Research background: Enterprises manage earnings in an effort to balance their profit fluctuations to provide increasingly consistent earnings in every reporting period. Earnings management is legal ...and very effective method of accounting techniques and may be used to obtain specific objectives of the enterprises involving the manipulation of accruals. Therefore, there is a need to analyze it in the context of group of countries, while the issue of their detection in the new ways appears. Purpose of the article: The analysis of annual earnings before interest and taxes (EBIT) of 5,640 enterprises from the Visegrad Four during the period 2009–2018 confirms that the development of earnings management in these countries is not a randomness. Thus, the aim of this article is to determine the existence of positive trend in earnings management and to detect the change-point in its development for each Visegrad country. Methods: Grubbs test, Mann-Kendall trend test and Buishand test were used as appropriate statistical methods. Mann-Kendall test identifies significant monotonic trend occurrence in earnings manipulation in every country. Buishand test indicates significant years, which divides the development of EBIT into two homogenous groups with individual central lines. Findings & Value added: Based on the statistical analysis applied, we rejected randomness in the managing of earning, but we determined the trend of its increasing. The positive earnings manipulation was not homogenous in the analyzed period, however, a change-point was defined. Year 2014 was identified as a break-point for Slovak, Polish and Hungarian enterprises considering the earnings manipulation. Year 2013 was detected as a change-point in Czech enterprises. The methodical approach used may be very helpful for researchers from other countries to determine, detect and understand earnings management as well as for the investors to make decisions based on a specificities of an individual country.
Research background: Since the first bankruptcy prediction models were developed in the 60’s of the 20th century, numerous different models have been constructed all over the world. These individual ...models of bankruptcy prediction have been developed in different time and space using different methods and variables. Therefore, there is a need to analyse them in the context of various countries, while the question about their suitability arises. Purpose of the article: The analysis of more than 100 bankruptcy prediction models developed in V4 countries confirms that enterprises in each country prefer different explanatory variables. Thus, we aim to review systematically the bankruptcy prediction models developed in the countries of Visegrad four and analyse them, with the emphasis on explanatory variables used in these models, and evaluate them using appropriate statistical methods Methods: Cluster analysis and correspondence analysis were used to explore the mutual relationships among the selected categories, e.g. clusters of explanatory variables and countries of the Visegrad group. The use of the cluster analysis focuses on the identification of homogenous subgroups of the explanatory variables to sort the variables into clusters, so that the variables within a common cluster are as much similar as possible. The correspondence analysis is used to examine if there is any statistically significant dependence between the monitored factors — bankruptcy prediction models of Visegrad countries and explanatory variables. Findings & Value added: Based on the statistical analysis applied, we confirmed that each country prefers different explanatory variables for developing the bankruptcy prediction model. The choice of an appropriate and specific variable in a specific country may be very helpful for enterprises, researchers and investors in the process of construction and development of bankruptcy prediction models in conditions of an individual country.
Research background: Financial risk management is the task of monitoring financial risks and managing their impact. Financial risk is often perceived as the risk that a company may default on its ...debt payments. The issue of the debt, default or prosperity of the company are presented in the article as one of the ways of the risk management. A prediction of corporate default is an inseparable element of the risk management. Mainly the consequences of risk are the engine of research and development of methods and models, which enable to predict economic and financial situation in specific conditions of global economies. Purpose of the article: The main aim of the presented article is to assess financial risks of Slovak entities, realized by the identification of significant factors and determinants affecting the prosperity of Slovak companies. Methods: To conduct the research we have used the data of Slovak enterprises, obtained from annual financial reports covering the year 2015 and the calculated financial ratios of profitability, activity, liquidity and indebtedness that may affect the financial health of the company were applied in the regression analysis. Realizing the multiple regression analysis, the statistically significant determinants that affect the future financial development of the company are identified, as well as the regression model of the bankruptcy prediction. Findings & Value added: In the research aimed at the management of financial risks in Slovak enterprises, we focused on the revelation of significant economic risk factors using multiple regression. The results suggest that the most significant predictors are net return on capital, cash ratio, quick ratio, current ratio, net working capital, RE/TA ratio, current debt ratio, financial debt ratio and current assets turnover based on which the decision about the future company default can be made. These factors are significant enough to manage financial risks and to affect the profitability and prosperity of the company.
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•Optimization of composition of blends PBAT/TPS by selection of the plasticizer.•Strength of starch - plasticizer hydrogen bonds rules the blend’s properties.•Urea as TPS plasticizer ...leads to steep increase in strength and Young’s modulus.•Appropriate TPS plasticizer allows to design optimal materials for new applications.
Materials based on mixture of poly(butylene adipate-co-terephthalate) (PBAT) with thermoplastic starch (TPS) were investigated concerning mechanical properties and structure characterized by DMTA and SEM. TPS plasticized with two different plasticizers were tested, namely glycerol and urea. It was found that TPS with urea exhibits significantly higher tensile strength and modulus than TPS with starch plasticized by glycerol and this affects also the properties of mixtures PBAT/TPS. Tensile strength of mixtures containing 20% of both kinds of TPS is substantially lower than virgin PBAT but the strength for mixture with 50% of TPS with urea is approaching to the value for neat PBAT while the same content of TPS/glycerol leads to further decrease in stress. Differences in moduli for PBAT with TPS/urea and TPS/glycerol represent one order of magnitude. The reason for this behavior consists in much stronger interactions between urea and starch hydroxyl groups compared to glycerol resulting in prevention of void formation visible on fracture surfaces (SEM) and higher glass transitions temperature (DMTA).
