Tomas Bata University in Zlín
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Silane-modified kombucha-derived cellulose/polyurethane/polylactic acid biocomposites for prospective application as leather alternative
No full textThis work focuses on the preparation of cellulose-based biocomposites as a kind of potential leather-like alternative. Herein, Kombucha-derived bacterial cellulose (KBC) cultured from black tea, waste and cane sugar was modified with different silanes (dimethyldichlorosilane, hexadecyltrimethoxysilane, vinyltriethoxysilane and 3-aminopropyltriethoxysilane) to incorporate hydrophobic property followed by mixing with polyurethane (PU) and polylactic acid (PLA). The improved hydrophobicity of KBC played a vital role in enhancing compatibility, homogenous mixing and providing a stable structure for the final products. The untreated and silane treated KBC/PU/PLA biocomposites were characterized for surface morphology, chemical structure, X-ray diffraction, thermal and mechanical stability as well biodegradation. According to results, the optimized biocomposites contained KBC 13.74% w/w, PU 73.89% w/w, and PLA 12.50% w/w compressed at 155 °C for 5 min. The prepared biocomposites possessed good elasticity, hydrophobic surface and moderate biodegradability. Basically, the fabricated materials urged possible responses for essential requirements of newly developed leather substitutes with prospective application in fashion design industries like textile, footwear, bags, or interior covering products for the automotive industry.FRC/2022/2102, RP/CPS/2022/005; Tomas Bata University in Zlin, TBU; Ministerstvo Školství, Mládeže a Tělovýchovy, MŠMTTomas Bata University in Zlin, Czech Republic [IGA/CPS/2020/005, IGA/CPS/2021/002, IGA/CPS/2022/002]; Ministry of Education, Youth and Sports of the Czech Republic [DKRVO RP/CPS/2022/005, FRC/2022/2102
ZnO/Cu2O heterojunctions treated glass surface for photocatalytic and self-cleaning applications
Get PDFHere we report the synthesis route for glass surface functionalization by ZnO nanorods and nanowires-based Cu2O heterojunction. In the first step, ZnO elongated structures were grown on a seeded substrate following the classic hydrothermal method, and their thickness can be controlled by polyethyleneimine (PEI) concentration. In the second step, ZnO/Cu2O heterojunctions were fabricated by immersion of ZnO-grown substrate upside-down into the copper sulfate solution with glucose as a reducing agent. After characterization of prepared ZnO/Cu2O heterojunction by SEM, TEM, and XRD, its application capability for waste-water treatment was successfully demonstrated on Estriol (E3) hormone degradation under UV light by using a continuous Drip Flow Biofilm Reactor. Furthermore, functionalized glasses were shown to be effective for designing self-cleaning surfaces. The photocatalytic-induced self-cleaning ability was demonstrated by resazurin-based smart ink and tert-butyl alcohol-based methylene blue ink.Ministerstvo Školství, Mládeže a Tělovýchovy, MŠMT: LTT20010, RP/CPS/2022/007Ministry of Education, Youth and Sports of the Czech Republic [LTT20010, RP/CPS/2022/007
Short-text semantic similarity (STSS): Techniques, challenges and future perspectives
Get PDFIn natural language processing, short-text semantic similarity (STSS) is a very prominent field. It has a significant impact on a broad range of applications, such as question-answering systems, information retrieval, entity recognition, text analytics, sentiment classification, and so on. Despite their widespread use, many traditional machine learning techniques are incapable of identifying the semantics of short text. Traditional methods are based on ontologies, knowledge graphs, and corpus-based methods. The performance of these methods is influenced by the manually defined rules. Applying such measures is still difficult, since it poses various semantic challenges. In the existing literature, the most recent advances in short-text semantic similarity (STSS) research are not included. This study presents the systematic literature review (SLR) with the aim to (i) explain short sentence barriers in semantic similarity, (ii) identify the most appropriate standard deep learning techniques for the semantics of a short text, (iii) classify the language models that produce high-level contextual semantic information, (iv) determine appropriate datasets that are only intended for short text, and (v) highlight research challenges and proposed future improvements. To the best of our knowledge, we have provided an in-depth, comprehensive, and systematic review of short text semantic similarity trends, which will assist the researchers to reuse and enhance the semantic information.Yayasan UTP Pre-commercialization grant (YUTP-PRG) [015PBC-005]; Computer and Information Science Department of Universiti Teknologi PETRONASYayasan UTP, YUTP: 015PBC-00
Sub PPM detection of NO2 using strontium doped bismuth ferrite nanostructures
