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Accurate and reliable characterization of current transformer (CT) performance is essential for maintaining grid stability and power quality in modern electrical networks. CT measurements are key to effective monitoring of harmonic distortions, supporting regulatory compliance and ensuring the safe operation of the grid. This paper addresses a method for the characterization of CTs across an extended frequency range from 50 Hz up to 150 kHz, driven by increasing power quality issues introduced by renewable energy installations and non-linear loads. Traditional CT calibration approaches involve measurement setups that offer ppm-level uncertainty but are complex to operate and limited in practical frequency range. To simplify and expand calibration capabilities, a calibration system employing a sampling ammeter (power analyzer) was developed, enabling the direct measurement of CT secondary currents of an unknown CT and a reference CT without any further auxiliary equipment. The resulting expanded magnitude ratio uncertainties for the wideband CT calibration system are 10 ppm (k=2) up to 10 kHz and less than 120 ppm from 10 kHz to 150 kHz; these uncertainties do not include the uncertainty of the reference CT. Additionally, the operational conditions and setup design choices, such as instrument warm-up duration, grounding methods, measurement shunt selection, and cable type, were evaluated for their impact on measurement uncertainty and repeatability. The results highlight the significance of minimizing parasitic impedances at higher frequencies and maintaining consistent testing conditions. The developed calibration setup provides a robust foundation for future standardization efforts and practical guidance to characterize CT performance in the increasingly important supraharmonic frequency range.

Nuisance fuse blowing because of miscoordination between fuse and recloser in power distribution network is very critical issue particularly when distributed generations (DGs) are incorporated. This study presents a new adaptive digital relaying scheme for power distribution network containing DG, which circumvents miscoordination between recloser and fuse. It is based on calculation of the ratio of feeder current and recloser current. With the help of this philosophy, the proposed scheme automatically modifies the time dial setting of the relay and hence enhances margin between fuse and recloser in order to avoid miscoordination between fuse and recloser. The proposed scheme has been extensively tested for various types of faults in radial distribution network containing DG. Fault data are generated by modelling an existing part of 11 kV Indian power distribution network using PSCAD/EMTDC software package. Furthermore, the impact of different DG capacities on the margin (coordination) between fuse and recloser are also analysed. It has been observed that the proposed scheme maintains proper coordination between fuse and recloser for all types of fault. Moreover, it also provides satisfactory operation during high resistance single line-to-ground faults.

In the current work, we report the fabrication of titanium dioxide polymer nanocomposite (TiO2 PNC) memory devices. TiO2 PNCs were fabricated at three different solution volume ratios with polymer polyvinyl alcohol (PVA), i.e. TiO2-PVA :: 1:100, 1:50 and 1:10. The effect of increased concentration of TiO2 nanoparticles (NPs) was studied. TiO2 NPs were synthesized by the sol–gel method. High-resolution transmission electron microscopy images of the prepared TiO2 NPs were acquired. Fluorine-doped tin oxide (FTO)-coated glass was used as a substrate for device fabrication. PNCs were characterized by x-ray diffraction spectroscopy, and the TiO2-PVA (1:10) device was also morphologically characterized by field emission scanning electron microscopy. The thickness of the PNC film is 14 μm. These devices exhibit bipolar switching behavior, with the maximum ON/OFF current ratio (ION/IOFF) of ∼ 103 for the FTO/TiO2-PVA (1:10)/Ag device. Current–voltage (I–V) curves show hysteresis as a result of the formation and rupture of conductive filaments due to the migration of oxygen vacancies. Write-read-erase-read test cycles show good repeatability, stability and retention properties. The results thus prove that the TiO2-PVA devices are strong candidates for next-generation non-volatile memory devices because of their large ON/OFF current ratio, repeatability and stability.

