香港

Water is very vital in our lives as we cannot live without it. However our world is now facing a serious problem. Owing to the increasing population, water resources are scarce. In recent years, we can see that droughts have been affecting millions of people around the globe. In the meantime, people in developed countries have been wasting huge amount of water for flushing the toilet. According to the US Environmental Protection Agency, 30% of household water goes toward flushing the toilet. Countries like China, US, Canada and UK are still using fresh water in flushing, consuming 190 million L of fresh water every day, not to mention the energy needed in pumping the water. In fact, it is not necessary to use so much water to flush away substances like tissue, hair, urine etc. The water we used is far more than we need. However, as we cannot control how much water is used when we flush, all water in the cistern is flushed away. Realizing the seriousness of water shortage and wastage in flushing, we tried to invent a device to conserve water by controlling the amount of flushing water used. Firstly, we study the principle of normal flushing system so as to understand why flushing cannot be controlled. Then, we tried to think of ways to control flushing. We have tried various methods and materials. After the 6-month testing and modification, we successfully invented Fast Fabulous Flush. It is a device which can be fit into existing cistern to conserve water. With our invention, users can control the amount of water flushed according to needs, so as not to waste unnecessary water. Our invention costs a low price which is no more than 2 US dollar. Also, it can be fit into existing cistern within 3 minutes with simple installation process. Most importantly, flushing water can be conserved effectively. It is estimated that around 200L of water can be saved per household every day.

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.

Transiency… something which only stays for a short time, and changes\r frequently. You’re probably wondering now what this has to do with our sports and\r we must admit that at first sight it really doesn’t seem to, but think of the world an\r how many changes sports have experienced. Is it not time we thought of how sports\r facilities could be improved? And what if you were told that there would be an\r “ever-changing” sports centre which you could use?\r You really might get the chance to use such a sports centre one day, and that’s\r what our idea is all about. A multipurpose sports center is what you could call it, but\r it’s not in the least like any one you’ve seen before. In places like Hong Kong, where\r space is everything, multipurpose sports centers are common, but they always have\r so many colored clines that tend to confuse both players on the court and spectators\r off the court. Just how often have you seen referees and players arguing about\r whether the ball is out or not? And how often have you found that you are not\r enjoying the game as much as you should? Yup, we’re sure it happens all the time,\r but you don’t have to worry anymore, as our innovative design will solve all your\r problems. Yes, its time for us to change…\r In our dream sports mat, we’ll have lines which can change and also detectors to\r tell you where the balls land. You’re probably thinking, “Lines which change?”, and\r yes that’s it! The perfect solution to all those confusing lines would be lines which\r could change their positions. And to do this, we’ve made use of some new technology\r called ‘E-INK’ which would make this possible. Of course it sounds like something\r which is really costly but in fact, this technology doesn’t cost that much and its really\r durable, so it’s really worth the money to start changing. Moreover, these mats can\r also be rolled up and stored somewhere else, so when you don’t need to use the sports\r ground you can just pack it up and the venue can be used for other purposes.

There are numerous problems caused by today's railway system. This makes Hong Kong a less attractive place to live in. We have to tackle these problems in order to make Hong Kong a better place. Our model can recycle the energy dissipated in the rail vibration, reuse the sound energy produced by the wheels and the rail by a sound energy conversion system, recycle the wind power in the tunnel by a new type of wind turbine, the Wind Power Generator Underground (WPGU), recycle the thermal energy produced by the air-conditioning system of railway stations by a new system, the Thermal Energy Conversion (TEC). When the rail is bent, the magnets attached to it are also pulled down. When the rail returns to its original position, the magnets attached to it are pulled out of the coils. In both cases, the magnets move against a force. The work done to move the magnets against the force is converted to electrical energy. Also, the bottom of the MTR is designed to be curved. The sound waves produced by the contact point of the wheels and the rail directing towards the bottom of the MTR would be reflected to an elastic material which has a number of magnets attached to it and corresponding number of solenoids are fixed on the ground below the magnets. Sound energy can be converted to electrical energy in this case. When a train approaches or passes through the section that the WPGU is installed, wind is generated. The wind forces the wind turbine to rotate at a certain high speed. The turbine transmits the rotation to the coils in the dynamo, and hence electricity is generated. Heat released from the air-conditioner is absorbed by water. The hot water is then pumped into the system. As the hot water in the pipe flows through the evaporator, liquid ammonia inside will evaporate and flow into the electricity generator. Inside the electricity generator, the gas will push the turbine to rotate and hence electricity is generated. The ammonia gas is then condensed in the condenser and flows back to the evaporator. Hence ammonia is used circularly. In order to explain our principle, we would like to introduce the Lenz's Law, an induced current flows in such a direction as to oppose the movement that started it, the Faraday's Law of electromagnetic induction, the induced electromotive force in a circuit is equal to the rate of change of magnetic flux through that circuit, the Law of Conservation of Energy, energy can neither be created nor destroyed, but can transform from one form to the other.

