全國中小學科展

二等獎

Quantitative Analysis of Organism Growth Using Fractal Dimension Statistics

Cultures of bacteria were analyzed using fractal geometry and statistics to provide a method for predicting organism growth, paving the way for a better design of treatment drugs. Images of three cultures of isolated Bacillus subtilis were taken at time intervals of two to three hours for eight days. The images were processed using the IDOLON program and quantitatively described using three statistical formulas: fractal dimension D, Renyi dimension and Hausdorff-Besicovitch dimension. The three variables were integrated to compute the maximum of the distribution and were used as coordinates for a 3-dimensional graph f. A 2-dimensional graph g containing the maximum of a distribution under time analysis was also constructed. Topological properties of the graphs, including slope, direction and area were used to determine the interrelationship of the three fractal values. The two graphs, described as φ - : X -? P1 where X is the smooth algebraic assimilation of the four variables under time analysis, was extended using Java. A computer-aided prediction model of the graphs f and g were made which combined the topology of f and g at infinity. The computed fractal values showed the existence of a fractal pattern in the growth of Bacillus subtilis with fractal dimension ranging from 0.900 to 4.000, indicating a linear iteration. This was supported by the values of the Renyi dimension, which showed a horizontal growth pattern of the bacterial cultures, establishing the growth of the bacteria to be inclined to go towards the North East direction. There was consistency in the computed fractal values, maximum of distribution and topographical computations of all three cultures which also indicated the existence of a pattern of growth which could be extended to tinfinity, thereby allowing prediction of the direction and rate of growth of the bacterial colonies. The fractal patterns in the growth of bacteria, in this case Bacillus subtilis, yielded the direction and rate of growth of the bacteria as shown by the analysis of the fractal patterns and statistical values, showing that the growth of harmful organisms can therefore be predicted, making it possible to improve on the design of drugs for the control of perilous cells. By preventing the growth of insidious cells, the potential effects of virulent organisms may be avoided, and treatment may be made more possible.

Investigation of phytoremediative ability of macrophytes and a design of a phytofiltration system for Singapore’s waterways

"Nitrates and phosphates cause eutrophication when present in high concentrations.\r This project aims to employ macrophytes to reduce such macronutrients in water bodies via growth and kinetic studies, which is a unique fusion of methodologies. It also involves a novel design and analysis of several enclosure prototypes to introduce macrophytes into waterways and their effects on the waterway’s ability to convey storm water rapidly away from flood-prone areas.\r Tropical macrophytes (emergent macrophytes Typha angustifolia and Cyperus haspan, submerged macrophytes Hydrilla verticillata and Cabomba aquatica, floating macrophytes Lemna minor) were grown in simulated wastewater with high nitrate and phosphate concentrations. Analysis of the growth and uptake kinetics of the macrophytes showed a correlation between high growth rate and high nitrates and phosphates uptake. C. aquatica had the highest uptake rate for nitrates and phosphates as well as the highest growth rate of 6.11 ± 1.2 % day-1 . The remaining macrophytes were proven to exhibit good phytoremediative properties, with emergent macrophytes C. haspan and T. angustifolia having great affinity (as indicated by a low Km value) for phosphate and nitrate respectively. An analysis of the phytoremediative abilities of each macrophyte was done to provide recommendations for growth in different aquatic areas.\r A total of eight nettings, made from different materials-linen and plastic, and pore sizes were used to design the enclosure prototypes. These enclosures possess a metal skeletal structure for greater stability. Results show that a combination of 2 different nettings provided the best trade-off between ensuring that the macrophytes were contained within the enclosures and minimising the enclosure’s impact on the flow velocity of the waterways. Enclosures could then be attached to existing infrastructure like the float booms as a platform for large scale phytoremediation locally."

