全國中小學科展

2013年

Smart Washer

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.

Expression of TRPV5 in Astrocytes: Implications for Ischemic Stroke

Elevation of intracellular calcium secondary to increased calcium influx along with increased gliosis are implicated in the pathogenesis of focal ischemic stroke. In astrocytes, which play a major role in maintaining homeostasis in brain ischemia, the identities of the ion channels responsible for increased calcium influx during ischemia is relatively unknown although several Ca2+-permeable transient receptor potential (TRP) channels have been identified to have contributing roles. The transient receptor potential vanilloid 5 (TRPV5) channel is a Ca2+-permeable cationic channel expressed primarily in kidney epithelial cells and at low levels in the brain, but the exact localization and role this channel plays in the brain has not been explored. To investigate the possible role TRPV5 plays in astrocytic calcium influx in ischemia, we examined the functional expression of TRPV5 in astrocytes subjected to hypoxia-ischemia in vitro and in rat models of ischemic stroke in vivo. We hypothesize that TRPV5 contributes to increased calcium influx in ischemia. By treating astrocytes with culture conditions without glucose and with low oxygen levels, we found that TRPV5 is upregulated with increasing durations of simulated hypoxia-ischemia in vitro. Similarly, rat models of ischemic stroke with middle cerebral artery occlusion also show TRPV5 upregulation in reactive astrocytes, suggesting a possible role of TRPV5 in reactive gliosis in vivo. Microfluorimetric intracellular calcium imaging using Fura-2 on primary cultured astrocytes show a voltage-independent increase in astrocytic calcium influx after hypoxia-ischemia in vitro that is selective for extracellular Ca2+ concentration and is reduced by inhibition of TRPV5 with ruthenium red. Electrophysiology measurements using the whole-cell patch clamp technique on primary cultured astrocytes reveal a non-selective cation current similar to that of TRPV5 that is inhibited by Mg2+, another inhibitor of TRPV5. Preliminary results on astrocyte cell viability during hypoxia-ischemia with TRPV5 inhibition by ruthenium red also suggest that inhibition of TRPV5 could enhance astrocyte survival and reactive gliosis in vitro, indicating a beneficial role in blocking non-selective Ca2+ entry via TRPV5 into astrocytes. Since TRPV5 is highly selective for Ca2+ and an important channel for Ca2+ absorption in various epithelial cells, TRPV5 upregulation may contribute significantly to elevated Ca2+ influx in astrocytes in hypoxia-ischemia. Also, Ca2+ influx has been demonstrated to play a crucial role in reactive gliosis, further suggesting that TRPV5 upregulation is involved in reactive gliosis. We propose that TRPV5 is involved in ischemia-induced calcium influx in astrocytes, and might participate in the pathogenesis of focal ischemic stroke.

「綠」野仙蹤-利用增強子陷阱分析斑馬魚基因序列與側線組織再生

基因陷阱(Gene trap)和增強子陷阱(enhancer trap)在近年來被廣泛應用於斑馬魚的研究上。 因此,本實驗利用實驗室現有的增強子陷阱,包含熱休克蛋白(Hsp-70)促進子和綠螢光蛋白基因(GFP)及兩端的Tol2重複序列,得到不同位置發亮的斑馬魚。其中,本實驗選用側線細胞之套細胞(mantle cell)和中間神經肥大細胞(Interneuromast cell)表現綠色螢光蛋白的斑馬魚(HG7L)進行研究,推測sortilin-related VPS10 domain containing receptor 3 (sorcs3)為部份的被取代基因。另外,將HG7L互相交配後,進行被取代基因對側線組織再生之功能的實驗,發現雙股皆被取代的斑馬魚的毛細胞(hair cell)再生較遲緩且排列凌亂,推測被取代基因對側線發育有影響。再者,藉由被標定的套細胞觀察側線組織的發育,並模仿前人的實驗方法,觀察得知側線的發育過程不只與套細胞更和中間神經肥大細胞有關。

