全國中小學科展

第二名

Waste Not,Want Not

Many people in South Africa still use open fires for cooking. There is a\r large amount of wasted heat lost by four methods of heat transfer:-\r radiation, convection, conduction and evaporation.\r I constructed a vessel that would reduce heat loss, and focus the heat\r emitted from a fire onto the bottom of a pot. I used materials that were\r cheap and easy to obtain, so that those using open fires would be able to\r construct similar vessels to save energy and reduce pollution.\r The vessels were made up of a standard wire mesh frame that was\r surround by trial coverings, namely tin foil, asbestos rope, industrial foil,\r papier mache, ceramic, and 2 ceiling insulators.\r 5 mls of methylated spirits was burned in each vessel. The temperature\r gain of 100mls of water in a standard pot was recorded. 5 trials on each\r vessel were performed. 2 groups of vessel were found. Those that\r produced high temperature gains, burned quickly, and produced a large\r amount of soot deposits on the pot, and a second group that did the\r opposite.\r I compared the rate of heating from my best vessel to that of a stove as\r well as a microwave oven. Heating from the vessel was faster than that of\r the stove, and slightly slower than the microwave.\r I measured the heat emitted from a fire in a three-dimensional pattern and\r found that the maximal heat was some distance above the flame.\r From these results I devised 12 guidelines that would minimize the\r energy need, and pollution produced, when cooking on an open fire

Swimming Pool safety Device "Baby Buzzer"

Annually several baby’s and toddlers drown. There are safety devices available on the\r market for ex: Safety nets in which toddlers can get strangled. Pool covers that have to be\r taken off when people swim and replaced after they have swam. If they are not replaced\r afterwards, babies could fall in the water and drown. Fences around the pool:- The gate\r could accidentally be left open and the toddler could fall in and drown.

Ectomycorrhizal Inoculation of Anisoptera thurifera and Shorea guiso : GROWTH AND PHOSPHORUS DYNAMIC

Dipterocarps coming from Southeast Asia comprise about 53% of the world’s\r total exports of tropical hardwood products. However, the supply of dipterocarps is\r rapidly declining. The government is currently embarking on the establishment of\r dipterocarp plantations and encourages inoculation with ectomycorrhizal fungi to\r improve seedling growth and survival in degraded sites. Anisoptera thurifera (Blanco)\r Blume and Shorea guiso (Blanco) Blume rooted cuttings were inoculated with\r mycelial beads containing either Pisolithus PTG, Pisolithus H6394, or Astreus sp.\r Pisolithus PTG was collected from Acacia mangium stand in Malaysia, Pisolithus\r H6394 from Eucalyptus trees growing in a heavy metal contaminated area in New\r Caledonia, Astreus sp obtained from dipterocarp forest in Mt. Makiling, Philippines.\r The results showed that Astreus sp gave the highest root colonization (38%), height\r increment (86%), fine root (51%), coarse root (27%), shoot (43%) and total dry\r weight (40%) of A. thurifera over the control treatment. Astreus – inoculated plants\r had the highest shoot P uptake (41%) while PTG inoculated ones obtained the highest\r fine root P uptake (0.273 mg/root). The uninoculated plants had the lowest height\r increment, dry weight, and P uptake. In S. guiso, Pisolithus H6394, gave the highest\r increment (100%). Data were only obtained from four months of nursery experiments,\r hence, a longer nursery and field experiments should be conducted to achieve a\r complete evaluation of the physiological functions of ectomycorrhizal associations.\r Moreover, a wide range of ectomycorrhizal fungi associated with dipterocarps should\r be incorporated for selection of host compatibility.

Construction of a Mechanical Prototype of a Microtremor Recorder

Ambient vibration, the movement of the ground caused by transient objects such as the relative to values obtained using the commercial recorder. The natural ambient vibration of a control site was simultaneously obtained using the mechanical prototype and the commercial recorder, which were situated next to each other during the actual recording. Moreover, both sensors were used to record a control stimulus for a constant amount of time. The data obtained from these subparts were processed using WinWaveShot which quantified and presented ambient vibration as waves. The deviations of the maximum and minimum amplitudes, mode and median values of these waves, as graphed by DADiSP2002, was performed to verify the accuracy or reliability of the prototype. These graphs were converted to their DFT graphs and histograms, with accompanying converted wave properties which characterized the predominant frequency. Based from the results, the recordings obtained from the mAVR are proportional from the ones obtained from the eAVR. Therefore, the mechanical prototype is capable of recording the predominant frequency of a site. The prototype, when improved, is a potential alternative to commercial sensors since it is able to record actual movements and its scale is proportional to the scale of the eAVR. Since the prototype was constructed and can be reproduced from readily available and inexpensive materials, ambient vibration analysis can be used more commonly by architects and engineers for construction purposes. To verify the reliability of the values obtained using the prototype, the ambient vibration of other sites must be recorded and compared to those using the eAVR. wind, sounds and human activities, is one major site effect evaluation method presently used. The respective predominant frequencies of a site and the structures above it obtained using this method serve as reference to the renovation and/or construction of structures. Predominant frequencies of the landmass and the structures above it should be non-identical to avoid prolonged shaking with the occurrence of an extensive movement of the ground as dictated by resonance effect. Since electronic ambient vibration or microtremor recorders, specifically their sensors, are expensive and inaccessible, a mechanical prototype of such device was designed and constructed. The proposed design of the mechanical ambient vibration recorder (mAVR) was mainly based on the IRIS Seismograph which makes use of the principle of electromagnetic induction. The relationship between ground motion and the movement of the prototype lever, which is a direct proportion, was the concept highlighted by the prototype’s mechanism. After the design of the mAVR prototype was finalized, its assembly, which consisted of the calibration of the solenoid and the inertial mass, was performed. The calibration of the solenoid was based on the voltage output of its solenoid based on the number of turns while the inertial mass was determined based on the equilibrium level of the prototype lever. Having proven the mAVR’s capacity to function by simulating stimulus, the testing of its accuracy was done with two setups: recording of (1) natural and (2) induced ambient vibration. This tested the prototype’s accuracy

