全國中小學科展

化學

Detection Device for Alcoholic Drunk Persons

The purpose of this project was to create a detection device for alcoholic drunk condition in human by using the principle of vapor pressure difference between breath samplings from normal and alcoholic-drunk men. The work comprises of three major steps. The first task was an experiment to determine an average air volume that can be fully blown out from the lungs of non-drunk people as a control. Twenty adult Thai volunteers weighing between 50 - 80 kg (average 59 kg) were used. The average blown out air volume was found to be 369.9 mL, with the range in values from 340-400 mL (sample size N = 20, SD = 15.47). The second task was an experiment to measure relationship between the blown air volume (100-700 mL, both from alcoholic-drunk and control groups of people) and the resulted vapor pressure by using manometer. The vapor pressure of normal breath increased from 400 to 1,600 newton/m2 with increasing blown air volume, whereas that of the alcoholic-drunk was found to be 600 to 1,800 newton/m2. The last task was to create a detection device prototype to gauge the alcoholic content in the human body from the breath. Air volume of 300 mL was arbitrary chosen to trigger lighting up of indicator lamps. The breath samples of low vapor pressure (low amount of alcohol, 21.12-44.00 mL, equivalent to 14.00-29.17 mg%) would trigger a green lamp to light up. A moderate vapor pressure range (medium amount of alcohol, 88-132 mL, equivalent to 58.33-87.57 mg%) would trigger green and yellow lamps to light up while a high vapor pressure (high amount of alcohol, 250 mL, equivalent to 165.72 mg%) would trigger green, yellow and red lamps to all light up. None of the three lamps would light up from (non-alcoholic) breath of control people. This device has also been tested to external group of volunteers. The work in this project has successfully demonstrated a useful application of simple principle in chemistry on partial vapor pressure.

光觸媒(TiO2)對還原重金屬離子之研究

光催化氧化反應以半導體金屬氧化物為催化劑,進行有機性空氣污染物之快速分解反應。其原理係將半導體材質(如:二氧化鈦,TiO2),在適合之光能量照射下,將半導體激發成為具有氧化/還原能力之催化劑,可加速氧化還原反應之進行,迅速分解有機污染物。 研究動機在於利用TiO2在紫外光的照射下,將H2O 分解產生自由基,使其和水中的重金屬離子進行氧化還原反應,期待可以還原水中的重金屬藉以降低水中重金屬離子濃度,同時藉由使用界面活性劑對奈米微粒具保護作用,可回收重金屬奈米微粒。 由實驗結果得知在紫外光照射下,TiO2 使用量0.5 克,AgNO3(aq) 0.01M,照光24 小時其電導度值上升最多且在溶液表面觀察到銀白色銀金屬薄膜生成而所測得銀金屬析出量明顯增加。探討超音波振盪對TiO2還原力的影響得知,超音波震盪的時間越久,所上升的電導度值愈多。 探討常見的界面活性劑(陽離子型及陰離子型)對TiO2還原力的影響:從數據中可觀察到,加入陰離子界面劑時,電導度值明顯上升;而加入陽離子界面活性劑後,電導度值迅速下降,照光後電導度值也不理想。 探討日光及不同頻率的紫外光照射光源對TiO2還原力的影響:發現紫外光的波長愈短,銀金屬析出的量愈多。 探討除氧處理之溶液對TiO2 還原力的影響得知,除氧處理後所配製的AgNO3(aq)0.01M, 經照光24 小時後電導度值明顯上升,且在溶液表面觀察到大片銀白色銀金屬薄膜生成而所測得銀的析出量也大幅增加。 ;In the experiment, we used the properties of T i O 2 that can catalyzed by UV rays and breaking the molecules of water and produce free radicals, which free radicals can redox metallic oxide as accelerator to analyze organic pollutant briskly. We use different shinning time and to find the best effect of the redox reaction . So we want to use this attribute to begin the redox reaction with the metal ion (for example: Ag+) in water, expecting to reduce them. And then we can use this method to recycle the metal and to reduce the pollution in rivers. Throughout shining UV rays in 24 hours, we can find out the best effect of TiO2 reducing the metal ion solution. We can also find that we use ultrasonic first; the more redox it will have. In this research ,we can observed that if we put more anion surface-active agent, the more redox it will have. We find the effect of UV rays is better than visible light. The most important is that we deoxidize the metal ion solution, we can get the best effect of the redox reaction . In our research,we can't get the satisfing result of the copper sulphate (CuSO4) by TiO2 accelerating the redox reaction under UV rays.

