全國中小學科展

一等獎

以奈米銦顆粒或鈉離子修飾竹子導電作為新型熱電材料之研究

熱電材料的條件為導熱差,電導率高的材料,此特性可將熱能轉換成電能,為一新興的再生能源。竹子生長快,為一導熱差的材質,但電導率低。本實驗將野生孟宗竹加工裁切,浸泡於飽和食鹽水加上奈米銦顆粒(73mg/ml)環境中,以高壓蒸氣(121℃、1.1 atm/cm2)處理40分鐘後測量處理前後其電阻變化、增加兩端溫度差及電壓改變的電流密度、增加溫度改變的電流,及熱導率等,並以複式顯微鏡觀察,確認奈米銦顆粒的確有進入竹子維管束內。實驗結果顯示,以飽和食鹽水及奈米銦顆粒高壓蒸氣法處理的竹片,相對於對照組,電導率上升了約1706倍,但熱擴散度只上升了約10%,熱電優值(Thermoelectric Figure of Merit) ZT為 0.059。本實驗方法有效提升竹子的電導率,證實竹子是一個有潛力的新興熱電材料。

金山神祕海岸浮石事件解密

浮石是一種多孔的火山碎屑岩,氣孔佔總體積很高的比例,因此能浮在水上。本研究針對臺灣新北市金山區神祕海岸所出露沉積層中的浮石進行探討,藉由閱讀文獻、實地考察、採樣、實驗分析等方式,來瞭解浮石的化學組成、礦物種類及可能形成機制與搬運途徑。依照化學成份分析及礦物種類比較結果顯示神祕海岸的浮石與日本、菲律賓的浮石較無關聯,最可能是來自台灣地區並由台灣北部大屯火山系或觀音山噴發所造成。至於其搬運方式,沉積物粒徑大小分析的結果顯示浮石是經由力量強大的海洋搬運作用攜至當地沉積。綜合上述,我們認為金山神祕海岸的浮石最有可能的生成方式為:1867年,由與大屯火山有相同岩漿系統的海底火山噴發出,接著此火山爆發所引發的海嘯將浮石帶至神祕海岸進行沉積。

Hay Aliens

The purpose of my project was to prove if the seeds of invasive plants are spread throughout the Peace region in hay harvested by local farmers. Invasive plants are so dangerous because they adapt to their environment fast and some of them can cause harm to both animals and humans. Within a year they can completely wipe the ecosystem out of native plants. Many invasive plants are either poisonous or can affect the systems of the animals body’s. I collected 22 hay samples from local farms around the North Peace region. I conducted a survey to help collect information about the samples. A pretest was conducted to determine which of two homemade sifters (one with three layers of decreasing size wire mesh, and one with 6 layers of materials with larger size holes) was the best for sifting through hay. I was able to determine that the larger sifter was easier for sifting hay. I sifted through all 22 samples with the larger sifter. I individually looked through each layer and removed what I believed to be seeds. Each seed was individually bagged, labeled, and photographed through a microscope. After each seed was photographed they were planted to help identify the seeds. I contacted a seed specialist. I was able to send him the images of my seeds. He helped me to identify my findings. I removed a total of 5568 potential seeds in my 22 samples. Out of all the potential seeds found 628 seeds were invasive. All invasive plants identified either cause pain to animals or they easily over take the native plants.

Reactivity of styrylmalonates as synthetic equivalents of Donor–acceptor cyclopropanes with aldehydes in the presence of BF3•Et2O

Donor–acceptor cyclopropanes (DACs), which can act as sources of 1,2- and 1,3-zwitterions in the presence of Lewis acids, are widely used in organic synthesis for the preparation of various carbo- and heterocyclic compounds, including natural compounds and their analogues. To date, many types of DACs reactivity have been identified. However, the chemistry of styrylmalonates (isomers of DACs, which can be easily generated from DACs) is almost undescribed and has a powerful synthetic potential. The use of styrylmalonates as synthetic equivalents of DACs allows us cardinally change the known reaction pathways of DACs. In this work, a new strategy for cascade assembly of substituted pyrenes based on the reactions of styrylmalonates with aldehydes in the presence of BF3•Et2O has been developed. Generation of formal 1,2-zwitterionic intermediates owing to complexation of dicarboxylate groups with BF3•Et2O is the driving force of the reaction discovered. This method makes it possible to assemble pyrenes or 5,6-dihydro-2H-pyran-2-ones in one synthetic stage from readily available starting compounds with high regio- and diastereoselectivity, and use these pyrenes in futher reactions. We’ve optimized conditions of the reaction and synthesized a number of various substituted pyrenes. Moreover, the reaction shows good results with various aromatic and heteroaromatic substituents. Pyrenes can be easily purified by crystallization. Every product was obtained selectively and determined by full set of physical-chemical methods, including X-ray analysis. 5,6-dihydro-2H-pyran-2-one skeleton is found in various natural compounds demonstrating a broad spectrum of biological activity, such as antiviral and antineoplastic.