台灣的黯化現象與形成因素探討

本研究在探討台灣的黯化現象與形成因素,黯化現象為太陽輻射量到達地表的減少現象。我們藉由比較西元1961~ 2008年間,台北、台中、台南、大武、蘭嶼、花蓮六個測站的各項氣象因子進行分析處理並探討其變化情形與成因。 \r 研究結果顯示,台灣地區的都市測站(台北、台中、台南)日照時數、日照率、全天空輻射量均呈現先下降後上升的趨勢,顯示1961至2000年間確實存在黯化現象,而在鄉村測站(大武、蘭嶼)則有微幅改變但較不顯著。並藉由可能影響黯化現象各氣象因子的比對,發現最高溫的增加幅度遠小於最低溫,可能表示黯化現象部分削弱了暖化現象。另外,溫度均較差也逐年縮小,亦可以當成黯化現象的一個顯著的指摽。在造成黯化現象成因中,污染物和雲量最為明顯。在有雲量的影響下,台灣地區汙染物濃度對黯化現象的影響程度,依序為硝酸鹽類>PM10>二氧化硫,此外少量污染物也會使雲量大幅增加,故兩者對黯化現象會產生交互影響。由雲量改變量對應日照時數改變量/雲量改變量的分析圖中,可看出都市地區年平均雲量改變量大於15%時,其雲量每減少10%,日照時數約減少3~22%;若年平均雲量改變量小於15%時,則對黯化現象不具統計意義。取每年十月中雲量在1以下的天數來分析各污染物對全天空輻射量影響,可發現雲量極低時,單位污染物濃度對黯化現象影響,SO2最大,NOx次之,PM10最小。

Synthesis and Characterization of Starch-Nanosized Calcium Phosphate Composites

Nano-sized calcium phosphate was used in the synthesis of starch-based composite plastics to provide a cheap but sturdier biodegradable alternative to petroleum derived plastics used in film packaging. Nano-sized calcium phosphates were produced from the precipitation reaction of calcium nitrate tetrahydrate (Ca(NO3)2 ‧ 4H2O) and phosphoric acid (H3PO4). The nanoparticles were co-extruded and molded with thermoplastic starch (TPS) at ratios of 0%, 1%, and 5% by mass. Tensile strength and elongation percentage of the resultant composite plastics were tested in three replicates. The results show that there is a significant difference between the tensile strengths of the 0% and 5% calcium phosphate composites at a 5% level of significance. The trend between the composite’s tensile strength and percentage calcium phosphate follows a geometric progression, enabling a projection for the 10% nano-calcium phosphate to have a tensile strength of 10 MPa, the average tensile strength for low-density polyethylene (LDPE). This shows that it is feasible to synthesize a 10% nano-calcium phosphate-TPS plastic that can be a viable substitute for LDPE plastics in film packaging, paving the way for the commercialization of starch-based plastics. The use of biodegradable plastics with improved physical characteristics will lessen consumer dependence on petroleum derived plastics and solve the environmental issues brought about by the use of such plastics.

極速火龍-利用軟片顯影法觀測氫爆的火焰傳遞

用塑膠軟管作為氫爆安全反應器,從封閉端點燃氫氧預混氣,管中火焰\r 傳遞快速,肉眼難以觀察,因此研製「氣爆顯影記錄器」來觀測,如下圖,\r 光纖導引偵測點的火光至暗箱,記錄於高速旋轉的軟片,從光電轉速計讀取\r 轉速,軟片沖洗後量測各顯影間距,可得火焰位置與時間的關係圖,量測時\r 間最小刻度可達2. 2 微秒。\r 解讀軟片的顯影,得知氫爆初期,火焰加速傳遞,大部分在25cm 位置\r 左右,火焰的速率出現急速飆升(爆燃轉變為爆震),而且火光亮度也急速升\r 高,有時火焰速率出現飆升過高,再回降趨於穩定?的現象,在50 cm 位置\r 左右,火焰進入等速傳遞階段,此階段有穩定的火焰模型,火焰頂端的亮度\r 最高,往後亮度遞減。