Finding a Better Brain Booster

The purpose of my project was to determine which activity improved academic performance the most: 10 minutes of exercise, 10 minutes of Brain Gym (cross-lateral movements), or a combination of 5 minutes exercise and 5 minutes Brain Gym. This project was conducted to find which activity would be a better learning aid in grade 4 students. There were many steps to conducting this study. First, I located teachers and classes, willing to allow the testing and determined days and times to test. Next, I created consent forms to explain the project and had permission forms from the students and their parents signed. Then I prepared 15 math and reading tests at students’ grade level. There were two tests for 15 days- labeled Before Test and After Test. When I administered the tests for the classes doing the activities, I made sure the tests were given by the classroom teacher, which kept the students motivated. Tests were given every day for 5 days. The Before Test was given at 1:00 pm. Then at 1:30 pm students did 10 minutes of the planned activity for that week. Immediately after the activity, students were given the After Test. This was done every day and was repeated for Exercise, Brain Gym, and Combination week. The control class was designed to determine if doing the test for a second time in a day improved the student’s performance. The Before Test was given at 1:00 pm and then at 1:30 pm. When the Before Tests were completed, the students continued with their daily work for 10 minutes. Then at 1:40 pm students were given the After Test. This was repeated for Exercise, Brain Gym, and Combination week. Students were given 10 minutes to complete the scheduled activity that week; either Exercises, Brain Gym or a combination of the two. During the week of Exercise, Jumping jacks, Skipping, Stride jumps, Burpies, Twisties and Jogging on the spot were completed in the 10 minutes provided. During the Brain Gym week, there were 26 Brain Gym movements. The lists of movements were rotated each day; so all movements were performed. The test results of this study were intriguing. (Bar=Standard Deviation) I concluded that 10 minutes of exercise was the better brain booster. Exercise improved academic performance by 9.8%. Brain Gym improved academic performance by 0.2% and the combination activities increased test scores by an average of 3.2%. The control class test scores decreased on average by 1.0% indicating that writing the tests twice in a day, did not improve students’ test scores. Exercising for 10 minutes improved student’s math scores by 11.0% and reading scores by 6.9%. Brain Gym math test scores decreased by 1.4%, and increased in reading by 1.8%. In the combination of the two, the math test scores decreased by 1.0%, reading test scores increased by 7.4%. Overall, the most effective and reliable brain booster was 10 minutes of mild aerobic exercise alone.

Recycled PET bottles for vacuum packaging

Vacuum packaging is a packaging technique intended to extend the shelf life of food via the removal of air from an enclosed package prior to sealing. This process limits the growth of aerobic bacteria or fungi due to oxygen deprivation. In this work, we present a novel do-it-yourself vacuum packaging device using the exchange of water and air between two bottles to continuously generate a vacuum-suction effect. The sizes of bottle and vacuum bag were investigated for its impact on the vacuum generation in a plastic bag containing smoked fish sausages. Large commercial 3.1-litre PET bottle generated more vacuum than the smaller ones. An equilibrated vacuum pressure of a smaller plastic bag was lower than that of a larger size. With 3.1-litre PET bottles, the vacuum pressure for 3”x5”, 5”x8” and 6”x9” bags was equilibrated at 8, 10, 18 mmHg, respectively. Sausages packaged by our device last for 14 days when they were kept in -20oC refrigerator, which was comparable to those packed by the commercial vacuum packaging system for household use. This project demonstrates an application of simple science in a real life situation as well as a promotion of environmental protection idea as the electricity is not used in the vacuum generation process and the disposed plastic bottles can be reused.

一種新的圖形導覽介面

利用電腦瀏覽圖形式資訊的時候,常受到螢幕空間大小的限制,沒有辦法在顯示圖形整體結構的同時也顯示細節部分。超廣角鏡頭是一種短焦距、大視角的相機鏡頭,鏡頭成像的時候,會有中間部分放大而周邊部分縮小的情形,藉由這個特性,我們發展出了一種新的圖形導覽介面,在瀏覽圖形式資訊的時候,有個圓形區域,該區域可隨著使用者的意願而自由移動,而區域內的圖形是以模擬超廣角鏡頭成像的方式呈現,且能夠與圓形區域外的圖形做銜接,如此,在瀏覽圖形式資訊的時候,除能夠顯示整體的結構外,也可以不開啟新視窗及無遮蔽的方式,即時地將想要觀察的部分做局部放大以展現細節。

特殊型pell方程式之矩陣解研究

本研究接續去年的研究主題”驚奇的數”,邊長為平方數的三邊形數亦為四邊形數的問題。解決這個問題後,利用Pell方程式與矩陣計算來求哪些邊長的p邊形數亦同時為四邊形數。處理方法分為兩類:第一類可以使用矩陣計算來討論,已討論出附帶方程式部分的初始解情形,並嘗試改進矩陣計算的漏解問題以及對數據做詳細分析、歸納。目前已有兩種方法:1.放寬附帶方程式初始解的限制,也就是縮小遞迴式的係數;2.伸縮雙曲線為一套固定的方法,可以解出原矩陣計算所遺漏的解。第二類無法使用矩陣計算,利用因式分解的技巧處理,發現結果與切比雪夫多項式有著密切關係。

