Tomas Bata University in Zlín
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Composite scaffolds based on bacterial cellulose for wound dressing application
Get PDFWound dressing materials fabricated using biocompatible polymers have become quite relevant in medical applications, and one such material is bacterial cellulose (BC) with exceptional properties in terms of biocompatibility, high purity, crystallinity (∼88%), and high water holding capacity. However, the lack of antibacterial activity slightly restricts its application as a wound dressing material. In this work, polycaprolactone (PCL) was first impregnated into the BC matrix to fabricate flexible bacterial cellulose-based PCL membranes (BCP), which was further functionalized with antibiotics gentamicin (GEN) and streptomycin (SM) separately, to form wound dressing composite scaffolds to aid infectious wound healing. Fourier transform infrared spectroscopy (FT-IR) results confirmed the presence of characteristic PCL and cellulose peaks in the composite scaffolds at 1720 cm-1, 3400 cm-1, and 2895 cm-1, respectively, explaining the successful interaction of PCL with the BC matrix, which is further corroborated by scanning electron microscopy (SEM) images. X-ray diffraction (XRD) studies revealed the formation of highly crystalline BCP films (∼86%). In vitro studies of the BC and BCP scaffolds against baby hamster kidney (BHK-21) cells revealed their cytocompatible nature; also the wettability studies indicated the hydrophilicity of the developed scaffolds, qualifying the main criterion in wound dressing applications. Energy dispersive X-ray analysis (EDX) of the drug loaded scaffolds showed the presence of sulfur in the composites. The prepared scaffolds also exhibited excellent antimicrobial activity against Escherichia coli and Staphylococcus aureus. The release profiles initially indicated a burst release (6 h) followed by controlled release of GEN (∼42%) and SM (∼58%) from the prepared scaffolds within 48 h. Hence, these results interpret that the prepared drug-functionalized cellulosic scaffolds have great potential as a wound dressing material in biomedical applications. © 2022 American Chemical Society.Tomas Bata University in Zlin, TB
Strengthening resilience in the energy critical infrastructure: Methodological overview
Get PDFAs the number of threats and the severity of their impact increases, an ever greater emphasis is being placed on the protection of critical infrastructure. Thus, the issue of resilience, or its assessment and strengthening, is increasingly coming to the fore. The resilience assessment of critical infrastructure, especially in the energy sector, has received considerable attention due to the high level of interest in this issue. However, the issue of strengthening resilience poses a significant challenge not only in the energy sector but also in the entire critical infrastructure system. Despite the great importance of this area, there is not a large number of authors moving in this direction and paying attention to resilience-strengthening tools. For this reason, the aim of this article is to provide the reader with a comprehensive methodological overview of resilience strengthening in the critical energy infrastructure sector. This article also provides an overview of internal and external tools suitable for strengthening resilience and presents a possible procedure for their application to energy critical infrastructure elements.Ministry of the Interior of the Czech Republic [VI20192022151]; VSB-Technical University of Ostrava [SP2022/70]Ministerstvo Vnitra České Republiky: SP2022/70, VI2019202215
Understanding revisit intention towards religious attraction of Kartarpur temple: Moderation analysis of religiosity
Get PDFThis study examines the effect of destination image, cultural contact and perceived risk on revisit intention of Sikh pilgrims to Kartarpur temple, mediated by tourist satisfaction. The literature has debated the moderating effect of religiosity in a different tourism context. However, studies rarely investigate the moderating role of religiosity in the relationship of destination image, cultural contact and perceived risk with tourist satisfaction. This study follows a cross-sectional approach and self-administered survey method to collect data from 613 Sikh pilgrims who visited Kartarpur temple. A quantitative study with covariance-based structural equation modeling was employed to examine the research hypothesis through Amos 2 version. The results show that tourists' satisfaction partially mediates the relationship of destination image and cultural contact with revisit intention. Nevertheless, perceived risk significantly affects the revisit intention effect via tourist satisfaction. So, tourist satisfaction was the significant mediator between destination image, cultural contact, perceived risk and revisit intentions. The findings confirm that the religiosity of Sikh pilgrims significantly moderates the relationship of destination image, cultural contact and perceived risk with revisit intentions. Practically, the findings offer the managers of such attractions to formulate suitable marketing strategies for developing the revisit intention and sustainable branding.Internal Grant Agency of FaME TBU [IGA/FaME/2021/009, IGA-K-TRINITY/2022/005]IGA-K-TRINITY/2022/00
The influence of tool's surface topography on mechanical properties of injection moulded product
