全國中小學科展

第二名

Touch screen Clock

The Sunflower Peeler

It is used by pigeon owners, farmers and squatters. The machine peels thesunflower seeds and leaves them separate from each other. The seeds can be used for pigeons,birds and making of flour. The shells of the seeds can be used as compost and ferilizer. This is an eco-friendly system.

Tharn Din-Alternative Energy Source of The Future

This scientific research project “Tharn Din - Alternative Energy Source of the Future” is directed toward producing a new type of soil charcoal. Tharn Din, with excellent combustibility. The experiments were divided into six steps. First, we selected soils of exceptional adhesion property Next, we looked into many different combustible materials for soil admixtures. Many different formulas of soils and admixtures were tested. The most promising formulas were then optimized for maximum combustibility. After which, the best formula was chosen and we further optimized its combustibility. Combustion and ignition rate and characteristics of this formula were investigated. And lastly the effect of surface area on combustible rate was examined. It was found that mud was the best adhesive and wood chip was the best admixture. Tharn Din made of one part of mud and 3 parts of wood chips released higher thermal energy than normal charcoals. We found that a special type of Thai soil, Din See-eaw, when mixed with wood chips created Tharn Din of exceptional combustibi1it Ignition and combustible rates are proportional to the surface area of Tharn Din.

Baseball and the Markov Chain Theory

Keeping Cool

My aim was to test the effectiveness of coolboxes under different\r conditions, to use this information to do comparisons using commercially\r available coolboxes and finally to build an effective and cheaper coolbox\r appropriate to Namibia\r The general method used to compare different coolboxes involved\r measuring the rate at which ice melted inside the cool boxes under\r different conditions.

Self-Reinforced Polymer Composite from Postconsumer Scraps

The Development of an Orbital Angular Momentum Sorter for TransferHigh-Speed Data Transfer

An orbital angular momentum (OAM) sorter concept was designed for high-speed data transfer. The OAM of a light beam known as an optical vortex can exist in one of an infinite number of states and may be used to carry information. The augmented alphabet of states carries the potential to increase date transfer speeds over conventional binary (0 and 1) methods. A vortex generator, or OAM encoder , was constructed from a slit cover slip functioning as an adjustable spiral phase plate, and a vortex analyzer, or OAM measurer, was created using a transparent print of a computer-generated hologram. The two components were then incorporated in an OAM sorter concept that that employs a novel combinatoric method for sorting data. The vortex generator and analyzer created were inexpensive simpli-fications of previous devices and have the potential to increase the alphabet of transmission states several thousand times over binary methods if implemented in the OAM sorter concept.

Effect of Salt Concentration on Evaporation of Sea Water

Every year more soluble and insoluble substances are added to the oceans by runoff. This process slowly increases the salinity of the oceans. As the salinity of the oceans increase, what effect will this have on our climate? The purpose of this investigation is to determine how an increase in salt concentration affects the evaporation of sea water. Four ten liter aquaria were filled with six liters of distilled water in each aquarium. One aquarium contained only water. The other three aquaria had different amounts of Kosher salt added as follows: 120. grams, 240.grams and 480.grams. Measurements of the level of water in each tank were taken over a period of two months. The tank with the highest concentration of salt had the smallest rate of evaporation. In the feature with less evaporation of sea water the atmosphere will receive less moisture. This could result in fewer clouds and less rain fall for the planet.

Are there any speical reasons the Traditional Korea horn bow is excellent?

Our traditional bow is a kind of horn bow which appeared at the side wall in the sepulcher\r around A.D 600. A lot of traits of the horn bow have been handed down to us in an\r unwritten form. This is the reason why I would like to research and investigate the several\r potential capacities in the field of Physics, such as structures, materials and efficiency.

Listen to Your Heart

a. Purpose of the Research Nowadays people are getting unhealthy, especially the heart. Since the outbreak of SARS, the Hong Kong citizens cared more about their health. In the past two decades, due to the technological advancement, many medical instruments that were used by doctors are now available to the public. One of the examples is the sphygmomanometer used for measuring blood pressure. On the other hand, very few heart monitoring devices are developed for public use. As a result, there is a need that such heart monitors should be available to the public. b. The device Our device is a modified stethoscope, which electronic components are added to this common medical instrument. The device mainly consists of 3 parts: 1. The sensor: modified from ordinary stethoscope, which a condenser microphone is added to change the heart sounds into electrical signals 2. The signal processor: integrated circuits and resistor-capacitor couples, which the cost is much lower than digital electronic components, are used to amplify and filter the noise in the electrical signals. The processor is divided into 3 stages: - Preamplifier: Amplifies the electrical signals converted from heart sounds - Low pass filter: Filters the noise in the signal. The cut-off frequency is 600Hz, which most of the heart sounds are below 600Hz. - Power amplifier: Amplifies the filtered signals before outputting into computers or earphones. 3. The output devices: it can be a computer or an earphone. In a computer, the heart sounds can be converted into graphs, enabling precise graphical analysis. Since many abnormal heart conditions will alter the heart sounds, with the aid of computers and graphs, people can know whether their hearts are normal or not, and can seek for medical support before developing any critical situation. Moreover, abnormal heart sounds are more significant in graphs, so any heart problems can be discovered more easily. c. Data During an exhibition in Hong Kong, about 1000 people tried the device. Among them approximately 150 people were confirmed to have heart problems with abnormal heart sounds. Using our device, we discovered 109 of them. As a result, the accuracy of the device is about 72.6% d. Conclusion With the low cost of our device (~€9.80/US$12.80), everyone would be able to afford it. As a result, people can check their conditions of their hearts more frequently, and would be able to discover any early heart problems.