Tomas Bata University in Zlín
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Electrorheological and magnetorheological properties of liquid composites based on polypyrrole nanotubes/magnetite nanoparticles
No full textThis research presents an in-depth exploration of the electrical and magnetic properties of a polypyrrole nanotubes/magnetite nanoparticles (PPyM) material embedded in a silicone oil matrix. A key finding of our study is the dual nature of the composite, i.e. it exhibits a behaviour akin to both electro- and magnetorheological suspensions. This unique duality is evident in its response to varying electric and magnetic field intensities. Our study focuses on examining the electrical properties of the composite, including its dielectric permittivity and dielectric loss factor. Additionally, we conduct an extensive analysis of its rheological behavior, with a particular emphasis on how its viscosity changes in response to electromagnetic stimuli. This property notably underscores the material’s dual-responsive nature. Employing a custom experimental design, we integrate the composite into a passive electrical circuit element subjected to alternating electric fields. This methodological approach allows us to precisely measure the material’s response in terms of resistance, capacitance, and charge under different field conditions. Our findings reveal substantial changes in the material’s electrical conductivity and rheological characteristics, which are significantly influenced by the intensity of the applied fields. These results enhance the understanding of electro-magnetorheological properties of PPyM-based magnetic composites, and also highlight their potential in applications involving smart materials. The distinct electrical, magnetic and rheological modulation capabilities demonstrated by this composite render it as promising candidate for advanced applications. These include sensory technology, actuation systems, and energy storage solutions.Grantová Agentura České Republiky, GA ČR, (23-07244S); Grantová Agentura České Republiky, GA ČRGrantov Agentura Ccaron;esk Republikyhttp://dx.doi.org/10.13039/501100001824 [23-07244S]; Czech Science Foundatio
Tailoring electrochemical properties of hydrogel by different types of graphene oxide
No full textIn this study, different concentrations of graphene oxides prepared according to Brodie's and Hummers’ method (GOB and GOH, respectively) were integrated with mixture of citric acid and hydroxyethyl cellulose (HEC-CA). This three-component solution could be easily coated on glassy carbon electrode surface and thermally crosslinked, forming solid films of nanohybrid hydrogels (HEC-CA-GOB and HEC-CA-GOH). The coated electrodes were characterized by different electrochemical techniques, which revealed that, compared to GOB, GOH significantly hindered diffusion of electroactive species to the electrode surface. Furthermore, application of the electrodes coated with HEC-CA-GOB and HEC-CA-GOH as voltammetric detectors of toxic metals and histamine was investigated. For the former, a low amount (0.075 mg mL−1) of GOB in HEC-CA enhanced the voltammetric response towards Pb2+ and Cu2+ up to 6.5 and 10 times, respectively while effect of GOH was less sound. In histamine detection, 1 mg mL−1 GOB or GOH in HEC-CA improved the response of the electrodes towards the histamine by approximately 25 % and improved antifouling properties of the sensors. As a conclusion, adjusting of GO content in the hydrogel was shown as an interesting and facile tool for preparation of electrodes with wide range of properties adjustable such as to meet requirements of various applications.Slovenská Akadémia Vied, SAV; Matej Micusik of Polymer institute; Ministerstvo Školství, Mládeže a Tělovýchovy, MŠMT; Tomas Bata University in Zlín, TBU, (IGA/FT/2022/006); DKRVO, (RP/CPS/2022/003)Tomas Bata University in Zlin [IGA/FT/2022/006]; Ministry of Education, Youth and Sports of the Czech Republic - DKRVO [RP/CPS/2022/003
Perpetrators in multimodal media discourse: a case study of personalization in images from The Telegraph
Get PDFThe article deals with the visual and linguistic representation of alleged perpetrators through personalization in news reporting from The Telegraph’s online media platform. The analysis shows how visual message, along with verbal labelling in the text, represent different groups of alleged perpetrators as more or less ‘dangerous’ in news reports. Agency is analyzed through a focus on the lens range and its influence on perceived social distance, the angle of the shot and its role in the understanding of social relations, as well as the direction of an alleged perpetrator’s gaze in images as a way of social interaction with the viewer. The photos of alleged perpetrators appear in The Telegraph with the aim of informing the public about the danger these individuals pose, as well as legitimizing the actions of law enforcement institutions. It appears that verbal and visual identification of these individuals is done with the intention of ‘excluding’ the most dangerous social actors, such as ‘murderers’, from ingroups
Influence of non-woven antistatic substrate materials on polyvinylidene fluoride electrospun nanofibers: fabrication, characterization, and performance evaluation