凸n 邊形等分面積線數量之分布探索

(一) 本研究首先導出ΔABC等分面積線移動所包絡出的曲線方程式,其圖形是由等分面積線段PQ(其中P、Q皆在ΔABC的周界上)的中點所構成,具有3 條曲線段(分別為3 條雙曲線之一部分)的封閉曲線,形成內文所謂的「包絡區」。利用包絡區的區隔,我們找出:1.當P 點在包絡區內,則有3 條等分面積線。2.當P 點在包絡區周界上,則有2 條等分面積線。3.當P 點曲線段的端點或在包絡區外,則有1 條等分面積線。(二) 以三角形的研究當基礎,擴展到凸n 邊形(不包含點對稱圖形),我們發現:等分面積線數量之分布,仍然與包絡區息息相關,且1.凸2m +1邊形最多有2m +1條等分面積線。2.凸2m邊形,必發生內文所謂的「換軌」。因此,最多只有2m ?1條等分面積線。3.包絡曲線所分割出的區域,於相同區域其等分面積線數量相同,且相鄰兩區域數量差兩條。(三) 若凸n邊形有k個「換軌點」,則此n邊形過定點等分面積線至多有n ? k 條。(四) 若凸n 邊形為點對稱圖形(如正偶數邊形、平行四邊形),則所有等分面積線皆過中心點。1) Our study got a curve equation of bisectors of a triangle. When a bisector is moving, we get three curves. They’re constructed by the midpoints of PQ. The three parts of the three curves make a closed curve which we called “the Envelope Area”. We found out:\r 1. When Point P is in the Envelope Area, we can get 3 bisectors. 2. When Point P is on the curves of the Envelope Area, we can get 2 bisectors. 3. When Point P is outside of the Envelope Area, we can get only 1 bisector. 2) Based on our study of triangles, we found that in Convex polygons(not including Point Symmetry Convex polygons), the distribution of bisectors is related to the Envelope Area. 1. We can get at most 2m +1 bisectors in a 2m +1 Convex polygon. 2. We can get at most 2m ?1 bisectors in a 2m Convex polygon, and the bisectors on the curves will “Change the Track”. 3. Envelope curve will divide a Convex polygon into several areas. The same area has the same numbers of bisectors, and the near areas have less or more 2 bisectors. 3) If a Convex polygon has k points to change the track, it will have at most n – k bisectors.\r 4) In a Point Symmetry Convex polygon (ex. Regular 2m convex polygons and parallelograms), all the bisectors will come through the center point.

以Hα、K-Line、UV、Soft X-ray波段太陽影像試求太陽光球層之上的徑向較差自轉.

本研究以網路上Soft X-ray、UV195Å、K-Line、Hα波段太陽影像上黑子,光斑經度位置的逐時變量,試求太陽自光球層以上各層是否有越高層轉速越慢的現象?經試用數種方法求大量黑子、光斑位置,最後以省時,且誤差減小的"由PhotoShop軟體讀出黑子、光斑在圖檔中位置,於EXCEL軟體中套用日面座標公式",以Peter Meadows的黑子定位程式抽樣對驗,來求其經緯度值。結果:在任何緯度,光球層以上各層轉速不同(徑向較差自轉現象),但並非越高層越慢,而是在大部分緯度處其各層速度變化呈 的快慢交替現象。

