Tomas Bata University in Zlín
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How does uncertainty impact IPO activity? International evidence
No full textThis paper examines the impact of economic uncertainty on IPO activity in 52 countries. Using a dataset of 70,760 IPOs from 1990 to 2021, we find that economic uncertainty (proxied by the World Uncertainty Index) has a negative effect on IPO activity (both IPO count and proceeds). Additionally, we show that a country's institutional quality, characterized using the World Governance Indicators, alleviates the negative effect of uncertainty on IPO activity. These findings are robust to alternative model specifications. Relevant policy implications are also provided.Ministry of Science, Innovation, (PID2020-114797GB-I00); Fundação para a Ciência e a Tecnologia, FCT, (UIDB/04105/2020
Physical characterization of a novel carrot juice whey-enriched beverage fermented with milk or water kefir starter cultures
Get PDFThe purpose of this work was to evaluate the selected physicochemical, rheological, and sensory properties of a new whey-enriched carrot juice beverage (carrot juice: whey ratios of 100:0; 95:5; 85:15; 75:25; 65:35) fermented with milk or water kefir starter cultures over a storage period of 21 days (at 4 ± 1 °C). In general, for all tested samples, the values of total soluble solids, pH, and density decreased with increasing storage time. In contrast, the values of ethanol, degree of fermentation, and total dissolved solids increased with the prolongation of the storage time. Furthermore, it was found that all the model samples exhibited pseudoplastic behavior. Based on the sensory analysis performed, samples containing 25% (w/w) whey were evaluated as the most acceptable. Last but not least, the present study can serve as a basis for optimizing the manufacturing technology of a novel fermented vegetable beverage enriched with whey.Univerzita Tomáše Bati ve Zlíně, (IGA/FT/2023/007)Tomas Bata University in Zli
Waste bunker size optimization under uncertainty: Application of inventory models with real data simulation
No full textWaste-to-Energy (WtE) technologies play a prominent role in recovering energy from waste. One of the aspects ensuring the operability and economic sustainability of WtE plants is the size optimization of a waste bunker assigned to each WtE plant, whose main target is to ensure waste homogeneity for effective operation. Each WtE plant faces various uncertain challenges, such as planned and unplanned shutdowns during which the plant is inactive and not ideally coordinated with waste collection companies, further importing the collected waste into the waste bunker, mainly due to existing contracts. This work aims to develop a scenario-based model to support strategic capacity planning by capturing various uncertain attributes and optimizing the waste bunker size while minimizing the total costs composing the investment, inventory, and waste shortage costs. The model is tested on a case study from the Czech Republic. The main result can be summarized such that for a specific case of a newly situated WtE facility with a considered capacity of 100kt/y, the model suggests a bunker of size ca. 4,200m3 for a middle scenario. However, this is strongly related to other attributes of a particular WtE project (e.g., waste properties or cost parameters).Methods and Operations Research Perspectives” of the Czech Science Foundation; Technology Agency of the Czech Republic, TACR, (SS02030008
The role of intercultural interaction in international student enrolment: A conceptual study from the Czech Republic
No full textThe internationalisation of higher education drive continues to gain grounds as most universities all over the world strive to attract international students into their schools in order to fulfil the internationalisation mandate. Most institutions of higher learning keep designing and re-shaping strategies for attracting foreign/international students into their fold. Intercultural communication is very important in breeding the feeling of belongingness among people. Social media platforms continue to be explored by institutions to attract targets. The aim of the study is to examine the perception of international students on the effect of intercultural interaction on decision making regarding choice of university, with particular focus on universities in the Czech Republic. Partially, we seek to explore the role of social media platforms operated by universities in attracting foreign students. Employing a qualitative methodology of inquiry, and specifically using document analysis vis-à-vis opinions from experts, the authors assessed the antecedents and consequences of intercultural communication on international student enrolment. We then conceptualised a research model for future qualitative/quantitative study which could consider in-depth interviews from international students in Tomas Bata University (TBU) as well as a survey from higher institutions of learning in the Czech Republic for analysis with the use of multivariate analysis or partial least square and equation modelling (PLS-SEM). This initiative would propel the validation of the proposed conceptual model of the study. The literature review revealed that intercultural interaction among international students plays a major role in the decision-making process of prospective international students regarding the choice of institution of higher learning. The quest to internationalise motivates most universities to implement numerous international student-friendly policies in the bid to attract more international students to their institutions. Finally, the literature showed that social media platforms produce maximum results with regards to attraction of international students. Research implications have been discussed. © 8th European Conference on Social Media, ECSM 2021.Tomas Bata University in Zlin, TBU: IGA/FMK/2020/00
