Tomas Bata University in Zlín
Institutional repository of Tomas Bata University LibraryNot a member yet
10673 research outputs found
Sort by
Production of hydrogen as value added product from the photovoltaic thermal system operated with graphene nanoparticles: An experimental study
Get PDFHydrogen is a growing alternative for fossil fuels that may be used to combat the energy shortfall that exists in a variety of industries, most notably the transportation and power generation industries. In this research work, the utilization of solar energy for the generation of electricity and production of hydrogen are thoroughly covered. A hybrid photovoltaic thermal system (PVT) has been used to generate the hydrogen via electrolysis process. To enhance the thermal efficiency of the PVT, graphene oxide nanofluids have been utilized. Graphene oxide nanofluids dispersed at the mass flow rates, such as 0.8 g/s, 1.0 g/s, and 1.2 g/s using sonication technique. A series of tests conducted between 9.00 A.M. to 4.00 P.M. to determine the parameters such as cell temperature, electrical efficiency, thermal efficiency and hydrogen mass flow rate. The procured results of the PVT carried out with the utilization of air and water as coolants were compared with PVT with nanofluids. From the findings it is evident that the performance of the system was significantly enhanced by the utilization of nanofluids at the optimized concentration compared to conventional water and air. With regard to the nanofluids mass flow rate, concentration of 1.2 g/s reported higher electrical (8.6%) and thermal efficiency (33.3%) compared to water. Added to above, there is a profound increase in the mass flow rate of hydrogen that has been observed at 1.2 g/s.King Saud University, Riyadh, Saudi Arabia; [RSP-2021/228
Insect rearing on biowaste represents a competitive advantage for fish farming
No full textFeeding cost is among the main drivers in the price competitiveness of intensively-fed-aquaculture (IFA) products. As soaring energy prices increase the costs of technologies used to increase the digestibility of plant protein feeds, there is an urgent call for comprehensive knowledge on the mass use of insects as fish feed. This review identifies the key aspects of insect incorporation into established IFA practices and puts them into a commercial context. Larvae of Black soldier fly (BSFL) is identified as the most versatile in terms of (a) variety of biowaste usable for its rearing, (b) automatization and scaling up, (c) nutritional value and (d) circular and environmental aspects. Furthermore, modifications insect diets can increase the levels of valuable compounds such as omega-3 fatty acids in fish. Other insects such as ants or mealworms have the potential to meet the nutritional requirements of various fish species. While today the production costs of BSFL (mostly around 3.5 euro kg(-1)) are mostly determined by labour costs, it is predicted that intensified industrialization of insect rearing could reduce the production cost below 2 euro kg(-1). In addition, multiple positive economic impacts, as well as environmental spillovers, have been identified. It is proposed that further research should be directed towards the refining and further valorization of byproducts from insect farming which could further dissolve the rearing cost. Bringing the IFA into compliance with the principles of the circular economy increases its competitiveness by reducing production costs and improving public opinion
Regional unemployment and investment incentives in Czechia
Get PDFThe paper aims to verify whether setting up the system of investment incentives in Czechia has determined the over-proportional location of supported jobs to regions with an over-proportional size of unemployed and thus meets the declared objectives of regional policy. Concentration analysis on the territorial level of districts and regions NUTS III of the Czechia was used to fulfil this goal. Regions according to the concentration of unemployed and supported jobs can be divided into five basic types: T1 - regions where the support is well targeted and implemented (regions with high unemployment and job support), T2 - regions with inappropriately targeted support (regions with low unemployment and high support), T3 - regions that are not eligible for support and support is realised on low level (low unemployment and low support), T4 - regions where support is lacking (high unemployment and low support), T5 - regions that cannot be clearly classified (their position changes significantly over time). Regional policy objectives are achieved through support realised in regions with a large amount of unemployment. Setting up a system of investment incentives in Czechia does not ensure an above-proportional direction of supported investments to regions with a larger size of unemployment and thus does not meet the declared objectives of regional policy.Technology Agency of the Czech Republic, TACR, (TL03000319