Get PDFThe present work investigates the NO2 sensing properties of acceptor-doped ferrite perovskite nanostructures. The Sr-doped BiFeO3 nanostructures were synthesized by a salt precursor-based modified pechini method and characterized by X-ray diffraction (XRD), scanning electron microscopy (SEM), and X-ray photoelectron spectroscopy (XPS). The synthesized materials were drop coated to fabricate chemoresistive gas sensors, delivering a maximum sensitivity of 5.2 towards 2 ppm NO2 at 260 degrees C. The recorded values of response and recovery time are 95 s and 280 s, respectively. The sensor based on Bi0.8Sr0.2FeO3-delta (BSFO) that was operated was shown to have a LOD (limit of detection) as low as 200 ppb. The sensor proved to be promising for repeatability and selectivity measurements, indicating that the Sr doping Bismuth ferrite could be a potentially competitive material for sensing applications. A relevant gas-sensing mechanism is also proposed based on the surface adsorption and reaction behavior of the material.IGA/CPS/2022/002, IGA/CPS/2023/006; Ministerstvo Školství, Mládeže a Tělovýchovy, MŠMT: RP/CPS/2022/00
Coating of leather with dye-containing antibacterial and conducting polypyrrole
Get PDFIn the search for functional organic biomaterials, leather constituted by collagen fibers was coated with a conducting polymer, polypyrrole. The coating was carried out during the oxidation of pyrrole in an aqueous solution of poly(N-vinylpyrrolidone) in the presence of five organic dyes: crystal violet, neutral red, methyl orange, acriflavine, and methylene blue. This technique ensures the uniform coating of collagen fibers with polypyrrole and incorporation of organic dyes. The surface morphology was observed with scanning electron microscopy and the transverse profile, reflecting the penetration of the conducting phase into the leather body with optical microscopy. While the polypyrrole coating endows leather with electrical conductivity, organic dyes are expected to affect the polymer morphology and to provide an antibacterial effect. The lowest sheet resistance and antibacterial activity were obtained with crystal violet. This type of coating was characterized in more detail. Infrared spectroscopy confirmed the coating of collagen fibers with polypyrrole and dye incorporation. Mechanical properties were extended to the cyclic bending of the leather at various angles over 5000 cycles. The relative resistance changes were a few percent, indicating good electrical stability during repeated mechanical stress.Ministry of Education, Youth and Sports of the Czech Republic [FRC RO70200003025/2102]Ministerstvo Školství, Mládeže a Tělovýchovy, MŠMT: FRC RO70200003025/210
Application 3D forensic science in a criminal investigation
Get PDFThis manuscript discusses the modern approach and application of 3D digital imaging in forensic science. It presents the basic principles and approaches of 3D modeling methods. Selected methods of image capture and its subsequent processing into a 3D model are applied to a specific object. This object is captured by a mobile phone camera, a LiDar sensor, and a 3D scanner for further image processing for different desired image outputs. The text describes the photogrammetry method, the workflow with the LiDar sensor, and the 3D model of the object intended for 3D printing. The paper discusses the potential of the selected methods and their application in forensic sciences.IGA/CebiaTech/2022/00
The impact of selected environmental factors on the perception of a company’s financial performance in the SME segment
Get PDFThe environmental dimension is a significant part of a firm’s development, which is crucial to retaining and increasing competitiveness. The aim of the paper was to define and quantify the influence of selected environmental aspects on perceiving the financial performance of a company in the segment of small and medium-sized enterprises (SMEs) in V4 countries. The empirical research included 1,398 respondents who expressed their opinions on statements by means of which the influence of selected environmental aspects on the perception of a company’s financial performance was examined. The formulated statistical hypotheses were verified using a linear regression model. The results of the research confirmed the statistically significant positive influence of all the researched environmental factors on the perception of financial performance of SMEs in V4 countries and the survival of SMEs in the markets in the upcoming five-year period. SMEs in V4 countries positively perceive environmental responsibility as a significant part of company management, within which this responsibility is also considered. SMEs in V4 countries also agreed with the fact that including environmental practices in company management is associated with higher costs. The relatively strongest dependency was determined between the factors of considering environmental responsibility and the statement that responsibility brings about higher costs
Impact of negative emotions on financial behavior: An assessment through general strain theory
Get PDFResearch background: The research has two objectives and employs a serial mediation approach. First, using the general strain theory, it examines the mediating role of negative feelings and impact of economic adversity on people's risk tolerance and prudent financial behavior. The second is determining the various categories' variations according to age.
