Tomas Bata University in Zlín
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Boosting photocatalytic degradation of estrone hormone by silica-supported g-C3N4/WO3 using response surface methodology coupled with Box-Behnken design
Get PDFIn this article, we report on the preparation and characterization of silica-supported g-C3N4/WO3 nanocomposite with boosted photocatalytic performance towards the degradation of estrone hormone by using response surface methodology (RSM) coupled with the Box-Behnken model to determine the synergistic effects of three independent experimental parameters (hormone concentration, solution pH, and photocatalyst dosage). The RSM results were consistent with the prediction model (R-2 > 0.958 and 0.934 for UV and visible light irradiation, respectively). The optimized experimental test conditions were evaluated as follows: 3000 mu g of photocatalyst dosage, 300 mu g/L of hormone concentration, and pH 7. The hormone photodegradation efficiencies under these experimental parameters were 100% and 96% after 3 h of UV and visible light irradiation, respectively. Additionally, degradation kinetics (first-order, second-order, and intraparticle diffusion model), adsorption isotherms (Freundlich and Langmuir), and antibacterial activity of the prepared sample were also examined. Radical scavenging tests were performed to elucidate the photodegradation mechanism and the existence of reactive oxygen species. The recyclability test showed that the efficiency remained above 75% after seven consecutive cycles. The results indicate that the RSM based on the Box-Behnken model is an excellent approach for determining optimized experimental parameters for specific degradation of estrogenic hormones.IGA/CPS/2022/002, IGA/CPS/2022/003, IGA/CPS/2023/006; Ministerstvo Školství, Mládeže a Tělovýchovy, MŠMT: LTT20010, RP/CPS/2022/002, RP/CPS/2022/005, RP/CPS/2022/007Ministry of Education, Youth and Sports of the Czech Republic [RP/CPS/2022/002, RP/CPS/2022/005, RP/CPS/2022/007, IGA/CPS/2022/003]; Internal Grant Agency (IGA) of TBU in Zlin [IGA/CPS/2022/002, IGA/CPS/2023/006]; [LTT20010
Parametrical function describing influences of the redistribution of incorporated oil for rupture process reconstruction in rubber
Get PDFThe present work is focused on finding (i) the tearing energy at rupture and (ii) the redistribution of incorporated paraffin oil on the ruptured surfaces as functions of (a) the initial oil concentration and (b) the speed of deformation to the total rupture in a uniaxially induced deformation to rupture on an initially homogeneously oil incorporated styrene butadiene rubber (SBR) matrix. The aim is to understand the deforming speed of the rupture by calculating the concentration of the redistributed oil after rupture using infrared (IR) spectroscopy in an advanced continuation of a previously published work. The redistribution of the oil after tensile rupture for samples that have three different initial oil concentrations with a control sample that has no initial oil has been studied at three defined deformation speeds of rupture along with a cryo-ruptured sample. Single-edge notched tensile (SENT) specimens were used in the study. Parametric fittings of data at different deformation speeds were used to relate the concentration of the initial oil against the concentration of the redistributed oil. The novelty of this work is in the use of a simple IR spectroscopic method to reconstruct a fractographic process to rupture in relation to the speed of the deformation to rupture.RP/CPS/2022/006; Ministerstvo Školství, Mládeže a Tělovýchovy, MŠMTMinistry of Education, Youth and Sports of the Czech Republic-DKRVO [RP/CPS/2022/006
Silica supported WO3/Cu2O heterostructured nanoparticles for photocatalytic degradation of hormones
Get PDFIn this study, a WO3/Cu2O based heterojunction was synthesized via a facile solvothermal method. The as-prepared nanocomposite was characterized by XRD, SEM, and UV-vis spectroscopy. The photocatalytic activity of the as-prepared heterojunction was evaluated by the means of estradiol (E2) and 17α-ethinylestradiol (EE2) hormone degradation under UV LED illumination wavelength at λmax~ 365 nm. The degradation results showed that the prepared photocatalyst was able to achieve considerable photoactivity owing to the intrinsic heterojunction charge transfer mechanism. Photocatalytic degradation rates of 27 and 35 % were achieved for the E2 and EE2 hormones, respectively.IGA/CPS/2021/002; Ministerstvo Školství, Mládeže a Tělovýchovy, MŠMT: LTT20010; Technologická Agentura České Republiky: FW0101058
