This study presents a novel approach for the optimal placement of distributed generation (DG) resources, electric vehicle (EV) charging stations, and shunt capacitors (SC) in power distribution systems. The primary objective is to improve power efficiency and voltage profiles while considering practical and nonlinear constraints. The proposed model combines competitive search optimization (CSO) with fuzzy and chaotic theory to develop an efficient and effective solution. The use of fuzzy theory in the model enables the identification of optimal locations for DG sources and SCs, leading to significant enhancements in power index, generation, power losses, and system voltage. Moreover, the proposed fuzzy method is employed to determine the best locations for EV charging stations, further optimizing the overall system performance. The theoretical analysis demonstrates substantial improvements in both accuracy and convergence speed, highlighting the robustness of the proposed approach. In addition, the utilization of chaos theory enhances the local search optimization process, making the proposed method more efficient in finding high-quality solutions. To validate the performance of the model, extensive simulations are conducted on a 69-bus distribution system and various test functions. The results consistently reveal the superiority of the proposed method compared to other conventional optimization techniques. The key contribution of this study lies in its development of a comprehensive and efficient approach for the optimal placement of DG, EV charging stations, and SCs in power distribution systems. The integration of CSO, fuzzy theory, and chaotic theory enables the simultaneous consideration of multiple objectives and constraints, resulting in enhanced power dissipation reduction and voltage profile improvement. The obtained results demonstrate the practical applicability and superiority of the proposed method, which can significantly benefit power system planners and operators in real-world scenarios.

Source-water switching can lead to instability in drinking water distribution systems. In estuarine cities using surface water as source water where salt tide occasionally happens, the influence can be particularly complex due to changes of Larson Index (LI). The objective of this study was to investigate the effects of different switching patterns on the stability of water in an estuarine city. Fluctuated LI was found in the current distribution system. LI of the new source water was lower and more stable. Susceptible areas with a high frequency of over standard water quality were identified and pipe scales there were mainly composed of relatively stable iron oxides with dense crystal structures (Fe3O4 and α-FeOOH). Two old pipe sections were used to simulate different switching patterns. The microbial risk did not increase significantly when the original and new water sources were combined in different ratios (2∶8, 5∶5), when multiple water sources were used (3∶3∶4) or when salinity increased. The better water quality, lower LI of the new source water, and stability of the current distribution system together contributed to the biostability. Total iron increased after switching, then declined and stabilized for most switching patterns. Salt tide can lead to sharp iron release. The results provided insightful information for distribution systems that have cast iron pipes and that might encounter source-water switching patterns.

In this paper, a false data injection prevention protocol (FDIPP) for smart grid distribution systems is proposed. The protocol is designed to work over a novel hierarchical communication network architecture that matches the distribution system hierarchy and its vast number of entities. The proposed protocol guarantees both system and data integrity via preventing packet injection, duplication, alteration, and rogue node access. Therefore, it prevents service disruption or damaging power network assets due to drawing the wrong conclusions about the current operating status of the power grid. Moreover, the impact of the FDIPP protocol on communication network performance is studied using intensive computer simulations. The simulation study shows that the proposed communication architecture is scalable and meets the packet delay requirements of inter-substation communication as mandated by IEC 61850-90-1 with a minimal packet loss while the security overhead of FDIPP is taken into account.

Changes in water quality from source water to finished water and tap water at two conventional drinking water treatment plants (DWTPs) were monitored. Beside the routine water quality testing, Caenorhabditis elegans-based toxicity assays and the fluorescence excitation-emission matrices technique were also applied. Both DWTPs supplied drinking water that met government standards. Under current test conditions, both the investigated finished water and tap water samples exhibited stronger lethal, genotoxic and reprotoxic potential than the relative source water sample, and the tap water sample was more lethal but tended to be less genotoxic than the corresponding finished water sample. Meanwhile, the nearly complete removal of tryptophan-like substances and newly generated tyrosine-like substances were observed after the treatment of drinking water, and humic-like substances were identified in the tap water. Based on these findings, toxic pollutants, including genotoxic/reproductive toxicants, are produced in the drinking water treatment and/or distribution processes. Moreover, further studies are needed to clarify the potentially important roles of tyrosine-like and humic-like substances in mediating drinking water toxicity and to identify the potential sources of these contaminants. Additionally, tryptophan-like fluorescence may be adopted as a useful parameter to monitor the treatment performance of DWTPs. Our observations provided insights into the importance of utilizing biotoxicity assays and fluorescence spectroscopy as tools to complement the routine evaluation of drinking water.