Tomas Bata University in Zlín
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A physicochemical study of the antioxidant activity of corn silk extracts
Get PDFCorn silk (CS) extracts are reported to contain flavonoids (appx. 59.65 mg quercetin/g), polysaccharides (appx. 58.75 w.%), steroids (appx. 38.3 × 10−3 to 368.9 × 10−3 mg/mL), polyphenols (appx. 77.89 mg/GAE/g) and other functional biological substances. This study investigated the antioxidant activity of corn silk extracts related to their functional compounds. The radical scavenging effect of corn silk extracts was evaluated by the spin-trapping electron paramagnetic resonance (EPR) technique, 1,1-diphenyl-2-picrylhydrazyl (DPPH), 2,2′-azino-bis(3-ethylbenzo-thiazoline-6-sulfonate) (ABTS•+) free radical measurement, ferric ion-reducing antioxidant power, and copper ion reductive capacity. It was found that the maturity stage of CS plant materials and the applied extraction procedure of their bioactive compounds have a profound effect on the radical scavenging capacity. Differences in the antioxidant activity of the studied corn silk samples based on their maturity were also confirmed. The strongest DPPH radical scavenging effect was observed for the corn silk mature stage (CS-M)stage (CS-MS) (65.20 ± 0.90)%, followed by the silky stage (CS-S) (59.33 ± 0.61)% and the milky stage (CS-M) (59.20 ± 0.92)%, respectively. In general, the final maturity stage (CS-MS) provided the most potent antioxidant effect, followed by the earliest maturity stage (CS-S) and the second maturity stage (CS-M).Tomas Bata University in Zlin, TBU: IGA/FT/2023/007; Univerzita Palackého v Olomouci, UP: IGA_PrF_2023_024Tomas Bata University in Zlin [IGA/FT/2023/007]; Palacky University Olomouc [IGA_PrF_2023_024
Enhancing citizen participation through social media engagement: The case of Czech municipal Facebook
No full textThe popularity of social media is expanding, and so is the interaction between towns and residents. Municipalities in the Czech Republic rely heavily on Facebook as a direct communication medium with citizens. The main goal of this research is to assess the drivers of municipal social media engagement with citizens. To do so, we looked at 183 official Facebook sites of Czech municipalities with extended powers. We applied the first generational statistical techniques, specifically the correlation and regression analyses in delving into the nexus between the citizenry engagement on local government issues via facebook toward onward local government development. Our results indicated that indeed most local governments have a Facebook page with little activity and large municipalities dominated most social media activity. The study found out that Facebook activity, interactivity and mood are the factors driving citizen engagement on municipality social media pages
Rheology of polysaccharide based self-cross-linked injectable hydrogel
No full textInjectable hydrogel systems are the current interest in health care or medical field for therapeutic agent delivery, disease/cancer therapy, and tissue engineering. On the other hand, polysaccharide-based hydrogels are appealing materials for biomedical applications due to their polyfunctionality, biodegradability as well as originality (origin from nature). Hence, attention has been given in preparation of polysaccharide based injectable hydrogel. But the stability, usability, and application of injectable hydrogel in the biomedical field is determined by rheological properties, which is the most significant features of injectable hydrogels. This article reports about rheological behaviors such as storage (G') and loss modulus (G"), complex viscosity, shear stress and gel point of polysaccharide based injectable hydrogels prepared with oxidized bacterial cellulose, pectin, and chitosan, designated as S-0.5, S-0.75, S-1.0 and S-1.5. They appeared as transparent white, self-crosslinked, and soft polymeric gel with gel formation within less than 30 second possessing depicting viscoelastic properties under oscillatory shear deformation.Tomas Bata University in Zlin and Technology Agency of the Czech Republic; Technology Agency of the Czech Republic, TACRTomas Bata University in Zlin; Technology Agency of the Czech Republic (TACR)-M-ERA.NET [TH71020005]; Ministry of Education, Youth & Sports of the Czech Republic-DKRVO [RP/CPS/2020/005
Magneto-active ferrite-based paint pigments