No full textThe production of nanofibers holds significant importance in both laboratory-based research and industrial applications. This study employed multiple spinnerets in the process of electrospinning to produce polyvinylidene fluoride (PVDF) nanofibers, which exhibited a desirable characteristic of being both thin and uniform. The spinning performance of multiple jet electrospinning was done. In addition, an examination was conducted to assess the impact of antistatic non-woven support materials on the fiber morphology of PVDF electrospun nanofibers. The morphology and β-phase (beta phase) of the electrospun nanofibers were analyzed using characterization techniques, such as scanning electron microscopy (SEM) and Fourier transform infrared spectroscopy (FTIR). The findings of the study indicate that the selection of antistatic non-woven support material had a notable impact on fiber morphology. Upon the utilization of various suitable substrate materials, polyethylene terephthalate (PET) contributed to the successful formation of well-structured and consistent nanofibers with a lesser diameter of 173 ± 38 nm, 92.8% β-fraction and a surface area of 12.99 m2/g. The laminating temperature and density of the fiber decreased the porosity and air permeability by 50%. The excellent flux recovery of 400 L/(m2 h) on the nanofibers laminated at 130 °C of pore size of 0.54 µm even after dried and stored for 48 h at room temperature. A finite-element analysis (FEA) was conducted on computer-aided design (CAD) fiber structure, and results showed that at low pressure of 0.01 N, a max of 130.29 MPa stress was generated on fibers
Monitoring the connection between the application of EFQM model principles and the results of organisations
Get PDFPurpose: The present paper evaluated the connections between the degree of fulfilment of the EFQM model's requirements and the organisation's size, key results, social responsibility, employee satisfaction and customer satisfaction.
Methodology/Approach: The dataset was acquired via an internet-based survey hosted on Google Forms. The survey targeted managerial personnel within manufacturing entities situated within the geographical boundaries of the Czech Republic.
Findings: Research on the relationship between the degree of fulfilment of the EFQM model requirements and the organisation's size, critical organisational results, social responsibility, employee satisfaction, customer satisfaction and overall organisational results demonstrated a moderately significant to strong correlation for all monitored indicators.
Research limitation/implication: The data is collected only in one specific country, but the production organisations in which the research was carried out are mainly foreign-owned.
Originality/Value of paper: The current research results offer practical and theoretical implications. Theoretically, the research expands the literature on the EFQM model and its connection with current trends, which are the higher innovative activity of organisations and correlation with Industry 4. Practically, the research results will benefit managers, directors, and leaders of companies by allowing them to maintain an optimal level of quality management and estimate future requirements for complex enterprise integration.Internal Grant Agency of FaME TBU [IGA/FaME/2023/003
Old Juniper Troll stand - The oldest shrub population from Scandinavia
Get PDFOld plant communities are of utmost importance for nature conservation, carbon sequestration, as well as gene pool maintenance. Shrub populations occurring in extreme environments beyond abiotic tree-lines provide diverse ecosystem services and have potential as proxy archives because they often inhabit areas with scarce and short instrumental records. We provide dendrochronological insight into one such population made up of prostrate Juniperus communis shrubs in the northern Scandinavian tundra (Norway), growing on a competition-free boulder field. We dated and provided a growth chronology of the oldest living shrub population (190 ± 148 years) from Scandinavia with the oldest individual being 683 years old. This is a conservative estimate, as shrubs in extreme environments do not form even a single row of cells in some years. The cross-dating issues of poorly growing shrubs do not fully allow to rely on climate sensitivity of the juniper population studied, although the species' potential for dendroclimatological reconstructions is generally considered high, also because the common juniper is an abundant woody species distributed globally. Old populations present an important gene source in plant recruitment, particularly in the context of the present environmental change.European Commission, EC; Horizon 2020, (262693); Horizon 2020European Union as part of the Horizon 2020 project INTERACT [262693
Data analytics in supply chain management: A state-of-the-art literature review
