Tomas Bata University in Zlín
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New Insights into the comprehensive system of thermodynamic sensors and electronic nose and its practical applications in dough fermentation monitoring
Get PDFThis study focuses on an applicability of the device designed for monitoring dough fermentation. The device combines a complex system of thermodynamic sensors (TDSs) with an electronic nose (E-nose). The device’s behavior was tested in experiments with dough samples. The configuration of the sensors in the thermodynamic system was explored and their response to various positions of the heat source was investigated. When the distance of the heat source and its intensity from two thermodynamic sensors changes, the output signal of the thermodynamic system changes as well. Thus, as the distance of the heat source decreases or the intensity increases, there is a higher change in the output signal of the system. The linear trend of this change reaches an R2 value of 0.936. Characteristics of the doughs prepared from traditional and non-traditional flours were successfully detected using the electronic nose. To validate findings, the results of the measurements were compared with signals from the rheofermentometer Rheo F4, and the correlation between the output signals was closely monitored. The data after statistical evaluation show that the measurements using thermodynamic sensors and electronic nose directly correlate the most with the measured values of the fermenting dough volume. Pearson’s correlation coefficient for TDSs and rheofermentometer reaches up to 0.932. The E-nose signals also correlate well with dough volume development, up to 0.973. The data and their analysis provided by this study declare that the used system configuration and methods are fully usable for this type of food analysis and also could be usable in other types of food based on the controlled fermentation. The system configuration, based on the result, will be also used in future studies.DKRVO, (RP/CPS/2022/007); Internal Grant Agency of Tomas Bata University in Zlin, (IGA/FT/2024/006); Ministerstvo Školství, Mládeže a Tělovýchovy, MŠMT; Vysoké Učení Technické v Brně, BUT, (FEKT-S-23-8162)Internal Grant Agency of Tomas Bata Universit
Optical trapping of polystyrene beads in mixed solvents
No full textOptical traps are devices used to micromanipulation microscopic objects using a focused laser beam in an optical microscope field of view. Trapping such objects is possible only when their refractive index is higher than the environment's. Typically, trapping experiments are carried out in aqueous solutions, exploiting the low refractive index of water. Experiments in different pure organic solvents were also reported, showing not very good dependence of the optical-trap force constant on the solvent refractive index. In this study, we carry out optical trapping experiments in mixed water:organic solvents where the organic components are dimethyl sulfoxide, ethylene glycol, and glycerol. Trends of corner frequencies measured in these mixtures follow the theoretical calculations well for all the studied systems in the whole molar-fraction range, indicating their dominant dependence on the refractive index. The conversion of the corner frequencies to the force constants of the trap is strongly influenced by the differences in viscosity throughout the molar-fraction range that emphasizes experimental errors in the regions where it is high. In addition, the force-constant and corner-frequency curves can serve as an indicator of ideality of the potential profile of the optical trap.TBU in Zlin, (CZ.02.2.69/0.0/0.0/19_073/0016941)Project OP RDE Junior Grants of TBU in Zlin [CZ.02.2.69/0.0/0.0/19_073/0016941
Examining the natural resources-ecological degradation nexus: The role of energy innovation and human capital in BRICST nations
No full textThe growing global consensus on addressing climate change and advancing environmental sustainability underscores the need for effective environmental and natural resource management frameworks to achieve ecological balance. This study contributes to ongoing policy discussions by examining the impact of green energy innovation, economic growth, human capital, and natural resources on ecological footprints in the BRICST economies from 1992 to 2020. The objective of this study is to assess the relationships between green energy innovation, economic growth, human capital, natural resources, and ecological footprints in the BRICST economies, providing insights into the factors influencing environmental sustainability. To achieve this objective, we employ various econometric methods, including the method of moments quantile regression, Fully Modified Ordinary Least Squares, Dynamic Ordinary Least Squares, and Fixed Effects Ordinary Least Squares. These methods allow us to analyze the impact of the selected variables on ecological footprints comprehensively. Our analysis reveals noteworthy findings. Firstly, green energy innovation has a positive influence on environmental sustainability, suggesting that