No full textSmart materials, including magnetorheological (MR) fluids, have been emerging in a wide range of applications. Ferrite-based paint pigments, nickel ferrite and barium ferrite, are tested as a dispersed phase of a MR fluid in this study. The anticorrosive properties of both pigments have been previously reported, as such, they have a potential to be applied as hybrid corrosion-protection and magneto-active paint. Both pigments were characterized by scanning electron microscopy, X-ray diffraction spectroscopy, and their magnetic properties were evaluated by vibrating-sample magnetometer. Finally, the MR properties were evaluated by rotational rheometer employed with a magneto-cell. The MR performance of both ferrites was compared, with the nickel ferrite as the superior of the two. Thus, the studied pigments have the potential to be applied as a hybrid magneto-active anticorrosive paint.Ministry of Education, Youth and Sports of the Czech Republic [RP/CPS/2022/007
Novel perspectives on self-monitoring internal rubber failure using piezoresistivity
No full textCarbon black (CB) fillers are often used to increase the ultimate strength and durability of rubber products. Incidentally, CBs are also electrically conductive and this property at low filler concentrations was successfully exploited by several researchers to monitor changes in mechanical properties of rubber by piezoresistance evaluation. In the present work, piezoresistive response of deformed natural rubber (NR) filled with higher concentrations of CB, which are often encountered in rubber products under dynamic loading conditions like tires, conveyor belts, vibration dampers and the like was investigated. Unfortunately, high carbon black content significantly decreased piezoresistive signal, severely limiting the self-monitoring capability. Moreover, unexpectedly high and undesirable for electromechanical application such as precursor of shoulder peak phenomenon (PSPP) and shoulder peak phenomenon (SPP) were observed. However, these otherwise undesirable phenomena in a noble way was used for self-monitoring the rubber integrity during cyclic deformation. The gradual increase in residual strain, indicating rubber matrix fatigue, was clearly related to changes in experimentally detectable electrical resistance as a function of PSPP and SPP. The study is optimistic of a new concept for self-monitoring and forecasting rubber structure degradation under long-term cyclic loading predictable from simple obtainable piezoresistive response.DKRVO, (RP/CPS/2022/006); Ministerstvo Školství, Mládeže a Tělovýchovy, MŠMTMinistry of Education, Youth and Sports of the Czech Republic - DKRVO [RP/CPS/2022/006]; Ministry of Education Youth and Sports of the Czech Republi
Institutional pressures and the adoption of responsible management education at universities and business schools in Central and Eastern Europe
Get PDFBusiness schools, and universities providing business education, from across the globe have increasingly engaged in responsible management education (RME), that is in embedding social, environmental and ethical topics in their teaching and research. However, we still do not fully understand the institutional pressures that have led to the adoption of RME, in particular concerning under-researched regions like Central and Eastern Europe (CEE). Hence, we undertook what is to our knowledge the most comprehensive study into the adoption of RME in CEE to date (including 13 countries: Belarus, Bulgaria, Croatia, Czech Republic, Estonia, Hungary, Latvia, Lithuania, Poland, Romania, Russia, Slovenia and Ukraine). We find that, with regard to RME, isomorphic pressures seem to shape teaching and research in different ways, which suggests that the idea of a holistic approach to RME, promoted by, for example, the Principles of Responsible Management Education (PRME), needs to be revisited; rather, different trajectories of organizational engagement may emerge for each principle. As a contribution to institutional theory, we discuss how a highly fragmented organizational field—like RME with its multiple dimensions—impacts on notions of actor centrality, where actors achieve centrality with regard to some dimensions of the field but fail to do so for others. In particular, we found that the European Union holds centrality in the area of RME teaching, but not in RME research. Our findings thus suggest that the concept of field centrality needs further clarification.IABS; International Association for Business and SocietyInternational Association for Business and Societ
Setting an opposition: Antithesis in propaganda for 1960 Ukrainian SSR
Get PDFThe study zeroes in on the propagandist discourse of the Communist Party and its leaders in one of the official newspapers of the Ukrainian SSR, targeted at the young men and women, the Molod Ukrajiny published during January – June 1960. Cognitive antithesis (PEAC
Emerging from the chaos of Management Theory Jungle: a historical analysis of the development of the four principles of management
No full textPurpose: This paper aims to map the antecedents and precursory contexts regarding the four principles of management. Moreover, a description of its codification and coalescence as a unified teaching framework is provided, critically reviewing key theoretical underpinnings of management principles in academic research and management textbooks.
