Present perfect, future scientific

pune: electronic sensors to help the blind get around, electronic burglar alarms, a novel "earthquake indicator" and innovative solar cookers were some of the devices developed and displayed by budding indian scientists and technologists at the 9th national children's science congress, which began in the city on thursday. these young brains made the most of the opportunity to showcase their scientific skills in front of eminent scientists dr a.p.j.abdul kalam, prof. yash pal and dr ashok kolaskar. they put up a proud display of miniature working models, from washing machines and rockets. one of the biggest crowd-pullers was the earthquake indicator designed by the karanja-based vidya bharati junior college. made from a 1.5-foot pvc pipe and some small components like a bell and a pendulum and four light emitting diodes, the device has the ability to record all tremors, no matter how minor they are, claimed raja gore, the project director. "experiments show that it is even better than the seismograph in terms of cost as well as usage," explained 16-year old shital patil, the mind behind the equipment. "while the seismograph costs thousands, our equipment can me made for only rs 85," she said, adding that the indicator could locate the source of a tremor from nine directions as against four directions shown by the seismograph. a parabolic solar cooker, designed by four aspiring technologists from the bal sikshan mandir english medium school, pune, was another popular item on display. it demonstrated how solar energy can be effectively used for preparing ayurvedic medicines. as amruta toglekar, one of the four teenagers associated with the project explained, "our aim is to bring the use of non-conventional resources into focus." the cooker, which incurs a one-time cost of rs 4,500 because of the use of nine high-quality aluminium sheets, has been scientifically tested to prepare shatavari oil and shatavari kalp, the herbal medicines used to treat pregnant women and anaemic patients. vikram singh from kendriya vidyalaya, lucknow, had his innovative electronic gadget on display which, when fitted on to the walking stick of the blind helps them tide over navigational problems at traffic intersections and while crossing roads. the sensor, made of a battery and a small sound alarm, produces a beep as soon as it hits any surface, the 17-year-old explained. mostly in the age group of 14 to 17 years, over 600 children are participating in this year's science congress. while uttar pradesh has the highest representation of 42, andhra pradesh, bihar, karnataka, madhya pradesh, maharashtra, rajasthan, tamil nadu and west bengal follow with 30 each. there are 26 children from assam, gujarat and orissa. a key feature of this year's congress is the participation of four students each from russia, portugal and the persian gulf.