NOW, HERE'S a refreshing thought ... How about having bus-stops throughout Hong Kong that have colourful garden plants covering their roofs that not only look good but are also able to purify the air on busy thoroughfares? Here's another one: an intelligent cooking pan that could switch itself off and never burn your food. Well, if you think these are ideas from sci-fi movies, then it's well worth your time to visit the Science Museum during the next six days. The 36th Joint School Science Exhibition (JSSE), which is currently being held at this Tsim Sha Tsui venue, solely exhibiting the work of Form Six students, has entered its final stage. More than 20 secondary schools have their final chance to show off how their scientific knowledge and intelligence could enhance the charm of a city. The theme of this year's exhibition, which is sponsored by electronics giant Philips, is City Charm. It aims to encourage students to pay more attention to their surroundings. This year, 54 Hong Kong schools submitted proposals. After two rounds of selections, 23 were selected to set up booths to display their scientific inventions in the exhibition. Judges will further evaluate the schools' displayed projects and the public can also vote for the idea they like most. The winning school will receive a cash prize of $10,000 while the first runner-up and the second runner-up will recieve a cash prize of $6,000 and $4,000 respectively. Besides the participating schools, five local universities and four overseas entrants from America, the mainland, Taiwan and Namibia were also invited to set up booths in the exhibition to exchange scientific knowledge and ideas. One particular project that caught visitors' attention at yesterday's opening was the Oasis in the City - The Green Bus-stop. 'I often wait at the bus-stop. It's hot and the exhaust emitted from the buses make us irritable,' explained Rachel Liang Pui-tak, one of the designers in the St Paul's Convent School team. 'So the idea of making a green bus-stop came to us.' Secretary for Financial Services and the Treasury Frederick Ma Si-hang, when he stopped by at the booth, was so impressed he told the students that they should introduce this idea to local bus companies. The environmentally-friendly bus-stop, decorated with a variety of colourful plants and flowers, is coated with titanium dioxide - a chemical that absorbs toxic substances such as nitrogen monoxide and nitrogen dioxide released by road traffic. 'Titanium dioxide also absorbs water. So when it rains, the dust on the coating can be washed away,' said Amabel Wong May-bo, another member of the green bus-stop's design team. While a number of inventions and entries show concern about the environment, A Little Smart Lid, designed by Tai Po Sam Yuk Secondary School, focuses on home safety. The device is a lid designed for cooking pots and pans. It has a built-in thermostat and an infra-red emitter. When the thermostat detects a temperature of 120 degrees Celsius, the cooking pot/pan simply switches off piped gas supply after transmitting an infra-red distres signal. 'After installing it, you can concentrate on your cooking without worrying about home safety,' said Silicon Shiu Kai-yin, whose school is taking part in the exhibition for the first time. There are a lot more interesting and creative inventions at the exhibition for you to explore and find out. Read more reports on the JSSE in this week's Young Post.