Tomas Bata University in Zlín
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Polypropylene blends: Impact of long chain-branched polypropylene on crystallization of linear polypropylene
No full textThis study compares the efficiency of commercially available sorbitol-based clarifying agent (NA) and varying amounts of long chain-branched polypropylene (LCBPP) acting as a specific alpha-nucleating agent for linear polypropylene (PP). The sorbitol-based clarifying agent, 1,3;2,4-bis(3,4-dimethyl benzylidene)sorbitol (Millad 3988), in concentration 0.2 wt%, and LCBPP in the concentration of 1, 2, 5 and 10 wt% were mixed into PP. The comparison of the effect of NA and long branches under isothermal conditions on the crystallization process, crystallinity and polymorphic composition was realized by differential scanning calorimetry and wide-angle X-ray scattering. The addition of long chain-branched polypropylene, even at the lowest concentration, performs better at higher crystallization temperatures and has a superior effect on the crystallization process, crystallization rate and overall crystallization than the addition of NA
Composite materials for supercapacitor electrodes utilizing polypyrrole nanotubes, reduced graphene oxides and metal-organic framework
No full textPolypyrrole (PPy) is favoured in energy storage for its high pseudo-capacitive performance, notably as polypyrrole nanotubes (PPyNTs) due to their easy synthesis, cost-effectiveness and electrochemical solid properties. Metal–organic frameworks (MOFs) have also gained attention for enhancing supercapacitors (SCs). In this study, we fabricated aerogel composites with PPyNTs, MOFs and reduced graphene oxide (rGO) as SC electrode materials. Varying concentrations of PPyNTs and rGO were explored, with MOFs added to assess their impact. Electrochemical tests revealed that the composite with PPyNTs and Zn-MOF achieved the highest specific capacitance of approximately 270 F/g at 0.5 A/g.Hori-zon Europe project TwinVECTOR of the European Union [101078935]; Horizon Europe - Horizontal Pillar [101078935] Funding Source: Horizon Europe - Horizontal PillarHORIZON EUROPE Framework Programme; European Commission, EC, (101078935); European Commission, ECHORIZON EUROPE Framework Programme; European Commission, EC, (101078935); European Commission, E
The nexus between economic policy uncertainty and innovation performance in Visegrad group countries
Get PDFResearch background: Research and development (R&D) spending and innovation initiatives play a crucial role in promoting growth. However, economic policy uncertainty (EPU) is a reality that cannot be avoided when making business decisions. The Visegrad Group (V4), consisting of Poland, Hungary, the Czech Republic, and Slovakia, is considered a regional alliance of four Central European countries with significant potential for innovation and economic development because these nations’ economies are encountering the so-called ‘middle-income trap'.
Purpose of the article: The paper’s main objective is to examine the impact of economic policy uncertainty on innovation performance and R&D expenditures in the Visegrad Group countries.
Methods: The study used comparative panel models analysis (fixed effect, random effect, and system generalized method of moments [GMM]) between 2012 and 2021. The models include the lag periods for EPU to provide a better perspective on the short-term impact and even long-term consequences of EPU.
Findings & value added: The directions of innovation output and R&D expenditures are directly related to EPU. In V4 economies, businesses may reduce their spending on R&D and innovation activities when confronted with high EPU; however, over time, the volatility of economic uncertainties is adjusted for. Additionally, the political and economic control variables increase the number of dimensions used in the models, which will motivate additional EPU studies in the field. Although EPU studies are widely accepted, our investigation shows that the topic is still not properly developed for Visegrad Group countries in relation to how EPU affects innovation activity. Another unique feature of the current study is the diversity of variables used, including the EPU lag variables, variables representing essential economic and political issues, as well as control variables, thus incorporating complex panel models.Internal Grant Agency of FaME TBU [IGA/FaME/2023/004, IGA/FaME/2024/011
Enhancing the employability of young researchers in higher education and research institutions through intersectional praxis : a scrutiny of publication indices