利用福衛三號氣溫數據觀測北半球平流層急劇增溫現象

出於對溫度在人類的生活圈和地球各高度多樣的好奇,我們在本研究中,利用福衛三號的大氣溫度資料分析「北半球平流層急劇增溫現象(SSW)」這個特殊現象,發現:此現象明顯出現在冬末春初;高度方面,低空較不易觀察,而30公里以上高空受影響的程度較大;緯度方面,北緯40度以南的地區在SSW發生時降溫,幅度較小,而北緯40度以北升溫,幅度隨緯度增加而漸大。 同時,我們比較西元2006年~2010年的資料,試著探討海陸差異和週期性,雖然海陸沒有顯著成果,但我們發現SSW在西元2009年為近年來高峰,且有類似週期性的變化;另外,我們也近一步對南半球做延伸探討,希望得到更完整的資訊。 經由此研究,我們不但更了解SSW,也更確信福衛三號在未來極有可能成為新興的氣候變化觀測依據。

Experimental Study on Vibration Mitigation of Structure by Utilizing Paraboloidal Tank Tuned Liquid Damper (TLD)

本研究以自製模型模擬「結構物裝設拋物體液槽阻尼器(TLD)」。此TLD以多個拋物面容器組成,實驗評估其容器曲率、盛水深、盛水質量比(水質量/總質量)及結構物振幅等參數對減振效應的影響。在不同曲率容器內調整盛水深,使「水體自然擺盪頻率」接近「結構物振動頻率」;水體強烈擺盪時易觀察到水面碎波現象,衍生側向擾動,使水體旋轉,此時「旋轉頻率」亦幾乎等於「結構物振動頻率」,產生更大之共振效應,因此水體可提供較大反向作用力,增加減振效果。結構物振幅越大,水體旋轉可能性越高,減振效應越顯著;增加盛水質量比亦減振效果較佳。但水體旋轉時,結構物亦產生側向位移,因此於容器底部加裝潛沒式導流板,可有效控制液體旋轉方向,使其成對異向旋轉,減低結構物側向位移量。實驗證實藉調整拋物面容器之TLD的上述參數,可有效達到減振效果。

Antimicrobial and Heavy Metal Sequestration Capacities of Graphene Polymer Nanofilms

Membrane bioreactors (MBR) are important components in the production of effluent in wastewater treatment systems. However, MBR are susceptible to biofouling, a process by which bacteria colonize the surface of the membrane in contact with water. Graphene could be a solution to biofilm formation. In this study, the graphene polymer nanocomposite’s antimicrobial and heavy metal removal properties and the mechanisms behind the properties were investigated. Five different films of nanocomposites with a form of graphene and a polymer were synthesized: Graphene, Graphene Oxide, PVK-GO, PVK-G, PVK. A Büchner funnel and a vacuum pump were used to coat membrane filters with solutions of each nanomaterial. Using the Büchner funnel, E. coli and B. subtilis bacteria were filtered through the filter and both the filtrate and the filter were examined for bacterial content. Similarly, a Pb2+ solution was filtered through the coated filters and percentage removal of the ion was calculated using Atomic Absorbtion Spectrometry. Further analysis from SEM data, ATR-IR, and an Oxidative Stress test revealed that the PVK-GO nanocomposite inactivates bacteria by causing oxidative stress and the carboxyl group binds to lead ions. PVK-GO was most effective at removing the highest percentage of heavy metal and inactivated the most bacteria and displayed the most antimicrobial properties. PVK-GO coatings provide an efficient and economical alternative to the current wastewater industry standard and can save millions of dollars and reduce environmental waste. Also, the coatings have applications in indwelling medical devices and can reduce the risks associated with biofilm formational and bacterial infections.