Development of an ECG-System using AndroidTM and Modified Bluebeatc Hardware

Electrocardiograms are important medical devices used to monitor the cardiac activity of patients over a period of time. Designed to provide convenient monitoring of patients, although most useful, ECG’s however are expensive and usually not portable, limiting its availability and therefore usefulness. Taking advantage of current technological developments, the researchers developed an ECG System with Androidâ„¢ smartphone based monitor, and Bluebeat© ECG Front circuit based electrodes. The system is divided into two, software and hardware interface. The developed software interface code used an Android based Java language which displays the converted ADC values in the LCD. Saving and user friendly features were also included in the smartphone. The hardware interface is composed of the ECG front and the Data Acquisition Module. The ECG front contains the filters and amplifiers that will receive the human cardiac signal. The DAT Module will then receive it with its Gizduino (Arduinoâ„¢ clone) microcontroller which converts the analog signals into ADC values, and finally sends it to the smartphone using Bluetooth© wireless communication. The first phase of data gathering used signal generator and indicates the system’s accuracy and speed. The second phase testing of the study meanwhile utilizes the ECG front to get actual cardiac signals from human. This phase has already been done, though it still needs more polishing and further trials. For the final testing, nine patients of varying ages and cardiac health status will be taken with ECG readings, three replicates from the developed ECG system, and one from an actual ECG device. Using cardiologists’ and patients’ feedback, the user friendliness and accuracy of the ECG-system will be confirmed, and further modifications shall be made. Lastly, the overall cost of producing the ECG system shall be compared to the price of an ECG device, to see if the developed system is indeed cheaper. However, it is ensured that the system is far more portable than its bulkier ancestors. Once the project is fully finished, the accuracy, replicability and usefulness of the system shall be confirmed using F-test.

Drawing versus Clay

1. Purpose of Research / Project The purpose of this research was to find out whether clay has any diagnostic value as a three-dimensional medium compare to drawing which is two dimensional medium and to determine if learners would prefer to work with clay or to rather draw a picture when depicting their ″feeling-stories″. Furthermore to do research on the effect that different coloured clay has on the emotions and behavior of learners during therapy. 2. Procedure A number of learners from different backgrounds, ages and cultures were used in this empirical research. They were asked to draw a ″feeling-story″ with a two-dimensional medium and then depict a ″feeling-story″ with different coloured clay which is a three-dimensional medium. Afterwards they had to describe their stories. They also had to choose what they liked best-the two-dimensional medium (drawing) or the three-dimensional medium (clay). 3. Data From the results it was clear that clay projections have diagnostic value. The learners were able to communicate their ″feeling-story″ better by using the three-dimensional figures in a verbal and non-verbal way. Through actions and the choice of coloured clay they used, they could portray and describe their emotions and symbolic messages. This indicated that they enjoyed the clay projections more than the drawings they made. 4. Conclusion From my research I found that clay as a three-dimensional medium has diagnostic value and can be applied as a supplementary projection medium. Different coloured clay can be associated with different emotions and behaviours in children. More learners preferred to work with clay (three-dimensional) as a medium in depicting their ″feeling-story″ rather than drawing two-dimensional pictures.

綠色能源-天然微生物燃料電池之開發

本研究開發以天然資材為原料之綠色微型微生物燃料電池。電池以碳紙為陰陽極,陽極槽以酵母菌對葡萄糖之厭氣氧化反應,陰極則塗佈有葉綠素鐵傳遞電子,以催化氧氣的還原反應,使電之進行,成功的以修飾中心金屬離子後的葉綠素取代傳統微生物燃料電池使用的金屬卟啉類化合物。實驗發現,陽極以每克酵母菌溶以1.5mL的葡萄糖液進行氧化,將葉綠素鐵0.1g塗佈於陰極,並加入純水,曝於自然光,即可有效增加微生物燃料電池電壓,電壓可達0.62 V,與典型的燃料電池在全額負載下可產生的 0.5 - 0.8 V 相當,顯示出所開發的微型微生物燃料電池是具有應用潛力。為了提升所開發電池的實用性,將微生物燃料電池微型化設計便於攜帶及未來直接結合植物光合作用之組合,同時發展不需使用具毒性之電子傳遞介質的陽極反應,使能連續從植物光合作用取得葡萄糖作為燃料的可行性。本研究所開發的微型微生物燃料電池構造簡單,所使用的酵母菌、葡萄糖、葉綠素及氧氣等資材皆可於自然界取得,符合永續經營與綠色能源的目的。未來結合直接採用植物光合作用產生之葡萄糖為燃料來發電,更可發展為就地使用完全無污染的綠色植物太陽能源。