「金」枝「玉」葉—金奈米與葉綠素的交互作用

本實驗在探討,當金奈米粒子和植物中的葉綠素產生鍵結作用力時,能量轉移的結果是否能幫助葉綠素激發電子。經由兩者混合後光譜的變化,發現兩者之間發生能量轉移。為探討此轉移現象和濃度的關係,我們將大小不同的金奈米和不同毫升數的葉綠素作用,並將其結果和金奈米與葉綠素的吸收強度和作比較,使用正規化的計算方法算出比值,由此看出兩者之間能量轉移的效率。當金顆粒約大於30nm時,正規化的數值隨的葉綠素濃度的增加而變大;而當金奈米顆粒約小於30nm時,則隨著葉綠素的增加而變小。Much attention is currently focused on chromophoric molecules because they can not only mimic natural antenna systems but also exhibit unique optical and physical properties. Chlorophyll , produced by extracting from green leaves, has electrostatic interactions with Au nanoparticles through carboxyl groups. Herein, we report the charge transfer between chlorophyll and Au nanoparticles using UV-vis electronic absorption spectroscopy. The efficiency of charge transfer from chlorophyll to Au nanoparticles was estimated by the normalization of Q-ban absorption intensity. From the observation of absorption intensity versus concentration of chlorophyll curves, we find that the efficiency of charge transfer is increased while the size of Au-particle is larger than 30nm, but decreased while the size smaller than 30nm.

本土藥材金銀花的研究與分析

本實驗以薄膜色層層析(TLC)、高效能液相層析(HPLC)分析等化學方法,進行金銀花品種差異的鑑識;此外,配合生藥學的顯微鏡檢視,如中藥材組織鏡檢、藥材粉末鏡檢等比對,以期找出辨別金銀花品種的方法。研究至目前為止,由金銀花之薄膜色層分析的Rf值(0.225、0.425、0.7、0.85、0.95)可確認出金銀花藥材,並得知金銀花藥材中皆含有綠原酸的成分;以高效能液相層析的圖譜與成分峰的積分面積可用來判別金銀花的品種,並從質譜分析瞭解成分含量;進行生藥學的藥材粉末組織鏡檢,發現無法作為金銀花藥材的分類憑藉。未來將持續延伸實驗,朝向中藥奈米化與一般粉末在藥效、成分上差異的比較,並進行金銀花萃取液的抗菌作用試驗,瞭解不同品種之金銀花藥材在藥理作用的異同,接續著奈米化藥材的應用與實踐。Using thin layer chromatograph (TLC) and high performance liquid chromatography (HPLC), we can study how to differentiate the species variation of honeysuckle; beside, based on the observation of biopharmaceutical microscope, such as comparing the histology of Chinese herbs and its powder, we suggest that we could differentiate the species of honeysuckle. From the present, firstly, we could distinguish the honeysuckle from other herbs by the Rf value of TLC(0.225, 0.425, 0.7, 0.85, 0.95), from which we find that all honeysuckles contain the component of Chlorogenic acid. Secondly, we could tell the species of honeysuckle according to the map of HPLC and the peak area after integration, as well as the integrants of honeysuckle by way of LC-Mass analysis. Thirdly, while studying the histological analysis based on the observation of biopharmaceutical microscope, we found that it shows no difference between all the honeysuckles; thus, it fails to be a scientific method used to distinguish the herb honeysuckle. However, in the biochemical experiments of honeysuckles, we found honeysuckles from different sources and the place of origin shows difference in their antibiotic effect, showing the importance of local medicine. When it comes to my future work, in order to extend my experiments on honeysuckles, I would compare the nano-scale honeysuckle powder with normal-sized one in their clinical effects and components.

