material is conditioned by the aging of the epoxy resin (matrix). Carbon fibers (reinforcement) are relatively stable. The weight change, micro-hardness, and surface quality depend on the time of exposure to acidic solution and temperature. The micro-hardness tests show a significant influence on exposure time. The biggest changes in weight change and surface quality of the CFRP composite were observed after exposure at the temperature of 60 degrees C.Vedecká Grantová Agentúra MŠVVaŠ SR a SAV, VEGA: 1/0741/21; European Regional Development Fund, ERDFOperational Program Integrated Infrastructure [ITMS 313011V334]; European Regional Development Fund [VEGA 1/0741/21
Efficient representation and derivation of fundamental transformation of relationships using Euler angles and quaternions
Get PDFThis paper introduces and defines two principal rotational methods;the Euler angles and the quaternions theories with a brief insight into their definitions and algebraic properties. These methods are widely used in various scientific fields, only marginally in the aircraft industry, the robotics, the quantum mechanics, the electro mechanics, the cameras systems, the computer graphics, the heavy industry and other. The main part of this paper is devoted to the derivation of basic equations of the vector rotation around each rotational x, y, z axis using both rotational methods. Then, the general three-dimensional rotation matrix and the general operator of the quaternion rotation are derived. Finally the utilization of the matrices and quaternion equations are demonstrated on a simple example.3019604102
Hierarchical clustering-based algorithms for optimal waste collection point locations in large-scale problems: A framework development and case study
No full textThe cities face the challenge of optimizing investments in waste management to meet EU standards while maintaining economic affordability. One of the issues is the optimal location for specialized waste collection points. The main target is to find the lowest number of collection points that would still attain waste production, and the average walking distance to the waste container would be kept beneath the tolerable limit for citizens. The population density and waste production vary over city parts; thus, the need for specialized containers in more populated city centers, industrial zones, or household streets differs. This paper develops a new compu-tational approach providing a robust generalized decision-support tool for waste collection bin location and allocation. This task leads to a mixed-integer linear program which is not solvable for larger cities in a reasonable time. Therefore, hierarchical clustering is applied to simplify the model. Two strategies for solving waste bin allocation (for multiple variants of the model formulation) are implemented and compared - sub-problem definition and representative selection approaches. The resulting framework is tested on the artificial instance and a few case studies where the structure and properties of results are discussed. The combination of presented approaches proved to be appropriate for large-scale instances. The representative selection approach leads to a better distribution of containers within the area in the single-objective model formulation.Development of Sustainable Waste Management: Methods and Operations Research Perspectives" of the Czech Science Foundation [GA 20-00091Y]; Technology Agency of the Czech Republic [SS02030008]; Tomas Bata University [FSR FORD 5-6/2022-23/FLK.R/001]Methods and Operations Research Perspectives” of the Czech Science Foundation; Technology Agency of the Czech Republic, TACR, (SS02030008); Univerzita Tomáše Bati ve Zlíně, (FSR FORD 5-6/2022-23/FLKŘ/001
New insights of the application of water or ethanol-water plant extract rich in active compounds in food
Get PDFPlants are recognized as natural sources of antioxidants (e.g., polyphenols, flavonoids, vitamins, and other active compounds) that can be extracted by green solvents like water, ethanol, or their binary mixtures. Plant extracts are becoming more used as food additives in various food systems due to their antioxidant abilities. Their application in food increases the shelf life of products by preventing undesirable changes in nutritional and sensory properties, such as the formation off-flavors in lipid-rich food. This review summarizes the most recent literature about water or ethanol-water plant extracts used as flavors, colorings, and preservatives to fortify food and beverages. This study is performed with particular attention to describing the benefits of plant extract-fortified products such as meat, vegetable oils, biscuits, pastries, some beverages, yogurt, cheese, and other dairy products. Antioxidant-rich plant extracts can positively affect food safety by partially or fully replacing synthetic antioxidants, which have lately been linked to safety and health issues such as toxicological and carcinogenic consequences. On the other hand, the limitations and challenges of using the extract in food should be considered, like stability, level of purity, compatibility with matrix, price, sensory aspects like distinct taste, and others. In the future, continuous development and a tendency to use these natural extracts as food ingredients are expected, as indicated by the number of published works in this area, particularly in the past decade.Tomas Bata University in Zlin, TBU: IGA/FT/2023/003Tomas Bata University in Zlin [IGA/FT/2023/003
The amount of excise tax and its effect on the consumption of alcohol and cigarettes in European countries
Get PDFBACKGROUND: Tobacco smoking and alcohol consumption are widespread practices that are legal and socially accepted in many societies. One of the common tools to reduce the consumption of these legal drugs is increasing prices. The prices for customers include taxes (value added tax and excise tax). Hundreds of studies from around the world are interested in the impact of taxes and prices on the demand for tobacco products. This topic is also relevant for governments of all countries trying to regulate consumption.
AIM: The aim of the paper is to describe the amount of excise tax on legal drugs (alcohol, cigarettes) and compare their consumption in Europe and the countries of the European Union.
METHODS: The sources of data for this research were publicly available from the World Health Organization (WHO), Global Information System on Alcohol and Health (GISAH), Tax Foundation, and Eurostat. In the paper selected scientific methods are used (analysis, synthesis, induction, and deduction). For the literature review Scopus and Web of Science (WoS) were used.
SAMPLE: Data from Europe was used to examine alcohol and its taxation; a total of 31 countries were examined. All 27 countries of the European Union were examined for the assessment of cigarette consumption and its taxation.