Nowadays, many people are suffering from eye defects and thus eye-glasses play a vital role in their life. On a sunny day, bright light enters our eyes without any adjustment of light intensity, causing discomfort and harm to our eyes. Therefore, sunglasses are right here to satisfy our needs. However, it is very inconvenient for some people who suffer from eye sight problems to bring two pairs of glasses and change them frequently. In order to solve this problem, our Esglasses are designed to combine both glasses together.\r To show the details of the physics theories behind our displays, we would like to illustrate the various components of a liquid crystal as well as the whole structure briefly. The liquid crystal we use is made up of molecules that have no positional order but tend to point in the same direction.

Data and records show accidents caused by loose bolts or nuts often occur in building or mechanical structures all over the world. They may be train derailments, parts falling off amusement rides, escalator breakdowns or wheels coming off automobiles. These incidents can often cause serious casualties and should not be ignored. At present, the only devices used to prevent screws loose are spring washer and nylon locking nuts, but they are not readily detectable with the naked eye when they failed to tighten. Based on simple mechanics and spring principled, our “Smart Washer” has been designed to detect loosen screws. Whenever the bolt or nut gets even slightly loose, the lower part of the washer will spring up, this is a sign to alert and remind the user to carry out maintenance and re-tighten the loosen screw before serious accidents occur.

The research is based on the production of biodegradable plastic-like material by only using household materials. Also, it can be made at home and it causes no harm to the environment. The biodegradable plastic-like materials made by different ratio of amylose, amylopectin, glycerol and water has different use. The finished product has smooth surface, highly transparency and well flexibility. Also, it can support strong load and be able to be deformed under stress. Ratios of components are tested on: 1. Easy to injection mold 2. Flexibility 3. Tensile strength and ductility & 4. Water resistance. It is found that the ratio of tapioca starch: glycerol: water = 1.5: 0.5: 9 can withstand 13N of force and 1.5: 0.93: 9 with high ductility. To improve water resistance, more amylopectin should be added to amylose. The best water resistance ratio is glutinous rice flour: tapioca starch: glycerol: water = 0.6:0.91:0.5:9 can withstand 16N force, while 0.6:0.91: 0.93:9 and 1.35:0.16: 0.5:9 with high ductility. All materials are available in supermarkets. Higher ratio of tapioca starch can produce bookmark, with laminate effect. More tough, higher ratio of glutinous rice flour can make cups, spoons and dishes.