The effect of cosmetic treatment and gel laser therapy on the improvement of comedogenic skin type
Get PDFComedogenic skin care receives little attention compared to the care or treatment of more serious acne manifestations. Traditional therapies may have limited success with potential side effects. Cosmetic care supported by the effect of a biostimulating laser may offer a desirable alternative. The aim of the study was to evaluate the biological effectiveness of combined cosmetic treatment with lasotherapy on comedogenic skin type using noninvasive bioengineering methods. Twelve volunteers with comedogenic skin type underwent a 28-week application of Lasocare Basic 645® cosmetic gel containing Lactoperoxidase and Lactoferrin in combination with laser therapy (Lasocare® method). The effect of treatment on skin condition was monitored using noninvasive diagnostic methods. The parameters were the amount of sebum, the pore count, the ultraviolet-induced red fluorescence assessment of comedonic lesions (percentage of the area and quantification of orange-red spots), hydration, transepidermal water loss, and pH. A statistically significant decrease in sebum production was observed on the skin of the treated volunteers, as well as a decrease in porphyrins, indicating the presence of Cutibacterium acnes populating comedones and causing enlarged pores. The balance of epidermal water in the skin was regulated adjusting the acidity of the skin coat in individual zones, which decreased the presence of Cutibacterium acnes. Cosmetic treatment in combination with the Lasocare® method successfully improved the condition of comedogenic skin. In addition to transient erythema, there were no other adverse effects. The chosen procedure appears to be a suitable and safe alternative to traditional treatment procedures known from dermatological practice
Comprehensive evaluation of photoelectrochemical performance dependence on geometric features of ZnO nanorod electrodes
No full textThe impact of geometric features, light absorption spectra, and electrochemical active surface area on photoelectrochemical properties was investigated in this work. Nanoforests of ZnO nanorods with rationally controlled morphologies were grown on ITO substrates by the hydrothermal method and utilized as a model for this purpose. The size of the nanorods was systematically adjusted by varying the concentration of polyethyleneimine as a cation surfactant in the growth solution. It was found that the emergent geometric characteristics (i.e. the aspect ratio) increased almost at the same pace as the electrochemically active surface area, but the light scattering effect slightly increased as a result of the random spatial orientation of the nanorods. The large surface area and the void space between nanorods increased the photon-to-current conversion efficiency by promoting the hole transfer process at the electrode/electrolyte interface. A maximum photocurrent density of 0.06 mA cm(-2) (0.5 V vs. NHE) for smaller diameter and length ZnO nanorods (ZnO-P1) was obtained under 365 nm UV light illumination. Additionally, we provide visual evidence that a shorter photogenerated hole diffusion distance results in improved charge separation efficiency using Mn2+ as the photogenerated hole imaging agent. Therefore, the present work demonstrates a facile strategy for nanoforest morphology improvement for generating strong contact at the ZnO NR electrode/electrolyte interface, which is favourable in energy conversion and storage technologies.LTT20010; RP/CPS/2022/007Ministry of Education, Youth and Sports of the Czech Republic DKRVO [RP/CPS/2022/007, LTT20010
The cytisine-enriched poly(3-hydroxybutyrate) fibers for sustained-release dosage form