300°C operation of a normally-off AlGaN/GaN metal-oxide semiconductor field-effect transistor (MOSFET) is successfully demonstrated, which is fabricated using a self-terminating gate recess etching technique. At 300°C, by employing a 15 nm-thick Al2O3 as the gate dielectric deposited by atomic layer deposition, the fabricated normally-off MOSFET exhibits a threshold voltage (Vth) of 3.2 V, a low off-state leakage current of ∼10−7 A/mm and a low forward gate leakage current of ∼10−7 A/mm. Thus, a high on/off current ratio of ∼ 106 is obtained. Furthermore, the normally-off MOSFET also exhibits small variations in terms of its Vth from room temperature to 300°C with a maximum relative variation of 6.7% in a such temperature range. These results make this normally-off AlGaN/GaN MOSFET very promising for high-temperature digital electronics.

The aim of this article is to determine the relationship between working capital and profitability of companies operating in the food industry in the Czech Republic and then find out how working capital affects the profitability of these companies from 2009 to 2019. In the first part of the research we estimate the links between working capital measured by variables such as cash conversion cycle, current assets ratio, current liabilities ratio, working capital ratio and corporate profitability measured by return on sales. In the next part of the research, we estimate the effect of working capital measured by variables such as cash conversion cycle, current assets ratio, current liabilities ratio, working capital ratio on corporate profitability measured by return on sales. Correlation analysis and the GMM method will be used to determine the relationship between working capital and the profitability of companies and how working capital affects the profitability of these companies. The results of the correlation analysis showed statistically significant links between return on sales and variables such as cash conversion cycle, current assets ratio, current liabilities ratio and working capital ratio. The results of the GMM method showed a statistically significant effect of variables such as cash conversion cycle, current assets ratio, current liabilities ratio and working capital ratio on the profitability of companies measured by the return on sales indicator. All mitigated effects have been demonstrated for companies operating in the food industry as a whole, as well as in the production of food products and beverages.

The aim of this article is to determine the relationship between working capital and profitability of companies operating in the food industry in the Czech Republic and then find out how working capital affects the profitability of these companies from 2009 to 2019. In the first part of the research we estimate the links between working capital measured by variables such as cash conversion cycle, current assets ratio, current liabilities ratio, working capital ratio and corporate profitability measured by return on sales. In the next part of the research, we estimate the effect of working capital measured by variables such as cash conversion cycle, current assets ratio, current liabilities ratio, working capital ratio on corporate profitability measured by return on sales. Correlation analysis and the GMM method will be used to determine the relationship between working capital and the profitability of companies and how working capital affects the profitability of these companies. The results of the correlation analysis showed statistically significant links between return on sales and variables such as cash conversion cycle, current assets ratio, current liabilities ratio and working capital ratio. The results of the GMM method showed a statistically significant effect of variables such as cash conversion cycle, current assets ratio, current liabilities ratio and working capital ratio on the profitability of companies measured by the return on sales indicator. All mitigated effects have been demonstrated for companies operating in the food industry as a whole, as well as in the production of food products and beverages.

Titanium aluminium (TiAl) alloy thin films were deposited on silicon wafer and stainless steel substrate by sputtering method. The effects of the Al/Ti target current ratio (R) on chemical composition, structure, surface morphology, wettability, and corrosion resistance of the deposited films were investigated using energy dispersive X-ray spectroscopy (EDX), X-ray diffraction (XRD), scanning electron microscopy (SEM), atomic force microscopy (AFM), contact angle measurement, and potentiostat, respectively. In the experiment, when the Al/Ti target current ratio increased from 0.375 to 1.5, the Al/Ti concentration ratio of the deposited films increased. When the Al/Ti target current ratios were 1.0 and 1.5, the deposited film structure exhibited γ-TiAl phase with tetragonal crystal structure. Moreover, the Al/Ti target current ratio of 1.5 provided the deposited film with the highest crystallinity, surface roughness, hydrophobicity, and corrosion resistance.