Get PDFThis publication deals with influence of tool topography (injection mould) on properties of a product. Surface of the mould was machined by various finishing technologies(milling, grinding, polishing and electrical discharge machining)which resulted in varying surface quality of the tool. The tested topography had an effect on the flow length of polymer and topographical and mechanical properties of the specimen. Examined properties(surface topography and mechanical properties)were measured in several places along the length of the product (starting at the gate and finishing at the end of the specimen). The results show that increase of the tool’s surface roughness leads to longer flow length. These findings disprove the necessity for polishing of each and every shaping part of the mould when manufacturing non-visual products. Thus, from economical and manufacturing perspective the milled or grinded tool surfaces are sufficient. Furthermore, replication of the tool’s topography is nonhomogenous, which results in varying mechanical properties throughout the product. The discrepancy in mechanical properties along the length of the product is caused by differing cooling speeds in the mould. In practice, guided cooling can be used to achieve varying mechanical properties in desired places of the injected article. For example, highly stressed parts can be manufactured with the goal of having improved mechanical properties in specific places of the product. Future application of these findings poses a significant benefit for industrial practice, as it could lower the manufacturing cost of the injection mould in order of tens of percent.TBU in Zlin Internal Grant Agency [IGA/FT/2022/002
Modelling study on freezing process of water droplet on inclined cold plate surface with droplet dynamic behavior considered
Get PDFDroplet freezing on inclined surfaces exists widely in engineering fields. To accurately predict and control the freezing process of a sessile water droplet on inclined surface, a theoretical model based on the heat-enthalpy method is presented in this study, with two types of dynamic behavior considered, deformation and spreading. After the validation of model by droplet profiles and freezing duration from experiments, the freezing characteristics are analyzed, including contact area, frozen height and vertex offset, etc. As found, the effect of inclined angle on less than 10.34 µL water droplet is greater than that on larger than 10.34 µL droplet, due to the mutual relation between surface tension and gravity effect. When the inclined angle of surface changes from 0° to 40°, the contact area keeps at 11.61 mm2 for 10 µL water droplet, and increases by 5.64% from 23.04 to 24.34 mm2 for 25 µL water droplet. The initial heights of 10 and 25 µL water droplets decrease by 0.85% from 1.18 mm to 1.17 mm and by 1.91% from 1.51 mm to 1.49 mm, respectively. That means it is easier frozen for the same water droplet on bigger inclined angle surface. This study is beneficial for the optimization of anti-frosting and defrosting technologies. © 2022IADL20200104; National Natural Science Foundation of China, NSFC: 52076013; Beijing Municipal Science and Technology Commission, BMSTC: 3212024National Natural Science Foundation of China [52076013]; Beijing Municipal Science & Technology Commission [3212024]; Open Fund of Key Laboratory of Icing [IADL20200104
Atom transfer radical polymerization of pyrrole-bearing methacrylate for production of carbonyl iron particles with conducting shell for enhanced electromagnetic hielding
Get PDFThe conducting polymer poly(2-(1H-pyrrole-1-yl)ethyl methacrylate (PPEMA) was synthesized by conventional atom transfer radical polymerization for the first time from free as well as surface-bonded alkyl bromide initiator. When grafted from the surface of carbonyl iron (CI) a substantial conducting shell on the magnetic core was obtained. Synthesis of the monomer as well as its polymer was confirmed using proton spectrum nuclear magnetic resonance (H-1 NMR). Polymers with various molar masses and low dispersity showed the variability of this approach, providing a system with a tailorable structure and brush-like morphology. Successful grafting from the CI surface was elucidate by transmission electron microscopy and Fourier-transform infrared spectroscopy. Very importantly, thanks to the targeted nanometer-scale shell thickness of the PPEMA coating, the magnetization properties of the particles were negligibly affected, as confirmed using vibration sample magnetometry. Smart elastomers (SE) consisting of bare CI or CI grafted with PPEMA chains (CI-PPEMA) and silicone elastomer were prepared and dynamic mechanical properties as well as interference shielding ones were investigated. It was found that short polymer chains grafted to the CI particles exhibited the plasticizing effect, which might be interesting from the magnetorheological point of view, and more interestingly, in comparison to the neat CI-based sample, it provided enhanced electromagnetic shielding of nearly 30 dB in thickness of 500 mu m. Thus, SE containing the newly synthesized CI-PPEMA hybrid particles also exhibited considerably enhanced damping factor and proper mechanical performance, which make the material highly promising from various practical application points of view.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/2021/003]; Integrated Infrastructure Operational Programme - ERDF [313021T081]; Slovak Research and Development Agency [APVV-19-0338]; Slovak Grant Agency VEGA [2/0129/19]; Qatar University Grant [QUCG-CAM-22/23-504]RP/CPS/2022/003; Slovenská Akadémia Vied, SAV: 313021T081; Tomas Bata University in Zlin, TBU: IGA/CPS/2021/003; Qatar University, QU: QUCG-CAM-22/23-504; Agentúra na Podporu Výskumu a Vývoja, APVV: APVV-19-0338; Vedecká Grantová Agentúra MŠVVaŠ SR a SAV, VEGA: 2/0129/19; European Regional Development Fund, ERD
