全國中小學科展

2017年

How to spill your coffee

We all do it – walk along with a cup in hand, and carelessly spill it. While it’s usually more annoying than anything else, it happens to affect almost all of us, and little is done to minimise the likelihood of it occurring. So my aim was to explain the physics behind why we spill drinks when we walk, and to investigate how we can minimise the likelihood of this occurring. I broke this investigation into two distinct parts, explaining the system of the cup, and explaining the effect of walking. From initial observations, it was clear that the cup was a resonating system. Like any resonating system, the cup has a natural frequency. When the cup is oscillated – moved back and forth – at near this frequency, the size of the liquid oscillations is very large. This is because the acceleration is in phase with the motion of the liquid, so in each cycle maximum energy is input into the system. In my investigation I experimentally measured this natural frequency, and created a mathematical model to explain this frequency. It was also found that as the size of liquid oscillations in the cup increases, so does distortion of the fluid surface, possibly enabling spilling. To systematically analyse the effect of walking, I had subjects walk on a treadmill, so walking surface and speed were controlled. However, I also needed an accurate way of measuring the motion of a carried cup. Firstly, I tried to use video analysis; however I found this far too imprecise for measuring small changes in velocity of a cup. In the end I used a smartphone to record the acceleration of a carried cup, as acceleration is what causes the movement of liquid in a cup. This allowed surprisingly accurate measurements to be made, and allowed both the size and frequency of the acceleration to be recorded. In order to relate the system of the cup and the oscillation provided whilst walking I conducted a qualitative experiment into the effect of stride frequency on the likelihood of spilling. When stride frequency was very close to the natural frequency of the cup, spilling occurred almost instantly, while it did not occur if stride frequency was much higher or lower. In the end, my research showed that to minimise the likelihood of spilling your drink walk slowly, use a narrow cup, focus on walking smoothly, and fill the cup well below the rim. Despite this, some people happen to be much smoother cup carriers than others, likely due to their individual biomechanics. And, if you really don’t want to spill your drink, you can always use a lid.

[3+3]-annelation of cyclic nitronates with enol diazoacetates

The purpose of this research is to prevent the desertification by using my original “agar sheets”. The dry regions, in other words, the desert has already occupied about forty percent of the surface of the earth (Figure 1). In addition, it is said that land of seven million hectares turn into desert every year. However, we can reproduce the green-bosomed earth by using appropriate means, because this desertification originated in excessive farming, excessive pasturing, and deforestation caused by human beings. I learned “Cape Erimo’s Green Construction Method”, which has succeeded in planting trees in the coast of Japan by using seaweed, and this method led me to use the agar to prevent the desertification, which is a familiar Japanese food made from seaweed. I think that it is possible to prevent the desertification of any conditioned lands by using my original “agar sheets.”

不同形態鈀金奈米觸媒的探討及對直接乙醇燃料電池的應用

本實驗成功在水相以及相對低溫中合成均一度高的鈀金奈米觸媒,並藉由引入不同比例的界面活性劑到合成系統中,來促使不同形態的鈀金奈米觸媒生成。此種奈米觸媒於不同成分比例下可產生相異之催化表現,且具長時間穩定的優點,故為具潛力的燃料電池觸媒。 實驗過程除了探討不同形態的鈀金奈米觸媒的合成外,並進行CO電氧化、乙醇電氧化以及長時間穩定測試。由合成的結果可得知,不同比例的CTAB及CTAC搭配可以得到合金或核殼結構的鈀金奈米觸媒;電催化實驗中,首先藉由CO吸脫附電氧化求得觸媒的活性表面積後,再進行乙醇電氧化測試,進而發現以核殼AuPd為1:1活性表現最佳,較商用Pd觸媒高約4.09倍;長時間穩定測試中AuPd核殼觸媒比商用Pd觸媒有有約16倍的穩定度及容忍力的提升。本研究結果有助進一步利用鈀金觸媒改善純鈀在進行乙醇燃料電池上的應用。

Stop the Spread of Desertification by Agar

The purpose of this research is to prevent the desertification by using my original “agar sheets”. The dry regions, in other words, the desert has already occupied about forty percent of the surface of the earth (Figure 1). In addition, it is said that land of seven million hectares turn into desert every year. However, we can reproduce the green-bosomed earth by using appropriate means, because this desertification originated in excessive farming, excessive pasturing, and deforestation caused by human beings. I learned “Cape Erimo’s Green Construction Method”, which has succeeded in planting trees in the coast of Japan by using seaweed, and this method led me to use the agar to prevent the desertification, which is a familiar Japanese food made from seaweed. I think that it is possible to prevent the desertification of any conditioned lands by using my original “agar sheets.”