Endofibrosis as a causative agent of the peripheral artery disease: A report of two cases for professional cyclists
Get PDFEndofibrosis is a rare disease that predominantly affects athletes and is caused by a gradual occlusion of the (usually iliac) artery due to a thickening of the intima. From our experience, we report in this article two cases with the entity of endofibrosis in females around 30 years old. The first case presented with acute limb ischemia, and the second one was with pain in the leg during exercise. In addition, both cases are professional cyclists. They were eventually diagnosed with endofibrosis and underwent surgical procedures. They are now pursuing their professional career successfully. Last but not least, endofibrosis might be classified as an occupational disease, particularly, in the case of professional athletes or cyclists
Electrochemical deposition of a hydroxyapatite layer onto the surface of porous additively manufactured Ti6Al4V scaffolds
Get PDFSuccessful acceptance of biomaterials by a patient's body significantly depends on an interaction between the surface and the biological components of the host environment. In the case of orthopedic scaffolds, surface treatment may improve their osseointegration. This study deals with the electrochemical deposition of ceramic hydroxyapatite (HAp) coatings onto additively manufactured titanium specimens with a porous structure. The specimens of three different types (pore sizes of 200, 400, and 600 mu m) were modeled using CAD software and fabricated using the Ti6Al4V titanium alloy. HAp coatings were electrochemically deposited onto the surface of un-annealed specimens using four different experimental conditions. Based on the results and optimization of the conditions with the un-annealed specimens, ideal conditions were selected for the coating of the annealed specimens. The nature of the ceramic layer on un-annealed and annealed samples was compared. Surface morphology and distribution of ceramic coatings on the surface of the specimens were compared and evaluated by scanning electron microscopy (SEM), X-ray diffraction (XRD), and energy-dispersive X-ray spectroscopy (EDX). The un-annealed specimens exhibited more compact surfaces and larger deposits of nanocrystalline HAp when compared to the annealed specimens. The results indicate that electrochemical deposition is a suitable method for the production of a ceramic coating layer onto the surface of porous titanium specimens with promising potential for clinical applications.ITMS2014, RP/CPS/2022/005; Ministerstvo Školství, Mládeže a Tělovýchovy, MŠMT; Agentúra na Podporu Výskumu a Vývoja, APVV: APVV-20-0278; European Regional Development Fund, ERDFSlovak Research and Development Agency [APVV-20-0278]; Ministry of Ed-ucation, Youth and Sports of the Czech Republic (DKRVO) [RP/CPS/2022/005]; European Regional Develop-ment Fund [ITMS2014+: 313011 V358
Preparation of gelatin from broiler chicken stomach collagen
Get PDFWith the increasing consumption of poultry meat around the world, the use of chicken stomachs as a source of collagen is being offered. The objective of this study was to extract gelatin from the stomachs of broiler chickens and to estimate their gel strength, ash content, viscosity, gelling point, melting point, clarity and digestibility. An innovative biotechnological method based on the conditioning of collagen with a microbial endoproteinase (Protamex®) and hot-water extraction was used to control the chemical and thermal denaturation process of collagen to prepare gelatin. The experiments were planned using a Taguchi design, 2 factors at 3 levels; factor A for the amount of proteolytic enzyme (0.10, 0.15 and 0.20%) and factor B for the extraction temperature (55.0, 62.5 and 70.0 °C). Data were statistically processed and analyzed at a significance level of 95%. The gelatin yield averaged 65 ± 8%; the gel strength ranged from 25 ± 1 to 439 ± 6 Bloom, the viscosity from 1.0 ± 0.4 to 3.40 ± 0.03 mPa·s, gelling point from 14.0 ± 2.0 to 22.0 ± 2.0 °C, melting point from 28.0 ± 1.0 to 37.0 ± 1.0 °C. The digestibility of gelatin was 100.0% in all samples; the ash content was very low (0.44 ± 0.02–0.81 ± 0.02%). The optimal conditions for the enzymatic treatment of collagen from chicken stomachs were achieved at a higher temperature (70.0 °C) and a lower amount of enzyme (0.10–0.15%). Conditioning chicken collagen with a microbial endoproteinase is an economically and environmentally friendly processing method, an alternative to the usual acid- or alkaline-based treatment that is used industrially. The extracted products can be used for food and pharmaceutical applications. © 2022 by the authors.Univerzita Tomáše Bati ve Zlíně: IGA/FT/2022/00