Shock Induced Battery

a. Purpose of the Research Evidence has shown that people are becoming more aware of environmental protection than in the past. Not only has the government made every effort to implement the policies of environmental protection, but Hong Kong citizens are also more willing to cooperate and help out. However, when it comes to conservation of energy and reduction of wastage, many people still regard it as a burden and they just take it lightly. In fact, environmental protection can be achieved in a convenient and simple way. We can easily put in practice in our daily lives. Because of this, we would like to introduce our invention - “shock Induced battery” by using our knowledge of Physics. b. Procedures The “Shock Induced battery” makes use of locomotion of human bodies to generate electricity. The electrical current generated from the specially designed generator will pass through the diode bridges, which adjust the current to one direction. This enables the electrical energy to be stored in the capacitor. This energy will be released when the battery is correctly connected to a circuit with a switch and a resistor. One of the features of the battery is that it is portable. It is mainly used to charge up electrical devices. But it is hoped that it will replace non-chargeable cells one day, and can directly be used in any electrical devices. In fact, our ultimate goal is to reduce the wastage of materials for making the cells, and to solve the problem of disposal of these cells. c. Data The induced a.c. voltage is full-wave rectified by the diode bridge. d. Conclusions In a word, we are trying to provide a chance for people to put environmental protection in practice, so as to raise the awareness of people about environmental protection. After all, high-tech products only solve the power-saving problem to a certain extent, but it is the awareness and the initiatives of the public which matter. We are convinced that environmental protection brings fun to your daily lives, as you will find practices on environmental protection both convenient and simple.

Keyboard for Blinds

The reason for making this project was with the intention to help the blind persons. A lot of people with vision problems don’t have the resources available to acquire equipment or programs that make it easier for them to use a computer to write, to communicate etc... Being aware of this problem we took the liberty of researching at a community center that helps the blind persons in Tijuana Baja California, Mexico. We found that they had a type writer (Perkins) with only 6 keys that symbolized Braille. They also had a normal keyboard that had the Braille code over each key, but it is complicated to learn because of its many keys. Due to our research our intention was to design a system that respect the Braille symbols of the Perkins type writer and translated them to the common alphabet. We believe that this project will help many people especially the blind, with writing books, letters, articles, etc. So they can be integrated to activities and jobs reserved, until now, for people with the sight sense. My project also has 8 keys, when the person press a key combination the PC emits the sound of the letter. And when a word is completed the PC reproduce the whole word on the speaker. When the entire paragraph is completed there is an option to reproduce it. It has also other functions as erase everything, back space, etc. All these with the 8 keys. To control the system I used the parallel port of a PC, with a control program made in Visual Basic. Currently there are systems for the blind but are very expensive, they have a cost of approximately $900.00 US dollars, which is a high price to pay for some people. My project has a cost of $70.00 US dollars thus making it easy for a person who has a computer to be able to buy this keyboard. This project is being use in the “Blind Persons Training Center” of Tijuana city. They helped us to develop it, giving some ideas to improve it.

Development of a bio-monitoring system using behavioral pattern recognition of the medaka(Oryzias la

Water pollution is a severe problem for human beings. Sewage and hot water\r coming from homes and factories have changed the environment for aquatic\r animals. To manage a polluted environment, an accurately designed monitoring\r system is needed that will detect signs of toxic material or increase in temperature as\r fast as possible. A new and more accurate bio-monitoring system, which involves\r actual creatures, needs to be developed to save the aquatic environment from\r pollution.\r This experiment focused on discovering a new way to monitor aquatic\r creatures by observing the behavioral patterns of the medaka and observing how\r they changed when exposed to external stress, especially an increase in temperature\r or exposure to insecticide. The behavioral patterns of the medaka were observed and\r measured by a tracking program called the Movement Viewer. In the transition\r period, that is, when the temperature was raised from 25°C to 35°C, the total moving\r distance of the medaka suddenly increased compared to that in 25°C. When the\r medaka was in a temperature of 35°C, it slowly adapted to the new environment and\r the total moving distance showed a similar value to that in 25°C. For section\r dominance, the medaka showed a sudden increase in the dominance of the top part\r of the tank, meaning that the medaka tended to swim on the surface of the\r experimental aquarium. Again, it slowly adapted when the temperature had\r completely changed to 35°C.

Tuning the Hydrophobic Nature of CNT Arrays with Micro-Patterning

Trespasser:Farmer or Leopard?

Sisa-Friend or Foe?

It is beyond my logistical ability to determine the extent of the sisal problem in Namibia and as such I have investigated the following aspects, which should be of value to countries such as Tanzania and Kenya where there are still large plantations of the sisal plant. There is also a need to establish industries in Namibia and it is for these reasons that plant has been investigated.