No full textIn an ever-changing and uncertain world, it is challenging to tackle the multiple factors that influence the job prospects of young researchers as well as their employability enhancement opportunities. This academic research is intended to address the spill overs of gender-based gaps, and to unveil the manifestations of postcolonial dynamics within Higher Education, Research, and Innovation (HERI) institutions contexts. Specifically, by recognizing the key elements of intersectionality that assist in or hinder young researchers in (i) acquiring, keeping, and finding jobs; (ii) comprehending the intricate social encounters that are fortified by intersectional investigation to overcome distinct obstacles; and (iii) enhancing employability skills and qualities in the educational setting intelligently and sustainably. The study is informed by ‘intersectional praxis’ for institutional transformation in HERI contexts. The paper’s discussion delves into ways how intersectionality is both a catalyst for employability enhancement and institutional excellence. Methodologically, the study comprised a qualitative scrutiny of how the concept of intersectionality featured in a selection of articles published 5-10 years earlier and scoped from established databases (WOS, SCOPUS). The findings support the discussion on the impact of postcolonial perspective(s) of young researchers on disrupting socio-political discourses, fostering further sustainable, nuanced, and comprehensive treatments of (anti) and (de)colonizing HERI contexts and experiences.University Institute; Tomas Bata University in Zlín, TBU, (CZ.02.2.69 / 0.0 / 0.0 / 16_028 / 0006243
Evaluating mean squared error as a fitness function in SOMA for software effort estimation: Insights from the NASA dataset
No full textSoftware effort estimation plays a pivotal role in software development. The Constructive Cost Model (COCOMO) is one of the most well-known algorithmic models for estimating software effort. However, the precision of these estimates is susceptible to input constants, potentially resulting in inaccuracies. To address this challenge, this research employs the Self-Organizing Migration Algorithm (SOMA), a metaheuristic algorithm, to optimize input constants of the basic COCOMO. This study uses the NASA18 dataset to evaluate the proposed experiment’s performance against the original COCOMO. Evaluation criteria such as MMRE, PRED(0.25), MAE, and MSE, with MSE serving as a fitness function, were employed to validate results. Comparative analysis indicates that optimized COCOMO estimates exhibit improved prediction accuracy. Building on these promising findings, future research will extend testing more deeply with other datasets and involve investigation of the intermediate COCOMO and COCOMO II.Tomas Bata University in Zlin, Faculty of Applied Informatics, (IGA/CebiaTech/2023/004
3D production process of spectrophotometer holder
No full textThis paper describes the entire 3D production process (pipeline) starting from the design of the product, through the construction of its graphic model to the output on the 3D printer. Initially, general knowledge in this field is briefly described. Then the process is described on a specific technical component - a spectrophotometer holder, which we have produced in this way. Based on the experience we have gained; the findings are summarized and recommendations are given at the end that are important in this process. Autocad was used to design this component and a 3D graphical model was created in Autodesk Inventor. The Original Prusa i3 MK3S+ printer with Fused Deposition Modeling (FDM) printing technology was used for 3D printing
Possibilities of using a virtual source model to refine the prediction of the impact of injurious effects in massive releases of toxic gases
No full textMassive leaks of toxic substances occur not only during accidents connected with the operation of industrial enterprises, but also during their transfers by the means of transport. These events pose a serious threat to both people and the environment. Particularly dangerous are situations where dense gas clouds are formed after the release of the given substance. These spread very quickly, while they tend to remain at the earth's surface for a relatively long time and flow into various depressions. In a few minutes, the toxic gas can reach a large area, as confirmed by the conclusions from the Jack Rabbit field tests. Knowledge of the behavior of heavy gas, as well as knowledge of events influencing its dispersion in real conditions, thus provide important information needed for effective management of the resulting accident. The key data is the extent of the harmful effects of the given hazardous substance, which can be obtained by simulating the predicted emergency situation using modeling software (e.g. ALOHA). However, the fundamental shortcoming of this approach is that these software usually generate overestimated results. The fact that dangerous concentrations in the real environment do not reach such distances from the source of leakage has been repeatedly proven by past accidents. The reason for this discrepancy is that the computer programs used do not allow to model with sufficient accuracy all the simultaneous physico-chemical processes that are applied during the dispersion of dense gas clouds. This task is far too complicated and only a part of it can be solved with the necessary precision. However, for the needs of emergency planning, these inaccuracies represent a relatively fundamental limitation. One way how to deal with this problem is to use a virtual resource (sometimes called a virtual point) model. It is successfully used in various areas where it is necessary to simplify the otherwise demanding physical modeling of the temporal and spatial distribution of matter emitted from a surface or volume source. The main idea of a virtual source is that the real primary emission source is approximated to an imaginary source that is located at a different location but acts and appears outwardly as if it were a real source of leakage. The key task of this solution is to determine the parameters of this source, because this is the only way to obtain results with significantly higher reliability during the subsequent simulation of the considered accident scenario
