Tomas Bata University in Zlín
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Method for in situ polypyrrole coating, and the example of its use for functionalization of polyurethane anisotropic electrospun mats
Get PDFThe in situ coating of polymer substrate with polypyrrole, described herein with detailed know-how, represents a novel technique of surface functionalization. The choice of oxidizing agent and the polymerization time both affect the properties of the thin polypyrrole layer. The specific conductivity, free surface energy, thickness, topography, and FTIR spectra of polypyrrole layer were determined. The conductive coatings were further used to functionalize both isotropic and anisotropic electrospun polyurethane nanofibrous mats to show their applicability and study the bioactive effect of both the anisotropy and conductivity together. The morphology of composites was studied by means of atomic force microscopy and scanning electron microscopy. A complex cytocompatibility study was performed, including determining cytotoxicity by optical and fluorescence microscopy, the advanced qualification of cell morphology by cell-image analysis, and a study of stem cell behavior. The results clearly showed the significant impact of substrate modification on cells, especially on fibroblasts while the embryonic stem cells were less affected. This study shows not only the effective way to prepare a thin conducting layer based on polypyrrole but also demonstrates its importance for the fabrication of smart biomaterials.Czech Science Foundation [23-07425S]; Ministry of Education, Youth and Sports of the Czech Republic [RP/CPS/2022/001, RP/CPS/2022/007]; Internal Grant Agency of Tomas Bata University in Zln, Czech Republic [IGA/CPS/2024/007
Recent advances on outstanding microwave absorption and electromagnetic interference shielding nanocomposites of ZnO semiconductor
No full textThe electromagnetic interference shielding and microwave attenuation capabilities of ZnO semiconductor nanocomposites have recently been improved using a variety of approaches by correctly modifying their permittivity. To improve microwave attenuation, ZnO semiconductor nanostructures have been combined with graphene, multi-wall carbon nanotubes, metal nanoparticles and their alloys, two-dimensional MXene, spinel ferrite magnetic nanoparticles, polymer systems, and textiles. This paper covers the opportunities and constraints that these cutting-edge nanocomposites in the field of electromagnetic wave absorption encounter as well as the research progress of ZnO semiconductor-based nanocomposite. The structure-function relationship of electromagnetic wave absorption nanocomposites, design strategies, synthesis techniques, and various types of advanced nanocomposites based on ZnO semiconductor are also covered. In order to design and prepare high efficiency ZnO semiconductor based electromagnetic wave absorbing materials for use in applications of next-generation electronics and aerospace, this article can offer some useful ideas.Ministry of Education, Youth, and Sports of the Czech Republic- DKRVO at the Centre of Polymer Systems, Tomas Bata University in Zlin, Czech Republic [RP/CPS/2022/007
Root cause analysis of coining tool failure with proposed solution to extend its service life
Get PDFThe article deals with a root cause analysis of coining tool failure after its untimely discarding and the design to extend its service life by innovating the manufacturing process. The analysis was performed on the coining die which had to be put out of service due to the insufficient quality of minted stainless coins. The purity of steel and the microstructure of the material of the semi-finished goods were evaluated. Furthermore, an analysis of the coining die failure under the surface and in the core was performed as well as the state of the chromium layer failure on the coining die relief. Based on the results of the analysis, a new experimental coining die was designed and produced according to an innovative manufacturing process. The pressing of the relief was carried out in a vacuum furnace and relief was coated with a TiAlN by the PVD method. New processes introduced in the production of coining die prevented the failure of die punches, extended the time of operation, thereby increasing quality of the coin production.European Regional Development Fund, ERDF; Ministerstvo školstva, vedy, výskumu a športu Slovenskej republiky, (APVV - 19-0550
Concentration fluctuation/microheterogeneity duality illustrated with aqueous 1,4-dioxane mixtures
No full textThe structural properties of aqueous 1-4 dioxane mixtures are studied by computer simulations of different water and dioxane force field models, from the perspective of illustrating the link between structural properties at the molecular level and measurable properties such as radiation scattering intensities and Kirkwood-Buff integrals (KBIs). A strategy to consistently correct the KBI obtained from simulations is proposed, which allows us to obtain the genuine KBI corresponding to a given pair of molecular species, in the entire concentration range, and without necessitating excessively large system sizes. The application of this method to the aqueous dioxane mixtures, with an all-atom CHARMM dioxane model and 2 water models, namely, SPC/E and TIP3P, allows one to understand the differences in the structure of the corresponding mixtures at the molecular level, particularly concerning the role of the water aggregates and its model dependence. This study allows us to characterize the dual role played by the concentration fluctuations and the domain segregation, particularly in what concerns the calculated X-ray spectra.Erasmus+; Erasmus progra
Model of sustainability of SMEs in V4 countries