Self driving car

Autonomous car is a very new concept, being a car without any driver. Several concurrent software process data using Artificial Intelligence to recognize and propose a path which the car should follow. The goal of the project is that a driverless car can reduce the distance between the cars, lowering the degree of road loadings, reducing the number of traffic jams, avoid human errors, and allowing people with disabilities(even blind people) to travel using an autonomous car. Theoretically a car without driver in the future should be much safer, because human reaction speed is higher than 200 ms, and the computing power of the newest computers allows traffic calculations even to 10 ms. The necessary power is provided by three multi-core laptops that process with Artificial Intelligence in order to recognize traffic signs, traffic lanes , traffic car fingerprints, processing the data from a 3D radar, using particle filters to localize car in a GPS map, the management of database with traffic signs, magnetic sensors, acceleration sensors, a distributed software, a supervisory system and the software which drives the stepper motor to turn the steering wheel (acceleration and braking). Currently the software is able to recognize the traffic signs, register them in a database using Google Maps. The fields record the sign and direction of travel from that area. Each car participating in the traffic and using this software will register new signs detected and the will modify the degree of confidence of recognition for other users. Another software component is able to recognize the demarcation lines between lanes, with three cameras to calculate exactly or using probabilities where it is on the road, where the roadsides are and to propose a new direction even in the absence of traffic signs for the next seconds. Another part of the software is trying to use Artificial Intelligence to detect other car fingerprints from webcam images. The calculation was performed on 3 computers, requiring distributed processing. I developed a management information system based on semaphores that allows data processing and supervision from 3 different computers. This project presents a hardware version of a LIDAR – a 3D radar and a software for creating a 3D environment in which the car navigates and using it the car will take decision to avoid obstacles. The LIRDAR contains a total of 16 avalanche photo-detector mounted on a stepper motor that spins at a frequency of 10 Hz. The information provided by my radar is about 576.000 pixels at resolution of 10 bits. The 3D radar helps the entire software system to increase the confidence of decision.

The gyroscopic effect of bicycle wheels

The aim was to determine whether there is an amount of gyroscopic force that keeps a bicycle wheel upright and stable. Two hypotheses were used, the first being as the mass of a wheel increases so does the force required to tilt the wheel by thirty degrees and the second that as the speed at which the wheel is spun increases so does the force required to tilt the wheel.

Fabrication and Characterization of Dye-Sensitized Solar Cells Using Bixa orellana Seeds and Basella alba Leaves

Dye-sensitized solar cells (DSSCs) have cheaper and easier means of fabrication compared to the currently used solar cells, which are mostly silicon-based, so DSSCs are developed for a prospect of solar energy accounting for a higher percentage in the world’s total energy production, which is currently 0.1%. However, compared to their inorganic counterparts, their efficiencies are low, and the search for a dye that will maximize the potential of DSSCs is still ongoing. The aim of this study is to be able to evaluate the absorption range in the solar spectrum of dyes extracted from Basella alba leaves and Bixin orellana seeds, and of dyes resulting from the mixture of both extracts, using UV-Vis Spectrophotometer, with the objective of increasing the absorption; to be able to fabricate functional DSSCs from the individual and mixed dyes; and to be able to evaluate the different conversion efficiencies of the DSSCs of the individual and mixed dyes using Linear Sweep Voltammetry, with the aim of increasing the conversion efficiency due to a wider absorption range. B. alba leaves and B. orellana seeds were extracted using soxhlet extraction. The clean extracts were mixed in different proportions, and were characterized using UV-Vis Spectrophotometer. The two individual dyes together with two proportions of the mixed B. alba:B. orellana dyes, 1:1 and 2:1, were then incorporated into DSSCs. In the fabrication of DSSCs, twelve plates of Fluorine doped tin oxide were coated with titanium dioxide (TiO2) using spray pyrolysis. They were sintered and scraped, and were afterwards immersed in the four dyes for four days. Platinum plates were placed on top, and iodine-triiodide couple electrolyte was introduced via capillary action. The sealed DSSCs were subjected to Linear Sweep Voltammetry under dark and illuminated conditions, using a sun simulator. Results from the UV-Vis spectrophotometry showed that mixing the dyes had increased the absorption range of the individual dyes, although not superpositionally, and that the 2:1 mixed dye has the most potential. Being incorporated into DSSCs, the dyes, including the mixed ones, have successfully converted solar energy into electrical energy, as shown by the significance in conversion efficiencies under dark and illuminated conditions. However, despite the increase in the absorption range, neither of the mixed dyes have shown a higher conversion efficiency than the individual ones, which can be accounted for a possible weaker interaction between the two dyes and the TiO2, resulting to lower efficiencies. The study has been able to obtain and characterize dyes from B. orellana seeds and B. alba leaves and has been able to incorporate the dyes into DSSCs. With the wider absorption range of the mixed dyes, the study has been able to confirm the possibility of the dyes to maximize the potential of DSSCs, as shown by the successful conversion of solar energy into electrical energy of all fabricated DSSCs, including those of mixed dyes. If the possible problem with the dye-dye as well as the dye-TiO2 interactions could be solved, the possibility of much higher conversion efficiencies could be expected.