investments in eco-friendly technology can lead to reduced ecological footprints. Conversely, we find that human capital, economic growth, and natural resources are associated with increased environmental challenges, indicating the need for careful management of these factors. Causality tests confirm the presence of a unidirectional causal relationship between ecological footprints to green energy innovation, economic growth, and natural resources. Additionally, we identify a unidirectional causal association between human capital to ecological footprints. We advise policymakers to encourage structural changes and the adoption of green energy technology in the production sector. These steps will help address environmental challenges and promote ecological sustainability in BRICST economies, in line with global climate change efforts
Relationship between real estate tokens and other asset classes: Evidence from quantile connectedness approach
No full textIn this paper, we analyze the quantile return connectedness between the real estate tokens (PROPY, LATOKEN, ATLANT, IHT Real Estate Protocol) and other asset classes, namely oil, gold, bond, currency, equity, Bitcoin, and real estate investment trust for the period August 27, 2018, to April 25, 2022. We perform the connectedness at the mean, median, extreme lower quantile, and extreme upper quantile levels. At the mean and median levels, we find a low level of connectedness between real estate tokens and REIT, and a relatively higher level of connectedness with BTC. This highlights the importance of BTC contributing a high shock of spillover to the whole system, followed by equity and then oil markets. Then, extending our analysis to the extreme lower and upper quantiles, we uncover similar results, yet, this connectedness increases in extreme market conditions compared to the median level. Finally, we provide some implications for investment and portfolio diversification benefits using these assets
Tensile properties of 3D printed INCONEL 718 cellular specimens
Get PDFThe aim of the presented research by the authors was to compare the behaviour of four types of cellular structures under quasi-static tensile stress, while two samples were formed by mono-structures Gyroid 10 % and Diamond 10 %, and the other two types were bi-structures, which were created by combining two single structures (Gyroid 5 % + Gyroid 5 %) and (Gyroid 5 % + Diamond 5 %). The samples were made of Inconel 718 by Direct Metal Laser Sintering technology on an EOS EOSINT M270 machine, and they were heat treated according to AMS 5664 procedure. Tensile tests were performed on an Instron 8802 servo-hydraulic testing machine with a maximum capacity of 250 kN at ambient temperature. The results showed that the maximum load corresponded to the diamond (D) cellular structure (approximately 48 kN), while the minimum load was observed for the gyroid-gyroid (GG) structure (approximately 32 kN).Ministry of Education of the Slovak Republic [APVV-19-0550, KEGA 005TUKE-4/2021, ERASMUS+ 2021-1-PL01-KA220HED-000031182, KEGA 032TUKE-4/2022
Towards anomally detection using stationary and non-stationary signal analysis
No full textThis paper focuses on demonstration of an enhanced model for investigating data signals features, i.e., whether the given signal has stationary or non-stationary features. The accurate detection of the features of signals is crucial for the right directions towards methodology of further preprocessing to perform data analysis of the data signal, specifically in the tasks of finding anomalies in the given signal and big data environment. A problem often encountered is the exact determination of the occurrence of stationary or non-stationary data signal features in data processing. Within this research paper, the mathematical foundations of data signal processing are described. Based on the mathematical model of the input signal processing, an improved workflow using the enhanced statistical KPSS test and autocorrelation function (graphical) analysis is demonstrated here, to confirm the accuracy and usability of selected methodology. The alternative approach described here leads to a much lower computational effort and the achievement of accurate identification of signal features in big data environment for possible deployment of A.I. or machine learning anomaly detection pipeline. The obtained dataset and model are based on the real environment and measured signals in the production process of machine tools in company Tajmac-ZPS Zlin
Investigation of dynamic behavior and process stability at turning of thin-walled tubular workpieces made of 42CrMo4 steel alloy
