Nitrate removal or denitrification, involves reduction of nitrate into nitrogen and oxygen. The use of nanoparticles zero valent metals for denitrification receives great attention as they have been proven to be effective and environmentally safe. In this work, the nanoparticles were prepared by reducing the metals salts, dissolved in a mixed solution of water and ethanol, using sodium borohydrate. The nitrate reduction reaction took place in an ambient environment – room temperature, neutral pH and aerobic condition. Results from the experiments carried out showed that nitrate has been successfully reduced up to a maximum of 40% in all the samples without an increase in the pH of the solution, a strong indication that ammonia was not produced. As for the study on the reactivity of the recycled NZVI, the samples synthesized with 4:1 (v/v) ethanol/water and using 9: 1 (v/v) ethanol/water, the reactivity of the iron is similar to the fresh NZVI for the first two hours of the study.

Robotics is an applied science subject in engineering course that concerning control and automation in manufacturing industry now. Engineering students are forced to learn all theories and formulas that encompass the areas of mathematics, physics, micro-electronics, dynamics and kinematics, control systems, human factors, and manufacturing operation in a single subject without any hands-on practical skills. This paper provides an idea to break the barriers of conventional lecturing and laboratory exercising for engineering students with new development of educational robotic kit. This practical approach is able to support low cost robotics course and offers simple, time saving instruction outcomes to engineering students in the kinematics study of robot manipulators with consideration of structure design, serial servo circuit board, microcontroller programming, and graphical user interface (GUI) of PC controller. General architecture of 3-degree-of-freedom (DOF) robot manipulator with two links can be solved easily with the help of this robotic kit.

Natural rubber is highly resilient and possesses many outstanding characteristics but inferior in aspects like modulus and hardness. This however can be improved by reinforcement, forming a composite. The rubber compound in this study was prepared according to the ASTM D3184 standards and reinforced using cellulose acetate (CA) from recycled cigarette filter, partly as an effort to reduce the amount of waste. Moreover, cigarette filter is highly toxic due to the nicotine content thus requires care when is recycled. From the rheological and mechanical testing conducted i.e. scorch and cure time, torque, tensile test and tear strength, it seems to indicate a small amount of up 4 phr (parts per hundred rubber) of CA, is beneficial in improving the properties of the rubber compound.