Development of new health risk assessment of nanoparticles: EPA health risk assessment revised
Get PDFThe concentration of nanoparticles in the ambient air can lead to induced toxicities; however, it appears that nanoparticles' unique properties are completely omitted when assessing health risks. This paper aims to enhance the EPA health risk assessment by incorporating two new variables that consider the size of nanoparticles: the toxicity multiplier and the size multiplier. The former considers the qualitative aspect of the size of particles within a concentration, whilst the latter takes into account the effects associated with the number of particles of the specific i-th size distribution interval. To observe the impact of the new variables, a case study was performed. The studied element was cadmium, which was measured using ICP-MS to discover concentrations of size fractions, ranging from <15.1 to <9830 nm. Next, the cadmium concentration is assessed using both the current state-of-the-art method and the proposed method with adjustments. Based on the new approach, the final risk was 1.1 × 10−5, which was almost 24 times higher compared with the current method. The contribution of nanoparticles to the risk value grew from barely 6% to an alarming 88%. Therefore, the enhanced method can lead to more realistic results when assessing the health risks of nanoparticles.Ministerstvo Školství, Mládeže a Tělovýchovy, MŠMT: RP/CPS/2022/007; Ministry of Transport of the People's Republic of China, MOT; Univerzita Tomáše Bati ve Zlíně: IGA/CPS/2019/007, IGA/CPS/2020/003, IGA/CPS/2021/002, IGA/CPS/2022/00
Antibacterial and antifouling efficiency of essential oils-loaded electrospun polyvinylidene difluoride membranes
Get PDFNanofibers have become a promising material in many industries in recent years, mainly due to their various properties. The only disadvantage of nanofibers as a potential filtration membrane is their short life due to clogging by bacteria in water treatment. The enrichment of nanofibers with active molecules could prevent these negative effects, represented by essential oils components such as Thymol, Eugenol, Linalool, Cinnamaldehyde and Carvacrol. Our study deals with the preparation of electrospun polyvinylidene difluoride (PVDF)-based nanofibers with incorporated essential oils, their characterization, testing their antibacterial properties and the evaluation of biofilm formation on the membrane surface. The study of the nanofibers' morphology points to the nanofibers' diverse fiber diameters ranging from 570 to 900 nm. Besides that, the nanofibers were detected as hydrophobic material with wettability over 130°. The satisfactory results of PVDF membranes were observed in nanofibers enriched with Thymol and Eugenol that showed their antifouling activity against the tested bacteria Escherichia coli ATCC 25922 and Staphylococcus aureus ATCC 25923. Therefore, these PVDF membranes could find potential applications as filtration membranes in healthcare or the environment.Internal Grant Agency of Tomas Bata University in Zlin; [IGA/FT/2022/006
Public procurement efficiency in the Slovak Republic: NUTS 3 level
No full textAt present, public procurement processes and their efficiency represent one of the key determinants of the public finance system. The article’s main aim is to identify the impact of the number of bids, type of contract, use of EU funds, e-auction, quality criteria and the presence of a subcontractor in achieving the public procurement savings with emphasis on NUTS 3 level in Slovakia. There were analysed 957 contracts during the period 2016 – 2020. Robust estimation, which uses the WLS method, was applied to quantify the impact of determinants of public procurement efficiency on a level of savings. The results confirmed that an increase in the number of bids also increases the level of savings by 5 percentage points. The savings are higher by 6.6 percentage points if the contract is not funded by EU funds in comparison to contracts funded by EU funds. Also, the savings are higher by 7.4 percentage points when e-auction was not used. Once, the contract does not allow the subcontractor relationships, the savings are higher by 11.6 percentage points. If the quality criterion is not applied in the contract, then the savings are higher by 10.7 percentage points. The analysis confirmed statistically significant differences between individual regions in Slovakia. The most significant difference is evident between the Košice Region and the Bratislava Region, while the Bratislava Region achieved savings higher by more than 20 percentage points. Similarly, the Prešov Region achieved higher savings by more than 19 percentage points compared to the Košice Region. © 2022, Bucharest University of Economic Studies Publishing House. All rights reserved.Tomas Bata University in Zlin, TB