Traditional fossil energy sources are increasingly exhausted, leading to the need for mankind to exploit alternative energy sources; and solar energy can be viewed as infinite. Solar photovoltaic and its applications are increasingly widely studied. However, due to its nonlinearity and unstable nature, high technology is required to achieve good conversion efficiency. One of the techniques to optimize solar cell efficiency is to use the Maximum Power Point Tracking algorithm (MPPT) and P&O is a relatively easy algorithm to implement. This article will present some problems about photovoltaic cells, power converters in solar power systems and using PSIM software to simulate an independent solar system with several harvesting solutions for solar power and compare the efficiency of them.

Indigofera aspalathoides Vahl ex DC. belongs to the Fabaceae family. I. aspalathoides is applied to heal tumors, inflammations, diabetes, leprosy, and kidney illnesses in traditional medicines. Compounds including kaempferol, kaempferol 5-O-β-D-glucopyranoside, 5,4'-dihydroxy 6,8-dimethoxy 7-O-rhamnosyl flavone, indigocarpan, and mucronulatol have isolated from this plant species. Hitherto, there is no comprehensive review available regarding the reported bioactivities of I. aspalathoides. Thus, this article goals to analyze, summarize and document the published bioactivities-related publications. Electronic databases the Web of Science, Scopus, ScienceDirect, and PubMed used to find relevant publications from 1900 to December 2020. Thus far, only in vivo and in vitro scientific evidence levels of bioactivities are available. I. aspalathoides holds such as anti-inflammatory, anticancer, antihepatotoxic, anti-arthritic, immunomodulatory, and antidiabetic properties. Overall, immunomodulatory, anti-inflammatory, and anticancer compounds have been isolated from this plant species Therefore, additional bioactivity and phytochemical-related researches would need to perform to generate more scientific evidence for other applications. This work will be useful for further bioactivity and phytochemical studies using this plant species.

With the development of information technology, many applications of robots are increasingly being applied to support research, learning, and teaching. This paper mainly investigates the modeling and simulation of a robotic arm with 3 degrees of freedom (dofs) for different applications. First, Kinematics and dynamics model of the robot based on the standard Denavit Hartenberg (D-H) modeling method, where the forward kinematics of robot is analyzed and computed to obtain by using the inverse kinematics, and then the solution of the robot dynamics is derived. Second, a CAD model of the robot is designed on CATIA software to convert to MapleSim software to simulation and control. Final, numerical simulation is presented to display results. This work provides a potential basis for the realization of the robotic arm in the industrial, education, and research field, which is of great significance for improving manufacturing efficiency and support teaching and research in the robot field.

Macadamia shells were used to prepare modified carbon by chemical agent H2O2 (25%) in 48 hours with coke ratio: H2O2 = 1:10. Modified carbon from Macadamia shells with chemical agent H2O2 has capable of adsorption heavy metal copper (Cu 2+ ) at an assumption concentration is 30ppm in the optimum conditions such as pH = 4, dose is 1.8 g/l, and the processing time is 30 minutes. The result showed that the adsorption ability of the material reached the highest efficiency is 78.33%. This result showed that modified carbon from shells Macadamia by chemical agent H2O2 capable of removing applications on heavy metal copper (Cu2+) in wastewater.