RESULTS: The overview shows that low taxation can lead to high alcohol consumption (Estonia, France). On the other hand, even relatively high taxation may not lead to low alcohol consumption (Germany, Slovenia, Czechia, and Austria). However, a very high excise tax can lead to a reduction in alcohol consumption, for example in Norway, Iceland, Sweden, and also in Finland. In Finland and Denmark, it was confirmed that a high excise tax (Finland €6.14 and Denmark €5.27) leads to lower consumption of cigarettes (Finland 9.9% and Denmark 11.7%). In Bulgaria the data shows that a low excise tax (€1.81) leads to a large number of people who smoke cigarettes daily (28.7%). As many as 12.9% of people smoke more than 20 cigarettes a day, which is the highest value in the European Union. If we compare it with the average (6%), it is a very high value.
CONCLUSIONS: In many countries, e.g. Finland, Bulgaria, Sweden, Denmark, Norway, and France, it has been confirmed that the amount of consumption tax leads to greater or lesser consumption of legal drugs (alcohol, cigarettes)
Effect of selected factors influencing biogenic amines degradation by bacillus subtilis isolated from food
Get PDFModern food technology research has researched possible approaches to reducing the concentration of biogenic amines in food and thereby enhance and guarantee food safety. Applying adjunct cultures that can metabolise biogenic amines is a potential approach to reach the latter mentioned goal. Therefore, this study aims to study the crucial factors that could determine the decrease in biogenic amines concentration (histamine, tyramine, phenylethylamine, putrescine and cadaverine) in foodstuffs using Bacillus subtilis DEPE IB1 isolated from gouda-type cheese. The combined effects of cultivation temperature (8 °C, 23 °C and 30 °C) and the initial pH of the medium (5.0, 6.0, 7.0 and 8.0) under aerobic and also anaerobic conditions resulted in the decrease of the tested biogenic amines concentration during the cultivation time (another factor tested). Bacillus subtilis was cultivated (in vitro) in a medium supplemented with biogenic amines, and their degradation was detected using the high-performance liquid chromatography equipped with UV-detector. The course of biogenic amines degradation by Bacillus subtilis DEPE IB1 was significantly influenced by cultivation temperature and also the initial pH of the medium (p < 0.05). At the end of the cultivation, the concentration of all of the monitored biogenic amines was significantly reduced by 65–85% (p < 0.05). Therefore, this strain could be used for preventive purposes and contributes to food safety enhance.IGA/FT/2023/002; Ministerstvo Obrany České Republiky, MOČRInternal Grant of TBU in Zlin [IGA/FT/2023/002]; Ministry of Defence of the Czech Republi
Use of maturity model to create an effective marketing mix with a focus on educational facilities
Get PDFThe presented article focuses on the acute topics of process management in educational institutions. A maturity model is here proposed in order to develop an effective marketing mix for educational facilities. It is used to assess the current state of each element of the marketing mix and identify areas for improvement. The main contribution is the detailed description of why it is necessary to create a maturity model when creating a marketing mix in the school sector. To achieve this, individual process information programs are analyzed and specifics for the educational sector are given. The article focuses on educational facilities, such as schools, universities, and training centers. By utilizing a maturity model, educational facilities can identify gaps in their marketing strategies and develop a more effective marketing mix to attract and retain students. Furthermore, up-to-date maturity models were analyzed and, as a result of the research, a new, separate model was created with detailed description. Part of the new model is also an analysis of practical use by employees in selected school establishments. The results of this study can provide insights for educational institutions to enhance their marketing strategies and better meet the needs of their target audience
Assessment of combustion and acoustic characteristics of scenedesmus dimorphus blended with hydrogen fuel on internal combustion engine
No full textBiodiesel, which may be produced from crops, animal fat, as well as waste products from both industrial and residential sectors, is one of the alternative fuels that are utilized extensively. These biodiesels may either be used on their own or combined with regular diesel. Because biodiesels are becoming increasingly popular as a substitute for fossil fuels, the amount of attention paid to studying them has been growing steadily over the past few years. However, the results on the features of the noise and vibration are still missing, and much more emphasis has to be placed on the study conducted in that particular field. In this study, the combustion, noise, and vibration properties of Scenedesmus dimorphus microalgae biodiesel were investigated both with and without the provision of hydrogen. At the rate of 5 l/min, the supply of hydrogen was made available. Both B10 (10% of Scenedesmus dimorphus microalgae biodiesel and 90% pure diesel) and B20 (20% of Scenedesmus dimorphus microalgae biodiesel and 80% pure diesel) were employed as the biodiesel compositions. In addition, the source of hydrogen was made available for the diesel in its purest form as well as the two biodiesel mixes that remained. The fuels that were obtained consisted of neat microalgae blends containing 0% microalgae B0H5, 10% microalgae B10H5, and 20% microalgae containing B20H5. In this study, the performance of pure diesel was compared to the findings obtained from hydrogen-enriched fuel blends, simple biodiesel blends, and a combination of the two. Each and every experimental test was carried out using a diesel engine with a single-cylinder, water cooling, and four strokes. The tests were carried out with the load varying 25% in-between from 0% to 100%. Based on the findings, it was discovered that increasing the proportion of biodiesel fuel and adding hydrogen to the engine both contributed to a reduction in the amount of vibration and noise that was generated by the vehicle. The combustion qualities were also improved by the mixing of hydrogen and biodiesel as hybrid fuel.National Key R&D Program of China [2022YFD2200105]; Natural Science Foundation of Jiangsu Province [CX(22)2045]; Jiangsu Agriculture Science and Technology Innovation Fund [RSP-2022/230]; King Saud University, Riyadh, Saudi Arabia; [BK20200775]Jiangsu Agricultural Science and Technology Innovation Fund, JASTIF, (CX(22)2045, RSP-2022/230); King Saud University, KSU; Natural Science Foundation of Jiangsu Province, (BK20200775, Province10.13039/501100004608); National Key Research and Development Program of China, NKRDPC, (2022YFD2200105