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Abstract One factor that significantly limits blade service life and reliability in GT-100 power turbines is sulphide-oxide metal corrosion of guide and rotating blades. Application of coatings is the most efficient method to prevent corrosion failure. An electron beam physical vapour deposition CoCrAlY coating is used for high and low pressure turbine first-stage rotating blades made from E1 893 alloy. Studies of CoCrAlY-coated blades after different service periods (from 390 to 5900 h) showed that this coating most efficiently protects rotating blades in turbines which operate in northern regions of the country. Because of low temperature hot corrosion leakage, corrosion failure is observed in turbines operating in southern regions of the country. In order to improve corrosion resistance, a ceramic coating has been developed. These coatings increase the endurance of equipment and make it possible to save energy.

The paper proves the economic feasibility of using a local autonomous source of energy supply, which is formed from electrical equipment of other functional purposes based on an asynchronous machine with capacitive self-excitation. To assess the technical and economic indicators of the effectiveness of introducing a local autonomous source of energy supply, the discounted method is adopted, where an indicator of savings from possible losses due to the exclusion of labor resources from production is used as an additional influence factor.

AbstractDespite the rapid increase in the performance of perovskite solar cells (PSC), they still suffer from low lab‐to‐lab or people‐to‐people reproducibility. Aiming for a universal condition to high‐performance devices, we investigated the morphology evolution of a composite perovskite by tuning annealing temperature and precursor concentration of the perovskite film. Here, we introduce thermal annealing as a powerful tool to generate a well‐controlled excess of PbI2 in the perovskite formulation and show that this benefits the photovoltaic performance. We demonstrated the correlation between the film microstructure and electronic property and device performance. An optimized average grain size/thickness aspect ratio of the perovskite crystallite is identified, which brings about a highly reproducible power conversion efficiency (PCE) of 19.5 %, with a certified value of 19.08 %. Negligible hysteresis and outstanding morphology stability are observed with these devices. These findings lay the foundation for further boosting the PCE of PSC and can be very instructive for fabrication of high‐quality perovskite films for a variety of applications, such as light‐emitting diodes, field‐effect transistors, and photodetectors.

Abstract This paper proposes a framework to estimate the effects of exogenous fiscal policy and oil revenue shocks on the macroeconomic activity of price-taking oil producers. We use a structural vector autoregressive model estimated with Bayesian methods and apply it to the Ecuadorian economy. Specifically, we investigate the effects of unanticipated changes in taxes, government consumption spending, government investment spending, and oil revenues on economic activity. The results show that unanticipated expansive fiscal policy either through taxes or government investment can have positive effects on output. However, contrary to most studies in the literature, consumption spending shocks do not significantly affect gross domestic product. We also find that oil revenue shocks influence all the variables in the model, evidencing the vulnerability of the Ecuadorian economy to fluctuations of oil revenues. Historically, oil revenue shocks have been the most important driving force to move output above or below trend.

The electrochemical behavior of zirconium and boron and the synthesis of disperse zirconium diboride powders and coatings from the chloride-fluoride melts have been studied by voltammetry, galvanic and potentiostatic electrolysis, and X-ray phase analysis. It has been shown that the electrochemical reduction of Zr in the chloride-fluoride melts has the different mechanisms for the low and high concentration of the fluoride ion in the melt. In the first case, it proceeds according to the scheme of auto-inhibition; in the second case, the 4-electron reverse one-stage discharge process is observed. By adjusting the ratio [F-]: [Zr(IV ) ] in the melt, it is possible to find the conditions for the implementation of the one-stage 4-electron discharge process of zirconium and its diboride. During the electrometallurgical synthesis of ZrB2, the electro-active particles that formed as a result of the chemical interaction of zirconium- and boron-containing particles and that have different compositions than those formed in the partial zirconium- and boron-containing melts are discharged.

The model of resonance energy transfer (RET) in membrane systems containing donors randomly distributed over two parallel planes separated by fixed distance and acceptors confined to a single plane is presented. Factors determining energy transfer rate are considered with special attention being given to the contribution from orientational heterogeneity of the donor emission and acceptor absorption transition dipoles. Analysis of simulated data suggests that RET in membranes, as compared to intramolecular energy transfer, is substantially less sensitive to the degree of reorientational freedom of chromophores due to averaging over multiple donor-acceptor pairs. The uncertainties in the distance estimation resulting from the unknown mutual orientation of the donor and acceptor are analyzed.

This study examines the impact of government spending, income, and tourism consumption on CO2 emissions in the 50 US states through a novel theoretical model derived from the Armey Curve model and the Environmental Kuznets Curve hypothesis. The findings of this research are essential for policymakers to develop effective strategies for mitigating environmental pollution. Utilizing panel cointegration analysis, the study provides valuable insights into whether continued increases in government spending contribute to higher pollution levels. By identifying the threshold point of spending as a percentage of GDP, policymakers can make informed decisions to avoid the trade-off between increased spending and environmental degradation. For instance, the analysis reveals that Hawaii's tipping point is 16.40%. The empirical results underscore the importance of adopting sustainable policies that foster economic growth while minimizing environmental harm. These findings will aid policymakers in formulating targeted and efficient approaches to tackle climate change and promote long-term environmental sustainability in the United States. Moreover, the impact of tourism development on CO2 emissions varies across states, with some US states experiencing a decrease while others see an increase.

Abstract A new technique is proposed for the calculation of the width W of space charge region and consequently the concentration of uncompensated acceptors NA–ND, which is based on the open-circuit analysis of thin film heterojunction solar cells illuminated by monochromatic light with the wavelength within photosensitivity region. The proposed method was simulated under different values of the theoretically considered parameters (ideality coefficient n, saturation current I0 and shunt resistance Rsh) of a CdS/CdTe heterojunction solar cell. The calculated values of W and NA–ND were established to be dependent on the mentioned above electrical parameters.

The results of an experimental study of a high-energy spark ignition system with self-stabilization of the discharge current are presented. A description of the physical principle that provides self-stabilization is given. The effect of a high-speed gas flow on such parameters of a spark discharge as discharge current, resistance of the discharge gap, voltage across the spark gap, the energy input into the spark discharge, the duration and efficiency of the input is studied.