全國中小學科展

2023年

Utilization of Escherichia coli in Contiminated Water in the Citarum River as a Dual Chamber Baed On Microbial Fuel Cell (MFC) Substrat

Citarum River is the longest and largest river in West Java. The upstream of the Citarum River starts from Mount Wayang, Bandung Regency and ends at the mouth of the Java Sea which is located in Muara Gembong, Bekasi Regency. The Citarum River plays an important role as raw water for PDAM drinking water, supplies electricity in Java-Bali and provides water for rice field irrigation in West Java. Citarum watershed is dominated by the manufacturing industry sector such as chemicals, textiles, leather, paper, pharmaceuticals, metals, food and beverage products, and others. Based on data from the World Bank, every day, the Citarum River is polluted by approximately 20,000 tons of waste and 340,000 tons of waste water with the majority of the waste contributors coming from 2,000 textile industries. By looking at these events, there is no doubt that the sustainability of the ecosystem and the environment in the Citarum River is damaged and polluted. (Zahra Fani Robyanti; 2020). The West Java Regional Environmental Management Agency stated that the content of E. coli bacteria in the Citarum River had increased. The bacteria that cause diarrhea come from industrial and household waste. In addition to E. coli bacteria, other pollutants in the Citarum River that have increased are biological oxygen demand (BOD), chemical oxygen demand (COD) and Suspended Solids. One of the efforts that can be done regarding E. coli bacteria that pollute the Citarum river is to make it as a substrate for Microbial Fuel Cell (MFC). Bacteria present in organic media convert organic matter into electrical energy. The nature of bacteria that can degrade organic media (enrichment media) in MFC produces electron and proton ions. It is these ions that produce an electric potential difference so that energy can be generated. Generally in conventional systems, MFC consists of two chambers consisting of anode and cathode chambers. The two spaces are separated by a membrane where proton exchange occurs. This system has not fully worked with bacteria because only the anode side contains bacteria, while on the cathode side it still works using chemical compounds such as Polyaluminum Chloride (PAC). However, recently MFC has been developed using bacteria at the cathode, or better known as biocathode. Bacteria in the cathode space have the same function as electron mediators that were previously carried out by chemical compounds. In many studies on MFCs, acetate is commonly used as a substrate for bacteria to generate electricity. These chemical compounds are easier for bacteria to process than wastewater. Acetate is a simple chemical compound that serves as a carbon source for bacteria. Another advantage of acetate is that this compound does not cause other reactions to bacteria such as fermentation and methanogenesis at room temperature. Based on this thought, the author will design a study entitled Utilization of Escherichia coli Bacteria in Contaminated Water in the Citarum River as a Dual Chamber Based Microbial Fuel Cell (MFC) Substrate.

Silver Moringa Cloth: Silver Nanoparticle Fabric Based on Moringa Extract (Moringa oleifera) as Antibacterial Against Methicilin Resistant Staphylococcus aureus

Staphylococcus aureus is addressed as one of the most common pathogens in hospital settings and in the community. This pathogen causes invasive infections, sepsis, and death. The emergence of antibiotic-resistant bacteria is due to bacterial mutations and the use of antibiotic drugs that are not by procedures. Resistance makes MRSA infections difficult to treat, resulting in high healthcare costs. These problems lead to an urgent need to find alternative drugs to control MRSA infection. Therefore, developing new drugs and procedures such as antibacterial nanoparticles, are particularly promising. Indonesia has many medicinal plants with antibiotic activity, including Moringa oleifera. Moringa oleifera contains several active compounds such as alkaloids, flavonoids, and saponins which are known to have antibiotic activity. Silver nanoparticles or AgNPs are currently used as antimicrobial agents because they are toxic to prokaryotic cells (bacteria) but relatively safe for eukaryotic cells. AgNP synthesis mediated by M. oleifera extract has the advantages of being non-toxic, pollution-free, and environmentally friendly. Sisal is a potential source of naturally derived fabric and a prospective source of multifunctional textiles. Recent studies have utilized and functionalized sisal to develop composite materials. However, functionalizing of sisal using nanosilver-based materials has not been studied yet. Bioactive chemicals from plant-extracted nanoparticles also provide additional antimicrobial properties. This study aims to produce AgNPs mediated by M. oleifera leaf extract and to analyze its antimicrobial effect on MRSA growth. The powdered Moringa (4g) was boiled with 100 ml of distilled water (550 C) for 15 minutes. The mixture was filtered through Whatman No 1 filter paper and store refrigerated. The nanoparticle was synthesized by rinsing sisal fabric cloth to several concentrations of AgNO3 (1mM, 10mM, and 20mM) with Moringa extract. Nanoparticle synthesis from AgNO3 done with the help of Moringa oleifera extract. The resulting AgNPs have MIC values (Minimum Inhibitory Concentration) and MBC (Minimum Bacteriocidal Concentration) of 1.25 mg/ml. The resulting silver nanoparticles showed antibiotic activity against MRSA with an average inhibition zone diameter of 15.677 mm. XRD and SEM studies are going to be held to support the data.

