Tomas Bata University in Zlín
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Servant leadership knowledge structures: A bibliometric review
No full textServant leadership is an emerging approach that appears timely debate for scientific progress in leadership research. There have been several qualitative, quantitative, and systematic reviews on servant leadership. Surprisingly, there needs to be more research using bibliometric analysis on servant leadership. For this reason, this study addresses methodological limitations by using a bibliometric review to analyze and visualize the historical background of servant leadership, its present state of knowledge structures and emerging trends. To do so, we included a sample of 214 peer-reviewed articles over the period 2004 to 2022 by using the Web of Science (WoS) database. The bibliometric analysis revealed three major clusters in servant leadership: (1) Servant leadership and innovativeness, (2) Servant leadership with employees' extra-role behaviours and personality traits, (3) Attitudinal and behavioural employee outcomes such as emotional labour and ethical followers. Significantly, our contribution recognizes more nuanced results than previously partially identified and highlights servant leadership research. This study also opens a fresh avenue for future scholars by providing future research questions.FaME TBU, (IGA/FaME/2023/012
Photocatalytic reduction of CO2 over Ti3+ self-doped TiO2-based nanomaterials
Get PDFIn this study, we explored the photocatalytic efficacy of Ti3+-doped TiO2-based photocatalysts for CO2 reduction. The Ti3+ self-doped photocatalysts were synthesized using a straightforward chemical reduction with sodium borohydride (NaBH4). Our investigation aimed to elucidate the intricate interplay between the synthesis process and the quantity of NaBH4 reductant on the physical-chemical and photocatalytic attributes of the defective TiO2-based photocatalysts. We explored three different commercially available TiO2 materials labeled P25, (S)TiO2, and KRONOClean7050, which were reduced (2 g of TiO2) with 0.75 and 1.5 g of NaBH4. The reduction with 0.75 g of NaBH4 led to a significant decrease of photocatalytic activity in all three cases. It was caused by clogging of the photocatalysts surface by sodium ions which resulted in the surface recombination of charge carriers. Oppositely, the reduction with 1.5 g of NaBH4, led to an increase of the photocatalytic activity with superior performance of KRONOClean7050. The comprehensive characterization of all the samples explained this superior performance of KC7050_RED_1.5 sample. Importantly, it did not contain any amorphous phase and the crystal size was two times higher compared to other 2 samples reduced by 1.5 g of NaBH4. In the addition to higher crystallinity, the formation of a disordered TiO2−x layer, enriched with Ti3+ defects and oxygen vacancies, was confirmed. These structural features enhance the light absorption and mitigate undesired recombination of photogenerated charge carriers. These results would trigger farther investigation of defect engineering towards enhancement of the efficiency of metal oxide photocatalysts.European Union's Horizon 2020 project SAN4Fuel, (101079384, HORIZON-WIDERA-2021-ACCESS-03–01); European Commission, EC, (101120397, CZ.10.03.01/00/22_003/0000048, HORIZON-WIDERA-2022-TALENTS, RRC/12/2022); Grantová Agentura České Republiky, GA ČR, (GA CR 21-24268K); Narodowe Centrum Badań i Rozwoju, NCBR, (NOR/POLNORCCS/PhotoRed/0007/2019-00)Large Research Infrastructure ENREGAT [LM2023056]; Norway Grants 2014-2021 via the National Centre for Research and Development [NOR/POLNORCCS/PhotoRed/0007/2019-00]; Czech Science Foundation [GA CR 21-24268K]; European Union [HORIZON-WIDERA-2021-ACCESS-03-01: 101079384, CZ.10.03.01/00/22_003/0000048]; Support for Science and Research in the Moravia- Silesia Region 2022 [RRC/12/2022]; APPROACH [101120397
Computational analysis and classification of hernia repairs