Bright, Luminescent Silicon Nanoparticles for Biological Applications

In the last two decades, there has been increased interest in the utility of quantum scale semiconductors. These fluorescent single crystals can be as small as 1 nm in diameter, and their size and shape has been shown to be controlled by the duration, temperature, and ligand molecules used in their synthesis. Quantum dots, provide clear benefits over the organic dyes currently used for tracking biological processes. Yet, as the production of quantum dots is often very costly, the search continues for finding an industry-ready synthesis for a quantum scale semiconductor which would have high yield, optimal durability, high luminescence, and a broad absorbance range. Silicon, in particular, has been of great interest as it is the second most abundant element on the Earth’s crust and is generally a bioinert and electrochemically stable element. We report the synthesis of water-soluble, luminescent silicon nanoparticles with potential applications to bioimaging. Through a solution state top-down approach, the synthesis of hydrogen capped silicon nanoparticles was achieved in various organic solvents. The surface of the nanoparticles was capped with the functional organic molecules rendering the Si-QDs both air and water stable. Cell studies performed with our silicon nanoparticles and human monocytes show the direct applications these particles could have for tracking biological processes and the progression of cancer in the human body. In attempt to shift the luminescence of these particles, alterations of experimental methodology was also explored in the areas of reaction solvent and heating time. Through these changes, shape control of silicon nanoparticles was achieved in the form of silicon nanorods. The synthesis of this new shape of silicon at the quantum scale was confirmed by ultraviolet spectroscopy, photoluminescence, and transmission electron microscopy. The results of this study indicate that the use of silicon nanocrystals for biomedical applications is feasible.

瓦斯熱水爐一氧化碳觸媒轉化器之研究

瓦斯熱水爐使用大火時廢氣的CO 濃度非常高是導致一氧化碳中毒事件的關鍵原因,要解決這個問題觸媒轉化是一種可行的方式。影響觸媒性能的因素中以活性中心的種類最為重要,我們發現對轉化一氧化碳為二氧化碳的反應而言鈷有最好的催化效果,其次分別為:鎳、銅、鐵。最好的載體是三氧化二鋁,鈷的含量使用10%,煅燒溫度使用300℃可兼顧性能與成本。 本研究中所研發的 Co/Al2O3 觸媒具備有實用的潛力,可以在空間速度高達1000min-1 的情況下將濃度14,632ppm 的CO 百分之百轉化為CO2,而僅需233℃的反應溫度。因此,應該可以應用在瓦斯熱水爐上以降低一氧化碳中毒的風險。 The incorrect usage of a natural gas powered water heater always generates high carbon monoxide concentration in a closed environment. The dangerous CO gas can be fatal to the careless user of the water heater. Catalytic conversion of CO to CO2 can be a convenient method to solve this problem. The effect of the support, the supported metal, loading of the metal, reaction temperature, gas concentration, and reactants flow rate on the performance of the CO oxidation catalysts have been investigated. X-ray diffraction, gas adsorption and Infrared spectroscopy were applied to study the characteristics of catalysts. A 100% conversion of CO to CO2 can be achieved when 1.46% CO/6% oxygen/N2 reactants was catalyzed by a 10% Co/Al2O3 catalyst at 233℃ with a space velocity of 1000min-1 . This reaction condition is sufficient to remove the entire CO generated by a family-sized natural gas water heater.

Recovering bioethanol from fruit wastes

1. Purpose of the research: Recovering bioethanol from fruit wastes by using brewing yeast and enzyme Viscozyme L\r 2. Procedures: Four different experiments were conducted in our project.\r Experiment-1: Samples in RM by the addition of only S.Cerevisia.\r Experiment-2: Samples in RM broth meduim by the addtion of 100 μl/g ViscozymeL and S. Cerevisiae\r Experiment-3 : ViscozymeL with different concentration\r Experiment-4: to determenine whether the enzyme with high concentration inhibited the fermentation.\r Analysis of ethanol: HPLC method was used for the analysis;\r HPLC method: (high performance liquid chromatography)\r 3. Data\r HPLC measured initial and final concentrations of glucose and ethanol by the addtion of S. Cerevisiae.\r Initial glucose concentration and final ethanol concentration was the highest in Grape pulp 12 and 9 g/L respectively. Despite the glucose concentration was the lowest, the ethanol concentration was quite high (7 g/L) in the mixture with orange. The lowest ethanol was produced in the mixture with pomegranate.\r Concentrations of ethanol and glucose from the samples in RM broth meduim by the addtion of 100 μl/g ViscozymeL and S. Cerevisiae\r After the 24 hour incubation by the addition of enzyme glucose concentration incresed by 1, 4 and 2 respectively in sample 1, 2 and 3. The ethanol concentrations in comparison to first experiment were higher especially in the sample1 (grape pulp).\r Effect of ViscozymeL with different concentration on glucose production.\r The glucose concentration generally increased by the addition of 200 micro L of enzyme as the time proceeded. In grape pulp sample glucose concentartion didnt increased by the addition of 500 micro L enzyme.\r The remaning glucose and produced ethanol concentrations by the addition of viscozyme L with two different concentartion and S. Cerevisiae\r As the concentartion of enzyme added incresed the amout of ethanol also inreased in sample 2 and 3 but in the sample 3 the fermentation was inhibited.\r 4. Conclusions\r In this study sugars in fruit wastes that are regularly not recylecled were fermented successfully into ethanol by using S. Cerevisiae.\r Generally we get more ethanol from the samples when the enzyme was used. As the graph5 shows the ethanol concentration generally increased as the enzyme concentration increased. But especially in the sample1 (mixture with pomegranate) at 200 and 500 micro liter concentrations, ethanol production were 2 and 0 g/L respectively. In the light of this daha we conluded that the enzyme with high concentartion might inhibit the fermentation. When the activity of enzyme was inhibited by keeping the pretreated enzyme in boiling water, the fermentation restarted and recovered more ethanol; 8 and 12 g/L at the enzyme concentration of 200 and 500 microliter respectively.