Forensics science and using a color model digital twin artwork to identify a counterfeit
No full textThis article discusses the use of color and color space analysis in the space of 3D reconstruction of a real object. The text focuses on the area of point clouds as a carrier of color information in 3D space. This issue is applied to the 3D reconstruction of an original work of art using the method of photogrammetry into 3D point clouds to use the above procedures in the field of forensic science and the issue of falsification of works of art in digital and virtual environments.Department of Security Engineering, Faculty of Applied Informatics; Grand Agency of Tomas Bata University in Zlin, (IGA/CebiaTech/2023/003); Tomas Bata University in Zlin, TB
Polylactide-based networks containing dynamic tetraphenylethane groups for 3D printed repairable and reprocessable constructs
No full textThis study aims to synthesize sustainable polylactide (PLA) materials, specifically polyester-urethanes based on PLAs with various molecular weights, to enhance thermal shape stability through crosslinking and enable reprocessing due to the presence of a new type of dynamic/reversible covalent bonds in the polymer structure. PLA-based networks containing dynamic bonds were prepared by coupling (using hexamethylene diisocyanate) PLA star polymers bearing four terminal -OH groups with a low molecular weight diol containing groups that undergo reversible dissociation upon heating. The PLAs prepolymers of two molecular weights (Mn = 3700 and 7800 g/mol) were synthesized via cationic polymerization of D,L-lactide to obtain the networks of different crosslinking densities. The low molecular weight diol, containing a tetraphenylethane moiety (TPE) with an easy dissociating bond, was synthesized from 4-hydroxybenzophenone. Networks without reversible bonds, containing 1,1′-bi-2-naphthol (binol) instead of TPE units, were also prepared as a reference. All networks were analyzed by Fourier transform infrared spectroscopy, differential scanning calorimetry, and thermogravimetric analysis and were subjected to tensile tests. The tensile strength of all networks was in the range of 22–45 MPa. The elongations at break of networks differed based on the type of used low molecular weight diol, with values in the range of 28–67% for TPE-containing networks, in comparison with 10% for reference samples. Rheological studies of these materials were performed at a higher temperature (150 °C) to clearly demonstrate the behavioral differences between networks with and without “reversible” bonds. Only the networks with TPE groups were able to recover their previous strength after strain deformation at 150 °C in four subsequent cycles. Moreover, it was shown that networks with reversible groups were repairable and 3D printable at temperatures as low as 150 °C, while those containing non-reversible bonds did not exhibit such capability.DKRVO, (RP/CPS/2022/003); Tomas Bata University in Zlin, TBU, (IGA/CPS/2021/004); Ministerstvo Školství, Mládeže a Tělovýchovy, MŠMT; Narodowe Centrum Nauki, NCN, (2018/31/B/ST8/01969)National Science Centre, Poland [2018/31/B/ST8/01969]; Ministry of Education, Youth and Sports of the Czech Republic - DKRVO [RP/CPS/2022/003]; Internal Grant Agency of Tomas Bata University in Zlin [IGA/CPS/2021/004
Potential of polyurethane functionalized electrospun nanofiber membrane as self-cleaning water filter
No full textIn the present research, a single-step electrospinning technique was implemented to develop homogeneous hydrophilic nanostructures with a self-cleaning characteristic based on non-woven polyurethane (PU) altered by quaternary ammonium salts (QAS). By transferring the nanofibrous structures to the polyethylene terephthalate substrate, the filtering membranes were fabricated. The fabricated PU and PU/QAS membranes were compared and characterized for assessing their self-cleaning properties. The synthesized nanofibers were mechanically tested and also characterized by scanning electron microscopy. At low trans-membrane pressure of 7.5 kPa, water permeation flux and biofouling effect of electrospun nanocomposite membrane performance were primarily studied by means of dead-end filtration. Following a 5-day filtration, the modified nanofibrous structure displayed promising results in the recovery of the flux after a day 3 and inhibited the development of biofilm as well. The tensile strength and modulus of PU-QAS were 7.5MP and 31.7% higher compared to PU membrane. The pore size was also observed to be 360n in PU, while for PU-QAS, it was observed as 340 nm. It was concluded that the developed PU/QAS membrane can be restored to its original flow properties by cleaning with tap water