No full textIn recent years, there has been a growing surge of interest in the application of data analytics (DA) within the realm of supply chain management (SCM), attracting attention from both practitioners and researchers. This paper presents a comprehensive examination of recent implementations of DA in SCM. Employing a systematic literature review (SLR), we conducted a meticulous analysis of over 354 papers. Building upon a prior SLR conducted in 2018, we identify contemporary areas where DA has been applied across various functions within the supply chain and scrutinize the DA models and techniques that have been employed. A comparison between past findings and the current literature reveals a notable upsurge in the utilization of DA across most SCM functions, with a particular emphasis on the prevalence of predictive analytics models in contemporary SCM applications. The findings of this paper offer a detailed insight into the specific DA models and techniques currently in use across various SCM functions. Additionally, a discernible increase in the adoption of mixed or hybrid DA models is observed. However, several research gaps persist, including the need for more attention to real-time DA in SCM, the integration of publicly available data, and the application of DA to mitigate uncertainty in SCM. To address these areas and guide future research endeavors, the paper concludes by delineating six concrete research directions. These directions offer valuable avenues for further exploration in the field.Christian Doppler Forschungsgesellschaft, CD
Heterogeneous Cr-doped Co3S4/NiMoS4 bifunctional electrocatalyst for efficient overall water splitting
No full textExploration of efficient and robust catalysts for electrocatalytic water splitting is paramount yet challenging for economical hydrogen production. Here, nanoforest-like heterostructures composed of inner NiMoS4 nanowires and outer Cr-doped Co3S4 nanosheets were grown on nickel foams (Cr–Co3S4/NiMoS4) as highly efficient bifunctional electrocatalysts. As a result, Cr–Co3S4/NiMoS4 heterostructures exhibit low overpotentials of 72 mV and 243 mV for hydrogen evolution reaction (HER) and oxygen evolution reaction (OER) at 10 mA cm−2, respectively. Moreover, the water electrolyzer assembled by Cr–Co3S4/NiMoS4 as bifunctional electrodes reaches 10 mA cm−2 at 1.587 V and maintains exceptional stability over 200 h. The experimental and theoretical characterizations collectively unveil that the charge redistribution occurs at the heterointerface between Cr-doped Co3S4 and NiMoS4, resulting in the regulation of both their electronic structures, which optimizes the adsorption of HER intermediates and decreases the energy barrier of determining step for OER. Additionally, the Cr doping and nanoforest-like morphology increase the intrinsic conductivity and the exposure of active sites, collectively improving the water electrolysis efficiency. This finding presents a promising way to construct and adjust the heterojunction engineering for bifunctional electrocatalysts toward water electrolysis.National Natural Science Foundation of China, NSFC, (22108079); National Natural Science Foundation of China, NSFC; Shanghai Pujiang Program, (21PJD018); China Postdoctoral Science Foundation, (2020M681208); China Postdoctoral Science Foundatio
Exploring the relationship between digital gaming, language attitudes, and academic success in EFL university students
Get PDFThe potential of digital games in education has been widely discussed, yet there is a significant gap in the literature regarding their influence on foreign language learning, particularly in Central Europe, and using mixed-method research designs. This study aims to fill this gap by providing empirical data from a new cultural context. Using a mixed-method research design, it investigates the impact of gaming on language learning outcomes of English as a Foreign Language (EFL) university students. A total of 99 Slovak university students of English as a foreign language were selected by convenience sampling, of which 10 were chosen for qualitative interviews to triangulate the data. The results reveal a significant improvement in vocabulary knowledge and a reported increase in positive language attitudes among gamers compared to non-gamers, with no significant difference in grade point averages between the two groups. These findings highlight the potential of digital gaming to enhance vocabulary learning and foster positive attitudes towards language learning among EFL students. Recommendations for future research are provided.KEGA, (001UKF-4/2024)project KEGA [001UKF-4/2024
The relationship between intra-organisational trust and knowledge sharing: empirical evidence from the Czech Republic
No full textKnowledge sharing has a significant impact on the performance of organisations. Some researchers mentioned trust to be a key factor in knowledge sharing and its success. Can knowledge sharing be really facilitated by trust? And if yes, what kind of trust is important for that? This study examined the influence of trust on the intensity of knowledge sharing in organisations and tries to develop a model of the dimensions of trust. A quantitative approach to the research and an opinion-based questionnaire as a method of data gaining was used. The findings indicate that the extent of trust in the organisation has a significant positive effect on the extent of knowledge sharing in the organisation. Based on the previous studies, four dimensions of trusts were suggested. However, only three dimensions of trust (trust in co-workers, trust in the management of the organisation, and trust in the direct superior) predicted knowledge sharing.Univerzita Tomáše Bati ve Zlíně, UTB, (RO/2023/02); Univerzita Tomáše Bati ve Zlíně, UTBInternal project of Tomas Bata University in Zlin [RO/2023/02