A comprehensive exploration of biomass gasification technologies advancing United Nations sustainable development goals: Part I : Mechanisms, sources, processes and products of gasification
Get PDFThis two-part paper provides an overview of the various technologies now available for the process of biomass gasification. Compared to other renewable energy sources, which have undergone significant technological advancements in recent years, the field of biomass conversion is still relatively new. Keeping up with the newest breakthroughs becomes increasingly crucial as new conversion techniques are rapidly being created. In the thermochemical conversion process called ‘biomass gasification’, biomass solid source materials are degraded or incompletely burned in an oxygen-free or oxygen-deficient high-temperature atmosphere, resulting in the production of biomass gas. Part I delves into different biomass gasification techniques, including upstream, gasification and downstream processes, highlighting their importance in transforming biomass into clean and combustible gases.Nederlandse Onderzoekschool Voor Astronomie, NOV
Aero-TiO2 three-dimensional nanoarchitecture for photocatalytic degradation of tetracycline
Get PDFOne of the biggest issues of wide bandgap semiconductor use in photocatalytic wastewater treatment is the reusability of the material and avoiding the contamination of water with the material itself. In this paper, we report on a novel TiO2 aeromaterial (aero-TiO2) consisting of hollow microtetrapods with Zn2Ti3O8 inclusions. Atomic layer deposition has been used to obtain particles of unique shape allowing them to interlock thereby protecting the photocatalyst from erosion and damage when incorporated in active filters. The performance of the aero-TiO2 material was investigated regarding photocatalytic degradation of tetracycline under UV and visible light irradiation. Upon irradiation with a 3.4 mW/cm2 UV source, the tetracycline concentration decreases by about 90% during 150 min, while upon irradiation with a Solar Simulator (87.5 mW/cm2) the concentration of antibiotic decreases by about 75% during 180 min. The experiments conducted under liquid flow conditions over a photocatalyst fixed in a testing cell have demonstrated the proper reusability of the material.Univerzita Tomáše Bati ve Zlíně, UTB; Romanian Ministry of Research, Innovation and Digitalization, (760285/27.03.2024, PNRRIII-C9-2023-I8-161); Ministerstvo Školství, Mládeže a Tělovýchovy, MŠMT, (RP/CPS/2024-28/007); Ministerstvo Školství, Mládeže a Tělovýchovy, MŠMT; Ministry of Foreign Affairs of the Czech Republic, (23-PKVV-UM-7); National Agency for Research and Development of the Republic of Moldova, (24.80012.5007.12TC)Ministry of Foreign Affairs of the Czech Republic [23-PKVV-UM-7]; Romanian Ministry of Research, Innovation and Digitalization within the National Recovery and Resilience Plan [PNRRIII-C9-2023-I8-161, 760285/27.03.2024]; National Agency for Research and Development of the Republic of Moldova [24.80012.5007.12TC]; Ministry of Education, Youth and Sports of the Czech Republic [RP/CPS/2024-28/007
Effects of environmental temperature and trapped air bubbles on the mechanical properties of ice cubes
Get PDFIce is a widespread material in natural and industrial fields. Trapped air bubbles form in ice cubes due to the differences in the solubility of air in ice and water, which directly affects the mechanical strength of the ice cubes. To investigate the effects of environmental temperature and trapped air bubbles on the mechanical properties of ice cubes, a series of experiments are designed and carried out. A mathematical model that predicts the mechanical strength of ice cubes with an accuracy over 80% is developed and validated. The results show that even a volume content of trapped air bubbles in an ice cube as low as 1.98% can greatly impact the mechanical properties. This model reveals the mechanisms and principles governing the influences of environmental temperature and bubble volume content on the mechanical strength of ice cubes. As the environmental temperature decreases from 0 to −20 °C, the compressive strength of clear ice cubes increases from 1.71 to 2.10 MPa, while that of bubble ice cubes increases from 1.58 to 1.95 MPa. This study has implications for utilizing trapped air bubbles to regulate the mechanical properties of ice and for optimizing various mechanical deicing techniques.Key Laboratory of Icing and Anti; National Natural Science Foundation of China, NSFC, (52406007, 52076013, 52306003); National Natural Science Foundation of China, NSFC; Deicing, (IADL20230113, IADL20220304); Beijing Municipal Science and Technology Commission, Adminitrative Commission of Zhongguancun Science Park, (3212024, 324406, 3232032); Beijing Municipal Science and Technology Commission, Adminitrative Commission of Zhongguancun Science Park; Beijing Association for Science and Technology, BAST, (BYESS2023352); Beijing Association for Science and Technology, BASTNational Natural Science Foundation of China [52076013, 52406007, 52306003]; National Natural Science Foundation of China [3212024, 324406, 3232032, IADL20230113, IADL20220304]; Beijing Municipal Science & Technology Commission [BYESS2023352]; Young Elite Scientist Sponsorship Program by BAS