Synthetic Analogs of Smoothened Intracellular Loop as Potent Inhibitors of Cancer Cells Growth

Smoothened (SMO) is a critical component of Hedgehog (HH) pathway that is essential for stem cell renewal and is dysregulated in many cancer types. SMO is a seven transmembrane domain protein with three intracellular loops. Primary structures of SMO intracellular loops are unique and very much conserved among the species, which is indicative of significant and unique roles in intermolecular or intramolecular interactions. The hypothesis was that synthetic analogs of SMO intracellular loops may function as HH pathway inhibitors. Derivatives of second intracellular loop were synthesized utilizing automated solid phase peptide synthesis based on Fmoc chemistry. Peptides were purified by HPLC and there anti-proliferative activity tested on melanoma cells by MTT assay. Targeted libraries of second loop derivatives of varying length helped to identify compounds that inhibited the growth of melanoma cells in vitro with IC50 in nanomolar range. The most potent of antagonists obtained is the palmitoyl derivative of the Nterminal half of the loop, and is 12 residues long. Lipidation proved to be critical for the activity. Remarkably, retro-inverso versions of the peptide, in which all amino acids are in D-configuration, are even more potent and have IC50 in subnanomolar range. Circular dichroism studies proved that the peptides are folded both in aqueous solutions and in the presence of lipids mimicking the membrane environment. They also suggested that retroinverso analogs have a different fold, which may contribute to higher activity. The new compounds are promising drug candidates and present convenient tools for solving the\r mechanisms of hedgehog signaling.

海格的爆尾釘蝦-鹼性電池的探討

鹼性電池使用的電解液均為強鹼,電池中的鋅極會與其發生腐蝕反應,使得電池放電壽命降低,並產生氫氣,而大量氫氣使得電池有爆裂的危險,為了改善上述問題,我們自行設計了氣體觀測儀器,用來檢測銀鋅電池充放電與靜置時之氣體產生量,更藉由探討影響變因的過程找出銀鋅電池較合適之使用條件,其中包含電解液種類及濃度之選擇、電極面積與充電電流對使用效果之影響,並改善電池腐蝕程度;我們將鋅極以浸鍍處理(Sn:Pb =1:1 )並搭配電解液添加物(KOH:Zn(OH)42 -= 2:1) 可效率地抑制氣體產生;更用氯化銀粉末取代傳統氧化銀極片為正極,發現氯化銀可代替氧化銀電極,且有不錯的放電效果。;As we know, the electrolyte solution used in an alkalinebattery is a concentrated alkaline solution, which corrodes the zinc electrode in a battery of this kind. The corrosive reaction not only reduces the lifespan of the battery but also produces hydrogen, causing the battery to explode. This study is intended to help us design a device to measure the quantity of hydrogen gas generated in the charging of a zinc-silver battery. We have studied several factors affecting zinc-silver battery, including the variety of electrolyte, the concentration of alkaline solution, the surface of electrode, and the density of charging current, etc. To reduce the corrosion of zinc electrode, we plate the zinc electrode by the immersion electroless plating method, using several kinds of low-polluting anti-corrosive additives (metallic compounds such as lead and tin). We also add zincate ion into electrolyte solution to further reduce the quantity of hydrogen produced. The experiments show a zinc-silver alkaline battery works most efficiently, if the powder of silver chloride is used instead of silver oxide.

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.