Tourist motivation as an antecedent of destination and ecotourism loyalty
Get PDFObjective: This study evaluates the role of tourist motivation in the determination of destination and ecotourism loyalty using push and pull motivation theory and the theory of planned behavior. The paper also analyses the mediating effects of satisfaction and destination image in the relationships between motivation and the two types of loyalty. Method/analysis: Primary data has been gathered from surveys involving 522 Vietnamese tourists traveling to the Bohemian Switzerland National Park in the Czech Republic. Data analysis was conducted using structural equation modeling (SEM) techniques in R. Findings: The findings support both direct and indirect positive associations between tourist motivation and destination and ecotourism loyalty. In terms of ecotourism loyalty, the effect is mediated by destination image. In terms of destination loyalty, the effect is mediated by satisfaction and destination image. Novelty/improvement: This study has further expanded the theory of planned behavior in the context of ecotourism by linking it to travel career pattern theory and functionalist theory. These are complementary theories that can explain the behavior of ecotourists and help operators and marketers adjust their strategies to attract and retain visitors to ecotourist destinations. © 2022 by the authors.IGA/FaME/2022/01
Green human resource management, a gateway to employer branding: Mediating role of corporate environmental sustainability and corporate social sustainability
Get PDFThis study proposes a model based on competitive advantage and signaling theories that show how green human resource management (GHRM) leads to corporate environmental sustainability and corporate social sustainability and is thus source of employer branding. Structural equational modeling was used for data analysis through Smart PLS. The results confirm that GHRM positively influences on corporate environmental sustainability, which in turn positively influences corporate social sustainability. Furthermore, the results confirm that corporate social sustainability has a positive influence on employer branding. The results also support the mediating effects of corporate environmental sustainability between GHRM and corporate social sustainability. Additionally, we show the mediating effect of corporate social sustainability between corporate environmental sustainability and employer branding. In the human resource literature, previous studies emphasize on corporate environmental sustainability. By contrast, this study confirms that a corporate social sustainability is a source of employer branding. By implementing GHRM, organizations can gain a competitive edge, which helps them attract potential employee.Internal Grant Agency of FaME [IGA/FaME/2021/008
Design of information system for advanced technologies production sustainability
No full textEnvironmental protection is an integral part of the strategy of responsible companies and organizations. Through industrial production, the planet's resources are degraded and destroyed for a long time. The only way to preserve nature is to slow down and finally stop the unsustainable method of production. The article deals with the application of information system developed at the Technical University of Kosice to the analysis of basic legal and professional approaches to sustainable production methods evaluation and with application to advanced technologies process planning. A simple methodology implemented in the Information system was created in cooperation with a multidisciplinary international team. The methodology can be used for various sizes of manufacturing companies. This methodology is based on the ISO 14040 standard and offers the possibility of an effective comparison of the economic and environmental impacts of the proposed production processes. The contribution presents an evaluation of the information system in production process design for a selected part and presents the economic and environmental impact of the five selected processes. © 2022 IEEE
Zinc ferrite/polyaniline composite particles: Pigment applicable as electro-active paint
Get PDFHybrid conductive paint pigments composed of zinc ferrites (ZF) and polyaniline (PANI) were analysed as both a potential electro-active and corrosion-protective paint from the electrorheological (ER) point of view. The particles were characterised using scanning electron microscopy and X-ray diffraction spectroscopy. These hybrid conductive particles are used as pigments suitable for applications in paints which was confirmed by determining the consumption of linseed oil, the specific conductivity of aqueous extracts and the density of the tested pigments according to the relevant standardized methods. The chemical stability of particles was evaluated by means of durability tests in aggressive environment showing excellent results for the coated particles. Both ZF/PANI particles and pure ZF were dispersed in silicone oil and their ER behaviour was analysed through controlled shear rate and dynamic oscillatory tests. The ER performance of the pure ZF and the composite ZF/PANI suspensions were compared, showing promising results and enhanced ER performance and attention-worthy ER efficiency of the later (in particular, the ER efficiency of the coated particles exceeded 105 % at 0.01 s−1). Lastly, the results were further validated via dielectric spectroscopy. Thus, the ZF/PANI particles have the potential to be applied as a hybrid ER fluid and an electro-active paint.Ministerstvo Školství, Mládeže a Tělovýchovy, MŠMTMinistry of Education, Youth and Sports of the Czech Republic [RP/CPS/2022/007