The Dependence of Perceived Business Risks on the Size of SMEs

The issues of risk management in small and medium-sized enterprises (SMEs) have been analysed and discussed for a long time. Nevertheless, it is still necessary to concentrate on this field, especially in the Slovak Republic. SMEs are very sensitive to changes in the business environment which are always reflected in the quantitative characteristics of this sector in a certain time interval. According to various global surveys and studies, risk management represents a significant contribution to the increasing competitiveness of enterprises in changes of the business environment. The aim of this paper is to statistically assess the dependence of perceived key business risks of SMEs on their size in Slovakia based on own empirical research carried out in 2017. The contribution also includes an assessment of key risk sources and an evaluation of the survey results compared to the results of surveys taken last year. Based on the results, market, financial, economic and personnel risks comprise the four most important risks that negatively affect the business environment of SMEs. Dependence perceived by the SME entrepreneurs was found among market factors, personnel risks, and business size. No dependence was found among the financial, economic and business risks. The overall results of the empirical research point to the need and importance of addressing the assessment of key risks and their resources in SMEs in Slovakia. The goal of the paper is to highlight through a relevant study the need to apply risk management in the SMEs and to bring the results of the research in Slovakia closer to world trends

Preparation and characterization of fibrous non-woven textile decorated by silver nanoparticles for water filtration

The environmentally friendly preparation of silver nanoparticles was proposed for the production of antibacterial non-woven textile used in water filtration. The silver nanoparticles were prepared by chemical reduction of silver nitrate using two environmentally friendly reducing agents, such as fructose or ascorbic acid. For comparison also commonly used reducing agent-sodium borohydride was used. The silver nanoparticles in various size and yield were produced by immersion of the plasma pre-treated polypropylene (PP) nonwoven textile in the colloidal solutions for different periods (35, 45 and 135 min). The morphology of the silver nanoparticles was characterized by SEM and EDX analysis. Additionally, the antibacterial activity of the silver decorated PP non-woven textile was evaluated by an agar diffusion test using both Gram-positive Staphylococcus Aureus and Gram-negative Escherichia coli. The results suggest that the type of the reducing agent has major effect both on the morphology of silver nanoparticles and the antibacterial activity. © NANOCON 2018 - Conference Proceedings, 10th Anniversary International Conference on Nanomaterials - Research and Application. All rights reserved.Institutional Research Project [RVO 67985874]; Ministry of Education, Youth and Sports of the Czech Republic - Programme NPU I [LO1504

Pressure-Driven Piezoelectric Sensors and Energy Harvesting in Biaxially Oriented Polyethylene Terephthalate Film

This study reports the possibility of using biaxially oriented polyethylene terephthalate (BOPET) plastic packaging to convert mechanical energy into electrical energy. Electricity is generated due to the piezoelectricity of BOPET. Electricity generation depends on the mechanical deformation of the processing aids (inorganic crystals), which were found and identified by SEM and EDAX analyses as SiO2. BOPET, as an electron source, was assembled and tested as an energy conversion and self-powered mechanical stimuli sensor using potential applications in wearable electronics. When a pressure pulse after pendulum impact with a maximum stress of 926 kPa and an impact velocity of 2.1 m/s was applied, a voltage of 60 V was generated with short-circuit current and charge densities of 15 μAcm−2 and 138 nCm−2, respectively. Due to the orientation and stress-induced crystallization of polymer chains, BOPET films acquire very good mechanical properties, which are not lost during their primary usage as packaging materials and are beneficial for the durability of the sensors. The signals detected using BOPET sensors derived from pendulum impact and sieve analyses were also harvested for up to 80 cycles and up to 40 s with short-circuit voltages of 107 V and 95 V, respectively. In addition to their low price, the advantage of sensors made from BOPET plastic packaging waste lies in their chemical resistance and stability under exposure to oxygen, ultraviolet light, and moisture

Solid-State Synthesis of Direct Z-Scheme Cu₂O/WO₃ Nanocomposites with Enhanced Visible-Light Photocatalytic Performance

In this paper, we report the preparation of visible-light active direct Z-scheme Cu2O/WO3 nanocomposite photocatalyst by a solid-state reaction avoiding the otherwise inevitable formation of CuWO4 phase in wet syntheses. Structure, morphology, and thermal and optical properties of prepared WO3 nanoplatelets decorated by Cu2O were investigated by XRD, Raman spectroscopy, SEM/TEM, combined thermogravimetric (TG)/differential scanning calorimetry (DSC) analysis, and UV–VIS spectroscopy. The photocatalytic performance of the prepared samples under UV and visible light was studied through monitoring discoloration of methylene blue under illumination by selected wavelengths, allowing for the distinguishing between the contributions of the two semiconductive components. Experimental results showed that the decoration of WO3 nanoplates by Cu2O nanoparticles led to an improvement in photocatalytic performance, regardless of used LED (Light-Emitting Diode) wavelength, even at low concentrations. By using scavengers selectively blocking reactive species involved in the discoloration reaction, we determined that the Cu2O/WO3 nanocomposite exhibited the characteristics of direct Z-scheme-type photocatalyst