Development of Biomimetic Skins

The objective of the project is to develop a novel biomimetic membrane and/or a scaffold for the said membrane. The approach of the project is to use animal skin from the domesticated pig or fish as a scaffold material for the adherence and growth of human skin fibroblasts to create a biomimetic membrane that can be used in medical applications as an alternative to today’s gold standards of Xenograft, Allograft and Autograft procedures. The biomimetic skin membrane can be used to treat victims of burns or scarring with a natural material that would be eliminated via natural bodily functions while eliminating the side effects and drawbacks such as scarring, secondary infections and tissue damage resulting from the current gold standard graft procedures on donor sites. Pig and fish skins were treated with ethanol and dehydrated followed by perfusion with Phosphate buffer solution and Cell culture media. Human skin fibroblasts (NF3 cells) were seeded on the animal skin scaffold. The human skin fibroblasts were then observed to determine their morphology and membrane formation properties. It was observed that the human skin fibroblasts were able to adhere to the non-human skin scaffolding and proliferate. More research is needed to determine their viability as a biomimetic membrane.

Development of a compact, self-stabilizing handheld camera mount

My purpose of the Research was build a small, compact device for the GoPro, which minimizes shocks that are typically caused by running and makes the video stable. The device must fit into a backpack and must be designed for the GoPro. This scenario raised two central questions for me: Which laws of physics are used for the stabilization of the camera? How can those laws of physics constructively be transformed into a working device? I have built four prototypes. To know which prototype was the best, I compared them and gained data into diagrams. The result with the last prototype was very impressive and encouraging, whether your are walking, running or skiing, the videos were no longer shaky. My final prototype consisted of a hollow tube which extended vertically. My conclusions: First the handheld camera mount mustn't be too light, as the inertia of the device is too low. Second it mustn't be too heavy, because you normally have to hold it over a certain time interval. Inertia as well as lever principal were essential to produce a smooth video. The most difficult part to build was the fully gimbaled suspension because it requires as little friction as possible and it must be precise and solid.

Neolema ogloblini- An agent in the biological control of Tradescantia

Tradescantia (Tradescantia fluminensis) is the worst weed in New Zealand. By smothering and shading out seedlings, Tradescantia prevents forest regeneration. Current control methods are ineffective and simultaneously cause harm to native forest. In 2011 Neolema ogloblini, a Brazilian beetle was introduced into New Zealand as a biological control for Tradescantia. To be successful in New Zealand, a country with different environmental factors, the beetles’ ranges of preference (temperature and light intensity) had to be investigated. A gender specific trait also identified, to enable desired sex ratios within founding populations to be selected. [18] This would ensure that the beetles are not released in areas of physiological stress, and can be optimised to have the greatest impact on Tradscantia. To establish how the intensity of light affects the distribution and amount of Tradescantia eaten by N.ogloblini a choice chamber investigation was conducted. Different layers of shade cloth provided a range of light intensities 150-3450Lux (likely to be found under forest canopy where Tradescantia is problematic). Thirty beetles of a range of sizes and approximately same maturity were randomly distributed through the chambers. Each chamber contained a shoot of Tradescantia with 5 leaves. After a 24hour period the number of beetles in each chamber were counted and the amount of surface area of the leaves eaten measured. The effect of temperature on the amount of leaf surface area eaten was investigated by selecting 90 beetles of a range of sizes and withholding food for 24hours. Five beetles were placed in each of three containers containing two leaves. Each trial container was precooled/warmed to the test temperature before the beetles were added. Leaves of a similar size, shape, mass and maturity were used. All leaves were genetically identical and collected from the same location. Sets of three containers were held in the dark at the following temperatures for 24hours: 9°C, 15°C, 20°C, 25°C, 30°C and 35°C. The surface area of leaf eaten at each temperature (mm2) was calculated. Lastly, microscopic dissections were conducted, using 32 beetles ranging in size, to establish if length (measured from the top of the head to the base of the abdomen) could be used as a phenotypic marker to identify beetle gender. While only a very weak positive relationship between increasing light intensity and the number of beetles was found a significantly higher area of leaf was eaten at a light intensity of 3450Lux compared to 150Lux. The amount of leaf area eaten is significantly reduced at temperatures of 15˚C and below, and significantly increased at 35˚C. There is no significant difference in the amount of leaf area eaten when comparing temperatures between 20-30˚C. Females have on average a larger body length (median=4.92mm) than the males (median=4.215mm). Therefore, sites with warmer temperatures in dappled light conditions (3450Lux) should be prioritised for the release of N.ogloblini, as this is the location in New Zealand at which their use as a biological control will be optimised. Beetle length can be confidently used to select desired gender ratios.