Get PDFThe research’s objective was to develop a thorough model of the viability of SMEs in the V4 countries based on predetermined variables. The following factors were defined: human resources management, business ethics, corporate social responsibility, company digitalisation, environmental considerations, financial management, and sustainability of SMEs. The model was developed on the solid empirical research carried out in the Visegrad Four countries in June 2022 by the renowned external agency MNFORCE using a sample of 1,398 respondents and the “Computer Assisted Web Interviewing” technique. According to the research, the developed complex model of SMEs’ sustainability depending on the listed criteria is statistically significant. Each investigated factor has a favourable impact on SMEs’ sustainability. The study’s findings supported the notion that the environmental aspects of the business have the strongest positive impact on the long-term sustainability of SMEs. The study’s findings indicate that the management of human resources, finances, and the degree of digitalisation of SMEs significantly influence the viability of businesses. The findings provide an important platform for managers responsible for the sustainability of the SME segment at the worldwide level (International council for small business), national level (particularly for V4 nations), as well as institutions supporting SMEs and SME owners.Scientific Grant Agency of the Ministry of Education, Science, Research, and Sport of the Slovak Republic; Slovenská Akadémia Vied, SAV; Vedecká Grantová Agentúra MŠVVaŠ SR a SAV, VEGA, (1/0364/22)Grant Agency Academia Aurea [GAAA/2022/5
Quantification of factors influencing differences in the Case Mix Index and their significance for health systems sustainability
Get PDFCase Mix Index (CMI) represents a standard indicator of hospital disease seriousness at both the national and international level. CMI is structured to compute hospital payments and not to follow up disease seriousness. It is considerably related to the data accuracy as well as patients’ medical records. The main aim of the study was to quantify the factors influencing the differences in CMI depending on the types of healthcare facilities, their geographical location, as well as the procedural aspects within the Slovak healthcare system. We use data published by the Institute for Economic and Social Reforms, which continuously surveys the quality and outputs of healthcare provided in the Slovak Republic. The data comes from multiple datasets that are issued by healthcare authorities and stakeholders is the Slovak Republic such as insurance companies, the Ministry of Health of the Slovak Republic, the Ministry of Finance of the Slovak Republic, healthcare facilities, the National Health Information Centre etc. Regression analysis indicates that the positive impact on the Case Mix Index is possessed by the Operating experience of doctors and Overall inpatients satisfaction; whilst the negative impact on Case Mix Index values is documented for variables Total rehospitalisation within 30 d, Intensive care unit mortality, Economy, and Transparency.Tomas Bata University in Zlín, TBU, (RVO/2022); Tomas Bata University in Zlín, TB
The tearing energy threshold of crack growth in rubber exposed to ozone: an experimental–numerical approach
Get PDFThe global rubber industry is seeking alternatives to the widely-used antiozonant, N-(1,3-dimethylbutyl)-N′-phenyl-p-phenylenediamine (6PPD), due to its environmental toxicity concerns when used in automobile tires. These substantial research and development efforts on new antiozonants for rubber are hindered by a general inability to characterize the fundamental physical parameter of ozone-induced tearing energy threshold for crack growth, which underlies the practical ozone resistance of rubber products. Therefore, this paper presents, for the first time, a novel experimental–numerical combined approach to determine the tearing energy threshold in rubber exposed to ozone, which is a key criterion for assessing the resistance of rubber to ozone crack growth. The approach is based on in-situ optical analysis of ozone crack growth on the rubber surface and the determination of the crack growth rate when the rubber is stretched. Subsequently, the growth rates form the basis for calculating the energy release rates at the crack tips using the finite element method in Ansys software. By comparing the calculated energy release rates and experimentally measured crack growth rates, the energy release rate interval corresponding to the threshold tearing energy is determined. Based on this approach, the tearing energy threshold for carbon black reinforced natural rubber exposed to ozone was found to be a maximum of 2.12 J/m2. This value is 96% lower than the threshold for the non-ozone-exposed specimens. In conclusion, this novel methodology was able to determine the ozone threshold tearing energy and represents a powerful, unique tool for an efficient future development of environmentally friendly antiozonants.National Technical Library in Prague; Ministerstvo Školství, Mládeže a Tělovýchovy, MŠMT; DKRVO, (RP/CPS/2022/006); Tomas Bata University in Zlín, TBU, (CZ.02.2.69/0.0/0.0/19_073/0016941); Deutsche Forschungsgemeinschaft, DFG, (380321452/GRK2430)Ministry of Education, Youth and Sports of the Czech Republic-DKRVO [RP/CPS/2022/006]; Project OP RDE Junior Grants of TBU in Zlin [CZ.02.2.69/0.0/0.0/19_073/0016941]; DFG (Deutsche Forschungsgemeinschaft) research training group "Interactive Fiber-Rubber Composites [380321452/GRK2430
Analytical framework for industry-oriented leading cyclical indicators: Empirical investigation of EU economic cycles
No full textThis research developed an analytical framework for industry-oriented leading cyclical indicators (CII), focusing on monitoring and forecasting economic cycles within the European Union (EU). Various methodologies for constructing these indicators were examined through an exhaustive sector analysis. A salient conclusion drawn is the non-feasibility of a one-size-fits-all composite leading indicator for all EU members. It underscores the imperative to tailor these indicators in congruence with the unique industrial characteristics of each country. The study provides empirical evidence that countries like Denmark, Germany, Austria, Estonia, Lithuania, Latvia, Finland and Sweden can benefit from high-caliber composite leading indicators tailored to their economies. Our analysis suggests that GDP is a more robust metric than the Industrial Production Index for predicting economic cycles for the EU countries
