全國中小學科展

2007年

鄒之風聲-風笛

「風笛」是台灣原住民鄒族的信號用具及祈雨法器,由一條繩子綁一支竹片構成。轉動風笛時,竹片會繞繩子自轉並拍打空氣而發出聲音,並有上下飛舞的現象。風笛產生聲音的原因,為竹片拍打空氣而造成的渦流共振現象;又由於繩子扭力大小及方向改變,使風笛的音調忽高忽低、響度忽大忽小、且竹片會在兩個平面上公轉,而有週期性變化。施力使風笛公轉轉速加快時,竹片自轉速率也變快,使其音調愈高、響度愈大;而繩愈短、愈粗時,竹片的公轉週期將愈短。The wind whistler was once used by Tsou aborigines as a tool for message transfer. It is composed of a string and a bamboo flapper. When swung around, the flapper spins, beats the air, and makes sounds. Moreover, the flapper flies up and down during the revolution. The spinning flapper beats the air, causes the vortex resonance phenomenon, and thus produces sound. As the twist torque and direction change, there is periodical variation in the sound volume, sound pitch, and the movement of the flapper, which orbits up and down at two planes. If given force to speed up its revolution, the flapper,s spinning frequency also increases, which makes the sound pitch higher and the sound volume greater. Besides, when the string is shorter or thicker, the flapper,s revolution period will be shorter.

流體碰撞物體所產生的波形之研究及應用

當流體由圓管流下,在碰撞到物體後水流會產生類似駐波的形狀。為瞭解此現象的產生機制,及影響此現象的變因,我們改變流體的表面張力、流速及與碰撞物體間的距離,以探討各變因對波形所產生的影響,進而研究此現象的成因。由實驗結果發現波形會因流速加快、擋板距離增加、表面張力減少而有波長變短的趨勢,且可以用表面張力波的理論解釋。由理論推導的結果,可測量液體表面張力。由於圓球狀的外型使表面積增大,可增加液體之散熱的面積,因此可應用在水冷系統方面。A phenomenon similar to the standing wave, which occurs when a slow-velocity fluid jet collides with an obstacle, was observed. Because the free surface profile was observed to be stable, the phenomenon was not considered as standing wave. To understand the mechanism of this phenomenon and the factors that can affect the free surface profile, the surface tension of the fluid, jet velocity and the distance between the exit of the tube and the obstacle are varied to study their influences on the free surface profile. According to our experiment, the wave length is shortened when the jet velocity or the distance between the tube and the obstacle increases or when the surface tension decreases. The tendency of the investigated phenomenon can be explained by the capillary wave theory. Based on Bernoulli’s principle, continuity principle and surface tension\r equation, an ODE (ordinary differential equation) could be formulated. By using numerical method to solve this ODE, we predict the free surface profile which could match the experimental photo well. The tendency of the phenomenon can also be explained by the ODE. In order to measure the surface tension of the fluid, we wish to minimize the experiment apparatus. To enhance our assumption we use laser to locate the individual particle that we add in the fluid and calculate the velocity field of the flow jet.

新型空氣清淨燈具之研究與開發

本研究主要的目的是在開發同時具有空氣清淨與照明的兩種燈具。其中桌燈是基於自然對流原理,利用燈泡發熱讓氣流通過燈具上方的濾網達到過濾功能,為了尋求過濾效果與照度兼顧的最佳值,本研究並提出比較因子的概念。在吊燈方面,除了運用自然對流原理之外,還更進一步利用太陽能驅動風扇,進行強制對流,強化過濾的效果,使得本研究成果更趨於完善。 由實驗結果可得知,桌燈在四星期長期測試條件之下,其過濾效果增進率分別為39.1, 40.8與 40.1%。在吊燈四週長期實驗的結果方面,螺旋與 100W 鎢絲燈泡在自然對流的過濾效果增進率分別為49.1%與 51.4%,而100W鎢絲燈強制對流方面過濾效果增進率則為60.2%。由整個研究結果可以發現,本燈具對於空氣清淨有極佳的效果,在不增加額外耗能條件之下,能增加燈具的散熱效果與延長壽命,同時又具備空氣清淨效果,對環境空氣品質具有相當的貢獻。 The purpose of this study is to develop a novel lamp with both the functions of air-cleaning and lighting. One of it is the desk light. Basing on free convection principle, it makes the air run through the filter on the top of the lamp by its heat in order to attain the aim of air cleaning. To find the optimum value of both cleaning effect and illumination, we advanced the compare factor. The other is the droplight, though it is based on the same principle, we use the solar energy as its power to drive the fan. So that the effect of the filter can be augmented and the result of this research approach perfect. According to the experimental result, in the four-week experiment with desk light, the enhanced efficiency of filter is 39.1%, 40.8% and 40.1% respectively. On the way of droplight with four-week experiment, the enhanced efficiency of filter is 49.1% and 51.4% with helix and tungsten(100W) lamp under the condition of free convection; the enhanced efficiency of filter is 60.2% with tungsten(100W) lamp under forced convection. All these results of the research shows that the novel lamp has great performance on air cleaning and much better effect of heat sink without extra consuming of energy, also the lifespan of the lamp can be extended. Furthermore, it is capable of air cleaning and contributes to the quality of environmental air.