Carbon quantum dots and their incorporation in various polymer matrices are reviewed. In general, the importance of such polymer nanocomposites in biomedical applications is highlighted. In ...particular, the physical and antimicrobial properties of carbon quantum dots and their ability to produce reactive oxygen species under certain conditions using the principle of photodynamic therapy are explored. The characterization, preparation, mechanism of action, and use of carbon quantum dots are discussed. The known combinations of polymers and carbon quantum dots and their use in various industries are also described.
Carbon quantum dots and their incorporation in various polymers, especially in biomedical applications, are evaluated. The characterization, preparation, mechanism of action, and use of carbon quantum dots are discussed. Additionally, the known combinations of polymers and carbon quantum dots and their use in various industries are described.
Due to its slow degradation rate, polycaprolactone (PCL) is frequently used in biomedical applications. This study deals with the development of antibacterial nanofibers based on PCL and halloysite ...nanotubes (HNTs). Thanks to a combination with HNTs, the prepared nanofibers can be used as low-cost nanocontainers for the encapsulation of a wide variety of substances, including drugs, enzymes, and DNA. In our work, HNTs were used as a nanocarrier for erythromycin (ERY) as a model antibacterial active compound with a wide range of antibacterial activity. Nanofibers based on PCL and HNT/ERY were prepared by electrospinning. The antibacterial activity was evaluated as a sterile zone of inhibition around the PCL nanofibers containing 7.0 wt.% HNT/ERY. The morphology was observed with SEM and TEM. The efficiency of HNT/ERY loading was evaluated with thermogravimetric analysis. It was found that the nanofibers exhibited outstanding antibacterial properties and inhibited both Gram- (
) and Gram+ (
) bacteria. Moreover, a significant enhancement of mechanical properties was achieved. The potential uses of antibacterial, environmentally friendly, nontoxic, biodegradable PCL/HNT/ERY nanofiber materials are mainly in tissue engineering, wound healing, the prevention of bacterial infections, and other biomedical applications.
In the present, there is a big need for materials that can replace materials currently used in technologies, improving mainly the performance and ecological impact of manufacturing. Graphene-based ...materials are such an alternative, primarily graphene oxide (GO) and reduced graphene oxide (rGO). This work presents a scalable, fast, safe, and eco-friendly method for preparing rGO thin paper (∼5 μm) with conductivity reaching 435 S/m. These rGO papers were fabricated by reducing thin GO paper prepared in an in-house-built vacuum chamber and applying spraying cycles of GO dispersion for a precise and highly controllable deposition process. The atmospheric plasma generated by Diffuse Coplanar Surface Barrier Discharge (DCSBD) plasma source was employed for rapid GO reduction-exfoliation (in the order of seconds) to prepare highly porous rGO paper. Prepared rGO papers were then post-processed by a cold rolling press into uniform conductive self-standing pure rGO papers to create more precisely defined samples and enhance their mechanical and electrical properties. The morphology of GO and rGO papers was studied by SEM and AFM, the chemical changes before/after the plasma reduction were analyzed by the XPS technique and the electrical parameters of the fabricated papers were analyzed by the 4-point probe method and the structure of GO and rGO was analyzed by Raman and XRD methods. The short duration and the scalability potential of the herein-described plasma-reduction-exfoliation method open new possibilities for large-scale implementation of rGO papers in industrial applications.
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•Vacuum spraying is a fast method of graphene oxide paper preparation.•DCSBD electrical plasma can trigger fast ∼ 1s reduction of graphene oxide paper.•Rapid reduction leads to significant expansion of the reduced graphene oxide paper.•Sample compression further enhances electrical properties.•The whole production process of GO paper is compatible with in-line production.
The presented study proposes an efficient utilization of a common
Thymus serpyllum
L. (wild thyme) plant as a highly potent biosorbent of Cu(II) and Pb(II) ions and the efficient interaction of the ...copper-laden plant with two opportunistic bacteria. Apart from biochars that are commonly used for adsorption, here we report the direct use of native plant, which is potentially interesting also for soil remediation. The highest adsorption capacity for Cu(II) and Pb(II) ions (
q
e
= 12.66 and 53.13 mg g
−1
, respectively) was achieved after 10 and 30 min of adsorption, respectively. Moreover, the Cu-laden plant was shown to be an efficient antibacterial agent against the bacteria
Escherichia coli
and
Staphylococcus aureus
, the results being slightly better in the former case. Such an activity is enabled only via the interaction of the adsorbed ions effectively distributed within the biological matrix of the plant with bacterial cells. Thus, the sustainable resource can be used both for the treatment of wastewater and, after an effective embedment of metal ions, for the fight against microbes.
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