冰棒棍骨牌模型建立與運動分析

本研究主要研究冰棒棍骨牌在崩解時波峰的軌跡,並且逐步分析物理原理。首先,討論冰棒棍的基本性質,接著拍攝崩解時的影片,並分析產生眼鏡蛇波的原理,過程中發現了不同的排列順序會分別產生眼鏡蛇波或C波,以及當以眼鏡蛇波結尾時,波峰都會有一個旋轉的現象我們使用了Tracker程式來追蹤冰棒棍骨牌崩解時的波峰軌跡,且發現大部分冰棒棍軌跡都呈現相同的函數關係,並建立模型來研究其性質。 本研究已有初步的結果,我們計算出了冰棒棍的楊氏係數,並且做出了冰棒棍波形的擬合。另外也從不同觀察角度觀察出冰棒棍的運動情形,分析出單一冰棒棍的整體受力與運動情形。根據單一冰棒棍的轉動狀況,觀察出類似於進動現象,並對此深入討論。 未來我們希望能夠結合楊氏係數、冰棒棍波形疊合以及冰棒棍受力情形來建立專屬於冰棒棍波的物理模型,並研究其轉動互換模式。將其利用在工程學上。

氧化鎢摻雜銅原子於人工光合作用之應用

光觸媒被視為極具潛力解決二氧化碳過度排放的方式。二氧化碳因線性且高鍵結強度(~532 kJ/mol)的結構,當催化劑吸附二氧化碳分子並提供電子時,可降低二氧化碳最低未占分子軌域能階位置,有助於其進行氧化還原反應,轉化成再生能源。 本研究使用三氧化鎢(WO3)並摻雜不同濃度的銅原子作為主要光觸媒,期望銅能扮演施體(donor),提供額外的電子,幫助二氧化碳光催化反應。我們藉由穿隧式電子顯微鏡(TEM)觀察樣品結構,利用拉曼光譜儀、X光繞射分析儀器(XRD)、X光吸收光譜儀(XAS)確認摻雜形式; X射線光電子能譜儀(XPS)得知銅的實際摻雜濃度。以紫外光-可見光光譜儀(UV-Vis)測量吸收光譜,最後以氣相層析儀(GC)分析光催化結果。我們目前成功配置出摻雜五種不同濃度銅的氧化鎢,光催化結果可發現摻雜銅確實有助於二氧化碳的轉換。未來希望提高產物一致性,成為高效的再生能源,實際應用改善環境。

雙金屬觸媒(Binary alloy catalyst)在二氧化碳還原反應上的應用探討

二氧化碳在大氣濃度中不斷飆升,進而加劇溫室效應。該如何降低二氧化碳的汙染成為一個重要的議題,而其中將CO2RR有很好的發展,運用電化學將二氧化碳經過金屬觸媒進行還原反應,得到的產物可以做為燃料電池的燃料來源或化工原料…等許多應用,被視為將來很有潛力的環保科技。 然而以銅做為觸媒雖然可以獲得多樣的產物,卻缺乏選擇性,因此我們決定以銀作為輔助,製作雙金屬觸媒,進行改善。 本實驗合成核殼結構的銅銀奈米粒子,並以碳黑作為載體,來製作金屬觸媒,可以防止銅在反應過程中氧化,並同時保留兩種金屬的特性。我們開始思考還原溫度如何影響雙金屬觸媒的生成,進而影響產物的選擇性。我們計劃以油胺油酸法合成銅銀金屬觸媒,改變溫度條件,並嘗試不同的金屬比例,尋找提升效率的最佳反應條件。