EXPERIMENT 1---The effect of NaCl and Glucose Concentration on the efficiency of the cell I. Introduction Experiment on different concentrations of standard glucose solution (ranged from 0.125 M to 1.000 M) and standard sodium chloride solution (ranged from 0.250 M to 4.000 M) were done. We investigated the full concentration effect, which included both concentration of glucose solution and sodium chloride solution on the fuel cell’s output voltage, current and power. II. Procedures 1. Add 25.0 cm3 of Glucose solution of the tested concentration to the beaker representing the anode, and add 25.0 cm3 of distilled water to the beaker representing the cathode. 2. Add 50.0 cm3 of 0.250 M NaCl (aq) to both beakers representatively. 3. Fold a piece of filter paper and soak in fully into NaCl (aq) at cathode. 4. Clean and place the silver wires into the beakers representatively, and connect the air pump to the cathode. 5. Connect the cell to two multi-meters, each acting as a voltmeter and an ammeter respectively 6. Take the readings of multi-meters after 30 seconds. 7. Repeat steps 1 to 6 twice for the second and third reading of the cell. 8. Take average value among three values as the final reading of the cell. 9. Repeat steps 1 to 8 by replacing the NaCl (aq) with concentrations of 0.000 M, 0.500 M, 1.000 M, 2.000 M and 4.000 M, and the standard glucose solution with concentrations of 0.000 M, 0.125 M, 0.250 M, 0.500 M, 0.750 M and 1.000 M. III. Result of Experiment 1 When glucose concentration is increased from 0.000 M to 0.250 M, the output power increases, it is found that power generated is maximized at glucose concentrations between 0.125 M and 0.250 M. However, with further increase in glucose concentration from 0.250 M to 1.000 M, the power generated decreases. This shows that high concentration of glucose inhibits the generation of electricity, while higher concentration of sodium chloride solution can increase the output. EXPERIMENT 2---The effect of temperature on the efficiency of the cell I. Introduction In this experiment, the second effect - temperature on the fuel cell’s output voltage, current and power was investigated. In order to get a significant result, the effect of temperature on these measures with fixed 0.250 M glucose solution and sodium chloride solution concentrations varied from 0.500 M to 4.000 M had been investigated. II. Procedures 1. Add 25.0 cm3 of Glucose solution of the tested concentration (0.25 M) to the beaker representing the anode, and add 25.0 cm3 of distilled water to the beaker representing the cathode. 2. Add 50.0 cm3 of 0.500 M NaCl (aq) to both beakers representatively. 3. Fold a piece of filter paper and soak in fully into NaCl (aq) at cathode. 4. Clean and place the silver wires into the beakers respectively, and connect the air pump to the cathode. 5. Connect the cell to two multi-meters, each acting as a voltmeter and an ammeter respectively 6. Take the readings of multi-meters after 30 seconds. 7. Repeat steps 1 to 6 twice for the second and third reading of the cell. 8. Take average value among three values as the final reading of the cell. 9. Repeat steps 1 to 8 by varying the temperature from 42℃ to 32℃. 10. Repeat steps 1 to 9 by replacing the NaCl solution of 0.000 M, 1.000 M, 2.000 M, and 4.000 M respectively. III. Result of Experiment 2 The results showed a consistent trend and relationship of the effect of temperature on the output current, voltage and power of the fuel cell for 4 different concentrations of sodium chloride solution with fixed 0.25 M glucose solution. Generally, the results showed that the output power increases with temperature. EXPERIMENT 3---The effect of dialysis tubing and Nafion 117 on the efficiency of the cell I. Introduction Semi-permeable membrane separating glucose and oxygen, ensure the glucose oxidation only occurs at the anode, and preventing glucose oxidation occurs at the cathode, responds to maximize power output. Experimental study on two kinds of membranes, dialysis membranes and Nafion 117 films were done, by studying their fuel cell output voltage, current and power effects. Previous experiments showed that the optimal output of the battery is at 0.250 M glucose solution, Therefore, experimental conditions for glucose concentration is fixed on 0.250 M and sodium chloride solution concentration varies from 0.500 to 4.000 M. II. Procedures The Effect of Dialysis Tubing on voltage and current of the fuel cell 1. Pour 50 cm3 1.000 M NaCl (aq) to each compartment of the beaker separated by dialysis tubing. 2. Pour 0.250 M Glucose Solution into the compartment representing anode. 3. Connect the cell to two multimeters, which act as a voltmeter and ammeter respectively 4. Take the reading of the multimeters after 30 seconds 5. Repeat steps 1 to 4 twice for the second and third reading of the cell. 6. Take average value among three values as the final reading of the cell. 7. Repeat steps 1 to 6 with NaCl (aq) with concentration of 0.000 M, 0.250 M, 0.500 M, 2.000 M and 4.000 M to obtain the remaining data. The Effect of Nafion 117 on voltage and current of the fuel cell 1. Add 50 cm3 1.000 M NaCl (aq) and 50 cm3 of 0.250 M of glucose solution to the beaker. 2. Add 1.000 M NaCl (aq) to the Nafion 117 membrane pouch, and silver plate was put inside to become the anode. 3. Connect the cell to two multimeters, which act as a voltmeter and ammeter respectively 4. Take the reading of the multimeters after 30 seconds 5. Repeat steps 1 to 4 twice for the second and third reading of the cell. 6. Take average value among three values as the final reading of the cell. 7. Repeat steps 1 to 6 with NaCl (aq) with concentration of 0.000 M, 0.250 M, 0.500 M, 2.000 M and 4.000 M to obtain the remaining data. III. Result of Experiment 3 The result had shown that when the solution does not contain glucose (i.e. Glucose concentration equals to 0.000 M), Nafion 117 Membrane Cells have similar power outputs compared to the dialysis tubing cells. However, in 0.250 M glucose solution, the output of Nafion 117 membrane cell is about 1 to 5 times more compared to that of dialysis tubing cell. According to the experiment results, it was found out that the power output was maximized when the concentration of glucose solution and NaCl (aq) are 0.250 M and 4.000 M respectively. Under this concentration, the out of Nafion 117 membrane cell was 1336.68 nW which was 5 times higher than that of dialysis tubing cell. Hence, adopting Nafion 117 as the selectively membrane can greatly enhance the output of cell. It is believed that the special structure of Nafion 117 has limited the movement of glucose molecules, and prevented their oxidation at cathode. This has enhanced the oxidation of glucose at anode, and thus increased the power output of the cell.