讓氣體無所遁形的微小黏度計

本實驗在微小的測試環境下,以熱線風速計偵測壓縮空氣流經圓柱鈍體後方渦旋逸放的頻率,推導出雷諾數(Re) 與史卓荷數(St) 之關係。預期能利用有效雷諾數的概念,探討加熱圓柱流場的Re-St 關係,將25℃、50℃、100℃、150℃、200℃時的臨界雷諾數回歸成有效臨界雷諾數,導出Re 之分母---空氣黏度,以後便能以此不同環境溫度所對應之空氣黏度方程式,於各式環境下量得空氣的黏度。但因為在實驗中碰到了量測精度的限制,所以這個部份只有做現象的探討,並由觀測渦流逸放頻率發現到加熱圓柱確實可有效地穩定流場。未來也將會提高量測的精度,以期望能達到辨識氣體的效果。;The purpose of this experiment is to measure the vortex-shedding frequency while the compressed air flow over a cylinder by hot-wire anemometer and all of the experiment is set up at the small testing environment. By this way, we can find out the relationship of Reynolds number and Strouhal number. We expect that research the relationship between Re and St while flow over a heated cylinder by using the concept of effective Reynolds number. We can get the effective Re by curving fitting the critical Re at 25℃、50℃、100℃、150℃、200℃each and derive out the viscosity of the air. After this, then we can measure the viscosity of the air everywhere after knowing the viscosity with respect to the specific temperature. We only discuss the phenomena at this part, because the limitation of the accuracy of the instrument. We also observe that a heated cylinder can stabilize the flow field effectively by the vortex-shedding frequency. We are going to enhance the accuracy of the instrument and fulfill the gas identification.

擺動知覺曉,觸角知多少!--光線與震動影響美洲蜚蠊觸角擺動模式之研究

During the biology classes from junior to senior high, we have learned many interesting instance of different animal behavior. Most people paid more attention on the Vertebrates as their experimental subjects. The other species around us, although with simple body structures, may behave rather complicated and versatile reactions. In particular, one of the most common insects with simple body structure in our neighborhood is the American cockroach (Periplaneta americana). The aim of this study is to investigate the different swing motion modes of antennae of American cockroach by computer-aided Imaging Analysis. The parameters of each swing motion mode were calculated in order to analyze how light (including light stimulation and light adaptation) and vibration may affect the antennae behavior of American cockroach. It was found that the antennae swing motion modes were significantly different under different types of stimulus. If two types of stimulus occurred at the same time, the reactions of antennae motion may become conformable. In conclusion, antennae behavior has shown to significantly affect the survivability and environmental adaptation of American cockroach. Not only the antennae are considered as the sensitive receivers; but also they are the important transmitters to reflect physiological status and environmental condition.從國中到高中的生物課堂上,我們學到許多有趣的動物行為例子,但前人多以脊椎動物作為研究對象,而我們身旁的許多生物,身體構造雖較為簡單,但行為表現卻豐富多樣,尤其是常見的美洲蟑螂(Periplaneta americana),可說是最親近我們的昆蟲之一。本研究以攝影紀錄的方式,透過電腦進行影像分析,記錄不同刺激下蟑螂的觸角擺動模式,並計算出各項觸角運動的參數,以瞭解光線(照光刺激或照光適應)與震動刺激對其觸角行為的影響。我們發現在不同因子的刺激下,觸角擺動的模式具有差異,若兩種刺激同時發生,蟑螂觸角的行為亦具有整合性的反應,證明蟑螂觸角的行為模式,對其生存與適應具有重要意義。這也代表觸角除了為敏感的受器,亦為能反映出生理與環境狀態的重要動器。

火災逃生指引系統

在台灣公共場合快速成長下,例如:大賣場、百貨公司、展覽會場,這些公共大型場合都有很好的消防設施,但始終有人葬身於火場? 原因就是幾乎所有的人都不會去特別注意逃生平面圖,導致花太多的時間尋找出口,這樣生存機率就大大降低。火場裡面有太多的致命因素,像是:高溫的空氣,毒氣、濃煙…等,所以必須把握每一分每一秒。為了加快逃生速度,我們將所有的通道都設有導引警示器,逃生者只要順著導引警示器就可以安全到達出口。為了因應公共場合有龐大的人群,所以逃生路線不能只有一條,因此我們設計上是有多條路線,一、可以解決龐大人群,二、可以加快速度。;With the rapid growth of public places in Taiwan, evacuation system is of more and more importance. Actually, public places, such as hyper malls, department stores and exhibitions, are not without fire-fighting equipment, but why is that there are still people getting killed in a fire? The reason is that almost no one actually pays attention to the evacuation plans. As a result, it often takes too much time to find the exits, which lowers the possibility of survival. In a fire, there are usually too many fatal factors, which could lead to death, such as high temperature and heavy smoke; therefore time is precious when escaping from a fire. To fasten the speed of evacuation, we set guiding alarms in every passageway. By following the guiding alarms, people can get to the exits safely. Besides, owing to the huge amount of population in public places, there can’t be only one route out. With regard to this, we design many routes in order to enable and fasten the speed of evacuation of huge amount of population.