阿拉伯芥茉莉酸結合酶FIN219參與生物韻律變化之研究

生物韻律與植物許多生長過程息息相關,其機制是生物學中重要的研究主題。FIN219能夠活化茉莉酸,進而引發植物對於逆境的防禦能力,也參與了藍光的訊息傳遞鏈,與植物的開花有關聯,其表現在長日照環境下也具有以24小時為週期的變化,因此很有可能參與了生物韻律的調控。本研究以GUS染色、西方墨點法與RT-PCR進行實驗,發現阿拉伯芥的FIN219基因與其蛋白質進入照光期後表現量會增加,進入黑暗期則會減少,此生物韻律也會受到外加JA與JA合成抑制劑DIECA的影響。再以RT-PCR比較生物韻律相關基因在野生種與剔除FIN219基因的突變株中的表現,也發現FIN219基因沒有表現時,相關基因TIC、TOC1、CAB2、CAB3、RBCS-1A和JAZ1表現的生物韻律會減弱。因此可知FIN219不但能夠增進植物的防禦能力,其引發的訊息傳遞也參與了生物韻律的調控機制。

水波虛擬干涉全像法與光聲成像

全像攝影運用光波干涉性質呈現物體影像。干涉是波基本性質因此嘗試改以水波當波源,經過全像攝影相同過程來呈現物體影像。 將訊號產生器產生訊號一分為二,一個接到振動器產生水波,用光感測器接收相當於全像攝影物體波,另一個訊號直接以電壓感測器測量作為一虛擬平面參考波,將兩數值相加模擬物體波與參考波干涉,得到一數位化水波全像片。然後以程式計算虛擬平面參考波通過水波全像片,全像片上各個點波源相互干涉結果,成功將影像重建出來。討論影響影像重建變因、鑑別率,將不同位置物體影像一層一層顯示達成斷層掃瞄效果。水波「虛擬干涉全像法」是我們自行發展出來,以關鍵字搜尋並沒有發現類似實驗。 最後將相同原理運用在「光聲成像」,將一調變頻率40KHz光照射在物體上,經光聲效應轉換成聲波,將聲波經由「虛擬干涉全像法」成功呈現物體影像。

利用混沌系統偵測植物覺知人體之反應

本研究證明用手觸摸植物或土壤時,會造成處於混沌狀態的蔡氏電路發生電位相圖的改變,經由微調並聯在模擬線路電源端的可變電容來比對相變過程,可以測量到非常微小的等效電容變化量。不同於傳統透過改變電阻來實現混沌行為的方法,證實本研究假設確實存在且具應用價值。 我們透過改變電極接點、電路初始狀態、人體靠近或觸摸不同部位等方式,探討兩種植物因微擾所產生的相變。結果發現微擾植物與其棲地時會產生「混沌制抑」的現象,整體系統的電容變動範圍界於0到100pF之間。更重要的是,本方法還可以偵測到微擾遠端植物時經根系及土壤同步產生的電容變化訊號,這是一般電容計所感測不到的。 利用混沌行為的特性,可以應用於偵測與分析生物體或宇宙間微弱且複雜的訊號,不需經由訊號轉換或放大等的處理程序,是本研究的重大發現,未來極具發展潛力。

北極震盪指數與北緯40度以北海溫距平值之相關係數探討

研究指出近年中高緯度天氣異常與北極震盪有關,本研究探討過去30年間北極震盪(AOI)、北大西洋震盪(NAOI)與南方震盪(SOI)特性及其間相關性,發現AOI與NAOI全年各月達中度相關以上,代表北極震盪暖相位時,西風有增強的趨勢,有利反聖嬰發展,說明海溫與北極震盪的連結。 分析2004至2013年北緯40度以北海溫資料,以月為單位各海域海溫距平值與AOI之相關係數,結合洋流圖進行區域互動之分析。發現當AOI正相位時,北大西洋暖流有增強的趨勢,與西風增強有關;海溫變化部份,6月、7月北緯85度以上北極海域低溫,應和夏季融冰或冷空氣封鎖極區有關,顯示高緯度海溫與北極震盪間的互動關係。

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.

A Novel Selection Process for the Conversion of Conventional Bacteria into Electrotrophs

The redox reactions of bacteria metabolism have been extrinsically studied. These mechanisms allow certain types of bacteria to be able to synthesize extremely valuable extracellular byproducts. Other types of bacteria are able to extract toxic metals from water by donating electrons directly to those aqueous metal ions, thus turning them into solid precipitates. However, the problem of these microorganisms is that their efficiency rates and production speeds are exceptionally low. This study focuses on the properties of electrotrophs, which are bacteria that can feed on pure electrons directly from an electrode (Rabaey et al 2010). Compared to normal organic-feeding bacteria, electrotrophs direct the majority of the electrons obtained to the production of metabolic byproducts (Nevin et al 2010). Therefore, when electrotrophs are employed in bioelectrochemical systems (BESs) their metabolic redox reaction efficiency rates are dramatically increased. This makes it possible to produce large quantities of valuable compounds such as hydrocarbons, plastics and medicine or efficiently remediating the environment (He et al 2016). Moreover, the usage of electricity as an energy source compared to conventional organic substrates is immensely cheaper (Rabaey et al 2010). However, not all bacteria are electrotrophs nor do all electrotrophs have favourable metabolic traits. Thus, there is a need for a novel procedure to turn conventional bacteria into electrotrophs which is a crucial step to making the BES an aggressive competitor in the sustainable energy industry.