Power Quality is an essential concern in the modern power system that can affect consumers and utility. The integration of renewable energy sources, smart grid systems and extensive use of power electronics equipment caused myriad problems in the modern electric power system. Current and voltage harmonics, voltage sag, and swell can damage the sensitive equipment. These devices are susceptible to input voltage variations created by interference with other parts of the system. Hence, in the modern age, with an increase in sensitive and expensive electronic equipment, power quality is essential for the power system’s reliable and safe operation. Dynamic Voltage Restorer (DVR) is a potential Distribution Flexible AC Transmission System (D-FACTS) device widely adopted to surmount the problems of non-standard voltage, current, or frequency in the distribution grid. It injects voltages in the distribution line to maintain the voltage profile and assures constant load voltage. The simulations were conducted in MATLAB/Simulink to show the DVR-based proposed strategy’s effectiveness to smooth the distorted voltage due to harmonics. A power system model with a programmable power source is used to include 3rd and 5th harmonics. The systems’ response for load voltage is evaluated for with and without DVR scenarios. It has been noted that the proposed DVR based strategy has effectively managed the voltage distortion, and a smooth compensated load voltage was achieved. The load voltage THD percentage was approximately 18% and 23% with insertion 3rd and 5th harmonics in the supply voltage, respectively. The inclusion of the proposed DVR has reduced THD around less than 4% in both cases.

The Klein–Fock–Gordon equation (KFGE), defined as the equation of relativistic wave related to NLEEs, has numerous implications for energy particle physics and is useful as a model for several types of matter, with deviation in the basic stuffs of particles and in crystals. In this work, the Sardar subequation method (SSM) is used for finding the solution of this KFGE. The advantage of SSM is that it provides many different kinds of solitons, such as dark, bright, singular, periodic singular, combined dark–singular and combined dark–bright solitons. The results show that the SSM is very reliable, simple and can be functionalized to other nonlinear equations. It is verified that all the attained solutions are stable by modulation instability process. To enhance the physical description of solutions, some 3D, contour and 2D graphs are plotted by taking precise values of parameters using Maple 18.

After food and water, clean air is essential for continuity of life on the planet. Complex trans-boundary air pollution problem is often linked to sustenance and eutrophication. Air pollution problem has no universal conventions like Montreal and Kyoto protocols in case of refrigerants, except regional cooperative solutions. Polluter-pays principle is typically restricted to the source country. Under article 16, International Environment Law mentions the polluter-pay principle without any legitimate power to mitigate the transboundary air pollution risks. Mongolia, Botswana, and Pakistan are ranked as the most polluted countries, although their accumulative emissions are lesser than any of the coal power producing countries. China, South Africa, and India produce 68–79% of their electricity using coal-fired power plants, emitting harmful pollutants into the common air. Regional winds drive upwind smog into their adjacent downwind countries like Pakistan. This paper compares the published transboundary air pollutant flows data of the most polluted countries (Mongolia, Botswana, Pakistan) with the cleanest ones (Estonia, Mauritius, Australia). Air pollution externality problem can only be solved either by regional cooperation or global environment law which yet does not exist. Drawing an analogy from water contamination laws, this work proposes an extension of the polluter-pays principle to transboundary air pollutants to compensate the public losses. We should collectively go for the international environmental law as we cannot divide air like land. Industrialization near the border may be banned to avoid air pollutant migrations to neighbors.