Abstract Many problems in life are composed of conflicting and influencing multiple objectives, and people often encounter the optimization problem of simultaneously optimizing multiple objectives in each area, which is called multi-objective optimization problem. Therefore, solving such problems has important scientific research value and practical significance. This paper proposes a Newton Gauss-Seidel iteration method for solving multi-objective constrained optimization problems by constructing Newton directions and introducing Gauss-Seidel (GS) iterative method for solving linear equations. The solution of this combination between Newton, Gauss-seidel and Lagrange multiplier method involves two stages: objective function and constraint condition processing stage. In the first stage, the original multi-objective function is scalarized, and only the decision-maker needs to give each objective function a weight, by transforming it into a single objective constrained optimization problem. Then the Lagrange multiplier method was used to transform the constrained optimization problem into an unconstrained optimization problem. The second stage is to use the Newton-Gauss-Seidel (NGS) iterative method to solve the transformed constrained optimization problem. Finally, numerical experiments showed that our proposed algorithm can achieve good results.

Abstract Seaweed and its derivatives serve as natural sources of bioactive compounds widely used as biostimulants in agricultural practices to augment plant growth and boost productivity. Tadong rice, a pigmented upland rice variety, is becoming increasingly favoured by consumers in Malaysia, attributed to its perceived health benefits. However, limited commercialization of Tadong rice is attributed to its low grain yield. The present work aimed to address these concerns by utilizing plant biostimulants derived from seaweed, which represents a more environmentally friendly alternative. Seaweed extract (SE) of a brown seaweed species (Sargassum polycystum) was applied to Tadong rice plants at different concentrations (20, 40, 60, and 80%) via foliar application, along with the recommended dose of fertilizer (RDF) in an insect-proof net house. Additionally, one commercial liquid biofertilizer and one control treatment (distilled water) were tested for comparison. The growth and yield of Tadong rice were evaluated along with numerous variables. The results demonstrated that S. polycystum at a 20% concentration had a favorable impact on several growth and yield parameters of Tadong rice. The treatment increased plant height, flag leaf length, flag leaf width, tiller number, panicle number/plant, 1000-grain weight, and yield/plant of Tadong rice (5.73 to 44.11% higher) compared to the control treatment. This study demonstrates that applying SE through foliar applications can boost the growth and yield of pigmented upland rice, providing advantages for upland rice farmers and making a positive contribution to sustainable agriculture and food security. The use of the 20% concentration of SE is particularly notable from an economic perspective, as it achieves these benefits with a lower amount of material compared to higher concentration.

Abstract The pollution of copper (II) ions, (Cu2+) in water has become one of the big concerns since this metal can spread easily through living organisms and the environment. The accumulation of ecotoxicological Cu2+ ions is extremely dangerous and causes severe adverse effects on plants, animals, aquatic life and humans. This toxic heavy metal can be removed effectively with an adsorption treatment method by using biochar, a green adsorbent made from biomass feedstock. In this study, the adsorption capacity of biochar derived from banana stems for the removal of Cu2+ ions are examined. The dried stem material was carbonized via slow pyrolysis at 300 °C for 1 h. The produced banana stem biochar was characterized by Scanning Electron Microscopy (SEM) and Energy-Dispersive X-ray Spectroscopy (EDX). The effect of the adsorption parameters that are initial Cu2+ ions concentration (100 – 400 mg/L), biochar dosage (0.1 – 0.6 g), pH solution (2 – 12), and stirring speed (60 – 210 rpm) were investigated in batch adsorption experiments at room temperature. Experimental setup parameters that affect the adsorption have been optimized by the one-factor-at-a-time (OFAT) technique. Adsorption of Cu2+ ions on biochar increased until reaching equilibrium with increasing initial Cu2+ concentration, increasing pH, increasing stirring speed up to 120 rpm and decreasing dosage. The maximum Cu2+ ions amount adsorbed of 300.10 mg/g was achieved with optimum adsorption parameters that are 350 mg/L of initial Cu2+ ions concentration, pH 6, 0.1 g of biochar dosage and 120 rpm stirring speed. Due to the high adsorption efficiency, banana stems are potentially to be employed as an alternative adsorbent material for removing Cu2+ ions from aqueous solution. As banana stems are abundantly available agricultural wastes, its utilization as adsorbent feedstock will reduce the production and operation cost of removing various toxic metals from wastewater and be beneficial in addressing environmental issues resulting from improper disposal of agricultural wastes.