No full textThe polymeric cytisine-enriched fibers based on poly(3-hydroxybutyrate) were obtained using electrospinning method. The biocompatibility study, advanced thermal analysis and release of cytisine from the poly(3-hydroxybutyrate) fibers were carried out. The nanofibers' morphology was evaluated by scanning electron mi-croscopy. The formation and description of phases during the thermal processes of fibers by the advanced thermal analysis were examined. The new quantitative thermal analysis of polymeric fibers with cytisine phases based on vibrational, solid and liquid heat capacities was presented. The apparent heat capacity of fibers was measured using the standard differential scanning calorimetry. The quantitative analysis allowed for the study of the glass transition and melting/crystallization process. The mobile amorphous fraction, degree of crystallinity and rigid amorphous fraction were determined depending on the thermal history of semicrystalline polymeric fibers. Furthermore, the cytisine dissolution behaviour was studied. It was observed that the kinetic of the release from polymeric nanofiber is delayed than for the marketed product. The immunosafety of the tested polymeric nanofibers with cytisine was confirmed by the Food and Drug Agency Guidance as well as the European Med-icines Agency. The polymeric matrix with cytisine seems to be a promising candidate for the prolonged release formulation.Ministerstvo Školství, Mládeže a Tělovýchovy, MŠMT: RP/CPS/2022/002; Narodowe Centrum Nauki, NCN: 2019/03/X/NZ7/00888; Narodowym Centrum Nauki, NCNNational Science Centre, Poland [2019/03/X/NZ7/00888]; Ministry of Education, Youth and Sports of the Czech Republic [RP/CPS/2022/002
Fruit quality characteristics of service tree (sorbus domestica l.) genotypes
No full textIn this study, agro-morphological properties, phenolic compounds, and organic acid contents in the fruits of service tree (Sorbus domestica L.) genotypes naturally grown in Türkiye (Bolu) were determined. The fruit weights of genotypes were found to be quite variable, ranging from 5.42 g (14MR05) to 12.54 g (14MR07). The highest L*, a*, and b* fruit external color values were found to be 34.65 (14MR04), 10.48 (14MR09), and 9.10 (14MR08), respectively. The highest chroma and hue values were recorded as 12.87 (14MR09) and 49.07 (14MR04), respectively. 14MR03 and 14MR08 genotypes exhibited the highest amount of soluble solid content and titratable acidity (TA) as 20.58 and 1.55%, respectively. The pH value was found to be in the range of 3.98 (14MR010)-4.32 (14MR04). Chlorogenic acid (14MR10, 48.49 mg/100 g), ferulic acid (14MR10, 36.93 mg/100 g), and rutin (14MR05, 36.95 mg/100 g) were predominant phenolic acids observed in the fruits of service tree genotypes. The predominant organic acid in all fruit samples was malic acid (14MR07, 34.14 g/kg fresh weight basis), and the highest quantity of vitamin C was detected at 95.83 mg/100 g in genotype 14MR02. Principal component analyses (%) were performed to determine the correlation between the morphological-physicochemical (60.6%) and biochemical characteristics of genotypes (phenolic compounds: 54.3%; organic acids and vitamin C: 79.9%). It was determined that measured genotypes were important genetic resources in terms of nutritional value
Extending UTAUT with competitive pressure for SMEs digitalization adoption in two European nations: a multi-group analysis
No full textPurpose: In this article, the authors draw-upon an extended unified theory of acceptance and use of technology (UTAUT) and propose a research model involving performance expectancy (PE), effort expectancy (EE), facilitating conditions (FC) and competitive pressure (CP) as potential salient factors explaining the adoption of digitalization in European SMEs. The authors also postulate that there may be cross-cultural differences, thereby leading us to include the country as a moderator in the model.
Design/methodology/approach: The authors validate this model with a cross-cultural sample involving 188 owner-managers from the Czech Republic and Slovakia and through the partial least square structural equation modeling (PLS-SEM) techniques as well as multi-group analysis.
Findings: The results using the study’s global dataset indicate that PE, FC and CP significantly affect owner-managers intentions toward digitalization in SMEs. The authors’ application of the multi-group analysis also suggests that although the two countries differ in digitalization adoption intention, the differences are statistically insignificant. In the conclusion, the authors highlight several implications these findings have for theory and practice.
