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The most severe failures in power grids are often characterized as cascading failures where an initial event triggers consequent failures all along the grid often leading to blackouts. Upon identifying a failure and its cascade potential, timely control actions should be performed by the grid operators to mitigate the effect of the cascade. These actions have to be delivered to one or more control devices, creating a dependency between the power grid and its control network. This paper examines the dependency of the operation of the power grid on the control network. Different from literature studies on failure control, our dependency model captures the impact of networking parameters. We formulate an algorithmic model that describes the impact of this dependency on cascade control. Based on this model, we propose an efficient cascade control algorithm using load shedding with consideration of delays in the communication network for power grids. Finally, we evaluate the impact of the power-communication network dependency with uncontrolled grids, ideal/simple control grids and our proposed control scheme. The results demonstrate that the proposed algorithm can significantly reduce the failure of power lines while sustaining larger power demand for users.

This paper reports the generalized results of computer simulation of physical processes at a rotor-disk film evaporating plant. Optimization of the operation mode cannot be achieved without establishing patterns in the course of physical processes. We have proposed a computer model of hydrodynamics that accounts for all the features, initial and boundary conditions. The results of computer simulations make it possible to adequately assess the effectiveness of using a rotor-disk film evaporating plant (RDFVP) for the concentration of heat-labile materials. We have established patterns in the course of physical processes within a structure of RDFVP by using computer simulation of hydrodynamics in the programming environment ANSYS and applying a k-e turbulence model. The result of simulation is the derived velocity fields of the concentrated fluid (w max =0.413 m/s) and the gas phase (w max =8.176 m/s), as well as the magnitude of values for shear stress τ=0.94·10 -6 Pa. It was established that the gas heat-carrier is characterized by the highly-turbulent flows with maximum values for kinetic energy TKE max =8.985·10 -1 m 2 /s 2 . The reliability of results is ensured by the correctness, completeness, and adequacy of physical assumptions when stating the problem and while solving it using the computer aided design system ANSYS. It has been established that the proposed structure is an effective alternative to equipment for the concentration of solutions. The data obtained could be used when designing heat-and-mass-exchange equipment for the highly efficient dehydration of thermolabile materials

This research presents a 100% renewable energy (RE) scenario by 2050 with a high share of electric vehicles on the grid (V2G) developed in Ecuador with the support of the EnergyPLAN analysis tool. Hour-by-hour data iterations were performed to determine solutions among various features, including energy storage, V2G connections that spanned the distribution system, and long-term evaluation. The high participation in V2G connections keeps the electrical system available; meanwhile, the high proportions of variable renewable energy are the pillar of the joint electrical system. The layout of the sustainable mobility scenario and the high V2G participation maintain the balance of the electrical system during most of the day, simplifying the storage equipment requirements. Consequently, the influence of V2G systems on storage is a significant result that must be considered in the energy transition that Ecuador is developing in the long term. The stored electricity will not only serve as storage for future grid use. Additionally, the V2G batteries serve as a buffer between generation from diversified renewable sources and the end-use stage.

The article presents analysis results in the reconstruction of the tectonic conditions dynamics for the formation of local plicative deformations and rupturing under conditions of the research both the macrostructure and its local separation using the example of the southwestern area of Kalmius-Toretska kettle-hole in the Donetsk basin. Authors applied the scientific cognition method, representing a sequence of actions to establish structural links between variables and constant elements of the Investigational tectonic system, based on statistical and mathematical methods of analysis. The characteristics of the anticlinal structure formation in the studied area - fields of the “Butivska” mine were obtained. It was revealed that the initial horizontal attitude of rocks of the studied area was changed by a monoclinal attitude with a north-western dip and a north-east strike. Afterwards, under the conditions of tectonic near latitudinal compression and near meridional tension, anticlinal folding was formed. Then, under the influence of shear fields when the deformation mode was enhanced, a compression duplex was formed within which local echelon folding and fracture was formed - Oktiabrskyi fault #1.

AbstractNumerical study of the influence of Prandtl number on free convection flow phenomena in a solar collector having glass cover plate and sinusoidal absorber is done. The working fluid is water-Al2O3 nanofluid. The cover plate has initially constant temperature Th, while bottom absorber is at temperature Tc, with Th > Tc. The remaining walls are considered adiabatic. By Penalty Finite Element Method the governing differential equations with boundary conditions are solved. The effect of the Prandtl number on the flow pattern and heat transfer has been depicted. Comprehensive average Nusselt number, average temperature and mean velocity inside the collector are presented as a function of the governing parameter mentioned above. The highest Pr causes the greatest heat transfer. The enhancing performance of heat transfer rate is more effective for the water-Al2O3 nanofluid than the base fluid.

The use of renewable energy in Latin America has increased significantly in recent years as a result of social pressure due to the negative effects generated by the use of polluting energy. However, there is still limited empirical evidence on the effect of clean energy on the output. The objective of this research is to examine the causal link among the growth rates of sustainable energy consumption, non-sustainable energy and the real per capita output in Latin America, a region with a high potential to generate clean energy. We used Pedroni (1999) and Westerlund (2007) cointegration techniques, and Dumitrescu and Hurlin (2012) causality test to evaluate the relationship among the variables. In order to evaluate the strength of the cointegration vector, we applied the dynamic ordinary least squares for individual countries and the panel dynamic ordinary least squares model for country groups. We find robust empirical evidence that suggests that the growth rate of renewable energy consumption, non-renewable energy and the rate of growth of real per capita output have a short-term and long-term equilibrium relationship. The force of the cointegration vector among the output and the renewable energy is more forceful in the countries of medium-high and medium-low incomes. The cointegration vector among the output and non-renewable energy is stronger in high-income countries. The results of the causality test suggest that renewable energy and the real per capita output have a bidirectional relationship in low-middle income countries. The output causes renewable energy in all groups of countries. Likewise, there is a unidirectional causality from the real per capita output towards non-renewable energy. One possible policy implication derived from this research is that high-income countries in the region should look for alternative sources of energy to achieve sustainable growth, and medium-high and medium-low income countries should encourage the use of energy clean, which does not limit the economic growth. Keywords: Energy. output. Cointegration. Causality. Panel data. Latin America, JEL classification: F43, P28, C23

In this study, mixed convective flow in a horizontal channel equipped with alternated baffles and external magnetic field is examined numerically. The channel is partially heated from its bottom wall at high temperature Th while remaining sections along with the top wall are thermally insulated. Two pairs of baffles are alternately located at both the horizontal walls. Cold nanofluid enters with parabolic velocity through the inlet port of the channel. The governing equations based on Boussinesq approximation are solved implementing finite element method. The results for the physical quantities flow and temperature fields are demonstrated via streamlines, temperature contours, average Nusselt number and average temperature. It is found that the fluid flow and heat transfer are modulated by the orientation and height of alternated baffles. Fluid motion is accelerated with rising Reynolds number and declined for increase in magnetic strength and concentration of nanoparticles. Optimum heat transfer is obtained in respect of appropriate orientation of baffles. The heat transfer augmentation is also reduced by 22.14% at Ha = 50 compared to heat transfer at Ha = 0. In addition, heat transfer rate is 33.86% more in nanofluid containing 5% nanoparticles than base fluid water.