Get PDFProblems related to ventral hernia repairs (VHR) are very common, and evaluating them using computational methods can assist in selecting the most appropriate treatment. This study is based upon data from 3339 patients from different European countries observed during the last 12 years (2012–2023), which were collected by specialists in hernia surgery. Most patients underwent standard surgical procedures, with a growing trend towards laparoscopic surgery. This paper focuses on statistically evaluating the treatment methods in relation to patient age, body mass index (BMI), and the type of repair. Appropriate mathematical methods are employed to extract and classify the selected features, with emphasis on computational and machine-learning techniques. The paper presents surgical hernia treatment statistics related to patient age, BMI, and repair methods. The main conclusions point to mean groin hernia repair (GHR) complications of 19% for patients in the database. The accuracy of separating GHR mesh surgery with and without postoperative complications reached 74.4% using a two-layer neural network classification. Robotic surgeries represent 22.9% of all the evaluated hernia repairs. The proposed methodology suggests both an interdisciplinary approach and the utilization of computational intelligence in hernia surgery, potentially applicable in a clinical setting.Ministerstvo Školství, Mládeže a Tělovýchovy, MŠMT, (SENDISO - CZ.02.01.01/00/22_008/0004596); Ministerstvo Školství, Mládeže a Tělovýchovy, MŠMTEuropean Union [CZ.02.01.01/00/22_008/0004590]; Operational Programme Johannes Amos Comenius; European Structural and Investment Funds; Czech Ministry of Education, Youth and Sports [SENDISO - CZ.02.01.01/00/22_008/0004596
Adverse childhood experiences among clients of juvenile detention centres: Research in Czech Republic
Get PDFThe issue of educational work with trauma in juvenile detention centres (JDC) is a less explored area in the Czech Republic, even though the literature points to a higher incidence of trauma among children at risk in this target group. The aim of our research was to determine the extent of adverse childhood experiences among young people in detention centres in the Czech Republic. A quantitative research strategy was applied in the research. The results show that more than 90% of the surveyed adolescents living in JDC had more than one adverse childhood experience (captured in the ACE-Q). In light of the findings, it seems important to pay attention to traumatic experience of youth in JDC and to design comprehensive holistic interventions based on the individual needs of the at-risk youth with traumatic experiences.Ostravská Univerzita v Ostravě, (SGS09/FSS/2023)University of Ostrava [SGS09/FSS/2023
Pilot preparation study of gold nanoparticle-chitosan composite catalyst
Get PDFThe wide range of applications of AuNPs is related to their different shapes and sizes, which are dependent on the synthesis process and reaction parameters. Therefore, the optimization of a novel and highly efficient approach to chitosan substrate decoration by AuNPs via covalent bonding using dialdehyde cellulose (DAC) is presented here. The covalent binding of AuDAC to chitosan nanofibers is mediated by a Schiff base reaction. This improves particle binding compared to conventional methods such as simple dip coating where AuNPs bind to the substrate only via weak interaction. In this work, initial attempts for the preparation of a composite material based on mixing the AuDAC solution with a chitosan solution were conducted. However, this process was found to be inefficient due to the inhomogeneous morphology of the resulting material, i.e., the formation of irregular chitosan micro-nanofibers and sheets sparsely decorated with AuDAC. Therefore, an optimized approach based on the binding of pre-made AuDAC nanoparticles to electrospun chitosan nanofibers was utilized. This method showed high binding efficiency and very dense decoration of nanofibers with AuDAC opposed to method involving mixing of chitosan and AuDAC solutions. Subsequently, the ability of the composite material in the form of a thin filtration layer to catalytically reduce 4-nitrophenol (4NP) to 4-aminophenol (4AP) was demonstrated. The efficacy of binding AuNPs to nanofibers was also compared to nanoparticles synthesized using another type of polysaccharide, specifically hyaluronic acid dialdehyde (DAH).Grantová Agentura České Republiky, GA ČR, (23-07361S); Tomas Bata University in Zlín, TBU, (IGA/CPS/2023/006)Czech Science Foundation [23-07361S]; Internal Grant Agency of TBU project [IGA/CPS/2023/006
Life cycle assessment of lithium-based batteries: Review of sustainability dimensions
Get PDFLithium-based batteries are essential because of their increasing importance across several industries, particularly when it comes to electric vehicles and renewable energy storage. Sustainable batteries throughout their entire life cycle represent a key enabling technology for the zero pollution objectives of the European Green Deal. The EU's (European Union) new regulatory framework for batteries is setting sustainability requirements along the whole battery, including value chains. For a comprehensive assessment of battery technologies, it is necessary to include a life cycle thinking approach into consideration from the beginning.
