Year 5 Josephians Win Two International Science Awards

25 Year 5 students mentored by five teachers participated in the "Global Scientist Award" as part of their virtual Global Experience Programme (GEP) with Ikeda High School (Kagoshima, Japan) that began in mid-August and ended with a final Zoom session on 15 November. The annual international competition hosted by Ikeda High School is backed by the Japanese education ministry and several research companies and Universities, including pharmaceutical giant Otsuka Pharmaceuticals and Chiba Institute of Technology. For the 5th year, the event this year involved a total of 68 teams of students from China, Finland, Japan and Singapore, across 3 categories: elementary school, junior high school and high school.

Two of the five SJI teams who participated in the high school category received awards. HE7 was one of the seven out of 55 high school teams that received the Outstanding Award while HE9 was awarded the Favourite Presentation by Otsuka Pharmaceuticals.

Outstanding Award (Team HE7):

• Lim Yee Kiat Zachary (LE510)

• Ong Li Ern Alicia (LE510)

• Vincentius Markandeya Santosa (LE510)

• Zhang Weihang (LE510)

• Teacher Advisor: Dr Sergei Prokopenko

Research Topic: NEWater Characteristic Analysis

The team presented their study, which aims to test a selected number of these parameters (both chemical and physical) to verify the safety and cleanliness of NEWater in Singapore. Their findings found that NEWater is both safe and clean for consumption despite the controversy of reclaiming used water. Their study contributed to the scientific basis supporting the process as a sustainable solution to the water issue, and the presentation received many positive comments and compliments from the judges.

Water is an essential resource for the function and survival of natural and socioeconomic systems. Despite this, over 1 billion people lack access to safe drinking water, a shortage which is expected to grow with the rising threat of global warming. Thus, there is a constant need to advance our technology to keep up with the growing demand for clean water. In Singapore, an innovative approach to the water issue is ‘NEWater’, a form of reclaimed water in which wastewater is treated and turned into high-purity clean water. This process employs three main technological operations: microfiltration, reverse osmosis and UV disinfection, all of which contribute to the removal of impurities, bacteria and viruses. NEWater has repeatedly met the clean drinking water standards set by the World Health Organisation.

Favourite Presentation (Team HE9):

• Andrew Tay Bin Song (ML512)

• Audrey Yeo Min Hui (ML512)

• Balaji Prakash Narayanan (ML512)

• Chuah Jiao Yao (ML512)

• Teacher Advisor: Mr Raymond Wong

Research Topic: Calcium demineralisation of Toothpaste
The team investigated the effectiveness of protection of the toothpaste of different brands that are widely used in Singapore and/or Japan. The experiment is carried out by coating 6 samples of bones with various brands of toothpaste for 24 hours, then drying and crushing to increase surface area. A bone without toothpaste is included as a control. The judges were impressed by the fact that the team compared toothpaste available in Japan and Singapore.

Hydroxyapatite Ca10 (PO4) 6 (OH) 2 makes up 70% to 80% of our enamel and dentin by weight, and this hard covering protects the teeth. Below the critical pH value (5.5), the calcium and phosphate ions in hydroxyapatite dissolve out of the enamel and react with the H+ ions derived from the acids present. This process is known as demineralisation. The pH of the oral environment drops due to an increase in presence of an acid, which occurs due to a plethora of reasons: (1) Sugar consumed reacts with bacteria to produce acid due to anaerobic conditions, (2) Consumption of food and drinks with acidic content. Common acid found in food is citric acid, and (3) The stomach’s contents, including hydrochloric acid, will flow back up into the oesophagus and enter backflow into the mouth during acid reflux, which occurs when the lower oesophagal sphincter muscle relaxes after a meal instead of closing tightly. Toothpaste contains fluoride compounds which allow for the remineralisation of the enamel.