There is currently an interest in developing supercapacitors as the booming of smartphones and other mobile electric devices. Despite offering key performance advantages, many capacitors pose significant environmental hazards once disposed. They often contain fluorine, sulfur, toxic transition metal and cyanide groups, which are harmful if discarded by using conventional landfill or incineration methods. The objective of this project is to find an environmentally benign alternative for building various key components of supercapacitors structures. From the electrolyte, carbon substrate and materials corresponding for Faradic reaction, all the materials were devised from renewable biomass. In our research, two novel designs of betanin/sulfonated carbon supercapacitor and quinone/sulfonated carbon supercapacitor were invented. Betanin and quinone, extracted from beets and Sencha, was preloaded on the sulfonated carbon nanosphere as the composite. While sulfonated carbon nanosphere were fabricated by hydrothermal synthesis of renewable biomaterial, followed by surface functionalization - sulfonation for increasing the loading capacity of nanoparticle. Nanostructured morphology and surface functional groups were examined and confirmed by SEM and IR spectroscopy. Specific capacitance can be boosted up through optimizing the particle size, morphology and surface polarity of carbon substrate and the type of electrolyte. From the experimental result, it is believed that the nano-architecture, with active functional groups, of carbon nanosphere enables the efficient charge transport and electrode stability, allowing the composite with high capacitance (94–209 F g–1 at a current density ranging from 1 to 4 mA cm–2), high capacitance retention of over 90% after over 20,000 cycles respectively, and over a wide range of temperature. Superior electrochemical performance of both betanin/sulfonated and quinone/sulfonated carbon supercapacitor can be attributed to the large accessible surface area of the porous structure, low interfacial resistance and its structural stability. It shows that they have relatively higher tolerant towards heat and extreme pH mediums. The green electrochemical capacitor exhibits a promising capacitive performance of 209 F g–1 with high capacitance retention of over 90%, opening up new possibilities for the production of environmental friendly, cost efficient and lightweight energy storage system using renewable biomass as the basic building materials without harming the environment.

Commercially available bandages such as hydrocolloid are neither biodegradable nor anti-bacterial. Chitin is known to be the second most naturally available polysaccharide which could be transformed to chitosan which is known to be anti-bacterial (Hasan, 2018) (Chao, 2019) and haemostatic (Okamoto, 2003) (Hu, 2018). Chitosan can be further converted to hydrogel which is bio-degradable and has good water absorbance. Anti-bacterial crab bio-bandages and crab bio-dressings should be bio-degradable as it took 42 days and a month for complete bio-degradation respectively, so they should be better than commercial bandages such as Nexcare Hydrocolloid as the disposal of anti-bacterial crab bio-bandages with bio-dressings would no longer pose burden to landfilling or threat to our environment. Anti-bacterial crab bio-bandages with bio-dressings are anti-bacterial with degree of deacetylation of DD% (measured using FTIR Spectrum II) 82.6% (due to the presence of chitosan) even without the application of other anti-bacterial agents and hence can provide complete protection of wounds from skin and soft tissues infections and haemostatic (due to the presence of chitosan). After testing and certification based on IS997:2004 and BS EN 13726-1, they should meet many requirements specified. Anti-bacterial crab bio-bandages should be eligible for marketing. Some results were as follows: 1.4 Anti-bacterial effect of crab hydrogels and roasted crab hydrogels Pure chitosan, crab chitosan, crab hydrogels and roasted crab hydrogels showed significant anti-bacterial effect. NO oral bacterial colonies were present in drinking water with crab hydrogels. Thus crab hydrogels could serve as effective anti-bacterial wound dressings. 1.6 Basing on IS997:2004 standard, the load per unit of area of anti-bacterial bio-bandages was 342g/m2 which met the minimum requirement of 36g/m2, the anti-bacterial bio-bandages had stronger tension strength (>20N both in dry and wet conditions) than commercial hydrocolloid. (2.7N dry 2.8N wet) which was comparable with that required (50-67N) and pH of about 7 which met the pH range of 4.5-8. 1.7 The FSA Free-Swell Absorbency of synthetic blood of crab hydrogel bio-dressings was 1.86g per 5cm x 5cm dressing which was much higher than that of commercial hydrocolloid (0.299g per 5cm x 5cm dressing) based on BS EN 13726-1.