Get PDFDuring machining, the surface of the machined materials is damaged and tool wear occurs, sometimes even to complete failure. Machining of thin-walled parts is generally cumbersome due to their low structural rigidity. The study deals with the effect of the feed rate and the thickness of the thin-walled part on the dynamic behavior and stability of the turning process during the roughing and finishing of thin-walled tubular workpieces made of steel alloy 42CrMo4. At the same time, the cutting forces and deformations of the workpiece were also evaluated via numerical and experimental approaches. The numerical study is based on a three-dimensional (3D) finite element model (FEM) developed using the ABAQUS/Explicit frame. In the model, the workpiece material is governed by the behavior law of Johnson–Cook. Numerical and experimental results show that the cutting forces and the quality of the machined surface depend not only on the choice of cutting parameters but also on the dynamic behavior of thin-walled parts due to their low rigidity and low structural damping during the machining operation. Cutting forces are proportional to the feed rate and inversely proportional to the thickness of the part. Their variations around the average values are low for roughing tests where the wall-part thickness is higher or equal to 3.5 mm. However, these variations intensify for finishing tests where the wall thickness is less or equal to 1.5 mm. Indeed, the recorded FFT spectra for a finishing operation show several harmonics that occurred at around 550 Hz, and the amplitude of the peaks, which describes the level of power contained in the signals, shows an increase similar to that of the amplitudes of the temporal signal. The flexibility of the part generates instability in the cutting process, but the frequencies of the vibrations are higher than the frequency of rotation of the part.Ministerstvo školstva, vedy, výskumu a športu Slovenskej republiky, (APVV-19-0550); Ministry of Higher Education and Scientific Research, Republic of Sudan, MHESRMinistry of Higher Education and Scientific Research of the Tunisia Republic; Ministry of Education, Science, Research, and Sport of the Slovak Republic [APVV-19-0550
From brush to dendritic structure: Tool for tunable interfacial compatibility between the iron-based particles and silicone oil in magnetorheological fluids
Get PDFComprehensive magnetic particle stability together with compatibility between them and liquid medium (silicone oil) is still a crucial issue in the case of magnetorheological (MR) suspensions to guarantee their overall stability and MR performance. Therefore, this study is aimed at improving the interfacial stability between the carbonyl iron (CI) particles and silicone oil. In this respect, the particles were modified with polymer brushes and dendritic structures of poly(2-(trimethylsilyloxy)ethyl methacrylate) (PHEMATMS), called CI-brushes or CI-dendrites, respectively, and their stability properties (corrosion, thermo-oxidation, and sedimentation) were compared to neat CI ones. Compatibility of the obtained particles and silicone oil was investigated using contact angle and off-state viscosity investigation. Finally, the magneto-responsive capabilities in terms of yield stress and reproducibility of the MR phenomenon were thoroughly investigated. It was found that MR suspensions based on CI-brushes had significantly improved compatibility properties than those of neat CI ones; however, the CI-dendrites-based suspension possessed the best capabilities, while the MR performance was negligibly suppressed.Ministerstvo Školství, Mládeže a Tělovýchovy, MŠMT, (RP/CPS/2022/003); Grantová Agentura České Republiky, GA ČR, (23-07244S); Narodowa Agencja Wymiany Akademickiej, NAWA, (PPM/ULM/2019/1/00102
Architecting robust full concentration gradient NCM712 cathodes for high-energy Li-Ion batteries
No full textFull concentration gradient ternary oxide cathodes, with a Ni-rich core and a Mn-rich surface, have been identified to effectively enhance their interfacial and structural stability for long-life Li-ion batteries. Nevertheless, a big challenge is to address the degradient effect during high-temperature lithiation. Herein, we demonstrate the synthesis of gradient LiNi0.70Co0.10Mn0.20O2 cathodes by F-doping and intergranular LixWyOz coating. The coating layer served as a physical barrier to mitigate the interdiffusion of transition metal ions during grain boundary merging. Meanwhile, the doped F ions, occupying the O sites, can further restrict ion transfer to inner primary particles by the formation of extremely strong M-F bonds. Accordingly, the resultant gradient cathodes deliver a high reversible capacity of 211.2 mAh g-1 at 0.1C in coin-type half-cells. A superior cycling stability is achieved with a high capacity retention of 93.0% at 1C after 500 cycles within 2.7-4.5 V in pouch-type full cells. This work provides a reliable technical route to obtain high-energy Li-ion batteries by the design of high-voltage concentration gradient Ni-rich cathodes.Fundamental Research Funds for the Central Universities; National Natural Science Foundation of China, NSFC, (U22A20429, 22308103); National Natural Science Foundation of China, NSFC; China Postdoctoral Science Foundation, (2023M731083); China Postdoctoral Science FoundationNational Natural Science Foundation of China [U22A20429, 22308103]; National Natural Science Foundation of China [2023M731083]; China Postdoctoral Science Foundation; Fundamental Research Funds for the Central Universitie