短暫高鹽刺激提升番茄果實品質

本研究透過對蕃茄施予短時間的不同高鹽份濃度刺激,觀察植株成長 情形並對果實進行品質測定,本研究對於品質之定義著重於總抗氧化能力、糖度及硬度的檢測。由實驗結果得知Na+、Cl-離子所造成的滲透壓差,確實有助於可溶性固形物及Na+、Cl-離子的累積,對於果實糖度及硬度上皆有顯著變化。但對於如何造成總抗氧化能力值的提升,在未來的研究中會再深入探討。We observe the germination of the tomatoes and assay "the quality" of the fruits in our research by giving plants short-range acridness of different high salinity. In this research, the definition of “quality” emphasizes the anti-oxidized ability, the brix, and the hardness. By the experimental result knew Na+ and Cl- ion creates the osmotic pressure, truly is helpful to the Soluble Solid Content and the Na+ and Cl- ion accumulation. Yet regarding by what the anti-oxidized ability promotes, we will treat in-depth in our intended research.

Low Cost Housing and Sanitation based on Hygiene

I live in the harbor town of Walvis Bay in the heart of Namib Desert which\r is surrounded by sea and dunes and both are famous in the world. Walvis\r Bay is situated in Namibia formally known as South West Africa.\r Walvis Bay is a fishing industry town with an international harbor\r The population of Walvis Bay is about 54000 people and growing daily.\r Our fish is daily exported to many European and some of Asian countries.\r Industry in Walvis Bay is contributing nearly 50% to the Namibian economy.\r The town has also been declared as an EPZ (Economic Production Zone). Its\r harbor serves as a corridor to the neighboring land locked countries.\r Walvis Bay offers more job possibilities than most other Namibian towns.\r Every year many jobless people, even foreigners, stream to this town to\r seek employment as laborers or as specialists in the various industries.\r These people are in need of accommodation and often have to make due\r with any sort of shelter in Walvis Bay.

A New 3-Dimensional Model for the Periodic Table of Codons

a. Purpose of research- Since the discovery of genetic codes and the dogma of 64 codons coding for 21 amino acids, scientists worldwide have been interested to know the reason(s) behind this unique number ratio (64:21). This ratio indicates certain form of inefficiency in the replication of amino acids. Such inefficiency can be explained through symmetries in the condons coding for the same amino acids. In the light of that, my project looks for patterns in the properties of amino acids and symmetries in the codons combinations. Using these analysis findings, I invented a three dimensional periodic table for the codons and amino acids that has a points to layers ratio of 64:21. b. Procedures- To get started with the project, I searched for relevant information in books and the Internet. After locating the relevant materials, I began my analysis by looking for non-random patterns in the correlation between codons and the respective amino acids they code for. At the same time, I try to look for symmetries in the codon distributions and suggest new and innovative models for a periodic table of codon combinations. I have come out with mainly a new model, with its own unique ideas and concepts behind it. Finally, I will try to match a property of the amino acids to the positions of the codons such that the table shows a gradual change in property of the amino acids, together with the symmetries. This will effectively explain the unique codons to amino acids ratio and lead to discovery of possible amino acids. c. Data- This research is primarily conducted based on the conventional 2D periodic table and no experimental data is collected. After much analysis, I have come up with the 3-sided triangular pyramid model. This model is inspired by the ratio of 64 codons coding for 21 amino acids, which can be easily approximated to 3:1. It is made up of a triangular pyramid that is three-faced, with the bottom side unutilized. As a triangular structure, each layer has dimensions in the multiples of 3. Layer 1 consists of 1 point, layer 2 with 3 points, layer 3 with 6 points and so on… until layer 7 with 18 points, having a total of 64 points. This 64 points to 21 layers ratio is consistent with the codons to amino acids ratio! d. Conclusions- The unique 64:21 ratio suggest certain form of inefficiency in the replication of amino acids. This may be explained through symmetries in condons coding for the same amino acids. A general 3:1 ratio can be approximated and this suggests a high possibility for the existence of a three-sided symmetry in codon combinations. Thus, this idea of a three-sided symmetry gives rise to my 3-sided triangular pyramid model. This new model of a 3-dimensional periodic table for codon combinations would be useful in explaining such a unique 64:21 ratio and serves to provide a basis for better understanding of the relationship between codons and amino acids. This new model may also lead to the discovery of currently unknown amino acids.

The Grapes of Math

This project determined which varietal of grapes grew best in the Lytton / Lillooet area. This project specifically measured growth rates, maturity levels, and breakage rates of the 18 grape varietals (9 red, 9 white) that grew on different slope positions. This experiment determined which varietal was best suited for the site specifically chosen in Lillooet and provided a ranking of the most desirable varietals for potential grape growers.