Purpose of the article: The study's main objective is to evaluate financial behaviour of people with lower and medium incomes after the second wave of COVID-19 in India, and to contribute to the body of knowledge on general strain theory.
Methods: The study examined the proposed framework and tested the serial mediation model based on the general strain theory used as a survey method for data collection, targeting lower and middle-income individuals in India's most populated state. The study applied PLS-SEM to test the framed hypotheses. Furthermore, the Kruskal Wallis test was applied to identify the difference in the various groups classified based on age.
Findings & value added: The results reveal that economic hardship significantly influences improved financial behavior. Risk aversion attitude, loneliness, and depression mediate the relationship between economic hardship and financial behavior. Moreover, the study found quite a few significant differences between the different age groups. The present study will add to the existing literature on financial behavior under the scope of general strain theory and probably be among the few that test general strain theory with financial variables impact on lower and middle-income group individuals from a developing nation in post-COVID-19 period
Poor single mothers: using Delors' pillars of education in social activation services
Get PDFThe aim of this article is to determine the effect of social work provided by social activation services to poor single mothers in the Czech Republic. Using the method of quasi-experimental research design, the study analyses the activities of the social activation service during the years 2017-2019. As defined by Delors, the pillars of social work with impoverished mothers in our study were conditioned by a cognitive-behavioral and a task-oriented approach. It was found that through long-term social work with poor single mothers, skills related to the pillars Learning to Be, Learning to Know, and Learning to Live Together could be developed. The finding of no statistically significant development of respondents' work skills associated with the Learning to Do pillar proved to be a noteworthy outcome. The research highlights the work of the social activation service in the Czech Republic, while it also outlines the significant challenges involved in working with poor single mothers. The paper proposes the development and institution of a new service dedicated to developing employment skills, by which the reduction of the negative impacts of the poverty on single mothers might be achieved.Univerzita Tomase Bati ve Zline [RO60211011025/2120
Integrative analysis of mRNA and miRNA expression profiles and somatic variants in oxysterol signaling in early-stage luminal breast cancer
Get PDFOxysterols, oxidized derivatives of cholesterol, act in breast cancer (BC) as selective estrogen receptor modulators and affect cholesterol homeostasis, drug transport, nuclear and cell receptors, and other signaling proteins. Using data from three highly overlapping sets of patients (N = 162 in total) with early-stage estrogen-receptor-positive luminal BC-high-coverage targeted DNA sequencing (113 genes), mRNA sequencing, and full micro-RNA (miRNA) transcriptome microarrays-we describe complex oxysterol-related interaction (correlation) networks, with validation in public datasets (n = 538) and 11 databases. The ESR1-CH25H-INSIG1-ABCA9 axis was the most prominent, interconnected through miR-125b-5p, miR-99a-5p, miR-100-5p, miR-143-3p, miR-199b-5p, miR-376a-3p, and miR-376c-3p. Mutations in SC5D, CYP46A1, and its functionally linked gene set were associated with multiple differentially expressed oxysterol-related genes. STARD5 was upregulated in patients with positive lymph node status. High expression of hsa-miR-19b-3p was weakly associated with poor survival. This is the first study of oxysterol-related genes in BC that combines DNA, mRNA, and miRNA multiomics with detailed clinical data. Future studies should provide links between intratumoral oxysterol signaling depicted here, circulating oxysterol levels, and therapy outcomes, enabling eventual clinical exploitation of present findings.Grantová Agentura, Univerzita Karlova, GA, UK, (207043, 698119); Agentura Pro Zdravotnický Výzkum České Republiky, AZV ČR, (NU22‐08‐00281)Charles University Grant Agency [698119]; Czech Health Research Council [207043]; program Cooperatio-Surgical Disciplines; [NU22-08-00281