This review offers a comprehensive study of Environmental Life Cycle Assessment (E-LCA), Life Cycle Costing (LCC), Social Life Cycle Assessment (S-LCA), and Life Cycle Sustainability Assessment (LCSA) methodologies in the context of lithium-based batteries. Notably, the study distinguishes itself by integrating not only environmental considerations but also social and economic dimensions, encapsulating the holistic concept of sustainability. Challenges unique to each assessment method are outlined, including data availability (with 35 % of the reviewed studies having openly accessible inventory data), methodological inconsistencies, uncertainty around future costs and social impacts. Difficulties such as data uncertainty, challenges in cost comparison, and the lack of standardized measures are underscored. The research identifies critical future directions for LCA, including the need for better data quality, adaptation to new technologies, and alignment with Sustainable Development Goals (SDGs). Future research directions are suggested -including the standardization of methodologies, and fostering interdisciplinary collaboration. Overcoming these challenges holds the potential to advance sustainable practices in the battery industry and contribute to a cleaner energy future
An application of TRIZ inventive approach in development strategy into fourth-party logistics
Get PDFPurpose: The study aims to affirm the application of TRIZ in logistics service and then develop innovative strategies for Vietnamese local logistics service providers (LSPs) to transform into fourth-party logistics (4PL) through TRIZ inventive methodology.
Methodology/Approach: The integration of Savransky’s methodology into TRIZ proposals enables to identify the core correlated dependencies of selected parameters. The analyses of the theoretical background and the application of the TRIZ matrix are comprehensively conducted to create innovation for three important attributes of 4PL.
Findings: The research results propose seven strategies through Savransky’s suggested steps from the analytical application of TRIZ. The established recommendations are categorised into short-term and long-term strategies and can be flexibly applied depending on the corporate growth process.
Research Limitation/implication: TRIZ approach was initially constructed for solving engineering problems. As a result, several inventive principles in the contradiction matrix were not entirely appropriate to the service area. In such cases, the authors can’t apply all suggested solutions from the contradiction matrix.
Originality/Value of paper: The study provides local LSPs in Vietnam with comprehensive strategies for improving their capabilities to meet the requirements of 4PLs’ power.
Category: Research paper
Synergistic toughening and strengthening of an epoxy resin modified by simultaneous use of two different modifiers
Get PDFThe present work investigates the effect of modifying an epoxy resin using two different modifiers. The mechanical and thermal properties were evaluated as a function of modifier type and content. The structure and morphology were also analyzed and related to the measured properties. Polyurethane (PUR) was used as a liquid modifier, while Cloisite Na+ and Nanomer I.28E are solid nanoparticles. Impact strength (IS) of hybrid nanocomposites based on 3.5 wt% PUR and 2 wt% Cloisite or 3.5 wt% PUR and 1 wt% Nanomer was maximally increased by 55% and 30%, respectively, as compared to the virgin epoxy matrix, exceeding that of the two epoxy/nanoparticle binaries but not that of the epoxy/PUR binary. Furthermore, a maximum increase in IS of approximately 20% as compared to the pristine matrix was obtained with the hybrid epoxy nanocomposite containing 0.5 wt% Cloisite and 1 wt% Nanomer, including a synergistic effect, due most likely to specific interactions between the nanoparticles and the epoxy matrix. The addition of polyurethane and nanoclays increased the thermal stability of epoxy composites significantly. However, DSC results showed that the addition of flexible polyurethane chains decreased the glass transition temperatures, while the softening point and the service temperature range of epoxy nanocomposites containing nanofillers were increased. FTIR analysis confirmed the occurrence of interaction between the epoxy matrix and added modifiers. All SEM micrographs showed significant roughness of the fracture surfaces with the formation of elongated platelets, explaining the increase in mechanical properties of the epoxy matrix
