Science Competition winners in Southeast Asia & Pacific

Four students from Surabaya Cambridge School in Indonesia won the Best in Region for their evaluation of citrus sinensis (a hybrid between pomelo and mandarin) orange extract as a natural ingredient for cockroach repellent.

Annabel Megan Irawan, Nathan Sandhi Goutama, Rubbie Kosasih, and Angel Zhou Si Qi used ethanol and propylene glycol to extract the essential oils from the orange peels of the jeruk berastagi (citrus sinensis) fruit, which is grown locally in Indonesia. They then tested the effect of four different concentrations of the extract – 25%, 50%, 75% and 100% – when combined with distilled water and added to filter paper that they used to section off a portion of their cockroaches’ cages. Their hypothesis was that the 100% concentrated extract would be the best at repelling the insects.

Interestingly, the team found that the 50% and 75% concentrations were the most effective, proving that extracts from the abundant jeruk berastagi fruit have the potential to be a substitute for chemical repellents as a clean, environmentally friendly, natural cockroach repellent.

The judges were impressed with the students’ research, stating: 'The team managed to strike a balance between scientific robustness and appropriate animal care, with every step of experimental design being well thought through. Their objective in reducing unsustainable pest control methods is a noble pursuit and it is exciting to see young people empowered to make a difference in their community through science.'

Reflecting on the competition, Angel Zhou Si Qi said: 'I believe that this research project has prepared me for the upcoming research and experiment for my future by helping me build critical thinking and analytical skills. This research has not only expanded my understanding of sustainable practices but has also sparked my interest in pursuing environmental science further in the future.'

Four students from Anglo Singapore International School in Thailand won the Best in Region award for their investigations into the efficiency of harvesting water from the atmosphere in response to water scarcity.

ZiKe Huang, Tan Hiranwat, Jintaporn Seemunta and Kunathorn Jesdaviriya designed and built an atmospheric moisture condensation system using a refrigeration pump, cooling module and collection surface. Once the air temperature in the system reached its dew point, water condensed into the collector and a fan pushed filtered air over a purification system to reduce contamination.

The team found that the resultant water had a pH level of 7 (neutral), the salinity measurement was low, and the mineral content was similar to distilled water. There was no detectable bacterial contamination, leading the team to conclude that atmospheric moisture condensation does have a great potential for water generation.

Team member Kunathorn Jesdaviriya (Ken) said: 'As one of the sustainable development goals set by the United Nations, even now it is difficult to find a way to ensure that there is enough water for everyone on the earth. After my deeper research, I gradually realized that there are tens of thousands of people in the world who are suffering from water scarcity. Maybe our project this time cannot effectively help those suffering people, but I believe that maybe one of our team will do it in the future.'

The judges were impressed with the team’s experiment and said: 'They built a prototype device and characterised its performance meticulously, with replicates, and errors on their measurements. They discussed their results and the potential applications of their device thoughtfully.'