Sensors and Machine Learning Applications EScience Press en-US Sensors and Machine Learning Applications 2753-4154 Overview and Progress of GNSS Anti-multipath Antenna Designs <p>This article provides a comprehensive review of recent applications of GNSS anti-multipath antenna. Emphasis is placed on the role of anti-multipath antenna in GNSS. A brief summary of the current anti-multipath antenna in satellite-based navigation systems is provided and also the GNSS anti-multipath antenna plays a key role is emphasised, which will help in getting a better understanding of the requirements on the various performance parameters of a GNSS antenna. In addition, we review GNSS anti-multipath antenna design strategies and specific design examples that highlight the application of various types of GNSS anti-multipath antenna. Ultimately, this articles seeks to demonstrate the value of GNSS anti-multipath antenna design insights for antenna engineering and look toward promising new research directions for GNSS antenna research.</p> Jianming Dong Qiang Hua Copyright (c) 2023 Sensors and Machine Learning Applications 2023-09-30 2023-09-30 2 3 10.55627/smla.002.03.00026 Modelling the impact of inter-electrode spacing on nitrate removal using Response Surface Methodology (RSM) <p>Nitrate contamination in water poses a significant concern for environmental engineers, as it has substantial and direct impacts on water quality, the economy, and public health. Consequently, managing nitrate levels in water sources ranks among the top priorities for water authorities. Currently, various treatment methods, including biological treatments and adsorption, are employed to eliminate nitrate from water or wastewater. A substantial body of literature exists focused on the application of electrocoagulation (EC) for nitrate removal from solutions. This method is favoured for its environmentally friendly attributes and ability to swiftly and cost-effectively remove pollutants. In this study, the EC method was employed to eliminate nitrate from water under varying inter-electrode spacing (I-ES) conditions ranging from 4 to 10 mm and different treatment durations (TD) spanning 5 to 55 minutes. The effects of I-ES and TD on nitrate removal were optimised using Response Surface Methodology (RSM). The study's results demonstrated that the most effective nitrate removal, reaching 91.3%, occurred at an I-ES of 4 mm and a TD of 50 minutes. The agreement between the experimentally observed and predicted removal rates was notably high, with an R<sup>2</sup> value of 0.973.</p> Mohammad Amir Khan Anas Al-Hayawi Copyright (c) 2023 Sensors and Machine Learning Applications 2023-09-30 2023-09-30 2 3 10.55627/smla.002.03.00029