Biopolymer compositions based on poly(3-hydroxybutyrate) and linear polyurethanes with aromatic rings—Preparation and properties evaluation
Get PDFPolymer biocompositions of poly(3-hydroxybutyrate) (P3HB) and linear polyurethanes (PU) with aromatic rings were produced by melt-blending at different P3HB/PU weight ratios (100/0, 95/5, 90/10, and 85/15). Polyurethanes have been prepared with 4,4′-diphenylmethane diisocyanate and polyethylene glycols with molar masses of 400 g/mol (PU400), 1000g/mol (PU1000), and 1500 g/mol (PU1500). The compatibility and morphology of the obtained polymer blends were determined by infrared spectroscopy (FTIR), scanning electron microscopy (SEM), and differential scanning calorimetry (DSC). The effect of the polyurethane content in the biocompositions on their thermal stability and mechanical properties was investigated and compared with those of the native P3HB. It was shown that increasing the PU content in P3HB-PU compositions to 10 wt.% leads to an improvement in the mentioned properties. The obtained results demonstrated that the thermal stability and mechanical properties of P3HB were improved, particularly in terms of increasing the degradation temperature, reducing hardness, and increasing impact strength. The best thermal and mechanical properties were shown by the P3HB-PU polymer compositions containing 10 wt.% of polyurethane modifiers, especially PU1000, which was also confirmed by the morphology analysis of these biocompositions. The presence of polyurethanes in the resulting polymer biocomposites decreases their glass transition temperatures, i.e., makes the materials more flexible. The resulting polymer biocompositions have suitable mechanical properties and thermal properties within the processing conditions for the predicted application as biodegradable, short-lived products for agriculture.Minister of Science and Higher Education of the Republic of Polan
Polyetheretherketone bioactivity induced by farringtonite
Get PDFPolyetheretherketone (PEEK) is considered as an excellent biomaterial for bone grafting and connective tissue replacement. The clinical potential is, however, limited by its bioinertness, poor osteoconduction, and weak antibacterial activity. These disadvantages can be overcome by introducing suitable additives to produce mineral-polymer composites or coatings. In this work, a PEEK-based bioactive composite has been obtained by blending the polymer with magnesium phosphate (Mg3(PO4)2) particles in amounts ranging from 1 to 10 wt.% using the hot press technique. The obtained composite exhibited improved mechanical and physical properties, above the lower limits set for bone engineering applications. The tested grafts were found to not induce cytotoxicity. The presence of magnesium phosphate induced the mineralisation process with no adverse effects on the expression of the marker crucial for osteoblastic differentiation. The most promising results were observed in the grafts containing 1 wt.% of magnesium phosphate embedded within the PEEK matrix. The improved bioactivity of grafts, together with suitable physical–chemical and mechanical properties, indicate this composite as a promising orthopaedic implant material.Akademie Věd České Republiky, AV ČR; Brno City Municipality; Institute of Theoretical and Applied Mechanics, (RVO 68378297); Grantová Agentura České Republiky, GA ČR, (20-00726S, 23-07425S); Grantová Agentura České Republiky, GA ČR; Ministry of Education, Youth and Sports of the Czech Republic-DKRVO, (RP/CPS/2022/003)Grantov Agentura Ccaron;esk Republiky [RVO 68378297]; Czech Academy of Sciences, Institute of Theoretical and Applied Mechanics [20-00726S]; Grant Agency of the Czech Republic [23-07425S]; Czech Science Foundation; Brno City Municipality [RP/CPS/2022/003]; Ministry of Education, Youth and Sports of the Czech Republic-DKRV