Printed electronics is a revolutionary technology aimed at unconventional electronic device manufacture on plastic foils, and will probably rely on polymeric semiconductors for organic thin-film transistor (OTFT) fabrication. In addition to having excellent charge-transport characteristics in ambient conditions, such materials must meet other key requirements, such as chemical stability, large solubility in common solvents, and inexpensive solution and/or low-temperature processing. Furthermore, compatibility of both p-channel (hole-transporting) and n-channel (electron-transporting) semiconductors with a single combination of gate dielectric and contact materials is highly desirable to enable powerful complementary circuit technologies, where p- and n-channel OTFTs operate in concert. Polymeric complementary circuits operating in ambient conditions are currently difficult to realize: although excellent p-channel polymers are widely available, the achievement of high-performance n-channel polymers is more challenging. Here we report a highly soluble (∼60 g l -1 ) and printable n-channel polymer exhibiting unprecedented OTFT characteristics (electron mobilities up to ∼0.45–0.85 cm 2  V -1  s -1 ) under ambient conditions in combination with Au contacts and various polymeric dielectrics. Several top-gate OTFTs on plastic substrates were fabricated with the semiconductor-dielectric layers deposited by spin-coating as well as by gravure, flexographic and inkjet printing, demonstrating great processing versatility. Finally, all-printed polymeric complementary inverters (with gain 25–65) have been demonstrated. Printed transistors Printed electronics devices show great potential for cheap consumer and health-care products and new applications are rapidly emerging. But device applications are limited by the fact that the plastic semiconductors currently available are almost exclusively 'hole-transporting' materials that operate via the conduction of positive charges. If an electron-transporting equivalent can be found — retaining good electrical transport properties, chemical stability and ease of processing — then it would be possible to use it in tandem with the existing plastic semiconductors to produce yet more powerful devices. Such combinations are known as 'complementary' circuitry. A team working at the Polyera Corporation labs in the United States and at BASF in Germany has produced a new material that achieves that goal. It is a highly soluble electron-transporting plastic semiconductor that exhibits unprecedented device performance, and is compatible with a broad range of printing and processing technologies. A range of plastic semiconductors have been developed that have the combination of physical and chemical properties required to enable printable electronic circuitry, but these are almost exclusively 'hole transporting' materials. If an electron-transporting equivalent could be found, it could be combined with the existing classes of materials to produce yet more powerful devices. This paper reports the development of a such a material: the electron-transporting plastic semiconductor exhibits unprecedented device performance, and is compatible with a broad range of printing and processing technologies.

The objective of this study is to estimate the impact of Covid-19 on business behavior and its spatial effect among companies. Four specifications have been developed to analyze the pandemic's influence on key variables determining business behavior: liquidity, indebtedness, profitability, and efficiency. This study has focused on the province of Barcelona, Spain, from which a database of failed and non-failed companies has been compiled, both before and after the pandemic. The models have been estimated using the spatial Seemingly Unrelated Regressions (SUR) methodology, and each equation was estimated following a spatial Differences-in-Differences model. The results confirm that the emergence of Covid-19 has had a significant impact on companies' financial ratios, worsening their positions in terms of liquidity, indebtedness, and efficiency, with the existence of a spatial contagion pattern.

This article presents a technique in nanoscale field effect diode structure to overcome the challenges in conventional field effect diode structures. By reducing the impurity, the amount of additional minority carriers injected from the source and drain areas into the channel and the possibility of band-to-band tunneling between the reservoirs is reduced. But with the decrease of impurity, the ON current also decreases. Using the properties of germanium material in the field effect diode has led to an increase in the ON current, a decrease in gate delay, and an increase in the speed of this device compared to conventional silicon-based structures. In addition, due to the small bandgap of germanium compared to silicon, this device can be used in low-power applications. By comparing the results obtained in the proposed structure with conventional structures, the ON/OFF current ratio is 500 times better, as well as the gate delay and EDP have been reduced from 114 to 0.26 ps and 5.023 × 10 –26 to 1.87 × 10 –28 j.s, respectively.