Practical implications: The authors recommend that the providers of emerging digital technologies should improve on the performance features of those technologies and ensure they are relevant to the SMEs. By doing so, the adoption of digitalization will grow, because owner-managers of SMEs will have the confidence that adopting such technologies will improve their operations. Second, SMEs are required to provide adequate organizational and technical infrastructure to support digitalization adoption.
Originality/value: Aside from being among the few attempts to extend the explanatory power of UTAUT with PE, EE, FC and CP in investigating digitalization adoption in SMEs context, this study also validates its model with rigorous methodological approach as well as three datasets (global, Czech Republic and Slovakia) thereby strengthening the validity of the results.Visegrad project [MVFSG- 22110036]; Horizon Europe (HORIZON) [101071300]; Project FSR FORD [IGA/FaME/2023/009]; [5-6/2021-23/FaME/003]; [IGA/FaME/2022/003]; [IGA/FaME/2021/003
More accurate cost estimation for internet of things projects by adaptation of use case points methodology
No full textThis article adapts the use case points (UCPs) method to estimate the size and development effort (DE) required for the Internet of Things systems. Despite the extensive use of UCP in software engineering, it has yet to be adapted for IoT systems, which is essential for project management and resource planning. Our proposed adaptation, UCP for IoT, is based on a four-layer IoT architecture and tailors the standard software UCP to the specifications of IoT systems. It was validated using a case study of three IoT systems, demonstrating its applicability and effectiveness in estimating the DE required for IoT projects. However, the results also highlight the need for further improvements, particularly given the absence of historical data sets for IoT projects. Our future work will focus on gathering such data sets and further refining the proposed model.Faculty of Applied Informatics, Tomas Bata University in Zlin [RVO/FAI/2021/002]; Department of Science and Technology-Science Education Institute (DOST-SEI) of the Republic of the Philippines through the Engineering Research and Advance Technology (ERDT) Postdoctoral Grant; Office of the Provost of the De La Salle University Manila, Philippine
Comparison of mechano- and PhotoATRP with ZnO nanocrystals
No full textZinc oxide (ZnO) was previously reported as an excellent cocatalyst for mechanically controlled atom transfer radical polymerization (mechanoATRP), but its photocatalytic properties in photoinduced ATRP (photoATRP) have been much less explored. Herein, well-defined ZnO nanocrystals were prepared via microwave-assisted synthesis and applied as a heterogeneous cocatalyst in mechano- and photoATRP. Both techniques yielded polymers with outstanding control over the molecular weight, but ZnO-cocatalyzed photoATRP was much faster than analogous mechanoATRP (conversion of 91% in 1 h vs 54% in 5 h). The kinetics of photoATRP was tuned by loadings of ZnO nanocrystals. PhotoATRP with ZnO did not require any excess of ligand versus Cu, in contrast to mechanoATRP, requiring an excess of ligand, acting as a reducing agent. ZnO-cocatalyzed photoATRP proceeded controllably without prior deoxygenation, since ZnO was involved in a cascade of reactions, leading to the rapid elimination of oxygen. The versatility and robustness of the technique were demonstrated for various (meth)acrylate monomers with good temporal control and preservation of end-group functionality, illustrated by the formation of tailored block copolymers.NSF [DMR 2202747, CHE 2108901]; J. W. Fulbright Commission in the Czech Republic [2022-21-1]; Ministry of Education, Youth and Sports of the Czech Republic; Fonds de recherche du Queebec (FRQNT) [RP/CPS/2022/007]; [301734]National Science Foundation, NSF, (CHE 2108901, DMR 2202747); US-UK Fulbright Commission, (2022-21-1, RP/CPS/2022/007); Ministerstvo Školství, Mládeže a Tělovýchovy, MŠMT; Fonds de recherche du Québec – Nature et technologies, FRQNT, (301734); Fonds de recherche du Québec, FR