「分」庭抗禮—礦石分配之研究

現在手中有許多礦石及k個袋子,我們認定「一套」礦石是將n個礦石分成k份的k堆礦石。每次取一套礦石,僅改變每堆礦石對應的袋子而不改變每堆的數量,將礦石放入對應的袋子中,這個操作稱為「放一套」。本研究先探討需放入的最少套數使得每個袋子中的礦石數一樣多,後段則討論可使礦石均分在袋子中的所有套數所形成之集合,亦結合部分圖論性質以完整證明。如果改變n,k及一套中的礦石分配方式,對於所需放入的套數有何影響?我從k=2、k=3慢慢試驗,搭配程式的輔助,進而快速找出需放最少套數的方法,及可達成均分套數與礦石分配的關聯。

液滴撞擊平板耗散能量之變因

本研究探討液滴碰撞時各種變因對撞擊前後耗散能量的影響,主要以直徑、速度、黏度作為變因進行實驗。實驗前,先完成接觸角、表面張力、黏度與密度等基本量測,再利用高速攝影機測量出液滴直徑、最大擴張直徑與液滴撞擊速度,將其數值代入能量守恆式,計算出耗散能量後,發現它受到直徑的二分之一次方、速度的二分之三次方、黏度的二分之一影響,其中黏度也會造成能量與韋伯數關係圖的斜率些微變化。

朱文錦意識行為探討

動物的學習能力與思考能力為判斷動物智力重要標準。本研究利用朱文錦的制約行為探討其學習能力、記憶能力、辨色能力與數感能力。研究以自製六邊形場地訓練朱文錦辨認顏色、測量其記憶時長與辨色精確度,並訓練其辨認數量多寡,以測定朱文錦數感能力。實驗結果發現朱文錦能辨認紅色,並能被訓練使特定顏色與食物產生連結,在紅色區域滯留較長時間,證明朱文錦可被訓練產生制約反應。停止訓練後其記憶力可長達7週,記憶強度與時間成高度相關。在數感測驗中,發現朱文錦具有可分辨數量的能力,且分辨能力與數量的比值與差皆有相關。本研究證明,朱文錦具學習能力,記憶力長達七週,辨識顏色精確度可達明度差±40,並具有一定數感能力。

探討清冠一號對小鼠腸道菌相的影響

部分COVID-19的確診者及未感染的民眾有服用清冠一號的需求與經驗,並且大部分民眾出現腹瀉的狀況。因此,我們想了解服用清冠一號是否會對腸道菌相造成影響,以及停用後腸道菌相是否會恢復為未服用前的樣子。本研究設計連續管餵小鼠清冠一號5天,在這5天期間及停止管餵5天後測量小鼠的體重與採集糞便檢體。以此實驗來探討服用清冠一號前、中、後,小鼠的腸道菌相變化。我們發現,服用清冠一號期間小鼠的腸道菌豐富度及多樣性降低,而停止管餵5天後,整體的腸道菌組成趨向服用清冠一號前,並且豐富度及多樣性也有恢復;在體重方面,管餵清冠一號第1天後,體重下降最為明顯,停止管餵後,體重逐漸上升。

Explorative Development of Ford Circle and Sierpinski Triangle in Hyperbolic Geometry

Explorations in mathematics are limited due to the negative image and perspective about Mathematics itself in high school. However, some topics in mathematics are found interesting in high schools such as geometry and sequences. Therefore, this research will look at the explorative development of Ford Circle that creates some interesting results while combined with other theories and geometry. The main focus of this research is to address and explore the ford circle with its connection to the Sierpinski Triangle in hyperbolic geometry. The investigation and exploration will focus on the properties of geometry in the hyperbolic plane, the fractal geometry of Ford Circle and Euclidean fractals through a hyperbolic perspective that brings a fascinating correlation between all the topics discussed in this research.