Review and proposition for model-based multivariable-multiobjective optimisation of extrusion-based bioprinting
Get PDFConsequent to the development of bioprinting technologies for biomedical applications, especially in tissue engineering, a comprehensive review of extrusion-based bioprinting (EBB) has been written. The review was executed in a manner that laid a foundation for effective optimisation strategies to improve the print resolution or shape fidelity and cell viability of EBB through bioink. However, before achieving this aim the shearing characteristic of the bioink (i.e., shear-thinning or thickening) was described by the Ostwald-de Waele and Herschel-Bulkley models, among other reported models. The dependence of bioink shearing characteristics on temperature and time was also discussed. Emphasis on how these dependencies can be influenced by crosslinking of bioink molecules was further highlighted, which can be covalent (chemical-, photo-cross-linking, etc.) or noncovalent (physical cross-linking, host-guest inclusion, ionic interaction, etc.). Models from literature that can physically describe print resolution and cell viability in EBB were discussed and compared. Therefore, multivariable-multiobjective optimisation strategies were proposed with these models.Univerzita Tomáše Bati ve Zlíně, (CZ.02.2.69/0.0/0.0/19_073/0016941)Tomas Bata University, Zlin, Czech Republic [CZ.02.2.69/0.0/0.0/19_073/0016941
Method for mapping and analysis of electromagnetic background in urban area
No full textThis paper presents a method for mapping and analysis of electromagnetic background in an urban area. The uniqueness of our environment causes the inability to simulate electromagnetic fields of the real world as there is an unknown amount of sources and a near infinite amount of obstacles that could obscure the traveling wave or bounce it in a different direction altogether. The proposed method allows mapping an area of 64 hectares in less than 24 hours using only one person, antenna, software-defined radio, laptop, and optionally external drive to store data, which ensures the possibility of having multiple setups to multiply results. The general analysis of gathered data consists of three parts. The first is the compression ratio, a valuable byproduct of data compression for long-term storage. The second uses geographical locations to determine variance by distance, in a straight line and a cluster. The final tool for analysis is a Pearson's and Kendall's correlations to a baseline measurement to find potential errors and/or anomalies within a data set.Univerzita Tomáše Bati ve Zlíně, (IGA/CebiaTech/2023/002
Lessons and insights from managing crisis: Evidence from EU pharmaceutical sector
No full textCrisis management for the Covid-19 epidemic is unquestionably an emergent issue. It also taught us several lessons about how to prepare for future crises. When it comes to the healthcare industry, the need for urgent discussion as well as innovation to address the issue takes precedence. Over the last two years, there has been a high crisis in emergency drugs, scarcity of drug ingredients, and patients have become helpless in the fight against the coronavirus disease all over the world. The European Union (EU) was the central hub of this tragedy, and the EU is mobilizing all available resources to assist member states in coordinating their national responses, which includes providing objective information about the virus's spread, effective containment efforts, and measures taken to repair the pandemic's economic and social damage. The research explains pharmaceutical business models and tools that can help businesses respond to emergency situations. A systematic literature review was conducted, and a list of bibliographic notes is mentioned in the reference section of the paper, where future research ideas can be found.Internal Grant Agency of FaME TBU [IGA/FaME/2022/001, IGA/FaME/2022/011
A 3D visualization of Zlín in the eighteen–nineties in the Unreal Engine environment
No full textThis paper describes a 3D interactive desktop application that visualizes the appearance of the town of Zlín in the Eighteen–nineties. The Blender software suite was used to create a complex 3D model of Zlín and its municipality in previous years. Now, this model has been revisited, improved and extended. This was followed by work in order to export it into the Unreal Engine environment. Using this software, the terrain has been further improved to be more realistic and additional assets (grass, trees, bridges, fences) were added to achieve more reality. Then, a user interface with a basic menu was created, user interaction was implemented and initial animation has been added. Then everything was compiled into a fully functional application. © 2023, The Author(s), under exclusive license to Springer Nature Switzerland AG.RVO/FAI/2021/00