Design/methodology/approach: A historiographic approach reviewed seminal works for theory origins of the four principles of management, by analyzing 260 management textbooks from 1935 to 2013 to document their adoption in management education. This study used critical hermeneutics (Prasad, 2002) to explore the framework’s progression by providing the context of cultural, political and economic influences.
Findings: This research study tracked and mapped the creation of the four principles of management, as it became the commonly accepted teaching framework in management education. Today, every predominant management principles textbook uses the four principles of management – plan, lead, organize and control – as the basis for teaching students.
Research limitations/implications: There is limited research on the application of the four principles of management in contemporary management, despite its ubiquity in management education. The study’s historical account of its formation provides insights into its adoption and utilization in modern education context. The study’s primary limitation stems from the generalization of the representative sample of textbooks used in the study (1917–2013). However, data saturation was achieved for the scale of textbooks and writings which was reviewed.
Originality/value: Through a critical analysis into the formation of the four principles of management, this research not only provides a historical account of its construction but, as importantly, the influencing factors that led to its development. This research fills a gap in critical literature, as a post mortem exegesis has never been conducted on the four principles of management in the afteryears of its amalgamation
Deployment of creative actors and varieties of their impact on the quaternary sector and regional growth: a case study of NUTS2 regions of the Czech Republic
Get PDFThe current era acknowledges the immense impact of creativity on economic growth and regional development. There is an ongoing debate about the position of creativity and its sources and implications in regional economies when thorougly examining regional disparities. We contribute to the debate by piloting an investigation of five groups of creative actors whose links and consequences for regional growth and the quaternary sector were explored. As a case study, the NUTS2 regions of the Czech Republic were selected for analysis (2015-2017). Given the nature of selected indicators, the causality results and the substantive importance of our investigation, the selected time period is not a limiting factor for our analyses. The empirical conclusions of the conducted study clearly confirmed the theoretically and logically defined thesis on the diverse importance of creative actors in regional economies.European Commission, EC, (SK-FR-19-0009); Vedecká Grantová Agentúra MŠVVaŠ SR a SAV, VEGAEuropean Union [CZ.02.1.01/0.0/0.0/17_049/0008452]; APVV [SK-FR-19-0009]; VEGA [1/0380/20
Toward a better microlevel understanding of the use of emerging technologies at work: The interplay between virtual teams, knowledge sharing, and innovation output
No full textThe COVID-19 pandemic has forced many organizations to make an unprecedented shift to remote work, with virtual teams becoming an increasingly important tool for organizations to configure and manage team-based work. The way teams are configured has major implications for how individuals, teams, and organizations collect and contribute knowledge in order to innovate. By looking at team member diversity, this research paper examines the impact of different forms of diversity on the knowledge sharing processes and innovation output of virtual teams. Responses from 103 virtual team members based in the U.K. are used to assess the role of diversity inputs, on knowledge sharing processes and innovation output. Partial least squares structural equation modeling was employed to assess and validate the input-process-output model with statistically significant empirical results presented. Furthermore, the empirical results infer that knowledge sharing plays a critical role in mediating the role between diversity and innovation output in virtual team settings. Findings are discussed and implications are presented